/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:4;tab-width:4;coding:utf-8 -*-│ │vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│ ╞══════════════════════════════════════════════════════════════════════════════╡ │ Copyright The Mbed TLS Contributors │ │ │ │ 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. │ ╚─────────────────────────────────────────────────────────────────────────────*/ #include "libc/log/log.h" #include "third_party/mbedtls/chk.h" #include "third_party/mbedtls/common.h" #include "third_party/mbedtls/config.h" #include "third_party/mbedtls/debug.h" #include "third_party/mbedtls/endian.h" #include "third_party/mbedtls/error.h" #include "third_party/mbedtls/oid.h" #include "third_party/mbedtls/platform.h" #include "third_party/mbedtls/ssl.h" #include "third_party/mbedtls/ssl_ciphersuites.h" #include "third_party/mbedtls/ssl_internal.h" #include "third_party/mbedtls/version.h" asm(".ident\t\"\\n\\n\ Mbed TLS (Apache 2.0)\\n\ Copyright ARM Limited\\n\ Copyright Mbed TLS Contributors\""); asm(".include \"libc/disclaimer.inc\""); /* clang-format off */ /** * @fileoverview SSLv3/TLSv1 shared functions * * The SSL 3.0 specification was drafted by Netscape in 1996, * and became an IETF standard in 1999. * * @see http://wp.netscape.com/eng/ssl3/ * @see http://www.ietf.org/rfc/rfc2246.txt * @see http://www.ietf.org/rfc/rfc4346.txt */ #if defined(MBEDTLS_SSL_TLS_C) #if defined(MBEDTLS_SSL_PROTO_DTLS) #if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) /* Top-level Connection ID API */ /** * \brief Specify the length of Connection IDs for incoming * encrypted DTLS records, as well as the behaviour * on unexpected CIDs. * * By default, the CID length is set to \c 0, * and unexpected CIDs are silently ignored. * * \param conf The SSL configuration to modify. * \param len The length in Bytes of the CID fields in encrypted * DTLS records using the CID mechanism. This must * not be larger than #MBEDTLS_SSL_CID_OUT_LEN_MAX. * \param ignore_other_cids This determines the stack's behaviour when * receiving a record with an unexpected CID. * Possible values are: * - #MBEDTLS_SSL_UNEXPECTED_CID_IGNORE * In this case, the record is silently ignored. * - #MBEDTLS_SSL_UNEXPECTED_CID_FAIL * In this case, the stack fails with the specific * error code #MBEDTLS_ERR_SSL_UNEXPECTED_CID. * * \note The CID specification allows implementations to either * use a common length for all incoming connection IDs or * allow variable-length incoming IDs. Mbed TLS currently * requires a common length for all connections sharing the * same SSL configuration; this allows simpler parsing of * record headers. * * \return \c 0 on success. * \return #MBEDTLS_ERR_SSL_BAD_INPUT_DATA if \p own_cid_len * is too large. */ int mbedtls_ssl_conf_cid( mbedtls_ssl_config *conf, size_t len, int ignore_other_cid ) { if( len > MBEDTLS_SSL_CID_IN_LEN_MAX ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); if( ignore_other_cid != MBEDTLS_SSL_UNEXPECTED_CID_FAIL && ignore_other_cid != MBEDTLS_SSL_UNEXPECTED_CID_IGNORE ) { return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); } conf->ignore_unexpected_cid = ignore_other_cid; conf->cid_len = len; return( 0 ); } /** * \brief Configure the use of the Connection ID (CID) * extension in the next handshake. * * Reference: draft-ietf-tls-dtls-connection-id-05 * https://tools.ietf.org/html/draft-ietf-tls-dtls-connection-id-05 * * The DTLS CID extension allows the reliable association of * DTLS records to DTLS connections across changes in the * underlying transport (changed IP and Port metadata) by * adding explicit connection identifiers (CIDs) to the * headers of encrypted DTLS records. The desired CIDs are * configured by the application layer and are exchanged in * new `ClientHello` / `ServerHello` extensions during the * handshake, where each side indicates the CID it wants the * peer to use when writing encrypted messages. The CIDs are * put to use once records get encrypted: the stack discards * any incoming records that don't include the configured CID * in their header, and adds the peer's requested CID to the * headers of outgoing messages. * * This API enables or disables the use of the CID extension * in the next handshake and sets the value of the CID to * be used for incoming messages. * * \param ssl The SSL context to configure. This must be initialized. * \param enable This value determines whether the CID extension should * be used or not. Possible values are: * - MBEDTLS_SSL_CID_ENABLED to enable the use of the CID. * - MBEDTLS_SSL_CID_DISABLED (default) to disable the use * of the CID. * \param own_cid The address of the readable buffer holding the CID we want * the peer to use when sending encrypted messages to us. * This may be \c NULL if \p own_cid_len is \c 0. * This parameter is unused if \p enabled is set to * MBEDTLS_SSL_CID_DISABLED. * \param own_cid_len The length of \p own_cid. * This parameter is unused if \p enabled is set to * MBEDTLS_SSL_CID_DISABLED. * * \note The value of \p own_cid_len must match the value of the * \c len parameter passed to mbedtls_ssl_conf_cid() * when configuring the ::mbedtls_ssl_config that \p ssl * is bound to. * * \note This CID configuration applies to subsequent handshakes * performed on the SSL context \p ssl, but does not trigger * one. You still have to call `mbedtls_ssl_handshake()` * (for the initial handshake) or `mbedtls_ssl_renegotiate()` * (for a renegotiation handshake) explicitly after a * successful call to this function to run the handshake. * * \note This call cannot guarantee that the use of the CID * will be successfully negotiated in the next handshake, * because the peer might not support it. Specifically: * - On the Client, enabling the use of the CID through * this call implies that the `ClientHello` in the next * handshake will include the CID extension, thereby * offering the use of the CID to the server. Only if * the `ServerHello` contains the CID extension, too, * the CID extension will actually be put to use. * - On the Server, enabling the use of the CID through * this call implies that that the server will look for * the CID extension in a `ClientHello` from the client, * and, if present, reply with a CID extension in its * `ServerHello`. * * \note To check whether the use of the CID was negotiated * after the subsequent handshake has completed, please * use the API mbedtls_ssl_get_peer_cid(). * * \warning If the use of the CID extension is enabled in this call * and the subsequent handshake negotiates its use, Mbed TLS * will silently drop every packet whose CID does not match * the CID configured in \p own_cid. It is the responsibility * of the user to adapt the underlying transport to take care * of CID-based demultiplexing before handing datagrams to * Mbed TLS. * * \return \c 0 on success. In this case, the CID configuration * applies to the next handshake. * \return A negative error code on failure. */ int mbedtls_ssl_set_cid( mbedtls_ssl_context *ssl, int enable, unsigned char const *own_cid, size_t own_cid_len ) { if( ssl->conf->transport != MBEDTLS_SSL_TRANSPORT_DATAGRAM ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); ssl->negotiate_cid = enable; if( enable == MBEDTLS_SSL_CID_DISABLED ) { MBEDTLS_SSL_DEBUG_MSG( 3, ( "Disable use of CID extension." ) ); return( 0 ); } MBEDTLS_SSL_DEBUG_MSG( 3, ( "Enable use of CID extension." ) ); MBEDTLS_SSL_DEBUG_BUF( 3, "Own CID", own_cid, own_cid_len ); if( own_cid_len != ssl->conf->cid_len ) { MBEDTLS_SSL_DEBUG_MSG( 3, ( "CID length %u does not match CID length %u in config", (unsigned) own_cid_len, (unsigned) ssl->conf->cid_len ) ); return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); } memcpy( ssl->own_cid, own_cid, own_cid_len ); /* Truncation is not an issue here because * MBEDTLS_SSL_CID_IN_LEN_MAX at most 255. */ ssl->own_cid_len = (uint8_t) own_cid_len; return( 0 ); } /** * \brief Get information about the use of the CID extension * in the current connection. * * \param ssl The SSL context to query. * \param enabled The address at which to store whether the CID extension * is currently in use or not. If the CID is in use, * `*enabled` is set to MBEDTLS_SSL_CID_ENABLED; * otherwise, it is set to MBEDTLS_SSL_CID_DISABLED. * \param peer_cid The address of the buffer in which to store the CID * chosen by the peer (if the CID extension is used). * This may be \c NULL in case the value of peer CID * isn't needed. If it is not \c NULL, \p peer_cid_len * must not be \c NULL. * \param peer_cid_len The address at which to store the size of the CID * chosen by the peer (if the CID extension is used). * This is also the number of Bytes in \p peer_cid that * have been written. * This may be \c NULL in case the length of the peer CID * isn't needed. If it is \c NULL, \p peer_cid must be * \c NULL, too. * * \note This applies to the state of the CID negotiated in * the last complete handshake. If a handshake is in * progress, this function will attempt to complete * the handshake first. * * \note If CID extensions have been exchanged but both client * and server chose to use an empty CID, this function * sets `*enabled` to #MBEDTLS_SSL_CID_DISABLED * (the rationale for this is that the resulting * communication is the same as if the CID extensions * hadn't been used). * * \return \c 0 on success. * \return A negative error code on failure. */ int mbedtls_ssl_get_peer_cid( mbedtls_ssl_context *ssl, int *enabled, unsigned char peer_cid[ MBEDTLS_SSL_CID_OUT_LEN_MAX ], size_t *peer_cid_len ) { *enabled = MBEDTLS_SSL_CID_DISABLED; if( ssl->conf->transport != MBEDTLS_SSL_TRANSPORT_DATAGRAM || ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER ) { return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); } /* We report MBEDTLS_SSL_CID_DISABLED in case the CID extensions * were used, but client and server requested the empty CID. * This is indistinguishable from not using the CID extension * in the first place. */ if( ssl->transform_in->in_cid_len == 0 && ssl->transform_in->out_cid_len == 0 ) { return( 0 ); } if( peer_cid_len != NULL ) { *peer_cid_len = ssl->transform_in->out_cid_len; if( peer_cid != NULL ) { memcpy( peer_cid, ssl->transform_in->out_cid, ssl->transform_in->out_cid_len ); } } *enabled = MBEDTLS_SSL_CID_ENABLED; return( 0 ); } #endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */ #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 */ int mbedtls_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 defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE) if( src->peer_cert != NULL ) { int ret = MBEDTLS_ERR_THIS_CORRUPTION; 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 ); } } #else /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */ if( src->peer_cert_digest != NULL ) { dst->peer_cert_digest = mbedtls_calloc( 1, src->peer_cert_digest_len ); if( dst->peer_cert_digest == NULL ) return( MBEDTLS_ERR_SSL_ALLOC_FAILED ); memcpy( dst->peer_cert_digest, src->peer_cert_digest, src->peer_cert_digest_len ); dst->peer_cert_digest_type = src->peer_cert_digest_type; dst->peer_cert_digest_len = src->peer_cert_digest_len; } #endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */ #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 ); } #if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH) static int resize_buffer( unsigned char **buffer, size_t len_new, size_t *len_old ) { unsigned char* resized_buffer = mbedtls_calloc( 1, len_new ); if( resized_buffer == NULL ) return -1; /* We want to copy len_new bytes when downsizing the buffer, and * len_old bytes when upsizing, so we choose the smaller of two sizes, * to fit one buffer into another. Size checks, ensuring that no data is * lost, are done outside of this function. */ memcpy( resized_buffer, *buffer, ( len_new < *len_old ) ? len_new : *len_old ); mbedtls_platform_zeroize( *buffer, *len_old ); mbedtls_free( *buffer ); *buffer = resized_buffer; *len_old = len_new; return 0; } static void handle_buffer_resizing( mbedtls_ssl_context *ssl, int downsizing, size_t in_buf_new_len, size_t out_buf_new_len ) { int modified = 0; size_t written_in = 0, iv_offset_in = 0, len_offset_in = 0; size_t written_out = 0, iv_offset_out = 0, len_offset_out = 0; if( ssl->in_buf != NULL ) { written_in = ssl->in_msg - ssl->in_buf; iv_offset_in = ssl->in_iv - ssl->in_buf; len_offset_in = ssl->in_len - ssl->in_buf; if( downsizing ? ssl->in_buf_len > in_buf_new_len && ssl->in_left < in_buf_new_len : ssl->in_buf_len < in_buf_new_len ) { if( resize_buffer( &ssl->in_buf, in_buf_new_len, &ssl->in_buf_len ) != 0 ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "input buffer resizing failed - out of memory" ) ); } else { MBEDTLS_SSL_DEBUG_MSG( 2, ( "Reallocating in_buf to %" MBEDTLS_PRINTF_SIZET, in_buf_new_len ) ); modified = 1; } } } if( ssl->out_buf != NULL ) { written_out = ssl->out_msg - ssl->out_buf; iv_offset_out = ssl->out_iv - ssl->out_buf; len_offset_out = ssl->out_len - ssl->out_buf; if( downsizing ? ssl->out_buf_len > out_buf_new_len && ssl->out_left < out_buf_new_len : ssl->out_buf_len < out_buf_new_len ) { if( resize_buffer( &ssl->out_buf, out_buf_new_len, &ssl->out_buf_len ) != 0 ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "output buffer resizing failed - out of memory" ) ); } else { MBEDTLS_SSL_DEBUG_MSG( 2, ( "Reallocating out_buf to %" MBEDTLS_PRINTF_SIZET, out_buf_new_len ) ); modified = 1; } } } if( modified ) { /* Update pointers here to avoid doing it twice. */ mbedtls_ssl_reset_in_out_pointers( ssl ); /* Fields below might not be properly updated with record * splitting or with CID, so they are manually updated here. */ ssl->out_msg = ssl->out_buf + written_out; ssl->out_len = ssl->out_buf + len_offset_out; ssl->out_iv = ssl->out_buf + iv_offset_out; ssl->in_msg = ssl->in_buf + written_in; ssl->in_len = ssl->in_buf + len_offset_in; ssl->in_iv = ssl->in_buf + iv_offset_in; } } #endif /* MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH */ /* * 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]; 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 ); MBEDTLS_CHK( mbedtls_sha1_starts_ret( &sha1 ) ); MBEDTLS_CHK( mbedtls_sha1_update_ret( &sha1, padding, 1 + i ) ); MBEDTLS_CHK( mbedtls_sha1_update_ret( &sha1, secret, slen ) ); MBEDTLS_CHK( mbedtls_sha1_update_ret( &sha1, random, rlen ) ); MBEDTLS_CHK( mbedtls_sha1_finish_ret( &sha1, sha1sum ) ); MBEDTLS_CHK( mbedtls_md5_starts_ret( &md5 ) ); MBEDTLS_CHK( mbedtls_md5_update_ret( &md5, secret, slen ) ); MBEDTLS_CHK( mbedtls_md5_update_ret( &md5, sha1sum, 20 ) ); MBEDTLS_CHK( mbedtls_md5_finish_ret( &md5, dstbuf + i * 16 ) ); } cleanup: 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; size_t tmp_len = 0; unsigned char h_i[20]; const mbedtls_md_info_t *md_info; mbedtls_md_context_t md_ctx; int ret = MBEDTLS_ERR_THIS_CORRUPTION; mbedtls_md_init( &md_ctx ); tmp_len = 20 + strlen( label ) + rlen; if( !( tmp = mbedtls_calloc( 1, tmp_len ) ) ) { ret = MBEDTLS_ERR_SSL_ALLOC_FAILED; goto exit; } 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 ) ) ) { ret = MBEDTLS_ERR_SSL_INTERNAL_ERROR; goto exit; } if( ( ret = mbedtls_md_setup( &md_ctx, md_info, 1 ) ) != 0 ) { goto exit; } 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 ) ) ) { ret = MBEDTLS_ERR_SSL_INTERNAL_ERROR; goto exit; } if( ( ret = mbedtls_md_setup( &md_ctx, md_info, 1 ) ) != 0 ) { goto exit; } 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] ); } exit: mbedtls_md_free( &md_ctx ); mbedtls_platform_zeroize( tmp, tmp_len ); mbedtls_platform_zeroize( h_i, sizeof( h_i ) ); mbedtls_free( tmp ); return( ret ); } #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; size_t tmp_len = 0; unsigned char h_i[MBEDTLS_MD_MAX_SIZE]; const mbedtls_md_info_t *md_info; mbedtls_md_context_t md_ctx; int ret = MBEDTLS_ERR_THIS_CORRUPTION; 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 ); tmp_len = md_len + strlen( label ) + rlen; tmp = mbedtls_calloc( 1, tmp_len ); if( tmp == NULL ) { ret = MBEDTLS_ERR_SSL_ALLOC_FAILED; goto exit; } 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 ) goto exit; 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]; } exit: mbedtls_md_free( &md_ctx ); mbedtls_platform_zeroize( tmp, tmp_len ); mbedtls_platform_zeroize( h_i, sizeof( h_i ) ); mbedtls_free( tmp ); return( ret ); } #if defined(MBEDTLS_SHA256_C) static int tls_prf_sha256( const unsigned char *secret, size_t slen, const char *label, const unsigned char *random, size_t rlen, unsigned char *dstbuf, size_t dlen ) { return( tls_prf_generic( MBEDTLS_MD_SHA256, secret, slen, label, random, rlen, dstbuf, dlen ) ); } #endif /* MBEDTLS_SHA256_C */ #if defined(MBEDTLS_SHA512_C) static int tls_prf_sha384( const unsigned char *secret, size_t slen, const char *label, const unsigned char *random, size_t rlen, unsigned char *dstbuf, size_t dlen ) { return( tls_prf_generic( MBEDTLS_MD_SHA384, secret, slen, label, random, rlen, dstbuf, dlen ) ); } #endif /* MBEDTLS_SHA512_C */ #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */ static void ssl_update_checksum_start( mbedtls_ssl_context *, const unsigned char *, size_t ); #if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1) || \ defined(MBEDTLS_SSL_PROTO_TLS1_1) static void ssl_update_checksum_md5sha1( mbedtls_ssl_context *, const unsigned char *, size_t ); #endif #if defined(MBEDTLS_SSL_PROTO_SSL3) static void ssl_calc_verify_ssl( const mbedtls_ssl_context *, unsigned char *, size_t * ); static void ssl_calc_finished_ssl( mbedtls_ssl_context *, unsigned char *, int ); #endif #if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) static void ssl_calc_verify_tls( const mbedtls_ssl_context *, unsigned char*, size_t * ); static void ssl_calc_finished_tls( mbedtls_ssl_context *, unsigned char *, int ); #endif #if defined(MBEDTLS_SSL_PROTO_TLS1_2) #if defined(MBEDTLS_SHA256_C) static void ssl_update_checksum_sha256( mbedtls_ssl_context *, const unsigned char *, size_t ); static void ssl_calc_verify_tls_sha256( const mbedtls_ssl_context *,unsigned char*, size_t * ); static void ssl_calc_finished_tls_sha256( mbedtls_ssl_context *,unsigned char *, int ); #endif #if defined(MBEDTLS_SHA512_C) static void ssl_update_checksum_sha384( mbedtls_ssl_context *, const unsigned char *, size_t ); static void ssl_calc_verify_tls_sha384( const mbedtls_ssl_context *, unsigned char*, size_t * ); static void ssl_calc_finished_tls_sha384( mbedtls_ssl_context *, unsigned char *, int ); #endif #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */ #if defined(MBEDTLS_SSL_EXPORT_KEYS) static mbedtls_tls_prf_types tls_prf_get_type( mbedtls_ssl_tls_prf_cb *tls_prf ) { #if defined(MBEDTLS_SSL_PROTO_SSL3) if( tls_prf == ssl3_prf ) { return( MBEDTLS_SSL_TLS_PRF_SSL3 ); } else #endif #if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) if( tls_prf == tls1_prf ) { return( MBEDTLS_SSL_TLS_PRF_TLS1 ); } else #endif #if defined(MBEDTLS_SSL_PROTO_TLS1_2) #if defined(MBEDTLS_SHA512_C) if( tls_prf == tls_prf_sha384 ) { return( MBEDTLS_SSL_TLS_PRF_SHA384 ); } else #endif #if defined(MBEDTLS_SHA256_C) if( tls_prf == tls_prf_sha256 ) { return( MBEDTLS_SSL_TLS_PRF_SHA256 ); } else #endif #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */ return( MBEDTLS_SSL_TLS_PRF_NONE ); } #endif /* MBEDTLS_SSL_EXPORT_KEYS */ /** * \brief TLS-PRF function for key derivation. * * \param prf The tls_prf type funtion type to be used. * \param secret Secret for the key derivation function. * \param slen Length of the secret. * \param label String label for the key derivation function, * terminated with null character. * \param random Random bytes. * \param rlen Length of the random bytes buffer. * \param dstbuf The buffer holding the derived key. * \param dlen Length of the output buffer. * * \return 0 on sucess. An SSL specific error on failure. */ int mbedtls_ssl_tls_prf( const mbedtls_tls_prf_types prf, const unsigned char *secret, size_t slen, const char *label, const unsigned char *random, size_t rlen, unsigned char *dstbuf, size_t dlen ) { mbedtls_ssl_tls_prf_cb *tls_prf = NULL; switch( prf ) { #if defined(MBEDTLS_SSL_PROTO_SSL3) case MBEDTLS_SSL_TLS_PRF_SSL3: tls_prf = ssl3_prf; break; #endif /* MBEDTLS_SSL_PROTO_SSL3 */ #if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) case MBEDTLS_SSL_TLS_PRF_TLS1: tls_prf = tls1_prf; break; #endif /* MBEDTLS_SSL_PROTO_TLS1 || MBEDTLS_SSL_PROTO_TLS1_1 */ #if defined(MBEDTLS_SSL_PROTO_TLS1_2) #if defined(MBEDTLS_SHA512_C) case MBEDTLS_SSL_TLS_PRF_SHA384: tls_prf = tls_prf_sha384; break; #endif /* MBEDTLS_SHA512_C */ #if defined(MBEDTLS_SHA256_C) case MBEDTLS_SSL_TLS_PRF_SHA256: tls_prf = tls_prf_sha256; break; #endif /* MBEDTLS_SHA256_C */ #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */ default: return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE ); } return( tls_prf( secret, slen, label, random, rlen, dstbuf, dlen ) ); } /* Type for the TLS PRF */ typedef int ssl_tls_prf_t(const unsigned char *, size_t, const char *, const unsigned char *, size_t, unsigned char *, size_t); /* * Populate a transform structure with session keys and all the other * necessary information. * * Parameters: * - [in/out]: transform: structure to populate * [in] must be just initialised with mbedtls_ssl_transform_init() * [out] fully populated, ready for use by mbedtls_ssl_{en,de}crypt_buf() * - [in] ciphersuite * - [in] master * - [in] encrypt_then_mac * - [in] trunc_hmac * - [in] compression * - [in] tls_prf: pointer to PRF to use for key derivation * - [in] randbytes: buffer holding ServerHello.random + ClientHello.random * - [in] minor_ver: SSL/TLS minor version * - [in] endpoint: client or server * - [in] ssl: optionally used for: * - MBEDTLS_SSL_HW_RECORD_ACCEL: whole context (non-const) * - MBEDTLS_SSL_EXPORT_KEYS: ssl->conf->{f,p}_export_keys * - MBEDTLS_DEBUG_C: ssl->conf->{f,p}_dbg */ static int ssl_populate_transform( mbedtls_ssl_transform *transform, int ciphersuite, const unsigned char master[48], #if defined(MBEDTLS_SSL_SOME_MODES_USE_MAC) #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC) int encrypt_then_mac, #endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */ #endif /* MBEDTLS_SSL_SOME_MODES_USE_MAC */ #if defined(MBEDTLS_ZLIB_SUPPORT) int compression, #endif ssl_tls_prf_t tls_prf, const unsigned char randbytes[64], int minor_ver, unsigned endpoint, #if !defined(MBEDTLS_SSL_HW_RECORD_ACCEL) const #endif mbedtls_ssl_context *ssl ) { int ret = 0; unsigned char keyblk[256]; unsigned char *key1; unsigned char *key2; unsigned char *mac_enc; unsigned char *mac_dec; size_t mac_key_len = 0; size_t iv_copy_len; unsigned keylen; const mbedtls_ssl_ciphersuite_t *ciphersuite_info; const mbedtls_cipher_info_t *cipher_info; const mbedtls_md_info_t *md_info; #if !defined(MBEDTLS_SSL_HW_RECORD_ACCEL) && \ !defined(MBEDTLS_SSL_EXPORT_KEYS) && \ !defined(MBEDTLS_DEBUG_C) ssl = NULL; /* make sure we don't use it except for those cases */ (void) ssl; #endif /* * Some data just needs copying into the structure */ #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC) && \ defined(MBEDTLS_SSL_SOME_MODES_USE_MAC) transform->encrypt_then_mac = encrypt_then_mac; #endif transform->minor_ver = minor_ver; #if defined(MBEDTLS_SSL_CONTEXT_SERIALIZATION) memcpy( transform->randbytes, randbytes, sizeof( transform->randbytes ) ); #endif /* * Get various info structures */ ciphersuite_info = mbedtls_ssl_ciphersuite_from_id( ciphersuite ); if( ciphersuite_info == NULL ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "ciphersuite info for %d not found", ciphersuite ) ); return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); } cipher_info = mbedtls_cipher_info_from_type( ciphersuite_info->cipher ); if( cipher_info == NULL ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "cipher info for %u not found", ciphersuite_info->cipher ) ); return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); } md_info = mbedtls_md_info_from_type( ciphersuite_info->mac ); if( md_info == NULL ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "mbedtls_md info for %u not found", (unsigned) ciphersuite_info->mac ) ); return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); } #if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) /* Copy own and peer's CID if the use of the CID * extension has been negotiated. */ if( ssl->handshake->cid_in_use == MBEDTLS_SSL_CID_ENABLED ) { MBEDTLS_SSL_DEBUG_MSG( 3, ( "Copy CIDs into SSL transform" ) ); transform->in_cid_len = ssl->own_cid_len; memcpy( transform->in_cid, ssl->own_cid, ssl->own_cid_len ); MBEDTLS_SSL_DEBUG_BUF( 3, "Incoming CID", transform->in_cid, transform->in_cid_len ); transform->out_cid_len = ssl->handshake->peer_cid_len; memcpy( transform->out_cid, ssl->handshake->peer_cid, ssl->handshake->peer_cid_len ); MBEDTLS_SSL_DEBUG_BUF( 3, "Outgoing CID", transform->out_cid, transform->out_cid_len ); } #endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */ /* * Compute key block using the PRF */ ret = tls_prf( master, 48, "key expansion", randbytes, 64, keyblk, 256 ); if( ret != