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mbedtls/library/ssl_tls.c
Hanno Becker 33c3dc8591 Don't store the peer CRT chain twice during renegotiation 
Context: During a handshake, the SSL/TLS handshake logic constructs
an instance of ::mbedtls_ssl_session representing the SSL session
being established. This structure contains information such as the
session's master secret, the peer certificate, or the session ticket
issues by the server (if applicable).
During a renegotiation, the new session is constructed aside the existing
one and destroys and replaces the latter only when the renegotiation is
complete. While conceptually clear, this means that during the renegotiation,
large pieces of information such as the peer's CRT or the session ticket
exist twice in memory, even though the original versions are removed
eventually.

This commit removes the simultaneous presence of two peer CRT chains
in memory during renegotiation, in the following way:
- Unlike in the case of SessionTickets handled in the previous commit,
  we cannot simply free the peer's CRT chain from the previous handshake
  before parsing the new one, as we need to verify that the peer's end-CRT
  hasn't changed to mitigate the 'Triple Handshake Attack'.
- Instead, we perform a binary comparison of the original peer end-CRT
  with the one presented during renegotiation, and if it succeeds, we
  avoid re-parsing CRT by moving the corresponding CRT pointer from the
  old to the new session structure.
- The remaining CRTs in the peer's chain are not affected by the triple
  handshake attack protection, and for them we may employ the canonical
  approach of freeing them before parsing the remainder of the new chain.

Note that this commit intends to not change any observable behavior
of the stack. In particular:
- The peer's CRT chain is still verified during renegotiation.
- The tail of the peer's CRT chain may change during renegotiation.
2019-06-05 14:25:28 +01:00

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/*
* SSLv3/TLSv1 shared functions
*
* Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* This file is part of mbed TLS (https://tls.mbed.org)
*/
/*
* The SSL 3.0 specification was drafted by Netscape in 1996,
* and became an IETF standard in 1999.
*
* http://wp.netscape.com/eng/ssl3/
* http://www.ietf.org/rfc/rfc2246.txt
* http://www.ietf.org/rfc/rfc4346.txt
*/
#if !defined(MBEDTLS_CONFIG_FILE)
#include "mbedtls/config.h"
#else
#include MBEDTLS_CONFIG_FILE
#endif
#if defined(MBEDTLS_SSL_TLS_C)
#if defined(MBEDTLS_PLATFORM_C)
#include "mbedtls/platform.h"
#else
#include <stdlib.h>
#define mbedtls_calloc calloc
#define mbedtls_free free
#endif
#include "mbedtls/debug.h"
#include "mbedtls/ssl.h"
#include "mbedtls/ssl_internal.h"
#include "mbedtls/platform_util.h"
#include "mbedtls/version.h"
#include <string.h>
#if defined(MBEDTLS_X509_CRT_PARSE_C)
#include "mbedtls/oid.h"
#endif
static void ssl_reset_in_out_pointers( mbedtls_ssl_context *ssl );
static uint32_t ssl_get_hs_total_len( mbedtls_ssl_context const *ssl );
/* Length of the "epoch" field in the record header */
static inline size_t ssl_ep_len( const mbedtls_ssl_context *ssl )
{
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
return( 2 );
#else
((void) ssl);
#endif
return( 0 );
}
/*
* Start a timer.
* Passing millisecs = 0 cancels a running timer.
*/
static void ssl_set_timer( mbedtls_ssl_context *ssl, uint32_t millisecs )
{
if( ssl->f_set_timer == NULL )
return;
MBEDTLS_SSL_DEBUG_MSG( 3, ( "set_timer to %d ms", (int) millisecs ) );
ssl->f_set_timer( ssl->p_timer, millisecs / 4, millisecs );
}
/*
* Return -1 is timer is expired, 0 if it isn't.
*/
static int ssl_check_timer( mbedtls_ssl_context *ssl )
{
if( ssl->f_get_timer == NULL )
return( 0 );
if( ssl->f_get_timer( ssl->p_timer ) == 2 )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "timer expired" ) );
return( -1 );
}
return( 0 );
}
static void ssl_update_out_pointers( mbedtls_ssl_context *ssl,
mbedtls_ssl_transform *transform );
static void ssl_update_in_pointers( mbedtls_ssl_context *ssl );
#define SSL_DONT_FORCE_FLUSH 0
#define SSL_FORCE_FLUSH 1
#if defined(MBEDTLS_SSL_PROTO_DTLS)
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
/* Top-level Connection ID API */
int mbedtls_ssl_conf_cid( mbedtls_ssl_config *conf,
size_t len,
int ignore_other_cid )
{
if( len > MBEDTLS_SSL_CID_IN_LEN_MAX )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
if( ignore_other_cid != MBEDTLS_SSL_UNEXPECTED_CID_FAIL &&
ignore_other_cid != MBEDTLS_SSL_UNEXPECTED_CID_IGNORE )
{
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
}
conf->ignore_unexpected_cid = ignore_other_cid;
conf->cid_len = len;
return( 0 );
}
int mbedtls_ssl_set_cid( mbedtls_ssl_context *ssl,
int enable,
unsigned char const *own_cid,
size_t own_cid_len )
{
if( ssl->conf->transport != MBEDTLS_SSL_TRANSPORT_DATAGRAM )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
ssl->negotiate_cid = enable;
if( enable == MBEDTLS_SSL_CID_DISABLED )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "Disable use of CID extension." ) );
return( 0 );
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "Enable use of CID extension." ) );
MBEDTLS_SSL_DEBUG_BUF( 3, "Own CID", own_cid, own_cid_len );
if( own_cid_len != ssl->conf->cid_len )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "CID length %u does not match CID length %u in config",
(unsigned) own_cid_len,
(unsigned) ssl->conf->cid_len ) );
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
}
memcpy( ssl->own_cid, own_cid, own_cid_len );
/* Truncation is not an issue here because
* MBEDTLS_SSL_CID_IN_LEN_MAX at most 255. */
ssl->own_cid_len = (uint8_t) own_cid_len;
return( 0 );
}
int mbedtls_ssl_get_peer_cid( mbedtls_ssl_context *ssl,
int *enabled,
unsigned char peer_cid[ MBEDTLS_SSL_CID_OUT_LEN_MAX ],
size_t *peer_cid_len )
{
*enabled = MBEDTLS_SSL_CID_DISABLED;
if( ssl->conf->transport != MBEDTLS_SSL_TRANSPORT_DATAGRAM ||
ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER )
{
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
}
/* We report MBEDTLS_SSL_CID_DISABLED in case the CID extensions
* were used, but client and server requested the empty CID.
* This is indistinguishable from not using the CID extension
* in the first place. */
if( ssl->transform_in->in_cid_len == 0 &&
ssl->transform_in->out_cid_len == 0 )
{
return( 0 );
}
if( peer_cid_len != NULL )
{
*peer_cid_len = ssl->transform_in->out_cid_len;
if( peer_cid != NULL )
{
memcpy( peer_cid, ssl->transform_in->out_cid,
ssl->transform_in->out_cid_len );
}
}
*enabled = MBEDTLS_SSL_CID_ENABLED;
return( 0 );
}
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
/* Forward declarations for functions related to message buffering. */
static void ssl_buffering_free( mbedtls_ssl_context *ssl );
static void ssl_buffering_free_slot( mbedtls_ssl_context *ssl,
uint8_t slot );
static void ssl_free_buffered_record( mbedtls_ssl_context *ssl );
static int ssl_load_buffered_message( mbedtls_ssl_context *ssl );
static int ssl_load_buffered_record( mbedtls_ssl_context *ssl );
static int ssl_buffer_message( mbedtls_ssl_context *ssl );
static int ssl_buffer_future_record( mbedtls_ssl_context *ssl );
static int ssl_next_record_is_in_datagram( mbedtls_ssl_context *ssl );
static size_t ssl_get_current_mtu( const mbedtls_ssl_context *ssl );
static size_t ssl_get_maximum_datagram_size( mbedtls_ssl_context const *ssl )
{
size_t mtu = ssl_get_current_mtu( ssl );
if( mtu != 0 && mtu < MBEDTLS_SSL_OUT_BUFFER_LEN )
return( mtu );
return( MBEDTLS_SSL_OUT_BUFFER_LEN );
}
static int ssl_get_remaining_space_in_datagram( mbedtls_ssl_context const *ssl )
{
size_t const bytes_written = ssl->out_left;
size_t const mtu = ssl_get_maximum_datagram_size( ssl );
/* Double-check that the write-index hasn't gone
* past what we can transmit in a single datagram. */
if( bytes_written > mtu )
{
/* Should never happen... */
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
return( (int) ( mtu - bytes_written ) );
}
static int ssl_get_remaining_payload_in_datagram( mbedtls_ssl_context const *ssl )
{
int ret;
size_t remaining, expansion;
size_t max_len = MBEDTLS_SSL_OUT_CONTENT_LEN;
#if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
const size_t mfl = mbedtls_ssl_get_max_frag_len( ssl );
if( max_len > mfl )
max_len = mfl;
/* By the standard (RFC 6066 Sect. 4), the MFL extension
* only limits the maximum record payload size, so in theory
* we would be allowed to pack multiple records of payload size
* MFL into a single datagram. However, this would mean that there's
* no way to explicitly communicate MTU restrictions to the peer.
*
* The following reduction of max_len makes sure that we never
* write datagrams larger than MFL + Record Expansion Overhead.
*/
if( max_len <= ssl->out_left )
return( 0 );
max_len -= ssl->out_left;
#endif
ret = ssl_get_remaining_space_in_datagram( ssl );
if( ret < 0 )
return( ret );
remaining = (size_t) ret;
ret = mbedtls_ssl_get_record_expansion( ssl );
if( ret < 0 )
return( ret );
expansion = (size_t) ret;
if( remaining <= expansion )
return( 0 );
remaining -= expansion;
if( remaining >= max_len )
remaining = max_len;
return( (int) remaining );
}
/*
* Double the retransmit timeout value, within the allowed range,
* returning -1 if the maximum value has already been reached.
*/
static int ssl_double_retransmit_timeout( mbedtls_ssl_context *ssl )
{
uint32_t new_timeout;
if( ssl->handshake->retransmit_timeout >= ssl->conf->hs_timeout_max )
return( -1 );
/* Implement the final paragraph of RFC 6347 section 4.1.1.1
* in the following way: after the initial transmission and a first
* retransmission, back off to a temporary estimated MTU of 508 bytes.
* This value is guaranteed to be deliverable (if not guaranteed to be
* delivered) of any compliant IPv4 (and IPv6) network, and should work
* on most non-IP stacks too. */
if( ssl->handshake->retransmit_timeout != ssl->conf->hs_timeout_min )
{
ssl->handshake->mtu = 508;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "mtu autoreduction to %d bytes", ssl->handshake->mtu ) );
}
new_timeout = 2 * ssl->handshake->retransmit_timeout;
/* Avoid arithmetic overflow and range overflow */
if( new_timeout < ssl->handshake->retransmit_timeout ||
new_timeout > ssl->conf->hs_timeout_max )
{
new_timeout = ssl->conf->hs_timeout_max;
}
ssl->handshake->retransmit_timeout = new_timeout;
MBEDTLS_SSL_DEBUG_MSG( 3, ( "update timeout value to %d millisecs",
ssl->handshake->retransmit_timeout ) );
return( 0 );
}
static void ssl_reset_retransmit_timeout( mbedtls_ssl_context *ssl )
{
ssl->handshake->retransmit_timeout = ssl->conf->hs_timeout_min;
MBEDTLS_SSL_DEBUG_MSG( 3, ( "update timeout value to %d millisecs",
ssl->handshake->retransmit_timeout ) );
}
#endif /* MBEDTLS_SSL_PROTO_DTLS */
#if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
/*
* Convert max_fragment_length codes to length.
* RFC 6066 says:
* enum{
* 2^9(1), 2^10(2), 2^11(3), 2^12(4), (255)
* } MaxFragmentLength;
* and we add 0 -> extension unused
*/
static unsigned int ssl_mfl_code_to_length( int mfl )
{
switch( mfl )
{
case MBEDTLS_SSL_MAX_FRAG_LEN_NONE:
return ( MBEDTLS_TLS_EXT_ADV_CONTENT_LEN );
case MBEDTLS_SSL_MAX_FRAG_LEN_512:
return 512;
case MBEDTLS_SSL_MAX_FRAG_LEN_1024:
return 1024;
case MBEDTLS_SSL_MAX_FRAG_LEN_2048:
return 2048;
case MBEDTLS_SSL_MAX_FRAG_LEN_4096:
return 4096;
default:
return ( MBEDTLS_TLS_EXT_ADV_CONTENT_LEN );
}
}
#endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */
#if defined(MBEDTLS_SSL_CLI_C)
static int ssl_session_copy( mbedtls_ssl_session *dst, const mbedtls_ssl_session *src )
{
mbedtls_ssl_session_free( dst );
memcpy( dst, src, sizeof( mbedtls_ssl_session ) );
#if defined(MBEDTLS_X509_CRT_PARSE_C)
if( src->peer_cert != NULL )
{
int ret;
dst->peer_cert = mbedtls_calloc( 1, sizeof(mbedtls_x509_crt) );
if( dst->peer_cert == NULL )
return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
mbedtls_x509_crt_init( dst->peer_cert );
if( ( ret = mbedtls_x509_crt_parse_der( dst->peer_cert, src->peer_cert->raw.p,
src->peer_cert->raw.len ) ) != 0 )
{
mbedtls_free( dst->peer_cert );
dst->peer_cert = NULL;
return( ret );
}
}
#endif /* MBEDTLS_X509_CRT_PARSE_C */
#if defined(MBEDTLS_SSL_SESSION_TICKETS) && defined(MBEDTLS_SSL_CLI_C)
if( src->ticket != NULL )
{
dst->ticket = mbedtls_calloc( 1, src->ticket_len );
if( dst->ticket == NULL )
return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
memcpy( dst->ticket, src->ticket, src->ticket_len );
}
#endif /* MBEDTLS_SSL_SESSION_TICKETS && MBEDTLS_SSL_CLI_C */
return( 0 );
}
#endif /* MBEDTLS_SSL_CLI_C */
#if defined(MBEDTLS_SSL_HW_RECORD_ACCEL)
int (*mbedtls_ssl_hw_record_init)( mbedtls_ssl_context *ssl,
const unsigned char *key_enc, const unsigned char *key_dec,
size_t keylen,
const unsigned char *iv_enc, const unsigned char *iv_dec,
size_t ivlen,
const unsigned char *mac_enc, const unsigned char *mac_dec,
size_t maclen ) = NULL;
int (*mbedtls_ssl_hw_record_activate)( mbedtls_ssl_context *ssl, int direction) = NULL;
int (*mbedtls_ssl_hw_record_reset)( mbedtls_ssl_context *ssl ) = NULL;
int (*mbedtls_ssl_hw_record_write)( mbedtls_ssl_context *ssl ) = NULL;
int (*mbedtls_ssl_hw_record_read)( mbedtls_ssl_context *ssl ) = NULL;
int (*mbedtls_ssl_hw_record_finish)( mbedtls_ssl_context *ssl ) = NULL;
#endif /* MBEDTLS_SSL_HW_RECORD_ACCEL */
/*
* Key material generation
*/
#if defined(MBEDTLS_SSL_PROTO_SSL3)
static int ssl3_prf( const unsigned char *secret, size_t slen,
const char *label,
const unsigned char *random, size_t rlen,
unsigned char *dstbuf, size_t dlen )
{
int ret = 0;
size_t i;
mbedtls_md5_context md5;
mbedtls_sha1_context sha1;
unsigned char padding[16];
unsigned char sha1sum[20];
((void)label);
mbedtls_md5_init( &md5 );
mbedtls_sha1_init( &sha1 );
/*
* SSLv3:
* block =
* MD5( secret + SHA1( 'A' + secret + random ) ) +
* MD5( secret + SHA1( 'BB' + secret + random ) ) +
* MD5( secret + SHA1( 'CCC' + secret + random ) ) +
* ...
*/
for( i = 0; i < dlen / 16; i++ )
{
memset( padding, (unsigned char) ('A' + i), 1 + i );
if( ( ret = mbedtls_sha1_starts_ret( &sha1 ) ) != 0 )
goto exit;
if( ( ret = mbedtls_sha1_update_ret( &sha1, padding, 1 + i ) ) != 0 )
goto exit;
if( ( ret = mbedtls_sha1_update_ret( &sha1, secret, slen ) ) != 0 )
goto exit;
if( ( ret = mbedtls_sha1_update_ret( &sha1, random, rlen ) ) != 0 )
goto exit;
if( ( ret = mbedtls_sha1_finish_ret( &sha1, sha1sum ) ) != 0 )
goto exit;
if( ( ret = mbedtls_md5_starts_ret( &md5 ) ) != 0 )
goto exit;
if( ( ret = mbedtls_md5_update_ret( &md5, secret, slen ) ) != 0 )
goto exit;
if( ( ret = mbedtls_md5_update_ret( &md5, sha1sum, 20 ) ) != 0 )
goto exit;
if( ( ret = mbedtls_md5_finish_ret( &md5, dstbuf + i * 16 ) ) != 0 )
goto exit;
}
exit:
mbedtls_md5_free( &md5 );
mbedtls_sha1_free( &sha1 );
mbedtls_platform_zeroize( padding, sizeof( padding ) );
mbedtls_platform_zeroize( sha1sum, sizeof( sha1sum ) );
return( ret );
}
#endif /* MBEDTLS_SSL_PROTO_SSL3 */
#if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1)
static int tls1_prf( const unsigned char *secret, size_t slen,
const char *label,
const unsigned char *random, size_t rlen,
unsigned char *dstbuf, size_t dlen )
{
size_t nb, hs;
size_t i, j, k;
const unsigned char *S1, *S2;
unsigned char tmp[128];
unsigned char h_i[20];
const mbedtls_md_info_t *md_info;
mbedtls_md_context_t md_ctx;
int ret;
mbedtls_md_init( &md_ctx );
if( sizeof( tmp ) < 20 + strlen( label ) + rlen )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
hs = ( slen + 1 ) / 2;
S1 = secret;
S2 = secret + slen - hs;
nb = strlen( label );
memcpy( tmp + 20, label, nb );
memcpy( tmp + 20 + nb, random, rlen );
nb += rlen;
/*
* First compute P_md5(secret,label+random)[0..dlen]
*/
if( ( md_info = mbedtls_md_info_from_type( MBEDTLS_MD_MD5 ) ) == NULL )
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
if( ( ret = mbedtls_md_setup( &md_ctx, md_info, 1 ) ) != 0 )
return( ret );
mbedtls_md_hmac_starts( &md_ctx, S1, hs );
mbedtls_md_hmac_update( &md_ctx, tmp + 20, nb );
mbedtls_md_hmac_finish( &md_ctx, 4 + tmp );
for( i = 0; i < dlen; i += 16 )
{
mbedtls_md_hmac_reset ( &md_ctx );
mbedtls_md_hmac_update( &md_ctx, 4 + tmp, 16 + nb );
mbedtls_md_hmac_finish( &md_ctx, h_i );
mbedtls_md_hmac_reset ( &md_ctx );
mbedtls_md_hmac_update( &md_ctx, 4 + tmp, 16 );
mbedtls_md_hmac_finish( &md_ctx, 4 + tmp );
k = ( i + 16 > dlen ) ? dlen % 16 : 16;
for( j = 0; j < k; j++ )
dstbuf[i + j] = h_i[j];
}
mbedtls_md_free( &md_ctx );
/*
* XOR out with P_sha1(secret,label+random)[0..dlen]
*/
if( ( md_info = mbedtls_md_info_from_type( MBEDTLS_MD_SHA1 ) ) == NULL )
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
if( ( ret = mbedtls_md_setup( &md_ctx, md_info, 1 ) ) != 0 )
return( ret );
mbedtls_md_hmac_starts( &md_ctx, S2, hs );
mbedtls_md_hmac_update( &md_ctx, tmp + 20, nb );
mbedtls_md_hmac_finish( &md_ctx, tmp );
for( i = 0; i < dlen; i += 20 )
{
mbedtls_md_hmac_reset ( &md_ctx );
mbedtls_md_hmac_update( &md_ctx, tmp, 20 + nb );
mbedtls_md_hmac_finish( &md_ctx, h_i );
mbedtls_md_hmac_reset ( &md_ctx );
mbedtls_md_hmac_update( &md_ctx, tmp, 20 );
mbedtls_md_hmac_finish( &md_ctx, tmp );
k = ( i + 20 > dlen ) ? dlen % 20 : 20;
for( j = 0; j < k; j++ )
dstbuf[i + j] = (unsigned char)( dstbuf[i + j] ^ h_i[j] );
}
mbedtls_md_free( &md_ctx );
mbedtls_platform_zeroize( tmp, sizeof( tmp ) );
mbedtls_platform_zeroize( h_i, sizeof( h_i ) );
return( 0 );
}
#endif /* MBEDTLS_SSL_PROTO_TLS1) || MBEDTLS_SSL_PROTO_TLS1_1 */
#if defined(MBEDTLS_SSL_PROTO_TLS1_2)
static int tls_prf_generic( mbedtls_md_type_t md_type,
const unsigned char *secret, size_t slen,
const char *label,
const unsigned char *random, size_t rlen,
unsigned char *dstbuf, size_t dlen )
{
size_t nb;
size_t i, j, k, md_len;
unsigned char tmp[128];
unsigned char h_i[MBEDTLS_MD_MAX_SIZE];
const mbedtls_md_info_t *md_info;
mbedtls_md_context_t md_ctx;
int ret;
mbedtls_md_init( &md_ctx );
if( ( md_info = mbedtls_md_info_from_type( md_type ) ) == NULL )
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
md_len = mbedtls_md_get_size( md_info );
if( sizeof( tmp ) < md_len + strlen( label ) + rlen )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
nb = strlen( label );
memcpy( tmp + md_len, label, nb );
memcpy( tmp + md_len + nb, random, rlen );
nb += rlen;
/*
* Compute P_<hash>(secret, label + random)[0..dlen]
*/
if ( ( ret = mbedtls_md_setup( &md_ctx, md_info, 1 ) ) != 0 )
return( ret );
mbedtls_md_hmac_starts( &md_ctx, secret, slen );
mbedtls_md_hmac_update( &md_ctx, tmp + md_len, nb );
mbedtls_md_hmac_finish( &md_ctx, tmp );
for( i = 0; i < dlen; i += md_len )
{
mbedtls_md_hmac_reset ( &md_ctx );
mbedtls_md_hmac_update( &md_ctx, tmp, md_len + nb );
mbedtls_md_hmac_finish( &md_ctx, h_i );
mbedtls_md_hmac_reset ( &md_ctx );
mbedtls_md_hmac_update( &md_ctx, tmp, md_len );
mbedtls_md_hmac_finish( &md_ctx, tmp );
k = ( i + md_len > dlen ) ? dlen % md_len : md_len;
for( j = 0; j < k; j++ )
dstbuf[i + j] = h_i[j];
}
mbedtls_md_free( &md_ctx );
mbedtls_platform_zeroize( tmp, sizeof( tmp ) );
mbedtls_platform_zeroize( h_i, sizeof( h_i ) );
return( 0 );
}
#if defined(MBEDTLS_SHA256_C)
static int tls_prf_sha256( const unsigned char *secret, size_t slen,
const char *label,
const unsigned char *random, size_t rlen,
unsigned char *dstbuf, size_t dlen )
{
return( tls_prf_generic( MBEDTLS_MD_SHA256, secret, slen,
label, random, rlen, dstbuf, dlen ) );
}
#endif /* MBEDTLS_SHA256_C */
#if defined(MBEDTLS_SHA512_C)
static int tls_prf_sha384( const unsigned char *secret, size_t slen,
const char *label,
const unsigned char *random, size_t rlen,
unsigned char *dstbuf, size_t dlen )
{
return( tls_prf_generic( MBEDTLS_MD_SHA384, secret, slen,
label, random, rlen, dstbuf, dlen ) );
}
#endif /* MBEDTLS_SHA512_C */
#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
static void ssl_update_checksum_start( mbedtls_ssl_context *, const unsigned char *, size_t );
#if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1) || \
defined(MBEDTLS_SSL_PROTO_TLS1_1)
static void ssl_update_checksum_md5sha1( mbedtls_ssl_context *, const unsigned char *, size_t );
#endif
#if defined(MBEDTLS_SSL_PROTO_SSL3)
static void ssl_calc_verify_ssl( const mbedtls_ssl_context *, unsigned char *, size_t * );
static void ssl_calc_finished_ssl( mbedtls_ssl_context *, unsigned char *, int );
#endif
#if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1)
static void ssl_calc_verify_tls( const mbedtls_ssl_context *, unsigned char *, size_t * );
static void ssl_calc_finished_tls( mbedtls_ssl_context *, unsigned char *, int );
#endif
#if defined(MBEDTLS_SSL_PROTO_TLS1_2)
#if defined(MBEDTLS_SHA256_C)
static void ssl_update_checksum_sha256( mbedtls_ssl_context *, const unsigned char *, size_t );
static void ssl_calc_verify_tls_sha256( const mbedtls_ssl_context *,unsigned char *, size_t * );
static void ssl_calc_finished_tls_sha256( mbedtls_ssl_context *,unsigned char *, int );
#endif
#if defined(MBEDTLS_SHA512_C)
static void ssl_update_checksum_sha384( mbedtls_ssl_context *, const unsigned char *, size_t );
static void ssl_calc_verify_tls_sha384( const mbedtls_ssl_context *, unsigned char *, size_t * );
static void ssl_calc_finished_tls_sha384( mbedtls_ssl_context *, unsigned char *, int );
#endif
#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
/* Type for the TLS PRF */
typedef int ssl_tls_prf_t(const unsigned char *, size_t, const char *,
const unsigned char *, size_t,
unsigned char *, size_t);
/*
* Populate a transform structure with session keys and all the other
* necessary information.
*
* Parameters:
* - [in/out]: transform: structure to populate
* [in] must be just initialised with mbedtls_ssl_transform_init()
* [out] fully populated, ready for use by mbedtls_ssl_{en,de}crypt_buf()
* - [in] ciphersuite
* - [in] master
* - [in] encrypt_then_mac
* - [in] trunc_hmac
* - [in] compression
* - [in] tls_prf: pointer to PRF to use for key derivation
* - [in] randbytes: buffer holding ServerHello.random + ClientHello.random
* - [in] minor_ver: SSL/TLS minor version
* - [in] endpoint: client or server
* - [in] ssl: optionally used for:
* - MBEDTLS_SSL_HW_RECORD_ACCEL: whole context
* - MBEDTLS_SSL_EXPORT_KEYS: ssl->conf->{f,p}_export_keys
* - MBEDTLS_DEBUG_C: ssl->conf->{f,p}_dbg
*/
static int ssl_populate_transform( mbedtls_ssl_transform *transform,
int ciphersuite,
const unsigned char master[48],
#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
int encrypt_then_mac,
#endif
#if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
int trunc_hmac,
#endif
#if defined(MBEDTLS_ZLIB_SUPPORT)
int compression,
#endif
ssl_tls_prf_t tls_prf,
const unsigned char randbytes[64],
int minor_ver,
unsigned endpoint,
const mbedtls_ssl_context *ssl )
{
int ret = 0;
unsigned char keyblk[256];
unsigned char *key1;
unsigned char *key2;
unsigned char *mac_enc;
unsigned char *mac_dec;
size_t mac_key_len;
size_t iv_copy_len;
unsigned keylen;
const mbedtls_ssl_ciphersuite_t *ciphersuite_info;
const mbedtls_cipher_info_t *cipher_info;
const mbedtls_md_info_t *md_info;
#if !defined(MBEDTLS_SSL_HW_RECORD_ACCEL) && \
!defined(MBEDTLS_SSL_EXPORT_KEYS) && \
!defined(MBEDTLS_DEBUG_C)
ssl = NULL; /* make sure we don't use it except for those cases */
(void) ssl;
#endif
/* Copy info about negotiated version and extensions */
#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
transform->encrypt_then_mac = encrypt_then_mac;
#endif
transform->minor_ver = minor_ver;
/*
* Get various info structures
*/
ciphersuite_info = mbedtls_ssl_ciphersuite_from_id( ciphersuite );
if( ciphersuite_info == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "ciphersuite info for %d not found",
ciphersuite ) );
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
}
cipher_info = mbedtls_cipher_info_from_type( ciphersuite_info->cipher );
if( cipher_info == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "cipher info for %d not found",
ciphersuite_info->cipher ) );
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
}
md_info = mbedtls_md_info_from_type( ciphersuite_info->mac );
if( md_info == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "mbedtls_md info for %d not found",
ciphersuite_info->mac ) );
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
}
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
/* Copy own and peer's CID if the use of the CID
* extension has been negotiated. */
if( ssl->handshake->cid_in_use == MBEDTLS_SSL_CID_ENABLED )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "Copy CIDs into SSL transform" ) );
transform->in_cid_len = ssl->own_cid_len;
memcpy( transform->in_cid, ssl->own_cid, ssl->own_cid_len );
MBEDTLS_SSL_DEBUG_BUF( 3, "Incoming CID", transform->in_cid,
transform->in_cid_len );
transform->out_cid_len = ssl->handshake->peer_cid_len;
memcpy( transform->out_cid, ssl->handshake->peer_cid,
ssl->handshake->peer_cid_len );
MBEDTLS_SSL_DEBUG_BUF( 3, "Outgoing CID", transform->out_cid,
transform->out_cid_len );
}
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
/*
* Compute key block using the PRF
*/
ret = tls_prf( master, 48, "key expansion", randbytes, 64, keyblk, 256 );
if( ret != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "prf", ret );
return( ret );
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "ciphersuite = %s",
mbedtls_ssl_get_ciphersuite_name( ciphersuite ) ) );
MBEDTLS_SSL_DEBUG_BUF( 3, "master secret", master, 48 );
MBEDTLS_SSL_DEBUG_BUF( 4, "random bytes", randbytes, 64 );
MBEDTLS_SSL_DEBUG_BUF( 4, "key block", keyblk, 256 );
/*
* Determine the appropriate key, IV and MAC length.
*/
keylen = cipher_info->key_bitlen / 8;
#if defined(MBEDTLS_GCM_C) || \
defined(MBEDTLS_CCM_C) || \
defined(MBEDTLS_CHACHAPOLY_C)
if( cipher_info->mode == MBEDTLS_MODE_GCM ||
cipher_info->mode == MBEDTLS_MODE_CCM ||
cipher_info->mode == MBEDTLS_MODE_CHACHAPOLY )
{
size_t explicit_ivlen;
transform->maclen = 0;
mac_key_len = 0;
transform->taglen =
ciphersuite_info->flags & MBEDTLS_CIPHERSUITE_SHORT_TAG ? 8 : 16;
/* All modes haves 96-bit IVs;
* GCM and CCM has 4 implicit and 8 explicit bytes
* ChachaPoly has all 12 bytes implicit
*/
transform->ivlen = 12;
if( cipher_info->mode == MBEDTLS_MODE_CHACHAPOLY )
transform->fixed_ivlen = 12;
else
transform->fixed_ivlen = 4;
/* Minimum length of encrypted record */
explicit_ivlen = transform->ivlen - transform->fixed_ivlen;
transform->minlen = explicit_ivlen + transform->taglen;
}
else
#endif /* MBEDTLS_GCM_C || MBEDTLS_CCM_C || MBEDTLS_CHACHAPOLY_C */
#if defined(MBEDTLS_SSL_SOME_MODES_USE_MAC)
if( cipher_info->mode == MBEDTLS_MODE_STREAM ||
cipher_info->mode == MBEDTLS_MODE_CBC )
{
/* Initialize HMAC contexts */
if( ( ret = mbedtls_md_setup( &transform->md_ctx_enc, md_info, 1 ) ) != 0 ||
( ret = mbedtls_md_setup( &transform->md_ctx_dec, md_info, 1 ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_md_setup", ret );
return( ret );
}
/* Get MAC length */
mac_key_len = mbedtls_md_get_size( md_info );
transform->maclen = mac_key_len;
#if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
/*
* If HMAC is to be truncated, we shall keep the leftmost bytes,
* (rfc 6066 page 13 or rfc 2104 section 4),
* so we only need to adjust the length here.
*/
if( trunc_hmac == MBEDTLS_SSL_TRUNC_HMAC_ENABLED )
{
transform->maclen = MBEDTLS_SSL_TRUNCATED_HMAC_LEN;
#if defined(MBEDTLS_SSL_TRUNCATED_HMAC_COMPAT)
/* Fall back to old, non-compliant version of the truncated
* HMAC implementation which also truncates the key
* (Mbed TLS versions from 1.3 to 2.6.0) */
mac_key_len = transform->maclen;
#endif
}
#endif /* MBEDTLS_SSL_TRUNCATED_HMAC */
/* IV length */
transform->ivlen = cipher_info->iv_size;
/* Minimum length */
if( cipher_info->mode == MBEDTLS_MODE_STREAM )
transform->minlen = transform->maclen;
else
{
/*
* GenericBlockCipher:
* 1. if EtM is in use: one block plus MAC
* otherwise: * first multiple of blocklen greater than maclen
* 2. IV except for SSL3 and TLS 1.0
*/
#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
if( encrypt_then_mac == MBEDTLS_SSL_ETM_ENABLED )
{
transform->minlen = transform->maclen
+ cipher_info->block_size;
}
else
#endif
{
transform->minlen = transform->maclen
+ cipher_info->block_size
- transform->maclen % cipher_info->block_size;
}
#if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1)
if( minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 ||
minor_ver == MBEDTLS_SSL_MINOR_VERSION_1 )
; /* No need to adjust minlen */
else
#endif
#if defined(MBEDTLS_SSL_PROTO_TLS1_1) || defined(MBEDTLS_SSL_PROTO_TLS1_2)
if( minor_ver == MBEDTLS_SSL_MINOR_VERSION_2 ||
minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 )
{
transform->minlen += transform->ivlen;
}
else
#endif
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
}
}
else
#endif /* MBEDTLS_SSL_SOME_MODES_USE_MAC */
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "keylen: %u, minlen: %u, ivlen: %u, maclen: %u",
(unsigned) keylen,
(unsigned) transform->minlen,
(unsigned) transform->ivlen,
(unsigned) transform->maclen ) );
/*
* Finally setup the cipher contexts, IVs and MAC secrets.
*/
#if defined(MBEDTLS_SSL_CLI_C)
if( endpoint == MBEDTLS_SSL_IS_CLIENT )
{
key1 = keyblk + mac_key_len * 2;
key2 = keyblk + mac_key_len * 2 + keylen;
mac_enc = keyblk;
mac_dec = keyblk + mac_key_len;
/*
* This is not used in TLS v1.1.
*/
iv_copy_len = ( transform->fixed_ivlen ) ?
transform->fixed_ivlen : transform->ivlen;
memcpy( transform->iv_enc, key2 + keylen, iv_copy_len );
memcpy( transform->iv_dec, key2 + keylen + iv_copy_len,
iv_copy_len );
}
else
#endif /* MBEDTLS_SSL_CLI_C */
#if defined(MBEDTLS_SSL_SRV_C)
if( endpoint == MBEDTLS_SSL_IS_SERVER )
{
key1 = keyblk + mac_key_len * 2 + keylen;
key2 = keyblk + mac_key_len * 2;
mac_enc = keyblk + mac_key_len;
mac_dec = keyblk;
/*
* This is not used in TLS v1.1.
*/
iv_copy_len = ( transform->fixed_ivlen ) ?
transform->fixed_ivlen : transform->ivlen;
memcpy( transform->iv_dec, key1 + keylen, iv_copy_len );
memcpy( transform->iv_enc, key1 + keylen + iv_copy_len,
iv_copy_len );
}
else
#endif /* MBEDTLS_SSL_SRV_C */
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
#if defined(MBEDTLS_SSL_SOME_MODES_USE_MAC)
#if defined(MBEDTLS_SSL_PROTO_SSL3)
if( minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 )
{
if( mac_key_len > sizeof( transform->mac_enc ) )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
memcpy( transform->mac_enc, mac_enc, mac_key_len );
memcpy( transform->mac_dec, mac_dec, mac_key_len );
}
else
#endif /* MBEDTLS_SSL_PROTO_SSL3 */
#if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) || \
defined(MBEDTLS_SSL_PROTO_TLS1_2)
if( minor_ver >= MBEDTLS_SSL_MINOR_VERSION_1 )
{
/* For HMAC-based ciphersuites, initialize the HMAC transforms.
