blob: a8331d9bb3417344f98bd4b142793e63e80a96f0 [file] [log] [blame]
/*
* SSLv3/TLSv1 client-side functions
*
* Copyright The Mbed TLS Contributors
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "common.h"
#if defined(MBEDTLS_SSL_CLI_C)
#if defined(MBEDTLS_PLATFORM_C)
#include "mbedtls/platform.h"
#else
#include <stdlib.h>
#define mbedtls_calloc calloc
#define mbedtls_free free
#endif
#include "mbedtls/ssl.h"
#include "mbedtls/ssl_internal.h"
#include "mbedtls/debug.h"
#include "mbedtls/error.h"
#if defined(MBEDTLS_USE_PSA_CRYPTO)
#include "mbedtls/psa_util.h"
#endif /* MBEDTLS_USE_PSA_CRYPTO */
#include <string.h>
#include <stdint.h>
#if defined(MBEDTLS_HAVE_TIME)
#include "mbedtls/platform_time.h"
#endif
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
#include "mbedtls/platform_util.h"
#endif
#if defined(MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED)
static int ssl_conf_has_static_psk( mbedtls_ssl_config const *conf )
{
if( conf->psk_identity == NULL ||
conf->psk_identity_len == 0 )
{
return( 0 );
}
if( conf->psk != NULL && conf->psk_len != 0 )
return( 1 );
#if defined(MBEDTLS_USE_PSA_CRYPTO)
if( ! mbedtls_svc_key_id_is_null( conf->psk_opaque ) )
return( 1 );
#endif /* MBEDTLS_USE_PSA_CRYPTO */
return( 0 );
}
#if defined(MBEDTLS_USE_PSA_CRYPTO)
static int ssl_conf_has_static_raw_psk( mbedtls_ssl_config const *conf )
{
if( conf->psk_identity == NULL ||
conf->psk_identity_len == 0 )
{
return( 0 );
}
if( conf->psk != NULL && conf->psk_len != 0 )
return( 1 );
return( 0 );
}
#endif /* MBEDTLS_USE_PSA_CRYPTO */
#endif /* MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED */
#if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
static int ssl_write_hostname_ext( mbedtls_ssl_context *ssl,
unsigned char *buf,
const unsigned char *end,
size_t *olen )
{
unsigned char *p = buf;
size_t hostname_len;
*olen = 0;
if( ssl->hostname == NULL )
return( 0 );
MBEDTLS_SSL_DEBUG_MSG( 3,
( "client hello, adding server name extension: %s",
ssl->hostname ) );
hostname_len = strlen( ssl->hostname );
MBEDTLS_SSL_CHK_BUF_PTR( p, end, hostname_len + 9 );
/*
* Sect. 3, RFC 6066 (TLS Extensions Definitions)
*
* In order to provide any of the server names, clients MAY include an
* extension of type "server_name" in the (extended) client hello. The
* "extension_data" field of this extension SHALL contain
* "ServerNameList" where:
*
* struct {
* NameType name_type;
* select (name_type) {
* case host_name: HostName;
* } name;
* } ServerName;
*
* enum {
* host_name(0), (255)
* } NameType;
*
* opaque HostName<1..2^16-1>;
*
* struct {
* ServerName server_name_list<1..2^16-1>
* } ServerNameList;
*
*/
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SERVERNAME >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SERVERNAME ) & 0xFF );
*p++ = (unsigned char)( ( (hostname_len + 5) >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( (hostname_len + 5) ) & 0xFF );
*p++ = (unsigned char)( ( (hostname_len + 3) >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( (hostname_len + 3) ) & 0xFF );
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SERVERNAME_HOSTNAME ) & 0xFF );
*p++ = (unsigned char)( ( hostname_len >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( hostname_len ) & 0xFF );
memcpy( p, ssl->hostname, hostname_len );
*olen = hostname_len + 9;
return( 0 );
}
#endif /* MBEDTLS_SSL_SERVER_NAME_INDICATION */
#if defined(MBEDTLS_SSL_RENEGOTIATION)
static int ssl_write_renegotiation_ext( mbedtls_ssl_context *ssl,
unsigned char *buf,
const unsigned char *end,
size_t *olen )
{
unsigned char *p = buf;
*olen = 0;
/* We're always including an TLS_EMPTY_RENEGOTIATION_INFO_SCSV in the
* initial ClientHello, in which case also adding the renegotiation
* info extension is NOT RECOMMENDED as per RFC 5746 Section 3.4. */
if( ssl->renego_status != MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS )
return( 0 );
MBEDTLS_SSL_DEBUG_MSG( 3,
( "client hello, adding renegotiation extension" ) );
MBEDTLS_SSL_CHK_BUF_PTR( p, end, 5 + ssl->verify_data_len );
/*
* Secure renegotiation
*/
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_RENEGOTIATION_INFO >> 8 )
& 0xFF );
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_RENEGOTIATION_INFO )
& 0xFF );
*p++ = 0x00;
*p++ = ( ssl->verify_data_len + 1 ) & 0xFF;
*p++ = ssl->verify_data_len & 0xFF;
memcpy( p, ssl->own_verify_data, ssl->verify_data_len );
*olen = 5 + ssl->verify_data_len;
return( 0 );
}
#endif /* MBEDTLS_SSL_RENEGOTIATION */
/*
* Only if we handle at least one key exchange that needs signatures.
*/
#if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \
defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
static int ssl_write_signature_algorithms_ext( mbedtls_ssl_context *ssl,
unsigned char *buf,
const unsigned char *end,
size_t *olen )
{
unsigned char *p = buf;
size_t sig_alg_len = 0;
const int *md;
#if defined(MBEDTLS_RSA_C) || defined(MBEDTLS_ECDSA_C)
unsigned char *sig_alg_list = buf + 6;
#endif
*olen = 0;
if( ssl->conf->max_minor_ver != MBEDTLS_SSL_MINOR_VERSION_3 )
return( 0 );
MBEDTLS_SSL_DEBUG_MSG( 3,
( "client hello, adding signature_algorithms extension" ) );
if( ssl->conf->sig_hashes == NULL )
return( MBEDTLS_ERR_SSL_BAD_CONFIG );
for( md = ssl->conf->sig_hashes; *md != MBEDTLS_MD_NONE; md++ )
{
#if defined(MBEDTLS_ECDSA_C)
sig_alg_len += 2;
#endif
#if defined(MBEDTLS_RSA_C)
sig_alg_len += 2;
#endif
if( sig_alg_len > MBEDTLS_SSL_MAX_SIG_HASH_ALG_LIST_LEN )
{
MBEDTLS_SSL_DEBUG_MSG( 3,
( "length in bytes of sig-hash-alg extension too big" ) );
return( MBEDTLS_ERR_SSL_BAD_CONFIG );
}
}
/* Empty signature algorithms list, this is a configuration error. */
if( sig_alg_len == 0 )
return( MBEDTLS_ERR_SSL_BAD_CONFIG );
MBEDTLS_SSL_CHK_BUF_PTR( p, end, sig_alg_len + 6 );
/*
* Prepare signature_algorithms extension (TLS 1.2)
*/
sig_alg_len = 0;
for( md = ssl->conf->sig_hashes; *md != MBEDTLS_MD_NONE; md++ )
{
#if defined(MBEDTLS_ECDSA_C)
sig_alg_list[sig_alg_len++] = mbedtls_ssl_hash_from_md_alg( *md );
sig_alg_list[sig_alg_len++] = MBEDTLS_SSL_SIG_ECDSA;
#endif
#if defined(MBEDTLS_RSA_C)
sig_alg_list[sig_alg_len++] = mbedtls_ssl_hash_from_md_alg( *md );
sig_alg_list[sig_alg_len++] = MBEDTLS_SSL_SIG_RSA;
#endif
}
/*
* enum {
* none(0), md5(1), sha1(2), sha224(3), sha256(4), sha384(5),
* sha512(6), (255)
* } HashAlgorithm;
*
* enum { anonymous(0), rsa(1), dsa(2), ecdsa(3), (255) }
* SignatureAlgorithm;
*
* struct {
* HashAlgorithm hash;
* SignatureAlgorithm signature;
* } SignatureAndHashAlgorithm;
*
* SignatureAndHashAlgorithm
* supported_signature_algorithms<2..2^16-2>;
*/
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SIG_ALG >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SIG_ALG ) & 0xFF );
*p++ = (unsigned char)( ( ( sig_alg_len + 2 ) >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( ( sig_alg_len + 2 ) ) & 0xFF );
*p++ = (unsigned char)( ( sig_alg_len >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( sig_alg_len ) & 0xFF );
*olen = 6 + sig_alg_len;
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_write_supported_elliptic_curves_ext( mbedtls_ssl_context *ssl,
