mirror of
https://github.com/yuzu-emu/mbedtls.git
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3aae5d4ed7
Fix buffer overflow with NIST-KW in cipher layer
6038 lines
203 KiB
C
6038 lines
203 KiB
C
/*
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* Generic SSL/TLS messaging layer functions
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* (record layer + retransmission state machine)
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*
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* Copyright The Mbed TLS Contributors
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* SPDX-License-Identifier: Apache-2.0
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*
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* Licensed under the Apache License, Version 2.0 (the "License"); you may
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* not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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/*
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* The SSL 3.0 specification was drafted by Netscape in 1996,
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* and became an IETF standard in 1999.
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*
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* http://wp.netscape.com/eng/ssl3/
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* http://www.ietf.org/rfc/rfc2246.txt
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* http://www.ietf.org/rfc/rfc4346.txt
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*/
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#include "common.h"
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#if defined(MBEDTLS_SSL_TLS_C)
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#if defined(MBEDTLS_PLATFORM_C)
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#include "mbedtls/platform.h"
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#else
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#include <stdlib.h>
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#define mbedtls_calloc calloc
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#define mbedtls_free free
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#endif
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#include "mbedtls/ssl.h"
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#include "mbedtls/ssl_internal.h"
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#include "mbedtls/debug.h"
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#include "mbedtls/error.h"
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#include "mbedtls/platform_util.h"
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#include "mbedtls/version.h"
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#include "ssl_invasive.h"
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#include <string.h>
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#if defined(MBEDTLS_USE_PSA_CRYPTO)
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#include "mbedtls/psa_util.h"
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#include "psa/crypto.h"
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#endif
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#if defined(MBEDTLS_X509_CRT_PARSE_C)
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#include "mbedtls/oid.h"
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#endif
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static uint32_t ssl_get_hs_total_len( mbedtls_ssl_context const *ssl );
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/*
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* Start a timer.
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* Passing millisecs = 0 cancels a running timer.
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*/
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void mbedtls_ssl_set_timer( mbedtls_ssl_context *ssl, uint32_t millisecs )
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{
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if( ssl->f_set_timer == NULL )
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return;
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MBEDTLS_SSL_DEBUG_MSG( 3, ( "set_timer to %d ms", (int) millisecs ) );
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ssl->f_set_timer( ssl->p_timer, millisecs / 4, millisecs );
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}
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/*
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* Return -1 is timer is expired, 0 if it isn't.
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*/
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int mbedtls_ssl_check_timer( mbedtls_ssl_context *ssl )
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{
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if( ssl->f_get_timer == NULL )
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return( 0 );
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if( ssl->f_get_timer( ssl->p_timer ) == 2 )
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{
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MBEDTLS_SSL_DEBUG_MSG( 3, ( "timer expired" ) );
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return( -1 );
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}
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return( 0 );
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}
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#if defined(MBEDTLS_SSL_RECORD_CHECKING)
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static int ssl_parse_record_header( mbedtls_ssl_context const *ssl,
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unsigned char *buf,
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size_t len,
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mbedtls_record *rec );
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int mbedtls_ssl_check_record( mbedtls_ssl_context const *ssl,
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unsigned char *buf,
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size_t buflen )
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{
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int ret = 0;
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MBEDTLS_SSL_DEBUG_MSG( 1, ( "=> mbedtls_ssl_check_record" ) );
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MBEDTLS_SSL_DEBUG_BUF( 3, "record buffer", buf, buflen );
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/* We don't support record checking in TLS because
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* (a) there doesn't seem to be a usecase for it, and
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* (b) In SSLv3 and TLS 1.0, CBC record decryption has state
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* and we'd need to backup the transform here.
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*/
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if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_STREAM )
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{
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ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE;
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goto exit;
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}
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#if defined(MBEDTLS_SSL_PROTO_DTLS)
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else
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{
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mbedtls_record rec;
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ret = ssl_parse_record_header( ssl, buf, buflen, &rec );
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if( ret != 0 )
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{
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MBEDTLS_SSL_DEBUG_RET( 3, "ssl_parse_record_header", ret );
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goto exit;
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}
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if( ssl->transform_in != NULL )
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{
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ret = mbedtls_ssl_decrypt_buf( ssl, ssl->transform_in, &rec );
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if( ret != 0 )
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{
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MBEDTLS_SSL_DEBUG_RET( 3, "mbedtls_ssl_decrypt_buf", ret );
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goto exit;
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}
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}
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}
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#endif /* MBEDTLS_SSL_PROTO_DTLS */
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exit:
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/* On success, we have decrypted the buffer in-place, so make
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* sure we don't leak any plaintext data. */
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mbedtls_platform_zeroize( buf, buflen );
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/* For the purpose of this API, treat messages with unexpected CID
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* as well as such from future epochs as unexpected. */
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if( ret == MBEDTLS_ERR_SSL_UNEXPECTED_CID ||
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ret == MBEDTLS_ERR_SSL_EARLY_MESSAGE )
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{
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ret = MBEDTLS_ERR_SSL_UNEXPECTED_RECORD;
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}
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MBEDTLS_SSL_DEBUG_MSG( 1, ( "<= mbedtls_ssl_check_record" ) );
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return( ret );
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}
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#endif /* MBEDTLS_SSL_RECORD_CHECKING */
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#define SSL_DONT_FORCE_FLUSH 0
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#define SSL_FORCE_FLUSH 1
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#if defined(MBEDTLS_SSL_PROTO_DTLS)
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/* Forward declarations for functions related to message buffering. */
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static void ssl_buffering_free_slot( mbedtls_ssl_context *ssl,
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uint8_t slot );
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static void ssl_free_buffered_record( mbedtls_ssl_context *ssl );
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static int ssl_load_buffered_message( mbedtls_ssl_context *ssl );
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static int ssl_load_buffered_record( mbedtls_ssl_context *ssl );
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static int ssl_buffer_message( mbedtls_ssl_context *ssl );
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static int ssl_buffer_future_record( mbedtls_ssl_context *ssl,
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mbedtls_record const *rec );
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static int ssl_next_record_is_in_datagram( mbedtls_ssl_context *ssl );
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static size_t ssl_get_maximum_datagram_size( mbedtls_ssl_context const *ssl )
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{
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size_t mtu = mbedtls_ssl_get_current_mtu( ssl );
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#if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH)
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size_t out_buf_len = ssl->out_buf_len;
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#else
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size_t out_buf_len = MBEDTLS_SSL_OUT_BUFFER_LEN;
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#endif
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if( mtu != 0 && mtu < out_buf_len )
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return( mtu );
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return( out_buf_len );
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}
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static int ssl_get_remaining_space_in_datagram( mbedtls_ssl_context const *ssl )
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{
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size_t const bytes_written = ssl->out_left;
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size_t const mtu = ssl_get_maximum_datagram_size( ssl );
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/* Double-check that the write-index hasn't gone
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* past what we can transmit in a single datagram. */
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if( bytes_written > mtu )
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{
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/* Should never happen... */
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return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
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}
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return( (int) ( mtu - bytes_written ) );
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}
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static int ssl_get_remaining_payload_in_datagram( mbedtls_ssl_context const *ssl )
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{
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int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
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size_t remaining, expansion;
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size_t max_len = MBEDTLS_SSL_OUT_CONTENT_LEN;
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#if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
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const size_t mfl = mbedtls_ssl_get_output_max_frag_len( ssl );
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if( max_len > mfl )
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max_len = mfl;
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/* By the standard (RFC 6066 Sect. 4), the MFL extension
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* only limits the maximum record payload size, so in theory
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* we would be allowed to pack multiple records of payload size
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* MFL into a single datagram. However, this would mean that there's
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* no way to explicitly communicate MTU restrictions to the peer.
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*
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* The following reduction of max_len makes sure that we never
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* write datagrams larger than MFL + Record Expansion Overhead.
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*/
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if( max_len <= ssl->out_left )
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return( 0 );
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max_len -= ssl->out_left;
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#endif
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ret = ssl_get_remaining_space_in_datagram( ssl );
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if( ret < 0 )
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return( ret );
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remaining = (size_t) ret;
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ret = mbedtls_ssl_get_record_expansion( ssl );
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if( ret < 0 )
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return( ret );
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expansion = (size_t) ret;
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if( remaining <= expansion )
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return( 0 );
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remaining -= expansion;
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if( remaining >= max_len )
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remaining = max_len;
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return( (int) remaining );
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}
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/*
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* Double the retransmit timeout value, within the allowed range,
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* returning -1 if the maximum value has already been reached.
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*/
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static int ssl_double_retransmit_timeout( mbedtls_ssl_context *ssl )
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{
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uint32_t new_timeout;
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if( ssl->handshake->retransmit_timeout >= ssl->conf->hs_timeout_max )
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return( -1 );
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/* Implement the final paragraph of RFC 6347 section 4.1.1.1
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* in the following way: after the initial transmission and a first
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* retransmission, back off to a temporary estimated MTU of 508 bytes.
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* This value is guaranteed to be deliverable (if not guaranteed to be
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* delivered) of any compliant IPv4 (and IPv6) network, and should work
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* on most non-IP stacks too. */
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if( ssl->handshake->retransmit_timeout != ssl->conf->hs_timeout_min )
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{
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ssl->handshake->mtu = 508;
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MBEDTLS_SSL_DEBUG_MSG( 2, ( "mtu autoreduction to %d bytes", ssl->handshake->mtu ) );
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}
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new_timeout = 2 * ssl->handshake->retransmit_timeout;
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/* Avoid arithmetic overflow and range overflow */
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if( new_timeout < ssl->handshake->retransmit_timeout ||
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new_timeout > ssl->conf->hs_timeout_max )
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{
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new_timeout = ssl->conf->hs_timeout_max;
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}
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ssl->handshake->retransmit_timeout = new_timeout;
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MBEDTLS_SSL_DEBUG_MSG( 3, ( "update timeout value to %d millisecs",
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ssl->handshake->retransmit_timeout ) );
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return( 0 );
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}
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static void ssl_reset_retransmit_timeout( mbedtls_ssl_context *ssl )
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{
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ssl->handshake->retransmit_timeout = ssl->conf->hs_timeout_min;
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MBEDTLS_SSL_DEBUG_MSG( 3, ( "update timeout value to %d millisecs",
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ssl->handshake->retransmit_timeout ) );
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}
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#endif /* MBEDTLS_SSL_PROTO_DTLS */
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#if defined(MBEDTLS_SSL_HW_RECORD_ACCEL)
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int (*mbedtls_ssl_hw_record_init)( mbedtls_ssl_context *ssl,
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const unsigned char *key_enc, const unsigned char *key_dec,
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size_t keylen,
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const unsigned char *iv_enc, const unsigned char *iv_dec,
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size_t ivlen,
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const unsigned char *mac_enc, const unsigned char *mac_dec,
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size_t maclen ) = NULL;
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int (*mbedtls_ssl_hw_record_activate)( mbedtls_ssl_context *ssl, int direction) = NULL;
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int (*mbedtls_ssl_hw_record_reset)( mbedtls_ssl_context *ssl ) = NULL;
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int (*mbedtls_ssl_hw_record_write)( mbedtls_ssl_context *ssl ) = NULL;
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int (*mbedtls_ssl_hw_record_read)( mbedtls_ssl_context *ssl ) = NULL;
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int (*mbedtls_ssl_hw_record_finish)( mbedtls_ssl_context *ssl ) = NULL;
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#endif /* MBEDTLS_SSL_HW_RECORD_ACCEL */
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/*
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* Encryption/decryption functions
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*/
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#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) || \
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defined(MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL)
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static size_t ssl_compute_padding_length( size_t len,
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size_t granularity )
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{
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return( ( granularity - ( len + 1 ) % granularity ) % granularity );
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}
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/* This functions transforms a (D)TLS plaintext fragment and a record content
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* type into an instance of the (D)TLSInnerPlaintext structure. This is used
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* in DTLS 1.2 + CID and within TLS 1.3 to allow flexible padding and to protect
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* a record's content type.
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*
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* struct {
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* opaque content[DTLSPlaintext.length];
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* ContentType real_type;
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* uint8 zeros[length_of_padding];
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* } (D)TLSInnerPlaintext;
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*
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* Input:
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* - `content`: The beginning of the buffer holding the
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* plaintext to be wrapped.
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* - `*content_size`: The length of the plaintext in Bytes.
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* - `max_len`: The number of Bytes available starting from
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* `content`. This must be `>= *content_size`.
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* - `rec_type`: The desired record content type.
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*
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* Output:
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* - `content`: The beginning of the resulting (D)TLSInnerPlaintext structure.
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* - `*content_size`: The length of the resulting (D)TLSInnerPlaintext structure.
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*
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* Returns:
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* - `0` on success.
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* - A negative error code if `max_len` didn't offer enough space
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* for the expansion.
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*/
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static int ssl_build_inner_plaintext( unsigned char *content,
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size_t *content_size,
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size_t remaining,
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uint8_t rec_type,
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size_t pad )
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{
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size_t len = *content_size;
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/* Write real content type */
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if( remaining == 0 )
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return( -1 );
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content[ len ] = rec_type;
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len++;
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remaining--;
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if( remaining < pad )
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return( -1 );
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memset( content + len, 0, pad );
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len += pad;
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remaining -= pad;
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*content_size = len;
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return( 0 );
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}
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/* This function parses a (D)TLSInnerPlaintext structure.
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* See ssl_build_inner_plaintext() for details. */
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static int ssl_parse_inner_plaintext( unsigned char const *content,
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size_t *content_size,
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uint8_t *rec_type )
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{
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size_t remaining = *content_size;
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/* Determine length of padding by skipping zeroes from the back. */
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do
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{
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if( remaining == 0 )
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return( -1 );
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remaining--;
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} while( content[ remaining ] == 0 );
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*content_size = remaining;
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*rec_type = content[ remaining ];
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return( 0 );
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}
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#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID ||
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MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL */
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/* `add_data` must have size 13 Bytes if the CID extension is disabled,
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* and 13 + 1 + CID-length Bytes if the CID extension is enabled. */
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static void ssl_extract_add_data_from_record( unsigned char* add_data,
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size_t *add_data_len,
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mbedtls_record *rec,
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unsigned minor_ver )
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{
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/* Quoting RFC 5246 (TLS 1.2):
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*
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* additional_data = seq_num + TLSCompressed.type +
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* TLSCompressed.version + TLSCompressed.length;
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*
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* For the CID extension, this is extended as follows
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* (quoting draft-ietf-tls-dtls-connection-id-05,
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* https://tools.ietf.org/html/draft-ietf-tls-dtls-connection-id-05):
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*
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* additional_data = seq_num + DTLSPlaintext.type +
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* DTLSPlaintext.version +
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* cid +
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* cid_length +
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* length_of_DTLSInnerPlaintext;
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*
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* For TLS 1.3, the record sequence number is dropped from the AAD
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* and encoded within the nonce of the AEAD operation instead.
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*/
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unsigned char *cur = add_data;
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#if defined(MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL)
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if( minor_ver != MBEDTLS_SSL_MINOR_VERSION_4 )
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#endif /* MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL */
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{
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((void) minor_ver);
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memcpy( cur, rec->ctr, sizeof( rec->ctr ) );
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cur += sizeof( rec->ctr );
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}
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*cur = rec->type;
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cur++;
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memcpy( cur, rec->ver, sizeof( rec->ver ) );
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cur += sizeof( rec->ver );
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|
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#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
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if( rec->cid_len != 0 )
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{
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memcpy( cur, rec->cid, rec->cid_len );
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cur += rec->cid_len;
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*cur = rec->cid_len;
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cur++;
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cur[0] = ( rec->data_len >> 8 ) & 0xFF;
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cur[1] = ( rec->data_len >> 0 ) & 0xFF;
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cur += 2;
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}
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else
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#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
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{
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cur[0] = ( rec->data_len >> 8 ) & 0xFF;
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cur[1] = ( rec->data_len >> 0 ) & 0xFF;
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cur += 2;
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}
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*add_data_len = cur - add_data;
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}
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|
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#if defined(MBEDTLS_SSL_PROTO_SSL3)
|
|
|
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#define SSL3_MAC_MAX_BYTES 20 /* MD-5 or SHA-1 */
|
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|
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/*
|
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* SSLv3.0 MAC functions
|
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*/
|
|
static void ssl_mac( mbedtls_md_context_t *md_ctx,
|
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const unsigned char *secret,
|
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const unsigned char *buf, size_t len,
|
|
const unsigned char *ctr, int type,
|
|
unsigned char out[SSL3_MAC_MAX_BYTES] )
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|
{
|
|
unsigned char header[11];
|
|
unsigned char padding[48];
|
|
int padlen;
|
|
int md_size = mbedtls_md_get_size( md_ctx->md_info );
|
|
int md_type = mbedtls_md_get_type( md_ctx->md_info );
|
|
|
|
/* Only MD5 and SHA-1 supported */
|
|
if( md_type == MBEDTLS_MD_MD5 )
|
|
padlen = 48;
|
|
else
|
|
padlen = 40;
|
|
|
|
memcpy( header, ctr, 8 );
|
|
header[ 8] = (unsigned char) type;
|
|
header[ 9] = (unsigned char)( len >> 8 );
|
|
header[10] = (unsigned char)( len );
|
|
|
|
memset( padding, 0x36, padlen );
|
|
mbedtls_md_starts( md_ctx );
|
|
mbedtls_md_update( md_ctx, secret, md_size );
|
|
mbedtls_md_update( md_ctx, padding, padlen );
|
|
mbedtls_md_update( md_ctx, header, 11 );
|
|
mbedtls_md_update( md_ctx, buf, len );
|
|
mbedtls_md_finish( md_ctx, out );
|
|
|
|
memset( padding, 0x5C, padlen );
|
|
mbedtls_md_starts( md_ctx );
|
|
mbedtls_md_update( md_ctx, secret, md_size );
|
|
mbedtls_md_update( md_ctx, padding, padlen );
|
|
mbedtls_md_update( md_ctx, out, md_size );
|
|
mbedtls_md_finish( md_ctx, out );
|
|
}
|
|
#endif /* MBEDTLS_SSL_PROTO_SSL3 */
|
|
|
|
#if defined(MBEDTLS_GCM_C) || \
|
|
defined(MBEDTLS_CCM_C) || \
|
|
defined(MBEDTLS_CHACHAPOLY_C)
|
|
static int ssl_transform_aead_dynamic_iv_is_explicit(
|
|
mbedtls_ssl_transform const *transform )
|
|
{
|
|
return( transform->ivlen != transform->fixed_ivlen );
|
|
}
|
|
|
|
/* Compute IV := ( fixed_iv || 0 ) XOR ( 0 || dynamic_IV )
|
|
*
|
|
* Concretely, this occurs in two variants:
|
|
*
|
|
* a) Fixed and dynamic IV lengths add up to total IV length, giving
|
|
* IV = fixed_iv || dynamic_iv
|
|
*
|
|
* This variant is used in TLS 1.2 when used with GCM or CCM.
|
|
*
|
|
* b) Fixed IV lengths matches total IV length, giving
|
|
* IV = fixed_iv XOR ( 0 || dynamic_iv )
|
|
*
|
|
* This variant occurs in TLS 1.3 and for TLS 1.2 when using ChaChaPoly.
|
|
*
|
|
* See also the documentation of mbedtls_ssl_transform.
|
|
*
|
|
* This function has the precondition that
|
|
*
|
|
* dst_iv_len >= max( fixed_iv_len, dynamic_iv_len )
|
|
*
|
|
* which has to be ensured by the caller. If this precondition
|
|
* violated, the behavior of this function is undefined.
|
|
*/
|
|
static void ssl_build_record_nonce( unsigned char *dst_iv,
|
|
size_t dst_iv_len,
|
|
unsigned char const *fixed_iv,
|
|
size_t fixed_iv_len,
|
|
unsigned char const *dynamic_iv,
|
|
size_t dynamic_iv_len )
|
|
{
|
|
size_t i;
|
|
|
|
/* Start with Fixed IV || 0 */
|
|
memset( dst_iv, 0, dst_iv_len );
|
|
memcpy( dst_iv, fixed_iv, fixed_iv_len );
|
|
|
|
dst_iv += dst_iv_len - dynamic_iv_len;
|
|
for( i = 0; i < dynamic_iv_len; i++ )
|
|
dst_iv[i] ^= dynamic_iv[i];
|
|
}
|
|
#endif /* MBEDTLS_GCM_C || MBEDTLS_CCM_C || MBEDTLS_CHACHAPOLY_C */
|
|
|
|
int mbedtls_ssl_encrypt_buf( mbedtls_ssl_context *ssl,
|
|
mbedtls_ssl_transform *transform,
|
|
mbedtls_record *rec,
|
|
int (*f_rng)(void *, unsigned char *, size_t),
|
|
void *p_rng )
|
|
{
|
|
mbedtls_cipher_mode_t mode;
|
|
int auth_done = 0;
|
|
unsigned char * data;
|
|
unsigned char add_data[13 + 1 + MBEDTLS_SSL_CID_OUT_LEN_MAX ];
|
|
size_t add_data_len;
|
|
size_t post_avail;
|
|
|
|
/* The SSL context is only used for debugging purposes! */
|
|
#if !defined(MBEDTLS_DEBUG_C)
|
|
ssl = NULL; /* make sure we don't use it except for debug */
|
|
((void) ssl);
|
|
#endif
|
|
|
|
/* The PRNG is used for dynamic IV generation that's used
|
|
* for CBC transformations in TLS 1.1 and TLS 1.2. */
|
|
#if !( defined(MBEDTLS_SSL_SOME_SUITES_USE_CBC) && \
|
|
( defined(MBEDTLS_SSL_PROTO_TLS1_1) || defined(MBEDTLS_SSL_PROTO_TLS1_2) ) )
|
|
((void) f_rng);
|
|
((void) p_rng);
|
|
#endif
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> encrypt buf" ) );
|
|
|
|
if( transform == NULL )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "no transform provided to encrypt_buf" ) );
|
|
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
|
|
}
|
|
if( rec == NULL
|
|
|| rec->buf == NULL
|
|
|| rec->buf_len < rec->data_offset
|
|
|| rec->buf_len - rec->data_offset < rec->data_len
|
|
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
|
|
|| rec->cid_len != 0
|
|
#endif
|
|
)
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad record structure provided to encrypt_buf" ) );
|
|
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
|
|
}
|
|
|
|
data = rec->buf + rec->data_offset;
|
|
post_avail = rec->buf_len - ( rec->data_len + rec->data_offset );
|
|
MBEDTLS_SSL_DEBUG_BUF( 4, "before encrypt: output payload",
|
|
data, rec->data_len );
|
|
|
|
mode = mbedtls_cipher_get_cipher_mode( &transform->cipher_ctx_enc );
|
|
|
|
if( rec->data_len > MBEDTLS_SSL_OUT_CONTENT_LEN )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "Record content %u too large, maximum %d",
|
|
(unsigned) rec->data_len,
|
|
MBEDTLS_SSL_OUT_CONTENT_LEN ) );
|
|
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
|
|
}
|
|
|
|
/* The following two code paths implement the (D)TLSInnerPlaintext
|
|
* structure present in TLS 1.3 and DTLS 1.2 + CID.
|
|
*
|
|
* See ssl_build_inner_plaintext() for more information.
|
|
*
|
|
* Note that this changes `rec->data_len`, and hence
|
|
* `post_avail` needs to be recalculated afterwards.
|
|
*
|
|
* Note also that the two code paths cannot occur simultaneously
|
|
* since they apply to different versions of the protocol. There
|
|
* is hence no risk of double-addition of the inner plaintext.
|
|
*/
|
|
#if defined(MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL)
|
|
if( transform->minor_ver == MBEDTLS_SSL_MINOR_VERSION_4 )
|
|
{
|
|
size_t padding =
|
|
ssl_compute_padding_length( rec->data_len,
|
|
MBEDTLS_SSL_TLS1_3_PADDING_GRANULARITY );
|
|
if( ssl_build_inner_plaintext( data,
|
|
&rec->data_len,
|
|
post_avail,
|
|
rec->type,
|
|
padding ) != 0 )
|
|
{
|
|
return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
|
|
}
|
|
|
|
rec->type = MBEDTLS_SSL_MSG_APPLICATION_DATA;
|
|
}
|
|
#endif /* MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL */
|
|
|
|
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
|
|
/*
|
|
* Add CID information
|
|
*/
|
|
rec->cid_len = transform->out_cid_len;
|
|
memcpy( rec->cid, transform->out_cid, transform->out_cid_len );
|
|
MBEDTLS_SSL_DEBUG_BUF( 3, "CID", rec->cid, rec->cid_len );
|
|
|
|
if( rec->cid_len != 0 )
|
|
{
|
|
size_t padding =
|
|
ssl_compute_padding_length( rec->data_len,
|
|
MBEDTLS_SSL_CID_PADDING_GRANULARITY );
|
|
/*
|
|
* Wrap plaintext into DTLSInnerPlaintext structure.
|
|
* See ssl_build_inner_plaintext() for more information.
|
|
*
|
|
* Note that this changes `rec->data_len`, and hence
|
|
* `post_avail` needs to be recalculated afterwards.
|
|
*/
|
|
if( ssl_build_inner_plaintext( data,
|
|
&rec->data_len,
|
|
post_avail,
|
|
rec->type,
|
|
padding ) != 0 )
|
|
{
|
|
return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
|
|
}
|
|
|
|
rec->type = MBEDTLS_SSL_MSG_CID;
|
|
}
|
|
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
|
|
|
|
post_avail = rec->buf_len - ( rec->data_len + rec->data_offset );
|
|
|
|
/*
|
|
* Add MAC before if needed
|
|
*/
|
|
#if defined(MBEDTLS_SSL_SOME_MODES_USE_MAC)
|
|
if( mode == MBEDTLS_MODE_STREAM ||
|
|
( mode == MBEDTLS_MODE_CBC
|
|
#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
|
|
&& transform->encrypt_then_mac == MBEDTLS_SSL_ETM_DISABLED
|
|
#endif
|
|
) )
|
|
{
|
|
if( post_avail < transform->maclen )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "Buffer provided for encrypted record not large enough" ) );
|
|
return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
|
|
}
|
|
|
|
#if defined(MBEDTLS_SSL_PROTO_SSL3)
|
|
if( transform->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 )
|
|
{
|
|
unsigned char mac[SSL3_MAC_MAX_BYTES];
|
|
ssl_mac( &transform->md_ctx_enc, transform->mac_enc,
|
|
data, rec->data_len, rec->ctr, rec->type, mac );
|
|
memcpy( data + rec->data_len, mac, transform->maclen );
|
|
}
|
|
else
|
|
#endif
|
|
#if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) || \
|
|
defined(MBEDTLS_SSL_PROTO_TLS1_2)
|
|
if( transform->minor_ver >= MBEDTLS_SSL_MINOR_VERSION_1 )
|
|
{
|
|
unsigned char mac[MBEDTLS_SSL_MAC_ADD];
|
|
|
|
ssl_extract_add_data_from_record( add_data, &add_data_len, rec,
|
|
transform->minor_ver );
|
|
|
|
mbedtls_md_hmac_update( &transform->md_ctx_enc, add_data,
|
|
add_data_len );
|
|
mbedtls_md_hmac_update( &transform->md_ctx_enc,
|
|
data, rec->data_len );
|
|
mbedtls_md_hmac_finish( &transform->md_ctx_enc, mac );
|
|
mbedtls_md_hmac_reset( &transform->md_ctx_enc );
|
|
|
|
memcpy( data + rec->data_len, mac, transform->maclen );
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
|
|
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
|
|
}
|
|
|
|
MBEDTLS_SSL_DEBUG_BUF( 4, "computed mac", data + rec->data_len,
|
|
transform->maclen );
|
|
|
|
rec->data_len += transform->maclen;
|
|
post_avail -= transform->maclen;
|
|
auth_done++;
|
|
}
|
|
#endif /* MBEDTLS_SSL_SOME_MODES_USE_MAC */
|
|
|
|
/*
|
|
* Encrypt
|
|
*/
|
|
#if defined(MBEDTLS_ARC4_C) || defined(MBEDTLS_CIPHER_NULL_CIPHER)
|
|
if( mode == MBEDTLS_MODE_STREAM )
|
|
{
|
|
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
|
|
size_t olen;
|
|
MBEDTLS_SSL_DEBUG_MSG( 3, ( "before encrypt: msglen = %d, "
|
|
"including %d bytes of padding",
|
|
rec->data_len, 0 ) );
|
|
|
|
if( ( ret = mbedtls_cipher_crypt( &transform->cipher_ctx_enc,
|
|
transform->iv_enc, transform->ivlen,
|
|
data, rec->data_len,
|
|
data, &olen ) ) != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_crypt", ret );
|
|
return( ret );
|
|
}
|
|
|
|
if( rec->data_len != olen )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
|
|
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
|
|
}
|
|
}
|
|
else
|
|
#endif /* MBEDTLS_ARC4_C || MBEDTLS_CIPHER_NULL_CIPHER */
|
|
|
|
#if defined(MBEDTLS_GCM_C) || \
|
|
defined(MBEDTLS_CCM_C) || \
|
|
defined(MBEDTLS_CHACHAPOLY_C)
|
|
if( mode == MBEDTLS_MODE_GCM ||
|
|
mode == MBEDTLS_MODE_CCM ||
|
|
mode == MBEDTLS_MODE_CHACHAPOLY )
|
|
{
|
|
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
|
|
unsigned char iv[12];
|
|
unsigned char *dynamic_iv;
|
|
size_t dynamic_iv_len;
|
|
int dynamic_iv_is_explicit =
|
|
ssl_transform_aead_dynamic_iv_is_explicit( transform );
|
|
|
|
/* Check that there's space for the authentication tag. */
|
|
if( post_avail < transform->taglen )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "Buffer provided for encrypted record not large enough" ) );
|
|
return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
|
|
}
|
|
|
|
/*
|
|
* Build nonce for AEAD encryption.