For AEAD-based ciphersuites, there is nothing to do here. */
if( mac_key_len != 0 )
{
mbedtls_md_hmac_starts( &transform->md_ctx_enc, mac_enc, mac_key_len );
mbedtls_md_hmac_starts( &transform->md_ctx_dec, mac_dec, mac_key_len );
}
}
else
#endif
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
#endif /* MBEDTLS_SSL_SOME_MODES_USE_MAC */
#if defined(MBEDTLS_SSL_HW_RECORD_ACCEL)
if( mbedtls_ssl_hw_record_init != NULL )
{
int ret = 0;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "going for mbedtls_ssl_hw_record_init()" ) );
if( ( ret = mbedtls_ssl_hw_record_init( ssl, key1, key2, keylen,
transform->iv_enc, transform->iv_dec,
iv_copy_len,
mac_enc, mac_dec,
mac_key_len ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_hw_record_init", ret );
return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
}
}
#else
((void) mac_dec);
((void) mac_enc);
#endif /* MBEDTLS_SSL_HW_RECORD_ACCEL */
#if defined(MBEDTLS_SSL_EXPORT_KEYS)
if( ssl->conf->f_export_keys != NULL )
{
ssl->conf->f_export_keys( ssl->conf->p_export_keys,
master, keyblk,
mac_key_len, keylen,
iv_copy_len );
}
#endif
if( ( ret = mbedtls_cipher_setup( &transform->cipher_ctx_enc,
cipher_info ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_setup", ret );
return( ret );
}
if( ( ret = mbedtls_cipher_setup( &transform->cipher_ctx_dec,
cipher_info ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_setup", ret );
return( ret );
}
if( ( ret = mbedtls_cipher_setkey( &transform->cipher_ctx_enc, key1,
cipher_info->key_bitlen,
MBEDTLS_ENCRYPT ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_setkey", ret );
return( ret );
}
if( ( ret = mbedtls_cipher_setkey( &transform->cipher_ctx_dec, key2,
cipher_info->key_bitlen,
MBEDTLS_DECRYPT ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_setkey", ret );
return( ret );
}
#if defined(MBEDTLS_CIPHER_MODE_CBC)
if( cipher_info->mode == MBEDTLS_MODE_CBC )
{
if( ( ret = mbedtls_cipher_set_padding_mode( &transform->cipher_ctx_enc,
MBEDTLS_PADDING_NONE ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_set_padding_mode", ret );
return( ret );
}
if( ( ret = mbedtls_cipher_set_padding_mode( &transform->cipher_ctx_dec,
MBEDTLS_PADDING_NONE ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_set_padding_mode", ret );
return( ret );
}
}
#endif /* MBEDTLS_CIPHER_MODE_CBC */
mbedtls_platform_zeroize( keyblk, sizeof( keyblk ) );
/* Initialize Zlib contexts */
#if defined(MBEDTLS_ZLIB_SUPPORT)
if( compression == MBEDTLS_SSL_COMPRESS_DEFLATE )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "Initializing zlib states" ) );
memset( &transform->ctx_deflate, 0, sizeof( transform->ctx_deflate ) );
memset( &transform->ctx_inflate, 0, sizeof( transform->ctx_inflate ) );
if( deflateInit( &transform->ctx_deflate,
Z_DEFAULT_COMPRESSION ) != Z_OK ||
inflateInit( &transform->ctx_inflate ) != Z_OK )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "Failed to initialize compression" ) );
return( MBEDTLS_ERR_SSL_COMPRESSION_FAILED );
}
}
#endif /* MBEDTLS_ZLIB_SUPPORT */
return( 0 );
}
/*
* Set appropriate PRF function and other SSL / TLS 1.0/1.1 / TLS1.2 functions
*
* Inputs:
* - SSL/TLS minor version
* - hash associated with the ciphersuite (only used by TLS 1.2)
*
* Outputs:
* - the tls_prf, calc_verify and calc_finished members of handshake structure
*/
static int ssl_set_handshake_prfs( mbedtls_ssl_handshake_params *handshake,
int minor_ver,
mbedtls_md_type_t hash )
{
#if !defined(MBEDTLS_SSL_PROTO_TLS1_2) || !defined(MBEDTLS_SHA512_C)
(void) hash;
#endif
#if defined(MBEDTLS_SSL_PROTO_SSL3)
if( minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 )
{
handshake->tls_prf = ssl3_prf;
handshake->calc_verify = ssl_calc_verify_ssl;
handshake->calc_finished = ssl_calc_finished_ssl;
}
else
#endif
#if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1)
if( minor_ver < MBEDTLS_SSL_MINOR_VERSION_3 )
{
handshake->tls_prf = tls1_prf;
handshake->calc_verify = ssl_calc_verify_tls;
handshake->calc_finished = ssl_calc_finished_tls;
}
else
#endif
#if defined(MBEDTLS_SSL_PROTO_TLS1_2)
#if defined(MBEDTLS_SHA512_C)
if( minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 &&
hash == MBEDTLS_MD_SHA384 )
{
handshake->tls_prf = tls_prf_sha384;
handshake->calc_verify = ssl_calc_verify_tls_sha384;
handshake->calc_finished = ssl_calc_finished_tls_sha384;
}
else
#endif
#if defined(MBEDTLS_SHA256_C)
if( minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 )
{
handshake->tls_prf = tls_prf_sha256;
handshake->calc_verify = ssl_calc_verify_tls_sha256;
handshake->calc_finished = ssl_calc_finished_tls_sha256;
}
else
#endif
#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
{
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
return( 0 );
}
/*
* Compute master secret if needed
*
* Parameters:
* [in/out] handshake
* [in] resume, premaster, extended_ms, calc_verify, tls_prf
* [out] premaster (cleared)
* [out] master
* [in] ssl: optionally used for debugging and calc_verify
*/
static int ssl_compute_master( mbedtls_ssl_handshake_params *handshake,
unsigned char *master,
const mbedtls_ssl_context *ssl )
{
int ret;
#if !defined(MBEDTLS_DEBUG_C) && !defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
ssl = NULL; /* make sure we don't use it except for debug and EMS */
(void) ssl;
#endif
if( handshake->resume != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "no premaster (session resumed)" ) );
return( 0 );
}
MBEDTLS_SSL_DEBUG_BUF( 3, "premaster secret", handshake->premaster,
handshake->pmslen );
#if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
if( handshake->extended_ms == MBEDTLS_SSL_EXTENDED_MS_ENABLED )
{
unsigned char session_hash[48];
size_t hash_len;
handshake->calc_verify( ssl, session_hash, &hash_len );
MBEDTLS_SSL_DEBUG_BUF( 3, "session hash for extended master secret",
session_hash, hash_len );
ret = handshake->tls_prf( handshake->premaster, handshake->pmslen,
"extended master secret",
session_hash, hash_len,
master, 48 );
}
else
#endif
{
ret = handshake->tls_prf( handshake->premaster, handshake->pmslen,
"master secret",
handshake->randbytes, 64,
master, 48 );
}
if( ret != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "prf", ret );
return( ret );
}
mbedtls_platform_zeroize( handshake->premaster,
sizeof(handshake->premaster) );
return( 0 );
}
int mbedtls_ssl_derive_keys( mbedtls_ssl_context *ssl )
{
int ret;
const mbedtls_ssl_ciphersuite_t * const ciphersuite_info =
ssl->handshake->ciphersuite_info;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> derive keys" ) );
/* Set PRF, calc_verify and calc_finished function pointers */
ret = ssl_set_handshake_prfs( ssl->handshake,
ssl->minor_ver,
ciphersuite_info->mac );
if( ret != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_set_handshake_prfs", ret );
return( ret );
}
/* Compute master secret if needed */
ret = ssl_compute_master( ssl->handshake,
ssl->session_negotiate->master,
ssl );
if( ret != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_compute_master", ret );
return( ret );
}
/* Swap the client and server random values:
* - MS derivation wanted client+server (RFC 5246 8.1)
* - key derivation wants server+client (RFC 5246 6.3) */
{
unsigned char tmp[64];
memcpy( tmp, ssl->handshake->randbytes, 64 );
memcpy( ssl->handshake->randbytes, tmp + 32, 32 );
memcpy( ssl->handshake->randbytes + 32, tmp, 32 );
mbedtls_platform_zeroize( tmp, sizeof( tmp ) );
}
/* Populate transform structure */
ret = ssl_populate_transform( ssl->transform_negotiate,
ssl->session_negotiate->ciphersuite,
ssl->session_negotiate->master,
#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
ssl->session_negotiate->encrypt_then_mac,
#endif
#if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
ssl->session_negotiate->trunc_hmac,
#endif
#if defined(MBEDTLS_ZLIB_SUPPORT)
ssl->session_negotiate->compression,
#endif
ssl->handshake->tls_prf,
ssl->handshake->randbytes,
ssl->minor_ver,
ssl->conf->endpoint,
ssl );
if( ret != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_populate_transform", ret );
return( ret );
}
/* We no longer need Server/ClientHello.random values */
mbedtls_platform_zeroize( ssl->handshake->randbytes,
sizeof( ssl->handshake->randbytes ) );
/* Allocate compression buffer */
#if defined(MBEDTLS_ZLIB_SUPPORT)
if( session->compression == MBEDTLS_SSL_COMPRESS_DEFLATE &&
ssl->compress_buf == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "Allocating compression buffer" ) );
ssl->compress_buf = mbedtls_calloc( 1, MBEDTLS_SSL_COMPRESS_BUFFER_LEN );
if( ssl->compress_buf == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "alloc(%d bytes) failed",
MBEDTLS_SSL_COMPRESS_BUFFER_LEN ) );
return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
}
}
#endif
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= derive keys" ) );
return( 0 );
}
#if defined(MBEDTLS_SSL_PROTO_SSL3)
void ssl_calc_verify_ssl( const mbedtls_ssl_context *ssl,
unsigned char hash[36],
size_t *hlen )
{
mbedtls_md5_context md5;
mbedtls_sha1_context sha1;
unsigned char pad_1[48];
unsigned char pad_2[48];
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> calc verify ssl" ) );
mbedtls_md5_init( &md5 );
mbedtls_sha1_init( &sha1 );
mbedtls_md5_clone( &md5, &ssl->handshake->fin_md5 );
mbedtls_sha1_clone( &sha1, &ssl->handshake->fin_sha1 );
memset( pad_1, 0x36, 48 );
memset( pad_2, 0x5C, 48 );
mbedtls_md5_update_ret( &md5, ssl->session_negotiate->master, 48 );
mbedtls_md5_update_ret( &md5, pad_1, 48 );
mbedtls_md5_finish_ret( &md5, hash );
mbedtls_md5_starts_ret( &md5 );
mbedtls_md5_update_ret( &md5, ssl->session_negotiate->master, 48 );
mbedtls_md5_update_ret( &md5, pad_2, 48 );
mbedtls_md5_update_ret( &md5, hash, 16 );
mbedtls_md5_finish_ret( &md5, hash );
mbedtls_sha1_update_ret( &sha1, ssl->session_negotiate->master, 48 );
mbedtls_sha1_update_ret( &sha1, pad_1, 40 );
mbedtls_sha1_finish_ret( &sha1, hash + 16 );
mbedtls_sha1_starts_ret( &sha1 );
mbedtls_sha1_update_ret( &sha1, ssl->session_negotiate->master, 48 );
mbedtls_sha1_update_ret( &sha1, pad_2, 40 );
mbedtls_sha1_update_ret( &sha1, hash + 16, 20 );
mbedtls_sha1_finish_ret( &sha1, hash + 16 );
*hlen = 36;
MBEDTLS_SSL_DEBUG_BUF( 3, "calculated verify result", hash, *hlen );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= calc verify" ) );
mbedtls_md5_free( &md5 );
mbedtls_sha1_free( &sha1 );
return;
}
#endif /* MBEDTLS_SSL_PROTO_SSL3 */
#if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1)
void ssl_calc_verify_tls( const mbedtls_ssl_context *ssl,
unsigned char hash[36],
size_t *hlen )
{
mbedtls_md5_context md5;
mbedtls_sha1_context sha1;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> calc verify tls" ) );
mbedtls_md5_init( &md5 );
mbedtls_sha1_init( &sha1 );
mbedtls_md5_clone( &md5, &ssl->handshake->fin_md5 );
mbedtls_sha1_clone( &sha1, &ssl->handshake->fin_sha1 );
mbedtls_md5_finish_ret( &md5, hash );
mbedtls_sha1_finish_ret( &sha1, hash + 16 );
*hlen = 36;
MBEDTLS_SSL_DEBUG_BUF( 3, "calculated verify result", hash, *hlen );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= calc verify" ) );
mbedtls_md5_free( &md5 );
mbedtls_sha1_free( &sha1 );
return;
}
#endif /* MBEDTLS_SSL_PROTO_TLS1 || MBEDTLS_SSL_PROTO_TLS1_1 */
#if defined(MBEDTLS_SSL_PROTO_TLS1_2)
#if defined(MBEDTLS_SHA256_C)
void ssl_calc_verify_tls_sha256( const mbedtls_ssl_context *ssl,
unsigned char hash[32],
size_t *hlen )
{
mbedtls_sha256_context sha256;
mbedtls_sha256_init( &sha256 );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> calc verify sha256" ) );
mbedtls_sha256_clone( &sha256, &ssl->handshake->fin_sha256 );
mbedtls_sha256_finish_ret( &sha256, hash );
*hlen = 32;
MBEDTLS_SSL_DEBUG_BUF( 3, "calculated verify result", hash, *hlen );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= calc verify" ) );
mbedtls_sha256_free( &sha256 );
return;
}
#endif /* MBEDTLS_SHA256_C */
#if defined(MBEDTLS_SHA512_C)
void ssl_calc_verify_tls_sha384( const mbedtls_ssl_context *ssl,
unsigned char hash[48],
size_t *hlen )
{
mbedtls_sha512_context sha512;
mbedtls_sha512_init( &sha512 );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> calc verify sha384" ) );
mbedtls_sha512_clone( &sha512, &ssl->handshake->fin_sha512 );
mbedtls_sha512_finish_ret( &sha512, hash );
*hlen = 48;
MBEDTLS_SSL_DEBUG_BUF( 3, "calculated verify result", hash, *hlen );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= calc verify" ) );
mbedtls_sha512_free( &sha512 );
return;
}
#endif /* MBEDTLS_SHA512_C */
#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
#if defined(MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED)
int mbedtls_ssl_psk_derive_premaster( mbedtls_ssl_context *ssl, mbedtls_key_exchange_type_t key_ex )
{
unsigned char *p = ssl->handshake->premaster;
unsigned char *end = p + sizeof( ssl->handshake->premaster );
const unsigned char *psk = ssl->conf->psk;
size_t psk_len = ssl->conf->psk_len;
/* If the psk callback was called, use its result */
if( ssl->handshake->psk != NULL )
{
psk = ssl->handshake->psk;
psk_len = ssl->handshake->psk_len;
}
/*
* PMS = struct {
* opaque other_secret<0..2^16-1>;
* opaque psk<0..2^16-1>;
* };
* with "other_secret" depending on the particular key exchange
*/
#if defined(MBEDTLS_KEY_EXCHANGE_PSK_ENABLED)
if( key_ex == MBEDTLS_KEY_EXCHANGE_PSK )
{
if( end - p < 2 )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
*(p++) = (unsigned char)( psk_len >> 8 );
*(p++) = (unsigned char)( psk_len );
if( end < p || (size_t)( end - p ) < psk_len )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
memset( p, 0, psk_len );
p += psk_len;
}
else
#endif /* MBEDTLS_KEY_EXCHANGE_PSK_ENABLED */
#if defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED)
if( key_ex == MBEDTLS_KEY_EXCHANGE_RSA_PSK )
{
/*
* other_secret already set by the ClientKeyExchange message,
* and is 48 bytes long
*/
if( end - p < 2 )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
*p++ = 0;
*p++ = 48;
p += 48;
}
else
#endif /* MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED */
#if defined(MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED)
if( key_ex == MBEDTLS_KEY_EXCHANGE_DHE_PSK )
{
int ret;
size_t len;
/* Write length only when we know the actual value */
if( ( ret = mbedtls_dhm_calc_secret( &ssl->handshake->dhm_ctx,
p + 2, end - ( p + 2 ), &len,
ssl->conf->f_rng, ssl->conf->p_rng ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_dhm_calc_secret", ret );
return( ret );
}
*(p++) = (unsigned char)( len >> 8 );
*(p++) = (unsigned char)( len );
p += len;
MBEDTLS_SSL_DEBUG_MPI( 3, "DHM: K ", &ssl->handshake->dhm_ctx.K );
}
else
#endif /* MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED */
#if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED)
if( key_ex == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK )
{
int ret;
size_t zlen;
if( ( ret = mbedtls_ecdh_calc_secret( &ssl->handshake->ecdh_ctx, &zlen,
p + 2, end - ( p + 2 ),
ssl->conf->f_rng, ssl->conf->p_rng ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecdh_calc_secret", ret );
return( ret );
}
*(p++) = (unsigned char)( zlen >> 8 );
*(p++) = (unsigned char)( zlen );
p += zlen;
MBEDTLS_SSL_DEBUG_ECDH( 3, &ssl->handshake->ecdh_ctx,
MBEDTLS_DEBUG_ECDH_Z );
}
else
#endif /* MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED */
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
/* opaque psk<0..2^16-1>; */
if( end - p < 2 )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
*(p++) = (unsigned char)( psk_len >> 8 );
*(p++) = (unsigned char)( psk_len );
if( end < p || (size_t)( end - p ) < psk_len )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
memcpy( p, psk, psk_len );
p += psk_len;
ssl->handshake->pmslen = p - ssl->handshake->premaster;
return( 0 );
}
#endif /* MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED */
#if defined(MBEDTLS_SSL_PROTO_SSL3)
/*
* SSLv3.0 MAC functions
*/
#define SSL_MAC_MAX_BYTES 20 /* MD-5 or SHA-1 */
static void ssl_mac( mbedtls_md_context_t *md_ctx,
const unsigned char *secret,
const unsigned char *buf, size_t len,
const unsigned char *ctr, int type,
unsigned char out[SSL_MAC_MAX_BYTES] )
{
unsigned char header[11];
unsigned char padding[48];
int padlen;
int md_size = mbedtls_md_get_size( md_ctx->md_info );
int md_type = mbedtls_md_get_type( md_ctx->md_info );
/* Only MD5 and SHA-1 supported */
if( md_type == MBEDTLS_MD_MD5 )
padlen = 48;
else
padlen = 40;
memcpy( header, ctr, 8 );
header[ 8] = (unsigned char) type;
header[ 9] = (unsigned char)( len >> 8 );
header[10] = (unsigned char)( len );
memset( padding, 0x36, padlen );
mbedtls_md_starts( md_ctx );
mbedtls_md_update( md_ctx, secret, md_size );
mbedtls_md_update( md_ctx, padding, padlen );
mbedtls_md_update( md_ctx, header, 11 );
mbedtls_md_update( md_ctx, buf, len );
mbedtls_md_finish( md_ctx, out );
memset( padding, 0x5C, padlen );
mbedtls_md_starts( md_ctx );
mbedtls_md_update( md_ctx, secret, md_size );
mbedtls_md_update( md_ctx, padding, padlen );
mbedtls_md_update( md_ctx, out, md_size );
mbedtls_md_finish( md_ctx, out );
}
#endif /* MBEDTLS_SSL_PROTO_SSL3 */
/* The function below is only used in the Lucky 13 counter-measure in
* mbedtls_ssl_decrypt_buf(). These are the defines that guard the call site. */
#if defined(MBEDTLS_SSL_SOME_MODES_USE_MAC) && \
( defined(MBEDTLS_SSL_PROTO_TLS1) || \
defined(MBEDTLS_SSL_PROTO_TLS1_1) || \
defined(MBEDTLS_SSL_PROTO_TLS1_2) )
/* This function makes sure every byte in the memory region is accessed
* (in ascending addresses order) */
static void ssl_read_memory( unsigned char *p, size_t len )
{
unsigned char acc = 0;
volatile unsigned char force;
for( ; len != 0; p++, len-- )
acc ^= *p;
force = acc;
(void) force;
}
#endif /* SSL_SOME_MODES_USE_MAC && ( TLS1 || TLS1_1 || TLS1_2 ) */
/*
* Encryption/decryption functions
*/
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
/* This functions transforms a DTLS plaintext fragment and a record content
* type into an instance of the DTLSInnerPlaintext structure:
*
* struct {
* opaque content[DTLSPlaintext.length];
* ContentType real_type;
* uint8 zeros[length_of_padding];
* } DTLSInnerPlaintext;
*
* Input:
* - `content`: The beginning of the buffer holding the
* plaintext to be wrapped.
* - `*content_size`: The length of the plaintext in Bytes.
* - `max_len`: The number of Bytes available starting from
* `content`. This must be `>= *content_size`.
* - `rec_type`: The desired record content type.
*
* Output:
* - `content`: The beginning of the resulting DTLSInnerPlaintext structure.
* - `*content_size`: The length of the resulting DTLSInnerPlaintext structure.
*
* Returns:
* - `0` on success.
* - A negative error code if `max_len` didn't offer enough space
* for the expansion.
*/
static int ssl_cid_build_inner_plaintext( unsigned char *content,
size_t *content_size,
size_t remaining,
uint8_t rec_type )
{
size_t len = *content_size;
size_t pad = ( MBEDTLS_SSL_CID_PADDING_GRANULARITY -
( len + 1 ) % MBEDTLS_SSL_CID_PADDING_GRANULARITY ) %
MBEDTLS_SSL_CID_PADDING_GRANULARITY;
/* Write real content type */
if( remaining == 0 )
return( -1 );
content[ len ] = rec_type;
len++;
remaining--;
if( remaining < pad )
return( -1 );
memset( content + len, 0, pad );
len += pad;
remaining -= pad;
*content_size = len;
return( 0 );
}
/* This function parses a DTLSInnerPlaintext structure.
* See ssl_cid_build_inner_plaintext() for details. */
static int ssl_cid_parse_inner_plaintext( unsigned char const *content,
size_t *content_size,
uint8_t *rec_type )
{
size_t remaining = *content_size;
/* Determine length of padding by skipping zeroes from the back. */
do
{
if( remaining == 0 )
return( -1 );
remaining--;
} while( content[ remaining ] == 0 );
*content_size = remaining;
*rec_type = content[ remaining ];
return( 0 );
}
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
/* `add_data` must have size 13 Bytes if the CID extension is disabled,
* and 13 + 1 + CID-length Bytes if the CID extension is enabled. */
static void ssl_extract_add_data_from_record( unsigned char* add_data,
size_t *add_data_len,
mbedtls_record *rec )
{
/* Quoting RFC 5246 (TLS 1.2):
*
* additional_data = seq_num + TLSCompressed.type +
* TLSCompressed.version + TLSCompressed.length;
*
* For the CID extension, this is extended as follows
* (quoting draft-ietf-tls-dtls-connection-id-05,
* https://tools.ietf.org/html/draft-ietf-tls-dtls-connection-id-05):
*
* additional_data = seq_num + DTLSPlaintext.type +
* DTLSPlaintext.version +
* cid +
* cid_length +
* length_of_DTLSInnerPlaintext;
*/
memcpy( add_data, rec->ctr, sizeof( rec->ctr ) );
add_data[8] = rec->type;
memcpy( add_data + 9, rec->ver, sizeof( rec->ver ) );
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
if( rec->cid_len != 0 )
{
memcpy( add_data + 11, rec->cid, rec->cid_len );
add_data[11 + rec->cid_len + 0] = rec->cid_len;
add_data[11 + rec->cid_len + 1] = ( rec->data_len >> 8 ) & 0xFF;
add_data[11 + rec->cid_len + 2] = ( rec->data_len >> 0 ) & 0xFF;
*add_data_len = 13 + 1 + rec->cid_len;
}
else
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
{
add_data[11 + 0] = ( rec->data_len >> 8 ) & 0xFF;
add_data[11 + 1] = ( rec->data_len >> 0 ) & 0xFF;
*add_data_len = 13;
}
}
int mbedtls_ssl_encrypt_buf( mbedtls_ssl_context *ssl,
mbedtls_ssl_transform *transform,
mbedtls_record *rec,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng )
{
mbedtls_cipher_mode_t mode;
int auth_done = 0;
unsigned char * data;
unsigned char add_data[13 + 1 + MBEDTLS_SSL_CID_OUT_LEN_MAX ];
size_t add_data_len;
size_t post_avail;
/* The SSL context is only used for debugging purposes! */
#if !defined(MBEDTLS_DEBUG_C)
ssl = NULL; /* make sure we don't use it except for debug */
((void) ssl);
#endif
/* The PRNG is used for dynamic IV generation that's used
* for CBC transformations in TLS 1.1 and TLS 1.2. */
#if !( defined(MBEDTLS_CIPHER_MODE_CBC) && \
( defined(MBEDTLS_AES_C) || \
defined(MBEDTLS_ARIA_C) || \
defined(MBEDTLS_CAMELLIA_C) ) && \
( defined(MBEDTLS_SSL_PROTO_TLS1_1) || defined(MBEDTLS_SSL_PROTO_TLS1_2) ) )
((void) f_rng);
((void) p_rng);
#endif
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> encrypt buf" ) );
if( transform == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "no transform provided to encrypt_buf" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
if( rec == NULL
|| rec->buf == NULL
|| rec->buf_len < rec->data_offset
|| rec->buf_len - rec->data_offset < rec->data_len
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
|| rec->cid_len != 0
#endif
)
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad record structure provided to encrypt_buf" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
data = rec->buf + rec->data_offset;
post_avail = rec->buf_len - ( rec->data_len + rec->data_offset );
MBEDTLS_SSL_DEBUG_BUF( 4, "before encrypt: output payload",
data, rec->data_len );
mode = mbedtls_cipher_get_cipher_mode( &transform->cipher_ctx_enc );
if( rec->data_len > MBEDTLS_SSL_OUT_CONTENT_LEN )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "Record content %u too large, maximum %d",
(unsigned) rec->data_len,
MBEDTLS_SSL_OUT_CONTENT_LEN ) );
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
}
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
/*
* Add CID information
*/
rec->cid_len = transform->out_cid_len;
memcpy( rec->cid, transform->out_cid, transform->out_cid_len );
MBEDTLS_SSL_DEBUG_BUF( 3, "CID", rec->cid, rec->cid_len );
if( rec->cid_len != 0 )
{
/*
* Wrap plaintext into DTLSInnerPlaintext structure.
* See ssl_cid_build_inner_plaintext() for more information.
*
* Note that this changes `rec->data_len`, and hence
* `post_avail` needs to be recalculated afterwards.
*/
if( ssl_cid_build_inner_plaintext( data,
&rec->data_len,
post_avail,
rec->type ) != 0 )
{
return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
}
rec->type = MBEDTLS_SSL_MSG_CID;
}
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
post_avail = rec->buf_len - ( rec->data_len + rec->data_offset );
/*
* Add MAC before if needed
*/
#if defined(MBEDTLS_SSL_SOME_MODES_USE_MAC)
if( mode == MBEDTLS_MODE_STREAM ||
( mode == MBEDTLS_MODE_CBC
#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
&& transform->encrypt_then_mac == MBEDTLS_SSL_ETM_DISABLED
#endif
) )
{
if( post_avail < transform->maclen )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "Buffer provided for encrypted record not large enough" ) );
return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
}
#if defined(MBEDTLS_SSL_PROTO_SSL3)
if( transform->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 )
{
unsigned char mac[SSL_MAC_MAX_BYTES];
ssl_mac( &transform->md_ctx_enc, transform->mac_enc,
data, rec->data_len, rec->ctr, rec->type, mac );
memcpy( data + rec->data_len, mac, transform->maclen );
}
else
#endif
#if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) || \
defined(MBEDTLS_SSL_PROTO_TLS1_2)
if( transform->minor_ver >= MBEDTLS_SSL_MINOR_VERSION_1 )
{
unsigned char mac[MBEDTLS_SSL_MAC_ADD];
ssl_extract_add_data_from_record( add_data, &add_data_len, rec );
mbedtls_md_hmac_update( &transform->md_ctx_enc, add_data,
add_data_len );
mbedtls_md_hmac_update( &transform->md_ctx_enc,
data, rec->data_len );
mbedtls_md_hmac_finish( &transform->md_ctx_enc, mac );
mbedtls_md_hmac_reset( &transform->md_ctx_enc );
memcpy( data + rec->data_len, mac, transform->maclen );
}
else
#endif
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
MBEDTLS_SSL_DEBUG_BUF( 4, "computed mac", data + rec->data_len,
transform->maclen );
rec->data_len += transform->maclen;
post_avail -= transform->maclen;
auth_done++;
}
#endif /* MBEDTLS_SSL_SOME_MODES_USE_MAC */
/*
* Encrypt
*/
#if defined(MBEDTLS_ARC4_C) || defined(MBEDTLS_CIPHER_NULL_CIPHER)
if( mode == MBEDTLS_MODE_STREAM )
{
int ret;
size_t olen;
MBEDTLS_SSL_DEBUG_MSG( 3, ( "before encrypt: msglen = %d, "
"including %d bytes of padding",
rec->data_len, 0 ) );
if( ( ret = mbedtls_cipher_crypt( &transform->cipher_ctx_enc,
transform->iv_enc, transform->ivlen,
data, rec->data_len,
data, &olen ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_crypt", ret );
return( ret );
}
if( rec->data_len != olen )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
}
else
#endif /* MBEDTLS_ARC4_C || MBEDTLS_CIPHER_NULL_CIPHER */
#if defined(MBEDTLS_GCM_C) || \
defined(MBEDTLS_CCM_C) || \
defined(MBEDTLS_CHACHAPOLY_C)
if( mode == MBEDTLS_MODE_GCM ||
mode == MBEDTLS_MODE_CCM ||
mode == MBEDTLS_MODE_CHACHAPOLY )
{
int ret;
unsigned char iv[12];
size_t explicit_iv_len = transform->ivlen - transform->fixed_ivlen;
/* Check that there's space for both the authentication tag
* and the explicit IV before and after the record content. */
if( post_avail < transform->taglen ||
rec->data_offset < explicit_iv_len )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "Buffer provided for encrypted record not large enough" ) );
return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
}
/*
* Generate IV
*/
if( transform->ivlen == 12 && transform->fixed_ivlen == 4 )
{
/* GCM and CCM: fixed || explicit (=seqnum) */
memcpy( iv, transform->iv_enc, transform->fixed_ivlen );
memcpy( iv + transform->fixed_ivlen, rec->ctr,
explicit_iv_len );
/* Prefix record content with explicit IV. */
memcpy( data - explicit_iv_len, rec->ctr, explicit_iv_len );
}
else if( transform->ivlen == 12 && transform->fixed_ivlen == 12 )
{
/* ChachaPoly: fixed XOR sequence number */
unsigned char i;
memcpy( iv, transform->iv_enc, transform->fixed_ivlen );
for( i = 0; i < 8; i++ )
iv[i+4] ^= rec->ctr[i];
}
else
{
/* Reminder if we ever add an AEAD mode with a different size */
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
ssl_extract_add_data_from_record( add_data, &add_data_len, rec );
MBEDTLS_SSL_DEBUG_BUF( 4, "IV used (internal)",
iv, transform->ivlen );
MBEDTLS_SSL_DEBUG_BUF( 4, "IV used (transmitted)",
data - explicit_iv_len, explicit_iv_len );
MBEDTLS_SSL_DEBUG_BUF( 4, "additional data used for AEAD",
add_data, add_data_len );
MBEDTLS_SSL_DEBUG_MSG( 3, ( "before encrypt: msglen = %d, "
"including 0 bytes of padding",
rec->data_len ) );
/*
* Encrypt and authenticate
*/
if( ( ret = mbedtls_cipher_auth_encrypt( &transform->cipher_ctx_enc,
iv, transform->ivlen,
add_data, add_data_len, /* add data */
data, rec->data_len, /* source */
data, &rec->data_len, /* destination */
data + rec->data_len, transform->taglen ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_auth_encrypt", ret );
return( ret );
}
MBEDTLS_SSL_DEBUG_BUF( 4, "after encrypt: tag",
data + rec->data_len, transform->taglen );
rec->data_len += transform->taglen + explicit_iv_len;
rec->data_offset -= explicit_iv_len;
post_avail -= transform->taglen;
auth_done++;
}
else
#endif /* MBEDTLS_GCM_C || MBEDTLS_CCM_C */
#if defined(MBEDTLS_CIPHER_MODE_CBC) && \
( defined(MBEDTLS_AES_C) || defined(MBEDTLS_CAMELLIA_C) || defined(MBEDTLS_ARIA_C) )
if( mode == MBEDTLS_MODE_CBC )
{
int ret;
size_t padlen, i;
size_t olen;
/* Currently we're always using minimal padding
* (up to 255 bytes would be allowed). */
padlen = transform->ivlen - ( rec->data_len + 1 ) % transform->ivlen;
if( padlen == transform->ivlen )
padlen = 0;
/* Check there's enough space in the buffer for the padding. */
if( post_avail < padlen + 1 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "Buffer provided for encrypted record not large enough" ) );
return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
}
for( i = 0; i <= padlen; i++ )
data[rec->data_len + i] = (unsigned char) padlen;
rec->data_len += padlen + 1;
post_avail -= padlen + 1;
#if defined(MBEDTLS_SSL_PROTO_TLS1_1) || defined(MBEDTLS_SSL_PROTO_TLS1_2)
/*
* Prepend per-record IV for block cipher in TLS v1.1 and up as per
* Method 1 (6.2.3.2. in RFC4346 and RFC5246)
*/
if( transform->minor_ver >= MBEDTLS_SSL_MINOR_VERSION_2 )
{
if( f_rng == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "No PRNG provided to encrypt_record routine" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
if( rec->data_offset < transform->ivlen )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "Buffer provided for encrypted record not large enough" ) );
return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
}
/*
* Generate IV
*/
ret = f_rng( p_rng, transform->iv_enc, transform->ivlen );
if( ret != 0 )
return( ret );
memcpy( data - transform->ivlen, transform->iv_enc,
transform->ivlen );
}
#endif /* MBEDTLS_SSL_PROTO_TLS1_1 || MBEDTLS_SSL_PROTO_TLS1_2 */
MBEDTLS_SSL_DEBUG_MSG( 3, ( "before encrypt: msglen = %d, "
"including %d bytes of IV and %d bytes of padding",
rec->data_len, transform->ivlen,
padlen + 1 ) );
if( ( ret = mbedtls_cipher_crypt( &transform->cipher_ctx_enc,
transform->iv_enc,
transform->ivlen,
data, rec->data_len,
data, &olen ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_crypt", ret );
return( ret );
}
if( rec->data_len != olen )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
#if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1)
if( transform->minor_ver < MBEDTLS_SSL_MINOR_VERSION_2 )
{
/*
* Save IV in SSL3 and TLS1
*/
memcpy( transform->iv_enc, transform->cipher_ctx_enc.iv,
transform->ivlen );
}
else
#endif
{
data -= transform->ivlen;
rec->data_offset -= transform->ivlen;
rec->data_len += transform->ivlen;
}
#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
if( auth_done == 0 )
{
unsigned char mac[MBEDTLS_SSL_MAC_ADD];
/*
* MAC(MAC_write_key, seq_num +
* TLSCipherText.type +
* TLSCipherText.version +
* length_of( (IV +) ENC(...) ) +
* IV + // except for TLS 1.0
* ENC(content + padding + padding_length));
*/
if( post_avail < transform->maclen)
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "Buffer provided for encrypted record not large enough" ) );
return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
}
ssl_extract_add_data_from_record( add_data, &add_data_len, rec );
MBEDTLS_SSL_DEBUG_MSG( 3, ( "using encrypt then mac" ) );
MBEDTLS_SSL_DEBUG_BUF( 4, "MAC'd meta-data", add_data,
add_data_len );
mbedtls_md_hmac_update( &transform->md_ctx_enc, add_data,
add_data_len );
mbedtls_md_hmac_update( &transform->md_ctx_enc,
data, rec->data_len );
mbedtls_md_hmac_finish( &transform->md_ctx_enc, mac );
mbedtls_md_hmac_reset( &transform->md_ctx_enc );
memcpy( data + rec->data_len, mac, transform->maclen );
rec->data_len += transform->maclen;
post_avail -= transform->maclen;
auth_done++;
}
#endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */
}
else
#endif /* MBEDTLS_CIPHER_MODE_CBC &&
( MBEDTLS_AES_C || MBEDTLS_CAMELLIA_C || MBEDTLS_ARIA_C ) */
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
/* Make extra sure authentication was performed, exactly once */
if( auth_done != 1 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= encrypt buf" ) );
return( 0 );
}
int mbedtls_ssl_decrypt_buf( mbedtls_ssl_context *ssl,
mbedtls_ssl_transform *transform,
mbedtls_record *rec )
{
size_t olen;
mbedtls_cipher_mode_t mode;
int ret, auth_done = 0;
#if defined(MBEDTLS_SSL_SOME_MODES_USE_MAC)
size_t padlen = 0, correct = 1;
#endif
unsigned char* data;
unsigned char add_data[13 + 1 + MBEDTLS_SSL_CID_IN_LEN_MAX ];
size_t add_data_len;
#if !defined(MBEDTLS_DEBUG_C)
ssl = NULL; /* make sure we don't use it except for debug */
((void) ssl);
#endif
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> decrypt buf" ) );
if( transform == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "no transform provided to decrypt_buf" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
if( rec == NULL ||
rec->buf == NULL ||
rec->buf_len < rec->data_offset ||
rec->buf_len - rec->data_offset < rec->data_len )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad record structure provided to decrypt_buf" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
data = rec->buf + rec->data_offset;
mode = mbedtls_cipher_get_cipher_mode( &transform->cipher_ctx_dec );
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
/*
* Match record's CID with incoming CID.
*/
if( rec->cid_len != transform->in_cid_len ||
memcmp( rec->cid, transform->in_cid, rec->cid_len ) != 0 )
{
return( MBEDTLS_ERR_SSL_UNEXPECTED_CID );
}
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
#if defined(MBEDTLS_ARC4_C) || defined(MBEDTLS_CIPHER_NULL_CIPHER)
if( mode == MBEDTLS_MODE_STREAM )
{
padlen = 0;
if( ( ret = mbedtls_cipher_crypt( &transform->cipher_ctx_dec,
transform->iv_dec,
transform->ivlen,
data, rec->data_len,
data, &olen ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_crypt", ret );
return( ret );
}
if( rec->data_len != olen )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
}
else
#endif /* MBEDTLS_ARC4_C || MBEDTLS_CIPHER_NULL_CIPHER */
#if defined(MBEDTLS_GCM_C) || \
defined(MBEDTLS_CCM_C) || \
defined(MBEDTLS_CHACHAPOLY_C)
if( mode == MBEDTLS_MODE_GCM ||
mode == MBEDTLS_MODE_CCM ||
mode == MBEDTLS_MODE_CHACHAPOLY )
{
unsigned char iv[12];
size_t explicit_iv_len = transform->ivlen - transform->fixed_ivlen;
/*
* Compute and update sizes
*/
if( rec->data_len < explicit_iv_len + transform->taglen )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "msglen (%d) < explicit_iv_len (%d) "
"+ taglen (%d)", rec->data_len,
explicit_iv_len, transform->taglen ) );
return( MBEDTLS_ERR_SSL_INVALID_MAC );
}
/*
* Prepare IV
*/
if( transform->ivlen == 12 && transform->fixed_ivlen == 4 )
{
/* GCM and CCM: fixed || explicit (transmitted) */
memcpy( iv, transform->iv_dec, transform->fixed_ivlen );
memcpy( iv + transform->fixed_ivlen, data, 8 );
}
else if( transform->ivlen == 12 && transform->fixed_ivlen == 12 )
{
/* ChachaPoly: fixed XOR sequence number */
unsigned char i;
memcpy( iv, transform->iv_dec, transform->fixed_ivlen );
for( i = 0; i < 8; i++ )
iv[i+4] ^= rec->ctr[i];
}
else
{
/* Reminder if we ever add an AEAD mode with a different size */
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
data += explicit_iv_len;
rec->data_offset += explicit_iv_len;
rec->data_len -= explicit_iv_len + transform->taglen;
ssl_extract_add_data_from_record( add_data, &add_data_len, rec );
MBEDTLS_SSL_DEBUG_BUF( 4, "additional data used for AEAD",
add_data, add_data_len );
memcpy( transform->iv_dec + transform->fixed_ivlen,
data - explicit_iv_len, explicit_iv_len );
MBEDTLS_SSL_DEBUG_BUF( 4, "IV used", iv, transform->ivlen );
MBEDTLS_SSL_DEBUG_BUF( 4, "TAG used", data + rec->data_len,
transform->taglen );
/*
* Decrypt and authenticate
*/
if( ( ret = mbedtls_cipher_auth_decrypt( &transform->cipher_ctx_dec,
iv, transform->ivlen,
add_data, add_data_len,
data, rec->data_len,
data, &olen,
data + rec->data_len,
transform->taglen ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_auth_decrypt", ret );
if( ret == MBEDTLS_ERR_CIPHER_AUTH_FAILED )
return( MBEDTLS_ERR_SSL_INVALID_MAC );
return( ret );
}
auth_done++;
if( olen != rec->data_len )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
}
else
#endif /* MBEDTLS_GCM_C || MBEDTLS_CCM_C */
#if defined(MBEDTLS_CIPHER_MODE_CBC) && \
( defined(MBEDTLS_AES_C) || defined(MBEDTLS_CAMELLIA_C) || defined(MBEDTLS_ARIA_C) )
if( mode == MBEDTLS_MODE_CBC )
{
size_t minlen = 0;
/*
* Check immediate ciphertext sanity
*/
#if defined(MBEDTLS_SSL_PROTO_TLS1_1) || defined(MBEDTLS_SSL_PROTO_TLS1_2)
if( transform->minor_ver >= MBEDTLS_SSL_MINOR_VERSION_2 )
{
/* The ciphertext is prefixed with the CBC IV. */
minlen += transform->ivlen;
}
#endif
/* Size considerations:
*
* - The CBC cipher text must not be empty and hence
* at least of size transform->ivlen.
*
* Together with the potential IV-prefix, this explains
* the first of the two checks below.
*
* - The record must contain a MAC, either in plain or
* encrypted, depending on whether Encrypt-then-MAC
* is used or not.
* - If it is, the message contains the IV-prefix,
* the CBC ciphertext, and the MAC.
* - If it is not, the padded plaintext, and hence
* the CBC ciphertext, has at least length maclen + 1
* because there is at least the padding length byte.
*
* As the CBC ciphertext is not empty, both cases give the
* lower bound minlen + maclen + 1 on the record size, which
* we test for in the second check below.
*/
if( rec->data_len < minlen + transform->ivlen ||
rec->data_len < minlen + transform->maclen + 1 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "msglen (%d) < max( ivlen(%d), maclen (%d) "
"+ 1 ) ( + expl IV )", rec->data_len,
transform->ivlen,
transform->maclen ) );
return( MBEDTLS_ERR_SSL_INVALID_MAC );
}
/*
* Authenticate before decrypt if enabled
*/
#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
if( transform->encrypt_then_mac == MBEDTLS_SSL_ETM_ENABLED )
{
unsigned char mac_expect[MBEDTLS_SSL_MAC_ADD];
MBEDTLS_SSL_DEBUG_MSG( 3, ( "using encrypt then mac" ) );
/* Safe due to the check data_len >= minlen + maclen + 1 above. */
rec->data_len -= transform->maclen;
ssl_extract_add_data_from_record( add_data, &add_data_len, rec );
MBEDTLS_SSL_DEBUG_BUF( 4, "MAC'd meta-data", add_data,
add_data_len );
mbedtls_md_hmac_update( &transform->md_ctx_dec, add_data,
add_data_len );
mbedtls_md_hmac_update( &transform->md_ctx_dec,
data, rec->data_len );
mbedtls_md_hmac_finish( &transform->md_ctx_dec, mac_expect );
mbedtls_md_hmac_reset( &transform->md_ctx_dec );
MBEDTLS_SSL_DEBUG_BUF( 4, "message mac", data + rec->data_len,
transform->maclen );
MBEDTLS_SSL_DEBUG_BUF( 4, "expected mac", mac_expect,
transform->maclen );
if( mbedtls_ssl_safer_memcmp( data + rec->data_len, mac_expect,
transform->maclen ) != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "message mac does not match" ) );
return( MBEDTLS_ERR_SSL_INVALID_MAC );
}
auth_done++;
}
#endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */
/*
* Check length sanity
*/
if( rec->data_len % transform->ivlen != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "msglen (%d) %% ivlen (%d) != 0",
rec->data_len, transform->ivlen ) );
return( MBEDTLS_ERR_SSL_INVALID_MAC );
}
#if defined(MBEDTLS_SSL_PROTO_TLS1_1) || defined(MBEDTLS_SSL_PROTO_TLS1_2)
/*
* Initialize for prepended IV for block cipher in TLS v1.1 and up
*/
if( transform->minor_ver >= MBEDTLS_SSL_MINOR_VERSION_2 )
{
/* This is safe because data_len >= minlen + maclen + 1 initially,
* and at this point we have at most subtracted maclen (note that
* minlen == transform->ivlen here). */
memcpy( transform->iv_dec, data, transform->ivlen );
data += transform->ivlen;
rec->data_offset += transform->ivlen;
rec->data_len -= transform->ivlen;
}
#endif /* MBEDTLS_SSL_PROTO_TLS1_1 || MBEDTLS_SSL_PROTO_TLS1_2 */
if( ( ret = mbedtls_cipher_crypt( &transform->cipher_ctx_dec,
transform->iv_dec, transform->ivlen,
data, rec->data_len, data, &olen ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_crypt", ret );
return( ret );
}
if( rec->data_len != olen )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
#if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1)
if( transform->minor_ver < MBEDTLS_SSL_MINOR_VERSION_2 )
{
/*
* Save IV in SSL3 and TLS1
*/
memcpy( transform->iv_dec, transform->cipher_ctx_dec.iv,
transform->ivlen );
}
#endif
/* Safe since data_len >= minlen + maclen + 1, so after having
* subtracted at most minlen and maclen up to this point,
* data_len > 0. */
padlen = data[rec->data_len - 1];
if( auth_done == 1 )
{
correct *= ( rec->data_len >= padlen + 1 );
padlen *= ( rec->data_len >= padlen + 1 );
}
else
{
#if defined(MBEDTLS_SSL_DEBUG_ALL)
if( rec->data_len < transform->maclen + padlen + 1 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "msglen (%d) < maclen (%d) + padlen (%d)",
rec->data_len,
transform->maclen,
padlen + 1 ) );
}
#endif
correct *= ( rec->data_len >= transform->maclen + padlen + 1 );
padlen *= ( rec->data_len >= transform->maclen + padlen + 1 );
}
padlen++;
/* Regardless of the validity of the padding,
* we have data_len >= padlen here. */
#if defined(MBEDTLS_SSL_PROTO_SSL3)
if( transform->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 )
{
if( padlen > transform->ivlen )
{
#if defined(MBEDTLS_SSL_DEBUG_ALL)
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad padding length: is %d, "
"should be no more than %d",
padlen, transform->ivlen ) );
#endif
correct = 0;
}
}
else
#endif /* MBEDTLS_SSL_PROTO_SSL3 */
#if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) || \
defined(MBEDTLS_SSL_PROTO_TLS1_2)
if( transform->minor_ver > MBEDTLS_SSL_MINOR_VERSION_0 )
{
/* The padding check involves a series of up to 256
* consecutive memory reads at the end of the record
* plaintext buffer. In order to hide the length and
* validity of the padding, always perform exactly
* `min(256,plaintext_len)` reads (but take into account
* only the last `padlen` bytes for the padding check). */
size_t pad_count = 0;
size_t real_count = 0;
volatile unsigned char* const check = data;
/* Index of first padding byte; it has been ensured above
* that the subtraction is safe. */
size_t const padding_idx = rec->data_len - padlen;
size_t const num_checks = rec->data_len <= 256 ? rec->data_len : 256;
size_t const start_idx = rec->data_len - num_checks;
size_t idx;
for( idx = start_idx; idx < rec->data_len; idx++ )
{
real_count |= ( idx >= padding_idx );
pad_count += real_count * ( check[idx] == padlen - 1 );
}
correct &= ( pad_count == padlen );
#if defined(MBEDTLS_SSL_DEBUG_ALL)
if( padlen > 0 && correct == 0 )
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad padding byte detected" ) );
#endif
padlen &= correct * 0x1FF;
}
else
#endif /* MBEDTLS_SSL_PROTO_TLS1 || MBEDTLS_SSL_PROTO_TLS1_1 || \
MBEDTLS_SSL_PROTO_TLS1_2 */
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
/* If the padding was found to be invalid, padlen == 0
* and the subtraction is safe. If the padding was found valid,
* padlen hasn't been changed and the previous assertion
* data_len >= padlen still holds. */
rec->data_len -= padlen;
}
else
#endif /* MBEDTLS_CIPHER_MODE_CBC &&
( MBEDTLS_AES_C || MBEDTLS_CAMELLIA_C || MBEDTLS_ARIA_C ) */
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
#if defined(MBEDTLS_SSL_DEBUG_ALL)
MBEDTLS_SSL_DEBUG_BUF( 4, "raw buffer after decryption",
data, rec->data_len );
#endif
/*
* Authenticate if not done yet.
