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mbedtls/library/ssl_cli.c
Andrzej Kurek 84bde419e1
Add FI countermeasures to the ssl module 
This commit adds mainly buffer pointer and length duplication and checks,
but also some hamming distance and return values checking improvements.
Signed-off-by: Andrzej Kurek <andrzej.kurek@arm.com>
2020-07-06 15:27:34 -04:00

4352 lines
144 KiB
C
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/*
* SSLv3/TLSv1 client-side 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)
*/
#if !defined(MBEDTLS_CONFIG_FILE)
#include "mbedtls/config.h"
#else
#include MBEDTLS_CONFIG_FILE
#endif
#if defined(MBEDTLS_SSL_CLI_C)
#include "mbedtls/platform.h"
#if !defined(MBEDTLS_PLATFORM_C)
#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 <string.h>
#include <stdint.h>
#if defined(MBEDTLS_HAVE_TIME)
#include "mbedtls/platform_time.h"
#endif
#include "mbedtls/platform.h"
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
#include "mbedtls/platform_util.h"
#endif
#if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION) && !defined(MBEDTLS_X509_REMOVE_HOSTNAME_VERIFICATION)
static void ssl_write_hostname_ext( mbedtls_ssl_context *ssl,
unsigned char *buf,
size_t *olen )
{
unsigned char *p = buf;
const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN;
size_t hostname_len;
*olen = 0;
if( ssl->hostname == NULL )
return;
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding server name extension: %s",
ssl->hostname ) );
hostname_len = strlen( ssl->hostname );
if( end < p || (size_t)( end - p ) < hostname_len + 9 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
return;
}
/*
* Sect. 3, RFC 6066 (TLS Extensions Definitions)
*
* In order to provide any of the server names, clients MAY include an
* extension of type "server_name" in the (extended) client hello. The
* "extension_data" field of this extension SHALL contain
* "ServerNameList" where:
*
* struct {
* NameType name_type;
* select (name_type) {
* case host_name: HostName;
* } name;
* } ServerName;
*
* enum {
* host_name(0), (255)
* } NameType;
*
* opaque HostName<1..2^16-1>;
*
* struct {
* ServerName server_name_list<1..2^16-1>
* } ServerNameList;
*
*/
p = mbedtls_platform_put_uint16_be( p, MBEDTLS_TLS_EXT_SERVERNAME );
p = mbedtls_platform_put_uint16_be( p, hostname_len + 5 );
p = mbedtls_platform_put_uint16_be( p, hostname_len + 3 );
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SERVERNAME_HOSTNAME ) & 0xFF );
p = mbedtls_platform_put_uint16_be( p, hostname_len );
mbedtls_platform_memcpy( p, ssl->hostname, hostname_len );
*olen = hostname_len + 9;
}
#endif /* MBEDTLS_SSL_SERVER_NAME_INDICATION && !MBEDTLS_X509_REMOVE_HOSTNAME_VERIFICATION */
#if defined(MBEDTLS_SSL_RENEGOTIATION)
static void ssl_write_renegotiation_ext( mbedtls_ssl_context *ssl,
unsigned char *buf,
size_t *olen )
{
unsigned char *p = buf;
const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN;
*olen = 0;
/* We're always including an TLS_EMPTY_RENEGOTIATION_INFO_SCSV in the
* initial ClientHello, in which case also adding the renegotiation
* info extension is NOT RECOMMENDED as per RFC 5746 Section 3.4. */
if( ssl->renego_status != MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS )
return;
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding renegotiation extension" ) );
if( end < p || (size_t)( end - p ) < 5 + ssl->verify_data_len )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
return;
}
/*
* Secure renegotiation
*/
p = mbedtls_platform_put_uint16_be( p, MBEDTLS_TLS_EXT_RENEGOTIATION_INFO );
*p++ = 0x00;
*p++ = ( ssl->verify_data_len + 1 ) & 0xFF;
*p++ = ssl->verify_data_len & 0xFF;
mbedtls_platform_memcpy( p, ssl->own_verify_data, ssl->verify_data_len );
*olen = 5 + ssl->verify_data_len;
}
#endif /* MBEDTLS_SSL_RENEGOTIATION */
/*
* Only if we handle at least one key exchange that needs signatures.
*/
#if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \
defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)
static void ssl_write_signature_algorithms_ext( mbedtls_ssl_context *ssl,
unsigned char *buf,
size_t *olen )
{
unsigned char *p = buf;
const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN;
size_t sig_alg_len = 0;
#if defined(MBEDTLS_RSA_C) || defined(MBEDTLS_ECDSA_C) || \
defined(MBEDTLS_USE_TINYCRYPT)
unsigned char *sig_alg_list = buf + 6;
#endif
*olen = 0;
if( mbedtls_ssl_conf_get_max_minor_ver( ssl->conf ) !=
MBEDTLS_SSL_MINOR_VERSION_3 )
{
return;
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding signature_algorithms extension" ) );
MBEDTLS_SSL_BEGIN_FOR_EACH_SIG_HASH_TLS( hash )
((void) hash);
#if defined(MBEDTLS_ECDSA_C) || defined(MBEDTLS_USE_TINYCRYPT)
sig_alg_len += 2;
#endif
#if defined(MBEDTLS_RSA_C)
sig_alg_len += 2;
#endif
MBEDTLS_SSL_END_FOR_EACH_SIG_HASH_TLS
if( end < p || (size_t)( end - p ) < sig_alg_len + 6 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
return;
}
/*
* Prepare signature_algorithms extension (TLS 1.2)
*/
sig_alg_len = 0;
MBEDTLS_SSL_BEGIN_FOR_EACH_SIG_HASH_TLS( hash )
#if defined(MBEDTLS_ECDSA_C) || defined(MBEDTLS_USE_TINYCRYPT)
sig_alg_list[sig_alg_len++] = hash;
sig_alg_list[sig_alg_len++] = MBEDTLS_SSL_SIG_ECDSA;
#endif
#if defined(MBEDTLS_RSA_C)
sig_alg_list[sig_alg_len++] = hash;
sig_alg_list[sig_alg_len++] = MBEDTLS_SSL_SIG_RSA;
#endif
MBEDTLS_SSL_END_FOR_EACH_SIG_HASH_TLS
/*
* enum {
* none(0), md5(1), sha1(2), sha224(3), sha256(4), sha384(5),
* sha512(6), (255)
* } HashAlgorithm;
*
* enum { anonymous(0), rsa(1), dsa(2), ecdsa(3), (255) }
* SignatureAlgorithm;
*
* struct {
* HashAlgorithm hash;
* SignatureAlgorithm signature;
* } SignatureAndHashAlgorithm;
*
* SignatureAndHashAlgorithm
* supported_signature_algorithms<2..2^16-2>;
*/
p = mbedtls_platform_put_uint16_be( p, MBEDTLS_TLS_EXT_SIG_ALG );
p = mbedtls_platform_put_uint16_be( p, ( sig_alg_len + 2 ) );
p = mbedtls_platform_put_uint16_be( p, sig_alg_len );
*olen = 6 + sig_alg_len;
}
#endif /* MBEDTLS_SSL_PROTO_TLS1_2 &&
MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED */
#if defined(MBEDTLS_ECDH_C) || \
defined(MBEDTLS_ECDSA_C) || \
defined(MBEDTLS_USE_TINYCRYPT) || \
defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
static size_t ssl_get_ec_curve_list_length( mbedtls_ssl_context *ssl )
{
size_t ec_list_len = 0;
MBEDTLS_SSL_BEGIN_FOR_EACH_SUPPORTED_EC_TLS_ID( tls_id )
((void) tls_id);
ec_list_len++;
MBEDTLS_SSL_END_FOR_EACH_SUPPORTED_EC_TLS_ID
return( ec_list_len );
}
static void ssl_write_supported_elliptic_curves_ext( mbedtls_ssl_context *ssl,
unsigned char *buf,
size_t *olen )
{
unsigned char *p = buf;
const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN;
size_t elliptic_curve_len = 0;
*olen = 0;
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding supported_elliptic_curves extension" ) );
/* Each elliptic curve is encoded in 2 bytes. */
elliptic_curve_len = 2 * ssl_get_ec_curve_list_length( ssl );
if( elliptic_curve_len == 0 )
return;
if( end < p || (size_t)( end - p ) < 6 + elliptic_curve_len )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
return;
}
p = mbedtls_platform_put_uint16_be( p, MBEDTLS_TLS_EXT_SUPPORTED_ELLIPTIC_CURVES );
p = mbedtls_platform_put_uint16_be( p, elliptic_curve_len + 2 );
p = mbedtls_platform_put_uint16_be( p, elliptic_curve_len );
MBEDTLS_SSL_BEGIN_FOR_EACH_SUPPORTED_EC_TLS_ID( tls_id )
p = mbedtls_platform_put_uint16_be( p, tls_id );
MBEDTLS_SSL_END_FOR_EACH_SUPPORTED_EC_TLS_ID
*olen = 6 + elliptic_curve_len;
}
static void ssl_write_supported_point_formats_ext( mbedtls_ssl_context *ssl,
unsigned char *buf,
size_t *olen )
{
unsigned char *p = buf;
const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN;
*olen = 0;
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding supported_point_formats extension" ) );
if( end < p || (size_t)( end - p ) < 6 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
return;
}
p = mbedtls_platform_put_uint16_be( p, MBEDTLS_TLS_EXT_SUPPORTED_POINT_FORMATS );
*p++ = 0x00;
*p++ = 2;
*p++ = 1;
*p++ = MBEDTLS_SSL_EC_PF_UNCOMPRESSED;
*olen = 6;
}
#endif /* MBEDTLS_ECDH_C || MBEDTLS_ECDSA_C || MBEDTLS_USE_TINYCRYPT ||
MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
#if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
static void ssl_write_ecjpake_kkpp_ext( mbedtls_ssl_context *ssl,
unsigned char *buf,
size_t *olen )
{
int ret;
unsigned char *p = buf;
const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN;
size_t kkpp_len;
*olen = 0;
/* Skip costly extension if we can't use EC J-PAKE anyway */
if( mbedtls_ecjpake_check( &ssl->handshake->ecjpake_ctx ) != 0 )
return;
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding ecjpake_kkpp extension" ) );
if( end - p < 4 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
return;
}
p = mbedtls_platform_put_uint16_be( p, MBEDTLS_TLS_EXT_ECJPAKE_KKPP );
/*
* We may need to send ClientHello multiple times for Hello verification.
* We don't want to compute fresh values every time (both for performance
* and consistency reasons), so cache the extension content.
*/
if( ssl->handshake->ecjpake_cache == NULL ||
ssl->handshake->ecjpake_cache_len == 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "generating new ecjpake parameters" ) );
ret = mbedtls_ecjpake_write_round_one( &ssl->handshake->ecjpake_ctx,
p + 2, end - p - 2, &kkpp_len,
mbedtls_ssl_conf_get_frng( ssl->conf ),
mbedtls_ssl_conf_get_prng( ssl->conf ) );
if( ret != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1 , "mbedtls_ecjpake_write_round_one", ret );
return;
}
ssl->handshake->ecjpake_cache = mbedtls_calloc( 1, kkpp_len );
if( ssl->handshake->ecjpake_cache == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "allocation failed" ) );
return;
}
mbedtls_platform_memcpy( ssl->handshake->ecjpake_cache, p + 2, kkpp_len );
ssl->handshake->ecjpake_cache_len = kkpp_len;
}
else
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "re-using cached ecjpake parameters" ) );
kkpp_len = ssl->handshake->ecjpake_cache_len;
if( (size_t)( end - p - 2 ) < kkpp_len )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
return;
}
mbedtls_platform_memcpy( p + 2, ssl->handshake->ecjpake_cache, kkpp_len );
}
p = mbedtls_platform_put_uint16_be( p, kkpp_len );
*olen = kkpp_len + 4;
}
#endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
static void ssl_write_cid_ext( mbedtls_ssl_context *ssl,
unsigned char *buf,
size_t *olen )
{
unsigned char *p = buf;
size_t ext_len;
const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN;
/*
* Quoting draft-ietf-tls-dtls-connection-id-05
* https://tools.ietf.org/html/draft-ietf-tls-dtls-connection-id-05
*
* struct {
* opaque cid<0..2^8-1>;
* } ConnectionId;
*/
*olen = 0;
if( MBEDTLS_SSL_TRANSPORT_IS_TLS( ssl->conf->transport ) ||
ssl->negotiate_cid == MBEDTLS_SSL_CID_DISABLED )
{
return;
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding CID extension" ) );
/* ssl->own_cid_len is at most MBEDTLS_SSL_CID_IN_LEN_MAX
* which is at most 255, so the increment cannot overflow. */
if( end < p || (size_t)( end - p ) < (unsigned)( ssl->own_cid_len + 5 ) )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
return;
}
/* Add extension ID + size */
p = mbedtls_platform_put_uint16_be( p, MBEDTLS_TLS_EXT_CID );
ext_len = (size_t) ssl->own_cid_len + 1;
p = mbedtls_platform_put_uint16_be( p, ext_len );
*p++ = (uint8_t) ssl->own_cid_len;
/* Not using more secure mbedtls_platform_memcpy as cid is public */
memcpy( p, ssl->own_cid, ssl->own_cid_len );
*olen = ssl->own_cid_len + 5;
}
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
#if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
static void ssl_write_max_fragment_length_ext( mbedtls_ssl_context *ssl,
unsigned char *buf,
size_t *olen )
{
unsigned char *p = buf;
const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN;
*olen = 0;
if( ssl->conf->mfl_code == MBEDTLS_SSL_MAX_FRAG_LEN_NONE ) {
return;
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding max_fragment_length extension" ) );
if( end < p || (size_t)( end - p ) < 5 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
return;
}
p = mbedtls_platform_put_uint16_be( p, MBEDTLS_TLS_EXT_MAX_FRAGMENT_LENGTH );
*p++ = 0x00;
*p++ = 1;
*p++ = ssl->conf->mfl_code;
*olen = 5;
}
#endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */
#if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
static void ssl_write_truncated_hmac_ext( mbedtls_ssl_context *ssl,
unsigned char *buf, size_t *olen )
{
unsigned char *p = buf;
const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN;
*olen = 0;
if( ssl->conf->trunc_hmac == MBEDTLS_SSL_TRUNC_HMAC_DISABLED )
{
return;
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding truncated_hmac extension" ) );
if( end < p || (size_t)( end - p ) < 4 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
return;
}
p = mbedtls_platform_put_uint16_be( p, MBEDTLS_TLS_EXT_TRUNCATED_HMAC );
*p++ = 0x00;
*p++ = 0x00;
*olen = 4;
}
#endif /* MBEDTLS_SSL_TRUNCATED_HMAC */