|
|
*
|
|
* Note: In the case of CCM and GCM in TLS 1.2, the dynamic
|
|
* part of the IV is prepended to the ciphertext and
|
|
* can be chosen freely - in particular, it need not
|
|
* agree with the record sequence number.
|
|
* However, since ChaChaPoly as well as all AEAD modes
|
|
* in TLS 1.3 use the record sequence number as the
|
|
* dynamic part of the nonce, we uniformly use the
|
|
* record sequence number here in all cases.
|
|
*/
|
|
dynamic_iv = rec->ctr;
|
|
dynamic_iv_len = sizeof( rec->ctr );
|
|
|
|
ssl_build_record_nonce( iv, sizeof( iv ),
|
|
transform->iv_enc,
|
|
transform->fixed_ivlen,
|
|
dynamic_iv,
|
|
dynamic_iv_len );
|
|
|
|
/*
|
|
* Build additional data for AEAD encryption.
|
|
* This depends on the TLS version.
|
|
*/
|
|
ssl_extract_add_data_from_record( add_data, &add_data_len, rec,
|
|
transform->minor_ver );
|
|
|
|
MBEDTLS_SSL_DEBUG_BUF( 4, "IV used (internal)",
|
|
iv, transform->ivlen );
|
|
MBEDTLS_SSL_DEBUG_BUF( 4, "IV used (transmitted)",
|
|
dynamic_iv,
|
|
dynamic_iv_is_explicit ? dynamic_iv_len : 0 );
|
|
MBEDTLS_SSL_DEBUG_BUF( 4, "additional data used for AEAD",
|
|
add_data, add_data_len );
|
|
MBEDTLS_SSL_DEBUG_MSG( 3, ( "before encrypt: msglen = %d, "
|
|
"including 0 bytes of padding",
|
|
rec->data_len ) );
|
|
|
|
/*
|
|
* Encrypt and authenticate
|
|
*/
|
|
|
|
if( ( ret = mbedtls_cipher_auth_encrypt_ext( &transform->cipher_ctx_enc,
|
|
iv, transform->ivlen,
|
|
add_data, add_data_len,
|
|
data, rec->data_len, /* src */
|
|
data, rec->buf_len - (data - rec->buf), /* dst */
|
|
&rec->data_len,
|
|
transform->taglen ) ) != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_auth_encrypt", ret );
|
|
return( ret );
|
|
}
|
|
MBEDTLS_SSL_DEBUG_BUF( 4, "after encrypt: tag",
|
|
data + rec->data_len - transform->taglen,
|
|
transform->taglen );
|
|
/* Account for authentication tag. */
|
|
post_avail -= transform->taglen;
|
|
|
|
/*
|
|
* Prefix record content with dynamic IV in case it is explicit.
|
|
*/
|
|
if( dynamic_iv_is_explicit != 0 )
|
|
{
|
|
if( rec->data_offset < dynamic_iv_len )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "Buffer provided for encrypted record not large enough" ) );
|
|
return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
|
|
}
|
|
|
|
memcpy( data - dynamic_iv_len, dynamic_iv, dynamic_iv_len );
|
|
rec->data_offset -= dynamic_iv_len;
|
|
rec->data_len += dynamic_iv_len;
|
|
}
|
|
|
|
auth_done++;
|
|
}
|
|
else
|
|
#endif /* MBEDTLS_GCM_C || MBEDTLS_CCM_C || MBEDTLS_CHACHAPOLY_C */
|
|
#if defined(MBEDTLS_SSL_SOME_SUITES_USE_CBC)
|
|
if( mode == MBEDTLS_MODE_CBC )
|
|
{
|
|
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
|
|
size_t padlen, i;
|
|
size_t olen;
|
|
|
|
/* Currently we're always using minimal padding
|
|
* (up to 255 bytes would be allowed). */
|
|
padlen = transform->ivlen - ( rec->data_len + 1 ) % transform->ivlen;
|
|
if( padlen == transform->ivlen )
|
|
padlen = 0;
|
|
|
|
/* Check there's enough space in the buffer for the padding. */
|
|
if( post_avail < padlen + 1 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "Buffer provided for encrypted record not large enough" ) );
|
|
return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
|
|
}
|
|
|
|
for( i = 0; i <= padlen; i++ )
|
|
data[rec->data_len + i] = (unsigned char) padlen;
|
|
|
|
rec->data_len += padlen + 1;
|
|
post_avail -= padlen + 1;
|
|
|
|
#if defined(MBEDTLS_SSL_PROTO_TLS1_1) || defined(MBEDTLS_SSL_PROTO_TLS1_2)
|
|
/*
|
|
* Prepend per-record IV for block cipher in TLS v1.1 and up as per
|
|
* Method 1 (6.2.3.2. in RFC4346 and RFC5246)
|
|
*/
|
|
if( transform->minor_ver >= MBEDTLS_SSL_MINOR_VERSION_2 )
|
|
{
|
|
if( f_rng == NULL )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "No PRNG provided to encrypt_record routine" ) );
|
|
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
|
|
}
|
|
|
|
if( rec->data_offset < transform->ivlen )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "Buffer provided for encrypted record not large enough" ) );
|
|
return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
|
|
}
|
|
|
|
/*
|
|
* Generate IV
|
|
*/
|
|
ret = f_rng( p_rng, transform->iv_enc, transform->ivlen );
|
|
if( ret != 0 )
|
|
return( ret );
|
|
|
|
memcpy( data - transform->ivlen, transform->iv_enc,
|
|
transform->ivlen );
|
|
|
|
}
|
|
#endif /* MBEDTLS_SSL_PROTO_TLS1_1 || MBEDTLS_SSL_PROTO_TLS1_2 */
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 3, ( "before encrypt: msglen = %d, "
|
|
"including %d bytes of IV and %d bytes of padding",
|
|
rec->data_len, transform->ivlen,
|
|
padlen + 1 ) );
|
|
|
|
if( ( ret = mbedtls_cipher_crypt( &transform->cipher_ctx_enc,
|
|
transform->iv_enc,
|
|
transform->ivlen,
|
|
data, rec->data_len,
|
|
data, &olen ) ) != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_crypt", ret );
|
|
return( ret );
|
|
}
|
|
|
|
if( rec->data_len != olen )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
|
|
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
|
|
}
|
|
|
|
#if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1)
|
|
if( transform->minor_ver < MBEDTLS_SSL_MINOR_VERSION_2 )
|
|
{
|
|
/*
|
|
* Save IV in SSL3 and TLS1
|
|
*/
|
|
memcpy( transform->iv_enc, transform->cipher_ctx_enc.iv,
|
|
transform->ivlen );
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
data -= transform->ivlen;
|
|
rec->data_offset -= transform->ivlen;
|
|
rec->data_len += transform->ivlen;
|
|
}
|
|
|
|
#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
|
|
if( auth_done == 0 )
|
|
{
|
|
unsigned char mac[MBEDTLS_SSL_MAC_ADD];
|
|
|
|
/*
|
|
* MAC(MAC_write_key, seq_num +
|
|
* TLSCipherText.type +
|
|
* TLSCipherText.version +
|
|
* length_of( (IV +) ENC(...) ) +
|
|
* IV + // except for TLS 1.0
|
|
* ENC(content + padding + padding_length));
|
|
*/
|
|
|
|
if( post_avail < transform->maclen)
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "Buffer provided for encrypted record not large enough" ) );
|
|
return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
|
|
}
|
|
|
|
ssl_extract_add_data_from_record( add_data, &add_data_len,
|
|
rec, transform->minor_ver );
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 3, ( "using encrypt then mac" ) );
|
|
MBEDTLS_SSL_DEBUG_BUF( 4, "MAC'd meta-data", add_data,
|
|
add_data_len );
|
|
|
|
mbedtls_md_hmac_update( &transform->md_ctx_enc, add_data,
|
|
add_data_len );
|
|
mbedtls_md_hmac_update( &transform->md_ctx_enc,
|
|
data, rec->data_len );
|
|
mbedtls_md_hmac_finish( &transform->md_ctx_enc, mac );
|
|
mbedtls_md_hmac_reset( &transform->md_ctx_enc );
|
|
|
|
memcpy( data + rec->data_len, mac, transform->maclen );
|
|
|
|
rec->data_len += transform->maclen;
|
|
post_avail -= transform->maclen;
|
|
auth_done++;
|
|
}
|
|
#endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */
|
|
}
|
|
else
|
|
#endif /* MBEDTLS_SSL_SOME_SUITES_USE_CBC) */
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
|
|
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
|
|
}
|
|
|
|
/* Make extra sure authentication was performed, exactly once */
|
|
if( auth_done != 1 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
|
|
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
|
|
}
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= encrypt buf" ) );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
#if defined(MBEDTLS_SSL_SOME_SUITES_USE_TLS_CBC)
|
|
/*
|
|
* Turn a bit into a mask:
|
|
* - if bit == 1, return the all-bits 1 mask, aka (size_t) -1
|
|
* - if bit == 0, return the all-bits 0 mask, aka 0
|
|
*
|
|
* This function can be used to write constant-time code by replacing branches
|
|
* with bit operations using masks.
|
|
*
|
|
* This function is implemented without using comparison operators, as those
|
|
* might be translated to branches by some compilers on some platforms.
|
|
*/
|
|
static size_t mbedtls_ssl_cf_mask_from_bit( size_t bit )
|
|
{
|
|
/* MSVC has a warning about unary minus on unsigned integer types,
|
|
* but this is well-defined and precisely what we want to do here. */
|
|
#if defined(_MSC_VER)
|
|
#pragma warning( push )
|
|
#pragma warning( disable : 4146 )
|
|
#endif
|
|
return -bit;
|
|
#if defined(_MSC_VER)
|
|
#pragma warning( pop )
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* Constant-flow mask generation for "less than" comparison:
|
|
* - if x < y, return all bits 1, that is (size_t) -1
|
|
* - otherwise, return all bits 0, that is 0
|
|
*
|
|
* This function can be used to write constant-time code by replacing branches
|
|
* with bit operations using masks.
|
|
*
|
|
* This function is implemented without using comparison operators, as those
|
|
* might be translated to branches by some compilers on some platforms.
|
|
*/
|
|
static size_t mbedtls_ssl_cf_mask_lt( size_t x, size_t y )
|
|
{
|
|
/* This has the most significant bit set if and only if x < y */
|
|
const size_t sub = x - y;
|
|
|
|
/* sub1 = (x < y) ? 1 : 0 */
|
|
const size_t sub1 = sub >> ( sizeof( sub ) * 8 - 1 );
|
|
|
|
/* mask = (x < y) ? 0xff... : 0x00... */
|
|
const size_t mask = mbedtls_ssl_cf_mask_from_bit( sub1 );
|
|
|
|
return( mask );
|
|
}
|
|
|
|
/*
|
|
* Constant-flow mask generation for "greater or equal" comparison:
|
|
* - if x >= y, return all bits 1, that is (size_t) -1
|
|
* - otherwise, return all bits 0, that is 0
|
|
*
|
|
* This function can be used to write constant-time code by replacing branches
|
|
* with bit operations using masks.
|
|
*
|
|
* This function is implemented without using comparison operators, as those
|
|
* might be translated to branches by some compilers on some platforms.
|
|
*/
|
|
static size_t mbedtls_ssl_cf_mask_ge( size_t x, size_t y )
|
|
{
|
|
return( ~mbedtls_ssl_cf_mask_lt( x, y ) );
|
|
}
|
|
|
|
/*
|
|
* Constant-flow boolean "equal" comparison:
|
|
* return x == y
|
|
*
|
|
* This function can be used to write constant-time code by replacing branches
|
|
* with bit operations - it can be used in conjunction with
|
|
* mbedtls_ssl_cf_mask_from_bit().
|
|
*
|
|
* This function is implemented without using comparison operators, as those
|
|
* might be translated to branches by some compilers on some platforms.
|
|
*/
|
|
static size_t mbedtls_ssl_cf_bool_eq( size_t x, size_t y )
|
|
{
|
|
/* diff = 0 if x == y, non-zero otherwise */
|
|
const size_t diff = x ^ y;
|
|
|
|
/* MSVC has a warning about unary minus on unsigned integer types,
|
|
* but this is well-defined and precisely what we want to do here. */
|
|
#if defined(_MSC_VER)
|
|
#pragma warning( push )
|
|
#pragma warning( disable : 4146 )
|
|
#endif
|
|
|
|
/* diff_msb's most significant bit is equal to x != y */
|
|
const size_t diff_msb = ( diff | -diff );
|
|
|
|
#if defined(_MSC_VER)
|
|
#pragma warning( pop )
|
|
#endif
|
|
|
|
/* diff1 = (x != y) ? 1 : 0 */
|
|
const size_t diff1 = diff_msb >> ( sizeof( diff_msb ) * 8 - 1 );
|
|
|
|
return( 1 ^ diff1 );
|
|
}
|
|
|
|
/*
|
|
* Constant-flow conditional memcpy:
|
|
* - if c1 == c2, equivalent to memcpy(dst, src, len),
|
|
* - otherwise, a no-op,
|
|
* but with execution flow independent of the values of c1 and c2.
|
|
*
|
|
* This function is implemented without using comparison operators, as those
|
|
* might be translated to branches by some compilers on some platforms.
|
|
*/
|
|
static void mbedtls_ssl_cf_memcpy_if_eq( unsigned char *dst,
|
|
const unsigned char *src,
|
|
size_t len,
|
|
size_t c1, size_t c2 )
|
|
{
|
|
/* mask = c1 == c2 ? 0xff : 0x00 */
|
|
const size_t equal = mbedtls_ssl_cf_bool_eq( c1, c2 );
|
|
const unsigned char mask = (unsigned char) mbedtls_ssl_cf_mask_from_bit( equal );
|
|
|
|
/* dst[i] = c1 == c2 ? src[i] : dst[i] */
|
|
for( size_t i = 0; i < len; i++ )
|
|
dst[i] = ( src[i] & mask ) | ( dst[i] & ~mask );
|
|
}
|
|
|
|
/*
|
|
* Compute HMAC of variable-length data with constant flow.
|
|
*
|
|
* Only works with MD-5, SHA-1, SHA-256 and SHA-384.
|
|
* (Otherwise, computation of block_size needs to be adapted.)
|
|
*/
|
|
MBEDTLS_STATIC_TESTABLE int mbedtls_ssl_cf_hmac(
|
|
mbedtls_md_context_t *ctx,
|
|
const unsigned char *add_data, size_t add_data_len,
|
|
const unsigned char *data, size_t data_len_secret,
|
|
size_t min_data_len, size_t max_data_len,
|
|
unsigned char *output )
|
|
{
|
|
/*
|
|
* This function breaks the HMAC abstraction and uses the md_clone()
|
|
* extension to the MD API in order to get constant-flow behaviour.
|
|
*
|
|
* HMAC(msg) is defined as HASH(okey + HASH(ikey + msg)) where + means
|
|
* concatenation, and okey/ikey are the XOR of the key with some fixed bit
|
|
* patterns (see RFC 2104, sec. 2), which are stored in ctx->hmac_ctx.
|
|
*
|
|
* We'll first compute inner_hash = HASH(ikey + msg) by hashing up to
|
|
* minlen, then cloning the context, and for each byte up to maxlen
|
|
* finishing up the hash computation, keeping only the correct result.
|
|
*
|
|
* Then we only need to compute HASH(okey + inner_hash) and we're done.
|
|
*/
|
|
const mbedtls_md_type_t md_alg = mbedtls_md_get_type( ctx->md_info );
|
|
/* TLS 1.0-1.2 only support SHA-384, SHA-256, SHA-1, MD-5,
|
|
* all of which have the same block size except SHA-384. */
|
|
const size_t block_size = md_alg == MBEDTLS_MD_SHA384 ? 128 : 64;
|
|
const unsigned char * const ikey = ctx->hmac_ctx;
|
|
const unsigned char * const okey = ikey + block_size;
|
|
const size_t hash_size = mbedtls_md_get_size( ctx->md_info );
|
|
|
|
unsigned char aux_out[MBEDTLS_MD_MAX_SIZE];
|
|
mbedtls_md_context_t aux;
|
|
size_t offset;
|
|
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
|
|
|
|
mbedtls_md_init( &aux );
|
|
|
|
#define MD_CHK( func_call ) \
|
|
do { \
|
|
ret = (func_call); \
|
|
if( ret != 0 ) \
|
|
goto cleanup; \
|
|
} while( 0 )
|
|
|
|
MD_CHK( mbedtls_md_setup( &aux, ctx->md_info, 0 ) );
|
|
|
|
/* After hmac_start() of hmac_reset(), ikey has already been hashed,
|
|
* so we can start directly with the message */
|
|
MD_CHK( mbedtls_md_update( ctx, add_data, add_data_len ) );
|
|
MD_CHK( mbedtls_md_update( ctx, data, min_data_len ) );
|
|
|
|
/* For each possible length, compute the hash up to that point */
|
|
for( offset = min_data_len; offset <= max_data_len; offset++ )
|
|
{
|
|
MD_CHK( mbedtls_md_clone( &aux, ctx ) );
|
|
MD_CHK( mbedtls_md_finish( &aux, aux_out ) );
|
|
/* Keep only the correct inner_hash in the output buffer */
|
|
mbedtls_ssl_cf_memcpy_if_eq( output, aux_out, hash_size,
|
|
offset, data_len_secret );
|
|
|
|
if( offset < max_data_len )
|
|
MD_CHK( mbedtls_md_update( ctx, data + offset, 1 ) );
|
|
}
|
|
|
|
/* Now compute HASH(okey + inner_hash) */
|
|
MD_CHK( mbedtls_md_starts( ctx ) );
|
|
MD_CHK( mbedtls_md_update( ctx, okey, block_size ) );
|
|
MD_CHK( mbedtls_md_update( ctx, output, hash_size ) );
|
|
MD_CHK( mbedtls_md_finish( ctx, output ) );
|
|
|
|
/* Done, get ready for next time */
|
|
MD_CHK( mbedtls_md_hmac_reset( ctx ) );
|
|
|
|
#undef MD_CHK
|
|
|
|
cleanup:
|
|
mbedtls_md_free( &aux );
|
|
return( ret );
|
|
}
|
|
|
|
/*
|
|
* Constant-flow memcpy from variable position in buffer.
|
|
* - functionally equivalent to memcpy(dst, src + offset_secret, len)
|
|
* - but with execution flow independent from the value of offset_secret.
|
|
*/
|
|
MBEDTLS_STATIC_TESTABLE void mbedtls_ssl_cf_memcpy_offset(
|
|
unsigned char *dst,
|
|
const unsigned char *src_base,
|
|
size_t offset_secret,
|
|
size_t offset_min, size_t offset_max,
|
|
size_t len )
|
|
{
|
|
size_t offset;
|
|
|
|
for( offset = offset_min; offset <= offset_max; offset++ )
|
|
{
|
|
mbedtls_ssl_cf_memcpy_if_eq( dst, src_base + offset, len,
|
|
offset, offset_secret );
|
|
}
|
|
}
|
|
#endif /* MBEDTLS_SSL_SOME_SUITES_USE_TLS_CBC */
|
|
|
|
int mbedtls_ssl_decrypt_buf( mbedtls_ssl_context const *ssl,
|
|
mbedtls_ssl_transform *transform,
|
|
mbedtls_record *rec )
|
|
{
|
|
size_t olen;
|
|
mbedtls_cipher_mode_t mode;
|
|
int ret, auth_done = 0;
|
|
#if defined(MBEDTLS_SSL_SOME_MODES_USE_MAC)
|
|
size_t padlen = 0, correct = 1;
|
|
#endif
|
|
unsigned char* data;
|
|
unsigned char add_data[13 + 1 + MBEDTLS_SSL_CID_IN_LEN_MAX ];
|
|
size_t add_data_len;
|
|
|
|
#if !defined(MBEDTLS_DEBUG_C)
|
|
ssl = NULL; /* make sure we don't use it except for debug */
|
|
((void) ssl);
|
|
#endif
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> decrypt buf" ) );
|
|
if( rec == NULL ||
|
|
rec->buf == NULL ||
|
|
rec->buf_len < rec->data_offset ||
|
|
rec->buf_len - rec->data_offset < rec->data_len )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad record structure provided to decrypt_buf" ) );
|
|
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
|
|
}
|
|
|
|
data = rec->buf + rec->data_offset;
|
|
mode = mbedtls_cipher_get_cipher_mode( &transform->cipher_ctx_dec );
|
|
|
|
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
|
|
/*
|
|
* Match record's CID with incoming CID.
|
|
*/
|
|
if( rec->cid_len != transform->in_cid_len ||
|
|
memcmp( rec->cid, transform->in_cid, rec->cid_len ) != 0 )
|
|
{
|
|
return( MBEDTLS_ERR_SSL_UNEXPECTED_CID );
|
|
}
|
|
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
|
|
|
|
#if defined(MBEDTLS_ARC4_C) || defined(MBEDTLS_CIPHER_NULL_CIPHER)
|
|
if( mode == MBEDTLS_MODE_STREAM )
|
|
{
|
|
padlen = 0;
|
|
if( ( ret = mbedtls_cipher_crypt( &transform->cipher_ctx_dec,
|
|
transform->iv_dec,
|
|
transform->ivlen,
|
|
data, rec->data_len,
|
|
data, &olen ) ) != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_crypt", ret );
|
|
return( ret );
|
|
}
|
|
|
|
if( rec->data_len != olen )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
|
|
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
|
|
}
|
|
}
|
|
else
|
|
#endif /* MBEDTLS_ARC4_C || MBEDTLS_CIPHER_NULL_CIPHER */
|
|
#if defined(MBEDTLS_GCM_C) || \
|
|
defined(MBEDTLS_CCM_C) || \
|
|
defined(MBEDTLS_CHACHAPOLY_C)
|
|
if( mode == MBEDTLS_MODE_GCM ||
|
|
mode == MBEDTLS_MODE_CCM ||
|
|
mode == MBEDTLS_MODE_CHACHAPOLY )
|
|
{
|
|
unsigned char iv[12];
|
|
unsigned char *dynamic_iv;
|
|
size_t dynamic_iv_len;
|
|
|
|
/*
|
|
* Extract dynamic part of nonce for AEAD decryption.
|
|
*
|
|
* Note: In the case of CCM and GCM in TLS 1.2, the dynamic
|
|
* part of the IV is prepended to the ciphertext and
|
|
* can be chosen freely - in particular, it need not
|
|
* agree with the record sequence number.
|
|
*/
|
|
dynamic_iv_len = sizeof( rec->ctr );
|
|
if( ssl_transform_aead_dynamic_iv_is_explicit( transform ) == 1 )
|
|
{
|
|
if( rec->data_len < dynamic_iv_len )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "msglen (%d) < explicit_iv_len (%d) ",
|
|
rec->data_len,
|
|
dynamic_iv_len ) );
|
|
return( MBEDTLS_ERR_SSL_INVALID_MAC );
|
|
}
|
|
dynamic_iv = data;
|
|
|
|
data += dynamic_iv_len;
|
|
rec->data_offset += dynamic_iv_len;
|
|
rec->data_len -= dynamic_iv_len;
|
|
}
|
|
else
|
|
{
|
|
dynamic_iv = rec->ctr;
|
|
}
|
|
|
|
/* Check that there's space for the authentication tag. */
|
|
if( rec->data_len < transform->taglen )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "msglen (%d) < taglen (%d) ",
|
|
rec->data_len,
|
|
transform->taglen ) );
|
|
return( MBEDTLS_ERR_SSL_INVALID_MAC );
|
|
}
|
|
rec->data_len -= transform->taglen;
|
|
|
|
/*
|
|
* Prepare nonce from dynamic and static parts.
|
|
*/
|
|
ssl_build_record_nonce( iv, sizeof( iv ),
|
|
transform->iv_dec,
|
|
transform->fixed_ivlen,
|
|
dynamic_iv,
|
|
dynamic_iv_len );
|
|
|
|
/*
|
|
* Build additional data for AEAD encryption.
|
|
* This depends on the TLS version.
|
|
*/
|
|
ssl_extract_add_data_from_record( add_data, &add_data_len, rec,
|
|
transform->minor_ver );
|
|
MBEDTLS_SSL_DEBUG_BUF( 4, "additional data used for AEAD",
|
|
add_data, add_data_len );
|
|
|
|
/* Because of the check above, we know that there are
|
|
* explicit_iv_len Bytes preceeding data, and taglen
|
|
* bytes following data + data_len. This justifies
|
|
* the debug message and the invocation of
|
|
* mbedtls_cipher_auth_decrypt() below. */
|
|
|
|
MBEDTLS_SSL_DEBUG_BUF( 4, "IV used", iv, transform->ivlen );
|
|
MBEDTLS_SSL_DEBUG_BUF( 4, "TAG used", data + rec->data_len,
|
|
transform->taglen );
|
|
|
|
/*
|
|
* Decrypt and authenticate
|
|
*/
|
|
if( ( ret = mbedtls_cipher_auth_decrypt_ext( &transform->cipher_ctx_dec,
|
|
iv, transform->ivlen,
|
|
add_data, add_data_len,
|
|
data, rec->data_len + transform->taglen, /* src */
|
|
data, rec->buf_len - (data - rec->buf), &olen, /* dst */
|
|
transform->taglen ) ) != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_auth_decrypt", ret );
|
|
|
|
if( ret == MBEDTLS_ERR_CIPHER_AUTH_FAILED )
|
|
return( MBEDTLS_ERR_SSL_INVALID_MAC );
|
|
|
|
return( ret );
|
|
}
|
|
auth_done++;
|
|
|
|
/* Double-check that AEAD decryption doesn't change content length. */
|
|
if( olen != rec->data_len )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
|
|
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
|
|
}
|
|
}
|
|
else
|
|
#endif /* MBEDTLS_GCM_C || MBEDTLS_CCM_C */
|
|
#if defined(MBEDTLS_SSL_SOME_SUITES_USE_CBC)
|
|
if( mode == MBEDTLS_MODE_CBC )
|
|
{
|
|
size_t minlen = 0;
|
|
|
|
/*
|
|
* Check immediate ciphertext sanity
|
|
*/
|
|
#if defined(MBEDTLS_SSL_PROTO_TLS1_1) || defined(MBEDTLS_SSL_PROTO_TLS1_2)
|
|
if( transform->minor_ver >= MBEDTLS_SSL_MINOR_VERSION_2 )
|
|
{
|
|
/* The ciphertext is prefixed with the CBC IV. */
|
|
minlen += transform->ivlen;
|
|
}
|
|
#endif
|
|
|
|
/* Size considerations:
|
|
*
|
|
* - The CBC cipher text must not be empty and hence
|
|
* at least of size transform->ivlen.
|
|
*
|
|
* Together with the potential IV-prefix, this explains
|
|
* the first of the two checks below.
|
|
*
|
|
* - The record must contain a MAC, either in plain or
|
|
* encrypted, depending on whether Encrypt-then-MAC
|
|
* is used or not.
|
|
* - If it is, the message contains the IV-prefix,
|
|
* the CBC ciphertext, and the MAC.
|
|
* - If it is not, the padded plaintext, and hence
|
|
* the CBC ciphertext, has at least length maclen + 1
|
|
* because there is at least the padding length byte.
|
|
*
|
|
* As the CBC ciphertext is not empty, both cases give the
|
|
* lower bound minlen + maclen + 1 on the record size, which
|
|
* we test for in the second check below.
|
|
*/
|
|
if( rec->data_len < minlen + transform->ivlen ||
|
|
rec->data_len < minlen + transform->maclen + 1 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "msglen (%d) < max( ivlen(%d), maclen (%d) "
|
|
"+ 1 ) ( + expl IV )", rec->data_len,
|
|
transform->ivlen,
|
|
transform->maclen ) );
|
|
return( MBEDTLS_ERR_SSL_INVALID_MAC );
|
|
}
|
|
|
|
/*
|
|
* Authenticate before decrypt if enabled
|
|
*/
|
|
#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
|
|
if( transform->encrypt_then_mac == MBEDTLS_SSL_ETM_ENABLED )
|
|
{
|
|
unsigned char mac_expect[MBEDTLS_SSL_MAC_ADD];
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 3, ( "using encrypt then mac" ) );
|
|
|
|
/* Update data_len in tandem with add_data.