* Compute the MAC regardless of the padding result (RFC4346, CBCTIME).
*/
#if defined(MBEDTLS_SSL_SOME_MODES_USE_MAC)
if( auth_done == 0 )
{
unsigned char mac_expect[MBEDTLS_SSL_MAC_ADD];
/* If the initial value of padlen was such that
* data_len < maclen + padlen + 1, then padlen
* got reset to 1, and the initial check
* data_len >= minlen + maclen + 1
* guarantees that at this point we still
* have at least data_len >= maclen.
*
* If the initial value of padlen was such that
* data_len >= maclen + padlen + 1, then we have
* subtracted either padlen + 1 (if the padding was correct)
* or 0 (if the padding was incorrect) since then,
* hence data_len >= maclen in any case.
*/
rec->data_len -= transform->maclen;
ssl_extract_add_data_from_record( add_data, &add_data_len, rec );
#if defined(MBEDTLS_SSL_PROTO_SSL3)
if( transform->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 )
{
ssl_mac( &transform->md_ctx_dec,
transform->mac_dec,
data, rec->data_len,
rec->ctr, rec->type,
mac_expect );
}
else
#endif /* MBEDTLS_SSL_PROTO_SSL3 */
#if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) || \
defined(MBEDTLS_SSL_PROTO_TLS1_2)
if( transform->minor_ver > MBEDTLS_SSL_MINOR_VERSION_0 )
{
/*
* Process MAC and always update for padlen afterwards to make
* total time independent of padlen.
*
* Known timing attacks:
* - Lucky Thirteen (http://www.isg.rhul.ac.uk/tls/TLStiming.pdf)
*
* To compensate for different timings for the MAC calculation
* depending on how much padding was removed (which is determined
* by padlen), process extra_run more blocks through the hash
* function.
*
* The formula in the paper is
* extra_run = ceil( (L1-55) / 64 ) - ceil( (L2-55) / 64 )
* where L1 is the size of the header plus the decrypted message
* plus CBC padding and L2 is the size of the header plus the
* decrypted message. This is for an underlying hash function
* with 64-byte blocks.
* We use ( (Lx+8) / 64 ) to handle 'negative Lx' values
* correctly. We round down instead of up, so -56 is the correct
* value for our calculations instead of -55.
*
* Repeat the formula rather than defining a block_size variable.
* This avoids requiring division by a variable at runtime
* (which would be marginally less efficient and would require
* linking an extra division function in some builds).
*/
size_t j, extra_run = 0;
unsigned char tmp[MBEDTLS_MD_MAX_BLOCK_SIZE];
/*
* The next two sizes are the minimum and maximum values of
* in_msglen over all padlen values.
*
* They're independent of padlen, since we previously did
* in_msglen -= padlen.
*
* Note that max_len + maclen is never more than the buffer
* length, as we previously did in_msglen -= maclen too.
*/
const size_t max_len = rec->data_len + padlen;
const size_t min_len = ( max_len > 256 ) ? max_len - 256 : 0;
memset( tmp, 0, sizeof( tmp ) );
switch( mbedtls_md_get_type( transform->md_ctx_dec.md_info ) )
{
#if defined(MBEDTLS_MD5_C) || defined(MBEDTLS_SHA1_C) || \
defined(MBEDTLS_SHA256_C)
case MBEDTLS_MD_MD5:
case MBEDTLS_MD_SHA1:
case MBEDTLS_MD_SHA256:
/* 8 bytes of message size, 64-byte compression blocks */
extra_run =
( add_data_len + rec->data_len + padlen + 8 ) / 64 -
( add_data_len + rec->data_len + 8 ) / 64;
break;
#endif
#if defined(MBEDTLS_SHA512_C)
case MBEDTLS_MD_SHA384:
/* 16 bytes of message size, 128-byte compression blocks */
extra_run =
( add_data_len + rec->data_len + padlen + 16 ) / 128 -
( add_data_len + rec->data_len + 16 ) / 128;
break;
#endif
default:
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
extra_run &= correct * 0xFF;
mbedtls_md_hmac_update( &transform->md_ctx_dec, add_data,
add_data_len );
mbedtls_md_hmac_update( &transform->md_ctx_dec, data,
rec->data_len );
/* Make sure we access everything even when padlen > 0. This
* makes the synchronisation requirements for just-in-time
* Prime+Probe attacks much tighter and hopefully impractical. */
ssl_read_memory( data + rec->data_len, padlen );
mbedtls_md_hmac_finish( &transform->md_ctx_dec, mac_expect );
/* Call mbedtls_md_process at least once due to cache attacks
* that observe whether md_process() was called of not */
for( j = 0; j < extra_run + 1; j++ )
mbedtls_md_process( &transform->md_ctx_dec, tmp );
mbedtls_md_hmac_reset( &transform->md_ctx_dec );
/* Make sure we access all the memory that could contain the MAC,
* before we check it in the next code block. This makes the
* synchronisation requirements for just-in-time Prime+Probe
* attacks much tighter and hopefully impractical. */
ssl_read_memory( data + min_len,
max_len - min_len + transform->maclen );
}
else
#endif /* MBEDTLS_SSL_PROTO_TLS1 || MBEDTLS_SSL_PROTO_TLS1_1 || \
MBEDTLS_SSL_PROTO_TLS1_2 */
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
#if defined(MBEDTLS_SSL_DEBUG_ALL)
MBEDTLS_SSL_DEBUG_BUF( 4, "expected mac", mac_expect, transform->maclen );
MBEDTLS_SSL_DEBUG_BUF( 4, "message mac", data + rec->data_len, transform->maclen );
#endif
if( mbedtls_ssl_safer_memcmp( data + rec->data_len, mac_expect,
transform->maclen ) != 0 )
{
#if defined(MBEDTLS_SSL_DEBUG_ALL)
MBEDTLS_SSL_DEBUG_MSG( 1, ( "message mac does not match" ) );
#endif
correct = 0;
}
auth_done++;
}
/*
* Finally check the correct flag
*/
if( correct == 0 )
return( MBEDTLS_ERR_SSL_INVALID_MAC );
#endif /* MBEDTLS_SSL_SOME_MODES_USE_MAC */
/* Make extra sure authentication was performed, exactly once */
if( auth_done != 1 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
if( rec->cid_len != 0 )
{
ret = ssl_cid_parse_inner_plaintext( data, &rec->data_len,
&rec->type );
if( ret != 0 )
return( MBEDTLS_ERR_SSL_INVALID_RECORD );
}
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= decrypt buf" ) );
return( 0 );
}
#undef MAC_NONE
#undef MAC_PLAINTEXT
#undef MAC_CIPHERTEXT
#if defined(MBEDTLS_ZLIB_SUPPORT)
/*
* Compression/decompression functions
*/
static int ssl_compress_buf( mbedtls_ssl_context *ssl )
{
int ret;
unsigned char *msg_post = ssl->out_msg;
ptrdiff_t bytes_written = ssl->out_msg - ssl->out_buf;
size_t len_pre = ssl->out_msglen;
unsigned char *msg_pre = ssl->compress_buf;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> compress buf" ) );
if( len_pre == 0 )
return( 0 );
memcpy( msg_pre, ssl->out_msg, len_pre );
MBEDTLS_SSL_DEBUG_MSG( 3, ( "before compression: msglen = %d, ",
ssl->out_msglen ) );
MBEDTLS_SSL_DEBUG_BUF( 4, "before compression: output payload",
ssl->out_msg, ssl->out_msglen );
ssl->transform_out->ctx_deflate.next_in = msg_pre;
ssl->transform_out->ctx_deflate.avail_in = len_pre;
ssl->transform_out->ctx_deflate.next_out = msg_post;
ssl->transform_out->ctx_deflate.avail_out = MBEDTLS_SSL_OUT_BUFFER_LEN - bytes_written;
ret = deflate( &ssl->transform_out->ctx_deflate, Z_SYNC_FLUSH );
if( ret != Z_OK )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "failed to perform compression (%d)", ret ) );
return( MBEDTLS_ERR_SSL_COMPRESSION_FAILED );
}
ssl->out_msglen = MBEDTLS_SSL_OUT_BUFFER_LEN -
ssl->transform_out->ctx_deflate.avail_out - bytes_written;
MBEDTLS_SSL_DEBUG_MSG( 3, ( "after compression: msglen = %d, ",
ssl->out_msglen ) );
MBEDTLS_SSL_DEBUG_BUF( 4, "after compression: output payload",
ssl->out_msg, ssl->out_msglen );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= compress buf" ) );
return( 0 );
}
static int ssl_decompress_buf( mbedtls_ssl_context *ssl )
{
int ret;
unsigned char *msg_post = ssl->in_msg;
ptrdiff_t header_bytes = ssl->in_msg - ssl->in_buf;
size_t len_pre = ssl->in_msglen;
unsigned char *msg_pre = ssl->compress_buf;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> decompress buf" ) );
if( len_pre == 0 )
return( 0 );
memcpy( msg_pre, ssl->in_msg, len_pre );
MBEDTLS_SSL_DEBUG_MSG( 3, ( "before decompression: msglen = %d, ",
ssl->in_msglen ) );
MBEDTLS_SSL_DEBUG_BUF( 4, "before decompression: input payload",
ssl->in_msg, ssl->in_msglen );
ssl->transform_in->ctx_inflate.next_in = msg_pre;
ssl->transform_in->ctx_inflate.avail_in = len_pre;
ssl->transform_in->ctx_inflate.next_out = msg_post;
ssl->transform_in->ctx_inflate.avail_out = MBEDTLS_SSL_IN_BUFFER_LEN -
header_bytes;
ret = inflate( &ssl->transform_in->ctx_inflate, Z_SYNC_FLUSH );
if( ret != Z_OK )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "failed to perform decompression (%d)", ret ) );
return( MBEDTLS_ERR_SSL_COMPRESSION_FAILED );
}
ssl->in_msglen = MBEDTLS_SSL_IN_BUFFER_LEN -
ssl->transform_in->ctx_inflate.avail_out - header_bytes;
MBEDTLS_SSL_DEBUG_MSG( 3, ( "after decompression: msglen = %d, ",
ssl->in_msglen ) );
MBEDTLS_SSL_DEBUG_BUF( 4, "after decompression: input payload",
ssl->in_msg, ssl->in_msglen );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= decompress buf" ) );
return( 0 );
}
#endif /* MBEDTLS_ZLIB_SUPPORT */
#if defined(MBEDTLS_SSL_SRV_C) && defined(MBEDTLS_SSL_RENEGOTIATION)
static int ssl_write_hello_request( mbedtls_ssl_context *ssl );
#if defined(MBEDTLS_SSL_PROTO_DTLS)
static int ssl_resend_hello_request( mbedtls_ssl_context *ssl )
{
/* If renegotiation is not enforced, retransmit until we would reach max
* timeout if we were using the usual handshake doubling scheme */
if( ssl->conf->renego_max_records < 0 )
{
uint32_t ratio = ssl->conf->hs_timeout_max / ssl->conf->hs_timeout_min + 1;
unsigned char doublings = 1;
while( ratio != 0 )
{
++doublings;
ratio >>= 1;
}
if( ++ssl->renego_records_seen > doublings )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "no longer retransmitting hello request" ) );
return( 0 );
}
}
return( ssl_write_hello_request( ssl ) );
}
#endif
#endif /* MBEDTLS_SSL_SRV_C && MBEDTLS_SSL_RENEGOTIATION */
/*
* Fill the input message buffer by appending data to it.
* The amount of data already fetched is in ssl->in_left.
*
* If we return 0, is it guaranteed that (at least) nb_want bytes are
* available (from this read and/or a previous one). Otherwise, an error code
* is returned (possibly EOF or WANT_READ).
*
* With stream transport (TLS) on success ssl->in_left == nb_want, but
* with datagram transport (DTLS) on success ssl->in_left >= nb_want,
* since we always read a whole datagram at once.
*
* For DTLS, it is up to the caller to set ssl->next_record_offset when
* they're done reading a record.
*/
int mbedtls_ssl_fetch_input( mbedtls_ssl_context *ssl, size_t nb_want )
{
int ret;
size_t len;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> fetch input" ) );
if( ssl->f_recv == NULL && ssl->f_recv_timeout == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "Bad usage of mbedtls_ssl_set_bio() "
"or mbedtls_ssl_set_bio()" ) );
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
}
if( nb_want > MBEDTLS_SSL_IN_BUFFER_LEN - (size_t)( ssl->in_hdr - ssl->in_buf ) )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "requesting more data than fits" ) );
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
}
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
{
uint32_t timeout;
/* Just to be sure */
if( ssl->f_set_timer == NULL || ssl->f_get_timer == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "You must use "
"mbedtls_ssl_set_timer_cb() for DTLS" ) );
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
}
/*
* The point is, we need to always read a full datagram at once, so we
* sometimes read more then requested, and handle the additional data.
* It could be the rest of the current record (while fetching the
* header) and/or some other records in the same datagram.
*/
/*
* Move to the next record in the already read datagram if applicable
*/
if( ssl->next_record_offset != 0 )
{
if( ssl->in_left < ssl->next_record_offset )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
ssl->in_left -= ssl->next_record_offset;
if( ssl->in_left != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "next record in same datagram, offset: %d",
ssl->next_record_offset ) );
memmove( ssl->in_hdr,
ssl->in_hdr + ssl->next_record_offset,
ssl->in_left );
}
ssl->next_record_offset = 0;
}
MBEDTLS_SSL_DEBUG_MSG( 2, ( "in_left: %d, nb_want: %d",
ssl->in_left, nb_want ) );
/*
* Done if we already have enough data.
*/
if( nb_want <= ssl->in_left)
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= fetch input" ) );
return( 0 );
}
/*
* A record can't be split accross datagrams. If we need to read but
* are not at the beginning of a new record, the caller did something
* wrong.
*/
if( ssl->in_left != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
/*
* Don't even try to read if time's out already.
* This avoids by-passing the timer when repeatedly receiving messages
* that will end up being dropped.
*/
if( ssl_check_timer( ssl ) != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "timer has expired" ) );
ret = MBEDTLS_ERR_SSL_TIMEOUT;
}
else
{
len = MBEDTLS_SSL_IN_BUFFER_LEN - ( ssl->in_hdr - ssl->in_buf );
if( ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER )
timeout = ssl->handshake->retransmit_timeout;
else
timeout = ssl->conf->read_timeout;
MBEDTLS_SSL_DEBUG_MSG( 3, ( "f_recv_timeout: %u ms", timeout ) );
if( ssl->f_recv_timeout != NULL )
ret = ssl->f_recv_timeout( ssl->p_bio, ssl->in_hdr, len,
timeout );
else
ret = ssl->f_recv( ssl->p_bio, ssl->in_hdr, len );
MBEDTLS_SSL_DEBUG_RET( 2, "ssl->f_recv(_timeout)", ret );
if( ret == 0 )
return( MBEDTLS_ERR_SSL_CONN_EOF );
}
if( ret == MBEDTLS_ERR_SSL_TIMEOUT )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "timeout" ) );
ssl_set_timer( ssl, 0 );
if( ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER )
{
if( ssl_double_retransmit_timeout( ssl ) != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "handshake timeout" ) );
return( MBEDTLS_ERR_SSL_TIMEOUT );
}
if( ( ret = mbedtls_ssl_resend( ssl ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_resend", ret );
return( ret );
}
return( MBEDTLS_ERR_SSL_WANT_READ );
}
#if defined(MBEDTLS_SSL_SRV_C) && defined(MBEDTLS_SSL_RENEGOTIATION)
else if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER &&
ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_PENDING )
{
if( ( ret = ssl_resend_hello_request( ssl ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_resend_hello_request", ret );
return( ret );
}
return( MBEDTLS_ERR_SSL_WANT_READ );
}
#endif /* MBEDTLS_SSL_SRV_C && MBEDTLS_SSL_RENEGOTIATION */
}
if( ret < 0 )
return( ret );
ssl->in_left = ret;
}
else
#endif
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "in_left: %d, nb_want: %d",
ssl->in_left, nb_want ) );
while( ssl->in_left < nb_want )
{
len = nb_want - ssl->in_left;
if( ssl_check_timer( ssl ) != 0 )
ret = MBEDTLS_ERR_SSL_TIMEOUT;
else
{
if( ssl->f_recv_timeout != NULL )
{
ret = ssl->f_recv_timeout( ssl->p_bio,
ssl->in_hdr + ssl->in_left, len,
ssl->conf->read_timeout );
}
else
{
ret = ssl->f_recv( ssl->p_bio,
ssl->in_hdr + ssl->in_left, len );
}
}
MBEDTLS_SSL_DEBUG_MSG( 2, ( "in_left: %d, nb_want: %d",
ssl->in_left, nb_want ) );
MBEDTLS_SSL_DEBUG_RET( 2, "ssl->f_recv(_timeout)", ret );
if( ret == 0 )
return( MBEDTLS_ERR_SSL_CONN_EOF );
if( ret < 0 )
return( ret );
if ( (size_t)ret > len || ( INT_MAX > SIZE_MAX && ret > SIZE_MAX ) )
{
MBEDTLS_SSL_DEBUG_MSG( 1,
( "f_recv returned %d bytes but only %lu were requested",
ret, (unsigned long)len ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
ssl->in_left += ret;
}
}
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= fetch input" ) );
return( 0 );
}
/*
* Flush any data not yet written
*/
int mbedtls_ssl_flush_output( mbedtls_ssl_context *ssl )
{
int ret;
unsigned char *buf;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> flush output" ) );
if( ssl->f_send == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "Bad usage of mbedtls_ssl_set_bio() "
"or mbedtls_ssl_set_bio()" ) );
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
}
/* Avoid incrementing counter if data is flushed */
if( ssl->out_left == 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= flush output" ) );
return( 0 );
}
while( ssl->out_left > 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "message length: %d, out_left: %d",
mbedtls_ssl_out_hdr_len( ssl ) + ssl->out_msglen, ssl->out_left ) );
buf = ssl->out_hdr - ssl->out_left;
ret = ssl->f_send( ssl->p_bio, buf, ssl->out_left );
MBEDTLS_SSL_DEBUG_RET( 2, "ssl->f_send", ret );
if( ret <= 0 )
return( ret );
if( (size_t)ret > ssl->out_left || ( INT_MAX > SIZE_MAX && ret > SIZE_MAX ) )
{
MBEDTLS_SSL_DEBUG_MSG( 1,
( "f_send returned %d bytes but only %lu bytes were sent",
ret, (unsigned long)ssl->out_left ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
ssl->out_left -= ret;
}
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
{
ssl->out_hdr = ssl->out_buf;
}
else
#endif
{
ssl->out_hdr = ssl->out_buf + 8;
}
ssl_update_out_pointers( ssl, ssl->transform_out );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= flush output" ) );
return( 0 );
}
/*
* Functions to handle the DTLS retransmission state machine
*/
#if defined(MBEDTLS_SSL_PROTO_DTLS)
/*
* Append current handshake message to current outgoing flight
*/
static int ssl_flight_append( mbedtls_ssl_context *ssl )
{
mbedtls_ssl_flight_item *msg;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> ssl_flight_append" ) );
MBEDTLS_SSL_DEBUG_BUF( 4, "message appended to flight",
ssl->out_msg, ssl->out_msglen );
/* Allocate space for current message */
if( ( msg = mbedtls_calloc( 1, sizeof( mbedtls_ssl_flight_item ) ) ) == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "alloc %d bytes failed",
sizeof( mbedtls_ssl_flight_item ) ) );
return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
}
if( ( msg->p = mbedtls_calloc( 1, ssl->out_msglen ) ) == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "alloc %d bytes failed", ssl->out_msglen ) );
mbedtls_free( msg );
return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
}
/* Copy current handshake message with headers */
memcpy( msg->p, ssl->out_msg, ssl->out_msglen );
msg->len = ssl->out_msglen;
msg->type = ssl->out_msgtype;
msg->next = NULL;
/* Append to the current flight */
if( ssl->handshake->flight == NULL )
ssl->handshake->flight = msg;
else
{
mbedtls_ssl_flight_item *cur = ssl->handshake->flight;
while( cur->next != NULL )
cur = cur->next;
cur->next = msg;
}
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= ssl_flight_append" ) );
return( 0 );
}
/*
* Free the current flight of handshake messages
*/
static void ssl_flight_free( mbedtls_ssl_flight_item *flight )
{
mbedtls_ssl_flight_item *cur = flight;
mbedtls_ssl_flight_item *next;
while( cur != NULL )
{
next = cur->next;
mbedtls_free( cur->p );
mbedtls_free( cur );
cur = next;
}
}
#if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY)
static void ssl_dtls_replay_reset( mbedtls_ssl_context *ssl );
#endif
/*
* Swap transform_out and out_ctr with the alternative ones
*/
static void ssl_swap_epochs( mbedtls_ssl_context *ssl )
{
mbedtls_ssl_transform *tmp_transform;
unsigned char tmp_out_ctr[8];
if( ssl->transform_out == ssl->handshake->alt_transform_out )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "skip swap epochs" ) );
return;
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "swap epochs" ) );
/* Swap transforms */
tmp_transform = ssl->transform_out;
ssl->transform_out = ssl->handshake->alt_transform_out;
ssl->handshake->alt_transform_out = tmp_transform;
/* Swap epoch + sequence_number */
memcpy( tmp_out_ctr, ssl->cur_out_ctr, 8 );
memcpy( ssl->cur_out_ctr, ssl->handshake->alt_out_ctr, 8 );
memcpy( ssl->handshake->alt_out_ctr, tmp_out_ctr, 8 );
/* Adjust to the newly activated transform */
ssl_update_out_pointers( ssl, ssl->transform_out );
#if defined(MBEDTLS_SSL_HW_RECORD_ACCEL)
if( mbedtls_ssl_hw_record_activate != NULL )
{
if( ( ret = mbedtls_ssl_hw_record_activate( ssl, MBEDTLS_SSL_CHANNEL_OUTBOUND ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_hw_record_activate", ret );
return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
}
}
#endif
}
/*
* Retransmit the current flight of messages.
*/
int mbedtls_ssl_resend( mbedtls_ssl_context *ssl )
{
int ret = 0;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> mbedtls_ssl_resend" ) );
ret = mbedtls_ssl_flight_transmit( ssl );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= mbedtls_ssl_resend" ) );
return( ret );
}
/*
* Transmit or retransmit the current flight of messages.
*
* Need to remember the current message in case flush_output returns
* WANT_WRITE, causing us to exit this function and come back later.
* This function must be called until state is no longer SENDING.
*/
int mbedtls_ssl_flight_transmit( mbedtls_ssl_context *ssl )
{
int ret;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> mbedtls_ssl_flight_transmit" ) );
if( ssl->handshake->retransmit_state != MBEDTLS_SSL_RETRANS_SENDING )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "initialise flight transmission" ) );
ssl->handshake->cur_msg = ssl->handshake->flight;
ssl->handshake->cur_msg_p = ssl->handshake->flight->p + 12;
ssl_swap_epochs( ssl );
ssl->handshake->retransmit_state = MBEDTLS_SSL_RETRANS_SENDING;
}
while( ssl->handshake->cur_msg != NULL )
{
size_t max_frag_len;
const mbedtls_ssl_flight_item * const cur = ssl->handshake->cur_msg;
int const is_finished =
( cur->type == MBEDTLS_SSL_MSG_HANDSHAKE &&
cur->p[0] == MBEDTLS_SSL_HS_FINISHED );
uint8_t const force_flush = ssl->disable_datagram_packing == 1 ?
SSL_FORCE_FLUSH : SSL_DONT_FORCE_FLUSH;
/* Swap epochs before sending Finished: we can't do it after
* sending ChangeCipherSpec, in case write returns WANT_READ.
* Must be done before copying, may change out_msg pointer */
if( is_finished && ssl->handshake->cur_msg_p == ( cur->p + 12 ) )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "swap epochs to send finished message" ) );
ssl_swap_epochs( ssl );
}
ret = ssl_get_remaining_payload_in_datagram( ssl );
if( ret < 0 )
return( ret );
max_frag_len = (size_t) ret;
/* CCS is copied as is, while HS messages may need fragmentation */
if( cur->type == MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC )
{
if( max_frag_len == 0 )
{
if( ( ret = mbedtls_ssl_flush_output( ssl ) ) != 0 )
return( ret );
continue;
}
memcpy( ssl->out_msg, cur->p, cur->len );
ssl->out_msglen = cur->len;
ssl->out_msgtype = cur->type;
/* Update position inside current message */
ssl->handshake->cur_msg_p += cur->len;
}
else
{
const unsigned char * const p = ssl->handshake->cur_msg_p;
const size_t hs_len = cur->len - 12;
const size_t frag_off = p - ( cur->p + 12 );
const size_t rem_len = hs_len - frag_off;
size_t cur_hs_frag_len, max_hs_frag_len;
if( ( max_frag_len < 12 ) || ( max_frag_len == 12 && hs_len != 0 ) )
{
if( is_finished )
ssl_swap_epochs( ssl );
if( ( ret = mbedtls_ssl_flush_output( ssl ) ) != 0 )
return( ret );
continue;
}
max_hs_frag_len = max_frag_len - 12;
cur_hs_frag_len = rem_len > max_hs_frag_len ?
max_hs_frag_len : rem_len;
if( frag_off == 0 && cur_hs_frag_len != hs_len )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "fragmenting handshake message (%u > %u)",
(unsigned) cur_hs_frag_len,
(unsigned) max_hs_frag_len ) );
}
/* Messages are stored with handshake headers as if not fragmented,
* copy beginning of headers then fill fragmentation fields.
* Handshake headers: type(1) len(3) seq(2) f_off(3) f_len(3) */
memcpy( ssl->out_msg, cur->p, 6 );
ssl->out_msg[6] = ( ( frag_off >> 16 ) & 0xff );
ssl->out_msg[7] = ( ( frag_off >> 8 ) & 0xff );
ssl->out_msg[8] = ( ( frag_off ) & 0xff );
ssl->out_msg[ 9] = ( ( cur_hs_frag_len >> 16 ) & 0xff );
ssl->out_msg[10] = ( ( cur_hs_frag_len >> 8 ) & 0xff );
ssl->out_msg[11] = ( ( cur_hs_frag_len ) & 0xff );
MBEDTLS_SSL_DEBUG_BUF( 3, "handshake header", ssl->out_msg, 12 );
/* Copy the handshake message content and set records fields */
memcpy( ssl->out_msg + 12, p, cur_hs_frag_len );
ssl->out_msglen = cur_hs_frag_len + 12;
ssl->out_msgtype = cur->type;
/* Update position inside current message */
ssl->handshake->cur_msg_p += cur_hs_frag_len;
}
/* If done with the current message move to the next one if any */
if( ssl->handshake->cur_msg_p >= cur->p + cur->len )
{
if( cur->next != NULL )
{
ssl->handshake->cur_msg = cur->next;
ssl->handshake->cur_msg_p = cur->next->p + 12;
}
else
{
ssl->handshake->cur_msg = NULL;
ssl->handshake->cur_msg_p = NULL;
}
}
/* Actually send the message out */
if( ( ret = mbedtls_ssl_write_record( ssl, force_flush ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_record", ret );
return( ret );
}
}
if( ( ret = mbedtls_ssl_flush_output( ssl ) ) != 0 )
return( ret );
/* Update state and set timer */
if( ssl->state == MBEDTLS_SSL_HANDSHAKE_OVER )
ssl->handshake->retransmit_state = MBEDTLS_SSL_RETRANS_FINISHED;
else
{
ssl->handshake->retransmit_state = MBEDTLS_SSL_RETRANS_WAITING;
ssl_set_timer( ssl, ssl->handshake->retransmit_timeout );
}
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= mbedtls_ssl_flight_transmit" ) );
return( 0 );
}
/*
* To be called when the last message of an incoming flight is received.
*/
void mbedtls_ssl_recv_flight_completed( mbedtls_ssl_context *ssl )
{
/* We won't need to resend that one any more */
ssl_flight_free( ssl->handshake->flight );
ssl->handshake->flight = NULL;
ssl->handshake->cur_msg = NULL;
/* The next incoming flight will start with this msg_seq */
ssl->handshake->in_flight_start_seq = ssl->handshake->in_msg_seq;
/* We don't want to remember CCS's across flight boundaries. */
ssl->handshake->buffering.seen_ccs = 0;
/* Clear future message buffering structure. */
ssl_buffering_free( ssl );
/* Cancel timer */
ssl_set_timer( ssl, 0 );
if( ssl->in_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE &&
ssl->in_msg[0] == MBEDTLS_SSL_HS_FINISHED )
{
ssl->handshake->retransmit_state = MBEDTLS_SSL_RETRANS_FINISHED;
}
else
ssl->handshake->retransmit_state = MBEDTLS_SSL_RETRANS_PREPARING;
}
/*
* To be called when the last message of an outgoing flight is send.
*/
void mbedtls_ssl_send_flight_completed( mbedtls_ssl_context *ssl )
{
ssl_reset_retransmit_timeout( ssl );
ssl_set_timer( ssl, ssl->handshake->retransmit_timeout );
if( ssl->in_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE &&
ssl->in_msg[0] == MBEDTLS_SSL_HS_FINISHED )
{
ssl->handshake->retransmit_state = MBEDTLS_SSL_RETRANS_FINISHED;
}
else
ssl->handshake->retransmit_state = MBEDTLS_SSL_RETRANS_WAITING;
}
#endif /* MBEDTLS_SSL_PROTO_DTLS */
/*
* Handshake layer functions
*/
/*
* Write (DTLS: or queue) current handshake (including CCS) message.
*
* - fill in handshake headers
* - update handshake checksum
* - DTLS: save message for resending
* - then pass to the record layer
*
* DTLS: except for HelloRequest, messages are only queued, and will only be
* actually sent when calling flight_transmit() or resend().
*
* Inputs:
* - ssl->out_msglen: 4 + actual handshake message len
* (4 is the size of handshake headers for TLS)
* - ssl->out_msg[0]: the handshake type (ClientHello, ServerHello, etc)
* - ssl->out_msg + 4: the handshake message body
*
* Outputs, ie state before passing to flight_append() or write_record():
* - ssl->out_msglen: the length of the record contents
* (including handshake headers but excluding record headers)
* - ssl->out_msg: the record contents (handshake headers + content)
*/
int mbedtls_ssl_write_handshake_msg( mbedtls_ssl_context *ssl )
{
int ret;
const size_t hs_len = ssl->out_msglen - 4;
const unsigned char hs_type = ssl->out_msg[0];
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write handshake message" ) );
/*
* Sanity checks
*/
if( ssl->out_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE &&
ssl->out_msgtype != MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC )
{
/* In SSLv3, the client might send a NoCertificate alert. */
#if defined(MBEDTLS_SSL_PROTO_SSL3) && defined(MBEDTLS_SSL_CLI_C)
if( ! ( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 &&
ssl->out_msgtype == MBEDTLS_SSL_MSG_ALERT &&
ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT ) )
#endif /* MBEDTLS_SSL_PROTO_SSL3 && MBEDTLS_SSL_SRV_C */
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
}
/* Whenever we send anything different from a
* HelloRequest we should be in a handshake - double check. */
if( ! ( ssl->out_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE &&
hs_type == MBEDTLS_SSL_HS_HELLO_REQUEST ) &&
ssl->handshake == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
ssl->handshake != NULL &&
ssl->handshake->retransmit_state == MBEDTLS_SSL_RETRANS_SENDING )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
#endif
/* Double-check that we did not exceed the bounds
* of the outgoing record buffer.
* This should never fail as the various message
* writing functions must obey the bounds of the
* outgoing record buffer, but better be safe.
*
* Note: We deliberately do not check for the MTU or MFL here.
*/
if( ssl->out_msglen > MBEDTLS_SSL_OUT_CONTENT_LEN )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "Record too large: "
"size %u, maximum %u",
(unsigned) ssl->out_msglen,
(unsigned) MBEDTLS_SSL_OUT_CONTENT_LEN ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
/*
* Fill handshake headers
*/
if( ssl->out_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE )
{
ssl->out_msg[1] = (unsigned char)( hs_len >> 16 );
ssl->out_msg[2] = (unsigned char)( hs_len >> 8 );
ssl->out_msg[3] = (unsigned char)( hs_len );
/*
* DTLS has additional fields in the Handshake layer,
* between the length field and the actual payload:
* uint16 message_seq;
* uint24 fragment_offset;
* uint24 fragment_length;
*/
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
{
/* Make room for the additional DTLS fields */
if( MBEDTLS_SSL_OUT_CONTENT_LEN - ssl->out_msglen < 8 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "DTLS handshake message too large: "
"size %u, maximum %u",
(unsigned) ( hs_len ),
(unsigned) ( MBEDTLS_SSL_OUT_CONTENT_LEN - 12 ) ) );
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
}
memmove( ssl->out_msg + 12, ssl->out_msg + 4, hs_len );
ssl->out_msglen += 8;
/* Write message_seq and update it, except for HelloRequest */
if( hs_type != MBEDTLS_SSL_HS_HELLO_REQUEST )
{
ssl->out_msg[4] = ( ssl->handshake->out_msg_seq >> 8 ) & 0xFF;
ssl->out_msg[5] = ( ssl->handshake->out_msg_seq ) & 0xFF;
++( ssl->handshake->out_msg_seq );
}
else
{
ssl->out_msg[4] = 0;
ssl->out_msg[5] = 0;
}
/* Handshake hashes are computed without fragmentation,
* so set frag_offset = 0 and frag_len = hs_len for now */
memset( ssl->out_msg + 6, 0x00, 3 );
memcpy( ssl->out_msg + 9, ssl->out_msg + 1, 3 );
}
#endif /* MBEDTLS_SSL_PROTO_DTLS */
/* Update running hashes of handshake messages seen */
if( hs_type != MBEDTLS_SSL_HS_HELLO_REQUEST )
ssl->handshake->update_checksum( ssl, ssl->out_msg, ssl->out_msglen );
}
/* Either send now, or just save to be sent (and resent) later */
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
! ( ssl->out_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE &&
hs_type == MBEDTLS_SSL_HS_HELLO_REQUEST ) )
{
if( ( ret = ssl_flight_append( ssl ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_flight_append", ret );
return( ret );
}
}
else
#endif
{
if( ( ret = mbedtls_ssl_write_record( ssl, SSL_FORCE_FLUSH ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_write_record", ret );
return( ret );
}
}
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write handshake message" ) );
return( 0 );
}
/*
* Record layer functions
*/
/*
* Write current record.
*
* Uses:
* - ssl->out_msgtype: type of the message (AppData, Handshake, Alert, CCS)
* - ssl->out_msglen: length of the record content (excl headers)
* - ssl->out_msg: record content
*/
int mbedtls_ssl_write_record( mbedtls_ssl_context *ssl, uint8_t force_flush )
{
int ret, done = 0;
size_t len = ssl->out_msglen;
uint8_t flush = force_flush;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write record" ) );
#if defined(MBEDTLS_ZLIB_SUPPORT)
if( ssl->transform_out != NULL &&
ssl->session_out->compression == MBEDTLS_SSL_COMPRESS_DEFLATE )
{
if( ( ret = ssl_compress_buf( ssl ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_compress_buf", ret );
return( ret );
}
len = ssl->out_msglen;
}
#endif /*MBEDTLS_ZLIB_SUPPORT */
#if defined(MBEDTLS_SSL_HW_RECORD_ACCEL)
if( mbedtls_ssl_hw_record_write != NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "going for mbedtls_ssl_hw_record_write()" ) );
ret = mbedtls_ssl_hw_record_write( ssl );
if( ret != 0 && ret != MBEDTLS_ERR_SSL_HW_ACCEL_FALLTHROUGH )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_hw_record_write", ret );
return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
}
if( ret == 0 )
done = 1;
}
#endif /* MBEDTLS_SSL_HW_RECORD_ACCEL */
if( !done )
{
unsigned i;
size_t protected_record_size;
/* Skip writing the record content type to after the encryption,
* as it may change when using the CID extension. */
mbedtls_ssl_write_version( ssl->major_ver, ssl->minor_ver,
ssl->conf->transport, ssl->out_hdr + 1 );
memcpy( ssl->out_ctr, ssl->cur_out_ctr, 8 );
ssl->out_len[0] = (unsigned char)( len >> 8 );
ssl->out_len[1] = (unsigned char)( len );
if( ssl->transform_out != NULL )
{
mbedtls_record rec;
rec.buf = ssl->out_iv;
rec.buf_len = MBEDTLS_SSL_OUT_BUFFER_LEN -
( ssl->out_iv - ssl->out_buf );
rec.data_len = ssl->out_msglen;
rec.data_offset = ssl->out_msg - rec.buf;
memcpy( &rec.ctr[0], ssl->out_ctr, 8 );
mbedtls_ssl_write_version( ssl->major_ver, ssl->minor_ver,
ssl->conf->transport, rec.ver );
rec.type = ssl->out_msgtype;
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
/* The CID is set by mbedtls_ssl_encrypt_buf(). */
rec.cid_len = 0;
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
if( ( ret = mbedtls_ssl_encrypt_buf( ssl, ssl->transform_out, &rec,
ssl->conf->f_rng, ssl->conf->p_rng ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_encrypt_buf", ret );
return( ret );
}
if( rec.data_offset != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
/* Update the record content type and CID. */
ssl->out_msgtype = rec.type;
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID )
memcpy( ssl->out_cid, rec.cid, rec.cid_len );
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
ssl->out_msglen = len = rec.data_len;
ssl->out_len[0] = (unsigned char)( rec.data_len >> 8 );
ssl->out_len[1] = (unsigned char)( rec.data_len );
}
protected_record_size = len + mbedtls_ssl_out_hdr_len( ssl );
#if defined(MBEDTLS_SSL_PROTO_DTLS)
/* In case of DTLS, double-check that we don't exceed
* the remaining space in the datagram. */
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
{
ret = ssl_get_remaining_space_in_datagram( ssl );
if( ret < 0 )
return( ret );
if( protected_record_size > (size_t) ret )
{
/* Should never happen */
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
}
#endif /* MBEDTLS_SSL_PROTO_DTLS */
/* Now write the potentially updated record content type. */
ssl->out_hdr[0] = (unsigned char) ssl->out_msgtype;
MBEDTLS_SSL_DEBUG_MSG( 3, ( "output record: msgtype = %d, "
"version = [%d:%d], msglen = %d",
ssl->out_hdr[0], ssl->out_hdr[1],
ssl->out_hdr[2], len ) );
MBEDTLS_SSL_DEBUG_BUF( 4, "output record sent to network",
ssl->out_hdr, protected_record_size );
ssl->out_left += protected_record_size;
ssl->out_hdr += protected_record_size;
ssl_update_out_pointers( ssl, ssl->transform_out );
for( i = 8; i > ssl_ep_len( ssl ); i-- )
if( ++ssl->cur_out_ctr[i - 1] != 0 )
break;
/* The loop goes to its end iff the counter is wrapping */
if( i == ssl_ep_len( ssl ) )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "outgoing message counter would wrap" ) );
return( MBEDTLS_ERR_SSL_COUNTER_WRAPPING );
}
}
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
flush == SSL_DONT_FORCE_FLUSH )
{
size_t remaining;
ret = ssl_get_remaining_payload_in_datagram( ssl );
if( ret < 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_get_remaining_payload_in_datagram",
ret );
return( ret );
}
remaining = (size_t) ret;
if( remaining == 0 )
{
flush = SSL_FORCE_FLUSH;
}
else
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Still %u bytes available in current datagram", (unsigned) remaining ) );
}
}
#endif /* MBEDTLS_SSL_PROTO_DTLS */
if( ( flush == SSL_FORCE_FLUSH ) &&
( ret = mbedtls_ssl_flush_output( ssl ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_flush_output", ret );
return( ret );
}
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write record" ) );
return( 0 );
}
#if defined(MBEDTLS_SSL_PROTO_DTLS)
static int ssl_hs_is_proper_fragment( mbedtls_ssl_context *ssl )
{
if( ssl->in_msglen < ssl->in_hslen ||
memcmp( ssl->in_msg + 6, "\0\0\0", 3 ) != 0 ||
memcmp( ssl->in_msg + 9, ssl->in_msg + 1, 3 ) != 0 )
{
return( 1 );
}
return( 0 );
}
static uint32_t ssl_get_hs_frag_len( mbedtls_ssl_context const *ssl )
{
return( ( ssl->in_msg[9] << 16 ) |
( ssl->in_msg[10] << 8 ) |
ssl->in_msg[11] );
}
static uint32_t ssl_get_hs_frag_off( mbedtls_ssl_context const *ssl )
{
return( ( ssl->in_msg[6] << 16 ) |
( ssl->in_msg[7] << 8 ) |
ssl->in_msg[8] );
}
static int ssl_check_hs_header( mbedtls_ssl_context const *ssl )
{
uint32_t msg_len, frag_off, frag_len;
msg_len = ssl_get_hs_total_len( ssl );
frag_off = ssl_get_hs_frag_off( ssl );
frag_len = ssl_get_hs_frag_len( ssl );
if( frag_off > msg_len )
return( -1 );
if( frag_len > msg_len - frag_off )
return( -1 );
if( frag_len + 12 > ssl->in_msglen )
return( -1 );
return( 0 );
}
/*
* Mark bits in bitmask (used for DTLS HS reassembly)
*/
static void ssl_bitmask_set( unsigned char *mask, size_t offset, size_t len )
{
unsigned int start_bits, end_bits;
start_bits = 8 - ( offset % 8 );
if( start_bits != 8 )
{
size_t first_byte_idx = offset / 8;
/* Special case */
if( len <= start_bits )
{
for( ; len != 0; len-- )
mask[first_byte_idx] |= 1 << ( start_bits - len );
/* Avoid potential issues with offset or len becoming invalid */
return;
}
offset += start_bits; /* Now offset % 8 == 0 */
len -= start_bits;
for( ; start_bits != 0; start_bits-- )
mask[first_byte_idx] |= 1 << ( start_bits - 1 );
}
end_bits = len % 8;
if( end_bits != 0 )
{
size_t last_byte_idx = ( offset + len ) / 8;
len -= end_bits; /* Now len % 8 == 0 */
for( ; end_bits != 0; end_bits-- )
mask[last_byte_idx] |= 1 << ( 8 - end_bits );
}
memset( mask + offset / 8, 0xFF, len / 8 );
}
/*
* Check that bitmask is full
*/
static int ssl_bitmask_check( unsigned char *mask, size_t len )
{
size_t i;
for( i = 0; i < len / 8; i++ )
if( mask[i] != 0xFF )
return( -1 );
for( i = 0; i < len % 8; i++ )
if( ( mask[len / 8] & ( 1 << ( 7 - i ) ) ) == 0 )
return( -1 );
return( 0 );
}
/* msg_len does not include the handshake header */
static size_t ssl_get_reassembly_buffer_size( size_t msg_len,
unsigned add_bitmap )
{
size_t alloc_len;
alloc_len = 12; /* Handshake header */
alloc_len += msg_len; /* Content buffer */
if( add_bitmap )
alloc_len += msg_len / 8 + ( msg_len % 8 != 0 ); /* Bitmap */
return( alloc_len );
}
#endif /* MBEDTLS_SSL_PROTO_DTLS */
static uint32_t ssl_get_hs_total_len( mbedtls_ssl_context const *ssl )
{
return( ( ssl->in_msg[1] << 16 ) |
( ssl->in_msg[2] << 8 ) |
ssl->in_msg[3] );
}
int mbedtls_ssl_prepare_handshake_record( mbedtls_ssl_context *ssl )
{
if( ssl->in_msglen < mbedtls_ssl_hs_hdr_len( ssl ) )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "handshake message too short: %d",
ssl->in_msglen ) );
return( MBEDTLS_ERR_SSL_INVALID_RECORD );
}
ssl->in_hslen = mbedtls_ssl_hs_hdr_len( ssl ) + ssl_get_hs_total_len( ssl );
MBEDTLS_SSL_DEBUG_MSG( 3, ( "handshake message: msglen ="
" %d, type = %d, hslen = %d",
ssl->in_msglen, ssl->in_msg[0], ssl->in_hslen ) );
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
{
int ret;
unsigned int recv_msg_seq = ( ssl->in_msg[4] << 8 ) | ssl->in_msg[5];
if( ssl_check_hs_header( ssl ) != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "invalid handshake header" ) );
return( MBEDTLS_ERR_SSL_INVALID_RECORD );
}
if( ssl->handshake != NULL &&
( ( ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER &&
recv_msg_seq != ssl->handshake->in_msg_seq ) ||
( ssl->state == MBEDTLS_SSL_HANDSHAKE_OVER &&
ssl->in_msg[0] != MBEDTLS_SSL_HS_CLIENT_HELLO ) ) )
{
if( recv_msg_seq > ssl->handshake->in_msg_seq )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "received future handshake message of sequence number %u (next %u)",
recv_msg_seq,
ssl->handshake->in_msg_seq ) );
return( MBEDTLS_ERR_SSL_EARLY_MESSAGE );
}
/* Retransmit only on last message from previous flight, to avoid
* too many retransmissions.