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "prf", ret ); return( ret ); } MBEDTLS_SSL_DEBUG_MSG( 3, ( "ciphersuite = %s", mbedtls_ssl_get_ciphersuite_name( ciphersuite ) ) ); MBEDTLS_SSL_DEBUG_BUF( 3, "master secret", master, 48 ); MBEDTLS_SSL_DEBUG_BUF( 4, "random bytes", randbytes, 64 ); MBEDTLS_SSL_DEBUG_BUF( 4, "key block", keyblk, 256 ); /* * Determine the appropriate key, IV and MAC length. */ keylen = cipher_info->key_bitlen / 8; #if defined(MBEDTLS_GCM_C) || \ defined(MBEDTLS_CCM_C) || \ defined(MBEDTLS_CHACHAPOLY_C) if( cipher_info->mode == MBEDTLS_MODE_GCM || cipher_info->mode == MBEDTLS_MODE_CCM || cipher_info->mode == MBEDTLS_MODE_CHACHAPOLY ) { size_t explicit_ivlen; transform->maclen = 0; mac_key_len = 0; transform->taglen = ciphersuite_info->flags & MBEDTLS_CIPHERSUITE_SHORT_TAG ? 8 : 16; /* All modes haves 96-bit IVs, but the length of the static parts vary * with mode and version: * - For GCM and CCM in TLS 1.2, there's a static IV of 4 Bytes * (to be concatenated with a dynamically chosen IV of 8 Bytes) * - For ChaChaPoly in TLS 1.2, and all modes in TLS 1.3, there's * a static IV of 12 Bytes (to be XOR'ed with the 8 Byte record * sequence number). */ transform->ivlen = 12; #if defined(MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL) if( minor_ver == MBEDTLS_SSL_MINOR_VERSION_4 ) { transform->fixed_ivlen = 12; } else #endif /* MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL */ { if( cipher_info->mode == MBEDTLS_MODE_CHACHAPOLY ) transform->fixed_ivlen = 12; else transform->fixed_ivlen = 4; } /* Minimum length of encrypted record */ explicit_ivlen = transform->ivlen - transform->fixed_ivlen; transform->minlen = explicit_ivlen + transform->taglen; } else #endif /* MBEDTLS_GCM_C || MBEDTLS_CCM_C || MBEDTLS_CHACHAPOLY_C */ #if defined(MBEDTLS_SSL_SOME_MODES_USE_MAC) if( cipher_info->mode == MBEDTLS_MODE_STREAM || cipher_info->mode == MBEDTLS_MODE_CBC ) { /* Initialize HMAC contexts */ if( ( ret = mbedtls_md_setup( &transform->md_ctx_enc, md_info, 1 ) ) != 0 || ( ret = mbedtls_md_setup( &transform->md_ctx_dec, md_info, 1 ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_md_setup", ret ); goto end; } /* Get MAC length */ mac_key_len = mbedtls_md_get_size( md_info ); transform->maclen = mac_key_len; /* IV length */ transform->ivlen = cipher_info->iv_size; /* Minimum length */ if( cipher_info->mode == MBEDTLS_MODE_STREAM ) transform->minlen = transform->maclen; else { /* * GenericBlockCipher: * 1. if EtM is in use: one block plus MAC * otherwise: * first multiple of blocklen greater than maclen * 2. IV except for SSL3 and TLS 1.0 */ #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC) if( encrypt_then_mac == MBEDTLS_SSL_ETM_ENABLED ) { transform->minlen = transform->maclen + cipher_info->block_size; } else #endif { transform->minlen = transform->maclen + cipher_info->block_size - transform->maclen % cipher_info->block_size; } #if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1) if( minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 || minor_ver == MBEDTLS_SSL_MINOR_VERSION_1 ) ; /* No need to adjust minlen */ else #endif #if defined(MBEDTLS_SSL_PROTO_TLS1_1) || defined(MBEDTLS_SSL_PROTO_TLS1_2) if( minor_ver == MBEDTLS_SSL_MINOR_VERSION_2 || minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 ) { transform->minlen += transform->ivlen; } else #endif { MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); ret = MBEDTLS_ERR_SSL_INTERNAL_ERROR; goto end; } } } else #endif /* MBEDTLS_SSL_SOME_MODES_USE_MAC */ { MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); } MBEDTLS_SSL_DEBUG_MSG( 3, ( "keylen: %u, minlen: %u, ivlen: %u, maclen: %u", (unsigned) keylen, (unsigned) transform->minlen, (unsigned) transform->ivlen, (unsigned) transform->maclen ) ); /* * Finally setup the cipher contexts, IVs and MAC secrets. */ #if defined(MBEDTLS_SSL_CLI_C) if( endpoint == MBEDTLS_SSL_IS_CLIENT ) { key1 = keyblk + mac_key_len * 2; key2 = keyblk + mac_key_len * 2 + keylen; mac_enc = keyblk; mac_dec = keyblk + mac_key_len; /* * This is not used in TLS v1.1. */ iv_copy_len = ( transform->fixed_ivlen ) ? transform->fixed_ivlen : transform->ivlen; memcpy( transform->iv_enc, key2 + keylen, iv_copy_len ); memcpy( transform->iv_dec, key2 + keylen + iv_copy_len, iv_copy_len ); } else #endif /* MBEDTLS_SSL_CLI_C */ #if defined(MBEDTLS_SSL_SRV_C) if( endpoint == MBEDTLS_SSL_IS_SERVER ) { key1 = keyblk + mac_key_len * 2 + keylen; key2 = keyblk + mac_key_len * 2; mac_enc = keyblk + mac_key_len; mac_dec = keyblk; /* * This is not used in TLS v1.1. */ iv_copy_len = ( transform->fixed_ivlen ) ? transform->fixed_ivlen : transform->ivlen; memcpy( transform->iv_dec, key1 + keylen, iv_copy_len ); memcpy( transform->iv_enc, key1 + keylen + iv_copy_len, iv_copy_len ); } else #endif /* MBEDTLS_SSL_SRV_C */ { MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); ret = MBEDTLS_ERR_SSL_INTERNAL_ERROR; goto end; } #if defined(MBEDTLS_SSL_SOME_MODES_USE_MAC) #if defined(MBEDTLS_SSL_PROTO_SSL3) if( minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 ) { if( mac_key_len > sizeof( transform->mac_enc ) ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); ret = MBEDTLS_ERR_SSL_INTERNAL_ERROR; goto end; } memcpy( transform->mac_enc, mac_enc, mac_key_len ); memcpy( transform->mac_dec, mac_dec, mac_key_len ); } else #endif /* MBEDTLS_SSL_PROTO_SSL3 */ #if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) || \ defined(MBEDTLS_SSL_PROTO_TLS1_2) if( minor_ver >= MBEDTLS_SSL_MINOR_VERSION_1 ) { /* For HMAC-based ciphersuites, initialize the HMAC transforms. For AEAD-based ciphersuites, there is nothing to do here. */ if( mac_key_len != 0 ) { mbedtls_md_hmac_starts( &transform->md_ctx_enc, mac_enc, mac_key_len ); mbedtls_md_hmac_starts( &transform->md_ctx_dec, mac_dec, mac_key_len ); } } else #endif { MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); ret = MBEDTLS_ERR_SSL_INTERNAL_ERROR; goto end; } #endif /* MBEDTLS_SSL_SOME_MODES_USE_MAC */ #if defined(MBEDTLS_SSL_HW_RECORD_ACCEL) if( mbedtls_ssl_hw_record_init != NULL ) { ret = 0; MBEDTLS_SSL_DEBUG_MSG( 2, ( "going for mbedtls_ssl_hw_record_init()" ) ); if( ( ret = mbedtls_ssl_hw_record_init( ssl, key1, key2, keylen, transform->iv_enc, transform->iv_dec, iv_copy_len, mac_enc, mac_dec, mac_key_len ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_hw_record_init", ret ); ret = MBEDTLS_ERR_SSL_HW_ACCEL_FAILED; goto end; } } #else ((void) mac_dec); ((void) mac_enc); #endif /* MBEDTLS_SSL_HW_RECORD_ACCEL */ #if defined(MBEDTLS_SSL_EXPORT_KEYS) if( ssl->conf->f_export_keys != NULL ) { ssl->conf->f_export_keys( ssl->conf->p_export_keys, master, keyblk, mac_key_len, keylen, iv_copy_len ); } if( ssl->conf->f_export_keys_ext != NULL ) { ssl->conf->f_export_keys_ext( ssl->conf->p_export_keys, master, keyblk, mac_key_len, keylen, iv_copy_len, randbytes + 32, randbytes, tls_prf_get_type( tls_prf ) ); } #endif if( ( ret = mbedtls_cipher_setup( &transform->cipher_ctx_enc, cipher_info ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_setup", ret ); goto end; } if( ( ret = mbedtls_cipher_setup( &transform->cipher_ctx_dec, cipher_info ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_setup", ret ); goto end; } 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 ); goto end; } 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 ); goto end; } #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 ); goto end; } 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 ); goto end; } } #endif /* MBEDTLS_CIPHER_MODE_CBC */ /* Initialize Zlib contexts */ #if defined(MBEDTLS_ZLIB_SUPPORT) if( compression == MBEDTLS_SSL_COMPRESS_DEFLATE ) { MBEDTLS_SSL_DEBUG_MSG( 3, ( "Initializing zlib states" ) ); mbedtls_platform_zeroize( &transform->ctx_deflate, sizeof( transform->ctx_deflate ) ); mbedtls_platform_zeroize( &transform->ctx_inflate, 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" ) ); ret = MBEDTLS_ERR_SSL_COMPRESSION_FAILED; goto end; } } #endif /* MBEDTLS_ZLIB_SUPPORT */ end: mbedtls_platform_zeroize( keyblk, sizeof( keyblk ) ); return( ret ); } /* * Set appropriate PRF function and other SSL / TLS 1.0/1.1 / TLS1.2 functions * * Inputs: * - SSL/TLS minor version * - hash associated with the ciphersuite (only used by TLS 1.2) * * Outputs: * - the tls_prf, calc_verify and calc_finished members of handshake structure */ static int ssl_set_handshake_prfs( mbedtls_ssl_handshake_params *handshake, int minor_ver, mbedtls_md_type_t hash ) { #if !defined(MBEDTLS_SSL_PROTO_TLS1_2) || !defined(MBEDTLS_SHA512_C) (void) hash; #endif #if defined(MBEDTLS_SSL_PROTO_SSL3) if( minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 ) { handshake->tls_prf = ssl3_prf; handshake->calc_verify = ssl_calc_verify_ssl; handshake->calc_finished = ssl_calc_finished_ssl; } else #endif #if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) if( minor_ver < MBEDTLS_SSL_MINOR_VERSION_3 ) { handshake->tls_prf = tls1_prf; handshake->calc_verify = ssl_calc_verify_tls; handshake->calc_finished = ssl_calc_finished_tls; } else #endif #if defined(MBEDTLS_SSL_PROTO_TLS1_2) #if defined(MBEDTLS_SHA512_C) if( minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 && hash == MBEDTLS_MD_SHA384 ) { handshake->tls_prf = tls_prf_sha384; handshake->calc_verify = ssl_calc_verify_tls_sha384; handshake->calc_finished = ssl_calc_finished_tls_sha384; } else #endif #if defined(MBEDTLS_SHA256_C) if( minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 ) { handshake->tls_prf = tls_prf_sha256; handshake->calc_verify = ssl_calc_verify_tls_sha256; handshake->calc_finished = ssl_calc_finished_tls_sha256; } else #endif #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */ { return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); } return( 0 ); } /* * Compute master secret if needed * * Parameters: * [in/out] handshake * [in] resume, premaster, extended_ms, calc_verify, tls_prf * (PSA-PSK) ciphersuite_info, psk_opaque * [out] premaster (cleared) * [out] master * [in] ssl: optionally used for debugging, EMS and PSA-PSK * debug: conf->f_dbg, conf->p_dbg * EMS: passed to calc_verify (debug + (SSL3) session_negotiate) * PSA-PSA: minor_ver, conf */ static int ssl_compute_master( mbedtls_ssl_handshake_params *handshake, unsigned char *master, const mbedtls_ssl_context *ssl ) { int ret = MBEDTLS_ERR_THIS_CORRUPTION; /* cf. RFC 5246, Section 8.1: * "The master secret is always exactly 48 bytes in length." */ size_t const master_secret_len = 48; #if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET) unsigned char session_hash[48]; #endif /* MBEDTLS_SSL_EXTENDED_MASTER_SECRET */ /* The label for the KDF used for key expansion. * This is either "master secret" or "extended master secret" * depending on whether the Extended Master Secret extension * is used. */ char const *lbl = "master secret"; /* The salt for the KDF used for key expansion. * - If the Extended Master Secret extension is not used, * this is ClientHello.Random + ServerHello.Random * (see Sect. 8.1 in RFC 5246). * - If the Extended Master Secret extension is used, * this is the transcript of the handshake so far. * (see Sect. 4 in RFC 7627). */ unsigned char const *salt = handshake->randbytes; size_t salt_len = 64; #if !defined(MBEDTLS_DEBUG_C) && \ !defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET) && \ !(defined(MBEDTLS_USE_PSA_CRYPTO) && \ defined(MBEDTLS_KEY_EXCHANGE_PSK_ENABLED)) ssl = NULL; /* make sure we don't use it except for those cases */ (void) ssl; #endif if( handshake->resume != 0 ) { MBEDTLS_SSL_DEBUG_MSG( 3, ( "no premaster (session resumed)" ) ); return( 0 ); } #if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET) if( handshake->extended_ms == MBEDTLS_SSL_EXTENDED_MS_ENABLED ) { lbl = "extended master secret"; salt = session_hash; handshake->calc_verify( ssl, session_hash, &salt_len ); MBEDTLS_SSL_DEBUG_BUF( 3, "session hash for extended master secret", session_hash, salt_len ); } #endif /* MBEDTLS_SSL_EXTENDED_MS_ENABLED */ ret = handshake->tls_prf( handshake->premaster, handshake->pmslen, lbl, salt, salt_len, master, master_secret_len ); if( ret != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "prf", ret ); return( ret ); } MBEDTLS_SSL_DEBUG_BUF( 3, "premaster secret", handshake->premaster, handshake->pmslen ); mbedtls_platform_zeroize( handshake->premaster, sizeof(handshake->premaster) ); return( 0 ); } int mbedtls_ssl_derive_keys( mbedtls_ssl_context *ssl ) { int ret = MBEDTLS_ERR_THIS_CORRUPTION; const mbedtls_ssl_ciphersuite_t * const ciphersuite_info = ssl->handshake->ciphersuite_info; MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> derive keys" ) ); /* Set PRF, calc_verify and calc_finished function pointers */ ret = ssl_set_handshake_prfs( ssl->handshake, ssl->minor_ver, ciphersuite_info->mac ); if( ret != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "ssl_set_handshake_prfs", ret ); return( ret ); } /* Compute master secret if needed */ ret = ssl_compute_master( ssl->handshake, ssl->session_negotiate->master, ssl ); if( ret != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "ssl_compute_master", ret ); return( ret ); } /* Swap the client and server random values: * - MS derivation wanted client+server (RFC 5246 8.1) * - key derivation wants server+client (RFC 5246 6.3) */ { unsigned char tmp[64]; memcpy( tmp, ssl->handshake->randbytes, 64 ); memcpy( ssl->handshake->randbytes, tmp + 32, 32 ); memcpy( ssl->handshake->randbytes + 32, tmp, 32 ); mbedtls_platform_zeroize( tmp, sizeof( tmp ) ); } /* Populate transform structure */ ret = ssl_populate_transform( ssl->transform_negotiate, ssl->session_negotiate->ciphersuite, ssl->session_negotiate->master, #if defined(MBEDTLS_SSL_SOME_MODES_USE_MAC) #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC) ssl->session_negotiate->encrypt_then_mac, #endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */ #endif /* MBEDTLS_SSL_SOME_MODES_USE_MAC */ #if defined(MBEDTLS_ZLIB_SUPPORT) ssl->session_negotiate->compression, #endif ssl->handshake->tls_prf, ssl->handshake->randbytes, ssl->minor_ver, ssl->conf->endpoint, ssl ); if( ret != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "ssl_populate_transform", ret ); return( ret ); } /* We no longer need Server/ClientHello.random values */ mbedtls_platform_zeroize( ssl->handshake->randbytes, sizeof( ssl->handshake->randbytes ) ); /* Allocate compression buffer */ #if defined(MBEDTLS_ZLIB_SUPPORT) if( ssl->session_negotiate->compression == MBEDTLS_SSL_COMPRESS_DEFLATE && ssl->compress_buf == NULL ) { MBEDTLS_SSL_DEBUG_MSG( 3, ( "Allocating compression buffer" ) ); ssl->compress_buf = mbedtls_calloc( 1, MBEDTLS_SSL_COMPRESS_BUFFER_LEN ); if( ssl->compress_buf == NULL ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "alloc(%d bytes) failed", MBEDTLS_SSL_COMPRESS_BUFFER_LEN ) ); return( MBEDTLS_ERR_SSL_ALLOC_FAILED ); } } #endif MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= derive keys" ) ); return( 0 ); } #if defined(MBEDTLS_SSL_PROTO_SSL3) void ssl_calc_verify_ssl( const mbedtls_ssl_context *ssl, unsigned char *hash, size_t *hlen ) { mbedtls_md5_context md5; mbedtls_sha1_context sha1; unsigned char pad_1[48]; unsigned char pad_2[48]; MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> calc verify ssl" ) ); mbedtls_md5_init( &md5 ); mbedtls_sha1_init( &sha1 ); mbedtls_md5_clone( &md5, &ssl->handshake->fin_md5 ); mbedtls_sha1_clone( &sha1, &ssl->handshake->fin_sha1 ); memset( pad_1, 0x36, 48 ); memset( pad_2, 0x5C, 48 ); mbedtls_md5_update_ret( &md5, ssl->session_negotiate->master, 48 ); mbedtls_md5_update_ret( &md5, pad_1, 48 ); mbedtls_md5_finish_ret( &md5, hash ); mbedtls_md5_starts_ret( &md5 ); mbedtls_md5_update_ret( &md5, ssl->session_negotiate->master, 48 ); mbedtls_md5_update_ret( &md5, pad_2, 48 ); mbedtls_md5_update_ret( &md5, hash, 16 ); mbedtls_md5_finish_ret( &md5, hash ); mbedtls_sha1_update_ret( &sha1, ssl->session_negotiate->master, 48 ); mbedtls_sha1_update_ret( &sha1, pad_1, 40 ); mbedtls_sha1_finish_ret( &sha1, hash + 16 ); mbedtls_sha1_starts_ret( &sha1 ); mbedtls_sha1_update_ret( &sha1, ssl->session_negotiate->master, 48 ); mbedtls_sha1_update_ret( &sha1, pad_2, 40 ); mbedtls_sha1_update_ret( &sha1, hash + 16, 20 ); mbedtls_sha1_finish_ret( &sha1, hash + 16 ); *hlen = 36; MBEDTLS_SSL_DEBUG_BUF( 3, "calculated verify result", hash, *hlen ); MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= calc verify" ) ); mbedtls_md5_free( &md5 ); mbedtls_sha1_free( &sha1 ); return; } #endif /* MBEDTLS_SSL_PROTO_SSL3 */ #if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) void ssl_calc_verify_tls( const mbedtls_ssl_context *ssl, unsigned char *hash, size_t *hlen ) { mbedtls_md5_context md5; mbedtls_sha1_context sha1; MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> calc verify tls" ) ); mbedtls_md5_init( &md5 ); mbedtls_sha1_init( &sha1 ); mbedtls_md5_clone( &md5, &ssl->handshake->fin_md5 ); mbedtls_sha1_clone( &sha1, &ssl->handshake->fin_sha1 ); mbedtls_md5_finish_ret( &md5, hash ); mbedtls_sha1_finish_ret( &sha1, hash + 16 ); *hlen = 36; MBEDTLS_SSL_DEBUG_BUF( 3, "calculated verify result", hash, *hlen ); MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= calc verify" ) ); mbedtls_md5_free( &md5 ); mbedtls_sha1_free( &sha1 ); return; } #endif /* MBEDTLS_SSL_PROTO_TLS1 || MBEDTLS_SSL_PROTO_TLS1_1 */ #if defined(MBEDTLS_SSL_PROTO_TLS1_2) #if defined(MBEDTLS_SHA256_C) void ssl_calc_verify_tls_sha256( const mbedtls_ssl_context *ssl, unsigned char *hash, size_t *hlen ) { mbedtls_sha256_context sha256; mbedtls_sha256_init( &sha256 ); MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> calc verify sha256" ) ); mbedtls_sha256_clone( &sha256, &ssl->handshake->fin_sha256 ); mbedtls_sha256_finish_ret( &sha256, hash ); *hlen = 32; MBEDTLS_SSL_DEBUG_BUF( 3, "calculated verify result", hash, *hlen ); MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= calc verify" ) ); mbedtls_sha256_free( &sha256 ); return; } #endif /* MBEDTLS_SHA256_C */ #if defined(MBEDTLS_SHA512_C) void ssl_calc_verify_tls_sha384( const mbedtls_ssl_context *ssl, unsigned char *hash, size_t *hlen ) { mbedtls_sha512_context sha512; mbedtls_sha512_init( &sha512 ); MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> calc verify sha384" ) ); mbedtls_sha512_clone( &sha512, &ssl->handshake->fin_sha512 ); mbedtls_sha512_finish_ret( &sha512, hash ); *hlen = 48; MBEDTLS_SSL_DEBUG_BUF( 3, "calculated verify result", hash, *hlen ); MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= calc verify" ) ); mbedtls_sha512_free( &sha512 ); return; } #endif /* MBEDTLS_SHA512_C */ #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */ #if defined(MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED) int mbedtls_ssl_psk_derive_premaster( mbedtls_ssl_context *ssl, mbedtls_key_exchange_type_t key_ex ) { unsigned char *p = ssl->handshake->premaster; unsigned char *end = p + sizeof( ssl->handshake->premaster ); const unsigned char *psk = NULL; size_t psk_len = 0; if( mbedtls_ssl_get_psk( ssl, &psk, &psk_len ) == MBEDTLS_ERR_SSL_PRIVATE_KEY_REQUIRED ) { /* * This should never happen because the existence of a PSK is always * checked before calling this function */ MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); } /* * 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 ); mbedtls_platform_zeroize( p, 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 = MBEDTLS_ERR_THIS_CORRUPTION; 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 = MBEDTLS_ERR_THIS_CORRUPTION; 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_SRV_C) && defined(MBEDTLS_SSL_RENEGOTIATION) static int ssl_write_hello_request( mbedtls_ssl_context *ssl ); #if defined(MBEDTLS_SSL_PROTO_DTLS) int mbedtls_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 */ #if defined(MBEDTLS_X509_CRT_PARSE_C) static void ssl_clear_peer_cert( mbedtls_ssl_session *session ) { #if defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE) if( session->peer_cert != NULL ) { mbedtls_x509_crt_free( session->peer_cert ); mbedtls_free( session->peer_cert ); session->peer_cert = NULL; } #else /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */ if( session->peer_cert_digest != NULL ) { /* Zeroization is not necessary. */ mbedtls_free( session->peer_cert_digest ); session->peer_cert_digest = NULL; session->peer_cert_digest_type = MBEDTLS_MD_NONE; session->peer_cert_digest_len = 0; } #endif /* !