|
|
*
|
|
* The subtraction is safe because of the previous check
|
|
* data_len >= minlen + maclen + 1.
|
|
*
|
|
* Afterwards, we know that data + data_len is followed by at
|
|
* least maclen Bytes, which justifies the call to
|
|
* mbedtls_ssl_safer_memcmp() below.
|
|
*
|
|
* Further, we still know that data_len > minlen */
|
|
rec->data_len -= transform->maclen;
|
|
ssl_extract_add_data_from_record( add_data, &add_data_len, rec,
|
|
transform->minor_ver );
|
|
|
|
/* Calculate expected MAC. */
|
|
MBEDTLS_SSL_DEBUG_BUF( 4, "MAC'd meta-data", add_data,
|
|
add_data_len );
|
|
mbedtls_md_hmac_update( &transform->md_ctx_dec, add_data,
|
|
add_data_len );
|
|
mbedtls_md_hmac_update( &transform->md_ctx_dec,
|
|
data, rec->data_len );
|
|
mbedtls_md_hmac_finish( &transform->md_ctx_dec, mac_expect );
|
|
mbedtls_md_hmac_reset( &transform->md_ctx_dec );
|
|
|
|
MBEDTLS_SSL_DEBUG_BUF( 4, "message mac", data + rec->data_len,
|
|
transform->maclen );
|
|
MBEDTLS_SSL_DEBUG_BUF( 4, "expected mac", mac_expect,
|
|
transform->maclen );
|
|
|
|
/* Compare expected MAC with MAC at the end of the record. */
|
|
if( mbedtls_ssl_safer_memcmp( data + rec->data_len, mac_expect,
|
|
transform->maclen ) != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "message mac does not match" ) );
|
|
return( MBEDTLS_ERR_SSL_INVALID_MAC );
|
|
}
|
|
auth_done++;
|
|
}
|
|
#endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */
|
|
|
|
/*
|
|
* Check length sanity
|
|
*/
|
|
|
|
/* We know from above that data_len > minlen >= 0,
|
|
* so the following check in particular implies that
|
|
* data_len >= minlen + ivlen ( = minlen or 2 * minlen ). */
|
|
if( rec->data_len % transform->ivlen != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "msglen (%d) %% ivlen (%d) != 0",
|
|
rec->data_len, transform->ivlen ) );
|
|
return( MBEDTLS_ERR_SSL_INVALID_MAC );
|
|
}
|
|
|
|
#if defined(MBEDTLS_SSL_PROTO_TLS1_1) || defined(MBEDTLS_SSL_PROTO_TLS1_2)
|
|
/*
|
|
* Initialize for prepended IV for block cipher in TLS v1.1 and up
|
|
*/
|
|
if( transform->minor_ver >= MBEDTLS_SSL_MINOR_VERSION_2 )
|
|
{
|
|
/* Safe because data_len >= minlen + ivlen = 2 * ivlen. */
|
|
memcpy( transform->iv_dec, data, transform->ivlen );
|
|
|
|
data += transform->ivlen;
|
|
rec->data_offset += transform->ivlen;
|
|
rec->data_len -= transform->ivlen;
|
|
}
|
|
#endif /* MBEDTLS_SSL_PROTO_TLS1_1 || MBEDTLS_SSL_PROTO_TLS1_2 */
|
|
|
|
/* We still have data_len % ivlen == 0 and data_len >= ivlen here. */
|
|
|
|
if( ( ret = mbedtls_cipher_crypt( &transform->cipher_ctx_dec,
|
|
transform->iv_dec, transform->ivlen,
|
|
data, rec->data_len, data, &olen ) ) != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_crypt", ret );
|
|
return( ret );
|
|
}
|
|
|
|
/* Double-check that length hasn't changed during decryption. */
|
|
if( rec->data_len != olen )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
|
|
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
|
|
}
|
|
|
|
#if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1)
|
|
if( transform->minor_ver < MBEDTLS_SSL_MINOR_VERSION_2 )
|
|
{
|
|
/*
|
|
* Save IV in SSL3 and TLS1, where CBC decryption of consecutive
|
|
* records is equivalent to CBC decryption of the concatenation
|
|
* of the records; in other words, IVs are maintained across
|
|
* record decryptions.
|
|
*/
|
|
memcpy( transform->iv_dec, transform->cipher_ctx_dec.iv,
|
|
transform->ivlen );
|
|
}
|
|
#endif
|
|
|
|
/* Safe since data_len >= minlen + maclen + 1, so after having
|
|
* subtracted at most minlen and maclen up to this point,
|
|
* data_len > 0 (because of data_len % ivlen == 0, it's actually
|
|
* >= ivlen ). */
|
|
padlen = data[rec->data_len - 1];
|
|
|
|
if( auth_done == 1 )
|
|
{
|
|
const size_t mask = mbedtls_ssl_cf_mask_ge(
|
|
rec->data_len,
|
|
padlen + 1 );
|
|
correct &= mask;
|
|
padlen &= mask;
|
|
}
|
|
else
|
|
{
|
|
#if defined(MBEDTLS_SSL_DEBUG_ALL)
|
|
if( rec->data_len < transform->maclen + padlen + 1 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "msglen (%d) < maclen (%d) + padlen (%d)",
|
|
rec->data_len,
|
|
transform->maclen,
|
|
padlen + 1 ) );
|
|
}
|
|
#endif
|
|
|
|
const size_t mask = mbedtls_ssl_cf_mask_ge(
|
|
rec->data_len,
|
|
transform->maclen + padlen + 1 );
|
|
correct &= mask;
|
|
padlen &= mask;
|
|
}
|
|
|
|
padlen++;
|
|
|
|
/* Regardless of the validity of the padding,
|
|
* we have data_len >= padlen here. */
|
|
|
|
#if defined(MBEDTLS_SSL_PROTO_SSL3)
|
|
if( transform->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 )
|
|
{
|
|
/* This is the SSL 3.0 path, we don't have to worry about Lucky
|
|
* 13, because there's a strictly worse padding attack built in
|
|
* the protocol (known as part of POODLE), so we don't care if the
|
|
* code is not constant-time, in particular branches are OK. */
|
|
if( padlen > transform->ivlen )
|
|
{
|
|
#if defined(MBEDTLS_SSL_DEBUG_ALL)
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad padding length: is %d, "
|
|
"should be no more than %d",
|
|
padlen, transform->ivlen ) );
|
|
#endif
|
|
correct = 0;
|
|
}
|
|
}
|
|
else
|
|
#endif /* MBEDTLS_SSL_PROTO_SSL3 */
|
|
#if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) || \
|
|
defined(MBEDTLS_SSL_PROTO_TLS1_2)
|
|
if( transform->minor_ver > MBEDTLS_SSL_MINOR_VERSION_0 )
|
|
{
|
|
/* The padding check involves a series of up to 256
|
|
* consecutive memory reads at the end of the record
|
|
* plaintext buffer. In order to hide the length and
|
|
* validity of the padding, always perform exactly
|
|
* `min(256,plaintext_len)` reads (but take into account
|
|
* only the last `padlen` bytes for the padding check). */
|
|
size_t pad_count = 0;
|
|
volatile unsigned char* const check = data;
|
|
|
|
/* Index of first padding byte; it has been ensured above
|
|
* that the subtraction is safe. */
|
|
size_t const padding_idx = rec->data_len - padlen;
|
|
size_t const num_checks = rec->data_len <= 256 ? rec->data_len : 256;
|
|
size_t const start_idx = rec->data_len - num_checks;
|
|
size_t idx;
|
|
|
|
for( idx = start_idx; idx < rec->data_len; idx++ )
|
|
{
|
|
/* pad_count += (idx >= padding_idx) &&
|
|
* (check[idx] == padlen - 1);
|
|
*/
|
|
const size_t mask = mbedtls_ssl_cf_mask_ge( idx, padding_idx );
|
|
const size_t equal = mbedtls_ssl_cf_bool_eq( check[idx],
|
|
padlen - 1 );
|
|
pad_count += mask & equal;
|
|
}
|
|
correct &= mbedtls_ssl_cf_bool_eq( pad_count, padlen );
|
|
|
|
#if defined(MBEDTLS_SSL_DEBUG_ALL)
|
|
if( padlen > 0 && correct == 0 )
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad padding byte detected" ) );
|
|
#endif
|
|
padlen &= mbedtls_ssl_cf_mask_from_bit( correct );
|
|
}
|
|
else
|
|
#endif /* MBEDTLS_SSL_PROTO_TLS1 || MBEDTLS_SSL_PROTO_TLS1_1 || \
|
|
MBEDTLS_SSL_PROTO_TLS1_2 */
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
|
|
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
|
|
}
|
|
|
|
/* If the padding was found to be invalid, padlen == 0
|
|
* and the subtraction is safe. If the padding was found valid,
|
|
* padlen hasn't been changed and the previous assertion
|
|
* data_len >= padlen still holds. */
|
|
rec->data_len -= padlen;
|
|
}
|
|
else
|
|
#endif /* MBEDTLS_SSL_SOME_SUITES_USE_CBC */
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
|
|
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
|
|
}
|
|
|
|
#if defined(MBEDTLS_SSL_DEBUG_ALL)
|
|
MBEDTLS_SSL_DEBUG_BUF( 4, "raw buffer after decryption",
|
|
data, rec->data_len );
|
|
#endif
|
|
|
|
/*
|
|
* Authenticate if not done yet.
|
|
* Compute the MAC regardless of the padding result (RFC4346, CBCTIME).
|
|
*/
|
|
#if defined(MBEDTLS_SSL_SOME_MODES_USE_MAC)
|
|
if( auth_done == 0 )
|
|
{
|
|
unsigned char mac_expect[MBEDTLS_SSL_MAC_ADD];
|
|
unsigned char mac_peer[MBEDTLS_SSL_MAC_ADD];
|
|
|
|
/* If the initial value of padlen was such that
|
|
* data_len < maclen + padlen + 1, then padlen
|
|
* got reset to 1, and the initial check
|
|
* data_len >= minlen + maclen + 1
|
|
* guarantees that at this point we still
|
|
* have at least data_len >= maclen.
|
|
*
|
|
* If the initial value of padlen was such that
|
|
* data_len >= maclen + padlen + 1, then we have
|
|
* subtracted either padlen + 1 (if the padding was correct)
|
|
* or 0 (if the padding was incorrect) since then,
|
|
* hence data_len >= maclen in any case.
|
|
*/
|
|
rec->data_len -= transform->maclen;
|
|
ssl_extract_add_data_from_record( add_data, &add_data_len, rec,
|
|
transform->minor_ver );
|
|
|
|
#if defined(MBEDTLS_SSL_PROTO_SSL3)
|
|
if( transform->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 )
|
|
{
|
|
ssl_mac( &transform->md_ctx_dec,
|
|
transform->mac_dec,
|
|
data, rec->data_len,
|
|
rec->ctr, rec->type,
|
|
mac_expect );
|
|
memcpy( mac_peer, data + rec->data_len, transform->maclen );
|
|
}
|
|
else
|
|
#endif /* MBEDTLS_SSL_PROTO_SSL3 */
|
|
#if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) || \
|
|
defined(MBEDTLS_SSL_PROTO_TLS1_2)
|
|
if( transform->minor_ver > MBEDTLS_SSL_MINOR_VERSION_0 )
|
|
{
|
|
/*
|
|
* The next two sizes are the minimum and maximum values of
|
|
* data_len over all padlen values.
|
|
*
|
|
* They're independent of padlen, since we previously did
|
|
* data_len -= padlen.
|
|
*
|
|
* Note that max_len + maclen is never more than the buffer
|
|
* length, as we previously did in_msglen -= maclen too.
|
|
*/
|
|
const size_t max_len = rec->data_len + padlen;
|
|
const size_t min_len = ( max_len > 256 ) ? max_len - 256 : 0;
|
|
|
|
ret = mbedtls_ssl_cf_hmac( &transform->md_ctx_dec,
|
|
add_data, add_data_len,
|
|
data, rec->data_len, min_len, max_len,
|
|
mac_expect );
|
|
if( ret != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_cf_hmac", ret );
|
|
return( ret );
|
|
}
|
|
|
|
mbedtls_ssl_cf_memcpy_offset( mac_peer, data,
|
|
rec->data_len,
|
|
min_len, max_len,
|
|
transform->maclen );
|
|
}
|
|
else
|
|
#endif /* MBEDTLS_SSL_PROTO_TLS1 || MBEDTLS_SSL_PROTO_TLS1_1 || \
|
|
MBEDTLS_SSL_PROTO_TLS1_2 */
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
|
|
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
|
|
}
|
|
|
|
#if defined(MBEDTLS_SSL_DEBUG_ALL)
|
|
MBEDTLS_SSL_DEBUG_BUF( 4, "expected mac", mac_expect, transform->maclen );
|
|
MBEDTLS_SSL_DEBUG_BUF( 4, "message mac", mac_peer, transform->maclen );
|
|
#endif
|
|
|
|
if( mbedtls_ssl_safer_memcmp( mac_peer, mac_expect,
|
|
transform->maclen ) != 0 )
|
|
{
|
|
#if defined(MBEDTLS_SSL_DEBUG_ALL)
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "message mac does not match" ) );
|
|
#endif
|
|
correct = 0;
|
|
}
|
|
auth_done++;
|
|
}
|
|
|
|
/*
|
|
* Finally check the correct flag
|
|
*/
|
|
if( correct == 0 )
|
|
return( MBEDTLS_ERR_SSL_INVALID_MAC );
|
|
#endif /* MBEDTLS_SSL_SOME_MODES_USE_MAC */
|
|
|
|
/* Make extra sure authentication was performed, exactly once */
|
|
if( auth_done != 1 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
|
|
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
|
|
}
|
|
|
|
#if defined(MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL)
|
|
if( transform->minor_ver == MBEDTLS_SSL_MINOR_VERSION_4 )
|
|
{
|
|
/* Remove inner padding and infer true content type. */
|
|
ret = ssl_parse_inner_plaintext( data, &rec->data_len,
|
|
&rec->type );
|
|
|
|
if( ret != 0 )
|
|
return( MBEDTLS_ERR_SSL_INVALID_RECORD );
|
|
}
|
|
#endif /* MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL */
|
|
|
|
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
|
|
if( rec->cid_len != 0 )
|
|
{
|
|
ret = ssl_parse_inner_plaintext( data, &rec->data_len,
|
|
&rec->type );
|
|
if( ret != 0 )
|
|
return( MBEDTLS_ERR_SSL_INVALID_RECORD );
|
|
}
|
|
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= decrypt buf" ) );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
#undef MAC_NONE
|
|
#undef MAC_PLAINTEXT
|
|
#undef MAC_CIPHERTEXT
|
|
|
|
#if defined(MBEDTLS_ZLIB_SUPPORT)
|
|
/*
|
|
* Compression/decompression functions
|
|
*/
|
|
static int ssl_compress_buf( mbedtls_ssl_context *ssl )
|
|
{
|
|
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
|
|
unsigned char *msg_post = ssl->out_msg;
|
|
ptrdiff_t bytes_written = ssl->out_msg - ssl->out_buf;
|
|
size_t len_pre = ssl->out_msglen;
|
|
unsigned char *msg_pre = ssl->compress_buf;
|
|
#if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH)
|
|
size_t out_buf_len = ssl->out_buf_len;
|
|
#else
|
|
size_t out_buf_len = MBEDTLS_SSL_OUT_BUFFER_LEN;
|
|
#endif
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> compress buf" ) );
|
|
|
|
if( len_pre == 0 )
|
|
return( 0 );
|
|
|
|
memcpy( msg_pre, ssl->out_msg, len_pre );
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 3, ( "before compression: msglen = %d, ",
|
|
ssl->out_msglen ) );
|
|
|
|
MBEDTLS_SSL_DEBUG_BUF( 4, "before compression: output payload",
|
|
ssl->out_msg, ssl->out_msglen );
|
|
|
|
ssl->transform_out->ctx_deflate.next_in = msg_pre;
|
|
ssl->transform_out->ctx_deflate.avail_in = len_pre;
|
|
ssl->transform_out->ctx_deflate.next_out = msg_post;
|
|
ssl->transform_out->ctx_deflate.avail_out = out_buf_len - bytes_written;
|
|
|
|
ret = deflate( &ssl->transform_out->ctx_deflate, Z_SYNC_FLUSH );
|
|
if( ret != Z_OK )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "failed to perform compression (%d)", ret ) );
|
|
return( MBEDTLS_ERR_SSL_COMPRESSION_FAILED );
|
|
}
|
|
|
|
ssl->out_msglen = out_buf_len -
|
|
ssl->transform_out->ctx_deflate.avail_out - bytes_written;
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 3, ( "after compression: msglen = %d, ",
|
|
ssl->out_msglen ) );
|
|
|
|
MBEDTLS_SSL_DEBUG_BUF( 4, "after compression: output payload",
|
|
ssl->out_msg, ssl->out_msglen );
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= compress buf" ) );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
static int ssl_decompress_buf( mbedtls_ssl_context *ssl )
|
|
{
|
|
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
|
|
unsigned char *msg_post = ssl->in_msg;
|
|
ptrdiff_t header_bytes = ssl->in_msg - ssl->in_buf;
|
|
size_t len_pre = ssl->in_msglen;
|
|
unsigned char *msg_pre = ssl->compress_buf;
|
|
#if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH)
|
|
size_t in_buf_len = ssl->in_buf_len;
|
|
#else
|
|
size_t in_buf_len = MBEDTLS_SSL_IN_BUFFER_LEN;
|
|
#endif
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> decompress buf" ) );
|
|
|
|
if( len_pre == 0 )
|
|
return( 0 );
|
|
|
|
memcpy( msg_pre, ssl->in_msg, len_pre );
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 3, ( "before decompression: msglen = %d, ",
|
|
ssl->in_msglen ) );
|
|
|
|
MBEDTLS_SSL_DEBUG_BUF( 4, "before decompression: input payload",
|
|
ssl->in_msg, ssl->in_msglen );
|
|
|
|
ssl->transform_in->ctx_inflate.next_in = msg_pre;
|
|
ssl->transform_in->ctx_inflate.avail_in = len_pre;
|
|
ssl->transform_in->ctx_inflate.next_out = msg_post;
|
|
ssl->transform_in->ctx_inflate.avail_out = in_buf_len - header_bytes;
|
|
|
|
ret = inflate( &ssl->transform_in->ctx_inflate, Z_SYNC_FLUSH );
|
|
if( ret != Z_OK )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "failed to perform decompression (%d)", ret ) );
|
|
return( MBEDTLS_ERR_SSL_COMPRESSION_FAILED );
|
|
}
|
|
|
|
ssl->in_msglen = in_buf_len -
|
|
ssl->transform_in->ctx_inflate.avail_out - header_bytes;
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 3, ( "after decompression: msglen = %d, ",
|
|
ssl->in_msglen ) );
|
|
|
|
MBEDTLS_SSL_DEBUG_BUF( 4, "after decompression: input payload",
|
|
ssl->in_msg, ssl->in_msglen );
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= decompress buf" ) );
|
|
|
|
return( 0 );
|
|
}
|
|
#endif /* MBEDTLS_ZLIB_SUPPORT */
|
|
|
|
/*
|
|
* Fill the input message buffer by appending data to it.
|
|
* The amount of data already fetched is in ssl->in_left.
|
|
*
|
|
* If we return 0, is it guaranteed that (at least) nb_want bytes are
|
|
* available (from this read and/or a previous one). Otherwise, an error code
|
|
* is returned (possibly EOF or WANT_READ).
|
|
*
|
|
* With stream transport (TLS) on success ssl->in_left == nb_want, but
|
|
* with datagram transport (DTLS) on success ssl->in_left >= nb_want,
|
|
* since we always read a whole datagram at once.
|
|
*
|
|
* For DTLS, it is up to the caller to set ssl->next_record_offset when
|
|
* they're done reading a record.
|
|
*/
|
|
int mbedtls_ssl_fetch_input( mbedtls_ssl_context *ssl, size_t nb_want )
|
|
{
|
|
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
|
|
size_t len;
|
|
#if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH)
|
|
size_t in_buf_len = ssl->in_buf_len;
|
|
#else
|
|
size_t in_buf_len = MBEDTLS_SSL_IN_BUFFER_LEN;
|
|
#endif
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> fetch input" ) );
|
|
|
|
if( ssl->f_recv == NULL && ssl->f_recv_timeout == NULL )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "Bad usage of mbedtls_ssl_set_bio() "
|
|
"or mbedtls_ssl_set_bio()" ) );
|
|
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
|
|
}
|
|
|
|
if( nb_want > in_buf_len - (size_t)( ssl->in_hdr - ssl->in_buf ) )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "requesting more data than fits" ) );
|
|
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
|
|
}
|
|
|
|
#if defined(MBEDTLS_SSL_PROTO_DTLS)
|
|
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
|
|
{
|
|
uint32_t timeout;
|
|
|
|
/*
|
|
* The point is, we need to always read a full datagram at once, so we
|
|
* sometimes read more then requested, and handle the additional data.
|
|
* It could be the rest of the current record (while fetching the
|
|
* header) and/or some other records in the same datagram.
|
|
*/
|
|
|
|
/*
|
|
* Move to the next record in the already read datagram if applicable
|
|
*/
|
|
if( ssl->next_record_offset != 0 )
|
|
{
|
|
if( ssl->in_left < ssl->next_record_offset )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
|
|
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
|
|
}
|
|
|
|
ssl->in_left -= ssl->next_record_offset;
|
|
|
|
if( ssl->in_left != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "next record in same datagram, offset: %d",
|
|
ssl->next_record_offset ) );
|
|
memmove( ssl->in_hdr,
|
|
ssl->in_hdr + ssl->next_record_offset,
|
|
ssl->in_left );
|
|
}
|
|
|
|
ssl->next_record_offset = 0;
|
|
}
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "in_left: %d, nb_want: %d",
|
|
ssl->in_left, nb_want ) );
|
|
|
|
/*
|
|
* Done if we already have enough data.
|
|
*/
|
|
if( nb_want <= ssl->in_left)
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= fetch input" ) );
|
|
return( 0 );
|
|
}
|
|
|
|
/*
|
|
* A record can't be split across datagrams. If we need to read but
|
|
* are not at the beginning of a new record, the caller did something
|
|
* wrong.
|
|
*/
|
|
if( ssl->in_left != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
|
|
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
|
|
}
|
|
|
|
/*
|
|
* Don't even try to read if time's out already.
|
|
* This avoids by-passing the timer when repeatedly receiving messages
|
|
* that will end up being dropped.
|
|
*/
|
|
if( mbedtls_ssl_check_timer( ssl ) != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "timer has expired" ) );
|
|
ret = MBEDTLS_ERR_SSL_TIMEOUT;
|
|
}
|
|
else
|
|
{
|
|
len = in_buf_len - ( ssl->in_hdr - ssl->in_buf );
|
|
|
|
if( ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER )
|
|
timeout = ssl->handshake->retransmit_timeout;
|
|
else
|
|
timeout = ssl->conf->read_timeout;
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 3, ( "f_recv_timeout: %u ms", timeout ) );
|
|
|
|
if( ssl->f_recv_timeout != NULL )
|
|
ret = ssl->f_recv_timeout( ssl->p_bio, ssl->in_hdr, len,
|
|
timeout );
|
|
else
|
|
ret = ssl->f_recv( ssl->p_bio, ssl->in_hdr, len );
|
|
|
|
MBEDTLS_SSL_DEBUG_RET( 2, "ssl->f_recv(_timeout)", ret );
|
|
|
|
if( ret == 0 )
|
|
return( MBEDTLS_ERR_SSL_CONN_EOF );
|
|
}
|
|
|
|
if( ret == MBEDTLS_ERR_SSL_TIMEOUT )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "timeout" ) );
|
|
mbedtls_ssl_set_timer( ssl, 0 );
|
|
|
|
if( ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER )
|
|
{
|
|
if( ssl_double_retransmit_timeout( ssl ) != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "handshake timeout" ) );
|
|
return( MBEDTLS_ERR_SSL_TIMEOUT );
|
|
}
|
|
|
|
if( ( ret = mbedtls_ssl_resend( ssl ) ) != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_resend", ret );
|
|
return( ret );
|
|
}
|
|
|
|
return( MBEDTLS_ERR_SSL_WANT_READ );
|
|
}
|
|
#if defined(MBEDTLS_SSL_SRV_C) && defined(MBEDTLS_SSL_RENEGOTIATION)
|
|
else if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER &&
|
|
ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_PENDING )
|
|
{
|
|
if( ( ret = mbedtls_ssl_resend_hello_request( ssl ) ) != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_resend_hello_request",
|
|
ret );
|
|
return( ret );
|
|
}
|
|
|
|
return( MBEDTLS_ERR_SSL_WANT_READ );
|
|
}
|
|
#endif /* MBEDTLS_SSL_SRV_C && MBEDTLS_SSL_RENEGOTIATION */
|
|
}
|
|
|
|
if( ret < 0 )
|
|
return( ret );
|
|
|
|
ssl->in_left = ret;
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "in_left: %d, nb_want: %d",
|
|
ssl->in_left, nb_want ) );
|
|
|
|
while( ssl->in_left < nb_want )
|
|
{
|
|
len = nb_want - ssl->in_left;
|
|
|
|
if( mbedtls_ssl_check_timer( ssl ) != 0 )
|
|
ret = MBEDTLS_ERR_SSL_TIMEOUT;
|
|
else
|
|
{
|
|
if( ssl->f_recv_timeout != NULL )
|
|
{
|
|
ret = ssl->f_recv_timeout( ssl->p_bio,
|
|
ssl->in_hdr + ssl->in_left, len,
|
|
ssl->conf->read_timeout );
|
|
}
|
|
else
|
|
{
|
|
ret = ssl->f_recv( ssl->p_bio,
|
|
ssl->in_hdr + ssl->in_left, len );
|
|
}
|
|
}
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "in_left: %d, nb_want: %d",
|
|
ssl->in_left, nb_want ) );
|
|
MBEDTLS_SSL_DEBUG_RET( 2, "ssl->f_recv(_timeout)", ret );
|
|
|
|
if( ret == 0 )
|
|
return( MBEDTLS_ERR_SSL_CONN_EOF );
|
|
|
|
if( ret < 0 )
|
|
return( ret );
|
|
|
|
if ( (size_t)ret > len || ( INT_MAX > SIZE_MAX && ret > (int)SIZE_MAX ) )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1,
|
|
( "f_recv returned %d bytes but only %lu were requested",
|
|
ret, (unsigned long)len ) );
|
|
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
|
|
}
|
|
|
|
ssl->in_left += ret;
|
|
}
|
|
}
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= fetch input" ) );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
/*
|
|
* Flush any data not yet written
|
|
*/
|
|
int mbedtls_ssl_flush_output( mbedtls_ssl_context *ssl )
|
|
{
|
|
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
|
|
unsigned char *buf;
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> flush output" ) );
|
|
|
|
if( ssl->f_send == NULL )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "Bad usage of mbedtls_ssl_set_bio() "
|
|
"or mbedtls_ssl_set_bio()" ) );
|
|
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
|
|
}
|
|
|
|
/* Avoid incrementing counter if data is flushed */
|
|
if( ssl->out_left == 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= flush output" ) );
|
|
return( 0 );
|
|
}
|
|
|
|
while( ssl->out_left > 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "message length: %d, out_left: %d",
|
|
mbedtls_ssl_out_hdr_len( ssl ) + ssl->out_msglen, ssl->out_left ) );
|
|
|
|
buf = ssl->out_hdr - ssl->out_left;
|
|
ret = ssl->f_send( ssl->p_bio, buf, ssl->out_left );
|
|
|
|
MBEDTLS_SSL_DEBUG_RET( 2, "ssl->f_send", ret );
|
|
|
|
if( ret <= 0 )
|
|
return( ret );
|
|
|
|
if( (size_t)ret > ssl->out_left || ( INT_MAX > SIZE_MAX && ret > (int)SIZE_MAX ) )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1,
|
|
( "f_send returned %d bytes but only %lu bytes were sent",
|
|
ret, (unsigned long)ssl->out_left ) );
|
|
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
|
|
}
|
|
|
|
ssl->out_left -= ret;
|
|
}
|
|
|
|
#if defined(MBEDTLS_SSL_PROTO_DTLS)
|
|
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
|
|
{
|
|
ssl->out_hdr = ssl->out_buf;
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
ssl->out_hdr = ssl->out_buf + 8;
|
|
}
|
|
mbedtls_ssl_update_out_pointers( ssl, ssl->transform_out );
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= flush output" ) );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
/*
|
|
* Functions to handle the DTLS retransmission state machine
|
|
*/
|
|
#if defined(MBEDTLS_SSL_PROTO_DTLS)
|
|
/*
|
|
* Append current handshake message to current outgoing flight
|
|
*/
|
|
static int ssl_flight_append( mbedtls_ssl_context *ssl )
|
|
{
|
|
mbedtls_ssl_flight_item *msg;
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> ssl_flight_append" ) );
|
|
MBEDTLS_SSL_DEBUG_BUF( 4, "message appended to flight",
|
|
ssl->out_msg, ssl->out_msglen );
|
|
|
|
/* Allocate space for current message */
|
|
if( ( msg = mbedtls_calloc( 1, sizeof( mbedtls_ssl_flight_item ) ) ) == NULL )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "alloc %d bytes failed",
|
|
sizeof( mbedtls_ssl_flight_item ) ) );
|
|
return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
|
|
}
|
|
|
|
if( ( msg->p = mbedtls_calloc( 1, ssl->out_msglen ) ) == NULL )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "alloc %d bytes failed", ssl->out_msglen ) );
|
|
mbedtls_free( msg );
|
|
return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
|
|
}
|
|
|
|
/* Copy current handshake message with headers */
|
|
memcpy( msg->p, ssl->out_msg, ssl->out_msglen );
|
|
msg->len = ssl->out_msglen;
|
|
msg->type = ssl->out_msgtype;
|
|
msg->next = NULL;
|
|
|
|
/* Append to the current flight */
|
|
if( ssl->handshake->flight == NULL )
|
|
ssl->handshake->flight = msg;
|
|
else
|
|
{
|
|
mbedtls_ssl_flight_item *cur = ssl->handshake->flight;
|
|
while( cur->next != NULL )
|
|
cur = cur->next;
|
|
cur->next = msg;
|
|
}
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= ssl_flight_append" ) );
|
|
return( 0 );
|
|
}
|
|
|
|
/*
|
|
* Free the current flight of handshake messages
|
|
*/
|
|
void mbedtls_ssl_flight_free( mbedtls_ssl_flight_item *flight )
|
|
{
|
|
mbedtls_ssl_flight_item *cur = flight;
|
|
mbedtls_ssl_flight_item *next;
|
|
|
|
while( cur != NULL )
|
|
{
|
|
next = cur->next;
|
|
|
|
mbedtls_free( cur->p );
|
|
mbedtls_free( cur );
|
|
|
|
cur = next;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Swap transform_out and out_ctr with the alternative ones
|
|
*/
|
|
static int ssl_swap_epochs( mbedtls_ssl_context *ssl )
|
|
{
|
|
mbedtls_ssl_transform *tmp_transform;
|
|
unsigned char tmp_out_ctr[8];
|
|
|
|
if( ssl->transform_out == ssl->handshake->alt_transform_out )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 3, ( "skip swap epochs" ) );
|
|
return( 0 );
|
|
}
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 3, ( "swap epochs" ) );
|
|
|
|
/* Swap transforms */
|
|
tmp_transform = ssl->transform_out;
|
|
ssl->transform_out = ssl->handshake->alt_transform_out;
|
|
ssl->handshake->alt_transform_out = tmp_transform;
|
|
|
|
/* Swap epoch + sequence_number */
|
|
memcpy( tmp_out_ctr, ssl->cur_out_ctr, 8 );
|
|
memcpy( ssl->cur_out_ctr, ssl->handshake->alt_out_ctr, 8 );
|
|
memcpy( ssl->handshake->alt_out_ctr, tmp_out_ctr, 8 );
|
|
|
|
/* Adjust to the newly activated transform */
|
|
mbedtls_ssl_update_out_pointers( ssl, ssl->transform_out );
|
|
|
|
#if defined(MBEDTLS_SSL_HW_RECORD_ACCEL)
|
|
if( mbedtls_ssl_hw_record_activate != NULL )
|
|
{
|
|
int ret = mbedtls_ssl_hw_record_activate( ssl, MBEDTLS_SSL_CHANNEL_OUTBOUND );
|
|
if( ret != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_hw_record_activate", ret );
|
|
return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
|
|
}
|
|
}
|
|
#endif
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
/*
|
|
* Retransmit the current flight of messages.