#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
static void ssl_write_encrypt_then_mac_ext( mbedtls_ssl_context *ssl,
unsigned char *buf, size_t *olen )
{
unsigned char *p = buf;
const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN;
*olen = 0;
if( ssl->conf->encrypt_then_mac == MBEDTLS_SSL_ETM_DISABLED ||
mbedtls_ssl_conf_get_max_minor_ver( ssl->conf ) ==
MBEDTLS_SSL_MINOR_VERSION_0 )
{
return;
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding encrypt_then_mac "
"extension" ) );
if( end < p || (size_t)( end - p ) < 4 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
return;
}
p = mbedtls_platform_put_uint16_be( p, MBEDTLS_TLS_EXT_ENCRYPT_THEN_MAC );
*p++ = 0x00;
*p++ = 0x00;
*olen = 4;
}
#endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */
#if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
static void ssl_write_extended_ms_ext( mbedtls_ssl_context *ssl,
unsigned char *buf, size_t *olen )
{
unsigned char *p = buf;
const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN;
*olen = 0;
if( mbedtls_ssl_conf_get_ems( ssl->conf ) ==
MBEDTLS_SSL_EXTENDED_MS_DISABLED ||
mbedtls_ssl_conf_get_max_minor_ver( ssl->conf ) ==
MBEDTLS_SSL_MINOR_VERSION_0 )
{
return;
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding extended_master_secret "
"extension" ) );
if( end < p || (size_t)( end - p ) < 4 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
return;
}
p = mbedtls_platform_put_uint16_be( p, MBEDTLS_TLS_EXT_EXTENDED_MASTER_SECRET );
*p++ = 0x00;
*p++ = 0x00;
*olen = 4;
}
#endif /* MBEDTLS_SSL_EXTENDED_MASTER_SECRET */
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
static void ssl_write_session_ticket_ext( mbedtls_ssl_context *ssl,
unsigned char *buf, size_t *olen )
{
unsigned char *p = buf;
const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN;
size_t tlen = ssl->session_negotiate->ticket_len;
*olen = 0;
if( ssl->conf->session_tickets == MBEDTLS_SSL_SESSION_TICKETS_DISABLED )
{
return;
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding session ticket extension" ) );
if( end < p || (size_t)( end - p ) < 4 + tlen )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
return;
}
p = mbedtls_platform_put_uint16_be( p, MBEDTLS_TLS_EXT_SESSION_TICKET );
p = mbedtls_platform_put_uint16_be( p, tlen );
*olen = 4;
if( ssl->session_negotiate->ticket == NULL || tlen == 0 )
{
return;
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "sending session ticket of length %d", tlen ) );
mbedtls_platform_memcpy( p, ssl->session_negotiate->ticket, tlen );
*olen += tlen;
}
#endif /* MBEDTLS_SSL_SESSION_TICKETS */
#if defined(MBEDTLS_SSL_ALPN)
static void ssl_write_alpn_ext( mbedtls_ssl_context *ssl,
unsigned char *buf, size_t *olen )
{
unsigned char *p = buf;
const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN;
size_t alpnlen = 0;
const char **cur;
*olen = 0;
if( ssl->conf->alpn_list == NULL )
{
return;
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding alpn extension" ) );
for( cur = ssl->conf->alpn_list; *cur != NULL; cur++ )
alpnlen += (unsigned char)( strlen( *cur ) & 0xFF ) + 1;
if( end < p || (size_t)( end - p ) < 6 + alpnlen )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
return;
}
p = mbedtls_platform_put_uint16_be( p, MBEDTLS_TLS_EXT_ALPN );
/*
* opaque ProtocolName<1..2^8-1>;
*
* struct {
* ProtocolName protocol_name_list<2..2^16-1>
* } ProtocolNameList;
*/
/* Skip writing extension and list length for now */
p += 4;
for( cur = ssl->conf->alpn_list; *cur != NULL; cur++ )
{
*p = (unsigned char)( strlen( *cur ) & 0xFF );
mbedtls_platform_memcpy( p + 1, *cur, *p );
p += 1 + *p;
}
*olen = p - buf;
/* List length = olen - 2 (ext_type) - 2 (ext_len) - 2 (list_len) */
(void)mbedtls_platform_put_uint16_be( &buf[4], ( *olen - 6 ) );
/* Extension length = olen - 2 (ext_type) - 2 (ext_len) */
(void)mbedtls_platform_put_uint16_be( &buf[2], ( *olen - 4 ) );
}
#endif /* MBEDTLS_SSL_ALPN */
/*
* Generate random bytes for ClientHello
*/
static int ssl_generate_random( mbedtls_ssl_context *ssl )
{
int ret = MBEDTLS_ERR_PLATFORM_FAULT_DETECTED;
unsigned char *p = ssl->handshake->randbytes;
#if defined(MBEDTLS_HAVE_TIME)
mbedtls_time_t t;
#endif
ssl->handshake->hello_random_set = MBEDTLS_SSL_FI_FLAG_UNSET;
/*
* When responding to a verify request, MUST reuse random (RFC 6347 4.2.1)
*/
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( MBEDTLS_SSL_TRANSPORT_IS_DTLS( ssl->conf->transport ) &&
ssl->handshake->verify_cookie != NULL )
{
return( 0 );
}
#endif
#if defined(MBEDTLS_HAVE_TIME)
t = mbedtls_time( NULL );
p = mbedtls_platform_put_uint32_be( p, (uint32_t) t );
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, current time: %lu", t ) );
#else
if( ( ret = mbedtls_ssl_conf_get_frng( ssl->conf )
( mbedtls_ssl_conf_get_prng( ssl->conf ), p, 4 ) ) != 0 )
{
return( ret );
}
p += 4;
#endif /* MBEDTLS_HAVE_TIME */
ret = mbedtls_ssl_conf_get_frng( ssl->conf )
( mbedtls_ssl_conf_get_prng( ssl->conf ), p, 28 );
if( ret == 0 )
{
mbedtls_platform_random_delay();
if( ret == 0 )
{
ssl->handshake->hello_random_set = MBEDTLS_SSL_FI_FLAG_SET;
return( 0 );
}
else
{
ret = MBEDTLS_ERR_PLATFORM_FAULT_DETECTED;
}
}
return( ret );
}
/**
* \brief Validate cipher suite against config in SSL context.
*
* \param suite_info cipher suite to validate
* \param ssl SSL context
* \param min_minor_ver Minimal minor version to accept a cipher suite
* \param max_minor_ver Maximal minor version to accept a cipher suite
*
* \return 0 if valid, else 1
*/
static int ssl_validate_ciphersuite( mbedtls_ssl_ciphersuite_handle_t suite_info,
const mbedtls_ssl_context * ssl,
int min_minor_ver, int max_minor_ver )
{
(void) ssl;
if( suite_info == MBEDTLS_SSL_CIPHERSUITE_INVALID_HANDLE )
return( 1 );
if( mbedtls_ssl_ver_gt( mbedtls_ssl_suite_get_min_minor_ver( suite_info ),
max_minor_ver ) ||
mbedtls_ssl_ver_lt( mbedtls_ssl_suite_get_max_minor_ver( suite_info ),
min_minor_ver ) )
{
return( 1 );
}
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( MBEDTLS_SSL_TRANSPORT_IS_DTLS( ssl->conf->transport ) &&
( mbedtls_ssl_suite_get_flags( suite_info ) &
MBEDTLS_CIPHERSUITE_NODTLS ) != 0 )
{
return( 1 );
}
#endif
#if defined(MBEDTLS_ARC4_C)
if( ssl->conf->arc4_disabled == MBEDTLS_SSL_ARC4_DISABLED &&
mbedtls_ssl_suite_get_cipher( suite_info ) == MBEDTLS_CIPHER_ARC4_128 )
{
return( 1 );
}
#endif
#if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
if( mbedtls_ssl_suite_get_key_exchange( suite_info ) ==
MBEDTLS_KEY_EXCHANGE_ECJPAKE &&
mbedtls_ecjpake_check( &ssl->handshake->ecjpake_ctx ) != 0 )
{
return( 1 );
}
#endif
return( 0 );
}
static int ssl_write_client_hello( mbedtls_ssl_context *ssl )
{
int ret;
size_t i, n, olen, ext_len = 0;
unsigned char *buf;
unsigned char *p, *q;
unsigned char offer_compress;
#if defined(MBEDTLS_USE_TINYCRYPT) || \
defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \
defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
int uses_ec = 0;
#endif
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write client hello" ) );
if( mbedtls_ssl_conf_get_frng( ssl->conf ) == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "no RNG provided") );
return( MBEDTLS_ERR_SSL_NO_RNG );
}
if( mbedtls_ssl_get_renego_status( ssl ) == MBEDTLS_SSL_INITIAL_HANDSHAKE )
{
#if !defined(MBEDTLS_SSL_CONF_FIXED_MAJOR_VER)
ssl->major_ver = mbedtls_ssl_conf_get_min_major_ver( ssl->conf );
#endif /* !MBEDTLS_SSL_CONF_FIXED_MAJOR_VER */
#if !defined(MBEDTLS_SSL_CONF_FIXED_MINOR_VER)
ssl->minor_ver = mbedtls_ssl_conf_get_min_minor_ver( ssl->conf );
#endif /* !MBEDTLS_SSL_CONF_FIXED_MINOR_VER */
}
if( mbedtls_ssl_conf_get_max_major_ver( ssl->conf ) == 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "configured max major version is invalid, "
"consider using mbedtls_ssl_config_defaults()" ) );
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
}
/*
* 0 . 0 handshake type
* 1 . 3 handshake length
* 4 . 5 highest version supported
* 6 . 9 current UNIX time
* 10 . 37 random bytes
*/
buf = ssl->out_msg;
p = buf + 4;
mbedtls_ssl_write_version( mbedtls_ssl_conf_get_max_major_ver( ssl->conf ),
mbedtls_ssl_conf_get_max_minor_ver( ssl->conf ),
ssl->conf->transport, p );
p += 2;
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, max version: [%d:%d]",
buf[4], buf[5] ) );
if( ( ret = ssl_generate_random( ssl ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_generate_random", ret );
return( ret );
}
mbedtls_platform_memcpy( p, ssl->handshake->randbytes, 32 );
MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, random bytes", p, 32 );
p += 32;
/*
* 38 . 38 session id length
* 39 . 39+n session id
* 39+n . 39+n DTLS only: cookie length (1 byte)
* 40+n . .. DTSL only: cookie
* .. . .. ciphersuitelist length (2 bytes)
* .. . .. ciphersuitelist
* .. . .. compression methods length (1 byte)
* .. . .. compression methods
* .. . .. extensions length (2 bytes)
* .. . .. extensions
*/
/*
* We'll write a session of non-zero length if resumption was requested
* by the user, we're not renegotiating, and the session ID is of
* appropriate length. Otherwise make the length 0 (for now, see next code
* block for behaviour with tickets).
*/
if( mbedtls_ssl_handshake_get_resume( ssl->handshake ) == MBEDTLS_SSL_FI_FLAG_UNSET ||
mbedtls_ssl_get_renego_status( ssl ) != MBEDTLS_SSL_INITIAL_HANDSHAKE ||
ssl->session_negotiate->id_len < 16 ||
ssl->session_negotiate->id_len > 32 )
{
n = 0;
}
else
{
n = ssl->session_negotiate->id_len;
}
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
/*
* RFC 5077 section 3.4: "When presenting a ticket, the client MAY
* generate and include a Session ID in the TLS ClientHello."
*/
if( mbedtls_ssl_get_renego_status( ssl ) == MBEDTLS_SSL_INITIAL_HANDSHAKE &&
ssl->session_negotiate->ticket != NULL &&
ssl->session_negotiate->ticket_len != 0 )
{
ret = mbedtls_ssl_conf_get_frng( ssl->conf )
( mbedtls_ssl_conf_get_prng( ssl->conf ), ssl->session_negotiate->id, 32 );
if( ret != 0 )
return( ret );
ssl->session_negotiate->id_len = n = 32;
}
#endif /* MBEDTLS_SSL_SESSION_TICKETS */
*p++ = (unsigned char) n;
for( i = 0; i < n; i++ )
*p++ = ssl->session_negotiate->id[i];
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, session id len.: %d", n ) );
MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, session id", buf + 39, n );
/*
* DTLS cookie
*/
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( MBEDTLS_SSL_TRANSPORT_IS_DTLS( ssl->conf->transport ) )
{
if( ssl->handshake->verify_cookie == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "no verify cookie to send" ) );
*p++ = 0;
}
else
{
MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, cookie",
ssl->handshake->verify_cookie,
ssl->handshake->verify_cookie_len );
*p++ = ssl->handshake->verify_cookie_len;
mbedtls_platform_memcpy( p, ssl->handshake->verify_cookie,
ssl->handshake->verify_cookie_len );
p += ssl->handshake->verify_cookie_len;
}
}
#endif
/*
* Ciphersuite list
*/
/* Skip writing ciphersuite length for now */
n = 0;
q = p;
p += 2;
MBEDTLS_SSL_BEGIN_FOR_EACH_CIPHERSUITE( ssl,
mbedtls_ssl_get_minor_ver( ssl ),
ciphersuite_info )
{
if( ssl_validate_ciphersuite( ciphersuite_info, ssl,
mbedtls_ssl_conf_get_min_minor_ver( ssl->conf ),
mbedtls_ssl_conf_get_max_minor_ver( ssl->conf ) ) != 0 )
{
continue;
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, add ciphersuite: %04x",
mbedtls_ssl_suite_get_id( ciphersuite_info ) ) );
#if defined(MBEDTLS_USE_TINYCRYPT) || \
defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \
defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
uses_ec |= mbedtls_ssl_ciphersuite_uses_ec( ciphersuite_info );
#endif
n++;
*p++ = (unsigned char)(
mbedtls_ssl_suite_get_id( ciphersuite_info ) >> 8 );
*p++ = (unsigned char)(
mbedtls_ssl_suite_get_id( ciphersuite_info ) );
}
MBEDTLS_SSL_END_FOR_EACH_CIPHERSUITE
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, got %d ciphersuites (excluding SCSVs)", n ) );
/*
* Add TLS_EMPTY_RENEGOTIATION_INFO_SCSV
*/
if( mbedtls_ssl_get_renego_status( ssl ) == MBEDTLS_SSL_INITIAL_HANDSHAKE )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "adding EMPTY_RENEGOTIATION_INFO_SCSV" ) );
p = mbedtls_platform_put_uint16_be( p, MBEDTLS_SSL_EMPTY_RENEGOTIATION_INFO );
n++;
}
/* Some versions of OpenSSL don't handle it correctly if not at end */
#if defined(MBEDTLS_SSL_FALLBACK_SCSV)
if( ssl->conf->fallback == MBEDTLS_SSL_IS_FALLBACK )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "adding FALLBACK_SCSV" ) );
p = mbedtls_platform_put_uint16_be( p, MBEDTLS_SSL_FALLBACK_SCSV_VALUE );
n++;
}
#endif
*q++ = (unsigned char)( n >> 7 );
*q++ = (unsigned char)( n << 1 );
#if defined(MBEDTLS_ZLIB_SUPPORT)
offer_compress = 1;
#else
offer_compress = 0;
#endif
/*
* We don't support compression with DTLS right now: if many records come
* in the same datagram, uncompressing one could overwrite the next one.
* We don't want to add complexity for handling that case unless there is
* an actual need for it.
