diff options
Diffstat (limited to 'thirdparty/mbedtls/library/ssl_srv.c')
| -rw-r--r-- | thirdparty/mbedtls/library/ssl_srv.c | 4096 |
1 files changed, 4096 insertions, 0 deletions
diff --git a/thirdparty/mbedtls/library/ssl_srv.c b/thirdparty/mbedtls/library/ssl_srv.c new file mode 100644 index 0000000000..aca4235e6e --- /dev/null +++ b/thirdparty/mbedtls/library/ssl_srv.c @@ -0,0 +1,4096 @@ +/* + * SSLv3/TLSv1 server-side functions + * + * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved + * SPDX-License-Identifier: Apache-2.0 + * + * Licensed under the Apache License, Version 2.0 (the "License"); you may + * not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT + * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + * + * This file is part of mbed TLS (https://tls.mbed.org) + */ + +#if !defined(MBEDTLS_CONFIG_FILE) +#include "mbedtls/config.h" +#else +#include MBEDTLS_CONFIG_FILE +#endif + +#if defined(MBEDTLS_SSL_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/debug.h" +#include "mbedtls/ssl.h" +#include "mbedtls/ssl_internal.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_SESSION_TICKETS) +/* Implementation that should never be optimized out by the compiler */ +static void mbedtls_zeroize( void *v, size_t n ) { + volatile unsigned char *p = v; while( n-- ) *p++ = 0; +} +#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; + size_t servername_list_size, hostname_len; + const unsigned char *p; + + MBEDTLS_SSL_DEBUG_MSG( 3, ( "parse ServerName extension" ) ); + + 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 > 0 ) + { + 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 */ + +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; + + 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 %d and hash %d", + sig_cur, md_cur ) ); + } + else + { + MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello v3, signature_algorithm ext: " + "hash alg %d not supported", 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; + + 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; + + list_size = buf[0]; + if( list_size + 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 ); + } + + 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; + + 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_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->minor_ver != MBEDTLS_SSL_MINOR_VERSION_0 ) + { + 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->minor_ver != MBEDTLS_SSL_MINOR_VERSION_0 ) + { + 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_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: %d", 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_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 */ + +/* + * 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 ) + { + MBEDTLS_SSL_DEBUG_CRT( 3, "candidate certificate chain, certificate", + cur->cert ); + + if( ! mbedtls_pk_can_do( cur->key, 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->key, 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: %s", 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_ARC4_C) + if( ssl->conf->arc4_disabled == MBEDTLS_SSL_ARC4_DISABLED && + suite_info->cipher == MBEDTLS_CIPHER_ARC4_128 ) + { + MBEDTLS_SSL_DEBUG_MSG( 3, ( "ciphersuite mismatch: rc4" ) ); + 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->f_psk == NULL && + ( ssl->conf->psk == NULL || ssl->conf->psk_identity == NULL || + ssl->conf->psk_identity_len == 0 || ssl->conf->psk_len == 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 %d", 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 ); +} + +#if defined(MBEDTLS_SSL_SRV_SUPPORT_SSLV2_CLIENT_HELLO) +static int ssl_parse_client_hello_v2( mbedtls_ssl_context *ssl ) +{ + int ret, got_common_suite; + unsigned int i, j; + size_t n; + unsigned int ciph_len, sess_len, chal_len; + unsigned char *buf, *p; + const int *ciphersuites; + const mbedtls_ssl_ciphersuite_t *ciphersuite_info; + + MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse client hello v2" ) ); + +#if defined(MBEDTLS_SSL_RENEGOTIATION) + if( ssl->renego_status != MBEDTLS_SSL_INITIAL_HANDSHAKE ) + { + MBEDTLS_SSL_DEBUG_MSG( 1, ( "client hello v2 illegal for 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 /* MBEDTLS_SSL_RENEGOTIATION */ + + buf = ssl->in_hdr; + + MBEDTLS_SSL_DEBUG_BUF( 4, "record header", buf, 5 ); + + MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello v2, message type: %d", + buf[2] ) ); + MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello v2, message len.: %d", + ( ( buf[0] & 0x7F ) << 8 ) | buf[1] ) ); + MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello v2, max. version: [%d:%d]", + buf[3], buf[4] ) ); + + /* + * SSLv2 Client Hello + * + * Record layer: + * 0 . 1 message length + * + * SSL layer: + * 2 . 2 message type + * 3 . 4 protocol version + */ + if( buf[2] != MBEDTLS_SSL_HS_CLIENT_HELLO || + buf[3] != MBEDTLS_SSL_MAJOR_VERSION_3 ) + { + MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); + return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); + } + + n = ( ( buf[0] << 8 ) | buf[1] ) & 0x7FFF; + + if( n < 17 || n > 512 ) + { + MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); + return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); + } + + ssl->major_ver = MBEDTLS_SSL_MAJOR_VERSION_3; + ssl->minor_ver = ( buf[4] <= ssl->conf->max_minor_ver ) + ? buf[4] : ssl->conf->max_minor_ver; + + if( 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 ); + } + + ssl->handshake->max_major_ver = buf[3]; + ssl->handshake->max_minor_ver = buf[4]; + + if( ( ret = mbedtls_ssl_fetch_input( ssl, 2 + n ) ) != 0 ) + { + MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_fetch_input", ret ); + return( ret ); + } + + ssl->handshake->update_checksum( ssl, buf + 2, n ); + + buf = ssl->in_msg; + n = ssl->in_left - 5; + + /* + * 0 . 1 ciphersuitelist length + * 2 . 3 session id length + * 4 . 