|
|
*/
|
|
int mbedtls_ssl_resend( mbedtls_ssl_context *ssl )
|
|
{
|
|
int ret = 0;
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> mbedtls_ssl_resend" ) );
|
|
|
|
ret = mbedtls_ssl_flight_transmit( ssl );
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= mbedtls_ssl_resend" ) );
|
|
|
|
return( ret );
|
|
}
|
|
|
|
/*
|
|
* Transmit or retransmit the current flight of messages.
|
|
*
|
|
* Need to remember the current message in case flush_output returns
|
|
* WANT_WRITE, causing us to exit this function and come back later.
|
|
* This function must be called until state is no longer SENDING.
|
|
*/
|
|
int mbedtls_ssl_flight_transmit( mbedtls_ssl_context *ssl )
|
|
{
|
|
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> mbedtls_ssl_flight_transmit" ) );
|
|
|
|
if( ssl->handshake->retransmit_state != MBEDTLS_SSL_RETRANS_SENDING )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "initialise flight transmission" ) );
|
|
|
|
ssl->handshake->cur_msg = ssl->handshake->flight;
|
|
ssl->handshake->cur_msg_p = ssl->handshake->flight->p + 12;
|
|
ret = ssl_swap_epochs( ssl );
|
|
if( ret != 0 )
|
|
return( ret );
|
|
|
|
ssl->handshake->retransmit_state = MBEDTLS_SSL_RETRANS_SENDING;
|
|
}
|
|
|
|
while( ssl->handshake->cur_msg != NULL )
|
|
{
|
|
size_t max_frag_len;
|
|
const mbedtls_ssl_flight_item * const cur = ssl->handshake->cur_msg;
|
|
|
|
int const is_finished =
|
|
( cur->type == MBEDTLS_SSL_MSG_HANDSHAKE &&
|
|
cur->p[0] == MBEDTLS_SSL_HS_FINISHED );
|
|
|
|
uint8_t const force_flush = ssl->disable_datagram_packing == 1 ?
|
|
SSL_FORCE_FLUSH : SSL_DONT_FORCE_FLUSH;
|
|
|
|
/* Swap epochs before sending Finished: we can't do it after
|
|
* sending ChangeCipherSpec, in case write returns WANT_READ.
|
|
* Must be done before copying, may change out_msg pointer */
|
|
if( is_finished && ssl->handshake->cur_msg_p == ( cur->p + 12 ) )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "swap epochs to send finished message" ) );
|
|
ret = ssl_swap_epochs( ssl );
|
|
if( ret != 0 )
|
|
return( ret );
|
|
}
|
|
|
|
ret = ssl_get_remaining_payload_in_datagram( ssl );
|
|
if( ret < 0 )
|
|
return( ret );
|
|
max_frag_len = (size_t) ret;
|
|
|
|
/* CCS is copied as is, while HS messages may need fragmentation */
|
|
if( cur->type == MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC )
|
|
{
|
|
if( max_frag_len == 0 )
|
|
{
|
|
if( ( ret = mbedtls_ssl_flush_output( ssl ) ) != 0 )
|
|
return( ret );
|
|
|
|
continue;
|
|
}
|
|
|
|
memcpy( ssl->out_msg, cur->p, cur->len );
|
|
ssl->out_msglen = cur->len;
|
|
ssl->out_msgtype = cur->type;
|
|
|
|
/* Update position inside current message */
|
|
ssl->handshake->cur_msg_p += cur->len;
|
|
}
|
|
else
|
|
{
|
|
const unsigned char * const p = ssl->handshake->cur_msg_p;
|
|
const size_t hs_len = cur->len - 12;
|
|
const size_t frag_off = p - ( cur->p + 12 );
|
|
const size_t rem_len = hs_len - frag_off;
|
|
size_t cur_hs_frag_len, max_hs_frag_len;
|
|
|
|
if( ( max_frag_len < 12 ) || ( max_frag_len == 12 && hs_len != 0 ) )
|
|
{
|
|
if( is_finished )
|
|
{
|
|
ret = ssl_swap_epochs( ssl );
|
|
if( ret != 0 )
|
|
return( ret );
|
|
}
|
|
|
|
if( ( ret = mbedtls_ssl_flush_output( ssl ) ) != 0 )
|
|
return( ret );
|
|
|
|
continue;
|
|
}
|
|
max_hs_frag_len = max_frag_len - 12;
|
|
|
|
cur_hs_frag_len = rem_len > max_hs_frag_len ?
|
|
max_hs_frag_len : rem_len;
|
|
|
|
if( frag_off == 0 && cur_hs_frag_len != hs_len )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "fragmenting handshake message (%u > %u)",
|
|
(unsigned) cur_hs_frag_len,
|
|
(unsigned) max_hs_frag_len ) );
|
|
}
|
|
|
|
/* Messages are stored with handshake headers as if not fragmented,
|
|
* copy beginning of headers then fill fragmentation fields.
|
|
* Handshake headers: type(1) len(3) seq(2) f_off(3) f_len(3) */
|
|
memcpy( ssl->out_msg, cur->p, 6 );
|
|
|
|
ssl->out_msg[6] = ( ( frag_off >> 16 ) & 0xff );
|
|
ssl->out_msg[7] = ( ( frag_off >> 8 ) & 0xff );
|
|
ssl->out_msg[8] = ( ( frag_off ) & 0xff );
|
|
|
|
ssl->out_msg[ 9] = ( ( cur_hs_frag_len >> 16 ) & 0xff );
|
|
ssl->out_msg[10] = ( ( cur_hs_frag_len >> 8 ) & 0xff );
|
|
ssl->out_msg[11] = ( ( cur_hs_frag_len ) & 0xff );
|
|
|
|
MBEDTLS_SSL_DEBUG_BUF( 3, "handshake header", ssl->out_msg, 12 );
|
|
|
|
/* Copy the handshake message content and set records fields */
|
|
memcpy( ssl->out_msg + 12, p, cur_hs_frag_len );
|
|
ssl->out_msglen = cur_hs_frag_len + 12;
|
|
ssl->out_msgtype = cur->type;
|
|
|
|
/* Update position inside current message */
|
|
ssl->handshake->cur_msg_p += cur_hs_frag_len;
|
|
}
|
|
|
|
/* If done with the current message move to the next one if any */
|
|
if( ssl->handshake->cur_msg_p >= cur->p + cur->len )
|
|
{
|
|
if( cur->next != NULL )
|
|
{
|
|
ssl->handshake->cur_msg = cur->next;
|
|
ssl->handshake->cur_msg_p = cur->next->p + 12;
|
|
}
|
|
else
|
|
{
|
|
ssl->handshake->cur_msg = NULL;
|
|
ssl->handshake->cur_msg_p = NULL;
|
|
}
|
|
}
|
|
|
|
/* Actually send the message out */
|
|
if( ( ret = mbedtls_ssl_write_record( ssl, force_flush ) ) != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_record", ret );
|
|
return( ret );
|
|
}
|
|
}
|
|
|
|
if( ( ret = mbedtls_ssl_flush_output( ssl ) ) != 0 )
|
|
return( ret );
|
|
|
|
/* Update state and set timer */
|
|
if( ssl->state == MBEDTLS_SSL_HANDSHAKE_OVER )
|
|
ssl->handshake->retransmit_state = MBEDTLS_SSL_RETRANS_FINISHED;
|
|
else
|
|
{
|
|
ssl->handshake->retransmit_state = MBEDTLS_SSL_RETRANS_WAITING;
|
|
mbedtls_ssl_set_timer( ssl, ssl->handshake->retransmit_timeout );
|
|
}
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= mbedtls_ssl_flight_transmit" ) );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
/*
|
|
* To be called when the last message of an incoming flight is received.
|
|
*/
|
|
void mbedtls_ssl_recv_flight_completed( mbedtls_ssl_context *ssl )
|
|
{
|
|
/* We won't need to resend that one any more */
|
|
mbedtls_ssl_flight_free( ssl->handshake->flight );
|
|
ssl->handshake->flight = NULL;
|
|
ssl->handshake->cur_msg = NULL;
|
|
|
|
/* The next incoming flight will start with this msg_seq */
|
|
ssl->handshake->in_flight_start_seq = ssl->handshake->in_msg_seq;
|
|
|
|
/* We don't want to remember CCS's across flight boundaries. */
|
|
ssl->handshake->buffering.seen_ccs = 0;
|
|
|
|
/* Clear future message buffering structure. */
|
|
mbedtls_ssl_buffering_free( ssl );
|
|
|
|
/* Cancel timer */
|
|
mbedtls_ssl_set_timer( ssl, 0 );
|
|
|
|
if( ssl->in_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE &&
|
|
ssl->in_msg[0] == MBEDTLS_SSL_HS_FINISHED )
|
|
{
|
|
ssl->handshake->retransmit_state = MBEDTLS_SSL_RETRANS_FINISHED;
|
|
}
|
|
else
|
|
ssl->handshake->retransmit_state = MBEDTLS_SSL_RETRANS_PREPARING;
|
|
}
|
|
|
|
/*
|
|
* To be called when the last message of an outgoing flight is send.
|
|
*/
|
|
void mbedtls_ssl_send_flight_completed( mbedtls_ssl_context *ssl )
|
|
{
|
|
ssl_reset_retransmit_timeout( ssl );
|
|
mbedtls_ssl_set_timer( ssl, ssl->handshake->retransmit_timeout );
|
|
|
|
if( ssl->in_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE &&
|
|
ssl->in_msg[0] == MBEDTLS_SSL_HS_FINISHED )
|
|
{
|
|
ssl->handshake->retransmit_state = MBEDTLS_SSL_RETRANS_FINISHED;
|
|
}
|
|
else
|
|
ssl->handshake->retransmit_state = MBEDTLS_SSL_RETRANS_WAITING;
|
|
}
|
|
#endif /* MBEDTLS_SSL_PROTO_DTLS */
|
|
|
|
/*
|
|
* Handshake layer functions
|
|
*/
|
|
|
|
/*
|
|
* Write (DTLS: or queue) current handshake (including CCS) message.
|
|
*
|
|
* - fill in handshake headers
|
|
* - update handshake checksum
|
|
* - DTLS: save message for resending
|
|
* - then pass to the record layer
|
|
*
|
|
* DTLS: except for HelloRequest, messages are only queued, and will only be
|
|
* actually sent when calling flight_transmit() or resend().
|
|
*
|
|
* Inputs:
|
|
* - ssl->out_msglen: 4 + actual handshake message len
|
|
* (4 is the size of handshake headers for TLS)
|
|
* - ssl->out_msg[0]: the handshake type (ClientHello, ServerHello, etc)
|
|
* - ssl->out_msg + 4: the handshake message body
|
|
*
|
|
* Outputs, ie state before passing to flight_append() or write_record():
|
|
* - ssl->out_msglen: the length of the record contents
|
|
* (including handshake headers but excluding record headers)
|
|
* - ssl->out_msg: the record contents (handshake headers + content)
|
|
*/
|
|
int mbedtls_ssl_write_handshake_msg( mbedtls_ssl_context *ssl )
|
|
{
|
|
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
|
|
const size_t hs_len = ssl->out_msglen - 4;
|
|
const unsigned char hs_type = ssl->out_msg[0];
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write handshake message" ) );
|
|
|
|
/*
|
|
* Sanity checks
|
|
*/
|
|
if( ssl->out_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE &&
|
|
ssl->out_msgtype != MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC )
|
|
{
|
|
/* In SSLv3, the client might send a NoCertificate alert. */
|
|
#if defined(MBEDTLS_SSL_PROTO_SSL3) && defined(MBEDTLS_SSL_CLI_C)
|
|
if( ! ( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 &&
|
|
ssl->out_msgtype == MBEDTLS_SSL_MSG_ALERT &&
|
|
ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT ) )
|
|
#endif /* MBEDTLS_SSL_PROTO_SSL3 && MBEDTLS_SSL_SRV_C */
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
|
|
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
|
|
}
|
|
}
|
|
|
|
/* Whenever we send anything different from a
|
|
* HelloRequest we should be in a handshake - double check. */
|
|
if( ! ( ssl->out_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE &&
|
|
hs_type == MBEDTLS_SSL_HS_HELLO_REQUEST ) &&
|
|
ssl->handshake == NULL )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
|
|
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
|
|
}
|
|
|
|
#if defined(MBEDTLS_SSL_PROTO_DTLS)
|
|
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
|
|
ssl->handshake != NULL &&
|
|
ssl->handshake->retransmit_state == MBEDTLS_SSL_RETRANS_SENDING )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
|
|
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
|
|
}
|
|
#endif
|
|
|
|
/* Double-check that we did not exceed the bounds
|
|
* of the outgoing record buffer.
|
|
* This should never fail as the various message
|
|
* writing functions must obey the bounds of the
|
|
* outgoing record buffer, but better be safe.
|
|
*
|
|
* Note: We deliberately do not check for the MTU or MFL here.
|
|
*/
|
|
if( ssl->out_msglen > MBEDTLS_SSL_OUT_CONTENT_LEN )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "Record too large: "
|
|
"size %u, maximum %u",
|
|
(unsigned) ssl->out_msglen,
|
|
(unsigned) MBEDTLS_SSL_OUT_CONTENT_LEN ) );
|
|
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
|
|
}
|
|
|
|
/*
|
|
* Fill handshake headers
|
|
*/
|
|
if( ssl->out_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE )
|
|
{
|
|
ssl->out_msg[1] = (unsigned char)( hs_len >> 16 );
|
|
ssl->out_msg[2] = (unsigned char)( hs_len >> 8 );
|
|
ssl->out_msg[3] = (unsigned char)( hs_len );
|
|
|
|
/*
|
|
* DTLS has additional fields in the Handshake layer,
|
|
* between the length field and the actual payload:
|
|
* uint16 message_seq;
|
|
* uint24 fragment_offset;
|
|
* uint24 fragment_length;
|
|
*/
|
|
#if defined(MBEDTLS_SSL_PROTO_DTLS)
|
|
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
|
|
{
|
|
/* Make room for the additional DTLS fields */
|
|
if( MBEDTLS_SSL_OUT_CONTENT_LEN - ssl->out_msglen < 8 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "DTLS handshake message too large: "
|
|
"size %u, maximum %u",
|
|
(unsigned) ( hs_len ),
|
|
(unsigned) ( MBEDTLS_SSL_OUT_CONTENT_LEN - 12 ) ) );
|
|
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
|
|
}
|
|
|
|
memmove( ssl->out_msg + 12, ssl->out_msg + 4, hs_len );
|
|
ssl->out_msglen += 8;
|
|
|
|
/* Write message_seq and update it, except for HelloRequest */
|
|
if( hs_type != MBEDTLS_SSL_HS_HELLO_REQUEST )
|
|
{
|
|
ssl->out_msg[4] = ( ssl->handshake->out_msg_seq >> 8 ) & 0xFF;
|
|
ssl->out_msg[5] = ( ssl->handshake->out_msg_seq ) & 0xFF;
|
|
++( ssl->handshake->out_msg_seq );
|
|
}
|
|
else
|
|
{
|
|
ssl->out_msg[4] = 0;
|
|
ssl->out_msg[5] = 0;
|
|
}
|
|
|
|
/* Handshake hashes are computed without fragmentation,
|
|
* so set frag_offset = 0 and frag_len = hs_len for now */
|
|
memset( ssl->out_msg + 6, 0x00, 3 );
|
|
memcpy( ssl->out_msg + 9, ssl->out_msg + 1, 3 );
|
|
}
|
|
#endif /* MBEDTLS_SSL_PROTO_DTLS */
|
|
|
|
/* Update running hashes of handshake messages seen */
|
|
if( hs_type != MBEDTLS_SSL_HS_HELLO_REQUEST )
|
|
ssl->handshake->update_checksum( ssl, ssl->out_msg, ssl->out_msglen );
|
|
}
|
|
|
|
/* Either send now, or just save to be sent (and resent) later */
|
|
#if defined(MBEDTLS_SSL_PROTO_DTLS)
|
|
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
|
|
! ( ssl->out_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE &&
|
|
hs_type == MBEDTLS_SSL_HS_HELLO_REQUEST ) )
|
|
{
|
|
if( ( ret = ssl_flight_append( ssl ) ) != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_flight_append", ret );
|
|
return( ret );
|
|
}
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
if( ( ret = mbedtls_ssl_write_record( ssl, SSL_FORCE_FLUSH ) ) != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_write_record", ret );
|
|
return( ret );
|
|
}
|
|
}
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write handshake message" ) );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
/*
|
|
* Record layer functions
|
|
*/
|
|
|
|
/*
|
|
* Write current record.
|
|
*
|
|
* Uses:
|
|
* - ssl->out_msgtype: type of the message (AppData, Handshake, Alert, CCS)
|
|
* - ssl->out_msglen: length of the record content (excl headers)
|
|
* - ssl->out_msg: record content
|
|
*/
|
|
int mbedtls_ssl_write_record( mbedtls_ssl_context *ssl, uint8_t force_flush )
|
|
{
|
|
int ret, done = 0;
|
|
size_t len = ssl->out_msglen;
|
|
uint8_t flush = force_flush;
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write record" ) );
|
|
|
|
#if defined(MBEDTLS_ZLIB_SUPPORT)
|
|
if( ssl->transform_out != NULL &&
|
|
ssl->session_out->compression == MBEDTLS_SSL_COMPRESS_DEFLATE )
|
|
{
|
|
if( ( ret = ssl_compress_buf( ssl ) ) != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_compress_buf", ret );
|
|
return( ret );
|
|
}
|
|
|
|
len = ssl->out_msglen;
|
|
}
|
|
#endif /*MBEDTLS_ZLIB_SUPPORT */
|
|
|
|
#if defined(MBEDTLS_SSL_HW_RECORD_ACCEL)
|
|
if( mbedtls_ssl_hw_record_write != NULL )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "going for mbedtls_ssl_hw_record_write()" ) );
|
|
|
|
ret = mbedtls_ssl_hw_record_write( ssl );
|
|
if( ret != 0 && ret != MBEDTLS_ERR_SSL_HW_ACCEL_FALLTHROUGH )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_hw_record_write", ret );
|
|
return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
|
|
}
|
|
|
|
if( ret == 0 )
|
|
done = 1;
|
|
}
|
|
#endif /* MBEDTLS_SSL_HW_RECORD_ACCEL */
|
|
if( !done )
|
|
{
|
|
unsigned i;
|
|
size_t protected_record_size;
|
|
#if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH)
|
|
size_t out_buf_len = ssl->out_buf_len;
|
|
#else
|
|
size_t out_buf_len = MBEDTLS_SSL_OUT_BUFFER_LEN;
|
|
#endif
|
|
/* Skip writing the record content type to after the encryption,
|
|
* as it may change when using the CID extension. */
|
|
|
|
mbedtls_ssl_write_version( ssl->major_ver, ssl->minor_ver,
|
|
ssl->conf->transport, ssl->out_hdr + 1 );
|
|
|
|
memcpy( ssl->out_ctr, ssl->cur_out_ctr, 8 );
|
|
ssl->out_len[0] = (unsigned char)( len >> 8 );
|
|
ssl->out_len[1] = (unsigned char)( len );
|
|
|
|
if( ssl->transform_out != NULL )
|
|
{
|
|
mbedtls_record rec;
|
|
|
|
rec.buf = ssl->out_iv;
|
|
rec.buf_len = out_buf_len - ( ssl->out_iv - ssl->out_buf );
|
|
rec.data_len = ssl->out_msglen;
|
|
rec.data_offset = ssl->out_msg - rec.buf;
|
|
|
|
memcpy( &rec.ctr[0], ssl->out_ctr, 8 );
|
|
mbedtls_ssl_write_version( ssl->major_ver, ssl->minor_ver,
|
|
ssl->conf->transport, rec.ver );
|
|
rec.type = ssl->out_msgtype;
|
|
|
|
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
|
|
/* The CID is set by mbedtls_ssl_encrypt_buf(). */
|
|
rec.cid_len = 0;
|
|
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
|
|
|
|
if( ( ret = mbedtls_ssl_encrypt_buf( ssl, ssl->transform_out, &rec,
|
|
ssl->conf->f_rng, ssl->conf->p_rng ) ) != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_encrypt_buf", ret );
|
|
return( ret );
|
|
}
|
|
|
|
if( rec.data_offset != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
|
|
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
|
|
}
|
|
|
|
/* Update the record content type and CID. */
|
|
ssl->out_msgtype = rec.type;
|
|
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID )
|
|
memcpy( ssl->out_cid, rec.cid, rec.cid_len );
|
|
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
|
|
ssl->out_msglen = len = rec.data_len;
|
|
ssl->out_len[0] = (unsigned char)( rec.data_len >> 8 );
|
|
ssl->out_len[1] = (unsigned char)( rec.data_len );
|
|
}
|
|
|
|
protected_record_size = len + mbedtls_ssl_out_hdr_len( ssl );
|
|
|
|
#if defined(MBEDTLS_SSL_PROTO_DTLS)
|
|
/* In case of DTLS, double-check that we don't exceed
|
|
* the remaining space in the datagram. */
|
|
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
|
|
{
|
|
ret = ssl_get_remaining_space_in_datagram( ssl );
|
|
if( ret < 0 )
|
|
return( ret );
|
|
|
|
if( protected_record_size > (size_t) ret )
|
|
{
|
|
/* Should never happen */
|
|
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
|
|
}
|
|
}
|
|
#endif /* MBEDTLS_SSL_PROTO_DTLS */
|
|
|
|
/* Now write the potentially updated record content type. */
|
|
ssl->out_hdr[0] = (unsigned char) ssl->out_msgtype;
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 3, ( "output record: msgtype = %d, "
|
|
"version = [%d:%d], msglen = %d",
|
|
ssl->out_hdr[0], ssl->out_hdr[1],
|
|
ssl->out_hdr[2], len ) );
|
|
|
|
MBEDTLS_SSL_DEBUG_BUF( 4, "output record sent to network",
|
|
ssl->out_hdr, protected_record_size );
|
|
|
|
ssl->out_left += protected_record_size;
|
|
ssl->out_hdr += protected_record_size;
|
|
mbedtls_ssl_update_out_pointers( ssl, ssl->transform_out );
|
|
|
|
for( i = 8; i > mbedtls_ssl_ep_len( ssl ); i-- )
|
|
if( ++ssl->cur_out_ctr[i - 1] != 0 )
|
|
break;
|
|
|
|
/* The loop goes to its end iff the counter is wrapping */
|
|
if( i == mbedtls_ssl_ep_len( ssl ) )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "outgoing message counter would wrap" ) );
|
|
return( MBEDTLS_ERR_SSL_COUNTER_WRAPPING );
|
|
}
|
|
}
|
|
|
|
#if defined(MBEDTLS_SSL_PROTO_DTLS)
|
|
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
|
|
flush == SSL_DONT_FORCE_FLUSH )
|
|
{
|
|
size_t remaining;
|
|
ret = ssl_get_remaining_payload_in_datagram( ssl );
|
|
if( ret < 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_get_remaining_payload_in_datagram",
|
|
ret );
|
|
return( ret );
|
|
}
|
|
|
|
remaining = (size_t) ret;
|
|
if( remaining == 0 )
|
|
{
|
|
flush = SSL_FORCE_FLUSH;
|
|
}
|
|
else
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Still %u bytes available in current datagram", (unsigned) remaining ) );
|
|
}
|
|
}
|
|
#endif /* MBEDTLS_SSL_PROTO_DTLS */
|
|
|
|
if( ( flush == SSL_FORCE_FLUSH ) &&
|
|
( ret = mbedtls_ssl_flush_output( ssl ) ) != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_flush_output", ret );
|
|
return( ret );
|
|
}
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write record" ) );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
#if defined(MBEDTLS_SSL_PROTO_DTLS)
|
|
|
|
static int ssl_hs_is_proper_fragment( mbedtls_ssl_context *ssl )
|
|
{
|
|
if( ssl->in_msglen < ssl->in_hslen ||
|
|
memcmp( ssl->in_msg + 6, "\0\0\0", 3 ) != 0 ||
|
|
memcmp( ssl->in_msg + 9, ssl->in_msg + 1, 3 ) != 0 )
|
|
{
|
|
return( 1 );
|
|
}
|
|
return( 0 );
|
|
}
|
|
|
|
static uint32_t ssl_get_hs_frag_len( mbedtls_ssl_context const *ssl )
|
|
{
|
|
return( ( ssl->in_msg[9] << 16 ) |
|
|
( ssl->in_msg[10] << 8 ) |
|
|
ssl->in_msg[11] );
|
|
}
|
|
|
|
static uint32_t ssl_get_hs_frag_off( mbedtls_ssl_context const *ssl )
|
|
{
|
|
return( ( ssl->in_msg[6] << 16 ) |
|
|
( ssl->in_msg[7] << 8 ) |
|
|
ssl->in_msg[8] );
|
|
}
|
|
|
|
static int ssl_check_hs_header( mbedtls_ssl_context const *ssl )
|
|
{
|
|
uint32_t msg_len, frag_off, frag_len;
|
|
|
|
msg_len = ssl_get_hs_total_len( ssl );
|
|
frag_off = ssl_get_hs_frag_off( ssl );
|
|
frag_len = ssl_get_hs_frag_len( ssl );
|
|
|
|
if( frag_off > msg_len )
|
|
return( -1 );
|
|
|
|
if( frag_len > msg_len - frag_off )
|
|
return( -1 );
|
|
|
|
if( frag_len + 12 > ssl->in_msglen )
|
|
return( -1 );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
/*
|
|
* Mark bits in bitmask (used for DTLS HS reassembly)
|
|
*/
|
|
static void ssl_bitmask_set( unsigned char *mask, size_t offset, size_t len )
|
|
{
|
|
unsigned int start_bits, end_bits;
|
|
|
|
start_bits = 8 - ( offset % 8 );
|
|
if( start_bits != 8 )
|
|
{
|
|
size_t first_byte_idx = offset / 8;
|
|
|
|
/* Special case */
|
|
if( len <= start_bits )
|
|
{
|
|
for( ; len != 0; len-- )
|
|
mask[first_byte_idx] |= 1 << ( start_bits - len );
|
|
|
|
/* Avoid potential issues with offset or len becoming invalid */
|
|
return;
|
|
}
|
|
|
|
offset += start_bits; /* Now offset % 8 == 0 */
|
|
len -= start_bits;
|
|
|
|
for( ; start_bits != 0; start_bits-- )
|
|
mask[first_byte_idx] |= 1 << ( start_bits - 1 );
|
|
}
|
|
|
|
end_bits = len % 8;
|
|
if( end_bits != 0 )
|
|
{
|
|
size_t last_byte_idx = ( offset + len ) / 8;
|
|
|
|
len -= end_bits; /* Now len % 8 == 0 */
|
|
|
|
for( ; end_bits != 0; end_bits-- )
|
|
mask[last_byte_idx] |= 1 << ( 8 - end_bits );
|
|
}
|
|
|
|
memset( mask + offset / 8, 0xFF, len / 8 );
|
|
}
|
|
|
|
/*
|
|
* Check that bitmask is full
|
|
*/
|
|
static int ssl_bitmask_check( unsigned char *mask, size_t len )
|
|
{
|
|
size_t i;
|
|
|
|
for( i = 0; i < len / 8; i++ )
|
|
if( mask[i] != 0xFF )
|
|
return( -1 );
|
|
|
|
for( i = 0; i < len % 8; i++ )
|
|
if( ( mask[len / 8] & ( 1 << ( 7 - i ) ) ) == 0 )
|
|
return( -1 );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
/* msg_len does not include the handshake header */
|
|
static size_t ssl_get_reassembly_buffer_size( size_t msg_len,
|
|
unsigned add_bitmap )
|
|
{
|
|
size_t alloc_len;
|
|
|
|
alloc_len = 12; /* Handshake header */
|
|
alloc_len += msg_len; /* Content buffer */
|
|
|
|
if( add_bitmap )
|
|
alloc_len += msg_len / 8 + ( msg_len % 8 != 0 ); /* Bitmap */
|
|
|
|
return( alloc_len );
|
|
}
|
|
|
|
#endif /* MBEDTLS_SSL_PROTO_DTLS */
|
|
|
|
static uint32_t ssl_get_hs_total_len( mbedtls_ssl_context const *ssl )
|
|
{
|
|
return( ( ssl->in_msg[1] << 16 ) |
|
|
( ssl->in_msg[2] << 8 ) |
|
|
ssl->in_msg[3] );
|
|
}
|
|
|
|
int mbedtls_ssl_prepare_handshake_record( mbedtls_ssl_context *ssl )
|
|
{
|
|
if( ssl->in_msglen < mbedtls_ssl_hs_hdr_len( ssl ) )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "handshake message too short: %d",
|
|
ssl->in_msglen ) );
|
|
return( MBEDTLS_ERR_SSL_INVALID_RECORD );
|
|
}
|
|
|
|
ssl->in_hslen = mbedtls_ssl_hs_hdr_len( ssl ) + ssl_get_hs_total_len( ssl );
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 3, ( "handshake message: msglen ="
|
|
" %d, type = %d, hslen = %d",
|
|
ssl->in_msglen, ssl->in_msg[0], ssl->in_hslen ) );
|
|
|
|
#if defined(MBEDTLS_SSL_PROTO_DTLS)
|
|
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
|
|
{
|
|
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
|
|
unsigned int recv_msg_seq = ( ssl->in_msg[4] << 8 ) | ssl->in_msg[5];
|
|
|
|
if( ssl_check_hs_header( ssl ) != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "invalid handshake header" ) );
|
|
return( MBEDTLS_ERR_SSL_INVALID_RECORD );
|
|
}
|
|
|
|
if( ssl->handshake != NULL &&
|
|
( ( ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER &&
|
|
recv_msg_seq != ssl->handshake->in_msg_seq ) ||
|
|
( ssl->state == MBEDTLS_SSL_HANDSHAKE_OVER &&
|
|
ssl->in_msg[0] != MBEDTLS_SSL_HS_CLIENT_HELLO ) ) )
|
|
{
|
|
if( recv_msg_seq > ssl->handshake->in_msg_seq )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "received future handshake message of sequence number %u (next %u)",
|
|
recv_msg_seq,
|
|
ssl->handshake->in_msg_seq ) );
|
|
return( MBEDTLS_ERR_SSL_EARLY_MESSAGE );
|
|
}
|
|
|
|
/* Retransmit only on last message from previous flight, to avoid
|
|
* too many retransmissions.