*/
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( MBEDTLS_SSL_TRANSPORT_IS_DTLS( ssl->conf->transport ) )
offer_compress = 0;
#endif
if( offer_compress )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, compress len.: %d", 2 ) );
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, compress alg.: %d %d",
MBEDTLS_SSL_COMPRESS_DEFLATE, MBEDTLS_SSL_COMPRESS_NULL ) );
*p++ = 2;
*p++ = MBEDTLS_SSL_COMPRESS_DEFLATE;
*p++ = MBEDTLS_SSL_COMPRESS_NULL;
}
else
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, compress len.: %d", 1 ) );
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, compress alg.: %d",
MBEDTLS_SSL_COMPRESS_NULL ) );
*p++ = 1;
*p++ = MBEDTLS_SSL_COMPRESS_NULL;
}
// First write extensions, then the total length
//
#if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION) && !defined(MBEDTLS_X509_REMOVE_HOSTNAME_VERIFICATION)
ssl_write_hostname_ext( ssl, p + 2 + ext_len, &olen );
ext_len += olen;
#endif
/* Note that TLS_EMPTY_RENEGOTIATION_INFO_SCSV is always added
* even if MBEDTLS_SSL_RENEGOTIATION is not defined. */
#if defined(MBEDTLS_SSL_RENEGOTIATION)
ssl_write_renegotiation_ext( ssl, p + 2 + ext_len, &olen );
ext_len += olen;
#endif
#if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \
defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)
ssl_write_signature_algorithms_ext( ssl, p + 2 + ext_len, &olen );
ext_len += olen;
#endif
#if defined(MBEDTLS_USE_TINYCRYPT) || \
defined(MBEDTLS_ECDH_C) || \
defined(MBEDTLS_ECDSA_C) || \
defined(MBEDTLS_USE_TINYCRYPT) || \
defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
if( uses_ec )
{
ssl_write_supported_elliptic_curves_ext( ssl, p + 2 + ext_len, &olen );
ext_len += olen;
ssl_write_supported_point_formats_ext( ssl, p + 2 + ext_len, &olen );
ext_len += olen;
}
#endif
#if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
ssl_write_ecjpake_kkpp_ext( ssl, p + 2 + ext_len, &olen );
ext_len += olen;
#endif
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
ssl_write_cid_ext( ssl, p + 2 + ext_len, &olen );
ext_len += olen;
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
#if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
ssl_write_max_fragment_length_ext( ssl, p + 2 + ext_len, &olen );
ext_len += olen;
#endif
#if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
ssl_write_truncated_hmac_ext( ssl, p + 2 + ext_len, &olen );
ext_len += olen;
#endif
#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
ssl_write_encrypt_then_mac_ext( ssl, p + 2 + ext_len, &olen );
ext_len += olen;
#endif
#if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
ssl_write_extended_ms_ext( ssl, p + 2 + ext_len, &olen );
ext_len += olen;
#endif
#if defined(MBEDTLS_SSL_ALPN)
ssl_write_alpn_ext( ssl, p + 2 + ext_len, &olen );
ext_len += olen;
#endif
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
ssl_write_session_ticket_ext( ssl, p + 2 + ext_len, &olen );
ext_len += olen;
#endif
/* olen unused if all extensions are disabled */
((void) olen);
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, total extension length: %d",
ext_len ) );
if( ext_len > 0 )
{
p = mbedtls_platform_put_uint16_be( p, ext_len );
p += ext_len;
}
ssl->out_msglen = p - buf;
ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE;
ssl->out_msg[0] = MBEDTLS_SSL_HS_CLIENT_HELLO;
ssl->state = MBEDTLS_SSL_SERVER_HELLO;
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( MBEDTLS_SSL_TRANSPORT_IS_DTLS( ssl->conf->transport ) )
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( MBEDTLS_SSL_TRANSPORT_IS_DTLS( ssl->conf->transport ) &&
( ret = mbedtls_ssl_flight_transmit( ssl ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_flight_transmit", ret );
return( ret );
}
#endif /* MBEDTLS_SSL_PROTO_DTLS */
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write client hello" ) );
return( 0 );
}
static int ssl_parse_renegotiation_info( mbedtls_ssl_context *ssl,
const unsigned char *buf,
size_t len )
{
#if defined(MBEDTLS_SSL_RENEGOTIATION)
if( ssl->renego_status != MBEDTLS_SSL_INITIAL_HANDSHAKE )
{
/* Check verify-data in constant-time. The length OTOH is no secret */
if( len != 1 + ssl->verify_data_len * 2 ||
buf[0] != ssl->verify_data_len * 2 ||
mbedtls_platform_memcmp( buf + 1,
ssl->own_verify_data, ssl->verify_data_len ) != 0 ||
mbedtls_platform_memcmp( buf + 1 + ssl->verify_data_len,
ssl->peer_verify_data, ssl->verify_data_len ) != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "non-matching renegotiation info" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
}
else
#endif /* MBEDTLS_SSL_RENEGOTIATION */
{
if( len != 1 || buf[0] != 0x00 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "non-zero length renegotiation info" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
ssl->secure_renegotiation = MBEDTLS_SSL_SECURE_RENEGOTIATION;
}
return( 0 );
}
#if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
static int ssl_parse_max_fragment_length_ext( mbedtls_ssl_context *ssl,
const unsigned char *buf,
size_t len )
{
/*
* server should use the extension only if we did,
* and if so the server's value should match ours (and len is always 1)
*/
if( ssl->conf->mfl_code == MBEDTLS_SSL_MAX_FRAG_LEN_NONE ||
len != 1 ||
buf[0] != ssl->conf->mfl_code )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "non-matching max fragment length extension" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
return( 0 );
}
#endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */
#if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
static int ssl_parse_truncated_hmac_ext( mbedtls_ssl_context *ssl,
const unsigned char *buf,
size_t len )
{
if( ssl->conf->trunc_hmac == MBEDTLS_SSL_TRUNC_HMAC_DISABLED ||
len != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "non-matching truncated HMAC extension" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
((void) buf);
ssl->session_negotiate->trunc_hmac = MBEDTLS_SSL_TRUNC_HMAC_ENABLED;
return( 0 );
}
#endif /* MBEDTLS_SSL_TRUNCATED_HMAC */
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
static int ssl_parse_cid_ext( mbedtls_ssl_context *ssl,
const unsigned char *buf,
size_t len )
{
size_t peer_cid_len;
if( /* CID extension only makes sense in DTLS */
MBEDTLS_SSL_TRANSPORT_IS_TLS( ssl->conf->transport ) ||
/* The server must only send the CID extension if we have offered it. */
ssl->negotiate_cid == MBEDTLS_SSL_CID_DISABLED )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "CID extension unexpected" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
if( len == 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "CID extension invalid" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
peer_cid_len = *buf++;
len--;
if( peer_cid_len > MBEDTLS_SSL_CID_OUT_LEN_MAX )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "CID extension invalid" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
if( len != peer_cid_len )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "CID extension invalid" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
ssl->handshake->cid_in_use = MBEDTLS_SSL_CID_ENABLED;
ssl->handshake->peer_cid_len = (uint8_t) peer_cid_len;
/* Not using more secure mbedtls_platform_memcpy as peer_cid is public */
memcpy( ssl->handshake->peer_cid, buf, peer_cid_len );
MBEDTLS_SSL_DEBUG_MSG( 3, ( "Use of CID extension negotiated" ) );
MBEDTLS_SSL_DEBUG_BUF( 3, "Server CID", buf, peer_cid_len );
return( 0 );
}
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
static int ssl_parse_encrypt_then_mac_ext( mbedtls_ssl_context *ssl,
const unsigned char *buf,
size_t len )
{
if( ssl->conf->encrypt_then_mac == MBEDTLS_SSL_ETM_DISABLED ||
mbedtls_ssl_get_minor_ver( ssl ) == MBEDTLS_SSL_MINOR_VERSION_0 ||
len != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "non-matching encrypt-then-MAC extension" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
((void) buf);
ssl->session_negotiate->encrypt_then_mac = MBEDTLS_SSL_ETM_ENABLED;
return( 0 );
}
#endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */
#if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
static int ssl_parse_extended_ms_ext( mbedtls_ssl_context *ssl,
const unsigned char *buf,
size_t len )
{
if( mbedtls_ssl_conf_get_ems( ssl->conf ) ==
MBEDTLS_SSL_EXTENDED_MS_DISABLED ||
mbedtls_ssl_get_minor_ver( ssl ) == MBEDTLS_SSL_MINOR_VERSION_0 ||
len != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "non-matching extended master secret extension" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
((void) buf);
return( 0 );
}
#endif /* MBEDTLS_SSL_EXTENDED_MASTER_SECRET */
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
static int ssl_parse_session_ticket_ext( mbedtls_ssl_context *ssl,
const unsigned char *buf,
size_t len )
{
if( ssl->conf->session_tickets == MBEDTLS_SSL_SESSION_TICKETS_DISABLED ||
len != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "non-matching session ticket extension" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
((void) buf);
ssl->handshake->new_session_ticket = 1;
return( 0 );
}
#endif /* MBEDTLS_SSL_SESSION_TICKETS */
#if defined(MBEDTLS_ECDH_C) || \
defined(MBEDTLS_ECDSA_C) || \
defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED) || \
defined(MBEDTLS_USE_TINYCRYPT)
static int ssl_parse_supported_point_formats_ext( mbedtls_ssl_context *ssl,
const unsigned char *buf,
size_t len )
{
size_t list_size;
const unsigned char *p;
if( len == 0 || (size_t)( buf[0] + 1 ) != len )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
list_size = buf[0];
p = buf + 1;
while( list_size > 0 )
{
if( p[0] == MBEDTLS_SSL_EC_PF_UNCOMPRESSED ||
p[0] == MBEDTLS_SSL_EC_PF_COMPRESSED )
{
#if defined(MBEDTLS_ECDH_C)
ssl->handshake->ecdh_ctx.point_format = p[0];
#endif
#if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
ssl->handshake->ecjpake_ctx.point_format = p[0];
#endif
MBEDTLS_SSL_DEBUG_MSG( 4, ( "point format selected: %d", p[0] ) );
return( 0 );
}
list_size--;
p++;
}
MBEDTLS_SSL_DEBUG_MSG( 1, ( "no point format in common" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
#endif /* MBEDTLS_ECDH_C || MBEDTLS_ECDSA_C || MBEDTLS_USE_TINYCRYPT ||
MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
#if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
static int ssl_parse_ecjpake_kkpp( mbedtls_ssl_context *ssl,
const unsigned char *buf,
size_t len )
{
int ret;
if( mbedtls_ssl_suite_get_key_exchange(
mbedtls_ssl_handshake_get_ciphersuite( ssl->handshake ) )
!= MBEDTLS_KEY_EXCHANGE_ECJPAKE )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "skip ecjpake kkpp extension" ) );
return( 0 );
}
/* If we got here, we no longer need our cached extension */
mbedtls_free( ssl->handshake->ecjpake_cache );
ssl->handshake->ecjpake_cache = NULL;
ssl->handshake->ecjpake_cache_len = 0;
if( ( ret = mbedtls_ecjpake_read_round_one( &ssl->handshake->ecjpake_ctx,
buf, len ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecjpake_read_round_one", ret );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( ret );
}
return( 0 );
}
#endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
#if defined(MBEDTLS_SSL_ALPN)
static int ssl_parse_alpn_ext( mbedtls_ssl_context *ssl,
const unsigned char *buf, size_t len )
{
size_t list_len, name_len;
const char **p;
/* If we didn't send it, the server shouldn't send it */
if( ssl->conf->alpn_list == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "non-matching ALPN extension" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
/*
* opaque ProtocolName<1..2^8-1>;
*
* struct {
* ProtocolName protocol_name_list<2..2^16-1>
* } ProtocolNameList;
*
* the "ProtocolNameList" MUST contain exactly one "ProtocolName"
*/
/* Min length is 2 (list_len) + 1 (name_len) + 1 (name) */
if( len < 4 )
{
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
list_len = mbedtls_platform_get_uint16_be( buf );
if( list_len != len - 2 )
{
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
name_len = buf[2];
if( name_len != list_len - 1 )
{
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
/* Check that the server chosen protocol was in our list and save it */
for( p = ssl->conf->alpn_list; *p != NULL; p++ )
{
if( name_len == strlen( *p ) &&
mbedtls_platform_memcmp( buf + 3, *p, name_len ) == 0 )
{
ssl->alpn_chosen = *p;
return( 0 );
}
}
MBEDTLS_SSL_DEBUG_MSG( 1, ( "ALPN extension: no matching protocol" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
#endif /* MBEDTLS_SSL_ALPN */
/*
* Parse HelloVerifyRequest. Only called after verifying the HS type.
*/
#if defined(MBEDTLS_SSL_PROTO_DTLS)
static int ssl_parse_hello_verify_request( mbedtls_ssl_context *ssl )
{
const unsigned char *p = ssl->in_msg + mbedtls_ssl_hs_hdr_len( ssl );
int major_ver, minor_ver;
unsigned char cookie_len;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse hello verify request" ) );
/* Check that there is enough room for:
* - 2 bytes of version
* - 1 byte of cookie_len
*/
if( mbedtls_ssl_hs_hdr_len( ssl ) + 3 > ssl->in_msglen )
{
MBEDTLS_SSL_DEBUG_MSG( 1,
( "incoming HelloVerifyRequest message is too short" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
/*
* struct {
* ProtocolVersion server_version;
* opaque cookie<0..2^8-1>;
* } HelloVerifyRequest;
*/
MBEDTLS_SSL_DEBUG_BUF( 3, "server version", p, 2 );
mbedtls_ssl_read_version( &major_ver, &minor_ver, ssl->conf->transport, p );
p += 2;
/*
* Since the RFC is not clear on this point, accept DTLS 1.0 (TLS 1.1)
* even is lower than our min version.
