/* * SSLv3/TLSv1 shared functions * * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved * SPDX-License-Identifier: Apache-2.0 * * Licensed under the Apache License, Version 2.0 (the "License"); you may * not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * * This file is part of mbed TLS (https://tls.mbed.org) */ /* * The SSL 3.0 specification was drafted by Netscape in 1996, * and became an IETF standard in 1999. * * http://wp.netscape.com/eng/ssl3/ * http://www.ietf.org/rfc/rfc2246.txt * http://www.ietf.org/rfc/rfc4346.txt */ #if !defined(MBEDTLS_CONFIG_FILE) #include "mbedtls/config.h" #else #include MBEDTLS_CONFIG_FILE #endif #if defined(MBEDTLS_SSL_TLS_C) #if defined(MBEDTLS_PLATFORM_C) #include "mbedtls/platform.h" #else #include #define mbedtls_calloc calloc #define mbedtls_free free #endif #include "mbedtls/debug.h" #include "mbedtls/ssl.h" #include "mbedtls/ssl_internal.h" #include "mbedtls/platform_util.h" #include #if defined(MBEDTLS_X509_CRT_PARSE_C) #include "mbedtls/oid.h" #endif static void ssl_reset_in_out_pointers( mbedtls_ssl_context *ssl ); static uint32_t ssl_get_hs_total_len( mbedtls_ssl_context const *ssl ); /* Length of the "epoch" field in the record header */ static inline size_t ssl_ep_len( const mbedtls_ssl_context *ssl ) { #if defined(MBEDTLS_SSL_PROTO_DTLS) if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) return( 2 ); #else ((void) ssl); #endif return( 0 ); } /* * Start a timer. * Passing millisecs = 0 cancels a running timer. */ static void ssl_set_timer( mbedtls_ssl_context *ssl, uint32_t millisecs ) { if( ssl->f_set_timer == NULL ) return; MBEDTLS_SSL_DEBUG_MSG( 3, ( "set_timer to %d ms", (int) millisecs ) ); ssl->f_set_timer( ssl->p_timer, millisecs / 4, millisecs ); } /* * Return -1 is timer is expired, 0 if it isn't. */ static int ssl_check_timer( mbedtls_ssl_context *ssl ) { if( ssl->f_get_timer == NULL ) return( 0 ); if( ssl->f_get_timer( ssl->p_timer ) == 2 ) { MBEDTLS_SSL_DEBUG_MSG( 3, ( "timer expired" ) ); return( -1 ); } return( 0 ); } static void ssl_update_out_pointers( mbedtls_ssl_context *ssl, mbedtls_ssl_transform *transform ); static void ssl_update_in_pointers( mbedtls_ssl_context *ssl, mbedtls_ssl_transform *transform ); #define SSL_DONT_FORCE_FLUSH 0 #define SSL_FORCE_FLUSH 1 #if defined(MBEDTLS_SSL_PROTO_DTLS) /* Forward declarations for functions related to message buffering. */ static void ssl_buffering_free( mbedtls_ssl_context *ssl ); static void ssl_buffering_free_slot( mbedtls_ssl_context *ssl, uint8_t slot ); static void ssl_free_buffered_record( mbedtls_ssl_context *ssl ); static int ssl_load_buffered_message( mbedtls_ssl_context *ssl ); static int ssl_load_buffered_record( mbedtls_ssl_context *ssl ); static int ssl_buffer_message( mbedtls_ssl_context *ssl ); static int ssl_buffer_future_record( mbedtls_ssl_context *ssl ); static int ssl_next_record_is_in_datagram( mbedtls_ssl_context *ssl ); static size_t ssl_get_current_mtu( const mbedtls_ssl_context *ssl ); static size_t ssl_get_maximum_datagram_size( mbedtls_ssl_context const *ssl ) { size_t mtu = ssl_get_current_mtu( ssl ); if( mtu != 0 && mtu < MBEDTLS_SSL_OUT_BUFFER_LEN ) return( mtu ); return( MBEDTLS_SSL_OUT_BUFFER_LEN ); } static int ssl_get_remaining_space_in_datagram( mbedtls_ssl_context const *ssl ) { size_t const bytes_written = ssl->out_left; size_t const mtu = ssl_get_maximum_datagram_size( ssl ); /* Double-check that the write-index hasn't gone * past what we can transmit in a single datagram. */ if( bytes_written > mtu ) { /* Should never happen... */ return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); } return( (int) ( mtu - bytes_written ) ); } static int ssl_get_remaining_payload_in_datagram( mbedtls_ssl_context const *ssl ) { int ret; size_t remaining, expansion; size_t max_len = MBEDTLS_SSL_OUT_CONTENT_LEN; #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH) const size_t mfl = mbedtls_ssl_get_max_frag_len( ssl ); if( max_len > mfl ) max_len = mfl; /* By the standard (RFC 6066 Sect. 4), the MFL extension * only limits the maximum record payload size, so in theory * we would be allowed to pack multiple records of payload size * MFL into a single datagram. However, this would mean that there's * no way to explicitly communicate MTU restrictions to the peer. * * The following reduction of max_len makes sure that we never * write datagrams larger than MFL + Record Expansion Overhead. */ if( max_len <= ssl->out_left ) return( 0 ); max_len -= ssl->out_left; #endif ret = ssl_get_remaining_space_in_datagram( ssl ); if( ret < 0 ) return( ret ); remaining = (size_t) ret; ret = mbedtls_ssl_get_record_expansion( ssl ); if( ret < 0 ) return( ret ); expansion = (size_t) ret; if( remaining <= expansion ) return( 0 ); remaining -= expansion; if( remaining >= max_len ) remaining = max_len; return( (int) remaining ); } /* * Double the retransmit timeout value, within the allowed range, * returning -1 if the maximum value has already been reached. */ static int ssl_double_retransmit_timeout( mbedtls_ssl_context *ssl ) { uint32_t new_timeout; if( ssl->handshake->retransmit_timeout >= ssl->conf->hs_timeout_max ) return( -1 ); /* Implement the final paragraph of RFC 6347 section 4.1.1.1 * in the following way: after the initial transmission and a first * retransmission, back off to a temporary estimated MTU of 508 bytes. * This value is guaranteed to be deliverable (if not guaranteed to be * delivered) of any compliant IPv4 (and IPv6) network, and should work * on most non-IP stacks too. */ if( ssl->handshake->retransmit_timeout != ssl->conf->hs_timeout_min ) { ssl->handshake->mtu = 508; MBEDTLS_SSL_DEBUG_MSG( 2, ( "mtu autoreduction to %d bytes", ssl->handshake->mtu ) ); } new_timeout = 2 * ssl->handshake->retransmit_timeout; /* Avoid arithmetic overflow and range overflow */ if( new_timeout < ssl->handshake->retransmit_timeout || new_timeout > ssl->conf->hs_timeout_max ) { new_timeout = ssl->conf->hs_timeout_max; } ssl->handshake->retransmit_timeout = new_timeout; MBEDTLS_SSL_DEBUG_MSG( 3, ( "update timeout value to %d millisecs", ssl->handshake->retransmit_timeout ) ); return( 0 ); } static void ssl_reset_retransmit_timeout( mbedtls_ssl_context *ssl ) { ssl->handshake->retransmit_timeout = ssl->conf->hs_timeout_min; MBEDTLS_SSL_DEBUG_MSG( 3, ( "update timeout value to %d millisecs", ssl->handshake->retransmit_timeout ) ); } #endif /* MBEDTLS_SSL_PROTO_DTLS */ #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH) /* * Convert max_fragment_length codes to length. * RFC 6066 says: * enum{ * 2^9(1), 2^10(2), 2^11(3), 2^12(4), (255) * } MaxFragmentLength; * and we add 0 -> extension unused */ static unsigned int ssl_mfl_code_to_length( int mfl ) { switch( mfl ) { case MBEDTLS_SSL_MAX_FRAG_LEN_NONE: return ( MBEDTLS_TLS_EXT_ADV_CONTENT_LEN ); case MBEDTLS_SSL_MAX_FRAG_LEN_512: return 512; case MBEDTLS_SSL_MAX_FRAG_LEN_1024: return 1024; case MBEDTLS_SSL_MAX_FRAG_LEN_2048: return 2048; case MBEDTLS_SSL_MAX_FRAG_LEN_4096: return 4096; default: return ( MBEDTLS_TLS_EXT_ADV_CONTENT_LEN ); } } #endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */ #if defined(MBEDTLS_SSL_CLI_C) static int ssl_session_copy( mbedtls_ssl_session *dst, const mbedtls_ssl_session *src ) { mbedtls_ssl_session_free( dst ); memcpy( dst, src, sizeof( mbedtls_ssl_session ) ); #if defined(MBEDTLS_X509_CRT_PARSE_C) if( src->peer_cert != NULL ) { int ret; dst->peer_cert = mbedtls_calloc( 1, sizeof(mbedtls_x509_crt) ); if( dst->peer_cert == NULL ) return( MBEDTLS_ERR_SSL_ALLOC_FAILED ); mbedtls_x509_crt_init( dst->peer_cert ); if( ( ret = mbedtls_x509_crt_parse_der( dst->peer_cert, src->peer_cert->raw.p, src->peer_cert->raw.len ) ) != 0 ) { mbedtls_free( dst->peer_cert ); dst->peer_cert = NULL; return( ret ); } } #endif /* MBEDTLS_X509_CRT_PARSE_C */ #if defined(MBEDTLS_SSL_SESSION_TICKETS) && defined(MBEDTLS_SSL_CLI_C) if( src->ticket != NULL ) { dst->ticket = mbedtls_calloc( 1, src->ticket_len ); if( dst->ticket == NULL ) return( MBEDTLS_ERR_SSL_ALLOC_FAILED ); memcpy( dst->ticket, src->ticket, src->ticket_len ); } #endif /* MBEDTLS_SSL_SESSION_TICKETS && MBEDTLS_SSL_CLI_C */ return( 0 ); } #endif /* MBEDTLS_SSL_CLI_C */ #if defined(MBEDTLS_SSL_HW_RECORD_ACCEL) int (*mbedtls_ssl_hw_record_init)( mbedtls_ssl_context *ssl, const unsigned char *key_enc, const unsigned char *key_dec, size_t keylen, const unsigned char *iv_enc, const unsigned char *iv_dec, size_t ivlen, const unsigned char *mac_enc, const unsigned char *mac_dec, size_t maclen ) = NULL; int (*mbedtls_ssl_hw_record_activate)( mbedtls_ssl_context *ssl, int direction) = NULL; int (*mbedtls_ssl_hw_record_reset)( mbedtls_ssl_context *ssl ) = NULL; int (*mbedtls_ssl_hw_record_write)( mbedtls_ssl_context *ssl ) = NULL; int (*mbedtls_ssl_hw_record_read)( mbedtls_ssl_context *ssl ) = NULL; int (*mbedtls_ssl_hw_record_finish)( mbedtls_ssl_context *ssl ) = NULL; #endif /* MBEDTLS_SSL_HW_RECORD_ACCEL */ /* * Key material generation */ #if defined(MBEDTLS_SSL_PROTO_SSL3) static int ssl3_prf( const unsigned char *secret, size_t slen, const char *label, const unsigned char *random, size_t rlen, unsigned char *dstbuf, size_t dlen ) { int ret = 0; size_t i; mbedtls_md5_context md5; mbedtls_sha1_context sha1; unsigned char padding[16]; unsigned char sha1sum[20]; ((void)label); mbedtls_md5_init( &md5 ); mbedtls_sha1_init( &sha1 ); /* * SSLv3: * block = * MD5( secret + SHA1( 'A' + secret + random ) ) + * MD5( secret + SHA1( 'BB' + secret + random ) ) + * MD5( secret + SHA1( 'CCC' + secret + random ) ) + * ... */ for( i = 0; i < dlen / 16; i++ ) { memset( padding, (unsigned char) ('A' + i), 1 + i ); if( ( ret = mbedtls_sha1_starts_ret( &sha1 ) ) != 0 ) goto exit; if( ( ret = mbedtls_sha1_update_ret( &sha1, padding, 1 + i ) ) != 0 ) goto exit; if( ( ret = mbedtls_sha1_update_ret( &sha1, secret, slen ) ) != 0 ) goto exit; if( ( ret = mbedtls_sha1_update_ret( &sha1, random, rlen ) ) != 0 ) goto exit; if( ( ret = mbedtls_sha1_finish_ret( &sha1, sha1sum ) ) != 0 ) goto exit; if( ( ret = mbedtls_md5_starts_ret( &md5 ) ) != 0 ) goto exit; if( ( ret = mbedtls_md5_update_ret( &md5, secret, slen ) ) != 0 ) goto exit; if( ( ret = mbedtls_md5_update_ret( &md5, sha1sum, 20 ) ) != 0 ) goto exit; if( ( ret = mbedtls_md5_finish_ret( &md5, dstbuf + i * 16 ) ) != 0 ) goto exit; } exit: mbedtls_md5_free( &md5 ); mbedtls_sha1_free( &sha1 ); mbedtls_platform_zeroize( padding, sizeof( padding ) ); mbedtls_platform_zeroize( sha1sum, sizeof( sha1sum ) ); return( ret ); } #endif /* MBEDTLS_SSL_PROTO_SSL3 */ #if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) static int tls1_prf( const unsigned char *secret, size_t slen, const char *label, const unsigned char *random, size_t rlen, unsigned char *dstbuf, size_t dlen ) { size_t nb, hs; size_t i, j, k; const unsigned char *S1, *S2; unsigned char tmp[128]; unsigned char h_i[20]; const mbedtls_md_info_t *md_info; mbedtls_md_context_t md_ctx; int ret; mbedtls_md_init( &md_ctx ); if( sizeof( tmp ) < 20 + strlen( label ) + rlen ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); hs = ( slen + 1 ) / 2; S1 = secret; S2 = secret + slen - hs; nb = strlen( label ); memcpy( tmp + 20, label, nb ); memcpy( tmp + 20 + nb, random, rlen ); nb += rlen; /* * First compute P_md5(secret,label+random)[0..dlen] */ if( ( md_info = mbedtls_md_info_from_type( MBEDTLS_MD_MD5 ) ) == NULL ) return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); if( ( ret = mbedtls_md_setup( &md_ctx, md_info, 1 ) ) != 0 ) return( ret ); mbedtls_md_hmac_starts( &md_ctx, S1, hs ); mbedtls_md_hmac_update( &md_ctx, tmp + 20, nb ); mbedtls_md_hmac_finish( &md_ctx, 4 + tmp ); for( i = 0; i < dlen; i += 16 ) { mbedtls_md_hmac_reset ( &md_ctx ); mbedtls_md_hmac_update( &md_ctx, 4 + tmp, 16 + nb ); mbedtls_md_hmac_finish( &md_ctx, h_i ); mbedtls_md_hmac_reset ( &md_ctx ); mbedtls_md_hmac_update( &md_ctx, 4 + tmp, 16 ); mbedtls_md_hmac_finish( &md_ctx, 4 + tmp ); k = ( i + 16 > dlen ) ? dlen % 16 : 16; for( j = 0; j < k; j++ ) dstbuf[i + j] = h_i[j]; } mbedtls_md_free( &md_ctx ); /* * XOR out with P_sha1(secret,label+random)[0..dlen] */ if( ( md_info = mbedtls_md_info_from_type( MBEDTLS_MD_SHA1 ) ) == NULL ) return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); if( ( ret = mbedtls_md_setup( &md_ctx, md_info, 1 ) ) != 0 ) return( ret ); mbedtls_md_hmac_starts( &md_ctx, S2, hs ); mbedtls_md_hmac_update( &md_ctx, tmp + 20, nb ); mbedtls_md_hmac_finish( &md_ctx, tmp ); for( i = 0; i < dlen; i += 20 ) { mbedtls_md_hmac_reset ( &md_ctx ); mbedtls_md_hmac_update( &md_ctx, tmp, 20 + nb ); mbedtls_md_hmac_finish( &md_ctx, h_i ); mbedtls_md_hmac_reset ( &md_ctx ); mbedtls_md_hmac_update( &md_ctx, tmp, 20 ); mbedtls_md_hmac_finish( &md_ctx, tmp ); k = ( i + 20 > dlen ) ? dlen % 20 : 20; for( j = 0; j < k; j++ ) dstbuf[i + j] = (unsigned char)( dstbuf[i + j] ^ h_i[j] ); } mbedtls_md_free( &md_ctx ); mbedtls_platform_zeroize( tmp, sizeof( tmp ) ); mbedtls_platform_zeroize( h_i, sizeof( h_i ) ); return( 0 ); } #endif /* MBEDTLS_SSL_PROTO_TLS1) || MBEDTLS_SSL_PROTO_TLS1_1 */ #if defined(MBEDTLS_SSL_PROTO_TLS1_2) static int tls_prf_generic( mbedtls_md_type_t md_type, const unsigned char *secret, size_t slen, const char *label, const unsigned char *random, size_t rlen, unsigned char *dstbuf, size_t dlen ) { size_t nb; size_t i, j, k, md_len; unsigned char tmp[128]; unsigned char h_i[MBEDTLS_MD_MAX_SIZE]; const mbedtls_md_info_t *md_info; mbedtls_md_context_t md_ctx; int ret; mbedtls_md_init( &md_ctx ); if( ( md_info = mbedtls_md_info_from_type( md_type ) ) == NULL ) return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); md_len = mbedtls_md_get_size( md_info ); if( sizeof( tmp ) < md_len + strlen( label ) + rlen ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); nb = strlen( label ); memcpy( tmp + md_len, label, nb ); memcpy( tmp + md_len + nb, random, rlen ); nb += rlen; /* * Compute P_(secret, label + random)[0..dlen] */ if ( ( ret = mbedtls_md_setup( &md_ctx, md_info, 1 ) ) != 0 ) return( ret ); mbedtls_md_hmac_starts( &md_ctx, secret, slen ); mbedtls_md_hmac_update( &md_ctx, tmp + md_len, nb ); mbedtls_md_hmac_finish( &md_ctx, tmp ); for( i = 0; i < dlen; i += md_len ) { mbedtls_md_hmac_reset ( &md_ctx ); mbedtls_md_hmac_update( &md_ctx, tmp, md_len + nb ); mbedtls_md_hmac_finish( &md_ctx, h_i ); mbedtls_md_hmac_reset ( &md_ctx ); mbedtls_md_hmac_update( &md_ctx, tmp, md_len ); mbedtls_md_hmac_finish( &md_ctx, tmp ); k = ( i + md_len > dlen ) ? dlen % md_len : md_len; for( j = 0; j < k; j++ ) dstbuf[i + j] = h_i[j]; } mbedtls_md_free( &md_ctx ); mbedtls_platform_zeroize( tmp, sizeof( tmp ) ); mbedtls_platform_zeroize( h_i, sizeof( h_i ) ); return( 0 ); } #if defined(MBEDTLS_SHA256_C) static int tls_prf_sha256( const unsigned char *secret, size_t slen, const char *label, const unsigned char *random, size_t rlen, unsigned char *dstbuf, size_t dlen ) { return( tls_prf_generic( MBEDTLS_MD_SHA256, secret, slen, label, random, rlen, dstbuf, dlen ) ); } #endif /* MBEDTLS_SHA256_C */ #if defined(MBEDTLS_SHA512_C) static int tls_prf_sha384( const unsigned char *secret, size_t slen, const char *label, const unsigned char *random, size_t rlen, unsigned char *dstbuf, size_t dlen ) { return( tls_prf_generic( MBEDTLS_MD_SHA384, secret, slen, label, random, rlen, dstbuf, dlen ) ); } #endif /* MBEDTLS_SHA512_C */ #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */ static void ssl_update_checksum_start( mbedtls_ssl_context *, const unsigned char *, size_t ); #if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1) || \ defined(MBEDTLS_SSL_PROTO_TLS1_1) static void ssl_update_checksum_md5sha1( mbedtls_ssl_context *, const unsigned char *, size_t ); #endif #if defined(MBEDTLS_SSL_PROTO_SSL3) static void ssl_calc_verify_ssl( mbedtls_ssl_context *, unsigned char * ); static void ssl_calc_finished_ssl( mbedtls_ssl_context *, unsigned char *, int ); #endif #if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) static void ssl_calc_verify_tls( mbedtls_ssl_context *, unsigned char * ); static void ssl_calc_finished_tls( mbedtls_ssl_context *, unsigned char *, int ); #endif #if defined(MBEDTLS_SSL_PROTO_TLS1_2) #if defined(MBEDTLS_SHA256_C) static void ssl_update_checksum_sha256( mbedtls_ssl_context *, const unsigned char *, size_t ); static void ssl_calc_verify_tls_sha256( mbedtls_ssl_context *,unsigned char * ); static void ssl_calc_finished_tls_sha256( mbedtls_ssl_context *,unsigned char *, int ); #endif #if defined(MBEDTLS_SHA512_C) static void ssl_update_checksum_sha384( mbedtls_ssl_context *, const unsigned char *, size_t ); static void ssl_calc_verify_tls_sha384( mbedtls_ssl_context *, unsigned char * ); static void ssl_calc_finished_tls_sha384( mbedtls_ssl_context *, unsigned char *, int ); #endif #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */ int mbedtls_ssl_derive_keys( mbedtls_ssl_context *ssl ) { int ret = 0; unsigned char tmp[64]; unsigned char keyblk[256]; unsigned char *key1; unsigned char *key2; unsigned char *mac_enc; unsigned char *mac_dec; size_t mac_key_len; size_t iv_copy_len; const mbedtls_cipher_info_t *cipher_info; const mbedtls_md_info_t *md_info; mbedtls_ssl_session *session = ssl->session_negotiate; mbedtls_ssl_transform *transform = ssl->transform_negotiate; mbedtls_ssl_handshake_params *handshake = ssl->handshake; MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> derive keys" ) ); cipher_info = mbedtls_cipher_info_from_type( transform->ciphersuite_info->cipher ); if( cipher_info == NULL ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "cipher info for %d not found", transform->ciphersuite_info->cipher ) ); return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); } md_info = mbedtls_md_info_from_type( transform->ciphersuite_info->mac ); if( md_info == NULL ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "mbedtls_md info for %d not found", transform->ciphersuite_info->mac ) ); return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); } /* * Set appropriate PRF function and other SSL / TLS / TLS1.2 functions */ #if defined(MBEDTLS_SSL_PROTO_SSL3) if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 ) { handshake->tls_prf = ssl3_prf; handshake->calc_verify = ssl_calc_verify_ssl; handshake->calc_finished = ssl_calc_finished_ssl; } else #endif #if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) if( ssl->minor_ver < MBEDTLS_SSL_MINOR_VERSION_3 ) { handshake->tls_prf = tls1_prf; handshake->calc_verify = ssl_calc_verify_tls; handshake->calc_finished = ssl_calc_finished_tls; } else #endif #if defined(MBEDTLS_SSL_PROTO_TLS1_2) #if defined(MBEDTLS_SHA512_C) if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 && transform->ciphersuite_info->mac == MBEDTLS_MD_SHA384 ) { handshake->tls_prf = tls_prf_sha384; handshake->calc_verify = ssl_calc_verify_tls_sha384; handshake->calc_finished = ssl_calc_finished_tls_sha384; } else #endif #if defined(MBEDTLS_SHA256_C) if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 ) { handshake->tls_prf = tls_prf_sha256; handshake->calc_verify = ssl_calc_verify_tls_sha256; handshake->calc_finished = ssl_calc_finished_tls_sha256; } else #endif #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */ { MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); } /* * SSLv3: * master = * MD5( premaster + SHA1( 'A' + premaster + randbytes ) ) + * MD5( premaster + SHA1( 'BB' + premaster + randbytes ) ) + * MD5( premaster + SHA1( 'CCC' + premaster + randbytes ) ) * * TLSv1+: * master = PRF( premaster, "master secret", randbytes )[0..47] */ if( handshake->resume == 0 ) { MBEDTLS_SSL_DEBUG_BUF( 3, "premaster secret", handshake->premaster, handshake->pmslen ); #if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET) if( ssl->handshake->extended_ms == MBEDTLS_SSL_EXTENDED_MS_ENABLED ) { unsigned char session_hash[48]; size_t hash_len; MBEDTLS_SSL_DEBUG_MSG( 3, ( "using extended master secret" ) ); ssl->handshake->calc_verify( ssl, session_hash ); #if defined(MBEDTLS_SSL_PROTO_TLS1_2) if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 ) { #if defined(MBEDTLS_SHA512_C) if( ssl->transform_negotiate->ciphersuite_info->mac == MBEDTLS_MD_SHA384 ) { hash_len = 48; } else #endif hash_len = 32; } else #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */ hash_len = 36; MBEDTLS_SSL_DEBUG_BUF( 3, "session hash", session_hash, hash_len ); ret = handshake->tls_prf( handshake->premaster, handshake->pmslen, "extended master secret", session_hash, hash_len, session->master, 48 ); if( ret != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "prf", ret ); return( ret ); } } else #endif ret = handshake->tls_prf( handshake->premaster, handshake->pmslen, "master secret", handshake->randbytes, 64, session->master, 48 ); if( ret != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "prf", ret ); return( ret ); } mbedtls_platform_zeroize( handshake->premaster, sizeof(handshake->premaster) ); } else MBEDTLS_SSL_DEBUG_MSG( 3, ( "no premaster (session resumed)" ) ); /* * Swap the client and server random values. */ memcpy( tmp, handshake->randbytes, 64 ); memcpy( handshake->randbytes, tmp + 32, 32 ); memcpy( handshake->randbytes + 32, tmp, 32 ); mbedtls_platform_zeroize( tmp, sizeof( tmp ) ); /* * SSLv3: * key block = * MD5( master + SHA1( 'A' + master + randbytes ) ) + * MD5( master + SHA1( 'BB' + master + randbytes ) ) + * MD5( master + SHA1( 'CCC' + master + randbytes ) ) + * MD5( master + SHA1( 'DDDD' + master + randbytes ) ) + * ... * * TLSv1: * key block = PRF( master, "key expansion", randbytes ) */ ret = handshake->tls_prf( session->master, 48, "key expansion", handshake->randbytes, 64, keyblk, 256 ); if( ret != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "prf", ret ); return( ret ); } MBEDTLS_SSL_DEBUG_MSG( 3, ( "ciphersuite = %s", mbedtls_ssl_get_ciphersuite_name( session->ciphersuite ) ) ); MBEDTLS_SSL_DEBUG_BUF( 3, "master secret", session->master, 48 ); MBEDTLS_SSL_DEBUG_BUF( 4, "random bytes", handshake->randbytes, 64 ); MBEDTLS_SSL_DEBUG_BUF( 4, "key block", keyblk, 256 ); mbedtls_platform_zeroize( handshake->randbytes, sizeof( handshake->randbytes ) ); /* * Determine the appropriate key, IV and MAC length. */ transform->keylen = cipher_info->key_bitlen / 8; if( cipher_info->mode == MBEDTLS_MODE_GCM || cipher_info->mode == MBEDTLS_MODE_CCM || cipher_info->mode == MBEDTLS_MODE_CHACHAPOLY ) { size_t taglen, explicit_ivlen; transform->maclen = 0; mac_key_len = 0; /* All modes haves 96-bit IVs; * GCM and CCM has 4 implicit and 8 explicit bytes * ChachaPoly has all 12 bytes implicit */ transform->ivlen = 12; if( cipher_info->mode == MBEDTLS_MODE_CHACHAPOLY ) transform->fixed_ivlen = 12; else transform->fixed_ivlen = 4; /* All modes have 128-bit tags, except CCM_8 (ciphersuite flag) */ taglen = transform->ciphersuite_info->flags & MBEDTLS_CIPHERSUITE_SHORT_TAG ? 8 : 16; /* Minimum length of encrypted record */ explicit_ivlen = transform->ivlen - transform->fixed_ivlen; transform->minlen = explicit_ivlen + taglen; } else { /* Initialize HMAC contexts */ if( ( ret = mbedtls_md_setup( &transform->md_ctx_enc, md_info, 1 ) ) != 0 || ( ret = mbedtls_md_setup( &transform->md_ctx_dec, md_info, 1 ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_md_setup", ret ); return( ret ); } /* Get MAC length */ mac_key_len = mbedtls_md_get_size( md_info ); transform->maclen = mac_key_len; #if defined(MBEDTLS_SSL_TRUNCATED_HMAC) /* * If HMAC is to be truncated, we shall keep the leftmost bytes, * (rfc 6066 page 13 or rfc 2104 section 4), * so we only need to adjust the length here. */ if( session->trunc_hmac == MBEDTLS_SSL_TRUNC_HMAC_ENABLED ) { transform->maclen = MBEDTLS_SSL_TRUNCATED_HMAC_LEN; #if defined(MBEDTLS_SSL_TRUNCATED_HMAC_COMPAT) /* Fall back to old, non-compliant version of the truncated * HMAC implementation which also truncates the key * (Mbed TLS versions from 1.3 to 2.6.0) */ mac_key_len = transform->maclen; #endif } #endif /* MBEDTLS_SSL_TRUNCATED_HMAC */ /* IV length */ transform->ivlen = cipher_info->iv_size; /* Minimum length */ if( cipher_info->mode == MBEDTLS_MODE_STREAM ) transform->minlen = transform->maclen; else { /* * GenericBlockCipher: * 1. if EtM is in use: one block plus MAC * otherwise: * first multiple of blocklen greater than maclen * 2. IV except for SSL3 and TLS 1.0 */ #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC) if( session->encrypt_then_mac == MBEDTLS_SSL_ETM_ENABLED ) { transform->minlen = transform->maclen + cipher_info->block_size; } else #endif { transform->minlen = transform->maclen + cipher_info->block_size - transform->maclen % cipher_info->block_size; } #if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1) if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 || ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_1 ) ; /* No need to adjust minlen */ else #endif #if defined(MBEDTLS_SSL_PROTO_TLS1_1) || defined(MBEDTLS_SSL_PROTO_TLS1_2) if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_2 || ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 ) { transform->minlen += transform->ivlen; } else #endif { MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); } } } MBEDTLS_SSL_DEBUG_MSG( 3, ( "keylen: %d, minlen: %d, ivlen: %d, maclen: %d", transform->keylen, transform->minlen, transform->ivlen, transform->maclen ) ); /* * Finally setup the cipher contexts, IVs and MAC secrets. */ #if defined(MBEDTLS_SSL_CLI_C) if( ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT ) { key1 = keyblk + mac_key_len * 2; key2 = keyblk + mac_key_len * 2 + transform->keylen; mac_enc = keyblk; mac_dec = keyblk + mac_key_len; /* * This is not used in TLS v1.1. */ iv_copy_len = ( transform->fixed_ivlen ) ? transform->fixed_ivlen : transform->ivlen; memcpy( transform->iv_enc, key2 + transform->keylen, iv_copy_len ); memcpy( transform->iv_dec, key2 + transform->keylen + iv_copy_len, iv_copy_len ); } else #endif /* MBEDTLS_SSL_CLI_C */ #if defined(MBEDTLS_SSL_SRV_C) if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER ) { key1 = keyblk + mac_key_len * 2 + transform->keylen; key2 = keyblk + mac_key_len * 2; mac_enc = keyblk + mac_key_len; mac_dec = keyblk; /* * This is not used in TLS v1.1. */ iv_copy_len = ( transform->fixed_ivlen ) ? transform->fixed_ivlen : transform->ivlen; memcpy( transform->iv_dec, key1 + transform->keylen, iv_copy_len ); memcpy( transform->iv_enc, key1 + transform->keylen + iv_copy_len, iv_copy_len ); } else #endif /* MBEDTLS_SSL_SRV_C */ { MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); } #if defined(MBEDTLS_SSL_PROTO_SSL3) if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 ) { if( mac_key_len > sizeof transform->mac_enc ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); } memcpy( transform->mac_enc, mac_enc, mac_key_len ); memcpy( transform->mac_dec, mac_dec, mac_key_len ); } else #endif /* MBEDTLS_SSL_PROTO_SSL3 */ #if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) || \ defined(MBEDTLS_SSL_PROTO_TLS1_2) if( ssl->minor_ver >= MBEDTLS_SSL_MINOR_VERSION_1 ) { /* For HMAC-based ciphersuites, initialize the HMAC transforms. For AEAD-based ciphersuites, there is nothing to do here. */ if( mac_key_len != 0 ) { mbedtls_md_hmac_starts( &transform->md_ctx_enc, mac_enc, mac_key_len ); mbedtls_md_hmac_starts( &transform->md_ctx_dec, mac_dec, mac_key_len ); } } else #endif { MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); } #if defined(MBEDTLS_SSL_HW_RECORD_ACCEL) if( mbedtls_ssl_hw_record_init != NULL ) { int ret = 0; MBEDTLS_SSL_DEBUG_MSG( 2, ( "going for mbedtls_ssl_hw_record_init()" ) ); if( ( ret = mbedtls_ssl_hw_record_init( ssl, key1, key2, transform->keylen, transform->iv_enc, transform->iv_dec, iv_copy_len, mac_enc, mac_dec, mac_key_len ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_hw_record_init", ret ); return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED ); } } #endif /* MBEDTLS_SSL_HW_RECORD_ACCEL */ #if defined(MBEDTLS_SSL_EXPORT_KEYS) if( ssl->conf->f_export_keys != NULL ) { ssl->conf->f_export_keys( ssl->conf->p_export_keys, session->master, keyblk, mac_key_len, transform->keylen, iv_copy_len ); } #endif if( ( ret = mbedtls_cipher_setup( &transform->cipher_ctx_enc, cipher_info ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_setup", ret ); return( ret ); } if( ( ret = mbedtls_cipher_setup( &transform->cipher_ctx_dec, cipher_info ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_setup", ret ); return( ret ); } if( ( ret = mbedtls_cipher_setkey( &transform->cipher_ctx_enc, key1, cipher_info->key_bitlen, MBEDTLS_ENCRYPT ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_setkey", ret ); return( ret ); } if( ( ret = mbedtls_cipher_setkey( &transform->cipher_ctx_dec, key2, cipher_info->key_bitlen, MBEDTLS_DECRYPT ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_setkey", ret ); return( ret ); } #if defined(MBEDTLS_CIPHER_MODE_CBC) if( cipher_info->mode == MBEDTLS_MODE_CBC ) { if( ( ret = mbedtls_cipher_set_padding_mode( &transform->cipher_ctx_enc, MBEDTLS_PADDING_NONE ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_set_padding_mode", ret ); return( ret ); } if( ( ret = mbedtls_cipher_set_padding_mode( &transform->cipher_ctx_dec, MBEDTLS_PADDING_NONE ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_set_padding_mode", ret ); return( ret ); } } #endif /* MBEDTLS_CIPHER_MODE_CBC */ mbedtls_platform_zeroize( keyblk, sizeof( keyblk ) ); #if defined(MBEDTLS_ZLIB_SUPPORT) // Initialize compression // if( session->compression == MBEDTLS_SSL_COMPRESS_DEFLATE ) { if( ssl->compress_buf == NULL ) { MBEDTLS_SSL_DEBUG_MSG( 3, ( "Allocating compression buffer" ) ); ssl->compress_buf = mbedtls_calloc( 1, MBEDTLS_SSL_COMPRESS_BUFFER_LEN ); if( ssl->compress_buf == NULL ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "alloc(%d bytes) failed", MBEDTLS_SSL_COMPRESS_BUFFER_LEN ) ); return( MBEDTLS_ERR_SSL_ALLOC_FAILED ); } } MBEDTLS_SSL_DEBUG_MSG( 3, ( "Initializing zlib states" ) ); memset( &transform->ctx_deflate, 0, sizeof( transform->ctx_deflate ) ); memset( &transform->ctx_inflate, 0, sizeof( transform->ctx_inflate ) ); if( deflateInit( &transform->ctx_deflate, Z_DEFAULT_COMPRESSION ) != Z_OK || inflateInit( &transform->ctx_inflate ) != Z_OK ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "Failed to initialize compression" ) ); return( MBEDTLS_ERR_SSL_COMPRESSION_FAILED ); } } #endif /* MBEDTLS_ZLIB_SUPPORT */ MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= derive keys" ) ); return( 0 ); } #if defined(MBEDTLS_SSL_PROTO_SSL3) void ssl_calc_verify_ssl( mbedtls_ssl_context *ssl, unsigned char hash[36] ) { mbedtls_md5_context md5; mbedtls_sha1_context sha1; unsigned char pad_1[48]; unsigned char pad_2[48]; MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> calc verify ssl" ) ); mbedtls_md5_init( &md5 ); mbedtls_sha1_init( &sha1 ); mbedtls_md5_clone( &md5, &ssl->handshake->fin_md5 ); mbedtls_sha1_clone( &sha1, &ssl->handshake->fin_sha1 ); memset( pad_1, 0x36, 48 ); memset( pad_2, 0x5C, 48 ); mbedtls_md5_update_ret( &md5, ssl->session_negotiate->master, 48 ); mbedtls_md5_update_ret( &md5, pad_1, 48 ); mbedtls_md5_finish_ret( &md5, hash ); mbedtls_md5_starts_ret( &md5 ); mbedtls_md5_update_ret( &md5, ssl->session_negotiate->master, 48 ); mbedtls_md5_update_ret( &md5, pad_2, 48 ); mbedtls_md5_update_ret( &md5, hash, 16 ); mbedtls_md5_finish_ret( &md5, hash ); mbedtls_sha1_update_ret( &sha1, ssl->session_negotiate->master, 48 ); mbedtls_sha1_update_ret( &sha1, pad_1, 40 ); mbedtls_sha1_finish_ret( &sha1, hash + 16 ); mbedtls_sha1_starts_ret( &sha1 ); mbedtls_sha1_update_ret( &sha1, ssl->session_negotiate->master, 48 ); mbedtls_sha1_update_ret( &sha1, pad_2, 40 ); mbedtls_sha1_update_ret( &sha1, hash + 16, 20 ); mbedtls_sha1_finish_ret( &sha1, hash + 16 ); MBEDTLS_SSL_DEBUG_BUF( 3, "calculated verify result", hash, 36 ); MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= calc verify" ) ); mbedtls_md5_free( &md5 ); mbedtls_sha1_free( &sha1 ); return; } #endif /* MBEDTLS_SSL_PROTO_SSL3 */ #if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) void ssl_calc_verify_tls( mbedtls_ssl_context *ssl, unsigned char hash[36] ) { mbedtls_md5_context md5; mbedtls_sha1_context sha1; MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> calc verify tls" ) ); mbedtls_md5_init( &md5 ); mbedtls_sha1_init( &sha1 ); mbedtls_md5_clone( &md5, &ssl->handshake->fin_md5 ); mbedtls_sha1_clone( &sha1, &ssl->handshake->fin_sha1 ); mbedtls_md5_finish_ret( &md5, hash ); mbedtls_sha1_finish_ret( &sha1, hash + 16 ); MBEDTLS_SSL_DEBUG_BUF( 3, "calculated verify result", hash, 36 ); MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= calc verify" ) ); mbedtls_md5_free( &md5 ); mbedtls_sha1_free( &sha1 ); return; } #endif /* MBEDTLS_SSL_PROTO_TLS1 || MBEDTLS_SSL_PROTO_TLS1_1 */ #if defined(MBEDTLS_SSL_PROTO_TLS1_2) #if defined(MBEDTLS_SHA256_C) void ssl_calc_verify_tls_sha256( mbedtls_ssl_context *ssl, unsigned char hash[32] ) { mbedtls_sha256_context sha256; mbedtls_sha256_init( &sha256 ); MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> calc verify sha256" ) ); mbedtls_sha256_clone( &sha256, &ssl->handshake->fin_sha256 ); mbedtls_sha256_finish_ret( &sha256, hash ); MBEDTLS_SSL_DEBUG_BUF( 3, "calculated verify result", hash, 32 ); MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= calc verify" ) ); mbedtls_sha256_free( &sha256 ); return; } #endif /* MBEDTLS_SHA256_C */ #if defined(MBEDTLS_SHA512_C) void ssl_calc_verify_tls_sha384( mbedtls_ssl_context *ssl, unsigned char hash[48] ) { mbedtls_sha512_context sha512; mbedtls_sha512_init( &sha512 ); MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> calc verify sha384" ) ); mbedtls_sha512_clone( &sha512, &ssl->handshake->fin_sha512 ); mbedtls_sha512_finish_ret( &sha512, hash ); MBEDTLS_SSL_DEBUG_BUF( 3, "calculated verify result", hash, 48 ); MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= calc verify" ) ); mbedtls_sha512_free( &sha512 ); return; } #endif /* MBEDTLS_SHA512_C */ #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */ #if defined(MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED) int mbedtls_ssl_psk_derive_premaster( mbedtls_ssl_context *ssl, mbedtls_key_exchange_type_t key_ex ) { unsigned char *p = ssl->handshake->premaster; unsigned char *end = p + sizeof( ssl->handshake->premaster ); const unsigned char *psk = ssl->conf->psk; size_t psk_len = ssl->conf->psk_len; /* If the psk callback was called, use its result */ if( ssl->handshake->psk != NULL ) { psk = ssl->handshake->psk; psk_len = ssl->handshake->psk_len; } /* * PMS = struct { * opaque other_secret<0..2^16-1>; * opaque psk<0..2^16-1>; * }; * with "other_secret" depending on the particular key exchange */ #if defined(MBEDTLS_KEY_EXCHANGE_PSK_ENABLED) if( key_ex == MBEDTLS_KEY_EXCHANGE_PSK ) { if( end - p < 2 ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); *(p++) = (unsigned char)( psk_len >> 8 ); *(p++) = (unsigned char)( psk_len ); if( end < p || (size_t)( end - p ) < psk_len ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); memset( p, 0, psk_len ); p += psk_len; } else #endif /* MBEDTLS_KEY_EXCHANGE_PSK_ENABLED */ #if defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED) if( key_ex == MBEDTLS_KEY_EXCHANGE_RSA_PSK ) { /* * other_secret already set by the ClientKeyExchange message, * and is 48 bytes long */ if( end - p < 2 ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); *p++ = 0; *p++ = 48; p += 48; } else #endif /* MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED */ #if defined(MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED) if( key_ex == MBEDTLS_KEY_EXCHANGE_DHE_PSK ) { int ret; size_t len; /* Write length only when we know the actual value */ if( ( ret = mbedtls_dhm_calc_secret( &ssl->handshake->dhm_ctx, p + 2, end - ( p + 2 ), &len, ssl->conf->f_rng, ssl->conf->p_rng ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_dhm_calc_secret", ret ); return( ret ); } *(p++) = (unsigned char)( len >> 8 ); *(p++) = (unsigned char)( len ); p += len; MBEDTLS_SSL_DEBUG_MPI( 3, "DHM: K ", &ssl->handshake->dhm_ctx.K ); } else #endif /* MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED */ #if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED) if( key_ex == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK ) { int ret; size_t zlen; if( ( ret = mbedtls_ecdh_calc_secret( &ssl->handshake->ecdh_ctx, &zlen, p + 2, end - ( p + 2 ), ssl->conf->f_rng, ssl->conf->p_rng ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecdh_calc_secret", ret ); return( ret ); } *(p++) = (unsigned char)( zlen >> 8 ); *(p++) = (unsigned char)( zlen ); p += zlen; MBEDTLS_SSL_DEBUG_ECDH( 3, &ssl->handshake->ecdh_ctx, MBEDTLS_DEBUG_ECDH_Z ); } else #endif /* MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED */ { MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); } /* opaque psk<0..2^16-1>; */ if( end - p < 2 ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); *(p++) = (unsigned char)( psk_len >> 8 ); *(p++) = (unsigned char)( psk_len ); if( end < p || (size_t)( end - p ) < psk_len ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); memcpy( p, psk, psk_len ); p += psk_len; ssl->handshake->pmslen = p - ssl->handshake->premaster; return( 0 ); } #endif /* MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED */ #if defined(MBEDTLS_SSL_PROTO_SSL3) /* * SSLv3.0 MAC functions */ #define SSL_MAC_MAX_BYTES 20 /* MD-5 or SHA-1 */ static void ssl_mac( mbedtls_md_context_t *md_ctx, const unsigned char *secret, const unsigned char *buf, size_t len, const unsigned char *ctr, int type, unsigned char out[SSL_MAC_MAX_BYTES] ) { unsigned char header[11]; unsigned char padding[48]; int padlen; int md_size = mbedtls_md_get_size( md_ctx->md_info ); int md_type = mbedtls_md_get_type( md_ctx->md_info ); /* Only MD5 and SHA-1 supported */ if( md_type == MBEDTLS_MD_MD5 ) padlen = 48; else padlen = 40; memcpy( header, ctr, 8 ); header[ 8] = (unsigned char) type; header[ 9] = (unsigned char)( len >> 8 ); header[10] = (unsigned char)( len ); memset( padding, 0x36, padlen ); mbedtls_md_starts( md_ctx ); mbedtls_md_update( md_ctx, secret, md_size ); mbedtls_md_update( md_ctx, padding, padlen ); mbedtls_md_update( md_ctx, header, 11 ); mbedtls_md_update( md_ctx, buf, len ); mbedtls_md_finish( md_ctx, out ); memset( padding, 0x5C, padlen ); mbedtls_md_starts( md_ctx ); mbedtls_md_update( md_ctx, secret, md_size ); mbedtls_md_update( md_ctx, padding, padlen ); mbedtls_md_update( md_ctx, out, md_size ); mbedtls_md_finish( md_ctx, out ); } #endif /* MBEDTLS_SSL_PROTO_SSL3 */ #if defined(MBEDTLS_ARC4_C) || defined(MBEDTLS_CIPHER_NULL_CIPHER) || \ ( defined(MBEDTLS_CIPHER_MODE_CBC) && \ ( defined(MBEDTLS_AES_C) || defined(MBEDTLS_CAMELLIA_C) || defined(MBEDTLS_ARIA_C)) ) #define SSL_SOME_MODES_USE_MAC #endif /* The function below is only used in the Lucky 13 counter-measure in * ssl_decrypt_buf(). These are the defines that guard the call site. */ #if defined(SSL_SOME_MODES_USE_MAC) && \ ( defined(MBEDTLS_SSL_PROTO_TLS1) || \ defined(MBEDTLS_SSL_PROTO_TLS1_1) || \ defined(MBEDTLS_SSL_PROTO_TLS1_2) ) /* This function makes sure every byte in the memory region is accessed * (in ascending addresses order) */ static void ssl_read_memory( unsigned char *p, size_t len ) { unsigned char acc = 0; volatile unsigned char force; for( ; len != 0; p++, len-- ) acc ^= *p; force = acc; (void) force; } #endif /* SSL_SOME_MODES_USE_MAC && ( TLS1 || TLS1_1 || TLS1_2 ) */ /* * Encryption/decryption functions */ static int ssl_encrypt_buf( mbedtls_ssl_context *ssl ) { mbedtls_cipher_mode_t mode; int auth_done = 0; MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> encrypt buf" ) ); if( ssl->session_out == NULL || ssl->transform_out == NULL ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); } mode = mbedtls_cipher_get_cipher_mode( &ssl->transform_out->cipher_ctx_enc ); MBEDTLS_SSL_DEBUG_BUF( 4, "before encrypt: output payload", ssl->out_msg, ssl->out_msglen ); /* * Add MAC before if needed */ #if defined(SSL_SOME_MODES_USE_MAC) if( mode == MBEDTLS_MODE_STREAM || ( mode == MBEDTLS_MODE_CBC #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC) && ssl->session_out->encrypt_then_mac == MBEDTLS_SSL_ETM_DISABLED #endif ) ) { #if defined(MBEDTLS_SSL_PROTO_SSL3) if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 ) { unsigned char mac[SSL_MAC_MAX_BYTES]; ssl_mac( &ssl->transform_out->md_ctx_enc, ssl->transform_out->mac_enc, ssl->out_msg, ssl->out_msglen, ssl->out_ctr, ssl->out_msgtype, mac ); memcpy( ssl->out_msg + ssl->out_msglen, mac, ssl->transform_out->maclen ); } else #endif #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 ) { unsigned char mac[MBEDTLS_SSL_MAC_ADD]; mbedtls_md_hmac_update( &ssl->transform_out->md_ctx_enc, ssl->out_ctr, 8 ); mbedtls_md_hmac_update( &ssl->transform_out->md_ctx_enc, ssl->out_hdr, 3 ); mbedtls_md_hmac_update( &ssl->transform_out->md_ctx_enc, ssl->out_len, 2 ); mbedtls_md_hmac_update( &ssl->transform_out->md_ctx_enc, ssl->out_msg, ssl->out_msglen ); mbedtls_md_hmac_finish( &ssl->transform_out->md_ctx_enc, mac ); mbedtls_md_hmac_reset( &ssl->transform_out->md_ctx_enc ); memcpy( ssl->out_msg + ssl->out_msglen, mac, ssl->transform_out->maclen ); } else #endif { MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); } MBEDTLS_SSL_DEBUG_BUF( 4, "computed mac", ssl->out_msg + ssl->out_msglen, ssl->transform_out->maclen ); ssl->out_msglen += ssl->transform_out->maclen; auth_done++; } #endif /* AEAD not the only option */ /* * Encrypt */ #if defined(MBEDTLS_ARC4_C) || defined(MBEDTLS_CIPHER_NULL_CIPHER) if( mode == MBEDTLS_MODE_STREAM ) { int ret; size_t olen = 0; MBEDTLS_SSL_DEBUG_MSG( 3, ( "before encrypt: msglen = %d, " "including %d bytes of padding", ssl->out_msglen, 0 ) ); if( ( ret = mbedtls_cipher_crypt( &ssl->transform_out->cipher_ctx_enc, ssl->transform_out->iv_enc, ssl->transform_out->ivlen, ssl->out_msg, ssl->out_msglen, ssl->out_msg, &olen ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_crypt", ret ); return( ret ); } if( ssl->out_msglen != 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; size_t enc_msglen, olen; unsigned char *enc_msg; unsigned char add_data[13]; unsigned char iv[12]; mbedtls_ssl_transform *transform = ssl->transform_out; unsigned char taglen = transform->ciphersuite_info->flags & MBEDTLS_CIPHERSUITE_SHORT_TAG ? 8 : 16; size_t explicit_ivlen = transform->ivlen - transform->fixed_ivlen; /* * Prepare additional authenticated data */ memcpy( add_data, ssl->out_ctr, 8 ); add_data[8] = ssl->out_msgtype; mbedtls_ssl_write_version( ssl->major_ver, ssl->minor_ver, ssl->conf->transport, add_data + 9 ); add_data[11] = ( ssl->out_msglen >> 8 ) & 0xFF; add_data[12] = ssl->out_msglen & 0xFF; MBEDTLS_SSL_DEBUG_BUF( 4, "additional data for AEAD", add_data, 13 ); /* * Generate IV */ if( transform->ivlen == 12 && transform->fixed_ivlen == 4 ) { /* GCM and CCM: fixed || explicit (=seqnum) */ memcpy( iv, transform->iv_enc, transform->fixed_ivlen ); memcpy( iv + transform->fixed_ivlen, ssl->out_ctr, 8 ); memcpy( ssl->out_iv, ssl->out_ctr, 8 ); } else if( transform->ivlen == 12 && transform->fixed_ivlen == 12 ) { /* ChachaPoly: fixed XOR sequence number */ unsigned char i; memcpy( iv, transform->iv_enc, transform->fixed_ivlen ); for( i = 0; i < 8; i++ ) iv[i+4] ^= ssl->out_ctr[i]; } else { /* Reminder if we ever add an AEAD mode with a different size */ MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); } MBEDTLS_SSL_DEBUG_BUF( 4, "IV used (internal)", iv, transform->ivlen ); MBEDTLS_SSL_DEBUG_BUF( 4, "IV used (transmitted)", ssl->out_iv, explicit_ivlen ); /* * Fix message length with added IV */ enc_msg = ssl->out_msg; enc_msglen = ssl->out_msglen; ssl->out_msglen += explicit_ivlen; MBEDTLS_SSL_DEBUG_MSG( 3, ( "before encrypt: msglen = %d, " "including 0 bytes of padding", ssl->out_msglen ) ); /* * Encrypt and authenticate */ if( ( ret = mbedtls_cipher_auth_encrypt( &transform->cipher_ctx_enc, iv, transform->ivlen, add_data, 13, enc_msg, enc_msglen, enc_msg, &olen, enc_msg + enc_msglen, taglen ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_auth_encrypt", ret ); return( ret ); } if( olen != enc_msglen ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); } ssl->out_msglen += taglen; auth_done++; MBEDTLS_SSL_DEBUG_BUF( 4, "after encrypt: tag", enc_msg + enc_msglen, taglen ); } else #endif /* MBEDTLS_GCM_C || MBEDTLS_CCM_C */ #if defined(MBEDTLS_CIPHER_MODE_CBC) && \ ( defined(MBEDTLS_AES_C) || defined(MBEDTLS_CAMELLIA_C) || defined(MBEDTLS_ARIA_C) ) if( mode == MBEDTLS_MODE_CBC ) { int ret; unsigned char *enc_msg; size_t enc_msglen, padlen, olen = 0, i; padlen = ssl->transform_out->ivlen - ( ssl->out_msglen + 1 ) % ssl->transform_out->ivlen; if( padlen == ssl->transform_out->ivlen ) padlen = 0; for( i = 0; i <= padlen; i++ ) ssl->out_msg[ssl->out_msglen + i] = (unsigned char) padlen; ssl->out_msglen += padlen + 1; enc_msglen = ssl->out_msglen; enc_msg = ssl->out_msg; #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( ssl->minor_ver >= MBEDTLS_SSL_MINOR_VERSION_2 ) { /* * Generate IV */ ret = ssl->conf->f_rng( ssl->conf->p_rng, ssl->transform_out->iv_enc, ssl->transform_out->ivlen ); if( ret != 0 ) return( ret ); memcpy( ssl->out_iv, ssl->transform_out->iv_enc, ssl->transform_out->ivlen ); /* * Fix pointer positions and message length with added IV */ enc_msg = ssl->out_msg; enc_msglen = ssl->out_msglen; ssl->out_msglen += ssl->transform_out->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", ssl->out_msglen, ssl->transform_out->ivlen, padlen + 1 ) ); if( ( ret = mbedtls_cipher_crypt( &ssl->transform_out->cipher_ctx_enc, ssl->transform_out->iv_enc, ssl->transform_out->ivlen, enc_msg, enc_msglen, enc_msg, &olen ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_crypt", ret ); return( ret ); } if( enc_msglen != 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( ssl->minor_ver < MBEDTLS_SSL_MINOR_VERSION_2 ) { /* * Save IV in SSL3 and TLS1 */ memcpy( ssl->transform_out->iv_enc, ssl->transform_out->cipher_ctx_enc.iv, ssl->transform_out->ivlen ); } #endif #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)); */ unsigned char pseudo_hdr[13]; MBEDTLS_SSL_DEBUG_MSG( 3, ( "using encrypt then mac" ) ); memcpy( pseudo_hdr + 0, ssl->out_ctr, 8 ); memcpy( pseudo_hdr + 8, ssl->out_hdr, 3 ); pseudo_hdr[11] = (unsigned char)( ( ssl->out_msglen >> 8 ) & 0xFF ); pseudo_hdr[12] = (unsigned char)( ( ssl->out_msglen ) & 0xFF ); MBEDTLS_SSL_DEBUG_BUF( 4, "MAC'd meta-data", pseudo_hdr, 13 ); mbedtls_md_hmac_update( &ssl->transform_out->md_ctx_enc, pseudo_hdr, 13 ); mbedtls_md_hmac_update( &ssl->transform_out->md_ctx_enc, ssl->out_iv, ssl->out_msglen ); mbedtls_md_hmac_finish( &ssl->transform_out->md_ctx_enc, mac ); mbedtls_md_hmac_reset( &ssl->transform_out->md_ctx_enc ); memcpy( ssl->out_iv + ssl->out_msglen, mac, ssl->transform_out->maclen ); ssl->out_msglen += ssl->transform_out->maclen; auth_done++; } #endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */ } else #endif /* MBEDTLS_CIPHER_MODE_CBC && ( MBEDTLS_AES_C || MBEDTLS_CAMELLIA_C || MBEDTLS_ARIA_C ) */ { MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); } /* Make extra sure authentication was performed, exactly once */ if( auth_done != 1 ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); } MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= encrypt buf" ) ); return( 0 ); } static int ssl_decrypt_buf( mbedtls_ssl_context *ssl ) { mbedtls_cipher_mode_t mode; int auth_done = 0; #if defined(SSL_SOME_MODES_USE_MAC) size_t padlen = 0, correct = 1; #endif MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> decrypt buf" ) ); if( ssl->session_in == NULL || ssl->transform_in == NULL ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); } mode = mbedtls_cipher_get_cipher_mode( &ssl->transform_in->cipher_ctx_dec ); if( ssl->in_msglen < ssl->transform_in->minlen ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "in_msglen (%d) < minlen (%d)", ssl->in_msglen, ssl->transform_in->minlen ) ); return( MBEDTLS_ERR_SSL_INVALID_MAC ); } #if defined(MBEDTLS_ARC4_C) || defined(MBEDTLS_CIPHER_NULL_CIPHER) if( mode == MBEDTLS_MODE_STREAM ) { int ret; size_t olen = 0; padlen = 0; if( ( ret = mbedtls_cipher_crypt( &ssl->transform_in->cipher_ctx_dec, ssl->transform_in->iv_dec, ssl->transform_in->ivlen, ssl->in_msg, ssl->in_msglen, ssl->in_msg, &olen ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_crypt", ret ); return( ret ); } if( ssl->in_msglen != 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; size_t dec_msglen, olen; unsigned char *dec_msg; unsigned char *dec_msg_result; unsigned char add_data[13]; unsigned char iv[12]; mbedtls_ssl_transform *transform = ssl->transform_in; unsigned char taglen = transform->ciphersuite_info->flags & MBEDTLS_CIPHERSUITE_SHORT_TAG ? 8 : 16; size_t explicit_iv_len = transform->ivlen - transform->fixed_ivlen; /* * Compute and update sizes */ if( ssl->in_msglen < explicit_iv_len + taglen ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "msglen (%d) < explicit_iv_len (%d) " "+ taglen (%d)", ssl->in_msglen, explicit_iv_len, taglen ) ); return( MBEDTLS_ERR_SSL_INVALID_MAC ); } dec_msglen = ssl->in_msglen - explicit_iv_len - taglen; dec_msg = ssl->in_msg; dec_msg_result = ssl->in_msg; ssl->in_msglen = dec_msglen; /* * Prepare additional authenticated data */ memcpy( add_data, ssl->in_ctr, 8 ); add_data[8] = ssl->in_msgtype; mbedtls_ssl_write_version( ssl->major_ver, ssl->minor_ver, ssl->conf->transport, add_data + 9 ); add_data[11] = ( ssl->in_msglen >> 8 ) & 0xFF; add_data[12] = ssl->in_msglen & 0xFF; MBEDTLS_SSL_DEBUG_BUF( 4, "additional data for AEAD", add_data, 13 ); /* * Prepare IV */ if( transform->ivlen == 12 && transform->fixed_ivlen == 4 ) { /* GCM and CCM: fixed || explicit (transmitted) */ memcpy( iv, transform->iv_dec, transform->fixed_ivlen ); memcpy( iv + transform->fixed_ivlen, ssl->in_iv, 8 ); } else if( transform->ivlen == 12 && transform->fixed_ivlen == 12 ) { /* ChachaPoly: fixed XOR sequence number */ unsigned char i; memcpy( iv, transform->iv_dec, transform->fixed_ivlen ); for( i = 0; i < 8; i++ ) iv[i+4] ^= ssl->in_ctr[i]; } else { /* Reminder if we ever add an AEAD mode with a different size */ MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); } MBEDTLS_SSL_DEBUG_BUF( 4, "IV used", iv, transform->ivlen ); MBEDTLS_SSL_DEBUG_BUF( 4, "TAG used", dec_msg + dec_msglen, taglen ); /* * Decrypt and authenticate */ if( ( ret = mbedtls_cipher_auth_decrypt( &ssl->transform_in->cipher_ctx_dec, iv, transform->ivlen, add_data, 13, dec_msg, dec_msglen, dec_msg_result, &olen, dec_msg + dec_msglen, taglen ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_auth_decrypt", ret ); if( ret == MBEDTLS_ERR_CIPHER_AUTH_FAILED ) return( MBEDTLS_ERR_SSL_INVALID_MAC ); return( ret ); } auth_done++; if( olen != dec_msglen ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); } } else #endif /* MBEDTLS_GCM_C || MBEDTLS_CCM_C */ #if defined(MBEDTLS_CIPHER_MODE_CBC) && \ ( defined(MBEDTLS_AES_C) || defined(MBEDTLS_CAMELLIA_C) || defined(MBEDTLS_ARIA_C) ) if( mode == MBEDTLS_MODE_CBC ) { /* * Decrypt and check the padding */ int ret; unsigned char *dec_msg; unsigned char *dec_msg_result; size_t dec_msglen; size_t minlen = 0; size_t olen = 0; /* * Check immediate ciphertext sanity */ #if defined(MBEDTLS_SSL_PROTO_TLS1_1) || defined(MBEDTLS_SSL_PROTO_TLS1_2) if( ssl->minor_ver >= MBEDTLS_SSL_MINOR_VERSION_2 ) minlen += ssl->transform_in->ivlen; #endif if( ssl->in_msglen < minlen + ssl->transform_in->ivlen || ssl->in_msglen < minlen + ssl->transform_in->maclen + 1 ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "msglen (%d) < max( ivlen(%d), maclen (%d) " "+ 1 ) ( + expl IV )", ssl->in_msglen, ssl->transform_in->ivlen, ssl->transform_in->maclen ) ); return( MBEDTLS_ERR_SSL_INVALID_MAC ); } dec_msglen = ssl->in_msglen; dec_msg = ssl->in_msg; dec_msg_result = ssl->in_msg; /* * Authenticate before decrypt if enabled */ #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC) if( ssl->session_in->encrypt_then_mac == MBEDTLS_SSL_ETM_ENABLED ) { unsigned char mac_expect[MBEDTLS_SSL_MAC_ADD]; unsigned char pseudo_hdr[13]; MBEDTLS_SSL_DEBUG_MSG( 3, ( "using encrypt then mac" ) ); dec_msglen -= ssl->transform_in->maclen; ssl->in_msglen -= ssl->transform_in->maclen; memcpy( pseudo_hdr + 0, ssl->in_ctr, 8 ); memcpy( pseudo_hdr + 8, ssl->in_hdr, 3 ); pseudo_hdr[11] = (unsigned char)( ( ssl->in_msglen >> 8 ) & 0xFF ); pseudo_hdr[12] = (unsigned char)( ( ssl->in_msglen ) & 0xFF ); MBEDTLS_SSL_DEBUG_BUF( 4, "MAC'd meta-data", pseudo_hdr, 13 ); mbedtls_md_hmac_update( &ssl->transform_in->md_ctx_dec, pseudo_hdr, 13 ); mbedtls_md_hmac_update( &ssl->transform_in->md_ctx_dec, ssl->in_iv, ssl->in_msglen ); mbedtls_md_hmac_finish( &ssl->transform_in->md_ctx_dec, mac_expect ); mbedtls_md_hmac_reset( &ssl->transform_in->md_ctx_dec ); MBEDTLS_SSL_DEBUG_BUF( 4, "message mac", ssl->in_iv + ssl->in_msglen, ssl->transform_in->maclen ); MBEDTLS_SSL_DEBUG_BUF( 4, "expected mac", mac_expect, ssl->transform_in->maclen ); if( mbedtls_ssl_safer_memcmp( ssl->in_iv + ssl->in_msglen, mac_expect, ssl->transform_in->maclen ) != 0 ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "message mac does not match" ) ); return( MBEDTLS_ERR_SSL_INVALID_MAC ); } auth_done++; } #endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */ /* * Check length sanity */ if( ssl->in_msglen % ssl->transform_in->ivlen != 0 ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "msglen (%d) %% ivlen (%d) != 0", ssl->in_msglen, ssl->transform_in->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( ssl->minor_ver >= MBEDTLS_SSL_MINOR_VERSION_2 ) { unsigned char i; dec_msglen -= ssl->transform_in->ivlen; ssl->in_msglen -= ssl->transform_in->ivlen; for( i = 0; i < ssl->transform_in->ivlen; i++ ) ssl->transform_in->iv_dec[i] = ssl->in_iv[i]; } #endif /* MBEDTLS_SSL_PROTO_TLS1_1 || MBEDTLS_SSL_PROTO_TLS1_2 */ if( ( ret = mbedtls_cipher_crypt( &ssl->transform_in->cipher_ctx_dec, ssl->transform_in->iv_dec, ssl->transform_in->ivlen, dec_msg, dec_msglen, dec_msg_result, &olen ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_crypt", ret ); return( ret ); } if( dec_msglen != 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( ssl->minor_ver < MBEDTLS_SSL_MINOR_VERSION_2 ) { /* * Save IV in SSL3 and TLS1 */ memcpy( ssl->transform_in->iv_dec, ssl->transform_in->cipher_ctx_dec.iv, ssl->transform_in->ivlen ); } #endif padlen = 1 + ssl->in_msg[ssl->in_msglen - 1]; if( ssl->in_msglen < ssl->transform_in->maclen + padlen && auth_done == 0 ) { #if defined(MBEDTLS_SSL_DEBUG_ALL) MBEDTLS_SSL_DEBUG_MSG( 1, ( "msglen (%d) < maclen (%d) + padlen (%d)", ssl->in_msglen, ssl->transform_in->maclen, padlen ) ); #endif padlen = 0; correct = 0; } #if defined(MBEDTLS_SSL_PROTO_SSL3) if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 ) { if( padlen > ssl->transform_in->ivlen ) { #if defined(MBEDTLS_SSL_DEBUG_ALL) MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad padding length: is %d, " "should be no more than %d", padlen, ssl->transform_in->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( ssl->minor_ver > MBEDTLS_SSL_MINOR_VERSION_0 ) { /* * TLSv1+: always check the padding up to the first failure * and fake check up to 256 bytes of padding */ size_t pad_count = 0, real_count = 1; size_t padding_idx = ssl->in_msglen - padlen; size_t i; /* * Padding is guaranteed to be incorrect if: * 1. padlen > ssl->in_msglen * * 2. padding_idx > MBEDTLS_SSL_IN_CONTENT_LEN + * ssl->transform_in->maclen * * In both cases we reset padding_idx to a safe value (0) to * prevent out-of-buffer reads. */ correct &= ( padlen <= ssl->in_msglen ); correct &= ( padding_idx <= MBEDTLS_SSL_IN_CONTENT_LEN + ssl->transform_in->maclen ); padding_idx *= correct; for( i = 0; i < 256; i++ ) { real_count &= ( i < padlen ); pad_count += real_count * ( ssl->in_msg[padding_idx + i] == padlen - 1 ); } correct &= ( pad_count == padlen ); /* Only 1 on correct padding */ #if defined(MBEDTLS_SSL_DEBUG_ALL) if( padlen > 0 && correct == 0 ) MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad padding byte detected" ) ); #endif padlen &= correct * 0x1FF; } else #endif /* MBEDTLS_SSL_PROTO_TLS1 || MBEDTLS_SSL_PROTO_TLS1_1 || \ MBEDTLS_SSL_PROTO_TLS1_2 */ { MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); } ssl->in_msglen -= padlen; } else #endif /* MBEDTLS_CIPHER_MODE_CBC && ( MBEDTLS_AES_C || MBEDTLS_CAMELLIA_C || MBEDTLS_ARIA_C ) */ { MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); } #if defined(MBEDTLS_SSL_DEBUG_ALL) MBEDTLS_SSL_DEBUG_BUF( 4, "raw buffer after decryption", ssl->in_msg, ssl->in_msglen ); #endif /* * Authenticate if not done yet. * Compute the MAC regardless of the padding result (RFC4346, CBCTIME). */ #if defined(SSL_SOME_MODES_USE_MAC) if( auth_done == 0 ) { unsigned char mac_expect[MBEDTLS_SSL_MAC_ADD]; ssl->in_msglen -= ssl->transform_in->maclen; ssl->in_len[0] = (unsigned char)( ssl->in_msglen >> 8 ); ssl->in_len[1] = (unsigned char)( ssl->in_msglen ); #if defined(MBEDTLS_SSL_PROTO_SSL3) if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 ) { ssl_mac( &ssl->transform_in->md_ctx_dec, ssl->transform_in->mac_dec, ssl->in_msg, ssl->in_msglen, ssl->in_ctr, ssl->in_msgtype, mac_expect ); } else #endif /* MBEDTLS_SSL_PROTO_SSL3 */ #if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) || \ defined(MBEDTLS_SSL_PROTO_TLS1_2) if( ssl->minor_ver > MBEDTLS_SSL_MINOR_VERSION_0 ) { /* * Process MAC and always update for padlen afterwards to make * total time independent of padlen. * * Known timing attacks: * - Lucky Thirteen (http://www.isg.rhul.ac.uk/tls/TLStiming.pdf) * * To compensate for different timings for the MAC calculation * depending on how much padding was removed (which is determined * by padlen), process extra_run more blocks through the hash * function. * * The formula in the paper is * extra_run = ceil( (L1-55) / 64 ) - ceil( (L2-55) / 64 ) * where L1 is the size of the header plus the decrypted message * plus CBC padding and L2 is the size of the header plus the * decrypted message. This is for an underlying hash function * with 64-byte blocks. * We use ( (Lx+8) / 64 ) to handle 'negative Lx' values * correctly. We round down instead of up, so -56 is the correct * value for our calculations instead of -55. * * Repeat the formula rather than defining a block_size variable. * This avoids requiring division by a variable at runtime * (which would be marginally less efficient and would require * linking an extra division function in some builds). */ size_t j, extra_run = 0; /* * The next two sizes are the minimum and maximum values of * in_msglen over all padlen values. * * They're independent of padlen, since we previously did * in_msglen -= padlen. * * Note that max_len + maclen is never more than the buffer * length, as we previously did in_msglen -= maclen too. */ const size_t max_len = ssl->in_msglen + padlen; const size_t min_len = ( max_len > 256 ) ? max_len - 256 : 0; switch( ssl->transform_in->ciphersuite_info->mac ) { #if defined(MBEDTLS_MD5_C) || defined(MBEDTLS_SHA1_C) || \ defined(MBEDTLS_SHA256_C) case MBEDTLS_MD_MD5: case MBEDTLS_MD_SHA1: case MBEDTLS_MD_SHA256: /* 8 bytes of message size, 64-byte compression blocks */ extra_run = ( 13 + ssl->in_msglen + padlen + 8 ) / 64 - ( 13 + ssl->in_msglen + 8 ) / 64; break; #endif #if defined(MBEDTLS_SHA512_C) case MBEDTLS_MD_SHA384: /* 16 bytes of message size, 128-byte compression blocks */ extra_run = ( 13 + ssl->in_msglen + padlen + 16 ) / 128 - ( 13 + ssl->in_msglen + 16 ) / 128; break; #endif default: MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); } extra_run &= correct * 0xFF; mbedtls_md_hmac_update( &ssl->transform_in->md_ctx_dec, ssl->in_ctr, 8 ); mbedtls_md_hmac_update( &ssl->transform_in->md_ctx_dec, ssl->in_hdr, 3 ); mbedtls_md_hmac_update( &ssl->transform_in->md_ctx_dec, ssl->in_len, 2 ); mbedtls_md_hmac_update( &ssl->transform_in->md_ctx_dec, ssl->in_msg, ssl->in_msglen ); /* Make sure we access everything even when padlen > 0. This * makes the synchronisation requirements for just-in-time * Prime+Probe attacks much tighter and hopefully impractical. */ ssl_read_memory( ssl->in_msg + ssl->in_msglen, padlen ); mbedtls_md_hmac_finish( &ssl->transform_in->md_ctx_dec, mac_expect ); /* Call mbedtls_md_process at least once due to cache attacks * that observe whether md_process() was called of not */ for( j = 0; j < extra_run + 1; j++ ) mbedtls_md_process( &ssl->transform_in->md_ctx_dec, ssl->in_msg ); mbedtls_md_hmac_reset( &ssl->transform_in->md_ctx_dec ); /* Make sure we access all the memory that could contain the MAC, * before we check it in the next code block. This makes the * synchronisation requirements for just-in-time Prime+Probe * attacks much tighter and hopefully impractical. */ ssl_read_memory( ssl->in_msg + min_len, max_len - min_len + ssl->transform_in->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, ssl->transform_in->maclen ); MBEDTLS_SSL_DEBUG_BUF( 4, "message mac", ssl->in_msg + ssl->in_msglen, ssl->transform_in->maclen ); #endif if( mbedtls_ssl_safer_memcmp( ssl->in_msg + ssl->in_msglen, mac_expect, ssl->transform_in->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 /* 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( ssl->in_msglen == 0 ) { #if defined(MBEDTLS_SSL_PROTO_TLS1_2) if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 && ssl->in_msgtype != MBEDTLS_SSL_MSG_APPLICATION_DATA ) { /* TLS v1.2 explicitly disallows zero-length messages which are not application data */ MBEDTLS_SSL_DEBUG_MSG( 1, ( "invalid zero-length message type: %d", ssl->in_msgtype ) ); return( MBEDTLS_ERR_SSL_INVALID_RECORD ); } #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */ ssl->nb_zero++; /* * Three or more empty messages may be a DoS attack * (excessive CPU consumption). */ if( ssl->nb_zero > 3 ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "received four consecutive empty " "messages, possible DoS attack" ) ); 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 char i; for( i = 8; i > ssl_ep_len( ssl ); i-- ) if( ++ssl->in_ctr[i - 1] != 0 ) break; /* The loop goes to its end iff the counter is wrapping */ if( i == ssl_ep_len( ssl ) ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "incoming message counter would wrap" ) ); return( MBEDTLS_ERR_SSL_COUNTER_WRAPPING ); } } MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= decrypt buf" ) ); return( 0 ); } #undef MAC_NONE #undef MAC_PLAINTEXT #undef MAC_CIPHERTEXT #if defined(MBEDTLS_ZLIB_SUPPORT) /* * Compression/decompression functions */ static int ssl_compress_buf( mbedtls_ssl_context *ssl ) { int ret; unsigned char *msg_post = ssl->out_msg; ptrdiff_t bytes_written = ssl->out_msg - ssl->out_buf; size_t len_pre = ssl->out_msglen; unsigned char *msg_pre = ssl->compress_buf; MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> compress buf" ) ); if( len_pre == 0 ) return( 0 ); memcpy( msg_pre, ssl->out_msg, len_pre ); MBEDTLS_SSL_DEBUG_MSG( 3, ( "before compression: msglen = %d, ", ssl->out_msglen ) ); MBEDTLS_SSL_DEBUG_BUF( 4, "before compression: output payload", ssl->out_msg, ssl->out_msglen ); ssl->transform_out->ctx_deflate.next_in = msg_pre; ssl->transform_out->ctx_deflate.avail_in = len_pre; ssl->transform_out->ctx_deflate.next_out = msg_post; ssl->transform_out->ctx_deflate.avail_out = MBEDTLS_SSL_OUT_BUFFER_LEN - bytes_written; ret = deflate( &ssl->transform_out->ctx_deflate, Z_SYNC_FLUSH ); if( ret != Z_OK ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "failed to perform compression (%d)", ret ) ); return( MBEDTLS_ERR_SSL_COMPRESSION_FAILED ); } ssl->out_msglen = MBEDTLS_SSL_OUT_BUFFER_LEN - ssl->transform_out->ctx_deflate.avail_out - bytes_written; MBEDTLS_SSL_DEBUG_MSG( 3, ( "after compression: msglen = %d, ", ssl->out_msglen ) ); MBEDTLS_SSL_DEBUG_BUF( 