diff options
Diffstat (limited to 'FreeRTOS-Labs/Source/mbedtls/library/ssl_srv.c')
| -rw-r--r-- | FreeRTOS-Labs/Source/mbedtls/library/ssl_srv.c | 4573 |
1 files changed, 4573 insertions, 0 deletions
diff --git a/FreeRTOS-Labs/Source/mbedtls/library/ssl_srv.c b/FreeRTOS-Labs/Source/mbedtls/library/ssl_srv.c new file mode 100644 index 000000000..c5331213f --- /dev/null +++ b/FreeRTOS-Labs/Source/mbedtls/library/ssl_srv.c @@ -0,0 +1,4573 @@ +/*
+ * 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 "mbedtls/platform_util.h"
+
+#include <string.h>
+
+#if defined(MBEDTLS_ECP_C)
+#include "mbedtls/ecp.h"
+#endif
+
+#if defined(MBEDTLS_HAVE_TIME)
+#include "mbedtls/platform_time.h"
+#endif
+
+#if defined(MBEDTLS_SSL_DTLS_HELLO_VERIFY)
+int mbedtls_ssl_set_client_transport_id( mbedtls_ssl_context *ssl,
+ const unsigned char *info,
+ size_t ilen )
+{
+ if( ssl->conf->endpoint != MBEDTLS_SSL_IS_SERVER )
+ return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
+
+ mbedtls_free( ssl->cli_id );
+
+ if( ( ssl->cli_id = mbedtls_calloc( 1, ilen ) ) == NULL )
+ return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
+
+ memcpy( ssl->cli_id, info, ilen );
+ ssl->cli_id_len = ilen;
+
+ return( 0 );
+}
+
+void mbedtls_ssl_conf_dtls_cookies( mbedtls_ssl_config *conf,
+ mbedtls_ssl_cookie_write_t *f_cookie_write,
+ mbedtls_ssl_cookie_check_t *f_cookie_check,
+ void *p_cookie )
+{
+ conf->f_cookie_write = f_cookie_write;
+ conf->f_cookie_check = f_cookie_check;
+ conf->p_cookie = p_cookie;
+}
+#endif /* MBEDTLS_SSL_DTLS_HELLO_VERIFY */
+
+#if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
+static int ssl_parse_servername_ext( mbedtls_ssl_context *ssl,
+ const unsigned char *buf,
+ size_t len )
+{
+ int ret;
+ size_t servername_list_size, hostname_len;
+ const unsigned char *p;
+
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "parse ServerName extension" ) );
+
+ if( len < 2 )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+ MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
+ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+ servername_list_size = ( ( buf[0] << 8 ) | ( buf[1] ) );
+ if( servername_list_size + 2 != len )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+ MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
+ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ p = buf + 2;
+ while( servername_list_size > 2 )
+ {
+ hostname_len = ( ( p[1] << 8 ) | p[2] );
+ if( hostname_len + 3 > servername_list_size )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+ MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
+ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ if( p[0] == MBEDTLS_TLS_EXT_SERVERNAME_HOSTNAME )
+ {
+ ret = ssl->conf->f_sni( ssl->conf->p_sni,
+ ssl, p + 3, hostname_len );
+ if( ret != 0 )
+ {
+ MBEDTLS_SSL_DEBUG_RET( 1, "ssl_sni_wrapper", ret );
+ mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+ MBEDTLS_SSL_ALERT_MSG_UNRECOGNIZED_NAME );
+ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+ return( 0 );
+ }
+
+ servername_list_size -= hostname_len + 3;
+ p += hostname_len + 3;
+ }
+
+ if( servername_list_size != 0 )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+ MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
+ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ return( 0 );
+}
+#endif /* MBEDTLS_SSL_SERVER_NAME_INDICATION */
+
+#if defined(MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED)
+static int ssl_conf_has_psk_or_cb( mbedtls_ssl_config const *conf )
+{
+ if( conf->f_psk != NULL )
+ return( 1 );
+
+ if( conf->psk_identity_len == 0 || conf->psk_identity == NULL )
+ return( 0 );
+
+ if( conf->psk != NULL && conf->psk_len != 0 )
+ return( 1 );
+
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+ if( conf->psk_opaque != 0 )
+ return( 1 );
+#endif /* MBEDTLS_USE_PSA_CRYPTO */
+
+ return( 0 );
+}
+
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+static int ssl_use_opaque_psk( mbedtls_ssl_context const *ssl )
+{
+ if( ssl->conf->f_psk != NULL )
+ {
+ /* If we've used a callback to select the PSK,
+ * the static configuration is irrelevant. */
+
+ if( ssl->handshake->psk_opaque != 0 )
+ return( 1 );
+
+ return( 0 );
+ }
+
+ if( ssl->conf->psk_opaque != 0 )
+ return( 1 );
+
+ return( 0 );
+}
+#endif /* MBEDTLS_USE_PSA_CRYPTO */
+#endif /* MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED */
+
+static int ssl_parse_renegotiation_info( mbedtls_ssl_context *ssl,
+ const unsigned char *buf,
+ size_t len )
+{
+#if defined(MBEDTLS_SSL_RENEGOTIATION)
+ if( ssl->renego_status != MBEDTLS_SSL_INITIAL_HANDSHAKE )
+ {
+ /* Check verify-data in constant-time. The length OTOH is no secret */
+ if( len != 1 + ssl->verify_data_len ||
+ buf[0] != ssl->verify_data_len ||
+ mbedtls_ssl_safer_memcmp( buf + 1, ssl->peer_verify_data,
+ ssl->verify_data_len ) != 0 )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "non-matching renegotiation info" ) );
+ mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+ MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
+ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+ }
+ else
+#endif /* MBEDTLS_SSL_RENEGOTIATION */
+ {
+ if( len != 1 || buf[0] != 0x0 )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "non-zero length renegotiation info" ) );
+ mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+ MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
+ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ ssl->secure_renegotiation = MBEDTLS_SSL_SECURE_RENEGOTIATION;
+ }
+
+ return( 0 );
+}
+
+#if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \
+ defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)
+
+/*
+ * Status of the implementation of signature-algorithms extension:
+ *
+ * Currently, we are only considering the signature-algorithm extension
+ * to pick a ciphersuite which allows us to send the ServerKeyExchange
+ * message with a signature-hash combination that the user allows.
+ *
+ * We do *not* check whether all certificates in our certificate
+ * chain are signed with an allowed signature-hash pair.
+ * This needs to be done at a later stage.
+ *
+ */
+static int ssl_parse_signature_algorithms_ext( mbedtls_ssl_context *ssl,
+ const unsigned char *buf,
+ size_t len )
+{
+ size_t sig_alg_list_size;
+
+ const unsigned char *p;
+ const unsigned char *end = buf + len;
+
+ mbedtls_md_type_t md_cur;
+ mbedtls_pk_type_t sig_cur;
+
+ if ( len < 2 ) {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+ MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
+ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+ sig_alg_list_size = ( ( buf[0] << 8 ) | ( buf[1] ) );
+ if( sig_alg_list_size + 2 != len ||
+ sig_alg_list_size % 2 != 0 )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+ MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
+ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ /* Currently we only guarantee signing the ServerKeyExchange message according
+ * to the constraints specified in this extension (see above), so it suffices
+ * to remember only one suitable hash for each possible signature algorithm.
+ *
+ * This will change when we also consider certificate signatures,
+ * in which case we will need to remember the whole signature-hash
+ * pair list from the extension.