5 challenge length + * 6 . .. ciphersuitelist + * .. . .. session id + * .. . .. challenge + */ + MBEDTLS_SSL_DEBUG_BUF( 4, "record contents", buf, n ); + + ciph_len = ( buf[0] << 8 ) | buf[1]; + sess_len = ( buf[2] << 8 ) | buf[3]; + chal_len = ( buf[4] << 8 ) | buf[5]; + + MBEDTLS_SSL_DEBUG_MSG( 3, ( "ciph_len: %d, sess_len: %d, chal_len: %d", + ciph_len, sess_len, chal_len ) ); + + /* + * Make sure each parameter length is valid + */ + if( ciph_len < 3 || ( ciph_len % 3 ) != 0 ) + { + MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); + return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); + } + + if( sess_len > 32 ) + { + MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); + return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); + } + + if( chal_len < 8 || chal_len > 32 ) + { + MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); + return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); + } + + if( n != 6 + ciph_len + sess_len + chal_len ) + { + MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); + return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); + } + + MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, ciphersuitelist", + buf + 6, ciph_len ); + MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, session id", + buf + 6 + ciph_len, sess_len ); + MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, challenge", + buf + 6 + ciph_len + sess_len, chal_len ); + + p = buf + 6 + ciph_len; + ssl->session_negotiate->id_len = sess_len; + memset( ssl->session_negotiate->id, 0, + sizeof( ssl->session_negotiate->id ) ); + memcpy( ssl->session_negotiate->id, p, ssl->session_negotiate->id_len ); + + p += sess_len; + memset( ssl->handshake->randbytes, 0, 64 ); + memcpy( ssl->handshake->randbytes + 32 - chal_len, p, chal_len ); + + /* + * Check for TLS_EMPTY_RENEGOTIATION_INFO_SCSV + */ + for( i = 0, p = buf + 6; i < ciph_len; i += 3, p += 3 ) + { + if( p[0] == 0 && p[1] == 0 && p[2] == 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 /* MBEDTLS_SSL_RENEGOTIATION */ + ssl->secure_renegotiation = MBEDTLS_SSL_SECURE_RENEGOTIATION; + break; + } + } + +#if defined(MBEDTLS_SSL_FALLBACK_SCSV) + for( i = 0, p = buf + 6; i < ciph_len; i += 3, p += 3 ) + { + if( p[0] == 0 && + p[1] == (unsigned char)( ( MBEDTLS_SSL_FALLBACK_SCSV_VALUE >> 8 ) & 0xff ) && + p[2] == (unsigned char)( ( MBEDTLS_SSL_FALLBACK_SCSV_VALUE ) & 0xff ) ) + { + MBEDTLS_SSL_DEBUG_MSG( 3, ( "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 */ + + got_common_suite = 0; + ciphersuites = ssl->conf->ciphersuite_list[ssl->minor_ver]; + ciphersuite_info = NULL; +#if defined(MBEDTLS_SSL_SRV_RESPECT_CLIENT_PREFERENCE) + for( j = 0, p = buf + 6; j < ciph_len; j += 3, p += 3 ) + for( i = 0; ciphersuites[i] != 0; i++ ) +#else + for( i = 0; ciphersuites[i] != 0; i++ ) + for( j = 0, p = buf + 6; j < ciph_len; j += 3, p += 3 ) +#endif + { + if( p[0] != 0 || + p[1] != ( ( ciphersuites[i] >> 8 ) & 0xFF ) || + p[2] != ( ( 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_v2; + } + + if( got_common_suite ) + { + MBEDTLS_SSL_DEBUG_MSG( 1, ( "got ciphersuites in common, " + "but none of them usable" ) ); + return( MBEDTLS_ERR_SSL_NO_USABLE_CIPHERSUITE ); + } + else + { + MBEDTLS_SSL_DEBUG_MSG( 1, ( "got no ciphersuites in common" ) ); + return( MBEDTLS_ERR_SSL_NO_CIPHER_CHOSEN ); + } + +have_ciphersuite_v2: + MBEDTLS_SSL_DEBUG_MSG( 2, ( "selected ciphersuite: %s", ciphersuite_info->name ) ); + + ssl->session_negotiate->ciphersuite = ciphersuites[i]; + ssl->transform_negotiate->ciphersuite_info = ciphersuite_info; + + /* + * SSLv2 Client Hello relevant renegotiation security checks + */ + if( ssl->secure_renegotiation == MBEDTLS_SSL_LEGACY_RENEGOTIATION && + ssl->conf->allow_legacy_renegotiation == MBEDTLS_SSL_LEGACY_BREAK_HANDSHAKE ) + { + MBEDTLS_SSL_DEBUG_MSG( 1, ( "legacy renegotiation, breaking off handshake" ) ); + 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->in_left = 0; + ssl->state++; + + MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse client hello v2" ) ); + + return( 0 ); +} +#endif /* MBEDTLS_SSL_SRV_SUPPORT_SSLV2_CLIENT_HELLO */ + +/* 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; + +#if defined(MBEDTLS_SSL_SRV_SUPPORT_SSLV2_CLIENT_HELLO) +#if defined(MBEDTLS_SSL_PROTO_DTLS) + if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_STREAM ) +#endif + if( ( buf[0] & 0x80 ) != 0 ) + return( ssl_parse_client_hello_v2( ssl ) ); +#endif + + MBEDTLS_SSL_DEBUG_BUF( 4, "record header", buf, mbedtls_ssl_hdr_len( ssl ) ); + + /* + * SSLv3/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 v3, 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 v3, message len.: %d", + ( ssl->in_len[0] << 8 ) | ssl->in_len[1] ) ); + + MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello v3, 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->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_MAX_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_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_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: " + "%d (expected %d)", 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 ommitted) 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; +#if defined(MBEDTLS_ZLIB_SUPPORT) + for( i = 0; i < comp_len; ++i ) + { + if( buf[comp_offset + 1 + i] == MBEDTLS_SSL_COMPRESS_DEFLATE ) + { + ssl->session_negotiate->compression = MBEDTLS_SSL_COMPRESS_DEFLATE; + break; + } + } +#endif + + /* 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 + + /* Do not parse the extensions if the protocol is SSLv3 */ +#if defined(MBEDTLS_SSL_PROTO_SSL3) + if( ( ssl->major_ver != 3 ) || ( ssl->minor_ver != 0 ) ) + { +#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( ( ext_len > 0 && ext_len < 4 ) || + 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 = ( ( ext[0] << 8 ) + | ( ext[1] ) ); + unsigned int 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_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 */ + + default: + MBEDTLS_SSL_DEBUG_MSG( 3, ( "unknown extension found: %d (ignoring)", + ext_id ) ); + } + + ext_len -= 4 + ext_size; + ext += 4 + ext_size; + + if( ext_len > 0 && ext_len < 4 ) + { + MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad 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 defined(MBEDTLS_SSL_PROTO_SSL3) + } +#endif + +#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 = ssl->conf->ciphersuite_list[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->transform_negotiate->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 " + "%d - should not happen", 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_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 || + ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 ) + { + *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 || + ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 ) + { + *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; + unsigned char *p = buf; + const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_MAX_CONTENT_LEN; + size_t kkpp_len; + + *olen = 0; + + /* Skip costly computation if not needed */ + if( ssl->transform_negotiate->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_HELLO_VERIFY) +static int ssl_write_hello_verify_request( mbedtls_ssl_context *ssl ) +{ + int ret; + 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_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_record( ssl ) ) != 0 ) + { + MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_record", ret ); + return( ret ); + } + + 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; + 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: %lu", 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.: %d", 