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */ } #endif /* MBEDTLS_X509_CRT_PARSE_C */ /* * Handshake functions */ #if !defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED) /* No certificate support -> dummy functions */ int mbedtls_ssl_write_certificate( mbedtls_ssl_context *ssl ) { const mbedtls_ssl_ciphersuite_t *ciphersuite_info = ssl->handshake->ciphersuite_info; MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write certificate" ) ); if( !mbedtls_ssl_ciphersuite_uses_srv_cert( ciphersuite_info ) ) { MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip write certificate" ) ); ssl->state++; return( 0 ); } MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); } int mbedtls_ssl_parse_certificate( mbedtls_ssl_context *ssl ) { const mbedtls_ssl_ciphersuite_t *ciphersuite_info = ssl->handshake->ciphersuite_info; MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse certificate" ) ); if( !mbedtls_ssl_ciphersuite_uses_srv_cert( ciphersuite_info ) ) { 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 /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */ /* Some certificate support -> implement write and parse */ int mbedtls_ssl_write_certificate( mbedtls_ssl_context *ssl ) { int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE; size_t i, n; const mbedtls_x509_crt *crt; const mbedtls_ssl_ciphersuite_t *ciphersuite_info = ssl->handshake->ciphersuite_info; MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write certificate" ) ); if( !mbedtls_ssl_ciphersuite_uses_srv_cert( ciphersuite_info ) ) { 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, %" MBEDTLS_PRINTF_SIZET " > %" MBEDTLS_PRINTF_SIZET, i + 3 + n, (size_t) 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 ); } #if defined(MBEDTLS_SSL_RENEGOTIATION) && defined(MBEDTLS_SSL_CLI_C) #if defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE) static int ssl_check_peer_crt_unchanged( mbedtls_ssl_context *ssl, unsigned char *crt_buf, size_t crt_buf_len ) { mbedtls_x509_crt const * const peer_crt = ssl->session->peer_cert; if( peer_crt == NULL ) return( -1 ); if( peer_crt->raw.len != crt_buf_len ) return( -1 ); return( timingsafe_bcmp( peer_crt->raw.p, crt_buf, peer_crt->raw.len ) ); } #else /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */ static int ssl_check_peer_crt_unchanged( mbedtls_ssl_context *ssl, unsigned char *crt_buf, size_t crt_buf_len ) { int ret = MBEDTLS_ERR_THIS_CORRUPTION; unsigned char const * const peer_cert_digest = ssl->session->peer_cert_digest; mbedtls_md_type_t const peer_cert_digest_type = ssl->session->peer_cert_digest_type; mbedtls_md_info_t const * const digest_info = mbedtls_md_info_from_type( peer_cert_digest_type ); unsigned char tmp_digest[MBEDTLS_SSL_PEER_CERT_DIGEST_MAX_LEN]; size_t digest_len; if( peer_cert_digest == NULL || digest_info == NULL ) return( -1 ); digest_len = mbedtls_md_get_size( digest_info ); if( digest_len > MBEDTLS_SSL_PEER_CERT_DIGEST_MAX_LEN ) return( -1 ); ret = mbedtls_md( digest_info, crt_buf, crt_buf_len, tmp_digest ); if( ret != 0 ) return( -1 ); return( timingsafe_bcmp( tmp_digest, peer_cert_digest, digest_len ) ); } #endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */ #endif /* MBEDTLS_SSL_RENEGOTIATION && MBEDTLS_SSL_CLI_C */ /* * 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, mbedtls_x509_crt *chain ) { int ret = MBEDTLS_ERR_THIS_CORRUPTION; #if defined(MBEDTLS_SSL_RENEGOTIATION) && defined(MBEDTLS_SSL_CLI_C) int crt_cnt=0; #endif size_t i, n; uint8_t alert; if( ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate message" ) ); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE ); return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE ); } if( ssl->in_msg[0] != MBEDTLS_SSL_HS_CERTIFICATE || ssl->in_hslen < mbedtls_ssl_hs_hdr_len( ssl ) + 3 + 3 ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate message" ) ); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR ); return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE ); } i = mbedtls_ssl_hs_hdr_len( ssl ); /* * Same message structure as in mbedtls_ssl_write_certificate() */ n = ( ssl->in_msg[i+1] << 8 ) | ssl->in_msg[i+2]; if( ssl->in_msg[i] != 0 || ssl->in_hslen != n + 3 + mbedtls_ssl_hs_hdr_len( ssl ) ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate message" ) ); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR ); return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE ); } /* Make &ssl->in_msg[i] point to the beginning of the CRT chain. */ i += 3; /* Iterate through and parse the CRTs in the provided chain. */ while( i < ssl->in_hslen ) { /* Check that there's room for the next CRT's length fields. */ if ( i + 3 > ssl->in_hslen ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate message" ) ); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR ); return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE ); } /* In theory, the CRT can be up to 2**24 Bytes, but we don't support * anything beyond 2**16 ~ 64K. */ if( ssl->in_msg[i] != 0 ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate message" ) ); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR ); return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE ); } /* Read length of the next CRT in the chain. */ n = ( (unsigned int) ssl->in_msg[i + 1] << 8 ) | (unsigned int) ssl->in_msg[i + 2]; i += 3; if( n < 128 || i + n > ssl->in_hslen ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate message" ) ); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR ); return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE ); } /* Check if we're handling the first CRT in the chain. */ #if defined(MBEDTLS_SSL_RENEGOTIATION) && defined(MBEDTLS_SSL_CLI_C) if( crt_cnt++ == 0 && ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT && ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS ) { /* During client-side renegotiation, check that the server's * end-CRTs hasn't changed compared to the initial handshake, * mitigating the triple handshake attack. On success, reuse * the original end-CRT instead of parsing it again. */ MBEDTLS_SSL_DEBUG_MSG( 3, ( "Check that peer CRT hasn't changed during renegotiation" ) ); if( ssl_check_peer_crt_unchanged( ssl, &ssl->in_msg[i], n ) != 0 ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "new server cert during renegotiation" ) ); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_ACCESS_DENIED ); return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE ); } /* Now we can safely free the original chain. */ ssl_clear_peer_cert( ssl->session ); } #endif /* MBEDTLS_SSL_RENEGOTIATION && MBEDTLS_SSL_CLI_C */ /* Parse the next certificate in the chain. */ #if defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE) ret = mbedtls_x509_crt_parse_der( chain, ssl->in_msg + i, n ); #else /* If we don't need to store the CRT chain permanently, parse * it in-place from the input buffer instead of making a copy. */ ret = mbedtls_x509_crt_parse_der_nocopy( chain, ssl->in_msg + i, n ); #endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */ 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", chain ); return( 0 ); } #if defined(MBEDTLS_SSL_SRV_C) static int ssl_srv_check_client_no_crt_notification( mbedtls_ssl_context *ssl ) { if( ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT ) return( -1 ); #if defined(MBEDTLS_SSL_PROTO_SSL3) /* * Check if the client sent an empty certificate */ if( 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" ) ); return( 0 ); } return( -1 ); } #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->in_hslen == 3 + mbedtls_ssl_hs_hdr_len( ssl ) && ssl->in_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE && ssl->in_msg[0] == MBEDTLS_SSL_HS_CERTIFICATE && timingsafe_bcmp( ssl->in_msg + mbedtls_ssl_hs_hdr_len( ssl ), "\0\0\0", 3 ) == 0 ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "TLSv1 client has no certificate" ) ); return( 0 ); } return( -1 ); #endif /* MBEDTLS_SSL_PROTO_TLS1 || MBEDTLS_SSL_PROTO_TLS1_1 || \ MBEDTLS_SSL_PROTO_TLS1_2 */ } #endif /* MBEDTLS_SSL_SRV_C */ /* Check if a certificate message is expected. * Return either * - SSL_CERTIFICATE_EXPECTED, or * - SSL_CERTIFICATE_SKIP * indicating whether a Certificate message is expected or not. */ #define SSL_CERTIFICATE_EXPECTED 0 #define SSL_CERTIFICATE_SKIP 1 static int ssl_parse_certificate_coordinate( mbedtls_ssl_context *ssl, int authmode ) { const mbedtls_ssl_ciphersuite_t *ciphersuite_info = ssl->handshake->ciphersuite_info; if( !mbedtls_ssl_ciphersuite_uses_srv_cert( ciphersuite_info ) ) return( SSL_CERTIFICATE_SKIP ); #if defined(MBEDTLS_SSL_SRV_C) if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER ) { if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK ) return( SSL_CERTIFICATE_SKIP ); if( authmode == MBEDTLS_SSL_VERIFY_NONE ) { ssl->session_negotiate->verify_result = MBEDTLS_X509_BADCERT_SKIP_VERIFY; return( SSL_CERTIFICATE_SKIP ); } } #else ((void) authmode); #endif /* MBEDTLS_SSL_SRV_C */ return( SSL_CERTIFICATE_EXPECTED ); } static int ssl_parse_certificate_verify( mbedtls_ssl_context *ssl, int authmode, mbedtls_x509_crt *chain, void *rs_ctx ) { int ret = 0; const mbedtls_ssl_ciphersuite_t *ciphersuite_info = ssl->handshake->ciphersuite_info; int have_ca_chain = 0; int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *); void *p_vrfy; if( authmode == MBEDTLS_SSL_VERIFY_NONE ) return( 0 ); if( ssl->f_vrfy != NULL ) { MBEDTLS_SSL_DEBUG_MSG( 3, ( "Use context-specific verification callback" ) ); f_vrfy = ssl->f_vrfy; p_vrfy = ssl->p_vrfy; } else { MBEDTLS_SSL_DEBUG_MSG( 3, ( "Use configuration-specific verification callback" ) ); f_vrfy = ssl->conf->f_vrfy; p_vrfy = ssl->conf->p_vrfy; } /* * Main check: verify certificate */ #if defined(MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK) if( ssl->conf->f_ca_cb != NULL ) { ((void) rs_ctx); have_ca_chain = 1; MBEDTLS_SSL_DEBUG_MSG( 3, ( "use CA callback for X.509 CRT verification" ) ); ret = mbedtls_x509_crt_verify_with_ca_cb( chain, ssl->conf->f_ca_cb, ssl->conf->p_ca_cb, ssl->conf->cert_profile, ssl->hostname, &ssl->session_negotiate->verify_result, f_vrfy, p_vrfy ); } else #endif /* MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK */ { 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; } if( ca_chain != NULL ) have_ca_chain = 1; ret = mbedtls_x509_crt_verify_restartable( chain, ca_chain, ca_crl, ssl->conf->cert_profile, ssl->hostname, &ssl->session_negotiate->verify_result, f_vrfy, p_vrfy, rs_ctx ); } if( ret != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "x509_verify_cert", ret ); } #if defined(MBEDTLS_SSL_ECP_RESTARTABLE_ENABLED) 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 = &chain->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( chain, 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( have_ca_chain == 0 && 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 %08x", (unsigned int) ssl->session_negotiate->verify_result ) ); } else { MBEDTLS_SSL_DEBUG_MSG( 3, ( "Certificate verification flags clear" ) ); } #endif /* MBEDTLS_DEBUG_C */ return( ret ); } #if !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE) static int ssl_remember_peer_crt_digest( mbedtls_ssl_context *ssl, unsigned char *start, size_t len ) { int ret = MBEDTLS_ERR_THIS_CORRUPTION; /* Remember digest of the peer's end-CRT. */ ssl->session_negotiate->peer_cert_digest = mbedtls_calloc( 1, MBEDTLS_SSL_PEER_CERT_DIGEST_DFL_LEN ); if( ssl->session_negotiate->peer_cert_digest == NULL ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "alloc(%d bytes) failed", MBEDTLS_SSL_PEER_CERT_DIGEST_DFL_LEN ) ); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_INTERNAL_ERROR ); return( MBEDTLS_ERR_SSL_ALLOC_FAILED ); } ret = mbedtls_md( mbedtls_md_info_from_type( MBEDTLS_SSL_PEER_CERT_DIGEST_DFL_TYPE ), start, len, ssl->session_negotiate->peer_cert_digest ); ssl->session_negotiate->peer_cert_digest_type = MBEDTLS_SSL_PEER_CERT_DIGEST_DFL_TYPE; ssl->session_negotiate->peer_cert_digest_len = MBEDTLS_SSL_PEER_CERT_DIGEST_DFL_LEN; return( ret ); } static int ssl_remember_peer_pubkey( mbedtls_ssl_context *ssl, unsigned char *start, size_t len ) { unsigned char *end = start + len; int ret = MBEDTLS_ERR_THIS_CORRUPTION; /* Make a copy of the peer's raw public key. */ mbedtls_pk_init( &ssl->handshake->peer_pubkey ); ret = mbedtls_pk_parse_subpubkey( &start, end, &ssl->handshake->peer_pubkey ); if( ret != 0 ) { /* We should have parsed the public key before. */ return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); } return( 0 ); } #endif /* !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */ int mbedtls_ssl_parse_certificate( mbedtls_ssl_context *ssl ) { int ret = 0; int crt_expected; #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_x509_crt *chain = NULL; MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse certificate" ) ); crt_expected = ssl_parse_certificate_coordinate( ssl, authmode ); if( crt_expected == SSL_CERTIFICATE_SKIP ) { MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate" ) ); goto exit; } #if defined(MBEDTLS_SSL_ECP_RESTARTABLE_ENABLED) if( ssl->handshake->ecrs_enabled && ssl->handshake->ecrs_state == ssl_ecrs_crt_verify ) { chain = ssl->handshake->ecrs_peer_cert; ssl->handshake->ecrs_peer_cert = NULL; 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 ); goto exit; } #if defined(MBEDTLS_SSL_SRV_C) if( ssl_srv_check_client_no_crt_notification( ssl ) == 0 ) { ssl->session_negotiate->verify_result = MBEDTLS_X509_BADCERT_MISSING; if( authmode != MBEDTLS_SSL_VERIFY_OPTIONAL ) ret = MBEDTLS_ERR_SSL_NO_CLIENT_CERTIFICATE; goto exit; } #endif /* MBEDTLS_SSL_SRV_C */ /* Clear existing peer CRT structure in case we tried to * reuse a session but it failed, and allocate a new one. */ ssl_clear_peer_cert( ssl->session_negotiate ); chain = mbedtls_calloc( 1, sizeof( mbedtls_x509_crt ) ); if( chain == NULL ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "alloc(%" MBEDTLS_PRINTF_SIZET " bytes) failed", sizeof( mbedtls_x509_crt ) ) ); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_INTERNAL_ERROR ); ret = MBEDTLS_ERR_SSL_ALLOC_FAILED; goto exit; } mbedtls_x509_crt_init( chain ); ret = ssl_parse_certificate_chain( ssl, chain ); if( ret != 0 ) goto exit; #if defined(MBEDTLS_SSL_ECP_RESTARTABLE_ENABLED) 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 ret = ssl_parse_certificate_verify( ssl, authmode, chain, rs_ctx ); if( ret != 0 ) goto exit; #if !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE) { unsigned char *crt_start, *pk_start; size_t crt_len, pk_len; /* We parse the CRT chain without copying, so * these pointers point into the input buffer, * and are hence still valid after freeing the * CRT chain. */ crt_start = chain->raw.p; crt_len = chain->raw.len; pk_start = chain->pk_raw.p; pk_len = chain->pk_raw.len; /* Free the CRT structures before computing * digest and copying the peer's public key. */ mbedtls_x509_crt_free( chain ); mbedtls_free( chain ); chain = NULL; ret = ssl_remember_peer_crt_digest( ssl, crt_start, crt_len ); if( ret != 0 ) goto exit; ret = ssl_remember_peer_pubkey( ssl, pk_start, pk_len ); if( ret != 0 ) goto exit; } #else /* !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */ /* Pass ownership to session structure. */ ssl->session_negotiate->peer_cert = chain; chain = NULL; #endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */ MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse certificate" ) ); exit: if( ret == 0 ) ssl->state++; #if defined(MBEDTLS_SSL_ECP_RESTARTABLE_ENABLED) if( ret == MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS ) { ssl->handshake->ecrs_peer_cert = chain; chain = NULL; } #endif if( chain != NULL ) { mbedtls_x509_crt_free( chain ); mbedtls_free( chain ); } return( ret ); } #endif /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */ 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; unsigned char padbuf[32]; mbedtls_sha256_context sha256; mbedtls_ssl_session *session = ssl->session_negotiate; if( !session ) session = ssl->session; sender = ( from == MBEDTLS_SSL_IS_CLIENT ) ? "client finished" : "server finished"; 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 mbedtls_sha256_finish_ret( &sha256, padbuf ); mbedtls_sha256_free( &sha256 ); ssl->handshake->tls_prf( session->master, 48, sender, padbuf, 32, buf, len ); MBEDTLS_SSL_DEBUG_BUF( 3, "calc finished result", buf, len ); mbedtls_platform_zeroize( padbuf, sizeof( padbuf ) ); MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= calc finished" ) ); } #endif /* MBEDTLS_SHA256_C */ #if defined(MBEDTLS_SHA512_C) typedef int (*finish_sha384_t)(mbedtls_sha512_context*, unsigned char*); static void ssl_calc_finished_tls_sha384( mbedtls_ssl_context *ssl, unsigned char *buf, int from ) { int len = 12; const char *sender; unsigned char padbuf[64]; mbedtls_sha512_context sha512; mbedtls_ssl_session *session = ssl->session_negotiate; if( !session ) session = ssl->session; sender = ( from == MBEDTLS_SSL_IS_CLIENT ) ? "client finished" : "server finished"; 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 ) ); /* * For SHA-384, we can save 16 bytes by keeping padbuf 48 bytes long. * However, to avoid stringop-overflow warning in gcc, we have to cast * mbedtls_sha512_finish_ret(). */ finish_sha384_t finish = (finish_sha384_t)mbedtls_sha512_finish_ret; finish( &sha512, padbuf ); mbedtls_sha512_free( &sha512 ); #endif ssl->handshake->tls_prf( session->master, 48, sender, padbuf, 48, buf, len ); MBEDTLS_SSL_DEBUG_BUF( 3, "calc finished result", buf, len ); mbedtls_platform_zeroize( padbuf, sizeof( padbuf ) ); MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= calc finished" ) ); } #endif /* MBEDTLS_SHA512_C */ #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */ void mbedtls_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 */ mbedtls_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 mbedtls_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" ) ); mbedtls_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 */ mbedtls_platform_zeroize( ssl->cur_out_ctr + 2, 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 */ mbedtls_platform_zeroize( ssl->cur_out_ctr, 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 = MBEDTLS_ERR_THIS_CORRUPTION; 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( timingsafe_bcmp( 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 ) { mbedtls_platform_zeroize( handshake, 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_ENABLED) mbedtls_x509_crt_restart_init( &handshake->ecrs_ctx ); #endif #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION) handshake->sni_authmode = MBEDTLS_SSL_VERIFY_UNSET; #endif #if defined(MBEDTLS_X509_CRT_PARSE_C) && \ !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE) mbedtls_pk_init( &handshake->peer_pubkey ); #endif } void mbedtls_ssl_transform_init( mbedtls_ssl_transform *transform ) { mbedtls_platform_zeroize( transform, sizeof(mbedtls_ssl_transform) ); mbedtls_cipher_init( &transform->cipher_ctx_enc ); mbedtls_cipher_init( &transform->cipher_ctx_dec ); #if defined(MBEDTLS_SSL_SOME_MODES_USE_MAC) mbedtls_md_init( &transform->md_ctx_enc ); mbedtls_md_init( &transform->md_ctx_dec ); #endif } /** * \brief Initialize SSL session structure * * \param session SSL session */ void mbedtls_ssl_session_init( mbedtls_ssl_session *session ) { mbedtls_platform_zeroize( session, sizeof(mbedtls_ssl_session) ); } static int ssl_handshake_init( mbedtls_ssl_context *ssl ) { /* Clear old handshake information if present */ ssl->curve = 0; 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) ); } #if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH) /* If the buffers are too small - reallocate */ handle_buffer_resizing( ssl, 0, MBEDTLS_SSL_IN_BUFFER_LEN, MBEDTLS_SSL_OUT_BUFFER_LEN ); #endif /* All pointers should exist and can be directly freed without issue */ if( ssl->handshake == NULL || ssl->transform_negotiate == NULL || ssl->session_negotiate == NULL ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "alloc() of ssl sub-contexts failed" ) ); mbedtls_free( ssl->handshake ); mbedtls_free( ssl->transform_negotiate ); mbedtls_free( ssl->session_negotiate ); ssl->handshake = NULL; ssl->transform_negotiate = NULL; ssl->session_negotiate = NULL; return( MBEDTLS_ERR_SSL_ALLOC_FAILED ); } /* Initialize structures */ mbedtls_ssl_session_init( ssl->session_negotiate ); mbedtls_ssl_transform_init( ssl->transform_negotiate ); ssl_handshake_params_init( ssl->handshake ); #if defined(MBEDTLS_SSL_PROTO_DTLS) if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) { ssl->handshake->alt_transform_out = ssl->transform_out; if( ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT ) ssl->handshake->retransmit_state = MBEDTLS_SSL_RETRANS_PREPARING; else ssl->handshake->retransmit_state = MBEDTLS_SSL_RETRANS_WAITING; mbedtls_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 */ /** * \brief Initialize an SSL context * Just makes the context ready for mbedtls_ssl_setup() or * mbedtls_ssl_free() * * \param ssl SSL context */ void mbedtls_ssl_init( mbedtls_ssl_context *ssl ) { mbedtls_platform_zeroize( ssl, sizeof( mbedtls_ssl_context ) ); } /** * \brief Set up an SSL context for use * * \note No copy of the configuration context is made, it can be * shared by many mbedtls_ssl_context structures. * * \warning The conf structure will be accessed during the session. * It must not be modified or freed as long as the session * is active. * * \warning This function must be called exactly once per context. * Calling mbedtls_ssl_setup again is not supported, even * if no session is active. * * \param ssl SSL context * \param conf SSL configuration to use * * \return 0 if successful, or MBEDTLS_ERR_SSL_ALLOC_FAILED if * memory allocation failed */ int mbedtls_ssl_setup( mbedtls_ssl_context *ssl, const mbedtls_ssl_config *conf ) { int ret = MBEDTLS_ERR_THIS_CORRUPTION; size_t in_buf_len = MBEDTLS_SSL_IN_BUFFER_LEN; size_t out_buf_len = MBEDTLS_SSL_OUT_BUFFER_LEN; ssl->conf = conf; /* * Prepare base structures */ /* Set to NULL in case of an error condition */ ssl->out_buf = NULL; #if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH) ssl->in_buf_len = in_buf_len; #endif ssl->in_buf = mbedtls_calloc( 1, in_buf_len ); if( ssl->in_buf == NULL ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "alloc(%" MBEDTLS_PRINTF_SIZET " bytes) failed", in_buf_len ) ); ret = MBEDTLS_ERR_SSL_ALLOC_FAILED; goto error; } #if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH) ssl->out_buf_len = out_buf_len; #endif ssl->out_buf = mbedtls_calloc( 1, out_buf_len ); if( ssl->out_buf == NULL ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "alloc(%" MBEDTLS_PRINTF_SIZET " bytes) failed", out_buf_len ) ); ret = MBEDTLS_ERR_SSL_ALLOC_FAILED; goto error; } mbedtls_ssl_reset_in_out_pointers( ssl ); #if defined(MBEDTLS_SSL_DTLS_SRTP) mbedtls_platform_zeroize( &ssl->dtls_srtp_info, sizeof(ssl->dtls_srtp_info) ); #endif 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; #if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH) ssl->in_buf_len = 0; ssl->out_buf_len = 0; #endif 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.) */ int mbedtls_ssl_session_reset_int( mbedtls_ssl_context *ssl, int partial ) { int ret = MBEDTLS_ERR_THIS_CORRUPTION; #if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH) size_t in_buf_len = ssl->in_buf_len; size_t out_buf_len = ssl->out_buf_len; #else