4, "after compression: output payload", ssl->out_msg, ssl->out_msglen ); MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= compress buf" ) ); return( 0 ); } static int ssl_decompress_buf( mbedtls_ssl_context *ssl ) { int ret; unsigned char *msg_post = ssl->in_msg; ptrdiff_t header_bytes = ssl->in_msg - ssl->in_buf; size_t len_pre = ssl->in_msglen; unsigned char *msg_pre = ssl->compress_buf; MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> decompress buf" ) ); if( len_pre == 0 ) return( 0 ); memcpy( msg_pre, ssl->in_msg, len_pre ); MBEDTLS_SSL_DEBUG_MSG( 3, ( "before decompression: msglen = %d, ", ssl->in_msglen ) ); MBEDTLS_SSL_DEBUG_BUF( 4, "before decompression: input payload", ssl->in_msg, ssl->in_msglen ); ssl->transform_in->ctx_inflate.next_in = msg_pre; ssl->transform_in->ctx_inflate.avail_in = len_pre; ssl->transform_in->ctx_inflate.next_out = msg_post; ssl->transform_in->ctx_inflate.avail_out = MBEDTLS_SSL_IN_BUFFER_LEN - header_bytes; ret = inflate( &ssl->transform_in->ctx_inflate, Z_SYNC_FLUSH ); if( ret != Z_OK ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "failed to perform decompression (%d)", ret ) ); return( MBEDTLS_ERR_SSL_COMPRESSION_FAILED ); } ssl->in_msglen = MBEDTLS_SSL_IN_BUFFER_LEN - ssl->transform_in->ctx_inflate.avail_out - header_bytes; MBEDTLS_SSL_DEBUG_MSG( 3, ( "after decompression: msglen = %d, ", ssl->in_msglen ) ); MBEDTLS_SSL_DEBUG_BUF( 4, "after decompression: input payload", ssl->in_msg, ssl->in_msglen ); MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= decompress buf" ) ); return( 0 ); } #endif /* MBEDTLS_ZLIB_SUPPORT */ #if defined(MBEDTLS_SSL_SRV_C) && defined(MBEDTLS_SSL_RENEGOTIATION) static int ssl_write_hello_request( mbedtls_ssl_context *ssl ); #if defined(MBEDTLS_SSL_PROTO_DTLS) static int ssl_resend_hello_request( mbedtls_ssl_context *ssl ) { /* If renegotiation is not enforced, retransmit until we would reach max * timeout if we were using the usual handshake doubling scheme */ if( ssl->conf->renego_max_records < 0 ) { uint32_t ratio = ssl->conf->hs_timeout_max / ssl->conf->hs_timeout_min + 1; unsigned char doublings = 1; while( ratio != 0 ) { ++doublings; ratio >>= 1; } if( ++ssl->renego_records_seen > doublings ) { MBEDTLS_SSL_DEBUG_MSG( 2, ( "no longer retransmitting hello request" ) ); return( 0 ); } } return( ssl_write_hello_request( ssl ) ); } #endif #endif /* MBEDTLS_SSL_SRV_C && MBEDTLS_SSL_RENEGOTIATION */ /* * Fill the input message buffer by appending data to it. * The amount of data already fetched is in ssl->in_left. * * If we return 0, is it guaranteed that (at least) nb_want bytes are * available (from this read and/or a previous one). Otherwise, an error code * is returned (possibly EOF or WANT_READ). * * With stream transport (TLS) on success ssl->in_left == nb_want, but * with datagram transport (DTLS) on success ssl->in_left >= nb_want, * since we always read a whole datagram at once. * * For DTLS, it is up to the caller to set ssl->next_record_offset when * they're done reading a record. */ int mbedtls_ssl_fetch_input( mbedtls_ssl_context *ssl, size_t nb_want ) { int ret; size_t len; MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> fetch input" ) ); if( ssl->f_recv == NULL && ssl->f_recv_timeout == NULL ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "Bad usage of mbedtls_ssl_set_bio() " "or mbedtls_ssl_set_bio()" ) ); return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); } if( nb_want > MBEDTLS_SSL_IN_BUFFER_LEN - (size_t)( ssl->in_hdr - ssl->in_buf ) ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "requesting more data than fits" ) ); return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); } #if defined(MBEDTLS_SSL_PROTO_DTLS) if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) { uint32_t timeout; /* Just to be sure */ if( ssl->f_set_timer == NULL || ssl->f_get_timer == NULL ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "You must use " "mbedtls_ssl_set_timer_cb() for DTLS" ) ); return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); } /* * The point is, we need to always read a full datagram at once, so we * sometimes read more then requested, and handle the additional data. * It could be the rest of the current record (while fetching the * header) and/or some other records in the same datagram. */ /* * Move to the next record in the already read datagram if applicable */ if( ssl->next_record_offset != 0 ) { if( ssl->in_left < ssl->next_record_offset ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); } ssl->in_left -= ssl->next_record_offset; if( ssl->in_left != 0 ) { MBEDTLS_SSL_DEBUG_MSG( 2, ( "next record in same datagram, offset: %d", ssl->next_record_offset ) ); memmove( ssl->in_hdr, ssl->in_hdr + ssl->next_record_offset, ssl->in_left ); } ssl->next_record_offset = 0; } MBEDTLS_SSL_DEBUG_MSG( 2, ( "in_left: %d, nb_want: %d", ssl->in_left, nb_want ) ); /* * Done if we already have enough data. */ if( nb_want <= ssl->in_left) { MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= fetch input" ) ); return( 0 ); } /* * A record can't be split accross datagrams. If we need to read but * are not at the beginning of a new record, the caller did something * wrong. */ if( ssl->in_left != 0 ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); } /* * Don't even try to read if time's out already. * This avoids by-passing the timer when repeatedly receiving messages * that will end up being dropped. */ if( ssl_check_timer( ssl ) != 0 ) { MBEDTLS_SSL_DEBUG_MSG( 2, ( "timer has expired" ) ); ret = MBEDTLS_ERR_SSL_TIMEOUT; } else { len = MBEDTLS_SSL_IN_BUFFER_LEN - ( ssl->in_hdr - ssl->in_buf ); if( ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER ) timeout = ssl->handshake->retransmit_timeout; else timeout = ssl->conf->read_timeout; MBEDTLS_SSL_DEBUG_MSG( 3, ( "f_recv_timeout: %u ms", timeout ) ); if( ssl->f_recv_timeout != NULL ) ret = ssl->f_recv_timeout( ssl->p_bio, ssl->in_hdr, len, timeout ); else ret = ssl->f_recv( ssl->p_bio, ssl->in_hdr, len ); MBEDTLS_SSL_DEBUG_RET( 2, "ssl->f_recv(_timeout)", ret ); if( ret == 0 ) return( MBEDTLS_ERR_SSL_CONN_EOF ); } if( ret == MBEDTLS_ERR_SSL_TIMEOUT ) { MBEDTLS_SSL_DEBUG_MSG( 2, ( "timeout" ) ); ssl_set_timer( ssl, 0 ); if( ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER ) { if( ssl_double_retransmit_timeout( ssl ) != 0 ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "handshake timeout" ) ); return( MBEDTLS_ERR_SSL_TIMEOUT ); } if( ( ret = mbedtls_ssl_resend( ssl ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_resend", ret ); return( ret ); } return( MBEDTLS_ERR_SSL_WANT_READ ); } #if defined(MBEDTLS_SSL_SRV_C) && defined(MBEDTLS_SSL_RENEGOTIATION) else if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER && ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_PENDING ) { if( ( ret = ssl_resend_hello_request( ssl ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "ssl_resend_hello_request", ret ); return( ret ); } return( MBEDTLS_ERR_SSL_WANT_READ ); } #endif /* MBEDTLS_SSL_SRV_C && MBEDTLS_SSL_RENEGOTIATION */ } if( ret < 0 ) return( ret ); ssl->in_left = ret; } else #endif { MBEDTLS_SSL_DEBUG_MSG( 2, ( "in_left: %d, nb_want: %d", ssl->in_left, nb_want ) ); while( ssl->in_left < nb_want ) { len = nb_want - ssl->in_left; if( ssl_check_timer( ssl ) != 0 ) ret = MBEDTLS_ERR_SSL_TIMEOUT; else { if( ssl->f_recv_timeout != NULL ) { ret = ssl->f_recv_timeout( ssl->p_bio, ssl->in_hdr + ssl->in_left, len, ssl->conf->read_timeout ); } else { ret = ssl->f_recv( ssl->p_bio, ssl->in_hdr + ssl->in_left, len ); } } MBEDTLS_SSL_DEBUG_MSG( 2, ( "in_left: %d, nb_want: %d", ssl->in_left, nb_want ) ); MBEDTLS_SSL_DEBUG_RET( 2, "ssl->f_recv(_timeout)", ret ); if( ret == 0 ) return( MBEDTLS_ERR_SSL_CONN_EOF ); if( ret < 0 ) return( ret ); if ( (size_t)ret > len || ( INT_MAX > SIZE_MAX && ret > SIZE_MAX ) ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "f_recv returned %d bytes but only %lu were requested", ret, (unsigned long)len ) ); return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); } ssl->in_left += ret; } } MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= fetch input" ) ); return( 0 ); } /* * Flush any data not yet written */ int mbedtls_ssl_flush_output( mbedtls_ssl_context *ssl ) { int ret; unsigned char *buf; MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> flush output" ) ); if( ssl->f_send == NULL ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "Bad usage of mbedtls_ssl_set_bio() " "or mbedtls_ssl_set_bio()" ) ); return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); } /* Avoid incrementing counter if data is flushed */ if( ssl->out_left == 0 ) { MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= flush output" ) ); return( 0 ); } while( ssl->out_left > 0 ) { MBEDTLS_SSL_DEBUG_MSG( 2, ( "message length: %d, out_left: %d", mbedtls_ssl_hdr_len( ssl ) + ssl->out_msglen, ssl->out_left ) ); buf = ssl->out_hdr - ssl->out_left; ret = ssl->f_send( ssl->p_bio, buf, ssl->out_left ); MBEDTLS_SSL_DEBUG_RET( 2, "ssl->f_send", ret ); if( ret <= 0 ) return( ret ); if( (size_t)ret > ssl->out_left || ( INT_MAX > SIZE_MAX && ret > SIZE_MAX ) ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "f_send returned %d bytes but only %lu bytes were sent", ret, (unsigned long)ssl->out_left ) ); return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); } ssl->out_left -= ret; } #if defined(MBEDTLS_SSL_PROTO_DTLS) if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) { ssl->out_hdr = ssl->out_buf; } else #endif { ssl->out_hdr = ssl->out_buf + 8; } ssl_update_out_pointers( ssl, ssl->transform_out ); MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= flush output" ) ); return( 0 ); } /* * Functions to handle the DTLS retransmission state machine */ #if defined(MBEDTLS_SSL_PROTO_DTLS) /* * Append current handshake message to current outgoing flight */ static int ssl_flight_append( mbedtls_ssl_context *ssl ) { mbedtls_ssl_flight_item *msg; MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> ssl_flight_append" ) ); MBEDTLS_SSL_DEBUG_BUF( 4, "message appended to flight", ssl->out_msg, ssl->out_msglen ); /* Allocate space for current message */ if( ( msg = mbedtls_calloc( 1, sizeof( mbedtls_ssl_flight_item ) ) ) == NULL ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "alloc %d bytes failed", sizeof( mbedtls_ssl_flight_item ) ) ); return( MBEDTLS_ERR_SSL_ALLOC_FAILED ); } if( ( msg->p = mbedtls_calloc( 1, ssl->out_msglen ) ) == NULL ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "alloc %d bytes failed", ssl->out_msglen ) ); mbedtls_free( msg ); return( MBEDTLS_ERR_SSL_ALLOC_FAILED ); } /* Copy current handshake message with headers */ memcpy( msg->p, ssl->out_msg, ssl->out_msglen ); msg->len = ssl->out_msglen; msg->type = ssl->out_msgtype; msg->next = NULL; /* Append to the current flight */ if( ssl->handshake->flight == NULL ) ssl->handshake->flight = msg; else { mbedtls_ssl_flight_item *cur = ssl->handshake->flight; while( cur->next != NULL ) cur = cur->next; cur->next = msg; } MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= ssl_flight_append" ) ); return( 0 ); } /* * Free the current flight of handshake messages */ static void ssl_flight_free( mbedtls_ssl_flight_item *flight ) { mbedtls_ssl_flight_item *cur = flight; mbedtls_ssl_flight_item *next; while( cur != NULL ) { next = cur->next; mbedtls_free( cur->p ); mbedtls_free( cur ); cur = next; } } #if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY) static void ssl_dtls_replay_reset( mbedtls_ssl_context *ssl ); #endif /* * Swap transform_out and out_ctr with the alternative ones */ static void ssl_swap_epochs( mbedtls_ssl_context *ssl ) { mbedtls_ssl_transform *tmp_transform; unsigned char tmp_out_ctr[8]; if( ssl->transform_out == ssl->handshake->alt_transform_out ) { MBEDTLS_SSL_DEBUG_MSG( 3, ( "skip swap epochs" ) ); return; } MBEDTLS_SSL_DEBUG_MSG( 3, ( "swap epochs" ) ); /* Swap transforms */ tmp_transform = ssl->transform_out; ssl->transform_out = ssl->handshake->alt_transform_out; ssl->handshake->alt_transform_out = tmp_transform; /* Swap epoch + sequence_number */ memcpy( tmp_out_ctr, ssl->cur_out_ctr, 8 ); memcpy( ssl->cur_out_ctr, ssl->handshake->alt_out_ctr, 8 ); memcpy( ssl->handshake->alt_out_ctr, tmp_out_ctr, 8 ); /* Adjust to the newly activated transform */ ssl_update_out_pointers( ssl, ssl->transform_out ); #if defined(MBEDTLS_SSL_HW_RECORD_ACCEL) if( mbedtls_ssl_hw_record_activate != NULL ) { if( ( ret = mbedtls_ssl_hw_record_activate( ssl, MBEDTLS_SSL_CHANNEL_OUTBOUND ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_hw_record_activate", ret ); return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED ); } } #endif } /* * Retransmit the current flight of messages. */ int mbedtls_ssl_resend( mbedtls_ssl_context *ssl ) { int ret = 0; MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> mbedtls_ssl_resend" ) ); ret = mbedtls_ssl_flight_transmit( ssl ); MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= mbedtls_ssl_resend" ) ); return( ret ); } /* * Transmit or retransmit the current flight of messages. * * Need to remember the current message in case flush_output returns * WANT_WRITE, causing us to exit this function and come back later. * This function must be called until state is no longer SENDING. */ int mbedtls_ssl_flight_transmit( mbedtls_ssl_context *ssl ) { int ret; MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> mbedtls_ssl_flight_transmit" ) ); if( ssl->handshake->retransmit_state != MBEDTLS_SSL_RETRANS_SENDING ) { MBEDTLS_SSL_DEBUG_MSG( 2, ( "initialise flight transmission" ) ); ssl->handshake->cur_msg = ssl->handshake->flight; ssl->handshake->cur_msg_p = ssl->handshake->flight->p + 12; ssl_swap_epochs( ssl ); ssl->handshake->retransmit_state = MBEDTLS_SSL_RETRANS_SENDING; } while( ssl->handshake->cur_msg != NULL ) { size_t max_frag_len; const mbedtls_ssl_flight_item * const cur = ssl->handshake->cur_msg; int const is_finished = ( cur->type == MBEDTLS_SSL_MSG_HANDSHAKE && cur->p[0] == MBEDTLS_SSL_HS_FINISHED ); uint8_t const force_flush = ssl->disable_datagram_packing == 1 ? SSL_FORCE_FLUSH : SSL_DONT_FORCE_FLUSH; /* Swap epochs before sending Finished: we can't do it after * sending ChangeCipherSpec, in case write returns WANT_READ. * Must be done before copying, may change out_msg pointer */ if( is_finished && ssl->handshake->cur_msg_p == ( cur->p + 12 ) ) { MBEDTLS_SSL_DEBUG_MSG( 2, ( "swap epochs to send finished message" ) ); ssl_swap_epochs( ssl ); } ret = ssl_get_remaining_payload_in_datagram( ssl ); if( ret < 0 ) return( ret ); max_frag_len = (size_t) ret; /* CCS is copied as is, while HS messages may need fragmentation */ if( cur->type == MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC ) { if( max_frag_len == 0 ) { if( ( ret = mbedtls_ssl_flush_output( ssl ) ) != 0 ) return( ret ); continue; } memcpy( ssl->out_msg, cur->p, cur->len ); ssl->out_msglen = cur->len; ssl->out_msgtype = cur->type; /* Update position inside current message */ ssl->handshake->cur_msg_p += cur->len; } else { const unsigned char * const p = ssl->handshake->cur_msg_p; const size_t hs_len = cur->len - 12; const size_t frag_off = p - ( cur->p + 12 ); const size_t rem_len = hs_len - frag_off; size_t cur_hs_frag_len, max_hs_frag_len; if( ( max_frag_len < 12 ) || ( max_frag_len == 12 && hs_len != 0 ) ) { if( is_finished ) ssl_swap_epochs( ssl ); if( ( ret = mbedtls_ssl_flush_output( ssl ) ) != 0 ) return( ret ); continue; } max_hs_frag_len = max_frag_len - 12; cur_hs_frag_len = rem_len > max_hs_frag_len ? max_hs_frag_len : rem_len; if( frag_off == 0 && cur_hs_frag_len != hs_len ) { MBEDTLS_SSL_DEBUG_MSG( 2, ( "fragmenting handshake message (%u > %u)", (unsigned) cur_hs_frag_len, (unsigned) max_hs_frag_len ) ); } /* Messages are stored with handshake headers as if not fragmented, * copy beginning of headers then fill fragmentation fields. * Handshake headers: type(1) len(3) seq(2) f_off(3) f_len(3) */ memcpy( ssl->out_msg, cur->p, 6 ); ssl->out_msg[6] = ( ( frag_off >> 16 ) & 0xff ); ssl->out_msg[7] = ( ( frag_off >> 8 ) & 0xff ); ssl->out_msg[8] = ( ( frag_off ) & 0xff ); ssl->out_msg[ 9] = ( ( cur_hs_frag_len >> 16 ) & 0xff ); ssl->out_msg[10] = ( ( cur_hs_frag_len >> 8 ) & 0xff ); ssl->out_msg[11] = ( ( cur_hs_frag_len ) & 0xff ); MBEDTLS_SSL_DEBUG_BUF( 3, "handshake header", ssl->out_msg, 12 ); /* Copy the handshake message content and set records fields */ memcpy( ssl->out_msg + 12, p, cur_hs_frag_len ); ssl->out_msglen = cur_hs_frag_len + 12; ssl->out_msgtype = cur->type; /* Update position inside current message */ ssl->handshake->cur_msg_p += cur_hs_frag_len; } /* If done with the current message move to the next one if any */ if( ssl->handshake->cur_msg_p >= cur->p + cur->len ) { if( cur->next != NULL ) { ssl->handshake->cur_msg = cur->next; ssl->handshake->cur_msg_p = cur->next->p + 12; } else { ssl->handshake->cur_msg = NULL; ssl->handshake->cur_msg_p = NULL; } } /* Actually send the message out */ if( ( ret = mbedtls_ssl_write_record( ssl, force_flush ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_record", ret ); return( ret ); } } if( ( ret = mbedtls_ssl_flush_output( ssl ) ) != 0 ) return( ret ); /* Update state and set timer */ if( ssl->state == MBEDTLS_SSL_HANDSHAKE_OVER ) ssl->handshake->retransmit_state = MBEDTLS_SSL_RETRANS_FINISHED; else { ssl->handshake->retransmit_state = MBEDTLS_SSL_RETRANS_WAITING; ssl_set_timer( ssl, ssl->handshake->retransmit_timeout ); } MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= mbedtls_ssl_flight_transmit" ) ); return( 0 ); } /* * To be called when the last message of an incoming flight is received. */ void mbedtls_ssl_recv_flight_completed( mbedtls_ssl_context *ssl ) { /* We won't need to resend that one any more */ ssl_flight_free( ssl->handshake->flight ); ssl->handshake->flight = NULL; ssl->handshake->cur_msg = NULL; /* The next incoming flight will start with this msg_seq */ ssl->handshake->in_flight_start_seq = ssl->handshake->in_msg_seq; /* We don't want to remember CCS's across flight boundaries. */ ssl->handshake->buffering.seen_ccs = 0; /* Clear future message buffering structure. */ ssl_buffering_free( ssl ); /* Cancel timer */ ssl_set_timer( ssl, 0 ); if( ssl->in_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE && ssl->in_msg[0] == MBEDTLS_SSL_HS_FINISHED ) { ssl->handshake->retransmit_state = MBEDTLS_SSL_RETRANS_FINISHED; } else ssl->handshake->retransmit_state = MBEDTLS_SSL_RETRANS_PREPARING; } /* * To be called when the last message of an outgoing flight is send. */ void mbedtls_ssl_send_flight_completed( mbedtls_ssl_context *ssl ) { ssl_reset_retransmit_timeout( ssl ); ssl_set_timer( ssl, ssl->handshake->retransmit_timeout ); if( ssl->in_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE && ssl->in_msg[0] == MBEDTLS_SSL_HS_FINISHED ) { ssl->handshake->retransmit_state = MBEDTLS_SSL_RETRANS_FINISHED; } else ssl->handshake->retransmit_state = MBEDTLS_SSL_RETRANS_WAITING; } #endif /* MBEDTLS_SSL_PROTO_DTLS */ /* * Handshake layer functions */ /* * Write (DTLS: or queue) current handshake (including CCS) message. * * - fill in handshake headers * - update handshake checksum * - DTLS: save message for resending * - then pass to the record layer * * DTLS: except for HelloRequest, messages are only queued, and will only be * actually sent when calling flight_transmit() or resend(). * * Inputs: * - ssl->out_msglen: 4 + actual handshake message len * (4 is the size of handshake headers for TLS) * - ssl->out_msg[0]: the handshake type (ClientHello, ServerHello, etc) * - ssl->out_msg + 4: the handshake message body * * Outputs, ie state before passing to flight_append() or write_record(): * - ssl->out_msglen: the length of the record contents * (including handshake headers but excluding record headers) * - ssl->out_msg: the record contents (handshake headers + content) */ int mbedtls_ssl_write_handshake_msg( mbedtls_ssl_context *ssl ) { int ret; const size_t hs_len = ssl->out_msglen - 4; const unsigned char hs_type = ssl->out_msg[0]; MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write handshake message" ) ); /* * Sanity checks */ if( ssl->out_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE && ssl->out_msgtype != MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC ) { /* In SSLv3, the client might send a NoCertificate alert. */ #if defined(MBEDTLS_SSL_PROTO_SSL3) && defined(MBEDTLS_SSL_CLI_C) if( ! ( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 && ssl->out_msgtype == MBEDTLS_SSL_MSG_ALERT && ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT ) ) #endif /* MBEDTLS_SSL_PROTO_SSL3 && MBEDTLS_SSL_SRV_C */ { MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); } } /* Whenever we send anything different from a * HelloRequest we should be in a handshake - double check. */ if( ! ( ssl->out_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE && hs_type == MBEDTLS_SSL_HS_HELLO_REQUEST ) && ssl->handshake == NULL ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); } #if defined(MBEDTLS_SSL_PROTO_DTLS) if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM && ssl->handshake != NULL && ssl->handshake->retransmit_state == MBEDTLS_SSL_RETRANS_SENDING ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); } #endif /* Double-check that we did not exceed the bounds * of the outgoing record buffer. * This should never fail as the various message * writing functions must obey the bounds of the * outgoing record buffer, but better be safe. * * Note: We deliberately do not check for the MTU or MFL here. */ if( ssl->out_msglen > MBEDTLS_SSL_OUT_CONTENT_LEN ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "Record too large: " "size %u, maximum %u", (unsigned) ssl->out_msglen, (unsigned) MBEDTLS_SSL_OUT_CONTENT_LEN ) ); return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); } /* * Fill handshake headers */ if( ssl->out_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE ) { ssl->out_msg[1] = (unsigned char)( hs_len >> 16 ); ssl->out_msg[2] = (unsigned char)( hs_len >> 8 ); ssl->out_msg[3] = (unsigned char)( hs_len ); /* * DTLS has additional fields in the Handshake layer, * between the length field and the actual payload: * uint16 message_seq; * uint24 fragment_offset; * uint24 fragment_length; */ #if defined(MBEDTLS_SSL_PROTO_DTLS) if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) { /* Make room for the additional DTLS fields */ if( MBEDTLS_SSL_OUT_CONTENT_LEN - ssl->out_msglen < 8 ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "DTLS handshake message too large: " "size %u, maximum %u", (unsigned) ( hs_len ), (unsigned) ( MBEDTLS_SSL_OUT_CONTENT_LEN - 12 ) ) ); return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); } memmove( ssl->out_msg + 12, ssl->out_msg + 4, hs_len ); ssl->out_msglen += 8; /* Write message_seq and update it, except for HelloRequest */ if( hs_type != MBEDTLS_SSL_HS_HELLO_REQUEST ) { ssl->out_msg[4] = ( ssl->handshake->out_msg_seq >> 8 ) & 0xFF; ssl->out_msg[5] = ( ssl->handshake->out_msg_seq ) & 0xFF; ++( ssl->handshake->out_msg_seq ); } else { ssl->out_msg[4] = 0; ssl->out_msg[5] = 0; } /* Handshake hashes are computed without fragmentation, * so set frag_offset = 0 and frag_len = hs_len for now */ memset( ssl->out_msg + 6, 0x00, 3 ); memcpy( ssl->out_msg + 9, ssl->out_msg + 1, 3 ); } #endif /* MBEDTLS_SSL_PROTO_DTLS */ /* Update running hashes of handshake messages seen */ if( hs_type != MBEDTLS_SSL_HS_HELLO_REQUEST ) ssl->handshake->update_checksum( ssl, ssl->out_msg, ssl->out_msglen ); } /* Either send now, or just save to be sent (and resent) later */ #if defined(MBEDTLS_SSL_PROTO_DTLS) if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM && ! ( ssl->out_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE && hs_type == MBEDTLS_SSL_HS_HELLO_REQUEST ) ) { if( ( ret = ssl_flight_append( ssl ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "ssl_flight_append", ret ); return( ret ); } } else #endif { if( ( ret = mbedtls_ssl_write_record( ssl, SSL_FORCE_FLUSH ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "ssl_write_record", ret ); return( ret ); } } MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write handshake message" ) ); return( 0 ); } /* * Record layer functions */ /* * Write current record. * * Uses: * - ssl->out_msgtype: type of the message (AppData, Handshake, Alert, CCS) * - ssl->out_msglen: length of the record content (excl headers) * - ssl->out_msg: record content */ int mbedtls_ssl_write_record( mbedtls_ssl_context *ssl, uint8_t force_flush ) { int ret, done = 0; size_t len = ssl->out_msglen; uint8_t flush = force_flush; MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write record" ) ); #if defined(MBEDTLS_ZLIB_SUPPORT) if( ssl->transform_out != NULL && ssl->session_out->compression == MBEDTLS_SSL_COMPRESS_DEFLATE ) { if( ( ret = ssl_compress_buf( ssl ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "ssl_compress_buf", ret ); return( ret ); } len = ssl->out_msglen; } #endif /*MBEDTLS_ZLIB_SUPPORT */ #if defined(MBEDTLS_SSL_HW_RECORD_ACCEL) if( mbedtls_ssl_hw_record_write != NULL ) { MBEDTLS_SSL_DEBUG_MSG( 2, ( "going for mbedtls_ssl_hw_record_write()" ) ); ret = mbedtls_ssl_hw_record_write( ssl ); if( ret != 0 && ret != MBEDTLS_ERR_SSL_HW_ACCEL_FALLTHROUGH ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_hw_record_write", ret ); return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED ); } if( ret == 0 ) done = 1; } #endif /* MBEDTLS_SSL_HW_RECORD_ACCEL */ if( !done ) { unsigned i; size_t protected_record_size; ssl->out_hdr[0] = (unsigned char) ssl->out_msgtype; 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 ) { if( ( ret = ssl_encrypt_buf( ssl ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "ssl_encrypt_buf", ret ); return( ret ); } len = ssl->out_msglen; ssl->out_len[0] = (unsigned char)( len >> 8 ); ssl->out_len[1] = (unsigned char)( len ); } protected_record_size = len + mbedtls_ssl_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 */ MBEDTLS_SSL_DEBUG_MSG( 3, ( "output record: msgtype = %d, " "version = [%d:%d], msglen = %d", ssl->out_hdr[0], ssl->out_hdr[1], ssl->out_hdr[2], len ) ); MBEDTLS_SSL_DEBUG_BUF( 4, "output record sent to network", ssl->out_hdr, protected_record_size ); ssl->out_left += protected_record_size; ssl->out_hdr += protected_record_size; ssl_update_out_pointers( ssl, ssl->transform_out ); for( i = 8; i > ssl_ep_len( ssl ); i-- ) if( ++ssl->cur_out_ctr[i - 1] != 0 ) break; /* The loop goes to its end iff the counter is wrapping */ if( i == ssl_ep_len( ssl ) ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "outgoing message counter would wrap" ) ); return( MBEDTLS_ERR_SSL_COUNTER_WRAPPING ); } } #if defined(MBEDTLS_SSL_PROTO_DTLS) if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM && flush == SSL_DONT_FORCE_FLUSH ) { size_t remaining; ret = ssl_get_remaining_payload_in_datagram( ssl ); if( ret < 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "ssl_get_remaining_payload_in_datagram", ret ); return( ret ); } remaining = (size_t) ret; if( remaining == 0 ) { flush = SSL_FORCE_FLUSH; } else { MBEDTLS_SSL_DEBUG_MSG( 2, ( "Still %u bytes available in current datagram", (unsigned) remaining ) ); } } #endif /* MBEDTLS_SSL_PROTO_DTLS */ if( ( flush == SSL_FORCE_FLUSH ) && ( ret = mbedtls_ssl_flush_output( ssl ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_flush_output", ret ); return( ret ); } MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write record" ) ); return( 0 ); } #if defined(MBEDTLS_SSL_PROTO_DTLS) static int ssl_hs_is_proper_fragment( mbedtls_ssl_context *ssl ) { if( ssl->in_msglen < ssl->in_hslen || memcmp( ssl->in_msg + 6, "\0\0\0", 3 ) != 0 || memcmp( ssl->in_msg + 9, ssl->in_msg + 1, 3 ) != 0 ) { return( 1 ); } return( 0 ); } static uint32_t ssl_get_hs_frag_len( mbedtls_ssl_context const *ssl ) { return( ( ssl->in_msg[9] << 16 ) | ( ssl->in_msg[10] << 8 ) | ssl->in_msg[11] ); } static uint32_t ssl_get_hs_frag_off( mbedtls_ssl_context const *ssl ) { return( ( ssl->in_msg[6] << 16 ) | ( ssl->in_msg[7] << 8 ) | ssl->in_msg[8] ); } static int ssl_check_hs_header( mbedtls_ssl_context const *ssl ) { uint32_t msg_len, frag_off, frag_len; msg_len = ssl_get_hs_total_len( ssl ); frag_off = ssl_get_hs_frag_off( ssl ); frag_len = ssl_get_hs_frag_len( ssl ); if( frag_off > msg_len ) return( -1 ); if( frag_len > msg_len - frag_off ) return( -1 ); if( frag_len + 12 > ssl->in_msglen ) return( -1 ); return( 0 ); } /* * Mark bits in bitmask (used for DTLS HS reassembly) */ static void ssl_bitmask_set( unsigned char *mask, size_t offset, size_t len ) { unsigned int start_bits, end_bits; start_bits = 8 - ( offset % 8 ); if( start_bits != 8 ) { size_t first_byte_idx = offset / 8; /* Special case */ if( len <= start_bits ) { for( ; len != 0; len-- ) mask[first_byte_idx] |= 1 << ( start_bits - len ); /* Avoid potential issues with offset or len becoming invalid */ return; } offset += start_bits; /* Now offset % 8 == 0 */ len -= start_bits; for( ; start_bits != 0; start_bits-- ) mask[first_byte_idx] |= 1 << ( start_bits - 1 ); } end_bits = len % 8; if( end_bits != 0 ) { size_t last_byte_idx = ( offset + len ) / 8; len -= end_bits; /* Now len % 8 == 0 */ for( ; end_bits != 0; end_bits-- ) mask[last_byte_idx] |= 1 << ( 8 - end_bits ); } memset( mask + offset / 8, 0xFF, len / 8 ); } /* * Check that bitmask is full */ static int ssl_bitmask_check( unsigned char *mask, size_t len ) { size_t i; for( i = 0; i < len / 8; i++ ) if( mask[i] != 0xFF ) return( -1 ); for( i = 0; i < len % 8; i++ ) if( ( mask[len / 8] & ( 1 << ( 7 - i ) ) ) == 0 ) return( -1 ); return( 0 ); } /* msg_len does not include the handshake header */ static size_t ssl_get_reassembly_buffer_size( size_t msg_len, unsigned add_bitmap ) { size_t alloc_len; alloc_len = 12; /* Handshake header */ alloc_len += msg_len; /* Content buffer */ if( add_bitmap ) alloc_len += msg_len / 8 + ( msg_len % 8 != 0 ); /* Bitmap */ return( alloc_len ); } #endif /* MBEDTLS_SSL_PROTO_DTLS */ static uint32_t ssl_get_hs_total_len( mbedtls_ssl_context const *ssl ) { return( ( ssl->in_msg[1] << 16 ) | ( ssl->in_msg[2] << 8 ) | ssl->in_msg[3] ); } int mbedtls_ssl_prepare_handshake_record( mbedtls_ssl_context *ssl ) { if( ssl->in_msglen < mbedtls_ssl_hs_hdr_len( ssl ) ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "handshake message too short: %d", ssl->in_msglen ) ); return( MBEDTLS_ERR_SSL_INVALID_RECORD ); } ssl->in_hslen = mbedtls_ssl_hs_hdr_len( ssl ) + ssl_get_hs_total_len( ssl ); MBEDTLS_SSL_DEBUG_MSG( 3, ( "handshake message: msglen =" " %d, type = %d, hslen = %d", ssl->in_msglen, ssl->in_msg[0], ssl->in_hslen ) ); #if defined(MBEDTLS_SSL_PROTO_DTLS) if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) { int ret; unsigned int recv_msg_seq = ( ssl->in_msg[4] << 8 ) | ssl->in_msg[5]; if( ssl_check_hs_header( ssl ) != 0 ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "invalid handshake header" ) ); return( MBEDTLS_ERR_SSL_INVALID_RECORD ); } if( ssl->handshake != NULL && ( ( ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER && recv_msg_seq != ssl->handshake->in_msg_seq ) || ( ssl->state == MBEDTLS_SSL_HANDSHAKE_OVER && ssl->in_msg[0] != MBEDTLS_SSL_HS_CLIENT_HELLO ) ) ) { if( recv_msg_seq > ssl->handshake->in_msg_seq ) { MBEDTLS_SSL_DEBUG_MSG( 2, ( "received future handshake message of sequence number %u (next %u)", recv_msg_seq, ssl->handshake->in_msg_seq ) ); return( MBEDTLS_ERR_SSL_EARLY_MESSAGE ); } /* Retransmit only on last message from previous flight, to avoid * too many retransmissions. * Besides, No sane server ever retransmits HelloVerifyRequest */ if( recv_msg_seq == ssl->handshake->in_flight_start_seq - 1 && ssl->in_msg[0] != MBEDTLS_SSL_HS_HELLO_VERIFY_REQUEST ) { MBEDTLS_SSL_DEBUG_MSG( 2, ( "received message from last flight, " "message_seq = %d, start_of_flight = %d", recv_msg_seq, ssl->handshake->in_flight_start_seq ) ); if( ( ret = mbedtls_ssl_resend( ssl ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_resend", ret ); return( ret ); } } else { MBEDTLS_SSL_DEBUG_MSG( 2, ( "dropping out-of-sequence message: " "message_seq = %d, expected = %d", recv_msg_seq, ssl->handshake->in_msg_seq ) ); } return( MBEDTLS_ERR_SSL_CONTINUE_PROCESSING ); } /* Wait until message completion to increment in_msg_seq */ /* Message reassembly is handled alongside buffering of future * messages; the commonality is that both handshake fragments and * future messages cannot be forwarded immediately to the * handshake logic layer. */ if( ssl_hs_is_proper_fragment( ssl ) == 1 ) { MBEDTLS_SSL_DEBUG_MSG( 2, ( "found fragmented DTLS handshake message" ) ); return( MBEDTLS_ERR_SSL_EARLY_MESSAGE ); } } else #endif /* MBEDTLS_SSL_PROTO_DTLS */ /* With TLS we don't handle fragmentation (for now) */ if( ssl->in_msglen < ssl->in_hslen ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "TLS handshake fragmentation not supported" ) ); return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE ); } return( 0 ); } void mbedtls_ssl_update_handshake_status( mbedtls_ssl_context *ssl ) { mbedtls_ssl_handshake_params * const hs = ssl->handshake; if( ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER && hs != NULL ) { ssl->handshake->update_checksum( ssl, ssl->in_msg, ssl->in_hslen ); } /* Handshake message is complete, increment counter */ #if defined(MBEDTLS_SSL_PROTO_DTLS) if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM && ssl->handshake != NULL ) { unsigned offset; mbedtls_ssl_hs_buffer *hs_buf; /* Increment handshake sequence number */ hs->in_msg_seq++; /* * Clear up handshake buffering and reassembly structure. */ /* Free first entry */ ssl_buffering_free_slot( ssl, 0 ); /* Shift all other entries */ for( offset = 0, hs_buf = &hs->buffering.hs[0]; offset + 1 < MBEDTLS_SSL_MAX_BUFFERED_HS; offset++, hs_buf++ ) { *hs_buf = *(hs_buf + 1); } /* Create a fresh last entry */ memset( hs_buf, 0, sizeof( mbedtls_ssl_hs_buffer ) ); } #endif } /* * DTLS anti-replay: RFC 6347 4.1.2.6 * * in_window is a field of bits numbered from 0 (lsb) to 63 (msb). * Bit n is set iff record number in_window_top - n has been seen. * * Usually, in_window_top is the last record number seen and the lsb of * in_window is set. The only exception is the initial state (record number 0 * not seen yet). */ #if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY) static void ssl_dtls_replay_reset( mbedtls_ssl_context *ssl ) { ssl->in_window_top = 0; ssl->in_window = 0; } static inline uint64_t ssl_load_six_bytes( unsigned char *buf ) { return( ( (uint64_t) buf[0] << 40 ) | ( (uint64_t) buf[1] << 32 ) | ( (uint64_t) buf[2] << 24 ) | ( (uint64_t) buf[3] << 16 ) | ( (uint64_t) buf[4] << 8 ) | ( (uint64_t) buf[5] ) ); } /* * Return 0 if sequence number is acceptable, -1 otherwise */ int mbedtls_ssl_dtls_replay_check( mbedtls_ssl_context *ssl ) { uint64_t rec_seqnum = ssl_load_six_bytes( ssl->in_ctr + 2 ); uint64_t bit; if( ssl->conf->anti_replay == MBEDTLS_SSL_ANTI_REPLAY_DISABLED ) return( 0 ); if( rec_seqnum > ssl->in_window_top ) return( 0 ); bit = ssl->in_window_top - rec_seqnum; if( bit >= 64 ) return( -1 ); if( ( ssl->in_window & ( (uint64_t) 1 << bit ) ) != 0 ) return( -1 ); return( 0 ); } /* * Update replay window on new validated record */ void mbedtls_ssl_dtls_replay_update( mbedtls_ssl_context *ssl ) { uint64_t rec_seqnum = ssl_load_six_bytes( ssl->in_ctr + 2 ); if( ssl->conf->anti_replay == MBEDTLS_SSL_ANTI_REPLAY_DISABLED ) return; if( rec_seqnum > ssl->in_window_top ) { /* Update window_top and the contents of the window */ uint64_t shift = rec_seqnum - ssl->in_window_top; if( shift >= 64 ) ssl->in_window = 1; else { ssl->in_window <<= shift; ssl->in_window |= 1; } ssl->in_window_top = rec_seqnum; } else { /* Mark that number as seen in the current window */ uint64_t bit = ssl->in_window_top - rec_seqnum; if( bit < 64 ) /* Always true, but be extra sure */ ssl->in_window |= (uint64_t) 1 << bit; } } #endif /* MBEDTLS_SSL_DTLS_ANTI_REPLAY */ #if defined(MBEDTLS_SSL_DTLS_CLIENT_PORT_REUSE) && defined(MBEDTLS_SSL_SRV_C) /* Forward declaration */ static int ssl_session_reset_int( mbedtls_ssl_context *ssl, int partial ); /* * Without any SSL context, check if a datagram looks like a ClientHello with * a valid cookie, and if it doesn't, generate a HelloVerifyRequest message. * Both input and output include full DTLS headers. * * - if cookie is valid, return 0 * - if ClientHello looks superficially valid but cookie is not, * fill obuf and set olen, then * return MBEDTLS_ERR_SSL_HELLO_VERIFY_REQUIRED * - otherwise return a specific error code */ static int ssl_check_dtls_clihlo_cookie( mbedtls_ssl_cookie_write_t *f_cookie_write, mbedtls_ssl_cookie_check_t *f_cookie_check, void *p_cookie, const unsigned char *cli_id, size_t cli_id_len, const unsigned char *in, size_t in_len, unsigned char *obuf, size_t buf_len, size_t *olen ) { size_t sid_len, cookie_len; unsigned char *p; if( f_cookie_write == NULL || f_cookie_check == NULL ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); /* * Structure of ClientHello with record and handshake headers, * and expected values. We don't need to check a lot, more checks will be * done when actually parsing the ClientHello - skipping those checks * avoids code duplication and does not make cookie forging any easier. * * 0-0 ContentType type; copied, must be handshake * 1-2 ProtocolVersion version; copied * 3-4 uint16 epoch; copied, must be 0 * 5-10 uint48 sequence_number; copied * 11-12 uint16 length; (ignored) * * 13-13 HandshakeType msg_type; (ignored) * 14-16 uint24 length; (ignored) * 17-18 uint16 message_seq; copied * 19-21 uint24 fragment_offset; copied, must be 0 * 22-24 uint24 fragment_length; (ignored) * * 25-26 ProtocolVersion client_version; (ignored) * 27-58 Random random; (ignored) * 59-xx SessionID session_id; 1 byte len + sid_len content * 60+ opaque cookie<0..2^8-1>; 1 byte len + content * ... * * Minimum length is 61 bytes. */ if( in_len < 61 || in[0] != MBEDTLS_SSL_MSG_HANDSHAKE || in[3] != 0 || in[4] != 0 || in[19] != 0 || in[20] != 0 || in[21] != 0 ) { return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); } sid_len = in[59]; if( sid_len > in_len - 61 ) return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); cookie_len = in[60 + sid_len]; if( cookie_len > in_len - 60 ) return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); if( f_cookie_check( p_cookie, in + sid_len + 61, cookie_len, cli_id, cli_id_len ) == 0 ) { /* Valid cookie */ return( 0 ); } /* * If we get here, we've got an invalid cookie, let's prepare HVR. * * 0-0 ContentType type; copied * 1-2 ProtocolVersion version; copied * 3-4 uint16 epoch; copied * 5-10 uint48 sequence_number; copied * 11-12 uint16 length; olen - 13 * * 13-13 HandshakeType msg_type; hello_verify_request * 14-16 uint24 length; olen - 25 * 17-18 uint16 message_seq; copied * 19-21 uint24 fragment_offset; copied * 22-24 uint24 fragment_length; olen - 25 * * 25-26 ProtocolVersion server_version; 0xfe 0xff * 27-27 opaque cookie<0..2^8-1>; cookie_len = olen - 27, cookie * * Minimum length is 28. */ if( buf_len < 28 ) return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL ); /* Copy most fields and adapt others */ memcpy( obuf, in, 25 ); obuf[13] = MBEDTLS_SSL_HS_HELLO_VERIFY_REQUEST; obuf[25] = 0xfe; obuf[26] = 0xff; /* Generate and write actual cookie */ p = obuf + 28; if( f_cookie_write( p_cookie, &p, obuf + buf_len, cli_id, cli_id_len ) != 0 ) { return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); } *olen = p - obuf; /* Go back and fill length fields */ obuf[27] = (unsigned char)( *olen - 28 ); obuf[14] = obuf[22] = (unsigned char)( ( *olen - 25 ) >> 16 ); obuf[15] = obuf[23] = (unsigned char)( ( *olen - 25 ) >> 8 ); obuf[16] = obuf[24] = (unsigned char)( ( *olen - 25 ) ); obuf[11] = (unsigned char)( ( *olen - 13 ) >> 8 ); obuf[12] = (unsigned char)( ( *olen - 13 ) ); return( MBEDTLS_ERR_SSL_HELLO_VERIFY_REQUIRED ); } /* * Handle possible client reconnect with the same UDP quadruplet * (RFC 6347 Section 4.2.8). * * Called by ssl_parse_record_header() in case we receive an epoch 0 record * that looks like a ClientHello. * * - if the input looks like a ClientHello without cookies, * send back HelloVerifyRequest, then * return MBEDTLS_ERR_SSL_HELLO_VERIFY_REQUIRED * - if the input looks like a ClientHello with a valid cookie, * reset the session of the current context, and * return MBEDTLS_ERR_SSL_CLIENT_RECONNECT * - if anything goes wrong, return a specific error code * * mbedtls_ssl_read_record() will ignore the record if anything else than * MBEDTLS_ERR_SSL_CLIENT_RECONNECT or 0 is returned, although this function * cannot not return 0. */ static int ssl_handle_possible_reconnect( mbedtls_ssl_context *ssl ) { int ret; size_t len; ret = ssl_check_dtls_clihlo_cookie( ssl->conf->f_cookie_write, ssl->conf->f_cookie_check, ssl->conf->p_cookie, ssl->cli_id, ssl->cli_id_len, ssl->in_buf, ssl->in_left, ssl->out_buf, MBEDTLS_SSL_OUT_CONTENT_LEN, &len ); MBEDTLS_SSL_DEBUG_RET( 2, "ssl_check_dtls_clihlo_cookie", ret ); if( ret == MBEDTLS_ERR_SSL_HELLO_VERIFY_REQUIRED ) { /* Don't check write errors as we can't do anything here. * If the error is permanent we'll catch it later, * if it's not, then hopefully it'll work next time. */ (void) ssl->f_send( ssl->p_bio, ssl->out_buf, len ); return( MBEDTLS_ERR_SSL_HELLO_VERIFY_REQUIRED ); } if( ret == 0 ) { /* Got a valid cookie, partially reset context */ if( ( ret = ssl_session_reset_int( ssl, 1 ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "reset", ret ); return( ret ); } return( MBEDTLS_ERR_SSL_CLIENT_RECONNECT ); } return( ret ); } #endif /* MBEDTLS_SSL_DTLS_CLIENT_PORT_REUSE && MBEDTLS_SSL_SRV_C */ /* * ContentType type; * ProtocolVersion version; * uint16 epoch; // DTLS only * uint48 sequence_number; // DTLS only * uint16 length; * * Return 0 if header looks sane (and, for DTLS, the record is expected) * MBEDTLS_ERR_SSL_INVALID_RECORD if the header looks bad, * MBEDTLS_ERR_SSL_UNEXPECTED_RECORD (DTLS only) if sane but unexpected. * * With DTLS, mbedtls_ssl_read_record() will: * 1. proceed with the record if this function returns 0 * 2. drop only the current record if this function returns UNEXPECTED_RECORD * 3. return CLIENT_RECONNECT if this function return that value * 4. drop the whole datagram if this function returns anything else. * Point 2 is needed when the peer is resending, and we have already received * the first record from a datagram but are still waiting for the others. */ static int ssl_parse_record_header( mbedtls_ssl_context *ssl ) { int major_ver, minor_ver; MBEDTLS_SSL_DEBUG_BUF( 4, "input record header", ssl->in_hdr, mbedtls_ssl_hdr_len( ssl ) ); ssl->in_msgtype = ssl->in_hdr[0]; ssl->in_msglen = ( ssl->in_len[0] << 8 ) | ssl->in_len[1]; mbedtls_ssl_read_version( &major_ver, &minor_ver, ssl->conf->transport, ssl->in_hdr + 1 ); MBEDTLS_SSL_DEBUG_MSG( 3, ( "input record: msgtype = %d, " "version = [%d:%d], msglen = %d", ssl->in_msgtype, major_ver, minor_ver, ssl->in_msglen ) ); /* Check record type */ if( ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE && ssl->in_msgtype != MBEDTLS_SSL_MSG_ALERT && ssl->in_msgtype != MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC && ssl->in_msgtype != MBEDTLS_SSL_MSG_APPLICATION_DATA ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "unknown record type" ) ); #if defined(MBEDTLS_SSL_PROTO_DTLS) /* Silently ignore invalid DTLS records as recommended by RFC 6347 * Section 4.1.2.7 */ if( ssl->conf->transport != MBEDTLS_SSL_TRANSPORT_DATAGRAM ) #endif /* MBEDTLS_SSL_PROTO_DTLS */ mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE ); return( MBEDTLS_ERR_SSL_INVALID_RECORD ); } /* Check version */ if( major_ver != ssl->major_ver ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "major version mismatch" ) ); return( MBEDTLS_ERR_SSL_INVALID_RECORD ); } if( minor_ver > ssl->conf->max_minor_ver ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "minor version mismatch" ) ); return( MBEDTLS_ERR_SSL_INVALID_RECORD ); } /* Check length against the size of our buffer */ if( ssl->in_msglen > MBEDTLS_SSL_IN_BUFFER_LEN - (size_t)( ssl->in_msg - ssl->in_buf ) ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad message length" ) ); return( MBEDTLS_ERR_SSL_INVALID_RECORD ); } /* * DTLS-related tests. * Check epoch before checking length constraint because * the latter varies with the epoch. E.g., if a ChangeCipherSpec * message gets duplicated before the corresponding Finished message, * the second ChangeCipherSpec should be discarded because it belongs * to an old epoch, but not because its length is shorter than * the minimum record length for packets using the new record transform. * Note that these two kinds of failures are handled differently, * as an unexpected record is silently skipped but an invalid * record leads to the entire datagram being dropped. */ #if defined(MBEDTLS_SSL_PROTO_DTLS) if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) { unsigned int rec_epoch = ( ssl->in_ctr[0] << 8 ) | ssl->in_ctr[1]; /* Check epoch (and sequence number) with DTLS */ if( rec_epoch != ssl->in_epoch ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "record from another epoch: " "expected %d, received %d", ssl->in_epoch, rec_epoch ) ); #if defined(MBEDTLS_SSL_DTLS_CLIENT_PORT_REUSE) && defined(MBEDTLS_SSL_SRV_C) /* * Check for an epoch 0 ClientHello. We can't use in_msg here to * access the first byte of record content (handshake type), as we * have an active transform (possibly iv_len != 0), so use the * fact that the record header len is 13 instead. */ if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER && ssl->state == MBEDTLS_SSL_HANDSHAKE_OVER && rec_epoch == 0 && ssl->in_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE && ssl->in_left > 13 && ssl->in_buf[13] == MBEDTLS_SSL_HS_CLIENT_HELLO ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "possible client reconnect " "from the same port" ) ); return( ssl_handle_possible_reconnect( ssl ) ); } else #endif /* MBEDTLS_SSL_DTLS_CLIENT_PORT_REUSE && MBEDTLS_SSL_SRV_C */ { /* Consider buffering the record. */ if( rec_epoch == (unsigned int) ssl->in_epoch + 1 ) { MBEDTLS_SSL_DEBUG_MSG( 2, ( "Consider record for buffering" ) ); return( MBEDTLS_ERR_SSL_EARLY_MESSAGE ); } return( MBEDTLS_ERR_SSL_UNEXPECTED_RECORD ); } } #if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY) /* Replay detection only works for the current epoch */ if( rec_epoch == ssl->in_epoch && mbedtls_ssl_dtls_replay_check( ssl ) != 0 ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "replayed record" ) ); return( MBEDTLS_ERR_SSL_UNEXPECTED_RECORD ); } #endif /* 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_UNEXPECTED_RECORD ); } } #endif /* MBEDTLS_SSL_PROTO_DTLS */ /* Check length against bounds of the current transform and version */ if( ssl->transform_in == NULL ) { if( ssl->in_msglen < 1 || ssl->in_msglen > MBEDTLS_SSL_IN_CONTENT_LEN ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad message length" ) ); return( MBEDTLS_ERR_SSL_INVALID_RECORD ); } } else { if( ssl->in_msglen < ssl->transform_in->minlen ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad message length" ) ); return( MBEDTLS_ERR_SSL_INVALID_RECORD ); } #if defined(MBEDTLS_SSL_PROTO_SSL3) if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 && ssl->in_msglen > ssl->transform_in->minlen + MBEDTLS_SSL_IN_CONTENT_LEN ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad message length" ) ); return( MBEDTLS_ERR_SSL_INVALID_RECORD ); } #endif #if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) || \ defined(MBEDTLS_SSL_PROTO_TLS1_2) /* * TLS encrypted messages can have up to 256 bytes of padding */ if( ssl->minor_ver >= MBEDTLS_SSL_MINOR_VERSION_1 && ssl->in_msglen > ssl->transform_in->minlen + MBEDTLS_SSL_IN_CONTENT_LEN + 256 ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad message length" ) ); return( MBEDTLS_ERR_SSL_INVALID_RECORD ); } #endif } return( 0 ); } /* * If applicable, decrypt (and decompress) record content */ static int ssl_prepare_record_content( mbedtls_ssl_context *ssl ) { int ret, done = 0; MBEDTLS_SSL_DEBUG_BUF( 4, "input record from network", ssl->in_hdr, mbedtls_ssl_hdr_len( ssl ) + ssl->in_msglen ); #if defined(MBEDTLS_SSL_HW_RECORD_ACCEL) if( mbedtls_ssl_hw_record_read != NULL ) { MBEDTLS_SSL_DEBUG_MSG( 2, ( "going for mbedtls_ssl_hw_record_read()" ) ); ret = mbedtls_ssl_hw_record_read( ssl ); if( ret != 0 && ret != MBEDTLS_ERR_SSL_HW_ACCEL_FALLTHROUGH ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_hw_record_read", ret ); return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED ); } if( ret == 0 ) done = 1; } #endif /* MBEDTLS_SSL_HW_RECORD_ACCEL */ if( !done && ssl->transform_in != NULL ) { if( ( ret = ssl_decrypt_buf( ssl ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "ssl_decrypt_buf", ret ); return( ret ); } MBEDTLS_SSL_DEBUG_BUF( 4, "input payload after decrypt", ssl->in_msg, ssl->in_msglen ); if( ssl->in_msglen > MBEDTLS_SSL_IN_CONTENT_LEN ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad message length" ) ); return( MBEDTLS_ERR_SSL_INVALID_RECORD ); } } #if defined(MBEDTLS_ZLIB_SUPPORT) if( ssl->transform_in != NULL && ssl->session_in->compression == MBEDTLS_SSL_COMPRESS_DEFLATE ) { if( ( ret = ssl_decompress_buf( ssl ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "ssl_decompress_buf", ret ); return( ret ); } } #endif /* MBEDTLS_ZLIB_SUPPORT */ #if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY) if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) { mbedtls_ssl_dtls_replay_update( ssl ); } #endif return( 0 ); } static void ssl_handshake_wrapup_free_hs_transform( mbedtls_ssl_context *ssl ); /* * Read a record. * * Silently ignore non-fatal alert (and for DTLS, invalid records as well, * RFC 6347 4.1.2.7) and continue reading until a valid record is found. * */ /* Helper functions for mbedtls_ssl_read_record(). */ static int ssl_consume_current_message( mbedtls_ssl_context *ssl ); static int ssl_get_next_record( mbedtls_ssl_context *ssl ); static int ssl_record_is_in_progress( mbedtls_ssl_context *ssl ); int mbedtls_ssl_read_record( mbedtls_ssl_context *ssl, unsigned update_hs_digest ) { int ret; MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> read record" ) ); if( ssl->keep_current_message == 0 ) { do { ret = ssl_consume_current_message( ssl ); if( ret != 0 ) return( ret ); if( ssl_record_is_in_progress( ssl ) == 0 ) { #if defined(MBEDTLS_SSL_PROTO_DTLS) int have_buffered = 0; /* We only check for buffered messages if the * current datagram is fully consumed. */ if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM && ssl_next_record_is_in_datagram( ssl ) == 0 ) { if( ssl_load_buffered_message( ssl ) == 0 ) have_buffered = 1; } if( have_buffered == 0 ) #endif /* MBEDTLS_SSL_PROTO_DTLS */ { ret = ssl_get_next_record( ssl ); if( ret == MBEDTLS_ERR_SSL_CONTINUE_PROCESSING ) continue; if( ret != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, ( "ssl_get_next_record" ), ret ); return( ret ); } } } ret = mbedtls_ssl_handle_message_type( ssl ); #if defined(MBEDTLS_SSL_PROTO_DTLS) if( ret == MBEDTLS_ERR_SSL_EARLY_MESSAGE ) { /* Buffer future message */ ret = ssl_buffer_message( ssl ); if( ret != 0 ) return( ret ); ret = MBEDTLS_ERR_SSL_CONTINUE_PROCESSING; } #endif /* MBEDTLS_SSL_PROTO_DTLS */ } while( MBEDTLS_ERR_SSL_NON_FATAL == ret || MBEDTLS_ERR_SSL_CONTINUE_PROCESSING == ret ); if( 0 != ret ) { MBEDTLS_SSL_DEBUG_RET( 1, ( "mbedtls_ssl_handle_message_type" ), ret ); return( ret ); } if( ssl->in_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE && update_hs_digest == 1 ) { mbedtls_ssl_update_handshake_status( ssl ); } } else { MBEDTLS_SSL_DEBUG_MSG( 2, ( "reuse previously read message" ) ); ssl->keep_current_message = 0; } MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= read record" ) ); return( 0 ); } #if defined(MBEDTLS_SSL_PROTO_DTLS) static int ssl_next_record_is_in_datagram( mbedtls_ssl_context *ssl ) { if( ssl->in_left > ssl->next_record_offset ) return( 1 ); return( 0 ); } static int ssl_load_buffered_message( mbedtls_ssl_context *ssl ) { mbedtls_ssl_handshake_params * const hs = ssl->handshake; mbedtls_ssl_hs_buffer * hs_buf; int ret = 0; if( hs == NULL ) return( -1 ); MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> ssl_load_buffered_messsage" ) ); if( ssl->state == MBEDTLS_SSL_CLIENT_CHANGE_CIPHER_SPEC || ssl->state == MBEDTLS_SSL_SERVER_CHANGE_CIPHER_SPEC ) { /* Check if we have seen a ChangeCipherSpec before. * If yes, synthesize a CCS record. */ if( !hs->buffering.seen_ccs ) { MBEDTLS_SSL_DEBUG_MSG( 2, ( "CCS not seen in the current flight" ) ); ret = -1; goto exit; } MBEDTLS_SSL_DEBUG_MSG( 2, ( "Injecting buffered CCS message" ) ); ssl->in_msgtype = MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC; ssl->in_msglen = 1; ssl->in_msg[0] = 1; /* As long as they are equal, the exact value doesn't matter. */ ssl->in_left = 0; ssl->next_record_offset = 0; hs->buffering.seen_ccs = 0; goto exit; } #if defined(MBEDTLS_DEBUG_C) /* Debug only */ { unsigned offset; for( offset = 1; offset < MBEDTLS_SSL_MAX_BUFFERED_HS; offset++ ) { hs_buf = &hs->buffering.hs[offset]; if( hs_buf->is_valid == 1 ) { MBEDTLS_SSL_DEBUG_MSG( 2, ( "Future message with sequence number %u %s buffered.", hs->in_msg_seq + offset, hs_buf->is_complete ? "fully" : "partially" ) ); } } } #endif /* MBEDTLS_DEBUG_C */ /* Check if we have buffered and/or fully reassembled the * next handshake message. */ hs_buf = &hs->buffering.hs[0]; if( ( hs_buf->is_valid == 1 ) && ( hs_buf->is_complete == 1 ) ) { /* Synthesize a record containing the buffered HS message. */ size_t msg_len = ( hs_buf->data[1] << 16 ) | ( hs_buf->data[2] << 8 ) | hs_buf->data[3]; /* Double-check that we haven't accidentally buffered * a message that doesn't fit into the input buffer. */ if( msg_len + 12 > MBEDTLS_SSL_IN_CONTENT_LEN ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); } MBEDTLS_SSL_DEBUG_MSG( 2, ( "Next handshake message has been buffered - load" ) ); MBEDTLS_SSL_DEBUG_BUF( 3, "Buffered handshake message (incl. header)", hs_buf->data, msg_len + 12 ); ssl->in_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE; ssl->in_hslen = msg_len + 12; ssl->in_msglen = msg_len + 12; memcpy( ssl->in_msg, hs_buf->data, ssl->in_hslen ); ret = 0; goto exit; } else { MBEDTLS_SSL_DEBUG_MSG( 2, ( "Next handshake message %u not or only partially bufffered", hs->in_msg_seq ) ); } ret = -1; exit: MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= ssl_load_buffered_message" ) ); return( ret ); } static int ssl_buffer_make_space( mbedtls_ssl_context *ssl, size_t desired ) { int offset; mbedtls_ssl_handshake_params * const hs = ssl->handshake; MBEDTLS_SSL_DEBUG_MSG( 2, ( "Attempt to free buffered messages to have %u bytes available", (unsigned) desired ) ); /* Get rid of future records epoch first, if such exist. */ ssl_free_buffered_record( ssl ); /* Check if we have enough space available now. */ if( desired <= ( MBEDTLS_SSL_DTLS_MAX_BUFFERING - hs->buffering.total_bytes_buffered ) ) { MBEDTLS_SSL_DEBUG_MSG( 2, ( "Enough space available after freeing future epoch record" ) ); return( 0 ); } /* We don't have enough space to buffer the next expected handshake * message. Remove buffers used for future messages to gain space, * starting with the most distant one. */ for( offset = MBEDTLS_SSL_MAX_BUFFERED_HS - 1; offset >= 0; offset-- ) { MBEDTLS_SSL_DEBUG_MSG( 2, ( "Free buffering slot %d to make space for reassembly of next handshake message", offset ) ); ssl_buffering_free_slot( ssl, (uint8_t) offset ); /* Check if we have enough space available now. */ if( desired <= ( MBEDTLS_SSL_DTLS_MAX_BUFFERING - hs->buffering.total_bytes_buffered ) ) { MBEDTLS_SSL_DEBUG_MSG( 2, ( "Enough space available after freeing buffered HS messages" ) ); return( 0 ); } } return( -1 ); } static int ssl_buffer_message( mbedtls_ssl_context *ssl ) { int ret = 0; mbedtls_ssl_handshake_params * const hs = ssl->handshake; if( hs == NULL ) return( 0 ); MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> ssl_buffer_message" ) ); switch( ssl->in_msgtype ) { case MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC: MBEDTLS_SSL_DEBUG_MSG( 2, ( "Remember CCS message" ) ); hs->buffering.seen_ccs = 1; break; case MBEDTLS_SSL_MSG_HANDSHAKE: { unsigned recv_msg_seq_offset; unsigned recv_msg_seq = ( ssl->in_msg[4] << 8 ) | ssl->in_msg[5]; mbedtls_ssl_hs_buffer *hs_buf; size_t msg_len = ssl->in_hslen - 12; /* We should never receive an old handshake * message - double-check nonetheless. */ if( recv_msg_seq < ssl->handshake->in_msg_seq ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); } recv_msg_seq_offset = recv_msg_seq - ssl->handshake->in_msg_seq; if( recv_msg_seq_offset >= MBEDTLS_SSL_MAX_BUFFERED_HS ) { /* Silently ignore -- message too far in the future */ MBEDTLS_SSL_DEBUG_MSG( 2, ( "Ignore future HS message with sequence number %u, " "buffering window %u - %u", recv_msg_seq, ssl->handshake->in_msg_seq, ssl->handshake->in_msg_seq + MBEDTLS_SSL_MAX_BUFFERED_HS - 1 ) ); goto exit; } MBEDTLS_SSL_DEBUG_MSG( 2, ( "Buffering HS message with sequence number %u, offset %u ", recv_msg_seq, recv_msg_seq_offset ) ); hs_buf = &hs->buffering.hs[ recv_msg_seq_offset ]; /* Check if the buffering for this seq nr has already commenced. */ if( !hs_buf->is_valid ) { size_t reassembly_buf_sz; hs_buf->is_fragmented = ( ssl_hs_is_proper_fragment( ssl ) == 1 ); /* We copy the message back into the input buffer * after reassembly, so check that it's not too large. * This is an implementation-specific limitation * and not one from the standard, hence it is not * checked in ssl_check_hs_header(). */ if( msg_len + 12 > MBEDTLS_SSL_IN_CONTENT_LEN ) { /* Ignore message */ goto exit; } /* Check if we have enough space to buffer the message. */ if( hs->buffering.total_bytes_buffered > MBEDTLS_SSL_DTLS_MAX_BUFFERING ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); } reassembly_buf_sz = ssl_get_reassembly_buffer_size( msg_len, hs_buf->is_fragmented ); if( reassembly_buf_sz > ( MBEDTLS_SSL_DTLS_MAX_BUFFERING - hs->buffering.total_bytes_buffered ) ) { if( recv_msg_seq_offset > 0 ) { /* If we can't buffer a future message because * of space limitations -- ignore. */ MBEDTLS_SSL_DEBUG_MSG( 2, ( "Buffering of future message of size %u would exceed the compile-time limit %u (already %u bytes buffered) -- ignore\n", (unsigned) msg_len, MBEDTLS_SSL_DTLS_MAX_BUFFERING, (unsigned) hs->buffering.total_bytes_buffered ) ); goto exit; } else { MBEDTLS_SSL_DEBUG_MSG( 2, ( "Buffering of future message of size %u would exceed the compile-time limit %u (already %u bytes buffered) -- attempt to make space by freeing buffered future messages\n", (unsigned) msg_len, MBEDTLS_SSL_DTLS_MAX_BUFFERING, (unsigned) hs->buffering.total_bytes_buffered ) ); } if( ssl_buffer_make_space( ssl, reassembly_buf_sz ) != 0 ) { MBEDTLS_SSL_DEBUG_MSG( 2, ( "Reassembly of next message of size %u (%u with bitmap) would exceed the compile-time limit %u (already %u bytes buffered) -- fail\n", (unsigned) msg_len, (unsigned) reassembly_buf_sz, MBEDTLS_SSL_DTLS_MAX_BUFFERING, (unsigned) hs->buffering.total_bytes_buffered ) ); ret = MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL; goto exit; } } MBEDTLS_SSL_DEBUG_MSG( 2, ( "initialize reassembly, total length = %d", msg_len ) ); hs_buf->data = mbedtls_calloc( 1, reassembly_buf_sz ); if( hs_buf->data == NULL ) { ret = MBEDTLS_ERR_SSL_ALLOC_FAILED; goto exit; } hs_buf->data_len = reassembly_buf_sz; /* Prepare final header: copy msg_type, length and message_seq, * then add standardised fragment_offset and fragment_length */ memcpy( hs_buf->data, ssl->in_msg, 6 ); memset( hs_buf->data + 6, 0, 3 ); memcpy( hs_buf->data + 9, hs_buf->data + 1, 3 ); hs_buf->is_valid = 1; hs->buffering.total_bytes_buffered += reassembly_buf_sz; } else { /* Make sure msg_type and length are consistent */ if( memcmp( hs_buf->data, ssl->in_msg, 4 ) != 0 ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "Fragment header mismatch - ignore" ) ); /* Ignore */ goto exit; } } if( !hs_buf->is_complete ) { size_t frag_len, frag_off; unsigned char * const msg = hs_buf->data + 12; /* * Check and copy current fragment */ /* Validation of header fields already done in * mbedtls_ssl_prepare_handshake_record(). */ frag_off = ssl_get_hs_frag_off( ssl ); frag_len = ssl_get_hs_frag_len( ssl ); MBEDTLS_SSL_DEBUG_MSG( 2, ( "adding fragment, offset = %d, length = %d", frag_off, frag_len ) ); memcpy( msg + frag_off, ssl->in_msg + 12, frag_len ); if( hs_buf->is_fragmented ) { unsigned char * const bitmask = msg + msg_len; ssl_bitmask_set( bitmask, frag_off, frag_len ); hs_buf->is_complete = ( ssl_bitmask_check( bitmask, msg_len ) == 0 ); } else { hs_buf->is_complete = 1; } MBEDTLS_SSL_DEBUG_MSG( 2, ( "message %scomplete", hs_buf->is_complete ? "" : "not yet " ) ); } break; } default: /* We don't buffer other types of messages. */ break; } exit: MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= ssl_buffer_message" ) ); return( ret ); } #endif /* MBEDTLS_SSL_PROTO_DTLS */ static int ssl_consume_current_message( mbedtls_ssl_context *ssl ) { /* * Consume last content-layer message and potentially * update in_msglen which keeps track of the contents' * consumption state. * * (1) Handshake messages: * Remove last handshake message, move content * and adapt in_msglen. * * (2) Alert messages: * Consume whole record content, in_msglen = 0. * * (3) Change cipher spec: * Consume whole record content, in_msglen = 0. * * (4) Application data: * Don't do anything - the record layer provides * the application data as a stream transport * and consumes through mbedtls_ssl_read only. * */ /* Case (1): Handshake messages */ if( ssl->in_hslen != 0 ) { /* Hard assertion to be sure that no application data * is in flight, as corrupting ssl->in_msglen during * ssl->in_offt != NULL is fatal. */ if( ssl->in_offt != NULL ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); } /* * Get next Handshake message in the current record */ /* Notes: * (1) in_hslen is not necessarily the size of the * current handshake content: If DTLS handshake * fragmentation is used, that's the fragment * size instead. Using the total handshake message * size here is faulty and should be changed at * some point. * (2) While it doesn't seem to cause problems, one * has to be very careful not to assume that in_hslen * is always <= in_msglen in a sensible communication. * Again, it's wrong for DTLS handshake fragmentation. * The following check is therefore mandatory, and * should not be treated as a silently corrected assertion. * Additionally, ssl->in_hslen might be arbitrarily out of * bounds after handling a DTLS message with an unexpected * sequence number, see mbedtls_ssl_prepare_handshake_record. */ if( ssl->in_hslen < ssl->in_msglen ) { ssl->in_msglen -= ssl->in_hslen; memmove( ssl->in_msg, ssl->in_msg + ssl->in_hslen, ssl->in_msglen ); MBEDTLS_SSL_DEBUG_BUF( 4, "remaining content in record", ssl->in_msg, ssl->in_msglen ); } else { ssl->in_msglen = 0; } ssl->in_hslen = 0; } /* Case (4): Application data */ else if( ssl->in_offt != NULL ) { return( 0 ); } /* Everything else (CCS & Alerts) */ else { ssl->in_msglen = 0; } return( 0 ); } static int ssl_record_is_in_progress( mbedtls_ssl_context *ssl ) { if( ssl->in_msglen > 0 ) return( 1 ); return( 0 ); } #if defined(MBEDTLS_SSL_PROTO_DTLS) static void ssl_free_buffered_record( mbedtls_ssl_context *ssl ) { mbedtls_ssl_handshake_params * const hs = ssl->handshake; if( hs == NULL ) return; if( hs->buffering.future_record.data != NULL ) { hs->buffering.total_bytes_buffered -= hs->buffering.future_record.len; mbedtls_free( hs->buffering.future_record.data ); hs->buffering.future_record.data = NULL; } } static int ssl_load_buffered_record( mbedtls_ssl_context *ssl ) { mbedtls_ssl_handshake_params * const hs = ssl->handshake; unsigned char * rec; size_t rec_len; unsigned rec_epoch; if( ssl->conf->transport != MBEDTLS_SSL_TRANSPORT_DATAGRAM ) return( 0 ); if( hs == NULL ) return( 0 ); rec = hs->buffering.future_record.data; rec_len = hs->buffering.future_record.len; rec_epoch = hs->buffering.future_record.epoch; if( rec == NULL ) return( 0 ); /* Only consider loading future records if the * input buffer is empty. */ if( ssl_next_record_is_in_datagram( ssl ) == 1 ) return( 0 ); MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> ssl_load_buffered_record" ) ); if( rec_epoch != ssl->in_epoch ) { MBEDTLS_SSL_DEBUG_MSG( 2, ( "Buffered record not from current epoch." ) ); goto exit; } MBEDTLS_SSL_DEBUG_MSG( 2, ( "Found buffered record from current epoch - load" ) ); /* Double-check that the record is not too large */ if( rec_len > MBEDTLS_SSL_IN_BUFFER_LEN - (size_t)( ssl->in_hdr - ssl->in_buf ) ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); } memcpy( ssl->in_hdr, rec, rec_len ); ssl->in_left = rec_len; ssl->next_record_offset = 0; ssl_free_buffered_record( ssl ); exit: MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= ssl_load_buffered_record" ) ); return( 0 ); } static int ssl_buffer_future_record( mbedtls_ssl_context *ssl ) { mbedtls_ssl_handshake_params * const hs = ssl->handshake; size_t const rec_hdr_len = 13; size_t const total_buf_sz = rec_hdr_len + ssl->in_msglen; /* Don't buffer future records outside handshakes. */ if( hs == NULL ) return( 0 ); /* Only buffer handshake records (we are only interested * in Finished messages). */ if( ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE ) return( 0 ); /* Don't buffer more than one future epoch record. */ if( hs->buffering.future_record.data != NULL ) return( 0 ); /* Don't buffer record if there's not enough buffering space remaining. */ if( total_buf_sz > ( MBEDTLS_SSL_DTLS_MAX_BUFFERING - hs->buffering.total_bytes_buffered ) ) { MBEDTLS_SSL_DEBUG_MSG( 2, ( "Buffering of future epoch record of size %u would exceed the compile-time limit %u (already %u bytes buffered) -- ignore\n", (unsigned) total_buf_sz, MBEDTLS_SSL_DTLS_MAX_BUFFERING, (unsigned) hs->buffering.total_bytes_buffered ) ); return( 0 ); } /* Buffer record */ MBEDTLS_SSL_DEBUG_MSG( 2, ( "Buffer record from epoch %u", ssl->in_epoch + 1 ) ); MBEDTLS_SSL_DEBUG_BUF( 3, "Buffered record", ssl->in_hdr, rec_hdr_len + ssl->in_msglen ); /* ssl_parse_record_header() only considers records * of the next epoch as candidates for buffering. */ hs->buffering.future_record.epoch = ssl->in_epoch + 1; hs->buffering.future_record.len = total_buf_sz; hs->buffering.future_record.data = mbedtls_calloc( 1, hs->buffering.future_record.len ); if( hs->buffering.future_record.data == NULL ) { /* If we run out of RAM trying to buffer a * record from the next epoch, just ignore. */ return( 0 ); } memcpy( hs->buffering.future_record.data, ssl->in_hdr, total_buf_sz ); hs->buffering.total_bytes_buffered += total_buf_sz; return( 0 ); } #endif /* MBEDTLS_SSL_PROTO_DTLS */ static int ssl_get_next_record( mbedtls_ssl_context *ssl ) { int ret; #if defined(MBEDTLS_SSL_PROTO_DTLS) /* We might have buffered a future record; if so, * and if the epoch matches now, load it. * On success, this call will set ssl->in_left to * the length of the buffered record, so that * the calls to ssl_fetch_input() below will * essentially be no-ops. */ ret = ssl_load_buffered_record( ssl ); if( ret != 0 ) return( ret ); #endif /* MBEDTLS_SSL_PROTO_DTLS */ if( ( ret = mbedtls_ssl_fetch_input( ssl, mbedtls_ssl_hdr_len( ssl ) ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_fetch_input", ret ); return( ret ); } if( ( ret = ssl_parse_record_header( ssl ) ) != 0 ) { #if defined(MBEDTLS_SSL_PROTO_DTLS) if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM && ret != MBEDTLS_ERR_SSL_CLIENT_RECONNECT ) { if( ret == MBEDTLS_ERR_SSL_EARLY_MESSAGE ) { ret = ssl_buffer_future_record( ssl ); if( ret != 0 ) return( ret ); /* Fall through to handling of unexpected records */ ret = MBEDTLS_ERR_SSL_UNEXPECTED_RECORD; } if( ret == MBEDTLS_ERR_SSL_UNEXPECTED_RECORD ) { /* Skip unexpected record (but not whole datagram) */ ssl->next_record_offset = ssl->in_msglen + mbedtls_ssl_hdr_len( ssl ); MBEDTLS_SSL_DEBUG_MSG( 1, ( "discarding unexpected record " "(header)" ) ); } else { /* Skip invalid record and the rest of the datagram */ ssl->next_record_offset = 0; ssl->in_left = 0; MBEDTLS_SSL_DEBUG_MSG( 1, ( "discarding invalid record " "(header)" ) ); } /* Get next record */ return( MBEDTLS_ERR_SSL_CONTINUE_PROCESSING ); } #endif return( ret ); } /* * Read and optionally decrypt the message contents */ if( ( ret = mbedtls_ssl_fetch_input( ssl, mbedtls_ssl_hdr_len( ssl ) + ssl->in_msglen ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_fetch_input", ret ); return( ret ); } /* Done reading this record, get ready for the next one */ #if defined(MBEDTLS_SSL_PROTO_DTLS) if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) { ssl->next_record_offset = ssl->in_msglen + mbedtls_ssl_hdr_len( ssl ); if( ssl->next_record_offset < ssl->in_left ) { MBEDTLS_SSL_DEBUG_MSG( 3, ( "more than one record within datagram" ) ); } } else #endif ssl->in_left = 0; if( ( ret = ssl_prepare_record_content( ssl ) ) != 0 ) { #if defined(MBEDTLS_SSL_PROTO_DTLS) if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) { /* Silently discard invalid records */ if( ret == MBEDTLS_ERR_SSL_INVALID_RECORD || ret == MBEDTLS_ERR_SSL_INVALID_MAC ) { /* Except when waiting for Finished as a bad mac here * probably means something went wrong in the handshake * (eg wrong psk used, mitm downgrade attempt, etc.) */ if( ssl->state == MBEDTLS_SSL_CLIENT_FINISHED || ssl->state == MBEDTLS_SSL_SERVER_FINISHED ) { #if defined(MBEDTLS_SSL_ALL_ALERT_MESSAGES) if( ret == MBEDTLS_ERR_SSL_INVALID_MAC ) { mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_BAD_RECORD_MAC ); } #endif return( ret ); } #if defined(MBEDTLS_SSL_DTLS_BADMAC_LIMIT) if( ssl->conf->badmac_limit != 0 && ++ssl->badmac_seen >= ssl->conf->badmac_limit ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "too many records with bad MAC" ) ); return( MBEDTLS_ERR_SSL_INVALID_MAC ); } #endif /* As above, invalid records cause * dismissal of the whole datagram. */ ssl->next_record_offset = 0; ssl->in_left = 0; MBEDTLS_SSL_DEBUG_MSG( 1, ( "discarding invalid record (mac)" ) ); return( MBEDTLS_ERR_SSL_CONTINUE_PROCESSING ); } return( ret ); } else #endif { /* Error out (and send alert) on invalid records */ #if defined(MBEDTLS_SSL_ALL_ALERT_MESSAGES) if( ret == MBEDTLS_ERR_SSL_INVALID_MAC ) { mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_BAD_RECORD_MAC ); } #endif return( ret ); } } return( 0 ); } int mbedtls_ssl_handle_message_type( mbedtls_ssl_context *ssl ) { int ret; /* * Handle particular types of records */ if( ssl->in_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE ) { if( ( ret = mbedtls_ssl_prepare_handshake_record( ssl ) ) != 0 ) { return( ret ); } } if( ssl->in_msgtype == MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC ) { if( ssl->in_msglen != 1 ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "invalid CCS message, len: %d", ssl->in_msglen ) ); return( MBEDTLS_ERR_SSL_INVALID_RECORD ); } if( ssl->in_msg[0] != 1 ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "invalid CCS message, content: %02x", ssl->in_msg[0] ) ); return( MBEDTLS_ERR_SSL_INVALID_RECORD ); } #if defined(MBEDTLS_SSL_PROTO_DTLS) if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM && ssl->state != MBEDTLS_SSL_CLIENT_CHANGE_CIPHER_SPEC && ssl->state != MBEDTLS_SSL_SERVER_CHANGE_CIPHER_SPEC ) { if( ssl->handshake == NULL ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "dropping ChangeCipherSpec outside handshake" ) ); return( MBEDTLS_ERR_SSL_UNEXPECTED_RECORD ); } MBEDTLS_SSL_DEBUG_MSG( 1, ( "received out-of-order ChangeCipherSpec - remember" ) ); return( MBEDTLS_ERR_SSL_EARLY_MESSAGE ); } #endif } if( ssl->in_msgtype == MBEDTLS_SSL_MSG_ALERT ) { if( ssl->in_msglen != 2 ) { /* Note: Standard allows for more than one 2 byte alert to be packed in a single message, but Mbed TLS doesn't currently support this. */ MBEDTLS_SSL_DEBUG_MSG( 1, ( "invalid alert message, len: %d", ssl->in_msglen ) ); return( MBEDTLS_ERR_SSL_INVALID_RECORD ); } MBEDTLS_SSL_DEBUG_MSG( 2, ( "got an alert message, type: [%d:%d]", ssl->in_msg[0], ssl->in_msg[1] ) ); /* * Ignore non-fatal alerts, except close_notify and no_renegotiation */ if( ssl->in_msg[0] == MBEDTLS_SSL_ALERT_LEVEL_FATAL ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "is a fatal alert message (msg %d)", ssl->in_msg[1] ) ); return( MBEDTLS_ERR_SSL_FATAL_ALERT_MESSAGE ); } if( ssl->in_msg[0] == MBEDTLS_SSL_ALERT_LEVEL_WARNING && ssl->in_msg[1] == MBEDTLS_SSL_ALERT_MSG_CLOSE_NOTIFY ) { MBEDTLS_SSL_DEBUG_MSG( 2, ( "is a close notify message" ) ); return( MBEDTLS_ERR_SSL_PEER_CLOSE_NOTIFY ); } #if defined(MBEDTLS_SSL_RENEGOTIATION_ENABLED) if( ssl->in_msg[0] == MBEDTLS_SSL_ALERT_LEVEL_WARNING && ssl->in_msg[1] == MBEDTLS_SSL_ALERT_MSG_NO_RENEGOTIATION ) { MBEDTLS_SSL_DEBUG_MSG( 2, ( "is a SSLv3 no renegotiation alert" ) ); /* Will be handled when trying to parse ServerHello */ return( 0 ); } #endif #if defined(MBEDTLS_SSL_PROTO_SSL3) && defined(MBEDTLS_SSL_SRV_C) if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 && ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER && ssl->in_msg[0] == MBEDTLS_SSL_ALERT_LEVEL_WARNING && ssl->in_msg[1] == MBEDTLS_SSL_ALERT_MSG_NO_CERT ) { MBEDTLS_SSL_DEBUG_MSG( 2, ( "is a SSLv3 no_cert" ) ); /* Will be handled in mbedtls_ssl_parse_certificate() */ return( 0 ); } #endif /* MBEDTLS_SSL_PROTO_SSL3 && MBEDTLS_SSL_SRV_C */ /* Silently ignore: fetch new message */ return MBEDTLS_ERR_SSL_NON_FATAL; } #if defined(MBEDTLS_SSL_PROTO_DTLS) if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM && ssl->handshake != NULL && ssl->state == MBEDTLS_SSL_HANDSHAKE_OVER ) { ssl_handshake_wrapup_free_hs_transform( ssl ); } #endif return( 0 ); } int mbedtls_ssl_send_fatal_handshake_failure( mbedtls_ssl_context *ssl ) { int ret; if( ( ret = mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE ) ) != 0 ) { return( ret ); } return( 0 ); } int mbedtls_ssl_send_alert_message( mbedtls_ssl_context *ssl, unsigned char level, unsigned char message ) { int ret; if( ssl == NULL || ssl->conf == NULL ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> send alert message" ) ); MBEDTLS_SSL_DEBUG_MSG( 3, ( "send alert level=%u message=%u", level, message )); ssl->out_msgtype = MBEDTLS_SSL_MSG_ALERT; ssl->out_msglen = 2; ssl->out_msg[0] = level; ssl->out_msg[1] = message; if( ( ret = mbedtls_ssl_write_record( ssl, SSL_FORCE_FLUSH ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_record", ret ); return( ret ); } MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= send alert message" ) ); return( 0 ); } /* * Handshake functions */ #if !defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED) && \ !defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED) && \ !defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED) && \ !defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) && \ !defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) && \ !defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) && \ !defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED) /* No certificate support -> dummy functions */ int mbedtls_ssl_write_certificate( mbedtls_ssl_context *ssl ) { const mbedtls_ssl_ciphersuite_t *ciphersuite_info = ssl->transform_negotiate->ciphersuite_info; MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write certificate" ) ); if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK || ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK || ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK || ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE ) { MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip write certificate" ) ); ssl->state++; return( 0 ); } MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); } int mbedtls_ssl_parse_certificate( mbedtls_ssl_context *ssl ) { const mbedtls_ssl_ciphersuite_t *ciphersuite_info = ssl->transform_negotiate->ciphersuite_info; MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse certificate" ) ); if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK || ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK || ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK || ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE ) { MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate" ) ); ssl->state++; return( 0 ); } MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); } #else /* Some certificate support -> implement write and parse */ int mbedtls_ssl_write_certificate( mbedtls_ssl_context *ssl ) { int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE; size_t i, n; const mbedtls_x509_crt *crt; const mbedtls_ssl_ciphersuite_t *ciphersuite_info = ssl->transform_negotiate->ciphersuite_info; MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write certificate" ) ); if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK || ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK || ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK || ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE ) { MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip write certificate" ) ); ssl->state++; return( 0 ); } #if defined(MBEDTLS_SSL_CLI_C) if( ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT ) { if( ssl->client_auth == 0 ) { MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip write certificate" ) ); ssl->state++; return( 0 ); } #if defined(MBEDTLS_SSL_PROTO_SSL3) /* * If using SSLv3 and got no cert, send an Alert message * (otherwise an empty Certificate message will be sent). */ if( mbedtls_ssl_own_cert( ssl ) == NULL && ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 ) { ssl->out_msglen = 2; ssl->out_msgtype = MBEDTLS_SSL_MSG_ALERT; ssl->out_msg[0] = MBEDTLS_SSL_ALERT_LEVEL_WARNING; ssl->out_msg[1] = MBEDTLS_SSL_ALERT_MSG_NO_CERT; MBEDTLS_SSL_DEBUG_MSG( 2, ( "got no certificate to send" ) ); goto write_msg; } #endif /* MBEDTLS_SSL_PROTO_SSL3 */ } #endif /* MBEDTLS_SSL_CLI_C */ #if defined(MBEDTLS_SSL_SRV_C) if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER ) { if( mbedtls_ssl_own_cert( ssl ) == NULL ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "got no certificate to send" ) ); return( MBEDTLS_ERR_SSL_CERTIFICATE_REQUIRED ); } } #endif MBEDTLS_SSL_DEBUG_CRT( 3, "own certificate", mbedtls_ssl_own_cert( ssl ) ); /* * 0 . 0 handshake type * 1 . 3 handshake length * 4 . 6 length of all certs * 7 . 9 length of cert. 1 * 10 . n-1 peer certificate * n . n+2 length of cert. 2 * n+3 . ... upper level cert, etc. */ i = 7; crt = mbedtls_ssl_own_cert( ssl ); while( crt != NULL ) { n = crt->raw.len; if( n > MBEDTLS_SSL_OUT_CONTENT_LEN - 3 - i ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "certificate too large, %d > %d", i + 3 + n, MBEDTLS_SSL_OUT_CONTENT_LEN ) ); return( MBEDTLS_ERR_SSL_CERTIFICATE_TOO_LARGE ); } ssl->out_msg[i ] = (unsigned char)( n >> 16 ); ssl->out_msg[i + 1] = (unsigned char)( n >> 8 ); ssl->out_msg[i + 2] = (unsigned char)( n ); i += 3; memcpy( ssl->out_msg + i, crt->raw.p, n ); i += n; crt = crt->next; } ssl->out_msg[4] = (unsigned char)( ( i - 7 ) >> 16 ); ssl->out_msg[5] = (unsigned char)( ( i - 7 ) >> 8 ); ssl->out_msg[6] = (unsigned char)( ( i - 7 ) ); ssl->out_msglen = i; ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE; ssl->out_msg[0] = MBEDTLS_SSL_HS_CERTIFICATE; #if defined(MBEDTLS_SSL_PROTO_SSL3) && defined(MBEDTLS_SSL_CLI_C) write_msg: #endif ssl->state++; if( ( ret = mbedtls_ssl_write_handshake_msg( ssl ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_handshake_msg", ret ); return( ret ); } MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write certificate" ) ); return( ret ); } /* * Once the certificate message is read, parse it into a cert chain and * perform basic checks, but leave actual verification to the caller */ static int ssl_parse_certificate_chain( mbedtls_ssl_context *ssl ) { int ret; size_t i, n; uint8_t alert; #if defined(MBEDTLS_SSL_SRV_C) #if defined(MBEDTLS_SSL_PROTO_SSL3) /* * Check if the client sent an empty certificate */ if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER && ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 ) { if( ssl->in_msglen == 2 && ssl->in_msgtype == MBEDTLS_SSL_MSG_ALERT && ssl->in_msg[0] == MBEDTLS_SSL_ALERT_LEVEL_WARNING && ssl->in_msg[1] == MBEDTLS_SSL_ALERT_MSG_NO_CERT ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "SSLv3 client has no certificate" ) ); /* The client was asked for a certificate but didn't send one. The client should know what's going on, so we don't send an alert. */ ssl->session_negotiate->verify_result = MBEDTLS_X509_BADCERT_MISSING; return( MBEDTLS_ERR_SSL_NO_CLIENT_CERTIFICATE ); } } #endif /* MBEDTLS_SSL_PROTO_SSL3 */ #if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) || \ defined(MBEDTLS_SSL_PROTO_TLS1_2) if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER && ssl->minor_ver != MBEDTLS_SSL_MINOR_VERSION_0 ) { if( ssl->in_hslen == 3 + mbedtls_ssl_hs_hdr_len( ssl ) && ssl->in_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE && ssl->in_msg[0] == MBEDTLS_SSL_HS_CERTIFICATE && memcmp( ssl->in_msg + mbedtls_ssl_hs_hdr_len( ssl ), "\0\0\0", 3 ) == 0 ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "TLSv1 client has no certificate" ) ); /* The client was asked for a certificate but didn't send one. The client should know what's going on, so we don't send an alert. */ ssl->session_negotiate->verify_result = MBEDTLS_X509_BADCERT_MISSING; return( MBEDTLS_ERR_SSL_NO_CLIENT_CERTIFICATE ); } } #endif /* MBEDTLS_SSL_PROTO_TLS1 || MBEDTLS_SSL_PROTO_TLS1_1 || \ MBEDTLS_SSL_PROTO_TLS1_2 */ #endif /* MBEDTLS_SSL_SRV_C */ if( ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate message" ) ); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE ); return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE ); } if( ssl->in_msg[0] != MBEDTLS_SSL_HS_CERTIFICATE || ssl->in_hslen < mbedtls_ssl_hs_hdr_len( ssl ) + 3 + 3 ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate message" ) ); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR ); return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE ); } i = mbedtls_ssl_hs_hdr_len( ssl ); /* * Same message structure as in mbedtls_ssl_write_certificate() */ n = ( ssl->in_msg[i+1] << 8 ) | ssl->in_msg[i+2]; if( ssl->in_msg[i] != 0 || ssl->in_hslen != n + 3 + mbedtls_ssl_hs_hdr_len( ssl ) ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate message" ) ); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR ); return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE ); } /* In case we tried to reuse a session but it failed */ if( ssl->session_negotiate->peer_cert != NULL ) { mbedtls_x509_crt_free( ssl->session_negotiate->peer_cert ); mbedtls_free( ssl->session_negotiate->peer_cert ); } if( ( ssl->session_negotiate->peer_cert = mbedtls_calloc( 1, sizeof( mbedtls_x509_crt ) ) ) == NULL ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "alloc(%d bytes) failed", sizeof( mbedtls_x509_crt ) ) ); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_INTERNAL_ERROR ); return( MBEDTLS_ERR_SSL_ALLOC_FAILED ); } mbedtls_x509_crt_init( ssl->session_negotiate->peer_cert ); i += 3; while( i < ssl->in_hslen ) { if ( i + 3 > ssl->in_hslen ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate message" ) ); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR ); return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE ); } if( ssl->in_msg[i] != 0 ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate message" ) ); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR ); return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE ); } n = ( (unsigned int) ssl->in_msg[i + 1] << 8 ) | (unsigned int) ssl->in_msg[i + 2]; i += 3; if( n < 128 || i + n > ssl->in_hslen ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate message" ) ); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR ); return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE ); } ret = mbedtls_x509_crt_parse_der( ssl->session_negotiate->peer_cert, ssl->in_msg + i, n ); switch( ret ) { case 0: /*ok*/ case MBEDTLS_ERR_X509_UNKNOWN_SIG_ALG + MBEDTLS_ERR_OID_NOT_FOUND: /* Ignore certificate with an unknown algorithm: maybe a prior certificate was already trusted. */ break; case MBEDTLS_ERR_X509_ALLOC_FAILED: alert = MBEDTLS_SSL_ALERT_MSG_INTERNAL_ERROR; goto crt_parse_der_failed; case MBEDTLS_ERR_X509_UNKNOWN_VERSION: alert = MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_CERT; goto crt_parse_der_failed; default: alert = MBEDTLS_SSL_ALERT_MSG_BAD_CERT; crt_parse_der_failed: mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, alert ); MBEDTLS_SSL_DEBUG_RET( 1, " mbedtls_x509_crt_parse_der", ret ); return( ret ); } i += n; } MBEDTLS_SSL_DEBUG_CRT( 3, "peer certificate", ssl->session_negotiate->peer_cert ); /* * On client, make sure the server cert doesn't change during renego to * avoid "triple handshake" attack: https://secure-resumption.com/ */ #if defined(MBEDTLS_SSL_RENEGOTIATION) && defined(MBEDTLS_SSL_CLI_C) if( ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT && ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS ) { if( ssl->session->peer_cert == NULL ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "new server cert during renegotiation" ) ); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_ACCESS_DENIED ); return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE ); } if( ssl->session->peer_cert->raw.len != ssl->session_negotiate->peer_cert->raw.len || memcmp( ssl->session->peer_cert->raw.p, ssl->session_negotiate->peer_cert->raw.p, ssl->session->peer_cert->raw.len ) != 0 ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "server cert changed during renegotiation" ) ); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_ACCESS_DENIED ); return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE ); } } #endif /* MBEDTLS_SSL_RENEGOTIATION && MBEDTLS_SSL_CLI_C */ return( 0 ); } int mbedtls_ssl_parse_certificate( mbedtls_ssl_context *ssl ) { int ret; const mbedtls_ssl_ciphersuite_t * const ciphersuite_info = ssl->transform_negotiate->ciphersuite_info; #if defined(MBEDTLS_SSL_SRV_C) && defined(MBEDTLS_SSL_SERVER_NAME_INDICATION) const int authmode = ssl->handshake->sni_authmode != MBEDTLS_SSL_VERIFY_UNSET ? ssl->handshake->sni_authmode : ssl->conf->authmode; #else const int authmode = ssl->conf->authmode; #endif void *rs_ctx = NULL; MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse certificate" ) ); if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK || ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK || ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK || ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE ) { MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate" ) ); ssl->state++; return( 0 ); } #if defined(MBEDTLS_SSL_SRV_C) if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER && ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK ) { MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate" ) ); ssl->state++; return( 0 ); } if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER && authmode == MBEDTLS_SSL_VERIFY_NONE ) { ssl->session_negotiate->verify_result = MBEDTLS_X509_BADCERT_SKIP_VERIFY; MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate" ) ); ssl->state++; return( 0 ); } #endif #if defined(MBEDTLS_SSL__ECP_RESTARTABLE) if( ssl->handshake->ecrs_enabled && ssl->handshake->ecrs_state == ssl_ecrs_crt_verify ) { goto crt_verify; } #endif if( ( ret = mbedtls_ssl_read_record( ssl, 1 ) ) != 0 ) { /* mbedtls_ssl_read_record may have sent an alert already. We let it decide whether to alert. */ MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret ); return( ret ); } if( ( ret = ssl_parse_certificate_chain( ssl ) ) != 0 ) { #if defined(MBEDTLS_SSL_SRV_C) if( ret == MBEDTLS_ERR_SSL_NO_CLIENT_CERTIFICATE && authmode == MBEDTLS_SSL_VERIFY_OPTIONAL ) { ret = 0; } #endif ssl->state++; return( ret ); } #if defined(MBEDTLS_SSL__ECP_RESTARTABLE) if( ssl->handshake->ecrs_enabled) ssl->handshake->ecrs_state = ssl_ecrs_crt_verify; crt_verify: if( ssl->handshake->ecrs_enabled) rs_ctx = &ssl->handshake->ecrs_ctx; #endif if( authmode != MBEDTLS_SSL_VERIFY_NONE ) { mbedtls_x509_crt *ca_chain; mbedtls_x509_crl *ca_crl; #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION) if( ssl->handshake->sni_ca_chain != NULL ) { ca_chain = ssl->handshake->sni_ca_chain; ca_crl = ssl->handshake->sni_ca_crl; } else #endif { ca_chain = ssl->conf->ca_chain; ca_crl = ssl->conf->ca_crl; } /* * Main check: verify certificate */ ret = mbedtls_x509_crt_verify_restartable( ssl->session_negotiate->peer_cert, ca_chain, ca_crl, ssl->conf->cert_profile, ssl->hostname, &ssl->session_negotiate->verify_result, ssl->conf->f_vrfy, ssl->conf->p_vrfy, rs_ctx ); if( ret != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "x509_verify_cert", ret ); } #if defined(MBEDTLS_SSL__ECP_RESTARTABLE) if( ret == MBEDTLS_ERR_ECP_IN_PROGRESS ) return( MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS ); #endif /* * Secondary checks: always done, but change 'ret' only if it was 0 */ #if defined(MBEDTLS_ECP_C) { const mbedtls_pk_context *pk = &ssl->session_negotiate->peer_cert->pk; /* If certificate uses an EC key, make sure the curve is OK */ if( mbedtls_pk_can_do( pk, MBEDTLS_PK_ECKEY ) && mbedtls_ssl_check_curve( ssl, mbedtls_pk_ec( *pk )->grp.id ) != 0 ) { ssl->session_negotiate->verify_result |= MBEDTLS_X509_BADCERT_BAD_KEY; MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate (EC key curve)" ) ); if( ret == 0 ) ret = MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE; } } #endif /* MBEDTLS_ECP_C */ if( mbedtls_ssl_check_cert_usage( ssl->session_negotiate->peer_cert, ciphersuite_info, ! ssl->conf->endpoint, &ssl->session_negotiate->verify_result ) != 0 ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate (usage extensions)" ) ); if( ret == 0 ) ret = MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE; } /* mbedtls_x509_crt_verify_with_profile is supposed to report a * verification failure through MBEDTLS_ERR_X509_CERT_VERIFY_FAILED, * with details encoded in the verification flags. All other kinds * of error codes, including those from the user provided f_vrfy * functions, are treated as fatal and lead to a failure of * ssl_parse_certificate even if verification was optional. */ if( authmode == MBEDTLS_SSL_VERIFY_OPTIONAL && ( ret == MBEDTLS_ERR_X509_CERT_VERIFY_FAILED || ret == MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE ) ) { ret = 0; } if( ca_chain == NULL && authmode == MBEDTLS_SSL_VERIFY_REQUIRED ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "got no CA chain" ) ); ret = MBEDTLS_ERR_SSL_CA_CHAIN_REQUIRED; } if( ret != 0 ) { uint8_t alert; /* The certificate may have been rejected for several reasons. Pick one and send the corresponding alert. Which alert to send may be a subject of debate in some cases. */ if( ssl->session_negotiate->verify_result & MBEDTLS_X509_BADCERT_OTHER ) alert = MBEDTLS_SSL_ALERT_MSG_ACCESS_DENIED; else if( ssl->session_negotiate->verify_result & MBEDTLS_X509_BADCERT_CN_MISMATCH ) alert = MBEDTLS_SSL_ALERT_MSG_BAD_CERT; else if( ssl->session_negotiate->verify_result & MBEDTLS_X509_BADCERT_KEY_USAGE ) alert = MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_CERT; else if( ssl->session_negotiate->verify_result & MBEDTLS_X509_BADCERT_EXT_KEY_USAGE ) alert = MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_CERT; else if( ssl->session_negotiate->verify_result & MBEDTLS_X509_BADCERT_NS_CERT_TYPE ) alert = MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_CERT; else if( ssl->session_negotiate->verify_result & MBEDTLS_X509_BADCERT_BAD_PK ) alert = MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_CERT; else if( ssl->session_negotiate->verify_result & MBEDTLS_X509_BADCERT_BAD_KEY ) alert = MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_CERT; else if( ssl->session_negotiate->verify_result & MBEDTLS_X509_BADCERT_EXPIRED ) alert = MBEDTLS_SSL_ALERT_MSG_CERT_EXPIRED; else if( ssl->session_negotiate->verify_result & MBEDTLS_X509_BADCERT_REVOKED ) alert = MBEDTLS_SSL_ALERT_MSG_CERT_REVOKED; else if( ssl->session_negotiate->verify_result & MBEDTLS_X509_BADCERT_NOT_TRUSTED ) alert = MBEDTLS_SSL_ALERT_MSG_UNKNOWN_CA; else alert = MBEDTLS_SSL_ALERT_MSG_CERT_UNKNOWN; mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, alert ); } #if defined(MBEDTLS_DEBUG_C) if( ssl->session_negotiate->verify_result != 0 ) { MBEDTLS_SSL_DEBUG_MSG( 3, ( "! Certificate verification flags %x", ssl->session_negotiate->verify_result ) ); } else { MBEDTLS_SSL_DEBUG_MSG( 3, ( "Certificate verification flags clear" ) ); } #endif /* MBEDTLS_DEBUG_C */ } ssl->state++; MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse certificate" ) ); return( ret ); } #endif /* !MBEDTLS_KEY_EXCHANGE_RSA_ENABLED !MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED !MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED !MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED !MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED !MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED !MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED */ int mbedtls_ssl_write_change_cipher_spec( mbedtls_ssl_context *ssl ) { int ret; MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write change cipher spec" ) ); ssl->out_msgtype = MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC; ssl->out_msglen = 1; ssl->out_msg[0] = 1; ssl->state++; if( ( ret = mbedtls_ssl_write_handshake_msg( ssl ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_handshake_msg", ret ); return( ret ); } MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write change cipher spec" ) ); return( 0 ); } int mbedtls_ssl_parse_change_cipher_spec( mbedtls_ssl_context *ssl ) { int ret; MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse change cipher spec" ) ); if( ( ret = mbedtls_ssl_read_record( ssl, 1 ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret ); return( ret ); } if( ssl->in_msgtype != MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad change cipher spec message" ) ); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE ); return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE ); } /* CCS records are only accepted if they have length 1 and content '1', * so we don't need to check this here. */ /* * Switch to our negotiated transform and session parameters for inbound * data. */ MBEDTLS_SSL_DEBUG_MSG( 3, ( "switching to new transform spec for inbound data" ) ); ssl->transform_in = ssl->transform_negotiate; ssl->session_in = ssl->session_negotiate; #if defined(MBEDTLS_SSL_PROTO_DTLS) if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) { #if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY) ssl_dtls_replay_reset( ssl ); #endif /* Increment epoch */ if( ++ssl->in_epoch == 0 ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "DTLS epoch would wrap" ) ); /* This is highly unlikely to happen for legitimate reasons, so treat it as an attack and don't send an alert. */ return( MBEDTLS_ERR_SSL_COUNTER_WRAPPING ); } } else #endif /* MBEDTLS_SSL_PROTO_DTLS */ memset( ssl->in_ctr, 0, 8 ); ssl_update_in_pointers( ssl, ssl->transform_negotiate ); #if defined(MBEDTLS_SSL_HW_RECORD_ACCEL) if( mbedtls_ssl_hw_record_activate != NULL ) { if( ( ret = mbedtls_ssl_hw_record_activate( ssl, MBEDTLS_SSL_CHANNEL_INBOUND ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_hw_record_activate", ret ); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_INTERNAL_ERROR ); return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED ); } } #endif ssl->state++; MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse change cipher spec" ) ); return( 0 ); } void mbedtls_ssl_optimize_checksum( mbedtls_ssl_context *ssl, const mbedtls_ssl_ciphersuite_t *ciphersuite_info ) { ((void) ciphersuite_info); #if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1) || \ defined(MBEDTLS_SSL_PROTO_TLS1_1) if( ssl->minor_ver < MBEDTLS_SSL_MINOR_VERSION_3 ) ssl->handshake->update_checksum = ssl_update_checksum_md5sha1; else #endif #if defined(MBEDTLS_SSL_PROTO_TLS1_2) #if defined(MBEDTLS_SHA512_C) if( ciphersuite_info->mac == MBEDTLS_MD_SHA384 ) ssl->handshake->update_checksum = ssl_update_checksum_sha384; else #endif #if defined(MBEDTLS_SHA256_C) if( ciphersuite_info->mac != MBEDTLS_MD_SHA384 ) ssl->handshake->update_checksum = ssl_update_checksum_sha256; else #endif #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */ { MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return; } } void mbedtls_ssl_reset_checksum( mbedtls_ssl_context *ssl ) { #if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1) || \ defined(MBEDTLS_SSL_PROTO_TLS1_1) mbedtls_md5_starts_ret( &ssl->handshake->fin_md5 ); mbedtls_sha1_starts_ret( &ssl->handshake->fin_sha1 ); #endif #if defined(MBEDTLS_SSL_PROTO_TLS1_2) #if defined(MBEDTLS_SHA256_C) mbedtls_sha256_starts_ret( &ssl->handshake->fin_sha256, 0 ); #endif #if defined(MBEDTLS_SHA512_C) mbedtls_sha512_starts_ret( &ssl->handshake->fin_sha512, 1 ); #endif #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */ } static void ssl_update_checksum_start( mbedtls_ssl_context *ssl, const unsigned char *buf, size_t len ) { #if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1) || \ defined(MBEDTLS_SSL_PROTO_TLS1_1) mbedtls_md5_update_ret( &ssl->handshake->fin_md5 , buf, len ); mbedtls_sha1_update_ret( &ssl->handshake->fin_sha1, buf, len ); #endif #if defined(MBEDTLS_SSL_PROTO_TLS1_2) #if defined(MBEDTLS_SHA256_C) mbedtls_sha256_update_ret( &ssl->handshake->fin_sha256, buf, len ); #endif #if defined(MBEDTLS_SHA512_C) mbedtls_sha512_update_ret( &ssl->handshake->fin_sha512, buf, len ); #endif #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */ } #if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1) || \ defined(MBEDTLS_SSL_PROTO_TLS1_1) static void ssl_update_checksum_md5sha1( mbedtls_ssl_context *ssl, const unsigned char *buf, size_t len ) { mbedtls_md5_update_ret( &ssl->handshake->fin_md5 , buf, len ); mbedtls_sha1_update_ret( &ssl->handshake->fin_sha1, buf, len ); } #endif #if defined(MBEDTLS_SSL_PROTO_TLS1_2) #if defined(MBEDTLS_SHA256_C) static void ssl_update_checksum_sha256( mbedtls_ssl_context *ssl, const unsigned char *buf, size_t len ) { mbedtls_sha256_update_ret( &ssl->handshake->fin_sha256, buf, len ); } #endif #if defined(MBEDTLS_SHA512_C) static void ssl_update_checksum_sha384( mbedtls_ssl_context *ssl, const unsigned char *buf, size_t len ) { mbedtls_sha512_update_ret( &ssl->handshake->fin_sha512, buf, len ); } #endif #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */ #if defined(MBEDTLS_SSL_PROTO_SSL3) static void ssl_calc_finished_ssl( mbedtls_ssl_context *ssl, unsigned char *buf, int from ) { const char *sender; mbedtls_md5_context md5; mbedtls_sha1_context sha1; unsigned char padbuf[48]; unsigned char md5sum[16]; unsigned char sha1sum[20]; mbedtls_ssl_session *session = ssl->session_negotiate; if( !session ) session = ssl->session; MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> calc finished ssl" ) ); mbedtls_md5_init( &md5 ); mbedtls_sha1_init( &sha1 ); mbedtls_md5_clone( &md5, &ssl->handshake->fin_md5 ); mbedtls_sha1_clone( &sha1, &ssl->handshake->fin_sha1 ); /* * SSLv3: * hash = * MD5( master + pad2 + * MD5( handshake + sender + master + pad1 ) ) * + SHA1( master + pad2 + * SHA1( handshake + sender + master + pad1 ) ) */ #if !defined(MBEDTLS_MD5_ALT) MBEDTLS_SSL_DEBUG_BUF( 4, "finished md5 state", (unsigned char *) md5.state, sizeof( md5.state ) ); #endif #if !defined(MBEDTLS_SHA1_ALT) MBEDTLS_SSL_DEBUG_BUF( 4, "finished sha1 state", (unsigned char *) sha1.state, sizeof( sha1.state ) ); #endif sender = ( from == MBEDTLS_SSL_IS_CLIENT ) ? "CLNT" : "SRVR"; memset( padbuf, 0x36, 48 ); mbedtls_md5_update_ret( &md5, (const unsigned char *) sender, 4 ); mbedtls_md5_update_ret( &md5, session->master, 48 ); mbedtls_md5_update_ret( &md5, padbuf, 48 ); mbedtls_md5_finish_ret( &md5, md5sum ); mbedtls_sha1_update_ret( &sha1, (const unsigned char *) sender, 4 ); mbedtls_sha1_update_ret( &sha1, session->master, 48 ); mbedtls_sha1_update_ret( &sha1, padbuf, 40 ); mbedtls_sha1_finish_ret( &sha1, sha1sum ); memset( padbuf, 0x5C, 48 ); mbedtls_md5_starts_ret( &md5 ); mbedtls_md5_update_ret( &md5, session->master, 48 ); mbedtls_md5_update_ret( &md5, padbuf, 48 ); mbedtls_md5_update_ret( &md5, md5sum, 16 ); mbedtls_md5_finish_ret( &md5, buf ); mbedtls_sha1_starts_ret( &sha1 ); mbedtls_sha1_update_ret( &sha1, session->master, 48 ); mbedtls_sha1_update_ret( &sha1, padbuf , 40 ); mbedtls_sha1_update_ret( &sha1, sha1sum, 20 ); mbedtls_sha1_finish_ret( &sha1, buf + 16 ); MBEDTLS_SSL_DEBUG_BUF( 3, "calc finished result", buf, 36 ); mbedtls_md5_free( &md5 ); mbedtls_sha1_free( &sha1 ); mbedtls_platform_zeroize( padbuf, sizeof( padbuf ) ); mbedtls_platform_zeroize( md5sum, sizeof( md5sum ) ); mbedtls_platform_zeroize( sha1sum, sizeof( sha1sum ) ); MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= calc finished" ) ); } #endif /* MBEDTLS_SSL_PROTO_SSL3 */ #if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) static void ssl_calc_finished_tls( mbedtls_ssl_context *ssl, unsigned char *buf, int from ) { int len = 12; const char *sender; mbedtls_md5_context md5; mbedtls_sha1_context sha1; unsigned char padbuf[36]; mbedtls_ssl_session *session = ssl->session_negotiate; if( !session ) session = ssl->session; MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> calc finished tls" ) ); mbedtls_md5_init( &md5 ); mbedtls_sha1_init( &sha1 ); mbedtls_md5_clone( &md5, &ssl->handshake->fin_md5 ); mbedtls_sha1_clone( &sha1, &ssl->handshake->fin_sha1 ); /* * TLSv1: * hash = PRF( master, finished_label, * MD5( handshake ) + SHA1( handshake ) )[0..11] */ #if !defined(MBEDTLS_MD5_ALT) MBEDTLS_SSL_DEBUG_BUF( 4, "finished md5 state", (unsigned char *) md5.state, sizeof( md5.state ) ); #endif #if !defined(MBEDTLS_SHA1_ALT) MBEDTLS_SSL_DEBUG_BUF( 4, "finished sha1 state", (unsigned char *) sha1.state, sizeof( sha1.state ) ); #endif sender = ( from == MBEDTLS_SSL_IS_CLIENT ) ? "client finished" : "server finished"; mbedtls_md5_finish_ret( &md5, padbuf ); mbedtls_sha1_finish_ret( &sha1, padbuf + 16 ); ssl->handshake->tls_prf( session->master, 48, sender, padbuf, 36, buf, len ); MBEDTLS_SSL_DEBUG_BUF( 3, "calc finished result", buf, len ); mbedtls_md5_free( &md5 ); mbedtls_sha1_free( &sha1 ); mbedtls_platform_zeroize( padbuf, sizeof( padbuf ) ); MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= calc finished" ) ); } #endif /* MBEDTLS_SSL_PROTO_TLS1 || MBEDTLS_SSL_PROTO_TLS1_1 */ #if defined(MBEDTLS_SSL_PROTO_TLS1_2) #if defined(MBEDTLS_SHA256_C) static void ssl_calc_finished_tls_sha256( mbedtls_ssl_context *ssl, unsigned char *buf, int from ) { int len = 12; const char *sender; mbedtls_sha256_context sha256; unsigned char padbuf[32]; mbedtls_ssl_session *session = ssl->session_negotiate; if( !session ) session = ssl->session; mbedtls_sha256_init( &sha256 ); MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> calc finished tls sha256" ) ); mbedtls_sha256_clone( &sha256, &ssl->handshake->fin_sha256 ); /* * TLSv1.2: * hash = PRF( master, finished_label, * Hash( handshake ) )[0.11] */ #if !defined(MBEDTLS_SHA256_ALT) MBEDTLS_SSL_DEBUG_BUF( 4, "finished sha2 state", (unsigned char *) sha256.state, sizeof( sha256.state ) ); #endif sender = ( from == MBEDTLS_SSL_IS_CLIENT ) ? "client finished" : "server finished"; mbedtls_sha256_finish_ret( &sha256, padbuf ); ssl->handshake->tls_prf( session->master, 48, sender, padbuf, 32, buf, len ); MBEDTLS_SSL_DEBUG_BUF( 3, "calc finished result", buf, len ); mbedtls_sha256_free( &sha256 ); mbedtls_platform_zeroize( padbuf, sizeof( padbuf ) ); MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= calc finished" ) ); } #endif /* MBEDTLS_SHA256_C */ #if defined(MBEDTLS_SHA512_C) static void ssl_calc_finished_tls_sha384( mbedtls_ssl_context *ssl, unsigned char *buf, int from ) { int len = 12; const char *sender; mbedtls_sha512_context sha512; unsigned char padbuf[48]; mbedtls_ssl_session *session = ssl->session_negotiate; if( !session ) session = ssl->session; mbedtls_sha512_init( &sha512 ); MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> calc finished tls sha384" ) ); mbedtls_sha512_clone( &sha512, &ssl->handshake->fin_sha512 ); /* * TLSv1.2: * hash = PRF( master, finished_label, * Hash( handshake ) )[0.11] */ #if !defined(MBEDTLS_SHA512_ALT) MBEDTLS_SSL_DEBUG_BUF( 4, "finished sha512 state", (unsigned char *) sha512.state, sizeof( sha512.state ) ); #endif sender = ( from == MBEDTLS_SSL_IS_CLIENT ) ? "client finished" : "server finished"; mbedtls_sha512_finish_ret( &sha512, padbuf ); ssl->handshake->tls_prf( session->master, 48, sender, padbuf, 48, buf, len ); MBEDTLS_SSL_DEBUG_BUF( 3, "calc finished result", buf, len ); mbedtls_sha512_free( &sha512 ); mbedtls_platform_zeroize( padbuf, sizeof( padbuf ) ); MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= calc finished" ) ); } #endif /* MBEDTLS_SHA512_C */ #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */ static void ssl_handshake_wrapup_free_hs_transform( mbedtls_ssl_context *ssl ) { MBEDTLS_SSL_DEBUG_MSG( 3, ( "=> handshake wrapup: final free" ) ); /* * Free our handshake params */ mbedtls_ssl_handshake_free( ssl ); mbedtls_free( ssl->handshake ); ssl->handshake = NULL; /* * Free the previous transform and swith in the current one */ if( ssl->transform ) { mbedtls_ssl_transform_free( ssl->transform ); mbedtls_free( ssl->transform ); } ssl->transform = ssl->transform_negotiate; ssl->transform_negotiate = NULL; MBEDTLS_SSL_DEBUG_MSG( 3, ( "<= handshake wrapup: final free" ) ); } void mbedtls_ssl_handshake_wrapup( mbedtls_ssl_context *ssl ) { int resume = ssl->handshake->resume; MBEDTLS_SSL_DEBUG_MSG( 3, ( "=> handshake wrapup" ) ); #if defined(MBEDTLS_SSL_RENEGOTIATION) if( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS ) { ssl->renego_status = MBEDTLS_SSL_RENEGOTIATION_DONE; ssl->renego_records_seen = 0; } #endif /* * Free the previous session and switch in the current one */ if( ssl->session ) { #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC) /* RFC 7366 3.1: keep the EtM state */ ssl->session_negotiate->encrypt_then_mac = ssl->session->encrypt_then_mac; #endif mbedtls_ssl_session_free( ssl->session ); mbedtls_free( ssl->session ); } ssl->session = ssl->session_negotiate; ssl->session_negotiate = NULL; /* * Add cache entry */ if( ssl->conf->f_set_cache != NULL && ssl->session->id_len != 0 && resume == 0 ) { if( ssl->conf->f_set_cache( ssl->conf->p_cache, ssl->session ) != 0 ) MBEDTLS_SSL_DEBUG_MSG( 1, ( "cache did not store session" ) ); } #if defined(MBEDTLS_SSL_PROTO_DTLS) if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM && ssl->handshake->flight != NULL ) { /* Cancel handshake timer */ ssl_set_timer( ssl, 0 ); /* Keep last flight around in case we need to resend it: * we need the handshake and transform structures for that */ MBEDTLS_SSL_DEBUG_MSG( 3, ( "skip freeing handshake and transform" ) ); } else #endif ssl_handshake_wrapup_free_hs_transform( ssl ); ssl->state++; MBEDTLS_SSL_DEBUG_MSG( 3, ( "<= handshake wrapup" ) ); } int mbedtls_ssl_write_finished( mbedtls_ssl_context *ssl ) { int ret, hash_len; MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write finished" ) ); ssl_update_out_pointers( ssl, ssl->transform_negotiate ); ssl->handshake->calc_finished( ssl, ssl->out_msg + 4, ssl->conf->endpoint ); /* * RFC 5246 7.4.9 (Page 63) says 12 is the default length and ciphersuites * may define some other value. Currently (early 2016), no defined * ciphersuite does this (and this is unlikely to change as activity has * moved to TLS 1.3 now) so we can keep the hardcoded 12 here. */ hash_len = ( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 ) ? 36 : 12; #if defined(MBEDTLS_SSL_RENEGOTIATION) ssl->verify_data_len = hash_len; memcpy( ssl->own_verify_data, ssl->out_msg + 4, hash_len ); #endif ssl->out_msglen = 4 + hash_len; ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE; ssl->out_msg[0] = MBEDTLS_SSL_HS_FINISHED; /* * In case of session resuming, invert the client and server * ChangeCipherSpec messages order. */ if( ssl->handshake->resume != 0 ) { #if defined(MBEDTLS_SSL_CLI_C) if( ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT ) ssl->state = MBEDTLS_SSL_HANDSHAKE_WRAPUP; #endif #if defined(MBEDTLS_SSL_SRV_C) if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER ) ssl->state = MBEDTLS_SSL_CLIENT_CHANGE_CIPHER_SPEC; #endif } else ssl->state++; /* * Switch to our negotiated transform and session parameters for outbound * data. */ MBEDTLS_SSL_DEBUG_MSG( 3, ( "switching to new transform spec for outbound data" ) ); #if defined(MBEDTLS_SSL_PROTO_DTLS) if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) { unsigned char i; /* Remember current epoch settings for resending */ ssl->handshake->alt_transform_out = ssl->transform_out; memcpy( ssl->handshake->alt_out_ctr, ssl->cur_out_ctr, 8 ); /* Set sequence_number to zero */ memset( ssl->cur_out_ctr + 2, 0, 6 ); /* Increment epoch */ for( i = 2; i > 0; i-- ) if( ++ssl->cur_out_ctr[i - 1] != 0 ) break; /* The loop goes to its end iff the counter is wrapping */ if( i == 0 ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "DTLS epoch would wrap" ) ); return( MBEDTLS_ERR_SSL_COUNTER_WRAPPING ); } } else #endif /* MBEDTLS_SSL_PROTO_DTLS */ memset( ssl->cur_out_ctr, 0, 8 ); ssl->transform_out = ssl->transform_negotiate; ssl->session_out = ssl->session_negotiate; #if defined(MBEDTLS_SSL_HW_RECORD_ACCEL) if( mbedtls_ssl_hw_record_activate != NULL ) { if( ( ret = mbedtls_ssl_hw_record_activate( ssl, MBEDTLS_SSL_CHANNEL_OUTBOUND ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_hw_record_activate", ret ); return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED ); } } #endif #if defined(MBEDTLS_SSL_PROTO_DTLS) if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) mbedtls_ssl_send_flight_completed( ssl ); #endif if( ( ret = mbedtls_ssl_write_handshake_msg( ssl ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_handshake_msg", ret ); return( ret ); } #if defined(MBEDTLS_SSL_PROTO_DTLS) if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM && ( ret = mbedtls_ssl_flight_transmit( ssl ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_flight_transmit", ret ); return( ret ); } #endif MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write finished" ) ); return( 0 ); } #if defined(MBEDTLS_SSL_PROTO_SSL3) #define SSL_MAX_HASH_LEN 36 #else #define SSL_MAX_HASH_LEN 12 #endif int mbedtls_ssl_parse_finished( mbedtls_ssl_context *ssl ) { int ret; unsigned int hash_len; unsigned char buf[SSL_MAX_HASH_LEN]; MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse finished" ) ); ssl->handshake->calc_finished( ssl, buf, ssl->conf->endpoint ^ 1 ); if( ( ret = mbedtls_ssl_read_record( ssl, 1 ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret ); return( ret ); } if( ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad finished message" ) ); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE ); return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE ); } /* There is currently no ciphersuite using another length with TLS 1.2 */ #if defined(MBEDTLS_SSL_PROTO_SSL3) if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 ) hash_len = 36; else #endif hash_len = 12; if( ssl->in_msg[0] != MBEDTLS_SSL_HS_FINISHED || ssl->in_hslen != mbedtls_ssl_hs_hdr_len( ssl ) + hash_len ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad finished message" ) ); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR ); return( MBEDTLS_ERR_SSL_BAD_HS_FINISHED ); } if( mbedtls_ssl_safer_memcmp( ssl->in_msg + mbedtls_ssl_hs_hdr_len( ssl ), buf, hash_len ) != 0 ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad finished message" ) ); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR ); return( MBEDTLS_ERR_SSL_BAD_HS_FINISHED ); } #if defined(MBEDTLS_SSL_RENEGOTIATION) ssl->verify_data_len = hash_len; memcpy( ssl->peer_verify_data, buf, hash_len ); #endif if( ssl->handshake->resume != 0 ) { #if defined(MBEDTLS_SSL_CLI_C) if( ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT ) ssl->state = MBEDTLS_SSL_CLIENT_CHANGE_CIPHER_SPEC; #endif #if defined(MBEDTLS_SSL_SRV_C) if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER ) ssl->state = MBEDTLS_SSL_HANDSHAKE_WRAPUP; #endif } else ssl->state++; #if defined(MBEDTLS_SSL_PROTO_DTLS) if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) mbedtls_ssl_recv_flight_completed( ssl ); #endif MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse finished" ) ); return( 0 ); } static void ssl_handshake_params_init( mbedtls_ssl_handshake_params *handshake ) { memset( handshake, 0, sizeof( mbedtls_ssl_handshake_params ) ); #if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1) || \ defined(MBEDTLS_SSL_PROTO_TLS1_1) mbedtls_md5_init( &handshake->fin_md5 ); mbedtls_sha1_init( &handshake->fin_sha1 ); mbedtls_md5_starts_ret( &handshake->fin_md5 ); mbedtls_sha1_starts_ret( &handshake->fin_sha1 ); #endif #if defined(MBEDTLS_SSL_PROTO_TLS1_2) #if defined(MBEDTLS_SHA256_C) mbedtls_sha256_init( &handshake->fin_sha256 ); mbedtls_sha256_starts_ret( &handshake->fin_sha256, 0 ); #endif #if defined(MBEDTLS_SHA512_C) mbedtls_sha512_init( &handshake->fin_sha512 ); mbedtls_sha512_starts_ret( &handshake->fin_sha512, 1 ); #endif #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */ handshake->update_checksum = ssl_update_checksum_start; #if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \ defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED) mbedtls_ssl_sig_hash_set_init( &handshake->hash_algs ); #endif #if defined(MBEDTLS_DHM_C) mbedtls_dhm_init( &handshake->dhm_ctx ); #endif #if defined(MBEDTLS_ECDH_C) mbedtls_ecdh_init( &handshake->ecdh_ctx ); #endif #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED) mbedtls_ecjpake_init( &handshake->ecjpake_ctx ); #if defined(MBEDTLS_SSL_CLI_C) handshake->ecjpake_cache = NULL; handshake->ecjpake_cache_len = 0; #endif #endif #if defined(MBEDTLS_SSL__ECP_RESTARTABLE) mbedtls_x509_crt_restart_init( &handshake->ecrs_ctx ); #endif #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION) handshake->sni_authmode = MBEDTLS_SSL_VERIFY_UNSET; #endif } static void ssl_transform_init( mbedtls_ssl_transform *transform ) { memset( transform, 0, sizeof(mbedtls_ssl_transform) ); mbedtls_cipher_init( &transform->cipher_ctx_enc ); mbedtls_cipher_init( &transform->cipher_ctx_dec ); mbedtls_md_init( &transform->md_ctx_enc ); mbedtls_md_init( &transform->md_ctx_dec ); } void mbedtls_ssl_session_init( mbedtls_ssl_session *session ) { memset( session, 0, sizeof(mbedtls_ssl_session) ); } static int ssl_handshake_init( mbedtls_ssl_context *ssl ) { /* Clear old handshake information if present */ if( ssl->transform_negotiate ) mbedtls_ssl_transform_free( ssl->transform_negotiate ); if( ssl->session_negotiate ) mbedtls_ssl_session_free( ssl->session_negotiate ); if( ssl->handshake ) mbedtls_ssl_handshake_free( ssl ); /* * Either the pointers are now NULL or cleared properly and can be freed. * Now allocate missing structures. */ if( ssl->transform_negotiate == NULL ) { ssl->transform_negotiate = mbedtls_calloc( 1, sizeof(mbedtls_ssl_transform) ); } if( ssl->session_negotiate == NULL ) { ssl->session_negotiate = mbedtls_calloc( 1, sizeof(mbedtls_ssl_session) ); } if( ssl->handshake == NULL ) { ssl->handshake = mbedtls_calloc( 1, sizeof(mbedtls_ssl_handshake_params) ); } /* All pointers should exist and can be directly freed without issue */ if( ssl->handshake == NULL || ssl->transform_negotiate == NULL || ssl->session_negotiate == NULL ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "alloc() of ssl sub-contexts failed" ) ); mbedtls_free( ssl->handshake ); mbedtls_free( ssl->transform_negotiate ); mbedtls_free( ssl->session_negotiate ); ssl->handshake = NULL; ssl->transform_negotiate = NULL; ssl->session_negotiate = NULL; return( MBEDTLS_ERR_SSL_ALLOC_FAILED ); } /* Initialize structures */ mbedtls_ssl_session_init( ssl->session_negotiate ); ssl_transform_init( ssl->transform_negotiate ); ssl_handshake_params_init( ssl->handshake ); #if defined(MBEDTLS_SSL_PROTO_DTLS) if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) { ssl->handshake->alt_transform_out = ssl->transform_out; if( ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT ) ssl->handshake->retransmit_state = MBEDTLS_SSL_RETRANS_PREPARING; else ssl->handshake->retransmit_state = MBEDTLS_SSL_RETRANS_WAITING; ssl_set_timer( ssl, 0 ); } #endif return( 0 ); } #if defined(MBEDTLS_SSL_DTLS_HELLO_VERIFY) && defined(MBEDTLS_SSL_SRV_C) /* Dummy cookie callbacks for defaults */ static int ssl_cookie_write_dummy( void *ctx, unsigned char **p, unsigned char *end, const unsigned char *cli_id, size_t cli_id_len ) { ((void) ctx); ((void) p); ((void) end); ((void) cli_id); ((void) cli_id_len); return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE ); } static int ssl_cookie_check_dummy( void *ctx, const unsigned char *cookie, size_t cookie_len, const unsigned char *cli_id, size_t cli_id_len ) { ((void) ctx); ((void) cookie); ((void) cookie_len); ((void) cli_id); ((void) cli_id_len); return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE ); } #endif /* MBEDTLS_SSL_DTLS_HELLO_VERIFY && MBEDTLS_SSL_SRV_C */ /* Once ssl->out_hdr as the address of the beginning of the * next outgoing record is set, deduce the other pointers. * * Note: For TLS, we save the implicit record sequence number * (entering MAC computation) in the 8 bytes before ssl->out_hdr, * and the caller has to make sure there's space for this. */ static void ssl_update_out_pointers( mbedtls_ssl_context *ssl, mbedtls_ssl_transform *transform ) { #if defined(MBEDTLS_SSL_PROTO_DTLS) if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) { ssl->out_ctr = ssl->out_hdr + 3; ssl->out_len = ssl->out_hdr + 11; ssl->out_iv = ssl->out_hdr + 13; } else #endif { ssl->out_ctr = ssl->out_hdr - 8; ssl->out_len = ssl->out_hdr + 3; ssl->out_iv = ssl->out_hdr + 5; } /* Adjust out_msg to make space for explicit IV, if used. */ if( transform != NULL && ssl->minor_ver >= MBEDTLS_SSL_MINOR_VERSION_2 ) { ssl->out_msg = ssl->out_iv + transform->ivlen - transform->fixed_ivlen; } else ssl->out_msg = ssl->out_iv; } /* Once ssl->in_hdr as the address of the beginning of the * next incoming record is set, deduce the other pointers. * * Note: For TLS, we save the implicit record sequence number * (entering MAC computation) in the 8 bytes before ssl->in_hdr, * and the caller has to make sure there's space for this. */ static void ssl_update_in_pointers( mbedtls_ssl_context *ssl, mbedtls_ssl_transform *transform ) { #if defined(MBEDTLS_SSL_PROTO_DTLS) if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) { ssl->in_ctr = ssl->in_hdr + 3; ssl->in_len = ssl->in_hdr + 11; ssl->in_iv = ssl->in_hdr + 13; } else #endif { ssl->in_ctr = ssl->in_hdr - 8; ssl->in_len = ssl->in_hdr + 3; ssl->in_iv = ssl->in_hdr + 5; } /* Offset in_msg from in_iv to allow space for explicit IV, if used. */ if( transform != NULL && ssl->minor_ver >= MBEDTLS_SSL_MINOR_VERSION_2 ) { ssl->in_msg = ssl->in_iv + transform->ivlen - transform->fixed_ivlen; } else ssl->in_msg = ssl->in_iv; } /* * Initialize an SSL context */ void mbedtls_ssl_init( mbedtls_ssl_context *ssl ) { memset( ssl, 0, sizeof( mbedtls_ssl_context ) ); } /* * Setup an SSL context */ static void ssl_reset_in_out_pointers( mbedtls_ssl_context *ssl ) { /* Set the incoming and outgoing record pointers. */ #if defined(MBEDTLS_SSL_PROTO_DTLS) if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) { ssl->out_hdr = ssl->out_buf; ssl->in_hdr = ssl->in_buf; } else #endif /* MBEDTLS_SSL_PROTO_DTLS */ { ssl->out_hdr = ssl->out_buf + 8; ssl->in_hdr = ssl->in_buf + 8; } /* Derive other internal pointers. */ ssl_update_out_pointers( ssl, NULL /* no transform enabled */ ); ssl_update_in_pointers ( ssl, NULL /* no transform enabled */ ); } int mbedtls_ssl_setup( mbedtls_ssl_context *ssl, const mbedtls_ssl_config *conf ) { int ret; ssl->conf = conf; /* * Prepare base structures */ /* Set to NULL in case of an error condition */ ssl->out_buf = NULL; ssl->in_buf = mbedtls_calloc( 1, MBEDTLS_SSL_IN_BUFFER_LEN ); if( ssl->in_buf == NULL ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "alloc(%d bytes) failed", MBEDTLS_SSL_IN_BUFFER_LEN) ); ret = MBEDTLS_ERR_SSL_ALLOC_FAILED; goto error; } ssl->out_buf = mbedtls_calloc( 1, MBEDTLS_SSL_OUT_BUFFER_LEN ); if( ssl->out_buf == NULL ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "alloc(%d bytes) failed", MBEDTLS_SSL_OUT_BUFFER_LEN) ); ret = MBEDTLS_ERR_SSL_ALLOC_FAILED; goto error; } ssl_reset_in_out_pointers( ssl ); if( ( ret = ssl_handshake_init( ssl ) ) != 0 ) goto error; return( 0 ); error: mbedtls_free( ssl->in_buf ); mbedtls_free( ssl->out_buf ); ssl->conf = NULL; ssl->in_buf = NULL; ssl->out_buf = NULL; ssl->in_hdr = NULL; ssl->in_ctr = NULL; ssl->in_len = NULL; ssl->in_iv = NULL; ssl->in_msg = NULL; ssl->out_hdr = NULL; ssl->out_ctr = NULL; ssl->out_len = NULL; ssl->out_iv = NULL; ssl->out_msg = NULL; return( ret ); } /* * Reset an initialized and used SSL context for re-use while retaining * all application-set variables, function pointers and data. * * If partial is non-zero, keep data in the input buffer and client ID. * (Use when a DTLS client reconnects from the same port.) */ static int ssl_session_reset_int( mbedtls_ssl_context *ssl, int partial ) { int ret; #if !defined(MBEDTLS_SSL_DTLS_CLIENT_PORT_REUSE) || \ !defined(MBEDTLS_SSL_SRV_C) ((void) partial); #endif ssl->state = MBEDTLS_SSL_HELLO_REQUEST; /* Cancel any possibly running timer */ ssl_set_timer( ssl, 0 ); #if defined(MBEDTLS_SSL_RENEGOTIATION) ssl->renego_status = MBEDTLS_SSL_INITIAL_HANDSHAKE; ssl->renego_records_seen = 0; ssl->verify_data_len = 0; memset( ssl->own_verify_data, 0, MBEDTLS_SSL_VERIFY_DATA_MAX_LEN ); memset( ssl->peer_verify_data, 0, MBEDTLS_SSL_VERIFY_DATA_MAX_LEN ); #endif ssl->secure_renegotiation = MBEDTLS_SSL_LEGACY_RENEGOTIATION; ssl->in_offt = NULL; ssl_reset_in_out_pointers( ssl ); ssl->in_msgtype = 0; ssl->in_msglen = 0; #if defined(MBEDTLS_SSL_PROTO_DTLS) ssl->next_record_offset = 0; ssl->in_epoch = 0; #endif #if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY) ssl_dtls_replay_reset( ssl ); #endif ssl->in_hslen = 0; ssl->nb_zero = 0; ssl->keep_current_message = 0; ssl->out_msgtype = 0; ssl->out_msglen = 0; ssl->out_left = 0; #if defined(MBEDTLS_SSL_CBC_RECORD_SPLITTING) if( ssl->split_done != MBEDTLS_SSL_CBC_RECORD_SPLITTING_DISABLED ) ssl->split_done = 0; #endif memset( ssl->cur_out_ctr, 0, sizeof( ssl->cur_out_ctr ) ); ssl->transform_in = NULL; ssl->transform_out = NULL; ssl->session_in = NULL; ssl->session_out = NULL; memset( ssl->out_buf, 0, MBEDTLS_SSL_OUT_BUFFER_LEN ); #if defined(MBEDTLS_SSL_DTLS_CLIENT_PORT_REUSE) && defined(MBEDTLS_SSL_SRV_C) if( partial == 0 ) #endif /* MBEDTLS_SSL_DTLS_CLIENT_PORT_REUSE && MBEDTLS_SSL_SRV_C */ { ssl->in_left = 0; memset( ssl->in_buf, 0, MBEDTLS_SSL_IN_BUFFER_LEN ); } #if defined(MBEDTLS_SSL_HW_RECORD_ACCEL) if( mbedtls_ssl_hw_record_reset != NULL ) { MBEDTLS_SSL_DEBUG_MSG( 2, ( "going for mbedtls_ssl_hw_record_reset()" ) ); if( ( ret = mbedtls_ssl_hw_record_reset( ssl ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_hw_record_reset", ret ); return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED ); } } #endif if( ssl->transform ) { mbedtls_ssl_transform_free( ssl->transform ); mbedtls_free( ssl->transform ); ssl->transform = NULL; } if( ssl->session ) { mbedtls_ssl_session_free( ssl->session ); mbedtls_free( ssl->session ); ssl->session = NULL; } #if defined(MBEDTLS_SSL_ALPN) ssl->alpn_chosen = NULL; #endif #if defined(MBEDTLS_SSL_DTLS_HELLO_VERIFY) && defined(MBEDTLS_SSL_SRV_C) #if defined(MBEDTLS_SSL_DTLS_CLIENT_PORT_REUSE) if( partial == 0 ) #endif { mbedtls_free( ssl->cli_id ); ssl->cli_id = NULL; ssl->cli_id_len = 0; } #endif if( ( ret = ssl_handshake_init( ssl ) ) != 0 ) return( ret ); return( 0 ); } /* * Reset an initialized and used SSL context for re-use while retaining * all application-set variables, function pointers and data. */ int mbedtls_ssl_session_reset( mbedtls_ssl_context *ssl ) { return( ssl_session_reset_int( ssl, 0 ) ); } /* * SSL set accessors */ void mbedtls_ssl_conf_endpoint( mbedtls_ssl_config *conf, int endpoint ) { conf->endpoint = endpoint; } void mbedtls_ssl_conf_transport( mbedtls_ssl_config *conf, int transport ) { conf->transport = transport; } #if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY) void mbedtls_ssl_conf_dtls_anti_replay( mbedtls_ssl_config *conf, char mode ) { conf->anti_replay = mode; } #endif #if defined(MBEDTLS_SSL_DTLS_BADMAC_LIMIT) void mbedtls_ssl_conf_dtls_badmac_limit( mbedtls_ssl_config *conf, unsigned limit ) { conf->badmac_limit = limit; } #endif #if defined(MBEDTLS_SSL_PROTO_DTLS) void mbedtls_ssl_set_datagram_packing( mbedtls_ssl_context *ssl, unsigned allow_packing ) { ssl->disable_datagram_packing = !allow_packing; } void mbedtls_ssl_conf_handshake_timeout( mbedtls_ssl_config *conf, uint32_t min, uint32_t max ) { conf->hs_timeout_min = min; conf->hs_timeout_max = max; } #endif void mbedtls_ssl_conf_authmode( mbedtls_ssl_config *conf, int authmode ) { conf->authmode = authmode; } #if defined(MBEDTLS_X509_CRT_PARSE_C) void mbedtls_ssl_conf_verify( mbedtls_ssl_config *conf, int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *), void *p_vrfy ) { conf->f_vrfy = f_vrfy; conf->p_vrfy = p_vrfy; } #endif /* MBEDTLS_X509_CRT_PARSE_C */ void mbedtls_ssl_conf_rng( mbedtls_ssl_config *conf, int (*f_rng)(void *, unsigned char *, size_t), void *p_rng ) { conf->f_rng = f_rng; conf->p_rng = p_rng; } void mbedtls_ssl_conf_dbg( mbedtls_ssl_config *conf, void (*f_dbg)(void *, int, const char *, int, const char *), void *p_dbg ) { conf->f_dbg = f_dbg; conf->p_dbg = p_dbg; } void mbedtls_ssl_set_bio( mbedtls_ssl_context *ssl, void *p_bio, mbedtls_ssl_send_t *f_send, mbedtls_ssl_recv_t *f_recv, mbedtls_ssl_recv_timeout_t *f_recv_timeout ) { ssl->p_bio = p_bio; ssl->f_send = f_send; ssl->f_recv = f_recv; ssl->f_recv_timeout = f_recv_timeout; } #if defined(MBEDTLS_SSL_PROTO_DTLS) void mbedtls_ssl_set_mtu( mbedtls_ssl_context *ssl, uint16_t mtu ) { ssl->mtu = mtu; } #endif void mbedtls_ssl_conf_read_timeout( mbedtls_ssl_config *conf, uint32_t timeout ) { conf->read_timeout = timeout; } void mbedtls_ssl_set_timer_cb( mbedtls_ssl_context *ssl, void *p_timer, mbedtls_ssl_set_timer_t *f_set_timer, mbedtls_ssl_get_timer_t *f_get_timer ) { ssl->p_timer = p_timer; ssl->f_set_timer = f_set_timer; ssl->f_get_timer = f_get_timer; /* Make sure we start with no timer running */ ssl_set_timer( ssl, 0 ); } #if defined(MBEDTLS_SSL_SRV_C) void mbedtls_ssl_conf_session_cache( mbedtls_ssl_config *conf, void *p_cache, int (*f_get_cache)(void *, mbedtls_ssl_session *), int (*f_set_cache)(void *, const mbedtls_ssl_session *) ) { conf->p_cache = p_cache; conf->f_get_cache = f_get_cache; conf->f_set_cache = f_set_cache; } #endif /* MBEDTLS_SSL_SRV_C */ #if defined(MBEDTLS_SSL_CLI_C) int mbedtls_ssl_set_session( mbedtls_ssl_context *ssl, const mbedtls_ssl_session *session ) { int ret; if( ssl == NULL || session == NULL || ssl->session_negotiate == NULL || ssl->conf->endpoint != MBEDTLS_SSL_IS_CLIENT ) { return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); } if( ( ret = ssl_session_copy( ssl->session_negotiate, session ) ) != 0 ) return( ret ); ssl->handshake->resume = 1; return( 0 ); } #endif /* MBEDTLS_SSL_CLI_C */ void mbedtls_ssl_conf_ciphersuites( mbedtls_ssl_config *conf, const int *ciphersuites ) { conf->ciphersuite_list[MBEDTLS_SSL_MINOR_VERSION_0] = ciphersuites; conf->ciphersuite_list[MBEDTLS_SSL_MINOR_VERSION_1] = ciphersuites; conf->ciphersuite_list[MBEDTLS_SSL_MINOR_VERSION_2] = ciphersuites; conf->ciphersuite_list[MBEDTLS_SSL_MINOR_VERSION_3] = ciphersuites; } void mbedtls_ssl_conf_ciphersuites_for_version( mbedtls_ssl_config *conf, const int *ciphersuites, int major, int minor ) { if( major != MBEDTLS_SSL_MAJOR_VERSION_3 ) return; if( minor < MBEDTLS_SSL_MINOR_VERSION_0 || minor > MBEDTLS_SSL_MINOR_VERSION_3 ) return; conf->ciphersuite_list[minor] = ciphersuites; } #if defined(MBEDTLS_X509_CRT_PARSE_C) void mbedtls_ssl_conf_cert_profile( mbedtls_ssl_config *conf, const mbedtls_x509_crt_profile *profile ) { conf->cert_profile = profile; } /* Append a new keycert entry to a (possibly empty) list */ static int ssl_append_key_cert( mbedtls_ssl_key_cert **head, mbedtls_x509_crt *cert, mbedtls_pk_context *key ) { mbedtls_ssl_key_cert *new_cert; new_cert = mbedtls_calloc( 1, sizeof( mbedtls_ssl_key_cert ) ); if( new_cert == NULL ) return( MBEDTLS_ERR_SSL_ALLOC_FAILED ); new_cert->cert = cert; new_cert->key = key; new_cert->next = NULL; /* Update head is the list was null, else add to the end */ if( *head == NULL ) { *head = new_cert; } else { mbedtls_ssl_key_cert *cur = *head; while( cur->next != NULL ) cur = cur->next; cur->next = new_cert; } return( 0 ); } int mbedtls_ssl_conf_own_cert( mbedtls_ssl_config *conf, mbedtls_x509_crt *own_cert, mbedtls_pk_context *pk_key ) { return( ssl_append_key_cert( &conf->key_cert, own_cert, pk_key ) ); } void mbedtls_ssl_conf_ca_chain( mbedtls_ssl_config *conf, mbedtls_x509_crt *ca_chain, mbedtls_x509_crl *ca_crl ) { conf->ca_chain = ca_chain; conf->ca_crl = ca_crl; } #endif /* MBEDTLS_X509_CRT_PARSE_C */ #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION) int mbedtls_ssl_set_hs_own_cert( mbedtls_ssl_context *ssl, mbedtls_x509_crt *own_cert, mbedtls_pk_context *pk_key ) { return( ssl_append_key_cert( &ssl->handshake->sni_key_cert, own_cert, pk_key ) ); } void mbedtls_ssl_set_hs_ca_chain( mbedtls_ssl_context *ssl, mbedtls_x509_crt *ca_chain, mbedtls_x509_crl *ca_crl ) { ssl->handshake->sni_ca_chain = ca_chain; ssl->handshake->sni_ca_crl = ca_crl; } void mbedtls_ssl_set_hs_authmode( mbedtls_ssl_context *ssl, int authmode ) { ssl->handshake->sni_authmode = authmode; } #endif /* MBEDTLS_SSL_SERVER_NAME_INDICATION */ #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED) /* * Set EC J-PAKE password for current handshake */ int mbedtls_ssl_set_hs_ecjpake_password( mbedtls_ssl_context *ssl, const unsigned char *pw, size_t pw_len ) { mbedtls_ecjpake_role role; if( ssl->handshake == NULL || ssl->conf == NULL ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER ) role = MBEDTLS_ECJPAKE_SERVER; else role = MBEDTLS_ECJPAKE_CLIENT; return( mbedtls_ecjpake_setup( &ssl->handshake->ecjpake_ctx, role, MBEDTLS_MD_SHA256, MBEDTLS_ECP_DP_SECP256R1, pw, pw_len ) ); } #endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */ #if defined(MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED) int mbedtls_ssl_conf_psk( mbedtls_ssl_config *conf, const unsigned char *psk, size_t psk_len, const unsigned char *psk_identity, size_t psk_identity_len ) { if( psk == NULL || psk_identity == NULL ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); if( psk_len > MBEDTLS_PSK_MAX_LEN ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); /* Identity len will be encoded on two bytes */ if( ( psk_identity_len >> 16 ) != 0 || psk_identity_len > MBEDTLS_SSL_OUT_CONTENT_LEN ) { return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); } if( conf->psk != NULL ) { mbedtls_platform_zeroize( conf->psk, conf->psk_len ); mbedtls_free( conf->psk ); conf->psk = NULL; conf->psk_len = 0; } if( conf->psk_identity != NULL ) { mbedtls_free( conf->psk_identity ); conf->psk_identity = NULL; conf->psk_identity_len = 0; } if( ( conf->psk = mbedtls_calloc( 1, psk_len ) ) == NULL || ( conf->psk_identity = mbedtls_calloc( 1, psk_identity_len ) ) == NULL ) { mbedtls_free( conf->psk ); mbedtls_free( conf->psk_identity ); conf->psk = NULL; conf->psk_identity = NULL; return( MBEDTLS_ERR_SSL_ALLOC_FAILED ); } conf->psk_len = psk_len; conf->psk_identity_len = psk_identity_len; memcpy( conf->psk, psk, conf->psk_len ); memcpy( conf->psk_identity, psk_identity, conf->psk_identity_len ); return( 0 ); } int mbedtls_ssl_set_hs_psk( mbedtls_ssl_context *ssl, const unsigned char *psk, size_t psk_len ) { if( psk == NULL || ssl->handshake == NULL ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); if( psk_len > MBEDTLS_PSK_MAX_LEN ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); if( ssl->handshake->psk != NULL ) { mbedtls_platform_zeroize( ssl->handshake->psk, ssl->handshake->psk_len ); mbedtls_free( ssl->handshake->psk ); ssl->handshake->psk_len = 0; } if( ( ssl->handshake->psk = mbedtls_calloc( 1, psk_len ) ) == NULL ) return( MBEDTLS_ERR_SSL_ALLOC_FAILED ); ssl->handshake->psk_len = psk_len; memcpy( ssl->handshake->psk, psk, ssl->handshake->psk_len ); return( 0 ); } void mbedtls_ssl_conf_psk_cb( mbedtls_ssl_config *conf, int (*f_psk)(void *, mbedtls_ssl_context *, const unsigned char *, size_t), void *p_psk ) { conf->f_psk = f_psk; conf->p_psk = p_psk; } #endif /* MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED */ #if defined(MBEDTLS_DHM_C) && defined(MBEDTLS_SSL_SRV_C) #if !defined(MBEDTLS_DEPRECATED_REMOVED) int mbedtls_ssl_conf_dh_param( mbedtls_ssl_config *conf, const char *dhm_P, const char *dhm_G ) { int ret; if( ( ret = mbedtls_mpi_read_string( &conf->dhm_P, 16, dhm_P ) ) != 0 || ( ret = mbedtls_mpi_read_string( &conf->dhm_G, 16, dhm_G ) ) != 0 ) { mbedtls_mpi_free( &conf->dhm_P ); mbedtls_mpi_free( &conf->dhm_G ); return( ret ); } return( 0 ); } #endif /* MBEDTLS_DEPRECATED_REMOVED */ int mbedtls_ssl_conf_dh_param_bin( mbedtls_ssl_config *conf, const unsigned char *dhm_P, size_t P_len, const unsigned char *dhm_G, size_t G_len ) { int ret; if( ( ret = mbedtls_mpi_read_binary( &conf->dhm_P, dhm_P, P_len ) ) != 0 || ( ret = mbedtls_mpi_read_binary( &conf->dhm_G, dhm_G, G_len ) ) != 0 ) { mbedtls_mpi_free( &conf->dhm_P ); mbedtls_mpi_free( &conf->dhm_G ); return( ret ); } return( 0 ); } int mbedtls_ssl_conf_dh_param_ctx( mbedtls_ssl_config *conf, mbedtls_dhm_context *dhm_ctx ) { int ret; if( ( ret = mbedtls_mpi_copy( &conf->dhm_P, &dhm_ctx->P ) ) != 0 || ( ret = mbedtls_mpi_copy( &conf->dhm_G, &dhm_ctx->G ) ) != 0 ) { mbedtls_mpi_free( &conf->dhm_P ); mbedtls_mpi_free( &conf->dhm_G ); return( ret ); } return( 0 ); } #endif /* MBEDTLS_DHM_C && MBEDTLS_SSL_SRV_C */ #if defined(MBEDTLS_DHM_C) && defined(MBEDTLS_SSL_CLI_C) /* * Set the minimum length for Diffie-Hellman parameters */ void mbedtls_ssl_conf_dhm_min_bitlen( mbedtls_ssl_config *conf, unsigned int bitlen ) { conf->dhm_min_bitlen = bitlen; } #endif /* MBEDTLS_DHM_C && MBEDTLS_SSL_CLI_C */ #if defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED) /* * Set allowed/preferred hashes for handshake signatures */ void mbedtls_ssl_conf_sig_hashes( mbedtls_ssl_config *conf, const int *hashes ) { conf->sig_hashes = hashes; } #endif /* MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED */ #if defined(MBEDTLS_ECP_C) /* * Set the allowed elliptic curves */ void mbedtls_ssl_conf_curves( mbedtls_ssl_config *conf, const mbedtls_ecp_group_id *curve_list ) { conf->curve_list = curve_list; } #endif /* MBEDTLS_ECP_C */ #if defined(MBEDTLS_X509_CRT_PARSE_C) int mbedtls_ssl_set_hostname( mbedtls_ssl_context *ssl, const char *hostname ) { /* Initialize to suppress unnecessary compiler warning */ size_t hostname_len = 0; /* Check if new hostname is valid before * making any change to current one */ if( hostname != NULL ) { hostname_len = strlen( hostname ); if( hostname_len > MBEDTLS_SSL_MAX_HOST_NAME_LEN ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); } /* Now it's clear that we will overwrite the old hostname, * so we can free it safely */ if( ssl->hostname != NULL ) { mbedtls_platform_zeroize( ssl->hostname, strlen( ssl->hostname ) ); mbedtls_free( ssl->hostname ); } /* Passing NULL as hostname shall clear the old one */ if( hostname == NULL ) { ssl->hostname = NULL; } else { ssl->hostname = mbedtls_calloc( 1, hostname_len + 1 ); if( ssl->hostname == NULL ) return( MBEDTLS_ERR_SSL_ALLOC_FAILED ); memcpy( ssl->hostname, hostname, hostname_len ); ssl->hostname[hostname_len] = '\0'; } return( 0 ); } #endif /* MBEDTLS_X509_CRT_PARSE_C */ #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION) void mbedtls_ssl_conf_sni( mbedtls_ssl_config *conf, int (*f_sni)(void *, mbedtls_ssl_context *, const unsigned char *, size_t), void *p_sni ) { conf->f_sni = f_sni; conf->p_sni = p_sni; } #endif /* MBEDTLS_SSL_SERVER_NAME_INDICATION */ #if defined(MBEDTLS_SSL_ALPN) int mbedtls_ssl_conf_alpn_protocols( mbedtls_ssl_config *conf, const char **protos ) { size_t cur_len, tot_len; const char **p; /* * RFC 7301 3.1: "Empty strings MUST NOT be included and byte strings * MUST NOT be truncated." * We check lengths now rather than later. */ tot_len = 0; for( p = protos; *p != NULL; p++ ) { cur_len = strlen( *p ); tot_len += cur_len; if( cur_len == 0 || cur_len > 255 || tot_len > 65535 ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); } conf->alpn_list = protos; return( 0 ); } const char *mbedtls_ssl_get_alpn_protocol( const mbedtls_ssl_context *ssl ) { return( ssl->alpn_chosen ); } #endif /* MBEDTLS_SSL_ALPN */ void mbedtls_ssl_conf_max_version( mbedtls_ssl_config *conf, int major, int minor ) { conf->max_major_ver = major; conf->max_minor_ver = minor; } void mbedtls_ssl_conf_min_version( mbedtls_ssl_config *conf, int major, int minor ) { conf->min_major_ver = major; conf->min_minor_ver = minor; } #if defined(MBEDTLS_SSL_FALLBACK_SCSV) && defined(MBEDTLS_SSL_CLI_C) void mbedtls_ssl_conf_fallback( mbedtls_ssl_config *conf, char fallback ) { conf->fallback = fallback; } #endif #if defined(MBEDTLS_SSL_SRV_C) void mbedtls_ssl_conf_cert_req_ca_list( mbedtls_ssl_config *conf, char cert_req_ca_list ) { conf->cert_req_ca_list = cert_req_ca_list; } #endif #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC) void mbedtls_ssl_conf_encrypt_then_mac( mbedtls_ssl_config *conf, char etm ) { conf->encrypt_then_mac = etm; } #endif #if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET) void mbedtls_ssl_conf_extended_master_secret( mbedtls_ssl_config *conf, char ems ) { conf->extended_ms = ems; } #endif #if defined(MBEDTLS_ARC4_C) void mbedtls_ssl_conf_arc4_support( mbedtls_ssl_config *conf, char arc4 ) { conf->arc4_disabled = arc4; } #endif #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH) int mbedtls_ssl_conf_max_frag_len( mbedtls_ssl_config *conf, unsigned char mfl_code ) { if( mfl_code >= MBEDTLS_SSL_MAX_FRAG_LEN_INVALID || ssl_mfl_code_to_length( mfl_code ) > MBEDTLS_TLS_EXT_ADV_CONTENT_LEN ) { return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); } conf->mfl_code = mfl_code; return( 0 ); } #endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */ #if defined(MBEDTLS_SSL_TRUNCATED_HMAC) void mbedtls_ssl_conf_truncated_hmac( mbedtls_ssl_config *conf, int truncate ) { conf->trunc_hmac = truncate; } #endif /* MBEDTLS_SSL_TRUNCATED_HMAC */ #if defined(MBEDTLS_SSL_CBC_RECORD_SPLITTING) void mbedtls_ssl_conf_cbc_record_splitting( mbedtls_ssl_config *conf, char split ) { conf->cbc_record_splitting = split; } #endif void mbedtls_ssl_conf_legacy_renegotiation( mbedtls_ssl_config *conf, int allow_legacy ) { conf->allow_legacy_renegotiation = allow_legacy; } #if defined(MBEDTLS_SSL_RENEGOTIATION) void mbedtls_ssl_conf_renegotiation( mbedtls_ssl_config *conf, int renegotiation ) { conf->disable_renegotiation = renegotiation; } void mbedtls_ssl_conf_renegotiation_enforced( mbedtls_ssl_config *conf, int max_records ) { conf->renego_max_records = max_records; } void mbedtls_ssl_conf_renegotiation_period( mbedtls_ssl_config *conf, const unsigned char period[8] ) { memcpy( conf->renego_period, period, 8 ); } #endif /* MBEDTLS_SSL_RENEGOTIATION */ #if defined(MBEDTLS_SSL_SESSION_TICKETS) #if defined(MBEDTLS_SSL_CLI_C) void mbedtls_ssl_conf_session_tickets( mbedtls_ssl_config *conf, int use_tickets ) { conf->session_tickets = use_tickets; } #endif #if defined(MBEDTLS_SSL_SRV_C) void mbedtls_ssl_conf_session_tickets_cb( mbedtls_ssl_config *conf, mbedtls_ssl_ticket_write_t *f_ticket_write, mbedtls_ssl_ticket_parse_t *f_ticket_parse, void *p_ticket ) { conf->f_ticket_write = f_ticket_write; conf->f_ticket_parse = f_ticket_parse; conf->p_ticket = p_ticket; } #endif #endif /* MBEDTLS_SSL_SESSION_TICKETS */ #if defined(MBEDTLS_SSL_EXPORT_KEYS) void mbedtls_ssl_conf_export_keys_cb( mbedtls_ssl_config *conf, mbedtls_ssl_export_keys_t *f_export_keys, void *p_export_keys ) { conf->f_export_keys = f_export_keys; conf->p_export_keys = p_export_keys; } #endif #if defined(MBEDTLS_SSL_ASYNC_PRIVATE) void mbedtls_ssl_conf_async_private_cb( mbedtls_ssl_config *conf, mbedtls_ssl_async_sign_t *f_async_sign, mbedtls_ssl_async_decrypt_t *f_async_decrypt, mbedtls_ssl_async_resume_t *f_async_resume, mbedtls_ssl_async_cancel_t *f_async_cancel, void *async_config_data ) { conf->f_async_sign_start = f_async_sign; conf->f_async_decrypt_start = f_async_decrypt; conf->f_async_resume = f_async_resume; conf->f_async_cancel = f_async_cancel; conf->p_async_config_data = async_config_data; } void *mbedtls_ssl_conf_get_async_config_data( const mbedtls_ssl_config *conf ) { return( conf->p_async_config_data ); } void *mbedtls_ssl_get_async_operation_data( const mbedtls_ssl_context *ssl ) { if( ssl->handshake == NULL ) return( NULL ); else return( ssl->handshake->user_async_ctx ); } void mbedtls_ssl_set_async_operation_data( mbedtls_ssl_context *ssl, void *ctx ) { if( ssl->handshake != NULL ) ssl->handshake->user_async_ctx = ctx; } #endif /* MBEDTLS_SSL_ASYNC_PRIVATE */ /* * SSL get accessors */ size_t mbedtls_ssl_get_bytes_avail( const mbedtls_ssl_context *ssl ) { return( ssl->in_offt == NULL ? 0 : ssl->in_msglen ); } int mbedtls_ssl_check_pending( const mbedtls_ssl_context *ssl ) { /* * Case A: We're currently holding back * a message for further processing. */ if( ssl->keep_current_message == 1 ) { MBEDTLS_SSL_DEBUG_MSG( 3, ( "ssl_check_pending: record held back for processing" ) ); return( 1 ); } /* * Case B: Further records are pending in the current datagram. */ #if defined(MBEDTLS_SSL_PROTO_DTLS) if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM && ssl->in_left > ssl->next_record_offset ) { MBEDTLS_SSL_DEBUG_MSG( 3, ( "ssl_check_pending: more records within current datagram" ) ); return( 1 ); } #endif /* MBEDTLS_SSL_PROTO_DTLS */ /* * Case C: A handshake message is being processed. */ if( ssl->in_hslen > 0 && ssl->in_hslen < ssl->in_msglen ) { MBEDTLS_SSL_DEBUG_MSG( 3, ( "ssl_check_pending: more handshake messages within current record" ) ); return( 1 ); } /* * Case D: An application data message is being processed */ if( ssl->in_offt != NULL ) { MBEDTLS_SSL_DEBUG_MSG( 3, ( "ssl_check_pending: application data record is being processed" ) ); return( 1 ); } /* * In all other cases, the rest of the message can be dropped. * As in ssl_get_next_record, this needs to be adapted if * we implement support for multiple alerts in single records. */ MBEDTLS_SSL_DEBUG_MSG( 3, ( "ssl_check_pending: nothing pending" ) ); return( 0 ); } uint32_t mbedtls_ssl_get_verify_result( const mbedtls_ssl_context *ssl ) { if( ssl->session != NULL ) return( ssl->session->verify_result ); if( ssl->session_negotiate != NULL ) return( ssl->session_negotiate->verify_result ); return( 0xFFFFFFFF ); } const char *mbedtls_ssl_get_ciphersuite( const mbedtls_ssl_context *ssl ) { if( ssl == NULL || ssl->session == NULL ) return( NULL ); return mbedtls_ssl_get_ciphersuite_name( ssl->session->ciphersuite ); } const char *mbedtls_ssl_get_version( const mbedtls_ssl_context *ssl ) { #if defined(MBEDTLS_SSL_PROTO_DTLS) if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) { switch( ssl->minor_ver ) { case MBEDTLS_SSL_MINOR_VERSION_2: return( "DTLSv1.0" ); case MBEDTLS_SSL_MINOR_VERSION_3: return( "DTLSv1.2" ); default: return( "unknown (DTLS)" ); } } #endif switch( ssl->minor_ver ) { case MBEDTLS_SSL_MINOR_VERSION_0: return( "SSLv3.0" ); case MBEDTLS_SSL_MINOR_VERSION_1: return( "TLSv1.0" ); case MBEDTLS_SSL_MINOR_VERSION_2: return( "TLSv1.1" ); case MBEDTLS_SSL_MINOR_VERSION_3: return( "TLSv1.2" ); default: return( "unknown" ); } } int mbedtls_ssl_get_record_expansion( const mbedtls_ssl_context *ssl ) { size_t transform_expansion = 0; const mbedtls_ssl_transform *transform = ssl->transform_out; unsigned block_size; if( transform == NULL ) return( (int) mbedtls_ssl_hdr_len( ssl ) ); #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 ); } return( (int)( mbedtls_ssl_hdr_len( ssl ) + transform_expansion ) ); } #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH) size_t mbedtls_ssl_get_max_frag_len( const mbedtls_ssl_context *ssl ) { size_t max_len; /* * Assume mfl_code is correct since it was checked when set */ max_len = ssl_mfl_code_to_length( ssl->conf->mfl_code ); /* Check if a smaller max length was negotiated */ if( ssl->session_out != NULL && ssl_mfl_code_to_length( ssl->session_out->mfl_code ) < max_len ) { max_len = ssl_mfl_code_to_length( ssl->session_out->mfl_code ); } /* During a handshake, use the value being negotiated */ if( ssl->session_negotiate != NULL && ssl_mfl_code_to_length( ssl->session_negotiate->mfl_code ) < max_len ) { max_len = ssl_mfl_code_to_length( ssl->session_negotiate->mfl_code ); } return( max_len ); } #endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */ #if defined(MBEDTLS_SSL_PROTO_DTLS) static size_t ssl_get_current_mtu( const mbedtls_ssl_context *ssl ) { /* Return unlimited mtu for client hello messages to avoid fragmentation. */ if( ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT && ( ssl->state == MBEDTLS_SSL_CLIENT_HELLO || ssl->state == MBEDTLS_SSL_SERVER_HELLO ) ) return ( 0 ); if( ssl->handshake == NULL || ssl->handshake->mtu == 0 ) return( ssl->mtu ); if( ssl->mtu == 0 ) return( ssl->handshake->mtu ); return( ssl->mtu < ssl->handshake->mtu ? ssl->mtu : ssl->handshake->mtu ); } #endif /* MBEDTLS_SSL_PROTO_DTLS */ int mbedtls_ssl_get_max_out_record_payload( const mbedtls_ssl_context *ssl ) { size_t max_len = MBEDTLS_SSL_OUT_CONTENT_LEN; #if !defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH) && \ !defined(MBEDTLS_SSL_PROTO_DTLS) (void) ssl; #endif #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH) const size_t mfl = mbedtls_ssl_get_max_frag_len( ssl ); if( max_len > mfl ) max_len = mfl; #endif #if defined(MBEDTLS_SSL_PROTO_DTLS) if( ssl_get_current_mtu( ssl ) != 0 ) { const size_t mtu = ssl_get_current_mtu( ssl ); const int ret = mbedtls_ssl_get_record_expansion( ssl ); const size_t overhead = (size_t) ret; if( ret < 0 ) return( ret ); if( mtu <= overhead ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "MTU too low for record expansion" ) ); return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE ); } if( max_len > mtu - overhead ) max_len = mtu - overhead; } #endif /* MBEDTLS_SSL_PROTO_DTLS */ #if !defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH) && \ !defined(MBEDTLS_SSL_PROTO_DTLS) ((void) ssl); #endif return( (int) max_len ); } #if defined(MBEDTLS_X509_CRT_PARSE_C) const mbedtls_x509_crt *mbedtls_ssl_get_peer_cert( const mbedtls_ssl_context *ssl ) { if( ssl == NULL || ssl->session == NULL ) return( NULL ); return( ssl->session->peer_cert ); } #endif /* MBEDTLS_X509_CRT_PARSE_C */ #if defined(MBEDTLS_SSL_CLI_C) int mbedtls_ssl_get_session( const mbedtls_ssl_context *ssl, mbedtls_ssl_session *dst ) { if( ssl == NULL || dst == NULL || ssl->session == NULL || ssl->conf->endpoint != MBEDTLS_SSL_IS_CLIENT ) { return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); } return( ssl_session_copy( dst, ssl->session ) ); } #endif /* MBEDTLS_SSL_CLI_C */ /* * Perform a single step of the SSL handshake */ int mbedtls_ssl_handshake_step( mbedtls_ssl_context *ssl ) { int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE; if( ssl == NULL || ssl->conf == NULL ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); #if defined(MBEDTLS_SSL_CLI_C) if( ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT ) ret = mbedtls_ssl_handshake_client_step( ssl ); #endif #if defined(MBEDTLS_SSL_SRV_C) if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER ) ret = mbedtls_ssl_handshake_server_step( ssl ); #endif return( ret ); } /* * Perform the SSL handshake */ int mbedtls_ssl_handshake( mbedtls_ssl_context *ssl ) { int ret = 0; if( ssl == NULL || ssl->conf == NULL ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> handshake" ) ); while( ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER ) { ret = mbedtls_ssl_handshake_step( ssl ); if( ret != 0 ) break; } MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= handshake" ) ); return( ret ); } #if defined(MBEDTLS_SSL_RENEGOTIATION) #if defined(MBEDTLS_SSL_SRV_C) /* * Write HelloRequest to request renegotiation on server */ static int ssl_write_hello_request( mbedtls_ssl_context *ssl ) { int ret; MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write hello request" ) ); ssl->out_msglen = 4; ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE; ssl->out_msg[0] = MBEDTLS_SSL_HS_HELLO_REQUEST; if( ( ret = mbedtls_ssl_write_handshake_msg( ssl ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_handshake_msg", ret ); return( ret ); } MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write hello request" ) ); return( 0 ); } #endif /* MBEDTLS_SSL_SRV_C */ /* * Actually renegotiate current connection, triggered by either: * - any side: calling mbedtls_ssl_renegotiate(), * - client: receiving a HelloRequest during mbedtls_ssl_read(), * - server: receiving any handshake message on server during mbedtls_ssl_read() after * the initial handshake is completed. * If the handshake doesn't complete due to waiting for I/O, it will continue * during the next calls to mbedtls_ssl_renegotiate() or mbedtls_ssl_read() respectively. */ static int ssl_start_renegotiation( mbedtls_ssl_context *ssl ) { int ret; MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> renegotiate" ) ); if( ( ret = ssl_handshake_init( ssl ) ) != 0 ) return( ret ); /* RFC 6347 4.2.2: "[...] the HelloRequest will have message_seq = 0 and * the ServerHello will have message_seq = 1" */ #if defined(MBEDTLS_SSL_PROTO_DTLS) if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM && ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_PENDING ) { if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER ) ssl->handshake->out_msg_seq = 1; else ssl->handshake->in_msg_seq = 1; } #endif ssl->state = MBEDTLS_SSL_HELLO_REQUEST; ssl->renego_status = MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS; if( ( ret = mbedtls_ssl_handshake( ssl ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_handshake", ret ); return( ret ); } MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= renegotiate" ) ); return( 0 ); } /* * Renegotiate current connection on client, * or request renegotiation on server */ int mbedtls_ssl_renegotiate( mbedtls_ssl_context *ssl ) { int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE; if( ssl == NULL || ssl->conf == NULL ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); #if defined(MBEDTLS_SSL_SRV_C) /* On server, just send the request */ if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER ) { if( ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); ssl->renego_status = MBEDTLS_SSL_RENEGOTIATION_PENDING; /* Did we already try/start sending HelloRequest? */ if( ssl->out_left != 0 ) return( mbedtls_ssl_flush_output( ssl ) ); return( ssl_write_hello_request( ssl ) ); } #endif /* MBEDTLS_SSL_SRV_C */ #if defined(MBEDTLS_SSL_CLI_C) /* * On client, either start the renegotiation process or, * if already in progress, continue the handshake */ if( ssl->renego_status != MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS ) { if( ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); if( ( ret = ssl_start_renegotiation( ssl ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "ssl_start_renegotiation", ret ); return( ret ); } } else { if( ( ret = mbedtls_ssl_handshake( ssl ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_handshake", ret ); return( ret ); } } #endif /* MBEDTLS_SSL_CLI_C */ return( ret ); } /* * Check record counters and renegotiate if they're above the limit. */ static int ssl_check_ctr_renegotiate( mbedtls_ssl_context *ssl ) { size_t ep_len = ssl_ep_len( ssl ); int in_ctr_cmp; int out_ctr_cmp; if( ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER || ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_PENDING || ssl->conf->disable_renegotiation == MBEDTLS_SSL_RENEGOTIATION_DISABLED ) { return( 0 ); } in_ctr_cmp = memcmp( ssl->in_ctr + ep_len, ssl->conf->renego_period + ep_len, 8 - ep_len ); out_ctr_cmp = memcmp( ssl->cur_out_ctr + ep_len, ssl->conf->renego_period + ep_len, 8 - ep_len ); if( in_ctr_cmp <= 0 && out_ctr_cmp <= 0 ) { return( 0 ); } MBEDTLS_SSL_DEBUG_MSG( 1, ( "record counter limit reached: renegotiate" ) ); return( mbedtls_ssl_renegotiate( ssl ) ); } #endif /* MBEDTLS_SSL_RENEGOTIATION */ /* * Receive application data decrypted from the SSL layer */ int mbedtls_ssl_read( mbedtls_ssl_context *ssl, unsigned char *buf, size_t len ) { int ret; size_t n; if( ssl == NULL || ssl->conf == NULL ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> read" ) ); #if defined(MBEDTLS_SSL_PROTO_DTLS) if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) { if( ( ret = mbedtls_ssl_flush_output( ssl ) ) != 0 ) return( ret ); if( ssl->handshake != NULL && ssl->handshake->retransmit_state == MBEDTLS_SSL_RETRANS_SENDING ) { if( ( ret = mbedtls_ssl_flight_transmit( ssl ) ) != 0 ) return( ret ); } } #endif /* * Check if renegotiation is necessary and/or handshake is * in process. If yes, perform/continue, and fall through * if an unexpected packet is received while the client * is waiting for the ServerHello. * * (There is no equivalent to the last condition on * the server-side as it is not treated as within * a handshake while waiting for the ClientHello * after a renegotiation request.) */ #if defined(MBEDTLS_SSL_RENEGOTIATION) ret = ssl_check_ctr_renegotiate( ssl ); if( ret != MBEDTLS_ERR_SSL_WAITING_SERVER_HELLO_RENEGO && ret != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "ssl_check_ctr_renegotiate", ret ); return( ret ); } #endif if( ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER ) { ret = mbedtls_ssl_handshake( ssl ); if( ret != MBEDTLS_ERR_SSL_WAITING_SERVER_HELLO_RENEGO && ret != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_handshake", ret ); return( ret ); } } /* Loop as long as no application data record is available */ while( ssl->in_offt == NULL ) { /* Start timer if not already running */ if( ssl->f_get_timer != NULL && ssl->f_get_timer( ssl->p_timer ) == -1 ) { ssl_set_timer( ssl, ssl->conf->read_timeout ); } if( ( ret = mbedtls_ssl_read_record( ssl, 1 ) ) != 0 ) { if( ret == MBEDTLS_ERR_SSL_CONN_EOF ) return( 0 ); MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret ); return( ret ); } if( ssl->in_msglen == 0 && ssl->in_msgtype == MBEDTLS_SSL_MSG_APPLICATION_DATA ) { /* * OpenSSL sends empty messages to randomize the IV */ if( ( ret = mbedtls_ssl_read_record( ssl, 1 ) ) != 0 ) { if( ret == MBEDTLS_ERR_SSL_CONN_EOF ) return( 0 ); MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret ); return( ret ); } } if( ssl->in_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "received handshake message" ) ); /* * - For client-side, expect SERVER_HELLO_REQUEST. * - For server-side, expect CLIENT_HELLO. * - Fail (TLS) or silently drop record (DTLS) in other cases. */ #if defined(MBEDTLS_SSL_CLI_C) if( ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT && ( ssl->in_msg[0] != MBEDTLS_SSL_HS_HELLO_REQUEST || ssl->in_hslen != mbedtls_ssl_hs_hdr_len( ssl ) ) ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "handshake received (not HelloRequest)" ) ); /* With DTLS, drop the packet (probably from last handshake) */ #if defined(MBEDTLS_SSL_PROTO_DTLS) if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) { continue; } #endif return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE ); } #endif /* MBEDTLS_SSL_CLI_C */ #if defined(MBEDTLS_SSL_SRV_C) if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER && ssl->in_msg[0] != MBEDTLS_SSL_HS_CLIENT_HELLO ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "handshake received (not ClientHello)" ) ); /* With DTLS, drop the packet (probably from last handshake) */ #if defined(MBEDTLS_SSL_PROTO_DTLS) if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) { continue; } #endif return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE ); } #endif /* MBEDTLS_SSL_SRV_C */ #if defined(MBEDTLS_SSL_RENEGOTIATION) /* Determine whether renegotiation attempt should be accepted */ if( ! ( ssl->conf->disable_renegotiation == MBEDTLS_SSL_RENEGOTIATION_DISABLED || ( ssl->secure_renegotiation == MBEDTLS_SSL_LEGACY_RENEGOTIATION && ssl->conf->allow_legacy_renegotiation == MBEDTLS_SSL_LEGACY_NO_RENEGOTIATION ) ) ) { /* * Accept renegotiation request */ /* DTLS clients need to know renego is server-initiated */ #if defined(MBEDTLS_SSL_PROTO_DTLS) if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM && ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT ) { ssl->renego_status = MBEDTLS_SSL_RENEGOTIATION_PENDING; } #endif ret = ssl_start_renegotiation( ssl ); if( ret != MBEDTLS_ERR_SSL_WAITING_SERVER_HELLO_RENEGO && ret != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "ssl_start_renegotiation", ret ); return( ret ); } } else #endif /* MBEDTLS_SSL_RENEGOTIATION */ { /* * Refuse renegotiation */ MBEDTLS_SSL_DEBUG_MSG( 3, ( "refusing renegotiation, sending alert" ) ); #if defined(MBEDTLS_SSL_PROTO_SSL3) if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 ) { /* SSLv3 does not have a "no_renegotiation" warning, so we send a fatal alert and abort the connection. */ mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE ); return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE ); } else #endif /* MBEDTLS_SSL_PROTO_SSL3 */ #if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) || \ defined(MBEDTLS_SSL_PROTO_TLS1_2) if( ssl->minor_ver >= MBEDTLS_SSL_MINOR_VERSION_1 ) { if( ( ret = mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_WARNING, MBEDTLS_SSL_ALERT_MSG_NO_RENEGOTIATION ) ) != 0 ) { return( ret ); } } else #endif /* MBEDTLS_SSL_PROTO_TLS1 || MBEDTLS_SSL_PROTO_TLS1_1 || MBEDTLS_SSL_PROTO_TLS1_2 */ { MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); } } /* At this point, we don't know whether the renegotiation has been * completed or not. The cases to consider are the following: * 1) The renegotiation is complete. In this case, no new record * has been read yet. * 2) The renegotiation is incomplete because the client received * an application data record while awaiting the ServerHello. * 3) The renegotiation is incomplete because the client received * a non-handshake, non-application data message while awaiting * the ServerHello. * In each of these case, looping will be the proper action: * - For 1), the next iteration will read a new record and check * if it's application data. * - For 2), the loop condition isn't satisfied as application data * is present, hence continue is the same as break * - For 3), the loop condition is satisfied and read_record * will re-deliver the message that was held back by the client * when expecting the ServerHello. */ continue; } #if defined(MBEDTLS_SSL_RENEGOTIATION) else if( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_PENDING ) { if( ssl->conf->renego_max_records >= 0 ) { if( ++ssl->renego_records_seen > ssl->conf->renego_max_records ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "renegotiation requested, " "but not honored by client" ) ); return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE ); } } } #endif /* MBEDTLS_SSL_RENEGOTIATION */ /* Fatal and closure alerts handled by mbedtls_ssl_read_record() */ if( ssl->in_msgtype == MBEDTLS_SSL_MSG_ALERT ) { MBEDTLS_SSL_DEBUG_MSG( 2, ( "ignoring non-fatal non-closure alert" ) ); return( MBEDTLS_ERR_SSL_WANT_READ ); } if( ssl->in_msgtype != MBEDTLS_SSL_MSG_APPLICATION_DATA ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad application data message" ) ); return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE ); } ssl->in_offt = ssl->in_msg; /* We're going to return something now, cancel timer, * except if handshake (renegotiation) is in progress */ if( ssl->state == MBEDTLS_SSL_HANDSHAKE_OVER ) ssl_set_timer( ssl, 0 ); #if defined(MBEDTLS_SSL_PROTO_DTLS) /* If we requested renego but received AppData, resend HelloRequest. * Do it now, after setting in_offt, to avoid taking this branch * again if ssl_write_hello_request() returns WANT_WRITE */ #if defined(MBEDTLS_SSL_SRV_C) && defined(MBEDTLS_SSL_RENEGOTIATION) if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER && ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_PENDING ) { if( ( ret = ssl_resend_hello_request( ssl ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "ssl_resend_hello_request", ret ); return( ret ); } } #endif /* MBEDTLS_SSL_SRV_C && MBEDTLS_SSL_RENEGOTIATION */ #endif /* MBEDTLS_SSL_PROTO_DTLS */ } n = ( len < ssl->in_msglen ) ? len : ssl->in_msglen; memcpy( buf, ssl->in_offt, n ); ssl->in_msglen -= n; if( ssl->in_msglen == 0 ) { /* all bytes consumed */ ssl->in_offt = NULL; ssl->keep_current_message = 0; } else { /* more data available */ ssl->in_offt += n; } MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= read" ) ); return( (int) n ); } /* * Send application data to be encrypted by the SSL layer, taking care of max * fragment length and buffer size. * * According to RFC 5246 Section 6.2.1: * * Zero-length fragments of Application data MAY be sent as they are * potentially useful as a traffic analysis countermeasure. * * Therefore, it is possible that the input message length is 0 and the * corresponding return code is 0 on success. */ static int ssl_write_real( mbedtls_ssl_context *ssl, const unsigned char *buf, size_t len ) { int ret = mbedtls_ssl_get_max_out_record_payload( ssl ); const size_t max_len = (size_t) ret; if( ret < 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_get_max_out_record_payload", ret ); return( ret ); } if( len > max_len ) { #if defined(MBEDTLS_SSL_PROTO_DTLS) if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "fragment larger than the (negotiated) " "maximum fragment length: %d > %d", len, max_len ) ); return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); } else #endif len = max_len; } if( ssl->out_left != 0 ) { /* * The user has previously tried to send the data and * MBEDTLS_ERR_SSL_WANT_WRITE or the message was only partially * written. In this case, we expect the high-level write function * (e.g. mbedtls_ssl_write()) to be called with the same parameters */ if( ( ret = mbedtls_ssl_flush_output( ssl ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_flush_output", ret ); return( ret ); } } else { /* * The user is trying to send a message the first time, so we need to * copy the data into the internal buffers and setup the data structure * to keep track of partial writes */ ssl->out_msglen = len; ssl->out_msgtype = MBEDTLS_SSL_MSG_APPLICATION_DATA; memcpy( ssl->out_msg, buf, len ); if( ( ret = mbedtls_ssl_write_record( ssl, SSL_FORCE_FLUSH ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_record", ret ); return( ret ); } } return( (int) len ); } /* * Write application data, doing 1/n-1 splitting if necessary. * * With non-blocking I/O, ssl_write_real() may return WANT_WRITE, * then the caller will call us again with the same arguments, so * remember whether we already did the split or not. */ #if defined(MBEDTLS_SSL_CBC_RECORD_SPLITTING) static int ssl_write_split( mbedtls_ssl_context *ssl, const unsigned char *buf, size_t len ) { int ret; if( ssl->conf->cbc_record_splitting == MBEDTLS_SSL_CBC_RECORD_SPLITTING_DISABLED || len <= 1 || ssl->minor_ver > MBEDTLS_SSL_MINOR_VERSION_1 || mbedtls_cipher_get_cipher_mode( &ssl->transform_out->cipher_ctx_enc ) != MBEDTLS_MODE_CBC ) { return( ssl_write_real( ssl, buf, len ) ); } if( ssl->split_done == 0 ) { if( ( ret = ssl_write_real( ssl, buf, 1 ) ) <= 0 ) return( ret ); ssl->split_done = 1; } if( ( ret = ssl_write_real( ssl, buf + 1, len - 1 ) ) <= 0 ) return( ret ); ssl->split_done = 0; return( ret + 1 ); } #endif /* MBEDTLS_SSL_CBC_RECORD_SPLITTING */ /* * Write application data (public-facing wrapper) */ int mbedtls_ssl_write( mbedtls_ssl_context *ssl, const unsigned char *buf, size_t len ) { int ret; MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write" ) ); if( ssl == NULL || ssl->conf == NULL ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); #if defined(MBEDTLS_SSL_RENEGOTIATION) if( ( ret = ssl_check_ctr_renegotiate( ssl ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "ssl_check_ctr_renegotiate", ret ); return( ret ); } #endif if( ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER ) { if( ( ret = mbedtls_ssl_handshake( ssl ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_handshake", ret ); return( ret ); } } #if defined(MBEDTLS_SSL_CBC_RECORD_SPLITTING) ret = ssl_write_split( ssl, buf, len ); #else ret = ssl_write_real( ssl, buf, len ); #endif MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write" ) ); return( ret ); } /* * Notify the peer that the connection is being closed */ int mbedtls_ssl_close_notify( mbedtls_ssl_context *ssl ) { int ret; if( ssl == NULL || ssl->conf == NULL ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write close notify" ) ); if( ssl->out_left != 0 ) return( mbedtls_ssl_flush_output( ssl ) ); if( ssl->state == MBEDTLS_SSL_HANDSHAKE_OVER ) { if( ( ret = mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_WARNING, MBEDTLS_SSL_ALERT_MSG_CLOSE_NOTIFY ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_send_alert_message", ret ); return( ret ); } } MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write close notify" ) ); return( 0 ); } void mbedtls_ssl_transform_free( mbedtls_ssl_transform *transform ) { if( transform == NULL ) return; #if defined(MBEDTLS_ZLIB_SUPPORT) deflateEnd( &transform->ctx_deflate ); inflateEnd( &transform->ctx_inflate ); #endif mbedtls_cipher_free( &transform->cipher_ctx_enc ); mbedtls_cipher_free( &transform->cipher_ctx_dec ); mbedtls_md_free( &transform->md_ctx_enc ); mbedtls_md_free( &transform->md_ctx_dec ); mbedtls_platform_zeroize( transform, sizeof( mbedtls_ssl_transform ) ); } #if defined(MBEDTLS_X509_CRT_PARSE_C) static void ssl_key_cert_free( mbedtls_ssl_key_cert *key_cert ) { mbedtls_ssl_key_cert *cur = key_cert, *next; while( cur != NULL ) { next = cur->next; mbedtls_free( cur ); cur = next; } } #endif /* MBEDTLS_X509_CRT_PARSE_C */ #if defined(MBEDTLS_SSL_PROTO_DTLS) static void ssl_buffering_free( mbedtls_ssl_context *ssl ) { unsigned offset; mbedtls_ssl_handshake_params * const hs = ssl->handshake; if( hs == NULL ) return; ssl_free_buffered_record( ssl ); for( offset = 0; offset < MBEDTLS_SSL_MAX_BUFFERED_HS; offset++ ) ssl_buffering_free_slot( ssl, offset ); } static void ssl_buffering_free_slot( mbedtls_ssl_context *ssl, uint8_t slot ) { mbedtls_ssl_handshake_params * const hs = ssl->handshake; mbedtls_ssl_hs_buffer * const hs_buf = &hs->buffering.hs[slot]; if( slot >= MBEDTLS_SSL_MAX_BUFFERED_HS ) return; if( hs_buf->is_valid == 1 ) { hs->buffering.total_bytes_buffered -= hs_buf->data_len; mbedtls_platform_zeroize( hs_buf->data, hs_buf->data_len ); mbedtls_free( hs_buf->data ); memset( hs_buf, 0, sizeof( mbedtls_ssl_hs_buffer ) ); } } #endif /* MBEDTLS_SSL_PROTO_DTLS */ void mbedtls_ssl_handshake_free( mbedtls_ssl_context *ssl ) { mbedtls_ssl_handshake_params *handshake = ssl->handshake; if( handshake == NULL ) return; #if defined(MBEDTLS_SSL_ASYNC_PRIVATE) if( ssl->conf->f_async_cancel != NULL && handshake->async_in_progress != 0 ) { ssl->conf->f_async_cancel( ssl ); handshake->async_in_progress = 0; } #endif /* MBEDTLS_SSL_ASYNC_PRIVATE */ #if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1) || \ defined(MBEDTLS_SSL_PROTO_TLS1_1) mbedtls_md5_free( &handshake->fin_md5 ); mbedtls_sha1_free( &handshake->fin_sha1 ); #endif #if defined(MBEDTLS_SSL_PROTO_TLS1_2) #if defined(MBEDTLS_SHA256_C) mbedtls_sha256_free( &handshake->fin_sha256 ); #endif #if defined(MBEDTLS_SHA512_C) mbedtls_sha512_free( &handshake->fin_sha512 ); #endif #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */ #if defined(MBEDTLS_DHM_C) mbedtls_dhm_free( &handshake->dhm_ctx ); #endif #if defined(MBEDTLS_ECDH_C) mbedtls_ecdh_free( &handshake->ecdh_ctx ); #endif #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED) mbedtls_ecjpake_free( &handshake->ecjpake_ctx ); #if defined(MBEDTLS_SSL_CLI_C) mbedtls_free( handshake->ecjpake_cache ); handshake->ecjpake_cache = NULL; handshake->ecjpake_cache_len = 0; #endif #endif #if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \ defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED) /* explicit void pointer cast for buggy MS compiler */ mbedtls_free( (void *) handshake->curves ); #endif #if defined(MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED) if( handshake->psk != NULL ) { mbedtls_platform_zeroize( handshake->psk, handshake->psk_len ); mbedtls_free( handshake->psk ); } #endif #if defined(MBEDTLS_X509_CRT_PARSE_C) && \ defined(MBEDTLS_SSL_SERVER_NAME_INDICATION) /* * Free only the linked list wrapper, not the keys themselves * since the belong to the SNI callback */ if( handshake->sni_key_cert != NULL ) { mbedtls_ssl_key_cert *cur = handshake->sni_key_cert, *next; while( cur != NULL ) { next = cur->next; mbedtls_free( cur ); cur = next; } } #endif /* MBEDTLS_X509_CRT_PARSE_C && MBEDTLS_SSL_SERVER_NAME_INDICATION */ #if defined(MBEDTLS_SSL__ECP_RESTARTABLE) mbedtls_x509_crt_restart_free( &handshake->ecrs_ctx ); #endif #if defined(MBEDTLS_SSL_PROTO_DTLS) mbedtls_free( handshake->verify_cookie ); ssl_flight_free( handshake->flight ); ssl_buffering_free( ssl ); #endif mbedtls_platform_zeroize( handshake, sizeof( mbedtls_ssl_handshake_params ) ); } void mbedtls_ssl_session_free( mbedtls_ssl_session *session ) { if( session == NULL ) return; #if defined(MBEDTLS_X509_CRT_PARSE_C) if( session->peer_cert != NULL ) { mbedtls_x509_crt_free( session->peer_cert ); mbedtls_free( session->peer_cert ); } #endif #if defined(MBEDTLS_SSL_SESSION_TICKETS) && defined(MBEDTLS_SSL_CLI_C) mbedtls_free( session->ticket ); #endif mbedtls_platform_zeroize( session, sizeof( mbedtls_ssl_session ) ); } /* * Free an SSL context */ void mbedtls_ssl_free( mbedtls_ssl_context *ssl ) { if( ssl == NULL ) return; MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> free" ) ); if( ssl->out_buf != NULL ) { mbedtls_platform_zeroize( ssl->out_buf, MBEDTLS_SSL_OUT_BUFFER_LEN ); mbedtls_free( ssl->out_buf ); } if( ssl->in_buf != NULL ) { mbedtls_platform_zeroize( ssl->in_buf, MBEDTLS_SSL_IN_BUFFER_LEN ); mbedtls_free( ssl->in_buf ); } #if defined(MBEDTLS_ZLIB_SUPPORT) if( ssl->compress_buf != NULL ) { mbedtls_platform_zeroize( ssl->compress_buf, MBEDTLS_SSL_COMPRESS_BUFFER_LEN ); mbedtls_free( ssl->compress_buf ); } #endif if( ssl->transform ) { mbedtls_ssl_transform_free( ssl->transform ); mbedtls_free( ssl->transform ); } if( ssl->handshake ) { mbedtls_ssl_handshake_free( ssl ); mbedtls_ssl_transform_free( ssl->transform_negotiate ); mbedtls_ssl_session_free( ssl->session_negotiate ); mbedtls_free( ssl->handshake ); mbedtls_free( ssl->transform_negotiate ); mbedtls_free( ssl->session_negotiate ); } if( ssl->session ) { mbedtls_ssl_session_free( ssl->session ); mbedtls_free( ssl->session ); } #if defined(MBEDTLS_X509_CRT_PARSE_C) if( ssl->hostname != NULL ) { mbedtls_platform_zeroize( ssl->hostname, strlen( ssl->hostname ) ); mbedtls_free( ssl->hostname ); } #endif #if defined(MBEDTLS_SSL_HW_RECORD_ACCEL) if( mbedtls_ssl_hw_record_finish != NULL ) { MBEDTLS_SSL_DEBUG_MSG( 2, ( "going for mbedtls_ssl_hw_record_finish()" ) ); mbedtls_ssl_hw_record_finish( ssl ); } #endif #if defined(MBEDTLS_SSL_DTLS_HELLO_VERIFY) && defined(MBEDTLS_SSL_SRV_C) mbedtls_free( ssl->cli_id ); #endif MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= free" ) ); /* Actually clear after last debug message */ mbedtls_platform_zeroize( ssl, sizeof( mbedtls_ssl_context ) ); } /* * Initialze mbedtls_ssl_config */ void mbedtls_ssl_config_init( mbedtls_ssl_config *conf ) { memset( conf, 0, sizeof( mbedtls_ssl_config ) ); } #if defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED) static int ssl_preset_default_hashes[] = { #if defined(MBEDTLS_SHA512_C) MBEDTLS_MD_SHA512, MBEDTLS_MD_SHA384, #endif #if defined(MBEDTLS_SHA256_C) MBEDTLS_MD_SHA256, MBEDTLS_MD_SHA224, #endif #if defined(MBEDTLS_SHA1_C) && defined(MBEDTLS_TLS_DEFAULT_ALLOW_SHA1_IN_KEY_EXCHANGE) MBEDTLS_MD_SHA1, #endif MBEDTLS_MD_NONE }; #endif static int ssl_preset_suiteb_ciphersuites[] = { MBEDTLS_TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256, MBEDTLS_TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384, 0 }; #if defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED) static int ssl_preset_suiteb_hashes[] = { MBEDTLS_MD_SHA256, MBEDTLS_MD_SHA384, MBEDTLS_MD_NONE }; #endif #if defined(MBEDTLS_ECP_C) static mbedtls_ecp_group_id ssl_preset_suiteb_curves[] = { MBEDTLS_ECP_DP_SECP256R1, MBEDTLS_ECP_DP_SECP384R1, MBEDTLS_ECP_DP_NONE }; #endif /* * Load default in mbedtls_ssl_config */ int mbedtls_ssl_config_defaults( mbedtls_ssl_config *conf, int endpoint, int transport, int preset ) { #if defined(MBEDTLS_DHM_C) && defined(MBEDTLS_SSL_SRV_C) int ret; #endif /* Use the functions here so that they are covered in tests, * but otherwise access member directly for efficiency */ mbedtls_ssl_conf_endpoint( conf, endpoint ); mbedtls_ssl_conf_transport( conf, transport ); /* * Things that are common to all presets */ #if defined(MBEDTLS_SSL_CLI_C) if( endpoint == MBEDTLS_SSL_IS_CLIENT ) { conf->authmode = MBEDTLS_SSL_VERIFY_REQUIRED; #if defined(MBEDTLS_SSL_SESSION_TICKETS) conf->session_tickets = MBEDTLS_SSL_SESSION_TICKETS_ENABLED; #endif } #endif #if defined(MBEDTLS_ARC4_C) conf->arc4_disabled = MBEDTLS_SSL_ARC4_DISABLED; #endif #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC) conf->encrypt_then_mac = MBEDTLS_SSL_ETM_ENABLED; #endif #if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET) conf->extended_ms = MBEDTLS_SSL_EXTENDED_MS_ENABLED; #endif #if defined(MBEDTLS_SSL_CBC_RECORD_SPLITTING) conf->cbc_record_splitting = MBEDTLS_SSL_CBC_RECORD_SPLITTING_ENABLED; #endif #if defined(MBEDTLS_SSL_DTLS_HELLO_VERIFY) && defined(MBEDTLS_SSL_SRV_C) conf->f_cookie_write = ssl_cookie_write_dummy; conf->f_cookie_check = ssl_cookie_check_dummy; #endif #if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY) conf->anti_replay = MBEDTLS_SSL_ANTI_REPLAY_ENABLED; #endif #if defined(MBEDTLS_SSL_SRV_C) conf->cert_req_ca_list = MBEDTLS_SSL_CERT_REQ_CA_LIST_ENABLED; #endif #if defined(MBEDTLS_SSL_PROTO_DTLS) conf->hs_timeout_min = MBEDTLS_SSL_DTLS_TIMEOUT_DFL_MIN; conf->hs_timeout_max = MBEDTLS_SSL_DTLS_TIMEOUT_DFL_MAX; #endif #if defined(MBEDTLS_SSL_RENEGOTIATION) conf->renego_max_records = MBEDTLS_SSL_RENEGO_MAX_RECORDS_DEFAULT; memset( conf->renego_period, 0x00, 2 ); memset( conf->renego_period + 2, 0xFF, 6 ); #endif #if defined(MBEDTLS_DHM_C) && defined(MBEDTLS_SSL_SRV_C) if( endpoint == MBEDTLS_SSL_IS_SERVER ) { const unsigned char dhm_p[] = MBEDTLS_DHM_RFC3526_MODP_2048_P_BIN; const unsigned char dhm_g[] = MBEDTLS_DHM_RFC3526_MODP_2048_G_BIN; if ( ( ret = mbedtls_ssl_conf_dh_param_bin( conf, dhm_p, sizeof( dhm_p ), dhm_g, sizeof( dhm_g ) ) ) != 0 ) { return( ret ); } } #endif /* * Preset-specific defaults */ switch( preset ) { /* * NSA Suite B */ case MBEDTLS_SSL_PRESET_SUITEB: conf->min_major_ver = MBEDTLS_SSL_MAJOR_VERSION_3; conf->min_minor_ver = MBEDTLS_SSL_MINOR_VERSION_3; /* TLS 1.2 */ conf->max_major_ver = MBEDTLS_SSL_MAX_MAJOR_VERSION; conf->max_minor_ver = MBEDTLS_SSL_MAX_MINOR_VERSION; conf->ciphersuite_list[MBEDTLS_SSL_MINOR_VERSION_0] = conf->ciphersuite_list[MBEDTLS_SSL_MINOR_VERSION_1] = conf->ciphersuite_list[MBEDTLS_SSL_MINOR_VERSION_2] = conf->ciphersuite_list[MBEDTLS_SSL_MINOR_VERSION_3] = ssl_preset_suiteb_ciphersuites; #if defined(MBEDTLS_X509_CRT_PARSE_C) conf->cert_profile = &mbedtls_x509_crt_profile_suiteb; #endif #if defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED) conf->sig_hashes = ssl_preset_suiteb_hashes; #endif #if defined(MBEDTLS_ECP_C) conf->curve_list = ssl_preset_suiteb_curves; #endif break; /* * Default */ default: conf->min_major_ver = ( MBEDTLS_SSL_MIN_MAJOR_VERSION > MBEDTLS_SSL_MIN_VALID_MAJOR_VERSION ) ? MBEDTLS_SSL_MIN_MAJOR_VERSION : MBEDTLS_SSL_MIN_VALID_MAJOR_VERSION; conf->min_minor_ver = ( MBEDTLS_SSL_MIN_MINOR_VERSION > MBEDTLS_SSL_MIN_VALID_MINOR_VERSION ) ? MBEDTLS_SSL_MIN_MINOR_VERSION : MBEDTLS_SSL_MIN_VALID_MINOR_VERSION; conf->max_major_ver = MBEDTLS_SSL_MAX_MAJOR_VERSION; conf->max_minor_ver = MBEDTLS_SSL_MAX_MINOR_VERSION; #if defined(MBEDTLS_SSL_PROTO_DTLS) if( transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) conf->min_minor_ver = MBEDTLS_SSL_MINOR_VERSION_2; #endif conf->ciphersuite_list[MBEDTLS_SSL_MINOR_VERSION_0] = conf->ciphersuite_list[MBEDTLS_SSL_MINOR_VERSION_1] = conf->ciphersuite_list[MBEDTLS_SSL_MINOR_VERSION_2] = conf->ciphersuite_list[MBEDTLS_SSL_MINOR_VERSION_3] = mbedtls_ssl_list_ciphersuites(); #if defined(MBEDTLS_X509_CRT_PARSE_C) conf->cert_profile = &mbedtls_x509_crt_profile_default; #endif #if defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED) conf->sig_hashes = ssl_preset_default_hashes; #endif #if defined(MBEDTLS_ECP_C) conf->curve_list = mbedtls_ecp_grp_id_list(); #endif #if defined(MBEDTLS_DHM_C) && defined(MBEDTLS_SSL_CLI_C) conf->dhm_min_bitlen = 1024; #endif } return( 0 ); } /* * Free mbedtls_ssl_config */ void mbedtls_ssl_config_free( mbedtls_ssl_config *conf ) { #if defined(MBEDTLS_DHM_C) mbedtls_mpi_free( &conf->dhm_P ); mbedtls_mpi_free( &conf->dhm_G ); #endif #if defined(MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED) if( conf->psk != NULL ) { mbedtls_platform_zeroize( conf->psk, conf->psk_len ); mbedtls_free( conf->psk ); conf->psk = NULL; conf->psk_len = 0; } if( conf->psk_identity != NULL ) { mbedtls_platform_zeroize( conf->psk_identity, conf->psk_identity_len ); mbedtls_free( conf->psk_identity ); conf->psk_identity = NULL; conf->psk_identity_len = 0; } #endif #if defined(MBEDTLS_X509_CRT_PARSE_C) ssl_key_cert_free( conf->key_cert ); #endif mbedtls_platform_zeroize( conf, sizeof( mbedtls_ssl_config ) ); } #if defined(MBEDTLS_PK_C) && \ ( defined(MBEDTLS_RSA_C) || defined(MBEDTLS_ECDSA_C) ) /* * Convert between MBEDTLS_PK_XXX and SSL_SIG_XXX */ unsigned char mbedtls_ssl_sig_from_pk( mbedtls_pk_context *pk ) { #if defined(MBEDTLS_RSA_C) if( mbedtls_pk_can_do( pk, MBEDTLS_PK_RSA ) ) return( MBEDTLS_SSL_SIG_RSA ); #endif #if defined(MBEDTLS_ECDSA_C) if( mbedtls_pk_can_do( pk, MBEDTLS_PK_ECDSA ) ) return( MBEDTLS_SSL_SIG_ECDSA ); #endif return( MBEDTLS_SSL_SIG_ANON ); } unsigned char mbedtls_ssl_sig_from_pk_alg( mbedtls_pk_type_t type ) { switch( type ) { case MBEDTLS_PK_RSA: return( MBEDTLS_SSL_SIG_RSA ); case MBEDTLS_PK_ECDSA: case MBEDTLS_PK_ECKEY: return( MBEDTLS_SSL_SIG_ECDSA ); default: return( MBEDTLS_SSL_SIG_ANON ); } } mbedtls_pk_type_t mbedtls_ssl_pk_alg_from_sig( unsigned char sig ) { switch( sig ) { #if defined(MBEDTLS_RSA_C) case MBEDTLS_SSL_SIG_RSA: return( MBEDTLS_PK_RSA ); #endif #if defined(MBEDTLS_ECDSA_C) case MBEDTLS_SSL_SIG_ECDSA: return( MBEDTLS_PK_ECDSA ); #endif default: return( MBEDTLS_PK_NONE ); } } #endif /* MBEDTLS_PK_C && ( MBEDTLS_RSA_C || MBEDTLS_ECDSA_C ) */ #if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \ defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED) /* Find an entry in a signature-hash set matching a given hash algorithm. */ mbedtls_md_type_t mbedtls_ssl_sig_hash_set_find( mbedtls_ssl_sig_hash_set_t *set, mbedtls_pk_type_t sig_alg ) { switch( sig_alg ) { case MBEDTLS_PK_RSA: return( set->rsa ); case MBEDTLS_PK_ECDSA: return( set->ecdsa ); default: return( MBEDTLS_MD_NONE ); } } /* Add a signature-hash-pair to a signature-hash set */ void mbedtls_ssl_sig_hash_set_add( mbedtls_ssl_sig_hash_set_t *set, mbedtls_pk_type_t sig_alg, mbedtls_md_type_t md_alg ) { switch( sig_alg ) { case MBEDTLS_PK_RSA: if( set->rsa == MBEDTLS_MD_NONE ) set->rsa = md_alg; break; case MBEDTLS_PK_ECDSA: if( set->ecdsa == MBEDTLS_MD_NONE ) set->ecdsa = md_alg; break; default: break; } } /* Allow exactly one hash algorithm for each signature. */ void mbedtls_ssl_sig_hash_set_const_hash( mbedtls_ssl_sig_hash_set_t *set, mbedtls_md_type_t md_alg ) { set->rsa = md_alg; set->ecdsa = md_alg; } #endif /* MBEDTLS_SSL_PROTO_TLS1_2) && MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED */ /* * Convert from MBEDTLS_SSL_HASH_XXX to MBEDTLS_MD_XXX */ mbedtls_md_type_t mbedtls_ssl_md_alg_from_hash( unsigned char hash ) { switch( hash ) { #if defined(MBEDTLS_MD5_C) case MBEDTLS_SSL_HASH_MD5: return( MBEDTLS_MD_MD5 ); #endif #if defined(MBEDTLS_SHA1_C) case MBEDTLS_SSL_HASH_SHA1: return( MBEDTLS_MD_SHA1 ); #endif #if defined(MBEDTLS_SHA256_C) case MBEDTLS_SSL_HASH_SHA224: return( MBEDTLS_MD_SHA224 ); case MBEDTLS_SSL_HASH_SHA256: return( MBEDTLS_MD_SHA256 ); #endif #if defined(MBEDTLS_SHA512_C) case MBEDTLS_SSL_HASH_SHA384: return( MBEDTLS_MD_SHA384 ); case MBEDTLS_SSL_HASH_SHA512: return( MBEDTLS_MD_SHA512 ); #endif default: return( MBEDTLS_MD_NONE ); } } /* * Convert from MBEDTLS_MD_XXX to MBEDTLS_SSL_HASH_XXX */ unsigned char mbedtls_ssl_hash_from_md_alg( int md ) { switch( md ) { #if defined(MBEDTLS_MD5_C) case MBEDTLS_MD_MD5: return( MBEDTLS_SSL_HASH_MD5 ); #endif #if defined(MBEDTLS_SHA1_C) case MBEDTLS_MD_SHA1: return( MBEDTLS_SSL_HASH_SHA1 ); #endif #if defined(MBEDTLS_SHA256_C) case MBEDTLS_MD_SHA224: return( MBEDTLS_SSL_HASH_SHA224 ); case MBEDTLS_MD_SHA256: return( MBEDTLS_SSL_HASH_SHA256 ); #endif #if defined(MBEDTLS_SHA512_C) case MBEDTLS_MD_SHA384: return( MBEDTLS_SSL_HASH_SHA384 ); case MBEDTLS_MD_SHA512: return( MBEDTLS_SSL_HASH_SHA512 ); #endif default: return( MBEDTLS_SSL_HASH_NONE ); } } #if defined(MBEDTLS_ECP_C) /* * Check if a curve proposed by the peer is in our list. * Return 0 if we're willing to use it, -1 otherwise. */ int mbedtls_ssl_check_curve( const mbedtls_ssl_context *ssl, mbedtls_ecp_group_id grp_id ) { const mbedtls_ecp_group_id *gid; if( ssl->conf->curve_list == NULL ) return( -1 ); for( gid = ssl->conf->curve_list; *gid != MBEDTLS_ECP_DP_NONE; gid++ ) if( *gid == grp_id ) return( 0 ); return( -1 ); } #endif /* MBEDTLS_ECP_C */ #if defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED) /* * Check if a hash proposed by the peer is in our list. * Return 0 if we're willing to use it, -1 otherwise. */ int mbedtls_ssl_check_sig_hash( const mbedtls_ssl_context *ssl, mbedtls_md_type_t md ) { const int *cur; if( ssl->conf->sig_hashes == NULL ) return( -1 ); for( cur = ssl->conf->sig_hashes; *cur != MBEDTLS_MD_NONE; cur++ ) if( *cur == (int) md ) return( 0 ); return( -1 ); } #endif /* MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED */ #if defined(MBEDTLS_X509_CRT_PARSE_C) int mbedtls_ssl_check_cert_usage( const mbedtls_x509_crt *cert, const mbedtls_ssl_ciphersuite_t *ciphersuite, int cert_endpoint, uint32_t *flags ) { int ret = 0; #if defined(MBEDTLS_X509_CHECK_KEY_USAGE) int usage = 0; #endif #if defined(MBEDTLS_X509_CHECK_EXTENDED_KEY_USAGE) const char *ext_oid; size_t ext_len; #endif #if !defined(MBEDTLS_X509_CHECK_KEY_USAGE) && \ !defined(MBEDTLS_X509_CHECK_EXTENDED_KEY_USAGE) ((void) cert); ((void) cert_endpoint); ((void) flags); #endif #if defined(MBEDTLS_X509_CHECK_KEY_USAGE) if( cert_endpoint == MBEDTLS_SSL_IS_SERVER ) { /* Server part of the key exchange */ switch( ciphersuite->key_exchange ) { case MBEDTLS_KEY_EXCHANGE_RSA: case MBEDTLS_KEY_EXCHANGE_RSA_PSK: usage = MBEDTLS_X509_KU_KEY_ENCIPHERMENT; break; case MBEDTLS_KEY_EXCHANGE_DHE_RSA: case MBEDTLS_KEY_EXCHANGE_ECDHE_RSA: case MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA: usage = MBEDTLS_X509_KU_DIGITAL_SIGNATURE; break; case MBEDTLS_KEY_EXCHANGE_ECDH_RSA: case MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA: usage = MBEDTLS_X509_KU_KEY_AGREEMENT; break; /* Don't use default: we want warnings when adding new values */ case MBEDTLS_KEY_EXCHANGE_NONE: case MBEDTLS_KEY_EXCHANGE_PSK: case MBEDTLS_KEY_EXCHANGE_DHE_PSK: case MBEDTLS_KEY_EXCHANGE_ECDHE_PSK: case MBEDTLS_KEY_EXCHANGE_ECJPAKE: usage = 0; } } else { /* Client auth: we only implement rsa_sign and mbedtls_ecdsa_sign for now */ usage = MBEDTLS_X509_KU_DIGITAL_SIGNATURE; } if( mbedtls_x509_crt_check_key_usage( cert, usage ) != 0 ) { *flags |= MBEDTLS_X509_BADCERT_KEY_USAGE; ret = -1; } #else ((void) ciphersuite); #endif /* MBEDTLS_X509_CHECK_KEY_USAGE */ #if defined(MBEDTLS_X509_CHECK_EXTENDED_KEY_USAGE) if( cert_endpoint == MBEDTLS_SSL_IS_SERVER ) { ext_oid = MBEDTLS_OID_SERVER_AUTH; ext_len = MBEDTLS_OID_SIZE( MBEDTLS_OID_SERVER_AUTH ); } else { ext_oid = MBEDTLS_OID_CLIENT_AUTH; ext_len = MBEDTLS_OID_SIZE( MBEDTLS_OID_CLIENT_AUTH ); } if( mbedtls_x509_crt_check_extended_key_usage( cert, ext_oid, ext_len ) != 0 ) { *flags |= MBEDTLS_X509_BADCERT_EXT_KEY_USAGE; ret = -1; } #endif /* MBEDTLS_X509_CHECK_EXTENDED_KEY_USAGE */ return( ret ); } #endif /* MBEDTLS_X509_CRT_PARSE_C */ /* * Convert version numbers to/from wire format * and, for DTLS, to/from TLS equivalent. * * For TLS this is the identity. * For DTLS, use 1's complement (v -> 255 - v, and then map as follows: * 1.0 <-> 3.2 (DTLS 1.0 is based on TLS 1.1) * 1.x <-> 3.x+1 for x != 0 (DTLS 1.2 based on TLS 1.2) */ void mbedtls_ssl_write_version( int major, int minor, int transport, unsigned char ver[2] ) { #if defined(MBEDTLS_SSL_PROTO_DTLS) if( transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) { if( minor == MBEDTLS_SSL_MINOR_VERSION_2 ) --minor; /* DTLS 1.0 stored as TLS 1.1 internally */ ver[0] = (unsigned char)( 255 - ( major - 2 ) ); ver[1] = (unsigned char)( 255 - ( minor - 1 ) ); } else #else ((void) transport); #endif { ver[0] = (unsigned char) major; ver[1] = (unsigned char) minor; } } void mbedtls_ssl_read_version( int *major, int *minor, int transport, const unsigned char ver[2] ) { #if defined(MBEDTLS_SSL_PROTO_DTLS) if( transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) { *major = 255 - ver[0] + 2; *minor = 255 - ver[1] + 1; if( *minor == MBEDTLS_SSL_MINOR_VERSION_1 ) ++*minor; /* DTLS 1.0 stored as TLS 1.1 internally */ } else #else ((void) transport); #endif { *major = ver[0]; *minor = ver[1]; } } int mbedtls_ssl_set_calc_verify_md( mbedtls_ssl_context *ssl, int md ) { #if defined(MBEDTLS_SSL_PROTO_TLS1_2) if( ssl->minor_ver != MBEDTLS_SSL_MINOR_VERSION_3 ) return MBEDTLS_ERR_SSL_INVALID_VERIFY_HASH; switch( md ) { #if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) #if defined(MBEDTLS_MD5_C) case MBEDTLS_SSL_HASH_MD5: return MBEDTLS_ERR_SSL_INVALID_VERIFY_HASH; #endif #if defined(MBEDTLS_SHA1_C) case MBEDTLS_SSL_HASH_SHA1: ssl->handshake->calc_verify = ssl_calc_verify_tls; break; #endif #endif /* MBEDTLS_SSL_PROTO_TLS1 || MBEDTLS_SSL_PROTO_TLS1_1 */ #if defined(MBEDTLS_SHA512_C) case MBEDTLS_SSL_HASH_SHA384: ssl->handshake->calc_verify = ssl_calc_verify_tls_sha384; break; #endif #if defined(MBEDTLS_SHA256_C) case MBEDTLS_SSL_HASH_SHA256: ssl->handshake->calc_verify = ssl_calc_verify_tls_sha256; break; #endif default: return MBEDTLS_ERR_SSL_INVALID_VERIFY_HASH; } return 0; #else /* !MBEDTLS_SSL_PROTO_TLS1_2 */ (void) ssl; (void) md; return MBEDTLS_ERR_SSL_INVALID_VERIFY_HASH; #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */ } #if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1) || \ defined(MBEDTLS_SSL_PROTO_TLS1_1) int mbedtls_ssl_get_key_exchange_md_ssl_tls( mbedtls_ssl_context *ssl, unsigned char *output, unsigned char *data, size_t data_len ) { int ret = 0; mbedtls_md5_context mbedtls_md5; mbedtls_sha1_context mbedtls_sha1; mbedtls_md5_init( &mbedtls_md5 ); mbedtls_sha1_init( &mbedtls_sha1 ); /* * digitally-signed struct { * opaque md5_hash[16]; * opaque sha_hash[20]; * }; * * md5_hash * MD5(ClientHello.random + ServerHello.random * + ServerParams); * sha_hash * SHA(ClientHello.random + ServerHello.random * + ServerParams); */ if( ( ret = mbedtls_md5_starts_ret( &mbedtls_md5 ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_md5_starts_ret", ret ); goto exit; } if( ( ret = mbedtls_md5_update_ret( &mbedtls_md5, ssl->handshake->randbytes, 64 ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_md5_update_ret", ret ); goto exit; } if( ( ret = mbedtls_md5_update_ret( &mbedtls_md5, data, data_len ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_md5_update_ret", ret ); goto exit; } if( ( ret = mbedtls_md5_finish_ret( &mbedtls_md5, output ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_md5_finish_ret", ret ); goto exit; } if( ( ret = mbedtls_sha1_starts_ret( &mbedtls_sha1 ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_sha1_starts_ret", ret ); goto exit; } if( ( ret = mbedtls_sha1_update_ret( &mbedtls_sha1, ssl->handshake->randbytes, 64 ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_sha1_update_ret", ret ); goto exit; } if( ( ret = mbedtls_sha1_update_ret( &mbedtls_sha1, data, data_len ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_sha1_update_ret", ret ); goto exit; } if( ( ret = mbedtls_sha1_finish_ret( &mbedtls_sha1, output + 16 ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_sha1_finish_ret", ret ); goto exit; } exit: mbedtls_md5_free( &mbedtls_md5 ); mbedtls_sha1_free( &mbedtls_sha1 ); if( ret != 0 ) mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_INTERNAL_ERROR ); return( ret ); } #endif /* MBEDTLS_SSL_PROTO_SSL3 || MBEDTLS_SSL_PROTO_TLS1 || \ MBEDTLS_SSL_PROTO_TLS1_1 */ #if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) || \ defined(MBEDTLS_SSL_PROTO_TLS1_2) int mbedtls_ssl_get_key_exchange_md_tls1_2( mbedtls_ssl_context *ssl, unsigned char *hash, size_t *hashlen, unsigned char *data, size_t data_len, mbedtls_md_type_t md_alg ) { int ret = 0; mbedtls_md_context_t ctx; const mbedtls_md_info_t *md_info = mbedtls_md_info_from_type( md_alg ); *hashlen = mbedtls_md_get_size( md_info ); mbedtls_md_init( &ctx ); /* * digitally-signed struct { * opaque client_random[32]; * opaque server_random[32]; * ServerDHParams params; * }; */ if( ( ret = mbedtls_md_setup( &ctx, md_info, 0 ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_md_setup", ret ); goto exit; } if( ( ret = mbedtls_md_starts( &ctx ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_md_starts", ret ); goto exit; } if( ( ret = mbedtls_md_update( &ctx, ssl->handshake->randbytes, 64 ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_md_update", ret ); goto exit; } if( ( ret = mbedtls_md_update( &ctx, data, data_len ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_md_update", ret ); goto exit; } if( ( ret = mbedtls_md_finish( &ctx, hash ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_md_finish", ret ); goto exit; } exit: mbedtls_md_free( &ctx ); if( ret != 0 ) mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_INTERNAL_ERROR ); return( ret ); } #endif /* MBEDTLS_SSL_PROTO_TLS1 || MBEDTLS_SSL_PROTO_TLS1_1 || \ MBEDTLS_SSL_PROTO_TLS1_2 */ #endif /* MBEDTLS_SSL_TLS_C */