unsigned char *buf,
const unsigned char *end,
size_t *olen )
{
unsigned char *p = buf;
unsigned char *elliptic_curve_list = p + 6;
size_t elliptic_curve_len = 0;
const mbedtls_ecp_curve_info *info;
const mbedtls_ecp_group_id *grp_id;
*olen = 0;
MBEDTLS_SSL_DEBUG_MSG( 3,
( "client hello, adding supported_elliptic_curves extension" ) );
if( ssl->conf->curve_list == NULL )
return( MBEDTLS_ERR_SSL_BAD_CONFIG );
for( grp_id = ssl->conf->curve_list;
*grp_id != MBEDTLS_ECP_DP_NONE;
grp_id++ )
{
info = mbedtls_ecp_curve_info_from_grp_id( *grp_id );
if( info == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1,
( "invalid curve in ssl configuration" ) );
return( MBEDTLS_ERR_SSL_BAD_CONFIG );
}
elliptic_curve_len += 2;
if( elliptic_curve_len > MBEDTLS_SSL_MAX_CURVE_LIST_LEN )
{
MBEDTLS_SSL_DEBUG_MSG( 3,
( "malformed supported_elliptic_curves extension in config" ) );
return( MBEDTLS_ERR_SSL_BAD_CONFIG );
}
}
/* Empty elliptic curve list, this is a configuration error. */
if( elliptic_curve_len == 0 )
return( MBEDTLS_ERR_SSL_BAD_CONFIG );
MBEDTLS_SSL_CHK_BUF_PTR( p, end, 6 + elliptic_curve_len );
elliptic_curve_len = 0;
for( grp_id = ssl->conf->curve_list;
*grp_id != MBEDTLS_ECP_DP_NONE;
grp_id++ )
{
info = mbedtls_ecp_curve_info_from_grp_id( *grp_id );
elliptic_curve_list[elliptic_curve_len++] = info->tls_id >> 8;
elliptic_curve_list[elliptic_curve_len++] = info->tls_id & 0xFF;
}
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SUPPORTED_ELLIPTIC_CURVES >> 8 )
& 0xFF );
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SUPPORTED_ELLIPTIC_CURVES )
& 0xFF );
*p++ = (unsigned char)( ( ( elliptic_curve_len + 2 ) >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( ( elliptic_curve_len + 2 ) ) & 0xFF );
*p++ = (unsigned char)( ( ( elliptic_curve_len ) >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( ( elliptic_curve_len ) ) & 0xFF );
*olen = 6 + elliptic_curve_len;
return( 0 );
}
static int ssl_write_supported_point_formats_ext( mbedtls_ssl_context *ssl,
unsigned char *buf,
const unsigned char *end,
size_t *olen )
{
unsigned char *p = buf;
(void) ssl; /* ssl used for debugging only */
*olen = 0;
MBEDTLS_SSL_DEBUG_MSG( 3,
( "client hello, adding supported_point_formats extension" ) );
MBEDTLS_SSL_CHK_BUF_PTR( p, end, 6 );
*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;
return( 0 );
}
#endif /* MBEDTLS_ECDH_C || MBEDTLS_ECDSA_C ||
MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
#if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
static int ssl_write_ecjpake_kkpp_ext( mbedtls_ssl_context *ssl,
unsigned char *buf,
const unsigned char *end,
size_t *olen )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
unsigned char *p = buf;
size_t kkpp_len;
*olen = 0;
/* Skip costly extension if we can't use EC J-PAKE anyway */
if( mbedtls_ecjpake_check( &ssl->handshake->ecjpake_ctx ) != 0 )
return( 0 );
MBEDTLS_SSL_DEBUG_MSG( 3,
( "client hello, adding ecjpake_kkpp extension" ) );
MBEDTLS_SSL_CHK_BUF_PTR( p, end, 4 );
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_ECJPAKE_KKPP >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_ECJPAKE_KKPP ) & 0xFF );
/*
* We may need to send ClientHello multiple times for Hello verification.
* We don't want to compute fresh values every time (both for performance
* and consistency reasons), so cache the extension content.
*/
if( ssl->handshake->ecjpake_cache == NULL ||
ssl->handshake->ecjpake_cache_len == 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "generating new ecjpake parameters" ) );
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( ret );
}
ssl->handshake->ecjpake_cache = mbedtls_calloc( 1, kkpp_len );
if( ssl->handshake->ecjpake_cache == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "allocation failed" ) );
return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
}
memcpy( ssl->handshake->ecjpake_cache, p + 2, kkpp_len );
ssl->handshake->ecjpake_cache_len = kkpp_len;
}
else
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "re-using cached ecjpake parameters" ) );
kkpp_len = ssl->handshake->ecjpake_cache_len;
MBEDTLS_SSL_CHK_BUF_PTR( p + 2, end, kkpp_len );
memcpy( p + 2, ssl->handshake->ecjpake_cache, kkpp_len );
}
*p++ = (unsigned char)( ( kkpp_len >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( kkpp_len ) & 0xFF );
*olen = kkpp_len + 4;
return( 0 );
}
#endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
static int ssl_write_cid_ext( mbedtls_ssl_context *ssl,
unsigned char *buf,
const unsigned char *end,
size_t *olen )
{
unsigned char *p = buf;
size_t ext_len;
/*
* 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;
*/
*olen = 0;
if( ssl->conf->transport != MBEDTLS_SSL_TRANSPORT_DATAGRAM ||
ssl->negotiate_cid == MBEDTLS_SSL_CID_DISABLED )
{
return( 0 );
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding CID extension" ) );
/* ssl->own_cid_len is at most MBEDTLS_SSL_CID_IN_LEN_MAX
* which is at most 255, so the increment cannot overflow. */
MBEDTLS_SSL_CHK_BUF_PTR( p, end, (unsigned)( ssl->own_cid_len + 5 ) );
/* Add extension ID + size */
*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;
return( 0 );
}
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
#if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
static int ssl_write_max_fragment_length_ext( mbedtls_ssl_context *ssl,
unsigned char *buf,
const unsigned char *end,
size_t *olen )
{
unsigned char *p = buf;
*olen = 0;
if( ssl->conf->mfl_code == MBEDTLS_SSL_MAX_FRAG_LEN_NONE )
return( 0 );
MBEDTLS_SSL_DEBUG_MSG( 3,
( "client hello, adding max_fragment_length extension" ) );
MBEDTLS_SSL_CHK_BUF_PTR( p, end, 5 );
*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->conf->mfl_code;
*olen = 5;
return( 0 );
}
#endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */
#if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
static int ssl_write_truncated_hmac_ext( mbedtls_ssl_context *ssl,
unsigned char *buf,
const unsigned char *end,
size_t *olen )
{
unsigned char *p = buf;
*olen = 0;
if( ssl->conf->trunc_hmac == MBEDTLS_SSL_TRUNC_HMAC_DISABLED )
return( 0 );
MBEDTLS_SSL_DEBUG_MSG( 3,
( "client hello, adding truncated_hmac extension" ) );
MBEDTLS_SSL_CHK_BUF_PTR( p, end, 4 );
*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;
return( 0 );
}
#endif /* MBEDTLS_SSL_TRUNCATED_HMAC */
#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
static int ssl_write_encrypt_then_mac_ext( mbedtls_ssl_context *ssl,
unsigned char *buf,
const unsigned char *end,
size_t *olen )
{
unsigned char *p = buf;
*olen = 0;
if( ssl->conf->encrypt_then_mac == MBEDTLS_SSL_ETM_DISABLED ||
ssl->conf->max_minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 )
return( 0 );
MBEDTLS_SSL_DEBUG_MSG( 3,
( "client hello, adding encrypt_then_mac extension" ) );
MBEDTLS_SSL_CHK_BUF_PTR( p, end, 4 );
*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;
return( 0 );
}
#endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */
#if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
static int ssl_write_extended_ms_ext( mbedtls_ssl_context *ssl,
unsigned char *buf,
const unsigned char *end,
size_t *olen )
{
unsigned char *p = buf;
