| /* |
| * TLS server-side functions |
| * |
| * Copyright The Mbed TLS Contributors |
| * SPDX-License-Identifier: Apache-2.0 |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); you may |
| * not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT |
| * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #include "common.h" |
| |
| #if defined(MBEDTLS_SSL_SRV_C) |
| |
| #if defined(MBEDTLS_PLATFORM_C) |
| #include "mbedtls/platform.h" |
| #else |
| #include <stdlib.h> |
| #define mbedtls_calloc calloc |
| #define mbedtls_free free |
| #endif |
| |
| #include "mbedtls/ssl.h" |
| #include "ssl_misc.h" |
| #include "mbedtls/debug.h" |
| #include "mbedtls/error.h" |
| #include "mbedtls/platform_util.h" |
| |
| #include <string.h> |
| |
| #if defined(MBEDTLS_ECP_C) |
| #include "mbedtls/ecp.h" |
| #endif |
| |
| #if defined(MBEDTLS_HAVE_TIME) |
| #include "mbedtls/platform_time.h" |
| #endif |
| |
| #if defined(MBEDTLS_SSL_DTLS_HELLO_VERIFY) |
| int mbedtls_ssl_set_client_transport_id( mbedtls_ssl_context *ssl, |
| const unsigned char *info, |
| size_t ilen ) |
| { |
| if( ssl->conf->endpoint != MBEDTLS_SSL_IS_SERVER ) |
| return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); |
| |
| mbedtls_free( ssl->cli_id ); |
| |
| if( ( ssl->cli_id = mbedtls_calloc( 1, ilen ) ) == NULL ) |
| return( MBEDTLS_ERR_SSL_ALLOC_FAILED ); |
| |
| memcpy( ssl->cli_id, info, ilen ); |
| ssl->cli_id_len = ilen; |
| |
| return( 0 ); |
| } |
| |
| void mbedtls_ssl_conf_dtls_cookies( mbedtls_ssl_config *conf, |
| mbedtls_ssl_cookie_write_t *f_cookie_write, |
| mbedtls_ssl_cookie_check_t *f_cookie_check, |
| void *p_cookie ) |
| { |
| conf->f_cookie_write = f_cookie_write; |
| conf->f_cookie_check = f_cookie_check; |
| conf->p_cookie = p_cookie; |
| } |
| #endif /* MBEDTLS_SSL_DTLS_HELLO_VERIFY */ |
| |
| #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION) |
| static int ssl_parse_servername_ext( mbedtls_ssl_context *ssl, |
| const unsigned char *buf, |
| size_t len ) |
| { |
| int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| size_t servername_list_size, hostname_len; |
| const unsigned char *p; |
| |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "parse ServerName extension" ) ); |
| |
| if( len < 2 ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| servername_list_size = ( ( buf[0] << 8 ) | ( buf[1] ) ); |
| if( servername_list_size + 2 != len ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| p = buf + 2; |
| while( servername_list_size > 2 ) |
| { |
| hostname_len = ( ( p[1] << 8 ) | p[2] ); |
| if( hostname_len + 3 > servername_list_size ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| if( p[0] == MBEDTLS_TLS_EXT_SERVERNAME_HOSTNAME ) |
| { |
| ret = ssl->conf->f_sni( ssl->conf->p_sni, |
| ssl, p + 3, hostname_len ); |
| if( ret != 0 ) |
| { |
| MBEDTLS_SSL_DEBUG_RET( 1, "ssl_sni_wrapper", ret ); |
| mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| MBEDTLS_SSL_ALERT_MSG_UNRECOGNIZED_NAME ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| return( 0 ); |
| } |
| |
| servername_list_size -= hostname_len + 3; |
| p += hostname_len + 3; |
| } |
| |
| if( servername_list_size != 0 ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| return( 0 ); |
| } |
| #endif /* MBEDTLS_SSL_SERVER_NAME_INDICATION */ |
| |
| #if defined(MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED) |
| static int ssl_conf_has_psk_or_cb( mbedtls_ssl_config const *conf ) |
| { |
| if( conf->f_psk != NULL ) |
| return( 1 ); |
| |
| if( conf->psk_identity_len == 0 || conf->psk_identity == NULL ) |
| return( 0 ); |
| |
| if( conf->psk != NULL && conf->psk_len != 0 ) |
| return( 1 ); |
| |
| #if defined(MBEDTLS_USE_PSA_CRYPTO) |
| if( ! mbedtls_svc_key_id_is_null( conf->psk_opaque ) ) |
| return( 1 ); |
| #endif /* MBEDTLS_USE_PSA_CRYPTO */ |
| |
| return( 0 ); |
| } |
| |
| #if defined(MBEDTLS_USE_PSA_CRYPTO) |
| static int ssl_use_opaque_psk( mbedtls_ssl_context const *ssl ) |
| { |
| if( ssl->conf->f_psk != NULL ) |
| { |
| /* If we've used a callback to select the PSK, |
| * the static configuration is irrelevant. */ |
| |
| if( ! mbedtls_svc_key_id_is_null( ssl->handshake->psk_opaque ) ) |
| return( 1 ); |
| |
| return( 0 ); |
| } |
| |
| if( ! mbedtls_svc_key_id_is_null( ssl->conf->psk_opaque ) ) |
| return( 1 ); |
| |
| return( 0 ); |
| } |
| #endif /* MBEDTLS_USE_PSA_CRYPTO */ |
| #endif /* MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED */ |
| |
| static int ssl_parse_renegotiation_info( mbedtls_ssl_context *ssl, |
| const unsigned char *buf, |
| size_t len ) |
| { |
| #if defined(MBEDTLS_SSL_RENEGOTIATION) |
| if( ssl->renego_status != MBEDTLS_SSL_INITIAL_HANDSHAKE ) |
| { |
| /* Check verify-data in constant-time. The length OTOH is no secret */ |
| if( len != 1 + ssl->verify_data_len || |
| buf[0] != ssl->verify_data_len || |
| mbedtls_ssl_safer_memcmp( buf + 1, ssl->peer_verify_data, |
| ssl->verify_data_len ) != 0 ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "non-matching renegotiation info" ) ); |
| mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| } |
| else |
| #endif /* MBEDTLS_SSL_RENEGOTIATION */ |
| { |
| if( len != 1 || buf[0] != 0x0 ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "non-zero length renegotiation info" ) ); |
| mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| ssl->secure_renegotiation = MBEDTLS_SSL_SECURE_RENEGOTIATION; |
| } |
| |
| return( 0 ); |
| } |
| |
| #if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \ |
| defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED) |
| |
| /* |
| * Status of the implementation of signature-algorithms extension: |
| * |
| * Currently, we are only considering the signature-algorithm extension |
| * to pick a ciphersuite which allows us to send the ServerKeyExchange |
| * message with a signature-hash combination that the user allows. |
| * |
| * We do *not* check whether all certificates in our certificate |
| * chain are signed with an allowed signature-hash pair. |
| * This needs to be done at a later stage. |
| * |
| */ |
| static int ssl_parse_signature_algorithms_ext( mbedtls_ssl_context *ssl, |
| const unsigned char *buf, |
| size_t len ) |
| { |
| size_t sig_alg_list_size; |
| |
| const unsigned char *p; |
| const unsigned char *end = buf + len; |
| |
| mbedtls_md_type_t md_cur; |
| mbedtls_pk_type_t sig_cur; |
| |
| if ( len < 2 ) { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| sig_alg_list_size = ( ( buf[0] << 8 ) | ( buf[1] ) ); |
| if( sig_alg_list_size + 2 != len || |
| sig_alg_list_size % 2 != 0 ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| /* Currently we only guarantee signing the ServerKeyExchange message according |
| * to the constraints specified in this extension (see above), so it suffices |
| * to remember only one suitable hash for each possible signature algorithm. |
| * |
| * This will change when we also consider certificate signatures, |
| * in which case we will need to remember the whole signature-hash |
| * pair list from the extension. |
| */ |
| |
| for( p = buf + 2; p < end; p += 2 ) |
| { |
| /* Silently ignore unknown signature or hash algorithms. */ |
| |
| if( ( sig_cur = mbedtls_ssl_pk_alg_from_sig( p[1] ) ) == MBEDTLS_PK_NONE ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello v3, signature_algorithm ext" |
| " unknown sig alg encoding %d", p[1] ) ); |
| continue; |
| } |
| |
| /* Check if we support the hash the user proposes */ |
| md_cur = mbedtls_ssl_md_alg_from_hash( p[0] ); |
| if( md_cur == MBEDTLS_MD_NONE ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello v3, signature_algorithm ext:" |
| " unknown hash alg encoding %d", p[0] ) ); |
| continue; |
| } |
| |
| if( mbedtls_ssl_check_sig_hash( ssl, md_cur ) == 0 ) |
| { |
| mbedtls_ssl_sig_hash_set_add( &ssl->handshake->hash_algs, sig_cur, md_cur ); |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello v3, signature_algorithm ext:" |
| " match sig %u and hash %u", |
| (unsigned) sig_cur, (unsigned) md_cur ) ); |
| } |
| else |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello v3, signature_algorithm ext: " |
| "hash alg %u not supported", (unsigned) md_cur ) ); |
| } |
| } |
| |
| return( 0 ); |
| } |
| #endif /* MBEDTLS_SSL_PROTO_TLS1_2 && |
| MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */ |
| |
| #if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \ |
| defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED) |
| static int ssl_parse_supported_elliptic_curves( mbedtls_ssl_context *ssl, |
| const unsigned char *buf, |
| size_t len ) |
| { |
| size_t list_size, our_size; |
| const unsigned char *p; |
| const mbedtls_ecp_curve_info *curve_info, **curves; |
| |
| if ( len < 2 ) { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| list_size = ( ( buf[0] << 8 ) | ( buf[1] ) ); |
| if( list_size + 2 != len || |
| list_size % 2 != 0 ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| /* Should never happen unless client duplicates the extension */ |
| if( ssl->handshake->curves != NULL ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| /* Don't allow our peer to make us allocate too much memory, |
| * and leave room for a final 0 */ |
| our_size = list_size / 2 + 1; |
| if( our_size > MBEDTLS_ECP_DP_MAX ) |
| our_size = MBEDTLS_ECP_DP_MAX; |
| |
| if( ( curves = mbedtls_calloc( our_size, sizeof( *curves ) ) ) == NULL ) |
| { |
| mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| MBEDTLS_SSL_ALERT_MSG_INTERNAL_ERROR ); |
| return( MBEDTLS_ERR_SSL_ALLOC_FAILED ); |
| } |
| |
| ssl->handshake->curves = curves; |
| |
| p = buf + 2; |
| while( list_size > 0 && our_size > 1 ) |
| { |
| curve_info = mbedtls_ecp_curve_info_from_tls_id( ( p[0] << 8 ) | p[1] ); |
| |
| if( curve_info != NULL ) |
| { |
| *curves++ = curve_info; |
| our_size--; |
| } |
| |
| list_size -= 2; |
| p += 2; |
| } |
| |
| return( 0 ); |
| } |
| |
| static int ssl_parse_supported_point_formats( mbedtls_ssl_context *ssl, |
| const unsigned char *buf, |
| size_t len ) |
| { |
| size_t list_size; |
| const unsigned char *p; |
| |
| if( len == 0 || (size_t)( buf[0] + 1 ) != len ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| list_size = buf[0]; |
| |
| p = buf + 1; |
| while( list_size > 0 ) |
| { |
| if( p[0] == MBEDTLS_ECP_PF_UNCOMPRESSED || |
| p[0] == MBEDTLS_ECP_PF_COMPRESSED ) |
| { |
| #if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) |
| ssl->handshake->ecdh_ctx.point_format = p[0]; |
| #endif |
| #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED) |
| ssl->handshake->ecjpake_ctx.point_format = p[0]; |
| #endif |
| MBEDTLS_SSL_DEBUG_MSG( 4, ( "point format selected: %d", p[0] ) ); |
| return( 0 ); |
| } |
| |
| list_size--; |
| p++; |
| } |
| |
| return( 0 ); |
| } |
| #endif /* MBEDTLS_ECDH_C || MBEDTLS_ECDSA_C || |
| MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */ |
| |
| #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED) |
| static int ssl_parse_ecjpake_kkpp( mbedtls_ssl_context *ssl, |
| const unsigned char *buf, |
| size_t len ) |
| { |