|
|
* Besides, No sane server ever retransmits HelloVerifyRequest */
|
|
if( recv_msg_seq == ssl->handshake->in_flight_start_seq - 1 &&
|
|
ssl->in_msg[0] != MBEDTLS_SSL_HS_HELLO_VERIFY_REQUEST )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "received message from last flight, "
|
|
"message_seq = %d, start_of_flight = %d",
|
|
recv_msg_seq,
|
|
ssl->handshake->in_flight_start_seq ) );
|
|
|
|
if( ( ret = mbedtls_ssl_resend( ssl ) ) != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_resend", ret );
|
|
return( ret );
|
|
}
|
|
}
|
|
else
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "dropping out-of-sequence message: "
|
|
"message_seq = %d, expected = %d",
|
|
recv_msg_seq,
|
|
ssl->handshake->in_msg_seq ) );
|
|
}
|
|
|
|
return( MBEDTLS_ERR_SSL_CONTINUE_PROCESSING );
|
|
}
|
|
/* Wait until message completion to increment in_msg_seq */
|
|
|
|
/* Message reassembly is handled alongside buffering of future
|
|
* messages; the commonality is that both handshake fragments and
|
|
* future messages cannot be forwarded immediately to the
|
|
* handshake logic layer. */
|
|
if( ssl_hs_is_proper_fragment( ssl ) == 1 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "found fragmented DTLS handshake message" ) );
|
|
return( MBEDTLS_ERR_SSL_EARLY_MESSAGE );
|
|
}
|
|
}
|
|
else
|
|
#endif /* MBEDTLS_SSL_PROTO_DTLS */
|
|
/* With TLS we don't handle fragmentation (for now) */
|
|
if( ssl->in_msglen < ssl->in_hslen )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "TLS handshake fragmentation not supported" ) );
|
|
return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE );
|
|
}
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
void mbedtls_ssl_update_handshake_status( mbedtls_ssl_context *ssl )
|
|
{
|
|
mbedtls_ssl_handshake_params * const hs = ssl->handshake;
|
|
|
|
if( ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER && hs != NULL )
|
|
{
|
|
ssl->handshake->update_checksum( ssl, ssl->in_msg, ssl->in_hslen );
|
|
}
|
|
|
|
/* Handshake message is complete, increment counter */
|
|
#if defined(MBEDTLS_SSL_PROTO_DTLS)
|
|
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
|
|
ssl->handshake != NULL )
|
|
{
|
|
unsigned offset;
|
|
mbedtls_ssl_hs_buffer *hs_buf;
|
|
|
|
/* Increment handshake sequence number */
|
|
hs->in_msg_seq++;
|
|
|
|
/*
|
|
* Clear up handshake buffering and reassembly structure.
|
|
*/
|
|
|
|
/* Free first entry */
|
|
ssl_buffering_free_slot( ssl, 0 );
|
|
|
|
/* Shift all other entries */
|
|
for( offset = 0, hs_buf = &hs->buffering.hs[0];
|
|
offset + 1 < MBEDTLS_SSL_MAX_BUFFERED_HS;
|
|
offset++, hs_buf++ )
|
|
{
|
|
*hs_buf = *(hs_buf + 1);
|
|
}
|
|
|
|
/* Create a fresh last entry */
|
|
memset( hs_buf, 0, sizeof( mbedtls_ssl_hs_buffer ) );
|
|
}
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* DTLS anti-replay: RFC 6347 4.1.2.6
|
|
*
|
|
* in_window is a field of bits numbered from 0 (lsb) to 63 (msb).
|
|
* Bit n is set iff record number in_window_top - n has been seen.
|
|
*
|
|
* Usually, in_window_top is the last record number seen and the lsb of
|
|
* in_window is set. The only exception is the initial state (record number 0
|
|
* not seen yet).
|
|
*/
|
|
#if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY)
|
|
void mbedtls_ssl_dtls_replay_reset( mbedtls_ssl_context *ssl )
|
|
{
|
|
ssl->in_window_top = 0;
|
|
ssl->in_window = 0;
|
|
}
|
|
|
|
static inline uint64_t ssl_load_six_bytes( unsigned char *buf )
|
|
{
|
|
return( ( (uint64_t) buf[0] << 40 ) |
|
|
( (uint64_t) buf[1] << 32 ) |
|
|
( (uint64_t) buf[2] << 24 ) |
|
|
( (uint64_t) buf[3] << 16 ) |
|
|
( (uint64_t) buf[4] << 8 ) |
|
|
( (uint64_t) buf[5] ) );
|
|
}
|
|
|
|
static int mbedtls_ssl_dtls_record_replay_check( mbedtls_ssl_context *ssl, uint8_t *record_in_ctr )
|
|
{
|
|
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
|
|
unsigned char *original_in_ctr;
|
|
|
|
// save original in_ctr
|
|
original_in_ctr = ssl->in_ctr;
|
|
|
|
// use counter from record
|
|
ssl->in_ctr = record_in_ctr;
|
|
|
|
ret = mbedtls_ssl_dtls_replay_check( (mbedtls_ssl_context const *) ssl );
|
|
|
|
// restore the counter
|
|
ssl->in_ctr = original_in_ctr;
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Return 0 if sequence number is acceptable, -1 otherwise
|
|
*/
|
|
int mbedtls_ssl_dtls_replay_check( mbedtls_ssl_context const *ssl )
|
|
{
|
|
uint64_t rec_seqnum = ssl_load_six_bytes( ssl->in_ctr + 2 );
|
|
uint64_t bit;
|
|
|
|
if( ssl->conf->anti_replay == MBEDTLS_SSL_ANTI_REPLAY_DISABLED )
|
|
return( 0 );
|
|
|
|
if( rec_seqnum > ssl->in_window_top )
|
|
return( 0 );
|
|
|
|
bit = ssl->in_window_top - rec_seqnum;
|
|
|
|
if( bit >= 64 )
|
|
return( -1 );
|
|
|
|
if( ( ssl->in_window & ( (uint64_t) 1 << bit ) ) != 0 )
|
|
return( -1 );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
/*
|
|
* Update replay window on new validated record
|
|
*/
|
|
void mbedtls_ssl_dtls_replay_update( mbedtls_ssl_context *ssl )
|
|
{
|
|
uint64_t rec_seqnum = ssl_load_six_bytes( ssl->in_ctr + 2 );
|
|
|
|
if( ssl->conf->anti_replay == MBEDTLS_SSL_ANTI_REPLAY_DISABLED )
|
|
return;
|
|
|
|
if( rec_seqnum > ssl->in_window_top )
|
|
{
|
|
/* Update window_top and the contents of the window */
|
|
uint64_t shift = rec_seqnum - ssl->in_window_top;
|
|
|
|
if( shift >= 64 )
|
|
ssl->in_window = 1;
|
|
else
|
|
{
|
|
ssl->in_window <<= shift;
|
|
ssl->in_window |= 1;
|
|
}
|
|
|
|
ssl->in_window_top = rec_seqnum;
|
|
}
|
|
else
|
|
{
|
|
/* Mark that number as seen in the current window */
|
|
uint64_t bit = ssl->in_window_top - rec_seqnum;
|
|
|
|
if( bit < 64 ) /* Always true, but be extra sure */
|
|
ssl->in_window |= (uint64_t) 1 << bit;
|
|
}
|
|
}
|
|
#endif /* MBEDTLS_SSL_DTLS_ANTI_REPLAY */
|
|
|
|
#if defined(MBEDTLS_SSL_DTLS_CLIENT_PORT_REUSE) && defined(MBEDTLS_SSL_SRV_C)
|
|
/*
|
|
* Without any SSL context, check if a datagram looks like a ClientHello with
|
|
* a valid cookie, and if it doesn't, generate a HelloVerifyRequest message.
|
|
* Both input and output include full DTLS headers.
|
|
*
|
|
* - if cookie is valid, return 0
|
|
* - if ClientHello looks superficially valid but cookie is not,
|
|
* fill obuf and set olen, then
|
|
* return MBEDTLS_ERR_SSL_HELLO_VERIFY_REQUIRED
|
|
* - otherwise return a specific error code
|
|
*/
|
|
static int ssl_check_dtls_clihlo_cookie(
|
|
mbedtls_ssl_cookie_write_t *f_cookie_write,
|
|
mbedtls_ssl_cookie_check_t *f_cookie_check,
|
|
void *p_cookie,
|
|
const unsigned char *cli_id, size_t cli_id_len,
|
|
const unsigned char *in, size_t in_len,
|
|
unsigned char *obuf, size_t buf_len, size_t *olen )
|
|
{
|
|
size_t sid_len, cookie_len;
|
|
unsigned char *p;
|
|
|
|
/*
|
|
* Structure of ClientHello with record and handshake headers,
|
|
* and expected values. We don't need to check a lot, more checks will be
|
|
* done when actually parsing the ClientHello - skipping those checks
|
|
* avoids code duplication and does not make cookie forging any easier.
|
|
*
|
|
* 0-0 ContentType type; copied, must be handshake
|
|
* 1-2 ProtocolVersion version; copied
|
|
* 3-4 uint16 epoch; copied, must be 0
|
|
* 5-10 uint48 sequence_number; copied
|
|
* 11-12 uint16 length; (ignored)
|
|
*
|
|
* 13-13 HandshakeType msg_type; (ignored)
|
|
* 14-16 uint24 length; (ignored)
|
|
* 17-18 uint16 message_seq; copied
|
|
* 19-21 uint24 fragment_offset; copied, must be 0
|
|
* 22-24 uint24 fragment_length; (ignored)
|
|
*
|
|
* 25-26 ProtocolVersion client_version; (ignored)
|
|
* 27-58 Random random; (ignored)
|
|
* 59-xx SessionID session_id; 1 byte len + sid_len content
|
|
* 60+ opaque cookie<0..2^8-1>; 1 byte len + content
|
|
* ...
|
|
*
|
|
* Minimum length is 61 bytes.
|
|
*/
|
|
if( in_len < 61 ||
|
|
in[0] != MBEDTLS_SSL_MSG_HANDSHAKE ||
|
|
in[3] != 0 || in[4] != 0 ||
|
|
in[19] != 0 || in[20] != 0 || in[21] != 0 )
|
|
{
|
|
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
|
|
}
|
|
|
|
sid_len = in[59];
|
|
if( sid_len > in_len - 61 )
|
|
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
|
|
|
|
cookie_len = in[60 + sid_len];
|
|
if( cookie_len > in_len - 60 )
|
|
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
|
|
|
|
if( f_cookie_check( p_cookie, in + sid_len + 61, cookie_len,
|
|
cli_id, cli_id_len ) == 0 )
|
|
{
|
|
/* Valid cookie */
|
|
return( 0 );
|
|
}
|
|
|
|
/*
|
|
* If we get here, we've got an invalid cookie, let's prepare HVR.
|
|
*
|
|
* 0-0 ContentType type; copied
|
|
* 1-2 ProtocolVersion version; copied
|
|
* 3-4 uint16 epoch; copied
|
|
* 5-10 uint48 sequence_number; copied
|
|
* 11-12 uint16 length; olen - 13
|
|
*
|
|
* 13-13 HandshakeType msg_type; hello_verify_request
|
|
* 14-16 uint24 length; olen - 25
|
|
* 17-18 uint16 message_seq; copied
|
|
* 19-21 uint24 fragment_offset; copied
|
|
* 22-24 uint24 fragment_length; olen - 25
|
|
*
|
|
* 25-26 ProtocolVersion server_version; 0xfe 0xff
|
|
* 27-27 opaque cookie<0..2^8-1>; cookie_len = olen - 27, cookie
|
|
*
|
|
* Minimum length is 28.
|
|
*/
|
|
if( buf_len < 28 )
|
|
return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
|
|
|
|
/* Copy most fields and adapt others */
|
|
memcpy( obuf, in, 25 );
|
|
obuf[13] = MBEDTLS_SSL_HS_HELLO_VERIFY_REQUEST;
|
|
obuf[25] = 0xfe;
|
|
obuf[26] = 0xff;
|
|
|
|
/* Generate and write actual cookie */
|
|
p = obuf + 28;
|
|
if( f_cookie_write( p_cookie,
|
|
&p, obuf + buf_len, cli_id, cli_id_len ) != 0 )
|
|
{
|
|
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
|
|
}
|
|
|
|
*olen = p - obuf;
|
|
|
|
/* Go back and fill length fields */
|
|
obuf[27] = (unsigned char)( *olen - 28 );
|
|
|
|
obuf[14] = obuf[22] = (unsigned char)( ( *olen - 25 ) >> 16 );
|
|
obuf[15] = obuf[23] = (unsigned char)( ( *olen - 25 ) >> 8 );
|
|
obuf[16] = obuf[24] = (unsigned char)( ( *olen - 25 ) );
|
|
|
|
obuf[11] = (unsigned char)( ( *olen - 13 ) >> 8 );
|
|
obuf[12] = (unsigned char)( ( *olen - 13 ) );
|
|
|
|
return( MBEDTLS_ERR_SSL_HELLO_VERIFY_REQUIRED );
|
|
}
|
|
|
|
/*
|
|
* Handle possible client reconnect with the same UDP quadruplet
|
|
* (RFC 6347 Section 4.2.8).
|
|
*
|
|
* Called by ssl_parse_record_header() in case we receive an epoch 0 record
|
|
* that looks like a ClientHello.
|
|
*
|
|
* - if the input looks like a ClientHello without cookies,
|
|
* send back HelloVerifyRequest, then return 0
|
|
* - if the input looks like a ClientHello with a valid cookie,
|
|
* reset the session of the current context, and
|
|
* return MBEDTLS_ERR_SSL_CLIENT_RECONNECT
|
|
* - if anything goes wrong, return a specific error code
|
|
*
|
|
* This function is called (through ssl_check_client_reconnect()) when an
|
|
* unexpected record is found in ssl_get_next_record(), which will discard the
|
|
* record if we return 0, and bubble up the return value otherwise (this
|
|
* includes the case of MBEDTLS_ERR_SSL_CLIENT_RECONNECT and of unexpected
|
|
* errors, and is the right thing to do in both cases).
|
|
*/
|
|
static int ssl_handle_possible_reconnect( mbedtls_ssl_context *ssl )
|
|
{
|
|
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
|
|
size_t len;
|
|
|
|
if( ssl->conf->f_cookie_write == NULL ||
|
|
ssl->conf->f_cookie_check == NULL )
|
|
{
|
|
/* If we can't use cookies to verify reachability of the peer,
|
|
* drop the record. */
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "no cookie callbacks, "
|
|
"can't check reconnect validity" ) );
|
|
return( 0 );
|
|
}
|
|
|
|
ret = ssl_check_dtls_clihlo_cookie(
|
|
ssl->conf->f_cookie_write,
|
|
ssl->conf->f_cookie_check,
|
|
ssl->conf->p_cookie,
|
|
ssl->cli_id, ssl->cli_id_len,
|
|
ssl->in_buf, ssl->in_left,
|
|
ssl->out_buf, MBEDTLS_SSL_OUT_CONTENT_LEN, &len );
|
|
|
|
MBEDTLS_SSL_DEBUG_RET( 2, "ssl_check_dtls_clihlo_cookie", ret );
|
|
|
|
if( ret == MBEDTLS_ERR_SSL_HELLO_VERIFY_REQUIRED )
|
|
{
|
|
int send_ret;
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "sending HelloVerifyRequest" ) );
|
|
MBEDTLS_SSL_DEBUG_BUF( 4, "output record sent to network",
|
|
ssl->out_buf, len );
|
|
/* Don't check write errors as we can't do anything here.
|
|
* If the error is permanent we'll catch it later,
|
|
* if it's not, then hopefully it'll work next time. */
|
|
send_ret = ssl->f_send( ssl->p_bio, ssl->out_buf, len );
|
|
MBEDTLS_SSL_DEBUG_RET( 2, "ssl->f_send", send_ret );
|
|
(void) send_ret;
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
if( ret == 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "cookie is valid, resetting context" ) );
|
|
if( ( ret = mbedtls_ssl_session_reset_int( ssl, 1 ) ) != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "reset", ret );
|
|
return( ret );
|
|
}
|
|
|
|
return( MBEDTLS_ERR_SSL_CLIENT_RECONNECT );
|
|
}
|
|
|
|
return( ret );
|
|
}
|
|
#endif /* MBEDTLS_SSL_DTLS_CLIENT_PORT_REUSE && MBEDTLS_SSL_SRV_C */
|
|
|
|
static int ssl_check_record_type( uint8_t record_type )
|
|
{
|
|
if( record_type != MBEDTLS_SSL_MSG_HANDSHAKE &&
|
|
record_type != MBEDTLS_SSL_MSG_ALERT &&
|
|
record_type != MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC &&
|
|
record_type != MBEDTLS_SSL_MSG_APPLICATION_DATA )
|
|
{
|
|
return( MBEDTLS_ERR_SSL_INVALID_RECORD );
|
|
}
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
/*
|
|
* ContentType type;
|
|
* ProtocolVersion version;
|
|
* uint16 epoch; // DTLS only
|
|
* uint48 sequence_number; // DTLS only
|
|
* uint16 length;
|
|
*
|
|
* Return 0 if header looks sane (and, for DTLS, the record is expected)
|
|
* MBEDTLS_ERR_SSL_INVALID_RECORD if the header looks bad,
|
|
* MBEDTLS_ERR_SSL_UNEXPECTED_RECORD (DTLS only) if sane but unexpected.
|
|
*
|
|
* With DTLS, mbedtls_ssl_read_record() will:
|
|
* 1. proceed with the record if this function returns 0
|
|
* 2. drop only the current record if this function returns UNEXPECTED_RECORD
|
|
* 3. return CLIENT_RECONNECT if this function return that value
|
|
* 4. drop the whole datagram if this function returns anything else.
|
|
* Point 2 is needed when the peer is resending, and we have already received
|
|
* the first record from a datagram but are still waiting for the others.
|
|
*/
|
|
static int ssl_parse_record_header( mbedtls_ssl_context const *ssl,
|
|
unsigned char *buf,
|
|
size_t len,
|
|
mbedtls_record *rec )
|
|
{
|
|
int major_ver, minor_ver;
|
|
|
|
size_t const rec_hdr_type_offset = 0;
|
|
size_t const rec_hdr_type_len = 1;
|
|
|
|
size_t const rec_hdr_version_offset = rec_hdr_type_offset +
|
|
rec_hdr_type_len;
|
|
size_t const rec_hdr_version_len = 2;
|
|
|
|
size_t const rec_hdr_ctr_len = 8;
|
|
#if defined(MBEDTLS_SSL_PROTO_DTLS)
|
|
uint32_t rec_epoch;
|
|
size_t const rec_hdr_ctr_offset = rec_hdr_version_offset +
|
|
rec_hdr_version_len;
|
|
|
|
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
|
|
size_t const rec_hdr_cid_offset = rec_hdr_ctr_offset +
|
|
rec_hdr_ctr_len;
|
|
size_t rec_hdr_cid_len = 0;
|
|
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
|
|
#endif /* MBEDTLS_SSL_PROTO_DTLS */
|
|
|
|
size_t rec_hdr_len_offset; /* To be determined */
|
|
size_t const rec_hdr_len_len = 2;
|
|
|
|
/*
|
|
* Check minimum lengths for record header.
|
|
*/
|
|
|
|
#if defined(MBEDTLS_SSL_PROTO_DTLS)
|
|
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
|
|
{
|
|
rec_hdr_len_offset = rec_hdr_ctr_offset + rec_hdr_ctr_len;
|
|
}
|
|
else
|
|
#endif /* MBEDTLS_SSL_PROTO_DTLS */
|
|
{
|
|
rec_hdr_len_offset = rec_hdr_version_offset + rec_hdr_version_len;
|
|
}
|
|
|
|
if( len < rec_hdr_len_offset + rec_hdr_len_len )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "datagram of length %u too small to hold DTLS record header of length %u",
|
|
(unsigned) len,
|
|
(unsigned)( rec_hdr_len_len + rec_hdr_len_len ) ) );
|
|
return( MBEDTLS_ERR_SSL_INVALID_RECORD );
|
|
}
|
|
|
|
/*
|
|
* Parse and validate record content type
|
|
*/
|
|
|
|
rec->type = buf[ rec_hdr_type_offset ];
|
|
|
|
/* Check record content type */
|
|
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
|
|
rec->cid_len = 0;
|
|
|
|
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
|
|
ssl->conf->cid_len != 0 &&
|
|
rec->type == MBEDTLS_SSL_MSG_CID )
|
|
{
|
|
/* Shift pointers to account for record header including CID
|
|
* struct {
|
|
* ContentType special_type = tls12_cid;
|
|
* ProtocolVersion version;
|
|
* uint16 epoch;
|
|
* uint48 sequence_number;
|
|
* opaque cid[cid_length]; // Additional field compared to
|
|
* // default DTLS record format
|
|
* uint16 length;
|
|
* opaque enc_content[DTLSCiphertext.length];
|
|
* } DTLSCiphertext;
|
|
*/
|
|
|
|
/* So far, we only support static CID lengths
|
|
* fixed in the configuration. */
|
|
rec_hdr_cid_len = ssl->conf->cid_len;
|
|
rec_hdr_len_offset += rec_hdr_cid_len;
|
|
|
|
if( len < rec_hdr_len_offset + rec_hdr_len_len )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "datagram of length %u too small to hold DTLS record header including CID, length %u",
|
|
(unsigned) len,
|
|
(unsigned)( rec_hdr_len_offset + rec_hdr_len_len ) ) );
|
|
return( MBEDTLS_ERR_SSL_INVALID_RECORD );
|
|
}
|
|
|
|
/* configured CID len is guaranteed at most 255, see
|
|
* MBEDTLS_SSL_CID_OUT_LEN_MAX in check_config.h */
|
|
rec->cid_len = (uint8_t) rec_hdr_cid_len;
|
|
memcpy( rec->cid, buf + rec_hdr_cid_offset, rec_hdr_cid_len );
|
|
}
|
|
else
|
|
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
|
|
{
|
|
if( ssl_check_record_type( rec->type ) )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "unknown record type %u",
|
|
(unsigned) rec->type ) );
|
|
return( MBEDTLS_ERR_SSL_INVALID_RECORD );
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Parse and validate record version
|
|
*/
|
|
|
|
rec->ver[0] = buf[ rec_hdr_version_offset + 0 ];
|
|
rec->ver[1] = buf[ rec_hdr_version_offset + 1 ];
|
|
mbedtls_ssl_read_version( &major_ver, &minor_ver,
|
|
ssl->conf->transport,
|
|
&rec->ver[0] );
|
|
|
|
if( major_ver != ssl->major_ver )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "major version mismatch" ) );
|
|
return( MBEDTLS_ERR_SSL_INVALID_RECORD );
|
|
}
|
|
|
|
if( minor_ver > ssl->conf->max_minor_ver )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "minor version mismatch" ) );
|
|
return( MBEDTLS_ERR_SSL_INVALID_RECORD );
|
|
}
|
|
|
|
/*
|
|
* Parse/Copy record sequence number.