+ */
+
+ for( p = buf + 2; p < end; p += 2 )
+ {
+ /* Silently ignore unknown signature or hash algorithms. */
+
+ if( ( sig_cur = mbedtls_ssl_pk_alg_from_sig( p[1] ) ) == MBEDTLS_PK_NONE )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello v3, signature_algorithm ext"
+ " unknown sig alg encoding %d", p[1] ) );
+ continue;
+ }
+
+ /* Check if we support the hash the user proposes */
+ md_cur = mbedtls_ssl_md_alg_from_hash( p[0] );
+ if( md_cur == MBEDTLS_MD_NONE )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello v3, signature_algorithm ext:"
+ " unknown hash alg encoding %d", p[0] ) );
+ continue;
+ }
+
+ if( mbedtls_ssl_check_sig_hash( ssl, md_cur ) == 0 )
+ {
+ mbedtls_ssl_sig_hash_set_add( &ssl->handshake->hash_algs, sig_cur, md_cur );
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello v3, signature_algorithm ext:"
+ " match sig %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;
+
+ if ( len < 2 ) {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+ MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
+ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+ list_size = ( ( buf[0] << 8 ) | ( buf[1] ) );
+ if( list_size + 2 != len ||
+ list_size % 2 != 0 )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+ MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
+ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ /* Should never happen unless client duplicates the extension */
+ if( ssl->handshake->curves != NULL )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+ MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
+ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ /* Don't allow our peer to make us allocate too much memory,
+ * and leave room for a final 0 */
+ our_size = list_size / 2 + 1;
+ if( our_size > MBEDTLS_ECP_DP_MAX )
+ our_size = MBEDTLS_ECP_DP_MAX;
+
+ if( ( curves = mbedtls_calloc( our_size, sizeof( *curves ) ) ) == NULL )
+ {
+ mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+ MBEDTLS_SSL_ALERT_MSG_INTERNAL_ERROR );
+ return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
+ }
+
+ ssl->handshake->curves = curves;
+
+ p = buf + 2;
+ while( list_size > 0 && our_size > 1 )
+ {
+ curve_info = mbedtls_ecp_curve_info_from_tls_id( ( p[0] << 8 ) | p[1] );
+
+ if( curve_info != NULL )
+ {
+ *curves++ = curve_info;
+ our_size--;
+ }
+
+ list_size -= 2;
+ p += 2;
+ }
+
+ return( 0 );
+}
+
+static int ssl_parse_supported_point_formats( mbedtls_ssl_context *ssl,
+ const unsigned char *buf,
+ size_t len )
+{
+ size_t list_size;
+ const unsigned char *p;
+
+ if( len == 0 || (size_t)( buf[0] + 1 ) != len )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+ MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
+ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+ list_size = buf[0];
+
+ p = buf + 1;
+ while( list_size > 0 )
+ {
+ if( p[0] == MBEDTLS_ECP_PF_UNCOMPRESSED ||
+ p[0] == MBEDTLS_ECP_PF_COMPRESSED )
+ {
+#if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C)
+ ssl->handshake->ecdh_ctx.point_format = p[0];
+#endif
+#if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
+ ssl->handshake->ecjpake_ctx.point_format = p[0];
+#endif
+ MBEDTLS_SSL_DEBUG_MSG( 4, ( "point format selected: %d", p[0] ) );
+ return( 0 );
+ }
+
+ list_size--;
+ p++;
+ }
+
+ return( 0 );
+}
+#endif /* MBEDTLS_ECDH_C || MBEDTLS_ECDSA_C ||
+ MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
+
+#if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
+static int ssl_parse_ecjpake_kkpp( mbedtls_ssl_context *ssl,
+ const unsigned char *buf,
+ size_t len )
+{
+ int ret;
+
+ if( mbedtls_ecjpake_check( &ssl->handshake->ecjpake_ctx ) != 0 )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "skip ecjpake kkpp extension" ) );
+ return( 0 );
+ }
+
+ if( ( ret = mbedtls_ecjpake_read_round_one( &ssl->handshake->ecjpake_ctx,
+ buf, len ) ) != 0 )
+ {
+ MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecjpake_read_round_one", ret );
+ mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+ MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
+ return( ret );
+ }
+
+ /* Only mark the extension as OK when we're sure it is */
+ ssl->handshake->cli_exts |= MBEDTLS_TLS_EXT_ECJPAKE_KKPP_OK;
+
+ return( 0 );
+}
+#endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
+
+#if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
+static int ssl_parse_max_fragment_length_ext( mbedtls_ssl_context *ssl,
+ const unsigned char *buf,
+ size_t len )
+{
+ if( len != 1 || buf[0] >= MBEDTLS_SSL_MAX_FRAG_LEN_INVALID )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+ MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
+ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ ssl->session_negotiate->mfl_code = buf[0];
+
+ return( 0 );
+}
+#endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */
+
+#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
+static int ssl_parse_cid_ext( mbedtls_ssl_context *ssl,
+ const unsigned char *buf,
+ size_t len )
+{
+ size_t peer_cid_len;
+
+ /* CID extension only makes sense in DTLS */
+ if( ssl->conf->transport != MBEDTLS_SSL_TRANSPORT_DATAGRAM )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+ MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
+ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ /*
+ * Quoting draft-ietf-tls-dtls-connection-id-05
+ * https://tools.ietf.org/html/draft-ietf-tls-dtls-connection-id-05
+ *
+ * struct {
+ * opaque cid<0..2^8-1>;
+ * } ConnectionId;
+ */
+
+ if( len < 1 )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+ MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
+ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ peer_cid_len = *buf++;
+ len--;
+
+ if( len != peer_cid_len )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+ MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
+ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ /* Ignore CID if the user has disabled its use. */
+ if( ssl->negotiate_cid == MBEDTLS_SSL_CID_DISABLED )
+ {
+ /* Leave ssl->handshake->cid_in_use in its default
+ * value of MBEDTLS_SSL_CID_DISABLED. */
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "Client sent CID extension, but CID disabled" ) );
+ return( 0 );
+ }
+
+ if( peer_cid_len > MBEDTLS_SSL_CID_OUT_LEN_MAX )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+ MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
+ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ ssl->handshake->cid_in_use = MBEDTLS_SSL_CID_ENABLED;
+ ssl->handshake->peer_cid_len = (uint8_t) peer_cid_len;
+ memcpy( ssl->handshake->peer_cid, buf, peer_cid_len );
+
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "Use of CID extension negotiated" ) );
+ MBEDTLS_SSL_DEBUG_BUF( 3, "Client CID", buf, peer_cid_len );
+
+ return( 0 );
+}
+#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
+
+#if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
+static int ssl_parse_truncated_hmac_ext( mbedtls_ssl_context *ssl,
+ const unsigned char *buf,
+ size_t len )
+{
+ if( len != 0 )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+ MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
+ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ ((void) buf);
+
+ if( ssl->conf->trunc_hmac == MBEDTLS_SSL_TRUNC_HMAC_ENABLED )
+ ssl->session_negotiate->trunc_hmac = MBEDTLS_SSL_TRUNC_HMAC_ENABLED;
+
+ return( 0 );
+}
+#endif /* MBEDTLS_SSL_TRUNCATED_HMAC */
+
+#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
+static int ssl_parse_encrypt_then_mac_ext( mbedtls_ssl_context *ssl,
+ const unsigned char *buf,
+ size_t len )
+{
+ if( len != 0 )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+ MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
+ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ ((void) buf);
+
+ if( ssl->conf->encrypt_then_mac == MBEDTLS_SSL_ETM_ENABLED &&
+ ssl->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_platform_zeroize( &session, sizeof( mbedtls_ssl_session ) );
+
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "session successfully restored from ticket" ) );
+
+ ssl->handshake->resume = 1;
+
+ /* Don't send a new ticket after all, this one is OK */
+ ssl->handshake->new_session_ticket = 0;
+
+ return( 0 );
+}
+#endif /* MBEDTLS_SSL_SESSION_TICKETS */
+
+#if defined(MBEDTLS_SSL_ALPN)
+static int ssl_parse_alpn_ext( mbedtls_ssl_context *ssl,
+ const unsigned char *buf, size_t len )
+{
+ size_t list_len, cur_len, ours_len;
+ const unsigned char *theirs, *start, *end;
+ const char **ours;
+
+ /* If ALPN not configured, just ignore the extension */
+ if( ssl->conf->alpn_list == NULL )
+ return( 0 );
+
+ /*
+ * opaque ProtocolName<1..2^8-1>;
+ *
+ * struct {
+ * ProtocolName protocol_name_list<2..2^16-1>
+ * } ProtocolNameList;
+ */
+
+ /* Min length is 2 (list_len) + 1 (name_len) + 1 (name) */
+ if( len < 4 )
+ {
+ mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+ MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
+ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ list_len = ( buf[0] << 8 ) | buf[1];
+ if( list_len != len - 2 )
+ {
+ mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+ MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
+ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ /*
+ * Validate peer's list (lengths)
+ */
+ start = buf + 2;
+ end = buf + len;
+ for( theirs = start; theirs != end; theirs += cur_len )
+ {
+ cur_len = *theirs++;
+
+ /* Current identifier must fit in list */
+ if( cur_len > (size_t)( end - theirs ) )
+ {
+ mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+ MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
+ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ /* Empty strings MUST NOT be included */
+ if( cur_len == 0 )
+ {
+ mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+ MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
+ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+ }
+
+ /*
+ * Use our order of preference
+ */
+ for( ours = ssl->conf->alpn_list; *ours != NULL; ours++ )
+ {
+ ours_len = strlen( *ours );
+ for( theirs = start; theirs != end; theirs += cur_len )
+ {
+ cur_len = *theirs++;
+
+ if( cur_len == ours_len &&
+ memcmp( theirs, *ours, cur_len ) == 0 )
+ {
+ ssl->alpn_chosen = *ours;
+ return( 0 );
+ }
+ }
+ }
+
+ /* If we get there, no match was found */
+ mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+ MBEDTLS_SSL_ALERT_MSG_NO_APPLICATION_PROTOCOL );
+ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
+}
+#endif /* MBEDTLS_SSL_ALPN */
+
+/*
+ * 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->cert->pk, pk_alg ) )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "certificate mismatch: key type" ) );
+ continue;
+ }
+
+ /*
+ * This avoids sending the client a cert it'll reject based on
+ * keyUsage or other extensions.
+ *
+ * It also allows the user to provision different certificates for
+ * different uses based on keyUsage, eg if they want to avoid signing
+ * and decrypting with the same RSA key.
+ */
+ if( mbedtls_ssl_check_cert_usage( cur->cert, ciphersuite_info,
+ MBEDTLS_SSL_IS_SERVER, &flags ) != 0 )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "certificate mismatch: "
+ "(extended) key usage extension" ) );
+ continue;
+ }
+
+#if defined(MBEDTLS_ECDSA_C)
+ if( pk_alg == MBEDTLS_PK_ECDSA &&
+ ssl_check_key_curve( &cur->cert->pk, ssl->handshake->curves ) != 0 )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "certificate mismatch: elliptic curve" ) );
+ continue;
+ }
+#endif
+
+ /*
+ * Try to select a SHA-1 certificate for pre-1.2 clients, but still
+ * present them a SHA-higher cert rather than failing if it's the only
+ * one we got that satisfies the other conditions.