*olen = 0;
if( ssl->conf->extended_ms == MBEDTLS_SSL_EXTENDED_MS_DISABLED ||
ssl->conf->max_minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 )
return( 0 );
MBEDTLS_SSL_DEBUG_MSG( 3,
( "client hello, adding extended_master_secret extension" ) );
MBEDTLS_SSL_CHK_BUF_PTR( p, end, 4 );
*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;
return( 0 );
}
#endif /* MBEDTLS_SSL_EXTENDED_MASTER_SECRET */
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
static int ssl_write_session_ticket_ext( mbedtls_ssl_context *ssl,
unsigned char *buf,
const unsigned char *end,
size_t *olen )
{
unsigned char *p = buf;
size_t tlen = ssl->session_negotiate->ticket_len;
*olen = 0;
if( ssl->conf->session_tickets == MBEDTLS_SSL_SESSION_TICKETS_DISABLED )
return( 0 );
MBEDTLS_SSL_DEBUG_MSG( 3,
( "client hello, adding session ticket extension" ) );
/* The addition is safe here since the ticket length is 16 bit. */
MBEDTLS_SSL_CHK_BUF_PTR( p, end, 4 + tlen );
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SESSION_TICKET >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SESSION_TICKET ) & 0xFF );
*p++ = (unsigned char)( ( tlen >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( tlen ) & 0xFF );
*olen = 4;
if( ssl->session_negotiate->ticket == NULL || tlen == 0 )
return( 0 );
MBEDTLS_SSL_DEBUG_MSG( 3,
( "sending session ticket of length %d", tlen ) );
memcpy( p, ssl->session_negotiate->ticket, tlen );
*olen += tlen;
return( 0 );
}
#endif /* MBEDTLS_SSL_SESSION_TICKETS */
#if defined(MBEDTLS_SSL_ALPN)
static int ssl_write_alpn_ext( mbedtls_ssl_context *ssl,
unsigned char *buf,
const unsigned char *end,
size_t *olen )
{
unsigned char *p = buf;
size_t alpnlen = 0;
const char **cur;
*olen = 0;
if( ssl->conf->alpn_list == NULL )
return( 0 );
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding alpn extension" ) );
for( cur = ssl->conf->alpn_list; *cur != NULL; cur++ )
alpnlen += strlen( *cur ) + 1;
MBEDTLS_SSL_CHK_BUF_PTR( p, end, 6 + alpnlen );
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_ALPN >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_ALPN ) & 0xFF );
/*
* opaque ProtocolName<1..2^8-1>;
*
* struct {
* ProtocolName protocol_name_list<2..2^16-1>
* } ProtocolNameList;
*/
/* Skip writing extension and list length for now */
p += 4;
for( cur = ssl->conf->alpn_list; *cur != NULL; cur++ )
{
/*
* mbedtls_ssl_conf_set_alpn_protocols() checked that the length of
* protocol names is less than 255.
*/
*p = (unsigned char)strlen( *cur );
memcpy( p + 1, *cur, *p );
p += 1 + *p;
}
*olen = p - buf;
/* List length = olen - 2 (ext_type) - 2 (ext_len) - 2 (list_len) */
buf[4] = (unsigned char)( ( ( *olen - 6 ) >> 8 ) & 0xFF );
buf[5] = (unsigned char)( ( ( *olen - 6 ) ) & 0xFF );
/* Extension length = olen - 2 (ext_type) - 2 (ext_len) */
buf[2] = (unsigned char)( ( ( *olen - 4 ) >> 8 ) & 0xFF );
buf[3] = (unsigned char)( ( ( *olen - 4 ) ) & 0xFF );
return( 0 );
}
#endif /* MBEDTLS_SSL_ALPN */
#if defined(MBEDTLS_SSL_DTLS_SRTP)
static int ssl_write_use_srtp_ext( mbedtls_ssl_context *ssl,
unsigned char *buf,
const unsigned char *end,
size_t *olen )
{
unsigned char *p = buf;
size_t protection_profiles_index = 0, ext_len = 0;
uint16_t mki_len = 0, profile_value = 0;
*olen = 0;
if( ( ssl->conf->transport != MBEDTLS_SSL_TRANSPORT_DATAGRAM ) ||
( ssl->conf->dtls_srtp_profile_list == NULL ) ||
( ssl->conf->dtls_srtp_profile_list_len == 0 ) )
{
return( 0 );
}
/* RFC 5764 section 4.1.1
* uint8 SRTPProtectionProfile[2];
*
* struct {
* SRTPProtectionProfiles SRTPProtectionProfiles;
* opaque srtp_mki<0..255>;
* } UseSRTPData;
* SRTPProtectionProfile SRTPProtectionProfiles<2..2^16-1>;
*/
if( ssl->conf->dtls_srtp_mki_support == MBEDTLS_SSL_DTLS_SRTP_MKI_SUPPORTED )
{
mki_len = ssl->dtls_srtp_info.mki_len;
}
/* Extension length = 2 bytes for profiles length,
* ssl->conf->dtls_srtp_profile_list_len * 2 (each profile is 2 bytes length ),
* 1 byte for srtp_mki vector length and the mki_len value
*/
ext_len = 2 + 2 * ( ssl->conf->dtls_srtp_profile_list_len ) + 1 + mki_len;
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding use_srtp extension" ) );
/* Check there is room in the buffer for the extension + 4 bytes
* - the extension tag (2 bytes)
* - the extension length (2 bytes)
*/
MBEDTLS_SSL_CHK_BUF_PTR( p, end, ext_len + 4 );
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_USE_SRTP >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_USE_SRTP ) & 0xFF );
*p++ = (unsigned char)( ( ( ext_len & 0xFF00 ) >> 8 ) & 0xFF );
*p++ = (unsigned char)( ext_len & 0xFF );
/* protection profile length: 2*(ssl->conf->dtls_srtp_profile_list_len) */
/* micro-optimization:
* the list size is limited to MBEDTLS_TLS_SRTP_MAX_PROFILE_LIST_LENGTH
* which is lower than 127, so the upper byte of the length is always 0
* For the documentation, the more generic code is left in comments
* *p++ = (unsigned char)( ( ( 2 * ssl->conf->dtls_srtp_profile_list_len )
* >> 8 ) & 0xFF );
*/
*p++ = 0;
*p++ = (unsigned char)( ( 2 * ssl->conf->dtls_srtp_profile_list_len )
& 0xFF );
for( protection_profiles_index=0;
protection_profiles_index < ssl->conf->dtls_srtp_profile_list_len;
protection_profiles_index++ )
{
profile_value = mbedtls_ssl_check_srtp_profile_value
( ssl->conf->dtls_srtp_profile_list[protection_profiles_index] );
if( profile_value != MBEDTLS_TLS_SRTP_UNSET )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "ssl_write_use_srtp_ext, add profile: %04x",
profile_value ) );
*p++ = ( ( profile_value >> 8 ) & 0xFF );
*p++ = ( profile_value & 0xFF );
}
else
{
/*
* Note: we shall never arrive here as protection profiles
* is checked by mbedtls_ssl_conf_dtls_srtp_protection_profiles function
*/
MBEDTLS_SSL_DEBUG_MSG( 3,
( "client hello, "
"illegal DTLS-SRTP protection profile %d",
ssl->conf->dtls_srtp_profile_list[protection_profiles_index]
) );
return( MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED );
}
}
*p++ = mki_len & 0xFF;
if( mki_len != 0 )
{
memcpy( p, ssl->dtls_srtp_info.mki_value, mki_len );
/*
* Increment p to point to the current position.
*/
p += mki_len;
MBEDTLS_SSL_DEBUG_BUF( 3, "sending mki", ssl->dtls_srtp_info.mki_value,
ssl->dtls_srtp_info.mki_len );
}
/*
* total extension length: extension type (2 bytes)
* + extension length (2 bytes)
* + protection profile length (2 bytes)
* + 2 * number of protection profiles
* + srtp_mki vector length(1 byte)
* + mki value
*/
*olen = p - buf;
return( 0 );
}
#endif /* MBEDTLS_SSL_DTLS_SRTP */
/*
* Generate random bytes for ClientHello
*/
static int ssl_generate_random( mbedtls_ssl_context *ssl )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
unsigned char *p = ssl->handshake->randbytes;
#if defined(MBEDTLS_HAVE_TIME)
mbedtls_time_t t;
#endif
/*
* When responding to a verify request, MUST reuse random (RFC 6347 4.2.1)
*/
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
ssl->handshake->verify_cookie != NULL )
{
return( 0 );
}
#endif
#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, ( "client 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 );
return( 0 );
}
/**
* \brief Validate cipher suite against config in SSL context.