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", + ssl->session_negotiate->compression ) ); + + /* Do not write the extensions if the protocol is SSLv3 */ +#if defined(MBEDTLS_SSL_PROTO_SSL3) + if( ( ssl->major_ver != 3 ) || ( ssl->minor_ver != 0 ) ) + { +#endif + + /* + * 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_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) + 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 + + MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, total extension length: %d", ext_len ) ); + + if( ext_len > 0 ) + { + *p++ = (unsigned char)( ( ext_len >> 8 ) & 0xFF ); + *p++ = (unsigned char)( ( ext_len ) & 0xFF ); + p += ext_len; + } + +#if defined(MBEDTLS_SSL_PROTO_SSL3) + } +#endif + + 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_record( ssl ); + + MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write server hello" ) ); + + return( ret ); +} + +#if !defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED) && \ + !defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED) && \ + !defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) && \ + !defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) && \ + !defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)&& \ + !defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) +static int ssl_write_certificate_request( mbedtls_ssl_context *ssl ) +{ + const mbedtls_ssl_ciphersuite_t *ciphersuite_info = + ssl->transform_negotiate->ciphersuite_info; + + MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write certificate request" ) ); + + if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK || + ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK || + ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK || + ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK || + ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE ) + { + MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip write certificate request" ) ); + ssl->state++; + return( 0 ); + } + + MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); + return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); +} +#else +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->transform_negotiate->ciphersuite_info; + size_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_MAX_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( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK || + ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK || + ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK || + ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK || + ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE || + 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 ) + { +#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 ) + { + dn_size = crt->subject_raw.len; + + if( end < p || + (size_t)( end - p ) < dn_size || + (size_t)( end - p ) < 2 + 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_record( ssl ); + + MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write certificate request" ) ); + + return( ret ); +} +#endif /* !MBEDTLS_KEY_EXCHANGE_RSA_ENABLED && + !MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED && + !MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED && + !MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED && + !MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED && + !MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_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; + + 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 */ + +static int ssl_write_server_key_exchange( mbedtls_ssl_context *ssl ) +{ + int ret; + size_t n = 0; + const mbedtls_ssl_ciphersuite_t *ciphersuite_info = + ssl->transform_negotiate->ciphersuite_info; + +#if defined(MBEDTLS_KEY_EXCHANGE__SOME_PFS__ENABLED) + unsigned char *p = ssl->out_msg + 4; + size_t len; +#if defined(MBEDTLS_KEY_EXCHANGE__WITH_SERVER_SIGNATURE__ENABLED) + unsigned char *dig_signed = p; + size_t dig_signed_len = 0; +#endif /* MBEDTLS_KEY_EXCHANGE__WITH_SERVER_SIGNATURE__ENABLED */ +#endif /* MBEDTLS_KEY_EXCHANGE__SOME_PFS__ENABLED */ + + MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write server key exchange" ) ); + + /* + * + * Part 1: Extract static ECDH parameters and abort + * if ServerKeyExchange not needed. + * + */ + + /* For suites involving ECDH, extract DH parameters + * from certificate at this point. */ +#if defined(MBEDTLS_KEY_EXCHANGE__SOME__ECDH_ENABLED) + if( mbedtls_ssl_ciphersuite_uses_ecdh( ciphersuite_info ) ) + { + ssl_get_ecdh_params_from_cert( ssl ); + } +#endif /* MBEDTLS_KEY_EXCHANGE__SOME__ECDH_ENABLED */ + + /* Key exchanges not involving ephemeral keys don't use + * ServerKeyExchange, so end here. */ +#if defined(MBEDTLS_KEY_EXCHANGE__SOME_NON_PFS__ENABLED) + if( mbedtls_ssl_ciphersuite_no_pfs( ciphersuite_info ) ) + { + MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip write server key exchange" ) ); + ssl->state++; + return( 0 ); + } +#endif /* MBEDTLS_KEY_EXCHANGE__NON_PFS__ENABLED */ + + /* + * + * Part 2: 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 ) + { + const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_MAX_CONTENT_LEN; + + ret = mbedtls_ecjpake_write_round_two( &ssl->handshake->ecjpake_ctx, + p, end - p, &len, ssl->conf->f_rng, ssl->conf->p_rng ); + if( ret != 0 ) + { + MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecjpake_write_round_two", ret ); + return( ret ); + } + + p += len; + n += len; + } +#endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */ + + /* + * For (EC)DHE key exchanges with PSK, parameters are prefixed by support + * identity hint (RFC 4279, Sec. 3). Until someone needs this feature, + * we use empty support identity hints here. + **/ +#if defined(MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED) || \ + defined(MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED) + if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK || + ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK ) + { + *(p++) = 0x00; + *(p++) = 0x00; + + n += 2; + } +#endif /* MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED || + MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED */ + + /* + * - DHE key exchanges + */ +#if defined(MBEDTLS_KEY_EXCHANGE__SOME__DHE_ENABLED) + if( mbedtls_ssl_ciphersuite_uses_dhe( ciphersuite_info ) ) + { + if( ssl->conf->dhm_P.p == NULL || ssl->conf->dhm_G.p == NULL ) + { + MBEDTLS_SSL_DEBUG_MSG( 1, ( "no DH parameters set" ) ); + return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); + } + + /* + * Ephemeral DH parameters: + * + * struct { + * opaque dh_p<1..2^16-1>; + * opaque dh_g<1..2^16-1>; + * opaque dh_Ys<1..2^16-1>; + * } ServerDHParams; + */ + if( ( ret = mbedtls_dhm_set_group( &ssl->handshake->dhm_ctx, + &ssl->conf->dhm_P, + &ssl->conf->dhm_G ) ) != 0 ) + { + MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_dhm_set_group", ret ); + return( ret ); + } + + if( ( ret = mbedtls_dhm_make_params( &ssl->handshake->dhm_ctx, + (int) mbedtls_mpi_size( &ssl->handshake->dhm_ctx.P ), + p, &len, ssl->conf->f_rng, ssl->conf->p_rng ) ) != 0 ) + { + MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_dhm_make_params", ret ); + return( ret ); + } + +#if defined(MBEDTLS_KEY_EXCHANGE__WITH_SERVER_SIGNATURE__ENABLED) + dig_signed = p; + dig_signed_len = len; +#endif + + p += len; + n += len; + + MBEDTLS_SSL_DEBUG_MPI( 3, "DHM: X ", &ssl->handshake->dhm_ctx.X ); + MBEDTLS_SSL_DEBUG_MPI( 3, "DHM: P ", &ssl->handshake->dhm_ctx.P ); + MBEDTLS_SSL_DEBUG_MPI( 3, "DHM: G ", &ssl->handshake->dhm_ctx.G ); + MBEDTLS_SSL_DEBUG_MPI( 3, "DHM: GX", &ssl->handshake->dhm_ctx.GX ); + } +#endif /* MBEDTLS_KEY_EXCHANGE__SOME__DHE_ENABLED */ + + /* + * - ECDHE key exchanges + */ +#if defined(MBEDTLS_KEY_EXCHANGE__SOME__ECDHE_ENABLED) + if( mbedtls_ssl_ciphersuite_uses_ecdhe( ciphersuite_info ) ) + { + /* + * Ephemeral ECDH parameters: + * + * struct { + * ECParameters curve_params; + * ECPoint public; + * } ServerECDHParams; + */ + const mbedtls_ecp_curve_info **curve = NULL; + const mbedtls_ecp_group_id *gid; + + /* Match our preference list against the offered curves */ + for( gid = ssl->conf->curve_list; *gid != MBEDTLS_ECP_DP_NONE; gid++ ) + for( curve = ssl->handshake->curves; *curve != NULL; curve++ ) + if( (*curve)->grp_id == *gid ) + goto curve_matching_done; + +curve_matching_done: + if( curve == NULL || *curve == NULL ) + { + MBEDTLS_SSL_DEBUG_MSG( 1, ( "no matching curve for ECDHE" ) ); + return( MBEDTLS_ERR_SSL_NO_CIPHER_CHOSEN ); + } + + MBEDTLS_SSL_DEBUG_MSG( 2, ( "ECDHE curve: %s", (*curve)->name ) ); + + if( ( ret = mbedtls_ecp_group_load( &ssl->handshake->ecdh_ctx.grp, + (*curve)->grp_id ) ) != 0 ) + { + MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecp_group_load", ret ); + return( ret ); + } + + if( ( ret = mbedtls_ecdh_make_params( &ssl->handshake->ecdh_ctx, &len, + p, MBEDTLS_SSL_MAX_CONTENT_LEN - n, + ssl->conf->f_rng, ssl->conf->p_rng ) ) != 0 ) + { + MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecdh_make_params", ret ); + return( ret ); + } + +#if defined(MBEDTLS_KEY_EXCHANGE__WITH_SERVER_SIGNATURE__ENABLED) + dig_signed = p; + dig_signed_len = len; +#endif + + p += len; + n += len; + + MBEDTLS_SSL_DEBUG_ECP( 3, "ECDH: Q ", &ssl->handshake->ecdh_ctx.Q ); + } +#endif /* MBEDTLS_KEY_EXCHANGE__SOME__ECDHE_ENABLED */ + + /* + * + * Part 3: For key exchanges involving the server signing the + * exchange parameters, compute and add the signature here. + * + */ +#if defined(MBEDTLS_KEY_EXCHANGE__WITH_SERVER_SIGNATURE__ENABLED) + if( mbedtls_ssl_ciphersuite_uses_server_signature( ciphersuite_info ) ) + { + size_t signature_len = 0; + unsigned int hashlen = 0; + unsigned char hash[64]; + + /* + * 3.1: Choose hash algorithm: + * A: For TLS 1.2, obey signature-hash-algorithm extension + * to choose appropriate hash. + * B: For SSL3, TLS1.0, TLS1.1 and ECDHE_ECDSA, use SHA1 + * (RFC 4492, Sec. 5.4) + * C: Otherwise, use MD5 + SHA1 (RFC 4346, Sec. 7.4.3) + */ + + mbedtls_md_type_t md_alg; + +#if defined(MBEDTLS_SSL_PROTO_TLS1_2) + mbedtls_pk_type_t sig_alg = + mbedtls_ssl_get_ciphersuite_sig_pk_alg( ciphersuite_info ); + if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 ) + { + /* A: For TLS 1.2, obey signature-hash-algorithm extension + * (RFC 5246, Sec. 7.4.1.4.1). */ + if( sig_alg == MBEDTLS_PK_NONE || + ( md_alg = mbedtls_ssl_sig_hash_set_find( &ssl->handshake->hash_algs, + sig_alg ) ) == MBEDTLS_MD_NONE ) + { + MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); + /* (... because we choose a cipher suite + * only if there is a matching hash.) */ + return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); + } + } + else +#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */ +#if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1) || \ + defined(MBEDTLS_SSL_PROTO_TLS1_1) + if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA ) + { + /* B: Default hash SHA1 */ + md_alg = MBEDTLS_MD_SHA1; + } + else +#endif /* MBEDTLS_SSL_PROTO_SSL3 || MBEDTLS_SSL_PROTO_TLS1 || \ + MBEDTLS_SSL_PROTO_TLS1_1 */ + { + /* C: MD5 + SHA1 */ + md_alg = MBEDTLS_MD_NONE; + } + + MBEDTLS_SSL_DEBUG_MSG( 3, ( "pick hash algorithm %d for signing", md_alg ) ); + + /* + * 3.2: Compute the hash to be signed + */ +#if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1) || \ + defined(MBEDTLS_SSL_PROTO_TLS1_1) + if( md_alg == MBEDTLS_MD_NONE ) + { + hashlen = 36; + ret = mbedtls_ssl_get_key_exchange_md_ssl_tls( ssl, hash, + dig_signed, + dig_signed_len ); + if( ret != 0 ) + return( ret ); + } + else +#endif /* MBEDTLS_SSL_PROTO_SSL3 || MBEDTLS_SSL_PROTO_TLS1 || \ + MBEDTLS_SSL_PROTO_TLS1_1 */ +#if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) || \ + defined(MBEDTLS_SSL_PROTO_TLS1_2) + if( md_alg != MBEDTLS_MD_NONE ) + { + /* Info from md_alg will be used instead */ + hashlen = 0; + ret = mbedtls_ssl_get_key_exchange_md_tls1_2( ssl, hash, + dig_signed, + dig_signed_len, + md_alg ); + if( ret != 0 ) + return( ret ); + } + else +#endif /* MBEDTLS_SSL_PROTO_TLS1 || MBEDTLS_SSL_PROTO_TLS1_1 || \ + MBEDTLS_SSL_PROTO_TLS1_2 */ + { + MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); + return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); + } + + MBEDTLS_SSL_DEBUG_BUF( 3, "parameters hash", hash, hashlen != 0 ? hashlen : + (unsigned int) ( mbedtls_md_get_size( mbedtls_md_info_from_type( md_alg ) ) ) ); + + /* + * 3.3: Compute and add the signature + */ + if( mbedtls_ssl_own_key( ssl ) == NULL ) + { + MBEDTLS_SSL_DEBUG_MSG( 1, ( "got no private key" ) ); + return( MBEDTLS_ERR_SSL_PRIVATE_KEY_REQUIRED ); + } + +#if defined(MBEDTLS_SSL_PROTO_TLS1_2) + if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 ) + { + /* + * For TLS 1.2, we need to specify signature and hash algorithm + * explicitly through a prefix to the signature. + * + * struct { + * HashAlgorithm hash; + * SignatureAlgorithm signature; + * } SignatureAndHashAlgorithm; + * + * struct { + * SignatureAndHashAlgorithm algorithm; + * opaque signature<0..2^16-1>; + * } DigitallySigned; + * + */ + + *(p++) = mbedtls_ssl_hash_from_md_alg( md_alg ); + *(p++) = mbedtls_ssl_sig_from_pk_alg( sig_alg ); + + n += 2; + } +#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */ + + if( ( ret = mbedtls_pk_sign( mbedtls_ssl_own_key( ssl ), md_alg, hash, hashlen, + p + 2 , &signature_len, ssl->conf->f_rng, ssl->conf->p_rng ) ) != 0 ) + { + MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_pk_sign", ret ); + return( ret ); + } + + *(p++) = (unsigned char)( signature_len >> 8 ); + *(p++) = (unsigned char)( signature_len ); + n += 2; + + MBEDTLS_SSL_DEBUG_BUF( 3, "my