+ */
+ if( ssl->minor_ver < MBEDTLS_SSL_MINOR_VERSION_3 &&
+ cur->cert->sig_md != MBEDTLS_MD_SHA1 )
+ {
+ if( fallback == NULL )
+ fallback = cur;
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "certificate not preferred: "
+ "sha-2 with pre-TLS 1.2 client" ) );
+ continue;
+ }
+ }
+
+ /* If we get there, we got a winner */
+ break;
+ }
+
+ if( cur == NULL )
+ cur = fallback;
+
+ /* Do not update ssl->handshake->key_cert unless there is a match */
+ if( cur != NULL )
+ {
+ ssl->handshake->key_cert = cur;
+ MBEDTLS_SSL_DEBUG_CRT( 3, "selected certificate chain, certificate",
+ ssl->handshake->key_cert->cert );
+ return( 0 );
+ }
+
+ return( -1 );
+}
+#endif /* MBEDTLS_X509_CRT_PARSE_C */
+
+/*
+ * Check if a given ciphersuite is suitable for use with our config/keys/etc
+ * Sets ciphersuite_info only if the suite matches.
+ */
+static int ssl_ciphersuite_match( mbedtls_ssl_context *ssl, int suite_id,
+ const mbedtls_ssl_ciphersuite_t **ciphersuite_info )
+{
+ const mbedtls_ssl_ciphersuite_t *suite_info;
+
+#if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \
+ defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)
+ mbedtls_pk_type_t sig_type;
+#endif
+
+ suite_info = mbedtls_ssl_ciphersuite_from_id( suite_id );
+ if( suite_info == NULL )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
+ return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
+ }
+
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "trying ciphersuite: %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_has_psk_or_cb( ssl->conf ) == 0 )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "ciphersuite mismatch: no pre-shared key" ) );
+ return( 0 );
+ }
+#endif
+
+#if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \
+ defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)
+ /* If the ciphersuite requires signing, check whether
+ * a suitable hash algorithm is present. */
+ if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 )
+ {
+ sig_type = mbedtls_ssl_get_ciphersuite_sig_alg( suite_info );
+ if( sig_type != MBEDTLS_PK_NONE &&
+ mbedtls_ssl_sig_hash_set_find( &ssl->handshake->hash_algs, sig_type ) == MBEDTLS_MD_NONE )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "ciphersuite mismatch: no suitable hash algorithm "
+ "for signature algorithm %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->handshake->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_in_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->cur_out_ctr + 2, ssl->in_ctr + 2, 6 );
+
+#if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY)
+ if( mbedtls_ssl_dtls_replay_check( ssl ) != 0 )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "replayed record, discarding" ) );
+ ssl->next_record_offset = 0;
+ ssl->in_left = 0;
+ goto read_record_header;
+ }
+
+ /* No MAC to check yet, so we can update right now */
+ mbedtls_ssl_dtls_replay_update( ssl );
+#endif
+ }
+#endif /* MBEDTLS_SSL_PROTO_DTLS */
+
+ msg_len = ( ssl->in_len[0] << 8 ) | ssl->in_len[1];
+
+#if defined(MBEDTLS_SSL_RENEGOTIATION)
+ if( ssl->renego_status != MBEDTLS_SSL_INITIAL_HANDSHAKE )
+ {
+ /* Set by mbedtls_ssl_read_record() */
+ msg_len = ssl->in_hslen;
+ }
+ else
+#endif
+ {
+ if( msg_len > MBEDTLS_SSL_IN_CONTENT_LEN )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ if( ( ret = mbedtls_ssl_fetch_input( ssl,
+ mbedtls_ssl_in_hdr_len( ssl ) + msg_len ) ) != 0 )
+ {
+ MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_fetch_input", ret );
+ return( ret );
+ }
+
+ /* Done reading this record, get ready for the next one */
+#if defined(MBEDTLS_SSL_PROTO_DTLS)
+ if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
+ ssl->next_record_offset = msg_len + mbedtls_ssl_in_hdr_len( ssl );
+ else
+#endif
+ ssl->in_left = 0;
+ }
+
+ buf = ssl->in_msg;
+
+ MBEDTLS_SSL_DEBUG_BUF( 4, "record contents", buf, msg_len );
+
+ ssl->handshake->update_checksum( ssl, buf, msg_len );
+
+ /*
+ * Handshake layer:
+ * 0 . 0 handshake type
+ * 1 . 3 handshake length
+ * 4 . 5 DTLS only: message seqence number
+ * 6 . 8 DTLS only: fragment offset
+ * 9 . 11 DTLS only: fragment length
+ */
+ if( msg_len < mbedtls_ssl_hs_hdr_len( ssl ) )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello v3, handshake type: %d", buf[0] ) );
+
+ if( buf[0] != MBEDTLS_SSL_HS_CLIENT_HELLO )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello v3, handshake len.: %d",
+ ( buf[1] << 16 ) | ( buf[2] << 8 ) | buf[3] ) );
+
+ /* We don't support fragmentation of ClientHello (yet?) */
+ if( buf[1] != 0 ||
+ msg_len != mbedtls_ssl_hs_hdr_len( ssl ) + ( ( buf[2] << 8 ) | buf[3] ) )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+#if defined(MBEDTLS_SSL_PROTO_DTLS)
+ if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
+ {
+ /*
+ * Copy the client's handshake message_seq on initial handshakes,
+ * check sequence number on renego.
+ */
+#if defined(MBEDTLS_SSL_RENEGOTIATION)
+ if( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS )
+ {
+ /* This couldn't be done in ssl_prepare_handshake_record() */
+ unsigned int cli_msg_seq = ( ssl->in_msg[4] << 8 ) |
+ ssl->in_msg[5];
+
+ if( cli_msg_seq != ssl->handshake->in_msg_seq )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message_seq: "
+ "%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 omitted) is
+ * 2 + 32 + 1 + 2 + 1 = 38 bytes. Check that first, so that we can
+ * read at least up to session id length without worrying.
+ */
+ if( msg_len < 38 )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ /*
+ * Check and save the protocol version
+ */
+ MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, version", buf, 2 );
+
+ mbedtls_ssl_read_version( &ssl->major_ver, &ssl->minor_ver,
+ ssl->conf->transport, buf );
+
+ ssl->handshake->max_major_ver = ssl->major_ver;
+ ssl->handshake->max_minor_ver = ssl->minor_ver;
+
+ if( ssl->major_ver < ssl->conf->min_major_ver ||
+ ssl->minor_ver < ssl->conf->min_minor_ver )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "client only supports ssl smaller than minimum"
+ " [%d:%d] < [%d:%d]",
+ ssl->major_ver, ssl->minor_ver,
+ ssl->conf->min_major_ver, ssl->conf->min_minor_ver ) );
+ mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+ MBEDTLS_SSL_ALERT_MSG_PROTOCOL_VERSION );
+ return( MBEDTLS_ERR_SSL_BAD_HS_PROTOCOL_VERSION );
+ }
+
+ if( ssl->major_ver > ssl->conf->max_major_ver )
+ {
+ ssl->major_ver = ssl->conf->max_major_ver;
+ ssl->minor_ver = ssl->conf->max_minor_ver;
+ }
+ else if( ssl->minor_ver > ssl->conf->max_minor_ver )
+ ssl->minor_ver = ssl->conf->max_minor_ver;
+
+ /*
+ * Save client random (inc. Unix time)
+ */
+ MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, random bytes", buf + 2, 32 );
+
+ memcpy( ssl->handshake->randbytes, buf + 2, 32 );
+
+ /*
+ * Check the session ID length and save session ID
+ */
+ sess_len = buf[34];
+
+ if( sess_len > sizeof( ssl->session_negotiate->id ) ||
+ sess_len + 34 + 2 > msg_len ) /* 2 for cipherlist length field */
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+ MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
+ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, session id", buf + 35, sess_len );
+
+ ssl->session_negotiate->id_len = sess_len;
+ memset( ssl->session_negotiate->id, 0,
+ sizeof( ssl->session_negotiate->id ) );
+ memcpy( ssl->session_negotiate->id, buf + 35,
+ ssl->session_negotiate->id_len );
+
+ /*
+ * Check the cookie length and content
+ */
+#if defined(MBEDTLS_SSL_PROTO_DTLS)
+ if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
+ {
+ cookie_offset = 35 + sess_len;
+ cookie_len = buf[cookie_offset];
+
+ if( cookie_offset + 1 + cookie_len + 2 > msg_len )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+ MBEDTLS_SSL_ALERT_MSG_PROTOCOL_VERSION );
+ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, cookie",
+ buf + cookie_offset + 1, cookie_len );
+
+#if defined(MBEDTLS_SSL_DTLS_HELLO_VERIFY)
+ if( ssl->conf->f_cookie_check != NULL
+#if defined(MBEDTLS_SSL_RENEGOTIATION)
+ && ssl->renego_status == MBEDTLS_SSL_INITIAL_HANDSHAKE
+#endif
+ )
+ {
+ if( ssl->conf->f_cookie_check( ssl->conf->p_cookie,
+ buf + cookie_offset + 1, cookie_len,
+ ssl->cli_id, ssl->cli_id_len ) != 0 )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 2, ( "cookie verification failed" ) );