*
* \param suite_info cipher suite to validate
* \param ssl SSL context
* \param min_minor_ver Minimal minor version to accept a cipher suite
* \param max_minor_ver Maximal minor version to accept a cipher suite
*
* \return 0 if valid, else 1
*/
static int ssl_validate_ciphersuite(
const mbedtls_ssl_ciphersuite_t * suite_info,
const mbedtls_ssl_context * ssl,
int min_minor_ver, int max_minor_ver )
{
(void) ssl;
if( suite_info == NULL )
return( 1 );
if( suite_info->min_minor_ver > max_minor_ver ||
suite_info->max_minor_ver < min_minor_ver )
return( 1 );
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
( suite_info->flags & MBEDTLS_CIPHERSUITE_NODTLS ) )
return( 1 );
#endif
#if defined(MBEDTLS_ARC4_C)
if( ssl->conf->arc4_disabled == MBEDTLS_SSL_ARC4_DISABLED &&
suite_info->cipher == MBEDTLS_CIPHER_ARC4_128 )
return( 1 );
#endif
#if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
if( suite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE &&
mbedtls_ecjpake_check( &ssl->handshake->ecjpake_ctx ) != 0 )
return( 1 );
#endif
/* Don't suggest PSK-based ciphersuite if no PSK is available. */
#if defined(MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED)
if( mbedtls_ssl_ciphersuite_uses_psk( suite_info ) &&
ssl_conf_has_static_psk( ssl->conf ) == 0 )
{
return( 1 );
}
#endif /* MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED */
return( 0 );
}
static int ssl_write_client_hello( mbedtls_ssl_context *ssl )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t i, n, olen, ext_len = 0;
unsigned char *buf;
unsigned char *p, *q;
const unsigned char *end;
unsigned char offer_compress;
const int *ciphersuites;
const mbedtls_ssl_ciphersuite_t *ciphersuite_info;
#if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \
defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
int uses_ec = 0;
#endif
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write client hello" ) );
if( ssl->conf->f_rng == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "no RNG provided") );
return( MBEDTLS_ERR_SSL_NO_RNG );
}
#if defined(MBEDTLS_SSL_RENEGOTIATION)
if( ssl->renego_status == MBEDTLS_SSL_INITIAL_HANDSHAKE )
#endif
{
ssl->major_ver = ssl->conf->min_major_ver;
ssl->minor_ver = ssl->conf->min_minor_ver;
}
if( ssl->conf->max_major_ver == 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1,
( "configured max major version is invalid, consider using mbedtls_ssl_config_defaults()" ) );
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
}
buf = ssl->out_msg;
end = buf + MBEDTLS_SSL_OUT_CONTENT_LEN;
/*
* Check if there's enough space for the first part of the ClientHello
* consisting of the 38 bytes described below, the session identifier (at
* most 32 bytes) and its length (1 byte).
*
* Use static upper bounds instead of the actual values
* to allow the compiler to optimize this away.
*/
MBEDTLS_SSL_CHK_BUF_PTR( buf, end, 38 + 1 + 32 );
/*
* The 38 first bytes of the ClientHello:
* 0 . 0 handshake type (written later)
* 1 . 3 handshake length (written later)
* 4 . 5 highest version supported
* 6 . 9 current UNIX time
* 10 . 37 random bytes
*
* The current UNIX time (4 bytes) and following 28 random bytes are written
* by ssl_generate_random() into ssl->handshake->randbytes buffer and then
* copied from there into the output buffer.
*/
p = buf + 4;
mbedtls_ssl_write_version( ssl->conf->max_major_ver,
ssl->conf->max_minor_ver,
ssl->conf->transport, p );
p += 2;
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, max version: [%d:%d]",
buf[4], buf[5] ) );
if( ( ret = ssl_generate_random( ssl ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_generate_random", ret );
return( ret );
}
memcpy( p, ssl->handshake->randbytes, 32 );
MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, random bytes", p, 32 );
p += 32;
/*
* 38 . 38 session id length
* 39 . 39+n session id
* 39+n . 39+n DTLS only: cookie length (1 byte)
* 40+n . .. DTLS only: cookie
* .. . .. ciphersuitelist length (2 bytes)
* .. . .. ciphersuitelist
* .. . .. compression methods length (1 byte)
* .. . .. compression methods
* .. . .. extensions length (2 bytes)
* .. . .. extensions
*/
n = ssl->session_negotiate->id_len;
if( n < 16 || n > 32 ||
#if defined(MBEDTLS_SSL_RENEGOTIATION)
ssl->renego_status != MBEDTLS_SSL_INITIAL_HANDSHAKE ||
#endif
ssl->handshake->resume == 0 )
{
n = 0;
}
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
/*
* RFC 5077 section 3.4: "When presenting a ticket, the client MAY
* generate and include a Session ID in the TLS ClientHello."
*/
#if defined(MBEDTLS_SSL_RENEGOTIATION)
if( ssl->renego_status == MBEDTLS_SSL_INITIAL_HANDSHAKE )
#endif
{
if( ssl->session_negotiate->ticket != NULL &&
ssl->session_negotiate->ticket_len != 0 )
{
ret = ssl->conf->f_rng( ssl->conf->p_rng,
ssl->session_negotiate->id, 32 );
if( ret != 0 )
return( ret );
ssl->session_negotiate->id_len = n = 32;
}
}
#endif /* MBEDTLS_SSL_SESSION_TICKETS */
/*
* The first check of the output buffer size above (
* MBEDTLS_SSL_CHK_BUF_PTR( buf, end, 38 + 1 + 32 );)
* has checked that there is enough space in the output buffer for the
* session identifier length byte and the session identifier (n <= 32).
*/
*p++ = (unsigned char) n;
for( i = 0; i < n; i++ )
*p++ = ssl->session_negotiate->id[i];
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, session id len.: %d", n ) );
MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, session id", buf + 39, n );
/*
* With 'n' being the length of the session identifier
*
* 39+n . 39+n DTLS only: cookie length (1 byte)
* 40+n . .. DTLS only: cookie
* .. . .. ciphersuitelist length (2 bytes)
* .. . .. ciphersuitelist
* .. . .. compression methods length (1 byte)
* .. . .. compression methods
* .. . .. extensions length (2 bytes)
* .. . .. extensions
*/
/*
* DTLS cookie
*/
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
{
MBEDTLS_SSL_CHK_BUF_PTR( p, end, 1 );
if( ssl->handshake->verify_cookie == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "no verify cookie to send" ) );
*p++ = 0;
}
else
{
MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, cookie",
ssl->handshake->verify_cookie,
ssl->handshake->verify_cookie_len );
*p++ = ssl->handshake->verify_cookie_len;
MBEDTLS_SSL_CHK_BUF_PTR( p, end,
ssl->handshake->verify_cookie_len );
memcpy( p, ssl->handshake->verify_cookie,
ssl->handshake->verify_cookie_len );
p += ssl->handshake->verify_cookie_len;
}
}
#endif
/*
* Ciphersuite list
*/
ciphersuites = ssl->conf->ciphersuite_list[ssl->minor_ver];
/* Skip writing ciphersuite length for now */
n = 0;
q = p;
MBEDTLS_SSL_CHK_BUF_PTR( p, end, 2 );
p += 2;
for( i = 0; ciphersuites[i] != 0; i++ )
{
ciphersuite_info = mbedtls_ssl_ciphersuite_from_id( ciphersuites[i] );
if( ssl_validate_ciphersuite( ciphersuite_info, ssl,
ssl->conf->min_minor_ver,
ssl->conf->max_minor_ver ) != 0 )
continue;
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, add ciphersuite: %#04x (%s)",
ciphersuites[i], ciphersuite_info->name ) );
#if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \
defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
uses_ec |= mbedtls_ssl_ciphersuite_uses_ec( ciphersuite_info );
#endif
MBEDTLS_SSL_CHK_BUF_PTR( p, end, 2 );
n++;
*p++ = (unsigned char)( ciphersuites[i] >> 8 );
*p++ = (unsigned char)( ciphersuites[i] );
}
MBEDTLS_SSL_DEBUG_MSG( 3,
( "client hello, got %d ciphersuites (excluding SCSVs)", n ) );
/*
* Add TLS_EMPTY_RENEGOTIATION_INFO_SCSV
*/
#if defined(MBEDTLS_SSL_RENEGOTIATION)
if( ssl->renego_status == MBEDTLS_SSL_INITIAL_HANDSHAKE )
#endif
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "adding EMPTY_RENEGOTIATION_INFO_SCSV" ) );
MBEDTLS_SSL_CHK_BUF_PTR( p, end, 2 );
*p++ = (unsigned char)( MBEDTLS_SSL_EMPTY_RENEGOTIATION_INFO >> 8 );
*p++ = (unsigned char)( MBEDTLS_SSL_EMPTY_RENEGOTIATION_INFO );
n++;
}
/* Some versions of OpenSSL don't handle it correctly if not at end */
#if defined(MBEDTLS_SSL_FALLBACK_SCSV)
if( ssl->conf->fallback == MBEDTLS_SSL_IS_FALLBACK )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "adding FALLBACK_SCSV" ) );
MBEDTLS_SSL_CHK_BUF_PTR( p, end, 2 );
*p++ = (unsigned char)( MBEDTLS_SSL_FALLBACK_SCSV_VALUE >> 8 );
*p++ = (unsigned char)( MBEDTLS_SSL_FALLBACK_SCSV_VALUE );
n++;
}
#endif
*q++ = (unsigned char)( n >> 7 );
*q++ = (unsigned char)( n << 1 );
#if defined(MBEDTLS_ZLIB_SUPPORT)
offer_compress = 1;
#else
offer_compress = 0;
#endif
/*
* We don't support compression with DTLS right now: if many records come
* in the same datagram, uncompressing one could overwrite the next one.