|
|
*/
|
|
|
|
#if defined(MBEDTLS_SSL_PROTO_DTLS)
|
|
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
|
|
{
|
|
/* Copy explicit record sequence number from input buffer. */
|
|
memcpy( &rec->ctr[0], buf + rec_hdr_ctr_offset,
|
|
rec_hdr_ctr_len );
|
|
}
|
|
else
|
|
#endif /* MBEDTLS_SSL_PROTO_DTLS */
|
|
{
|
|
/* Copy implicit record sequence number from SSL context structure. */
|
|
memcpy( &rec->ctr[0], ssl->in_ctr, rec_hdr_ctr_len );
|
|
}
|
|
|
|
/*
|
|
* Parse record length.
|
|
*/
|
|
|
|
rec->data_offset = rec_hdr_len_offset + rec_hdr_len_len;
|
|
rec->data_len = ( (size_t) buf[ rec_hdr_len_offset + 0 ] << 8 ) |
|
|
( (size_t) buf[ rec_hdr_len_offset + 1 ] << 0 );
|
|
MBEDTLS_SSL_DEBUG_BUF( 4, "input record header", buf, rec->data_offset );
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 3, ( "input record: msgtype = %d, "
|
|
"version = [%d:%d], msglen = %d",
|
|
rec->type,
|
|
major_ver, minor_ver, rec->data_len ) );
|
|
|
|
rec->buf = buf;
|
|
rec->buf_len = rec->data_offset + rec->data_len;
|
|
|
|
if( rec->data_len == 0 )
|
|
return( MBEDTLS_ERR_SSL_INVALID_RECORD );
|
|
|
|
/*
|
|
* DTLS-related tests.
|
|
* Check epoch before checking length constraint because
|
|
* the latter varies with the epoch. E.g., if a ChangeCipherSpec
|
|
* message gets duplicated before the corresponding Finished message,
|
|
* the second ChangeCipherSpec should be discarded because it belongs
|
|
* to an old epoch, but not because its length is shorter than
|
|
* the minimum record length for packets using the new record transform.
|
|
* Note that these two kinds of failures are handled differently,
|
|
* as an unexpected record is silently skipped but an invalid
|
|
* record leads to the entire datagram being dropped.
|
|
*/
|
|
#if defined(MBEDTLS_SSL_PROTO_DTLS)
|
|
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
|
|
{
|
|
rec_epoch = ( rec->ctr[0] << 8 ) | rec->ctr[1];
|
|
|
|
/* Check that the datagram is large enough to contain a record
|
|
* of the advertised length. */
|
|
if( len < rec->data_offset + rec->data_len )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "Datagram of length %u too small to contain record of advertised length %u.",
|
|
(unsigned) len,
|
|
(unsigned)( rec->data_offset + rec->data_len ) ) );
|
|
return( MBEDTLS_ERR_SSL_INVALID_RECORD );
|
|
}
|
|
|
|
/* Records from other, non-matching epochs are silently discarded.
|
|
* (The case of same-port Client reconnects must be considered in
|
|
* the caller). */
|
|
if( rec_epoch != ssl->in_epoch )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "record from another epoch: "
|
|
"expected %d, received %d",
|
|
ssl->in_epoch, rec_epoch ) );
|
|
|
|
/* Records from the next epoch are considered for buffering
|
|
* (concretely: early Finished messages). */
|
|
if( rec_epoch == (unsigned) ssl->in_epoch + 1 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Consider record for buffering" ) );
|
|
return( MBEDTLS_ERR_SSL_EARLY_MESSAGE );
|
|
}
|
|
|
|
return( MBEDTLS_ERR_SSL_UNEXPECTED_RECORD );
|
|
}
|
|
#if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY)
|
|
/* For records from the correct epoch, check whether their
|
|
* sequence number has been seen before. */
|
|
else if( mbedtls_ssl_dtls_record_replay_check( (mbedtls_ssl_context *) ssl,
|
|
&rec->ctr[0] ) != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "replayed record" ) );
|
|
return( MBEDTLS_ERR_SSL_UNEXPECTED_RECORD );
|
|
}
|
|
#endif
|
|
}
|
|
#endif /* MBEDTLS_SSL_PROTO_DTLS */
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
|
|
#if defined(MBEDTLS_SSL_DTLS_CLIENT_PORT_REUSE) && defined(MBEDTLS_SSL_SRV_C)
|
|
static int ssl_check_client_reconnect( mbedtls_ssl_context *ssl )
|
|
{
|
|
unsigned int rec_epoch = ( ssl->in_ctr[0] << 8 ) | ssl->in_ctr[1];
|
|
|
|
/*
|
|
* Check for an epoch 0 ClientHello. We can't use in_msg here to
|
|
* access the first byte of record content (handshake type), as we
|
|
* have an active transform (possibly iv_len != 0), so use the
|
|
* fact that the record header len is 13 instead.
|
|
*/
|
|
if( rec_epoch == 0 &&
|
|
ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER &&
|
|
ssl->state == MBEDTLS_SSL_HANDSHAKE_OVER &&
|
|
ssl->in_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE &&
|
|
ssl->in_left > 13 &&
|
|
ssl->in_buf[13] == MBEDTLS_SSL_HS_CLIENT_HELLO )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "possible client reconnect "
|
|
"from the same port" ) );
|
|
return( ssl_handle_possible_reconnect( ssl ) );
|
|
}
|
|
|
|
return( 0 );
|
|
}
|
|
#endif /* MBEDTLS_SSL_DTLS_CLIENT_PORT_REUSE && MBEDTLS_SSL_SRV_C */
|
|
|
|
/*
|
|
* If applicable, decrypt record content
|
|
*/
|
|
static int ssl_prepare_record_content( mbedtls_ssl_context *ssl,
|
|
mbedtls_record *rec )
|
|
{
|
|
int ret, done = 0;
|
|
|
|
MBEDTLS_SSL_DEBUG_BUF( 4, "input record from network",
|
|
rec->buf, rec->buf_len );
|
|
|
|
#if defined(MBEDTLS_SSL_HW_RECORD_ACCEL)
|
|
if( mbedtls_ssl_hw_record_read != NULL )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "going for mbedtls_ssl_hw_record_read()" ) );
|
|
|
|
ret = mbedtls_ssl_hw_record_read( ssl );
|
|
if( ret != 0 && ret != MBEDTLS_ERR_SSL_HW_ACCEL_FALLTHROUGH )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_hw_record_read", ret );
|
|
return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
|
|
}
|
|
|
|
if( ret == 0 )
|
|
done = 1;
|
|
}
|
|
#endif /* MBEDTLS_SSL_HW_RECORD_ACCEL */
|
|
if( !done && ssl->transform_in != NULL )
|
|
{
|
|
unsigned char const old_msg_type = rec->type;
|
|
|
|
if( ( ret = mbedtls_ssl_decrypt_buf( ssl, ssl->transform_in,
|
|
rec ) ) != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_decrypt_buf", ret );
|
|
|
|
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
|
|
if( ret == MBEDTLS_ERR_SSL_UNEXPECTED_CID &&
|
|
ssl->conf->ignore_unexpected_cid
|
|
== MBEDTLS_SSL_UNEXPECTED_CID_IGNORE )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 3, ( "ignoring unexpected CID" ) );
|
|
ret = MBEDTLS_ERR_SSL_CONTINUE_PROCESSING;
|
|
}
|
|
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
|
|
|
|
return( ret );
|
|
}
|
|
|
|
if( old_msg_type != rec->type )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 4, ( "record type after decrypt (before %d): %d",
|
|
old_msg_type, rec->type ) );
|
|
}
|
|
|
|
MBEDTLS_SSL_DEBUG_BUF( 4, "input payload after decrypt",
|
|
rec->buf + rec->data_offset, rec->data_len );
|
|
|
|
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
|
|
/* We have already checked the record content type
|
|
* in ssl_parse_record_header(), failing or silently
|
|
* dropping the record in the case of an unknown type.
|
|
*
|
|
* Since with the use of CIDs, the record content type
|
|
* might change during decryption, re-check the record
|
|
* content type, but treat a failure as fatal this time. */
|
|
if( ssl_check_record_type( rec->type ) )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "unknown record type" ) );
|
|
return( MBEDTLS_ERR_SSL_INVALID_RECORD );
|
|
}
|
|
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
|
|
|
|
if( rec->data_len == 0 )
|
|
{
|
|
#if defined(MBEDTLS_SSL_PROTO_TLS1_2)
|
|
if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_3
|
|
&& rec->type != MBEDTLS_SSL_MSG_APPLICATION_DATA )
|
|
{
|
|
/* TLS v1.2 explicitly disallows zero-length messages which are not application data */
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "invalid zero-length message type: %d", ssl->in_msgtype ) );
|
|
return( MBEDTLS_ERR_SSL_INVALID_RECORD );
|
|
}
|
|
#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
|
|
|
|
ssl->nb_zero++;
|
|
|
|
/*
|
|
* Three or more empty messages may be a DoS attack
|
|
* (excessive CPU consumption).
|
|
*/
|
|
if( ssl->nb_zero > 3 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "received four consecutive empty "
|
|
"messages, possible DoS attack" ) );
|
|
/* Treat the records as if they were not properly authenticated,
|
|
* thereby failing the connection if we see more than allowed
|
|
* by the configured bad MAC threshold. */
|
|
return( MBEDTLS_ERR_SSL_INVALID_MAC );
|
|
}
|
|
}
|
|
else
|
|
ssl->nb_zero = 0;
|
|
|
|
#if defined(MBEDTLS_SSL_PROTO_DTLS)
|
|
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
|
|
{
|
|
; /* in_ctr read from peer, not maintained internally */
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
unsigned i;
|
|
for( i = 8; i > mbedtls_ssl_ep_len( ssl ); i-- )
|
|
if( ++ssl->in_ctr[i - 1] != 0 )
|
|
break;
|
|
|
|
/* The loop goes to its end iff the counter is wrapping */
|
|
if( i == mbedtls_ssl_ep_len( ssl ) )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "incoming message counter would wrap" ) );
|
|
return( MBEDTLS_ERR_SSL_COUNTER_WRAPPING );
|
|
}
|
|
}
|
|
|
|
}
|
|
|
|
#if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY)
|
|
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
|
|
{
|
|
mbedtls_ssl_dtls_replay_update( ssl );
|
|
}
|
|
#endif
|
|
|
|
/* Check actual (decrypted) record content length against
|
|
* configured maximum. */
|
|
if( ssl->in_msglen > MBEDTLS_SSL_IN_CONTENT_LEN )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad message length" ) );
|
|
return( MBEDTLS_ERR_SSL_INVALID_RECORD );
|
|
}
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
/*
|
|
* Read a record.
|
|
*
|
|
* Silently ignore non-fatal alert (and for DTLS, invalid records as well,
|
|
* RFC 6347 4.1.2.7) and continue reading until a valid record is found.
|
|
*
|
|
*/
|
|
|
|
/* Helper functions for mbedtls_ssl_read_record(). */
|
|
static int ssl_consume_current_message( mbedtls_ssl_context *ssl );
|
|
static int ssl_get_next_record( mbedtls_ssl_context *ssl );
|
|
static int ssl_record_is_in_progress( mbedtls_ssl_context *ssl );
|
|
|
|
int mbedtls_ssl_read_record( mbedtls_ssl_context *ssl,
|
|
unsigned update_hs_digest )
|
|
{
|
|
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> read record" ) );
|
|
|
|
if( ssl->keep_current_message == 0 )
|
|
{
|
|
do {
|
|
|
|
ret = ssl_consume_current_message( ssl );
|
|
if( ret != 0 )
|
|
return( ret );
|
|
|
|
if( ssl_record_is_in_progress( ssl ) == 0 )
|
|
{
|
|
#if defined(MBEDTLS_SSL_PROTO_DTLS)
|
|
int have_buffered = 0;
|
|
|
|
/* We only check for buffered messages if the
|
|
* current datagram is fully consumed. */
|
|
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
|
|
ssl_next_record_is_in_datagram( ssl ) == 0 )
|
|
{
|
|
if( ssl_load_buffered_message( ssl ) == 0 )
|
|
have_buffered = 1;
|
|
}
|
|
|
|
if( have_buffered == 0 )
|
|
#endif /* MBEDTLS_SSL_PROTO_DTLS */
|
|
{
|
|
ret = ssl_get_next_record( ssl );
|
|
if( ret == MBEDTLS_ERR_SSL_CONTINUE_PROCESSING )
|
|
continue;
|
|
|
|
if( ret != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, ( "ssl_get_next_record" ), ret );
|
|
return( ret );
|
|
}
|
|
}
|
|
}
|
|
|
|
ret = mbedtls_ssl_handle_message_type( ssl );
|
|
|
|
#if defined(MBEDTLS_SSL_PROTO_DTLS)
|
|
if( ret == MBEDTLS_ERR_SSL_EARLY_MESSAGE )
|
|
{
|
|
/* Buffer future message */
|
|
ret = ssl_buffer_message( ssl );
|
|
if( ret != 0 )
|
|
return( ret );
|
|
|
|
ret = MBEDTLS_ERR_SSL_CONTINUE_PROCESSING;
|
|
}
|
|
#endif /* MBEDTLS_SSL_PROTO_DTLS */
|
|
|
|
} while( MBEDTLS_ERR_SSL_NON_FATAL == ret ||
|
|
MBEDTLS_ERR_SSL_CONTINUE_PROCESSING == ret );
|
|
|
|
if( 0 != ret )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, ( "mbedtls_ssl_handle_message_type" ), ret );
|
|
return( ret );
|
|
}
|
|
|
|
if( ssl->in_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE &&
|
|
update_hs_digest == 1 )
|
|
{
|
|
mbedtls_ssl_update_handshake_status( ssl );
|
|
}
|
|
}
|
|
else
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "reuse previously read message" ) );
|
|
ssl->keep_current_message = 0;
|
|
}
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= read record" ) );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
#if defined(MBEDTLS_SSL_PROTO_DTLS)
|
|
static int ssl_next_record_is_in_datagram( mbedtls_ssl_context *ssl )
|
|
{
|
|
if( ssl->in_left > ssl->next_record_offset )
|
|
return( 1 );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
static int ssl_load_buffered_message( mbedtls_ssl_context *ssl )
|
|
{
|
|
mbedtls_ssl_handshake_params * const hs = ssl->handshake;
|
|
mbedtls_ssl_hs_buffer * hs_buf;
|
|
int ret = 0;
|
|
|
|
if( hs == NULL )
|
|
return( -1 );
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> ssl_load_buffered_messsage" ) );
|
|
|
|
if( ssl->state == MBEDTLS_SSL_CLIENT_CHANGE_CIPHER_SPEC ||
|
|
ssl->state == MBEDTLS_SSL_SERVER_CHANGE_CIPHER_SPEC )
|
|
{
|
|
/* Check if we have seen a ChangeCipherSpec before.
|
|
* If yes, synthesize a CCS record. */
|
|
if( !hs->buffering.seen_ccs )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "CCS not seen in the current flight" ) );
|
|
ret = -1;
|
|
goto exit;
|
|
}
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Injecting buffered CCS message" ) );
|
|
ssl->in_msgtype = MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC;
|
|
ssl->in_msglen = 1;
|
|
ssl->in_msg[0] = 1;
|
|
|
|
/* As long as they are equal, the exact value doesn't matter. */
|
|
ssl->in_left = 0;
|
|
ssl->next_record_offset = 0;
|
|
|
|
hs->buffering.seen_ccs = 0;
|
|
goto exit;
|
|
}
|
|
|
|
#if defined(MBEDTLS_DEBUG_C)
|
|
/* Debug only */
|
|
{
|
|
unsigned offset;
|
|
for( offset = 1; offset < MBEDTLS_SSL_MAX_BUFFERED_HS; offset++ )
|
|
{
|
|
hs_buf = &hs->buffering.hs[offset];
|
|
if( hs_buf->is_valid == 1 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Future message with sequence number %u %s buffered.",
|
|
hs->in_msg_seq + offset,
|
|
hs_buf->is_complete ? "fully" : "partially" ) );
|
|
}
|
|
}
|
|
}
|
|
#endif /* MBEDTLS_DEBUG_C */
|
|
|
|
/* Check if we have buffered and/or fully reassembled the
|
|
* next handshake message. */
|
|
hs_buf = &hs->buffering.hs[0];
|
|
if( ( hs_buf->is_valid == 1 ) && ( hs_buf->is_complete == 1 ) )
|
|
{
|
|
/* Synthesize a record containing the buffered HS message. */
|
|
size_t msg_len = ( hs_buf->data[1] << 16 ) |
|
|
( hs_buf->data[2] << 8 ) |
|
|
hs_buf->data[3];
|
|
|
|
/* Double-check that we haven't accidentally buffered
|
|
* a message that doesn't fit into the input buffer. */
|
|
if( msg_len + 12 > MBEDTLS_SSL_IN_CONTENT_LEN )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
|
|
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
|
|
}
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Next handshake message has been buffered - load" ) );
|
|
MBEDTLS_SSL_DEBUG_BUF( 3, "Buffered handshake message (incl. header)",
|
|
hs_buf->data, msg_len + 12 );
|
|
|
|
ssl->in_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE;
|
|
ssl->in_hslen = msg_len + 12;
|
|
ssl->in_msglen = msg_len + 12;
|
|
memcpy( ssl->in_msg, hs_buf->data, ssl->in_hslen );
|
|
|
|
ret = 0;
|
|
goto exit;
|
|
}
|
|
else
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Next handshake message %u not or only partially bufffered",
|
|
hs->in_msg_seq ) );
|
|
}
|
|
|
|
ret = -1;
|
|
|
|
exit:
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= ssl_load_buffered_message" ) );
|
|
return( ret );
|
|
}
|
|
|
|
static int ssl_buffer_make_space( mbedtls_ssl_context *ssl,
|
|
size_t desired )
|
|
{
|
|
int offset;
|
|
mbedtls_ssl_handshake_params * const hs = ssl->handshake;
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Attempt to free buffered messages to have %u bytes available",
|
|
(unsigned) desired ) );
|
|
|
|
/* Get rid of future records epoch first, if such exist. */
|
|
ssl_free_buffered_record( ssl );
|
|
|
|
/* Check if we have enough space available now. */
|
|
if( desired <= ( MBEDTLS_SSL_DTLS_MAX_BUFFERING -
|
|
hs->buffering.total_bytes_buffered ) )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Enough space available after freeing future epoch record" ) );
|
|
return( 0 );
|
|
}
|
|
|
|
/* We don't have enough space to buffer the next expected handshake
|
|
* message. Remove buffers used for future messages to gain space,
|
|
* starting with the most distant one. */
|
|
for( offset = MBEDTLS_SSL_MAX_BUFFERED_HS - 1;
|
|
offset >= 0; offset-- )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Free buffering slot %d to make space for reassembly of next handshake message",
|
|
offset ) );
|
|
|
|
ssl_buffering_free_slot( ssl, (uint8_t) offset );
|
|
|
|
/* Check if we have enough space available now. */
|
|
if( desired <= ( MBEDTLS_SSL_DTLS_MAX_BUFFERING -
|
|
hs->buffering.total_bytes_buffered ) )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Enough space available after freeing buffered HS messages" ) );
|
|
return( 0 );
|
|
}
|
|
}
|
|
|
|
return( -1 );
|
|
}
|
|
|
|
static int ssl_buffer_message( mbedtls_ssl_context *ssl )
|
|
{
|
|
int ret = 0;
|
|
mbedtls_ssl_handshake_params * const hs = ssl->handshake;
|
|
|
|
if( hs == NULL )
|
|
return( 0 );
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> ssl_buffer_message" ) );
|
|
|
|
switch( ssl->in_msgtype )
|
|
{
|
|
case MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC:
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Remember CCS message" ) );
|
|
|
|
hs->buffering.seen_ccs = 1;
|
|
break;
|
|
|
|
case MBEDTLS_SSL_MSG_HANDSHAKE:
|
|
{
|
|
unsigned recv_msg_seq_offset;
|
|
unsigned recv_msg_seq = ( ssl->in_msg[4] << 8 ) | ssl->in_msg[5];
|
|
mbedtls_ssl_hs_buffer *hs_buf;
|
|
size_t msg_len = ssl->in_hslen - 12;
|
|
|
|
/* We should never receive an old handshake
|
|
* message - double-check nonetheless. */
|
|
if( recv_msg_seq < ssl->handshake->in_msg_seq )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
|
|
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
|
|
}
|
|
|
|
recv_msg_seq_offset = recv_msg_seq - ssl->handshake->in_msg_seq;
|
|
if( recv_msg_seq_offset >= MBEDTLS_SSL_MAX_BUFFERED_HS )
|
|
{
|
|
/* Silently ignore -- message too far in the future */
|
|
MBEDTLS_SSL_DEBUG_MSG( 2,
|
|
( "Ignore future HS message with sequence number %u, "
|
|
"buffering window %u - %u",
|
|
recv_msg_seq, ssl->handshake->in_msg_seq,
|
|
ssl->handshake->in_msg_seq + MBEDTLS_SSL_MAX_BUFFERED_HS - 1 ) );
|
|
|
|
goto exit;
|
|
}
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Buffering HS message with sequence number %u, offset %u ",
|
|
recv_msg_seq, recv_msg_seq_offset ) );
|
|
|
|
hs_buf = &hs->buffering.hs[ recv_msg_seq_offset ];
|
|
|
|
/* Check if the buffering for this seq nr has already commenced. */
|
|
if( !hs_buf->is_valid )
|
|
{
|
|
size_t reassembly_buf_sz;
|
|
|
|
hs_buf->is_fragmented =
|
|
( ssl_hs_is_proper_fragment( ssl ) == 1 );
|
|
|
|
/* We copy the message back into the input buffer
|
|
* after reassembly, so check that it's not too large.
|
|
* This is an implementation-specific limitation
|
|
* and not one from the standard, hence it is not
|
|
* checked in ssl_check_hs_header(). */
|
|
if( msg_len + 12 > MBEDTLS_SSL_IN_CONTENT_LEN )
|
|
{
|
|
/* Ignore message */
|
|
goto exit;
|
|
}
|
|
|
|
/* Check if we have enough space to buffer the message. */
|
|
if( hs->buffering.total_bytes_buffered >
|
|
MBEDTLS_SSL_DTLS_MAX_BUFFERING )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
|
|
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
|
|
}
|
|
|
|
reassembly_buf_sz = ssl_get_reassembly_buffer_size( msg_len,
|
|
hs_buf->is_fragmented );
|
|
|
|
if( reassembly_buf_sz > ( MBEDTLS_SSL_DTLS_MAX_BUFFERING -
|
|
hs->buffering.total_bytes_buffered ) )
|
|
{
|
|
if( recv_msg_seq_offset > 0 )
|
|
{
|
|
/* If we can't buffer a future message because
|
|
* of space limitations -- ignore. */
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Buffering of future message of size %u would exceed the compile-time limit %u (already %u bytes buffered) -- ignore\n",
|
|
(unsigned) msg_len, MBEDTLS_SSL_DTLS_MAX_BUFFERING,
|
|
(unsigned) hs->buffering.total_bytes_buffered ) );
|
|
goto exit;
|
|
}
|
|
else
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Buffering of future message of size %u would exceed the compile-time limit %u (already %u bytes buffered) -- attempt to make space by freeing buffered future messages\n",
|
|
(unsigned) msg_len, MBEDTLS_SSL_DTLS_MAX_BUFFERING,
|
|
(unsigned) hs->buffering.total_bytes_buffered ) );
|
|
}
|
|
|
|
if( ssl_buffer_make_space( ssl, reassembly_buf_sz ) != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Reassembly of next message of size %u (%u with bitmap) would exceed the compile-time limit %u (already %u bytes buffered) -- fail\n",
|
|
(unsigned) msg_len,
|
|
(unsigned) reassembly_buf_sz,
|
|
MBEDTLS_SSL_DTLS_MAX_BUFFERING,
|
|
(unsigned) hs->buffering.total_bytes_buffered ) );
|
|
ret = MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL;
|
|
goto exit;
|
|
}
|
|
}
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "initialize reassembly, total length = %d",
|
|
msg_len ) );
|
|
|
|
hs_buf->data = mbedtls_calloc( 1, reassembly_buf_sz );
|
|
if( hs_buf->data == NULL )
|
|
{
|
|
ret = MBEDTLS_ERR_SSL_ALLOC_FAILED;
|
|
goto exit;
|
|
}
|
|
hs_buf->data_len = reassembly_buf_sz;
|
|
|
|
/* Prepare final header: copy msg_type, length and message_seq,
|
|
* then add standardised fragment_offset and fragment_length */
|
|
memcpy( hs_buf->data, ssl->in_msg, 6 );
|
|
memset( hs_buf->data + 6, 0, 3 );
|
|
memcpy( hs_buf->data + 9, hs_buf->data + 1, 3 );
|
|
|
|
hs_buf->is_valid = 1;
|
|
|
|
hs->buffering.total_bytes_buffered += reassembly_buf_sz;
|
|
}
|
|
else
|
|
{
|
|
/* Make sure msg_type and length are consistent */
|
|
if( memcmp( hs_buf->data, ssl->in_msg, 4 ) != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "Fragment header mismatch - ignore" ) );
|
|
/* Ignore */
|
|
goto exit;
|
|
}
|
|
}
|
|
|
|
if( !hs_buf->is_complete )
|
|
{
|
|
size_t frag_len, frag_off;
|
|
unsigned char * const msg = hs_buf->data + 12;
|
|
|
|
/*
|
|
* Check and copy current fragment
|
|
*/
|
|
|
|
/* Validation of header fields already done in
|
|
* mbedtls_ssl_prepare_handshake_record(). */
|
|
frag_off = ssl_get_hs_frag_off( ssl );
|
|
frag_len = ssl_get_hs_frag_len( ssl );
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "adding fragment, offset = %d, length = %d",
|
|
frag_off, frag_len ) );
|
|
memcpy( msg + frag_off, ssl->in_msg + 12, frag_len );
|
|
|
|
if( hs_buf->is_fragmented )
|
|
{
|
|
unsigned char * const bitmask = msg + msg_len;
|
|
ssl_bitmask_set( bitmask, frag_off, frag_len );
|
|
hs_buf->is_complete = ( ssl_bitmask_check( bitmask,
|
|
msg_len ) == 0 );
|
|
}
|
|
else
|
|
{
|
|
hs_buf->is_complete = 1;
|
|
}
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "message %scomplete",
|
|
hs_buf->is_complete ? "" : "not yet " ) );
|
|
}
|
|
|
|
break;
|
|
}
|
|
|
|
default:
|
|
/* We don't buffer other types of messages. */
|
|
break;
|
|
}
|
|
|
|
exit:
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= ssl_buffer_message" ) );
|
|
return( ret );
|
|
}
|
|
#endif /* MBEDTLS_SSL_PROTO_DTLS */
|
|
|
|
static int ssl_consume_current_message( mbedtls_ssl_context *ssl )
|
|
{
|
|
/*
|
|
* Consume last content-layer message and potentially
|
|
* update in_msglen which keeps track of the contents'
|
|
* consumption state.
|
|
*
|
|
* (1) Handshake messages:
|
|
* Remove last handshake message, move content
|
|
* and adapt in_msglen.
|
|
*
|
|
* (2) Alert messages:
|
|
* Consume whole record content, in_msglen = 0.
|
|
*
|
|
* (3) Change cipher spec:
|
|
* Consume whole record content, in_msglen = 0.
|
|
*
|
|
* (4) Application data:
|
|
* Don't do anything - the record layer provides
|
|
* the application data as a stream transport
|
|
* and consumes through mbedtls_ssl_read only.
|
|
*
|
|
*/
|
|
|
|
/* Case (1): Handshake messages */
|
|
if( ssl->in_hslen != 0 )
|
|
{
|
|
/* Hard assertion to be sure that no application data
|
|
* is in flight, as corrupting ssl->in_msglen during
|
|
* ssl->in_offt != NULL is fatal. */
|
|
if( ssl->in_offt != NULL )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
|
|
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
|
|
}
|
|
|
|
/*
|
|
* Get next Handshake message in the current record
|
|
*/
|
|
|
|
/* Notes:
|
|
* (1) in_hslen is not necessarily the size of the
|
|
* current handshake content: If DTLS handshake
|
|
* fragmentation is used, that's the fragment
|
|
* size instead. Using the total handshake message
|
|
* size here is faulty and should be changed at
|
|
* some point.
|
|
* (2) While it doesn't seem to cause problems, one
|
|
* has to be very careful not to assume that in_hslen
|
|
* is always <= in_msglen in a sensible communication.
|
|
* Again, it's wrong for DTLS handshake fragmentation.
|
|
* The following check is therefore mandatory, and
|
|
* should not be treated as a silently corrected assertion.
|
|
* Additionally, ssl->in_hslen might be arbitrarily out of
|
|
* bounds after handling a DTLS message with an unexpected
|
|
* sequence number, see mbedtls_ssl_prepare_handshake_record.