+ ssl->handshake->verify_cookie_len = 1;
+ }
+ else
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 2, ( "cookie verification passed" ) );
+ ssl->handshake->verify_cookie_len = 0;
+ }
+ }
+ else
+#endif /* MBEDTLS_SSL_DTLS_HELLO_VERIFY */
+ {
+ /* We know we didn't send a cookie, so it should be empty */
+ if( cookie_len != 0 )
+ {
+ /* This may be an attacker's probe, so don't send an alert */
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ MBEDTLS_SSL_DEBUG_MSG( 2, ( "cookie verification skipped" ) );
+ }
+
+ /*
+ * Check the ciphersuitelist length (will be parsed later)
+ */
+ ciph_offset = cookie_offset + 1 + cookie_len;
+ }
+ else
+#endif /* MBEDTLS_SSL_PROTO_DTLS */
+ ciph_offset = 35 + sess_len;
+
+ ciph_len = ( buf[ciph_offset + 0] << 8 )
+ | ( buf[ciph_offset + 1] );
+
+ if( ciph_len < 2 ||
+ ciph_len + 2 + ciph_offset + 1 > msg_len || /* 1 for comp. alg. len */
+ ( ciph_len % 2 ) != 0 )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+ MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
+ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, ciphersuitelist",
+ buf + ciph_offset + 2, ciph_len );
+
+ /*
+ * Check the compression algorithms length and pick one
+ */
+ comp_offset = ciph_offset + 2 + ciph_len;
+
+ comp_len = buf[comp_offset];
+
+ if( comp_len < 1 ||
+ comp_len > 16 ||
+ comp_len + comp_offset + 1 > msg_len )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+ MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
+ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, compression",
+ buf + comp_offset + 1, comp_len );
+
+ ssl->session_negotiate->compression = MBEDTLS_SSL_COMPRESS_NULL;
+#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;
+ unsigned int ext_size;
+ if ( ext_len < 4 ) {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+ MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
+ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+ ext_id = ( ( ext[0] << 8 ) | ( ext[1] ) );
+ ext_size = ( ( ext[2] << 8 ) | ( ext[3] ) );
+
+ if( ext_size + 4 > ext_len )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+ MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
+ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+ switch( ext_id )
+ {
+#if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
+ case MBEDTLS_TLS_EXT_SERVERNAME:
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "found ServerName extension" ) );
+ if( ssl->conf->f_sni == NULL )
+ break;
+
+ ret = ssl_parse_servername_ext( ssl, ext + 4, ext_size );
+ if( ret != 0 )
+ return( ret );
+ break;
+#endif /* MBEDTLS_SSL_SERVER_NAME_INDICATION */
+
+ case MBEDTLS_TLS_EXT_RENEGOTIATION_INFO:
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "found renegotiation extension" ) );
+#if defined(MBEDTLS_SSL_RENEGOTIATION)
+ renegotiation_info_seen = 1;
+#endif
+
+ ret = ssl_parse_renegotiation_info( ssl, ext + 4, ext_size );
+ if( ret != 0 )
+ return( ret );
+ break;
+
+#if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \
+ defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)
+ case MBEDTLS_TLS_EXT_SIG_ALG:
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "found signature_algorithms extension" ) );
+
+ ret = ssl_parse_signature_algorithms_ext( ssl, ext + 4, ext_size );
+ if( ret != 0 )
+ return( ret );
+
+ sig_hash_alg_ext_present = 1;
+ break;
+#endif /* MBEDTLS_SSL_PROTO_TLS1_2 &&
+ MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED */
+
+#if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \
+ defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
+ case MBEDTLS_TLS_EXT_SUPPORTED_ELLIPTIC_CURVES:
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "found supported elliptic curves extension" ) );
+
+ ret = ssl_parse_supported_elliptic_curves( ssl, ext + 4, ext_size );
+ if( ret != 0 )
+ return( ret );
+ break;
+
+ case MBEDTLS_TLS_EXT_SUPPORTED_POINT_FORMATS:
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "found supported point formats extension" ) );
+ ssl->handshake->cli_exts |= MBEDTLS_TLS_EXT_SUPPORTED_POINT_FORMATS_PRESENT;
+
+ ret = ssl_parse_supported_point_formats( ssl, ext + 4, ext_size );
+ if( ret != 0 )
+ return( ret );
+ break;
+#endif /* MBEDTLS_ECDH_C || MBEDTLS_ECDSA_C ||
+ MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
+
+#if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
+ case MBEDTLS_TLS_EXT_ECJPAKE_KKPP:
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "found ecjpake kkpp extension" ) );
+
+ ret = ssl_parse_ecjpake_kkpp( ssl, ext + 4, ext_size );
+ if( ret != 0 )
+ return( ret );
+ break;
+#endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
+
+#if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
+ case MBEDTLS_TLS_EXT_MAX_FRAGMENT_LENGTH:
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "found max fragment length extension" ) );
+
+ ret = ssl_parse_max_fragment_length_ext( ssl, ext + 4, ext_size );
+ if( ret != 0 )
+ return( ret );
+ break;
+#endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */
+
+#if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
+ case MBEDTLS_TLS_EXT_TRUNCATED_HMAC:
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "found truncated hmac extension" ) );
+
+ ret = ssl_parse_truncated_hmac_ext( ssl, ext + 4, ext_size );
+ if( ret != 0 )
+ return( ret );
+ break;
+#endif /* MBEDTLS_SSL_TRUNCATED_HMAC */
+
+#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
+ case MBEDTLS_TLS_EXT_CID:
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "found CID extension" ) );
+
+ ret = ssl_parse_cid_ext( ssl, ext + 4, ext_size );
+ if( ret != 0 )
+ return( ret );
+ break;
+#endif /* MBEDTLS_SSL_TRUNCATED_HMAC */
+
+#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
+ case MBEDTLS_TLS_EXT_ENCRYPT_THEN_MAC:
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "found encrypt then mac extension" ) );
+
+ ret = ssl_parse_encrypt_then_mac_ext( ssl, ext + 4, ext_size );
+ if( ret != 0 )
+ return( ret );
+ break;
+#endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */
+
+#if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
+ case MBEDTLS_TLS_EXT_EXTENDED_MASTER_SECRET:
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "found extended master secret extension" ) );
+
+ ret = ssl_parse_extended_ms_ext( ssl, ext + 4, ext_size );
+ if( ret != 0 )
+ return( ret );
+ break;
+#endif /* MBEDTLS_SSL_EXTENDED_MASTER_SECRET */
+
+#if defined(MBEDTLS_SSL_SESSION_TICKETS)
+ case MBEDTLS_TLS_EXT_SESSION_TICKET:
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "found session ticket extension" ) );
+
+ ret = ssl_parse_session_ticket_ext( ssl, ext + 4, ext_size );
+ if( ret != 0 )
+ return( ret );
+ break;
+#endif /* MBEDTLS_SSL_SESSION_TICKETS */
+
+#if defined(MBEDTLS_SSL_ALPN)
+ case MBEDTLS_TLS_EXT_ALPN:
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "found alpn extension" ) );
+
+ ret = ssl_parse_alpn_ext( ssl, ext + 4, ext_size );
+ if( ret != 0 )
+ return( ret );
+ break;
+#endif /* MBEDTLS_SSL_SESSION_TICKETS */
+
+ 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->handshake->ciphersuite_info = ciphersuite_info;
+
+ ssl->state++;
+
+#if defined(MBEDTLS_SSL_PROTO_DTLS)
+ if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
+ mbedtls_ssl_recv_flight_completed( ssl );
+#endif
+
+ /* Debugging-only output for testsuite */
+#if defined(MBEDTLS_DEBUG_C) && \
+ defined(MBEDTLS_SSL_PROTO_TLS1_2) && \
+ defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)
+ if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 )
+ {
+ mbedtls_pk_type_t sig_alg = mbedtls_ssl_get_ciphersuite_sig_alg( ciphersuite_info );
+ if( sig_alg != MBEDTLS_PK_NONE )
+ {
+ mbedtls_md_type_t md_alg = mbedtls_ssl_sig_hash_set_find( &ssl->handshake->hash_algs,
+ sig_alg );
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello v3, signature_algorithm ext: %d",
+ mbedtls_ssl_hash_from_md_alg( md_alg ) ) );
+ }
+ else
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "no hash algorithm for signature algorithm "
+ "%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_DTLS_CONNECTION_ID)
+static void ssl_write_cid_ext( mbedtls_ssl_context *ssl,
+ unsigned char *buf,
+ size_t *olen )
+{
+ unsigned char *p = buf;
+ size_t ext_len;
+ const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN;
+
+ *olen = 0;
+