* We don't want to add complexity for handling that case unless there is
* an actual need for it.
*/
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
offer_compress = 0;
#endif
if( offer_compress )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, compress len.: %d", 2 ) );
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, compress alg.: %d %d",
MBEDTLS_SSL_COMPRESS_DEFLATE,
MBEDTLS_SSL_COMPRESS_NULL ) );
MBEDTLS_SSL_CHK_BUF_PTR( p, end, 3 );
*p++ = 2;
*p++ = MBEDTLS_SSL_COMPRESS_DEFLATE;
*p++ = MBEDTLS_SSL_COMPRESS_NULL;
}
else
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, compress len.: %d", 1 ) );
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, compress alg.: %d",
MBEDTLS_SSL_COMPRESS_NULL ) );
MBEDTLS_SSL_CHK_BUF_PTR( p, end, 2 );
*p++ = 1;
*p++ = MBEDTLS_SSL_COMPRESS_NULL;
}
/* First write extensions, then the total length */
MBEDTLS_SSL_CHK_BUF_PTR( p, end, 2 );
#if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
if( ( ret = ssl_write_hostname_ext( ssl, p + 2 + ext_len,
end, &olen ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_write_hostname_ext", ret );
return( ret );
}
ext_len += olen;
#endif
/* Note that TLS_EMPTY_RENEGOTIATION_INFO_SCSV is always added
* even if MBEDTLS_SSL_RENEGOTIATION is not defined. */
#if defined(MBEDTLS_SSL_RENEGOTIATION)
if( ( ret = ssl_write_renegotiation_ext( ssl, p + 2 + ext_len,
end, &olen ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_write_renegotiation_ext", ret );
return( ret );
}
ext_len += olen;
#endif
#if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \
defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
if( ( ret = ssl_write_signature_algorithms_ext( ssl, p + 2 + ext_len,
end, &olen ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_write_signature_algorithms_ext", ret );
return( ret );
}
ext_len += olen;
#endif
#if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \
defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
if( uses_ec )
{
if( ( ret = ssl_write_supported_elliptic_curves_ext( ssl, p + 2 + ext_len,
end, &olen ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_write_supported_elliptic_curves_ext", ret );
return( ret );
}
ext_len += olen;
if( ( ret = ssl_write_supported_point_formats_ext( ssl, p + 2 + ext_len,
end, &olen ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_write_supported_point_formats_ext", ret );
return( ret );
}
ext_len += olen;
}
#endif
#if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
if( ( ret = ssl_write_ecjpake_kkpp_ext( ssl, p + 2 + ext_len,
end, &olen ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_write_ecjpake_kkpp_ext", ret );
return( ret );
}
ext_len += olen;
#endif
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
if( ( ret = ssl_write_cid_ext( ssl, p + 2 + ext_len, end, &olen ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_write_cid_ext", ret );
return( ret );
}
ext_len += olen;
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
#if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
if( ( ret = ssl_write_max_fragment_length_ext( ssl, p + 2 + ext_len,
end, &olen ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_write_max_fragment_length_ext", ret );
return( ret );
}
ext_len += olen;
#endif
#if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
if( ( ret = ssl_write_truncated_hmac_ext( ssl, p + 2 + ext_len,
end, &olen ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_write_truncated_hmac_ext", ret );
return( ret );
}
ext_len += olen;
#endif
#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
if( ( ret = ssl_write_encrypt_then_mac_ext( ssl, p + 2 + ext_len,
end, &olen ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_write_encrypt_then_mac_ext", ret );
return( ret );
}
ext_len += olen;
#endif
#if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
if( ( ret = ssl_write_extended_ms_ext( ssl, p + 2 + ext_len,
end, &olen ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_write_extended_ms_ext", ret );
return( ret );
}
ext_len += olen;
#endif
#if defined(MBEDTLS_SSL_ALPN)
if( ( ret = ssl_write_alpn_ext( ssl, p + 2 + ext_len,
end, &olen ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_write_alpn_ext", ret );
return( ret );
}
ext_len += olen;
#endif
#if defined(MBEDTLS_SSL_DTLS_SRTP)
if( ( ret = ssl_write_use_srtp_ext( ssl, p + 2 + ext_len,
end, &olen ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_write_use_srtp_ext", ret );
return( ret );
}
ext_len += olen;
#endif
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
if( ( ret = ssl_write_session_ticket_ext( ssl, p + 2 + ext_len,
end, &olen ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_write_session_ticket_ext", ret );
return( ret );
}
ext_len += olen;
#endif
/* olen unused if all extensions are disabled */
((void) olen);
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, total extension length: %d",
ext_len ) );
if( ext_len > 0 )
{
/* No need to check for space here, because the extension
* writing functions already took care of that. */
*p++ = (unsigned char)( ( ext_len >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( ext_len ) & 0xFF );
p += ext_len;
}
ssl->out_msglen = p - buf;
ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE;
ssl->out_msg[0] = MBEDTLS_SSL_HS_CLIENT_HELLO;
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 client hello" ) );
return( 0 );
}
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 * 2 ||
buf[0] != ssl->verify_data_len * 2 ||
mbedtls_ssl_safer_memcmp( buf + 1,
ssl->own_verify_data, ssl->verify_data_len ) != 0 ||
mbedtls_ssl_safer_memcmp( buf + 1 + ssl->verify_data_len,
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_SERVER_HELLO );
}
}
else
#endif /* MBEDTLS_SSL_RENEGOTIATION */
{
if( len != 1 || buf[0] != 0x00 )
{
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_SERVER_HELLO );
}
ssl->secure_renegotiation = MBEDTLS_SSL_SECURE_RENEGOTIATION;
}
return( 0 );
}
#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 )
{
/*
* server should use the extension only if we did,
* and if so the server's value should match ours (and len is always 1)
*/
if( ssl->conf->mfl_code == MBEDTLS_SSL_MAX_FRAG_LEN_NONE ||
len != 1 ||
buf[0] != ssl->conf->mfl_code )
{
MBEDTLS_SSL_DEBUG_MSG( 1,
( "non-matching max fragment length extension" ) );
mbedtls_ssl_send_alert_message(
ssl,
MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
return( 0 );
}
#endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */
#if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
static int ssl_parse_truncated_hmac_ext( mbedtls_ssl_context *ssl,
const unsigned char *buf,
size_t len )
{
if( ssl->conf->trunc_hmac == MBEDTLS_SSL_TRUNC_HMAC_DISABLED ||
len != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1,
( "non-matching truncated HMAC extension" ) );
mbedtls_ssl_send_alert_message(
ssl,
MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
((void) buf);
ssl->session_negotiate->trunc_hmac = MBEDTLS_SSL_TRUNC_HMAC_ENABLED;
return( 0 );
}
#endif /* MBEDTLS_SSL_TRUNCATED_HMAC */
#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;
if( /* CID extension only makes sense in DTLS */
ssl->conf->transport != MBEDTLS_SSL_TRANSPORT_DATAGRAM ||
/* The server must only send the CID extension if we have offered it. */
ssl->negotiate_cid == MBEDTLS_SSL_CID_DISABLED )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "CID extension unexpected" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
if( len == 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "CID extension invalid" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