* Besides, No sane server ever retransmits HelloVerifyRequest */
if( recv_msg_seq == ssl->handshake->in_flight_start_seq - 1 &&
ssl->in_msg[0] != MBEDTLS_SSL_HS_HELLO_VERIFY_REQUEST )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "received message from last flight, "
"message_seq = %d, start_of_flight = %d",
recv_msg_seq,
ssl->handshake->in_flight_start_seq ) );
if( ( ret = mbedtls_ssl_resend( ssl ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_resend", ret );
return( ret );
}
}
else
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "dropping out-of-sequence message: "
"message_seq = %d, expected = %d",
recv_msg_seq,
ssl->handshake->in_msg_seq ) );
}
return( MBEDTLS_ERR_SSL_CONTINUE_PROCESSING );
}
/* Wait until message completion to increment in_msg_seq */
/* Message reassembly is handled alongside buffering of future
* messages; the commonality is that both handshake fragments and
* future messages cannot be forwarded immediately to the
* handshake logic layer. */
if( ssl_hs_is_proper_fragment( ssl ) == 1 )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "found fragmented DTLS handshake message" ) );
return( MBEDTLS_ERR_SSL_EARLY_MESSAGE );
}
}
else
#endif /* MBEDTLS_SSL_PROTO_DTLS */
/* With TLS we don't handle fragmentation (for now) */
if( ssl->in_msglen < ssl->in_hslen )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "TLS handshake fragmentation not supported" ) );
return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE );
}
return( 0 );
}
void mbedtls_ssl_update_handshake_status( mbedtls_ssl_context *ssl )
{
mbedtls_ssl_handshake_params * const hs = ssl->handshake;
if( ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER && hs != NULL )
{
ssl->handshake->update_checksum( ssl, ssl->in_msg, ssl->in_hslen );
}
/* Handshake message is complete, increment counter */
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
ssl->handshake != NULL )
{
unsigned offset;
mbedtls_ssl_hs_buffer *hs_buf;
/* Increment handshake sequence number */
hs->in_msg_seq++;
/*
* Clear up handshake buffering and reassembly structure.
*/
/* Free first entry */
ssl_buffering_free_slot( ssl, 0 );
/* Shift all other entries */
for( offset = 0, hs_buf = &hs->buffering.hs[0];
offset + 1 < MBEDTLS_SSL_MAX_BUFFERED_HS;
offset++, hs_buf++ )
{
*hs_buf = *(hs_buf + 1);
}
/* Create a fresh last entry */
memset( hs_buf, 0, sizeof( mbedtls_ssl_hs_buffer ) );
}
#endif
}
/*
* DTLS anti-replay: RFC 6347 4.1.2.6
*
* in_window is a field of bits numbered from 0 (lsb) to 63 (msb).
* Bit n is set iff record number in_window_top - n has been seen.
*
* Usually, in_window_top is the last record number seen and the lsb of
* in_window is set. The only exception is the initial state (record number 0
* not seen yet).
*/
#if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY)
static void ssl_dtls_replay_reset( mbedtls_ssl_context *ssl )
{
ssl->in_window_top = 0;
ssl->in_window = 0;
}
static inline uint64_t ssl_load_six_bytes( unsigned char *buf )
{
return( ( (uint64_t) buf[0] << 40 ) |
( (uint64_t) buf[1] << 32 ) |
( (uint64_t) buf[2] << 24 ) |
( (uint64_t) buf[3] << 16 ) |
( (uint64_t) buf[4] << 8 ) |
( (uint64_t) buf[5] ) );
}
/*
* Return 0 if sequence number is acceptable, -1 otherwise
*/
int mbedtls_ssl_dtls_replay_check( mbedtls_ssl_context *ssl )
{
uint64_t rec_seqnum = ssl_load_six_bytes( ssl->in_ctr + 2 );
uint64_t bit;
if( ssl->conf->anti_replay == MBEDTLS_SSL_ANTI_REPLAY_DISABLED )
return( 0 );
if( rec_seqnum > ssl->in_window_top )
return( 0 );
bit = ssl->in_window_top - rec_seqnum;
if( bit >= 64 )
return( -1 );
if( ( ssl->in_window & ( (uint64_t) 1 << bit ) ) != 0 )
return( -1 );
return( 0 );
}
/*
* Update replay window on new validated record
*/
void mbedtls_ssl_dtls_replay_update( mbedtls_ssl_context *ssl )
{
uint64_t rec_seqnum = ssl_load_six_bytes( ssl->in_ctr + 2 );
if( ssl->conf->anti_replay == MBEDTLS_SSL_ANTI_REPLAY_DISABLED )
return;
if( rec_seqnum > ssl->in_window_top )
{
/* Update window_top and the contents of the window */
uint64_t shift = rec_seqnum - ssl->in_window_top;
if( shift >= 64 )
ssl->in_window = 1;
else
{
ssl->in_window <<= shift;
ssl->in_window |= 1;
}
ssl->in_window_top = rec_seqnum;
}
else
{
/* Mark that number as seen in the current window */
uint64_t bit = ssl->in_window_top - rec_seqnum;
if( bit < 64 ) /* Always true, but be extra sure */
ssl->in_window |= (uint64_t) 1 << bit;
}
}
#endif /* MBEDTLS_SSL_DTLS_ANTI_REPLAY */
#if defined(MBEDTLS_SSL_DTLS_CLIENT_PORT_REUSE) && defined(MBEDTLS_SSL_SRV_C)
/* Forward declaration */
static int ssl_session_reset_int( mbedtls_ssl_context *ssl, int partial );
/*
* Without any SSL context, check if a datagram looks like a ClientHello with
* a valid cookie, and if it doesn't, generate a HelloVerifyRequest message.
* Both input and output include full DTLS headers.
*
* - if cookie is valid, return 0
* - if ClientHello looks superficially valid but cookie is not,
* fill obuf and set olen, then
* return MBEDTLS_ERR_SSL_HELLO_VERIFY_REQUIRED
* - otherwise return a specific error code
*/
static int ssl_check_dtls_clihlo_cookie(
mbedtls_ssl_cookie_write_t *f_cookie_write,
mbedtls_ssl_cookie_check_t *f_cookie_check,
void *p_cookie,
const unsigned char *cli_id, size_t cli_id_len,
const unsigned char *in, size_t in_len,
unsigned char *obuf, size_t buf_len, size_t *olen )
{
size_t sid_len, cookie_len;
unsigned char *p;
if( f_cookie_write == NULL || f_cookie_check == NULL )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
/*
* Structure of ClientHello with record and handshake headers,
* and expected values. We don't need to check a lot, more checks will be
* done when actually parsing the ClientHello - skipping those checks
* avoids code duplication and does not make cookie forging any easier.
*
* 0-0 ContentType type; copied, must be handshake
* 1-2 ProtocolVersion version; copied
* 3-4 uint16 epoch; copied, must be 0
* 5-10 uint48 sequence_number; copied
* 11-12 uint16 length; (ignored)
*
* 13-13 HandshakeType msg_type; (ignored)
* 14-16 uint24 length; (ignored)
* 17-18 uint16 message_seq; copied
* 19-21 uint24 fragment_offset; copied, must be 0
* 22-24 uint24 fragment_length; (ignored)
*
* 25-26 ProtocolVersion client_version; (ignored)
* 27-58 Random random; (ignored)
* 59-xx SessionID session_id; 1 byte len + sid_len content
* 60+ opaque cookie<0..2^8-1>; 1 byte len + content
* ...
*
* Minimum length is 61 bytes.
*/
if( in_len < 61 ||
in[0] != MBEDTLS_SSL_MSG_HANDSHAKE ||
in[3] != 0 || in[4] != 0 ||
in[19] != 0 || in[20] != 0 || in[21] != 0 )
{
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
sid_len = in[59];
if( sid_len > in_len - 61 )
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
cookie_len = in[60 + sid_len];
if( cookie_len > in_len - 60 )
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
if( f_cookie_check( p_cookie, in + sid_len + 61, cookie_len,
cli_id, cli_id_len ) == 0 )
{
/* Valid cookie */
return( 0 );
}
/*
* If we get here, we've got an invalid cookie, let's prepare HVR.
*
* 0-0 ContentType type; copied
* 1-2 ProtocolVersion version; copied
* 3-4 uint16 epoch; copied
* 5-10 uint48 sequence_number; copied
* 11-12 uint16 length; olen - 13
*
* 13-13 HandshakeType msg_type; hello_verify_request
* 14-16 uint24 length; olen - 25
* 17-18 uint16 message_seq; copied
* 19-21 uint24 fragment_offset; copied
* 22-24 uint24 fragment_length; olen - 25
*
* 25-26 ProtocolVersion server_version; 0xfe 0xff
* 27-27 opaque cookie<0..2^8-1>; cookie_len = olen - 27, cookie
*
* Minimum length is 28.
*/
if( buf_len < 28 )
return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
/* Copy most fields and adapt others */
memcpy( obuf, in, 25 );
obuf[13] = MBEDTLS_SSL_HS_HELLO_VERIFY_REQUEST;
obuf[25] = 0xfe;
obuf[26] = 0xff;
/* Generate and write actual cookie */
p = obuf + 28;
if( f_cookie_write( p_cookie,
&p, obuf + buf_len, cli_id, cli_id_len ) != 0 )
{
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
*olen = p - obuf;
/* Go back and fill length fields */
obuf[27] = (unsigned char)( *olen - 28 );
obuf[14] = obuf[22] = (unsigned char)( ( *olen - 25 ) >> 16 );
obuf[15] = obuf[23] = (unsigned char)( ( *olen - 25 ) >> 8 );
obuf[16] = obuf[24] = (unsigned char)( ( *olen - 25 ) );
obuf[11] = (unsigned char)( ( *olen - 13 ) >> 8 );
obuf[12] = (unsigned char)( ( *olen - 13 ) );
return( MBEDTLS_ERR_SSL_HELLO_VERIFY_REQUIRED );
}
/*
* Handle possible client reconnect with the same UDP quadruplet
* (RFC 6347 Section 4.2.8).
*
* Called by ssl_parse_record_header() in case we receive an epoch 0 record
* that looks like a ClientHello.
*
* - if the input looks like a ClientHello without cookies,
* send back HelloVerifyRequest, then
* return MBEDTLS_ERR_SSL_HELLO_VERIFY_REQUIRED
* - if the input looks like a ClientHello with a valid cookie,
* reset the session of the current context, and
* return MBEDTLS_ERR_SSL_CLIENT_RECONNECT
* - if anything goes wrong, return a specific error code
*
* mbedtls_ssl_read_record() will ignore the record if anything else than
* MBEDTLS_ERR_SSL_CLIENT_RECONNECT or 0 is returned, although this function
* cannot not return 0.
*/
static int ssl_handle_possible_reconnect( mbedtls_ssl_context *ssl )
{
int ret;
size_t len;
ret = ssl_check_dtls_clihlo_cookie(
ssl->conf->f_cookie_write,
ssl->conf->f_cookie_check,
ssl->conf->p_cookie,
ssl->cli_id, ssl->cli_id_len,
ssl->in_buf, ssl->in_left,
ssl->out_buf, MBEDTLS_SSL_OUT_CONTENT_LEN, &len );
MBEDTLS_SSL_DEBUG_RET( 2, "ssl_check_dtls_clihlo_cookie", ret );
if( ret == MBEDTLS_ERR_SSL_HELLO_VERIFY_REQUIRED )
{
/* Don't check write errors as we can't do anything here.
* If the error is permanent we'll catch it later,
* if it's not, then hopefully it'll work next time. */
(void) ssl->f_send( ssl->p_bio, ssl->out_buf, len );
return( MBEDTLS_ERR_SSL_HELLO_VERIFY_REQUIRED );
}
if( ret == 0 )
{
/* Got a valid cookie, partially reset context */
if( ( ret = ssl_session_reset_int( ssl, 1 ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "reset", ret );
return( ret );
}
return( MBEDTLS_ERR_SSL_CLIENT_RECONNECT );
}
return( ret );
}
#endif /* MBEDTLS_SSL_DTLS_CLIENT_PORT_REUSE && MBEDTLS_SSL_SRV_C */
static int ssl_check_record_type( uint8_t record_type )
{
if( record_type != MBEDTLS_SSL_MSG_HANDSHAKE &&
record_type != MBEDTLS_SSL_MSG_ALERT &&
record_type != MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC &&
record_type != MBEDTLS_SSL_MSG_APPLICATION_DATA )
{
return( MBEDTLS_ERR_SSL_INVALID_RECORD );
}
return( 0 );
}
/*
* ContentType type;
* ProtocolVersion version;
* uint16 epoch; // DTLS only
* uint48 sequence_number; // DTLS only
* uint16 length;
*
* Return 0 if header looks sane (and, for DTLS, the record is expected)
* MBEDTLS_ERR_SSL_INVALID_RECORD if the header looks bad,
* MBEDTLS_ERR_SSL_UNEXPECTED_RECORD (DTLS only) if sane but unexpected.
*
* With DTLS, mbedtls_ssl_read_record() will:
* 1. proceed with the record if this function returns 0
* 2. drop only the current record if this function returns UNEXPECTED_RECORD
* 3. return CLIENT_RECONNECT if this function return that value
* 4. drop the whole datagram if this function returns anything else.
* Point 2 is needed when the peer is resending, and we have already received
* the first record from a datagram but are still waiting for the others.
*/
static int ssl_parse_record_header( mbedtls_ssl_context *ssl )
{
int major_ver, minor_ver;
int ret;
/* Parse and validate record content type and version */
ssl->in_msgtype = ssl->in_hdr[0];
mbedtls_ssl_read_version( &major_ver, &minor_ver, ssl->conf->transport, ssl->in_hdr + 1 );
/* Check record type */
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
ssl->in_msgtype == MBEDTLS_SSL_MSG_CID &&
ssl->conf->cid_len != 0 )
{
/* Shift pointers to account for record header including CID
* struct {
* ContentType special_type = tls12_cid;
* ProtocolVersion version;
* uint16 epoch;
* uint48 sequence_number;
* opaque cid[cid_length]; // Additional field compared to
* // default DTLS record format
* uint16 length;
* opaque enc_content[DTLSCiphertext.length];
* } DTLSCiphertext;
*/
/* So far, we only support static CID lengths
* fixed in the configuration. */
ssl->in_len = ssl->in_cid + ssl->conf->cid_len;
ssl->in_iv = ssl->in_msg = ssl->in_len + 2;
}
else
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
if( ssl_check_record_type( ssl->in_msgtype ) )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "unknown record type" ) );
#if defined(MBEDTLS_SSL_PROTO_DTLS)
/* Silently ignore invalid DTLS records as recommended by RFC 6347
* Section 4.1.2.7 */
if( ssl->conf->transport != MBEDTLS_SSL_TRANSPORT_DATAGRAM )
#endif /* MBEDTLS_SSL_PROTO_DTLS */
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE );
return( MBEDTLS_ERR_SSL_INVALID_RECORD );
}
/* Check version */
if( major_ver != ssl->major_ver )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "major version mismatch" ) );
return( MBEDTLS_ERR_SSL_INVALID_RECORD );
}
if( minor_ver > ssl->conf->max_minor_ver )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "minor version mismatch" ) );
return( MBEDTLS_ERR_SSL_INVALID_RECORD );
}
/* Now that the total length of the record header is known, ensure
* that the current datagram is large enough to hold it.
* This would fail, for example, if we received a datagram of
* size 13 + n Bytes where n is less than the size of incoming CIDs. */
ret = mbedtls_ssl_fetch_input( ssl, mbedtls_ssl_in_hdr_len( ssl ) );
if( ret != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_fetch_input", ret );
return( ret );
}
MBEDTLS_SSL_DEBUG_BUF( 4, "input record header", ssl->in_hdr, mbedtls_ssl_in_hdr_len( ssl ) );
/* Parse and validate record length
* This must happen after the CID parsing because
* its position in the record header depends on
* the presence of a CID. */
ssl->in_msglen = ( ssl->in_len[0] << 8 ) | ssl->in_len[1];
if( ssl->in_msglen > MBEDTLS_SSL_IN_BUFFER_LEN
- (size_t)( ssl->in_msg - ssl->in_buf ) )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad message length" ) );
return( MBEDTLS_ERR_SSL_INVALID_RECORD );
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "input record: msgtype = %d, "
"version = [%d:%d], msglen = %d",
ssl->in_msgtype,
major_ver, minor_ver, ssl->in_msglen ) );
/*
* DTLS-related tests.
* Check epoch before checking length constraint because
* the latter varies with the epoch. E.g., if a ChangeCipherSpec
* message gets duplicated before the corresponding Finished message,
* the second ChangeCipherSpec should be discarded because it belongs
* to an old epoch, but not because its length is shorter than
* the minimum record length for packets using the new record transform.
* Note that these two kinds of failures are handled differently,
* as an unexpected record is silently skipped but an invalid
* record leads to the entire datagram being dropped.
*/
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
{
unsigned int rec_epoch = ( ssl->in_ctr[0] << 8 ) | ssl->in_ctr[1];
/* Check epoch (and sequence number) with DTLS */
if( rec_epoch != ssl->in_epoch )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "record from another epoch: "
"expected %d, received %d",
ssl->in_epoch, rec_epoch ) );
#if defined(MBEDTLS_SSL_DTLS_CLIENT_PORT_REUSE) && defined(MBEDTLS_SSL_SRV_C)
/*
* Check for an epoch 0 ClientHello. We can't use in_msg here to
* access the first byte of record content (handshake type), as we
* have an active transform (possibly iv_len != 0), so use the
* fact that the record header len is 13 instead.
*/
if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER &&
ssl->state == MBEDTLS_SSL_HANDSHAKE_OVER &&
rec_epoch == 0 &&
ssl->in_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE &&
ssl->in_left > 13 &&
ssl->in_buf[13] == MBEDTLS_SSL_HS_CLIENT_HELLO )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "possible client reconnect "
"from the same port" ) );
return( ssl_handle_possible_reconnect( ssl ) );
}
else
#endif /* MBEDTLS_SSL_DTLS_CLIENT_PORT_REUSE && MBEDTLS_SSL_SRV_C */
{
/* Consider buffering the record. */
if( rec_epoch == (unsigned int) ssl->in_epoch + 1 )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Consider record for buffering" ) );
return( MBEDTLS_ERR_SSL_EARLY_MESSAGE );
}
return( MBEDTLS_ERR_SSL_UNEXPECTED_RECORD );
}
}
#if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY)
/* Replay detection only works for the current epoch */
if( rec_epoch == ssl->in_epoch &&
mbedtls_ssl_dtls_replay_check( ssl ) != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "replayed record" ) );
return( MBEDTLS_ERR_SSL_UNEXPECTED_RECORD );
}
#endif
}
#endif /* MBEDTLS_SSL_PROTO_DTLS */
/* Check length against bounds of the current transform and version */
if( ssl->transform_in == NULL )
{
if( ssl->in_msglen < 1 ||
ssl->in_msglen > MBEDTLS_SSL_IN_CONTENT_LEN )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad message length" ) );
return( MBEDTLS_ERR_SSL_INVALID_RECORD );
}
}
else
{
if( ssl->in_msglen < ssl->transform_in->minlen )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad message length" ) );
return( MBEDTLS_ERR_SSL_INVALID_RECORD );
}
#if defined(MBEDTLS_SSL_PROTO_SSL3)
if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 &&
ssl->in_msglen > ssl->transform_in->minlen + MBEDTLS_SSL_IN_CONTENT_LEN )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad message length" ) );
return( MBEDTLS_ERR_SSL_INVALID_RECORD );
}
#endif
#if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) || \
defined(MBEDTLS_SSL_PROTO_TLS1_2)
/*
* TLS encrypted messages can have up to 256 bytes of padding
*/
if( ssl->minor_ver >= MBEDTLS_SSL_MINOR_VERSION_1 &&
ssl->in_msglen > ssl->transform_in->minlen +
MBEDTLS_SSL_IN_CONTENT_LEN + 256 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad message length" ) );
return( MBEDTLS_ERR_SSL_INVALID_RECORD );
}
#endif
}
return( 0 );
}
/*
* If applicable, decrypt (and decompress) record content
*/
static int ssl_prepare_record_content( mbedtls_ssl_context *ssl )
{
int ret, done = 0;
MBEDTLS_SSL_DEBUG_BUF( 4, "input record from network",
ssl->in_hdr, mbedtls_ssl_in_hdr_len( ssl ) + ssl->in_msglen );
#if defined(MBEDTLS_SSL_HW_RECORD_ACCEL)
if( mbedtls_ssl_hw_record_read != NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "going for mbedtls_ssl_hw_record_read()" ) );
ret = mbedtls_ssl_hw_record_read( ssl );
if( ret != 0 && ret != MBEDTLS_ERR_SSL_HW_ACCEL_FALLTHROUGH )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_hw_record_read", ret );
return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
}
if( ret == 0 )
done = 1;
}
#endif /* MBEDTLS_SSL_HW_RECORD_ACCEL */
if( !done && ssl->transform_in != NULL )
{
mbedtls_record rec;
rec.buf = ssl->in_iv;
rec.buf_len = MBEDTLS_SSL_IN_BUFFER_LEN
- ( ssl->in_iv - ssl->in_buf );
rec.data_len = ssl->in_msglen;
rec.data_offset = 0;
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID )
rec.cid_len = (uint8_t)( ssl->in_len - ssl->in_cid );
memcpy( rec.cid, ssl->in_cid, rec.cid_len );
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
memcpy( &rec.ctr[0], ssl->in_ctr, 8 );
mbedtls_ssl_write_version( ssl->major_ver, ssl->minor_ver,
ssl->conf->transport, rec.ver );
rec.type = ssl->in_msgtype;
if( ( ret = mbedtls_ssl_decrypt_buf( ssl, ssl->transform_in,
&rec ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_decrypt_buf", ret );
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
if( ret == MBEDTLS_ERR_SSL_UNEXPECTED_CID &&
ssl->conf->ignore_unexpected_cid
== MBEDTLS_SSL_UNEXPECTED_CID_IGNORE )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "ignoring unexpected CID" ) );
ret = MBEDTLS_ERR_SSL_CONTINUE_PROCESSING;
}
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
return( ret );
}
if( ssl->in_msgtype != rec.type )
{
MBEDTLS_SSL_DEBUG_MSG( 4, ( "record type after decrypt (before %d): %d",
ssl->in_msgtype, rec.type ) );
}
/* The record content type may change during decryption,
* so re-read it. */
ssl->in_msgtype = rec.type;
/* Also update the input buffer, because unfortunately
* the server-side ssl_parse_client_hello() reparses the
* record header when receiving a ClientHello initiating
* a renegotiation. */
ssl->in_hdr[0] = rec.type;
ssl->in_msg = rec.buf + rec.data_offset;
ssl->in_msglen = rec.data_len;
ssl->in_len[0] = (unsigned char)( rec.data_len >> 8 );
ssl->in_len[1] = (unsigned char)( rec.data_len );
MBEDTLS_SSL_DEBUG_BUF( 4, "input payload after decrypt",
ssl->in_msg, ssl->in_msglen );
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
/* We have already checked the record content type
* in ssl_parse_record_header(), failing or silently
* dropping the record in the case of an unknown type.
*
* Since with the use of CIDs, the record content type
* might change during decryption, re-check the record
* content type, but treat a failure as fatal this time. */
if( ssl_check_record_type( ssl->in_msgtype ) )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "unknown record type" ) );
return( MBEDTLS_ERR_SSL_INVALID_RECORD );
}
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
if( ssl->in_msglen > MBEDTLS_SSL_IN_CONTENT_LEN )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad message length" ) );
return( MBEDTLS_ERR_SSL_INVALID_RECORD );
}
else if( ssl->in_msglen == 0 )
{
#if defined(MBEDTLS_SSL_PROTO_TLS1_2)
if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_3
&& ssl->in_msgtype != MBEDTLS_SSL_MSG_APPLICATION_DATA )
{
/* TLS v1.2 explicitly disallows zero-length messages which are not application data */
MBEDTLS_SSL_DEBUG_MSG( 1, ( "invalid zero-length message type: %d", ssl->in_msgtype ) );
return( MBEDTLS_ERR_SSL_INVALID_RECORD );
}
#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
ssl->nb_zero++;
/*
* Three or more empty messages may be a DoS attack
* (excessive CPU consumption).
*/
if( ssl->nb_zero > 3 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "received four consecutive empty "
"messages, possible DoS attack" ) );
/* Treat the records as if they were not properly authenticated,
* thereby failing the connection if we see more than allowed
* by the configured bad MAC threshold. */
return( MBEDTLS_ERR_SSL_INVALID_MAC );
}
}
else
ssl->nb_zero = 0;
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
{
; /* in_ctr read from peer, not maintained internally */
}
else
#endif
{
unsigned i;
for( i = 8; i > ssl_ep_len( ssl ); i-- )
if( ++ssl->in_ctr[i - 1] != 0 )
break;
/* The loop goes to its end iff the counter is wrapping */
if( i == ssl_ep_len( ssl ) )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "incoming message counter would wrap" ) );
return( MBEDTLS_ERR_SSL_COUNTER_WRAPPING );
}
}
}
#if defined(MBEDTLS_ZLIB_SUPPORT)
if( ssl->transform_in != NULL &&
ssl->session_in->compression == MBEDTLS_SSL_COMPRESS_DEFLATE )
{
if( ( ret = ssl_decompress_buf( ssl ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_decompress_buf", ret );
return( ret );
}
}
#endif /* MBEDTLS_ZLIB_SUPPORT */
#if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
{
mbedtls_ssl_dtls_replay_update( ssl );
}
#endif
return( 0 );
}
static void ssl_handshake_wrapup_free_hs_transform( mbedtls_ssl_context *ssl );
/*
* Read a record.
*
* Silently ignore non-fatal alert (and for DTLS, invalid records as well,
* RFC 6347 4.1.2.7) and continue reading until a valid record is found.
*
*/
/* Helper functions for mbedtls_ssl_read_record(). */
static int ssl_consume_current_message( mbedtls_ssl_context *ssl );
static int ssl_get_next_record( mbedtls_ssl_context *ssl );
static int ssl_record_is_in_progress( mbedtls_ssl_context *ssl );
int mbedtls_ssl_read_record( mbedtls_ssl_context *ssl,
unsigned update_hs_digest )
{
int ret;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> read record" ) );
if( ssl->keep_current_message == 0 )
{
do {
ret = ssl_consume_current_message( ssl );
if( ret != 0 )
return( ret );
if( ssl_record_is_in_progress( ssl ) == 0 )
{
#if defined(MBEDTLS_SSL_PROTO_DTLS)
int have_buffered = 0;
/* We only check for buffered messages if the
* current datagram is fully consumed. */
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
ssl_next_record_is_in_datagram( ssl ) == 0 )
{
if( ssl_load_buffered_message( ssl ) == 0 )
have_buffered = 1;
}
if( have_buffered == 0 )
#endif /* MBEDTLS_SSL_PROTO_DTLS */
{
ret = ssl_get_next_record( ssl );
if( ret == MBEDTLS_ERR_SSL_CONTINUE_PROCESSING )
continue;
if( ret != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, ( "ssl_get_next_record" ), ret );
return( ret );
}
}
}
ret = mbedtls_ssl_handle_message_type( ssl );
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ret == MBEDTLS_ERR_SSL_EARLY_MESSAGE )
{
/* Buffer future message */
ret = ssl_buffer_message( ssl );
if( ret != 0 )
return( ret );
ret = MBEDTLS_ERR_SSL_CONTINUE_PROCESSING;
}
#endif /* MBEDTLS_SSL_PROTO_DTLS */
} while( MBEDTLS_ERR_SSL_NON_FATAL == ret ||
MBEDTLS_ERR_SSL_CONTINUE_PROCESSING == ret );
if( 0 != ret )
{
MBEDTLS_SSL_DEBUG_RET( 1, ( "mbedtls_ssl_handle_message_type" ), ret );
return( ret );
}
if( ssl->in_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE &&
update_hs_digest == 1 )
{
mbedtls_ssl_update_handshake_status( ssl );
}
}
else
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "reuse previously read message" ) );
ssl->keep_current_message = 0;
}
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= read record" ) );
return( 0 );
}
#if defined(MBEDTLS_SSL_PROTO_DTLS)
static int ssl_next_record_is_in_datagram( mbedtls_ssl_context *ssl )
{
if( ssl->in_left > ssl->next_record_offset )
return( 1 );
return( 0 );
}
static int ssl_load_buffered_message( mbedtls_ssl_context *ssl )
{
mbedtls_ssl_handshake_params * const hs = ssl->handshake;
mbedtls_ssl_hs_buffer * hs_buf;
int ret = 0;
if( hs == NULL )
return( -1 );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> ssl_load_buffered_messsage" ) );
if( ssl->state == MBEDTLS_SSL_CLIENT_CHANGE_CIPHER_SPEC ||
ssl->state == MBEDTLS_SSL_SERVER_CHANGE_CIPHER_SPEC )
{
/* Check if we have seen a ChangeCipherSpec before.
* If yes, synthesize a CCS record. */
if( !hs->buffering.seen_ccs )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "CCS not seen in the current flight" ) );
ret = -1;
goto exit;
}
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Injecting buffered CCS message" ) );
ssl->in_msgtype = MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC;
ssl->in_msglen = 1;
ssl->in_msg[0] = 1;
/* As long as they are equal, the exact value doesn't matter. */
ssl->in_left = 0;
ssl->next_record_offset = 0;
hs->buffering.seen_ccs = 0;
goto exit;
}
#if defined(MBEDTLS_DEBUG_C)
/* Debug only */
{
unsigned offset;
for( offset = 1; offset < MBEDTLS_SSL_MAX_BUFFERED_HS; offset++ )
{
hs_buf = &hs->buffering.hs[offset];
if( hs_buf->is_valid == 1 )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Future message with sequence number %u %s buffered.",
hs->in_msg_seq + offset,
hs_buf->is_complete ? "fully" : "partially" ) );
}
}
}
#endif /* MBEDTLS_DEBUG_C */
/* Check if we have buffered and/or fully reassembled the
* next handshake message. */
hs_buf = &hs->buffering.hs[0];
if( ( hs_buf->is_valid == 1 ) && ( hs_buf->is_complete == 1 ) )
{
/* Synthesize a record containing the buffered HS message. */
size_t msg_len = ( hs_buf->data[1] << 16 ) |
( hs_buf->data[2] << 8 ) |
hs_buf->data[3];
/* Double-check that we haven't accidentally buffered
* a message that doesn't fit into the input buffer. */
if( msg_len + 12 > MBEDTLS_SSL_IN_CONTENT_LEN )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Next handshake message has been buffered - load" ) );
MBEDTLS_SSL_DEBUG_BUF( 3, "Buffered handshake message (incl. header)",
hs_buf->data, msg_len + 12 );
ssl->in_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE;
ssl->in_hslen = msg_len + 12;
ssl->in_msglen = msg_len + 12;
memcpy( ssl->in_msg, hs_buf->data, ssl->in_hslen );
ret = 0;
goto exit;
}
else
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Next handshake message %u not or only partially bufffered",
hs->in_msg_seq ) );
}
ret = -1;
exit:
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= ssl_load_buffered_message" ) );
return( ret );
}
static int ssl_buffer_make_space( mbedtls_ssl_context *ssl,
size_t desired )
{
int offset;
mbedtls_ssl_handshake_params * const hs = ssl->handshake;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Attempt to free buffered messages to have %u bytes available",
(unsigned) desired ) );
/* Get rid of future records epoch first, if such exist. */
ssl_free_buffered_record( ssl );
/* Check if we have enough space available now. */
if( desired <= ( MBEDTLS_SSL_DTLS_MAX_BUFFERING -
hs->buffering.total_bytes_buffered ) )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Enough space available after freeing future epoch record" ) );
return( 0 );
}
/* We don't have enough space to buffer the next expected handshake
* message. Remove buffers used for future messages to gain space,
* starting with the most distant one. */
for( offset = MBEDTLS_SSL_MAX_BUFFERED_HS - 1;
offset >= 0; offset-- )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Free buffering slot %d to make space for reassembly of next handshake message",
offset ) );
ssl_buffering_free_slot( ssl, (uint8_t) offset );
/* Check if we have enough space available now. */
if( desired <= ( MBEDTLS_SSL_DTLS_MAX_BUFFERING -
hs->buffering.total_bytes_buffered ) )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Enough space available after freeing buffered HS messages" ) );
return( 0 );
}
}
return( -1 );
}
static int ssl_buffer_message( mbedtls_ssl_context *ssl )
{
int ret = 0;
mbedtls_ssl_handshake_params * const hs = ssl->handshake;
if( hs == NULL )
return( 0 );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> ssl_buffer_message" ) );
switch( ssl->in_msgtype )
{
case MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC:
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Remember CCS message" ) );
hs->buffering.seen_ccs = 1;
break;
case MBEDTLS_SSL_MSG_HANDSHAKE:
{
unsigned recv_msg_seq_offset;
unsigned recv_msg_seq = ( ssl->in_msg[4] << 8 ) | ssl->in_msg[5];
mbedtls_ssl_hs_buffer *hs_buf;
size_t msg_len = ssl->in_hslen - 12;
/* We should never receive an old handshake
* message - double-check nonetheless. */
if( recv_msg_seq < ssl->handshake->in_msg_seq )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
recv_msg_seq_offset = recv_msg_seq - ssl->handshake->in_msg_seq;
if( recv_msg_seq_offset >= MBEDTLS_SSL_MAX_BUFFERED_HS )
{
/* Silently ignore -- message too far in the future */
MBEDTLS_SSL_DEBUG_MSG( 2,
( "Ignore future HS message with sequence number %u, "
"buffering window %u - %u",
recv_msg_seq, ssl->handshake->in_msg_seq,
ssl->handshake->in_msg_seq + MBEDTLS_SSL_MAX_BUFFERED_HS - 1 ) );
goto exit;
}
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Buffering HS message with sequence number %u, offset %u ",
recv_msg_seq, recv_msg_seq_offset ) );
hs_buf = &hs->buffering.hs[ recv_msg_seq_offset ];
/* Check if the buffering for this seq nr has already commenced. */
if( !hs_buf->is_valid )
{
size_t reassembly_buf_sz;
hs_buf->is_fragmented =
( ssl_hs_is_proper_fragment( ssl ) == 1 );
/* We copy the message back into the input buffer
* after reassembly, so check that it's not too large.
* This is an implementation-specific limitation
* and not one from the standard, hence it is not
* checked in ssl_check_hs_header(). */
if( msg_len + 12 > MBEDTLS_SSL_IN_CONTENT_LEN )
{
/* Ignore message */
goto exit;
}
/* Check if we have enough space to buffer the message. */
if( hs->buffering.total_bytes_buffered >
MBEDTLS_SSL_DTLS_MAX_BUFFERING )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
reassembly_buf_sz = ssl_get_reassembly_buffer_size( msg_len,
hs_buf->is_fragmented );
if( reassembly_buf_sz > ( MBEDTLS_SSL_DTLS_MAX_BUFFERING -
hs->buffering.total_bytes_buffered ) )
{
if( recv_msg_seq_offset > 0 )
{
/* If we can't buffer a future message because
* of space limitations -- ignore. */
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Buffering of future message of size %u would exceed the compile-time limit %u (already %u bytes buffered) -- ignore\n",
(unsigned) msg_len, MBEDTLS_SSL_DTLS_MAX_BUFFERING,
(unsigned) hs->buffering.total_bytes_buffered ) );
goto exit;
}
else
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Buffering of future message of size %u would exceed the compile-time limit %u (already %u bytes buffered) -- attempt to make space by freeing buffered future messages\n",
(unsigned) msg_len, MBEDTLS_SSL_DTLS_MAX_BUFFERING,
(unsigned) hs->buffering.total_bytes_buffered ) );
}
if( ssl_buffer_make_space( ssl, reassembly_buf_sz ) != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Reassembly of next message of size %u (%u with bitmap) would exceed the compile-time limit %u (already %u bytes buffered) -- fail\n",
(unsigned) msg_len,
(unsigned) reassembly_buf_sz,
MBEDTLS_SSL_DTLS_MAX_BUFFERING,
(unsigned) hs->buffering.total_bytes_buffered ) );
ret = MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL;
goto exit;
}
}
MBEDTLS_SSL_DEBUG_MSG( 2, ( "initialize reassembly, total length = %d",
msg_len ) );
hs_buf->data = mbedtls_calloc( 1, reassembly_buf_sz );
if( hs_buf->data == NULL )
{
ret = MBEDTLS_ERR_SSL_ALLOC_FAILED;
goto exit;
}
hs_buf->data_len = reassembly_buf_sz;
/* Prepare final header: copy msg_type, length and message_seq,
* then add standardised fragment_offset and fragment_length */
memcpy( hs_buf->data, ssl->in_msg, 6 );
memset( hs_buf->data + 6, 0, 3 );
memcpy( hs_buf->data + 9, hs_buf->data + 1, 3 );
hs_buf->is_valid = 1;
hs->buffering.total_bytes_buffered += reassembly_buf_sz;
}
else
{
/* Make sure msg_type and length are consistent */
if( memcmp( hs_buf->data, ssl->in_msg, 4 ) != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "Fragment header mismatch - ignore" ) );
/* Ignore */
goto exit;
}
}
if( !hs_buf->is_complete )
{
size_t frag_len, frag_off;
unsigned char * const msg = hs_buf->data + 12;
/*
* Check and copy current fragment
*/
/* Validation of header fields already done in
* mbedtls_ssl_prepare_handshake_record(). */
frag_off = ssl_get_hs_frag_off( ssl );
frag_len = ssl_get_hs_frag_len( ssl );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "adding fragment, offset = %d, length = %d",
frag_off, frag_len ) );
memcpy( msg + frag_off, ssl->in_msg + 12, frag_len );
if( hs_buf->is_fragmented )
{
unsigned char * const bitmask = msg + msg_len;
ssl_bitmask_set( bitmask, frag_off, frag_len );
hs_buf->is_complete = ( ssl_bitmask_check( bitmask,
msg_len ) == 0 );
}
else
{
hs_buf->is_complete = 1;
}
MBEDTLS_SSL_DEBUG_MSG( 2, ( "message %scomplete",
hs_buf->is_complete ? "" : "not yet " ) );
}
break;
}
default:
/* We don't buffer other types of messages. */
break;
}
exit:
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= ssl_buffer_message" ) );
return( ret );
}
#endif /* MBEDTLS_SSL_PROTO_DTLS */
static int ssl_consume_current_message( mbedtls_ssl_context *ssl )
{
/*
* Consume last content-layer message and potentially
* update in_msglen which keeps track of the contents'
* consumption state.
*
* (1) Handshake messages:
* Remove last handshake message, move content
* and adapt in_msglen.
*
* (2) Alert messages:
* Consume whole record content, in_msglen = 0.
*
* (3) Change cipher spec:
* Consume whole record content, in_msglen = 0.
*
* (4) Application data:
* Don't do anything - the record layer provides
* the application data as a stream transport
* and consumes through mbedtls_ssl_read only.
*
*/
/* Case (1): Handshake messages */
if( ssl->in_hslen != 0 )
{
/* Hard assertion to be sure that no application data
* is in flight, as corrupting ssl->in_msglen during
* ssl->in_offt != NULL is fatal. */
if( ssl->in_offt != NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
/*
* Get next Handshake message in the current record
*/
/* Notes:
* (1) in_hslen is not necessarily the size of the
* current handshake content: If DTLS handshake
* fragmentation is used, that's the fragment
* size instead. Using the total handshake message
* size here is faulty and should be changed at
* some point.