+ /* Skip writing the extension if we don't want to use it or if
+ * the client hasn't offered it. */
+ if( ssl->handshake->cid_in_use == MBEDTLS_SSL_CID_DISABLED )
+ return;
+
+ /* ssl->own_cid_len is at most MBEDTLS_SSL_CID_IN_LEN_MAX
+ * which is at most 255, so the increment cannot overflow. */
+ if( end < p || (size_t)( end - p ) < (unsigned)( ssl->own_cid_len + 5 ) )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
+ return;
+ }
+
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, adding CID extension" ) );
+
+ /*
+ * Quoting draft-ietf-tls-dtls-connection-id-05
+ * https://tools.ietf.org/html/draft-ietf-tls-dtls-connection-id-05
+ *
+ * struct {
+ * opaque cid<0..2^8-1>;
+ * } ConnectionId;
+ */
+
+ *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_CID >> 8 ) & 0xFF );
+ *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_CID ) & 0xFF );
+ ext_len = (size_t) ssl->own_cid_len + 1;
+ *p++ = (unsigned char)( ( ext_len >> 8 ) & 0xFF );
+ *p++ = (unsigned char)( ( ext_len ) & 0xFF );
+
+ *p++ = (uint8_t) ssl->own_cid_len;
+ memcpy( p, ssl->own_cid, ssl->own_cid_len );
+
+ *olen = ssl->own_cid_len + 5;
+}
+#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
+
+#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
+static void ssl_write_encrypt_then_mac_ext( mbedtls_ssl_context *ssl,
+ unsigned char *buf,
+ size_t *olen )
+{
+ unsigned char *p = buf;
+ const mbedtls_ssl_ciphersuite_t *suite = NULL;
+ const mbedtls_cipher_info_t *cipher = NULL;
+
+ if( ssl->session_negotiate->encrypt_then_mac == MBEDTLS_SSL_ETM_DISABLED ||
+ 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_OUT_CONTENT_LEN;
+ size_t kkpp_len;
+
+ *olen = 0;
+
+ /* Skip costly computation if not needed */
+ if( ssl->handshake->ciphersuite_info->key_exchange !=
+ MBEDTLS_KEY_EXCHANGE_ECJPAKE )
+ return;
+
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, ecjpake kkpp extension" ) );
+
+ if( end - p < 4 )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
+ return;
+ }
+
+ *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_ECJPAKE_KKPP >> 8 ) & 0xFF );
+ *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_ECJPAKE_KKPP ) & 0xFF );
+
+ ret = mbedtls_ecjpake_write_round_one( &ssl->handshake->ecjpake_ctx,
+ p + 2, end - p - 2, &kkpp_len,
+ ssl->conf->f_rng, ssl->conf->p_rng );
+ if( ret != 0 )
+ {
+ MBEDTLS_SSL_DEBUG_RET( 1 , "mbedtls_ecjpake_write_round_one", ret );
+ return;
+ }
+
+ *p++ = (unsigned char)( ( kkpp_len >> 8 ) & 0xFF );
+ *p++ = (unsigned char)( ( kkpp_len ) & 0xFF );
+
+ *olen = kkpp_len + 4;
+}
+#endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
+
+#if defined(MBEDTLS_SSL_ALPN )
+static void ssl_write_alpn_ext( mbedtls_ssl_context *ssl,
+ unsigned char *buf, size_t *olen )
+{
+ if( ssl->alpn_chosen == NULL )
+ {
+ *olen = 0;
+ return;
+ }
+
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, adding alpn extension" ) );
+
+ /*
+ * 0 . 1 ext identifier
+ * 2 . 3 ext length
+ * 4 . 5 protocol list length
+ * 6 . 6 protocol name length
+ * 7 . 7+n protocol name
+ */
+ buf[0] = (unsigned char)( ( MBEDTLS_TLS_EXT_ALPN >> 8 ) & 0xFF );
+ buf[1] = (unsigned char)( ( MBEDTLS_TLS_EXT_ALPN ) & 0xFF );
+
+ *olen = 7 + strlen( ssl->alpn_chosen );
+
+ buf[2] = (unsigned char)( ( ( *olen - 4 ) >> 8 ) & 0xFF );
+ buf[3] = (unsigned char)( ( ( *olen - 4 ) ) & 0xFF );
+
+ buf[4] = (unsigned char)( ( ( *olen - 6 ) >> 8 ) & 0xFF );
+ buf[5] = (unsigned char)( ( ( *olen - 6 ) ) & 0xFF );
+
+ buf[6] = (unsigned char)( ( ( *olen - 7 ) ) & 0xFF );
+
+ memcpy( buf + 7, ssl->alpn_chosen, *olen - 7 );
+}
+#endif /* MBEDTLS_ECDH_C || MBEDTLS_ECDSA_C */
+
+#if defined(MBEDTLS_SSL_DTLS_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_OUT_BUFFER_LEN,
+ ssl->cli_id, ssl->cli_id_len ) ) != 0 )
+ {
+ MBEDTLS_SSL_DEBUG_RET( 1, "f_cookie_write", ret );
+ return( ret );
+ }
+
+ *cookie_len_byte = (unsigned char)( p - ( cookie_len_byte + 1 ) );
+
+ MBEDTLS_SSL_DEBUG_BUF( 3, "cookie sent", cookie_len_byte + 1, *cookie_len_byte );
+
+ ssl->out_msglen = p - ssl->out_msg;
+ ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE;
+ ssl->out_msg[0] = MBEDTLS_SSL_HS_HELLO_VERIFY_REQUEST;
+
+ ssl->state = MBEDTLS_SSL_SERVER_HELLO_VERIFY_REQUEST_SENT;
+
+ if( ( ret = mbedtls_ssl_write_handshake_msg( ssl ) ) != 0 )
+ {
+ MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_handshake_msg", ret );
+ return( ret );
+ }
+
+#if defined(MBEDTLS_SSL_PROTO_DTLS)
+ if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
+ ( ret = mbedtls_ssl_flight_transmit( ssl ) ) != 0 )
+ {
+ MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_flight_transmit", ret );
+ return( ret );
+ }
+#endif /* MBEDTLS_SSL_PROTO_DTLS */
+
+ MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write hello verify request" ) );
+
+ return( 0 );
+}
+#endif /* MBEDTLS_SSL_DTLS_HELLO_VERIFY */
+
+static int ssl_write_server_hello( mbedtls_ssl_context *ssl )
+{
+#if defined(MBEDTLS_HAVE_TIME)
+ mbedtls_time_t t;
+#endif
+ int ret;
+ 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_DTLS_CONNECTION_ID)
+ ssl_write_cid_ext( ssl, p + 2 + ext_len, &olen );
+ ext_len += olen;
+#endif
+
+#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
+ ssl_write_encrypt_then_mac_ext( ssl, p + 2 + ext_len, &olen );
+ ext_len += olen;
+#endif
+
+#if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
+ ssl_write_extended_ms_ext( ssl, p + 2 + ext_len, &olen );
+ ext_len += olen;
+#endif
+
+#if defined(MBEDTLS_SSL_SESSION_TICKETS)
+ ssl_write_session_ticket_ext( ssl, p + 2 + ext_len, &olen );
+ ext_len += olen;
+#endif
+
+#if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \
+ defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
+ if ( mbedtls_ssl_ciphersuite_uses_ec(
+ mbedtls_ssl_ciphersuite_from_id( ssl->session_negotiate->ciphersuite ) ) )
+ {
+ ssl_write_supported_point_formats_ext( ssl, p + 2 + ext_len, &olen );
+ ext_len += olen;
+ }
+#endif
+
+#if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
+ ssl_write_ecjpake_kkpp_ext( ssl, p + 2 + ext_len, &olen );
+ ext_len += olen;
+#endif
+
+#if defined(MBEDTLS_SSL_ALPN)
+ ssl_write_alpn_ext( ssl, p + 2 + ext_len, &olen );
+ ext_len += olen;
+#endif
+
+ 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_handshake_msg( ssl );
+
+ MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write server hello" ) );
+
+ return( ret );
+}
+
+#if !defined(MBEDTLS_KEY_EXCHANGE__CERT_REQ_ALLOWED__ENABLED)
+static int ssl_write_certificate_request( mbedtls_ssl_context *ssl )
+{
+ const mbedtls_ssl_ciphersuite_t *ciphersuite_info =
+ ssl->handshake->ciphersuite_info;
+
+ MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write certificate request" ) );
+
+ if( !mbedtls_ssl_ciphersuite_cert_req_allowed( ciphersuite_info ) )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip write certificate request" ) );
+ ssl->state++;
+ return( 0 );
+ }
+
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
+ return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
+}
+#else /* !MBEDTLS_KEY_EXCHANGE__CERT_REQ_ALLOWED__ENABLED */
+static int ssl_write_certificate_request( mbedtls_ssl_context *ssl )
+{
+ int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE;
+ const mbedtls_ssl_ciphersuite_t *ciphersuite_info =
+ ssl->handshake->ciphersuite_info;
+ 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_OUT_CONTENT_LEN;
+ const mbedtls_x509_crt *crt;
+ int authmode;
+
+ MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write certificate request" ) );
+
+ ssl->state++;
+
+#if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
+ if( ssl->handshake->sni_authmode != MBEDTLS_SSL_VERIFY_UNSET )
+ authmode = ssl->handshake->sni_authmode;
+ else
+#endif
+ authmode = ssl->conf->authmode;
+
+ if( !mbedtls_ssl_ciphersuite_cert_req_allowed( ciphersuite_info ) ||
+ authmode == MBEDTLS_SSL_VERIFY_NONE )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip write certificate request" ) );
+ return( 0 );
+ }
+
+ /*
+ * 0 . 0 handshake type
+ * 1 . 3 handshake length
+ * 4 . 4 cert type count
+ * 5 .. m-1 cert types
+ * m .. m+1 sig alg length (TLS 1.2 only)
+ * m+1 .. n-1 SignatureAndHashAlgorithms (TLS 1.2 only)
+ * n .. n+1 length of all DNs
+ * n+2 .. n+3 length of DN 1
+ * n+4 .. ... Distinguished Name #1
+ * ... .. ... length of DN 2, etc.
