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/*
* 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 */
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_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->f_psk == NULL &&
( ssl->conf->psk == NULL || ssl->conf->psk_identity == NULL ||
ssl->conf->psk_identity_len == 0 || ssl->conf->psk_len == 0 ) )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "ciphersuite mismatch: no pre-shared key" ) );
return( 0 );
}
#endif
#if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \
defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)
/* If the ciphersuite requires signing, check whether
* a suitable hash algorithm is present. */
if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 )
{
sig_type = mbedtls_ssl_get_ciphersuite_sig_alg( suite_info );
if( sig_type != MBEDTLS_PK_NONE &&
mbedtls_ssl_sig_hash_set_find( &ssl->handshake->hash_algs, sig_type ) == MBEDTLS_MD_NONE )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "ciphersuite mismatch: no suitable hash algorithm "
"for signature algorithm %d", sig_type ) );
return( 0 );
}
}
#endif /* MBEDTLS_SSL_PROTO_TLS1_2 &&
MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED */
#if defined(MBEDTLS_X509_CRT_PARSE_C)
/*
* Final check: if ciphersuite requires us to have a
* certificate/key of a particular type:
* - select the appropriate certificate if we have one, or
* - try the next ciphersuite if we don't
* This must be done last since we modify the key_cert list.
*/
if( ssl_pick_cert( ssl, suite_info ) != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "ciphersuite mismatch: "
"no suitable certificate" ) );
return( 0 );
}
#endif
*ciphersuite_info = suite_info;
return( 0 );
}
#if defined(MBEDTLS_SSL_SRV_SUPPORT_SSLV2_CLIENT_HELLO)
static int ssl_parse_client_hello_v2( mbedtls_ssl_context *ssl )
{
int ret, got_common_suite;
unsigned int i, j;
size_t n;
unsigned int ciph_len, sess_len, chal_len;
unsigned char *buf, *p;
const int *ciphersuites;
const mbedtls_ssl_ciphersuite_t *ciphersuite_info;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse client hello v2" ) );
#if defined(MBEDTLS_SSL_RENEGOTIATION)
if( ssl->renego_status != MBEDTLS_SSL_INITIAL_HANDSHAKE )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "client hello v2 illegal for renegotiation" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
#endif /* MBEDTLS_SSL_RENEGOTIATION */
buf = ssl->in_hdr;
MBEDTLS_SSL_DEBUG_BUF( 4, "record header", buf, 5 );
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello v2, message type: %d",
buf[2] ) );
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello v2, message len.: %d",
( ( buf[0] & 0x7F ) << 8 ) | buf[1] ) );
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello v2, max. version: [%d:%d]",
buf[3], buf[4] ) );
/*
* SSLv2 Client Hello
*
* Record layer:
* 0 . 1 message length
*
* SSL layer:
* 2 . 2 message type
* 3 . 4 protocol version
*/
if( buf[2] != MBEDTLS_SSL_HS_CLIENT_HELLO ||
buf[3] != MBEDTLS_SSL_MAJOR_VERSION_3 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
n = ( ( buf[0] << 8 ) | buf[1] ) & 0x7FFF;
if( n < 17 || n > 512 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
ssl->major_ver = MBEDTLS_SSL_MAJOR_VERSION_3;
ssl->minor_ver = ( buf[4] <= ssl->conf->max_minor_ver )
? buf[4] : ssl->conf->max_minor_ver;
if( ssl->minor_ver < ssl->conf->min_minor_ver )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "client only supports ssl smaller than minimum"
" [%d:%d] < [%d:%d]",
ssl->major_ver, ssl->minor_ver,
ssl->conf->min_major_ver, ssl->conf->min_minor_ver ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_PROTOCOL_VERSION );
return( MBEDTLS_ERR_SSL_BAD_HS_PROTOCOL_VERSION );
}
ssl->handshake->max_major_ver = buf[3];
ssl->handshake->max_minor_ver = buf[4];
if( ( ret = mbedtls_ssl_fetch_input( ssl, 2 + n ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_fetch_input", ret );
return( ret );
}
ssl->handshake->update_checksum( ssl, buf + 2, n );
buf = ssl->in_msg;
n = ssl->in_left - 5;
/*
* 0 . 1 ciphersuitelist length
* 2 . 3 session id length
* 4 . 5 challenge length
* 6 . .. ciphersuitelist
* .. . .. session id
* .. . .. challenge
*/
MBEDTLS_SSL_DEBUG_BUF( 4, "record contents", buf, n );
ciph_len = ( buf[0] << 8 ) | buf[1];
sess_len = ( buf[2] << 8 ) | buf[3];
chal_len = ( buf[4] << 8 ) | buf[5];
MBEDTLS_SSL_DEBUG_MSG( 3, ( "ciph_len: %d, sess_len: %d, chal_len: %d",