size_t in_buf_len = MBEDTLS_SSL_IN_BUFFER_LEN; size_t out_buf_len = MBEDTLS_SSL_OUT_BUFFER_LEN; #endif #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 */ mbedtls_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; mbedtls_platform_zeroize( ssl->own_verify_data, MBEDTLS_SSL_VERIFY_DATA_MAX_LEN ); mbedtls_platform_zeroize( ssl->peer_verify_data, MBEDTLS_SSL_VERIFY_DATA_MAX_LEN ); #endif ssl->secure_renegotiation = MBEDTLS_SSL_LEGACY_RENEGOTIATION; ssl->in_offt = NULL; mbedtls_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) mbedtls_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 mbedtls_platform_zeroize( ssl->cur_out_ctr, sizeof( ssl->cur_out_ctr ) ); ssl->transform_in = NULL; ssl->transform_out = NULL; ssl->session_in = NULL; ssl->session_out = NULL; mbedtls_platform_zeroize( ssl->out_buf, out_buf_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; mbedtls_platform_zeroize( ssl->in_buf, in_buf_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 ); } /** * \brief Reset an already initialized SSL context for re-use * while retaining application-set variables, function * pointers and data. * * \param ssl SSL context * \return 0 if successful, or MBEDTLS_ERR_SSL_ALLOC_FAILED, MBEDTLS_ERR_SSL_HW_ACCEL_FAILED or * MBEDTLS_ERR_SSL_COMPRESSION_FAILED */ int mbedtls_ssl_session_reset( mbedtls_ssl_context *ssl ) { return( mbedtls_ssl_session_reset_int( ssl, 0 ) ); } /** * \brief Set the current endpoint type * * \param conf SSL configuration * \param endpoint must be MBEDTLS_SSL_IS_CLIENT or MBEDTLS_SSL_IS_SERVER */ void mbedtls_ssl_conf_endpoint( mbedtls_ssl_config *conf, int endpoint ) { conf->endpoint = endpoint; } /** * \brief Set the transport type (TLS or DTLS). * Default: TLS * * \note For DTLS, you must either provide a recv callback that * doesn't block, or one that handles timeouts, see * \c mbedtls_ssl_set_bio(). You also need to provide timer * callbacks with \c mbedtls_ssl_set_timer_cb(). * * \param conf SSL configuration * \param transport transport type: * MBEDTLS_SSL_TRANSPORT_STREAM for TLS, * MBEDTLS_SSL_TRANSPORT_DATAGRAM for DTLS. */ void mbedtls_ssl_conf_transport( mbedtls_ssl_config *conf, int transport ) { conf->transport = transport; } #if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY) /** * \brief Enable or disable anti-replay protection for DTLS. * (DTLS only, no effect on TLS.) * Default: enabled. * * \param conf SSL configuration * \param mode MBEDTLS_SSL_ANTI_REPLAY_ENABLED or MBEDTLS_SSL_ANTI_REPLAY_DISABLED. * * \warning Disabling this is a security risk unless the application * protocol handles duplicated packets in a safe way. You * should not disable this without careful consideration. * However, if your application already detects duplicated * packets and needs information about them to adjust its * transmission strategy, then you'll want to disable this. */ 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) /** * \brief Set a limit on the number of records with a bad MAC * before terminating the connection. * (DTLS only, no effect on TLS.) * Default: 0 (disabled). * * \param conf SSL configuration * \param limit Limit, or 0 to disable. * * \note If the limit is N, then the connection is terminated when * the Nth non-authentic record is seen. * * \note Records with an invalid header are not counted, only the * ones going through the authentication-decryption phase. * * \note This is a security trade-off related to the fact that it's * often relatively easy for an active attacker ot inject UDP * datagrams. On one hand, setting a low limit here makes it * easier for such an attacker to forcibly terminated a * connection. On the other hand, a high limit or no limit * might make us waste resources checking authentication on * many bogus packets. */ void mbedtls_ssl_conf_dtls_badmac_limit( mbedtls_ssl_config *conf, unsigned limit ) { conf->badmac_limit = limit; } #endif #if defined(MBEDTLS_SSL_PROTO_DTLS) /** * \brief Allow or disallow packing of multiple handshake records * within a single datagram. * * \param ssl The SSL context to configure. * \param allow_packing This determines whether datagram packing may * be used or not. A value of \c 0 means that every * record will be sent in a separate datagram; a * value of \c 1 means that, if space permits, * multiple handshake messages (including CCS) belonging to * a single flight may be packed within a single datagram. * * \note This is enabled by default and should only be disabled * for test purposes, or if datagram packing causes * interoperability issues with peers that don't support it. * * \note Allowing datagram packing reduces the network load since * there's less overhead if multiple messages share the same * datagram. Also, it increases the handshake efficiency * since messages belonging to a single datagram will not * be reordered in transit, and so future message buffering * or flight retransmission (if no buffering is used) as * means to deal with reordering are needed less frequently. * * \note Application records are not affected by this option and * are currently always sent in separate datagrams. * */ void mbedtls_ssl_set_datagram_packing( mbedtls_ssl_context *ssl, unsigned allow_packing ) { ssl->disable_datagram_packing = !allow_packing; } /** * \brief Set retransmit timeout values for the DTLS handshake. * (DTLS only, no effect on TLS.) * * \param conf SSL configuration * \param min Initial timeout value in milliseconds. * Default: 1000 (1 second). * \param max Maximum timeout value in milliseconds. * Default: 60000 (60 seconds). * * \note Default values are from RFC 6347 section 4.2.4.1. * * \note The 'min' value should typically be slightly above the * expected round-trip time to your peer, plus whatever time * it takes for the peer to process the message. For example, * if your RTT is about 600ms and you peer needs up to 1s to * do the cryptographic operations in the handshake, then you * should set 'min' slightly above 1600. Lower values of 'min' * might cause spurious resends which waste network resources, * while larger value of 'min' will increase overall latency * on unreliable network links. * * \note The more unreliable your network connection is, the larger * your max / min ratio needs to be in order to achieve * reliable handshakes. * * \note Messages are retransmitted up to log2(ceil(max/min)) times. * For example, if min = 1s and max = 5s, the retransmit plan * goes: send ... 1s -> resend ... 2s -> resend ... 4s -> * resend ... 5s -> give up and return a timeout error. */ 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 /* MBEDTLS_SSL_PROTO_DTLS */ /** * \brief Set the certificate verification mode * Default: NONE on server, REQUIRED on client * * \param conf SSL configuration * \param authmode can be: * * MBEDTLS_SSL_VERIFY_NONE: peer certificate is not checked * (default on server) * (insecure on client) * * MBEDTLS_SSL_VERIFY_OPTIONAL: peer certificate is checked, however the * handshake continues even if verification failed; * mbedtls_ssl_get_verify_result() can be called after the * handshake is complete. * * MBEDTLS_SSL_VERIFY_REQUIRED: peer *must* present a valid certificate, * handshake is aborted if verification failed. * (default on client) * * \note On client, MBEDTLS_SSL_VERIFY_REQUIRED is the recommended mode. * With MBEDTLS_SSL_VERIFY_OPTIONAL, the user needs to call mbedtls_ssl_get_verify_result() at * the right time(s), which may not be obvious, while REQUIRED always perform * the verification as soon as possible. For example, REQUIRED was protecting * against the "triple handshake" attack even before it was found. */ void mbedtls_ssl_conf_authmode( mbedtls_ssl_config *conf, int authmode ) { conf->authmode = authmode; } #if defined(MBEDTLS_X509_CRT_PARSE_C) /** * \brief Set the verification callback (Optional). * * If set, the provided verify callback is called for each * certificate in the peer's CRT chain, including the trusted * root. For more information, please see the documentation of * \c mbedtls_x509_crt_verify(). * * \note For per context callbacks and contexts, please use * mbedtls_ssl_set_verify() instead. * * \param conf The SSL configuration to use. * \param f_vrfy The verification callback to use during CRT verification. * \param p_vrfy The opaque context to be passed to the callback. */ 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 */ /** * \brief Set the random number generator callback * * \param conf SSL configuration * \param f_rng RNG function * \param p_rng RNG parameter */ 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; } /** * \brief Set the debug callback * * The callback has the following argument: * void * opaque context for the callback * int debug level * const char * file name * int line number * const char * message * * \param conf SSL configuration * \param f_dbg debug function * \param p_dbg debug parameter */ 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; } /** * \brief Set the underlying BIO callbacks for write, read and * read-with-timeout. * * \param ssl SSL context * \param p_bio parameter (context) shared by BIO callbacks * \param f_send write callback * \param f_recv read callback * \param f_recv_timeout blocking read callback with timeout. * * \note One of f_recv or f_recv_timeout can be NULL, in which case * the other is used. If both are non-NULL, f_recv_timeout is * used and f_recv is ignored (as if it were NULL). * * \note The two most common use cases are: * - non-blocking I/O, f_recv != NULL, f_recv_timeout == NULL * - blocking I/O, f_recv == NULL, f_recv_timout != NULL * * \note For DTLS, you need to provide either a non-NULL * f_recv_timeout callback, or a f_recv that doesn't block. * * \note See the documentations of \c mbedtls_ssl_send_t, * \c mbedtls_ssl_recv_t and \c mbedtls_ssl_recv_timeout_t for * the conventions those callbacks must follow. * * \note On some platforms, net_sockets.c provides * \c mbedtls_net_send(), \c mbedtls_net_recv() and * \c mbedtls_net_recv_timeout() that are suitable to be used * here. */ 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) /** * \brief Set the Maximum Tranport Unit (MTU). * Special value: 0 means unset (no limit). * This represents the maximum size of a datagram payload * handled by the transport layer (usually UDP) as determined * by the network link and stack. In practice, this controls * the maximum size datagram the DTLS layer will pass to the * \c f_send() callback set using \c mbedtls_ssl_set_bio(). * * \note The limit on datagram size is converted to a limit on * record payload by subtracting the current overhead of * encapsulation and encryption/authentication if any. * * \note This can be called at any point during the connection, for * example when a Path Maximum Transfer Unit (PMTU) * estimate becomes available from other sources, * such as lower (or higher) protocol layers. * * \note This setting only controls the size of the packets we send, * and does not restrict the size of the datagrams we're * willing to receive. Client-side, you can request the * server to use smaller records with \c * mbedtls_ssl_conf_max_frag_len(). * * \note If both a MTU and a maximum fragment length have been * configured (or negotiated with the peer), the resulting * lower limit on record payload (see first note) is used. * * \note This can only be used to decrease the maximum size * of datagrams (hence records, see first note) sent. It * cannot be used to increase the maximum size of records over * the limit set by #MBEDTLS_SSL_OUT_CONTENT_LEN. * * \note Values lower than the current record layer expansion will * result in an error when trying to send data. * * \note Using record compression together with a non-zero MTU value * will result in an error when trying to send data. * * \param ssl SSL context * \param mtu Value of the path MTU in bytes */ void mbedtls_ssl_set_mtu( mbedtls_ssl_context *ssl, uint16_t mtu ) { ssl->mtu = mtu; } #endif /** * \brief Set the timeout period for mbedtls_ssl_read() * (Default: no timeout.) * * \param conf SSL configuration context * \param timeout Timeout value in milliseconds. * Use 0 for no timeout (default). * * \note With blocking I/O, this will only work if a non-NULL * \c f_recv_timeout was set with \c mbedtls_ssl_set_bio(). * With non-blocking I/O, this will only work if timer * callbacks were set with \c mbedtls_ssl_set_timer_cb(). * * \note With non-blocking I/O, you may also skip this function * altogether and handle timeouts at the application layer. */ void mbedtls_ssl_conf_read_timeout( mbedtls_ssl_config *conf, uint32_t timeout ) { conf->read_timeout = timeout; } /** * \brief Set the timer callbacks (Mandatory for DTLS.) * * \param ssl SSL context * \param p_timer parameter (context) shared by timer callbacks * \param f_set_timer set timer callback * \param f_get_timer get timer callback. Must return: * * \note See the documentation of \c mbedtls_ssl_set_timer_t and * \c mbedtls_ssl_get_timer_t for the conventions this pair of * callbacks must follow. * * \note On some platforms, timing.c provides * \c mbedtls_timing_set_delay() and * \c mbedtls_timing_get_delay() that are suitable for using * here, except if using an event-driven style. * * \note See also the "DTLS tutorial" article in our knowledge base. * https://tls.mbed.org/kb/how-to/dtls-tutorial */ 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 */ mbedtls_ssl_set_timer( ssl, 0 ); } #if defined(MBEDTLS_SSL_SRV_C) /** * \brief Set the session cache callbacks (server-side only) * If not set, no session resuming is done (except if session * tickets are enabled too). * * The session cache has the responsibility to check for stale * entries based on timeout. See RFC 5246 for recommendations. * * Warning: session.peer_cert is cleared by the SSL/TLS layer on * connection shutdown, so do not cache the pointer! Either set * it to NULL or make a full copy of the certificate. * * The get callback is called once during the initial handshake * to enable session resuming. The get function has the * following parameters: (void *parameter, mbedtls_ssl_session *session) * If a valid entry is found, it should fill the master of * the session object with the cached values and return 0, * return 1 otherwise. Optionally peer_cert can be set as well * if it is properly present in cache entry. * * The set callback is called once during the initial handshake * to enable session resuming after the entire handshake has * been finished. The set function has the following parameters: * (void *parameter, const mbedtls_ssl_session *session). The function * should create a cache entry for future retrieval based on * the data in the session structure and should keep in mind * that the mbedtls_ssl_session object presented (and all its referenced * data) is cleared by the SSL/TLS layer when the connection is * terminated. It is recommended to add metadata to determine if * an entry is still valid in the future. Return 0 if * successfully cached, return 1 otherwise. * * \param conf SSL configuration * \param p_cache parmater (context) for both callbacks * \param f_get_cache session get callback * \param f_set_cache session set callback */ 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) /** * \brief Request resumption of session (client-side only) * Session data is copied from presented session structure. * * \param ssl SSL context * \param session session context * * \return 0 if successful, * MBEDTLS_ERR_SSL_ALLOC_FAILED if memory allocation failed, * MBEDTLS_ERR_SSL_BAD_INPUT_DATA if used server-side or * arguments are otherwise invalid * * \sa mbedtls_ssl_get_session() */ int mbedtls_ssl_set_session( mbedtls_ssl_context *ssl, const mbedtls_ssl_session *session ) { int ret = MBEDTLS_ERR_THIS_CORRUPTION; 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 = mbedtls_ssl_session_copy( ssl->session_negotiate, session ) ) != 0 ) return( ret ); ssl->handshake->resume = 1; return( 0 ); } #endif /* MBEDTLS_SSL_CLI_C */ /** * \brief Set the list of allowed ciphersuites and the preference * order. First in the list has the highest preference. * (Overrides all version-specific lists) * * The ciphersuites array is not copied, and must remain * valid for the lifetime of the ssl_config. * * Note: The server uses its own preferences * over the preference of the client unless * MBEDTLS_SSL_SRV_RESPECT_CLIENT_PREFERENCE is defined! * * \param conf SSL configuration * \param ciphersuites 0-terminated list of allowed ciphersuites */ void mbedtls_ssl_conf_ciphersuites( mbedtls_ssl_config *conf, const uint16_t *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; } /** * \brief Set the list of allowed ciphersuites and the * preference order for a specific version of the protocol. * (Only useful on the server side) * * The ciphersuites array is not copied, and must remain * valid for the lifetime of the ssl_config. * * \param conf SSL configuration * \param ciphersuites 0-terminated list of allowed ciphersuites * \param major Major version number (only MBEDTLS_SSL_MAJOR_VERSION_3 * supported) * \param minor Minor version number (MBEDTLS_SSL_MINOR_VERSION_0, * MBEDTLS_SSL_MINOR_VERSION_1 and MBEDTLS_SSL_MINOR_VERSION_2, * MBEDTLS_SSL_MINOR_VERSION_3 supported) * * \note With DTLS, use MBEDTLS_SSL_MINOR_VERSION_2 for DTLS 1.0 * and MBEDTLS_SSL_MINOR_VERSION_3 for DTLS 1.2 */ void mbedtls_ssl_conf_ciphersuites_for_version( mbedtls_ssl_config *conf, const uint16_t *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) /** * \brief Set the X.509 security profile used for verification * * \note The restrictions are enforced for all certificates in the * chain. However, signatures in the handshake are not covered * by this setting but by \b mbedtls_ssl_conf_sig_hashes(). * * \param conf SSL configuration * \param profile Profile to use */ 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 ); } /** * \brief Set own certificate chain and private key * * \note own_cert should contain in order from the bottom up your * certificate chain. The top certificate (self-signed) * can be omitted. * * \note On server, this function can be called multiple times to * provision more than one cert/key pair (eg one ECDSA, one * RSA with SHA-256, one RSA with SHA-1). An adequate * certificate will be selected according to the client's * advertised capabilities. In case multiple certificates are * adequate, preference is given to the one set by the first * call to this function, then second, etc. * * \note On client, only the first call has any effect. That is, * only one client certificate can be provisioned. The * server's preferences in its CertficateRequest message will * be ignored and our only cert will be sent regardless of * whether it matches those preferences - the server can then * decide what it wants to do with it. * * \note The provided \p pk_key needs to match the public key in the * first certificate in \p own_cert, or all handshakes using * that certificate will fail. It is your responsibility * to ensure that; this function will not perform any check. * You may use mbedtls_pk_check_pair() in order to perform * this check yourself, but be aware that this function can * be computationally expensive on some key types. * * \param conf SSL configuration * \param own_cert own public certificate chain * \param pk_key own private key * * \return 0 on success or MBEDTLS_ERR_SSL_ALLOC_FAILED */ 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 ) ); } /** * \brief Set the data required to verify peer certificate * * \note See \c mbedtls_x509_crt_verify() for notes regarding the * parameters ca_chain (maps to trust_ca for that function) * and ca_crl. * * \param conf SSL configuration * \param ca_chain trusted CA chain (meaning all fully trusted top-level CAs) * \param ca_crl trusted CA CRLs */ 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; #if defined(MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK) /* mbedtls_ssl_conf_ca_chain() and mbedtls_ssl_conf_ca_cb() * cannot be used together. */ conf->f_ca_cb = NULL; conf->p_ca_cb = NULL; #endif /* MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK */ } #if defined(MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK) /** * \brief Set the trusted certificate callback. * * This API allows to register the set of trusted certificates * through a callback, instead of a linked list as configured * by mbedtls_ssl_conf_ca_chain(). * * This is useful for example in contexts where a large number * of CAs are used, and the inefficiency of maintaining them * in a linked list cannot be tolerated. It is also useful when * the set of trusted CAs needs to be modified frequently. * * See the documentation of `mbedtls_x509_crt_ca_cb_t` for * more information. * * \param conf The SSL configuration to register the callback with. * \param f_ca_cb The trusted certificate callback to use when verifying * certificate chains. * \param p_ca_cb The context to be passed to \p f_ca_cb (for example, * a reference to a trusted CA database). * * \note This API is incompatible with mbedtls_ssl_conf_ca_chain(): * Any call to this function overwrites the values set through * earlier calls to mbedtls_ssl_conf_ca_chain() or * mbedtls_ssl_conf_ca_cb(). * * \note This API is incompatible with CA indication in * CertificateRequest messages: A server-side SSL context which * is bound to an SSL configuration that uses a CA callback * configured via mbedtls_ssl_conf_ca_cb(), and which requires * client authentication, will send an empty CA list in the * corresponding CertificateRequest message. * * \note This API is incompatible with mbedtls_ssl_set_hs_ca_chain(): * If an SSL context is bound to an SSL configuration which uses * CA callbacks configured via mbedtls_ssl_conf_ca_cb(), then * calls to mbedtls_ssl_set_hs_ca_chain() have no effect. * * \note The use of this API disables the use of restartable ECC * during X.509 CRT signature verification (but doesn't affect * other uses). * * \warning This API is incompatible with the use of CRLs. Any call to * mbedtls_ssl_conf_ca_cb() unsets CRLs configured through * earlier calls to mbedtls_ssl_conf_ca_chain(). * * \warning In multi-threaded environments, the callback \p f_ca_cb * must be thread-safe, and it is the user's responsibility * to guarantee this (for example through a mutex * contained in the callback context pointed to by \p p_ca_cb). */ void mbedtls_ssl_conf_ca_cb( mbedtls_ssl_config *conf, mbedtls_x509_crt_ca_cb_t f_ca_cb, void *p_ca_cb ) { conf->f_ca_cb = f_ca_cb; conf->p_ca_cb = p_ca_cb; /* mbedtls_ssl_conf_ca_chain() and mbedtls_ssl_conf_ca_cb() * cannot be used together. */ conf->ca_chain = NULL; conf->ca_crl = NULL; } #endif /* MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK */ #endif /* MBEDTLS_X509_CRT_PARSE_C */ #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION) /** * \brief Set own certificate and key for the current handshake * * \note Same as \c mbedtls_ssl_conf_own_cert() but