+ */
+ buf = ssl->out_msg;
+ p = buf + 4;
+
+ /*
+ * Supported certificate types
+ *
+ * ClientCertificateType certificate_types<1..2^8-1>;
+ * enum { (255) } ClientCertificateType;
+ */
+ ct_len = 0;
+
+#if defined(MBEDTLS_RSA_C)
+ p[1 + ct_len++] = MBEDTLS_SSL_CERT_TYPE_RSA_SIGN;
+#endif
+#if defined(MBEDTLS_ECDSA_C)
+ p[1 + ct_len++] = MBEDTLS_SSL_CERT_TYPE_ECDSA_SIGN;
+#endif
+
+ p[0] = (unsigned char) ct_len++;
+ p += ct_len;
+
+ sa_len = 0;
+#if defined(MBEDTLS_SSL_PROTO_TLS1_2)
+ /*
+ * Add signature_algorithms for verify (TLS 1.2)
+ *
+ * SignatureAndHashAlgorithm supported_signature_algorithms<2..2^16-2>;
+ *
+ * struct {
+ * HashAlgorithm hash;
+ * SignatureAlgorithm signature;
+ * } SignatureAndHashAlgorithm;
+ *
+ * enum { (255) } HashAlgorithm;
+ * enum { (255) } SignatureAlgorithm;
+ */
+ if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 )
+ {
+ const int *cur;
+
+ /*
+ * Supported signature algorithms
+ */
+ for( cur = ssl->conf->sig_hashes; *cur != MBEDTLS_MD_NONE; cur++ )
+ {
+ unsigned char hash = mbedtls_ssl_hash_from_md_alg( *cur );
+
+ if( MBEDTLS_SSL_HASH_NONE == hash || mbedtls_ssl_set_calc_verify_md( ssl, hash ) )
+ continue;
+
+#if defined(MBEDTLS_RSA_C)
+ p[2 + sa_len++] = hash;
+ p[2 + sa_len++] = MBEDTLS_SSL_SIG_RSA;
+#endif
+#if defined(MBEDTLS_ECDSA_C)
+ p[2 + sa_len++] = hash;
+ p[2 + sa_len++] = MBEDTLS_SSL_SIG_ECDSA;
+#endif
+ }
+
+ p[0] = (unsigned char)( sa_len >> 8 );
+ p[1] = (unsigned char)( sa_len );
+ sa_len += 2;
+ p += sa_len;
+ }
+#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
+
+ /*
+ * DistinguishedName certificate_authorities<0..2^16-1>;
+ * opaque DistinguishedName<1..2^16-1>;
+ */
+ p += 2;
+
+ total_dn_size = 0;
+
+ if( ssl->conf->cert_req_ca_list == MBEDTLS_SSL_CERT_REQ_CA_LIST_ENABLED )
+ {
+ /* NOTE: If trusted certificates are provisioned
+ * via a CA callback (configured through
+ * `mbedtls_ssl_conf_ca_cb()`, then the
+ * CertificateRequest is currently left empty. */
+
+#if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
+ if( ssl->handshake->sni_ca_chain != NULL )
+ crt = ssl->handshake->sni_ca_chain;
+ else
+#endif
+ crt = ssl->conf->ca_chain;
+
+ while( crt != NULL && crt->version != 0 )
+ {
+ 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_handshake_msg( ssl );
+
+ MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write certificate request" ) );
+
+ return( ret );
+}
+#endif /* MBEDTLS_KEY_EXCHANGE__CERT_REQ_ALLOWED__ENABLED */
+
+#if defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \
+ defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)
+static int ssl_get_ecdh_params_from_cert( mbedtls_ssl_context *ssl )
+{
+ int ret;
+
+ if( ! mbedtls_pk_can_do( mbedtls_ssl_own_key( ssl ), MBEDTLS_PK_ECKEY ) )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "server key not ECDH capable" ) );
+ return( MBEDTLS_ERR_SSL_PK_TYPE_MISMATCH );
+ }
+
+ if( ( ret = mbedtls_ecdh_get_params( &ssl->handshake->ecdh_ctx,
+ mbedtls_pk_ec( *mbedtls_ssl_own_key( ssl ) ),
+ MBEDTLS_ECDH_OURS ) ) != 0 )
+ {
+ MBEDTLS_SSL_DEBUG_RET( 1, ( "mbedtls_ecdh_get_params" ), ret );
+ return( ret );
+ }
+
+ return( 0 );
+}
+#endif /* MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) ||
+ MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED */
+
+#if defined(MBEDTLS_KEY_EXCHANGE__WITH_SERVER_SIGNATURE__ENABLED) && \
+ defined(MBEDTLS_SSL_ASYNC_PRIVATE)
+static int ssl_resume_server_key_exchange( mbedtls_ssl_context *ssl,
+ size_t *signature_len )
+{
+ /* Append the signature to ssl->out_msg, leaving 2 bytes for the
+ * signature length which will be added in ssl_write_server_key_exchange
+ * after the call to ssl_prepare_server_key_exchange.
+ * ssl_write_server_key_exchange also takes care of incrementing
+ * ssl->out_msglen. */
+ unsigned char *sig_start = ssl->out_msg + ssl->out_msglen + 2;
+ size_t sig_max_len = ( ssl->out_buf + MBEDTLS_SSL_OUT_CONTENT_LEN
+ - sig_start );
+ int ret = ssl->conf->f_async_resume( ssl,
+ sig_start, signature_len, sig_max_len );
+ if( ret != MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS )
+ {
+ ssl->handshake->async_in_progress = 0;
+ mbedtls_ssl_set_async_operation_data( ssl, NULL );
+ }
+ MBEDTLS_SSL_DEBUG_RET( 2, "ssl_resume_server_key_exchange", ret );
+ return( ret );
+}
+#endif /* defined(MBEDTLS_KEY_EXCHANGE__WITH_SERVER_SIGNATURE__ENABLED) &&
+ defined(MBEDTLS_SSL_ASYNC_PRIVATE) */
+
+/* Prepare the ServerKeyExchange message, up to and including
+ * calculating the signature if any, but excluding formatting the
+ * signature and sending the message. */
+static int ssl_prepare_server_key_exchange( mbedtls_ssl_context *ssl,
+ size_t *signature_len )
+{
+ const mbedtls_ssl_ciphersuite_t *ciphersuite_info =
+ ssl->handshake->ciphersuite_info;
+
+#if defined(MBEDTLS_KEY_EXCHANGE__SOME_PFS__ENABLED)
+#if defined(MBEDTLS_KEY_EXCHANGE__WITH_SERVER_SIGNATURE__ENABLED)
+ unsigned char *dig_signed = NULL;
+#endif /* MBEDTLS_KEY_EXCHANGE__WITH_SERVER_SIGNATURE__ENABLED */
+#endif /* MBEDTLS_KEY_EXCHANGE__SOME_PFS__ENABLED */
+
+ (void) ciphersuite_info; /* unused in some configurations */
+#if !defined(MBEDTLS_KEY_EXCHANGE__WITH_SERVER_SIGNATURE__ENABLED)
+ (void) signature_len;
+#endif /* MBEDTLS_KEY_EXCHANGE__WITH_SERVER_SIGNATURE__ENABLED */
+
+ ssl->out_msglen = 4; /* header (type:1, length:3) to be written later */
+
+ /*
+ *
+ * Part 1: Provide key exchange parameters for chosen ciphersuite.