| int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| |
| if( mbedtls_ecjpake_check( &ssl->handshake->ecjpake_ctx ) != 0 ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "skip ecjpake kkpp extension" ) ); |
| return( 0 ); |
| } |
| |
| if( ( ret = mbedtls_ecjpake_read_round_one( &ssl->handshake->ecjpake_ctx, |
| buf, len ) ) != 0 ) |
| { |
| MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecjpake_read_round_one", ret ); |
| mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER ); |
| return( ret ); |
| } |
| |
| /* Only mark the extension as OK when we're sure it is */ |
| ssl->handshake->cli_exts |= MBEDTLS_TLS_EXT_ECJPAKE_KKPP_OK; |
| |
| return( 0 ); |
| } |
| #endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */ |
| |
| #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH) |
| static int ssl_parse_max_fragment_length_ext( mbedtls_ssl_context *ssl, |
| const unsigned char *buf, |
| size_t len ) |
| { |
| if( len != 1 || buf[0] >= MBEDTLS_SSL_MAX_FRAG_LEN_INVALID ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| ssl->session_negotiate->mfl_code = buf[0]; |
| |
| return( 0 ); |
| } |
| #endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */ |
| |
| #if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) |
| static int ssl_parse_cid_ext( mbedtls_ssl_context *ssl, |
| const unsigned char *buf, |
| size_t len ) |
| { |
| size_t peer_cid_len; |
| |
| /* CID extension only makes sense in DTLS */ |
| if( ssl->conf->transport != MBEDTLS_SSL_TRANSPORT_DATAGRAM ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| /* |
| * Quoting draft-ietf-tls-dtls-connection-id-05 |
| * https://tools.ietf.org/html/draft-ietf-tls-dtls-connection-id-05 |
| * |
| * struct { |
| * opaque cid<0..2^8-1>; |
| * } ConnectionId; |
| */ |
| |
| if( len < 1 ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| peer_cid_len = *buf++; |
| len--; |
| |
| if( len != peer_cid_len ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| /* Ignore CID if the user has disabled its use. */ |
| if( ssl->negotiate_cid == MBEDTLS_SSL_CID_DISABLED ) |
| { |
| /* Leave ssl->handshake->cid_in_use in its default |
| * value of MBEDTLS_SSL_CID_DISABLED. */ |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "Client sent CID extension, but CID disabled" ) ); |
| return( 0 ); |
| } |
| |
| if( peer_cid_len > MBEDTLS_SSL_CID_OUT_LEN_MAX ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| ssl->handshake->cid_in_use = MBEDTLS_SSL_CID_ENABLED; |
| ssl->handshake->peer_cid_len = (uint8_t) peer_cid_len; |
| memcpy( ssl->handshake->peer_cid, buf, peer_cid_len ); |
| |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "Use of CID extension negotiated" ) ); |
| MBEDTLS_SSL_DEBUG_BUF( 3, "Client CID", buf, peer_cid_len ); |
| |
| return( 0 ); |
| } |
| #endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */ |
| |
| #if defined(MBEDTLS_SSL_TRUNCATED_HMAC) |
| static int ssl_parse_truncated_hmac_ext( mbedtls_ssl_context *ssl, |
| const unsigned char *buf, |
| size_t len ) |
| { |
| if( len != 0 ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| ((void) buf); |
| |
| if( ssl->conf->trunc_hmac == MBEDTLS_SSL_TRUNC_HMAC_ENABLED ) |
| ssl->session_negotiate->trunc_hmac = MBEDTLS_SSL_TRUNC_HMAC_ENABLED; |
| |
| return( 0 ); |
| } |
| #endif /* MBEDTLS_SSL_TRUNCATED_HMAC */ |
| |
| #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC) |
| static int ssl_parse_encrypt_then_mac_ext( mbedtls_ssl_context *ssl, |
| const unsigned char *buf, |
| size_t len ) |
| { |
| if( len != 0 ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| ((void) buf); |
| |
| if( ssl->conf->encrypt_then_mac == MBEDTLS_SSL_ETM_ENABLED ) |
| { |
| ssl->session_negotiate->encrypt_then_mac = MBEDTLS_SSL_ETM_ENABLED; |
| } |
| |
| return( 0 ); |
| } |
| #endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */ |
| |
| #if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET) |
| static int ssl_parse_extended_ms_ext( mbedtls_ssl_context *ssl, |
| const unsigned char *buf, |
| size_t len ) |
| { |
| if( len != 0 ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| ((void) buf); |
| |
| if( ssl->conf->extended_ms == MBEDTLS_SSL_EXTENDED_MS_ENABLED ) |
| { |
| ssl->handshake->extended_ms = MBEDTLS_SSL_EXTENDED_MS_ENABLED; |
| } |
| |
| return( 0 ); |
| } |
| #endif /* MBEDTLS_SSL_EXTENDED_MASTER_SECRET */ |
| |
| #if defined(MBEDTLS_SSL_SESSION_TICKETS) |
| static int ssl_parse_session_ticket_ext( mbedtls_ssl_context *ssl, |
| unsigned char *buf, |
| size_t len ) |
| { |
| int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| mbedtls_ssl_session session; |
| |
| mbedtls_ssl_session_init( &session ); |
| |
| if( ssl->conf->f_ticket_parse == NULL || |
| ssl->conf->f_ticket_write == NULL ) |
| { |
| return( 0 ); |
| } |
| |
| /* Remember the client asked us to send a new ticket */ |
| ssl->handshake->new_session_ticket = 1; |
| |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "ticket length: %" MBEDTLS_PRINTF_SIZET, len ) ); |
| |
| if( len == 0 ) |
| return( 0 ); |
| |
| #if defined(MBEDTLS_SSL_RENEGOTIATION) |
| if( ssl->renego_status != MBEDTLS_SSL_INITIAL_HANDSHAKE ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "ticket rejected: renegotiating" ) ); |
| return( 0 ); |
| } |
| #endif /* MBEDTLS_SSL_RENEGOTIATION */ |
| |
| /* |
| * Failures are ok: just ignore the ticket and proceed. |
| */ |
| if( ( ret = ssl->conf->f_ticket_parse( ssl->conf->p_ticket, &session, |
| buf, len ) ) != 0 ) |
| { |
| mbedtls_ssl_session_free( &session ); |
| |
| if( ret == MBEDTLS_ERR_SSL_INVALID_MAC ) |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "ticket is not authentic" ) ); |
| else if( ret == MBEDTLS_ERR_SSL_SESSION_TICKET_EXPIRED ) |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "ticket is expired" ) ); |
| else |
| MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_ticket_parse", ret ); |
| |
| return( 0 ); |
| } |
| |
| /* |
| * Keep the session ID sent by the client, since we MUST send it back to |
| * inform them we're accepting the ticket (RFC 5077 section 3.4) |
| */ |
| session.id_len = ssl->session_negotiate->id_len; |
| memcpy( &session.id, ssl->session_negotiate->id, session.id_len ); |
| |
| mbedtls_ssl_session_free( ssl->session_negotiate ); |
| memcpy( ssl->session_negotiate, &session, sizeof( mbedtls_ssl_session ) ); |
| |
| /* Zeroize instead of free as we copied the content */ |
| mbedtls_platform_zeroize( &session, sizeof( mbedtls_ssl_session ) ); |
| |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "session successfully restored from ticket" ) ); |
| |
| ssl->handshake->resume = 1; |
| |
| /* Don't send a new ticket after all, this one is OK */ |
| ssl->handshake->new_session_ticket = 0; |
| |
| return( 0 ); |
| } |
| #endif /* MBEDTLS_SSL_SESSION_TICKETS */ |
| |
| #if defined(MBEDTLS_SSL_ALPN) |
| static int ssl_parse_alpn_ext( mbedtls_ssl_context *ssl, |
| const unsigned char *buf, size_t len ) |
| { |
| size_t list_len, cur_len, ours_len; |
| const unsigned char *theirs, *start, *end; |
| const char **ours; |
| |
| /* If ALPN not configured, just ignore the extension */ |
| if( ssl->conf->alpn_list == NULL ) |
| return( 0 ); |
| |
| /* |
| * opaque ProtocolName<1..2^8-1>; |
| * |
| * struct { |
| * ProtocolName protocol_name_list<2..2^16-1> |
| * } ProtocolNameList; |
| */ |
| |
| /* Min length is 2 (list_len) + 1 (name_len) + 1 (name) */ |
| if( len < 4 ) |
| { |
| mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| list_len = ( buf[0] << 8 ) | buf[1]; |
| if( list_len != len - 2 ) |
| { |
| mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| /* |
| * Validate peer's list (lengths) |
| */ |
| start = buf + 2; |
| end = buf + len; |
| for( theirs = start; theirs != end; theirs += cur_len ) |
| { |
| cur_len = *theirs++; |
| |
| /* Current identifier must fit in list */ |
| if( cur_len > (size_t)( end - theirs ) ) |
| { |
| mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| /* Empty strings MUST NOT be included */ |
| if( cur_len == 0 ) |
| { |
| mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| } |
| |
| /* |
| * Use our order of preference |
| */ |
| for( ours = ssl->conf->alpn_list; *ours != NULL; ours++ ) |
| { |
| ours_len = strlen( *ours ); |
| for( theirs = start; theirs != end; theirs += cur_len ) |
| { |
| cur_len = *theirs++; |
| |
| if( cur_len == ours_len && |
| memcmp( theirs, *ours, cur_len ) == 0 ) |
| { |
| ssl->alpn_chosen = *ours; |
| return( 0 ); |
| } |
| } |
| } |
| |
| /* If we get there, no match was found */ |
| mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| MBEDTLS_SSL_ALERT_MSG_NO_APPLICATION_PROTOCOL ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| #endif /* MBEDTLS_SSL_ALPN */ |
| |
| #if defined(MBEDTLS_SSL_DTLS_SRTP) |
| static int ssl_parse_use_srtp_ext( mbedtls_ssl_context *ssl, |
| const unsigned char *buf, |
| size_t len ) |
| { |
| mbedtls_ssl_srtp_profile client_protection = MBEDTLS_TLS_SRTP_UNSET; |
| size_t i,j; |
| size_t profile_length; |
| uint16_t mki_length; |
| /*! 2 bytes for profile length and 1 byte for mki len */ |
| const size_t size_of_lengths = 3; |
| |
| /* If use_srtp is not configured, just ignore the extension */ |
| if( ( ssl->conf->transport != MBEDTLS_SSL_TRANSPORT_DATAGRAM ) || |
| ( ssl->conf->dtls_srtp_profile_list == NULL ) || |
| ( ssl->conf->dtls_srtp_profile_list_len == 0 ) ) |
| { |
| return( 0 ); |
| } |
| |
| /* RFC5764 section 4.1.1 |
| * uint8 SRTPProtectionProfile[2]; |
| * |
| * struct { |
| * SRTPProtectionProfiles SRTPProtectionProfiles; |
| * opaque srtp_mki<0..255>; |
| * } UseSRTPData; |
| |
| * SRTPProtectionProfile SRTPProtectionProfiles<2..2^16-1>; |
| */ |
| |
| /* |
| * Min length is 5: at least one protection profile(2 bytes) |
| * and length(2 bytes) + srtp_mki length(1 byte) |
| * Check here that we have at least 2 bytes of protection profiles length |
| * and one of srtp_mki length |
| */ |
| if( len < size_of_lengths ) |
| { |
| mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| ssl->dtls_srtp_info.chosen_dtls_srtp_profile = MBEDTLS_TLS_SRTP_UNSET; |
| |
| /* first 2 bytes are protection profile length(in bytes) */ |
| profile_length = ( buf[0] << 8 ) | buf[1]; |
| buf += 2; |
| |
| /* The profile length cannot be bigger than input buffer size - lengths fields */ |
| if( profile_length > len - size_of_lengths || |
| profile_length % 2 != 0 ) /* profiles are 2 bytes long, so the length must be even */ |
| { |
| mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| /* |
| * parse the extension list values are defined in |
| * http://www.iana.org/assignments/srtp-protection/srtp-protection.xhtml |
| */ |
| for( j = 0; j < profile_length; j += 2 ) |
| { |
| uint16_t protection_profile_value = buf[j] << 8 | buf[j + 1]; |
| client_protection = mbedtls_ssl_check_srtp_profile_value( protection_profile_value ); |
| |
| if( client_protection != MBEDTLS_TLS_SRTP_UNSET ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "found srtp profile: %s", |
| mbedtls_ssl_get_srtp_profile_as_string( |
| client_protection ) ) ); |
| } |