*/
if( mbedtls_ssl_ver_lt( major_ver, MBEDTLS_SSL_MAJOR_VERSION_3 ) ||
mbedtls_ssl_ver_lt( minor_ver, MBEDTLS_SSL_MINOR_VERSION_2 ) ||
mbedtls_ssl_ver_gt( major_ver,
mbedtls_ssl_conf_get_max_major_ver( ssl->conf ) ) ||
mbedtls_ssl_ver_gt( minor_ver,
mbedtls_ssl_conf_get_max_minor_ver( ssl->conf ) ) )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server version" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_PROTOCOL_VERSION );
return( MBEDTLS_ERR_SSL_BAD_HS_PROTOCOL_VERSION );
}
cookie_len = *p++;
if( ( ssl->in_msg + ssl->in_msglen ) - p < cookie_len )
{
MBEDTLS_SSL_DEBUG_MSG( 1,
( "cookie length does not match incoming message size" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
MBEDTLS_SSL_DEBUG_BUF( 3, "cookie", p, cookie_len );
mbedtls_free( ssl->handshake->verify_cookie );
ssl->handshake->verify_cookie = mbedtls_calloc( 1, cookie_len );
if( ssl->handshake->verify_cookie == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "alloc failed (%d bytes)", cookie_len ) );
return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
}
mbedtls_platform_memcpy( ssl->handshake->verify_cookie, p, cookie_len );
ssl->handshake->verify_cookie_len = cookie_len;
/* Start over at ClientHello */
ssl->state = MBEDTLS_SSL_CLIENT_HELLO;
mbedtls_ssl_reset_checksum( ssl );
mbedtls_ssl_recv_flight_completed( ssl );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse hello verify request" ) );
return( 0 );
}
#endif /* MBEDTLS_SSL_PROTO_DTLS */
static int ssl_parse_server_hello( mbedtls_ssl_context *ssl )
{
int ret, i;
size_t n;
size_t ext_len;
unsigned char *buf, *ext;
unsigned char comp;
#if defined(MBEDTLS_ZLIB_SUPPORT)
int accept_comp;
#endif
#if defined(MBEDTLS_SSL_RENEGOTIATION)
int renegotiation_info_seen = 0;
#endif
#if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
int extended_ms_seen = 0;
#endif
int handshake_failure = 0;
/* The ciphersuite chosen by the server. */
mbedtls_ssl_ciphersuite_handle_t server_suite_info;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse server hello" ) );
if( ( ret = mbedtls_ssl_read_record( ssl, 1 ) ) != 0 )
{
/* No alert on a read error. */
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret );
return( ret );
}
buf = ssl->in_msg;
if( ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE )
{
#if defined(MBEDTLS_SSL_RENEGOTIATION)
if( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS )
{
ssl->renego_records_seen++;
if( ssl->conf->renego_max_records >= 0 &&
ssl->renego_records_seen > ssl->conf->renego_max_records )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "renegotiation requested, "
"but not honored by server" ) );
return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
}
MBEDTLS_SSL_DEBUG_MSG( 1, ( "non-handshake message during renego" ) );
ssl->keep_current_message = 1;
return( MBEDTLS_ERR_SSL_WAITING_SERVER_HELLO_RENEGO );
}
#endif /* MBEDTLS_SSL_RENEGOTIATION */
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE );
return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
}
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( MBEDTLS_SSL_TRANSPORT_IS_DTLS( ssl->conf->transport ) )
{
if( buf[0] == MBEDTLS_SSL_HS_HELLO_VERIFY_REQUEST )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "received hello verify request" ) );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse server hello" ) );
return( ssl_parse_hello_verify_request( ssl ) );
}
else
{
/* We made it through the verification process */
mbedtls_free( ssl->handshake->verify_cookie );
ssl->handshake->verify_cookie = NULL;
ssl->handshake->verify_cookie_len = 0;
}
}
#endif /* MBEDTLS_SSL_PROTO_DTLS */
if( ssl->in_hslen < 38 + mbedtls_ssl_hs_hdr_len( ssl ) ||
buf[0] != MBEDTLS_SSL_HS_SERVER_HELLO )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
/*
* 0 . 1 server_version
* 2 . 33 random (maybe including 4 bytes of Unix time)
* 34 . 34 session_id length = n
* 35 . 34+n session_id
* 35+n . 36+n cipher_suite
* 37+n . 37+n compression_method
*
* 38+n . 39+n extensions length (optional)
* 40+n . .. extensions
*/
buf += mbedtls_ssl_hs_hdr_len( ssl );
{
int major_ver, minor_ver;
MBEDTLS_SSL_DEBUG_BUF( 3, "server hello, version", buf + 0, 2 );
mbedtls_ssl_read_version( &major_ver, &minor_ver,
ssl->conf->transport,
buf + 0 );
if( mbedtls_ssl_ver_lt( major_ver,
mbedtls_ssl_conf_get_min_major_ver( ssl->conf ) ) ||
mbedtls_ssl_ver_lt( minor_ver,
mbedtls_ssl_conf_get_min_minor_ver( ssl->conf ) ) ||
mbedtls_ssl_ver_gt( major_ver,
mbedtls_ssl_conf_get_max_major_ver( ssl->conf ) ) ||
mbedtls_ssl_ver_gt( minor_ver,
mbedtls_ssl_conf_get_max_minor_ver( ssl->conf ) ) )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "server version out of bounds - "
" min: [%d:%d], server: [%d:%d], max: [%d:%d]",
mbedtls_ssl_conf_get_min_major_ver( ssl->conf ),
mbedtls_ssl_conf_get_min_minor_ver( ssl->conf ),
major_ver, minor_ver,
mbedtls_ssl_conf_get_max_major_ver( ssl->conf ),
mbedtls_ssl_conf_get_max_minor_ver( ssl->conf ) ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_PROTOCOL_VERSION );
return( MBEDTLS_ERR_SSL_BAD_HS_PROTOCOL_VERSION );
}
#if !defined(MBEDTLS_SSL_CONF_FIXED_MINOR_VER)
ssl->minor_ver = minor_ver;
#endif /* !MBEDTLS_SSL_CONF_FIXED_MINOR_VER */
#if !defined(MBEDTLS_SSL_CONF_FIXED_MAJOR_VER)
ssl->major_ver = major_ver;
#endif /* !MBEDTLS_SSL_CONF_FIXED_MAJOR_VER */
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, current time: %lu",
(unsigned long)mbedtls_platform_get_uint32_be( &buf[2] ) ) );
ssl->handshake->hello_random_set = MBEDTLS_SSL_FI_FLAG_UNSET;
mbedtls_platform_memcpy( ssl->handshake->randbytes + 32, buf + 2, 32 );
if( mbedtls_platform_memcmp( ssl->handshake->randbytes + 32, buf + 2, 32 ) == 0 )
{
ssl->handshake->hello_random_set = MBEDTLS_SSL_FI_FLAG_SET;
}
n = buf[34];
MBEDTLS_SSL_DEBUG_BUF( 3, "server hello, random bytes", buf + 2, 32 );
if( n > 32 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
if( ssl->in_hslen > mbedtls_ssl_hs_hdr_len( ssl ) + 39 + n )
{
ext_len = mbedtls_platform_get_uint16_be( &buf[38 + n] );
if( ( ext_len > 0 && ext_len < 4 ) ||
ssl->in_hslen != mbedtls_ssl_hs_hdr_len( ssl ) + 40 + n + ext_len )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
}
else if( ssl->in_hslen == mbedtls_ssl_hs_hdr_len( ssl ) + 38 + n )
{
ext_len = 0;
}
else
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
/* ciphersuite (used later) */
i = (int)mbedtls_platform_get_uint16_be( &buf[ 35 + n ] );
/*
* Read and check compression
*/
comp = buf[37 + n];
#if defined(MBEDTLS_ZLIB_SUPPORT)
/* See comments in ssl_write_client_hello() */
accept_comp = MBEDTLS_SSL_TRANSPORT_IS_TLS( ssl->conf->transport );
if( comp != MBEDTLS_SSL_COMPRESS_NULL &&
( comp != MBEDTLS_SSL_COMPRESS_DEFLATE || accept_comp == 0 ) )
#else /* MBEDTLS_ZLIB_SUPPORT */
if( comp != MBEDTLS_SSL_COMPRESS_NULL )
#endif/* MBEDTLS_ZLIB_SUPPORT */
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "server hello, bad compression: %d", comp ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE );
}
/*
* Initialize update checksum functions
*/
server_suite_info = mbedtls_ssl_ciphersuite_from_id( i );
#if !defined(MBEDTLS_SSL_CONF_SINGLE_CIPHERSUITE)
ssl->handshake->ciphersuite_info = server_suite_info;
#endif
if( server_suite_info == MBEDTLS_SSL_CIPHERSUITE_INVALID_HANDLE )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "ciphersuite info for %04x not found", i ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_INTERNAL_ERROR );
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, session id len.: %d", n ) );
MBEDTLS_SSL_DEBUG_BUF( 3, "server hello, session id", buf + 35, n );
/*
* Check if the session can be resumed
*
* We're only resuming a session if it was requested (handshake->resume
* already set to 1 by mbedtls_ssl_set_session()), and further conditions
* are satisfied (not renegotiating, ID and ciphersuite match, etc).
*
* Update handshake->resume to the value it will keep for the rest of the
* handshake, and that will be used to determine the relative order
* client/server last flights, as well as in handshake_wrapup().
*/
#if !defined(MBEDTLS_SSL_NO_SESSION_RESUMPTION)
if( n == 0 ||
mbedtls_ssl_get_renego_status( ssl ) != MBEDTLS_SSL_INITIAL_HANDSHAKE ||
mbedtls_ssl_session_get_ciphersuite( ssl->session_negotiate ) != i ||
mbedtls_ssl_session_get_compression( ssl->session_negotiate ) != comp ||
ssl->session_negotiate->id_len != n ||
mbedtls_platform_memcmp( ssl->session_negotiate->id, buf + 35, n ) != 0 )
{
ssl->handshake->resume = MBEDTLS_SSL_FI_FLAG_UNSET;
}
#endif /* !MBEDTLS_SSL_NO_SESSION_RESUMPTION */
if( mbedtls_ssl_handshake_get_resume( ssl->handshake ) == MBEDTLS_SSL_FI_FLAG_SET )
{
/* Resume a session */
ssl->state = MBEDTLS_SSL_SERVER_CHANGE_CIPHER_SPEC;
if( ( ret = mbedtls_ssl_derive_keys( ssl ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_derive_keys", ret );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_INTERNAL_ERROR );
return( ret );
}
}
else
{
/* Start a new session */
ssl->state = MBEDTLS_SSL_SERVER_CERTIFICATE;
#if defined(MBEDTLS_HAVE_TIME)
ssl->session_negotiate->start = mbedtls_time( NULL );
#endif
#if !defined(MBEDTLS_SSL_CONF_SINGLE_CIPHERSUITE)
ssl->session_negotiate->ciphersuite = i;
#endif /* MBEDTLS_SSL_CONF_SINGLE_CIPHERSUITE */
#if defined(MBEDTLS_ZLIB_SUPPORT)
ssl->session_negotiate->compression = comp;
#endif
ssl->session_negotiate->id_len = n;
/* Not using more secure mbedtls_platform_memcpy as id is public */
memcpy( ssl->session_negotiate->id, buf + 35, n );
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "%s session has been resumed",
mbedtls_ssl_handshake_get_resume( ssl->handshake ) ? "a" : "no" ) );
MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, chosen ciphersuite: %04x", i ) );
MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, compress alg.: %d", buf[37 + n] ) );
/*
* Perform cipher suite validation in same way as in ssl_write_client_hello.
*/
MBEDTLS_SSL_BEGIN_FOR_EACH_CIPHERSUITE( ssl,
mbedtls_ssl_get_minor_ver( ssl ),
ciphersuite_info )
{
if( ssl_validate_ciphersuite( ciphersuite_info, ssl,
mbedtls_ssl_conf_get_min_minor_ver( ssl->conf ),
mbedtls_ssl_conf_get_max_minor_ver( ssl->conf ) ) != 0 )
{
continue;
}
if( ciphersuite_info != server_suite_info )
continue;
goto server_picked_valid_suite;
}
MBEDTLS_SSL_END_FOR_EACH_CIPHERSUITE
/* If we reach this code-path, the server's chosen ciphersuite
* wasn't among those advertised by us. */
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
server_picked_valid_suite:
MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, chosen ciphersuite: %s",
mbedtls_ssl_suite_get_name( server_suite_info ) ) );
#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
if( mbedtls_ssl_suite_get_key_exchange( server_suite_info ) ==
MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA &&
mbedtls_ssl_get_minor_ver( ssl ) == MBEDTLS_SSL_MINOR_VERSION_3 )
{
ssl->handshake->ecrs_enabled = 1;
}
#endif
if( comp != MBEDTLS_SSL_COMPRESS_NULL
#if defined(MBEDTLS_ZLIB_SUPPORT)
&& comp != MBEDTLS_SSL_COMPRESS_DEFLATE
#endif
)
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
#if defined(MBEDTLS_ZLIB_SUPPORT)
ssl->session_negotiate->compression = comp;
#endif
ext = buf + 40 + n;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "server hello, total extension length: %d",
ext_len ) );
while( ext_len )
{
unsigned int ext_id = (unsigned int)
mbedtls_platform_get_uint16_be( ext );
unsigned int ext_size = (unsigned int)
mbedtls_platform_get_uint16_be( &ext[2] );
if( ext_size + 4 > ext_len )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
switch( ext_id )
{
case MBEDTLS_TLS_EXT_RENEGOTIATION_INFO:
MBEDTLS_SSL_DEBUG_MSG( 3, ( "found renegotiation extension" ) );
#if defined(MBEDTLS_SSL_RENEGOTIATION)
renegotiation_info_seen = 1;
#endif
if( ( ret = ssl_parse_renegotiation_info( ssl, ext + 4,
ext_size ) ) != 0 )
return( ret );
break;
#if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
case MBEDTLS_TLS_EXT_MAX_FRAGMENT_LENGTH:
MBEDTLS_SSL_DEBUG_MSG( 3, ( "found max_fragment_length extension" ) );
if( ( ret = ssl_parse_max_fragment_length_ext( ssl,
ext + 4, ext_size ) ) != 0 )
{
return( ret );
}
break;
#endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */
#if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
case MBEDTLS_TLS_EXT_TRUNCATED_HMAC:
MBEDTLS_SSL_DEBUG_MSG( 3, ( "found truncated_hmac extension" ) );
if( ( ret = ssl_parse_truncated_hmac_ext( ssl,
ext + 4, ext_size ) ) != 0 )
{
return( ret );
}
break;
#endif /* MBEDTLS_SSL_TRUNCATED_HMAC */
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
case MBEDTLS_TLS_EXT_CID:
MBEDTLS_SSL_DEBUG_MSG( 3, ( "found CID extension" ) );
if( ( ret = ssl_parse_cid_ext( ssl,
ext + 4,
ext_size ) ) != 0 )
{
return( ret );
}
break;
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
case MBEDTLS_TLS_EXT_ENCRYPT_THEN_MAC:
MBEDTLS_SSL_DEBUG_MSG( 3, ( "found encrypt_then_mac extension" ) );
if( ( ret = ssl_parse_encrypt_then_mac_ext( ssl,
ext + 4, ext_size ) ) != 0 )
{
return( ret );
}
break;
#endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */
#if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
case MBEDTLS_TLS_EXT_EXTENDED_MASTER_SECRET:
MBEDTLS_SSL_DEBUG_MSG( 3, ( "found extended_master_secret extension" ) );
if( ( ret = ssl_parse_extended_ms_ext( ssl,
ext + 4, ext_size ) ) != 0 )
{
return( ret );
}
extended_ms_seen = 1;
break;
#endif /* MBEDTLS_SSL_EXTENDED_MASTER_SECRET */
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
case MBEDTLS_TLS_EXT_SESSION_TICKET:
MBEDTLS_SSL_DEBUG_MSG( 3, ( "found session_ticket extension" ) );
if( ( ret = ssl_parse_session_ticket_ext( ssl,
ext + 4, ext_size ) ) != 0 )
{
return( ret );
}
break;
#endif /* MBEDTLS_SSL_SESSION_TICKETS */
#if defined(MBEDTLS_USE_TINYCRYPT) || \
defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \
defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
case MBEDTLS_TLS_EXT_SUPPORTED_POINT_FORMATS:
MBEDTLS_SSL_DEBUG_MSG( 3, ( "found supported_point_formats extension" ) );
if( ( ret = ssl_parse_supported_point_formats_ext( ssl,
ext + 4, ext_size ) ) != 0 )
{
return( ret );
}
break;
#endif /* MBEDTLS_ECDH_C || MBEDTLS_ECDSA_C ||
MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
#if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
case MBEDTLS_TLS_EXT_ECJPAKE_KKPP:
MBEDTLS_SSL_DEBUG_MSG( 3, ( "found ecjpake_kkpp extension" ) );
if( ( ret = ssl_parse_ecjpake_kkpp( ssl,
ext + 4, ext_size ) ) != 0 )
{
return( ret );
}
break;
#endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
#if defined(MBEDTLS_SSL_ALPN)
case MBEDTLS_TLS_EXT_ALPN:
MBEDTLS_SSL_DEBUG_MSG( 3, ( "found alpn extension" ) );
if( ( ret = ssl_parse_alpn_ext( ssl, ext + 4, ext_size ) ) != 0 )
return( ret );
break;
#endif /* MBEDTLS_SSL_ALPN */
default:
MBEDTLS_SSL_DEBUG_MSG( 3, ( "unknown extension found: %d (ignoring)",
ext_id ) );
}
ext_len -= 4 + ext_size;
ext += 4 + ext_size;
if( ext_len > 0 && ext_len < 4 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
}
/*
* Renegotiation security checks
*/
if( ssl->secure_renegotiation == MBEDTLS_SSL_LEGACY_RENEGOTIATION &&
mbedtls_ssl_conf_get_allow_legacy_renegotiation( ssl->conf ) ==
MBEDTLS_SSL_LEGACY_BREAK_HANDSHAKE )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "legacy renegotiation, breaking off handshake" ) );
handshake_failure = 1;
}
#if defined(MBEDTLS_SSL_RENEGOTIATION)
else if( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS &&