|
|
*/
|
|
if( ssl->in_hslen < ssl->in_msglen )
|
|
{
|
|
ssl->in_msglen -= ssl->in_hslen;
|
|
memmove( ssl->in_msg, ssl->in_msg + ssl->in_hslen,
|
|
ssl->in_msglen );
|
|
|
|
MBEDTLS_SSL_DEBUG_BUF( 4, "remaining content in record",
|
|
ssl->in_msg, ssl->in_msglen );
|
|
}
|
|
else
|
|
{
|
|
ssl->in_msglen = 0;
|
|
}
|
|
|
|
ssl->in_hslen = 0;
|
|
}
|
|
/* Case (4): Application data */
|
|
else if( ssl->in_offt != NULL )
|
|
{
|
|
return( 0 );
|
|
}
|
|
/* Everything else (CCS & Alerts) */
|
|
else
|
|
{
|
|
ssl->in_msglen = 0;
|
|
}
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
static int ssl_record_is_in_progress( mbedtls_ssl_context *ssl )
|
|
{
|
|
if( ssl->in_msglen > 0 )
|
|
return( 1 );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
#if defined(MBEDTLS_SSL_PROTO_DTLS)
|
|
|
|
static void ssl_free_buffered_record( mbedtls_ssl_context *ssl )
|
|
{
|
|
mbedtls_ssl_handshake_params * const hs = ssl->handshake;
|
|
if( hs == NULL )
|
|
return;
|
|
|
|
if( hs->buffering.future_record.data != NULL )
|
|
{
|
|
hs->buffering.total_bytes_buffered -=
|
|
hs->buffering.future_record.len;
|
|
|
|
mbedtls_free( hs->buffering.future_record.data );
|
|
hs->buffering.future_record.data = NULL;
|
|
}
|
|
}
|
|
|
|
static int ssl_load_buffered_record( mbedtls_ssl_context *ssl )
|
|
{
|
|
mbedtls_ssl_handshake_params * const hs = ssl->handshake;
|
|
unsigned char * rec;
|
|
size_t rec_len;
|
|
unsigned rec_epoch;
|
|
#if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH)
|
|
size_t in_buf_len = ssl->in_buf_len;
|
|
#else
|
|
size_t in_buf_len = MBEDTLS_SSL_IN_BUFFER_LEN;
|
|
#endif
|
|
if( ssl->conf->transport != MBEDTLS_SSL_TRANSPORT_DATAGRAM )
|
|
return( 0 );
|
|
|
|
if( hs == NULL )
|
|
return( 0 );
|
|
|
|
rec = hs->buffering.future_record.data;
|
|
rec_len = hs->buffering.future_record.len;
|
|
rec_epoch = hs->buffering.future_record.epoch;
|
|
|
|
if( rec == NULL )
|
|
return( 0 );
|
|
|
|
/* Only consider loading future records if the
|
|
* input buffer is empty. */
|
|
if( ssl_next_record_is_in_datagram( ssl ) == 1 )
|
|
return( 0 );
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> ssl_load_buffered_record" ) );
|
|
|
|
if( rec_epoch != ssl->in_epoch )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Buffered record not from current epoch." ) );
|
|
goto exit;
|
|
}
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Found buffered record from current epoch - load" ) );
|
|
|
|
/* Double-check that the record is not too large */
|
|
if( rec_len > in_buf_len - (size_t)( ssl->in_hdr - ssl->in_buf ) )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
|
|
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
|
|
}
|
|
|
|
memcpy( ssl->in_hdr, rec, rec_len );
|
|
ssl->in_left = rec_len;
|
|
ssl->next_record_offset = 0;
|
|
|
|
ssl_free_buffered_record( ssl );
|
|
|
|
exit:
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= ssl_load_buffered_record" ) );
|
|
return( 0 );
|
|
}
|
|
|
|
static int ssl_buffer_future_record( mbedtls_ssl_context *ssl,
|
|
mbedtls_record const *rec )
|
|
{
|
|
mbedtls_ssl_handshake_params * const hs = ssl->handshake;
|
|
|
|
/* Don't buffer future records outside handshakes. */
|
|
if( hs == NULL )
|
|
return( 0 );
|
|
|
|
/* Only buffer handshake records (we are only interested
|
|
* in Finished messages). */
|
|
if( rec->type != MBEDTLS_SSL_MSG_HANDSHAKE )
|
|
return( 0 );
|
|
|
|
/* Don't buffer more than one future epoch record. */
|
|
if( hs->buffering.future_record.data != NULL )
|
|
return( 0 );
|
|
|
|
/* Don't buffer record if there's not enough buffering space remaining. */
|
|
if( rec->buf_len > ( MBEDTLS_SSL_DTLS_MAX_BUFFERING -
|
|
hs->buffering.total_bytes_buffered ) )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Buffering of future epoch record of size %u would exceed the compile-time limit %u (already %u bytes buffered) -- ignore\n",
|
|
(unsigned) rec->buf_len, MBEDTLS_SSL_DTLS_MAX_BUFFERING,
|
|
(unsigned) hs->buffering.total_bytes_buffered ) );
|
|
return( 0 );
|
|
}
|
|
|
|
/* Buffer record */
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Buffer record from epoch %u",
|
|
ssl->in_epoch + 1 ) );
|
|
MBEDTLS_SSL_DEBUG_BUF( 3, "Buffered record", rec->buf, rec->buf_len );
|
|
|
|
/* ssl_parse_record_header() only considers records
|
|
* of the next epoch as candidates for buffering. */
|
|
hs->buffering.future_record.epoch = ssl->in_epoch + 1;
|
|
hs->buffering.future_record.len = rec->buf_len;
|
|
|
|
hs->buffering.future_record.data =
|
|
mbedtls_calloc( 1, hs->buffering.future_record.len );
|
|
if( hs->buffering.future_record.data == NULL )
|
|
{
|
|
/* If we run out of RAM trying to buffer a
|
|
* record from the next epoch, just ignore. */
|
|
return( 0 );
|
|
}
|
|
|
|
memcpy( hs->buffering.future_record.data, rec->buf, rec->buf_len );
|
|
|
|
hs->buffering.total_bytes_buffered += rec->buf_len;
|
|
return( 0 );
|
|
}
|
|
|
|
#endif /* MBEDTLS_SSL_PROTO_DTLS */
|
|
|
|
static int ssl_get_next_record( mbedtls_ssl_context *ssl )
|
|
{
|
|
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
|
|
mbedtls_record rec;
|
|
|
|
#if defined(MBEDTLS_SSL_PROTO_DTLS)
|
|
/* We might have buffered a future record; if so,
|
|
* and if the epoch matches now, load it.
|
|
* On success, this call will set ssl->in_left to
|
|
* the length of the buffered record, so that
|
|
* the calls to ssl_fetch_input() below will
|
|
* essentially be no-ops. */
|
|
ret = ssl_load_buffered_record( ssl );
|
|
if( ret != 0 )
|
|
return( ret );
|
|
#endif /* MBEDTLS_SSL_PROTO_DTLS */
|
|
|
|
/* Ensure that we have enough space available for the default form
|
|
* of TLS / DTLS record headers (5 Bytes for TLS, 13 Bytes for DTLS,
|
|
* with no space for CIDs counted in). */
|
|
ret = mbedtls_ssl_fetch_input( ssl, mbedtls_ssl_in_hdr_len( ssl ) );
|
|
if( ret != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_fetch_input", ret );
|
|
return( ret );
|
|
}
|
|
|
|
ret = ssl_parse_record_header( ssl, ssl->in_hdr, ssl->in_left, &rec );
|
|
if( ret != 0 )
|
|
{
|
|
#if defined(MBEDTLS_SSL_PROTO_DTLS)
|
|
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
|
|
{
|
|
if( ret == MBEDTLS_ERR_SSL_EARLY_MESSAGE )
|
|
{
|
|
ret = ssl_buffer_future_record( ssl, &rec );
|
|
if( ret != 0 )
|
|
return( ret );
|
|
|
|
/* Fall through to handling of unexpected records */
|
|
ret = MBEDTLS_ERR_SSL_UNEXPECTED_RECORD;
|
|
}
|
|
|
|
if( ret == MBEDTLS_ERR_SSL_UNEXPECTED_RECORD )
|
|
{
|
|
#if defined(MBEDTLS_SSL_DTLS_CLIENT_PORT_REUSE) && defined(MBEDTLS_SSL_SRV_C)
|
|
/* Reset in pointers to default state for TLS/DTLS records,
|
|
* assuming no CID and no offset between record content and
|
|
* record plaintext. */
|
|
mbedtls_ssl_update_in_pointers( ssl );
|
|
|
|
/* Setup internal message pointers from record structure. */
|
|
ssl->in_msgtype = rec.type;
|
|
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
|
|
ssl->in_len = ssl->in_cid + rec.cid_len;
|
|
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
|
|
ssl->in_iv = ssl->in_msg = ssl->in_len + 2;
|
|
ssl->in_msglen = rec.data_len;
|
|
|
|
ret = ssl_check_client_reconnect( ssl );
|
|
MBEDTLS_SSL_DEBUG_RET( 2, "ssl_check_client_reconnect", ret );
|
|
if( ret != 0 )
|
|
return( ret );
|
|
#endif
|
|
|
|
/* Skip unexpected record (but not whole datagram) */
|
|
ssl->next_record_offset = rec.buf_len;
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "discarding unexpected record "
|
|
"(header)" ) );
|
|
}
|
|
else
|
|
{
|
|
/* Skip invalid record and the rest of the datagram */
|
|
ssl->next_record_offset = 0;
|
|
ssl->in_left = 0;
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "discarding invalid record "
|
|
"(header)" ) );
|
|
}
|
|
|
|
/* Get next record */
|
|
return( MBEDTLS_ERR_SSL_CONTINUE_PROCESSING );
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
return( ret );
|
|
}
|
|
}
|
|
|
|
#if defined(MBEDTLS_SSL_PROTO_DTLS)
|
|
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
|
|
{
|
|
/* Remember offset of next record within datagram. */
|
|
ssl->next_record_offset = rec.buf_len;
|
|
if( ssl->next_record_offset < ssl->in_left )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 3, ( "more than one record within datagram" ) );
|
|
}
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
/*
|
|
* Fetch record contents from underlying transport.
|
|
*/
|
|
ret = mbedtls_ssl_fetch_input( ssl, rec.buf_len );
|
|
if( ret != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_fetch_input", ret );
|
|
return( ret );
|
|
}
|
|
|
|
ssl->in_left = 0;
|
|
}
|
|
|
|
/*
|
|
* Decrypt record contents.
|
|
*/
|
|
|
|
if( ( ret = ssl_prepare_record_content( ssl, &rec ) ) != 0 )
|
|
{
|
|
#if defined(MBEDTLS_SSL_PROTO_DTLS)
|
|
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
|
|
{
|
|
/* Silently discard invalid records */
|
|
if( ret == MBEDTLS_ERR_SSL_INVALID_MAC )
|
|
{
|
|
/* Except when waiting for Finished as a bad mac here
|
|
* probably means something went wrong in the handshake
|
|
* (eg wrong psk used, mitm downgrade attempt, etc.) */
|
|
if( ssl->state == MBEDTLS_SSL_CLIENT_FINISHED ||
|
|
ssl->state == MBEDTLS_SSL_SERVER_FINISHED )
|
|
{
|
|
#if defined(MBEDTLS_SSL_ALL_ALERT_MESSAGES)
|
|
if( ret == MBEDTLS_ERR_SSL_INVALID_MAC )
|
|
{
|
|
mbedtls_ssl_send_alert_message( ssl,
|
|
MBEDTLS_SSL_ALERT_LEVEL_FATAL,
|
|
MBEDTLS_SSL_ALERT_MSG_BAD_RECORD_MAC );
|
|
}
|
|
#endif
|
|
return( ret );
|
|
}
|
|
|
|
#if defined(MBEDTLS_SSL_DTLS_BADMAC_LIMIT)
|
|
if( ssl->conf->badmac_limit != 0 &&
|
|
++ssl->badmac_seen >= ssl->conf->badmac_limit )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "too many records with bad MAC" ) );
|
|
return( MBEDTLS_ERR_SSL_INVALID_MAC );
|
|
}
|
|
#endif
|
|
|
|
/* As above, invalid records cause
|
|
* dismissal of the whole datagram. */
|
|
|
|
ssl->next_record_offset = 0;
|
|
ssl->in_left = 0;
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "discarding invalid record (mac)" ) );
|
|
return( MBEDTLS_ERR_SSL_CONTINUE_PROCESSING );
|
|
}
|
|
|
|
return( ret );
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
/* Error out (and send alert) on invalid records */
|
|
#if defined(MBEDTLS_SSL_ALL_ALERT_MESSAGES)
|
|
if( ret == MBEDTLS_ERR_SSL_INVALID_MAC )
|
|
{
|
|
mbedtls_ssl_send_alert_message( ssl,
|
|
MBEDTLS_SSL_ALERT_LEVEL_FATAL,
|
|
MBEDTLS_SSL_ALERT_MSG_BAD_RECORD_MAC );
|
|
}
|
|
#endif
|
|
return( ret );
|
|
}
|
|
}
|
|
|
|
|
|
/* Reset in pointers to default state for TLS/DTLS records,
|
|
* assuming no CID and no offset between record content and
|
|
* record plaintext. */
|
|
mbedtls_ssl_update_in_pointers( ssl );
|
|
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
|
|
ssl->in_len = ssl->in_cid + rec.cid_len;
|
|
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
|
|
ssl->in_iv = ssl->in_len + 2;
|
|
|
|
/* The record content type may change during decryption,
|
|
* so re-read it. */
|
|
ssl->in_msgtype = rec.type;
|
|
/* Also update the input buffer, because unfortunately
|
|
* the server-side ssl_parse_client_hello() reparses the
|
|
* record header when receiving a ClientHello initiating
|
|
* a renegotiation. */
|
|
ssl->in_hdr[0] = rec.type;
|
|
ssl->in_msg = rec.buf + rec.data_offset;
|
|
ssl->in_msglen = rec.data_len;
|
|
ssl->in_len[0] = (unsigned char)( rec.data_len >> 8 );
|
|
ssl->in_len[1] = (unsigned char)( rec.data_len );
|
|
|
|
#if defined(MBEDTLS_ZLIB_SUPPORT)
|
|
if( ssl->transform_in != NULL &&
|
|
ssl->session_in->compression == MBEDTLS_SSL_COMPRESS_DEFLATE )
|
|
{
|
|
if( ( ret = ssl_decompress_buf( ssl ) ) != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_decompress_buf", ret );
|
|
return( ret );
|
|
}
|
|
|
|
/* Check actual (decompress) record content length against
|
|
* configured maximum. */
|
|
if( ssl->in_msglen > MBEDTLS_SSL_IN_CONTENT_LEN )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad message length" ) );
|
|
return( MBEDTLS_ERR_SSL_INVALID_RECORD );
|
|
}
|
|
}
|
|
#endif /* MBEDTLS_ZLIB_SUPPORT */
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
int mbedtls_ssl_handle_message_type( mbedtls_ssl_context *ssl )
|
|
{
|
|
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
|
|
|
|
/*
|
|
* Handle particular types of records
|
|
*/
|
|
if( ssl->in_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE )
|
|
{
|
|
if( ( ret = mbedtls_ssl_prepare_handshake_record( ssl ) ) != 0 )
|
|
{
|
|
return( ret );
|
|
}
|
|
}
|
|
|
|
if( ssl->in_msgtype == MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC )
|
|
{
|
|
if( ssl->in_msglen != 1 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "invalid CCS message, len: %d",
|
|
ssl->in_msglen ) );
|
|
return( MBEDTLS_ERR_SSL_INVALID_RECORD );
|
|
}
|
|
|
|
if( ssl->in_msg[0] != 1 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "invalid CCS message, content: %02x",
|
|
ssl->in_msg[0] ) );
|
|
return( MBEDTLS_ERR_SSL_INVALID_RECORD );
|
|
}
|
|
|
|
#if defined(MBEDTLS_SSL_PROTO_DTLS)
|
|
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
|
|
ssl->state != MBEDTLS_SSL_CLIENT_CHANGE_CIPHER_SPEC &&
|
|
ssl->state != MBEDTLS_SSL_SERVER_CHANGE_CIPHER_SPEC )
|
|
{
|
|
if( ssl->handshake == NULL )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "dropping ChangeCipherSpec outside handshake" ) );
|
|
return( MBEDTLS_ERR_SSL_UNEXPECTED_RECORD );
|
|
}
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "received out-of-order ChangeCipherSpec - remember" ) );
|
|
return( MBEDTLS_ERR_SSL_EARLY_MESSAGE );
|
|
}
|
|
#endif
|
|
}
|
|
|
|
if( ssl->in_msgtype == MBEDTLS_SSL_MSG_ALERT )
|
|
{
|
|
if( ssl->in_msglen != 2 )
|
|
{
|
|
/* Note: Standard allows for more than one 2 byte alert
|
|
to be packed in a single message, but Mbed TLS doesn't
|
|
currently support this. */
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "invalid alert message, len: %d",
|
|
ssl->in_msglen ) );
|
|
return( MBEDTLS_ERR_SSL_INVALID_RECORD );
|
|
}
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "got an alert message, type: [%d:%d]",
|
|
ssl->in_msg[0], ssl->in_msg[1] ) );
|
|
|
|
/*
|
|
* Ignore non-fatal alerts, except close_notify and no_renegotiation
|
|
*/
|
|
if( ssl->in_msg[0] == MBEDTLS_SSL_ALERT_LEVEL_FATAL )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "is a fatal alert message (msg %d)",
|
|
ssl->in_msg[1] ) );
|
|
return( MBEDTLS_ERR_SSL_FATAL_ALERT_MESSAGE );
|
|
}
|
|
|
|
if( ssl->in_msg[0] == MBEDTLS_SSL_ALERT_LEVEL_WARNING &&
|
|
ssl->in_msg[1] == MBEDTLS_SSL_ALERT_MSG_CLOSE_NOTIFY )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "is a close notify message" ) );
|
|
return( MBEDTLS_ERR_SSL_PEER_CLOSE_NOTIFY );
|
|
}
|
|
|
|
#if defined(MBEDTLS_SSL_RENEGOTIATION_ENABLED)
|
|
if( ssl->in_msg[0] == MBEDTLS_SSL_ALERT_LEVEL_WARNING &&
|
|
ssl->in_msg[1] == MBEDTLS_SSL_ALERT_MSG_NO_RENEGOTIATION )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "is a SSLv3 no renegotiation alert" ) );
|
|
/* Will be handled when trying to parse ServerHello */
|
|
return( 0 );
|
|
}
|
|
#endif
|
|
|
|
#if defined(MBEDTLS_SSL_PROTO_SSL3) && defined(MBEDTLS_SSL_SRV_C)
|
|
if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 &&
|
|
ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER &&
|
|
ssl->in_msg[0] == MBEDTLS_SSL_ALERT_LEVEL_WARNING &&
|
|
ssl->in_msg[1] == MBEDTLS_SSL_ALERT_MSG_NO_CERT )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "is a SSLv3 no_cert" ) );
|
|
/* Will be handled in mbedtls_ssl_parse_certificate() */
|
|
return( 0 );
|
|
}
|
|
#endif /* MBEDTLS_SSL_PROTO_SSL3 && MBEDTLS_SSL_SRV_C */
|
|
|
|
/* Silently ignore: fetch new message */
|
|
return MBEDTLS_ERR_SSL_NON_FATAL;
|
|
}
|
|
|
|
#if defined(MBEDTLS_SSL_PROTO_DTLS)
|
|
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
|
|
{
|
|
/* Drop unexpected ApplicationData records,
|
|
* except at the beginning of renegotiations */
|
|
if( ssl->in_msgtype == MBEDTLS_SSL_MSG_APPLICATION_DATA &&
|
|
ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER
|
|
#if defined(MBEDTLS_SSL_RENEGOTIATION)
|
|
&& ! ( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS &&
|
|
ssl->state == MBEDTLS_SSL_SERVER_HELLO )
|
|
#endif
|
|
)
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "dropping unexpected ApplicationData" ) );
|
|
return( MBEDTLS_ERR_SSL_NON_FATAL );
|
|
}
|
|
|
|
if( ssl->handshake != NULL &&
|
|
ssl->state == MBEDTLS_SSL_HANDSHAKE_OVER )
|
|
{
|
|
mbedtls_ssl_handshake_wrapup_free_hs_transform( ssl );
|
|
}
|
|
}
|
|
#endif /* MBEDTLS_SSL_PROTO_DTLS */
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
int mbedtls_ssl_send_fatal_handshake_failure( mbedtls_ssl_context *ssl )
|
|
{
|
|
return( mbedtls_ssl_send_alert_message( ssl,
|
|
MBEDTLS_SSL_ALERT_LEVEL_FATAL,
|
|
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE ) );
|
|
}
|
|
|
|
int mbedtls_ssl_send_alert_message( mbedtls_ssl_context *ssl,
|
|
unsigned char level,
|
|
unsigned char message )
|
|
{
|
|
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
|
|
|
|
if( ssl == NULL || ssl->conf == NULL )
|
|
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> send alert message" ) );
|
|
MBEDTLS_SSL_DEBUG_MSG( 3, ( "send alert level=%u message=%u", level, message ));
|
|
|
|
ssl->out_msgtype = MBEDTLS_SSL_MSG_ALERT;
|
|
ssl->out_msglen = 2;
|
|
ssl->out_msg[0] = level;
|
|
ssl->out_msg[1] = message;
|
|
|
|
if( ( ret = mbedtls_ssl_write_record( ssl, SSL_FORCE_FLUSH ) ) != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_record", ret );
|
|
return( ret );
|
|
}
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= send alert message" ) );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
int mbedtls_ssl_write_change_cipher_spec( mbedtls_ssl_context *ssl )
|
|
{
|
|
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write change cipher spec" ) );
|
|
|
|
ssl->out_msgtype = MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC;
|
|
ssl->out_msglen = 1;
|
|
ssl->out_msg[0] = 1;
|
|
|
|
ssl->state++;
|
|
|
|
if( ( ret = mbedtls_ssl_write_handshake_msg( ssl ) ) != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_handshake_msg", ret );
|
|
return( ret );
|
|
}
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write change cipher spec" ) );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
int mbedtls_ssl_parse_change_cipher_spec( mbedtls_ssl_context *ssl )
|
|
{
|
|
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse change cipher spec" ) );
|
|
|
|
if( ( ret = mbedtls_ssl_read_record( ssl, 1 ) ) != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret );
|
|
return( ret );
|
|
}
|
|
|
|
if( ssl->in_msgtype != MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad change cipher spec message" ) );
|
|
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
|
|
MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE );
|
|
return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
|
|
}
|
|
|
|
/* CCS records are only accepted if they have length 1 and content '1',
|
|
* so we don't need to check this here. */
|
|
|
|
/*
|
|
* Switch to our negotiated transform and session parameters for inbound
|
|
* data.
|
|
*/
|
|
MBEDTLS_SSL_DEBUG_MSG( 3, ( "switching to new transform spec for inbound data" ) );
|
|
ssl->transform_in = ssl->transform_negotiate;
|
|
ssl->session_in = ssl->session_negotiate;
|
|
|
|
#if defined(MBEDTLS_SSL_PROTO_DTLS)
|
|
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
|
|
{
|
|
#if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY)
|
|
mbedtls_ssl_dtls_replay_reset( ssl );
|
|
#endif
|
|
|
|
/* Increment epoch */
|
|
if( ++ssl->in_epoch == 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "DTLS epoch would wrap" ) );
|
|
/* This is highly unlikely to happen for legitimate reasons, so
|
|
treat it as an attack and don't send an alert. */
|
|
return( MBEDTLS_ERR_SSL_COUNTER_WRAPPING );
|
|
}
|
|
}
|
|
else
|
|
#endif /* MBEDTLS_SSL_PROTO_DTLS */
|
|
memset( ssl->in_ctr, 0, 8 );
|
|
|
|
mbedtls_ssl_update_in_pointers( ssl );
|
|
|
|
#if defined(MBEDTLS_SSL_HW_RECORD_ACCEL)
|
|
if( mbedtls_ssl_hw_record_activate != NULL )
|
|
{
|
|
if( ( ret = mbedtls_ssl_hw_record_activate( ssl, MBEDTLS_SSL_CHANNEL_INBOUND ) ) != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_hw_record_activate", ret );
|
|
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
|
|
MBEDTLS_SSL_ALERT_MSG_INTERNAL_ERROR );
|
|
return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
|
|
}
|
|
}
|
|
#endif
|
|
|
|
ssl->state++;
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse change cipher spec" ) );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
/* Once ssl->out_hdr as the address of the beginning of the
|
|
* next outgoing record is set, deduce the other pointers.
|
|
*
|
|
* Note: For TLS, we save the implicit record sequence number
|
|
* (entering MAC computation) in the 8 bytes before ssl->out_hdr,
|
|
* and the caller has to make sure there's space for this.
|
|
*/
|
|
|
|
static size_t ssl_transform_get_explicit_iv_len(
|
|
mbedtls_ssl_transform const *transform )
|
|
{
|
|
if( transform->minor_ver < MBEDTLS_SSL_MINOR_VERSION_2 )
|
|
return( 0 );
|
|
|
|
return( transform->ivlen - transform->fixed_ivlen );
|
|
}
|
|
|
|
void mbedtls_ssl_update_out_pointers( mbedtls_ssl_context *ssl,
|
|
mbedtls_ssl_transform *transform )
|
|
{
|
|
#if defined(MBEDTLS_SSL_PROTO_DTLS)
|
|
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
|
|
{
|
|
ssl->out_ctr = ssl->out_hdr + 3;
|
|
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
|
|
ssl->out_cid = ssl->out_ctr + 8;
|
|
ssl->out_len = ssl->out_cid;
|
|
if( transform != NULL )
|
|
ssl->out_len += transform->out_cid_len;
|
|
#else /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
|
|
ssl->out_len = ssl->out_ctr + 8;
|
|
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
|
|
ssl->out_iv = ssl->out_len + 2;
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
ssl->out_ctr = ssl->out_hdr - 8;
|
|
ssl->out_len = ssl->out_hdr + 3;
|
|
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
|
|
ssl->out_cid = ssl->out_len;
|
|
#endif
|
|
ssl->out_iv = ssl->out_hdr + 5;
|
|
}
|
|
|
|
ssl->out_msg = ssl->out_iv;
|
|
/* Adjust out_msg to make space for explicit IV, if used. */
|
|
if( transform != NULL )
|
|
ssl->out_msg += ssl_transform_get_explicit_iv_len( transform );
|
|
}
|
|
|
|
/* Once ssl->in_hdr as the address of the beginning of the
|
|
* next incoming record is set, deduce the other pointers.
|
|
*
|
|
* Note: For TLS, we save the implicit record sequence number
|
|
* (entering MAC computation) in the 8 bytes before ssl->in_hdr,
|
|
* and the caller has to make sure there's space for this.
|
|
*/
|
|
|
|
void mbedtls_ssl_update_in_pointers( mbedtls_ssl_context *ssl )
|
|
{
|
|
/* This function sets the pointers to match the case
|
|
* of unprotected TLS/DTLS records, with both ssl->in_iv
|
|
* and ssl->in_msg pointing to the beginning of the record
|
|
* content.
|
|
*
|
|
* When decrypting a protected record, ssl->in_msg
|
|
* will be shifted to point to the beginning of the
|
|
* record plaintext.
|
|
*/
|
|
|
|
#if defined(MBEDTLS_SSL_PROTO_DTLS)
|
|
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
|
|
{
|
|
/* This sets the header pointers to match records
|
|
* without CID. When we receive a record containing
|
|
* a CID, the fields are shifted accordingly in
|
|
* ssl_parse_record_header(). */
|
|
ssl->in_ctr = ssl->in_hdr + 3;
|
|
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
|
|
ssl->in_cid = ssl->in_ctr + 8;
|
|
ssl->in_len = ssl->in_cid; /* Default: no CID */
|
|
#else /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
|
|
ssl->in_len = ssl->in_ctr + 8;
|
|
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
|
|
ssl->in_iv = ssl->in_len + 2;
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
ssl->in_ctr = ssl->in_hdr - 8;
|
|
ssl->in_len = ssl->in_hdr + 3;
|
|
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
|
|
ssl->in_cid = ssl->in_len;
|
|
#endif
|
|
ssl->in_iv = ssl->in_hdr + 5;
|
|
}
|
|
|
|
/* This will be adjusted at record decryption time. */
|
|
ssl->in_msg = ssl->in_iv;
|
|
}
|
|
|
|
/*
|
|
* Setup an SSL context
|
|
*/
|
|
|
|
void mbedtls_ssl_reset_in_out_pointers( mbedtls_ssl_context *ssl )
|
|
{
|
|
/* Set the incoming and outgoing record pointers. */
|
|
#if defined(MBEDTLS_SSL_PROTO_DTLS)
|
|
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
|
|
{
|
|
ssl->out_hdr = ssl->out_buf;
|
|
ssl->in_hdr = ssl->in_buf;
|
|
}
|
|
else
|
|
#endif /* MBEDTLS_SSL_PROTO_DTLS */
|
|
{
|
|
ssl->out_hdr = ssl->out_buf + 8;
|
|
ssl->in_hdr = ssl->in_buf + 8;
|
|
}
|
|
|
|
/* Derive other internal pointers. */
|
|
mbedtls_ssl_update_out_pointers( ssl, NULL /* no transform enabled */ );
|
|
mbedtls_ssl_update_in_pointers ( ssl );
|
|
}
|
|
|
|
/*
|
|
* SSL get accessors
|
|
*/
|
|
size_t mbedtls_ssl_get_bytes_avail( const mbedtls_ssl_context *ssl )
|
|
{
|
|
return( ssl->in_offt == NULL ? 0 : ssl->in_msglen );
|
|
}
|
|
|
|
int mbedtls_ssl_check_pending( const mbedtls_ssl_context *ssl )
|
|
{
|
|
/*
|
|
* Case A: We're currently holding back
|
|
* a message for further processing.