| else |
| { |
| continue; |
| } |
| /* check if suggested profile is in our list */ |
| for( i = 0; i < ssl->conf->dtls_srtp_profile_list_len; i++) |
| { |
| if( client_protection == ssl->conf->dtls_srtp_profile_list[i] ) |
| { |
| ssl->dtls_srtp_info.chosen_dtls_srtp_profile = ssl->conf->dtls_srtp_profile_list[i]; |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "selected srtp profile: %s", |
| mbedtls_ssl_get_srtp_profile_as_string( |
| client_protection ) ) ); |
| break; |
| } |
| } |
| if( ssl->dtls_srtp_info.chosen_dtls_srtp_profile != MBEDTLS_TLS_SRTP_UNSET ) |
| break; |
| } |
| buf += profile_length; /* buf points to the mki length */ |
| mki_length = *buf; |
| buf++; |
| |
| if( mki_length > MBEDTLS_TLS_SRTP_MAX_MKI_LENGTH || |
| mki_length + profile_length + size_of_lengths != len ) |
| { |
| mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| /* Parse the mki only if present and mki is supported locally */ |
| if( ssl->conf->dtls_srtp_mki_support == MBEDTLS_SSL_DTLS_SRTP_MKI_SUPPORTED && |
| mki_length > 0 ) |
| { |
| ssl->dtls_srtp_info.mki_len = mki_length; |
| |
| memcpy( ssl->dtls_srtp_info.mki_value, buf, mki_length ); |
| |
| MBEDTLS_SSL_DEBUG_BUF( 3, "using mki", ssl->dtls_srtp_info.mki_value, |
| ssl->dtls_srtp_info.mki_len ); |
| } |
| |
| return( 0 ); |
| } |
| #endif /* MBEDTLS_SSL_DTLS_SRTP */ |
| |
| /* |
| * Auxiliary functions for ServerHello parsing and related actions |
| */ |
| |
| #if defined(MBEDTLS_X509_CRT_PARSE_C) |
| /* |
| * Return 0 if the given key uses one of the acceptable curves, -1 otherwise |
| */ |
| #if defined(MBEDTLS_ECDSA_C) |
| static int ssl_check_key_curve( mbedtls_pk_context *pk, |
| const mbedtls_ecp_curve_info **curves ) |
| { |
| const mbedtls_ecp_curve_info **crv = curves; |
| mbedtls_ecp_group_id grp_id = mbedtls_pk_ec( *pk )->grp.id; |
| |
| while( *crv != NULL ) |
| { |
| if( (*crv)->grp_id == grp_id ) |
| return( 0 ); |
| crv++; |
| } |
| |
| return( -1 ); |
| } |
| #endif /* MBEDTLS_ECDSA_C */ |
| |
| /* |
| * Try picking a certificate for this ciphersuite, |
| * return 0 on success and -1 on failure. |
| */ |
| static int ssl_pick_cert( mbedtls_ssl_context *ssl, |
| const mbedtls_ssl_ciphersuite_t * ciphersuite_info ) |
| { |
| mbedtls_ssl_key_cert *cur, *list, *fallback = NULL; |
| mbedtls_pk_type_t pk_alg = |
| mbedtls_ssl_get_ciphersuite_sig_pk_alg( ciphersuite_info ); |
| uint32_t flags; |
| |
| #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION) |
| if( ssl->handshake->sni_key_cert != NULL ) |
| list = ssl->handshake->sni_key_cert; |
| else |
| #endif |
| list = ssl->conf->key_cert; |
| |
| if( pk_alg == MBEDTLS_PK_NONE ) |
| return( 0 ); |
| |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "ciphersuite requires certificate" ) ); |
| |
| if( list == NULL ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "server has no certificate" ) ); |
| return( -1 ); |
| } |
| |
| for( cur = list; cur != NULL; cur = cur->next ) |
| { |
| flags = 0; |
| MBEDTLS_SSL_DEBUG_CRT( 3, "candidate certificate chain, certificate", |
| cur->cert ); |
| |
| if( ! mbedtls_pk_can_do( &cur->cert->pk, pk_alg ) ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "certificate mismatch: key type" ) ); |
| continue; |
| } |
| |
| /* |
| * This avoids sending the client a cert it'll reject based on |
| * keyUsage or other extensions. |
| * |
| * It also allows the user to provision different certificates for |
| * different uses based on keyUsage, eg if they want to avoid signing |
| * and decrypting with the same RSA key. |
| */ |
| if( mbedtls_ssl_check_cert_usage( cur->cert, ciphersuite_info, |
| MBEDTLS_SSL_IS_SERVER, &flags ) != 0 ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "certificate mismatch: " |
| "(extended) key usage extension" ) ); |
| continue; |
| } |
| |
| #if defined(MBEDTLS_ECDSA_C) |
| if( pk_alg == MBEDTLS_PK_ECDSA && |
| ssl_check_key_curve( &cur->cert->pk, ssl->handshake->curves ) != 0 ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "certificate mismatch: elliptic curve" ) ); |
| continue; |
| } |
| #endif |
| |
| /* |
| * Try to select a SHA-1 certificate for pre-1.2 clients, but still |
| * present them a SHA-higher cert rather than failing if it's the only |
| * one we got that satisfies the other conditions. |
| */ |
| if( ssl->minor_ver < MBEDTLS_SSL_MINOR_VERSION_3 && |
| cur->cert->sig_md != MBEDTLS_MD_SHA1 ) |
| { |
| if( fallback == NULL ) |
| fallback = cur; |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "certificate not preferred: " |
| "sha-2 with pre-TLS 1.2 client" ) ); |
| continue; |
| } |
| } |
| |
| /* If we get there, we got a winner */ |
| break; |
| } |
| |
| if( cur == NULL ) |
| cur = fallback; |
| |
| /* Do not update ssl->handshake->key_cert unless there is a match */ |
| if( cur != NULL ) |
| { |
| ssl->handshake->key_cert = cur; |
| MBEDTLS_SSL_DEBUG_CRT( 3, "selected certificate chain, certificate", |
| ssl->handshake->key_cert->cert ); |
| return( 0 ); |
| } |
| |
| return( -1 ); |
| } |
| #endif /* MBEDTLS_X509_CRT_PARSE_C */ |
| |
| /* |
| * Check if a given ciphersuite is suitable for use with our config/keys/etc |
| * Sets ciphersuite_info only if the suite matches. |
| */ |
| static int ssl_ciphersuite_match( mbedtls_ssl_context *ssl, int suite_id, |
| const mbedtls_ssl_ciphersuite_t **ciphersuite_info ) |
| { |
| const mbedtls_ssl_ciphersuite_t *suite_info; |
| |
| #if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \ |
| defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED) |
| mbedtls_pk_type_t sig_type; |
| #endif |
| |
| suite_info = mbedtls_ssl_ciphersuite_from_id( suite_id ); |
| if( suite_info == NULL ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); |
| return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); |
| } |
| |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "trying ciphersuite: %#04x (%s)", |
| (unsigned int) suite_id, suite_info->name ) ); |
| |
| if( suite_info->min_minor_ver > ssl->minor_ver || |
| suite_info->max_minor_ver < ssl->minor_ver ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "ciphersuite mismatch: version" ) ); |
| return( 0 ); |
| } |
| |
| #if defined(MBEDTLS_SSL_PROTO_DTLS) |
| if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM && |
| ( suite_info->flags & MBEDTLS_CIPHERSUITE_NODTLS ) ) |
| return( 0 ); |
| #endif |
| |
| #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED) |
| if( suite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE && |
| ( ssl->handshake->cli_exts & MBEDTLS_TLS_EXT_ECJPAKE_KKPP_OK ) == 0 ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "ciphersuite mismatch: ecjpake " |
| "not configured or ext missing" ) ); |
| return( 0 ); |
| } |
| #endif |
| |
| |
| #if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) |
| if( mbedtls_ssl_ciphersuite_uses_ec( suite_info ) && |
| ( ssl->handshake->curves == NULL || |
| ssl->handshake->curves[0] == NULL ) ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "ciphersuite mismatch: " |
| "no common elliptic curve" ) ); |
| return( 0 ); |
| } |
| #endif |
| |
| #if defined(MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED) |
| /* If the ciphersuite requires a pre-shared key and we don't |
| * have one, skip it now rather than failing later */ |
| if( mbedtls_ssl_ciphersuite_uses_psk( suite_info ) && |
| ssl_conf_has_psk_or_cb( ssl->conf ) == 0 ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "ciphersuite mismatch: no pre-shared key" ) ); |
| return( 0 ); |
| } |
| #endif |
| |
| #if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \ |
| defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED) |
| /* If the ciphersuite requires signing, check whether |
| * a suitable hash algorithm is present. */ |
| if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 ) |
| { |
| sig_type = mbedtls_ssl_get_ciphersuite_sig_alg( suite_info ); |
| if( sig_type != MBEDTLS_PK_NONE && |
| mbedtls_ssl_sig_hash_set_find( &ssl->handshake->hash_algs, sig_type ) == MBEDTLS_MD_NONE ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "ciphersuite mismatch: no suitable hash algorithm " |
| "for signature algorithm %u", (unsigned) sig_type ) ); |
| return( 0 ); |
| } |
| } |
| |
| #endif /* MBEDTLS_SSL_PROTO_TLS1_2 && |
| MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */ |
| |
| #if defined(MBEDTLS_X509_CRT_PARSE_C) |
| /* |
| * Final check: if ciphersuite requires us to have a |
| * certificate/key of a particular type: |
| * - select the appropriate certificate if we have one, or |
| * - try the next ciphersuite if we don't |
| * This must be done last since we modify the key_cert list. |
| */ |
| if( ssl_pick_cert( ssl, suite_info ) != 0 ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "ciphersuite mismatch: " |
| "no suitable certificate" ) ); |
| return( 0 ); |
| } |
| #endif |
| |
| *ciphersuite_info = suite_info; |
| return( 0 ); |
| } |
| |
| /* This function doesn't alert on errors that happen early during |
| ClientHello parsing because they might indicate that the client is |
| not talking SSL/TLS at all and would not understand our alert. */ |
| static int ssl_parse_client_hello( mbedtls_ssl_context *ssl ) |
| { |
| int ret, got_common_suite; |
| size_t i, j; |
| size_t ciph_offset, comp_offset, ext_offset; |
| size_t msg_len, ciph_len, sess_len, comp_len, ext_len; |
| #if defined(MBEDTLS_SSL_PROTO_DTLS) |
| size_t cookie_offset, cookie_len; |
| #endif |
| unsigned char *buf, *p, *ext; |
| #if defined(MBEDTLS_SSL_RENEGOTIATION) |
| int renegotiation_info_seen = 0; |
| #endif |
| int handshake_failure = 0; |
| const int *ciphersuites; |
| const mbedtls_ssl_ciphersuite_t *ciphersuite_info; |
| int major, minor; |
| |
| /* If there is no signature-algorithm extension present, |
| * we need to fall back to the default values for allowed |
| * signature-hash pairs. */ |
| #if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \ |
| defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED) |
| int sig_hash_alg_ext_present = 0; |
| #endif /* MBEDTLS_SSL_PROTO_TLS1_2 && |
| MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */ |
| |
| MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse client hello" ) ); |
| |
| #if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY) |
| read_record_header: |
| #endif |
| /* |
| * If renegotiating, then the input was read with mbedtls_ssl_read_record(), |
| * otherwise read it ourselves manually in order to support SSLv2 |
| * ClientHello, which doesn't use the same record layer format. |
| */ |
| #if defined(MBEDTLS_SSL_RENEGOTIATION) |
| if( ssl->renego_status == MBEDTLS_SSL_INITIAL_HANDSHAKE ) |
| #endif |
| { |
| if( ( ret = mbedtls_ssl_fetch_input( ssl, 5 ) ) != 0 ) |
| { |
| /* No alert on a read error. */ |
| MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_fetch_input", ret ); |
| return( ret ); |
| } |
| } |
| |
| buf = ssl->in_hdr; |
| |
| MBEDTLS_SSL_DEBUG_BUF( 4, "record header", buf, mbedtls_ssl_in_hdr_len( ssl ) ); |
| |
| /* |
| * TLS Client Hello |
| * |
| * Record layer: |
| * 0 . 0 message type |