+ *
+ */
+
+ /*
+ * - ECJPAKE key exchanges
+ */
+#if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
+ if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE )
+ {
+ int ret;
+ size_t len = 0;
+
+ ret = mbedtls_ecjpake_write_round_two(
+ &ssl->handshake->ecjpake_ctx,
+ ssl->out_msg + ssl->out_msglen,
+ MBEDTLS_SSL_OUT_CONTENT_LEN - ssl->out_msglen, &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 );
+ }
+
+ ssl->out_msglen += 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 )
+ {
+ ssl->out_msg[ssl->out_msglen++] = 0x00;
+ ssl->out_msg[ssl->out_msglen++] = 0x00;
+ }
+#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 ) )
+ {
+ int ret;
+ size_t len = 0;
+
+ 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 ),
+ ssl->out_msg + ssl->out_msglen, &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 = ssl->out_msg + ssl->out_msglen;
+#endif
+
+ ssl->out_msglen += 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;
+ int ret;
+ size_t len = 0;
+
+ /* 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_ecdh_setup( &ssl->handshake->ecdh_ctx,
+ (*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,
+ ssl->out_msg + ssl->out_msglen,
+ MBEDTLS_SSL_OUT_CONTENT_LEN - ssl->out_msglen,
+ 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 = ssl->out_msg + ssl->out_msglen;
+#endif
+
+ ssl->out_msglen += len;
+
+ MBEDTLS_SSL_DEBUG_ECDH( 3, &ssl->handshake->ecdh_ctx,
+ MBEDTLS_DEBUG_ECDH_Q );
+ }
+#endif /* MBEDTLS_KEY_EXCHANGE__SOME__ECDHE_ENABLED */
+
+ /*
+ *
+ * Part 2: 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 dig_signed_len = ssl->out_msg + ssl->out_msglen - dig_signed;
+ size_t hashlen = 0;
+ unsigned char hash[MBEDTLS_MD_MAX_SIZE];
+ int ret;
+
+ /*
+ * 2.1: 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 ) );
+
+ /*
+ * 2.2: 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 )
+ {
+ ret = mbedtls_ssl_get_key_exchange_md_tls1_2( ssl, hash, &hashlen,
+ 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 );
+
+ /*
+ * 2.3: Compute and add the signature
+ */
+#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;
+ *
+ */
+
+ ssl->out_msg[ssl->out_msglen++] =
+ mbedtls_ssl_hash_from_md_alg( md_alg );
+ ssl->out_msg[ssl->out_msglen++] =
+ mbedtls_ssl_sig_from_pk_alg( sig_alg );
+ }
+#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
+
+#if defined(MBEDTLS_SSL_ASYNC_PRIVATE)
+ if( ssl->conf->f_async_sign_start != NULL )
+ {
+ ret = ssl->conf->f_async_sign_start( ssl,
+ mbedtls_ssl_own_cert( ssl ),
+ md_alg, hash, hashlen );
+ switch( ret )
+ {
+ case MBEDTLS_ERR_SSL_HW_ACCEL_FALLTHROUGH:
+ /* act as if f_async_sign was null */
+ break;
+ case 0:
+ ssl->handshake->async_in_progress = 1;
+ return( ssl_resume_server_key_exchange( ssl, signature_len ) );
+ case MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS:
+ ssl->handshake->async_in_progress = 1;
+ return( MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS );
+ default:
+ MBEDTLS_SSL_DEBUG_RET( 1, "f_async_sign_start", ret );
+ return( ret );
+ }
+ }
+#endif /* MBEDTLS_SSL_ASYNC_PRIVATE */
+
+ if( mbedtls_ssl_own_key( ssl ) == NULL )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "got no private key" ) );
+ return( MBEDTLS_ERR_SSL_PRIVATE_KEY_REQUIRED );
+ }
+
+ /* Append the signature to ssl->out_msg, leaving 2 bytes for the
+ * signature length which will be added in ssl_write_server_key_exchange
+ * after the call to ssl_prepare_server_key_exchange.
+ * ssl_write_server_key_exchange also takes care of incrementing
+ * ssl->out_msglen. */
+ if( ( ret = mbedtls_pk_sign( mbedtls_ssl_own_key( ssl ),
+ md_alg, hash, hashlen,
+ ssl->out_msg + ssl->out_msglen + 2,
+ signature_len,
+ ssl->conf->f_rng,
+ ssl->conf->p_rng ) ) != 0 )
+ {
+ MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_pk_sign", ret );
+ return( ret );
+ }
+ }
+#endif /* MBEDTLS_KEY_EXCHANGE__WITH_SERVER_SIGNATURE__ENABLED */
+
+ return( 0 );
+}
+
+/* Prepare the ServerKeyExchange message and send it. For ciphersuites
+ * that do not include a ServerKeyExchange message, do nothing. Either
+ * way, if successful, move on to the next step in the SSL state
+ * machine. */
+static int ssl_write_server_key_exchange( mbedtls_ssl_context *ssl )
+{
+ int ret;
+ size_t signature_len = 0;
+#if defined(MBEDTLS_KEY_EXCHANGE__SOME_NON_PFS__ENABLED)
+ const mbedtls_ssl_ciphersuite_t *ciphersuite_info =
+ ssl->handshake->ciphersuite_info;
+#endif /* MBEDTLS_KEY_EXCHANGE__SOME_NON_PFS__ENABLED */
+
+ MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write server key exchange" ) );
+
+#if defined(MBEDTLS_KEY_EXCHANGE__SOME_NON_PFS__ENABLED)
+ /* Extract static ECDH parameters and abort if ServerKeyExchange
+ * is not needed. */
+ if( mbedtls_ssl_ciphersuite_no_pfs( ciphersuite_info ) )
+ {
+ /* 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. */
+ MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip write server key exchange" ) );
+ ssl->state++;
+ return( 0 );
+ }
+#endif /* MBEDTLS_KEY_EXCHANGE__SOME_NON_PFS__ENABLED */
+
+#if defined(MBEDTLS_KEY_EXCHANGE__WITH_SERVER_SIGNATURE__ENABLED) && \
+ defined(MBEDTLS_SSL_ASYNC_PRIVATE)
+ /* If we have already prepared the message and there is an ongoing
+ * signature operation, resume signing. */
+ if( ssl->handshake->async_in_progress != 0 )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 2, ( "resuming signature operation" ) );
+ ret = ssl_resume_server_key_exchange( ssl, &signature_len );
+ }
+ else
+#endif /* defined(MBEDTLS_KEY_EXCHANGE__WITH_SERVER_SIGNATURE__ENABLED) &&
+ defined(MBEDTLS_SSL_ASYNC_PRIVATE) */
+ {
+ /* ServerKeyExchange is needed. Prepare the message. */
+ ret = ssl_prepare_server_key_exchange( ssl, &signature_len );
+ }
+
+ if( ret != 0 )
+ {
+ /* If we're starting to write a new message, set ssl->out_msglen
+ * to 0. But if we're resuming after an asynchronous message,
+ * out_msglen is the amount of data written so far and mst be
+ * preserved. */
+ if( ret == MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS )
+ MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write server key exchange (pending)" ) );
+ else
+ ssl->out_msglen = 0;
+ return( ret );
+ }
+
+ /* If there is a signature, write its length.
+ * ssl_prepare_server_key_exchange already wrote the signature
+ * itself at its proper place in the output buffer. */
+#if defined(MBEDTLS_KEY_EXCHANGE__WITH_SERVER_SIGNATURE__ENABLED)
+ if( signature_len != 0 )
+ {
+ ssl->out_msg[ssl->out_msglen++] = (unsigned char)( signature_len >> 8 );
+ ssl->out_msg[ssl->out_msglen++] = (unsigned char)( signature_len );
+
+ MBEDTLS_SSL_DEBUG_BUF( 3, "my signature",
+ ssl->out_msg + ssl->out_msglen,
+ signature_len );
+
+ /* Skip over the already-written signature */
+ ssl->out_msglen += signature_len;
+ }
+#endif /* MBEDTLS_KEY_EXCHANGE__WITH_SERVER_SIGNATURE__ENABLED */
+
+ /* Add header and send. */
+ ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE;
+ ssl->out_msg[0] = MBEDTLS_SSL_HS_SERVER_KEY_EXCHANGE;
+
+ ssl->state++;
+
+ if( ( ret = mbedtls_ssl_write_handshake_msg( ssl ) ) != 0 )
+ {
+ MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_handshake_msg", ret );
+ return( ret );
+ }
+
+ MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write 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_handshake_msg( ssl ) ) != 0 )
+ {
+ MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_handshake_msg", ret );
+ return( ret );
+ }
+
+#if defined(MBEDTLS_SSL_PROTO_DTLS)
+ if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
+ ( ret = mbedtls_ssl_flight_transmit( ssl ) ) != 0 )
+ {
+ MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_flight_transmit", ret );
+ return( ret );
+ }
+#endif /* MBEDTLS_SSL_PROTO_DTLS */
+
+ MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write 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)
+
+#if defined(MBEDTLS_SSL_ASYNC_PRIVATE)
+static int ssl_resume_decrypt_pms( mbedtls_ssl_context *ssl,
+ unsigned char *peer_pms,
+ size_t *peer_pmslen,
+ size_t peer_pmssize )
+{
+ int ret = ssl->conf->f_async_resume( ssl,
+ peer_pms, peer_pmslen, peer_pmssize );
+ if( ret != MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS )
+ {
+ ssl->handshake->async_in_progress = 0;
+ mbedtls_ssl_set_async_operation_data( ssl, NULL );
+ }
+ MBEDTLS_SSL_DEBUG_RET( 2, "ssl_decrypt_encrypted_pms", ret );
+ return( ret );
+}
+#endif /* MBEDTLS_SSL_ASYNC_PRIVATE */
+
+static int ssl_decrypt_encrypted_pms( mbedtls_ssl_context *ssl,
+ const unsigned char *p,
+ const unsigned char *end,
+ unsigned char *peer_pms,
+ size_t *peer_pmslen,
+ size_t peer_pmssize )
+{
+ int ret;
+ mbedtls_pk_context *private_key = mbedtls_ssl_own_key( ssl );
+ mbedtls_pk_context *public_key = &mbedtls_ssl_own_cert( ssl )->pk;
+ size_t len = mbedtls_pk_get_len( public_key );
+
+#if defined(MBEDTLS_SSL_ASYNC_PRIVATE)
+ /* If we have already started decoding the message and there is an ongoing
+ * decryption operation, resume signing. */
+ if( ssl->handshake->async_in_progress != 0 )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 2, ( "resuming decryption operation" ) );
+ return( ssl_resume_decrypt_pms( ssl,
+ peer_pms, peer_pmslen, peer_pmssize ) );
+ }
+#endif /* MBEDTLS_SSL_ASYNC_PRIVATE */
+
+ /*
+ * Prepare to 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 + 2 > end ) {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) );
+ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE );
+ }
+ 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 );
+ }
+
+ /*
+ * Decrypt the premaster secret
+ */
+#if defined(MBEDTLS_SSL_ASYNC_PRIVATE)
+ if( ssl->conf->f_async_decrypt_start != NULL )
+ {
+ ret = ssl->conf->f_async_decrypt_start( ssl,
+ mbedtls_ssl_own_cert( ssl ),
+ p, len );
+ switch( ret )
+ {
+ case MBEDTLS_ERR_SSL_HW_ACCEL_FALLTHROUGH:
+ /* act as if f_async_decrypt_start was null */
+ break;
+ case 0:
+ ssl->handshake->async_in_progress = 1;
+ return( ssl_resume_decrypt_pms( ssl,
+ peer_pms,
+ peer_pmslen,
+ peer_pmssize ) );
+ case MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS:
+ ssl->handshake->async_in_progress = 1;
+ return( MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS );
+ default:
+ MBEDTLS_SSL_DEBUG_RET( 1, "f_async_decrypt_start", ret );
+ return( ret );
+ }
+ }
+#endif /* MBEDTLS_SSL_ASYNC_PRIVATE */
+
+ if( ! mbedtls_pk_can_do( private_key, MBEDTLS_PK_RSA ) )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "got no RSA private key" ) );
+ return( MBEDTLS_ERR_SSL_PRIVATE_KEY_REQUIRED );
+ }
+
+ ret = mbedtls_pk_decrypt( private_key, p, len,
+ peer_pms, peer_pmslen, peer_pmssize,
+ ssl->conf->f_rng, ssl->conf->p_rng );
+ return( ret );
+}
+
+static int ssl_parse_encrypted_pms( mbedtls_ssl_context *ssl,
+ const unsigned char *p,
+ const unsigned char *end,
+ size_t pms_offset )
+{
+ int ret;
+ 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;
+
+ /* In case of a failure in decryption, the decryption may write less than
+ * 2 bytes of output, but we always read the first two bytes. It doesn't
+ * matter in the end because diff will be nonzero in that case due to
+ * peer_pmslen being less than 48, and we only care whether diff is 0.