ciph_len, sess_len, chal_len ) );
/*
* Make sure each parameter length is valid
*/
if( ciph_len < 3 || ( ciph_len % 3 ) != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
if( sess_len > 32 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
if( chal_len < 8 || chal_len > 32 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
if( n != 6 + ciph_len + sess_len + chal_len )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, ciphersuitelist",
buf + 6, ciph_len );
MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, session id",
buf + 6 + ciph_len, sess_len );
MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, challenge",
buf + 6 + ciph_len + sess_len, chal_len );
p = buf + 6 + ciph_len;
ssl->session_negotiate->id_len = sess_len;
memset( ssl->session_negotiate->id, 0,
sizeof( ssl->session_negotiate->id ) );
memcpy( ssl->session_negotiate->id, p, ssl->session_negotiate->id_len );
p += sess_len;
memset( ssl->handshake->randbytes, 0, 64 );
memcpy( ssl->handshake->randbytes + 32 - chal_len, p, chal_len );
/*
* Check for TLS_EMPTY_RENEGOTIATION_INFO_SCSV
*/
for( i = 0, p = buf + 6; i < ciph_len; i += 3, p += 3 )
{
if( p[0] == 0 && p[1] == 0 && p[2] == MBEDTLS_SSL_EMPTY_RENEGOTIATION_INFO )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "received TLS_EMPTY_RENEGOTIATION_INFO " ) );
#if defined(MBEDTLS_SSL_RENEGOTIATION)
if( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "received RENEGOTIATION SCSV "
"during renegotiation" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
#endif /* MBEDTLS_SSL_RENEGOTIATION */
ssl->secure_renegotiation = MBEDTLS_SSL_SECURE_RENEGOTIATION;
break;
}
}
#if defined(MBEDTLS_SSL_FALLBACK_SCSV)
for( i = 0, p = buf + 6; i < ciph_len; i += 3, p += 3 )
{
if( p[0] == 0 &&
p[1] == (unsigned char)( ( MBEDTLS_SSL_FALLBACK_SCSV_VALUE >> 8 ) & 0xff ) &&
p[2] == (unsigned char)( ( MBEDTLS_SSL_FALLBACK_SCSV_VALUE ) & 0xff ) )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "received FALLBACK_SCSV" ) );
if( ssl->minor_ver < ssl->conf->max_minor_ver )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "inapropriate fallback" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_INAPROPRIATE_FALLBACK );
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
break;
}
}
#endif /* MBEDTLS_SSL_FALLBACK_SCSV */
got_common_suite = 0;
ciphersuites = ssl->conf->ciphersuite_list[ssl->minor_ver];
ciphersuite_info = NULL;
#if defined(MBEDTLS_SSL_SRV_RESPECT_CLIENT_PREFERENCE)
for( j = 0, p = buf + 6; j < ciph_len; j += 3, p += 3 )
for( i = 0; ciphersuites[i] != 0; i++ )
#else
for( i = 0; ciphersuites[i] != 0; i++ )
for( j = 0, p = buf + 6; j < ciph_len; j += 3, p += 3 )
#endif
{
if( p[0] != 0 ||
p[1] != ( ( ciphersuites[i] >> 8 ) & 0xFF ) ||
p[2] != ( ( ciphersuites[i] ) & 0xFF ) )
continue;
got_common_suite = 1;
if( ( ret = ssl_ciphersuite_match( ssl, ciphersuites[i],
&ciphersuite_info ) ) != 0 )
return( ret );
if( ciphersuite_info != NULL )
goto have_ciphersuite_v2;
}
if( got_common_suite )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "got ciphersuites in common, "
"but none of them usable" ) );
return( MBEDTLS_ERR_SSL_NO_USABLE_CIPHERSUITE );
}
else
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "got no ciphersuites in common" ) );
return( MBEDTLS_ERR_SSL_NO_CIPHER_CHOSEN );
}
have_ciphersuite_v2:
MBEDTLS_SSL_DEBUG_MSG( 2, ( "selected ciphersuite: %s", ciphersuite_info->name ) );
ssl->session_negotiate->ciphersuite = ciphersuites[i];
ssl->transform_negotiate->ciphersuite_info = ciphersuite_info;
/*
* SSLv2 Client Hello relevant renegotiation security checks
*/
if( ssl->secure_renegotiation == MBEDTLS_SSL_LEGACY_RENEGOTIATION &&
ssl->conf->allow_legacy_renegotiation == MBEDTLS_SSL_LEGACY_BREAK_HANDSHAKE )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "legacy renegotiation, breaking off handshake" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
ssl->in_left = 0;
ssl->state++;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse client hello v2" ) );
return( 0 );
}
#endif /* MBEDTLS_SSL_SRV_SUPPORT_SSLV2_CLIENT_HELLO */
/* This function doesn't alert on errors that happen early during
ClientHello parsing because they might indicate that the client is
not talking SSL/TLS at all and would not understand our alert. */
static int ssl_parse_client_hello( mbedtls_ssl_context *ssl )
{
int ret, got_common_suite;
size_t i, j;
size_t ciph_offset, comp_offset, ext_offset;
size_t msg_len, ciph_len, sess_len, comp_len, ext_len;