| * 1 . 2 protocol version |
| * 3 . 11 DTLS: epoch + record sequence number |
| * 3 . 4 message length |
| */ |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, message type: %d", |
| buf[0] ) ); |
| |
| if( buf[0] != MBEDTLS_SSL_MSG_HANDSHAKE ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, message len.: %d", |
| ( ssl->in_len[0] << 8 ) | ssl->in_len[1] ) ); |
| |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, protocol version: [%d:%d]", |
| buf[1], buf[2] ) ); |
| |
| mbedtls_ssl_read_version( &major, &minor, ssl->conf->transport, buf + 1 ); |
| |
| /* According to RFC 5246 Appendix E.1, the version here is typically |
| * "{03,00}, the lowest version number supported by the client, [or] the |
| * value of ClientHello.client_version", so the only meaningful check here |
| * is the major version shouldn't be less than 3 */ |
| if( major < MBEDTLS_SSL_MAJOR_VERSION_3 ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| /* For DTLS if this is the initial handshake, remember the client sequence |
| * number to use it in our next message (RFC 6347 4.2.1) */ |
| #if defined(MBEDTLS_SSL_PROTO_DTLS) |
| if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM |
| #if defined(MBEDTLS_SSL_RENEGOTIATION) |
| && ssl->renego_status == MBEDTLS_SSL_INITIAL_HANDSHAKE |
| #endif |
| ) |
| { |
| /* Epoch should be 0 for initial handshakes */ |
| if( ssl->in_ctr[0] != 0 || ssl->in_ctr[1] != 0 ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| memcpy( ssl->cur_out_ctr + 2, ssl->in_ctr + 2, 6 ); |
| |
| #if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY) |
| if( mbedtls_ssl_dtls_replay_check( ssl ) != 0 ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "replayed record, discarding" ) ); |
| ssl->next_record_offset = 0; |
| ssl->in_left = 0; |
| goto read_record_header; |
| } |
| |
| /* No MAC to check yet, so we can update right now */ |
| mbedtls_ssl_dtls_replay_update( ssl ); |
| #endif |
| } |
| #endif /* MBEDTLS_SSL_PROTO_DTLS */ |
| |
| msg_len = ( ssl->in_len[0] << 8 ) | ssl->in_len[1]; |
| |
| #if defined(MBEDTLS_SSL_RENEGOTIATION) |
| if( ssl->renego_status != MBEDTLS_SSL_INITIAL_HANDSHAKE ) |
| { |
| /* Set by mbedtls_ssl_read_record() */ |
| msg_len = ssl->in_hslen; |
| } |
| else |
| #endif |
| { |
| if( msg_len > MBEDTLS_SSL_IN_CONTENT_LEN ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| if( ( ret = mbedtls_ssl_fetch_input( ssl, |
| mbedtls_ssl_in_hdr_len( ssl ) + msg_len ) ) != 0 ) |
| { |
| MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_fetch_input", ret ); |
| return( ret ); |
| } |
| |
| /* Done reading this record, get ready for the next one */ |
| #if defined(MBEDTLS_SSL_PROTO_DTLS) |
| if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) |
| ssl->next_record_offset = msg_len + mbedtls_ssl_in_hdr_len( ssl ); |
| else |
| #endif |
| ssl->in_left = 0; |
| } |
| |
| buf = ssl->in_msg; |
| |
| MBEDTLS_SSL_DEBUG_BUF( 4, "record contents", buf, msg_len ); |
| |
| ssl->handshake->update_checksum( ssl, buf, msg_len ); |
| |
| /* |
| * Handshake layer: |
| * 0 . 0 handshake type |
| * 1 . 3 handshake length |
| * 4 . 5 DTLS only: message seqence number |
| * 6 . 8 DTLS only: fragment offset |
| * 9 . 11 DTLS only: fragment length |
| */ |
| if( msg_len < mbedtls_ssl_hs_hdr_len( ssl ) ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello v3, handshake type: %d", buf[0] ) ); |
| |
| if( buf[0] != MBEDTLS_SSL_HS_CLIENT_HELLO ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello v3, handshake len.: %d", |
| ( buf[1] << 16 ) | ( buf[2] << 8 ) | buf[3] ) ); |
| |
| /* We don't support fragmentation of ClientHello (yet?) */ |
| if( buf[1] != 0 || |
| msg_len != mbedtls_ssl_hs_hdr_len( ssl ) + ( ( buf[2] << 8 ) | buf[3] ) ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| #if defined(MBEDTLS_SSL_PROTO_DTLS) |
| if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) |
| { |
| /* |
| * Copy the client's handshake message_seq on initial handshakes, |
| * check sequence number on renego. |
| */ |
| #if defined(MBEDTLS_SSL_RENEGOTIATION) |
| if( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS ) |
| { |
| /* This couldn't be done in ssl_prepare_handshake_record() */ |
| unsigned int cli_msg_seq = ( ssl->in_msg[4] << 8 ) | |
| ssl->in_msg[5]; |
| |
| if( cli_msg_seq != ssl->handshake->in_msg_seq ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message_seq: " |
| "%u (expected %u)", cli_msg_seq, |
| ssl->handshake->in_msg_seq ) ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| ssl->handshake->in_msg_seq++; |
| } |
| else |
| #endif |
| { |
| unsigned int cli_msg_seq = ( ssl->in_msg[4] << 8 ) | |
| ssl->in_msg[5]; |
| ssl->handshake->out_msg_seq = cli_msg_seq; |
| ssl->handshake->in_msg_seq = cli_msg_seq + 1; |
| } |
| |
| /* |
| * For now we don't support fragmentation, so make sure |
| * fragment_offset == 0 and fragment_length == length |
| */ |
| if( ssl->in_msg[6] != 0 || ssl->in_msg[7] != 0 || ssl->in_msg[8] != 0 || |
| memcmp( ssl->in_msg + 1, ssl->in_msg + 9, 3 ) != 0 ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "ClientHello fragmentation not supported" ) ); |
| return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE ); |
| } |
| } |
| #endif /* MBEDTLS_SSL_PROTO_DTLS */ |
| |
| buf += mbedtls_ssl_hs_hdr_len( ssl ); |
| msg_len -= mbedtls_ssl_hs_hdr_len( ssl ); |
| |
| /* |
| * ClientHello layer: |
| * 0 . 1 protocol version |
| * 2 . 33 random bytes (starting with 4 bytes of Unix time) |
| * 34 . 35 session id length (1 byte) |
| * 35 . 34+x session id |
| * 35+x . 35+x DTLS only: cookie length (1 byte) |
| * 36+x . .. DTLS only: cookie |
| * .. . .. ciphersuite list length (2 bytes) |
| * .. . .. ciphersuite list |
| * .. . .. compression alg. list length (1 byte) |
| * .. . .. compression alg. list |
| * .. . .. extensions length (2 bytes, optional) |
| * .. . .. extensions (optional) |
| */ |
| |
| /* |
| * Minimal length (with everything empty and extensions omitted) is |
| * 2 + 32 + 1 + 2 + 1 = 38 bytes. Check that first, so that we can |
| * read at least up to session id length without worrying. |
| */ |
| if( msg_len < 38 ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| /* |
| * Check and save the protocol version |
| */ |
| MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, version", buf, 2 ); |
| |
| mbedtls_ssl_read_version( &ssl->major_ver, &ssl->minor_ver, |
| ssl->conf->transport, buf ); |
| |
| ssl->handshake->max_major_ver = ssl->major_ver; |
| ssl->handshake->max_minor_ver = ssl->minor_ver; |
| |
| if( ssl->major_ver < ssl->conf->min_major_ver || |
| ssl->minor_ver < ssl->conf->min_minor_ver ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "client only supports ssl smaller than minimum" |
| " [%d:%d] < [%d:%d]", |
| ssl->major_ver, ssl->minor_ver, |
| ssl->conf->min_major_ver, ssl->conf->min_minor_ver ) ); |
| mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| MBEDTLS_SSL_ALERT_MSG_PROTOCOL_VERSION ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_PROTOCOL_VERSION ); |
| } |
| |
| if( ssl->major_ver > ssl->conf->max_major_ver ) |
| { |
| ssl->major_ver = ssl->conf->max_major_ver; |
| ssl->minor_ver = ssl->conf->max_minor_ver; |
| } |
| else if( ssl->minor_ver > ssl->conf->max_minor_ver ) |
| ssl->minor_ver = ssl->conf->max_minor_ver; |
| |
| /* |
| * Save client random (inc. Unix time) |
| */ |
| MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, random bytes", buf + 2, 32 ); |
| |
| memcpy( ssl->handshake->randbytes, buf + 2, 32 ); |
| |
| /* |
| * Check the session ID length and save session ID |
| */ |
| sess_len = buf[34]; |
| |
| if( sess_len > sizeof( ssl->session_negotiate->id ) || |
| sess_len + 34 + 2 > msg_len ) /* 2 for cipherlist length field */ |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, session id", buf + 35, sess_len ); |
| |
| ssl->session_negotiate->id_len = sess_len; |
| memset( ssl->session_negotiate->id, 0, |
| sizeof( ssl->session_negotiate->id ) ); |
| memcpy( ssl->session_negotiate->id, buf + 35, |
| ssl->session_negotiate->id_len ); |
| |
| /* |
| * Check the cookie length and content |
| */ |
| #if defined(MBEDTLS_SSL_PROTO_DTLS) |
| if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) |
| { |
| cookie_offset = 35 + sess_len; |
| cookie_len = buf[cookie_offset]; |
| |
| if( cookie_offset + 1 + cookie_len + 2 > msg_len ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| MBEDTLS_SSL_ALERT_MSG_PROTOCOL_VERSION ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, cookie", |
| buf + cookie_offset + 1, cookie_len ); |
| |
| #if defined(MBEDTLS_SSL_DTLS_HELLO_VERIFY) |
| if( ssl->conf->f_cookie_check != NULL |
| #if defined(MBEDTLS_SSL_RENEGOTIATION) |
| && ssl->renego_status == MBEDTLS_SSL_INITIAL_HANDSHAKE |
| #endif |
| ) |
| { |
| if( ssl->conf->f_cookie_check( ssl->conf->p_cookie, |
| buf + cookie_offset + 1, cookie_len, |
| ssl->cli_id, ssl->cli_id_len ) != 0 ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 2, ( "cookie verification failed" ) ); |
| ssl->handshake->verify_cookie_len = 1; |
| } |
| else |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 2, ( "cookie verification passed" ) ); |
| ssl->handshake->verify_cookie_len = 0; |
| } |
| } |
| else |
| #endif /* MBEDTLS_SSL_DTLS_HELLO_VERIFY */ |
| { |
| /* We know we didn't send a cookie, so it should be empty */ |
| if( cookie_len != 0 ) |
| { |
| /* This may be an attacker's probe, so don't send an alert */ |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| MBEDTLS_SSL_DEBUG_MSG( 2, ( "cookie verification skipped" ) ); |
| } |
| |
| /* |
| * Check the ciphersuitelist length (will be parsed later) |
| */ |
| ciph_offset = cookie_offset + 1 + cookie_len; |
| } |
| else |
| #endif /* MBEDTLS_SSL_PROTO_DTLS */ |
| ciph_offset = 35 + sess_len; |
| |
| ciph_len = ( buf[ciph_offset + 0] << 8 ) |
| | ( buf[ciph_offset + 1] ); |
| |
| if( ciph_len < 2 || |
| ciph_len + 2 + ciph_offset + 1 > msg_len || /* 1 for comp. alg. len */ |
| ( ciph_len % 2 ) != 0 ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, ciphersuitelist", |
| buf + ciph_offset + 2, ciph_len ); |
| |
| /* |
| * Check the compression algorithms length and pick one |
| */ |
| comp_offset = ciph_offset + 2 + ciph_len; |
| |
| comp_len = buf[comp_offset]; |
| |
| if( comp_len < 1 || |
| comp_len > 16 || |
| comp_len + comp_offset + 1 > msg_len ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, compression", |
| buf + comp_offset + 1, comp_len ); |
| |
| ssl->session_negotiate->compression = MBEDTLS_SSL_COMPRESS_NULL; |
| /* See comments in ssl_write_client_hello() */ |
| #if defined(MBEDTLS_SSL_PROTO_DTLS) |
| if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) |
| ssl->session_negotiate->compression = MBEDTLS_SSL_COMPRESS_NULL; |
| #endif |
| /* |
| * Check the extension length |
| */ |
| ext_offset = comp_offset + 1 + comp_len; |
| if( msg_len > ext_offset ) |
| { |
| if( msg_len < ext_offset + 2 ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| ext_len = ( buf[ext_offset + 0] << 8 ) |
| | ( buf[ext_offset + 1] ); |
| |