|
|
*/
|
|
|
|
if( ssl->keep_current_message == 1 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 3, ( "ssl_check_pending: record held back for processing" ) );
|
|
return( 1 );
|
|
}
|
|
|
|
/*
|
|
* Case B: Further records are pending in the current datagram.
|
|
*/
|
|
|
|
#if defined(MBEDTLS_SSL_PROTO_DTLS)
|
|
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
|
|
ssl->in_left > ssl->next_record_offset )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 3, ( "ssl_check_pending: more records within current datagram" ) );
|
|
return( 1 );
|
|
}
|
|
#endif /* MBEDTLS_SSL_PROTO_DTLS */
|
|
|
|
/*
|
|
* Case C: A handshake message is being processed.
|
|
*/
|
|
|
|
if( ssl->in_hslen > 0 && ssl->in_hslen < ssl->in_msglen )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 3, ( "ssl_check_pending: more handshake messages within current record" ) );
|
|
return( 1 );
|
|
}
|
|
|
|
/*
|
|
* Case D: An application data message is being processed
|
|
*/
|
|
if( ssl->in_offt != NULL )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 3, ( "ssl_check_pending: application data record is being processed" ) );
|
|
return( 1 );
|
|
}
|
|
|
|
/*
|
|
* In all other cases, the rest of the message can be dropped.
|
|
* As in ssl_get_next_record, this needs to be adapted if
|
|
* we implement support for multiple alerts in single records.
|
|
*/
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 3, ( "ssl_check_pending: nothing pending" ) );
|
|
return( 0 );
|
|
}
|
|
|
|
|
|
int mbedtls_ssl_get_record_expansion( const mbedtls_ssl_context *ssl )
|
|
{
|
|
size_t transform_expansion = 0;
|
|
const mbedtls_ssl_transform *transform = ssl->transform_out;
|
|
unsigned block_size;
|
|
|
|
size_t out_hdr_len = mbedtls_ssl_out_hdr_len( ssl );
|
|
|
|
if( transform == NULL )
|
|
return( (int) out_hdr_len );
|
|
|
|
#if defined(MBEDTLS_ZLIB_SUPPORT)
|
|
if( ssl->session_out->compression != MBEDTLS_SSL_COMPRESS_NULL )
|
|
return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE );
|
|
#endif
|
|
|
|
switch( mbedtls_cipher_get_cipher_mode( &transform->cipher_ctx_enc ) )
|
|
{
|
|
case MBEDTLS_MODE_GCM:
|
|
case MBEDTLS_MODE_CCM:
|
|
case MBEDTLS_MODE_CHACHAPOLY:
|
|
case MBEDTLS_MODE_STREAM:
|
|
transform_expansion = transform->minlen;
|
|
break;
|
|
|
|
case MBEDTLS_MODE_CBC:
|
|
|
|
block_size = mbedtls_cipher_get_block_size(
|
|
&transform->cipher_ctx_enc );
|
|
|
|
/* Expansion due to the addition of the MAC. */
|
|
transform_expansion += transform->maclen;
|
|
|
|
/* Expansion due to the addition of CBC padding;
|
|
* Theoretically up to 256 bytes, but we never use
|
|
* more than the block size of the underlying cipher. */
|
|
transform_expansion += block_size;
|
|
|
|
/* For TLS 1.1 or higher, an explicit IV is added
|
|
* after the record header. */
|
|
#if defined(MBEDTLS_SSL_PROTO_TLS1_1) || defined(MBEDTLS_SSL_PROTO_TLS1_2)
|
|
if( ssl->minor_ver >= MBEDTLS_SSL_MINOR_VERSION_2 )
|
|
transform_expansion += block_size;
|
|
#endif /* MBEDTLS_SSL_PROTO_TLS1_1 || MBEDTLS_SSL_PROTO_TLS1_2 */
|
|
|
|
break;
|
|
|
|
default:
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
|
|
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
|
|
}
|
|
|
|
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
|
|
if( transform->out_cid_len != 0 )
|
|
transform_expansion += MBEDTLS_SSL_MAX_CID_EXPANSION;
|
|
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
|
|
|
|
return( (int)( out_hdr_len + transform_expansion ) );
|
|
}
|
|
|
|
#if defined(MBEDTLS_SSL_RENEGOTIATION)
|
|
/*
|
|
* Check record counters and renegotiate if they're above the limit.
|
|
*/
|
|
static int ssl_check_ctr_renegotiate( mbedtls_ssl_context *ssl )
|
|
{
|
|
size_t ep_len = mbedtls_ssl_ep_len( ssl );
|
|
int in_ctr_cmp;
|
|
int out_ctr_cmp;
|
|
|
|
if( ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER ||
|
|
ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_PENDING ||
|
|
ssl->conf->disable_renegotiation == MBEDTLS_SSL_RENEGOTIATION_DISABLED )
|
|
{
|
|
return( 0 );
|
|
}
|
|
|
|
in_ctr_cmp = memcmp( ssl->in_ctr + ep_len,
|
|
ssl->conf->renego_period + ep_len, 8 - ep_len );
|
|
out_ctr_cmp = memcmp( ssl->cur_out_ctr + ep_len,
|
|
ssl->conf->renego_period + ep_len, 8 - ep_len );
|
|
|
|
if( in_ctr_cmp <= 0 && out_ctr_cmp <= 0 )
|
|
{
|
|
return( 0 );
|
|
}
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "record counter limit reached: renegotiate" ) );
|
|
return( mbedtls_ssl_renegotiate( ssl ) );
|
|
}
|
|
#endif /* MBEDTLS_SSL_RENEGOTIATION */
|
|
|
|
/*
|
|
* Receive application data decrypted from the SSL layer
|
|
*/
|
|
int mbedtls_ssl_read( mbedtls_ssl_context *ssl, unsigned char *buf, size_t len )
|
|
{
|
|
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
|
|
size_t n;
|
|
|
|
if( ssl == NULL || ssl->conf == NULL )
|
|
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> read" ) );
|
|
|
|
#if defined(MBEDTLS_SSL_PROTO_DTLS)
|
|
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
|
|
{
|
|
if( ( ret = mbedtls_ssl_flush_output( ssl ) ) != 0 )
|
|
return( ret );
|
|
|
|
if( ssl->handshake != NULL &&
|
|
ssl->handshake->retransmit_state == MBEDTLS_SSL_RETRANS_SENDING )
|
|
{
|
|
if( ( ret = mbedtls_ssl_flight_transmit( ssl ) ) != 0 )
|
|
return( ret );
|
|
}
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* Check if renegotiation is necessary and/or handshake is
|
|
* in process. If yes, perform/continue, and fall through
|
|
* if an unexpected packet is received while the client
|
|
* is waiting for the ServerHello.
|
|
*
|
|
* (There is no equivalent to the last condition on
|
|
* the server-side as it is not treated as within
|
|
* a handshake while waiting for the ClientHello
|
|
* after a renegotiation request.)
|
|
*/
|
|
|
|
#if defined(MBEDTLS_SSL_RENEGOTIATION)
|
|
ret = ssl_check_ctr_renegotiate( ssl );
|
|
if( ret != MBEDTLS_ERR_SSL_WAITING_SERVER_HELLO_RENEGO &&
|
|
ret != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_check_ctr_renegotiate", ret );
|
|
return( ret );
|
|
}
|
|
#endif
|
|
|
|
if( ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER )
|
|
{
|
|
ret = mbedtls_ssl_handshake( ssl );
|
|
if( ret != MBEDTLS_ERR_SSL_WAITING_SERVER_HELLO_RENEGO &&
|
|
ret != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_handshake", ret );
|
|
return( ret );
|
|
}
|
|
}
|
|
|
|
/* Loop as long as no application data record is available */
|
|
while( ssl->in_offt == NULL )
|
|
{
|
|
/* Start timer if not already running */
|
|
if( ssl->f_get_timer != NULL &&
|
|
ssl->f_get_timer( ssl->p_timer ) == -1 )
|
|
{
|
|
mbedtls_ssl_set_timer( ssl, ssl->conf->read_timeout );
|
|
}
|
|
|
|
if( ( ret = mbedtls_ssl_read_record( ssl, 1 ) ) != 0 )
|
|
{
|
|
if( ret == MBEDTLS_ERR_SSL_CONN_EOF )
|
|
return( 0 );
|
|
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret );
|
|
return( ret );
|
|
}
|
|
|
|
if( ssl->in_msglen == 0 &&
|
|
ssl->in_msgtype == MBEDTLS_SSL_MSG_APPLICATION_DATA )
|
|
{
|
|
/*
|
|
* OpenSSL sends empty messages to randomize the IV
|
|
*/
|
|
if( ( ret = mbedtls_ssl_read_record( ssl, 1 ) ) != 0 )
|
|
{
|
|
if( ret == MBEDTLS_ERR_SSL_CONN_EOF )
|
|
return( 0 );
|
|
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret );
|
|
return( ret );
|
|
}
|
|
}
|
|
|
|
if( ssl->in_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "received handshake message" ) );
|
|
|
|
/*
|
|
* - For client-side, expect SERVER_HELLO_REQUEST.
|
|
* - For server-side, expect CLIENT_HELLO.
|
|
* - Fail (TLS) or silently drop record (DTLS) in other cases.
|
|
*/
|
|
|
|
#if defined(MBEDTLS_SSL_CLI_C)
|
|
if( ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT &&
|
|
( ssl->in_msg[0] != MBEDTLS_SSL_HS_HELLO_REQUEST ||
|
|
ssl->in_hslen != mbedtls_ssl_hs_hdr_len( ssl ) ) )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "handshake received (not HelloRequest)" ) );
|
|
|
|
/* With DTLS, drop the packet (probably from last handshake) */
|
|
#if defined(MBEDTLS_SSL_PROTO_DTLS)
|
|
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
|
|
{
|
|
continue;
|
|
}
|
|
#endif
|
|
return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
|
|
}
|
|
#endif /* MBEDTLS_SSL_CLI_C */
|
|
|
|
#if defined(MBEDTLS_SSL_SRV_C)
|
|
if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER &&
|
|
ssl->in_msg[0] != MBEDTLS_SSL_HS_CLIENT_HELLO )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "handshake received (not ClientHello)" ) );
|
|
|
|
/* With DTLS, drop the packet (probably from last handshake) */
|
|
#if defined(MBEDTLS_SSL_PROTO_DTLS)
|
|
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
|
|
{
|
|
continue;
|
|
}
|
|
#endif
|
|
return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
|
|
}
|
|
#endif /* MBEDTLS_SSL_SRV_C */
|
|
|
|
#if defined(MBEDTLS_SSL_RENEGOTIATION)
|
|
/* Determine whether renegotiation attempt should be accepted */
|
|
if( ! ( ssl->conf->disable_renegotiation == MBEDTLS_SSL_RENEGOTIATION_DISABLED ||
|
|
( ssl->secure_renegotiation == MBEDTLS_SSL_LEGACY_RENEGOTIATION &&
|
|
ssl->conf->allow_legacy_renegotiation ==
|
|
MBEDTLS_SSL_LEGACY_NO_RENEGOTIATION ) ) )
|
|
{
|
|
/*
|
|
* Accept renegotiation request
|
|
*/
|
|
|
|
/* DTLS clients need to know renego is server-initiated */
|
|
#if defined(MBEDTLS_SSL_PROTO_DTLS)
|
|
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
|
|
ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT )
|
|
{
|
|
ssl->renego_status = MBEDTLS_SSL_RENEGOTIATION_PENDING;
|
|
}
|
|
#endif
|
|
ret = mbedtls_ssl_start_renegotiation( ssl );
|
|
if( ret != MBEDTLS_ERR_SSL_WAITING_SERVER_HELLO_RENEGO &&
|
|
ret != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_start_renegotiation",
|
|
ret );
|
|
return( ret );
|
|
}
|
|
}
|
|
else
|
|
#endif /* MBEDTLS_SSL_RENEGOTIATION */
|
|
{
|
|
/*
|
|
* Refuse renegotiation
|
|
*/
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 3, ( "refusing renegotiation, sending alert" ) );
|
|
|
|
#if defined(MBEDTLS_SSL_PROTO_SSL3)
|
|
if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 )
|
|
{
|
|
/* SSLv3 does not have a "no_renegotiation" warning, so
|
|
we send a fatal alert and abort the connection. */
|
|
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
|
|
MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE );
|
|
return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
|
|
}
|
|
else
|
|
#endif /* MBEDTLS_SSL_PROTO_SSL3 */
|
|
#if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) || \
|
|
defined(MBEDTLS_SSL_PROTO_TLS1_2)
|
|
if( ssl->minor_ver >= MBEDTLS_SSL_MINOR_VERSION_1 )
|
|
{
|
|
if( ( ret = mbedtls_ssl_send_alert_message( ssl,
|
|
MBEDTLS_SSL_ALERT_LEVEL_WARNING,
|
|
MBEDTLS_SSL_ALERT_MSG_NO_RENEGOTIATION ) ) != 0 )
|
|
{
|
|
return( ret );
|
|
}
|
|
}
|
|
else
|
|
#endif /* MBEDTLS_SSL_PROTO_TLS1 || MBEDTLS_SSL_PROTO_TLS1_1 ||
|
|
MBEDTLS_SSL_PROTO_TLS1_2 */
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
|
|
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
|
|
}
|
|
}
|
|
|
|
/* At this point, we don't know whether the renegotiation has been
|
|
* completed or not. The cases to consider are the following:
|
|
* 1) The renegotiation is complete. In this case, no new record
|
|
* has been read yet.
|
|
* 2) The renegotiation is incomplete because the client received
|
|
* an application data record while awaiting the ServerHello.
|
|
* 3) The renegotiation is incomplete because the client received
|
|
* a non-handshake, non-application data message while awaiting
|
|
* the ServerHello.
|
|
* In each of these case, looping will be the proper action:
|
|
* - For 1), the next iteration will read a new record and check
|
|
* if it's application data.
|
|
* - For 2), the loop condition isn't satisfied as application data
|
|
* is present, hence continue is the same as break
|
|
* - For 3), the loop condition is satisfied and read_record
|
|
* will re-deliver the message that was held back by the client
|
|
* when expecting the ServerHello.
|
|
*/
|
|
continue;
|
|
}
|
|
#if defined(MBEDTLS_SSL_RENEGOTIATION)
|
|
else if( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_PENDING )
|
|
{
|
|
if( ssl->conf->renego_max_records >= 0 )
|
|
{
|
|
if( ++ssl->renego_records_seen > ssl->conf->renego_max_records )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "renegotiation requested, "
|
|
"but not honored by client" ) );
|
|
return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
|
|
}
|
|
}
|
|
}
|
|
#endif /* MBEDTLS_SSL_RENEGOTIATION */
|
|
|
|
/* Fatal and closure alerts handled by mbedtls_ssl_read_record() */
|
|
if( ssl->in_msgtype == MBEDTLS_SSL_MSG_ALERT )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "ignoring non-fatal non-closure alert" ) );
|
|
return( MBEDTLS_ERR_SSL_WANT_READ );
|
|
}
|
|
|
|
if( ssl->in_msgtype != MBEDTLS_SSL_MSG_APPLICATION_DATA )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad application data message" ) );
|
|
return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
|
|
}
|
|
|
|
ssl->in_offt = ssl->in_msg;
|
|
|
|
/* We're going to return something now, cancel timer,
|
|
* except if handshake (renegotiation) is in progress */
|
|
if( ssl->state == MBEDTLS_SSL_HANDSHAKE_OVER )
|
|
mbedtls_ssl_set_timer( ssl, 0 );
|
|
|
|
#if defined(MBEDTLS_SSL_PROTO_DTLS)
|
|
/* If we requested renego but received AppData, resend HelloRequest.
|
|
* Do it now, after setting in_offt, to avoid taking this branch
|
|
* again if ssl_write_hello_request() returns WANT_WRITE */
|
|
#if defined(MBEDTLS_SSL_SRV_C) && defined(MBEDTLS_SSL_RENEGOTIATION)
|
|
if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER &&
|
|
ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_PENDING )
|
|
{
|
|
if( ( ret = mbedtls_ssl_resend_hello_request( ssl ) ) != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_resend_hello_request",
|
|
ret );
|
|
return( ret );
|
|
}
|
|
}
|
|
#endif /* MBEDTLS_SSL_SRV_C && MBEDTLS_SSL_RENEGOTIATION */
|
|
#endif /* MBEDTLS_SSL_PROTO_DTLS */
|
|
}
|
|
|
|
n = ( len < ssl->in_msglen )
|
|
? len : ssl->in_msglen;
|
|
|
|
memcpy( buf, ssl->in_offt, n );
|
|
ssl->in_msglen -= n;
|
|
|
|
/* Zeroising the plaintext buffer to erase unused application data
|
|
from the memory. */
|
|
mbedtls_platform_zeroize( ssl->in_offt, n );
|
|
|
|
if( ssl->in_msglen == 0 )
|
|
{
|
|
/* all bytes consumed */
|
|
ssl->in_offt = NULL;
|
|
ssl->keep_current_message = 0;
|
|
}
|
|
else
|
|
{
|
|
/* more data available */
|
|
ssl->in_offt += n;
|
|
}
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= read" ) );
|
|
|
|
return( (int) n );
|
|
}
|
|
|
|
/*
|
|
* Send application data to be encrypted by the SSL layer, taking care of max
|
|
* fragment length and buffer size.
|
|
*
|
|
* According to RFC 5246 Section 6.2.1:
|
|
*
|
|
* Zero-length fragments of Application data MAY be sent as they are
|
|
* potentially useful as a traffic analysis countermeasure.
|
|
*
|
|
* Therefore, it is possible that the input message length is 0 and the
|
|
* corresponding return code is 0 on success.
|
|
*/
|
|
static int ssl_write_real( mbedtls_ssl_context *ssl,
|
|
const unsigned char *buf, size_t len )
|
|
{
|
|
int ret = mbedtls_ssl_get_max_out_record_payload( ssl );
|
|
const size_t max_len = (size_t) ret;
|
|
|
|
if( ret < 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_get_max_out_record_payload", ret );
|
|
return( ret );
|
|
}
|
|
|
|
if( len > max_len )
|
|
{
|
|
#if defined(MBEDTLS_SSL_PROTO_DTLS)
|
|
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "fragment larger than the (negotiated) "
|
|
"maximum fragment length: %d > %d",
|
|
len, max_len ) );
|
|
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
|
|
}
|
|
else
|
|
#endif
|
|
len = max_len;
|
|
}
|
|
|
|
if( ssl->out_left != 0 )
|
|
{
|
|
/*
|
|
* The user has previously tried to send the data and
|
|
* MBEDTLS_ERR_SSL_WANT_WRITE or the message was only partially
|
|
* written. In this case, we expect the high-level write function
|
|
* (e.g. mbedtls_ssl_write()) to be called with the same parameters
|
|
*/
|
|
if( ( ret = mbedtls_ssl_flush_output( ssl ) ) != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_flush_output", ret );
|
|
return( ret );
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* The user is trying to send a message the first time, so we need to
|
|
* copy the data into the internal buffers and setup the data structure
|
|
* to keep track of partial writes
|
|
*/
|
|
ssl->out_msglen = len;
|
|
ssl->out_msgtype = MBEDTLS_SSL_MSG_APPLICATION_DATA;
|
|
memcpy( ssl->out_msg, buf, len );
|
|
|
|
if( ( ret = mbedtls_ssl_write_record( ssl, SSL_FORCE_FLUSH ) ) != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_record", ret );
|
|
return( ret );
|
|
}
|
|
}
|
|
|
|
return( (int) len );
|
|
}
|
|
|
|
/*
|
|
* Write application data, doing 1/n-1 splitting if necessary.
|
|
*
|
|
* With non-blocking I/O, ssl_write_real() may return WANT_WRITE,
|
|
* then the caller will call us again with the same arguments, so
|
|
* remember whether we already did the split or not.
|
|
*/
|
|
#if defined(MBEDTLS_SSL_CBC_RECORD_SPLITTING)
|
|
static int ssl_write_split( mbedtls_ssl_context *ssl,
|
|
const unsigned char *buf, size_t len )
|
|
{
|
|
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
|
|
|
|
if( ssl->conf->cbc_record_splitting ==
|
|
MBEDTLS_SSL_CBC_RECORD_SPLITTING_DISABLED ||
|
|
len <= 1 ||
|
|
ssl->minor_ver > MBEDTLS_SSL_MINOR_VERSION_1 ||
|
|
mbedtls_cipher_get_cipher_mode( &ssl->transform_out->cipher_ctx_enc )
|
|
!= MBEDTLS_MODE_CBC )
|
|
{
|
|
return( ssl_write_real( ssl, buf, len ) );
|
|
}
|
|
|
|
if( ssl->split_done == 0 )
|
|
{
|
|
if( ( ret = ssl_write_real( ssl, buf, 1 ) ) <= 0 )
|
|
return( ret );
|
|
ssl->split_done = 1;
|
|
}
|
|
|
|
if( ( ret = ssl_write_real( ssl, buf + 1, len - 1 ) ) <= 0 )
|
|
return( ret );
|
|
ssl->split_done = 0;
|
|
|
|
return( ret + 1 );
|
|
}
|
|
#endif /* MBEDTLS_SSL_CBC_RECORD_SPLITTING */
|
|
|
|
/*
|
|
* Write application data (public-facing wrapper)
|
|
*/
|
|
int mbedtls_ssl_write( mbedtls_ssl_context *ssl, const unsigned char *buf, size_t len )
|
|
{
|
|
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write" ) );
|
|
|
|
if( ssl == NULL || ssl->conf == NULL )
|
|
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
|
|
|
|
#if defined(MBEDTLS_SSL_RENEGOTIATION)
|
|
if( ( ret = ssl_check_ctr_renegotiate( ssl ) ) != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_check_ctr_renegotiate", ret );
|
|
return( ret );
|
|
}
|
|
#endif
|
|
|
|
if( ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER )
|
|
{
|
|
if( ( ret = mbedtls_ssl_handshake( ssl ) ) != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_handshake", ret );
|
|
return( ret );
|
|
}
|
|
}
|
|
|
|
#if defined(MBEDTLS_SSL_CBC_RECORD_SPLITTING)
|
|
ret = ssl_write_split( ssl, buf, len );
|
|
#else
|
|
ret = ssl_write_real( ssl, buf, len );
|
|
#endif
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write" ) );
|
|
|
|
return( ret );
|
|
}
|
|
|
|
/*
|
|
* Notify the peer that the connection is being closed
|
|
*/
|
|
int mbedtls_ssl_close_notify( mbedtls_ssl_context *ssl )
|
|
{
|
|
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
|
|
|
|
if( ssl == NULL || ssl->conf == NULL )
|
|
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write close notify" ) );
|
|
|
|
if( ssl->out_left != 0 )
|
|
return( mbedtls_ssl_flush_output( ssl ) );
|
|
|
|
if( ssl->state == MBEDTLS_SSL_HANDSHAKE_OVER )
|
|
{
|
|
if( ( ret = mbedtls_ssl_send_alert_message( ssl,
|
|
MBEDTLS_SSL_ALERT_LEVEL_WARNING,
|
|
MBEDTLS_SSL_ALERT_MSG_CLOSE_NOTIFY ) ) != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_send_alert_message", ret );
|
|
return( ret );
|
|
}
|
|
}
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write close notify" ) );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
void mbedtls_ssl_transform_free( mbedtls_ssl_transform *transform )
|
|
{
|
|
if( transform == NULL )
|
|
return;
|
|
|
|
#if defined(MBEDTLS_ZLIB_SUPPORT)
|
|
deflateEnd( &transform->ctx_deflate );
|
|
inflateEnd( &transform->ctx_inflate );
|
|
#endif
|
|
|
|
mbedtls_cipher_free( &transform->cipher_ctx_enc );
|
|
mbedtls_cipher_free( &transform->cipher_ctx_dec );
|
|
|
|
#if defined(MBEDTLS_SSL_SOME_MODES_USE_MAC)
|
|
mbedtls_md_free( &transform->md_ctx_enc );
|
|
mbedtls_md_free( &transform->md_ctx_dec );
|
|
#endif
|
|
|
|
mbedtls_platform_zeroize( transform, sizeof( mbedtls_ssl_transform ) );
|
|
}
|
|
|
|
#if defined(MBEDTLS_SSL_PROTO_DTLS)
|
|
|
|
void mbedtls_ssl_buffering_free( mbedtls_ssl_context *ssl )
|
|
{
|
|
unsigned offset;
|
|
mbedtls_ssl_handshake_params * const hs = ssl->handshake;
|
|
|
|
if( hs == NULL )
|
|
return;
|
|
|
|
ssl_free_buffered_record( ssl );
|
|
|
|
for( offset = 0; offset < MBEDTLS_SSL_MAX_BUFFERED_HS; offset++ )
|
|
ssl_buffering_free_slot( ssl, offset );
|
|
}
|
|
|
|
static void ssl_buffering_free_slot( mbedtls_ssl_context *ssl,
|
|
uint8_t slot )
|
|
{
|
|
mbedtls_ssl_handshake_params * const hs = ssl->handshake;
|
|
mbedtls_ssl_hs_buffer * const hs_buf = &hs->buffering.hs[slot];
|
|
|
|
if( slot >= MBEDTLS_SSL_MAX_BUFFERED_HS )
|
|
return;
|
|
|
|
if( hs_buf->is_valid == 1 )
|
|
{
|
|
hs->buffering.total_bytes_buffered -= hs_buf->data_len;
|
|
mbedtls_platform_zeroize( hs_buf->data, hs_buf->data_len );
|
|
mbedtls_free( hs_buf->data );
|
|
memset( hs_buf, 0, sizeof( mbedtls_ssl_hs_buffer ) );
|
|
}
|
|
}
|
|
|
|
#endif /* MBEDTLS_SSL_PROTO_DTLS */
|
|
|
|
/*
|
|
* Convert version numbers to/from wire format
|
|
* and, for DTLS, to/from TLS equivalent.
|
|
*
|
|
* For TLS this is the identity.
|
|
* For DTLS, use 1's complement (v -> 255 - v, and then map as follows:
|
|
* 1.0 <-> 3.2 (DTLS 1.0 is based on TLS 1.1)
|
|
* 1.x <-> 3.x+1 for x != 0 (DTLS 1.2 based on TLS 1.2)
|
|
*/
|
|
void mbedtls_ssl_write_version( int major, int minor, int transport,
|
|
unsigned char ver[2] )
|
|
{
|
|
#if defined(MBEDTLS_SSL_PROTO_DTLS)
|
|
if( transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
|
|
{
|
|
if( minor == MBEDTLS_SSL_MINOR_VERSION_2 )
|
|
--minor; /* DTLS 1.0 stored as TLS 1.1 internally */
|
|
|
|
ver[0] = (unsigned char)( 255 - ( major - 2 ) );
|
|
ver[1] = (unsigned char)( 255 - ( minor - 1 ) );
|
|
}
|
|
else
|
|
#else
|
|
((void) transport);
|
|
#endif
|
|
{
|
|
ver[0] = (unsigned char) major;
|
|
ver[1] = (unsigned char) minor;
|
|
}
|
|
}
|
|
|
|
void mbedtls_ssl_read_version( int *major, int *minor, int transport,
|
|
const unsigned char ver[2] )
|
|
{
|
|
#if defined(MBEDTLS_SSL_PROTO_DTLS)
|
|
if( transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
|
|
{
|
|
*major = 255 - ver[0] + 2;
|
|
*minor = 255 - ver[1] + 1;
|
|
|
|
if( *minor == MBEDTLS_SSL_MINOR_VERSION_1 )
|
|
++*minor; /* DTLS 1.0 stored as TLS 1.1 internally */
|
|
}
|
|
else
|
|
#else
|
|
((void) transport);
|
|
#endif
|
|
{
|
|
*major = ver[0];
|
|
*minor = ver[1];
|
|
}
|
|
}
|
|
|
|
#endif /* MBEDTLS_SSL_TLS_C */
|