* (2) While it doesn't seem to cause problems, one
* has to be very careful not to assume that in_hslen
* is always <= in_msglen in a sensible communication.
* Again, it's wrong for DTLS handshake fragmentation.
* The following check is therefore mandatory, and
* should not be treated as a silently corrected assertion.
* Additionally, ssl->in_hslen might be arbitrarily out of
* bounds after handling a DTLS message with an unexpected
* sequence number, see mbedtls_ssl_prepare_handshake_record.
*/
if( ssl->in_hslen < ssl->in_msglen )
{
ssl->in_msglen -= ssl->in_hslen;
memmove( ssl->in_msg, ssl->in_msg + ssl->in_hslen,
ssl->in_msglen );
MBEDTLS_SSL_DEBUG_BUF( 4, "remaining content in record",
ssl->in_msg, ssl->in_msglen );
}
else
{
ssl->in_msglen = 0;
}
ssl->in_hslen = 0;
}
/* Case (4): Application data */
else if( ssl->in_offt != NULL )
{
return( 0 );
}
/* Everything else (CCS & Alerts) */
else
{
ssl->in_msglen = 0;
}
return( 0 );
}
static int ssl_record_is_in_progress( mbedtls_ssl_context *ssl )
{
if( ssl->in_msglen > 0 )
return( 1 );
return( 0 );
}
#if defined(MBEDTLS_SSL_PROTO_DTLS)
static void ssl_free_buffered_record( mbedtls_ssl_context *ssl )
{
mbedtls_ssl_handshake_params * const hs = ssl->handshake;
if( hs == NULL )
return;
if( hs->buffering.future_record.data != NULL )
{
hs->buffering.total_bytes_buffered -=
hs->buffering.future_record.len;
mbedtls_free( hs->buffering.future_record.data );
hs->buffering.future_record.data = NULL;
}
}
static int ssl_load_buffered_record( mbedtls_ssl_context *ssl )
{
mbedtls_ssl_handshake_params * const hs = ssl->handshake;
unsigned char * rec;
size_t rec_len;
unsigned rec_epoch;
if( ssl->conf->transport != MBEDTLS_SSL_TRANSPORT_DATAGRAM )
return( 0 );
if( hs == NULL )
return( 0 );
rec = hs->buffering.future_record.data;
rec_len = hs->buffering.future_record.len;
rec_epoch = hs->buffering.future_record.epoch;
if( rec == NULL )
return( 0 );
/* Only consider loading future records if the
* input buffer is empty. */
if( ssl_next_record_is_in_datagram( ssl ) == 1 )
return( 0 );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> ssl_load_buffered_record" ) );
if( rec_epoch != ssl->in_epoch )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Buffered record not from current epoch." ) );
goto exit;
}
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Found buffered record from current epoch - load" ) );
/* Double-check that the record is not too large */
if( rec_len > MBEDTLS_SSL_IN_BUFFER_LEN -
(size_t)( ssl->in_hdr - ssl->in_buf ) )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
memcpy( ssl->in_hdr, rec, rec_len );
ssl->in_left = rec_len;
ssl->next_record_offset = 0;
ssl_free_buffered_record( ssl );
exit:
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= ssl_load_buffered_record" ) );
return( 0 );
}
static int ssl_buffer_future_record( mbedtls_ssl_context *ssl )
{
mbedtls_ssl_handshake_params * const hs = ssl->handshake;
size_t const rec_hdr_len = 13;
size_t const total_buf_sz = rec_hdr_len + ssl->in_msglen;
/* Don't buffer future records outside handshakes. */
if( hs == NULL )
return( 0 );
/* Only buffer handshake records (we are only interested
* in Finished messages). */
if( ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE )
return( 0 );
/* Don't buffer more than one future epoch record. */
if( hs->buffering.future_record.data != NULL )
return( 0 );
/* Don't buffer record if there's not enough buffering space remaining. */
if( total_buf_sz > ( MBEDTLS_SSL_DTLS_MAX_BUFFERING -
hs->buffering.total_bytes_buffered ) )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Buffering of future epoch record of size %u would exceed the compile-time limit %u (already %u bytes buffered) -- ignore\n",
(unsigned) total_buf_sz, MBEDTLS_SSL_DTLS_MAX_BUFFERING,
(unsigned) hs->buffering.total_bytes_buffered ) );
return( 0 );
}
/* Buffer record */
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Buffer record from epoch %u",
ssl->in_epoch + 1 ) );
MBEDTLS_SSL_DEBUG_BUF( 3, "Buffered record", ssl->in_hdr,
rec_hdr_len + ssl->in_msglen );
/* ssl_parse_record_header() only considers records
* of the next epoch as candidates for buffering. */
hs->buffering.future_record.epoch = ssl->in_epoch + 1;
hs->buffering.future_record.len = total_buf_sz;
hs->buffering.future_record.data =
mbedtls_calloc( 1, hs->buffering.future_record.len );
if( hs->buffering.future_record.data == NULL )
{
/* If we run out of RAM trying to buffer a
* record from the next epoch, just ignore. */
return( 0 );
}
memcpy( hs->buffering.future_record.data, ssl->in_hdr, total_buf_sz );
hs->buffering.total_bytes_buffered += total_buf_sz;
return( 0 );
}
#endif /* MBEDTLS_SSL_PROTO_DTLS */
static int ssl_get_next_record( mbedtls_ssl_context *ssl )
{
int ret;
#if defined(MBEDTLS_SSL_PROTO_DTLS)
/* We might have buffered a future record; if so,
* and if the epoch matches now, load it.
* On success, this call will set ssl->in_left to
* the length of the buffered record, so that
* the calls to ssl_fetch_input() below will
* essentially be no-ops. */
ret = ssl_load_buffered_record( ssl );
if( ret != 0 )
return( ret );
#endif /* MBEDTLS_SSL_PROTO_DTLS */
/* Reset in pointers to default state for TLS/DTLS records,
* assuming no CID and no offset between record content and
* record plaintext. */
ssl_update_in_pointers( ssl );
/* Ensure that we have enough space available for the default form
* of TLS / DTLS record headers (5 Bytes for TLS, 13 Bytes for DTLS,
* with no space for CIDs counted in). */
ret = mbedtls_ssl_fetch_input( ssl, mbedtls_ssl_in_hdr_len( ssl ) );
if( ret != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_fetch_input", ret );
return( ret );
}
if( ( ret = ssl_parse_record_header( ssl ) ) != 0 )
{
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
ret != MBEDTLS_ERR_SSL_CLIENT_RECONNECT )
{
if( ret == MBEDTLS_ERR_SSL_EARLY_MESSAGE )
{
ret = ssl_buffer_future_record( ssl );
if( ret != 0 )
return( ret );
/* Fall through to handling of unexpected records */
ret = MBEDTLS_ERR_SSL_UNEXPECTED_RECORD;
}
if( ret == MBEDTLS_ERR_SSL_UNEXPECTED_RECORD )
{
/* Skip unexpected record (but not whole datagram) */
ssl->next_record_offset = ssl->in_msglen
+ mbedtls_ssl_in_hdr_len( ssl );
MBEDTLS_SSL_DEBUG_MSG( 1, ( "discarding unexpected record "
"(header)" ) );
}
else
{
/* Skip invalid record and the rest of the datagram */
ssl->next_record_offset = 0;
ssl->in_left = 0;
MBEDTLS_SSL_DEBUG_MSG( 1, ( "discarding invalid record "
"(header)" ) );
}
/* Get next record */
return( MBEDTLS_ERR_SSL_CONTINUE_PROCESSING );
}
#endif
return( ret );
}
/*
* Read and optionally decrypt the message contents
*/
if( ( ret = mbedtls_ssl_fetch_input( ssl,
mbedtls_ssl_in_hdr_len( ssl ) + ssl->in_msglen ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_fetch_input", ret );
return( ret );
}
/* Done reading this record, get ready for the next one */
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
{
ssl->next_record_offset = ssl->in_msglen + mbedtls_ssl_in_hdr_len( ssl );
if( ssl->next_record_offset < ssl->in_left )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "more than one record within datagram" ) );
}
}
else
#endif
ssl->in_left = 0;
if( ( ret = ssl_prepare_record_content( ssl ) ) != 0 )
{
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
{
/* Silently discard invalid records */
if( ret == MBEDTLS_ERR_SSL_INVALID_MAC )
{
/* Except when waiting for Finished as a bad mac here
* probably means something went wrong in the handshake
* (eg wrong psk used, mitm downgrade attempt, etc.) */
if( ssl->state == MBEDTLS_SSL_CLIENT_FINISHED ||
ssl->state == MBEDTLS_SSL_SERVER_FINISHED )
{
#if defined(MBEDTLS_SSL_ALL_ALERT_MESSAGES)
if( ret == MBEDTLS_ERR_SSL_INVALID_MAC )
{
mbedtls_ssl_send_alert_message( ssl,
MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_BAD_RECORD_MAC );
}
#endif
return( ret );
}
#if defined(MBEDTLS_SSL_DTLS_BADMAC_LIMIT)
if( ssl->conf->badmac_limit != 0 &&
++ssl->badmac_seen >= ssl->conf->badmac_limit )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "too many records with bad MAC" ) );
return( MBEDTLS_ERR_SSL_INVALID_MAC );
}
#endif
/* As above, invalid records cause
* dismissal of the whole datagram. */
ssl->next_record_offset = 0;
ssl->in_left = 0;
MBEDTLS_SSL_DEBUG_MSG( 1, ( "discarding invalid record (mac)" ) );
return( MBEDTLS_ERR_SSL_CONTINUE_PROCESSING );
}
return( ret );
}
else
#endif
{
/* Error out (and send alert) on invalid records */
#if defined(MBEDTLS_SSL_ALL_ALERT_MESSAGES)
if( ret == MBEDTLS_ERR_SSL_INVALID_MAC )
{
mbedtls_ssl_send_alert_message( ssl,
MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_BAD_RECORD_MAC );
}
#endif
return( ret );
}
}
return( 0 );
}
int mbedtls_ssl_handle_message_type( mbedtls_ssl_context *ssl )
{
int ret;
/*
* Handle particular types of records
*/
if( ssl->in_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE )
{
if( ( ret = mbedtls_ssl_prepare_handshake_record( ssl ) ) != 0 )
{
return( ret );
}
}
if( ssl->in_msgtype == MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC )
{
if( ssl->in_msglen != 1 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "invalid CCS message, len: %d",
ssl->in_msglen ) );
return( MBEDTLS_ERR_SSL_INVALID_RECORD );
}
if( ssl->in_msg[0] != 1 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "invalid CCS message, content: %02x",
ssl->in_msg[0] ) );
return( MBEDTLS_ERR_SSL_INVALID_RECORD );
}
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
ssl->state != MBEDTLS_SSL_CLIENT_CHANGE_CIPHER_SPEC &&
ssl->state != MBEDTLS_SSL_SERVER_CHANGE_CIPHER_SPEC )
{
if( ssl->handshake == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "dropping ChangeCipherSpec outside handshake" ) );
return( MBEDTLS_ERR_SSL_UNEXPECTED_RECORD );
}
MBEDTLS_SSL_DEBUG_MSG( 1, ( "received out-of-order ChangeCipherSpec - remember" ) );
return( MBEDTLS_ERR_SSL_EARLY_MESSAGE );
}
#endif
}
if( ssl->in_msgtype == MBEDTLS_SSL_MSG_ALERT )
{
if( ssl->in_msglen != 2 )
{
/* Note: Standard allows for more than one 2 byte alert
to be packed in a single message, but Mbed TLS doesn't
currently support this. */
MBEDTLS_SSL_DEBUG_MSG( 1, ( "invalid alert message, len: %d",
ssl->in_msglen ) );
return( MBEDTLS_ERR_SSL_INVALID_RECORD );
}
MBEDTLS_SSL_DEBUG_MSG( 2, ( "got an alert message, type: [%d:%d]",
ssl->in_msg[0], ssl->in_msg[1] ) );
/*
* Ignore non-fatal alerts, except close_notify and no_renegotiation
*/
if( ssl->in_msg[0] == MBEDTLS_SSL_ALERT_LEVEL_FATAL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "is a fatal alert message (msg %d)",
ssl->in_msg[1] ) );
return( MBEDTLS_ERR_SSL_FATAL_ALERT_MESSAGE );
}
if( ssl->in_msg[0] == MBEDTLS_SSL_ALERT_LEVEL_WARNING &&
ssl->in_msg[1] == MBEDTLS_SSL_ALERT_MSG_CLOSE_NOTIFY )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "is a close notify message" ) );
return( MBEDTLS_ERR_SSL_PEER_CLOSE_NOTIFY );
}
#if defined(MBEDTLS_SSL_RENEGOTIATION_ENABLED)
if( ssl->in_msg[0] == MBEDTLS_SSL_ALERT_LEVEL_WARNING &&
ssl->in_msg[1] == MBEDTLS_SSL_ALERT_MSG_NO_RENEGOTIATION )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "is a SSLv3 no renegotiation alert" ) );
/* Will be handled when trying to parse ServerHello */
return( 0 );
}
#endif
#if defined(MBEDTLS_SSL_PROTO_SSL3) && defined(MBEDTLS_SSL_SRV_C)
if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 &&
ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER &&
ssl->in_msg[0] == MBEDTLS_SSL_ALERT_LEVEL_WARNING &&
ssl->in_msg[1] == MBEDTLS_SSL_ALERT_MSG_NO_CERT )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "is a SSLv3 no_cert" ) );
/* Will be handled in mbedtls_ssl_parse_certificate() */
return( 0 );
}
#endif /* MBEDTLS_SSL_PROTO_SSL3 && MBEDTLS_SSL_SRV_C */
/* Silently ignore: fetch new message */
return MBEDTLS_ERR_SSL_NON_FATAL;
}
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
{
/* Drop unexpected ApplicationData records,
* except at the beginning of renegotiations */
if( ssl->in_msgtype == MBEDTLS_SSL_MSG_APPLICATION_DATA &&
ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER
#if defined(MBEDTLS_SSL_RENEGOTIATION)
&& ! ( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS &&
ssl->state == MBEDTLS_SSL_SERVER_HELLO )
#endif
)
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "dropping unexpected ApplicationData" ) );
return( MBEDTLS_ERR_SSL_NON_FATAL );
}
if( ssl->handshake != NULL &&
ssl->state == MBEDTLS_SSL_HANDSHAKE_OVER )
{
ssl_handshake_wrapup_free_hs_transform( ssl );
}
}
#endif /* MBEDTLS_SSL_PROTO_DTLS */
return( 0 );
}
int mbedtls_ssl_send_fatal_handshake_failure( mbedtls_ssl_context *ssl )
{
int ret;
if( ( ret = mbedtls_ssl_send_alert_message( ssl,
MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE ) ) != 0 )
{
return( ret );
}
return( 0 );
}
int mbedtls_ssl_send_alert_message( mbedtls_ssl_context *ssl,
unsigned char level,
unsigned char message )
{
int ret;
if( ssl == NULL || ssl->conf == NULL )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> send alert message" ) );
MBEDTLS_SSL_DEBUG_MSG( 3, ( "send alert level=%u message=%u", level, message ));
ssl->out_msgtype = MBEDTLS_SSL_MSG_ALERT;
ssl->out_msglen = 2;
ssl->out_msg[0] = level;
ssl->out_msg[1] = message;
if( ( ret = mbedtls_ssl_write_record( ssl, SSL_FORCE_FLUSH ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_record", ret );
return( ret );
}
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= send alert message" ) );
return( 0 );
}
/*
* Handshake functions
*/
#if !defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED) && \
!defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED) && \
!defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED) && \
!defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) && \
!defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) && \
!defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) && \
!defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)
/* No certificate support -> dummy functions */
int mbedtls_ssl_write_certificate( mbedtls_ssl_context *ssl )
{
const mbedtls_ssl_ciphersuite_t *ciphersuite_info = ssl->handshake->ciphersuite_info;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write certificate" ) );
if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK ||
ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK ||
ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK ||
ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip write certificate" ) );
ssl->state++;
return( 0 );
}
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
int mbedtls_ssl_parse_certificate( mbedtls_ssl_context *ssl )
{
const mbedtls_ssl_ciphersuite_t *ciphersuite_info = ssl->handshake->ciphersuite_info;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse certificate" ) );
if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK ||
ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK ||
ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK ||
ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate" ) );
ssl->state++;
return( 0 );
}
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
#else
/* Some certificate support -> implement write and parse */
int mbedtls_ssl_write_certificate( mbedtls_ssl_context *ssl )
{
int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE;
size_t i, n;
const mbedtls_x509_crt *crt;
const mbedtls_ssl_ciphersuite_t *ciphersuite_info = ssl->handshake->ciphersuite_info;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write certificate" ) );
if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK ||
ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK ||
ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK ||
ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip write certificate" ) );
ssl->state++;
return( 0 );
}
#if defined(MBEDTLS_SSL_CLI_C)
if( ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT )
{
if( ssl->client_auth == 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip write certificate" ) );
ssl->state++;
return( 0 );
}
#if defined(MBEDTLS_SSL_PROTO_SSL3)
/*
* If using SSLv3 and got no cert, send an Alert message
* (otherwise an empty Certificate message will be sent).
*/
if( mbedtls_ssl_own_cert( ssl ) == NULL &&
ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 )
{
ssl->out_msglen = 2;
ssl->out_msgtype = MBEDTLS_SSL_MSG_ALERT;
ssl->out_msg[0] = MBEDTLS_SSL_ALERT_LEVEL_WARNING;
ssl->out_msg[1] = MBEDTLS_SSL_ALERT_MSG_NO_CERT;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "got no certificate to send" ) );
goto write_msg;
}
#endif /* MBEDTLS_SSL_PROTO_SSL3 */
}
#endif /* MBEDTLS_SSL_CLI_C */
#if defined(MBEDTLS_SSL_SRV_C)
if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER )
{
if( mbedtls_ssl_own_cert( ssl ) == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "got no certificate to send" ) );
return( MBEDTLS_ERR_SSL_CERTIFICATE_REQUIRED );
}
}
#endif
MBEDTLS_SSL_DEBUG_CRT( 3, "own certificate", mbedtls_ssl_own_cert( ssl ) );
/*
* 0 . 0 handshake type
* 1 . 3 handshake length
* 4 . 6 length of all certs
* 7 . 9 length of cert. 1
* 10 . n-1 peer certificate
* n . n+2 length of cert. 2
* n+3 . ... upper level cert, etc.
*/
i = 7;
crt = mbedtls_ssl_own_cert( ssl );
while( crt != NULL )
{
n = crt->raw.len;
if( n > MBEDTLS_SSL_OUT_CONTENT_LEN - 3 - i )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "certificate too large, %d > %d",
i + 3 + n, MBEDTLS_SSL_OUT_CONTENT_LEN ) );
return( MBEDTLS_ERR_SSL_CERTIFICATE_TOO_LARGE );
}
ssl->out_msg[i ] = (unsigned char)( n >> 16 );
ssl->out_msg[i + 1] = (unsigned char)( n >> 8 );
ssl->out_msg[i + 2] = (unsigned char)( n );
i += 3; memcpy( ssl->out_msg + i, crt->raw.p, n );
i += n; crt = crt->next;
}
ssl->out_msg[4] = (unsigned char)( ( i - 7 ) >> 16 );
ssl->out_msg[5] = (unsigned char)( ( i - 7 ) >> 8 );
ssl->out_msg[6] = (unsigned char)( ( i - 7 ) );
ssl->out_msglen = i;
ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE;
ssl->out_msg[0] = MBEDTLS_SSL_HS_CERTIFICATE;
#if defined(MBEDTLS_SSL_PROTO_SSL3) && defined(MBEDTLS_SSL_CLI_C)
write_msg:
#endif
ssl->state++;
if( ( ret = mbedtls_ssl_write_handshake_msg( ssl ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_handshake_msg", ret );
return( ret );
}
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write certificate" ) );
return( ret );
}
static int ssl_check_peer_crt_unchanged( mbedtls_ssl_context *ssl,
unsigned char *crt_buf,
size_t crt_buf_len )
{
mbedtls_x509_crt const * const peer_crt = ssl->session->peer_cert;
if( peer_crt == NULL )
return( -1 );
if( peer_crt->raw.len != crt_buf_len )
return( -1 );
return( memcmp( peer_crt->raw.p, crt_buf, crt_buf_len) );
}
/*
* Once the certificate message is read, parse it into a cert chain and
* perform basic checks, but leave actual verification to the caller
*/
static int ssl_parse_certificate_chain( mbedtls_ssl_context *ssl )
{
int ret;
size_t i, n;
uint8_t alert;
#if defined(MBEDTLS_SSL_SRV_C)
#if defined(MBEDTLS_SSL_PROTO_SSL3)
/*
* Check if the client sent an empty certificate
*/
if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER &&
ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 )
{
if( ssl->in_msglen == 2 &&
ssl->in_msgtype == MBEDTLS_SSL_MSG_ALERT &&
ssl->in_msg[0] == MBEDTLS_SSL_ALERT_LEVEL_WARNING &&
ssl->in_msg[1] == MBEDTLS_SSL_ALERT_MSG_NO_CERT )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "SSLv3 client has no certificate" ) );
/* The client was asked for a certificate but didn't send
one. The client should know what's going on, so we
don't send an alert. */
ssl->session_negotiate->verify_result = MBEDTLS_X509_BADCERT_MISSING;
return( MBEDTLS_ERR_SSL_NO_CLIENT_CERTIFICATE );
}
}
#endif /* MBEDTLS_SSL_PROTO_SSL3 */
#if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) || \
defined(MBEDTLS_SSL_PROTO_TLS1_2)
if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER &&
ssl->minor_ver != MBEDTLS_SSL_MINOR_VERSION_0 )
{
if( ssl->in_hslen == 3 + mbedtls_ssl_hs_hdr_len( ssl ) &&
ssl->in_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE &&
ssl->in_msg[0] == MBEDTLS_SSL_HS_CERTIFICATE &&
memcmp( ssl->in_msg + mbedtls_ssl_hs_hdr_len( ssl ), "\0\0\0", 3 ) == 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "TLSv1 client has no certificate" ) );
/* The client was asked for a certificate but didn't send
one. The client should know what's going on, so we
don't send an alert. */
ssl->session_negotiate->verify_result = MBEDTLS_X509_BADCERT_MISSING;
return( MBEDTLS_ERR_SSL_NO_CLIENT_CERTIFICATE );
}
}
#endif /* MBEDTLS_SSL_PROTO_TLS1 || MBEDTLS_SSL_PROTO_TLS1_1 || \
MBEDTLS_SSL_PROTO_TLS1_2 */
#endif /* MBEDTLS_SSL_SRV_C */
if( ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate message" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE );
return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
}
if( ssl->in_msg[0] != MBEDTLS_SSL_HS_CERTIFICATE ||
ssl->in_hslen < mbedtls_ssl_hs_hdr_len( ssl ) + 3 + 3 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate message" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE );
}
i = mbedtls_ssl_hs_hdr_len( ssl );
/*
* Same message structure as in mbedtls_ssl_write_certificate()
*/
n = ( ssl->in_msg[i+1] << 8 ) | ssl->in_msg[i+2];
if( ssl->in_msg[i] != 0 ||
ssl->in_hslen != n + 3 + mbedtls_ssl_hs_hdr_len( ssl ) )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate message" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE );
}
/* Make &ssl->in_msg[i] point to the beginning of the CRT chain. */
i += 3;
/* In case we tried to reuse a session but it failed */
if( ssl->session_negotiate->peer_cert != NULL )
{
mbedtls_x509_crt_free( ssl->session_negotiate->peer_cert );
mbedtls_free( ssl->session_negotiate->peer_cert );
ssl->session_negotiate->peer_cert = NULL;
}
/* Iterate through and parse the CRTs in the provided chain. */
while( i < ssl->in_hslen )
{
/* Check that there's room for the next CRT's length fields. */
if ( i + 3 > ssl->in_hslen ) {
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate message" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE );
}
/* In theory, the CRT can be up to 2**24 Bytes, but we don't support
* anything beyond 2**16 ~ 64K. */
if( ssl->in_msg[i] != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate message" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE );
}
/* Read length of the next CRT in the chain. */
n = ( (unsigned int) ssl->in_msg[i + 1] << 8 )
| (unsigned int) ssl->in_msg[i + 2];
i += 3;
if( n < 128 || i + n > ssl->in_hslen )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate message" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE );
}
/* Check if we're handling the first CRT in the chain. */
if( ssl->session_negotiate->peer_cert == NULL )
{
/* During client-side renegotiation, check the server's end-CRTs
* hasn't changed compared to the initial handshake, mitigating
* the triple handshake attack. On success, reuse the original
* end-CRT instead of parsing it again. */
#if defined(MBEDTLS_SSL_RENEGOTIATION) && defined(MBEDTLS_SSL_CLI_C)
if( ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT &&
ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "Check that peer CRT hasn't changed during renegotiation" ) );
if( ssl_check_peer_crt_unchanged( ssl, &ssl->in_msg[i], n ) != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "new server cert during renegotiation" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_ACCESS_DENIED );
return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE );
}
/* Move CRT chain structure to new session instance. */
ssl->session_negotiate->peer_cert = ssl->session->peer_cert;
ssl->session->peer_cert = NULL;
/* Delete all remaining CRTs from the original CRT chain. */
mbedtls_x509_crt_free( ssl->session_negotiate->peer_cert->next );
ssl->session_negotiate->peer_cert->next = NULL;
i += n;
continue;
}
#endif /* MBEDTLS_SSL_RENEGOTIATION && MBEDTLS_SSL_CLI_C */
/* Outside of client-side renegotiation, create a fresh X.509 CRT
* instance to parse the end-CRT into. */
ssl->session_negotiate->peer_cert =
mbedtls_calloc( 1, sizeof( mbedtls_x509_crt ) );
if( ssl->session_negotiate->peer_cert == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "alloc(%d bytes) failed",
sizeof( mbedtls_x509_crt ) ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_INTERNAL_ERROR );
return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
}
mbedtls_x509_crt_init( ssl->session_negotiate->peer_cert );
/* Intentional fall through */
}
/* Parse the next certificate in the chain. */
ret = mbedtls_x509_crt_parse_der( ssl->session_negotiate->peer_cert,
ssl->in_msg + i, n );
switch( ret )
{
case 0: /*ok*/
case MBEDTLS_ERR_X509_UNKNOWN_SIG_ALG + MBEDTLS_ERR_OID_NOT_FOUND:
/* Ignore certificate with an unknown algorithm: maybe a
prior certificate was already trusted. */
break;
case MBEDTLS_ERR_X509_ALLOC_FAILED:
alert = MBEDTLS_SSL_ALERT_MSG_INTERNAL_ERROR;
goto crt_parse_der_failed;
case MBEDTLS_ERR_X509_UNKNOWN_VERSION:
alert = MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_CERT;
goto crt_parse_der_failed;
default:
alert = MBEDTLS_SSL_ALERT_MSG_BAD_CERT;
crt_parse_der_failed:
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, alert );
MBEDTLS_SSL_DEBUG_RET( 1, " mbedtls_x509_crt_parse_der", ret );
return( ret );
}
i += n;
}
MBEDTLS_SSL_DEBUG_CRT( 3, "peer certificate", ssl->session_negotiate->peer_cert );
return( 0 );
}
int mbedtls_ssl_parse_certificate( mbedtls_ssl_context *ssl )
{
int ret;
const mbedtls_ssl_ciphersuite_t * const ciphersuite_info =
ssl->handshake->ciphersuite_info;
#if defined(MBEDTLS_SSL_SRV_C) && defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
const int authmode = ssl->handshake->sni_authmode != MBEDTLS_SSL_VERIFY_UNSET
? ssl->handshake->sni_authmode
: ssl->conf->authmode;
#else
const int authmode = ssl->conf->authmode;
#endif
void *rs_ctx = NULL;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse certificate" ) );
if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK ||
ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK ||
ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK ||
ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate" ) );
ssl->state++;
return( 0 );
}
#if defined(MBEDTLS_SSL_SRV_C)
if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER &&
ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate" ) );
ssl->state++;
return( 0 );
}
if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER &&
authmode == MBEDTLS_SSL_VERIFY_NONE )
{
ssl->session_negotiate->verify_result = MBEDTLS_X509_BADCERT_SKIP_VERIFY;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate" ) );
ssl->state++;
return( 0 );
}
#endif
#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
if( ssl->handshake->ecrs_enabled &&
ssl->handshake->ecrs_state == ssl_ecrs_crt_verify )
{
goto crt_verify;
}
#endif
if( ( ret = mbedtls_ssl_read_record( ssl, 1 ) ) != 0 )
{
/* mbedtls_ssl_read_record may have sent an alert already. We
let it decide whether to alert. */
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret );
return( ret );
}
if( ( ret = ssl_parse_certificate_chain( ssl ) ) != 0 )
{
#if defined(MBEDTLS_SSL_SRV_C)
if( ret == MBEDTLS_ERR_SSL_NO_CLIENT_CERTIFICATE &&
authmode == MBEDTLS_SSL_VERIFY_OPTIONAL )
{
ret = 0;
}
#endif
ssl->state++;
return( ret );
}
#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
if( ssl->handshake->ecrs_enabled)
ssl->handshake->ecrs_state = ssl_ecrs_crt_verify;
crt_verify:
if( ssl->handshake->ecrs_enabled)
rs_ctx = &ssl->handshake->ecrs_ctx;
#endif
if( authmode != MBEDTLS_SSL_VERIFY_NONE )
{
mbedtls_x509_crt *ca_chain;
mbedtls_x509_crl *ca_crl;
#if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
if( ssl->handshake->sni_ca_chain != NULL )
{
ca_chain = ssl->handshake->sni_ca_chain;
ca_crl = ssl->handshake->sni_ca_crl;
}
else
#endif
{
ca_chain = ssl->conf->ca_chain;
ca_crl = ssl->conf->ca_crl;
}
/*
* Main check: verify certificate
*/
ret = mbedtls_x509_crt_verify_restartable(
ssl->session_negotiate->peer_cert,
ca_chain, ca_crl,
ssl->conf->cert_profile,
ssl->hostname,
&ssl->session_negotiate->verify_result,
ssl->conf->f_vrfy, ssl->conf->p_vrfy, rs_ctx );
if( ret != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "x509_verify_cert", ret );
}
#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
if( ret == MBEDTLS_ERR_ECP_IN_PROGRESS )
return( MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS );
#endif
/*
* Secondary checks: always done, but change 'ret' only if it was 0
*/
#if defined(MBEDTLS_ECP_C)
{
const mbedtls_pk_context *pk = &ssl->session_negotiate->peer_cert->pk;
/* If certificate uses an EC key, make sure the curve is OK */
if( mbedtls_pk_can_do( pk, MBEDTLS_PK_ECKEY ) &&
mbedtls_ssl_check_curve( ssl, mbedtls_pk_ec( *pk )->grp.id ) != 0 )
{
ssl->session_negotiate->verify_result |= MBEDTLS_X509_BADCERT_BAD_KEY;
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate (EC key curve)" ) );
if( ret == 0 )
ret = MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE;
}
}
#endif /* MBEDTLS_ECP_C */
if( mbedtls_ssl_check_cert_usage( ssl->session_negotiate->peer_cert,
ciphersuite_info,
! ssl->conf->endpoint,
&ssl->session_negotiate->verify_result ) != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate (usage extensions)" ) );
if( ret == 0 )
ret = MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE;
}
/* mbedtls_x509_crt_verify_with_profile is supposed to report a
* verification failure through MBEDTLS_ERR_X509_CERT_VERIFY_FAILED,
* with details encoded in the verification flags. All other kinds
* of error codes, including those from the user provided f_vrfy
* functions, are treated as fatal and lead to a failure of
* ssl_parse_certificate even if verification was optional. */
if( authmode == MBEDTLS_SSL_VERIFY_OPTIONAL &&
( ret == MBEDTLS_ERR_X509_CERT_VERIFY_FAILED ||
ret == MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE ) )
{
ret = 0;
}
if( ca_chain == NULL && authmode == MBEDTLS_SSL_VERIFY_REQUIRED )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "got no CA chain" ) );
ret = MBEDTLS_ERR_SSL_CA_CHAIN_REQUIRED;
}
if( ret != 0 )
{
uint8_t alert;
/* The certificate may have been rejected for several reasons.
Pick one and send the corresponding alert. Which alert to send
may be a subject of debate in some cases. */
if( ssl->session_negotiate->verify_result & MBEDTLS_X509_BADCERT_OTHER )
alert = MBEDTLS_SSL_ALERT_MSG_ACCESS_DENIED;
else if( ssl->session_negotiate->verify_result & MBEDTLS_X509_BADCERT_CN_MISMATCH )
alert = MBEDTLS_SSL_ALERT_MSG_BAD_CERT;
else if( ssl->session_negotiate->verify_result & MBEDTLS_X509_BADCERT_KEY_USAGE )
alert = MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_CERT;
else if( ssl->session_negotiate->verify_result & MBEDTLS_X509_BADCERT_EXT_KEY_USAGE )
alert = MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_CERT;
else if( ssl->session_negotiate->verify_result & MBEDTLS_X509_BADCERT_NS_CERT_TYPE )
alert = MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_CERT;
else if( ssl->session_negotiate->verify_result & MBEDTLS_X509_BADCERT_BAD_PK )
alert = MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_CERT;
else if( ssl->session_negotiate->verify_result & MBEDTLS_X509_BADCERT_BAD_KEY )
alert = MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_CERT;
else if( ssl->session_negotiate->verify_result & MBEDTLS_X509_BADCERT_EXPIRED )
alert = MBEDTLS_SSL_ALERT_MSG_CERT_EXPIRED;
else if( ssl->session_negotiate->verify_result & MBEDTLS_X509_BADCERT_REVOKED )
alert = MBEDTLS_SSL_ALERT_MSG_CERT_REVOKED;
else if( ssl->session_negotiate->verify_result & MBEDTLS_X509_BADCERT_NOT_TRUSTED )
alert = MBEDTLS_SSL_ALERT_MSG_UNKNOWN_CA;
else
alert = MBEDTLS_SSL_ALERT_MSG_CERT_UNKNOWN;
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
alert );
}
#if defined(MBEDTLS_DEBUG_C)
if( ssl->session_negotiate->verify_result != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "! Certificate verification flags %x",
ssl->session_negotiate->verify_result ) );
}
else
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "Certificate verification flags clear" ) );
}
#endif /* MBEDTLS_DEBUG_C */
}
ssl->state++;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse certificate" ) );
return( ret );
}
#endif /* !MBEDTLS_KEY_EXCHANGE_RSA_ENABLED
!MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED
!MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED
!MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED
!MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED
!MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED
!MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED */
int mbedtls_ssl_write_change_cipher_spec( mbedtls_ssl_context *ssl )
{
int ret;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write change cipher spec" ) );
ssl->out_msgtype = MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC;
ssl->out_msglen = 1;
ssl->out_msg[0] = 1;
ssl->state++;
if( ( ret = mbedtls_ssl_write_handshake_msg( ssl ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_handshake_msg", ret );
return( ret );
}
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write change cipher spec" ) );
return( 0 );
}
int mbedtls_ssl_parse_change_cipher_spec( mbedtls_ssl_context *ssl )
{
int ret;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse change cipher spec" ) );
if( ( ret = mbedtls_ssl_read_record( ssl, 1 ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret );
return( ret );
}
if( ssl->in_msgtype != MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad change cipher spec message" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE );
return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
}
/* CCS records are only accepted if they have length 1 and content '1',
* so we don't need to check this here. */
/*
* Switch to our negotiated transform and session parameters for inbound
* data.