| if( msg_len != ext_offset + 2 + ext_len ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| } |
| else |
| ext_len = 0; |
| |
| ext = buf + ext_offset + 2; |
| MBEDTLS_SSL_DEBUG_BUF( 3, "client hello extensions", ext, ext_len ); |
| |
| while( ext_len != 0 ) |
| { |
| unsigned int ext_id; |
| unsigned int ext_size; |
| if ( ext_len < 4 ) { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| ext_id = ( ( ext[0] << 8 ) | ( ext[1] ) ); |
| ext_size = ( ( ext[2] << 8 ) | ( ext[3] ) ); |
| |
| if( ext_size + 4 > ext_len ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| switch( ext_id ) |
| { |
| #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION) |
| case MBEDTLS_TLS_EXT_SERVERNAME: |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "found ServerName extension" ) ); |
| if( ssl->conf->f_sni == NULL ) |
| break; |
| |
| ret = ssl_parse_servername_ext( ssl, ext + 4, ext_size ); |
| if( ret != 0 ) |
| return( ret ); |
| break; |
| #endif /* MBEDTLS_SSL_SERVER_NAME_INDICATION */ |
| |
| case MBEDTLS_TLS_EXT_RENEGOTIATION_INFO: |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "found renegotiation extension" ) ); |
| #if defined(MBEDTLS_SSL_RENEGOTIATION) |
| renegotiation_info_seen = 1; |
| #endif |
| |
| ret = ssl_parse_renegotiation_info( ssl, ext + 4, ext_size ); |
| if( ret != 0 ) |
| return( ret ); |
| break; |
| |
| #if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \ |
| defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED) |
| case MBEDTLS_TLS_EXT_SIG_ALG: |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "found signature_algorithms extension" ) ); |
| |
| ret = ssl_parse_signature_algorithms_ext( ssl, ext + 4, ext_size ); |
| if( ret != 0 ) |
| return( ret ); |
| |
| sig_hash_alg_ext_present = 1; |
| break; |
| #endif /* MBEDTLS_SSL_PROTO_TLS1_2 && |
| MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */ |
| |
| #if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \ |
| defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED) |
| case MBEDTLS_TLS_EXT_SUPPORTED_ELLIPTIC_CURVES: |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "found supported elliptic curves extension" ) ); |
| |
| ret = ssl_parse_supported_elliptic_curves( ssl, ext + 4, ext_size ); |
| if( ret != 0 ) |
| return( ret ); |
| break; |
| |
| case MBEDTLS_TLS_EXT_SUPPORTED_POINT_FORMATS: |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "found supported point formats extension" ) ); |
| ssl->handshake->cli_exts |= MBEDTLS_TLS_EXT_SUPPORTED_POINT_FORMATS_PRESENT; |
| |
| ret = ssl_parse_supported_point_formats( ssl, ext + 4, ext_size ); |
| if( ret != 0 ) |
| return( ret ); |
| break; |
| #endif /* MBEDTLS_ECDH_C || MBEDTLS_ECDSA_C || |
| MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */ |
| |
| #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED) |
| case MBEDTLS_TLS_EXT_ECJPAKE_KKPP: |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "found ecjpake kkpp extension" ) ); |
| |
| ret = ssl_parse_ecjpake_kkpp( ssl, ext + 4, ext_size ); |
| if( ret != 0 ) |
| return( ret ); |
| break; |
| #endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */ |
| |
| #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH) |
| case MBEDTLS_TLS_EXT_MAX_FRAGMENT_LENGTH: |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "found max fragment length extension" ) ); |
| |
| ret = ssl_parse_max_fragment_length_ext( ssl, ext + 4, ext_size ); |
| if( ret != 0 ) |
| return( ret ); |
| break; |
| #endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */ |
| |
| #if defined(MBEDTLS_SSL_TRUNCATED_HMAC) |
| case MBEDTLS_TLS_EXT_TRUNCATED_HMAC: |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "found truncated hmac extension" ) ); |
| |
| ret = ssl_parse_truncated_hmac_ext( ssl, ext + 4, ext_size ); |
| if( ret != 0 ) |
| return( ret ); |
| break; |
| #endif /* MBEDTLS_SSL_TRUNCATED_HMAC */ |
| |
| #if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) |
| case MBEDTLS_TLS_EXT_CID: |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "found CID extension" ) ); |
| |
| ret = ssl_parse_cid_ext( ssl, ext + 4, ext_size ); |
| if( ret != 0 ) |
| return( ret ); |
| break; |
| #endif /* MBEDTLS_SSL_TRUNCATED_HMAC */ |
| |
| #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC) |
| case MBEDTLS_TLS_EXT_ENCRYPT_THEN_MAC: |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "found encrypt then mac extension" ) ); |
| |
| ret = ssl_parse_encrypt_then_mac_ext( ssl, ext + 4, ext_size ); |
| if( ret != 0 ) |
| return( ret ); |
| break; |
| #endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */ |
| |
| #if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET) |
| case MBEDTLS_TLS_EXT_EXTENDED_MASTER_SECRET: |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "found extended master secret extension" ) ); |
| |
| ret = ssl_parse_extended_ms_ext( ssl, ext + 4, ext_size ); |
| if( ret != 0 ) |
| return( ret ); |
| break; |
| #endif /* MBEDTLS_SSL_EXTENDED_MASTER_SECRET */ |
| |
| #if defined(MBEDTLS_SSL_SESSION_TICKETS) |
| case MBEDTLS_TLS_EXT_SESSION_TICKET: |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "found session ticket extension" ) ); |
| |
| ret = ssl_parse_session_ticket_ext( ssl, ext + 4, ext_size ); |
| if( ret != 0 ) |
| return( ret ); |
| break; |
| #endif /* MBEDTLS_SSL_SESSION_TICKETS */ |
| |
| #if defined(MBEDTLS_SSL_ALPN) |
| case MBEDTLS_TLS_EXT_ALPN: |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "found alpn extension" ) ); |
| |
| ret = ssl_parse_alpn_ext( ssl, ext + 4, ext_size ); |
| if( ret != 0 ) |
| return( ret ); |
| break; |
| #endif /* MBEDTLS_SSL_SESSION_TICKETS */ |
| |
| #if defined(MBEDTLS_SSL_DTLS_SRTP) |
| case MBEDTLS_TLS_EXT_USE_SRTP: |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "found use_srtp extension" ) ); |
| |
| ret = ssl_parse_use_srtp_ext( ssl, ext + 4, ext_size ); |
| if( ret != 0 ) |
| return( ret ); |
| break; |
| #endif /* MBEDTLS_SSL_DTLS_SRTP */ |
| |
| default: |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "unknown extension found: %u (ignoring)", |
| ext_id ) ); |
| } |
| |
| ext_len -= 4 + ext_size; |
| ext += 4 + ext_size; |
| } |
| |
| #if defined(MBEDTLS_SSL_FALLBACK_SCSV) |
| for( i = 0, p = buf + ciph_offset + 2; i < ciph_len; i += 2, p += 2 ) |
| { |
| if( p[0] == (unsigned char)( ( MBEDTLS_SSL_FALLBACK_SCSV_VALUE >> 8 ) & 0xff ) && |
| p[1] == (unsigned char)( ( MBEDTLS_SSL_FALLBACK_SCSV_VALUE ) & 0xff ) ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 2, ( "received FALLBACK_SCSV" ) ); |
| |
| if( ssl->minor_ver < ssl->conf->max_minor_ver ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "inapropriate fallback" ) ); |
| |
| mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| MBEDTLS_SSL_ALERT_MSG_INAPROPRIATE_FALLBACK ); |
| |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| break; |
| } |
| } |
| #endif /* MBEDTLS_SSL_FALLBACK_SCSV */ |
| |
| #if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \ |
| defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED) |
| |
| /* |
| * Try to fall back to default hash SHA1 if the client |
| * hasn't provided any preferred signature-hash combinations. |
| */ |
| if( sig_hash_alg_ext_present == 0 ) |
| { |
| mbedtls_md_type_t md_default = MBEDTLS_MD_SHA1; |
| |
| if( mbedtls_ssl_check_sig_hash( ssl, md_default ) != 0 ) |
| md_default = MBEDTLS_MD_NONE; |
| |
| mbedtls_ssl_sig_hash_set_const_hash( &ssl->handshake->hash_algs, md_default ); |
| } |
| |
| #endif /* MBEDTLS_SSL_PROTO_TLS1_2 && |
| MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */ |
| |
| /* |
| * Check for TLS_EMPTY_RENEGOTIATION_INFO_SCSV |
| */ |
| for( i = 0, p = buf + ciph_offset + 2; i < ciph_len; i += 2, p += 2 ) |
| { |
| if( p[0] == 0 && p[1] == MBEDTLS_SSL_EMPTY_RENEGOTIATION_INFO ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "received TLS_EMPTY_RENEGOTIATION_INFO " ) ); |
| #if defined(MBEDTLS_SSL_RENEGOTIATION) |
| if( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "received RENEGOTIATION SCSV " |
| "during renegotiation" ) ); |
| mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| #endif |
| ssl->secure_renegotiation = MBEDTLS_SSL_SECURE_RENEGOTIATION; |
| break; |
| } |
| } |
| |
| /* |
| * Renegotiation security checks |
| */ |
| if( ssl->secure_renegotiation != MBEDTLS_SSL_SECURE_RENEGOTIATION && |
| ssl->conf->allow_legacy_renegotiation == MBEDTLS_SSL_LEGACY_BREAK_HANDSHAKE ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "legacy renegotiation, breaking off handshake" ) ); |
| handshake_failure = 1; |
| } |
| #if defined(MBEDTLS_SSL_RENEGOTIATION) |
| else if( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS && |
| ssl->secure_renegotiation == MBEDTLS_SSL_SECURE_RENEGOTIATION && |
| renegotiation_info_seen == 0 ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "renegotiation_info extension missing (secure)" ) ); |
| handshake_failure = 1; |
| } |
| else if( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS && |
| ssl->secure_renegotiation == MBEDTLS_SSL_LEGACY_RENEGOTIATION && |
| ssl->conf->allow_legacy_renegotiation == MBEDTLS_SSL_LEGACY_NO_RENEGOTIATION ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "legacy renegotiation not allowed" ) ); |
| handshake_failure = 1; |
| } |
| else if( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS && |
| ssl->secure_renegotiation == MBEDTLS_SSL_LEGACY_RENEGOTIATION && |
| renegotiation_info_seen == 1 ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "renegotiation_info extension present (legacy)" ) ); |
| handshake_failure = 1; |
| } |
| #endif /* MBEDTLS_SSL_RENEGOTIATION */ |
| |
| if( handshake_failure == 1 ) |
| { |
| mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE ); |
| return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| /* |
| * Search for a matching ciphersuite |
| * (At the end because we need information from the EC-based extensions |
| * and certificate from the SNI callback triggered by the SNI extension.) |
| */ |
| got_common_suite = 0; |
| ciphersuites = mbedtls_ssl_get_protocol_version_ciphersuites( ssl->conf, ssl->minor_ver ); |
| ciphersuite_info = NULL; |
| #if defined(MBEDTLS_SSL_SRV_RESPECT_CLIENT_PREFERENCE) |
| for( j = 0, p = buf + ciph_offset + 2; j < ciph_len; j += 2, p += 2 ) |
| for( i = 0; ciphersuites[i] != 0; i++ ) |
| #else |
| for( i = 0; ciphersuites[i] != 0; i++ ) |
| for( j = 0, p = buf + ciph_offset + 2; j < ciph_len; j += 2, p += 2 ) |
| #endif |
| { |
| if( p[0] != ( ( ciphersuites[i] >> 8 ) & 0xFF ) || |
| p[1] != ( ( ciphersuites[i] ) & 0xFF ) ) |
| continue; |
| |
| got_common_suite = 1; |
| |
| if( ( ret = ssl_ciphersuite_match( ssl, ciphersuites[i], |
| &ciphersuite_info ) ) != 0 ) |
| return( ret ); |
| |
| if( ciphersuite_info != NULL ) |
| goto have_ciphersuite; |
| } |
| |
| if( got_common_suite ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "got ciphersuites in common, " |
| "but none of them usable" ) ); |
| mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE ); |
| return( MBEDTLS_ERR_SSL_NO_USABLE_CIPHERSUITE ); |
| } |