signature", p, signature_len ); + + n += signature_len; + } +#endif /* MBEDTLS_KEY_EXCHANGE__WITH_SERVER_SIGNATURE__ENABLED */ + + /* Done with actual work; add header and send. */ + + ssl->out_msglen = 4 + n; + ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE; + ssl->out_msg[0] = MBEDTLS_SSL_HS_SERVER_KEY_EXCHANGE; + + ssl->state++; + + if( ( ret = mbedtls_ssl_write_record( ssl ) ) != 0 ) + { + MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_record", ret ); + return( ret ); + } + + MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write server key exchange" ) ); + + return( 0 ); +} + +static int ssl_write_server_hello_done( mbedtls_ssl_context *ssl ) +{ + int ret; + + MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write server hello done" ) ); + + ssl->out_msglen = 4; + ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE; + ssl->out_msg[0] = MBEDTLS_SSL_HS_SERVER_HELLO_DONE; + + ssl->state++; + +#if defined(MBEDTLS_SSL_PROTO_DTLS) + if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM ) + mbedtls_ssl_send_flight_completed( ssl ); +#endif + + if( ( ret = mbedtls_ssl_write_record( ssl ) ) != 0 ) + { + MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_record", ret ); + return( ret ); + } + + MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write server hello done" ) ); + + return( 0 ); +} + +#if defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED) || \ + defined(MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED) +static int ssl_parse_client_dh_public( mbedtls_ssl_context *ssl, unsigned char **p, + const unsigned char *end ) +{ + int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE; + size_t n; + + /* + * Receive G^Y mod P, premaster = (G^Y)^X mod P + */ + if( *p + 2 > end ) + { + MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) ); + return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE ); + } + + n = ( (*p)[0] << 8 ) | (*p)[1]; + *p += 2; + + if( *p + n > end ) + { + MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) ); + return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE ); + } + + if( ( ret = mbedtls_dhm_read_public( &ssl->handshake->dhm_ctx, *p, n ) ) != 0 ) + { + MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_dhm_read_public", ret ); + return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE_RP ); + } + + *p += n; + + MBEDTLS_SSL_DEBUG_MPI( 3, "DHM: GY", &ssl->handshake->dhm_ctx.GY ); + + return( ret ); +} +#endif /* MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED || + MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED */ + +#if defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED) || \ + defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED) +static int ssl_parse_encrypted_pms( mbedtls_ssl_context *ssl, + const unsigned char *p, + const unsigned char *end, + size_t pms_offset ) +{ + int ret; + size_t len = mbedtls_pk_get_len( mbedtls_ssl_own_key( ssl ) ); + unsigned char *pms = ssl->handshake->premaster + pms_offset; + unsigned char ver[2]; + unsigned char fake_pms[48], peer_pms[48]; + unsigned char mask; + size_t i, peer_pmslen; + unsigned int diff; + + if( ! mbedtls_pk_can_do( mbedtls_ssl_own_key( ssl ), MBEDTLS_PK_RSA ) ) + { + MBEDTLS_SSL_DEBUG_MSG( 1, ( "got no RSA private key" ) ); + return( MBEDTLS_ERR_SSL_PRIVATE_KEY_REQUIRED ); + } + + /* + * Decrypt the premaster using own private RSA key + */ +#if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) || \ + defined(MBEDTLS_SSL_PROTO_TLS1_2) + if( ssl->minor_ver != MBEDTLS_SSL_MINOR_VERSION_0 ) + { + if( *p++ != ( ( len >> 8 ) & 0xFF ) || + *p++ != ( ( len ) & 0xFF ) ) + { + MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) ); + return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE ); + } + } +#endif + + if( p + len != end ) + { + MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) ); + return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE ); + } + + mbedtls_ssl_write_version( ssl->handshake->max_major_ver, + ssl->handshake->max_minor_ver, + ssl->conf->transport, ver ); + + /* + * Protection against Bleichenbacher's attack: invalid PKCS#1 v1.5 padding + * must not cause the connection to end immediately; instead, send a + * bad_record_mac later in the handshake. + * Also, avoid data-dependant branches here to protect against + * timing-based variants. + */ + ret = ssl->conf->f_rng( ssl->conf->p_rng, fake_pms, sizeof( fake_pms ) ); + if( ret != 0 ) + return( ret ); + + ret = mbedtls_pk_decrypt( mbedtls_ssl_own_key( ssl ), p, len, + peer_pms, &peer_pmslen, + sizeof( peer_pms ), + ssl->conf->f_rng, ssl->conf->p_rng ); + + diff = (unsigned int) ret; + diff |= peer_pmslen ^ 48; + diff |= peer_pms[0] ^ ver[0]; + diff |= peer_pms[1] ^ ver[1]; + +#if defined(MBEDTLS_SSL_DEBUG_ALL) + if( diff != 0 ) + MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) ); +#endif + + if( sizeof( ssl->handshake->premaster ) < pms_offset || + sizeof( ssl->handshake->premaster ) - pms_offset < 48 ) + { + MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); + return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); + } + ssl->handshake->pmslen = 48; + + /* mask = diff ? 0xff : 0x00 using bit operations to avoid branches */ + /* MSVC has a warning about unary minus on unsigned, but this is + * well-defined and precisely what we want to do here */ +#if defined(_MSC_VER) +#pragma warning( push ) +#pragma warning( disable : 4146 ) +#endif + mask = - ( ( diff | - diff ) >> ( sizeof( unsigned int ) * 8 - 1 ) ); +#if defined(_MSC_VER) +#pragma warning( pop ) +#endif + + for( i = 0; i < ssl->handshake->pmslen; i++ ) + pms[i] = ( mask & fake_pms[i] ) | ( (~mask) & peer_pms[i] ); + + return( 0 ); +} +#endif /* MBEDTLS_KEY_EXCHANGE_RSA_ENABLED || + MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED */ + +#if defined(MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED) +static int ssl_parse_client_psk_identity( mbedtls_ssl_context *ssl, unsigned char **p, + const unsigned char *end ) +{ + int ret = 0; + size_t n; + + if( ssl->conf->f_psk == NULL && + ( ssl->conf->psk == NULL || ssl->conf->psk_identity == NULL || + ssl->conf->psk_identity_len == 0 || ssl->conf->psk_len == 0 ) ) + { + MBEDTLS_SSL_DEBUG_MSG( 1, ( "got no pre-shared key" ) ); + return( MBEDTLS_ERR_SSL_PRIVATE_KEY_REQUIRED ); + } + + /* + * Receive client pre-shared key identity name + */ + if( end - *p < 2 ) + { + MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) ); + return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE ); + } + + n = ( (*p)[0] << 8 ) | (*p)[1]; + *p += 2; + + if( n < 1 || n > 65535 || n > (size_t) ( end - *p ) ) + { + MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) ); + return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE ); + } + + if( ssl->conf->f_psk != NULL ) + { + if( ssl->conf->f_psk( ssl->conf->p_psk, ssl, *p, n ) != 0 ) + ret = MBEDTLS_ERR_SSL_UNKNOWN_IDENTITY; + } + else + { + /* Identity is not a big secret since clients send it in the clear, + * but treat it carefully anyway, just in case */ + if( n != ssl->conf->psk_identity_len || + mbedtls_ssl_safer_memcmp( ssl->conf->psk_identity, *p, n ) != 0 ) + { + ret = MBEDTLS_ERR_SSL_UNKNOWN_IDENTITY; + } + } + + if( ret == MBEDTLS_ERR_SSL_UNKNOWN_IDENTITY ) + { + MBEDTLS_SSL_DEBUG_BUF( 3, "Unknown PSK identity", *p, n ); + mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, + MBEDTLS_SSL_ALERT_MSG_UNKNOWN_PSK_IDENTITY ); + return( MBEDTLS_ERR_SSL_UNKNOWN_IDENTITY ); + } + + *p += n; + + return( 0 ); +} +#endif /* MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED */ + +static int ssl_parse_client_key_exchange( mbedtls_ssl_context *ssl ) +{ + int ret; + const mbedtls_ssl_ciphersuite_t *ciphersuite_info; + unsigned char *p, *end; + + ciphersuite_info = ssl->transform_negotiate->ciphersuite_info; + + MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse client key exchange" ) ); + + if( ( ret = mbedtls_ssl_read_record( ssl ) ) != 0 ) + { + MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret ); + return( ret ); + } + + p = ssl->in_msg + mbedtls_ssl_hs_hdr_len( ssl ); + end = ssl->in_msg + ssl->in_hslen; + + if( ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE ) + { + MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) ); + return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE ); + } + + if( ssl->in_msg[0] != MBEDTLS_SSL_HS_CLIENT_KEY_EXCHANGE ) + { + MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) ); + return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE ); + } + +#if defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED) + if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_RSA ) + { + if( ( ret = ssl_parse_client_dh_public( ssl, &p, end ) ) != 0 ) + { + MBEDTLS_SSL_DEBUG_RET( 1, ( "ssl_parse_client_dh_public" ), ret ); + return( ret ); + } + + if( p != end ) + { + MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client key exchange" ) ); + return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE ); + } + + if( ( ret = mbedtls_dhm_calc_secret( &ssl->handshake->dhm_ctx, + ssl->handshake->premaster, + MBEDTLS_PREMASTER_SIZE, + &ssl->handshake->pmslen, + ssl->conf->f_rng, ssl->conf->p_rng ) ) != 0 ) + { + MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_dhm_calc_secret", ret ); + return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE_CS ); + } + + MBEDTLS_SSL_DEBUG_MPI( 3, "DHM: K ", &ssl->handshake->dhm_ctx.K ); + } + else +#endif /* MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED */ +#if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \ + defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) || \ + defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \ + defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED) + if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_RSA || + ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA || + ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDH_RSA || + ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA ) + { + if( ( ret = mbedtls_ecdh_read_public( &ssl->handshake->ecdh_ctx, + p, end - p) ) != 0 ) + { + MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecdh_read_public", ret ); + return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE_RP ); + } + + MBEDTLS_SSL_DEBUG_ECP( 3, "ECDH: Qp ", &ssl->handshake->ecdh_ctx.Qp ); + + if( ( ret = mbedtls_ecdh_calc_secret( &ssl->handshake->ecdh_ctx, + &ssl->handshake->pmslen, + ssl->handshake->premaster, + MBEDTLS_MPI_MAX_SIZE, + ssl->conf->f_rng, ssl->conf->p_rng ) ) != 0 ) + { + MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecdh_calc_secret", ret ); + return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE_CS ); + } + + MBEDTLS_SSL_DEBUG_MPI( 3, "ECDH: z ", &ssl->handshake->ecdh_ctx.z ); + } + else +#endif /* MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED || + MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED || + MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED || + MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED */ +#if defined(MBEDTLS_KEY_EXCHANGE_PSK_ENABLED) + if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK ) + { + if( ( ret = ssl_parse_client_psk_identity( ssl, &p, end ) ) != 0 ) + { + MBEDTLS_SSL_DEBUG_RET( 1, ( "ssl_parse_client_psk_identity" ), ret ); + return( ret ); + } + + if( p != end ) + { + MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client key exchange" ) ); + return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE ); + } + + if( ( ret = mbedtls_ssl_psk_derive_premaster( ssl, + ciphersuite_info->key_exchange ) ) != 0 ) + { + MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_psk_derive_premaster", ret ); + return( ret ); + } + } + else +#endif /* MBEDTLS_KEY_EXCHANGE_PSK_ENABLED */ +#if defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED) + if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK ) + { + if( ( ret = ssl_parse_client_psk_identity( ssl, &p, end ) ) != 0 ) + { + MBEDTLS_SSL_DEBUG_RET( 1, ( "ssl_parse_client_psk_identity" ), ret ); + return( ret ); + } + + if( ( ret = ssl_parse_encrypted_pms( ssl, p, end, 2 ) ) != 0 ) + { + MBEDTLS_SSL_DEBUG_RET( 1, ( "ssl_parse_encrypted_pms" ), ret ); + return( ret ); + } + + if( ( ret = mbedtls_ssl_psk_derive_premaster( ssl, + ciphersuite_info->key_exchange ) ) != 0 ) + { + MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_psk_derive_premaster", ret ); + return( ret ); + } + } + else +#endif /* MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED */ +#if defined(MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED) + if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK ) + { + if( ( ret = ssl_parse_client_psk_identity( ssl, &p, end ) ) != 0 ) + { + MBEDTLS_SSL_DEBUG_RET( 1, ( "ssl_parse_client_psk_identity" ), ret ); + return( ret ); + } + if( ( ret = ssl_parse_client_dh_public( ssl, &p, end ) ) != 0 ) + { + MBEDTLS_SSL_DEBUG_RET( 1, ( "ssl_parse_client_dh_public" ), ret ); + return( ret ); + } + + if( p != end ) + { + MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client key exchange" ) ); + return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE ); + } + + if( ( ret = mbedtls_ssl_psk_derive_premaster( ssl, + ciphersuite_info->key_exchange ) ) != 0 ) + { + MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_psk_derive_premaster", ret ); + return( ret ); + } + } + else +#endif /* MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED */ +#if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED) + if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK ) + { + if( ( ret = ssl_parse_client_psk_identity( ssl, &p, end ) ) != 0 ) + { + MBEDTLS_SSL_DEBUG_RET( 1, ( "ssl_parse_client_psk_identity" ), ret ); + return( ret ); + } + + if( ( ret = mbedtls_ecdh_read_public( &ssl->handshake->ecdh_ctx, + p, end - p ) ) != 0 ) + { + MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecdh_read_public", ret ); + return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE_RP ); + } + + MBEDTLS_SSL_DEBUG_ECP( 3, "ECDH: Qp ", &ssl->handshake->ecdh_ctx.Qp ); + + if( ( ret = mbedtls_ssl_psk_derive_premaster( ssl, + ciphersuite_info->key_exchange ) ) != 0 ) + { + MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_psk_derive_premaster", ret ); + return( ret ); + } + } + else +#endif /* MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED */ +#if defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED) + if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA ) + { + if( ( ret = ssl_parse_encrypted_pms( ssl, p, end, 0 ) ) != 0 ) + { + MBEDTLS_SSL_DEBUG_RET( 1, ( "ssl_parse_parse_encrypted_pms_secret" ), ret ); + return( ret ); + } + } + else +#endif /* MBEDTLS_KEY_EXCHANGE_RSA_ENABLED */ +#if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED) + if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE ) + { + ret = mbedtls_ecjpake_read_round_two( &ssl->handshake->ecjpake_ctx, + p, end - p ); + if( ret != 0 ) + { + MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecjpake_read_round_two", ret ); + return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE ); + } + + ret = mbedtls_ecjpake_derive_secret( &ssl->handshake->ecjpake_ctx, + ssl->handshake->premaster, 32, &ssl->handshake->pmslen, + ssl->conf->f_rng, ssl->conf->p_rng ); + if( ret != 0 ) + { + MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecjpake_derive_secret", ret ); + return( ret ); + } + } + else +#endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */ + { + MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); + return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); + } + + if( ( ret = mbedtls_ssl_derive_keys( ssl ) ) != 0 ) + { + MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_derive_keys", ret ); + return( ret ); + } + + ssl->state++; + + MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse client key exchange" ) ); + + return( 0 ); +} + +#if !defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED) && \ + !defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED) && \ + !defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) && \ + !defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) && \ + !defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)&& \ + !defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) +static int ssl_parse_certificate_verify( mbedtls_ssl_context *ssl ) +{ + const mbedtls_ssl_ciphersuite_t *ciphersuite_info = + ssl->transform_negotiate->ciphersuite_info; + + MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse certificate verify" ) ); + + if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK || + ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK || + ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK || + ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK || + ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE ) + { + MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate verify" ) ); + ssl->state++; + return( 0 ); + } + + MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); + return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); +} +#else +static int ssl_parse_certificate_verify( mbedtls_ssl_context *ssl ) +{ + int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE; + size_t i, sig_len; + unsigned char hash[48]; + unsigned char *hash_start = hash; + size_t hashlen; +#if defined(MBEDTLS_SSL_PROTO_TLS1_2) + mbedtls_pk_type_t pk_alg; +#endif + mbedtls_md_type_t md_alg; + const mbedtls_ssl_ciphersuite_t *ciphersuite_info = + ssl->transform_negotiate->ciphersuite_info; + + MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse certificate verify" ) ); + + if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK || + ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK || + ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK || + ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK || + ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE || + ssl->session_negotiate->peer_cert == NULL ) + { + MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate verify" ) ); + ssl->state++; + return( 0 ); + } + + /* Read the message without adding it to the checksum */ + do { + + if( ( ret = mbedtls_ssl_read_record_layer( ssl ) ) != 0 ) + { + MBEDTLS_SSL_DEBUG_RET( 1, ( "mbedtls_ssl_read_record_layer" ), ret ); + return( ret ); + } + + ret = mbedtls_ssl_handle_message_type( ssl ); + + } while( MBEDTLS_ERR_SSL_NON_FATAL == ret ); + + if( 0 != ret ) + { + MBEDTLS_SSL_DEBUG_RET( 1, ( "mbedtls_ssl_handle_message_type" ), ret ); + return( ret ); + } + + ssl->state++; + + /* Process the message contents */ + if( ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE || + ssl->in_msg[0] != MBEDTLS_SSL_HS_CERTIFICATE_VERIFY ) + { + MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate verify message" ) ); + return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE_VERIFY ); + } + + i = mbedtls_ssl_hs_hdr_len( ssl ); + + /* + * struct { + * SignatureAndHashAlgorithm algorithm; -- TLS 1.2 only + * opaque signature<0..2^16-1>; + * } DigitallySigned; + */ +#if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1) || \ + defined(MBEDTLS_SSL_PROTO_TLS1_1) + if( ssl->minor_ver != MBEDTLS_SSL_MINOR_VERSION_3 ) + { + md_alg = MBEDTLS_MD_NONE; + hashlen = 36; + + /* For ECDSA, use SHA-1, not MD-5 + SHA-1 */ + if( mbedtls_pk_can_do( &ssl->session_negotiate->peer_cert->pk, + MBEDTLS_PK_ECDSA ) ) + { + hash_start += 16; + hashlen -= 16; + md_alg = MBEDTLS_MD_SHA1; + } + } + else +#endif /* MBEDTLS_SSL_PROTO_SSL3 || MBEDTLS_SSL_PROTO_TLS1 || + MBEDTLS_SSL_PROTO_TLS1_1 */ +#if defined(MBEDTLS_SSL_PROTO_TLS1_2) + if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 ) + { + if( i + 2 > ssl->in_hslen ) + { + MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate verify message" ) ); + return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE_VERIFY ); + } + + /* + * Hash + */ + md_alg = mbedtls_ssl_md_alg_from_hash( ssl->in_msg[i] ); + + if( md_alg == MBEDTLS_MD_NONE || mbedtls_ssl_set_calc_verify_md( ssl, ssl->in_msg[i] ) ) + { + MBEDTLS_SSL_DEBUG_MSG( 1, ( "peer not adhering to requested sig_alg" + " for verify message" ) ); + return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE_VERIFY ); + } + +#if !defined(MBEDTLS_MD_SHA1) + if( MBEDTLS_MD_SHA1 == md_alg ) + hash_start += 16; +#endif + + /* Info from md_alg will be used instead */ + hashlen = 0; + + i++; + + /* + * Signature + */ + if( ( pk_alg = mbedtls_ssl_pk_alg_from_sig( ssl->in_msg[i] ) ) + == MBEDTLS_PK_NONE ) + { + MBEDTLS_SSL_DEBUG_MSG( 1, ( "peer not adhering to requested sig_alg" + " for verify message" ) ); + return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE_VERIFY ); + } + + /* + * Check the certificate's key type matches the signature alg + */ + if( ! mbedtls_pk_can_do( &ssl->session_negotiate->peer_cert->pk, pk_alg ) ) + { + MBEDTLS_SSL_DEBUG_MSG( 1, ( "sig_alg doesn't match cert key" ) ); + return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE_VERIFY ); + } + + i++; + } + else +#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */ + { + MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); + return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); + } + + if( i + 2 > ssl->in_hslen ) + { + MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate verify message" ) ); + return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE_VERIFY ); + } + + sig_len = ( ssl->in_msg[i] << 8 ) | ssl->in_msg[i+1]; + i += 2; + + if( i + sig_len != ssl->in_hslen ) + { + MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate verify message" ) ); + return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE_VERIFY ); + } + + /* Calculate hash and verify signature */ + ssl->handshake->calc_verify( ssl, hash ); + + if( ( ret = mbedtls_pk_verify( &ssl->session_negotiate->peer_cert->pk, + md_alg, hash_start, hashlen, + ssl->in_msg + i, sig_len ) ) != 0 ) + { + MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_pk_verify", ret ); + return( ret ); + } + + mbedtls_ssl_update_handshake_status( ssl ); + + MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse certificate verify" ) ); + + return( ret ); +} +#endif /* !MBEDTLS_KEY_EXCHANGE_RSA_ENABLED && + !MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED && + !MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED && + !MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED && + !MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED && + !MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED */ + +#if defined(MBEDTLS_SSL_SESSION_TICKETS) +static int ssl_write_new_session_ticket( mbedtls_ssl_context *ssl ) +{ + int ret; + size_t tlen; + uint32_t lifetime; + + MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write new session ticket" ) ); + + ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE; + ssl->out_msg[0] = MBEDTLS_SSL_HS_NEW_SESSION_TICKET; + + /* + * struct { + * uint32 ticket_lifetime_hint; + * opaque ticket<0..2^16-1>; + * } NewSessionTicket; + * + * 4 . 7 ticket_lifetime_hint (0 = unspecified) + * 8 . 9 ticket_len (n) + * 10 . 9+n ticket content + */ + + if( ( ret = ssl->conf->f_ticket_write( ssl->conf->p_ticket, + ssl->session_negotiate, + ssl->out_msg + 10, + ssl->out_msg + MBEDTLS_SSL_MAX_CONTENT_LEN, + &tlen, &lifetime ) ) != 0 ) + { + MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_ticket_write", ret ); + tlen = 0; + } + + ssl->out_msg[4] = ( lifetime >> 24 ) & 0xFF; + ssl->out_msg[5] = ( lifetime >> 16 ) & 0xFF; + ssl->out_msg[6] = ( lifetime >> 8 ) & 0xFF; + ssl->out_msg[7] = ( lifetime ) & 0xFF; + + ssl->out_msg[8] = (unsigned char)( ( tlen >> 8 ) & 0xFF ); + ssl->out_msg[9] = (unsigned char)( ( tlen ) & 0xFF ); + + ssl->out_msglen = 10 + tlen; + + /* + * Morally equivalent to updating ssl->state, but NewSessionTicket and + * ChangeCipherSpec share the same state. + */ + ssl->handshake->new_session_ticket = 0; + + if( ( ret = mbedtls_ssl_write_record( ssl ) ) != 0 ) + { + MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_record", ret ); + return( ret ); + } + + MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write new session ticket" ) ); + + return( 0 ); +} +#endif /* MBEDTLS_SSL_SESSION_TICKETS */ + +/* + * SSL handshake -- server side -- single step + */ +int mbedtls_ssl_handshake_server_step( mbedtls_ssl_context *ssl ) +{ + int ret = 0; + + if( ssl->state == MBEDTLS_SSL_HANDSHAKE_OVER || ssl->handshake == NULL ) + return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); + + MBEDTLS_SSL_DEBUG_MSG( 2, ( "server state: %d", ssl->state ) ); + + if( ( ret = mbedtls_ssl_flush_output( ssl ) ) != 0 ) + return( ret ); + +#if defined(MBEDTLS_SSL_PROTO_DTLS) + if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM && + ssl->handshake->retransmit_state == MBEDTLS_SSL_RETRANS_SENDING ) + { + if( ( ret = mbedtls_ssl_resend( ssl ) ) != 0 ) + return( ret ); + } +#endif + + switch( ssl->state ) + { + case MBEDTLS_SSL_HELLO_REQUEST: + ssl->state = MBEDTLS_SSL_CLIENT_HELLO; + break; + + /* + * <== ClientHello + */ + case MBEDTLS_SSL_CLIENT_HELLO: + ret = ssl_parse_client_hello( ssl ); + break; + +#if defined(MBEDTLS_SSL_PROTO_DTLS) + case MBEDTLS_SSL_SERVER_HELLO_VERIFY_REQUEST_SENT: + return( MBEDTLS_ERR_SSL_HELLO_VERIFY_REQUIRED ); +#endif + + /* + * ==> ServerHello + * Certificate + * ( ServerKeyExchange ) + * ( CertificateRequest ) + * ServerHelloDone + */ + case MBEDTLS_SSL_SERVER_HELLO: + ret = ssl_write_server_hello( ssl ); + break; + + case MBEDTLS_SSL_SERVER_CERTIFICATE: + ret = mbedtls_ssl_write_certificate( ssl ); + break; + + case MBEDTLS_SSL_SERVER_KEY_EXCHANGE: + ret = ssl_write_server_key_exchange( ssl ); + break; + + case MBEDTLS_SSL_CERTIFICATE_REQUEST: + ret = ssl_write_certificate_request( ssl ); + break; + + case MBEDTLS_SSL_SERVER_HELLO_DONE: + ret = ssl_write_server_hello_done( ssl ); + break; + + /* + * <== ( Certificate/Alert ) + * ClientKeyExchange + * ( CertificateVerify ) + * ChangeCipherSpec + * Finished + */ + case MBEDTLS_SSL_CLIENT_CERTIFICATE: + ret = mbedtls_ssl_parse_certificate( ssl ); + break; + + case MBEDTLS_SSL_CLIENT_KEY_EXCHANGE: + ret = ssl_parse_client_key_exchange( ssl ); + break; + + case MBEDTLS_SSL_CERTIFICATE_VERIFY: + ret = ssl_parse_certificate_verify( ssl ); + break; + + case MBEDTLS_SSL_CLIENT_CHANGE_CIPHER_SPEC: + ret = mbedtls_ssl_parse_change_cipher_spec( ssl ); + break; + + case MBEDTLS_SSL_CLIENT_FINISHED: + ret = mbedtls_ssl_parse_finished( ssl ); + break; + + /* + * ==> ( NewSessionTicket ) + * ChangeCipherSpec + * Finished + */ + case MBEDTLS_SSL_SERVER_CHANGE_CIPHER_SPEC: +#if defined(MBEDTLS_SSL_SESSION_TICKETS) + if( ssl->handshake->new_session_ticket != 0 ) + ret = ssl_write_new_session_ticket( ssl ); + else +#endif + ret = mbedtls_ssl_write_change_cipher_spec( ssl ); + break; + + case MBEDTLS_SSL_SERVER_FINISHED: + ret = mbedtls_ssl_write_finished( ssl ); + break; + + case MBEDTLS_SSL_FLUSH_BUFFERS: + MBEDTLS_SSL_DEBUG_MSG( 2, ( "handshake: done" ) ); + ssl->state = MBEDTLS_SSL_HANDSHAKE_WRAPUP; + break; + + case MBEDTLS_SSL_HANDSHAKE_WRAPUP: + mbedtls_ssl_handshake_wrapup( ssl ); + break; + + default: + MBEDTLS_SSL_DEBUG_MSG( 1, ( "invalid state %d", ssl->state ) ); + return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA ); + } + + return( ret ); +} +#endif /* MBEDTLS_SSL_SRV_C */ |