*/
MBEDTLS_SSL_DEBUG_MSG( 3, ( "switching to new transform spec for inbound data" ) );
ssl->transform_in = ssl->transform_negotiate;
ssl->session_in = ssl->session_negotiate;
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
{
#if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY)
ssl_dtls_replay_reset( ssl );
#endif
/* Increment epoch */
if( ++ssl->in_epoch == 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "DTLS epoch would wrap" ) );
/* This is highly unlikely to happen for legitimate reasons, so
treat it as an attack and don't send an alert. */
return( MBEDTLS_ERR_SSL_COUNTER_WRAPPING );
}
}
else
#endif /* MBEDTLS_SSL_PROTO_DTLS */
memset( ssl->in_ctr, 0, 8 );
ssl_update_in_pointers( ssl );
#if defined(MBEDTLS_SSL_HW_RECORD_ACCEL)
if( mbedtls_ssl_hw_record_activate != NULL )
{
if( ( ret = mbedtls_ssl_hw_record_activate( ssl, MBEDTLS_SSL_CHANNEL_INBOUND ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_hw_record_activate", ret );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_INTERNAL_ERROR );
return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
}
}
#endif
ssl->state++;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse change cipher spec" ) );
return( 0 );
}
void mbedtls_ssl_optimize_checksum( mbedtls_ssl_context *ssl,
const mbedtls_ssl_ciphersuite_t *ciphersuite_info )
{
((void) ciphersuite_info);
#if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1) || \
defined(MBEDTLS_SSL_PROTO_TLS1_1)
if( ssl->minor_ver < MBEDTLS_SSL_MINOR_VERSION_3 )
ssl->handshake->update_checksum = ssl_update_checksum_md5sha1;
else
#endif
#if defined(MBEDTLS_SSL_PROTO_TLS1_2)
#if defined(MBEDTLS_SHA512_C)
if( ciphersuite_info->mac == MBEDTLS_MD_SHA384 )
ssl->handshake->update_checksum = ssl_update_checksum_sha384;
else
#endif
#if defined(MBEDTLS_SHA256_C)
if( ciphersuite_info->mac != MBEDTLS_MD_SHA384 )
ssl->handshake->update_checksum = ssl_update_checksum_sha256;
else
#endif
#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return;
}
}
void mbedtls_ssl_reset_checksum( mbedtls_ssl_context *ssl )
{
#if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1) || \
defined(MBEDTLS_SSL_PROTO_TLS1_1)
mbedtls_md5_starts_ret( &ssl->handshake->fin_md5 );
mbedtls_sha1_starts_ret( &ssl->handshake->fin_sha1 );
#endif
#if defined(MBEDTLS_SSL_PROTO_TLS1_2)
#if defined(MBEDTLS_SHA256_C)
mbedtls_sha256_starts_ret( &ssl->handshake->fin_sha256, 0 );
#endif
#if defined(MBEDTLS_SHA512_C)
mbedtls_sha512_starts_ret( &ssl->handshake->fin_sha512, 1 );
#endif
#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
}
static void ssl_update_checksum_start( mbedtls_ssl_context *ssl,
const unsigned char *buf, size_t len )
{
#if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1) || \
defined(MBEDTLS_SSL_PROTO_TLS1_1)
mbedtls_md5_update_ret( &ssl->handshake->fin_md5 , buf, len );
mbedtls_sha1_update_ret( &ssl->handshake->fin_sha1, buf, len );
#endif
#if defined(MBEDTLS_SSL_PROTO_TLS1_2)
#if defined(MBEDTLS_SHA256_C)
mbedtls_sha256_update_ret( &ssl->handshake->fin_sha256, buf, len );
#endif
#if defined(MBEDTLS_SHA512_C)
mbedtls_sha512_update_ret( &ssl->handshake->fin_sha512, buf, len );
#endif
#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
}
#if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1) || \
defined(MBEDTLS_SSL_PROTO_TLS1_1)
static void ssl_update_checksum_md5sha1( mbedtls_ssl_context *ssl,
const unsigned char *buf, size_t len )
{
mbedtls_md5_update_ret( &ssl->handshake->fin_md5 , buf, len );
mbedtls_sha1_update_ret( &ssl->handshake->fin_sha1, buf, len );
}
#endif
#if defined(MBEDTLS_SSL_PROTO_TLS1_2)
#if defined(MBEDTLS_SHA256_C)
static void ssl_update_checksum_sha256( mbedtls_ssl_context *ssl,
const unsigned char *buf, size_t len )
{
mbedtls_sha256_update_ret( &ssl->handshake->fin_sha256, buf, len );
}
#endif
#if defined(MBEDTLS_SHA512_C)
static void ssl_update_checksum_sha384( mbedtls_ssl_context *ssl,
const unsigned char *buf, size_t len )
{
mbedtls_sha512_update_ret( &ssl->handshake->fin_sha512, buf, len );
}
#endif
#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
#if defined(MBEDTLS_SSL_PROTO_SSL3)
static void ssl_calc_finished_ssl(
mbedtls_ssl_context *ssl, unsigned char *buf, int from )
{
const char *sender;
mbedtls_md5_context md5;
mbedtls_sha1_context sha1;
unsigned char padbuf[48];
unsigned char md5sum[16];
unsigned char sha1sum[20];
mbedtls_ssl_session *session = ssl->session_negotiate;
if( !session )
session = ssl->session;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> calc finished ssl" ) );
mbedtls_md5_init( &md5 );
mbedtls_sha1_init( &sha1 );
mbedtls_md5_clone( &md5, &ssl->handshake->fin_md5 );
mbedtls_sha1_clone( &sha1, &ssl->handshake->fin_sha1 );
/*
* SSLv3:
* hash =
* MD5( master + pad2 +
* MD5( handshake + sender + master + pad1 ) )
* + SHA1( master + pad2 +
* SHA1( handshake + sender + master + pad1 ) )
*/
#if !defined(MBEDTLS_MD5_ALT)
MBEDTLS_SSL_DEBUG_BUF( 4, "finished md5 state", (unsigned char *)
md5.state, sizeof( md5.state ) );
#endif
#if !defined(MBEDTLS_SHA1_ALT)
MBEDTLS_SSL_DEBUG_BUF( 4, "finished sha1 state", (unsigned char *)
sha1.state, sizeof( sha1.state ) );
#endif
sender = ( from == MBEDTLS_SSL_IS_CLIENT ) ? "CLNT"
: "SRVR";
memset( padbuf, 0x36, 48 );
mbedtls_md5_update_ret( &md5, (const unsigned char *) sender, 4 );
mbedtls_md5_update_ret( &md5, session->master, 48 );
mbedtls_md5_update_ret( &md5, padbuf, 48 );
mbedtls_md5_finish_ret( &md5, md5sum );
mbedtls_sha1_update_ret( &sha1, (const unsigned char *) sender, 4 );
mbedtls_sha1_update_ret( &sha1, session->master, 48 );
mbedtls_sha1_update_ret( &sha1, padbuf, 40 );
mbedtls_sha1_finish_ret( &sha1, sha1sum );
memset( padbuf, 0x5C, 48 );
mbedtls_md5_starts_ret( &md5 );
mbedtls_md5_update_ret( &md5, session->master, 48 );
mbedtls_md5_update_ret( &md5, padbuf, 48 );
mbedtls_md5_update_ret( &md5, md5sum, 16 );
mbedtls_md5_finish_ret( &md5, buf );
mbedtls_sha1_starts_ret( &sha1 );
mbedtls_sha1_update_ret( &sha1, session->master, 48 );
mbedtls_sha1_update_ret( &sha1, padbuf , 40 );
mbedtls_sha1_update_ret( &sha1, sha1sum, 20 );
mbedtls_sha1_finish_ret( &sha1, buf + 16 );
MBEDTLS_SSL_DEBUG_BUF( 3, "calc finished result", buf, 36 );
mbedtls_md5_free( &md5 );
mbedtls_sha1_free( &sha1 );
mbedtls_platform_zeroize( padbuf, sizeof( padbuf ) );
mbedtls_platform_zeroize( md5sum, sizeof( md5sum ) );
mbedtls_platform_zeroize( sha1sum, sizeof( sha1sum ) );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= calc finished" ) );
}
#endif /* MBEDTLS_SSL_PROTO_SSL3 */
#if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1)
static void ssl_calc_finished_tls(
mbedtls_ssl_context *ssl, unsigned char *buf, int from )
{
int len = 12;
const char *sender;
mbedtls_md5_context md5;
mbedtls_sha1_context sha1;
unsigned char padbuf[36];
mbedtls_ssl_session *session = ssl->session_negotiate;
if( !session )
session = ssl->session;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> calc finished tls" ) );
mbedtls_md5_init( &md5 );
mbedtls_sha1_init( &sha1 );
mbedtls_md5_clone( &md5, &ssl->handshake->fin_md5 );
mbedtls_sha1_clone( &sha1, &ssl->handshake->fin_sha1 );
/*
* TLSv1:
* hash = PRF( master, finished_label,
* MD5( handshake ) + SHA1( handshake ) )[0..11]
*/
#if !defined(MBEDTLS_MD5_ALT)
MBEDTLS_SSL_DEBUG_BUF( 4, "finished md5 state", (unsigned char *)
md5.state, sizeof( md5.state ) );
#endif
#if !defined(MBEDTLS_SHA1_ALT)
MBEDTLS_SSL_DEBUG_BUF( 4, "finished sha1 state", (unsigned char *)
sha1.state, sizeof( sha1.state ) );
#endif
sender = ( from == MBEDTLS_SSL_IS_CLIENT )
? "client finished"
: "server finished";
mbedtls_md5_finish_ret( &md5, padbuf );
mbedtls_sha1_finish_ret( &sha1, padbuf + 16 );
ssl->handshake->tls_prf( session->master, 48, sender,
padbuf, 36, buf, len );
MBEDTLS_SSL_DEBUG_BUF( 3, "calc finished result", buf, len );
mbedtls_md5_free( &md5 );
mbedtls_sha1_free( &sha1 );
mbedtls_platform_zeroize( padbuf, sizeof( padbuf ) );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= calc finished" ) );
}
#endif /* MBEDTLS_SSL_PROTO_TLS1 || MBEDTLS_SSL_PROTO_TLS1_1 */
#if defined(MBEDTLS_SSL_PROTO_TLS1_2)
#if defined(MBEDTLS_SHA256_C)
static void ssl_calc_finished_tls_sha256(
mbedtls_ssl_context *ssl, unsigned char *buf, int from )
{
int len = 12;
const char *sender;
mbedtls_sha256_context sha256;
unsigned char padbuf[32];
mbedtls_ssl_session *session = ssl->session_negotiate;
if( !session )
session = ssl->session;
mbedtls_sha256_init( &sha256 );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> calc finished tls sha256" ) );
mbedtls_sha256_clone( &sha256, &ssl->handshake->fin_sha256 );
/*
* TLSv1.2:
* hash = PRF( master, finished_label,
* Hash( handshake ) )[0.11]
*/
#if !defined(MBEDTLS_SHA256_ALT)
MBEDTLS_SSL_DEBUG_BUF( 4, "finished sha2 state", (unsigned char *)
sha256.state, sizeof( sha256.state ) );
#endif
sender = ( from == MBEDTLS_SSL_IS_CLIENT )
? "client finished"
: "server finished";
mbedtls_sha256_finish_ret( &sha256, padbuf );
ssl->handshake->tls_prf( session->master, 48, sender,
padbuf, 32, buf, len );
MBEDTLS_SSL_DEBUG_BUF( 3, "calc finished result", buf, len );
mbedtls_sha256_free( &sha256 );
mbedtls_platform_zeroize( padbuf, sizeof( padbuf ) );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= calc finished" ) );
}
#endif /* MBEDTLS_SHA256_C */
#if defined(MBEDTLS_SHA512_C)
static void ssl_calc_finished_tls_sha384(
mbedtls_ssl_context *ssl, unsigned char *buf, int from )
{
int len = 12;
const char *sender;
mbedtls_sha512_context sha512;
unsigned char padbuf[48];
mbedtls_ssl_session *session = ssl->session_negotiate;
if( !session )
session = ssl->session;
mbedtls_sha512_init( &sha512 );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> calc finished tls sha384" ) );
mbedtls_sha512_clone( &sha512, &ssl->handshake->fin_sha512 );
/*
* TLSv1.2:
* hash = PRF( master, finished_label,
* Hash( handshake ) )[0.11]
*/
#if !defined(MBEDTLS_SHA512_ALT)
MBEDTLS_SSL_DEBUG_BUF( 4, "finished sha512 state", (unsigned char *)
sha512.state, sizeof( sha512.state ) );
#endif
sender = ( from == MBEDTLS_SSL_IS_CLIENT )
? "client finished"
: "server finished";
mbedtls_sha512_finish_ret( &sha512, padbuf );
ssl->handshake->tls_prf( session->master, 48, sender,
padbuf, 48, buf, len );
MBEDTLS_SSL_DEBUG_BUF( 3, "calc finished result", buf, len );
mbedtls_sha512_free( &sha512 );
mbedtls_platform_zeroize( padbuf, sizeof( padbuf ) );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= calc finished" ) );
}
#endif /* MBEDTLS_SHA512_C */
#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
static void ssl_handshake_wrapup_free_hs_transform( mbedtls_ssl_context *ssl )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "=> handshake wrapup: final free" ) );
/*
* Free our handshake params
*/
mbedtls_ssl_handshake_free( ssl );
mbedtls_free( ssl->handshake );
ssl->handshake = NULL;
/*
* Free the previous transform and swith in the current one
*/
if( ssl->transform )
{
mbedtls_ssl_transform_free( ssl->transform );
mbedtls_free( ssl->transform );
}
ssl->transform = ssl->transform_negotiate;
ssl->transform_negotiate = NULL;
MBEDTLS_SSL_DEBUG_MSG( 3, ( "<= handshake wrapup: final free" ) );
}
void mbedtls_ssl_handshake_wrapup( mbedtls_ssl_context *ssl )
{
int resume = ssl->handshake->resume;
MBEDTLS_SSL_DEBUG_MSG( 3, ( "=> handshake wrapup" ) );
#if defined(MBEDTLS_SSL_RENEGOTIATION)
if( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS )
{
ssl->renego_status = MBEDTLS_SSL_RENEGOTIATION_DONE;
ssl->renego_records_seen = 0;
}
#endif
/*
* Free the previous session and switch in the current one
*/
if( ssl->session )
{
#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
/* RFC 7366 3.1: keep the EtM state */
ssl->session_negotiate->encrypt_then_mac =
ssl->session->encrypt_then_mac;
#endif
mbedtls_ssl_session_free( ssl->session );
mbedtls_free( ssl->session );
}
ssl->session = ssl->session_negotiate;
ssl->session_negotiate = NULL;
/*
* Add cache entry
*/
if( ssl->conf->f_set_cache != NULL &&
ssl->session->id_len != 0 &&
resume == 0 )
{
if( ssl->conf->f_set_cache( ssl->conf->p_cache, ssl->session ) != 0 )
MBEDTLS_SSL_DEBUG_MSG( 1, ( "cache did not store session" ) );
}
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
ssl->handshake->flight != NULL )
{
/* Cancel handshake timer */
ssl_set_timer( ssl, 0 );
/* Keep last flight around in case we need to resend it:
* we need the handshake and transform structures for that */
MBEDTLS_SSL_DEBUG_MSG( 3, ( "skip freeing handshake and transform" ) );
}
else
#endif
ssl_handshake_wrapup_free_hs_transform( ssl );
ssl->state++;
MBEDTLS_SSL_DEBUG_MSG( 3, ( "<= handshake wrapup" ) );
}
int mbedtls_ssl_write_finished( mbedtls_ssl_context *ssl )
{
int ret, hash_len;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write finished" ) );
ssl_update_out_pointers( ssl, ssl->transform_negotiate );
ssl->handshake->calc_finished( ssl, ssl->out_msg + 4, ssl->conf->endpoint );
/*
* RFC 5246 7.4.9 (Page 63) says 12 is the default length and ciphersuites
* may define some other value. Currently (early 2016), no defined
* ciphersuite does this (and this is unlikely to change as activity has
* moved to TLS 1.3 now) so we can keep the hardcoded 12 here.
*/
hash_len = ( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 ) ? 36 : 12;
#if defined(MBEDTLS_SSL_RENEGOTIATION)
ssl->verify_data_len = hash_len;
memcpy( ssl->own_verify_data, ssl->out_msg + 4, hash_len );
#endif
ssl->out_msglen = 4 + hash_len;
ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE;
ssl->out_msg[0] = MBEDTLS_SSL_HS_FINISHED;
/*
* In case of session resuming, invert the client and server
* ChangeCipherSpec messages order.
*/
if( ssl->handshake->resume != 0 )
{
#if defined(MBEDTLS_SSL_CLI_C)
if( ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT )
ssl->state = MBEDTLS_SSL_HANDSHAKE_WRAPUP;
#endif
#if defined(MBEDTLS_SSL_SRV_C)
if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER )
ssl->state = MBEDTLS_SSL_CLIENT_CHANGE_CIPHER_SPEC;
#endif
}
else
ssl->state++;
/*
* Switch to our negotiated transform and session parameters for outbound
* data.
*/
MBEDTLS_SSL_DEBUG_MSG( 3, ( "switching to new transform spec for outbound data" ) );
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
{
unsigned char i;
/* Remember current epoch settings for resending */
ssl->handshake->alt_transform_out = ssl->transform_out;
memcpy( ssl->handshake->alt_out_ctr, ssl->cur_out_ctr, 8 );
/* Set sequence_number to zero */
memset( ssl->cur_out_ctr + 2, 0, 6 );
/* Increment epoch */
for( i = 2; i > 0; i-- )
if( ++ssl->cur_out_ctr[i - 1] != 0 )
break;
/* The loop goes to its end iff the counter is wrapping */
if( i == 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "DTLS epoch would wrap" ) );
return( MBEDTLS_ERR_SSL_COUNTER_WRAPPING );
}
}
else
#endif /* MBEDTLS_SSL_PROTO_DTLS */
memset( ssl->cur_out_ctr, 0, 8 );
ssl->transform_out = ssl->transform_negotiate;
ssl->session_out = ssl->session_negotiate;
#if defined(MBEDTLS_SSL_HW_RECORD_ACCEL)
if( mbedtls_ssl_hw_record_activate != NULL )
{
if( ( ret = mbedtls_ssl_hw_record_activate( ssl, MBEDTLS_SSL_CHANNEL_OUTBOUND ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_hw_record_activate", ret );
return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
}
}
#endif
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
mbedtls_ssl_send_flight_completed( ssl );
#endif
if( ( ret = mbedtls_ssl_write_handshake_msg( ssl ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_handshake_msg", ret );
return( ret );
}
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
( ret = mbedtls_ssl_flight_transmit( ssl ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_flight_transmit", ret );
return( ret );
}
#endif
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write finished" ) );
return( 0 );
}
#if defined(MBEDTLS_SSL_PROTO_SSL3)
#define SSL_MAX_HASH_LEN 36
#else
#define SSL_MAX_HASH_LEN 12
#endif
int mbedtls_ssl_parse_finished( mbedtls_ssl_context *ssl )
{
int ret;
unsigned int hash_len;
unsigned char buf[SSL_MAX_HASH_LEN];
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse finished" ) );
ssl->handshake->calc_finished( ssl, buf, ssl->conf->endpoint ^ 1 );
if( ( ret = mbedtls_ssl_read_record( ssl, 1 ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret );
return( ret );
}
if( ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad finished message" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE );
return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
}
/* There is currently no ciphersuite using another length with TLS 1.2 */
#if defined(MBEDTLS_SSL_PROTO_SSL3)
if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 )
hash_len = 36;
else
#endif
hash_len = 12;
if( ssl->in_msg[0] != MBEDTLS_SSL_HS_FINISHED ||
ssl->in_hslen != mbedtls_ssl_hs_hdr_len( ssl ) + hash_len )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad finished message" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_FINISHED );
}
if( mbedtls_ssl_safer_memcmp( ssl->in_msg + mbedtls_ssl_hs_hdr_len( ssl ),
buf, hash_len ) != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad finished message" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_FINISHED );
}
#if defined(MBEDTLS_SSL_RENEGOTIATION)
ssl->verify_data_len = hash_len;
memcpy( ssl->peer_verify_data, buf, hash_len );
#endif
if( ssl->handshake->resume != 0 )
{
#if defined(MBEDTLS_SSL_CLI_C)
if( ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT )
ssl->state = MBEDTLS_SSL_CLIENT_CHANGE_CIPHER_SPEC;
#endif
#if defined(MBEDTLS_SSL_SRV_C)
if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER )
ssl->state = MBEDTLS_SSL_HANDSHAKE_WRAPUP;
#endif
}
else
ssl->state++;
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
mbedtls_ssl_recv_flight_completed( ssl );
#endif
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse finished" ) );
return( 0 );
}
static void ssl_handshake_params_init( mbedtls_ssl_handshake_params *handshake )
{
memset( handshake, 0, sizeof( mbedtls_ssl_handshake_params ) );
#if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1) || \
defined(MBEDTLS_SSL_PROTO_TLS1_1)
mbedtls_md5_init( &handshake->fin_md5 );
mbedtls_sha1_init( &handshake->fin_sha1 );
mbedtls_md5_starts_ret( &handshake->fin_md5 );
mbedtls_sha1_starts_ret( &handshake->fin_sha1 );
#endif
#if defined(MBEDTLS_SSL_PROTO_TLS1_2)
#if defined(MBEDTLS_SHA256_C)
mbedtls_sha256_init( &handshake->fin_sha256 );
mbedtls_sha256_starts_ret( &handshake->fin_sha256, 0 );
#endif
#if defined(MBEDTLS_SHA512_C)
mbedtls_sha512_init( &handshake->fin_sha512 );
mbedtls_sha512_starts_ret( &handshake->fin_sha512, 1 );
#endif
#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
handshake->update_checksum = ssl_update_checksum_start;
#if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \
defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)
mbedtls_ssl_sig_hash_set_init( &handshake->hash_algs );
#endif
#if defined(MBEDTLS_DHM_C)
mbedtls_dhm_init( &handshake->dhm_ctx );
#endif
#if defined(MBEDTLS_ECDH_C)
mbedtls_ecdh_init( &handshake->ecdh_ctx );
#endif
#if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
mbedtls_ecjpake_init( &handshake->ecjpake_ctx );
#if defined(MBEDTLS_SSL_CLI_C)
handshake->ecjpake_cache = NULL;
handshake->ecjpake_cache_len = 0;
#endif
#endif
#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
mbedtls_x509_crt_restart_init( &handshake->ecrs_ctx );
#endif
#if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
handshake->sni_authmode = MBEDTLS_SSL_VERIFY_UNSET;
#endif
}
void mbedtls_ssl_transform_init( mbedtls_ssl_transform *transform )
{
memset( transform, 0, sizeof(mbedtls_ssl_transform) );
mbedtls_cipher_init( &transform->cipher_ctx_enc );
mbedtls_cipher_init( &transform->cipher_ctx_dec );
#if defined(MBEDTLS_SSL_SOME_MODES_USE_MAC)
mbedtls_md_init( &transform->md_ctx_enc );
mbedtls_md_init( &transform->md_ctx_dec );
#endif
}
void mbedtls_ssl_session_init( mbedtls_ssl_session *session )
{
memset( session, 0, sizeof(mbedtls_ssl_session) );
}
static int ssl_handshake_init( mbedtls_ssl_context *ssl )
{
/* Clear old handshake information if present */
if( ssl->transform_negotiate )
mbedtls_ssl_transform_free( ssl->transform_negotiate );
if( ssl->session_negotiate )
mbedtls_ssl_session_free( ssl->session_negotiate );
if( ssl->handshake )
mbedtls_ssl_handshake_free( ssl );
/*
* Either the pointers are now NULL or cleared properly and can be freed.
* Now allocate missing structures.
*/
if( ssl->transform_negotiate == NULL )
{
ssl->transform_negotiate = mbedtls_calloc( 1, sizeof(mbedtls_ssl_transform) );
}
if( ssl->session_negotiate == NULL )
{
ssl->session_negotiate = mbedtls_calloc( 1, sizeof(mbedtls_ssl_session) );
}
if( ssl->handshake == NULL )
{
ssl->handshake = mbedtls_calloc( 1, sizeof(mbedtls_ssl_handshake_params) );
}
/* All pointers should exist and can be directly freed without issue */
if( ssl->handshake == NULL ||
ssl->transform_negotiate == NULL ||
ssl->session_negotiate == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "alloc() of ssl sub-contexts failed" ) );
mbedtls_free( ssl->handshake );
mbedtls_free( ssl->transform_negotiate );
mbedtls_free( ssl->session_negotiate );
ssl->handshake = NULL;
ssl->transform_negotiate = NULL;
ssl->session_negotiate = NULL;
return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
}
/* Initialize structures */
mbedtls_ssl_session_init( ssl->session_negotiate );
mbedtls_ssl_transform_init( ssl->transform_negotiate );
ssl_handshake_params_init( ssl->handshake );
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
{
ssl->handshake->alt_transform_out = ssl->transform_out;
if( ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT )
ssl->handshake->retransmit_state = MBEDTLS_SSL_RETRANS_PREPARING;
else
ssl->handshake->retransmit_state = MBEDTLS_SSL_RETRANS_WAITING;
ssl_set_timer( ssl, 0 );
}
#endif
return( 0 );
}
#if defined(MBEDTLS_SSL_DTLS_HELLO_VERIFY) && defined(MBEDTLS_SSL_SRV_C)
/* Dummy cookie callbacks for defaults */
static int ssl_cookie_write_dummy( void *ctx,
unsigned char **p, unsigned char *end,
const unsigned char *cli_id, size_t cli_id_len )
{
((void) ctx);
((void) p);
((void) end);
((void) cli_id);
((void) cli_id_len);
return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE );
}
static int ssl_cookie_check_dummy( void *ctx,
const unsigned char *cookie, size_t cookie_len,
const unsigned char *cli_id, size_t cli_id_len )
{
((void) ctx);
((void) cookie);
((void) cookie_len);
((void) cli_id);
((void) cli_id_len);
return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE );
}
#endif /* MBEDTLS_SSL_DTLS_HELLO_VERIFY && MBEDTLS_SSL_SRV_C */
/* Once ssl->out_hdr as the address of the beginning of the
* next outgoing record is set, deduce the other pointers.
*
* Note: For TLS, we save the implicit record sequence number
* (entering MAC computation) in the 8 bytes before ssl->out_hdr,
* and the caller has to make sure there's space for this.
*/
static void ssl_update_out_pointers( mbedtls_ssl_context *ssl,
mbedtls_ssl_transform *transform )
{
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
{
ssl->out_ctr = ssl->out_hdr + 3;
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
ssl->out_cid = ssl->out_ctr + 8;
ssl->out_len = ssl->out_cid;
if( transform != NULL )
ssl->out_len += transform->out_cid_len;
#else /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
ssl->out_len = ssl->out_ctr + 8;
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
ssl->out_iv = ssl->out_len + 2;
}
else
#endif
{
ssl->out_ctr = ssl->out_hdr - 8;
ssl->out_len = ssl->out_hdr + 3;
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
ssl->out_cid = ssl->out_len;
#endif
ssl->out_iv = ssl->out_hdr + 5;
}
/* Adjust out_msg to make space for explicit IV, if used. */
if( transform != NULL &&
ssl->minor_ver >= MBEDTLS_SSL_MINOR_VERSION_2 )
{
ssl->out_msg = ssl->out_iv + transform->ivlen - transform->fixed_ivlen;
}
else
ssl->out_msg = ssl->out_iv;
}
/* Once ssl->in_hdr as the address of the beginning of the
* next incoming record is set, deduce the other pointers.
*
* Note: For TLS, we save the implicit record sequence number
* (entering MAC computation) in the 8 bytes before ssl->in_hdr,
* and the caller has to make sure there's space for this.
*/
static void ssl_update_in_pointers( mbedtls_ssl_context *ssl )
{
/* This function sets the pointers to match the case
* of unprotected TLS/DTLS records, with both ssl->in_iv
* and ssl->in_msg pointing to the beginning of the record
* content.
*
* When decrypting a protected record, ssl->in_msg
* will be shifted to point to the beginning of the
* record plaintext.
*/
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
{
/* This sets the header pointers to match records
* without CID. When we receive a record containing
* a CID, the fields are shifted accordingly in
* ssl_parse_record_header(). */
ssl->in_ctr = ssl->in_hdr + 3;
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
ssl->in_cid = ssl->in_ctr + 8;
ssl->in_len = ssl->in_cid; /* Default: no CID */
#else /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
ssl->in_len = ssl->in_ctr + 8;
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
ssl->in_iv = ssl->in_len + 2;
}
else
#endif
{
ssl->in_ctr = ssl->in_hdr - 8;
ssl->in_len = ssl->in_hdr + 3;
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
ssl->in_cid = ssl->in_len;
#endif
ssl->in_iv = ssl->in_hdr + 5;
}
/* This will be adjusted at record decryption time. */
ssl->in_msg = ssl->in_iv;
}
/*
* Initialize an SSL context
*/
void mbedtls_ssl_init( mbedtls_ssl_context *ssl )
{
memset( ssl, 0, sizeof( mbedtls_ssl_context ) );
}
/*
* Setup an SSL context
*/
static void ssl_reset_in_out_pointers( mbedtls_ssl_context *ssl )
{
/* Set the incoming and outgoing record pointers. */
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
{
ssl->out_hdr = ssl->out_buf;
ssl->in_hdr = ssl->in_buf;
}
else
#endif /* MBEDTLS_SSL_PROTO_DTLS */
{
ssl->out_hdr = ssl->out_buf + 8;
ssl->in_hdr = ssl->in_buf + 8;
}
/* Derive other internal pointers. */
ssl_update_out_pointers( ssl, NULL /* no transform enabled */ );
ssl_update_in_pointers ( ssl );
}
int mbedtls_ssl_setup( mbedtls_ssl_context *ssl,
const mbedtls_ssl_config *conf )
{
int ret;
ssl->conf = conf;
/*
* Prepare base structures
*/
/* Set to NULL in case of an error condition */
ssl->out_buf = NULL;
ssl->in_buf = mbedtls_calloc( 1, MBEDTLS_SSL_IN_BUFFER_LEN );
if( ssl->in_buf == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "alloc(%d bytes) failed", MBEDTLS_SSL_IN_BUFFER_LEN) );
ret = MBEDTLS_ERR_SSL_ALLOC_FAILED;
goto error;
}
ssl->out_buf = mbedtls_calloc( 1, MBEDTLS_SSL_OUT_BUFFER_LEN );
if( ssl->out_buf == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "alloc(%d bytes) failed", MBEDTLS_SSL_OUT_BUFFER_LEN) );
ret = MBEDTLS_ERR_SSL_ALLOC_FAILED;
goto error;
}
ssl_reset_in_out_pointers( ssl );
if( ( ret = ssl_handshake_init( ssl ) ) != 0 )
goto error;
return( 0 );
error:
mbedtls_free( ssl->in_buf );
mbedtls_free( ssl->out_buf );
ssl->conf = NULL;
ssl->in_buf = NULL;
ssl->out_buf = NULL;
ssl->in_hdr = NULL;
ssl->in_ctr = NULL;
ssl->in_len = NULL;
ssl->in_iv = NULL;
ssl->in_msg = NULL;
ssl->out_hdr = NULL;
ssl->out_ctr = NULL;
ssl->out_len = NULL;
ssl->out_iv = NULL;
ssl->out_msg = NULL;
return( ret );
}
/*
* Reset an initialized and used SSL context for re-use while retaining
* all application-set variables, function pointers and data.
*
* If partial is non-zero, keep data in the input buffer and client ID.
* (Use when a DTLS client reconnects from the same port.)
*/
static int ssl_session_reset_int( mbedtls_ssl_context *ssl, int partial )
{
int ret;
#if !defined(MBEDTLS_SSL_DTLS_CLIENT_PORT_REUSE) || \
!defined(MBEDTLS_SSL_SRV_C)
((void) partial);
#endif
ssl->state = MBEDTLS_SSL_HELLO_REQUEST;
/* Cancel any possibly running timer */
ssl_set_timer( ssl, 0 );
#if defined(MBEDTLS_SSL_RENEGOTIATION)
ssl->renego_status = MBEDTLS_SSL_INITIAL_HANDSHAKE;
ssl->renego_records_seen = 0;
ssl->verify_data_len = 0;
memset( ssl->own_verify_data, 0, MBEDTLS_SSL_VERIFY_DATA_MAX_LEN );
memset( ssl->peer_verify_data, 0, MBEDTLS_SSL_VERIFY_DATA_MAX_LEN );
#endif
ssl->secure_renegotiation = MBEDTLS_SSL_LEGACY_RENEGOTIATION;
ssl->in_offt = NULL;
ssl_reset_in_out_pointers( ssl );
ssl->in_msgtype = 0;
ssl->in_msglen = 0;
#if defined(MBEDTLS_SSL_PROTO_DTLS)
ssl->next_record_offset = 0;
ssl->in_epoch = 0;
#endif
#if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY)
ssl_dtls_replay_reset( ssl );
#endif
ssl->in_hslen = 0;
ssl->nb_zero = 0;
ssl->keep_current_message = 0;
ssl->out_msgtype = 0;
ssl->out_msglen = 0;
ssl->out_left = 0;
#if defined(MBEDTLS_SSL_CBC_RECORD_SPLITTING)
if( ssl->split_done != MBEDTLS_SSL_CBC_RECORD_SPLITTING_DISABLED )
ssl->split_done = 0;
#endif
memset( ssl->cur_out_ctr, 0, sizeof( ssl->cur_out_ctr ) );
ssl->transform_in = NULL;
ssl->transform_out = NULL;
ssl->session_in = NULL;
ssl->session_out = NULL;
memset( ssl->out_buf, 0, MBEDTLS_SSL_OUT_BUFFER_LEN );
#if defined(MBEDTLS_SSL_DTLS_CLIENT_PORT_REUSE) && defined(MBEDTLS_SSL_SRV_C)
if( partial == 0 )
#endif /* MBEDTLS_SSL_DTLS_CLIENT_PORT_REUSE && MBEDTLS_SSL_SRV_C */
{
ssl->in_left = 0;
memset( ssl->in_buf, 0, MBEDTLS_SSL_IN_BUFFER_LEN );
}
#if defined(MBEDTLS_SSL_HW_RECORD_ACCEL)
if( mbedtls_ssl_hw_record_reset != NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "going for mbedtls_ssl_hw_record_reset()" ) );
if( ( ret = mbedtls_ssl_hw_record_reset( ssl ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_hw_record_reset", ret );
return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
}
}
#endif
if( ssl->transform )
{
mbedtls_ssl_transform_free( ssl->transform );
mbedtls_free( ssl->transform );
ssl->transform = NULL;
}
if( ssl->session )
{
mbedtls_ssl_session_free( ssl->session );
mbedtls_free( ssl->session );
ssl->session = NULL;
}
#if defined(MBEDTLS_SSL_ALPN)
ssl->alpn_chosen = NULL;
#endif
#if defined(MBEDTLS_SSL_DTLS_HELLO_VERIFY) && defined(MBEDTLS_SSL_SRV_C)
#if defined(MBEDTLS_SSL_DTLS_CLIENT_PORT_REUSE)
if( partial == 0 )
#endif
{
mbedtls_free( ssl->cli_id );
ssl->cli_id = NULL;
ssl->cli_id_len = 0;
}
#endif
if( ( ret = ssl_handshake_init( ssl ) ) != 0 )
return( ret );
return( 0 );
}
/*
* Reset an initialized and used SSL context for re-use while retaining
* all application-set variables, function pointers and data.
*/
int mbedtls_ssl_session_reset( mbedtls_ssl_context *ssl )
{
return( ssl_session_reset_int( ssl, 0 ) );
}
/*
* SSL set accessors
*/
void mbedtls_ssl_conf_endpoint( mbedtls_ssl_config *conf, int endpoint )
{
conf->endpoint = endpoint;
}
void mbedtls_ssl_conf_transport( mbedtls_ssl_config *conf, int transport )
{
conf->transport = transport;
}
#if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY)
void mbedtls_ssl_conf_dtls_anti_replay( mbedtls_ssl_config *conf, char mode )
{
conf->anti_replay = mode;
}
#endif
#if defined(MBEDTLS_SSL_DTLS_BADMAC_LIMIT)
void mbedtls_ssl_conf_dtls_badmac_limit( mbedtls_ssl_config *conf, unsigned limit )
{
conf->badmac_limit = limit;
}
#endif
#if defined(MBEDTLS_SSL_PROTO_DTLS)
void mbedtls_ssl_set_datagram_packing( mbedtls_ssl_context *ssl,
unsigned allow_packing )
{
ssl->disable_datagram_packing = !allow_packing;
}
void mbedtls_ssl_conf_handshake_timeout( mbedtls_ssl_config *conf,
uint32_t min, uint32_t max )
{
conf->hs_timeout_min = min;
conf->hs_timeout_max = max;
}
#endif
void mbedtls_ssl_conf_authmode( mbedtls_ssl_config *conf, int authmode )
{
conf->authmode = authmode;
}
#if defined(MBEDTLS_X509_CRT_PARSE_C)
void mbedtls_ssl_conf_verify( mbedtls_ssl_config *conf,
int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
void *p_vrfy )
{
conf->f_vrfy = f_vrfy;
conf->p_vrfy = p_vrfy;
}
#endif /* MBEDTLS_X509_CRT_PARSE_C */
void mbedtls_ssl_conf_rng( mbedtls_ssl_config *conf,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng )
{
conf->f_rng = f_rng;
conf->p_rng = p_rng;
}
void mbedtls_ssl_conf_dbg( mbedtls_ssl_config *conf,
void (*f_dbg)(void *, int, const char *, int, const char *),
void *p_dbg )
{
conf->f_dbg = f_dbg;
conf->p_dbg = p_dbg;
}
void mbedtls_ssl_set_bio( mbedtls_ssl_context *ssl,
void *p_bio,
mbedtls_ssl_send_t *f_send,
mbedtls_ssl_recv_t *f_recv,
mbedtls_ssl_recv_timeout_t *f_recv_timeout )
{
ssl->p_bio = p_bio;
ssl->f_send = f_send;
ssl->f_recv = f_recv;
ssl->f_recv_timeout = f_recv_timeout;
}
#if defined(MBEDTLS_SSL_PROTO_DTLS)
void mbedtls_ssl_set_mtu( mbedtls_ssl_context *ssl, uint16_t mtu )
{
ssl->mtu = mtu;
}
#endif
void mbedtls_ssl_conf_read_timeout( mbedtls_ssl_config *conf, uint32_t timeout )
{
conf->read_timeout = timeout;
}
void mbedtls_ssl_set_timer_cb( mbedtls_ssl_context *ssl,
void *p_timer,
mbedtls_ssl_set_timer_t *f_set_timer,
mbedtls_ssl_get_timer_t *f_get_timer )
{
ssl->p_timer = p_timer;
ssl->f_set_timer = f_set_timer;
ssl->f_get_timer = f_get_timer;
/* Make sure we start with no timer running */
ssl_set_timer( ssl, 0 );
}
#if defined(MBEDTLS_SSL_SRV_C)
void mbedtls_ssl_conf_session_cache( mbedtls_ssl_config *conf,
void *p_cache,
int (*f_get_cache)(void *, mbedtls_ssl_session *),
int (*f_set_cache)(void *, const mbedtls_ssl_session *) )
{
conf->p_cache = p_cache;
conf->f_get_cache = f_get_cache;
conf->f_set_cache = f_set_cache;
}
#endif /* MBEDTLS_SSL_SRV_C */
#if defined(MBEDTLS_SSL_CLI_C)
int mbedtls_ssl_set_session( mbedtls_ssl_context *ssl, const mbedtls_ssl_session *session )
{
int ret;
if( ssl == NULL ||
session == NULL ||
ssl->session_negotiate == NULL ||
ssl->conf->endpoint != MBEDTLS_SSL_IS_CLIENT )
{
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
}
if( ( ret = ssl_session_copy( ssl->session_negotiate, session ) ) != 0 )
return( ret );
ssl->handshake->resume = 1;
return( 0 );
}
#endif /* MBEDTLS_SSL_CLI_C */
void mbedtls_ssl_conf_ciphersuites( mbedtls_ssl_config *conf,
const int *ciphersuites )
{
conf->ciphersuite_list[MBEDTLS_SSL_MINOR_VERSION_0] = ciphersuites;
conf->ciphersuite_list[MBEDTLS_SSL_MINOR_VERSION_1] = ciphersuites;
conf->ciphersuite_list[MBEDTLS_SSL_MINOR_VERSION_2] = ciphersuites;
conf->ciphersuite_list[MBEDTLS_SSL_MINOR_VERSION_3] = ciphersuites;
}
void mbedtls_ssl_conf_ciphersuites_for_version( mbedtls_ssl_config *conf,
const int *ciphersuites,
int major, int minor )
{
if( major != MBEDTLS_SSL_MAJOR_VERSION_3 )
return;
if( minor < MBEDTLS_SSL_MINOR_VERSION_0 || minor > MBEDTLS_SSL_MINOR_VERSION_3 )
return;
conf->ciphersuite_list[minor] = ciphersuites;
}
#if defined(MBEDTLS_X509_CRT_PARSE_C)
void mbedtls_ssl_conf_cert_profile( mbedtls_ssl_config *conf,
const mbedtls_x509_crt_profile *profile )
{
conf->cert_profile = profile;
}
/* Append a new keycert entry to a (possibly empty) list */
static int ssl_append_key_cert( mbedtls_ssl_key_cert **head,
mbedtls_x509_crt *cert,
mbedtls_pk_context *key )
{
mbedtls_ssl_key_cert *new_cert;
new_cert = mbedtls_calloc( 1, sizeof( mbedtls_ssl_key_cert ) );
if( new_cert == NULL )
return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
new_cert->cert = cert;
new_cert->key = key;
new_cert->next = NULL;
/* Update head is the list was null, else add to the end */
if( *head == NULL )
{
*head = new_cert;
}
else
{
mbedtls_ssl_key_cert *cur = *head;
while( cur->next != NULL )
cur = cur->next;
cur->next = new_cert;
}
return( 0 );
}
int mbedtls_ssl_conf_own_cert( mbedtls_ssl_config *conf,
mbedtls_x509_crt *own_cert,
mbedtls_pk_context *pk_key )
{
return( ssl_append_key_cert( &conf->key_cert, own_cert, pk_key ) );
}
void mbedtls_ssl_conf_ca_chain( mbedtls_ssl_config *conf,
mbedtls_x509_crt *ca_chain,
mbedtls_x509_crl *ca_crl )
{
conf->ca_chain = ca_chain;
conf->ca_crl = ca_crl;
}
#endif /* MBEDTLS_X509_CRT_PARSE_C */
#if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
int mbedtls_ssl_set_hs_own_cert( mbedtls_ssl_context *ssl,
mbedtls_x509_crt *own_cert,
mbedtls_pk_context *pk_key )
{
return( ssl_append_key_cert( &ssl->handshake->sni_key_cert,
own_cert, pk_key ) );
}
void mbedtls_ssl_set_hs_ca_chain( mbedtls_ssl_context *ssl,
mbedtls_x509_crt *ca_chain,
mbedtls_x509_crl *ca_crl )
{
ssl->handshake->sni_ca_chain = ca_chain;
ssl->handshake->sni_ca_crl = ca_crl;
}
void mbedtls_ssl_set_hs_authmode( mbedtls_ssl_context *ssl,
int authmode )
{
ssl->handshake->sni_authmode = authmode;
}
#endif /* MBEDTLS_SSL_SERVER_NAME_INDICATION */
#if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
/*
* Set EC J-PAKE password for current handshake
*/
int mbedtls_ssl_set_hs_ecjpake_password( mbedtls_ssl_context *ssl,
const unsigned char *pw,
size_t pw_len )
{
mbedtls_ecjpake_role role;
if( ssl->handshake == NULL || ssl->conf == NULL )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER )
role = MBEDTLS_ECJPAKE_SERVER;
else
role = MBEDTLS_ECJPAKE_CLIENT;
return( mbedtls_ecjpake_setup( &ssl->handshake->ecjpake_ctx,
role,
MBEDTLS_MD_SHA256,
MBEDTLS_ECP_DP_SECP256R1,
pw, pw_len ) );
}
#endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
#if defined(MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED)
int mbedtls_ssl_conf_psk( mbedtls_ssl_config *conf,
const unsigned char *psk, size_t psk_len,
const unsigned char *psk_identity, size_t psk_identity_len )
{
if( psk == NULL || psk_identity == NULL )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
if( psk_len > MBEDTLS_PSK_MAX_LEN )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
/* Identity len will be encoded on two bytes */
if( ( psk_identity_len >> 16 ) != 0 ||
psk_identity_len > MBEDTLS_SSL_OUT_CONTENT_LEN )
{
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
}
if( conf->psk != NULL )
{
mbedtls_platform_zeroize( conf->psk, conf->psk_len );
mbedtls_free( conf->psk );
conf->psk = NULL;
conf->psk_len = 0;
}
if( conf->psk_identity != NULL )
{
mbedtls_free( conf->psk_identity );
conf->psk_identity = NULL;
conf->psk_identity_len = 0;
}
if( ( conf->psk = mbedtls_calloc( 1, psk_len ) ) == NULL ||
( conf->psk_identity = mbedtls_calloc( 1, psk_identity_len ) ) == NULL )
{
mbedtls_free( conf->psk );
mbedtls_free( conf->psk_identity );
conf->psk = NULL;
conf->psk_identity = NULL;
return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
}
conf->psk_len = psk_len;
conf->psk_identity_len = psk_identity_len;
memcpy( conf->psk, psk, conf->psk_len );
memcpy( conf->psk_identity, psk_identity, conf->psk_identity_len );
return( 0 );
}
int mbedtls_ssl_set_hs_psk( mbedtls_ssl_context *ssl,
const unsigned char *psk, size_t psk_len )
{
if( psk == NULL || ssl->handshake == NULL )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
if( psk_len > MBEDTLS_PSK_MAX_LEN )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
if( ssl->handshake->psk != NULL )
{
mbedtls_platform_zeroize( ssl->handshake->psk,
ssl->handshake->psk_len );
mbedtls_free( ssl->handshake->psk );
ssl->handshake->psk_len = 0;
}
if( ( ssl->handshake->psk = mbedtls_calloc( 1, psk_len ) ) == NULL )
return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
ssl->handshake->psk_len = psk_len;
memcpy( ssl->handshake->psk, psk, ssl->handshake->psk_len );
return( 0 );
}
void mbedtls_ssl_conf_psk_cb( mbedtls_ssl_config *conf,
int (*f_psk)(void *, mbedtls_ssl_context *, const unsigned char *,
size_t),
void *p_psk )
{
conf->f_psk = f_psk;
conf->p_psk = p_psk;
}
#endif /* MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED */
#if defined(MBEDTLS_DHM_C) && defined(MBEDTLS_SSL_SRV_C)
#if !defined(MBEDTLS_DEPRECATED_REMOVED)
int mbedtls_ssl_conf_dh_param( mbedtls_ssl_config *conf, const char *dhm_P, const char *dhm_G )
{
int ret;
if( ( ret = mbedtls_mpi_read_string( &conf->dhm_P, 16, dhm_P ) ) != 0 ||
( ret = mbedtls_mpi_read_string( &conf->dhm_G, 16, dhm_G ) ) != 0 )
{
mbedtls_mpi_free( &conf->dhm_P );
mbedtls_mpi_free( &conf->dhm_G );
return( ret );
}
return( 0 );
}
#endif /* MBEDTLS_DEPRECATED_REMOVED */
int mbedtls_ssl_conf_dh_param_bin( mbedtls_ssl_config *conf,
const unsigned char *dhm_P, size_t P_len,
const unsigned char *dhm_G, size_t G_len )
{
int ret;
if( ( ret = mbedtls_mpi_read_binary( &conf->dhm_P, dhm_P, P_len ) ) != 0 ||
( ret = mbedtls_mpi_read_binary( &conf->dhm_G, dhm_G, G_len ) ) != 0 )
{
mbedtls_mpi_free( &conf->dhm_P );
mbedtls_mpi_free( &conf->dhm_G );
return( ret );
}
return( 0 );
}
int mbedtls_ssl_conf_dh_param_ctx( mbedtls_ssl_config *conf, mbedtls_dhm_context *dhm_ctx )
{
int ret;
if( ( ret = mbedtls_mpi_copy( &conf->dhm_P, &dhm_ctx->P ) ) != 0 ||
( ret = mbedtls_mpi_copy( &conf->dhm_G, &dhm_ctx->G ) ) != 0 )
{
mbedtls_mpi_free( &conf->dhm_P );
mbedtls_mpi_free( &conf->dhm_G );
return( ret );
}
return( 0 );
}
#endif /* MBEDTLS_DHM_C && MBEDTLS_SSL_SRV_C */
#if defined(MBEDTLS_DHM_C) && defined(MBEDTLS_SSL_CLI_C)
/*
* Set the minimum length for Diffie-Hellman parameters
*/
void mbedtls_ssl_conf_dhm_min_bitlen( mbedtls_ssl_config *conf,
unsigned int bitlen )
{
conf->dhm_min_bitlen = bitlen;
}
#endif /* MBEDTLS_DHM_C && MBEDTLS_SSL_CLI_C */
#if defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)
/*
* Set allowed/preferred hashes for handshake signatures
*/
void mbedtls_ssl_conf_sig_hashes( mbedtls_ssl_config *conf,
const int *hashes )
{
conf->sig_hashes = hashes;
}
#endif /* MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED */
#if defined(MBEDTLS_ECP_C)
/*
* Set the allowed elliptic curves
*/
void mbedtls_ssl_conf_curves( mbedtls_ssl_config *conf,
const mbedtls_ecp_group_id *curve_list )
{
conf->curve_list = curve_list;
}
#endif /* MBEDTLS_ECP_C */
#if defined(MBEDTLS_X509_CRT_PARSE_C)
int mbedtls_ssl_set_hostname( mbedtls_ssl_context *ssl, const char *hostname )
{
/* Initialize to suppress unnecessary compiler warning */
size_t hostname_len = 0;
/* Check if new hostname is valid before
* making any change to current one */
if( hostname != NULL )
{
hostname_len = strlen( hostname );
if( hostname_len > MBEDTLS_SSL_MAX_HOST_NAME_LEN )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
}
/* Now it's clear that we will overwrite the old hostname,
* so we can free it safely */
if( ssl->hostname != NULL )
{
mbedtls_platform_zeroize( ssl->hostname, strlen( ssl->hostname ) );
mbedtls_free( ssl->hostname );
}
/* Passing NULL as hostname shall clear the old one */
if( hostname == NULL )
{
ssl->hostname = NULL;
}
else
{
ssl->hostname = mbedtls_calloc( 1, hostname_len + 1 );
if( ssl->hostname == NULL )
return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
memcpy( ssl->hostname, hostname, hostname_len );
ssl->hostname[hostname_len] = '\0';
}
return( 0 );
}
#endif /* MBEDTLS_X509_CRT_PARSE_C */
#if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
void mbedtls_ssl_conf_sni( mbedtls_ssl_config *conf,
int (*f_sni)(void *, mbedtls_ssl_context *,
const unsigned char *, size_t),
void *p_sni )
{
conf->f_sni = f_sni;
conf->p_sni = p_sni;
}
#endif /* MBEDTLS_SSL_SERVER_NAME_INDICATION */
#if defined(MBEDTLS_SSL_ALPN)
int mbedtls_ssl_conf_alpn_protocols( mbedtls_ssl_config *conf, const char **protos )
{
size_t cur_len, tot_len;
const char **p;
/*
* RFC 7301 3.1: "Empty strings MUST NOT be included and byte strings
* MUST NOT be truncated."