ssl->secure_renegotiation == MBEDTLS_SSL_SECURE_RENEGOTIATION &&
renegotiation_info_seen == 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "renegotiation_info extension missing (secure)" ) );
handshake_failure = 1;
}
else if( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS &&
ssl->secure_renegotiation == MBEDTLS_SSL_LEGACY_RENEGOTIATION &&
mbedtls_ssl_conf_get_allow_legacy_renegotiation( ssl->conf ) ==
MBEDTLS_SSL_LEGACY_NO_RENEGOTIATION )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "legacy renegotiation not allowed" ) );
handshake_failure = 1;
}
else if( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS &&
ssl->secure_renegotiation == MBEDTLS_SSL_LEGACY_RENEGOTIATION &&
renegotiation_info_seen == 1 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "renegotiation_info extension present (legacy)" ) );
handshake_failure = 1;
}
#endif /* MBEDTLS_SSL_RENEGOTIATION */
/*
* Check if extended master secret is being enforced
*/
#if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
if( mbedtls_ssl_conf_get_ems( ssl->conf ) ==
MBEDTLS_SSL_EXTENDED_MS_ENABLED )
{
if( extended_ms_seen )
{
#if !defined(MBEDTLS_SSL_EXTENDED_MS_ENFORCED)
ssl->handshake->extended_ms = MBEDTLS_SSL_EXTENDED_MS_ENABLED;
#endif /* !MBEDTLS_SSL_EXTENDED_MS_ENFORCED */
}
else if( mbedtls_ssl_conf_get_ems_enforced( ssl->conf ) ==
MBEDTLS_SSL_EXTENDED_MS_ENFORCE_ENABLED )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "Peer not offering extended master "
"secret, while it is enforced") );
handshake_failure = 1;
}
}
#endif /* MBEDTLS_SSL_EXTENDED_MASTER_SECRET */
if( handshake_failure == 1 )
{
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse server hello" ) );
return( 0 );
}
#if defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED) || \
defined(MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED)
static int ssl_parse_server_dh_params( mbedtls_ssl_context *ssl, unsigned char **p,
unsigned char *end )
{
int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE;
/*
* Ephemeral DH parameters:
*
* struct {
* opaque dh_p<1..2^16-1>;
* opaque dh_g<1..2^16-1>;
* opaque dh_Ys<1..2^16-1>;
* } ServerDHParams;
*/
if( ( ret = mbedtls_dhm_read_params( &ssl->handshake->dhm_ctx, p, end ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 2, ( "mbedtls_dhm_read_params" ), ret );
return( ret );
}
if( ssl->handshake->dhm_ctx.len * 8 < ssl->conf->dhm_min_bitlen )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "DHM prime too short: %d < %d",
ssl->handshake->dhm_ctx.len * 8,
ssl->conf->dhm_min_bitlen ) );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
}
MBEDTLS_SSL_DEBUG_MPI( 3, "DHM: P ", &ssl->handshake->dhm_ctx.P );
MBEDTLS_SSL_DEBUG_MPI( 3, "DHM: G ", &ssl->handshake->dhm_ctx.G );
MBEDTLS_SSL_DEBUG_MPI( 3, "DHM: GY", &ssl->handshake->dhm_ctx.GY );
return( ret );
}
#endif /* MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED ||
MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED */
#if defined(MBEDTLS_ECDH_C) && \
( defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \
defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) || \
defined(MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED) || \
defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \
defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED) )
static int ssl_check_server_ecdh_params( const mbedtls_ssl_context *ssl )
{
const mbedtls_ecp_curve_info *curve_info;
mbedtls_ecp_group_id grp_id;
#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
grp_id = ssl->handshake->ecdh_ctx.grp.id;
#else
grp_id = ssl->handshake->ecdh_ctx.grp_id;
#endif
curve_info = mbedtls_ecp_curve_info_from_grp_id( grp_id );
if( curve_info == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
MBEDTLS_SSL_DEBUG_MSG( 2, ( "ECDH curve: %s", curve_info->name ) );
#if defined(MBEDTLS_ECP_C)
if( mbedtls_ssl_check_curve( ssl, grp_id ) != 0 )
#else
if( ssl->handshake->ecdh_ctx.grp.nbits < 163 ||
ssl->handshake->ecdh_ctx.grp.nbits > 521 )
#endif
return( -1 );
MBEDTLS_SSL_DEBUG_ECDH( 3, &ssl->handshake->ecdh_ctx,
MBEDTLS_DEBUG_ECDH_QP );
return( 0 );
}
#endif /* MBEDTLS_ECDH_C &&
( MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED ||
MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED ||
MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED ||
MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED ||
MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED ) */
#if defined(MBEDTLS_ECDH_C) && \
( defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \
defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) || \
defined(MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED))
static int ssl_parse_server_ecdh_params( mbedtls_ssl_context *ssl,
unsigned char **p,
unsigned char *end )
{
int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE;
/*
* Ephemeral ECDH parameters:
*
* struct {
* ECParameters curve_params;
* ECPoint public;
* } ServerECDHParams;
*/
if( ( ret = mbedtls_ecdh_read_params( &ssl->handshake->ecdh_ctx,
(const unsigned char **) p, end ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, ( "mbedtls_ecdh_read_params" ), ret );
return( ret );
}
if( ssl_check_server_ecdh_params( ssl ) != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message (ECDHE curve)" ) );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
}
return( ret );
}
#endif /* MBEDTLS_ECDH_C &&
( MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED ||
MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED ||
MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED ) */
#if defined(MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED)
static int ssl_parse_server_psk_hint( mbedtls_ssl_context *ssl,
unsigned char **p,
unsigned char *end )
{
int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE;
size_t len;
((void) ssl);
/*
* PSK parameters:
*
* opaque psk_identity_hint<0..2^16-1>;
*/
if( end - (*p) < 2 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message "
"(psk_identity_hint length)" ) );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
}
len = mbedtls_platform_get_uint16_be( *p );
*p += 2;
if( end - (*p) < (int) len )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message "
"(psk_identity_hint length)" ) );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
}
/*
* Note: we currently ignore the PKS identity hint, as we only allow one
* PSK to be provisionned on the client. This could be changed later if
* someone needs that feature.
*/
*p += len;
ret = 0;
return( ret );
}
#endif /* MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED */
#if defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED) || \
defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED)
/* This function assumes that `out` points to a writable buffer
* of size 48 Bytes if `add_length_tag == 0` and size 50 Bytes
* if `add_length_tag != 0`. */
static int ssl_rsa_generate_partial_pms( mbedtls_ssl_context *ssl,
unsigned char* out,
unsigned add_length_tag )
{
volatile int ret = MBEDTLS_ERR_PLATFORM_FAULT_DETECTED;
/*
* Generate (part of) the pre-master secret as
* struct {
* [ uint16 length(48) ]
* ProtocolVersion client_version;
* opaque random[46];
* } PreMasterSecret;
*/
if( add_length_tag )
{
out[0] = 0;
out[1] = 48;
out += 2;
}
mbedtls_ssl_write_version( mbedtls_ssl_conf_get_max_major_ver( ssl->conf ),
mbedtls_ssl_conf_get_max_minor_ver( ssl->conf ),
ssl->conf->transport, out );
ret = mbedtls_ssl_conf_get_frng( ssl->conf )
( mbedtls_ssl_conf_get_prng( ssl->conf ), out + 2, 46 );
if( ret == 0 )
{
mbedtls_platform_random_delay();
if( ret == 0 )
{
ssl->handshake->premaster_generated = MBEDTLS_SSL_FI_FLAG_SET;
return( 0 );
}
else
{
ret = MBEDTLS_ERR_PLATFORM_FAULT_DETECTED;
}
}
MBEDTLS_SSL_DEBUG_RET( 1, "f_rng", ret );
return( ret );
}
/*
* Encrypt the randomly chosen part of the Premaster Secret with the
* server's RSA key and write it to the provided buffer.
*/
static int ssl_rsa_encrypt_partial_pms( mbedtls_ssl_context *ssl,
unsigned char const *ppms,
unsigned char *out, size_t buflen,
size_t *olen )
{
volatile int ret = MBEDTLS_ERR_PLATFORM_FAULT_DETECTED;
size_t len_bytes = mbedtls_ssl_get_minor_ver( ssl ) ==
MBEDTLS_SSL_MINOR_VERSION_0 ? 0 : 2;
mbedtls_pk_context *peer_pk = NULL;
if( buflen < len_bytes )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small for encrypted pms" ) );
return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
}
#if !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
if( ssl->handshake->got_peer_pubkey )
peer_pk = &ssl->handshake->peer_pubkey;
#else /* !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
if( ssl->session_negotiate->peer_cert != NULL )
{
ret = mbedtls_x509_crt_pk_acquire( ssl->session_negotiate->peer_cert,
&peer_pk );
if( ret != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_x509_crt_pk_acquire", ret );
return( ret );
}
}
#endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
if( peer_pk == NULL )
{
/* Should never happen */
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
/*
* Encrypt the partial premaster secret and write it out.
*/
if( ! mbedtls_pk_can_do( peer_pk, MBEDTLS_PK_RSA ) )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "certificate key type mismatch" ) );
ret = MBEDTLS_ERR_SSL_PK_TYPE_MISMATCH;
goto cleanup;
}
ret = mbedtls_pk_encrypt( peer_pk,
ppms, 48, out + len_bytes,
olen, buflen - len_bytes,
mbedtls_ssl_conf_get_frng( ssl->conf ),
mbedtls_ssl_conf_get_prng( ssl->conf ) );
if( ret == 0 )
{
mbedtls_platform_random_delay();
if( ret == 0 )
{
ssl->handshake->premaster_generated = MBEDTLS_SSL_FI_FLAG_SET;
}
else
{
ret = MBEDTLS_ERR_PLATFORM_FAULT_DETECTED;
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_rsa_pkcs1_encrypt", ret );
goto cleanup;
}
}
else
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_rsa_pkcs1_encrypt", ret );
goto cleanup;
}
#if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) || \
defined(MBEDTLS_SSL_PROTO_TLS1_2)
if( len_bytes == 2 )
{
(void)mbedtls_platform_put_uint16_be( out, *olen );
*olen += 2;
}
#endif
cleanup:
#if !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
/* We don't need the peer's public key anymore. Free it. */
mbedtls_pk_free( peer_pk );
#else
mbedtls_x509_crt_pk_release( ssl->session_negotiate->peer_cert );
#endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
return( ret );
}
#endif /* MBEDTLS_KEY_EXCHANGE_RSA_ENABLED ||
MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED */
#if defined(MBEDTLS_SSL_PROTO_TLS1_2)
#if defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED) || \
defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \
defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
static int ssl_parse_signature_algorithm( mbedtls_ssl_context *ssl,
unsigned char **p,
unsigned char *end,
mbedtls_md_type_t *md_alg,
mbedtls_pk_type_t *pk_alg )
{
((void) ssl);
*md_alg = MBEDTLS_MD_NONE;
*pk_alg = MBEDTLS_PK_NONE;
/* Only in TLS 1.2 */
if( mbedtls_ssl_get_minor_ver( ssl ) != MBEDTLS_SSL_MINOR_VERSION_3 )
{
return( 0 );
}
if( (*p) + 2 > end )
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
/*
* Get hash algorithm
*/
if( ( *md_alg = mbedtls_ssl_md_alg_from_hash( (*p)[0] ) ) == MBEDTLS_MD_NONE )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "Server used unsupported "
"HashAlgorithm %d", *(p)[0] ) );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
}
/*
* Get signature algorithm
*/
if( ( *pk_alg = mbedtls_ssl_pk_alg_from_sig( (*p)[1] ) ) == MBEDTLS_PK_NONE )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "server used unsupported "
"SignatureAlgorithm %d", (*p)[1] ) );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
}
/*
* Check if the hash is acceptable
*/
if( mbedtls_ssl_check_sig_hash( ssl, *md_alg ) != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "server used HashAlgorithm %d that was not offered",
*(p)[0] ) );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
}
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Server used SignatureAlgorithm %d", (*p)[1] ) );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Server used HashAlgorithm %d", (*p)[0] ) );
*p += 2;
return( 0 );
}
#endif /* MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED ||
MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED ||
MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED */
#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
#if defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \
defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)
static int ssl_get_ecdh_params_from_cert( mbedtls_ssl_context *ssl )
{
int ret;
mbedtls_pk_context * peer_pk;
/* Acquire peer's PK context: In case we store peer's entire
* certificate, we extract the context from it. Otherwise,
* we can use a temporary copy we've made for the purpose of
* signature verification. */
#if !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
peer_pk = &ssl->handshake->peer_pubkey;
#else /* !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
if( ssl->session_negotiate->peer_cert == NULL )
{
/* Should never happen */
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
ret = mbedtls_x509_crt_pk_acquire( ssl->session_negotiate->peer_cert,
&peer_pk );
if( ret != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_x509_crt_pk_acquire", ret );
return( ret );
}
#endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
if( ! mbedtls_pk_can_do( peer_pk, MBEDTLS_PK_ECKEY ) )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "server key not ECDH capable" ) );
ret = MBEDTLS_ERR_SSL_PK_TYPE_MISMATCH;
goto cleanup;
}
/* Extract ECDH parameters from peer's PK context. */
{
#if defined(MBEDTLS_USE_TINYCRYPT)
mbedtls_uecc_keypair *peer_key =
mbedtls_pk_uecc( *peer_pk );
mbedtls_platform_memcpy( ssl->handshake->ecdh_peerkey,
peer_key->public_key,
sizeof( ssl->handshake->ecdh_peerkey ) );
#else /* MBEDTLS_USE_TINYCRYPT */
const mbedtls_ecp_keypair *peer_key;
peer_key = mbedtls_pk_ec( *peer_pk );
if( ( ret = mbedtls_ecdh_get_params( &ssl->handshake->ecdh_ctx, peer_key,
MBEDTLS_ECDH_THEIRS ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, ( "mbedtls_ecdh_get_params" ), ret );
goto cleanup;
}
if( ssl_check_server_ecdh_params( ssl ) != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server certificate (ECDH curve)" ) );
ret = MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE;
goto cleanup;
}
#endif /* MBEDTLS_USE_TINYCRYPT */
}
cleanup:
#if !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
/* We don't need the peer's public key anymore. Free it,
* so that more RAM is available for upcoming expensive
* operations like ECDHE. */
mbedtls_pk_free( peer_pk );
#else
mbedtls_x509_crt_pk_release( ssl->session_negotiate->peer_cert );
#endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
return( ret );
}
#endif /* MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) ||
MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED */
/*
*
* STATE HANDLING: ServerKeyExchange
*
*/
/*
* Overview
*/
/* Main entry point; orchestrates the other functions. */
static int ssl_process_in_server_key_exchange( mbedtls_ssl_context *ssl );
/* Coordination:
* Check if a ServerKeyExchange message is expected, and skip if not.
* Returns a negative code on failure, or
* - SSL_SRV_KEY_EXCHANGE_SKIP
* - SSL_SRV_KEY_EXCHANGE_EXPECTED
* indicating if a ServerKeyExchange message is expected or not.