| else |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "got no ciphersuites in common" ) ); |
| mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE ); |
| return( MBEDTLS_ERR_SSL_NO_CIPHER_CHOSEN ); |
| } |
| |
| have_ciphersuite: |
| MBEDTLS_SSL_DEBUG_MSG( 2, ( "selected ciphersuite: %s", ciphersuite_info->name ) ); |
| |
| ssl->session_negotiate->ciphersuite = ciphersuites[i]; |
| ssl->handshake->ciphersuite_info = ciphersuite_info; |
| |
| ssl->state++; |
| |
| #if defined(MBEDTLS_SSL_PROTO_DTLS) |
| if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) |
| mbedtls_ssl_recv_flight_completed( ssl ); |
| #endif |
| |
| /* Debugging-only output for testsuite */ |
| #if defined(MBEDTLS_DEBUG_C) && \ |
| defined(MBEDTLS_SSL_PROTO_TLS1_2) && \ |
| defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED) |
| if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 ) |
| { |
| mbedtls_pk_type_t sig_alg = mbedtls_ssl_get_ciphersuite_sig_alg( ciphersuite_info ); |
| if( sig_alg != MBEDTLS_PK_NONE ) |
| { |
| mbedtls_md_type_t md_alg = mbedtls_ssl_sig_hash_set_find( &ssl->handshake->hash_algs, |
| sig_alg ); |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello v3, signature_algorithm ext: %d", |
| mbedtls_ssl_hash_from_md_alg( md_alg ) ) ); |
| } |
| else |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "no hash algorithm for signature algorithm " |
| "%u - should not happen", (unsigned) sig_alg ) ); |
| } |
| } |
| #endif |
| |
| MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse client hello" ) ); |
| |
| return( 0 ); |
| } |
| |
| #if defined(MBEDTLS_SSL_TRUNCATED_HMAC) |
| static void ssl_write_truncated_hmac_ext( mbedtls_ssl_context *ssl, |
| unsigned char *buf, |
| size_t *olen ) |
| { |
| unsigned char *p = buf; |
| |
| if( ssl->session_negotiate->trunc_hmac == MBEDTLS_SSL_TRUNC_HMAC_DISABLED ) |
| { |
| *olen = 0; |
| return; |
| } |
| |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, adding truncated hmac extension" ) ); |
| |
| *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_TRUNCATED_HMAC >> 8 ) & 0xFF ); |
| *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_TRUNCATED_HMAC ) & 0xFF ); |
| |
| *p++ = 0x00; |
| *p++ = 0x00; |
| |
| *olen = 4; |
| } |
| #endif /* MBEDTLS_SSL_TRUNCATED_HMAC */ |
| |
| #if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) |
| static void ssl_write_cid_ext( mbedtls_ssl_context *ssl, |
| unsigned char *buf, |
| size_t *olen ) |
| { |
| unsigned char *p = buf; |
| size_t ext_len; |
| const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN; |
| |
| *olen = 0; |
| |
| /* Skip writing the extension if we don't want to use it or if |
| * the client hasn't offered it. */ |
| if( ssl->handshake->cid_in_use == MBEDTLS_SSL_CID_DISABLED ) |
| return; |
| |
| /* ssl->own_cid_len is at most MBEDTLS_SSL_CID_IN_LEN_MAX |
| * which is at most 255, so the increment cannot overflow. */ |
| if( end < p || (size_t)( end - p ) < (unsigned)( ssl->own_cid_len + 5 ) ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) ); |
| return; |
| } |
| |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, adding CID extension" ) ); |
| |
| /* |
| * Quoting draft-ietf-tls-dtls-connection-id-05 |
| * https://tools.ietf.org/html/draft-ietf-tls-dtls-connection-id-05 |
| * |
| * struct { |
| * opaque cid<0..2^8-1>; |
| * } ConnectionId; |
| */ |
| |
| *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_CID >> 8 ) & 0xFF ); |
| *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_CID ) & 0xFF ); |
| ext_len = (size_t) ssl->own_cid_len + 1; |
| *p++ = (unsigned char)( ( ext_len >> 8 ) & 0xFF ); |
| *p++ = (unsigned char)( ( ext_len ) & 0xFF ); |
| |
| *p++ = (uint8_t) ssl->own_cid_len; |
| memcpy( p, ssl->own_cid, ssl->own_cid_len ); |
| |
| *olen = ssl->own_cid_len + 5; |
| } |
| #endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */ |
| |
| #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC) |
| static void ssl_write_encrypt_then_mac_ext( mbedtls_ssl_context *ssl, |
| unsigned char *buf, |
| size_t *olen ) |
| { |
| unsigned char *p = buf; |
| const mbedtls_ssl_ciphersuite_t *suite = NULL; |
| const mbedtls_cipher_info_t *cipher = NULL; |
| |
| if( ssl->session_negotiate->encrypt_then_mac == MBEDTLS_SSL_ETM_DISABLED ) |
| { |
| *olen = 0; |
| return; |
| } |
| |
| /* |
| * RFC 7366: "If a server receives an encrypt-then-MAC request extension |
| * from a client and then selects a stream or Authenticated Encryption |
| * with Associated Data (AEAD) ciphersuite, it MUST NOT send an |
| * encrypt-then-MAC response extension back to the client." |
| */ |
| if( ( suite = mbedtls_ssl_ciphersuite_from_id( |
| ssl->session_negotiate->ciphersuite ) ) == NULL || |
| ( cipher = mbedtls_cipher_info_from_type( suite->cipher ) ) == NULL || |
| cipher->mode != MBEDTLS_MODE_CBC ) |
| { |
| *olen = 0; |
| return; |
| } |
| |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, adding encrypt then mac extension" ) ); |
| |
| *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_ENCRYPT_THEN_MAC >> 8 ) & 0xFF ); |
| *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_ENCRYPT_THEN_MAC ) & 0xFF ); |
| |
| *p++ = 0x00; |
| *p++ = 0x00; |
| |
| *olen = 4; |
| } |
| #endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */ |
| |
| #if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET) |
| static void ssl_write_extended_ms_ext( mbedtls_ssl_context *ssl, |
| unsigned char *buf, |
| size_t *olen ) |
| { |
| unsigned char *p = buf; |
| |
| if( ssl->handshake->extended_ms == MBEDTLS_SSL_EXTENDED_MS_DISABLED ) |
| { |
| *olen = 0; |
| return; |
| } |
| |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, adding extended master secret " |
| "extension" ) ); |
| |
| *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_EXTENDED_MASTER_SECRET >> 8 ) & 0xFF ); |
| *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_EXTENDED_MASTER_SECRET ) & 0xFF ); |
| |
| *p++ = 0x00; |
| *p++ = 0x00; |
| |
| *olen = 4; |
| } |
| #endif /* MBEDTLS_SSL_EXTENDED_MASTER_SECRET */ |
| |
| #if defined(MBEDTLS_SSL_SESSION_TICKETS) |
| static void ssl_write_session_ticket_ext( mbedtls_ssl_context *ssl, |
| unsigned char *buf, |
| size_t *olen ) |
| { |
| unsigned char *p = buf; |
| |
| if( ssl->handshake->new_session_ticket == 0 ) |
| { |
| *olen = 0; |
| return; |
| } |
| |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, adding session ticket extension" ) ); |
| |
| *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SESSION_TICKET >> 8 ) & 0xFF ); |
| *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SESSION_TICKET ) & 0xFF ); |
| |
| *p++ = 0x00; |
| *p++ = 0x00; |
| |
| *olen = 4; |
| } |
| #endif /* MBEDTLS_SSL_SESSION_TICKETS */ |
| |
| static void ssl_write_renegotiation_ext( mbedtls_ssl_context *ssl, |
| unsigned char *buf, |
| size_t *olen ) |
| { |
| unsigned char *p = buf; |
| |
| if( ssl->secure_renegotiation != MBEDTLS_SSL_SECURE_RENEGOTIATION ) |
| { |
| *olen = 0; |
| return; |
| } |
| |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, secure renegotiation extension" ) ); |
| |
| *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_RENEGOTIATION_INFO >> 8 ) & 0xFF ); |
| *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_RENEGOTIATION_INFO ) & 0xFF ); |
| |
| #if defined(MBEDTLS_SSL_RENEGOTIATION) |
| if( ssl->renego_status != MBEDTLS_SSL_INITIAL_HANDSHAKE ) |
| { |
| *p++ = 0x00; |
| *p++ = ( ssl->verify_data_len * 2 + 1 ) & 0xFF; |
| *p++ = ssl->verify_data_len * 2 & 0xFF; |
| |
| memcpy( p, ssl->peer_verify_data, ssl->verify_data_len ); |
| p += ssl->verify_data_len; |
| memcpy( p, ssl->own_verify_data, ssl->verify_data_len ); |
| p += ssl->verify_data_len; |
| } |
| else |
| #endif /* MBEDTLS_SSL_RENEGOTIATION */ |
| { |
| *p++ = 0x00; |
| *p++ = 0x01; |
| *p++ = 0x00; |
| } |
| |
| *olen = p - buf; |
| } |
| |
| #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH) |
| static void ssl_write_max_fragment_length_ext( mbedtls_ssl_context *ssl, |
| unsigned char *buf, |
| size_t *olen ) |
| { |
| unsigned char *p = buf; |
| |
| if( ssl->session_negotiate->mfl_code == MBEDTLS_SSL_MAX_FRAG_LEN_NONE ) |
| { |
| *olen = 0; |
| return; |
| } |
| |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, max_fragment_length extension" ) ); |
| |
| *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_MAX_FRAGMENT_LENGTH >> 8 ) & 0xFF ); |
| *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_MAX_FRAGMENT_LENGTH ) & 0xFF ); |
| |
| *p++ = 0x00; |
| *p++ = 1; |
| |
| *p++ = ssl->session_negotiate->mfl_code; |
| |
| *olen = 5; |
| } |
| #endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */ |
| |
| #if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \ |
| defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED) |
| static void ssl_write_supported_point_formats_ext( mbedtls_ssl_context *ssl, |
| unsigned char *buf, |
| size_t *olen ) |
| { |
| unsigned char *p = buf; |
| ((void) ssl); |
| |
| if( ( ssl->handshake->cli_exts & |
| MBEDTLS_TLS_EXT_SUPPORTED_POINT_FORMATS_PRESENT ) == 0 ) |
| { |
| *olen = 0; |
| return; |
| } |
| |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, supported_point_formats extension" ) ); |
| |
| *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SUPPORTED_POINT_FORMATS >> 8 ) & 0xFF ); |
| *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SUPPORTED_POINT_FORMATS ) & 0xFF ); |
| |
| *p++ = 0x00; |
| *p++ = 2; |
| |
| *p++ = 1; |
| *p++ = MBEDTLS_ECP_PF_UNCOMPRESSED; |
| |
| *olen = 6; |
| } |
| #endif /* MBEDTLS_ECDH_C || MBEDTLS_ECDSA_C || MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */ |
| |
| #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED) |
| static void ssl_write_ecjpake_kkpp_ext( mbedtls_ssl_context *ssl, |
| unsigned char *buf, |
| size_t *olen ) |
| { |
| int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| unsigned char *p = buf; |
| const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN; |
| size_t kkpp_len; |
| |
| *olen = 0; |
| |
| /* Skip costly computation if not needed */ |
| if( ssl->handshake->ciphersuite_info->key_exchange != |
| MBEDTLS_KEY_EXCHANGE_ECJPAKE ) |
| return; |
| |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, ecjpake kkpp extension" ) ); |
| |
| if( end - p < 4 ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) ); |
| return; |
| } |
| |
| *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_ECJPAKE_KKPP >> 8 ) & 0xFF ); |
| *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_ECJPAKE_KKPP ) & 0xFF ); |
| |
| ret = mbedtls_ecjpake_write_round_one( &ssl->handshake->ecjpake_ctx, |
| p + 2, end - p - 2, &kkpp_len, |
| ssl->conf->f_rng, ssl->conf->p_rng ); |
| if( ret != 0 ) |
| { |
| MBEDTLS_SSL_DEBUG_RET( 1 , "mbedtls_ecjpake_write_round_one", ret ); |
| return; |
| } |
| |
| *p++ = (unsigned char)( ( kkpp_len >> 8 ) & 0xFF ); |
| *p++ = (unsigned char)( ( kkpp_len ) & 0xFF ); |
| |
| *olen = kkpp_len + 4; |
| } |
| #endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */ |
| |
| #if defined(MBEDTLS_SSL_ALPN ) |
| static void ssl_write_alpn_ext( mbedtls_ssl_context *ssl, |