for use within * the SNI callback. * * \param ssl SSL context * \param own_cert own public certificate chain * \param pk_key own private key * * \return 0 on success or MBEDTLS_ERR_SSL_ALLOC_FAILED */ 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 ) ); } /** * \brief Set the data required to verify peer certificate for the * current handshake * * \note Same as \c mbedtls_ssl_conf_ca_chain() but for use within * the SNI callback. * * \param ssl SSL context * \param ca_chain trusted CA chain (meaning all fully trusted top-level CAs) * \param ca_crl trusted CA CRLs */ 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; } /** * \brief Set authmode for the current handshake. * * \note Same as \c mbedtls_ssl_conf_authmode() but for use within * the SNI callback. * * \param ssl SSL context * \param authmode MBEDTLS_SSL_VERIFY_NONE, MBEDTLS_SSL_VERIFY_OPTIONAL or * MBEDTLS_SSL_VERIFY_REQUIRED */ 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_X509_CRT_PARSE_C) /** * \brief Set a connection-specific verification callback (optional). * * If set, the provided verify callback is called for each * certificate in the peer's CRT chain, including the trusted * root. For more information, please see the documentation of * \c mbedtls_x509_crt_verify(). * * \note This call is analogous to mbedtls_ssl_conf_verify() but * binds the verification callback and context to an SSL context * as opposed to an SSL configuration. * If mbedtls_ssl_conf_verify() and mbedtls_ssl_set_verify() * are both used, mbedtls_ssl_set_verify() takes precedence. * * \param ssl The SSL context to use. * \param f_vrfy The verification callback to use during CRT verification. * \param p_vrfy The opaque context to be passed to the callback. */ void mbedtls_ssl_set_verify( mbedtls_ssl_context *ssl, int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *), void *p_vrfy ) { ssl->f_vrfy = f_vrfy; ssl->p_vrfy = p_vrfy; } #endif #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED) /** * \brief Set the EC J-PAKE password for current handshake. * * \note An internal copy is made, and destroyed as soon as the * handshake is completed, or when the SSL context is reset or * freed. * * \note The SSL context needs to be already set up. The right place * to call this function is between \c mbedtls_ssl_setup() or * \c mbedtls_ssl_reset() and \c mbedtls_ssl_handshake(). * * \param ssl SSL context * \param pw EC J-PAKE password (pre-shared secret) * \param pw_len length of pw in bytes * * \return 0 on success, or a negative error code. */ 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) static void ssl_conf_remove_psk( mbedtls_ssl_config *conf ) { /* Remove reference to existing PSK, if any. */ if( conf->psk != NULL ) { mbedtls_platform_zeroize( conf->psk, conf->psk_len ); mbedtls_free( conf->psk ); conf->psk = NULL; conf->psk_len = 0; } /* Remove reference to PSK identity, if any. */ if( conf->psk_identity != NULL ) { mbedtls_free( conf->psk_identity ); conf->psk_identity = NULL; conf->psk_identity_len = 0; } } /* This function assumes that PSK identity in the SSL config is unset. * It checks that the provided identity is well-formed and attempts * to make a copy of it in the SSL config. * On failure, the PSK identity in the config remains unset. */ static int ssl_conf_set_psk_identity( mbedtls_ssl_config *conf, unsigned char const *psk_identity, size_t psk_identity_len ) { /* Identity len will be encoded on two bytes */ if( psk_identity == NULL || ( psk_identity_len >> 16 ) != 0 || psk_identity_len > MBEDTLS_SSL_OUT_CONTENT_LEN ) { return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); } conf->psk_identity = mbedtls_calloc( 1, psk_identity_len ); if( conf->psk_identity == NULL ) return( MBEDTLS_ERR_SSL_ALLOC_FAILED ); conf->psk_identity_len = psk_identity_len; memcpy( conf->psk_identity, psk_identity, conf->psk_identity_len ); return( 0 ); } /** * \brief Configure a pre-shared key (PSK) and identity * to be used in PSK-based ciphersuites. * * \note This is mainly useful for clients. Servers will usually * want to use \c mbedtls_ssl_conf_psk_cb() instead. * * \note A PSK set by \c mbedtls_ssl_set_hs_psk() in the PSK callback * takes precedence over a PSK configured by this function. * * \warning Currently, clients can only register a single pre-shared key. * Calling this function or mbedtls_ssl_conf_psk_opaque() more * than once will overwrite values configured in previous calls. * Support for setting multiple PSKs on clients and selecting * one based on the identity hint is not a planned feature, * but feedback is welcomed. * * \param conf The SSL configuration to register the PSK with. * \param psk The pointer to the pre-shared key to use. * \param psk_len The length of the pre-shared key in bytes. * \param psk_identity The pointer to the pre-shared key identity. * \param psk_identity_len The length of the pre-shared key identity * in bytes. * * \note The PSK and its identity are copied internally and * hence need not be preserved by the caller for the lifetime * of the SSL configuration. * * \return \c 0 if successful. * \return An \c MBEDTLS_ERR_SSL_XXX error code on failure. */ int mbedtls_ssl_conf_psk( mbedtls_ssl_config *conf, const void *psk, size_t psk_len, const void *psk_identity, size_t psk_identity_len ) { int ret = MBEDTLS_ERR_THIS_CORRUPTION; /* Remove opaque/raw PSK + PSK Identity */ ssl_conf_remove_psk( conf ); /* Check and set raw PSK */ if( psk == NULL ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); if( psk_len == 0 ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); if( psk_len > MBEDTLS_PSK_MAX_LEN ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); if( ( conf->psk = mbedtls_calloc( 1, psk_len ) ) == NULL ) return( MBEDTLS_ERR_SSL_ALLOC_FAILED ); conf->psk_len = psk_len; memcpy( conf->psk, psk, conf->psk_len ); /* Check and set PSK Identity */ ret = ssl_conf_set_psk_identity( conf, psk_identity, psk_identity_len ); if( ret != 0 ) ssl_conf_remove_psk( conf ); return( ret ); } static void ssl_remove_psk( mbedtls_ssl_context *ssl ) { 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; } } /** * \brief Set the pre-shared Key (PSK) for the current handshake. * * \note This should only be called inside the PSK callback, * i.e. the function passed to \c mbedtls_ssl_conf_psk_cb(). * * \note A PSK set by this function takes precedence over a PSK * configured by \c mbedtls_ssl_conf_psk(). * * \param ssl The SSL context to configure a PSK for. * \param psk The pointer to the pre-shared key. * \param psk_len The length of the pre-shared key in bytes. * * \return \c 0 if successful. * \return An \c MBEDTLS_ERR_SSL_XXX error code on failure. */ int mbedtls_ssl_set_hs_psk( mbedtls_ssl_context *ssl, const void *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 ); ssl_remove_psk( ssl ); 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 ); } /** * \brief Set the PSK callback (server-side only). * * If set, the PSK callback is called for each * handshake where a PSK-based ciphersuite was negotiated. * The caller provides the identity received and wants to * receive the actual PSK data and length. * * The callback has the following parameters: * - \c void*: The opaque pointer \p p_psk. * - \c mbedtls_ssl_context*: The SSL context to which * the operation applies. * - \c const unsigned char*: The PSK identity * selected by the client. * - \c size_t: The length of the PSK identity * selected by the client. * * If a valid PSK identity is found, the callback should use * \c mbedtls_ssl_set_hs_psk() or * \c mbedtls_ssl_set_hs_psk_opaque() * on the SSL context to set the correct PSK and return \c 0. * Any other return value will result in a denied PSK identity. * * \note A dynamic PSK (i.e. set by the PSK callback) takes * precedence over a static PSK (i.e. set by * \c mbedtls_ssl_conf_psk() or * \c mbedtls_ssl_conf_psk_opaque()). * This means that if you set a PSK callback using this * function, you don't need to set a PSK using * \c mbedtls_ssl_conf_psk() or * \c mbedtls_ssl_conf_psk_opaque()). * * \param conf The SSL configuration to register the callback with. * \param f_psk The callback for selecting and setting the PSK based * in the PSK identity chosen by the client. * \param p_psk A pointer to an opaque structure to be passed to * the callback, for example a PSK store. */ 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) /** * \brief Set the Diffie-Hellman public P and G values * from big-endian binary presentations. * (Default values: MBEDTLS_DHM_RFC3526_MODP_2048_[PG]_BIN) * * \param conf SSL configuration * \param dhm_P Diffie-Hellman-Merkle modulus in big-endian binary form * \param P_len Length of DHM modulus * \param dhm_G Diffie-Hellman-Merkle generator in big-endian binary form * \param G_len Length of DHM generator * * \return 0 if successful */ 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 = MBEDTLS_ERR_THIS_CORRUPTION; 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 ); } /** * \brief Set the Diffie-Hellman public P and G values, * read from existing context (server-side only) * * \param conf SSL configuration * \param dhm_ctx Diffie-Hellman-Merkle context * * \return 0 if successful */ int mbedtls_ssl_conf_dh_param_ctx( mbedtls_ssl_config *conf, mbedtls_dhm_context *dhm_ctx ) { int ret = MBEDTLS_ERR_THIS_CORRUPTION; 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) /** * \brief Set the minimum length for Diffie-Hellman parameters. * (Client-side only.) * (Default: 1024 bits.) * * \param conf SSL configuration * \param bitlen Minimum bit length of the DHM prime */ 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) /** * \brief Set the allowed hashes for signatures during the handshake. * (Default: all available hashes except MD5.) * * \note This only affects which hashes are offered and can be used * for signatures during the handshake. Hashes for message * authentication and the TLS PRF are controlled by the * ciphersuite, see \c mbedtls_ssl_conf_ciphersuites(). Hashes * used for certificate signature are controlled by the * verification profile, see \c mbedtls_ssl_conf_cert_profile(). * * \note This list should be ordered by decreasing preference * (preferred hash first). * * \param conf SSL configuration * \param hashes Ordered list of allowed signature hashes, * terminated by \c MBEDTLS_MD_NONE. */ void mbedtls_ssl_conf_sig_hashes( mbedtls_ssl_config *conf, const uint8_t *hashes ) { conf->sig_hashes = hashes; } #endif /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */ #if defined(MBEDTLS_ECP_C) /** * \brief Set the allowed curves in order of preference. * (Default: all defined curves.) * * On server: this only affects selection of the ECDHE curve; * the curves used for ECDH and ECDSA are determined by the * list of available certificates instead. * * On client: this affects the list of curves offered for any * use. The server can override our preference order. * * Both sides: limits the set of curves accepted for use in * ECDHE and in the peer's end-entity certificate. * * \note This has no influence on which curves are allowed inside the * certificate chains, see \c mbedtls_ssl_conf_cert_profile() * for that. For the end-entity certificate however, the key * will be accepted only if it is allowed both by this list * and by the cert profile. * * \note This list should be ordered by decreasing preference * (preferred curve first). * * \param conf SSL configuration * \param curves Ordered list of allowed curves, * terminated by MBEDTLS_ECP_DP_NONE. */ 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) /** * \brief Set or reset the hostname to check against the received * server certificate. It sets the ServerName TLS extension, * too, if that extension is enabled. (client-side only) * * \param ssl SSL context * \param hostname the server hostname, may be NULL to clear hostname * * \note Maximum hostname length MBEDTLS_SSL_MAX_HOST_NAME_LEN. * * \return 0 if successful, MBEDTLS_ERR_SSL_ALLOC_FAILED on * allocation failure, MBEDTLS_ERR_SSL_BAD_INPUT_DATA on * too long input hostname. * * Hostname set to the one provided on success (cleared * when NULL). On allocation failure hostname is cleared. * On too long input failure, old hostname is unchanged. */ 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) /** * \brief Set server side ServerName TLS extension callback * (optional, server-side only). * * If set, the ServerName callback is called whenever the * server receives a ServerName TLS extension from the client * during a handshake. The ServerName callback has the * following parameters: (void *parameter, mbedtls_ssl_context *ssl, * const unsigned char *hostname, size_t len). If a suitable * certificate is found, the callback must set the * certificate(s) and key(s) to use with \c * mbedtls_ssl_set_hs_own_cert() (can be called repeatedly), * and may optionally adjust the CA and associated CRL with \c * mbedtls_ssl_set_hs_ca_chain() as well as the client * authentication mode with \c mbedtls_ssl_set_hs_authmode(), * then must return 0. If no matching name is found, the * callback must either set a default cert, or * return non-zero to abort the handshake at this point. * * \param conf SSL configuration * \param f_sni verification function * \param p_sni verification parameter */ 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) /** * \brief Set the supported Application Layer Protocols. * * \param conf SSL configuration * \param protos Pointer to a NULL-terminated list of supported protocols, * in decreasing preference order. The pointer to the list is * recorded by the library for later reference as required, so * the lifetime of the table must be atleast as long as the * lifetime of the SSL configuration structure. * * \return 0 on success, or MBEDTLS_ERR_SSL_BAD_INPUT_DATA. */ 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 > MBEDTLS_SSL_MAX_ALPN_NAME_LEN ) || ( tot_len > MBEDTLS_SSL_MAX_ALPN_LIST_LEN ) ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); } conf->alpn_list = protos; return( 0 ); } /** * \brief Get the name of the negotiated Application Layer Protocol. * This function should be called after the handshake is * completed. * * \param ssl SSL context * * \return Protcol name, or NULL if no protocol was negotiated. */ const char *mbedtls_ssl_get_alpn_protocol( const mbedtls_ssl_context *ssl ) { return( ssl->alpn_chosen ); } #endif /* MBEDTLS_SSL_ALPN */ #if defined(MBEDTLS_SSL_DTLS_SRTP) /** * \brief Manage support for mki(master key id) value * in use_srtp extension. * MKI is an optional part of SRTP used for key management * and re-keying. See RFC3711 section 3.1 for details. * The default value is * #MBEDTLS_SSL_DTLS_SRTP_MKI_UNSUPPORTED. * * \param conf The SSL configuration to manage mki support. * \param support_mki_value Enable or disable mki usage. Values are * #MBEDTLS_SSL_DTLS_SRTP_MKI_UNSUPPORTED * or #MBEDTLS_SSL_DTLS_SRTP_MKI_SUPPORTED. */ void mbedtls_ssl_conf_srtp_mki_value_supported( mbedtls_ssl_config *conf, int support_mki_value ) { conf->dtls_srtp_mki_support = support_mki_value; } int mbedtls_ssl_dtls_srtp_set_mki_value( mbedtls_ssl_context *ssl, unsigned char *mki_value, uint16_t mki_len ) { if( mki_len > MBEDTLS_TLS_SRTP_MAX_MKI_LENGTH ) { return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); } if( ssl->conf->dtls_srtp_mki_support == MBEDTLS_SSL_DTLS_SRTP_MKI_UNSUPPORTED ) { return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE ); } memcpy( ssl->dtls_srtp_info.mki_value, mki_value, mki_len ); ssl->dtls_srtp_info.mki_len = mki_len; return( 0 ); } /** * \brief Set the supported DTLS-SRTP protection profiles. * * \param conf SSL configuration * \param profiles Pointer to a List of MBEDTLS_TLS_SRTP_UNSET terminated * supported protection profiles * in decreasing preference order. * The pointer to the list is recorded by the library * for later reference as required, so the lifetime * of the table must be at least as long as the lifetime * of the SSL configuration structure. * The list must not hold more than * MBEDTLS_TLS_SRTP_MAX_PROFILE_LIST_LENGTH elements * (excluding the terminating MBEDTLS_TLS_SRTP_UNSET). * * \return 0 on success * \return #MBEDTLS_ERR_SSL_BAD_INPUT_DATA when the list of * protection profiles is incorrect. */ int mbedtls_ssl_conf_dtls_srtp_protection_profiles( mbedtls_ssl_config *conf, const mbedtls_ssl_srtp_profile *profiles ) { const mbedtls_ssl_srtp_profile *p; size_t list_size = 0; /* check the profiles list: all entry must be valid, * its size cannot be more than the total number of supported profiles, currently 4 */ for( p = profiles; *p != MBEDTLS_TLS_SRTP_UNSET && list_size <= MBEDTLS_TLS_SRTP_MAX_PROFILE_LIST_LENGTH; p++ ) { if( mbedtls_ssl_check_srtp_profile_value( *p ) != MBEDTLS_TLS_SRTP_UNSET ) { list_size++; } else { /* unsupported value, stop parsing and set the size to an error value */ list_size = MBEDTLS_TLS_SRTP_MAX_PROFILE_LIST_LENGTH + 1; } } if( list_size > MBEDTLS_TLS_SRTP_MAX_PROFILE_LIST_LENGTH ) { conf->dtls_srtp_profile_list = NULL; conf->dtls_srtp_profile_list_len = 0; return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); } conf->dtls_srtp_profile_list = profiles; conf->dtls_srtp_profile_list_len = list_size; return( 0 ); } /** * \brief Set the mki_value for the current DTLS-SRTP session. * * \param ssl SSL context to use. * \param mki_value The MKI value to set. * \param mki_len The length of the MKI value. * * \note This function is relevant on client side only. * The server discovers the mki value during handshake. * A mki value set on server side using this function * is ignored. * * \return 0 on success * \return #MBEDTLS_ERR_SSL_BAD_INPUT_DATA * \return #MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE */ int mbedtls_ssl_dtls_srtp_set_mki_value( mbedtls_ssl_context *ssl, unsigned char *mki_value, uint16_t mki_len ); /** * \brief Get the negotiated DTLS-SRTP informations: * Protection profile and MKI value. * * \warning This function must be called after the handshake is * completed. The value returned by this function must * not be trusted or acted upon before the handshake completes. * * \param ssl The SSL context to query. * \param dtls_srtp_info The negotiated DTLS-SRTP informations: * - Protection profile in use. * A direct mapping of the iana defined value for protection * profile on an uint16_t. http://www.iana.org/assignments/srtp-protection/srtp-protection.xhtml * #MBEDTLS_TLS_SRTP_UNSET if the use of SRTP was not negotiated * or peer's Hello packet was not parsed yet. * - mki size and value( if size is > 0 ). */ void mbedtls_ssl_get_dtls_srtp_negotiation_result( const mbedtls_ssl_context *ssl, mbedtls_dtls_srtp_info *dtls_srtp_info ) { dtls_srtp_info->chosen_dtls_srtp_profile = ssl->dtls_srtp_info.chosen_dtls_srtp_profile; /* do not copy the mki value if there is no chosen profile */ if( dtls_srtp_info->chosen_dtls_srtp_profile == MBEDTLS_TLS_SRTP_UNSET ) { dtls_srtp_info->mki_len = 0; } else { dtls_srtp_info->mki_len = ssl->dtls_srtp_info.mki_len; memcpy( dtls_srtp_info->mki_value, ssl->dtls_srtp_info.mki_value, ssl->dtls_srtp_info.mki_len ); } } #endif /* MBEDTLS_SSL_DTLS_SRTP */ /** * \brief Set the maximum supported version sent from the client side * and/or accepted at the server side * (Default: MBEDTLS_SSL_MAX_MAJOR_VERSION, MBEDTLS_SSL_MAX_MINOR_VERSION) * * \note This ignores ciphersuites from higher versions. * * \note With DTLS, use MBEDTLS_SSL_MINOR_VERSION_2 for DTLS 1.0 and * MBEDTLS_SSL_MINOR_VERSION_3 for DTLS 1.2 * * \param conf SSL configuration * \param major Major version number (only MBEDTLS_SSL_MAJOR_VERSION_3 supported) * \param minor Minor version number (MBEDTLS_SSL_MINOR_VERSION_0, * MBEDTLS_SSL_MINOR_VERSION_1 and MBEDTLS_SSL_MINOR_VERSION_2, * MBEDTLS_SSL_MINOR_VERSION_3 supported) */ void mbedtls_ssl_conf_max_version( mbedtls_ssl_config *conf, int major, int minor ) { conf->max_major_ver = major; conf->max_minor_ver = minor; } /** * \brief Set the minimum accepted SSL/TLS protocol version * (Default: TLS 1.0) * * \note Input outside of the SSL_MAX_XXXXX_VERSION and * SSL_MIN_XXXXX_VERSION range is ignored. * * \note MBEDTLS_SSL_MINOR_VERSION_0 (SSL v3) should be avoided. * * \note With DTLS, use MBEDTLS_SSL_MINOR_VERSION_2 for DTLS 1.0 and * MBEDTLS_SSL_MINOR_VERSION_3 for DTLS 1.2 * * \param conf SSL configuration * \param major Major version number (only MBEDTLS_SSL_MAJOR_VERSION_3 supported) * \param minor Minor version number (MBEDTLS_SSL_MINOR_VERSION_0, * MBEDTLS_SSL_MINOR_VERSION_1 and MBEDTLS_SSL_MINOR_VERSION_2, * MBEDTLS_SSL_MINOR_VERSION_3 supported) */ 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) /** * \brief Set the fallback flag (client-side only). * (Default: MBEDTLS_SSL_IS_NOT_FALLBACK). * * \note Set to MBEDTLS_SSL_IS_FALLBACK when preparing a fallback * connection, that is a connection with max_version set to a * lower value than the value you're willing to use. Such * fallback connections are not recommended but are sometimes * necessary to interoperate with buggy (version-intolerant) * servers. * * \warning You should NOT set this to MBEDTLS_SSL_IS_FALLBACK for * non-fallback connections! This would appear to work for a * while, then cause failures when the server is upgraded to * support a newer TLS version. * * \param conf SSL configuration * \param fallback MBEDTLS_SSL_IS_NOT_FALLBACK or MBEDTLS_SSL_IS_FALLBACK */ void mbedtls_ssl_conf_fallback( mbedtls_ssl_config *conf, char fallback ) { conf->fallback = fallback; } #endif #if defined(MBEDTLS_SSL_SRV_C) /** * \brief Whether to send a list of acceptable CAs in * CertificateRequest messages. * (Default: do send) * * \param conf SSL configuration * \param cert_req_ca_list MBEDTLS_SSL_CERT_REQ_CA_LIST_ENABLED or * MBEDTLS_SSL_CERT_REQ_CA_LIST_DISABLED */ 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) /** * \brief Enable or disable Encrypt-then-MAC * (Default: MBEDTLS_SSL_ETM_ENABLED) * * \note This should always be enabled, it is a security * improvement, and should not cause any interoperability * issue (used only if the peer supports it too). * * \param conf SSL configuration * \param etm MBEDTLS_SSL_ETM_ENABLED or MBEDTLS_SSL_ETM_DISABLED */ 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) /** * \brief Enable or disable Extended Master Secret negotiation. * (Default: MBEDTLS_SSL_EXTENDED_MS_ENABLED) * * \note This should always be enabled, it is a security fix to the * protocol, and should not cause any interoperability issue * (used only if the peer supports it too). * * \param conf SSL configuration * \param ems MBEDTLS_SSL_EXTENDED_MS_ENABLED or MBEDTLS_SSL_EXTENDED_MS_DISABLED */ void mbedtls_ssl_conf_extended_master_secret( mbedtls_ssl_config *conf, char ems ) { conf->extended_ms = ems; } #endif #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH) /** * \brief Set the maximum fragment length to emit and/or negotiate. * (Typical: the smaller of #MBEDTLS_SSL_IN_CONTENT_LEN and * #MBEDTLS_SSL_OUT_CONTENT_LEN, usually `2^14` bytes) * (Server: set maximum fragment length to emit, * usually negotiated by the client during handshake) * (Client: set maximum fragment length to emit *and* * negotiate with the server during handshake) * (Default: #MBEDTLS_SSL_MAX_FRAG_LEN_NONE) * * \note On the client side, the maximum fragment length extension * *will not* be used, unless the maximum fragment length has * been set via this function to a value different than * #MBEDTLS_SSL_MAX_FRAG_LEN_NONE. * * \note With TLS, this currently only affects ApplicationData (sent * with \c mbedtls_ssl_read()), not handshake messages. * With DTLS, this affects both ApplicationData and handshake. * * \note This sets the maximum length for a record's payload, * excluding record overhead that will be added to it, see * \c mbedtls_ssl_get_record_expansion(). * * \note For DTLS, it is also possible to set a limit for the total * size of daragrams passed to the transport layer, including * record overhead, see \c mbedtls_ssl_set_mtu(). * * \param conf SSL configuration * \param mfl_code Code for maximum fragment length (allowed values: * MBEDTLS_SSL_MAX_FRAG_LEN_512, MBEDTLS_SSL_MAX_FRAG_LEN_1024, * MBEDTLS_SSL_MAX_FRAG_LEN_2048, MBEDTLS_SSL_MAX_FRAG_LEN_4096) * * \return 0 if successful or MBEDTLS_ERR_SSL_BAD_INPUT_DATA */ 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_CBC_RECORD_SPLITTING) /** * \brief Enable / Disable 1/n-1 record splitting * (Default: MBEDTLS_SSL_CBC_RECORD_SPLITTING_ENABLED) * * \note Only affects SSLv3 and TLS 1.0, not higher versions. * Does not affect non-CBC ciphersuites in any version. * * \param conf SSL configuration * \param split MBEDTLS_SSL_CBC_RECORD_SPLITTING_ENABLED or * MBEDTLS_SSL_CBC_RECORD_SPLITTING_DISABLED */ void mbedtls_ssl_conf_cbc_record_splitting( mbedtls_ssl_config *conf, char split ) { conf->cbc_record_splitting = split; } #endif /** * \brief Prevent or allow legacy renegotiation. * (Default: MBEDTLS_SSL_LEGACY_NO_RENEGOTIATION) * * MBEDTLS_SSL_LEGACY_NO_RENEGOTIATION allows connections to * be established even if the peer does not support * secure renegotiation, but does not allow renegotiation * to take place if not secure. * (Interoperable and secure option) * * MBEDTLS_SSL_LEGACY_ALLOW_RENEGOTIATION allows renegotiations * with non-upgraded peers. Allowing legacy renegotiation * makes the connection vulnerable to specific man in the * middle attacks. (See RFC 5746) * (Most interoperable and least secure option) * * MBEDTLS_SSL_LEGACY_BREAK_HANDSHAKE breaks off connections * if peer does not support secure renegotiation. Results * in interoperability issues with non-upgraded peers * that do not support renegotiation altogether. * (Most secure option, interoperability issues) * * \param conf SSL configuration * \param allow_legacy Prevent or allow (SSL_NO_LEGACY_RENEGOTIATION, * SSL_ALLOW_LEGACY_RENEGOTIATION or * MBEDTLS_SSL_LEGACY_BREAK_HANDSHAKE) */ void mbedtls_ssl_conf_legacy_renegotiation( mbedtls_ssl_config *conf, int allow_legacy ) { conf->allow_legacy_renegotiation = allow_legacy; } #if defined(MBEDTLS_SSL_RENEGOTIATION) /** * \brief Enable / Disable renegotiation support for connection when * initiated by peer * (Default: MBEDTLS_SSL_RENEGOTIATION_DISABLED) * * \warning It is recommended to always disable renegotation unless you * know you need it and you know what you're doing. In the * past, there have been several issues associated with * renegotiation or a poor understanding of its properties. * * \note Server-side, enabling renegotiation also makes the server * susceptible to a resource DoS by a malicious client. * * \param conf SSL configuration * \param renegotiation Enable or disable (MBEDTLS_SSL_RENEGOTIATION_ENABLED or * MBEDTLS_SSL_RENEGOTIATION_DISABLED) */ void mbedtls_ssl_conf_renegotiation( mbedtls_ssl_config *conf, int renegotiation ) { conf->disable_renegotiation = renegotiation; } /** * \brief Enforce renegotiation requests. * (Default: enforced, max_records = 16) * * When we request a renegotiation, the peer can comply or * ignore the request. This function allows us to decide * whether to enforce our renegotiation requests by closing * the connection if the peer doesn't comply. * * However, records could already be in transit from the peer * when the request is emitted. In order to increase * reliability, we can accept a number of records before the * expected handshake records. * * The optimal value is highly dependent on the specific usage * scenario. * * \note With DTLS and server-initiated renegotiation, the * HelloRequest is retransmited every time mbedtls_ssl_read() times * out or receives Application Data, until: * - max_records records have beens seen, if it is >= 0, or * - the number of retransmits that would happen during an * actual handshake has been reached. * Please remember the request might be lost a few times * if you consider setting max_records to a really low value. * * \warning On client, the grace period can only happen during * mbedtls_ssl_read(), as opposed to mbedtls_ssl_write() and mbedtls_ssl_renegotiate() * which always behave as if max_record was 0. The reason is, * if we receive application data from the server, we need a * place to write it, which only happens during mbedtls_ssl_read(). * * \param conf SSL configuration * \param max_records Use MBEDTLS_SSL_RENEGOTIATION_NOT_ENFORCED if you don't want to * enforce renegotiation, or a non-negative value to enforce * it but allow for a grace period of max_records records. */ void mbedtls_ssl_conf_renegotiation_enforced( mbedtls_ssl_config *conf, int max_records ) { conf->renego_max_records = max_records; } /** * \brief Set record counter threshold for periodic renegotiation. * (Default: 2^48 - 1) * * Renegotiation is automatically triggered when a record * counter (outgoing or incoming) crosses the defined * threshold. The default value is meant to prevent the * connection from being closed when the counter is about to * reached its maximal value (it is not allowed to wrap). * * Lower values can be used to enforce policies such as "keys * must be refreshed every N packets with cipher X". * * The renegotiation period can be disabled by setting * conf->disable_renegotiation to * MBEDTLS_SSL_RENEGOTIATION_DISABLED. * * \note When the configured transport is * MBEDTLS_SSL_TRANSPORT_DATAGRAM the maximum renegotiation * period is 2^48 - 1, and for MBEDTLS_SSL_TRANSPORT_STREAM, * the maximum renegotiation period is 2^64 - 1. * * \param conf SSL configuration * \param period The threshold value: a big-endian 64-bit number. */ 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) /** * \brief Enable / Disable session tickets (client only). * (Default: MBEDTLS_SSL_SESSION_TICKETS_ENABLED.) * * \note On server, use \c mbedtls_ssl_conf_session_tickets_cb(). * * \param conf SSL configuration * \param use_tickets Enable or disable (MBEDTLS_SSL_SESSION_TICKETS_ENABLED or * MBEDTLS_SSL_SESSION_TICKETS_DISABLED) */ 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) /** * \brief Configure SSL session ticket callbacks (server only). * (Default: none.) * * \note On server, session tickets are enabled by providing * non-NULL callbacks. * * \note On client, use \c mbedtls_ssl_conf_session_tickets(). * * \param conf SSL configuration context * \param f_ticket_write Callback for writing a ticket * \param f_ticket_parse Callback for parsing a ticket * \param p_ticket Context shared by the two callbacks */ 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) /** * \brief Configure key export callback. * (Default: none.) * * \note See \c mbedtls_ssl_export_keys_t. * * \param conf SSL configuration context * \param f_export_keys Callback for exporting keys * \param p_export_keys Context for the callback */ 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; } /** * \brief Configure extended key export callback. * (Default: none.) * * \note See \c mbedtls_ssl_export_keys_ext_t. * \warning Exported key material must not be used for any purpose * before the (D)TLS handshake is completed * * \param conf SSL configuration context * \param f_export_keys_ext Callback for exporting keys * \param p_export_keys Context for the callback */ void mbedtls_ssl_conf_export_keys_ext_cb( mbedtls_ssl_config *conf, mbedtls_ssl_export_keys_ext_t *f_export_keys_ext, void *p_export_keys ) { conf->f_export_keys_ext = f_export_keys_ext; conf->p_export_keys = p_export_keys; } #endif #if defined(MBEDTLS_SSL_ASYNC_PRIVATE) /** * \brief Configure asynchronous private key operation callbacks. * * \param conf SSL configuration context * \param f_async_sign Callback to start a signature operation. See * the description of ::mbedtls_ssl_async_sign_t * for more information. This may be \c NULL if the * external processor does not support any signature * operation; in this case the private key object * associated with the certificate will be used. * \param f_async_decrypt Callback to start a decryption operation. See * the description of ::mbedtls_ssl_async_decrypt_t * for more information. This may be \c NULL if the * external processor does not support any decryption * operation; in this case the private key object * associated with the certificate will be used. * \param f_async_resume Callback to resume an asynchronous operation. See * the description of ::mbedtls_ssl_async_resume_t * for more information. This may not be \c NULL unless * \p f_async_sign and \p f_async_decrypt are both * \c NULL. * \param f_async_cancel Callback to cancel an asynchronous operation. See * the description of ::mbedtls_ssl_async_cancel_t * for more information. This may be \c NULL if * no cleanup is needed. * \param config_data A pointer to configuration data which can be * retrieved with * mbedtls_ssl_conf_get_async_config_data(). The * library stores this value without dereferencing it. */ 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; } /** * \brief Retrieve the configuration data set by * mbedtls_ssl_conf_async_private_cb(). * * \param conf SSL configuration context * \return The configuration data set by * mbedtls_ssl_conf_async_private_cb(). */ void *mbedtls_ssl_conf_get_async_config_data( const mbedtls_ssl_config *conf ) { return( conf->p_async_config_data ); } /** * \brief Retrieve the asynchronous operation user context. * * \note This function may only be called while a handshake * is in progress. * * \param ssl The SSL context to access. * * \return The asynchronous operation user context that was last * set during the current handshake. If * mbedtls_ssl_set_async_operation_data() has not yet been * called during the current handshake, this function returns * \c NULL. */ 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 ); } /** * \brief Retrieve the asynchronous operation user context. * * \note This function may only be called while a handshake * is in progress. * * \param ssl The SSL context to access. * \param ctx The new value of the asynchronous operation user context. * Call mbedtls_ssl_get_async_operation_data() later during the * same handshake to retrieve this value. */ 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 */ /** * \brief Return the result of the certificate verification * * \param ssl The SSL context to use. * * \return \c 0 if the certificate verification was successful. * \return \c -1u if the result is not available. This may happen * e.g. if the handshake aborts early, or a verification * callback returned a fatal error. * \return A bitwise combination of \c MBEDTLS_X509_BADCERT_XXX * and \c MBEDTLS_X509_BADCRL_XXX failure flags; see x509.h. */ 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 ); } /** * \brief Return the name of the current ciphersuite * * \param ssl SSL context * * \return a string containing the ciphersuite name */ 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 ); } /** * \brief Return the current SSL version (SSLv3/TLSv1/etc) * * \param ssl SSL context * * \return a string containing the SSL version */ 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" ); } } #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH) /** * \brief Return the maximum fragment length (payload, in bytes) for * the input buffer. This is the negotiated maximum fragment * length, or, if there is none, MBEDTLS_SSL_MAX_CONTENT_LEN. * If it is not defined either, the value is 2^14. This function * works as its predecessor, \c mbedtls_ssl_get_max_frag_len(). * * \sa mbedtls_ssl_conf_max_frag_len() * \sa mbedtls_ssl_get_max_record_payload() * * \param ssl SSL context * * \return Current maximum fragment length for the output buffer. */ size_t mbedtls_ssl_get_input_max_frag_len( const mbedtls_ssl_context *ssl ) { size_t max_len = MBEDTLS_SSL_MAX_CONTENT_LEN; size_t read_mfl; /* Use the configured MFL for the client if we're past SERVER_HELLO_DONE */ if( ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT && ssl->state >= MBEDTLS_SSL_SERVER_HELLO_DONE ) { return ssl_mfl_code_to_length( ssl->conf->mfl_code ); } /* Check if a smaller max length was negotiated */ if( ssl->session_out != NULL ) { read_mfl = ssl_mfl_code_to_length( ssl->session_out->mfl_code ); if( read_mfl < max_len ) { max_len = read_mfl; } } // During a handshake, use the value being negotiated if( ssl->session_negotiate != NULL ) { read_mfl = ssl_mfl_code_to_length( ssl->session_negotiate->mfl_code ); if( read_mfl < max_len ) { max_len = read_mfl; } } return( max_len ); } /** * \brief Return the maximum fragment length (payload, in bytes) for * the output buffer. For the client, this is the configured * value. For the server, it is the minimum of two - the * configured value and the negotiated one. * * \sa mbedtls_ssl_conf_max_frag_len() * \sa mbedtls_ssl_get_max_record_payload() * * \param ssl SSL context * * \return Current maximum fragment length for the output buffer. */ size_t mbedtls_ssl_get_output_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) size_t mbedtls_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 */ /** * \brief Return the current maximum outgoing record payload in bytes. * This takes into account the config.h setting \c * MBEDTLS_SSL_OUT_CONTENT_LEN, the configured and negotiated * max fragment length extension if used, and for DTLS the * path MTU as configured and current record expansion. * * \note With DTLS, \c mbedtls_ssl_write() will return an error if * called with a larger length value. * With TLS, \c mbedtls_ssl_write() will fragment the input if * necessary and return the number of bytes written; it is up * to the caller to call \c mbedtls_ssl_write() again in * order to send the remaining bytes if any. * * \note This function is not available (always returns an error) * when record compression is enabled. * * \sa mbedtls_ssl_set_mtu() * \sa mbedtls_ssl_get_output_max_frag_len() * \sa mbedtls_ssl_get_input_max_frag_len() * \sa mbedtls_ssl_get_record_expansion() * * \param ssl SSL context * * \return Current maximum payload for an outgoing record, * or a negative error code. */ 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_output_max_frag_len( ssl ); if( max_len > mfl ) max_len = mfl; #endif #if defined(MBEDTLS_SSL_PROTO_DTLS) if( mbedtls_ssl_get_current_mtu( ssl ) != 0 ) { const size_t mtu = mbedtls_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) /** * \brief Return the peer certificate from the current connection. * * \param ssl The SSL context to use. This must be initialized and setup. * * \return The current peer certificate, if available. * The returned certificate is owned by the SSL context and * is valid only until the next call to the SSL API. * \return \c NULL if no peer certificate is available. This might * be because the chosen ciphersuite doesn't use CRTs * (PSK-based ciphersuites, for example), or because * #MBEDTLS_SSL_KEEP_PEER_CERTIFICATE has been disabled, * allowing the stack to free the peer's CRT to save memory. * * \note For one-time inspection of the peer's certificate during * the handshake, consider registering an X.509 CRT verification * callback through mbedtls_ssl_conf_verify() instead of calling * this function. Using mbedtls_ssl_conf_verify() also comes at * the benefit of allowing you to influence the verification * process, for example by masking expected and tolerated * verification failures. * * \warning You must not use the pointer returned by this function * after any further call to the SSL API, including * mbedtls_ssl_read() and mbedtls_ssl_write(); this is * because the pointer might change during renegotiation, * which happens transparently to the user. * If you want to use the certificate across API calls, * you must make a copy. */ const mbedtls_x509_crt *mbedtls_ssl_get_peer_cert( const mbedtls_ssl_context *ssl ) { if( ssl == NULL || ssl->session == NULL ) return( NULL ); #if defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE) return( ssl->session->peer_cert ); #else return( NULL ); #endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */ } #endif /* MBEDTLS_X509_CRT_PARSE_C */ #if defined(MBEDTLS_SSL_CLI_C) /** * \brief Save session in order to resume it later (client-side only) * Session data is copied to presented session structure. * * * \param ssl SSL context * \param session session context * * \return 0 if successful, * MBEDTLS_ERR_SSL_ALLOC_FAILED if memory allocation failed, * MBEDTLS_ERR_SSL_BAD_INPUT_DATA if used server-side or * arguments are otherwise invalid. * * \note Only the server certificate is copied, and not the full chain, * so you should not attempt to validate the certificate again * by calling \c mbedtls_x509_crt_verify() on it. * Instead, you should use the results from the verification * in the original handshake by calling \c mbedtls_ssl_get_verify_result() * after loading the session again into a new SSL context * using \c mbedtls_ssl_set_session(). * * \note Once the session object is not needed anymore, you should * free it by calling \c mbedtls_ssl_session_free(). * * \sa mbedtls_ssl_set_session() */ 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( mbedtls_ssl_session_copy( dst, ssl->session ) ); } #endif /* MBEDTLS_SSL_CLI_C */ /** * \brief Get a pointer to the current session structure, for example * to serialize it. * * \warning Ownership of the session remains with the SSL context, and * the returned pointer is only guaranteed to be valid until * the next API call operating on the same \p ssl context. * * \see mbedtls_ssl_session_save() * * \param ssl The SSL context. * * \return A pointer to the current session if successful. * \return \c NULL if no session is active. */ const mbedtls_ssl_session *mbedtls_ssl_get_session_pointer( const mbedtls_ssl_context *ssl ) { if( ssl == NULL ) return( NULL ); return( ssl->session ); } /* * Define ticket header determining Mbed TLS version * and structure of the ticket. */ /* * Define bitflag determining compile-time settings influencing * structure of serialized SSL sessions. */ #if defined(MBEDTLS_HAVE_TIME) #define SSL_SERIALIZED_SESSION_CONFIG_TIME 1 #else #define SSL_SERIALIZED_SESSION_CONFIG_TIME 0 #endif /* MBEDTLS_HAVE_TIME */ #if defined(MBEDTLS_X509_CRT_PARSE_C) #define SSL_SERIALIZED_SESSION_CONFIG_CRT 1 #else #define SSL_SERIALIZED_SESSION_CONFIG_CRT 0 #endif /* MBEDTLS_X509_CRT_PARSE_C */ #if defined(MBEDTLS_SSL_CLI_C) && defined(MBEDTLS_SSL_SESSION_TICKETS) #define SSL_SERIALIZED_SESSION_CONFIG_CLIENT_TICKET 1 #else #define SSL_SERIALIZED_SESSION_CONFIG_CLIENT_TICKET 0 #endif /* MBEDTLS_SSL_CLI_C && MBEDTLS_SSL_SESSION_TICKETS */ #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH) #define SSL_SERIALIZED_SESSION_CONFIG_MFL 1 #else #define SSL_SERIALIZED_SESSION_CONFIG_MFL 0 #endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */ #define SSL_SERIALIZED_SESSION_CONFIG_TRUNC_HMAC 0 #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC) #define SSL_SERIALIZED_SESSION_CONFIG_ETM 1 #else #define SSL_SERIALIZED_SESSION_CONFIG_ETM 0 #endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */ #if defined(MBEDTLS_SSL_SESSION_TICKETS) #define SSL_SERIALIZED_SESSION_CONFIG_TICKET 1 #else #define SSL_SERIALIZED_SESSION_CONFIG_TICKET 0 #endif /* MBEDTLS_SSL_SESSION_TICKETS */ #define SSL_SERIALIZED_SESSION_CONFIG_TIME_BIT 0 #define SSL_SERIALIZED_SESSION_CONFIG_CRT_BIT 1 #define SSL_SERIALIZED_SESSION_CONFIG_CLIENT_TICKET_BIT 2 #define SSL_SERIALIZED_SESSION_CONFIG_MFL_BIT 3 #define SSL_SERIALIZED_SESSION_CONFIG_TRUNC_HMAC_BIT 4 #define SSL_SERIALIZED_SESSION_CONFIG_ETM_BIT 5 #define SSL_SERIALIZED_SESSION_CONFIG_TICKET_BIT 6 #define SSL_SERIALIZED_SESSION_CONFIG_BITFLAG \ ( (uint16_t) ( \ ( SSL_SERIALIZED_SESSION_CONFIG_TIME << SSL_SERIALIZED_SESSION_CONFIG_TIME_BIT ) | \ ( SSL_SERIALIZED_SESSION_CONFIG_CRT << SSL_SERIALIZED_SESSION_CONFIG_CRT_BIT ) | \ ( SSL_SERIALIZED_SESSION_CONFIG_CLIENT_TICKET << SSL_SERIALIZED_SESSION_CONFIG_CLIENT_TICKET_BIT ) | \ ( SSL_SERIALIZED_SESSION_CONFIG_MFL << SSL_SERIALIZED_SESSION_CONFIG_MFL_BIT ) | \ ( SSL_SERIALIZED_SESSION_CONFIG_TRUNC_HMAC << SSL_SERIALIZED_SESSION_CONFIG_TRUNC_HMAC_BIT ) | \ ( SSL_SERIALIZED_SESSION_CONFIG_ETM << SSL_SERIALIZED_SESSION_CONFIG_ETM_BIT ) | \ ( SSL_SERIALIZED_SESSION_CONFIG_TICKET << SSL_SERIALIZED_SESSION_CONFIG_TICKET_BIT ) ) ) static unsigned char ssl_serialized_session_header[] = { MBEDTLS_VERSION_MAJOR, MBEDTLS_VERSION_MINOR, MBEDTLS_VERSION_PATCH, ( SSL_SERIALIZED_SESSION_CONFIG_BITFLAG >> 8 ) & 0xFF, ( SSL_SERIALIZED_SESSION_CONFIG_BITFLAG >> 0 ) & 0xFF, }; /* * Serialize a session in the following format: * (in the presentation language of TLS, RFC 8446 section 3) * * opaque mbedtls_version[3]; // major, minor, patch * opaque session_format[2]; // version-specific 16-bit field determining * // the format of the remaining * // serialized data. * * Note: When updating the format, remember to keep * these version+format bytes. * * // In this version, `session_format` determines * // the setting of those compile-time * // configuration options which influence * // the structure of mbedtls_ssl_session. * uint64 start_time; * uint8 ciphersuite[2]; // defined by the standard * uint8 compression; // 0 or 1 * uint8 session_id_len; // at most 32 * opaque session_id[32]; * opaque master[48]; // fixed length in the standard * uint32 verify_result; * opaque peer_cert<0..2^24-1>; // length 0 means no peer cert * opaque ticket<0..2^24-1>; // length 0 means no ticket * uint32 ticket_lifetime; * uint8 mfl_code; // up to 255 according to standard * uint8 trunc_hmac; // 0 or 1 * uint8 encrypt_then_mac; // 0 or 1 * * The order is the same as in the definition of the structure, except * verify_result is put before peer_cert so that all mandatory fields come * together in one block. */ static int ssl_session_save( const mbedtls_ssl_session *session, unsigned char omit_header, unsigned char *buf, size_t buf_len, size_t *olen ) { unsigned char *p = buf; size_t used = 0; #if defined(MBEDTLS_X509_CRT_PARSE_C) #if defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE) size_t cert_len; #endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */ #endif /* MBEDTLS_X509_CRT_PARSE_C */ if( !omit_header ) { /* * Add version identifier */ used += sizeof( ssl_serialized_session_header ); if( used <= buf_len ) { memcpy( p, ssl_serialized_session_header, sizeof( ssl_serialized_session_header ) ); p += sizeof( ssl_serialized_session_header ); } } /* * Time */ #if defined(MBEDTLS_HAVE_TIME) used += 8; if( used <= buf_len ) p = Write64be(p, session->start); #endif /* MBEDTLS_HAVE_TIME */ /* * Basic mandatory fields */ used += 2 /* ciphersuite */ + 1 /* compression */ + 1 /* id_len */ + sizeof( session->id ) + sizeof( session->master ) + 4; /* verify_result */ if( used <= buf_len ) { *p++ = (unsigned char)( ( session->ciphersuite >> 8 ) & 0xFF ); *p++ = (unsigned char)( ( session->ciphersuite ) & 0xFF ); *p++ = (unsigned char)( session->compression & 0xFF ); *p++ = (unsigned char)( session->id_len & 0xFF ); memcpy( p, session->id, 32 ); p += 32; memcpy( p, session->master, 48 ); p += 48; *p++ = (unsigned char)( ( session->verify_result >> 24 ) & 0xFF ); *p++ = (unsigned char)( ( session->verify_result >> 16 ) & 0xFF ); *p++ = (unsigned char)( ( session->verify_result >> 8 ) & 0xFF ); *p++ = (unsigned char)( ( session->verify_result ) & 0xFF ); } /* * Peer's end-entity certificate */ #if defined(MBEDTLS_X509_CRT_PARSE_C) #if defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE) if( session->peer_cert == NULL ) cert_len = 0; else cert_len = session->peer_cert->raw.len; used += 3 + cert_len; if( used <= buf_len ) { *p++ = (unsigned char)( ( cert_len >> 16 ) & 0xFF ); *p++ = (unsigned char)( ( cert_len >> 8 ) & 0xFF ); *p++ = (unsigned char)( ( cert_len ) & 0xFF ); if( session->peer_cert != NULL ) { memcpy( p, session->peer_cert->raw.p, cert_len ); p += cert_len; } } #else /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */ if( session->peer_cert_digest != NULL ) { used += 1 /* type */ + 1 /* length */ + session->peer_cert_digest_len; if( used <= buf_len ) { *p++ = (unsigned char) session->peer_cert_digest_type; *p++ = (unsigned char) session->peer_cert_digest_len; memcpy( p, session->peer_cert_digest, session->peer_cert_digest_len ); p += session->peer_cert_digest_len; } } else { used += 2; if( used <= buf_len ) { *p++ = (unsigned char) MBEDTLS_MD_NONE; *p++ = 0; } } #endif /* !