*/
#define SSL_SRV_KEY_EXCHANGE_SKIP 0
#define SSL_SRV_KEY_EXCHANGE_EXPECTED 1
static int ssl_in_server_key_exchange_coordinate( mbedtls_ssl_context *ssl );
/* Preparation
* If applicable, prepare DH parameters from Server certificate. */
static int ssl_in_server_key_exchange_prepare( mbedtls_ssl_context *ssl );
/* Parse SrvKeyExchange message and store contents
* (PSK or DH parameters) in handshake structure. */
static int ssl_in_server_key_exchange_parse( mbedtls_ssl_context *ssl,
unsigned char *buf,
size_t buflen );
/* Update the handshake state */
static int ssl_in_server_key_exchange_postprocess( mbedtls_ssl_context *ssl );
/*
* Implementation
*/
static int ssl_in_server_key_exchange_prepare( mbedtls_ssl_context *ssl )
{
mbedtls_ssl_ciphersuite_handle_t ciphersuite_info =
mbedtls_ssl_handshake_get_ciphersuite( ssl->handshake );
((void) ciphersuite_info);
/* If applicable, extract static DH parameters from Server CRT. */
#if defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \
defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)
if( mbedtls_ssl_suite_get_key_exchange( ciphersuite_info ) ==
MBEDTLS_KEY_EXCHANGE_ECDH_RSA ||
mbedtls_ssl_suite_get_key_exchange( ciphersuite_info ) ==
MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA )
{
int ret;
if( ( ret = ssl_get_ecdh_params_from_cert( ssl ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_get_ecdh_params_from_cert", ret );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( ret );
}
}
#endif /* MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED ||
MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED */
return( 0 );
}
static int ssl_in_server_key_exchange_coordinate( mbedtls_ssl_context *ssl )
{
int ret;
mbedtls_ssl_ciphersuite_handle_t ciphersuite_info =
mbedtls_ssl_handshake_get_ciphersuite( ssl->handshake );
/* The ServerKeyExchange message is not used for
* - RSA or
* - static ECDH
* ciphersuites.
* It MAY be used in PSK or RSA-PSK.
*/
#if defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED)
if( mbedtls_ssl_suite_get_key_exchange( ciphersuite_info ) ==
MBEDTLS_KEY_EXCHANGE_RSA )
{
return( SSL_SRV_KEY_EXCHANGE_SKIP );
}
#endif
#if defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \
defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)
if( mbedtls_ssl_suite_get_key_exchange( ciphersuite_info ) ==
MBEDTLS_KEY_EXCHANGE_ECDH_RSA ||
mbedtls_ssl_suite_get_key_exchange( ciphersuite_info ) ==
MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA )
{
return( SSL_SRV_KEY_EXCHANGE_SKIP );
}
#endif /* MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED ||
MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED */
/*
* ServerKeyExchange may be skipped with PSK and RSA-PSK when the server
* doesn't use a psk_identity_hint. Peek at next message to decide whether
* the ServerKeyExchange is being skipped or not.
*/
if( mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_PSK ||
mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_RSA_PSK )
{
if( ( ret = mbedtls_ssl_read_record( ssl, 1 ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret );
return( ret );
}
ssl->keep_current_message = 1;
if( ssl->in_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE &&
ssl->in_msg[0] != MBEDTLS_SSL_HS_SERVER_KEY_EXCHANGE )
{
/* Current message is probably either
* CertificateRequest or ServerHelloDone */
return( SSL_SRV_KEY_EXCHANGE_SKIP );
}
}
return( SSL_SRV_KEY_EXCHANGE_EXPECTED );
}
static int ssl_in_server_key_exchange_parse( mbedtls_ssl_context *ssl,
unsigned char *buf,
size_t buflen )
{
/*
* Initialising to an error value would need a significant
* structural change to provide default flow assumes failure
*/
volatile int ret = 0;
unsigned char *p;
unsigned char *end;
volatile unsigned char *buf_dup = buf;
volatile size_t buflen_dup = buflen;
mbedtls_ssl_ciphersuite_handle_t ciphersuite_info =
mbedtls_ssl_handshake_get_ciphersuite( ssl->handshake );
((void) buf_dup);
((void) buflen_dup);
p = buf + mbedtls_ssl_hs_hdr_len( ssl );
end = buf + buflen;
MBEDTLS_SSL_DEBUG_BUF( 3, "server key exchange", p, end - p );
#if defined(MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED)
if( mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_PSK ||
mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_RSA_PSK ||
mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_DHE_PSK ||
mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_ECDHE_PSK )
{
if( ssl_parse_server_psk_hint( ssl, &p, end ) != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
}
} /* FALLTROUGH */
#endif /* MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED */
#if defined(MBEDTLS_KEY_EXCHANGE_PSK_ENABLED) || \
defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED)
if( mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_PSK ||
mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_RSA_PSK )
{
; /* nothing more to do */
}
else
#endif /* MBEDTLS_KEY_EXCHANGE_PSK_ENABLED ||
MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED */
#if defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED) || \
defined(MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED)
if( mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_DHE_RSA ||
mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_DHE_PSK )
{
if( ssl_parse_server_dh_params( ssl, &p, end ) != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
}
}
else
#endif /* MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED ||
MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED */
#if defined(MBEDTLS_USE_TINYCRYPT)
if( mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_ECDHE_RSA ||
mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_ECDHE_PSK ||
mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA )
{
static const unsigned char ecdh_group[] = {
MBEDTLS_SSL_EC_TLS_NAMED_CURVE,
0 /* high bits of secp256r1 TLS ID */,
23 /* low bits of secp256r1 TLS ID */,
};
/* Check for fixed ECDH parameter preamble. */
if( (size_t)( end - p ) < sizeof( ecdh_group ) )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "Bad server key exchange (too short)" ) );
return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
}
if( mbedtls_platform_memcmp( p, ecdh_group, sizeof( ecdh_group ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "Bad server key exchange (unexpected header)" ) );
return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
}
p += sizeof( ecdh_group );
/* Read server's key share. */
if( mbedtls_ssl_ecdh_read_peerkey( ssl, &p, end ) != 0 )
return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
}
else
#endif /* MBEDTLS_USE_TINYCRYPT */
#if defined(MBEDTLS_ECDH_C) && \
( defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \
defined(MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED) || \
defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED ) )
if( mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_ECDHE_RSA ||
mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_ECDHE_PSK ||
mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA )
{
if( ssl_parse_server_ecdh_params( ssl, &p, end ) != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
}
}
else
#endif /* MBEDTLS_ECDH_C &&
( MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED ||
MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED ||
MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED ) */
#if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
if( mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_ECJPAKE )
{
ret = mbedtls_ecjpake_read_round_two( &ssl->handshake->ecjpake_ctx,
p, end - p );
if( ret != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecjpake_read_round_two", ret );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
}
}
else
#endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
{
((void) ret);
((void) p);
((void) end);
((void) ciphersuite_info);
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
#if defined(MBEDTLS_KEY_EXCHANGE__WITH_SERVER_SIGNATURE__ENABLED)
if( mbedtls_ssl_ciphersuite_uses_server_signature( ciphersuite_info ) )
{
size_t sig_len, hashlen;
unsigned char hash[64];
mbedtls_md_type_t md_alg = MBEDTLS_MD_NONE;
mbedtls_pk_type_t pk_alg = MBEDTLS_PK_NONE;
unsigned char *params = ssl->in_msg + mbedtls_ssl_hs_hdr_len( ssl );
size_t params_len = p - params;
void *rs_ctx = NULL;
mbedtls_pk_context * peer_pk;
/*
* Handle the digitally-signed structure
*/
#if defined(MBEDTLS_SSL_PROTO_TLS1_2)
if( mbedtls_ssl_get_minor_ver( ssl ) == MBEDTLS_SSL_MINOR_VERSION_3 )
{
if( ssl_parse_signature_algorithm( ssl, &p, end,
&md_alg, &pk_alg ) != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
}
if( pk_alg != mbedtls_ssl_get_ciphersuite_sig_pk_alg( ciphersuite_info ) )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
}
}
else
#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
#if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1) || \
defined(MBEDTLS_SSL_PROTO_TLS1_1)
if( mbedtls_ssl_ver_lt( mbedtls_ssl_get_minor_ver( ssl ),
MBEDTLS_SSL_MINOR_VERSION_3 ) )
{
pk_alg = mbedtls_ssl_get_ciphersuite_sig_pk_alg( ciphersuite_info );
/* Default hash for ECDSA is SHA-1 */
if( pk_alg == MBEDTLS_PK_ECDSA && md_alg == MBEDTLS_MD_NONE )
md_alg = MBEDTLS_MD_SHA1;
}
else
#endif
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
/*
* Read signature
*/
if( p > end - 2 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
}
sig_len = mbedtls_platform_get_uint16_be( p );
p += 2;
if( p != end - sig_len )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
}
MBEDTLS_SSL_DEBUG_BUF( 3, "signature", p, sig_len );
/*
* Compute the hash that has been signed
*/
#if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1) || \
defined(MBEDTLS_SSL_PROTO_TLS1_1)
if( md_alg == MBEDTLS_MD_NONE )
{
hashlen = 36;
ret = mbedtls_ssl_get_key_exchange_md_ssl_tls( ssl, hash, params,
params_len );
if( ret != 0 )
return( ret );
}
else
#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)
if( md_alg != MBEDTLS_MD_NONE )
{
ret = mbedtls_ssl_get_key_exchange_md_tls1_2( ssl, hash, &hashlen,
params, params_len,
md_alg );
if( ret != 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 );
}
MBEDTLS_SSL_DEBUG_BUF( 3, "parameters hash", hash, hashlen );
#if !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
peer_pk = &ssl->handshake->peer_pubkey;
#else /* !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
if( ssl->session_negotiate->peer_cert == NULL )
{
/* Should never happen */
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
ret = mbedtls_x509_crt_pk_acquire( ssl->session_negotiate->peer_cert,
&peer_pk );
if( ret != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_x509_crt_pk_acquire", ret );
return( ret );
}
#endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
/*
* Verify signature
*/
if( !mbedtls_pk_can_do( peer_pk, pk_alg ) )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
#if defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
mbedtls_x509_crt_pk_release( ssl->session_negotiate->peer_cert );
#endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
return( MBEDTLS_ERR_SSL_PK_TYPE_MISMATCH );
}
#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
if( ssl->handshake->ecrs_enabled )
rs_ctx = &ssl->handshake->ecrs_ctx.pk;
#endif
ret = mbedtls_pk_verify_restartable( peer_pk,
md_alg, hash, hashlen, p, sig_len, rs_ctx );
if( ret == 0 )
{
mbedtls_platform_random_delay();
if( ret == 0 && buf_dup == buf && buflen_dup == buflen )
{
#if !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
/* We don't need the peer's public key anymore. Free it,
* so that more RAM is available for upcoming expensive
* operations like ECDHE. */
mbedtls_pk_free( peer_pk );
#else
mbedtls_x509_crt_pk_release(
ssl->session_negotiate->peer_cert );
#endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
return( ret );
}
else
{
return( MBEDTLS_ERR_PLATFORM_FAULT_DETECTED );
}
}
#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
if( ret != MBEDTLS_ERR_ECP_IN_PROGRESS )
#endif
{
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_DECRYPT_ERROR );
}
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_pk_verify", ret );
#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
if( ret == MBEDTLS_ERR_ECP_IN_PROGRESS )
ret = MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS;
#endif
#if defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
mbedtls_x509_crt_pk_release( ssl->session_negotiate->peer_cert );
#endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
}
#endif /* MBEDTLS_KEY_EXCHANGE__WITH_SERVER_SIGNATURE__ENABLED */
return( ret );
}
static int ssl_in_server_key_exchange_postprocess( mbedtls_ssl_context *ssl )
{
ssl->state = MBEDTLS_SSL_CERTIFICATE_REQUEST;
return( 0 );
}
static int ssl_process_in_server_key_exchange( mbedtls_ssl_context *ssl )
{
int ret = MBEDTLS_ERR_PLATFORM_FAULT_DETECTED;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse server key exchange" ) );
/* Preparation:
* Potentially extract DH parameters from Server's certificate.
*
* Consider: Why don't we do this as post-processing after
* the server certificate has been read?
*/
MBEDTLS_SSL_CHK( ssl_in_server_key_exchange_prepare( ssl ) );
/* Coordination:
* Check if we expect a ServerKeyExchange */
MBEDTLS_SSL_CHK( ssl_in_server_key_exchange_coordinate( ssl ) );
if( ret == SSL_SRV_KEY_EXCHANGE_EXPECTED )
{
/* Reading step */
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 ||
ssl->in_msg[0] != MBEDTLS_SSL_HS_SERVER_KEY_EXCHANGE )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE );
ret = MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE;
goto cleanup;
}
else
{
MBEDTLS_SSL_CHK( ssl_in_server_key_exchange_parse( ssl, ssl->in_msg,
ssl->in_hslen ) );
}
}
else if( ret == SSL_SRV_KEY_EXCHANGE_SKIP )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse server key exchange" ) );
}
/* Update state */
MBEDTLS_SSL_CHK( ssl_in_server_key_exchange_postprocess( ssl ) );
cleanup:
#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
if( ret == MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS )
ssl->keep_current_message = 1;
#endif
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse server key exchange" ) );
return( ret );
}
#if ! defined(MBEDTLS_KEY_EXCHANGE__CERT_REQ_ALLOWED__ENABLED)
static int ssl_parse_certificate_request( mbedtls_ssl_context *ssl )
{
mbedtls_ssl_ciphersuite_handle_t ciphersuite_info =
mbedtls_ssl_handshake_get_ciphersuite( ssl->handshake );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse certificate request" ) );
if( ! mbedtls_ssl_ciphersuite_cert_req_allowed( ciphersuite_info ) )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate request" ) );
ssl->state = MBEDTLS_SSL_SERVER_HELLO_DONE;
return( 0 );
}
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
#else /* MBEDTLS_KEY_EXCHANGE__CERT_REQ_ALLOWED__ENABLED */
static int ssl_parse_certificate_request( mbedtls_ssl_context *ssl )
{
int ret;
unsigned char *buf;
size_t n = 0;
size_t cert_type_len = 0, dn_len = 0;
mbedtls_ssl_ciphersuite_handle_t ciphersuite_info =
mbedtls_ssl_handshake_get_ciphersuite( ssl->handshake );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse certificate request" ) );
if( ! mbedtls_ssl_ciphersuite_cert_req_allowed( ciphersuite_info ) )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate request" ) );
ssl->state = MBEDTLS_SSL_SERVER_HELLO_DONE;
return( 0 );
}
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 certificate request message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE );
return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
}
ssl->state = MBEDTLS_SSL_SERVER_HELLO_DONE;
ssl->client_auth = ( ssl->in_msg[0] == MBEDTLS_SSL_HS_CERTIFICATE_REQUEST );
MBEDTLS_SSL_DEBUG_MSG( 3, ( "got %s certificate request",
ssl->client_auth ? "a" : "no" ) );
if( ssl->client_auth == 0 )
{
/* Current message is probably the ServerHelloDone */
ssl->keep_current_message = 1;
goto exit;
}
/*
* struct {
* ClientCertificateType certificate_types<1..2^8-1>;
* SignatureAndHashAlgorithm
* supported_signature_algorithms<2^16-1>; -- TLS 1.2 only
* DistinguishedName certificate_authorities<0..2^16-1>;
* } CertificateRequest;
*
* Since we only support a single certificate on clients, let's just
* ignore all the information that's supposed to help us pick a
* certificate.