| unsigned char *buf, size_t *olen ) |
| { |
| if( ssl->alpn_chosen == NULL ) |
| { |
| *olen = 0; |
| return; |
| } |
| |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, adding alpn extension" ) ); |
| |
| /* |
| * 0 . 1 ext identifier |
| * 2 . 3 ext length |
| * 4 . 5 protocol list length |
| * 6 . 6 protocol name length |
| * 7 . 7+n protocol name |
| */ |
| buf[0] = (unsigned char)( ( MBEDTLS_TLS_EXT_ALPN >> 8 ) & 0xFF ); |
| buf[1] = (unsigned char)( ( MBEDTLS_TLS_EXT_ALPN ) & 0xFF ); |
| |
| *olen = 7 + strlen( ssl->alpn_chosen ); |
| |
| buf[2] = (unsigned char)( ( ( *olen - 4 ) >> 8 ) & 0xFF ); |
| buf[3] = (unsigned char)( ( ( *olen - 4 ) ) & 0xFF ); |
| |
| buf[4] = (unsigned char)( ( ( *olen - 6 ) >> 8 ) & 0xFF ); |
| buf[5] = (unsigned char)( ( ( *olen - 6 ) ) & 0xFF ); |
| |
| buf[6] = (unsigned char)( ( ( *olen - 7 ) ) & 0xFF ); |
| |
| memcpy( buf + 7, ssl->alpn_chosen, *olen - 7 ); |
| } |
| #endif /* MBEDTLS_ECDH_C || MBEDTLS_ECDSA_C */ |
| |
| #if defined(MBEDTLS_SSL_DTLS_SRTP ) && defined(MBEDTLS_SSL_PROTO_DTLS) |
| static void ssl_write_use_srtp_ext( mbedtls_ssl_context *ssl, |
| unsigned char *buf, |
| size_t *olen ) |
| { |
| size_t mki_len = 0, ext_len = 0; |
| uint16_t profile_value = 0; |
| const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN; |
| |
| *olen = 0; |
| |
| if( ( ssl->conf->transport != MBEDTLS_SSL_TRANSPORT_DATAGRAM ) || |
| ( ssl->dtls_srtp_info.chosen_dtls_srtp_profile == MBEDTLS_TLS_SRTP_UNSET ) ) |
| { |
| return; |
| } |
| |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, adding use_srtp extension" ) ); |
| |
| if( ssl->conf->dtls_srtp_mki_support == MBEDTLS_SSL_DTLS_SRTP_MKI_SUPPORTED ) |
| { |
| mki_len = ssl->dtls_srtp_info.mki_len; |
| } |
| |
| /* The extension total size is 9 bytes : |
| * - 2 bytes for the extension tag |
| * - 2 bytes for the total size |
| * - 2 bytes for the protection profile length |
| * - 2 bytes for the protection profile |
| * - 1 byte for the mki length |
| * + the actual mki length |
| * Check we have enough room in the output buffer */ |
| if( (size_t)( end - buf ) < mki_len + 9 ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) ); |
| return; |
| } |
| |
| /* extension */ |
| buf[0] = (unsigned char)( ( MBEDTLS_TLS_EXT_USE_SRTP >> 8 ) & 0xFF ); |
| buf[1] = (unsigned char)( ( MBEDTLS_TLS_EXT_USE_SRTP ) & 0xFF ); |
| /* |
| * total length 5 and mki value: only one profile(2 bytes) |
| * and length(2 bytes) and srtp_mki ) |
| */ |
| ext_len = 5 + mki_len; |
| buf[2] = (unsigned char)( ( ext_len >> 8 ) & 0xFF ); |
| buf[3] = (unsigned char)( ext_len & 0xFF ); |
| |
| /* protection profile length: 2 */ |
| buf[4] = 0x00; |
| buf[5] = 0x02; |
| profile_value = mbedtls_ssl_check_srtp_profile_value( |
| ssl->dtls_srtp_info.chosen_dtls_srtp_profile ); |
| if( profile_value != MBEDTLS_TLS_SRTP_UNSET ) |
| { |
| buf[6] = (unsigned char)( ( profile_value >> 8 ) & 0xFF ); |
| buf[7] = (unsigned char)( profile_value & 0xFF ); |
| } |
| else |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "use_srtp extension invalid profile" ) ); |
| return; |
| } |
| |
| buf[8] = mki_len & 0xFF; |
| memcpy( &buf[9], ssl->dtls_srtp_info.mki_value, mki_len ); |
| |
| *olen = 9 + mki_len; |
| } |
| #endif /* MBEDTLS_SSL_DTLS_SRTP */ |
| |
| #if defined(MBEDTLS_SSL_DTLS_HELLO_VERIFY) |
| static int ssl_write_hello_verify_request( mbedtls_ssl_context *ssl ) |
| { |
| int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| unsigned char *p = ssl->out_msg + 4; |
| unsigned char *cookie_len_byte; |
| |
| MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write hello verify request" ) ); |
| |
| /* |
| * struct { |
| * ProtocolVersion server_version; |
| * opaque cookie<0..2^8-1>; |
| * } HelloVerifyRequest; |
| */ |
| |
| /* The RFC is not clear on this point, but sending the actual negotiated |
| * version looks like the most interoperable thing to do. */ |
| mbedtls_ssl_write_version( ssl->major_ver, ssl->minor_ver, |
| ssl->conf->transport, p ); |
| MBEDTLS_SSL_DEBUG_BUF( 3, "server version", p, 2 ); |
| p += 2; |
| |
| /* If we get here, f_cookie_check is not null */ |
| if( ssl->conf->f_cookie_write == NULL ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "inconsistent cookie callbacks" ) ); |
| return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); |
| } |
| |
| /* Skip length byte until we know the length */ |
| cookie_len_byte = p++; |
| |
| if( ( ret = ssl->conf->f_cookie_write( ssl->conf->p_cookie, |
| &p, ssl->out_buf + MBEDTLS_SSL_OUT_BUFFER_LEN, |
| ssl->cli_id, ssl->cli_id_len ) ) != 0 ) |
| { |
| MBEDTLS_SSL_DEBUG_RET( 1, "f_cookie_write", ret ); |
| return( ret ); |
| } |
| |
| *cookie_len_byte = (unsigned char)( p - ( cookie_len_byte + 1 ) ); |
| |
| MBEDTLS_SSL_DEBUG_BUF( 3, "cookie sent", cookie_len_byte + 1, *cookie_len_byte ); |
| |
| ssl->out_msglen = p - ssl->out_msg; |
| ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE; |
| ssl->out_msg[0] = MBEDTLS_SSL_HS_HELLO_VERIFY_REQUEST; |
| |
| ssl->state = MBEDTLS_SSL_SERVER_HELLO_VERIFY_REQUEST_SENT; |
| |
| 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_PROTO_DTLS */ |
| |
| MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write hello verify request" ) ); |
| |
| return( 0 ); |
| } |
| #endif /* MBEDTLS_SSL_DTLS_HELLO_VERIFY */ |
| |
| static int ssl_write_server_hello( mbedtls_ssl_context *ssl ) |
| { |
| #if defined(MBEDTLS_HAVE_TIME) |
| mbedtls_time_t t; |
| #endif |
| int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| size_t olen, ext_len = 0, n; |
| unsigned char *buf, *p; |
| |
| MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write server hello" ) ); |
| |
| #if defined(MBEDTLS_SSL_DTLS_HELLO_VERIFY) |
| if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM && |
| ssl->handshake->verify_cookie_len != 0 ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 2, ( "client hello was not authenticated" ) ); |
| MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write server hello" ) ); |
| |
| return( ssl_write_hello_verify_request( ssl ) ); |
| } |
| #endif /* MBEDTLS_SSL_DTLS_HELLO_VERIFY */ |
| |
| if( ssl->conf->f_rng == NULL ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "no RNG provided") ); |
| return( MBEDTLS_ERR_SSL_NO_RNG ); |
| } |
| |
| /* |
| * 0 . 0 handshake type |
| * 1 . 3 handshake length |
| * 4 . 5 protocol version |
| * 6 . 9 UNIX time() |
| * 10 . 37 random bytes |
| */ |
| buf = ssl->out_msg; |
| p = buf + 4; |
| |
| mbedtls_ssl_write_version( ssl->major_ver, ssl->minor_ver, |
| ssl->conf->transport, p ); |
| p += 2; |
| |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, chosen version: [%d:%d]", |
| buf[4], buf[5] ) ); |
| |
| #if defined(MBEDTLS_HAVE_TIME) |
| t = mbedtls_time( NULL ); |
| *p++ = (unsigned char)( t >> 24 ); |
| *p++ = (unsigned char)( t >> 16 ); |
| *p++ = (unsigned char)( t >> 8 ); |
| *p++ = (unsigned char)( t ); |
| |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, current time: %" MBEDTLS_PRINTF_LONGLONG, |
| (long long) t ) ); |
| #else |
| if( ( ret = ssl->conf->f_rng( ssl->conf->p_rng, p, 4 ) ) != 0 ) |
| return( ret ); |
| |
| p += 4; |
| #endif /* MBEDTLS_HAVE_TIME */ |
| |
| if( ( ret = ssl->conf->f_rng( ssl->conf->p_rng, p, 28 ) ) != 0 ) |
| return( ret ); |
| |
| p += 28; |
| |
| memcpy( ssl->handshake->randbytes + 32, buf + 6, 32 ); |
| |
| MBEDTLS_SSL_DEBUG_BUF( 3, "server hello, random bytes", buf + 6, 32 ); |
| |
| /* |
| * Resume is 0 by default, see ssl_handshake_init(). |
| * It may be already set to 1 by ssl_parse_session_ticket_ext(). |
| * If not, try looking up session ID in our cache. |
| */ |
| if( ssl->handshake->resume == 0 && |
| #if defined(MBEDTLS_SSL_RENEGOTIATION) |
| ssl->renego_status == MBEDTLS_SSL_INITIAL_HANDSHAKE && |
| #endif |
| ssl->session_negotiate->id_len != 0 && |
| ssl->conf->f_get_cache != NULL && |
| ssl->conf->f_get_cache( ssl->conf->p_cache, ssl->session_negotiate ) == 0 ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "session successfully restored from cache" ) ); |
| ssl->handshake->resume = 1; |
| } |
| |
| if( ssl->handshake->resume == 0 ) |
| { |
| /* |
| * New session, create a new session id, |
| * unless we're about to issue a session ticket |
| */ |
| ssl->state++; |
| |
| #if defined(MBEDTLS_HAVE_TIME) |
| ssl->session_negotiate->start = mbedtls_time( NULL ); |
| #endif |
| |
| #if defined(MBEDTLS_SSL_SESSION_TICKETS) |
| if( ssl->handshake->new_session_ticket != 0 ) |
| { |
| ssl->session_negotiate->id_len = n = 0; |
| memset( ssl->session_negotiate->id, 0, 32 ); |
| } |
| else |
| #endif /* MBEDTLS_SSL_SESSION_TICKETS */ |
| { |
| ssl->session_negotiate->id_len = n = 32; |
| if( ( ret = ssl->conf->f_rng( ssl->conf->p_rng, ssl->session_negotiate->id, |
| n ) ) != 0 ) |
| return( ret ); |
| } |
| } |
| else |
| { |
| /* |
| * Resuming a session |
| */ |
| n = ssl->session_negotiate->id_len; |
| ssl->state = MBEDTLS_SSL_SERVER_CHANGE_CIPHER_SPEC; |
| |
| if( ( ret = mbedtls_ssl_derive_keys( ssl ) ) != 0 ) |
| { |
| MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_derive_keys", ret ); |
| return( ret ); |
| } |
| } |
| |
| /* |
| * 38 . 38 session id length |
| * 39 . 38+n session id |
| * 39+n . 40+n chosen ciphersuite |
| * 41+n . 41+n chosen compression alg. |
| * 42+n . 43+n extensions length |
| * 44+n . 43+n+m extensions |
| */ |
| *p++ = (unsigned char) ssl->session_negotiate->id_len; |
| memcpy( p, ssl->session_negotiate->id, ssl->session_negotiate->id_len ); |
| p += ssl->session_negotiate->id_len; |
| |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, session id len.: %" MBEDTLS_PRINTF_SIZET, n ) ); |
| MBEDTLS_SSL_DEBUG_BUF( 3, "server hello, session id", buf + 39, n ); |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "%s session has been resumed", |
| ssl->handshake->resume ? "a" : "no" ) ); |
| |
| *p++ = (unsigned char)( ssl->session_negotiate->ciphersuite >> 8 ); |
| *p++ = (unsigned char)( ssl->session_negotiate->ciphersuite ); |
| *p++ = (unsigned char)( ssl->session_negotiate->compression ); |
| |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, chosen ciphersuite: %s", |
| mbedtls_ssl_get_ciphersuite_name( ssl->session_negotiate->ciphersuite ) ) ); |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, compress alg.: 0x%02X", |
| (unsigned int) ssl->session_negotiate->compression ) ); |
| |
| /* |
| * First write extensions, then the total length |
| */ |
| ssl_write_renegotiation_ext( ssl, p + 2 + ext_len, &olen ); |
| ext_len += olen; |
| |
| #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH) |
| ssl_write_max_fragment_length_ext( ssl, p + 2 + ext_len, &olen ); |
| ext_len += olen; |
| #endif |
| |
| #if defined(MBEDTLS_SSL_TRUNCATED_HMAC) |
| ssl_write_truncated_hmac_ext( ssl, p + 2 + ext_len, &olen ); |
| ext_len += olen; |
| #endif |
| |
| #if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) |
| ssl_write_cid_ext( ssl, p + 2 + ext_len, &olen ); |
| ext_len += olen; |
| #endif |
| |
| #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC) |