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */ #endif /* MBEDTLS_X509_CRT_PARSE_C */ /* * Session ticket if any, plus associated data */ #if defined(MBEDTLS_SSL_SESSION_TICKETS) && defined(MBEDTLS_SSL_CLI_C) used += 3 + session->ticket_len + 4; /* len + ticket + lifetime */ if( used <= buf_len ) { *p++ = (unsigned char)( ( session->ticket_len >> 16 ) & 0xFF ); *p++ = (unsigned char)( ( session->ticket_len >> 8 ) & 0xFF ); *p++ = (unsigned char)( ( session->ticket_len ) & 0xFF ); if( session->ticket != NULL ) { memcpy( p, session->ticket, session->ticket_len ); p += session->ticket_len; } *p++ = (unsigned char)( ( session->ticket_lifetime >> 24 ) & 0xFF ); *p++ = (unsigned char)( ( session->ticket_lifetime >> 16 ) & 0xFF ); *p++ = (unsigned char)( ( session->ticket_lifetime >> 8 ) & 0xFF ); *p++ = (unsigned char)( ( session->ticket_lifetime ) & 0xFF ); } #endif /* MBEDTLS_SSL_SESSION_TICKETS && MBEDTLS_SSL_CLI_C */ /* * Misc extension-related info */ #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH) used += 1; if( used <= buf_len ) *p++ = session->mfl_code; #endif #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC) used += 1; if( used <= buf_len ) *p++ = (unsigned char)( ( session->encrypt_then_mac ) & 0xFF ); #endif /* Done */ *olen = used; if( used > buf_len ) return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL ); return( 0 ); } /** * \brief Save session structure as serialized data in a buffer. * On client, this can be used for saving session data, * potentially in non-volatile storage, for resuming later. * On server, this can be used for alternative implementations * of session cache or session tickets. * * \see mbedtls_ssl_session_load() * \see mbedtls_ssl_get_session_pointer() * * \param session The session structure to be saved. * \param buf The buffer to write the serialized data to. It must be a * writeable buffer of at least \p len bytes, or may be \c * NULL if \p len is \c 0. * \param buf_len The number of bytes available for writing in \p buf. * \param olen The size in bytes of the data that has been or would have * been written. It must point to a valid \c size_t. * * \note \p olen is updated to the correct value regardless of * whether \p buf_len was large enough. This makes it possible * to determine the necessary size by calling this function * with \p buf set to \c NULL and \p buf_len to \c 0. * * \return \c 0 if successful. * \return #MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL if \p buf is too small. */ int mbedtls_ssl_session_save( const mbedtls_ssl_session *session, unsigned char *buf, size_t buf_len, size_t *olen ) { return( ssl_session_save( session, 0, buf, buf_len, olen ) ); } /* * Deserialize session, see mbedtls_ssl_session_save() for format. * * This internal version is wrapped by a public function that cleans up in * case of error, and has an extra option omit_header. */ static int ssl_session_load( mbedtls_ssl_session *session, unsigned char omit_header, const unsigned char *buf, size_t len ) { const unsigned char *p = buf; const unsigned char * const end = buf + len; #if defined(MBEDTLS_HAVE_TIME) uint64_t start; #endif #if defined(MBEDTLS_X509_CRT_PARSE_C) #if defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE) size_t cert_len; #endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */ #endif /* MBEDTLS_X509_CRT_PARSE_C */ if( !omit_header ) { /* * Check version identifier */ if( (size_t)( end - p ) < sizeof( ssl_serialized_session_header ) ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); if( timingsafe_bcmp( p, ssl_serialized_session_header, sizeof( ssl_serialized_session_header ) ) != 0 ) { return( MBEDTLS_ERR_SSL_VERSION_MISMATCH ); } p += sizeof( ssl_serialized_session_header ); } /* * Time */ #if defined(MBEDTLS_HAVE_TIME) if( 8 > (size_t)( end - p ) ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); start = Read64be(p); p += 8; session->start = (int64_t) start; #endif /* MBEDTLS_HAVE_TIME */ /* * Basic mandatory fields */ if( 2 + 1 + 1 + 32 + 48 + 4 > (size_t)( end - p ) ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); session->ciphersuite = ( p[0] << 8 ) | p[1]; p += 2; session->compression = *p++; session->id_len = *p++; memcpy( session->id, p, 32 ); p += 32; memcpy( session->master, p, 48 ); p += 48; session->verify_result = Read32be(p); p += 4; /* Immediately clear invalid pointer values that have been read, in case * we exit early before we replaced them with valid ones. */ #if defined(MBEDTLS_X509_CRT_PARSE_C) #if defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE) session->peer_cert = NULL; #else session->peer_cert_digest = NULL; #endif /* !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */ #endif /* MBEDTLS_X509_CRT_PARSE_C */ #if defined(MBEDTLS_SSL_SESSION_TICKETS) && defined(MBEDTLS_SSL_CLI_C) session->ticket = NULL; #endif /* MBEDTLS_SSL_SESSION_TICKETS && MBEDTLS_SSL_CLI_C */ /* * Peer certificate */ #if defined(MBEDTLS_X509_CRT_PARSE_C) #if defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE) /* Deserialize CRT from the end of the ticket. */ if( 3 > (size_t)( end - p ) ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); cert_len = ( p[0] << 16 ) | ( p[1] << 8 ) | p[2]; p += 3; if( cert_len != 0 ) { int ret = MBEDTLS_ERR_THIS_CORRUPTION; if( cert_len > (size_t)( end - p ) ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); session->peer_cert = mbedtls_calloc( 1, sizeof( mbedtls_x509_crt ) ); if( session->peer_cert == NULL ) return( MBEDTLS_ERR_SSL_ALLOC_FAILED ); mbedtls_x509_crt_init( session->peer_cert ); if( ( ret = mbedtls_x509_crt_parse_der( session->peer_cert, p, cert_len ) ) != 0 ) { mbedtls_x509_crt_free( session->peer_cert ); mbedtls_free( session->peer_cert ); session->peer_cert = NULL; return( ret ); } p += cert_len; } #else /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */ /* Deserialize CRT digest from the end of the ticket. */ if( 2 > (size_t)( end - p ) ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); session->peer_cert_digest_type = (mbedtls_md_type_t) *p++; session->peer_cert_digest_len = (size_t) *p++; if( session->peer_cert_digest_len != 0 ) { const mbedtls_md_info_t *md_info = mbedtls_md_info_from_type( session->peer_cert_digest_type ); if( md_info == NULL ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); if( session->peer_cert_digest_len != mbedtls_md_get_size( md_info ) ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); if( session->peer_cert_digest_len > (size_t)( end - p ) ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); session->peer_cert_digest = mbedtls_calloc( 1, session->peer_cert_digest_len ); if( session->peer_cert_digest == NULL ) return( MBEDTLS_ERR_SSL_ALLOC_FAILED ); memcpy( session->peer_cert_digest, p, session->peer_cert_digest_len ); p += session->peer_cert_digest_len; } #endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */ #endif /* MBEDTLS_X509_CRT_PARSE_C */ /* * Session ticket and associated data */ #if defined(MBEDTLS_SSL_SESSION_TICKETS) && defined(MBEDTLS_SSL_CLI_C) if( 3 > (size_t)( end - p ) ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); session->ticket_len = ( p[0] << 16 ) | ( p[1] << 8 ) | p[2]; p += 3; if( session->ticket_len != 0 ) { if( session->ticket_len > (size_t)( end - p ) ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); session->ticket = mbedtls_calloc( 1, session->ticket_len ); if( session->ticket == NULL ) return( MBEDTLS_ERR_SSL_ALLOC_FAILED ); memcpy( session->ticket, p, session->ticket_len ); p += session->ticket_len; } if( 4 > (size_t)( end - p ) ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); session->ticket_lifetime = Read32be(p); p += 4; #endif /* MBEDTLS_SSL_SESSION_TICKETS && MBEDTLS_SSL_CLI_C */ /* * Misc extension-related info */ #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH) if( 1 > (size_t)( end - p ) ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); session->mfl_code = *p++; #endif #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC) if( 1 > (size_t)( end - p ) ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); session->encrypt_then_mac = *p++; #endif /* Done, should have consumed entire buffer */ if( p != end ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); return( 0 ); } /** * \brief Load serialized session data into a session structure. * On client, this can be used for loading saved sessions * before resuming them with mbedstls_ssl_set_session(). * On server, this can be used for alternative implementations * of session cache or session tickets. * * \warning If a peer certificate chain is associated with the session, * the serialized state will only contain the peer's * end-entity certificate and the result of the chain * verification (unless verification was disabled), but not * the rest of the chain. * * \see mbedtls_ssl_session_save() * \see mbedtls_ssl_set_session() * * \param session The session structure to be populated. It must have been * initialised with mbedtls_ssl_session_init() but not * populated yet. * \param buf The buffer holding the serialized session data. It must be a * readable buffer of at least \p len bytes. * \param len The size of the serialized data in bytes. * * \return \c 0 if successful. * \return #MBEDTLS_ERR_SSL_ALLOC_FAILED if memory allocation failed. * \return #MBEDTLS_ERR_SSL_BAD_INPUT_DATA if input data is invalid. * \return #MBEDTLS_ERR_SSL_VERSION_MISMATCH if the serialized data * was generated in a different version or configuration of * Mbed TLS. * \return Another negative value for other kinds of errors (for * example, unsupported features in the embedded certificate). */ int mbedtls_ssl_session_load( mbedtls_ssl_session *session, const unsigned char *buf, size_t len ) { int ret = ssl_session_load( session, 0, buf, len ); if( ret != 0 ) mbedtls_ssl_session_free( session ); return( ret ); } /** * \brief Perform a single step of the SSL handshake * * \note The state of the context (ssl->state) will be at * the next state after this function returns \c 0. Do not * call this function if state is MBEDTLS_SSL_HANDSHAKE_OVER. * * \param ssl SSL context * * \return See mbedtls_ssl_handshake(). * * \warning If this function returns something other than \c 0, * #MBEDTLS_ERR_SSL_WANT_READ, #MBEDTLS_ERR_SSL_WANT_WRITE, * #MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS or * #MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS, you must stop using * the SSL context for reading or writing, and either free it * or call \c mbedtls_ssl_session_reset() on it before * re-using it for a new connection; the current connection * must be closed. */ int mbedtls_ssl_handshake_step( mbedtls_ssl_context *ssl ) { if( ssl == NULL || ssl->conf == NULL || ssl->conf->f_step == NULL ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); return ssl->conf->f_step(ssl); } /** * \brief Perform the SSL handshake * * \param ssl SSL context * * \return \c 0 if successful. * \return #MBEDTLS_ERR_SSL_WANT_READ or #MBEDTLS_ERR_SSL_WANT_WRITE * if the handshake is incomplete and waiting for data to * be available for reading from or writing to the underlying * transport - in this case you must call this function again * when the underlying transport is ready for the operation. * \return #MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS if an asynchronous * operation is in progress (see * mbedtls_ssl_conf_async_private_cb()) - in this case you * must call this function again when the operation is ready. * \return #MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS if a cryptographic * operation is in progress (see mbedtls_ecp_set_max_ops()) - * in this case you must call this function again to complete * the handshake when you're done attending other tasks. * \return #MBEDTLS_ERR_SSL_HELLO_VERIFY_REQUIRED if DTLS is in use * and the client did not demonstrate reachability yet - in * this case you must stop using the context (see below). * \return Another SSL error code - in this case you must stop using * the context (see below). * * \warning If this function returns something other than * \c 0, * #MBEDTLS_ERR_SSL_WANT_READ, * #MBEDTLS_ERR_SSL_WANT_WRITE, * #MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS or * #MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS, * you must stop using the SSL context for reading or writing, * and either free it or call \c mbedtls_ssl_session_reset() * on it before re-using it for a new connection; the current * connection must be closed. * * \note If DTLS is in use, then you may choose to handle * #MBEDTLS_ERR_SSL_HELLO_VERIFY_REQUIRED specially for logging * purposes, as it is an expected return value rather than an * actual error, but you still need to reset/free the context. * * \note Remarks regarding event-driven DTLS: * If the function returns #MBEDTLS_ERR_SSL_WANT_READ, no datagram * from the underlying transport layer is currently being processed, * and it is safe to idle until the timer or the underlying transport * signal a new event. This is not true for a successful handshake, * in which case the datagram of the underlying transport that is * currently being processed might or might not contain further * DTLS records. */ int mbedtls_ssl_handshake( mbedtls_ssl_context *ssl ) { int ret = 0; /* Sanity checks */ if( ssl == NULL || ssl->conf == NULL || ssl->conf->f_step == NULL ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); #if defined(MBEDTLS_SSL_PROTO_DTLS) if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM && ( 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 ); } #endif /* MBEDTLS_SSL_PROTO_DTLS */ MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> handshake" ) ); /* Main handshake loop */ while( ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER ) { ret = ssl->conf->f_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_ERR_THIS_CORRUPTION; 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. */ int mbedtls_ssl_start_renegotiation( mbedtls_ssl_context *ssl ) { int ret = MBEDTLS_ERR_THIS_CORRUPTION; 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 ); } /** * \brief Initiate an SSL renegotiation on the running connection. * Client: perform the renegotiation right now. * Server: request renegotiation, which will be performed * during the next call to mbedtls_ssl_read() if honored by * client. * * \param ssl SSL context * * \return 0 if successful, or any mbedtls_ssl_handshake() return * value except #MBEDTLS_ERR_SSL_CLIENT_RECONNECT that can't * happen during a renegotiation. * * \warning If this function returns something other than \c 0, * #MBEDTLS_ERR_SSL_WANT_READ, #MBEDTLS_ERR_SSL_WANT_WRITE, * #MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS or * #MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS, you must stop using * the SSL context for reading or writing, and either free it * or call \c mbedtls_ssl_session_reset() on it before * re-using it for a new connection; the current connection * must be closed. * */ 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 = mbedtls_ssl_start_renegotiation( ssl ) ) != 0 ) { MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_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 ); } #endif /* MBEDTLS_SSL_RENEGOTIATION */ #if defined(MBEDTLS_X509_CRT_PARSE_C) void mbedtls_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 */ /** * \brief Free referenced items in an SSL handshake context and clear * memory * * \param ssl SSL context */ 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_ENABLED) mbedtls_x509_crt_restart_free( &handshake->ecrs_ctx ); if( handshake->ecrs_peer_cert != NULL ) { mbedtls_x509_crt_free( handshake->ecrs_peer_cert ); mbedtls_free( handshake->ecrs_peer_cert ); } #endif #if defined(MBEDTLS_X509_CRT_PARSE_C) && \ !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE) mbedtls_pk_free( &handshake->peer_pubkey ); #endif /* MBEDTLS_X509_CRT_PARSE_C && !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */ #if defined(MBEDTLS_SSL_PROTO_DTLS) mbedtls_free( handshake->verify_cookie ); mbedtls_ssl_flight_free( handshake->flight ); mbedtls_ssl_buffering_free( ssl ); #endif mbedtls_platform_zeroize( handshake, sizeof( mbedtls_ssl_handshake_params ) ); #if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH) /* If the buffers are too big - reallocate. Because of the way Mbed TLS * processes datagrams and the fact that a datagram is allowed to have * several records in it, it is possible that the I/O buffers are not * empty at this stage */ handle_buffer_resizing( ssl, 1, mbedtls_ssl_get_input_buflen( ssl ), mbedtls_ssl_get_output_buflen( ssl ) ); #endif } /** * \brief Free referenced items in an SSL session including the * peer certificate and clear memory * * \note A session object can be freed even if the SSL context * that was used to retrieve the session is still in use. * * \param session SSL session */ void mbedtls_ssl_session_free( mbedtls_ssl_session *session ) { if( session == NULL ) return; #if defined(MBEDTLS_X509_CRT_PARSE_C) ssl_clear_peer_cert( session ); #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 ) ); } #if defined(MBEDTLS_SSL_CONTEXT_SERIALIZATION) #if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) #define SSL_SERIALIZED_CONTEXT_CONFIG_DTLS_CONNECTION_ID 1u #else #define SSL_SERIALIZED_CONTEXT_CONFIG_DTLS_CONNECTION_ID 0u #endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */ #if defined(MBEDTLS_SSL_DTLS_BADMAC_LIMIT) #define SSL_SERIALIZED_CONTEXT_CONFIG_DTLS_BADMAC_LIMIT 1u #else #define SSL_SERIALIZED_CONTEXT_CONFIG_DTLS_BADMAC_LIMIT 0u #endif /* MBEDTLS_SSL_DTLS_BADMAC_LIMIT */ #if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY) #define SSL_SERIALIZED_CONTEXT_CONFIG_DTLS_ANTI_REPLAY 1u #else #define SSL_SERIALIZED_CONTEXT_CONFIG_DTLS_ANTI_REPLAY 0u #endif /* MBEDTLS_SSL_DTLS_ANTI_REPLAY */ #if defined(MBEDTLS_SSL_ALPN) #define SSL_SERIALIZED_CONTEXT_CONFIG_ALPN 1u #else #define SSL_SERIALIZED_CONTEXT_CONFIG_ALPN 0u #endif /* MBEDTLS_SSL_ALPN */ #define SSL_SERIALIZED_CONTEXT_CONFIG_DTLS_CONNECTION_ID_BIT 0 #define SSL_SERIALIZED_CONTEXT_CONFIG_DTLS_BADMAC_LIMIT_BIT 1 #define SSL_SERIALIZED_CONTEXT_CONFIG_DTLS_ANTI_REPLAY_BIT 2 #define SSL_SERIALIZED_CONTEXT_CONFIG_ALPN_BIT 3 #define SSL_SERIALIZED_CONTEXT_CONFIG_BITFLAG \ ( (uint32_t) ( \ ( SSL_SERIALIZED_CONTEXT_CONFIG_DTLS_CONNECTION_ID << SSL_SERIALIZED_CONTEXT_CONFIG_DTLS_CONNECTION_ID_BIT ) | \ ( SSL_SERIALIZED_CONTEXT_CONFIG_DTLS_BADMAC_LIMIT << SSL_SERIALIZED_CONTEXT_CONFIG_DTLS_BADMAC_LIMIT_BIT ) | \ ( SSL_SERIALIZED_CONTEXT_CONFIG_DTLS_ANTI_REPLAY << SSL_SERIALIZED_CONTEXT_CONFIG_DTLS_ANTI_REPLAY_BIT ) | \ ( SSL_SERIALIZED_CONTEXT_CONFIG_ALPN << SSL_SERIALIZED_CONTEXT_CONFIG_ALPN_BIT ) | \ 0u ) ) static unsigned char ssl_serialized_context_header[] = { MBEDTLS_VERSION_MAJOR, MBEDTLS_VERSION_MINOR, MBEDTLS_VERSION_PATCH, ( SSL_SERIALIZED_SESSION_CONFIG_BITFLAG >> 8 ) & 0xFF, ( SSL_SERIALIZED_SESSION_CONFIG_BITFLAG >> 0 ) & 0xFF, ( SSL_SERIALIZED_CONTEXT_CONFIG_BITFLAG >> 16 ) & 0xFF, ( SSL_SERIALIZED_CONTEXT_CONFIG_BITFLAG >> 8 ) & 0xFF, ( SSL_SERIALIZED_CONTEXT_CONFIG_BITFLAG >> 0 ) & 0xFF, }; /** * Serialize a full SSL context * * The format of the serialized data is: * (in the presentation language of TLS, RFC 8446 section 3) * * // header * opaque mbedtls_version[3]; // major, minor, patch * opaque context_format[5]; // version-specific field determining * // the format of the remaining * // serialized data. * Note: When updating the format, remember to keep these * version+format bytes. (We may make their size part of the API.) * * // session sub-structure * opaque session<1..2^32-1>; // see mbedtls_ssl_session_save() * // transform sub-structure * uint8 random[64]; // ServerHello.random+ClientHello.random * uint8 in_cid<0..2^8-1> // Connection ID: expected incoming value * uint8 out_cid<0..2^8-1> // Connection ID: outgoing value to use * // fields from ssl_context * uint32 badmac_seen; // DTLS: number of records with failing MAC * uint64 in_window_top; // DTLS: last validated record seq_num * uint64 in_window; // DTLS: bitmask for replay protection * uint8 disable_datagram_packing; // DTLS: only one record per datagram * uint64 cur_out_ctr; // Record layer: outgoing sequence number * uint16 mtu; // DTLS: path mtu (max outgoing fragment size) * uint8 alpn_chosen<0..2^8-1> // ALPN: negotiated application protocol * * Note that many fields of the ssl_context or sub-structures are not * serialized, as they fall in one of the following categories: * * 1. forced value (eg in_left must be 0) * 2. pointer to dynamically-allocated memory (eg session, transform) * 