* We check lengths now rather than later.
*/
tot_len = 0;
for( p = protos; *p != NULL; p++ )
{
cur_len = strlen( *p );
tot_len += cur_len;
if( cur_len == 0 || cur_len > 255 || tot_len > 65535 )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
}
conf->alpn_list = protos;
return( 0 );
}
const char *mbedtls_ssl_get_alpn_protocol( const mbedtls_ssl_context *ssl )
{
return( ssl->alpn_chosen );
}
#endif /* MBEDTLS_SSL_ALPN */
void mbedtls_ssl_conf_max_version( mbedtls_ssl_config *conf, int major, int minor )
{
conf->max_major_ver = major;
conf->max_minor_ver = minor;
}
void mbedtls_ssl_conf_min_version( mbedtls_ssl_config *conf, int major, int minor )
{
conf->min_major_ver = major;
conf->min_minor_ver = minor;
}
#if defined(MBEDTLS_SSL_FALLBACK_SCSV) && defined(MBEDTLS_SSL_CLI_C)
void mbedtls_ssl_conf_fallback( mbedtls_ssl_config *conf, char fallback )
{
conf->fallback = fallback;
}
#endif
#if defined(MBEDTLS_SSL_SRV_C)
void mbedtls_ssl_conf_cert_req_ca_list( mbedtls_ssl_config *conf,
char cert_req_ca_list )
{
conf->cert_req_ca_list = cert_req_ca_list;
}
#endif
#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
void mbedtls_ssl_conf_encrypt_then_mac( mbedtls_ssl_config *conf, char etm )
{
conf->encrypt_then_mac = etm;
}
#endif
#if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
void mbedtls_ssl_conf_extended_master_secret( mbedtls_ssl_config *conf, char ems )
{
conf->extended_ms = ems;
}
#endif
#if defined(MBEDTLS_ARC4_C)
void mbedtls_ssl_conf_arc4_support( mbedtls_ssl_config *conf, char arc4 )
{
conf->arc4_disabled = arc4;
}
#endif
#if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
int mbedtls_ssl_conf_max_frag_len( mbedtls_ssl_config *conf, unsigned char mfl_code )
{
if( mfl_code >= MBEDTLS_SSL_MAX_FRAG_LEN_INVALID ||
ssl_mfl_code_to_length( mfl_code ) > MBEDTLS_TLS_EXT_ADV_CONTENT_LEN )
{
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
}
conf->mfl_code = mfl_code;
return( 0 );
}
#endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */
#if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
void mbedtls_ssl_conf_truncated_hmac( mbedtls_ssl_config *conf, int truncate )
{
conf->trunc_hmac = truncate;
}
#endif /* MBEDTLS_SSL_TRUNCATED_HMAC */
#if defined(MBEDTLS_SSL_CBC_RECORD_SPLITTING)
void mbedtls_ssl_conf_cbc_record_splitting( mbedtls_ssl_config *conf, char split )
{
conf->cbc_record_splitting = split;
}
#endif
void mbedtls_ssl_conf_legacy_renegotiation( mbedtls_ssl_config *conf, int allow_legacy )
{
conf->allow_legacy_renegotiation = allow_legacy;
}
#if defined(MBEDTLS_SSL_RENEGOTIATION)
void mbedtls_ssl_conf_renegotiation( mbedtls_ssl_config *conf, int renegotiation )
{
conf->disable_renegotiation = renegotiation;
}
void mbedtls_ssl_conf_renegotiation_enforced( mbedtls_ssl_config *conf, int max_records )
{
conf->renego_max_records = max_records;
}
void mbedtls_ssl_conf_renegotiation_period( mbedtls_ssl_config *conf,
const unsigned char period[8] )
{
memcpy( conf->renego_period, period, 8 );
}
#endif /* MBEDTLS_SSL_RENEGOTIATION */
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
#if defined(MBEDTLS_SSL_CLI_C)
void mbedtls_ssl_conf_session_tickets( mbedtls_ssl_config *conf, int use_tickets )
{
conf->session_tickets = use_tickets;
}
#endif
#if defined(MBEDTLS_SSL_SRV_C)
void mbedtls_ssl_conf_session_tickets_cb( mbedtls_ssl_config *conf,
mbedtls_ssl_ticket_write_t *f_ticket_write,
mbedtls_ssl_ticket_parse_t *f_ticket_parse,
void *p_ticket )
{
conf->f_ticket_write = f_ticket_write;
conf->f_ticket_parse = f_ticket_parse;
conf->p_ticket = p_ticket;
}
#endif
#endif /* MBEDTLS_SSL_SESSION_TICKETS */
#if defined(MBEDTLS_SSL_EXPORT_KEYS)
void mbedtls_ssl_conf_export_keys_cb( mbedtls_ssl_config *conf,
mbedtls_ssl_export_keys_t *f_export_keys,
void *p_export_keys )
{
conf->f_export_keys = f_export_keys;
conf->p_export_keys = p_export_keys;
}
#endif
#if defined(MBEDTLS_SSL_ASYNC_PRIVATE)
void mbedtls_ssl_conf_async_private_cb(
mbedtls_ssl_config *conf,
mbedtls_ssl_async_sign_t *f_async_sign,
mbedtls_ssl_async_decrypt_t *f_async_decrypt,
mbedtls_ssl_async_resume_t *f_async_resume,
mbedtls_ssl_async_cancel_t *f_async_cancel,
void *async_config_data )
{
conf->f_async_sign_start = f_async_sign;
conf->f_async_decrypt_start = f_async_decrypt;
conf->f_async_resume = f_async_resume;
conf->f_async_cancel = f_async_cancel;
conf->p_async_config_data = async_config_data;
}
void *mbedtls_ssl_conf_get_async_config_data( const mbedtls_ssl_config *conf )
{
return( conf->p_async_config_data );
}
void *mbedtls_ssl_get_async_operation_data( const mbedtls_ssl_context *ssl )
{
if( ssl->handshake == NULL )
return( NULL );
else
return( ssl->handshake->user_async_ctx );
}
void mbedtls_ssl_set_async_operation_data( mbedtls_ssl_context *ssl,
void *ctx )
{
if( ssl->handshake != NULL )
ssl->handshake->user_async_ctx = ctx;
}
#endif /* MBEDTLS_SSL_ASYNC_PRIVATE */
/*
* SSL get accessors
*/
size_t mbedtls_ssl_get_bytes_avail( const mbedtls_ssl_context *ssl )
{
return( ssl->in_offt == NULL ? 0 : ssl->in_msglen );
}
int mbedtls_ssl_check_pending( const mbedtls_ssl_context *ssl )
{
/*
* Case A: We're currently holding back
* a message for further processing.
*/
if( ssl->keep_current_message == 1 )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "ssl_check_pending: record held back for processing" ) );
return( 1 );
}
/*
* Case B: Further records are pending in the current datagram.
*/
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
ssl->in_left > ssl->next_record_offset )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "ssl_check_pending: more records within current datagram" ) );
return( 1 );
}
#endif /* MBEDTLS_SSL_PROTO_DTLS */
/*
* Case C: A handshake message is being processed.
*/
if( ssl->in_hslen > 0 && ssl->in_hslen < ssl->in_msglen )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "ssl_check_pending: more handshake messages within current record" ) );
return( 1 );
}
/*
* Case D: An application data message is being processed
*/
if( ssl->in_offt != NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "ssl_check_pending: application data record is being processed" ) );
return( 1 );
}
/*
* In all other cases, the rest of the message can be dropped.
* As in ssl_get_next_record, this needs to be adapted if
* we implement support for multiple alerts in single records.
*/
MBEDTLS_SSL_DEBUG_MSG( 3, ( "ssl_check_pending: nothing pending" ) );
return( 0 );
}
uint32_t mbedtls_ssl_get_verify_result( const mbedtls_ssl_context *ssl )
{
if( ssl->session != NULL )
return( ssl->session->verify_result );
if( ssl->session_negotiate != NULL )
return( ssl->session_negotiate->verify_result );
return( 0xFFFFFFFF );
}
const char *mbedtls_ssl_get_ciphersuite( const mbedtls_ssl_context *ssl )
{
if( ssl == NULL || ssl->session == NULL )
return( NULL );
return mbedtls_ssl_get_ciphersuite_name( ssl->session->ciphersuite );
}
const char *mbedtls_ssl_get_version( const mbedtls_ssl_context *ssl )
{
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
{
switch( ssl->minor_ver )
{
case MBEDTLS_SSL_MINOR_VERSION_2:
return( "DTLSv1.0" );
case MBEDTLS_SSL_MINOR_VERSION_3:
return( "DTLSv1.2" );
default:
return( "unknown (DTLS)" );
}
}
#endif
switch( ssl->minor_ver )
{
case MBEDTLS_SSL_MINOR_VERSION_0:
return( "SSLv3.0" );
case MBEDTLS_SSL_MINOR_VERSION_1:
return( "TLSv1.0" );
case MBEDTLS_SSL_MINOR_VERSION_2:
return( "TLSv1.1" );
case MBEDTLS_SSL_MINOR_VERSION_3:
return( "TLSv1.2" );
default:
return( "unknown" );
}
}
int mbedtls_ssl_get_record_expansion( const mbedtls_ssl_context *ssl )
{
size_t transform_expansion = 0;
const mbedtls_ssl_transform *transform = ssl->transform_out;
unsigned block_size;
size_t out_hdr_len = mbedtls_ssl_out_hdr_len( ssl );
if( transform == NULL )
return( (int) out_hdr_len );
#if defined(MBEDTLS_ZLIB_SUPPORT)
if( ssl->session_out->compression != MBEDTLS_SSL_COMPRESS_NULL )
return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE );
#endif
switch( mbedtls_cipher_get_cipher_mode( &transform->cipher_ctx_enc ) )
{
case MBEDTLS_MODE_GCM:
case MBEDTLS_MODE_CCM:
case MBEDTLS_MODE_CHACHAPOLY:
case MBEDTLS_MODE_STREAM:
transform_expansion = transform->minlen;
break;
case MBEDTLS_MODE_CBC:
block_size = mbedtls_cipher_get_block_size(
&transform->cipher_ctx_enc );
/* Expansion due to the addition of the MAC. */
transform_expansion += transform->maclen;
/* Expansion due to the addition of CBC padding;
* Theoretically up to 256 bytes, but we never use
* more than the block size of the underlying cipher. */
transform_expansion += block_size;
/* For TLS 1.1 or higher, an explicit IV is added
* after the record header. */
#if defined(MBEDTLS_SSL_PROTO_TLS1_1) || defined(MBEDTLS_SSL_PROTO_TLS1_2)
if( ssl->minor_ver >= MBEDTLS_SSL_MINOR_VERSION_2 )
transform_expansion += block_size;
#endif /* MBEDTLS_SSL_PROTO_TLS1_1 || MBEDTLS_SSL_PROTO_TLS1_2 */
break;
default:
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
if( transform->out_cid_len != 0 )
transform_expansion += MBEDTLS_SSL_MAX_CID_EXPANSION;
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
return( (int)( out_hdr_len + transform_expansion ) );
}
#if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
size_t mbedtls_ssl_get_max_frag_len( const mbedtls_ssl_context *ssl )
{
size_t max_len;
/*
* Assume mfl_code is correct since it was checked when set
*/
max_len = ssl_mfl_code_to_length( ssl->conf->mfl_code );
/* Check if a smaller max length was negotiated */
if( ssl->session_out != NULL &&
ssl_mfl_code_to_length( ssl->session_out->mfl_code ) < max_len )
{
max_len = ssl_mfl_code_to_length( ssl->session_out->mfl_code );
}
/* During a handshake, use the value being negotiated */
if( ssl->session_negotiate != NULL &&
ssl_mfl_code_to_length( ssl->session_negotiate->mfl_code ) < max_len )
{
max_len = ssl_mfl_code_to_length( ssl->session_negotiate->mfl_code );
}
return( max_len );
}
#endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */
#if defined(MBEDTLS_SSL_PROTO_DTLS)
static size_t ssl_get_current_mtu( const mbedtls_ssl_context *ssl )
{
/* Return unlimited mtu for client hello messages to avoid fragmentation. */
if( ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT &&
( ssl->state == MBEDTLS_SSL_CLIENT_HELLO ||
ssl->state == MBEDTLS_SSL_SERVER_HELLO ) )
return ( 0 );
if( ssl->handshake == NULL || ssl->handshake->mtu == 0 )
return( ssl->mtu );
if( ssl->mtu == 0 )
return( ssl->handshake->mtu );
return( ssl->mtu < ssl->handshake->mtu ?
ssl->mtu : ssl->handshake->mtu );
}
#endif /* MBEDTLS_SSL_PROTO_DTLS */
int mbedtls_ssl_get_max_out_record_payload( const mbedtls_ssl_context *ssl )
{
size_t max_len = MBEDTLS_SSL_OUT_CONTENT_LEN;
#if !defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH) && \
!defined(MBEDTLS_SSL_PROTO_DTLS)
(void) ssl;
#endif
#if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
const size_t mfl = mbedtls_ssl_get_max_frag_len( ssl );
if( max_len > mfl )
max_len = mfl;
#endif
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl_get_current_mtu( ssl ) != 0 )
{
const size_t mtu = ssl_get_current_mtu( ssl );
const int ret = mbedtls_ssl_get_record_expansion( ssl );
const size_t overhead = (size_t) ret;
if( ret < 0 )
return( ret );
if( mtu <= overhead )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "MTU too low for record expansion" ) );
return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE );
}
if( max_len > mtu - overhead )
max_len = mtu - overhead;
}
#endif /* MBEDTLS_SSL_PROTO_DTLS */
#if !defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH) && \
!defined(MBEDTLS_SSL_PROTO_DTLS)
((void) ssl);
#endif
return( (int) max_len );
}
#if defined(MBEDTLS_X509_CRT_PARSE_C)
const mbedtls_x509_crt *mbedtls_ssl_get_peer_cert( const mbedtls_ssl_context *ssl )
{
if( ssl == NULL || ssl->session == NULL )
return( NULL );
return( ssl->session->peer_cert );
}
#endif /* MBEDTLS_X509_CRT_PARSE_C */
#if defined(MBEDTLS_SSL_CLI_C)
int mbedtls_ssl_get_session( const mbedtls_ssl_context *ssl, mbedtls_ssl_session *dst )
{
if( ssl == NULL ||
dst == NULL ||
ssl->session == NULL ||
ssl->conf->endpoint != MBEDTLS_SSL_IS_CLIENT )
{
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
}
return( ssl_session_copy( dst, ssl->session ) );
}
#endif /* MBEDTLS_SSL_CLI_C */
const mbedtls_ssl_session *mbedtls_ssl_get_session_pointer( const mbedtls_ssl_context *ssl )
{
if( ssl == NULL )
return( NULL );
return( ssl->session );
}
/*
* Define ticket header determining Mbed TLS version
* and structure of the ticket.
*/
/*
* Define bitflag determining compile-time settings influencing
* structure of serialized SSL sessions.
*/
#if defined(MBEDTLS_HAVE_TIME)
#define SSL_SERIALIZED_SESSION_CONFIG_TIME 1
#else
#define SSL_SERIALIZED_SESSION_CONFIG_TIME 0
#endif /* MBEDTLS_HAVE_TIME */
#if defined(MBEDTLS_X509_CRT_PARSE_C)
#define SSL_SERIALIZED_SESSION_CONFIG_CRT 1
#else
#define SSL_SERIALIZED_SESSION_CONFIG_CRT 0
#endif /* MBEDTLS_X509_CRT_PARSE_C */
#if defined(MBEDTLS_SSL_CLI_C) && defined(MBEDTLS_SSL_SESSION_TICKETS)
#define SSL_SERIALIZED_SESSION_CONFIG_CLIENT_TICKET 1
#else
#define SSL_SERIALIZED_SESSION_CONFIG_CLIENT_TICKET 0
#endif /* MBEDTLS_SSL_CLI_C && MBEDTLS_SSL_SESSION_TICKETS */
#if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
#define SSL_SERIALIZED_SESSION_CONFIG_MFL 1
#else
#define SSL_SERIALIZED_SESSION_CONFIG_MFL 0
#endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */
#if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
#define SSL_SERIALIZED_SESSION_CONFIG_TRUNC_HMAC 1
#else
#define SSL_SERIALIZED_SESSION_CONFIG_TRUNC_HMAC 0
#endif /* MBEDTLS_SSL_TRUNCATED_HMAC */
#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
#define SSL_SERIALIZED_SESSION_CONFIG_ETM 1
#else
#define SSL_SERIALIZED_SESSION_CONFIG_ETM 0
#endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
#define SSL_SERIALIZED_SESSION_CONFIG_TICKET 1
#else
#define SSL_SERIALIZED_SESSION_CONFIG_TICKET 0
#endif /* MBEDTLS_SSL_SESSION_TICKETS */
#define SSL_SERIALIZED_SESSION_CONFIG_TIME_BIT 0
#define SSL_SERIALIZED_SESSION_CONFIG_CRT_BIT 1
#define SSL_SERIALIZED_SESSION_CONFIG_CLIENT_TICKET_BIT 2
#define SSL_SERIALIZED_SESSION_CONFIG_MFL_BIT 3
#define SSL_SERIALIZED_SESSION_CONFIG_TRUNC_HMAC_BIT 4
#define SSL_SERIALIZED_SESSION_CONFIG_ETM_BIT 5
#define SSL_SERIALIZED_SESSION_CONFIG_TICKET_BIT 6
#define SSL_SERIALIZED_SESSION_CONFIG_BITFLAG \
( (uint16_t) ( \
( SSL_SERIALIZED_SESSION_CONFIG_TIME << SSL_SERIALIZED_SESSION_CONFIG_TIME_BIT ) | \
( SSL_SERIALIZED_SESSION_CONFIG_CRT << SSL_SERIALIZED_SESSION_CONFIG_CRT_BIT ) | \
( SSL_SERIALIZED_SESSION_CONFIG_CLIENT_TICKET << SSL_SERIALIZED_SESSION_CONFIG_CLIENT_TICKET_BIT ) | \
( SSL_SERIALIZED_SESSION_CONFIG_MFL << SSL_SERIALIZED_SESSION_CONFIG_MFL_BIT ) | \
( SSL_SERIALIZED_SESSION_CONFIG_TRUNC_HMAC << SSL_SERIALIZED_SESSION_CONFIG_TRUNC_HMAC_BIT ) | \
( SSL_SERIALIZED_SESSION_CONFIG_ETM << SSL_SERIALIZED_SESSION_CONFIG_ETM_BIT ) | \
( SSL_SERIALIZED_SESSION_CONFIG_TICKET << SSL_SERIALIZED_SESSION_CONFIG_TICKET_BIT ) ) )
static unsigned char ssl_serialized_session_header[] = {
MBEDTLS_VERSION_MAJOR,
MBEDTLS_VERSION_MINOR,
MBEDTLS_VERSION_PATCH,
( SSL_SERIALIZED_SESSION_CONFIG_BITFLAG >> 8 ) & 0xFF,
( SSL_SERIALIZED_SESSION_CONFIG_BITFLAG >> 0 ) & 0xFF,
};
/*
* Serialize a session in the following format:
* (in the presentation language of TLS, RFC 8446 section 3)
*
* opaque mbedtls_version[3]; // major, minor, patch
* opaque session_format[2]; // version-specific 16-bit field determining
* // the format of the remaining
* // serialized data.
*
* Note: When updating the format, remember to keep
* these version+format bytes.
*
* // In this version, `session_format` determines
* // the setting of those compile-time
* // configuration options which influence
* // the structure of mbedtls_ssl_session.
* uint64 start_time;
* uint8 ciphersuite[2]; // defined by the standard
* uint8 compression; // 0 or 1
* uint8 session_id_len; // at most 32
* opaque session_id[32];
* opaque master[48]; // fixed length in the standard
* uint32 verify_result;
* opaque peer_cert<0..2^24-1>; // length 0 means no peer cert
* opaque ticket<0..2^24-1>; // length 0 means no ticket
* uint32 ticket_lifetime;
* uint8 mfl_code; // up to 255 according to standard
* uint8 trunc_hmac; // 0 or 1
* uint8 encrypt_then_mac; // 0 or 1
*
* The order is the same as in the definition of the structure, except
* verify_result is put before peer_cert so that all mandatory fields come
* together in one block.
*/
int mbedtls_ssl_session_save( const mbedtls_ssl_session *session,
unsigned char *buf,
size_t buf_len,
size_t *olen )
{
unsigned char *p = buf;
size_t used = 0;
#if defined(MBEDTLS_HAVE_TIME)
uint64_t start;
#endif
#if defined(MBEDTLS_X509_CRT_PARSE_C)
size_t cert_len;
#endif
/*
* Add version identifier
*/
used += sizeof( ssl_serialized_session_header );
if( used <= buf_len )
{
memcpy( p, ssl_serialized_session_header,
sizeof( ssl_serialized_session_header ) );
p += sizeof( ssl_serialized_session_header );
}
/*
* Time
*/
#if defined(MBEDTLS_HAVE_TIME)
used += 8;
if( used <= buf_len )
{
start = (uint64_t) session->start;
*p++ = (unsigned char)( ( start >> 56 ) & 0xFF );
*p++ = (unsigned char)( ( start >> 48 ) & 0xFF );
*p++ = (unsigned char)( ( start >> 40 ) & 0xFF );
*p++ = (unsigned char)( ( start >> 32 ) & 0xFF );
*p++ = (unsigned char)( ( start >> 24 ) & 0xFF );
*p++ = (unsigned char)( ( start >> 16 ) & 0xFF );
*p++ = (unsigned char)( ( start >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( start ) & 0xFF );
}
#endif /* MBEDTLS_HAVE_TIME */
/*
* Basic mandatory fields
*/
used += 2 /* ciphersuite */
+ 1 /* compression */
+ 1 /* id_len */
+ sizeof( session->id )
+ sizeof( session->master )
+ 4; /* verify_result */
if( used <= buf_len )
{
*p++ = (unsigned char)( ( session->ciphersuite >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( session->ciphersuite ) & 0xFF );
*p++ = (unsigned char)( session->compression & 0xFF );
*p++ = (unsigned char)( session->id_len & 0xFF );
memcpy( p, session->id, 32 );
p += 32;
memcpy( p, session->master, 48 );
p += 48;
*p++ = (unsigned char)( ( session->verify_result >> 24 ) & 0xFF );
*p++ = (unsigned char)( ( session->verify_result >> 16 ) & 0xFF );
*p++ = (unsigned char)( ( session->verify_result >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( session->verify_result ) & 0xFF );
}
/*
* Peer's end-entity certificate
*/
#if defined(MBEDTLS_X509_CRT_PARSE_C)
if( session->peer_cert == NULL )
cert_len = 0;
else
cert_len = session->peer_cert->raw.len;
used += 3 + cert_len;
if( used <= buf_len )
{
*p++ = (unsigned char)( ( cert_len >> 16 ) & 0xFF );
*p++ = (unsigned char)( ( cert_len >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( cert_len ) & 0xFF );
if( session->peer_cert != NULL )
{
memcpy( p, session->peer_cert->raw.p, cert_len );
p += cert_len;
}
}
#endif /* MBEDTLS_X509_CRT_PARSE_C */
/*
* Session ticket if any, plus associated data
*/
#if defined(MBEDTLS_SSL_SESSION_TICKETS) && defined(MBEDTLS_SSL_CLI_C)
used += 3 + session->ticket_len + 4; /* len + ticket + lifetime */
if( used <= buf_len )
{
*p++ = (unsigned char)( ( session->ticket_len >> 16 ) & 0xFF );
*p++ = (unsigned char)( ( session->ticket_len >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( session->ticket_len ) & 0xFF );
if( session->ticket != NULL )
{
memcpy( p, session->ticket, session->ticket_len );
p += session->ticket_len;
}
*p++ = (unsigned char)( ( session->ticket_lifetime >> 24 ) & 0xFF );
*p++ = (unsigned char)( ( session->ticket_lifetime >> 16 ) & 0xFF );
*p++ = (unsigned char)( ( session->ticket_lifetime >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( session->ticket_lifetime ) & 0xFF );
}
#endif /* MBEDTLS_SSL_SESSION_TICKETS && MBEDTLS_SSL_CLI_C */
/*
* Misc extension-related info
*/
#if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
used += 1;
if( used <= buf_len )
*p++ = session->mfl_code;
#endif
#if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
used += 1;
if( used <= buf_len )
*p++ = (unsigned char)( ( session->trunc_hmac ) & 0xFF );
#endif
#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
used += 1;
if( used <= buf_len )
*p++ = (unsigned char)( ( session->encrypt_then_mac ) & 0xFF );
#endif
/* Done */
*olen = used;
if( used > buf_len )
return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
return( 0 );
}
/*
* Unserialize session, see mbedtls_ssl_session_save() for format.
*
* This internal version is wrapped by a public function that cleans up in
* case of error.
*/
static int ssl_session_load( mbedtls_ssl_session *session,
const unsigned char *buf,
size_t len )
{
const unsigned char *p = buf;
const unsigned char * const end = buf + len;
#if defined(MBEDTLS_HAVE_TIME)
uint64_t start;
#endif
#if defined(MBEDTLS_X509_CRT_PARSE_C)
size_t cert_len;
#endif /* MBEDTLS_X509_CRT_PARSE_C */
/*
* Check version identifier
*/
if( (size_t)( end - p ) < sizeof( ssl_serialized_session_header ) )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
if( memcmp( p, ssl_serialized_session_header,
sizeof( ssl_serialized_session_header ) ) != 0 )
{
return( MBEDTLS_ERR_SSL_VERSION_MISMATCH );
}
p += sizeof( ssl_serialized_session_header );
/*
* Time
*/
#if defined(MBEDTLS_HAVE_TIME)
if( 8 > (size_t)( end - p ) )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
start = ( (uint64_t) p[0] << 56 ) |
( (uint64_t) p[1] << 48 ) |
( (uint64_t) p[2] << 40 ) |
( (uint64_t) p[3] << 32 ) |
( (uint64_t) p[4] << 24 ) |
( (uint64_t) p[5] << 16 ) |
( (uint64_t) p[6] << 8 ) |
( (uint64_t) p[7] );
p += 8;
session->start = (time_t) start;
#endif /* MBEDTLS_HAVE_TIME */
/*
* Basic mandatory fields
*/
if( 2 + 1 + 1 + 32 + 48 + 4 > (size_t)( end - p ) )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
session->ciphersuite = ( p[0] << 8 ) | p[1];
p += 2;
session->compression = *p++;
session->id_len = *p++;
memcpy( session->id, p, 32 );
p += 32;
memcpy( session->master, p, 48 );
p += 48;
session->verify_result = ( (uint32_t) p[0] << 24 ) |
( (uint32_t) p[1] << 16 ) |
( (uint32_t) p[2] << 8 ) |
( (uint32_t) p[3] );
p += 4;
/* Immediately clear invalid pointer values that have been read, in case
* we exit early before we replaced them with valid ones. */
#if defined(MBEDTLS_X509_CRT_PARSE_C)
session->peer_cert = NULL;
#endif
#if defined(MBEDTLS_SSL_SESSION_TICKETS) && defined(MBEDTLS_SSL_CLI_C)
session->ticket = NULL;
#endif
/*
* Peer certificate
*/
#if defined(MBEDTLS_X509_CRT_PARSE_C)
if( 3 > (size_t)( end - p ) )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
cert_len = ( p[0] << 16 ) | ( p[1] << 8 ) | p[2];
p += 3;
if( cert_len == 0 )
{
session->peer_cert = NULL;
}
else
{
int ret;
if( cert_len > (size_t)( end - p ) )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
session->peer_cert = mbedtls_calloc( 1, sizeof( mbedtls_x509_crt ) );
if( session->peer_cert == NULL )
return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
mbedtls_x509_crt_init( session->peer_cert );
if( ( ret = mbedtls_x509_crt_parse_der( session->peer_cert,
p, cert_len ) ) != 0 )
{
mbedtls_x509_crt_free( session->peer_cert );
mbedtls_free( session->peer_cert );
session->peer_cert = NULL;
return( ret );
}
p += cert_len;
}
#endif /* MBEDTLS_X509_CRT_PARSE_C */
/*
* Session ticket and associated data
*/
#if defined(MBEDTLS_SSL_SESSION_TICKETS) && defined(MBEDTLS_SSL_CLI_C)
if( 3 > (size_t)( end - p ) )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
session->ticket_len = ( p[0] << 16 ) | ( p[1] << 8 ) | p[2];
p += 3;
if( session->ticket_len != 0 )
{
if( session->ticket_len > (size_t)( end - p ) )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
session->ticket = mbedtls_calloc( 1, session->ticket_len );
if( session->ticket == NULL )
return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
memcpy( session->ticket, p, session->ticket_len );
p += session->ticket_len;
}
if( 4 > (size_t)( end - p ) )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
session->ticket_lifetime = ( (uint32_t) p[0] << 24 ) |
( (uint32_t) p[1] << 16 ) |
( (uint32_t) p[2] << 8 ) |
( (uint32_t) p[3] );
p += 4;
#endif /* MBEDTLS_SSL_SESSION_TICKETS && MBEDTLS_SSL_CLI_C */
/*
* Misc extension-related info
*/
#if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
if( 1 > (size_t)( end - p ) )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
session->mfl_code = *p++;
#endif
#if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
if( 1 > (size_t)( end - p ) )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
session->trunc_hmac = *p++;
#endif
#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
if( 1 > (size_t)( end - p ) )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
session->encrypt_then_mac = *p++;
#endif
/* Done, should have consumed entire buffer */
if( p != end )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
return( 0 );
}
/*
* Unserialize session: public wrapper for error cleaning
*/
int mbedtls_ssl_session_load( mbedtls_ssl_session *session,
const unsigned char *buf,
size_t len )
{
int ret = ssl_session_load( session, buf, len );
if( ret != 0 )
mbedtls_ssl_session_free( session );
return( ret );
}
/*
* Perform a single step of the SSL handshake
*/
int mbedtls_ssl_handshake_step( mbedtls_ssl_context *ssl )
{
int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE;
if( ssl == NULL || ssl->conf == NULL )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
#if defined(MBEDTLS_SSL_CLI_C)
if( ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT )
ret = mbedtls_ssl_handshake_client_step( ssl );
#endif
#if defined(MBEDTLS_SSL_SRV_C)
if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER )
ret = mbedtls_ssl_handshake_server_step( ssl );
#endif
return( ret );
}
/*
* Perform the SSL handshake
*/
int mbedtls_ssl_handshake( mbedtls_ssl_context *ssl )
{
int ret = 0;
if( ssl == NULL || ssl->conf == NULL )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> handshake" ) );
while( ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER )
{
ret = mbedtls_ssl_handshake_step( ssl );
if( ret != 0 )
break;
}
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= handshake" ) );
return( ret );
}
#if defined(MBEDTLS_SSL_RENEGOTIATION)
#if defined(MBEDTLS_SSL_SRV_C)
/*
* Write HelloRequest to request renegotiation on server
*/
static int ssl_write_hello_request( mbedtls_ssl_context *ssl )
{
int ret;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write hello request" ) );
ssl->out_msglen = 4;
ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE;
ssl->out_msg[0] = MBEDTLS_SSL_HS_HELLO_REQUEST;
if( ( ret = mbedtls_ssl_write_handshake_msg( ssl ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_handshake_msg", ret );
return( ret );
}
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write hello request" ) );
return( 0 );
}
#endif /* MBEDTLS_SSL_SRV_C */
/*
* Actually renegotiate current connection, triggered by either:
* - any side: calling mbedtls_ssl_renegotiate(),
* - client: receiving a HelloRequest during mbedtls_ssl_read(),
* - server: receiving any handshake message on server during mbedtls_ssl_read() after
* the initial handshake is completed.
* If the handshake doesn't complete due to waiting for I/O, it will continue
* during the next calls to mbedtls_ssl_renegotiate() or mbedtls_ssl_read() respectively.
*/
static int ssl_start_renegotiation( mbedtls_ssl_context *ssl )
{
int ret;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> renegotiate" ) );
if( ( ret = ssl_handshake_init( ssl ) ) != 0 )
return( ret );
/* RFC 6347 4.2.2: "[...] the HelloRequest will have message_seq = 0 and
* the ServerHello will have message_seq = 1" */
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_PENDING )
{
if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER )
ssl->handshake->out_msg_seq = 1;
else
ssl->handshake->in_msg_seq = 1;
}
#endif
ssl->state = MBEDTLS_SSL_HELLO_REQUEST;
ssl->renego_status = MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS;
if( ( ret = mbedtls_ssl_handshake( ssl ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_handshake", ret );
return( ret );
}
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= renegotiate" ) );
return( 0 );
}
/*
* Renegotiate current connection on client,
* or request renegotiation on server
*/
int mbedtls_ssl_renegotiate( mbedtls_ssl_context *ssl )
{
int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE;
if( ssl == NULL || ssl->conf == NULL )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
#if defined(MBEDTLS_SSL_SRV_C)
/* On server, just send the request */
if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER )
{
if( ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
ssl->renego_status = MBEDTLS_SSL_RENEGOTIATION_PENDING;
/* Did we already try/start sending HelloRequest? */
if( ssl->out_left != 0 )
return( mbedtls_ssl_flush_output( ssl ) );
return( ssl_write_hello_request( ssl ) );
}
#endif /* MBEDTLS_SSL_SRV_C */
#if defined(MBEDTLS_SSL_CLI_C)
/*
* On client, either start the renegotiation process or,
* if already in progress, continue the handshake
*/
if( ssl->renego_status != MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS )
{
if( ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
if( ( ret = ssl_start_renegotiation( ssl ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_start_renegotiation", ret );
return( ret );
}
}
else
{
if( ( ret = mbedtls_ssl_handshake( ssl ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_handshake", ret );
return( ret );
}
}
#endif /* MBEDTLS_SSL_CLI_C */
return( ret );
}
/*
* Check record counters and renegotiate if they're above the limit.
*/
static int ssl_check_ctr_renegotiate( mbedtls_ssl_context *ssl )
{
size_t ep_len = ssl_ep_len( ssl );
int in_ctr_cmp;
int out_ctr_cmp;
if( ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER ||
ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_PENDING ||
ssl->conf->disable_renegotiation == MBEDTLS_SSL_RENEGOTIATION_DISABLED )
{
return( 0 );
}
in_ctr_cmp = memcmp( ssl->in_ctr + ep_len,
ssl->conf->renego_period + ep_len, 8 - ep_len );
out_ctr_cmp = memcmp( ssl->cur_out_ctr + ep_len,
ssl->conf->renego_period + ep_len, 8 - ep_len );
if( in_ctr_cmp <= 0 && out_ctr_cmp <= 0 )
{
return( 0 );
}
MBEDTLS_SSL_DEBUG_MSG( 1, ( "record counter limit reached: renegotiate" ) );
return( mbedtls_ssl_renegotiate( ssl ) );
}
#endif /* MBEDTLS_SSL_RENEGOTIATION */
/*
* Receive application data decrypted from the SSL layer
*/
int mbedtls_ssl_read( mbedtls_ssl_context *ssl, unsigned char *buf, size_t len )
{
int ret;
size_t n;
if( ssl == NULL || ssl->conf == NULL )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> read" ) );
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
{
if( ( ret = mbedtls_ssl_flush_output( ssl ) ) != 0 )
return( ret );
if( ssl->handshake != NULL &&
ssl->handshake->retransmit_state == MBEDTLS_SSL_RETRANS_SENDING )
{
if( ( ret = mbedtls_ssl_flight_transmit( ssl ) ) != 0 )
return( ret );
}
}
#endif
/*
* Check if renegotiation is necessary and/or handshake is
* in process. If yes, perform/continue, and fall through
* if an unexpected packet is received while the client
* is waiting for the ServerHello.
*
* (There is no equivalent to the last condition on
* the server-side as it is not treated as within
* a handshake while waiting for the ClientHello
* after a renegotiation request.)
*/
#if defined(MBEDTLS_SSL_RENEGOTIATION)
ret = ssl_check_ctr_renegotiate( ssl );
if( ret != MBEDTLS_ERR_SSL_WAITING_SERVER_HELLO_RENEGO &&
ret != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_check_ctr_renegotiate", ret );
return( ret );
}
#endif
if( ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER )
{
ret = mbedtls_ssl_handshake( ssl );
if( ret != MBEDTLS_ERR_SSL_WAITING_SERVER_HELLO_RENEGO &&
ret != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_handshake", ret );
return( ret );
}
}
/* Loop as long as no application data record is available */
while( ssl->in_offt == NULL )
{
/* Start timer if not already running */
if( ssl->f_get_timer != NULL &&
ssl->f_get_timer( ssl->p_timer ) == -1 )
{
ssl_set_timer( ssl, ssl->conf->read_timeout );
}
if( ( ret = mbedtls_ssl_read_record( ssl, 1 ) ) != 0 )
{
if( ret == MBEDTLS_ERR_SSL_CONN_EOF )
return( 0 );
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret );
return( ret );
}
if( ssl->in_msglen == 0 &&
ssl->in_msgtype == MBEDTLS_SSL_MSG_APPLICATION_DATA )
{
/*
* OpenSSL sends empty messages to randomize the IV
*/
if( ( ret = mbedtls_ssl_read_record( ssl, 1 ) ) != 0 )
{
if( ret == MBEDTLS_ERR_SSL_CONN_EOF )
return( 0 );
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret );
return( ret );
}
}
if( ssl->in_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "received handshake message" ) );
/*
* - For client-side, expect SERVER_HELLO_REQUEST.
* - For server-side, expect CLIENT_HELLO.
* - Fail (TLS) or silently drop record (DTLS) in other cases.
*/
#if defined(MBEDTLS_SSL_CLI_C)
if( ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT &&
( ssl->in_msg[0] != MBEDTLS_SSL_HS_HELLO_REQUEST ||
ssl->in_hslen != mbedtls_ssl_hs_hdr_len( ssl ) ) )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "handshake received (not HelloRequest)" ) );
/* With DTLS, drop the packet (probably from last handshake) */
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
{
continue;
}
#endif
return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
}
#endif /* MBEDTLS_SSL_CLI_C */
#if defined(MBEDTLS_SSL_SRV_C)
if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER &&
ssl->in_msg[0] != MBEDTLS_SSL_HS_CLIENT_HELLO )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "handshake received (not ClientHello)" ) );
/* With DTLS, drop the packet (probably from last handshake) */
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
{
continue;
}
#endif
return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
}
#endif /* MBEDTLS_SSL_SRV_C */
#if defined(MBEDTLS_SSL_RENEGOTIATION)
/* Determine whether renegotiation attempt should be accepted */
if( ! ( ssl->conf->disable_renegotiation == MBEDTLS_SSL_RENEGOTIATION_DISABLED ||
( ssl->secure_renegotiation == MBEDTLS_SSL_LEGACY_RENEGOTIATION &&
ssl->conf->allow_legacy_renegotiation ==
MBEDTLS_SSL_LEGACY_NO_RENEGOTIATION ) ) )
{
/*
* Accept renegotiation request
*/
/* DTLS clients need to know renego is server-initiated */
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT )
{
ssl->renego_status = MBEDTLS_SSL_RENEGOTIATION_PENDING;
}
#endif
ret = ssl_start_renegotiation( ssl );
if( ret != MBEDTLS_ERR_SSL_WAITING_SERVER_HELLO_RENEGO &&
ret != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_start_renegotiation", ret );
return( ret );
}
}
else
#endif /* MBEDTLS_SSL_RENEGOTIATION */
{
/*
* Refuse renegotiation
*/
MBEDTLS_SSL_DEBUG_MSG( 3, ( "refusing renegotiation, sending alert" ) );
#if defined(MBEDTLS_SSL_PROTO_SSL3)
if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 )
{
/* SSLv3 does not have a "no_renegotiation" warning, so
we send a fatal alert and abort the connection. */
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE );
return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
}
else
#endif /* MBEDTLS_SSL_PROTO_SSL3 */
#if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) || \
defined(MBEDTLS_SSL_PROTO_TLS1_2)
if( ssl->minor_ver >= MBEDTLS_SSL_MINOR_VERSION_1 )
{
if( ( ret = mbedtls_ssl_send_alert_message( ssl,
MBEDTLS_SSL_ALERT_LEVEL_WARNING,
MBEDTLS_SSL_ALERT_MSG_NO_RENEGOTIATION ) ) != 0 )
{
return( ret );
}
}
else
#endif /* MBEDTLS_SSL_PROTO_TLS1 || MBEDTLS_SSL_PROTO_TLS1_1 ||
MBEDTLS_SSL_PROTO_TLS1_2 */
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
}
/* At this point, we don't know whether the renegotiation has been
* completed or not. The cases to consider are the following:
* 1) The renegotiation is complete. In this case, no new record
* has been read yet.