| ssl_write_encrypt_then_mac_ext( ssl, p + 2 + ext_len, &olen ); |
| ext_len += olen; |
| #endif |
| |
| #if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET) |
| ssl_write_extended_ms_ext( ssl, p + 2 + ext_len, &olen ); |
| ext_len += olen; |
| #endif |
| |
| #if defined(MBEDTLS_SSL_SESSION_TICKETS) |
| ssl_write_session_ticket_ext( ssl, p + 2 + ext_len, &olen ); |
| ext_len += olen; |
| #endif |
| |
| #if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \ |
| defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED) |
| if ( mbedtls_ssl_ciphersuite_uses_ec( |
| mbedtls_ssl_ciphersuite_from_id( ssl->session_negotiate->ciphersuite ) ) ) |
| { |
| ssl_write_supported_point_formats_ext( ssl, p + 2 + ext_len, &olen ); |
| ext_len += olen; |
| } |
| #endif |
| |
| #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED) |
| ssl_write_ecjpake_kkpp_ext( ssl, p + 2 + ext_len, &olen ); |
| ext_len += olen; |
| #endif |
| |
| #if defined(MBEDTLS_SSL_ALPN) |
| ssl_write_alpn_ext( ssl, p + 2 + ext_len, &olen ); |
| ext_len += olen; |
| #endif |
| |
| #if defined(MBEDTLS_SSL_DTLS_SRTP) |
| ssl_write_use_srtp_ext( ssl, p + 2 + ext_len, &olen ); |
| ext_len += olen; |
| #endif |
| |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, total extension length: %" MBEDTLS_PRINTF_SIZET, |
| ext_len ) ); |
| |
| if( ext_len > 0 ) |
| { |
| *p++ = (unsigned char)( ( ext_len >> 8 ) & 0xFF ); |
| *p++ = (unsigned char)( ( ext_len ) & 0xFF ); |
| p += ext_len; |
| } |
| |
| ssl->out_msglen = p - buf; |
| ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE; |
| ssl->out_msg[0] = MBEDTLS_SSL_HS_SERVER_HELLO; |
| |
| ret = mbedtls_ssl_write_handshake_msg( ssl ); |
| |
| MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write server hello" ) ); |
| |
| return( ret ); |
| } |
| |
| #if !defined(MBEDTLS_KEY_EXCHANGE_CERT_REQ_ALLOWED_ENABLED) |
| static int ssl_write_certificate_request( mbedtls_ssl_context *ssl ) |
| { |
| const mbedtls_ssl_ciphersuite_t *ciphersuite_info = |
| ssl->handshake->ciphersuite_info; |
| |
| MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write certificate request" ) ); |
| |
| if( !mbedtls_ssl_ciphersuite_cert_req_allowed( ciphersuite_info ) ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip write certificate request" ) ); |
| ssl->state++; |
| return( 0 ); |
| } |
| |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); |
| return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); |
| } |
| #else /* !MBEDTLS_KEY_EXCHANGE_CERT_REQ_ALLOWED_ENABLED */ |
| static int ssl_write_certificate_request( mbedtls_ssl_context *ssl ) |
| { |
| int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE; |
| const mbedtls_ssl_ciphersuite_t *ciphersuite_info = |
| ssl->handshake->ciphersuite_info; |
| uint16_t dn_size, total_dn_size; /* excluding length bytes */ |
| size_t ct_len, sa_len; /* including length bytes */ |
| unsigned char *buf, *p; |
| const unsigned char * const end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN; |
| const mbedtls_x509_crt *crt; |
| int authmode; |
| |
| MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write certificate request" ) ); |
| |
| ssl->state++; |
| |
| #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION) |
| if( ssl->handshake->sni_authmode != MBEDTLS_SSL_VERIFY_UNSET ) |
| authmode = ssl->handshake->sni_authmode; |
| else |
| #endif |
| authmode = ssl->conf->authmode; |
| |
| if( !mbedtls_ssl_ciphersuite_cert_req_allowed( ciphersuite_info ) || |
| authmode == MBEDTLS_SSL_VERIFY_NONE ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip write certificate request" ) ); |
| return( 0 ); |
| } |
| |
| /* |
| * 0 . 0 handshake type |
| * 1 . 3 handshake length |
| * 4 . 4 cert type count |
| * 5 .. m-1 cert types |
| * m .. m+1 sig alg length (TLS 1.2 only) |
| * m+1 .. n-1 SignatureAndHashAlgorithms (TLS 1.2 only) |
| * n .. n+1 length of all DNs |
| * n+2 .. n+3 length of DN 1 |
| * n+4 .. ... Distinguished Name #1 |
| * ... .. ... length of DN 2, etc. |
| */ |
| buf = ssl->out_msg; |
| p = buf + 4; |
| |
| /* |
| * Supported certificate types |
| * |
| * ClientCertificateType certificate_types<1..2^8-1>; |
| * enum { (255) } ClientCertificateType; |
| */ |
| ct_len = 0; |
| |
| #if defined(MBEDTLS_RSA_C) |
| p[1 + ct_len++] = MBEDTLS_SSL_CERT_TYPE_RSA_SIGN; |
| #endif |
| #if defined(MBEDTLS_ECDSA_C) |
| p[1 + ct_len++] = MBEDTLS_SSL_CERT_TYPE_ECDSA_SIGN; |
| #endif |
| |
| p[0] = (unsigned char) ct_len++; |
| p += ct_len; |
| |
| sa_len = 0; |
| #if defined(MBEDTLS_SSL_PROTO_TLS1_2) |
| /* |
| * Add signature_algorithms for verify (TLS 1.2) |
| * |
| * SignatureAndHashAlgorithm supported_signature_algorithms<2..2^16-2>; |
| * |
| * struct { |
| * HashAlgorithm hash; |
| * SignatureAlgorithm signature; |
| * } SignatureAndHashAlgorithm; |
| * |
| * enum { (255) } HashAlgorithm; |
| * enum { (255) } SignatureAlgorithm; |
| */ |
| if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 ) |
| { |
| const int *cur; |
| |
| /* |
| * Supported signature algorithms |
| */ |
| for( cur = ssl->conf->sig_hashes; *cur != MBEDTLS_MD_NONE; cur++ ) |
| { |
| unsigned char hash = mbedtls_ssl_hash_from_md_alg( *cur ); |
| |
| if( MBEDTLS_SSL_HASH_NONE == hash || mbedtls_ssl_set_calc_verify_md( ssl, hash ) ) |
| continue; |
| |
| #if defined(MBEDTLS_RSA_C) |
| p[2 + sa_len++] = hash; |
| p[2 + sa_len++] = MBEDTLS_SSL_SIG_RSA; |
| #endif |
| #if defined(MBEDTLS_ECDSA_C) |
| p[2 + sa_len++] = hash; |
| p[2 + sa_len++] = MBEDTLS_SSL_SIG_ECDSA; |
| #endif |
| } |
| |
| p[0] = (unsigned char)( sa_len >> 8 ); |
| p[1] = (unsigned char)( sa_len ); |
| sa_len += 2; |
| p += sa_len; |
| } |
| #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */ |
| |
| /* |
| * DistinguishedName certificate_authorities<0..2^16-1>; |
| * opaque DistinguishedName<1..2^16-1>; |
| */ |
| p += 2; |
| |
| total_dn_size = 0; |
| |
| if( ssl->conf->cert_req_ca_list == MBEDTLS_SSL_CERT_REQ_CA_LIST_ENABLED ) |
| { |
| /* NOTE: If trusted certificates are provisioned |
| * via a CA callback (configured through |
| * `mbedtls_ssl_conf_ca_cb()`, then the |
| * CertificateRequest is currently left empty. */ |
| |
| #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION) |
| if( ssl->handshake->sni_ca_chain != NULL ) |
| crt = ssl->handshake->sni_ca_chain; |
| else |
| #endif |
| crt = ssl->conf->ca_chain; |
| |
| while( crt != NULL && crt->version != 0 ) |
| { |
| /* It follows from RFC 5280 A.1 that this length |
| * can be represented in at most 11 bits. */ |
| dn_size = (uint16_t) crt->subject_raw.len; |
| |
| if( end < p || (size_t)( end - p ) < 2 + (size_t) dn_size ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "skipping CAs: buffer too short" ) ); |
| break; |
| } |
| |
| *p++ = (unsigned char)( dn_size >> 8 ); |
| *p++ = (unsigned char)( dn_size ); |
| memcpy( p, crt->subject_raw.p, dn_size ); |
| p += dn_size; |
| |
| MBEDTLS_SSL_DEBUG_BUF( 3, "requested DN", p - dn_size, dn_size ); |
| |
| total_dn_size += 2 + dn_size; |
| crt = crt->next; |
| } |
| } |
| |
| ssl->out_msglen = p - buf; |
| ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE; |
| ssl->out_msg[0] = MBEDTLS_SSL_HS_CERTIFICATE_REQUEST; |
| ssl->out_msg[4 + ct_len + sa_len] = (unsigned char)( total_dn_size >> 8 ); |
| ssl->out_msg[5 + ct_len + sa_len] = (unsigned char)( total_dn_size ); |
| |
| ret = mbedtls_ssl_write_handshake_msg( ssl ); |
| |
| MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write certificate request" ) ); |
| |
| return( ret ); |
| } |
| #endif /* MBEDTLS_KEY_EXCHANGE_CERT_REQ_ALLOWED_ENABLED */ |
| |
| #if defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \ |
| defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED) |
| static int ssl_get_ecdh_params_from_cert( mbedtls_ssl_context *ssl ) |
| { |
| int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| |
| if( ! mbedtls_pk_can_do( mbedtls_ssl_own_key( ssl ), MBEDTLS_PK_ECKEY ) ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "server key not ECDH capable" ) ); |
| return( MBEDTLS_ERR_SSL_PK_TYPE_MISMATCH ); |
| } |
| |
| if( ( ret = mbedtls_ecdh_get_params( &ssl->handshake->ecdh_ctx, |
| mbedtls_pk_ec( *mbedtls_ssl_own_key( ssl ) ), |
| MBEDTLS_ECDH_OURS ) ) != 0 ) |
| { |
| MBEDTLS_SSL_DEBUG_RET( 1, ( "mbedtls_ecdh_get_params" ), ret ); |
| return( ret ); |
| } |
| |
| return( 0 ); |
| } |
| #endif /* MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) || |
| MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED */ |
| |
| #if defined(MBEDTLS_KEY_EXCHANGE_WITH_SERVER_SIGNATURE_ENABLED) && \ |
| defined(MBEDTLS_SSL_ASYNC_PRIVATE) |
| static int ssl_resume_server_key_exchange( mbedtls_ssl_context *ssl, |
| size_t *signature_len ) |
| { |
| /* Append the signature to ssl->out_msg, leaving 2 bytes for the |
| * signature length which will be added in ssl_write_server_key_exchange |
| * after the call to ssl_prepare_server_key_exchange. |
| * ssl_write_server_key_exchange also takes care of incrementing |
| * ssl->out_msglen. */ |
| unsigned char *sig_start = ssl->out_msg + ssl->out_msglen + 2; |
| size_t sig_max_len = ( ssl->out_buf + MBEDTLS_SSL_OUT_CONTENT_LEN |
| - sig_start ); |
| int ret = ssl->conf->f_async_resume( ssl, |
| sig_start, signature_len, sig_max_len ); |
| if( ret != MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS ) |
| { |
| ssl->handshake->async_in_progress = 0; |
| mbedtls_ssl_set_async_operation_data( ssl, NULL ); |
| } |
| MBEDTLS_SSL_DEBUG_RET( 2, "ssl_resume_server_key_exchange", ret ); |
| return( ret ); |
| } |
| #endif /* defined(MBEDTLS_KEY_EXCHANGE_WITH_SERVER_SIGNATURE_ENABLED) && |
| defined(MBEDTLS_SSL_ASYNC_PRIVATE) */ |
| |
| /* Prepare the ServerKeyExchange message, up to and including |
| * calculating the signature if any, but excluding formatting the |
| * signature and sending the message. */ |
| static int ssl_prepare_server_key_exchange( mbedtls_ssl_context *ssl, |
| size_t *signature_len ) |
| { |
| const mbedtls_ssl_ciphersuite_t *ciphersuite_info = |
| ssl->handshake->ciphersuite_info; |
| |
| #if defined(MBEDTLS_KEY_EXCHANGE_SOME_PFS_ENABLED) |
| #if defined(MBEDTLS_KEY_EXCHANGE_WITH_SERVER_SIGNATURE_ENABLED) |
| unsigned char *dig_signed = NULL; |
| #endif /* MBEDTLS_KEY_EXCHANGE_WITH_SERVER_SIGNATURE_ENABLED */ |
| #endif /* MBEDTLS_KEY_EXCHANGE_SOME_PFS_ENABLED */ |
| |
| (void) ciphersuite_info; /* unused in some configurations */ |
| #if !defined(MBEDTLS_KEY_EXCHANGE_WITH_SERVER_SIGNATURE_ENABLED) |
| (void) signature_len; |
| #endif /* MBEDTLS_KEY_EXCHANGE_WITH_SERVER_SIGNATURE_ENABLED */ |
| |
| ssl->out_msglen = 4; /* header (type:1, length:3) to be written later */ |
| |
| /* |
| * |
| * Part 1: Provide key exchange parameters for chosen ciphersuite. |
| * |
| */ |
| |
| /* |
| * - ECJPAKE key exchanges |
| */ |
| #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED) |
| if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE ) |
| { |
| int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| size_t len = 0; |
| |
| ret = mbedtls_ecjpake_write_round_two( |
| &ssl-> |