*
* We could check that our certificate matches the request, and bail out
* if it doesn't, but it's simpler to just send the certificate anyway,
* and give the server the opportunity to decide if it should terminate
* the connection when it doesn't like our certificate.
*
* Same goes for the hash in TLS 1.2's signature_algorithms: at this
* point we only have one hash available (see comments in
* write_certificate_verify), so let's just use what we have.
*
* However, we still minimally parse the message to check it is at least
* superficially sane.
*/
buf = ssl->in_msg;
/* certificate_types */
if( ssl->in_hslen <= mbedtls_ssl_hs_hdr_len( ssl ) )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate request message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE_REQUEST );
}
cert_type_len = buf[mbedtls_ssl_hs_hdr_len( ssl )];
n = cert_type_len;
/*
* In the subsequent code there are two paths that read from buf:
* * the length of the signature algorithms field (if minor version of
* SSL is 3),
* * distinguished name length otherwise.
* Both reach at most the index:
* ...hdr_len + 2 + n,
* therefore the buffer length at this point must be greater than that
* regardless of the actual code path.
*/
if( ssl->in_hslen <= mbedtls_ssl_hs_hdr_len( ssl ) + 2 + n )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate request message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE_REQUEST );
}
/* supported_signature_algorithms */
#if defined(MBEDTLS_SSL_PROTO_TLS1_2)
if( mbedtls_ssl_get_minor_ver( ssl ) == MBEDTLS_SSL_MINOR_VERSION_3 )
{
size_t sig_alg_len = mbedtls_platform_get_uint16_be( &buf[mbedtls_ssl_hs_hdr_len( ssl ) + 1 + n] );
#if defined(MBEDTLS_DEBUG_C)
unsigned char* sig_alg;
size_t i;
#endif
/*
* The furthest access in buf is in the loop few lines below:
* sig_alg[i + 1],
* where:
* sig_alg = buf + ...hdr_len + 3 + n,
* max(i) = sig_alg_len - 1.
* Therefore the furthest access is:
* buf[...hdr_len + 3 + n + sig_alg_len - 1 + 1],
* which reduces to:
* buf[...hdr_len + 3 + n + sig_alg_len],
* which is one less than we need the buf to be.
*/
if( ssl->in_hslen <= mbedtls_ssl_hs_hdr_len( ssl ) + 3 + n + sig_alg_len )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate request message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE_REQUEST );
}
#if defined(MBEDTLS_DEBUG_C)
sig_alg = buf + mbedtls_ssl_hs_hdr_len( ssl ) + 3 + n;
for( i = 0; i < sig_alg_len; i += 2 )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "Supported Signature Algorithm found: %d"
",%d", sig_alg[i], sig_alg[i + 1] ) );
}
#endif
n += 2 + sig_alg_len;
}
#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
/* certificate_authorities */
dn_len = mbedtls_platform_get_uint16_be( &buf[mbedtls_ssl_hs_hdr_len( ssl ) + 1 + n] );
n += dn_len;
if( ssl->in_hslen != mbedtls_ssl_hs_hdr_len( ssl ) + 3 + n )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate request message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE_REQUEST );
}
exit:
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse certificate request" ) );
return( 0 );
}
#endif /* MBEDTLS_KEY_EXCHANGE__CERT_REQ_ALLOWED__ENABLED */
static int ssl_parse_server_hello_done( mbedtls_ssl_context *ssl )
{
int ret = MBEDTLS_ERR_PLATFORM_FAULT_DETECTED;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse server hello done" ) );
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 server hello done message" ) );
return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
}
if( ssl->in_hslen != mbedtls_ssl_hs_hdr_len( ssl ) ||
ssl->in_msg[0] != MBEDTLS_SSL_HS_SERVER_HELLO_DONE )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello done message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO_DONE );
}
ssl->state = MBEDTLS_SSL_CLIENT_CERTIFICATE;
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( MBEDTLS_SSL_TRANSPORT_IS_DTLS( ssl->conf->transport ) )
mbedtls_ssl_recv_flight_completed( ssl );
#endif
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse server hello done" ) );
return( ret );
}
/*
*
* STATE HANDLING: Client Key Exchange
*
*/
/*
* Overview
*/
/* Main entry point; orchestrates the other functions */
static int ssl_process_out_client_key_exchange( mbedtls_ssl_context *ssl );
/* Preparation
* - For ECDH: Generate client params and derive premaster secret
* - For RSA-suites: Encrypt PMS
* - For ECJPAKE: Do Round 2
*/
static int ssl_out_client_key_exchange_prepare( mbedtls_ssl_context *ssl );
static int ssl_out_client_key_exchange_write( mbedtls_ssl_context *ssl,
unsigned char *buf,
size_t buflen,
size_t *olen );
static int ssl_out_client_key_exchange_postprocess( mbedtls_ssl_context *ssl );
/*
* Implementation
*/
static int ssl_process_out_client_key_exchange( mbedtls_ssl_context *ssl )
{
int ret = 0;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> process client key exchange" ) );
#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
if( ssl->handshake->ecrs_state == ssl_ecrs_cke_ecdh_calc_secret )
goto cli_key_exchange_postprocess;
if( ssl->handshake->ecrs_enabled )
mbedtls_ecdh_enable_restart( &ssl->handshake->ecdh_ctx );
#endif
MBEDTLS_SSL_CHK( ssl_out_client_key_exchange_prepare( ssl ) );
/* Prepare CertificateVerify message in output buffer. */
MBEDTLS_SSL_CHK( ssl_out_client_key_exchange_write( ssl, ssl->out_msg,
MBEDTLS_SSL_MAX_CONTENT_LEN,
&ssl->out_msglen ) );
ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE;
ssl->out_msg[0] = MBEDTLS_SSL_HS_CLIENT_KEY_EXCHANGE;
/* Calculate secrets and update state */
#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
if( ssl->handshake->ecrs_enabled )
ssl->handshake->ecrs_state = ssl_ecrs_cke_ecdh_calc_secret;
cli_key_exchange_postprocess:
#endif
ret = ssl_out_client_key_exchange_postprocess( ssl );
#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
if( ret == MBEDTLS_ERR_ECP_IN_PROGRESS )
ret = MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS;
#endif /* MBEDTLS_SSL__ECP_RESTARTABLE */
MBEDTLS_SSL_CHK( ret );
/* Dispatch message */
MBEDTLS_SSL_CHK( mbedtls_ssl_write_handshake_msg( ssl ) );
/* NOTE: For the new messaging layer, the postprocessing step
* might come after the dispatching step if the latter
* doesn't send the message immediately.
* At the moment, we must do the postprocessing
* prior to the dispatching because if the latter
* returns WANT_WRITE, we want the handshake state
* to be updated in order to not enter
* this function again on retry. */
cleanup:
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= process client key exchange" ) );
return( ret );
}
static int ssl_out_client_key_exchange_prepare( mbedtls_ssl_context *ssl )
{
int ret = 0;
mbedtls_ssl_ciphersuite_handle_t ciphersuite_info =
mbedtls_ssl_handshake_get_ciphersuite( ssl->handshake );
((void) ret);
((void) ciphersuite_info);
/* TODO: The current API for DH and ECDH does not allow
* to separate public key generation from public key export.
*
* Ideally, we would like to pick the private (EC)DH keys
* in this preparation step, exporting the corresponding
* public key in the writing step only.
*
* The necessary extension of the (EC)DH API is being
* considered, but until then we perform the public
* generation + export in the writing step.
*
*/
#if defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED)
if( mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_RSA_PSK )
{
/* For RSA-PSK, the premaster secret is composed of
* - Length tag with value 48, encoded as a uint16
* - 2 bytes indicating the TLS version
* - 46 randomly chosen bytes
* - the chosen PSK.
* The following call takes care of all but the PSK. */
ret = ssl_rsa_generate_partial_pms( ssl, ssl->handshake->premaster,
1 /* Add length tag */ );
if( ret != 0 )
return( ret );
}
#endif /* MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED */
#if defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED)
if( mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_RSA )
{
/* For RSA, the premaster secret is composed of
* - 2 bytes indicating the TLS version
* - 46 randomly chosen bytes
* which the following call generates. */
ret = ssl_rsa_generate_partial_pms( ssl, ssl->handshake->premaster,
0 /* Omit length tag */ );
if( ret != 0 )
return( ret );
}
#endif /* MBEDTLS_KEY_EXCHANGE_RSA_ENABLED */
return( 0 );
}
/* Warning: Despite accepting a length argument, this function is currently
* still lacking some bounds checks and assumes that `buf` has length
* `MBEDTLS_SSL_OUT_CONTENT_LEN`. Eventually, it should be rewritten to work
* with any buffer + length pair, returning MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL
* on insufficient writing space. */
static int ssl_out_client_key_exchange_write( mbedtls_ssl_context *ssl,
unsigned char *buf,
size_t buflen,
size_t *olen )
{
int ret;
unsigned char *p, *end;
volatile unsigned char *buf_dup = buf;
volatile size_t buflen_dup = buflen;
size_t n;
mbedtls_ssl_ciphersuite_handle_t ciphersuite_info =
mbedtls_ssl_handshake_get_ciphersuite( ssl->handshake );
/* NOTE: This function will generate different messages
* when it's called multiple times, because it currently
* includes private/public key generation in case of
* (EC)DH ciphersuites.
*
* It is therefore not suitable to be registered as a callback
* for retransmission, if such get introduced at some point.
*
* Also see the documentation of ssl_out_client_key_exchange_prepare().
*/
p = buf + 4;
end = buf + buflen;
#if defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED)
if( mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_DHE_RSA )
{
/*
* DHM key exchange -- send G^X mod P
*/
n = ssl->handshake->dhm_ctx.len;
if( (size_t)( end - p ) < n + 2 )
return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
p = mbedtls_platform_put_uint16_be( p, n );
ret = mbedtls_dhm_make_public( &ssl->handshake->dhm_ctx,
(int) mbedtls_mpi_size( &ssl->handshake->dhm_ctx.P ),
p, n, mbedtls_ssl_conf_get_frng( ssl->conf ),
mbedtls_ssl_conf_get_prng( ssl->conf ) );
if( ret != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_dhm_make_public", ret );
return( ret );
}
MBEDTLS_SSL_DEBUG_MPI( 3, "DHM: X ", &ssl->handshake->dhm_ctx.X );
MBEDTLS_SSL_DEBUG_MPI( 3, "DHM: GX", &ssl->handshake->dhm_ctx.GX );
p += n;
}
else
#endif /* MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED */
#if defined(MBEDTLS_USE_TINYCRYPT)
if( mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_ECDHE_RSA ||
mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA ||
mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_ECDH_RSA ||
mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA )
{
((void) n);
if( (size_t)( end - p ) < 2 * NUM_ECC_BYTES + 2 )
return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
*p++ = 2 * NUM_ECC_BYTES + 1;
*p++ = 0x04; /* uncompressed point presentation */
ret = uECC_make_key( p, ssl->handshake->ecdh_privkey );
if( ret == UECC_FAULT_DETECTED )
return( MBEDTLS_ERR_PLATFORM_FAULT_DETECTED );
if( ret != UECC_SUCCESS )
return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
p += 2 * NUM_ECC_BYTES;
}
else
#endif /* MBEDTLS_USE_TINYCRYPT */
#if defined(MBEDTLS_ECDH_C) && \
( 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) )
if( mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_ECDHE_RSA ||
mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA ||
mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_ECDH_RSA ||
mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA )
{
/*
* ECDH key exchange -- generate and send client public value
*/
/* NOTE: If we ever switch the ECDH stack/API to allow
* independent key generation and export, we should have
* generated our key share in the preparation step, and
* we'd only do the export here. */
ret = mbedtls_ecdh_make_public( &ssl->handshake->ecdh_ctx,
&n, p, end - p,
mbedtls_ssl_conf_get_frng( ssl->conf ),
mbedtls_ssl_conf_get_prng( ssl->conf ) );
if( ret != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecdh_make_public", ret );
#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
if( ret == MBEDTLS_ERR_ECP_IN_PROGRESS )
ret = MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS;
#endif
return( ret );
}
MBEDTLS_SSL_DEBUG_ECDH( 3, &ssl->handshake->ecdh_ctx,
MBEDTLS_DEBUG_ECDH_Q );
p += n;
}
else
#endif /* MBEDTLS_ECDH_C && (
( MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED ||
MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED ||
MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED ||
MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED ) */
#if defined(MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED)
if( mbedtls_ssl_ciphersuite_uses_psk( ciphersuite_info ) )
{
/*
* opaque psk_identity<0..2^16-1>;
*/
if( ssl->conf->psk == NULL || ssl->conf->psk_identity == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "got no private key for PSK" ) );
return( MBEDTLS_ERR_SSL_PRIVATE_KEY_REQUIRED );
}
n = ssl->conf->psk_identity_len;
if( buflen < n + 2 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "psk identity too long or "
"SSL buffer too short" ) );
return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
}
p = mbedtls_platform_put_uint16_be( p, n );
mbedtls_platform_memcpy( p, ssl->conf->psk_identity, n );
p += ssl->conf->psk_identity_len;
#if defined(MBEDTLS_KEY_EXCHANGE_PSK_ENABLED)
if( mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_PSK )
{
((void) ret);
((void) end);
}
else
#endif
#if defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED)
if( mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_RSA_PSK )
{
if( ( ret = ssl_rsa_encrypt_partial_pms( ssl,
ssl->handshake->premaster + 2,
p, end - p, &n ) ) != 0 )
return( ret );
p += n;
}
else
#endif
#if defined(MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED)
if( mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_DHE_PSK )
{
/*
* ClientDiffieHellmanPublic public (DHM send G^X mod P)
*/
((void) end);
n = ssl->handshake->dhm_ctx.len;
if( buflen < n + 2 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "psk identity or DHM size too long"
" or SSL buffer too short" ) );
return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
}
p = mbedtls_platform_put_uint16_be( p, n );
ret = mbedtls_dhm_make_public( &ssl->handshake->dhm_ctx,
(int) mbedtls_mpi_size( &ssl->handshake->dhm_ctx.P ),
p, n, mbedtls_ssl_conf_get_frng( ssl->conf ),