#if defined(MBEDTLS_SSL_PROTO_DTLS)
size_t cookie_offset, cookie_len;
#endif
unsigned char *buf, *p, *ext;
#if defined(MBEDTLS_SSL_RENEGOTIATION)
int renegotiation_info_seen = 0;
#endif
int handshake_failure = 0;
const int *ciphersuites;
const mbedtls_ssl_ciphersuite_t *ciphersuite_info;
int major, minor;
/* If there is no signature-algorithm extension present,
* we need to fall back to the default values for allowed
* signature-hash pairs. */
#if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \
defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)
int sig_hash_alg_ext_present = 0;
#endif /* MBEDTLS_SSL_PROTO_TLS1_2 &&
MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED */
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse client hello" ) );
#if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY)
read_record_header:
#endif
/*
* If renegotiating, then the input was read with mbedtls_ssl_read_record(),
* otherwise read it ourselves manually in order to support SSLv2
* ClientHello, which doesn't use the same record layer format.
*/
#if defined(MBEDTLS_SSL_RENEGOTIATION)
if( ssl->renego_status == MBEDTLS_SSL_INITIAL_HANDSHAKE )
#endif
{
if( ( ret = mbedtls_ssl_fetch_input( ssl, 5 ) ) != 0 )
{
/* No alert on a read error. */
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_fetch_input", ret );
return( ret );
}
}
buf = ssl->in_hdr;
#if defined(MBEDTLS_SSL_SRV_SUPPORT_SSLV2_CLIENT_HELLO)
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_STREAM )
#endif
if( ( buf[0] & 0x80 ) != 0 )
return( ssl_parse_client_hello_v2( ssl ) );
#endif
MBEDTLS_SSL_DEBUG_BUF( 4, "record header", buf, mbedtls_ssl_hdr_len( ssl ) );
/*
* SSLv3/TLS Client Hello
*
* Record layer:
* 0 . 0 message type
* 1 . 2 protocol version
* 3 . 11 DTLS: epoch + record sequence number
* 3 . 4 message length
*/
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello v3, message type: %d",
buf[0] ) );
if( buf[0] != MBEDTLS_SSL_MSG_HANDSHAKE )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello v3, message len.: %d",
( ssl->in_len[0] << 8 ) | ssl->in_len[1] ) );
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello v3, protocol version: [%d:%d]",
buf[1], buf[2] ) );
mbedtls_ssl_read_version( &major, &minor, ssl->conf->transport, buf + 1 );
/* According to RFC 5246 Appendix E.1, the version here is typically
* "{03,00}, the lowest version number supported by the client, [or] the
* value of ClientHello.client_version", so the only meaningful check here
* is the major version shouldn't be less than 3 */
if( major < MBEDTLS_SSL_MAJOR_VERSION_3 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
/* For DTLS if this is the initial handshake, remember the client sequence
* number to use it in our next message (RFC 6347 4.2.1) */
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM
#if defined(MBEDTLS_SSL_RENEGOTIATION)
&& ssl->renego_status == MBEDTLS_SSL_INITIAL_HANDSHAKE
#endif
)
{
/* Epoch should be 0 for initial handshakes */
if( ssl->in_ctr[0] != 0 || ssl->in_ctr[1] != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
memcpy( ssl->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_hdr_len( ssl ) + msg_len ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_fetch_input", ret );
return( ret );
}
/* Done reading this record, get ready for the next one */
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
ssl->next_record_offset = msg_len + mbedtls_ssl_hdr_len( ssl );
else
#endif
ssl->in_left = 0;
}
buf = ssl->in_msg;
MBEDTLS_SSL_DEBUG_BUF( 4, "record contents", buf, msg_len );
ssl->handshake->update_checksum( ssl, buf, msg_len );
/*
* Handshake layer:
* 0 . 0 handshake type
* 1 . 3 handshake length
* 4 . 5 DTLS only: message seqence number
* 6 . 8 DTLS only: fragment offset
* 9 . 11 DTLS only: fragment length
*/
if( msg_len < mbedtls_ssl_hs_hdr_len( ssl ) )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello v3, handshake type: %d", buf[0] ) );
if( buf[0] != MBEDTLS_SSL_HS_CLIENT_HELLO )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello v3, handshake len.: %d",
( buf[1] << 16 ) | ( buf[2] << 8 ) | buf[3] ) );
/* We don't support fragmentation of ClientHello (yet?) */
if( buf[1] != 0 ||
msg_len != mbedtls_ssl_hs_hdr_len( ssl ) + ( ( buf[2] << 8 ) | buf[3] ) )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
{
/*
* Copy the client's handshake message_seq on initial handshakes,
* check sequence number on renego.