3. value can be re-derived from other data (eg session keys from MS) * 4. value was temporary (eg content of input buffer) * 5. value will be provided by the user again (eg I/O callbacks and context) * * \brief Save an active connection as serialized data in a buffer. * This allows the freeing or re-using of the SSL context * while still picking up the connection later in a way that * it entirely transparent to the peer. * * \see mbedtls_ssl_context_load() * * \note This feature is currently only available under certain * conditions, see the documentation of the return value * #MBEDTLS_ERR_SSL_BAD_INPUT_DATA for details. * * \note When this function succeeds, it calls * mbedtls_ssl_session_reset() on \p ssl which as a result is * no longer associated with the connection that has been * serialized. This avoids creating copies of the connection * state. You're then free to either re-use the context * structure for a different connection, or call * mbedtls_ssl_free() on it. See the documentation of * mbedtls_ssl_session_reset() for more details. * * \param ssl The SSL context to save. On success, it is no longer * associated with the connection that has been serialized. * \param buf The buffer to write the serialized data to. It must be a * writeable buffer of at least \p buf_len bytes, or may be \c * NULL if \p buf_len is \c 0. * \param buf_len The number of bytes available for writing in \p buf. * \param olen The size in bytes of the data that has been or would have * been written. It must point to a valid \c size_t. * * \note \p olen is updated to the correct value regardless of * whether \p buf_len was large enough. This makes it possible * to determine the necessary size by calling this function * with \p buf set to \c NULL and \p buf_len to \c 0. However, * the value of \p olen is only guaranteed to be correct when * the function returns #MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL or * \c 0. If the return value is different, then the value of * \p olen is undefined. * * \return \c 0 if successful. * \return #MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL if \p buf is too small. * \return #MBEDTLS_ERR_SSL_ALLOC_FAILED if memory allocation failed * while reseting the context. * \return #MBEDTLS_ERR_SSL_BAD_INPUT_DATA if a handshake is in * progress, or there is pending data for reading or sending, * or the connection does not use DTLS 1.2 with an AEAD * ciphersuite, or renegotiation is enabled. */ int mbedtls_ssl_context_save( mbedtls_ssl_context *ssl, unsigned char *buf, size_t buf_len, size_t *olen ) { unsigned char *p = buf; size_t used = 0; size_t session_len; int ret = 0; /* * Enforce usage restrictions, see "return BAD_INPUT_DATA" in * this function's documentation. * * These are due to assumptions/limitations in the implementation. Some of * them are likely to stay (no handshake in progress) some might go away * (only DTLS) but are currently used to simplify the implementation. */ /* The initial handshake must be over */ if( ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "Initial handshake isn't over" ) ); return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); } if( ssl->handshake != NULL ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "Handshake isn't completed" ) ); return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); } /* Double-check that sub-structures are indeed ready */ if( ssl->transform == NULL || ssl->session == NULL ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "Serialised structures aren't ready" ) ); return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); } /* There must be no pending incoming or outgoing data */ if( mbedtls_ssl_check_pending( ssl ) != 0 ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "There is pending incoming data" ) ); return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); } if( ssl->out_left != 0 ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "There is pending outgoing data" ) ); return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); } /* Protocol must be DLTS, not TLS */ if( ssl->conf->transport != MBEDTLS_SSL_TRANSPORT_DATAGRAM ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "Only DTLS is supported" ) ); return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); } /* Version must be 1.2 */ if( ssl->major_ver != MBEDTLS_SSL_MAJOR_VERSION_3 ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "Only version 1.2 supported" ) ); return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); } if( ssl->minor_ver != MBEDTLS_SSL_MINOR_VERSION_3 ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "Only version 1.2 supported" ) ); return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); } /* We must be using an AEAD ciphersuite */ if( mbedtls_ssl_transform_uses_aead( ssl->transform ) != 1 ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "Only AEAD ciphersuites supported" ) ); return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); } /* Renegotiation must not be enabled */ #if defined(MBEDTLS_SSL_RENEGOTIATION) if( ssl->conf->disable_renegotiation != MBEDTLS_SSL_RENEGOTIATION_DISABLED ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "Renegotiation must not be enabled" ) ); return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); } #endif /* * Version and format identifier */ used += sizeof( ssl_serialized_context_header ); if( used <= buf_len ) { p = mempcpy( p, ssl_serialized_context_header, sizeof( ssl_serialized_context_header ) ); } /* * Session (length + data) */ ret = ssl_session_save( ssl->session, 1, NULL, 0, &session_len ); if( ret != MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL ) return( ret ); used += 4 + session_len; if( used <= buf_len ) { p = Write32be(p, session_len); ret = ssl_session_save( ssl->session, 1, p, session_len, &session_len ); if( ret != 0 ) return( ret ); p += session_len; } /* * Transform */ used += sizeof( ssl->transform->randbytes ); if( used <= buf_len ) { memcpy( p, ssl->transform->randbytes, sizeof( ssl->transform->randbytes ) ); p += sizeof( ssl->transform->randbytes ); } #if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) used += 2 + ssl->transform->in_cid_len + ssl->transform->out_cid_len; if( used <= buf_len ) { *p++ = ssl->transform->in_cid_len; memcpy( p, ssl->transform->in_cid, ssl->transform->in_cid_len ); p += ssl->transform->in_cid_len; *p++ = ssl->transform->out_cid_len; memcpy( p, ssl->transform->out_cid, ssl->transform->out_cid_len ); p += ssl->transform->out_cid_len; } #endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */ /* * Saved fields from top-level ssl_context structure */ #if defined(MBEDTLS_SSL_DTLS_BADMAC_LIMIT) used += 4; if( used <= buf_len ) { p = Write32be(p, ssl->badmac_seen); } #endif /* MBEDTLS_SSL_DTLS_BADMAC_LIMIT */ #if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY) used += 16; if( used <= buf_len ) { p = Write64be(p, ssl->in_window_top); p = Write64be(p, ssl->in_window); } #endif /* MBEDTLS_SSL_DTLS_ANTI_REPLAY */ #if defined(MBEDTLS_SSL_PROTO_DTLS) used += 1; if( used <= buf_len ) { *p++ = ssl->disable_datagram_packing; } #endif /* MBEDTLS_SSL_PROTO_DTLS */ used += 8; if( used <= buf_len ) { memcpy( p, ssl->cur_out_ctr, 8 ); p += 8; } #if defined(MBEDTLS_SSL_PROTO_DTLS) used += 2; if( used <= buf_len ) { *p++ = (unsigned char)( ( ssl->mtu >> 8 ) & 0xFF ); *p++ = (unsigned char)( ( ssl->mtu ) & 0xFF ); } #endif /* MBEDTLS_SSL_PROTO_DTLS */ #if defined(MBEDTLS_SSL_ALPN) { const uint8_t alpn_len = ssl->alpn_chosen ? (uint8_t) strlen( ssl->alpn_chosen ) : 0; used += 1 + alpn_len; if( used <= buf_len ) { *p++ = alpn_len; if( ssl->alpn_chosen != NULL ) { memcpy( p, ssl->alpn_chosen, alpn_len ); p += alpn_len; } } } #endif /* MBEDTLS_SSL_ALPN */ /* * Done */ *olen = used; if( used > buf_len ) return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL ); MBEDTLS_SSL_DEBUG_BUF( 4, "saved context", buf, used ); return( mbedtls_ssl_session_reset_int( ssl, 0 ) ); } /* * Helper to get TLS 1.2 PRF from ciphersuite * (Duplicates bits of logic from ssl_set_handshake_prfs().) */ typedef int (*tls_prf_fn)( const unsigned char *secret, size_t slen, const char *label, const unsigned char *random, size_t rlen, unsigned char *dstbuf, size_t dlen ); static tls_prf_fn ssl_tls12prf_from_cs( int ciphersuite_id ) { #if defined(MBEDTLS_SHA512_C) const mbedtls_ssl_ciphersuite_t * const ciphersuite_info = mbedtls_ssl_ciphersuite_from_id( ciphersuite_id ); if( ciphersuite_info->mac == MBEDTLS_MD_SHA384 ) return( tls_prf_sha384 ); #else (void) ciphersuite_id; #endif return( tls_prf_sha256 ); } /* * Deserialize context, see mbedtls_ssl_context_save() for format. * * This internal version is wrapped by a public function that cleans up in * case of error. */ static int ssl_context_load( mbedtls_ssl_context *ssl, const unsigned char *buf, size_t len ) { const unsigned char *p = buf; const unsigned char * const end = buf + len; size_t session_len; int ret = MBEDTLS_ERR_THIS_CORRUPTION; /* * The context should have been freshly setup or reset. * Give the user an error in case of obvious misuse. * (Checking session is useful because it won't be NULL if we're * renegotiating, or if the user mistakenly loaded a session first.) */ if( ssl->state != MBEDTLS_SSL_HELLO_REQUEST || ssl->session != NULL ) { return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); } /* * We can't check that the config matches the initial one, but we can at * least check it matches the requirements for serializing. */ if( ssl->conf->transport != MBEDTLS_SSL_TRANSPORT_DATAGRAM || ssl->conf->max_major_ver < MBEDTLS_SSL_MAJOR_VERSION_3 || ssl->conf->min_major_ver > MBEDTLS_SSL_MAJOR_VERSION_3 || ssl->conf->max_minor_ver < MBEDTLS_SSL_MINOR_VERSION_3 || ssl->conf->min_minor_ver > MBEDTLS_SSL_MINOR_VERSION_3 || #if defined(MBEDTLS_SSL_RENEGOTIATION) ssl->conf->disable_renegotiation != MBEDTLS_SSL_RENEGOTIATION_DISABLED || #endif 0 ) { return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); } MBEDTLS_SSL_DEBUG_BUF( 4, "context to load", buf, len ); /* * Check version identifier */ if( (size_t)( end - p ) < sizeof( ssl_serialized_context_header ) ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); if( timingsafe_bcmp( p, ssl_serialized_context_header, sizeof( ssl_serialized_context_header ) ) != 0 ) { return( MBEDTLS_ERR_SSL_VERSION_MISMATCH ); } p += sizeof( ssl_serialized_context_header ); /* * Session */ if( (size_t)( end - p ) < 4 ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); session_len = ( (size_t) p[0] << 24 ) | ( (size_t) p[1] << 16 ) | ( (size_t) p[2] << 8 ) | ( (size_t) p[3] ); p += 4; /* This has been allocated by ssl_handshake_init(), called by * by either mbedtls_ssl_session_reset_int() or mbedtls_ssl_setup(). */ ssl->session = ssl->session_negotiate; ssl->session_in = ssl->session; ssl->session_out = ssl->session; ssl->session_negotiate = NULL; if( (size_t)( end - p ) < session_len ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); ret = ssl_session_load( ssl->session, 1, p, session_len ); if( ret != 0 ) { mbedtls_ssl_session_free( ssl->session ); return( ret ); } p += session_len; /* * Transform */ /* This has been allocated by ssl_handshake_init(), called by * by either mbedtls_ssl_session_reset_int() or mbedtls_ssl_setup(). */ ssl->transform = ssl->transform_negotiate; ssl->transform_in = ssl->transform; ssl->transform_out = ssl->transform; ssl->transform_negotiate = NULL; /* Read random bytes and populate structure */ if( (size_t)( end - p ) < sizeof( ssl->transform->randbytes ) ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); ret = ssl_populate_transform( ssl->transform, ssl->session->ciphersuite, ssl->session->master, #if defined(MBEDTLS_SSL_SOME_MODES_USE_MAC) #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC) ssl->session->encrypt_then_mac, #endif #if defined(MBEDTLS_SSL_TRUNCATED_HMAC) ssl->session->trunc_hmac, #endif #endif /* MBEDTLS_SSL_SOME_MODES_USE_MAC */ #if defined(MBEDTLS_ZLIB_SUPPORT) ssl->session->compression, #endif ssl_tls12prf_from_cs( ssl->session->ciphersuite ), p, /* currently pointing to randbytes */ MBEDTLS_SSL_MINOR_VERSION_3, /* (D)TLS 1.2 is forced */ ssl->conf->endpoint, ssl ); if( ret != 0 ) return( ret ); p += sizeof( ssl->transform->randbytes ); #if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) /* Read connection IDs and store them */ if( (size_t)( end - p ) < 1 ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); ssl->transform->in_cid_len = *p++; if( (size_t)( end - p ) < ssl->transform->in_cid_len + 1u ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); memcpy( ssl->transform->in_cid, p, ssl->transform->in_cid_len ); p += ssl->transform->in_cid_len; ssl->transform->out_cid_len = *p++; if( (size_t)( end - p ) < ssl->transform->out_cid_len ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); memcpy( ssl->transform->out_cid, p, ssl->transform->out_cid_len ); p += ssl->transform->out_cid_len; #endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */ /* * Saved fields from top-level ssl_context structure */ #if defined(MBEDTLS_SSL_DTLS_BADMAC_LIMIT) if( (size_t)( end - p ) < 4 ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); ssl->badmac_seen = ( (uint32_t) p[0] << 24 ) | ( (uint32_t) p[1] << 16 ) | ( (uint32_t) p[2] << 8 ) | ( (uint32_t) p[3] ); p += 4; #endif /* MBEDTLS_SSL_DTLS_BADMAC_LIMIT */ #if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY) if( (size_t)( end - p ) < 16 ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); ssl->in_window_top = ( (uint64_t) p[0] << 56 ) | ( (uint64_t) p[1] << 48 ) | ( (uint64_t) p[2] << 40 ) | ( (uint64_t) p[3] << 32 ) | ( (uint64_t) p[4] << 24 ) | ( (uint64_t) p[5] << 16 ) | ( (uint64_t) p[6] << 8 ) | ( (uint64_t) p[7] ); p += 8; ssl->in_window = ( (uint64_t) p[0] << 56 ) | ( (uint64_t) p[1] << 48 ) | ( (uint64_t) p[2] << 40 ) | ( (uint64_t) p[3] << 32 ) | ( (uint64_t) p[4] << 24 ) | ( (uint64_t) p[5] << 16 ) | ( (uint64_t) p[6] << 8 ) | ( (uint64_t) p[7] ); p += 8; #endif /* MBEDTLS_SSL_DTLS_ANTI_REPLAY */ #if defined(MBEDTLS_SSL_PROTO_DTLS) if( (size_t)( end - p ) < 1 ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); ssl->disable_datagram_packing = *p++; #endif /* MBEDTLS_SSL_PROTO_DTLS */ if( (size_t)( end - p ) < 8 ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); memcpy( ssl->cur_out_ctr, p, 8 ); p += 8; #if defined(MBEDTLS_SSL_PROTO_DTLS) if( (size_t)( end - p ) < 2 ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); ssl->mtu = ( p[0] << 8 ) | p[1]; p += 2; #endif /* MBEDTLS_SSL_PROTO_DTLS */ #if defined(MBEDTLS_SSL_ALPN) { uint8_t alpn_len; const char **cur; if( (size_t)( end - p ) < 1 ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); alpn_len = *p++; if( alpn_len != 0 && ssl->conf->alpn_list != NULL ) { /* alpn_chosen should point to an item in the configured list */ for( cur = ssl->conf->alpn_list; *cur != NULL; cur++ ) { if( strlen( *cur ) == alpn_len && timingsafe_bcmp( p, cur, alpn_len ) == 0 ) { ssl->alpn_chosen = *cur; break; } } } /* can only happen on conf mismatch */ if( alpn_len != 0 && ssl->alpn_chosen == NULL ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); p += alpn_len; } #endif /* MBEDTLS_SSL_ALPN */ /* * Forced fields from top-level ssl_context structure * * Most of them already set to the correct value by mbedtls_ssl_init() and * mbedtls_ssl_reset(), so we only need to set the remaining ones. */ ssl->state = MBEDTLS_SSL_HANDSHAKE_OVER; ssl->major_ver = MBEDTLS_SSL_MAJOR_VERSION_3; ssl->minor_ver = MBEDTLS_SSL_MINOR_VERSION_3; /* Adjust pointers for header fields of outgoing records to * the given transform, accounting for explicit IV and CID. */ mbedtls_ssl_update_out_pointers( ssl, ssl->transform ); #if defined(MBEDTLS_SSL_PROTO_DTLS) ssl->in_epoch = 1; #endif /* mbedtls_ssl_reset() leaves the handshake sub-structure allocated, * which we don't want - otherwise we'd end up freeing the wrong transform * by calling mbedtls_ssl_handshake_wrapup_free_hs_transform() * inappropriately. */ if( ssl->handshake != NULL ) { mbedtls_ssl_handshake_free( ssl ); mbedtls_free( ssl->handshake ); ssl->handshake = NULL; } /* * Done - should have consumed entire buffer */ if( p != end ) return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); return( 0 ); } /** * \brief Load serialized connection data to an SSL context. * * \see mbedtls_ssl_context_save() * * \warning The same serialized data must never be loaded into more * that one context. In order to ensure that, after * successfully loading serialized data to an SSL context, you * should immediately destroy or invalidate all copies of the * serialized data that was loaded. Loading the same data in * more than one context would cause severe security failures * including but not limited to loss of confidentiality. * * \note Before calling this function, the SSL context must be * prepared in one of the two following ways. The first way is * to take a context freshly initialised with * mbedtls_ssl_init() and call mbedtls_ssl_setup() on it with * the same ::mbedtls_ssl_config structure that was used in * the original connection. The second way is to * call mbedtls_ssl_session_reset() on a context that was * previously prepared as above but used in the meantime. * Either way, you must not use the context to perform a * handshake between calling mbedtls_ssl_setup() or * mbedtls_ssl_session_reset() and calling this function. You * may however call other setter functions in that time frame * as indicated in the note below. * * \note Before or after calling this function successfully, you * also need to configure some connection-specific callbacks * and settings before you can use the connection again * (unless they were already set before calling * mbedtls_ssl_session_reset() and the values are suitable for * the present connection). Specifically, you want to call * at least mbedtls_ssl_set_bio() and * mbedtls_ssl_set_timer_cb(). All other SSL setter functions * are not necessary to call, either because they're only used * in handshakes, or because the setting is already saved. You * might choose to call them anyway, for example in order to * share code between the cases of establishing a new * connection and the case of loading an already-established * connection. * * \note If you have new information about the path MTU, you want to * call mbedtls_ssl_set_mtu() after calling this function, as * otherwise this function would overwrite your * newly-configured value with the value that was active when * the context was saved. * * \note When this function returns an error code, it calls * mbedtls_ssl_free() on \p ssl. In this case, you need to * prepare the context with the usual sequence starting with a * call to mbedtls_ssl_init() if you want to use it again. * * \param ssl The SSL context structure to be populated. It must have * been prepared as described in the note above. * \param buf The buffer holding the serialized connection data. It must * be a readable buffer of at least \p len bytes. * \param len The size of the serialized data in bytes. * * \return \c 0 if successful. * \return #MBEDTLS_ERR_SSL_ALLOC_FAILED if memory allocation failed. * \return #MBEDTLS_ERR_SSL_VERSION_MISMATCH if the serialized data * comes from a different Mbed TLS version or build. * \return #MBEDTLS_ERR_SSL_BAD_INPUT_DATA if input data is invalid. */ int mbedtls_ssl_context_load( mbedtls_ssl_context *context, const unsigned char *buf, size_t len ) { int ret = ssl_context_load( context, buf, len ); if( ret != 0 ) mbedtls_ssl_free( context ); return( ret ); } #endif /* MBEDTLS_SSL_CONTEXT_SERIALIZATION */ /** * \brief Free referenced items in an SSL context and clear memory * * \param ssl 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 ) { #if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH) size_t out_buf_len = ssl->out_buf_len; #else size_t out_buf_len = MBEDTLS_SSL_OUT_BUFFER_LEN; #endif mbedtls_platform_zeroize( ssl->out_buf, out_buf_len ); mbedtls_free( ssl->out_buf ); ssl->out_buf = NULL; } if( ssl->in_buf != NULL ) { #if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH) size_t in_buf_len = ssl->in_buf_len; #else size_t in_buf_len = MBEDTLS_SSL_IN_BUFFER_LEN; #endif mbedtls_platform_zeroize( ssl->in_buf, in_buf_len ); mbedtls_free( ssl->in_buf ); ssl->in_buf = NULL; } #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 ) ); } /** * \brief Initialize an SSL configuration context * Just makes the context ready for * mbedtls_ssl_config_defaults() or mbedtls_ssl_config_free(). * * \note You need to call mbedtls_ssl_config_defaults() unless you * manually set all of the relevant fields yourself. * * \param conf SSL configuration context */ void mbedtls_ssl_config_init( mbedtls_ssl_config *conf ) { mbedtls_platform_zeroize( conf, sizeof( mbedtls_ssl_config ) ); } #if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED) static uint8_t 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 uint16_t ssl_preset_suiteb_ciphersuites[] = { MBEDTLS_TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384, MBEDTLS_TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384, MBEDTLS_TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384, MBEDTLS_TLS_ECDHE_PSK_WITH_AES_256_GCM_SHA384, 0 }; #if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED) static uint8_t ssl_preset_suiteb_hashes[] = { MBEDTLS_MD_SHA384, MBEDTLS_MD_NONE }; #endif #if defined(MBEDTLS_ECP_C) static mbedtls_ecp_group_id ssl_preset_suiteb_curves[] = { #if defined(MBEDTLS_ECP_DP_SECP384R1_ENABLED) MBEDTLS_ECP_DP_SECP384R1, #endif #if defined(MBEDTLS_ECP_DP_SECP256R1_ENABLED) MBEDTLS_ECP_DP_SECP256R1, #endif MBEDTLS_ECP_DP_NONE }; #endif /* * Load default in mbedtls_ssl_config */ int mbedtls_ssl_config_defaults_impl( mbedtls_ssl_config *conf, int endpoint, int transport, int preset, int ssl_handshake_step(mbedtls_ssl_context *) ) { #if defined(MBEDTLS_DHM_C) && defined(MBEDTLS_SSL_SRV_C) int ret = MBEDTLS_ERR_THIS_CORRUPTION; #endif conf->f_step = ssl_handshake_step; /* 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_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 ); } /** * \brief Free an SSL configuration context * * \param conf SSL configuration context */ 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) mbedtls_ssl_key_cert_free( conf->key_cert ); #endif mbedtls_platform_zeroize( conf, sizeof( mbedtls_ssl_config ) ); } 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_SSL_DEBUG_MSG( 3, ( "Perform mbedtls-based computation of digest of ServerKeyExchange" ) ); 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 ); } #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 ); } } #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 ); } } /* 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_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 uint8_t *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 */ 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 */ #endif /* MBEDTLS_SSL_TLS_C */