peer_cid_len = *buf++;
len--;
if( peer_cid_len > MBEDTLS_SSL_CID_OUT_LEN_MAX )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "CID extension invalid" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
if( len != peer_cid_len )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "CID extension invalid" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_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, "Server CID", buf, peer_cid_len );
return( 0 );
}
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
#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( ssl->conf->encrypt_then_mac == MBEDTLS_SSL_ETM_DISABLED ||
ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 ||
len != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1,
( "non-matching encrypt-then-MAC extension" ) );
mbedtls_ssl_send_alert_message(
ssl,
MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
((void) buf);
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( ssl->conf->extended_ms == MBEDTLS_SSL_EXTENDED_MS_DISABLED ||
ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 ||
len != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1,
( "non-matching extended master secret extension" ) );
mbedtls_ssl_send_alert_message(
ssl,
MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
((void) buf);
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,
const unsigned char *buf,
size_t len )
{
if( ssl->conf->session_tickets == MBEDTLS_SSL_SESSION_TICKETS_DISABLED ||
len != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1,
( "non-matching session ticket extension" ) );
mbedtls_ssl_send_alert_message(
ssl,
MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
((void) buf);
ssl->handshake->new_session_ticket = 1;
return( 0 );
}
#endif /* MBEDTLS_SSL_SESSION_TICKETS */
#if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \
defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
static int ssl_parse_supported_point_formats_ext( 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 server 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_SERVER_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++;
}
MBEDTLS_SSL_DEBUG_MSG( 1, ( "no point format in common" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
#endif /* MBEDTLS_ECDH_C || MBEDTLS_ECDSA_C ||
MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
#if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
static int ssl_parse_ecjpake_kkpp( mbedtls_ssl_context *ssl,
const unsigned char *buf,
size_t len )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
if( ssl->handshake->ciphersuite_info->key_exchange !=
MBEDTLS_KEY_EXCHANGE_ECJPAKE )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "skip ecjpake kkpp extension" ) );
return( 0 );
}
/* If we got here, we no longer need our cached extension */
mbedtls_free( ssl->handshake->ecjpake_cache );
ssl->handshake->ecjpake_cache = NULL;
ssl->handshake->ecjpake_cache_len = 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_HANDSHAKE_FAILURE );
return( ret );
}
return( 0 );
}
#endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
#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, name_len;
const char **p;
/* If we didn't send it, the server shouldn't send it */
if( ssl->conf->alpn_list == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "non-matching ALPN extension" ) );
mbedtls_ssl_send_alert_message(
ssl,
MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
/*
* opaque ProtocolName<1..2^8-1>;
*
* struct {
* ProtocolName protocol_name_list<2..2^16-1>
* } ProtocolNameList;
*
* the "ProtocolNameList" MUST contain exactly one "ProtocolName"
*/
/* 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_SERVER_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_SERVER_HELLO );
}
name_len = buf[2];
if( name_len != list_len - 1 )
{
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
/* Check that the server chosen protocol was in our list and save it */
for( p = ssl->conf->alpn_list; *p != NULL; p++ )
{
if( name_len == strlen( *p ) &&
memcmp( buf + 3, *p, name_len ) == 0 )
{
ssl->alpn_chosen = *p;
return( 0 );
}
}
MBEDTLS_SSL_DEBUG_MSG( 1, ( "ALPN extension: no matching protocol" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
#endif /* MBEDTLS_SSL_ALPN */
#if defined(MBEDTLS_SSL_DTLS_SRTP)
static int ssl_parse_use_srtp_ext( mbedtls_ssl_context *ssl,
const unsigned char *buf,
size_t len )
{
mbedtls_ssl_srtp_profile server_protection = MBEDTLS_TLS_SRTP_UNSET;
size_t i, mki_len = 0;
uint16_t server_protection_profile_value = 0;
/* If use_srtp is not configured, just ignore the extension */
if( ( ssl->conf->transport != MBEDTLS_SSL_TRANSPORT_DATAGRAM ) ||
( ssl->conf->dtls_srtp_profile_list == NULL ) ||
( ssl->conf->dtls_srtp_profile_list_len == 0 ) )
return( 0 );
/* RFC 5764 section 4.1.1
* uint8 SRTPProtectionProfile[2];
*
* struct {
* SRTPProtectionProfiles SRTPProtectionProfiles;
* opaque srtp_mki<0..255>;
* } UseSRTPData;
* SRTPProtectionProfile SRTPProtectionProfiles<2..2^16-1>;
*
*/
if( ssl->conf->dtls_srtp_mki_support == MBEDTLS_SSL_DTLS_SRTP_MKI_SUPPORTED )
{
mki_len = ssl->dtls_srtp_info.mki_len;
}
/*
* Length is 5 + optional mki_value : one protection profile length (2 bytes)
* + protection profile (2 bytes)
* + mki_len(1 byte)
* and optional srtp_mki
*/
if( ( len < 5 ) || ( len != ( buf[4] + 5u ) ) )
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
/*
* get the server protection profile
*/
/*
* protection profile length must be 0x0002 as we must have only
* one protection profile in server Hello
*/
if( ( buf[0] != 0 ) || ( buf[1] != 2 ) )
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
server_protection_profile_value = ( buf[2] << 8 ) | buf[3];
server_protection = mbedtls_ssl_check_srtp_profile_value(
server_protection_profile_value );
if( server_protection != MBEDTLS_TLS_SRTP_UNSET )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "found srtp profile: %s",
mbedtls_ssl_get_srtp_profile_as_string(
server_protection ) ) );
}
ssl->dtls_srtp_info.chosen_dtls_srtp_profile = MBEDTLS_TLS_SRTP_UNSET;
/*
* Check we have the server profile in our list
*/
for( i=0; i < ssl->conf->dtls_srtp_profile_list_len; i++)
{
if( server_protection == ssl->conf->dtls_srtp_profile_list[i] )
{
ssl->dtls_srtp_info.chosen_dtls_srtp_profile = ssl->conf->dtls_srtp_profile_list[i];
MBEDTLS_SSL_DEBUG_MSG( 3, ( "selected srtp profile: %s",
mbedtls_ssl_get_srtp_profile_as_string(
server_protection ) ) );
break;
}
}
/* If no match was found : server problem, it shall never answer with incompatible profile */
if( ssl->dtls_srtp_info.chosen_dtls_srtp_profile == MBEDTLS_TLS_SRTP_UNSET )
{
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
/* If server does not use mki in its reply, make sure the client won't keep
* one as negotiated */
if( len == 5 )
{
ssl->dtls_srtp_info.mki_len = 0;
}
/*
* RFC5764:
* If the client detects a nonzero-length MKI in the server's response
* that is different than the one the client offered, then the client
* MUST abort the handshake and SHOULD send an invalid_parameter alert.
*/
if( len > 5 && ( buf[4] != mki_len ||
( memcmp( ssl->dtls_srtp_info.mki_value, &buf[5], mki_len ) ) ) )
{
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
#if defined (MBEDTLS_DEBUG_C)
if( len > 5 )
{
MBEDTLS_SSL_DEBUG_BUF( 3, "received mki", ssl->dtls_srtp_info.mki_value,
ssl->dtls_srtp_info.mki_len );
}
#endif
return( 0 );
}
#endif /* MBEDTLS_SSL_DTLS_SRTP */
/*
* Parse HelloVerifyRequest. Only called after verifying the HS type.