*/
#if defined(MBEDTLS_SSL_RENEGOTIATION)
if( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS )
{
/* This couldn't be done in ssl_prepare_handshake_record() */
unsigned int cli_msg_seq = ( ssl->in_msg[4] << 8 ) |
ssl->in_msg[5];
if( cli_msg_seq != ssl->handshake->in_msg_seq )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message_seq: "
"%d (expected %d)", cli_msg_seq,
ssl->handshake->in_msg_seq ) );
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
ssl->handshake->in_msg_seq++;
}
else
#endif
{
unsigned int cli_msg_seq = ( ssl->in_msg[4] << 8 ) |
ssl->in_msg[5];
ssl->handshake->out_msg_seq = cli_msg_seq;
ssl->handshake->in_msg_seq = cli_msg_seq + 1;
}
/*
* For now we don't support fragmentation, so make sure
* fragment_offset == 0 and fragment_length == length
*/
if( ssl->in_msg[6] != 0 || ssl->in_msg[7] != 0 || ssl->in_msg[8] != 0 ||
memcmp( ssl->in_msg + 1, ssl->in_msg + 9, 3 ) != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "ClientHello fragmentation not supported" ) );
return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE );
}
}
#endif /* MBEDTLS_SSL_PROTO_DTLS */
buf += mbedtls_ssl_hs_hdr_len( ssl );
msg_len -= mbedtls_ssl_hs_hdr_len( ssl );
/*
* ClientHello layer:
* 0 . 1 protocol version
* 2 . 33 random bytes (starting with 4 bytes of Unix time)
* 34 . 35 session id length (1 byte)
* 35 . 34+x session id
* 35+x . 35+x DTLS only: cookie length (1 byte)
* 36+x . .. DTLS only: cookie
* .. . .. ciphersuite list length (2 bytes)
* .. . .. ciphersuite list
* .. . .. compression alg. list length (1 byte)
* .. . .. compression alg. list
* .. . .. extensions length (2 bytes, optional)
* .. . .. extensions (optional)
*/
/*
* Minimal length (with everything empty and extensions ommitted) is
* 2 + 32 + 1 + 2 + 1 = 38 bytes. Check that first, so that we can
* read at least up to session id length without worrying.