mbedtls_ssl_conf_get_prng( ssl->conf ) );
if( ret != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_dhm_make_public", ret );
return( ret );
}
p += n;
}
else
#endif /* MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED */
#if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED)
if( mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_ECDHE_PSK )
{
#if defined(MBEDTLS_USE_TINYCRYPT)
((void) n);
if( (size_t)( end - p ) < 2 * NUM_ECC_BYTES + 2 )
return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
*p++ = 2 * NUM_ECC_BYTES + 1;
*p++ = 0x04; /* uncompressed point presentation */
ret = uECC_make_key( p, ssl->handshake->ecdh_privkey );
if( ret == UECC_FAULT_DETECTED )
return( MBEDTLS_ERR_PLATFORM_FAULT_DETECTED );
if( ret != UECC_SUCCESS )
return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
p += 2 * NUM_ECC_BYTES;
#else /* MBEDTLS_USE_TINYCRYPT */
/*
* ClientECDiffieHellmanPublic public;
*/
ret = mbedtls_ecdh_make_public( &ssl->handshake->ecdh_ctx, &n,
p, buflen,
mbedtls_ssl_conf_get_frng( ssl->conf ),
mbedtls_ssl_conf_get_prng( ssl->conf ) );
if( ret != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecdh_make_public", ret );
return( ret );
}
MBEDTLS_SSL_DEBUG_ECP( 3, "ECDH: Q", &ssl->handshake->ecdh_ctx.Q );
p += n;
#endif /* MBEDTLS_USE_TINYCRYPT */
}
else
#endif /* MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED */
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
}
else
#endif /* MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED */
#if defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED)
if( mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_RSA )
{
if( ( ret = ssl_rsa_encrypt_partial_pms( ssl, ssl->handshake->premaster,
p, end - p, &n ) ) != 0 )
return( ret );
p += n;
}
else
#endif /* MBEDTLS_KEY_EXCHANGE_RSA_ENABLED */
#if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
if( mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_ECJPAKE )
{
ret = mbedtls_ecjpake_write_round_two( &ssl->handshake->ecjpake_ctx,
p, end - p, &n,
mbedtls_ssl_conf_get_frng( ssl->conf ),
mbedtls_ssl_conf_get_prng( ssl->conf ) );
if( ret != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecjpake_write_round_two", ret );
return( ret );
}
p += n;
}
else
#endif /* MBEDTLS_KEY_EXCHANGE_RSA_ENABLED */
{
((void) ciphersuite_info);
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
*olen = p - buf;
/* Secure against buffer substitution */
if( buf_dup == buf && buflen_dup == buflen )
{
return( 0 );
}
return( MBEDTLS_ERR_PLATFORM_FAULT_DETECTED );
}
static int ssl_out_client_key_exchange_postprocess( mbedtls_ssl_context *ssl )
{
int ret;
if( ( ret = mbedtls_ssl_build_pms( ssl ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_build_pms", ret );
return( ret );
}
ssl->state = MBEDTLS_SSL_CERTIFICATE_VERIFY;
return( 0 );
}
#if !defined(MBEDTLS_KEY_EXCHANGE__CERT_REQ_ALLOWED__ENABLED)
static int ssl_write_certificate_verify( mbedtls_ssl_context *ssl )
{
mbedtls_ssl_ciphersuite_handle_t ciphersuite_info =
mbedtls_ssl_handshake_get_ciphersuite( ssl->handshake );
int ret;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write certificate verify" ) );
if( ( ret = mbedtls_ssl_derive_keys( ssl ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_derive_keys", ret );
return( ret );
}
if( !mbedtls_ssl_ciphersuite_cert_req_allowed( ciphersuite_info ) )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip write certificate verify" ) );
ssl->state = MBEDTLS_SSL_CLIENT_CHANGE_CIPHER_SPEC;
return( 0 );
}
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
#else /* !MBEDTLS_KEY_EXCHANGE__CERT_REQ_ALLOWED__ENABLED */
static int ssl_write_certificate_verify( mbedtls_ssl_context *ssl )
{
int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE;
mbedtls_ssl_ciphersuite_handle_t ciphersuite_info =
mbedtls_ssl_handshake_get_ciphersuite( ssl->handshake );
size_t n = 0, offset = 0;
unsigned char hash[48];
unsigned char *hash_start = hash;
mbedtls_md_type_t md_alg = MBEDTLS_MD_NONE;
size_t hashlen;
void *rs_ctx = NULL;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write certificate verify" ) );
#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
if( ssl->handshake->ecrs_enabled &&
ssl->handshake->ecrs_state == ssl_ecrs_crt_vrfy_sign )
{
goto sign;
}
#endif
if( ( ret = mbedtls_ssl_derive_keys( ssl ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_derive_keys", ret );
return( ret );
}
if( !mbedtls_ssl_ciphersuite_cert_req_allowed( ciphersuite_info ) )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip write certificate verify" ) );
ssl->state = MBEDTLS_SSL_CLIENT_CHANGE_CIPHER_SPEC;
return( 0 );
}
if( ssl->client_auth == 0 || mbedtls_ssl_own_cert( ssl ) == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip write certificate verify" ) );
ssl->state = MBEDTLS_SSL_CLIENT_CHANGE_CIPHER_SPEC;
return( 0 );
}
if( mbedtls_ssl_own_key( ssl ) == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "got no private key for certificate" ) );
return( MBEDTLS_ERR_SSL_PRIVATE_KEY_REQUIRED );
}
/*
* Make a signature of the handshake digests
*/
#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
if( ssl->handshake->ecrs_enabled )
ssl->handshake->ecrs_state = ssl_ecrs_crt_vrfy_sign;
sign:
#endif
mbedtls_ssl_calc_verify(
mbedtls_ssl_get_minor_ver( ssl ),
mbedtls_ssl_suite_get_mac( ciphersuite_info ),
ssl, hash, &hashlen );
#if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1) || \
defined(MBEDTLS_SSL_PROTO_TLS1_1)
if( mbedtls_ssl_get_minor_ver( ssl ) != MBEDTLS_SSL_MINOR_VERSION_3 )
{
/*
* digitally-signed struct {
* opaque md5_hash[16];
* opaque sha_hash[20];
* };
*
* md5_hash
* MD5(handshake_messages);
*
* sha_hash
* SHA(handshake_messages);
*/
md_alg = MBEDTLS_MD_NONE;
/*
* For ECDSA, default hash is SHA-1 only
*/
if( mbedtls_pk_can_do( mbedtls_ssl_own_key( ssl ), MBEDTLS_PK_ECDSA ) )
{
hash_start += 16;
hashlen -= 16;
md_alg = MBEDTLS_MD_SHA1;
}
}
else
#endif /* MBEDTLS_SSL_PROTO_SSL3 || MBEDTLS_SSL_PROTO_TLS1 || \
MBEDTLS_SSL_PROTO_TLS1_1 */
#if defined(MBEDTLS_SSL_PROTO_TLS1_2)
if( mbedtls_ssl_get_minor_ver( ssl ) == MBEDTLS_SSL_MINOR_VERSION_3 )
{
/*
* digitally-signed struct {
* opaque handshake_messages[handshake_messages_length];
* };
*
* Taking shortcut here. We assume that the server always allows the
* PRF Hash function and has sent it in the allowed signature
* algorithms list received in the Certificate Request message.
*
* Until we encounter a server that does not, we will take this
* shortcut.
*
* Reason: Otherwise we should have running hashes for SHA512 and SHA224
* in order to satisfy 'weird' needs from the server side.
*/
if( mbedtls_ssl_suite_get_mac(
mbedtls_ssl_handshake_get_ciphersuite( ssl->handshake ) )
== MBEDTLS_MD_SHA384 )
{
md_alg = MBEDTLS_MD_SHA384;
ssl->out_msg[4] = MBEDTLS_SSL_HASH_SHA384;
}
else
{
md_alg = MBEDTLS_MD_SHA256;
ssl->out_msg[4] = MBEDTLS_SSL_HASH_SHA256;
}
ssl->out_msg[5] = mbedtls_ssl_sig_from_pk( mbedtls_ssl_own_key( ssl ) );
/* Info from md_alg will be used instead */
hashlen = 0;
offset = 2;
}
else
#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
if( ssl->handshake->ecrs_enabled )
rs_ctx = &ssl->handshake->ecrs_ctx.pk;
#endif
if( ( ret = mbedtls_pk_sign_restartable( mbedtls_ssl_own_key( ssl ),
md_alg, hash_start, hashlen,
ssl->out_msg + 6 + offset, &n,
mbedtls_ssl_conf_get_frng( ssl->conf ),
mbedtls_ssl_conf_get_prng( ssl->conf ), rs_ctx ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_pk_sign", ret );
#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
if( ret == MBEDTLS_ERR_ECP_IN_PROGRESS )
ret = MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS;
#endif
return( ret );
}
(void)mbedtls_platform_put_uint16_be( &ssl->out_msg[4 + offset], n );
ssl->out_msglen = 6 + n + offset;
ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE;
ssl->out_msg[0] = MBEDTLS_SSL_HS_CERTIFICATE_VERIFY;
ssl->state = MBEDTLS_SSL_CLIENT_CHANGE_CIPHER_SPEC;
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 verify" ) );
return( ret );
}
#endif /* MBEDTLS_KEY_EXCHANGE__CERT_REQ_ALLOWED__ENABLED */
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
static int ssl_parse_new_session_ticket( mbedtls_ssl_context *ssl )
{
int ret;
uint32_t lifetime;
size_t ticket_len;
unsigned char *ticket;
const unsigned char *msg;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse new session ticket" ) );
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 new session ticket message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE );
return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
}
/*
* struct {
* uint32 ticket_lifetime_hint;
* opaque ticket<0..2^16-1>;
* } NewSessionTicket;
*
* 0 . 3 ticket_lifetime_hint
* 4 . 5 ticket_len (n)
* 6 . 5+n ticket content
*/
if( ssl->in_msg[0] != MBEDTLS_SSL_HS_NEW_SESSION_TICKET ||
ssl->in_hslen < 6 + mbedtls_ssl_hs_hdr_len( ssl ) )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad new session ticket message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_NEW_SESSION_TICKET );
}
msg = ssl->in_msg + mbedtls_ssl_hs_hdr_len( ssl );
lifetime = (uint32_t)mbedtls_platform_get_uint32_be( msg );
ticket_len = mbedtls_platform_get_uint16_be( &msg[4] );
if( ticket_len + 6 + mbedtls_ssl_hs_hdr_len( ssl ) != ssl->in_hslen )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad new session ticket message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_NEW_SESSION_TICKET );
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "ticket length: %d", ticket_len ) );
/* We're not waiting for a NewSessionTicket message any more */
ssl->handshake->new_session_ticket = 0;
ssl->state = MBEDTLS_SSL_SERVER_CHANGE_CIPHER_SPEC;
/*
* Zero-length ticket means the server changed his mind and doesn't want
* to send a ticket after all, so just forget it
*/
if( ticket_len == 0 )
return( 0 );
if( ssl->session != NULL && ssl->session->ticket != NULL )
{
mbedtls_platform_zeroize( ssl->session->ticket,
ssl->session->ticket_len );
mbedtls_free( ssl->session->ticket );
ssl->session->ticket = NULL;
ssl->session->ticket_len = 0;
}
mbedtls_platform_zeroize( ssl->session_negotiate->ticket,
ssl->session_negotiate->ticket_len );
mbedtls_free( ssl->session_negotiate->ticket );
ssl->session_negotiate->ticket = NULL;
ssl->session_negotiate->ticket_len = 0;
if( ( ticket = mbedtls_calloc( 1, ticket_len ) ) == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "ticket alloc failed" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_INTERNAL_ERROR );
return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
}
mbedtls_platform_memcpy( ticket, msg + 6, ticket_len );
ssl->session_negotiate->ticket = ticket;
ssl->session_negotiate->ticket_len = ticket_len;
ssl->session_negotiate->ticket_lifetime = lifetime;
/*
* RFC 5077 section 3.4:
* "If the client receives a session ticket from the server, then it
* discards any Session ID that was sent in the ServerHello."
*/
MBEDTLS_SSL_DEBUG_MSG( 3, ( "ticket in use, discarding session id" ) );
ssl->session_negotiate->id_len = 0;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse new session ticket" ) );
return( 0 );
}
#endif /* MBEDTLS_SSL_SESSION_TICKETS */
/*
* SSL handshake -- client side -- single step
*/
int mbedtls_ssl_handshake_client_step( mbedtls_ssl_context *ssl )
{
int ret = 0;
if( ssl->state == MBEDTLS_SSL_HANDSHAKE_OVER || ssl->handshake == NULL )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "client state: %d", ssl->state ) );
if( ( ret = mbedtls_ssl_flush_output( ssl ) ) != 0 )
return( ret );
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( MBEDTLS_SSL_TRANSPORT_IS_DTLS( ssl->conf->transport ) &&
ssl->handshake->retransmit_state == MBEDTLS_SSL_RETRANS_SENDING )
{
if( ( ret = mbedtls_ssl_flight_transmit( ssl ) ) != 0 )
return( ret );
}
#endif /* MBEDTLS_SSL_PROTO_DTLS */
/* Change state now, so that it is right in mbedtls_ssl_read_record(), used
* by DTLS for dropping out-of-sequence ChangeCipherSpec records */
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
if( ssl->state == MBEDTLS_SSL_SERVER_CHANGE_CIPHER_SPEC &&
ssl->handshake->new_session_ticket != 0 )
{
ssl->state = MBEDTLS_SSL_SERVER_NEW_SESSION_TICKET;
}
#endif
switch( ssl->state )
{
case MBEDTLS_SSL_HELLO_REQUEST:
ssl->state = MBEDTLS_SSL_CLIENT_HELLO;
break;
/*
* ==> ClientHello
*/
case MBEDTLS_SSL_CLIENT_HELLO:
ret = ssl_write_client_hello( ssl );
break;
/*
* <== ServerHello
* Certificate
* ( ServerKeyExchange )
* ( CertificateRequest )
* ServerHelloDone
*/
case MBEDTLS_SSL_SERVER_HELLO:
ret = ssl_parse_server_hello( ssl );
break;
case MBEDTLS_SSL_SERVER_CERTIFICATE:
ret = mbedtls_ssl_parse_certificate( ssl );
break;
case MBEDTLS_SSL_SERVER_KEY_EXCHANGE:
ret = ssl_process_in_server_key_exchange( ssl );
break;
case MBEDTLS_SSL_CERTIFICATE_REQUEST:
ret = ssl_parse_certificate_request( ssl );
break;
case MBEDTLS_SSL_SERVER_HELLO_DONE:
ret = ssl_parse_server_hello_done( ssl );
break;
/*
* ==> ( Certificate/Alert )
* ClientKeyExchange
* ( CertificateVerify )
* ChangeCipherSpec
* Finished
*/
case MBEDTLS_SSL_CLIENT_CERTIFICATE:
ret = mbedtls_ssl_write_certificate( ssl );
break;
case MBEDTLS_SSL_CLIENT_KEY_EXCHANGE:
ret = ssl_process_out_client_key_exchange( ssl );
break;
case MBEDTLS_SSL_CERTIFICATE_VERIFY:
ret = ssl_write_certificate_verify( ssl );
break;
case MBEDTLS_SSL_CLIENT_CHANGE_CIPHER_SPEC:
ret = mbedtls_ssl_write_change_cipher_spec( ssl );
break;
case MBEDTLS_SSL_CLIENT_FINISHED:
ret = mbedtls_ssl_write_finished( ssl );
break;
/*
* <== ( NewSessionTicket )
* ChangeCipherSpec
* Finished
*/
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
case MBEDTLS_SSL_SERVER_NEW_SESSION_TICKET:
ret = ssl_parse_new_session_ticket( ssl );
break;
#endif
case MBEDTLS_SSL_SERVER_CHANGE_CIPHER_SPEC:
ret = mbedtls_ssl_parse_change_cipher_spec( ssl );
break;
case MBEDTLS_SSL_SERVER_FINISHED:
ret = mbedtls_ssl_parse_finished( ssl );
break;
case MBEDTLS_SSL_FLUSH_BUFFERS:
MBEDTLS_SSL_DEBUG_MSG( 2, ( "handshake: done" ) );
ssl->state = MBEDTLS_SSL_HANDSHAKE_WRAPUP;
break;
case MBEDTLS_SSL_HANDSHAKE_WRAPUP:
ret = mbedtls_ssl_handshake_wrapup( ssl );
break;
case MBEDTLS_SSL_INVALID:
default:
MBEDTLS_SSL_DEBUG_MSG( 1, ( "invalid state %d", ssl->state ) );
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
}
return( ret );
}
#endif /* MBEDTLS_SSL_CLI_C */
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