*/
#if defined(MBEDTLS_SSL_PROTO_DTLS)
static int ssl_parse_hello_verify_request( mbedtls_ssl_context *ssl )
{
const unsigned char *p = ssl->in_msg + mbedtls_ssl_hs_hdr_len( ssl );
int major_ver, minor_ver;
unsigned char cookie_len;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse hello verify request" ) );
/* Check that there is enough room for:
* - 2 bytes of version
* - 1 byte of cookie_len
*/
if( mbedtls_ssl_hs_hdr_len( ssl ) + 3 > ssl->in_msglen )
{
MBEDTLS_SSL_DEBUG_MSG( 1,
( "incoming HelloVerifyRequest message is too short" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
/*
* struct {
* ProtocolVersion server_version;
* opaque cookie<0..2^8-1>;
* } HelloVerifyRequest;
*/
MBEDTLS_SSL_DEBUG_BUF( 3, "server version", p, 2 );
mbedtls_ssl_read_version( &major_ver, &minor_ver, ssl->conf->transport, p );
p += 2;
/*
* Since the RFC is not clear on this point, accept DTLS 1.0 (TLS 1.1)
* even is lower than our min version.
*/
if( major_ver < MBEDTLS_SSL_MAJOR_VERSION_3 ||
minor_ver < MBEDTLS_SSL_MINOR_VERSION_2 ||
major_ver > ssl->conf->max_major_ver ||
minor_ver > ssl->conf->max_minor_ver )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server version" ) );
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 );
}
cookie_len = *p++;
if( ( ssl->in_msg + ssl->in_msglen ) - p < cookie_len )
{
MBEDTLS_SSL_DEBUG_MSG( 1,
( "cookie length does not match incoming message size" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
MBEDTLS_SSL_DEBUG_BUF( 3, "cookie", p, cookie_len );
mbedtls_free( ssl->handshake->verify_cookie );
ssl->handshake->verify_cookie = mbedtls_calloc( 1, cookie_len );
if( ssl->handshake->verify_cookie == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "alloc failed (%d bytes)", cookie_len ) );
return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
}
memcpy( ssl->handshake->verify_cookie, p, cookie_len );
ssl->handshake->verify_cookie_len = cookie_len;
/* Start over at ClientHello */
ssl->state = MBEDTLS_SSL_CLIENT_HELLO;
mbedtls_ssl_reset_checksum( ssl );
mbedtls_ssl_recv_flight_completed( ssl );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse hello verify request" ) );
return( 0 );
}
#endif /* MBEDTLS_SSL_PROTO_DTLS */
static int ssl_parse_server_hello( mbedtls_ssl_context *ssl )
{
int ret, i;
size_t n;
size_t ext_len;
unsigned char *buf, *ext;
unsigned char comp;
#if defined(MBEDTLS_ZLIB_SUPPORT)
int accept_comp;
#endif
#if defined(MBEDTLS_SSL_RENEGOTIATION)
int renegotiation_info_seen = 0;
#endif
int handshake_failure = 0;
const mbedtls_ssl_ciphersuite_t *suite_info;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse server hello" ) );
if( ( ret = mbedtls_ssl_read_record( ssl, 1 ) ) != 0 )
{
/* No alert on a read error. */
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret );
return( ret );
}
buf = ssl->in_msg;
if( ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE )
{
#if defined(MBEDTLS_SSL_RENEGOTIATION)
if( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS )
{
ssl->renego_records_seen++;
if( ssl->conf->renego_max_records >= 0 &&
ssl->renego_records_seen > ssl->conf->renego_max_records )
{
MBEDTLS_SSL_DEBUG_MSG( 1,
( "renegotiation requested, but not honored by server" ) );
return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
}
MBEDTLS_SSL_DEBUG_MSG( 1,
( "non-handshake message during renegotiation" ) );
ssl->keep_current_message = 1;
return( MBEDTLS_ERR_SSL_WAITING_SERVER_HELLO_RENEGO );
}
#endif /* MBEDTLS_SSL_RENEGOTIATION */
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
mbedtls_ssl_send_alert_message(
ssl,
MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE );
return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
}
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
{
if( buf[0] == MBEDTLS_SSL_HS_HELLO_VERIFY_REQUEST )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "received hello verify request" ) );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse server hello" ) );
return( ssl_parse_hello_verify_request( ssl ) );
}
else
{
/* We made it through the verification process */
mbedtls_free( ssl->handshake->verify_cookie );
ssl->handshake->verify_cookie = NULL;
ssl->handshake->verify_cookie_len = 0;
}
}
#endif /* MBEDTLS_SSL_PROTO_DTLS */
if( ssl->in_hslen < 38 + mbedtls_ssl_hs_hdr_len( ssl ) ||
buf[0] != MBEDTLS_SSL_HS_SERVER_HELLO )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server 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_SERVER_HELLO );
}
/*
* 0 . 1 server_version
* 2 . 33 random (maybe including 4 bytes of Unix time)
* 34 . 34 session_id length = n
* 35 . 34+n session_id
* 35+n . 36+n cipher_suite
* 37+n . 37+n compression_method
*
* 38+n . 39+n extensions length (optional)
* 40+n . .. extensions
*/
buf += mbedtls_ssl_hs_hdr_len( ssl );
MBEDTLS_SSL_DEBUG_BUF( 3, "server hello, version", buf + 0, 2 );
mbedtls_ssl_read_version( &ssl->major_ver, &ssl->minor_ver,
ssl->conf->transport, buf + 0 );
if( ssl->major_ver < ssl->conf->min_major_ver ||
ssl->minor_ver < ssl->conf->min_minor_ver ||
ssl->major_ver > ssl->conf->max_major_ver ||
ssl->minor_ver > ssl->conf->max_minor_ver )
{
MBEDTLS_SSL_DEBUG_MSG( 1,
( "server version out of bounds - min: [%d:%d], server: [%d:%d], max: [%d:%d]",
ssl->conf->min_major_ver,
ssl->conf->min_minor_ver,
ssl->major_ver, ssl->minor_ver,
ssl->conf->max_major_ver,
ssl->conf->max_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 );
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, current time: %lu",
( (uint32_t) buf[2] << 24 ) |
( (uint32_t) buf[3] << 16 ) |
( (uint32_t) buf[4] << 8 ) |
( (uint32_t) buf[5] ) ) );
memcpy( ssl->handshake->randbytes + 32, buf + 2, 32 );
n = buf[34];
MBEDTLS_SSL_DEBUG_BUF( 3, "server hello, random bytes", buf + 2, 32 );
if( n > 32 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server 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_SERVER_HELLO );
}
if( ssl->in_hslen > mbedtls_ssl_hs_hdr_len( ssl ) + 39 + n )
{
ext_len = ( ( buf[38 + n] << 8 )
| ( buf[39 + n] ) );
if( ( ext_len > 0 && ext_len < 4 ) ||
ssl->in_hslen != mbedtls_ssl_hs_hdr_len( ssl ) + 40 + n + ext_len )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server 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_SERVER_HELLO );
}
}
else if( ssl->in_hslen == mbedtls_ssl_hs_hdr_len( ssl ) + 38 + n )
{
ext_len = 0;
}
else
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server 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_SERVER_HELLO );
}
/* ciphersuite (used later) */
i = ( buf[35 + n] << 8 ) | buf[36 + n];
/*
* Read and check compression
*/
comp = buf[37 + n];
#if defined(MBEDTLS_ZLIB_SUPPORT)
/* See comments in ssl_write_client_hello() */
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
accept_comp = 0;
else
#endif
accept_comp = 1;
if( comp != MBEDTLS_SSL_COMPRESS_NULL &&
( comp != MBEDTLS_SSL_COMPRESS_DEFLATE || accept_comp == 0 ) )
#else /* MBEDTLS_ZLIB_SUPPORT */
if( comp != MBEDTLS_SSL_COMPRESS_NULL )
#endif/* MBEDTLS_ZLIB_SUPPORT */
{
MBEDTLS_SSL_DEBUG_MSG( 1,
( "server hello, bad compression: %d", comp ) );
mbedtls_ssl_send_alert_message(
ssl,
MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE );
}
/*
* Initialize update checksum functions
*/
ssl->handshake->ciphersuite_info = mbedtls_ssl_ciphersuite_from_id( i );
if( ssl->handshake->ciphersuite_info == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1,
( "ciphersuite info for %04x not found", i ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_INTERNAL_ERROR );
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
}
mbedtls_ssl_optimize_checksum( ssl, ssl->handshake->ciphersuite_info );
MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, session id len.: %d", n ) );
MBEDTLS_SSL_DEBUG_BUF( 3, "server hello, session id", buf + 35, n );
/*
* Check if the session can be resumed
*/
if( ssl->handshake->resume == 0 || n == 0 ||
#if defined(MBEDTLS_SSL_RENEGOTIATION)
ssl->renego_status != MBEDTLS_SSL_INITIAL_HANDSHAKE ||
#endif
ssl->session_negotiate->ciphersuite != i ||
ssl->session_negotiate->compression != comp ||
ssl->session_negotiate->id_len != n ||
memcmp( ssl->session_negotiate->id, buf + 35, n ) != 0 )
{
ssl->state++;
ssl->handshake->resume = 0;
#if defined(MBEDTLS_HAVE_TIME)
ssl->session_negotiate->start = mbedtls_time( NULL );
#endif
ssl->session_negotiate->ciphersuite = i;
ssl->session_negotiate->compression = comp;
ssl->session_negotiate->id_len = n;
memcpy( ssl->session_negotiate->id, buf + 35, n );
}
else
{
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 );
mbedtls_ssl_send_alert_message(
ssl,
MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_INTERNAL_ERROR );
return( ret );
}
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "%s session has been resumed",
ssl->handshake->resume ? "a" : "no" ) );
MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, chosen ciphersuite: %04x", i ) );
MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, compress alg.: %d",
buf[37 + n] ) );
/*
* Perform cipher suite validation in same way as in ssl_write_client_hello.