* 2) The renegotiation is incomplete because the client received
* an application data record while awaiting the ServerHello.
* 3) The renegotiation is incomplete because the client received
* a non-handshake, non-application data message while awaiting
* the ServerHello.
* In each of these case, looping will be the proper action:
* - For 1), the next iteration will read a new record and check
* if it's application data.
* - For 2), the loop condition isn't satisfied as application data
* is present, hence continue is the same as break
* - For 3), the loop condition is satisfied and read_record
* will re-deliver the message that was held back by the client
* when expecting the ServerHello.
*/
continue;
}
#if defined(MBEDTLS_SSL_RENEGOTIATION)
else if( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_PENDING )
{
if( ssl->conf->renego_max_records >= 0 )
{
if( ++ssl->renego_records_seen > ssl->conf->renego_max_records )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "renegotiation requested, "
"but not honored by client" ) );
return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
}
}
}
#endif /* MBEDTLS_SSL_RENEGOTIATION */
/* Fatal and closure alerts handled by mbedtls_ssl_read_record() */
if( ssl->in_msgtype == MBEDTLS_SSL_MSG_ALERT )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "ignoring non-fatal non-closure alert" ) );
return( MBEDTLS_ERR_SSL_WANT_READ );
}
if( ssl->in_msgtype != MBEDTLS_SSL_MSG_APPLICATION_DATA )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad application data message" ) );
return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
}
ssl->in_offt = ssl->in_msg;
/* We're going to return something now, cancel timer,
* except if handshake (renegotiation) is in progress */
if( ssl->state == MBEDTLS_SSL_HANDSHAKE_OVER )
ssl_set_timer( ssl, 0 );
#if defined(MBEDTLS_SSL_PROTO_DTLS)
/* If we requested renego but received AppData, resend HelloRequest.
* Do it now, after setting in_offt, to avoid taking this branch
* again if ssl_write_hello_request() returns WANT_WRITE */
#if defined(MBEDTLS_SSL_SRV_C) && defined(MBEDTLS_SSL_RENEGOTIATION)
if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER &&
ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_PENDING )
{
if( ( ret = ssl_resend_hello_request( ssl ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_resend_hello_request", ret );
return( ret );
}
}
#endif /* MBEDTLS_SSL_SRV_C && MBEDTLS_SSL_RENEGOTIATION */
#endif /* MBEDTLS_SSL_PROTO_DTLS */
}
n = ( len < ssl->in_msglen )
? len : ssl->in_msglen;
memcpy( buf, ssl->in_offt, n );
ssl->in_msglen -= n;
if( ssl->in_msglen == 0 )
{
/* all bytes consumed */
ssl->in_offt = NULL;
ssl->keep_current_message = 0;
}
else
{
/* more data available */
ssl->in_offt += n;
}
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= read" ) );
return( (int) n );
}
/*
* Send application data to be encrypted by the SSL layer, taking care of max
* fragment length and buffer size.
*
* According to RFC 5246 Section 6.2.1:
*
* Zero-length fragments of Application data MAY be sent as they are
* potentially useful as a traffic analysis countermeasure.
*
* Therefore, it is possible that the input message length is 0 and the
* corresponding return code is 0 on success.
*/
static int ssl_write_real( mbedtls_ssl_context *ssl,
const unsigned char *buf, size_t len )
{
int ret = mbedtls_ssl_get_max_out_record_payload( ssl );
const size_t max_len = (size_t) ret;
if( ret < 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_get_max_out_record_payload", ret );
return( ret );
}
if( len > max_len )
{
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "fragment larger than the (negotiated) "
"maximum fragment length: %d > %d",
len, max_len ) );
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
}
else
#endif
len = max_len;
}
if( ssl->out_left != 0 )
{
/*
* The user has previously tried to send the data and
* MBEDTLS_ERR_SSL_WANT_WRITE or the message was only partially
* written. In this case, we expect the high-level write function
* (e.g. mbedtls_ssl_write()) to be called with the same parameters
*/
if( ( ret = mbedtls_ssl_flush_output( ssl ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_flush_output", ret );
return( ret );
}
}
else
{
/*
* The user is trying to send a message the first time, so we need to
* copy the data into the internal buffers and setup the data structure
* to keep track of partial writes
*/
ssl->out_msglen = len;
ssl->out_msgtype = MBEDTLS_SSL_MSG_APPLICATION_DATA;
memcpy( ssl->out_msg, buf, len );
if( ( ret = mbedtls_ssl_write_record( ssl, SSL_FORCE_FLUSH ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_record", ret );
return( ret );
}
}
return( (int) len );
}
/*
* Write application data, doing 1/n-1 splitting if necessary.
*
* With non-blocking I/O, ssl_write_real() may return WANT_WRITE,
* then the caller will call us again with the same arguments, so
* remember whether we already did the split or not.
*/
#if defined(MBEDTLS_SSL_CBC_RECORD_SPLITTING)
static int ssl_write_split( mbedtls_ssl_context *ssl,
const unsigned char *buf, size_t len )
{
int ret;
if( ssl->conf->cbc_record_splitting ==
MBEDTLS_SSL_CBC_RECORD_SPLITTING_DISABLED ||
len <= 1 ||
ssl->minor_ver > MBEDTLS_SSL_MINOR_VERSION_1 ||
mbedtls_cipher_get_cipher_mode( &ssl->transform_out->cipher_ctx_enc )
!= MBEDTLS_MODE_CBC )
{
return( ssl_write_real( ssl, buf, len ) );
}
if( ssl->split_done == 0 )
{
if( ( ret = ssl_write_real( ssl, buf, 1 ) ) <= 0 )
return( ret );
ssl->split_done = 1;
}
if( ( ret = ssl_write_real( ssl, buf + 1, len - 1 ) ) <= 0 )
return( ret );
ssl->split_done = 0;
return( ret + 1 );
}
#endif /* MBEDTLS_SSL_CBC_RECORD_SPLITTING */
/*
* Write application data (public-facing wrapper)
*/
int mbedtls_ssl_write( mbedtls_ssl_context *ssl, const unsigned char *buf, size_t len )
{
int ret;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write" ) );
if( ssl == NULL || ssl->conf == NULL )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
#if defined(MBEDTLS_SSL_RENEGOTIATION)
if( ( ret = ssl_check_ctr_renegotiate( ssl ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_check_ctr_renegotiate", ret );
return( ret );
}
#endif
if( ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER )
{
if( ( ret = mbedtls_ssl_handshake( ssl ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_handshake", ret );
return( ret );
}
}
#if defined(MBEDTLS_SSL_CBC_RECORD_SPLITTING)
ret = ssl_write_split( ssl, buf, len );
#else
ret = ssl_write_real( ssl, buf, len );
#endif
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write" ) );
return( ret );
}
/*
* Notify the peer that the connection is being closed
*/
int mbedtls_ssl_close_notify( mbedtls_ssl_context *ssl )
{
int ret;
if( ssl == NULL || ssl->conf == NULL )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write close notify" ) );
if( ssl->out_left != 0 )
return( mbedtls_ssl_flush_output( ssl ) );
if( ssl->state == MBEDTLS_SSL_HANDSHAKE_OVER )
{
if( ( ret = mbedtls_ssl_send_alert_message( ssl,
MBEDTLS_SSL_ALERT_LEVEL_WARNING,
MBEDTLS_SSL_ALERT_MSG_CLOSE_NOTIFY ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_send_alert_message", ret );
return( ret );
}
}
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write close notify" ) );
return( 0 );
}
void mbedtls_ssl_transform_free( mbedtls_ssl_transform *transform )
{
if( transform == NULL )
return;
#if defined(MBEDTLS_ZLIB_SUPPORT)
deflateEnd( &transform->ctx_deflate );
inflateEnd( &transform->ctx_inflate );
#endif
mbedtls_cipher_free( &transform->cipher_ctx_enc );
mbedtls_cipher_free( &transform->cipher_ctx_dec );
#if defined(MBEDTLS_SSL_SOME_MODES_USE_MAC)
mbedtls_md_free( &transform->md_ctx_enc );
mbedtls_md_free( &transform->md_ctx_dec );
#endif
mbedtls_platform_zeroize( transform, sizeof( mbedtls_ssl_transform ) );
}
#if defined(MBEDTLS_X509_CRT_PARSE_C)
static void ssl_key_cert_free( mbedtls_ssl_key_cert *key_cert )
{
mbedtls_ssl_key_cert *cur = key_cert, *next;
while( cur != NULL )
{
next = cur->next;
mbedtls_free( cur );
cur = next;
}
}
#endif /* MBEDTLS_X509_CRT_PARSE_C */
#if defined(MBEDTLS_SSL_PROTO_DTLS)
static void ssl_buffering_free( mbedtls_ssl_context *ssl )
{
unsigned offset;
mbedtls_ssl_handshake_params * const hs = ssl->handshake;
if( hs == NULL )
return;
ssl_free_buffered_record( ssl );
for( offset = 0; offset < MBEDTLS_SSL_MAX_BUFFERED_HS; offset++ )
ssl_buffering_free_slot( ssl, offset );
}
static void ssl_buffering_free_slot( mbedtls_ssl_context *ssl,
uint8_t slot )
{
mbedtls_ssl_handshake_params * const hs = ssl->handshake;
mbedtls_ssl_hs_buffer * const hs_buf = &hs->buffering.hs[slot];
if( slot >= MBEDTLS_SSL_MAX_BUFFERED_HS )
return;
if( hs_buf->is_valid == 1 )
{
hs->buffering.total_bytes_buffered -= hs_buf->data_len;
mbedtls_platform_zeroize( hs_buf->data, hs_buf->data_len );
mbedtls_free( hs_buf->data );
memset( hs_buf, 0, sizeof( mbedtls_ssl_hs_buffer ) );
}
}
#endif /* MBEDTLS_SSL_PROTO_DTLS */
void mbedtls_ssl_handshake_free( mbedtls_ssl_context *ssl )
{
mbedtls_ssl_handshake_params *handshake = ssl->handshake;
if( handshake == NULL )
return;
#if defined(MBEDTLS_SSL_ASYNC_PRIVATE)
if( ssl->conf->f_async_cancel != NULL && handshake->async_in_progress != 0 )
{
ssl->conf->f_async_cancel( ssl );
handshake->async_in_progress = 0;
}
#endif /* MBEDTLS_SSL_ASYNC_PRIVATE */
#if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1) || \
defined(MBEDTLS_SSL_PROTO_TLS1_1)
mbedtls_md5_free( &handshake->fin_md5 );
mbedtls_sha1_free( &handshake->fin_sha1 );
#endif
#if defined(MBEDTLS_SSL_PROTO_TLS1_2)
#if defined(MBEDTLS_SHA256_C)
mbedtls_sha256_free( &handshake->fin_sha256 );
#endif
#if defined(MBEDTLS_SHA512_C)
mbedtls_sha512_free( &handshake->fin_sha512 );
#endif
#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
#if defined(MBEDTLS_DHM_C)
mbedtls_dhm_free( &handshake->dhm_ctx );
#endif
#if defined(MBEDTLS_ECDH_C)
mbedtls_ecdh_free( &handshake->ecdh_ctx );
#endif
#if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
mbedtls_ecjpake_free( &handshake->ecjpake_ctx );
#if defined(MBEDTLS_SSL_CLI_C)
mbedtls_free( handshake->ecjpake_cache );
handshake->ecjpake_cache = NULL;
handshake->ecjpake_cache_len = 0;
#endif
#endif
#if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \
defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
/* explicit void pointer cast for buggy MS compiler */
mbedtls_free( (void *) handshake->curves );
#endif
#if defined(MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED)
if( handshake->psk != NULL )
{
mbedtls_platform_zeroize( handshake->psk, handshake->psk_len );
mbedtls_free( handshake->psk );
}
#endif
#if defined(MBEDTLS_X509_CRT_PARSE_C) && \
defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
/*
* Free only the linked list wrapper, not the keys themselves
* since the belong to the SNI callback
*/
if( handshake->sni_key_cert != NULL )
{
mbedtls_ssl_key_cert *cur = handshake->sni_key_cert, *next;
while( cur != NULL )
{
next = cur->next;
mbedtls_free( cur );
cur = next;
}
}
#endif /* MBEDTLS_X509_CRT_PARSE_C && MBEDTLS_SSL_SERVER_NAME_INDICATION */
#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
mbedtls_x509_crt_restart_free( &handshake->ecrs_ctx );
#endif
#if defined(MBEDTLS_SSL_PROTO_DTLS)
mbedtls_free( handshake->verify_cookie );
ssl_flight_free( handshake->flight );
ssl_buffering_free( ssl );
#endif
mbedtls_platform_zeroize( handshake,
sizeof( mbedtls_ssl_handshake_params ) );
}
void mbedtls_ssl_session_free( mbedtls_ssl_session *session )
{
if( session == NULL )
return;
#if defined(MBEDTLS_X509_CRT_PARSE_C)
if( session->peer_cert != NULL )
{
mbedtls_x509_crt_free( session->peer_cert );
mbedtls_free( session->peer_cert );
}
#endif
#if defined(MBEDTLS_SSL_SESSION_TICKETS) && defined(MBEDTLS_SSL_CLI_C)
mbedtls_free( session->ticket );
#endif
mbedtls_platform_zeroize( session, sizeof( mbedtls_ssl_session ) );
}
/*
* Free an SSL context
*/
void mbedtls_ssl_free( mbedtls_ssl_context *ssl )
{
if( ssl == NULL )
return;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> free" ) );
if( ssl->out_buf != NULL )
{
mbedtls_platform_zeroize( ssl->out_buf, MBEDTLS_SSL_OUT_BUFFER_LEN );
mbedtls_free( ssl->out_buf );
}
if( ssl->in_buf != NULL )
{
mbedtls_platform_zeroize( ssl->in_buf, MBEDTLS_SSL_IN_BUFFER_LEN );
mbedtls_free( ssl->in_buf );
}
#if defined(MBEDTLS_ZLIB_SUPPORT)
if( ssl->compress_buf != NULL )
{
mbedtls_platform_zeroize( ssl->compress_buf, MBEDTLS_SSL_COMPRESS_BUFFER_LEN );
mbedtls_free( ssl->compress_buf );
}
#endif
if( ssl->transform )
{
mbedtls_ssl_transform_free( ssl->transform );
mbedtls_free( ssl->transform );
}
if( ssl->handshake )
{
mbedtls_ssl_handshake_free( ssl );
mbedtls_ssl_transform_free( ssl->transform_negotiate );
mbedtls_ssl_session_free( ssl->session_negotiate );
mbedtls_free( ssl->handshake );
mbedtls_free( ssl->transform_negotiate );
mbedtls_free( ssl->session_negotiate );
}
if( ssl->session )
{
mbedtls_ssl_session_free( ssl->session );
mbedtls_free( ssl->session );
}
#if defined(MBEDTLS_X509_CRT_PARSE_C)
if( ssl->hostname != NULL )
{
mbedtls_platform_zeroize( ssl->hostname, strlen( ssl->hostname ) );
mbedtls_free( ssl->hostname );
}
#endif
#if defined(MBEDTLS_SSL_HW_RECORD_ACCEL)
if( mbedtls_ssl_hw_record_finish != NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "going for mbedtls_ssl_hw_record_finish()" ) );
mbedtls_ssl_hw_record_finish( ssl );
}
#endif
#if defined(MBEDTLS_SSL_DTLS_HELLO_VERIFY) && defined(MBEDTLS_SSL_SRV_C)
mbedtls_free( ssl->cli_id );
#endif
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= free" ) );
/* Actually clear after last debug message */
mbedtls_platform_zeroize( ssl, sizeof( mbedtls_ssl_context ) );
}
/*
* Initialze mbedtls_ssl_config
*/
void mbedtls_ssl_config_init( mbedtls_ssl_config *conf )
{
memset( conf, 0, sizeof( mbedtls_ssl_config ) );
}
#if defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)
static int ssl_preset_default_hashes[] = {
#if defined(MBEDTLS_SHA512_C)
MBEDTLS_MD_SHA512,
MBEDTLS_MD_SHA384,
#endif
#if defined(MBEDTLS_SHA256_C)
MBEDTLS_MD_SHA256,
MBEDTLS_MD_SHA224,
#endif
#if defined(MBEDTLS_SHA1_C) && defined(MBEDTLS_TLS_DEFAULT_ALLOW_SHA1_IN_KEY_EXCHANGE)
MBEDTLS_MD_SHA1,
#endif
MBEDTLS_MD_NONE
};
#endif
static int ssl_preset_suiteb_ciphersuites[] = {
MBEDTLS_TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,
MBEDTLS_TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,
0
};
#if defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)
static int ssl_preset_suiteb_hashes[] = {
MBEDTLS_MD_SHA256,
MBEDTLS_MD_SHA384,
MBEDTLS_MD_NONE
};
#endif
#if defined(MBEDTLS_ECP_C)
static mbedtls_ecp_group_id ssl_preset_suiteb_curves[] = {
MBEDTLS_ECP_DP_SECP256R1,
MBEDTLS_ECP_DP_SECP384R1,
MBEDTLS_ECP_DP_NONE
};
#endif
/*
* Load default in mbedtls_ssl_config
*/
int mbedtls_ssl_config_defaults( mbedtls_ssl_config *conf,
int endpoint, int transport, int preset )
{
#if defined(MBEDTLS_DHM_C) && defined(MBEDTLS_SSL_SRV_C)
int ret;
#endif
/* Use the functions here so that they are covered in tests,
* but otherwise access member directly for efficiency */
mbedtls_ssl_conf_endpoint( conf, endpoint );
mbedtls_ssl_conf_transport( conf, transport );
/*
* Things that are common to all presets
*/
#if defined(MBEDTLS_SSL_CLI_C)
if( endpoint == MBEDTLS_SSL_IS_CLIENT )
{
conf->authmode = MBEDTLS_SSL_VERIFY_REQUIRED;
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
conf->session_tickets = MBEDTLS_SSL_SESSION_TICKETS_ENABLED;
#endif
}
#endif
#if defined(MBEDTLS_ARC4_C)
conf->arc4_disabled = MBEDTLS_SSL_ARC4_DISABLED;
#endif
#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
conf->encrypt_then_mac = MBEDTLS_SSL_ETM_ENABLED;
#endif
#if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
conf->extended_ms = MBEDTLS_SSL_EXTENDED_MS_ENABLED;
#endif
#if defined(MBEDTLS_SSL_CBC_RECORD_SPLITTING)
conf->cbc_record_splitting = MBEDTLS_SSL_CBC_RECORD_SPLITTING_ENABLED;
#endif
#if defined(MBEDTLS_SSL_DTLS_HELLO_VERIFY) && defined(MBEDTLS_SSL_SRV_C)
conf->f_cookie_write = ssl_cookie_write_dummy;
conf->f_cookie_check = ssl_cookie_check_dummy;
#endif
#if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY)
conf->anti_replay = MBEDTLS_SSL_ANTI_REPLAY_ENABLED;
#endif
#if defined(MBEDTLS_SSL_SRV_C)
conf->cert_req_ca_list = MBEDTLS_SSL_CERT_REQ_CA_LIST_ENABLED;
#endif
#if defined(MBEDTLS_SSL_PROTO_DTLS)
conf->hs_timeout_min = MBEDTLS_SSL_DTLS_TIMEOUT_DFL_MIN;
conf->hs_timeout_max = MBEDTLS_SSL_DTLS_TIMEOUT_DFL_MAX;
#endif
#if defined(MBEDTLS_SSL_RENEGOTIATION)
conf->renego_max_records = MBEDTLS_SSL_RENEGO_MAX_RECORDS_DEFAULT;
memset( conf->renego_period, 0x00, 2 );
memset( conf->renego_period + 2, 0xFF, 6 );
#endif
#if defined(MBEDTLS_DHM_C) && defined(MBEDTLS_SSL_SRV_C)
if( endpoint == MBEDTLS_SSL_IS_SERVER )
{
const unsigned char dhm_p[] =
MBEDTLS_DHM_RFC3526_MODP_2048_P_BIN;
const unsigned char dhm_g[] =
MBEDTLS_DHM_RFC3526_MODP_2048_G_BIN;
if ( ( ret = mbedtls_ssl_conf_dh_param_bin( conf,
dhm_p, sizeof( dhm_p ),
dhm_g, sizeof( dhm_g ) ) ) != 0 )
{
return( ret );
}
}
#endif
/*
* Preset-specific defaults
*/
switch( preset )
{
/*
* NSA Suite B
*/
case MBEDTLS_SSL_PRESET_SUITEB:
conf->min_major_ver = MBEDTLS_SSL_MAJOR_VERSION_3;
conf->min_minor_ver = MBEDTLS_SSL_MINOR_VERSION_3; /* TLS 1.2 */
conf->max_major_ver = MBEDTLS_SSL_MAX_MAJOR_VERSION;
conf->max_minor_ver = MBEDTLS_SSL_MAX_MINOR_VERSION;
conf->ciphersuite_list[MBEDTLS_SSL_MINOR_VERSION_0] =
conf->ciphersuite_list[MBEDTLS_SSL_MINOR_VERSION_1] =
conf->ciphersuite_list[MBEDTLS_SSL_MINOR_VERSION_2] =
conf->ciphersuite_list[MBEDTLS_SSL_MINOR_VERSION_3] =
ssl_preset_suiteb_ciphersuites;
#if defined(MBEDTLS_X509_CRT_PARSE_C)
conf->cert_profile = &mbedtls_x509_crt_profile_suiteb;
#endif
#if defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)
conf->sig_hashes = ssl_preset_suiteb_hashes;
#endif
#if defined(MBEDTLS_ECP_C)
conf->curve_list = ssl_preset_suiteb_curves;
#endif
break;
/*
* Default
*/
default:
conf->min_major_ver = ( MBEDTLS_SSL_MIN_MAJOR_VERSION >
MBEDTLS_SSL_MIN_VALID_MAJOR_VERSION ) ?
MBEDTLS_SSL_MIN_MAJOR_VERSION :
MBEDTLS_SSL_MIN_VALID_MAJOR_VERSION;
conf->min_minor_ver = ( MBEDTLS_SSL_MIN_MINOR_VERSION >
MBEDTLS_SSL_MIN_VALID_MINOR_VERSION ) ?
MBEDTLS_SSL_MIN_MINOR_VERSION :
MBEDTLS_SSL_MIN_VALID_MINOR_VERSION;
conf->max_major_ver = MBEDTLS_SSL_MAX_MAJOR_VERSION;
conf->max_minor_ver = MBEDTLS_SSL_MAX_MINOR_VERSION;
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
conf->min_minor_ver = MBEDTLS_SSL_MINOR_VERSION_2;
#endif
conf->ciphersuite_list[MBEDTLS_SSL_MINOR_VERSION_0] =
conf->ciphersuite_list[MBEDTLS_SSL_MINOR_VERSION_1] =
conf->ciphersuite_list[MBEDTLS_SSL_MINOR_VERSION_2] =
conf->ciphersuite_list[MBEDTLS_SSL_MINOR_VERSION_3] =
mbedtls_ssl_list_ciphersuites();
#if defined(MBEDTLS_X509_CRT_PARSE_C)
conf->cert_profile = &mbedtls_x509_crt_profile_default;
#endif
#if defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)
conf->sig_hashes = ssl_preset_default_hashes;
#endif
#if defined(MBEDTLS_ECP_C)
conf->curve_list = mbedtls_ecp_grp_id_list();
#endif
#if defined(MBEDTLS_DHM_C) && defined(MBEDTLS_SSL_CLI_C)
conf->dhm_min_bitlen = 1024;
#endif
}
return( 0 );
}
/*
* Free mbedtls_ssl_config
*/
void mbedtls_ssl_config_free( mbedtls_ssl_config *conf )
{
#if defined(MBEDTLS_DHM_C)
mbedtls_mpi_free( &conf->dhm_P );
mbedtls_mpi_free( &conf->dhm_G );
#endif
#if defined(MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED)
if( conf->psk != NULL )
{
mbedtls_platform_zeroize( conf->psk, conf->psk_len );
mbedtls_free( conf->psk );
conf->psk = NULL;
conf->psk_len = 0;
}
if( conf->psk_identity != NULL )
{
mbedtls_platform_zeroize( conf->psk_identity, conf->psk_identity_len );
mbedtls_free( conf->psk_identity );
conf->psk_identity = NULL;
conf->psk_identity_len = 0;
}
#endif
#if defined(MBEDTLS_X509_CRT_PARSE_C)
ssl_key_cert_free( conf->key_cert );
#endif
mbedtls_platform_zeroize( conf, sizeof( mbedtls_ssl_config ) );
}
#if defined(MBEDTLS_PK_C) && \
( defined(MBEDTLS_RSA_C) || defined(MBEDTLS_ECDSA_C) )
/*
* Convert between MBEDTLS_PK_XXX and SSL_SIG_XXX
*/
unsigned char mbedtls_ssl_sig_from_pk( mbedtls_pk_context *pk )
{
#if defined(MBEDTLS_RSA_C)
if( mbedtls_pk_can_do( pk, MBEDTLS_PK_RSA ) )
return( MBEDTLS_SSL_SIG_RSA );
#endif
#if defined(MBEDTLS_ECDSA_C)
if( mbedtls_pk_can_do( pk, MBEDTLS_PK_ECDSA ) )
return( MBEDTLS_SSL_SIG_ECDSA );
#endif
return( MBEDTLS_SSL_SIG_ANON );
}
unsigned char mbedtls_ssl_sig_from_pk_alg( mbedtls_pk_type_t type )
{
switch( type ) {
case MBEDTLS_PK_RSA:
return( MBEDTLS_SSL_SIG_RSA );
case MBEDTLS_PK_ECDSA:
case MBEDTLS_PK_ECKEY:
return( MBEDTLS_SSL_SIG_ECDSA );
default:
return( MBEDTLS_SSL_SIG_ANON );
}
}
mbedtls_pk_type_t mbedtls_ssl_pk_alg_from_sig( unsigned char sig )
{
switch( sig )
{
#if defined(MBEDTLS_RSA_C)
case MBEDTLS_SSL_SIG_RSA:
return( MBEDTLS_PK_RSA );
#endif
#if defined(MBEDTLS_ECDSA_C)
case MBEDTLS_SSL_SIG_ECDSA:
return( MBEDTLS_PK_ECDSA );
#endif
default:
return( MBEDTLS_PK_NONE );
}
}
#endif /* MBEDTLS_PK_C && ( MBEDTLS_RSA_C || MBEDTLS_ECDSA_C ) */
#if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \
defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)
/* Find an entry in a signature-hash set matching a given hash algorithm. */
mbedtls_md_type_t mbedtls_ssl_sig_hash_set_find( mbedtls_ssl_sig_hash_set_t *set,
mbedtls_pk_type_t sig_alg )
{
switch( sig_alg )
{
case MBEDTLS_PK_RSA:
return( set->rsa );
case MBEDTLS_PK_ECDSA:
return( set->ecdsa );
default:
return( MBEDTLS_MD_NONE );
}
}
/* Add a signature-hash-pair to a signature-hash set */
void mbedtls_ssl_sig_hash_set_add( mbedtls_ssl_sig_hash_set_t *set,
mbedtls_pk_type_t sig_alg,
mbedtls_md_type_t md_alg )
{
switch( sig_alg )
{
case MBEDTLS_PK_RSA:
if( set->rsa == MBEDTLS_MD_NONE )
set->rsa = md_alg;
break;
case MBEDTLS_PK_ECDSA:
if( set->ecdsa == MBEDTLS_MD_NONE )
set->ecdsa = md_alg;
break;
default:
break;
}
}
/* Allow exactly one hash algorithm for each signature. */
void mbedtls_ssl_sig_hash_set_const_hash( mbedtls_ssl_sig_hash_set_t *set,
mbedtls_md_type_t md_alg )
{
set->rsa = md_alg;
set->ecdsa = md_alg;
}
#endif /* MBEDTLS_SSL_PROTO_TLS1_2) &&
MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED */
/*
* Convert from MBEDTLS_SSL_HASH_XXX to MBEDTLS_MD_XXX
*/
mbedtls_md_type_t mbedtls_ssl_md_alg_from_hash( unsigned char hash )
{
switch( hash )
{
#if defined(MBEDTLS_MD5_C)
case MBEDTLS_SSL_HASH_MD5:
return( MBEDTLS_MD_MD5 );
#endif
#if defined(MBEDTLS_SHA1_C)
case MBEDTLS_SSL_HASH_SHA1:
return( MBEDTLS_MD_SHA1 );
#endif
#if defined(MBEDTLS_SHA256_C)
case MBEDTLS_SSL_HASH_SHA224:
return( MBEDTLS_MD_SHA224 );
case MBEDTLS_SSL_HASH_SHA256:
return( MBEDTLS_MD_SHA256 );
#endif
#if defined(MBEDTLS_SHA512_C)
case MBEDTLS_SSL_HASH_SHA384:
return( MBEDTLS_MD_SHA384 );
case MBEDTLS_SSL_HASH_SHA512:
return( MBEDTLS_MD_SHA512 );
#endif
default:
return( MBEDTLS_MD_NONE );
}
}
/*
* Convert from MBEDTLS_MD_XXX to MBEDTLS_SSL_HASH_XXX
*/
unsigned char mbedtls_ssl_hash_from_md_alg( int md )
{
switch( md )
{
#if defined(MBEDTLS_MD5_C)
case MBEDTLS_MD_MD5:
return( MBEDTLS_SSL_HASH_MD5 );
#endif
#if defined(MBEDTLS_SHA1_C)
case MBEDTLS_MD_SHA1:
return( MBEDTLS_SSL_HASH_SHA1 );
#endif
#if defined(MBEDTLS_SHA256_C)
case MBEDTLS_MD_SHA224:
return( MBEDTLS_SSL_HASH_SHA224 );
case MBEDTLS_MD_SHA256:
return( MBEDTLS_SSL_HASH_SHA256 );
#endif
#if defined(MBEDTLS_SHA512_C)
case MBEDTLS_MD_SHA384:
return( MBEDTLS_SSL_HASH_SHA384 );
case MBEDTLS_MD_SHA512:
return( MBEDTLS_SSL_HASH_SHA512 );
#endif
default:
return( MBEDTLS_SSL_HASH_NONE );
}
}
#if defined(MBEDTLS_ECP_C)
/*
* Check if a curve proposed by the peer is in our list.
* Return 0 if we're willing to use it, -1 otherwise.
*/
int mbedtls_ssl_check_curve( const mbedtls_ssl_context *ssl, mbedtls_ecp_group_id grp_id )
{
const mbedtls_ecp_group_id *gid;
if( ssl->conf->curve_list == NULL )
return( -1 );
for( gid = ssl->conf->curve_list; *gid != MBEDTLS_ECP_DP_NONE; gid++ )
if( *gid == grp_id )
return( 0 );
return( -1 );
}
#endif /* MBEDTLS_ECP_C */
#if defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)
/*
* Check if a hash proposed by the peer is in our list.
* Return 0 if we're willing to use it, -1 otherwise.
*/
int mbedtls_ssl_check_sig_hash( const mbedtls_ssl_context *ssl,
mbedtls_md_type_t md )
{
const int *cur;
if( ssl->conf->sig_hashes == NULL )
return( -1 );
for( cur = ssl->conf->sig_hashes; *cur != MBEDTLS_MD_NONE; cur++ )
if( *cur == (int) md )
return( 0 );
return( -1 );
}
#endif /* MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED */
#if defined(MBEDTLS_X509_CRT_PARSE_C)
int mbedtls_ssl_check_cert_usage( const mbedtls_x509_crt *cert,
const mbedtls_ssl_ciphersuite_t *ciphersuite,
int cert_endpoint,
uint32_t *flags )
{
int ret = 0;
#if defined(MBEDTLS_X509_CHECK_KEY_USAGE)
int usage = 0;
#endif
#if defined(MBEDTLS_X509_CHECK_EXTENDED_KEY_USAGE)
const char *ext_oid;
size_t ext_len;
#endif
#if !defined(MBEDTLS_X509_CHECK_KEY_USAGE) && \
!defined(MBEDTLS_X509_CHECK_EXTENDED_KEY_USAGE)
((void) cert);
((void) cert_endpoint);
((void) flags);
#endif
#if defined(MBEDTLS_X509_CHECK_KEY_USAGE)
if( cert_endpoint == MBEDTLS_SSL_IS_SERVER )
{
/* Server part of the key exchange */
switch( ciphersuite->key_exchange )
{
case MBEDTLS_KEY_EXCHANGE_RSA:
case MBEDTLS_KEY_EXCHANGE_RSA_PSK:
usage = MBEDTLS_X509_KU_KEY_ENCIPHERMENT;
break;
case MBEDTLS_KEY_EXCHANGE_DHE_RSA:
case MBEDTLS_KEY_EXCHANGE_ECDHE_RSA:
case MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA:
usage = MBEDTLS_X509_KU_DIGITAL_SIGNATURE;
break;
case MBEDTLS_KEY_EXCHANGE_ECDH_RSA:
case MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA:
usage = MBEDTLS_X509_KU_KEY_AGREEMENT;
break;
/* Don't use default: we want warnings when adding new values */
case MBEDTLS_KEY_EXCHANGE_NONE:
case MBEDTLS_KEY_EXCHANGE_PSK:
case MBEDTLS_KEY_EXCHANGE_DHE_PSK:
case MBEDTLS_KEY_EXCHANGE_ECDHE_PSK:
case MBEDTLS_KEY_EXCHANGE_ECJPAKE:
usage = 0;
}
}
else
{
/* Client auth: we only implement rsa_sign and mbedtls_ecdsa_sign for now */
usage = MBEDTLS_X509_KU_DIGITAL_SIGNATURE;
}
if( mbedtls_x509_crt_check_key_usage( cert, usage ) != 0 )
{
*flags |= MBEDTLS_X509_BADCERT_KEY_USAGE;
ret = -1;
}
#else
((void) ciphersuite);
#endif /* MBEDTLS_X509_CHECK_KEY_USAGE */
#if defined(MBEDTLS_X509_CHECK_EXTENDED_KEY_USAGE)
if( cert_endpoint == MBEDTLS_SSL_IS_SERVER )
{
ext_oid = MBEDTLS_OID_SERVER_AUTH;
ext_len = MBEDTLS_OID_SIZE( MBEDTLS_OID_SERVER_AUTH );
}
else
{
ext_oid = MBEDTLS_OID_CLIENT_AUTH;
ext_len = MBEDTLS_OID_SIZE( MBEDTLS_OID_CLIENT_AUTH );
}
if( mbedtls_x509_crt_check_extended_key_usage( cert, ext_oid, ext_len ) != 0 )
{
*flags |= MBEDTLS_X509_BADCERT_EXT_KEY_USAGE;
ret = -1;
}
#endif /* MBEDTLS_X509_CHECK_EXTENDED_KEY_USAGE */
return( ret );
}
#endif /* MBEDTLS_X509_CRT_PARSE_C */
/*
* Convert version numbers to/from wire format
* and, for DTLS, to/from TLS equivalent.
*
* For TLS this is the identity.
* For DTLS, use 1's complement (v -> 255 - v, and then map as follows:
* 1.0 <-> 3.2 (DTLS 1.0 is based on TLS 1.1)
* 1.x <-> 3.x+1 for x != 0 (DTLS 1.2 based on TLS 1.2)
*/
void mbedtls_ssl_write_version( int major, int minor, int transport,
unsigned char ver[2] )
{
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
{
if( minor == MBEDTLS_SSL_MINOR_VERSION_2 )
--minor; /* DTLS 1.0 stored as TLS 1.1 internally */
ver[0] = (unsigned char)( 255 - ( major - 2 ) );
ver[1] = (unsigned char)( 255 - ( minor - 1 ) );
}
else
#else
((void) transport);
#endif
{
ver[0] = (unsigned char) major;
ver[1] = (unsigned char) minor;
}
}
void mbedtls_ssl_read_version( int *major, int *minor, int transport,
const unsigned char ver[2] )
{
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
{
*major = 255 - ver[0] + 2;
*minor = 255 - ver[1] + 1;
if( *minor == MBEDTLS_SSL_MINOR_VERSION_1 )
++*minor; /* DTLS 1.0 stored as TLS 1.1 internally */
}
else
#else
((void) transport);
#endif
{
*major = ver[0];
*minor = ver[1];
}
}
int mbedtls_ssl_set_calc_verify_md( mbedtls_ssl_context *ssl, int md )
{
#if defined(MBEDTLS_SSL_PROTO_TLS1_2)
if( ssl->minor_ver != MBEDTLS_SSL_MINOR_VERSION_3 )
return MBEDTLS_ERR_SSL_INVALID_VERIFY_HASH;
switch( md )
{
#if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1)
#if defined(MBEDTLS_MD5_C)
case MBEDTLS_SSL_HASH_MD5:
return MBEDTLS_ERR_SSL_INVALID_VERIFY_HASH;
#endif
#if defined(MBEDTLS_SHA1_C)
case MBEDTLS_SSL_HASH_SHA1:
ssl->handshake->calc_verify = ssl_calc_verify_tls;
break;
#endif
#endif /* MBEDTLS_SSL_PROTO_TLS1 || MBEDTLS_SSL_PROTO_TLS1_1 */
#if defined(MBEDTLS_SHA512_C)
case MBEDTLS_SSL_HASH_SHA384:
ssl->handshake->calc_verify = ssl_calc_verify_tls_sha384;
break;
#endif
#if defined(MBEDTLS_SHA256_C)
case MBEDTLS_SSL_HASH_SHA256:
ssl->handshake->calc_verify = ssl_calc_verify_tls_sha256;
break;
#endif
default:
return MBEDTLS_ERR_SSL_INVALID_VERIFY_HASH;
}
return 0;
#else /* !MBEDTLS_SSL_PROTO_TLS1_2 */
(void) ssl;
(void) md;
return MBEDTLS_ERR_SSL_INVALID_VERIFY_HASH;
#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
}
#if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1) || \
defined(MBEDTLS_SSL_PROTO_TLS1_1)
int mbedtls_ssl_get_key_exchange_md_ssl_tls( mbedtls_ssl_context *ssl,
unsigned char *output,
unsigned char *data, size_t data_len )
{
int ret = 0;
mbedtls_md5_context mbedtls_md5;
mbedtls_sha1_context mbedtls_sha1;
mbedtls_md5_init( &mbedtls_md5 );
mbedtls_sha1_init( &mbedtls_sha1 );
/*
* digitally-signed struct {
* opaque md5_hash[16];
* opaque sha_hash[20];
* };
*
* md5_hash
* MD5(ClientHello.random + ServerHello.random
* + ServerParams);
* sha_hash
* SHA(ClientHello.random + ServerHello.random
* + ServerParams);
*/
if( ( ret = mbedtls_md5_starts_ret( &mbedtls_md5 ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_md5_starts_ret", ret );
goto exit;
}
if( ( ret = mbedtls_md5_update_ret( &mbedtls_md5,
ssl->handshake->randbytes, 64 ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_md5_update_ret", ret );
goto exit;
}
if( ( ret = mbedtls_md5_update_ret( &mbedtls_md5, data, data_len ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_md5_update_ret", ret );
goto exit;
}
if( ( ret = mbedtls_md5_finish_ret( &mbedtls_md5, output ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_md5_finish_ret", ret );
goto exit;
}
if( ( ret = mbedtls_sha1_starts_ret( &mbedtls_sha1 ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_sha1_starts_ret", ret );
goto exit;
}
if( ( ret = mbedtls_sha1_update_ret( &mbedtls_sha1,
ssl->handshake->randbytes, 64 ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_sha1_update_ret", ret );
goto exit;
}
if( ( ret = mbedtls_sha1_update_ret( &mbedtls_sha1, data,
data_len ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_sha1_update_ret", ret );
goto exit;
}
if( ( ret = mbedtls_sha1_finish_ret( &mbedtls_sha1,
output + 16 ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_sha1_finish_ret", ret );
goto exit;
}
exit:
mbedtls_md5_free( &mbedtls_md5 );
mbedtls_sha1_free( &mbedtls_sha1 );
if( ret != 0 )
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_INTERNAL_ERROR );
return( ret );
}
#endif /* MBEDTLS_SSL_PROTO_SSL3 || MBEDTLS_SSL_PROTO_TLS1 || \
MBEDTLS_SSL_PROTO_TLS1_1 */
#if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) || \
defined(MBEDTLS_SSL_PROTO_TLS1_2)
int mbedtls_ssl_get_key_exchange_md_tls1_2( mbedtls_ssl_context *ssl,
unsigned char *hash, size_t *hashlen,
unsigned char *data, size_t data_len,
mbedtls_md_type_t md_alg )
{
int ret = 0;
mbedtls_md_context_t ctx;
const mbedtls_md_info_t *md_info = mbedtls_md_info_from_type( md_alg );
*hashlen = mbedtls_md_get_size( md_info );
mbedtls_md_init( &ctx );
/*
* digitally-signed struct {
* opaque client_random[32];
* opaque server_random[32];
* ServerDHParams params;
* };
*/
if( ( ret = mbedtls_md_setup( &ctx, md_info, 0 ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_md_setup", ret );
goto exit;
}
if( ( ret = mbedtls_md_starts( &ctx ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_md_starts", ret );
goto exit;
}
if( ( ret = mbedtls_md_update( &ctx, ssl->handshake->randbytes, 64 ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_md_update", ret );
goto exit;
}
if( ( ret = mbedtls_md_update( &ctx, data, data_len ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_md_update", ret );
goto exit;
}
if( ( ret = mbedtls_md_finish( &ctx, hash ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_md_finish", ret );
goto exit;
}
exit:
mbedtls_md_free( &ctx );
if( ret != 0 )
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_INTERNAL_ERROR );
return( ret );
}
#endif /* MBEDTLS_SSL_PROTO_TLS1 || MBEDTLS_SSL_PROTO_TLS1_1 || \
MBEDTLS_SSL_PROTO_TLS1_2 */
#endif /* MBEDTLS_SSL_TLS_C */
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