+ * But do initialize peer_pms for robustness anyway. This also makes
+ * memory analyzers happy (don't access uninitialized memory, even
+ * if it's an unsigned char). */
+ peer_pms[0] = peer_pms[1] = ~0;
+
+ ret = ssl_decrypt_encrypted_pms( ssl, p, end,
+ peer_pms,
+ &peer_pmslen,
+ sizeof( peer_pms ) );
+
+#if defined(MBEDTLS_SSL_ASYNC_PRIVATE)
+ if ( ret == MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS )
+ return( ret );
+#endif /* MBEDTLS_SSL_ASYNC_PRIVATE */
+
+ mbedtls_ssl_write_version( ssl->handshake->max_major_ver,
+ ssl->handshake->max_minor_ver,
+ ssl->conf->transport, ver );
+
+ /* Avoid data-dependent branches while checking for invalid
+ * padding, to protect against timing-based Bleichenbacher-type
+ * attacks. */
+ diff = (unsigned int) ret;
+ diff |= peer_pmslen ^ 48;
+ diff |= peer_pms[0] ^ ver[0];
+ diff |= peer_pms[1] ^ ver[1];
+
+ /* 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
+
+ /*
+ * 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.
+ * To protect against timing-based variants of the attack, we must
+ * not have any branch that depends on whether the decryption was
+ * successful. In particular, always generate the fake premaster secret,
+ * regardless of whether it will ultimately influence the output or not.
+ */
+ ret = ssl->conf->f_rng( ssl->conf->p_rng, fake_pms, sizeof( fake_pms ) );
+ if( ret != 0 )
+ {
+ /* It's ok to abort on an RNG failure, since this does not reveal
+ * anything about the RSA decryption. */
+ return( ret );
+ }
+
+#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;
+
+ /* Set pms to either the true or the fake PMS, without
+ * data-dependent branches. */
+ 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_has_psk_or_cb( ssl->conf ) == 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->handshake->ciphersuite_info;
+
+ MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse client key exchange" ) );
+
+#if defined(MBEDTLS_SSL_ASYNC_PRIVATE) && \
+ ( defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED) || \
+ defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED) )
+ if( ( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK ||
+ ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA ) &&
+ ( ssl->handshake->async_in_progress != 0 ) )
+ {
+ /* We've already read a record and there is an asynchronous
+ * operation in progress to decrypt it. So skip reading the
+ * record. */
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "will resume decryption of previously-read record" ) );
+ }
+ else
+#endif
+ if( ( ret = mbedtls_ssl_read_record( ssl, 1 ) ) != 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_ECDH( 3, &ssl->handshake->ecdh_ctx,
+ MBEDTLS_DEBUG_ECDH_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_ECDH( 3, &ssl->handshake->ecdh_ctx,
+ MBEDTLS_DEBUG_ECDH_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 defined(MBEDTLS_USE_PSA_CRYPTO)
+ /* For opaque PSKs, we perform the PSK-to-MS derivation atomatically
+ * and skip the intermediate PMS. */
+ if( ssl_use_opaque_psk( ssl ) == 1 )
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "skip PMS generation for opaque PSK" ) );
+ else
+#endif /* MBEDTLS_USE_PSA_CRYPTO */
+ 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 defined(MBEDTLS_SSL_ASYNC_PRIVATE)
+ if ( ssl->handshake->async_in_progress != 0 )
+ {
+ /* There is an asynchronous operation in progress to
+ * decrypt the encrypted premaster secret, so skip
+ * directly to resuming this operation. */
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "PSK identity already parsed" ) );
+ /* Update p to skip the PSK identity. ssl_parse_encrypted_pms
+ * won't actually use it, but maintain p anyway for robustness. */
+ p += ssl->conf->psk_identity_len + 2;
+ }
+ else
+#endif /* MBEDTLS_SSL_ASYNC_PRIVATE */
+ 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 defined(MBEDTLS_USE_PSA_CRYPTO)
+ /* Opaque PSKs are currently only supported for PSK-only. */
+ if( ssl_use_opaque_psk( ssl ) == 1 )
+ return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE );
+#endif
+
+ 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 defined(MBEDTLS_USE_PSA_CRYPTO)
+ /* Opaque PSKs are currently only supported for PSK-only. */
+ if( ssl_use_opaque_psk( ssl ) == 1 )
+ return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE );
+#endif
+
+ 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 );
+ }
+
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+ /* Opaque PSKs are currently only supported for PSK-only. */
+ if( ssl_use_opaque_psk( ssl ) == 1 )
+ return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE );
+#endif
+
+ MBEDTLS_SSL_DEBUG_ECDH( 3, &ssl->handshake->ecdh_ctx,
+ MBEDTLS_DEBUG_ECDH_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__CERT_REQ_ALLOWED__ENABLED)
+static int ssl_parse_certificate_verify( mbedtls_ssl_context *ssl )
+{
+ const mbedtls_ssl_ciphersuite_t *ciphersuite_info =
+ ssl->handshake->ciphersuite_info;
+
+ MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse certificate verify" ) );
+
+ if( !mbedtls_ssl_ciphersuite_cert_req_allowed( ciphersuite_info ) )
+ {
+ 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 /* !MBEDTLS_KEY_EXCHANGE__CERT_REQ_ALLOWED__ENABLED */
+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->handshake->ciphersuite_info;
+ mbedtls_pk_context * peer_pk;
+
+ MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse certificate verify" ) );
+
+ if( !mbedtls_ssl_ciphersuite_cert_req_allowed( ciphersuite_info ) )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate verify" ) );
+ ssl->state++;
+ return( 0 );
+ }
+
+#if defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
+ if( ssl->session_negotiate->peer_cert == NULL )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate verify" ) );
+ ssl->state++;
+ return( 0 );
+ }
+#else /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
+ if( ssl->session_negotiate->peer_cert_digest == NULL )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate verify" ) );
+ ssl->state++;
+ return( 0 );
+ }
+#endif /* !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
+
+ /* Read the message without adding it to the checksum */
+ ret = mbedtls_ssl_read_record( ssl, 0 /* no checksum update */ );
+ if( 0 != ret )
+ {
+ MBEDTLS_SSL_DEBUG_RET( 1, ( "mbedtls_ssl_read_record" ), 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 );
+
+#if !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
+ peer_pk = &ssl->handshake->peer_pubkey;
+#else /* !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
+ if( ssl->session_negotiate->peer_cert == NULL )
+ {
+ /* Should never happen */
+ return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
+ }
+ peer_pk = &ssl->session_negotiate->peer_cert->pk;
+#endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
+
+ /*
+ * 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( peer_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( peer_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( peer_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__CERT_REQ_ALLOWED__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_OUT_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_handshake_msg( ssl ) ) != 0 )
+ {
+ MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_handshake_msg", 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_flight_transmit( ssl ) ) != 0 )
+ return( ret );
+ }
+#endif /* MBEDTLS_SSL_PROTO_DTLS */
+
+ 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 */
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