*/
i = 0;
while( 1 )
{
if( ssl->conf->ciphersuite_list[ssl->minor_ver][i] == 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server 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_SERVER_HELLO );
}
if( ssl->conf->ciphersuite_list[ssl->minor_ver][i++] ==
ssl->session_negotiate->ciphersuite )
{
break;
}
}
suite_info = mbedtls_ssl_ciphersuite_from_id(
ssl->session_negotiate->ciphersuite );
if( ssl_validate_ciphersuite( suite_info, ssl, ssl->minor_ver,
ssl->minor_ver ) != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server 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_SERVER_HELLO );
}
MBEDTLS_SSL_DEBUG_MSG( 3,
( "server hello, chosen ciphersuite: %s", suite_info->name ) );
#if defined(MBEDTLS_SSL_ECP_RESTARTABLE_ENABLED)
if( suite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA &&
ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 )
{
ssl->handshake->ecrs_enabled = 1;
}
#endif
if( comp != MBEDTLS_SSL_COMPRESS_NULL
#if defined(MBEDTLS_ZLIB_SUPPORT)
&& comp != MBEDTLS_SSL_COMPRESS_DEFLATE
#endif
)
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server 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_SERVER_HELLO );
}
ssl->session_negotiate->compression = comp;
ext = buf + 40 + n;
MBEDTLS_SSL_DEBUG_MSG( 2,
( "server hello, total extension length: %d", ext_len ) );
while( ext_len )
{
unsigned int ext_id = ( ( ext[0] << 8 )
| ( ext[1] ) );
unsigned int ext_size = ( ( ext[2] << 8 )
| ( ext[3] ) );
if( ext_size + 4 > ext_len )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server 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_SERVER_HELLO );
}
switch( ext_id )
{
case MBEDTLS_TLS_EXT_RENEGOTIATION_INFO:
MBEDTLS_SSL_DEBUG_MSG( 3, ( "found renegotiation extension" ) );
#if defined(MBEDTLS_SSL_RENEGOTIATION)
renegotiation_info_seen = 1;
#endif
if( ( ret = ssl_parse_renegotiation_info( ssl, ext + 4,
ext_size ) ) != 0 )
return( ret );
break;
#if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
case MBEDTLS_TLS_EXT_MAX_FRAGMENT_LENGTH:
MBEDTLS_SSL_DEBUG_MSG( 3,
( "found max_fragment_length extension" ) );
if( ( ret = ssl_parse_max_fragment_length_ext( ssl,
ext + 4, ext_size ) ) != 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" ) );
if( ( ret = ssl_parse_truncated_hmac_ext( ssl,
ext + 4, ext_size ) ) != 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" ) );
if( ( ret = ssl_parse_cid_ext( ssl,
ext + 4,
ext_size ) ) != 0 )
{
return( ret );
}
break;
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
case MBEDTLS_TLS_EXT_ENCRYPT_THEN_MAC:
MBEDTLS_SSL_DEBUG_MSG( 3, ( "found encrypt_then_mac extension" ) );
if( ( ret = ssl_parse_encrypt_then_mac_ext( ssl,
ext + 4, ext_size ) ) != 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" ) );
if( ( ret = ssl_parse_extended_ms_ext( ssl,
ext + 4, ext_size ) ) != 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" ) );
if( ( ret = ssl_parse_session_ticket_ext( ssl,
ext + 4, ext_size ) ) != 0 )
{
return( ret );
}
break;
#endif /* MBEDTLS_SSL_SESSION_TICKETS */
#if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \
defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
case MBEDTLS_TLS_EXT_SUPPORTED_POINT_FORMATS:
MBEDTLS_SSL_DEBUG_MSG( 3,
( "found supported_point_formats extension" ) );
if( ( ret = ssl_parse_supported_point_formats_ext( ssl,
ext + 4, ext_size ) ) != 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" ) );
if( ( ret = ssl_parse_ecjpake_kkpp( ssl,
ext + 4, ext_size ) ) != 0 )
{
return( ret );
}
break;
#endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
#if defined(MBEDTLS_SSL_ALPN)
case MBEDTLS_TLS_EXT_ALPN:
MBEDTLS_SSL_DEBUG_MSG( 3, ( "found alpn extension" ) );
if( ( ret = ssl_parse_alpn_ext( ssl, ext + 4, ext_size ) ) != 0 )
return( ret );
break;
#endif /* MBEDTLS_SSL_ALPN */
#if defined(MBEDTLS_SSL_DTLS_SRTP)
case MBEDTLS_TLS_EXT_USE_SRTP:
MBEDTLS_SSL_DEBUG_MSG( 3, ( "found use_srtp extension" ) );
if( ( ret = ssl_parse_use_srtp_ext( ssl, ext + 4, ext_size ) ) != 0 )
return( ret );
break;
#endif /* MBEDTLS_SSL_DTLS_SRTP */
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 server hello message" ) );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
}
/*
* 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" ) );
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_SERVER_HELLO );
}
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse server hello" ) );
return( 0 );
}
#if defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED) || \
defined(MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED)
static int ssl_parse_server_dh_params( mbedtls_ssl_context *ssl,
unsigned char **p,
unsigned char *end )
{
int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE;
/*
* 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_read_params( &ssl->handshake->dhm_ctx,
p, end ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 2, ( "mbedtls_dhm_read_params" ), ret );
return( ret );
}
if( ssl->handshake->dhm_ctx.len * 8 < ssl->conf->dhm_min_bitlen )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "DHM prime too short: %d < %d",
ssl->handshake->dhm_ctx.len * 8,
ssl->conf->dhm_min_bitlen ) );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
}
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: 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_ECDHE_RSA_ENABLED) || \
defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) || \
defined(MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED) || \
defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \
defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)
static int ssl_check_server_ecdh_params( const mbedtls_ssl_context *ssl )
{
const mbedtls_ecp_curve_info *curve_info;
mbedtls_ecp_group_id grp_id;
#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
grp_id = ssl->handshake->ecdh_ctx.grp.id;
#else
grp_id = ssl->handshake->ecdh_ctx.grp_id;
#endif
curve_info = mbedtls_ecp_curve_info_from_grp_id( grp_id );
if( curve_info == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
MBEDTLS_SSL_DEBUG_MSG( 2, ( "ECDH curve: %s", curve_info->name ) );
#if defined(MBEDTLS_ECP_C)
if( mbedtls_ssl_check_curve( ssl, grp_id ) != 0 )
#else
if( ssl->handshake->ecdh_ctx.grp.nbits < 163 ||
ssl->handshake->ecdh_ctx.grp.nbits > 521 )
#endif
return( -1 );
MBEDTLS_SSL_DEBUG_ECDH( 3, &ssl->handshake->ecdh_ctx,
MBEDTLS_DEBUG_ECDH_QP );
return( 0 );
}
#endif /* MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED ||
MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED ||
MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED ||
MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED ||
MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED */
#if defined(MBEDTLS_USE_PSA_CRYPTO) && \
( defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \
defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) )
static int ssl_parse_server_ecdh_params_psa( mbedtls_ssl_context *ssl,
unsigned char **p,
unsigned char *end )
{
uint16_t tls_id;
size_t ecdh_bits = 0;
uint8_t ecpoint_len;
mbedtls_ssl_handshake_params *handshake = ssl->handshake;
/*
* Parse ECC group
*/