*/
if( msg_len < 38 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
/*
* Check and save the protocol version
*/
MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, version", buf, 2 );
mbedtls_ssl_read_version( &ssl->major_ver, &ssl->minor_ver,
ssl->conf->transport, buf );
ssl->handshake->max_major_ver = ssl->major_ver;
ssl->handshake->max_minor_ver = ssl->minor_ver;
if( ssl->major_ver < ssl->conf->min_major_ver ||
ssl->minor_ver < ssl->conf->min_minor_ver )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "client only supports ssl smaller than minimum"
" [%d:%d] < [%d:%d]",
ssl->major_ver, ssl->minor_ver,
ssl->conf->min_major_ver, ssl->conf->min_minor_ver ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_PROTOCOL_VERSION );
return( MBEDTLS_ERR_SSL_BAD_HS_PROTOCOL_VERSION );
}
if( ssl->major_ver > ssl->conf->max_major_ver )
{
ssl->major_ver = ssl->conf->max_major_ver;
ssl->minor_ver = ssl->conf->max_minor_ver;
}
else if( ssl->minor_ver > ssl->conf->max_minor_ver )
ssl->minor_ver = ssl->conf->max_minor_ver;
/*
* Save client random (inc. Unix time)
*/
MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, random bytes", buf + 2, 32 );
memcpy( ssl->handshake->randbytes, buf + 2, 32 );
/*
* Check the session ID length and save session ID
*/
sess_len = buf[34];
if( sess_len > sizeof( ssl->session_negotiate->id ) ||
sess_len + 34 + 2 > msg_len ) /* 2 for cipherlist length field */
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, session id", buf + 35, sess_len );
ssl->session_negotiate->id_len = sess_len;
memset( ssl->session_negotiate->id, 0,
sizeof( ssl->session_negotiate->id ) );
memcpy( ssl->session_negotiate->id, buf + 35,
ssl->session_negotiate->id_len );
/*
* Check the cookie length and content
*/
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
{
cookie_offset = 35 + sess_len;
cookie_len = buf[cookie_offset];
if( cookie_offset + 1 + cookie_len + 2 > msg_len )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_PROTOCOL_VERSION );
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, cookie",
buf + cookie_offset + 1, cookie_len );
#if defined(MBEDTLS_SSL_DTLS_HELLO_VERIFY)
if( ssl->conf->f_cookie_check != NULL
#if defined(MBEDTLS_SSL_RENEGOTIATION)
&& ssl->renego_status == MBEDTLS_SSL_INITIAL_HANDSHAKE
#endif
)
{
if( ssl->conf->f_cookie_check( ssl->conf->p_cookie,
buf + cookie_offset + 1, cookie_len,
ssl->cli_id, ssl->cli_id_len ) != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "cookie verification failed" ) );
ssl->handshake->verify_cookie_len = 1;
}
else
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "cookie verification passed" ) );
ssl->handshake->verify_cookie_len = 0;
}
}
else
#endif /* MBEDTLS_SSL_DTLS_HELLO_VERIFY */
{
/* We know we didn't send a cookie, so it should be empty */
if( cookie_len != 0 )
{
/* This may be an attacker's probe, so don't send an alert */
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
MBEDTLS_SSL_DEBUG_MSG( 2, ( "cookie verification skipped" ) );
}
/*
* Check the ciphersuitelist length (will be parsed later)
*/
ciph_offset = cookie_offset + 1 + cookie_len;
}
else
#endif /* MBEDTLS_SSL_PROTO_DTLS */
ciph_offset = 35 + sess_len;
ciph_len = ( buf[ciph_offset + 0] << 8 )
| ( buf[ciph_offset + 1] );
if( ciph_len < 2 ||
ciph_len + 2 + ciph_offset + 1 > msg_len || /* 1 for comp. alg. len */
( ciph_len % 2 ) != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, ciphersuitelist",
buf + ciph_offset + 2, ciph_len );
/*
* Check the compression algorithms length and pick one
*/
comp_offset = ciph_offset + 2 + ciph_len;
comp_len = buf[comp_offset];
if( comp_len < 1 ||
comp_len > 16 ||
comp_len + comp_offset + 1 > msg_len )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, compression",
buf + comp_offset + 1, comp_len );
ssl->session_negotiate->compression = MBEDTLS_SSL_COMPRESS_NULL;
#if defined(MBEDTLS_ZLIB_SUPPORT)
for( i = 0; i < comp_len; ++i )
{
if( buf[comp_offset + 1 + i] == MBEDTLS_SSL_COMPRESS_DEFLATE )
{
ssl->session_negotiate->compression = MBEDTLS_SSL_COMPRESS_DEFLATE;
break;
}
}
#endif
/* See comments in ssl_write_client_hello() */
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
ssl->session_negotiate->compression = MBEDTLS_SSL_COMPRESS_NULL;
#endif
/* Do not parse the extensions if the protocol is SSLv3 */
#if defined(MBEDTLS_SSL_PROTO_SSL3)
if( ( ssl->major_ver != 3 ) || ( ssl->minor_ver != 0 ) )
{
#endif
/*
* Check the extension length
*/
ext_offset = comp_offset + 1 + comp_len;
if( msg_len > ext_offset )
{
if( msg_len < ext_offset + 2 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
ext_len = ( buf[ext_offset + 0] << 8 )
| ( buf[ext_offset + 1] );
if( ( ext_len > 0 && ext_len < 4 ) ||
msg_len != ext_offset + 2 + ext_len )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
}
else
ext_len = 0;
ext = buf + ext_offset + 2;
MBEDTLS_SSL_DEBUG_BUF( 3, "client hello extensions", ext, ext_len );
while( ext_len != 0 )
{
unsigned int ext_id;
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_ENCRYPT_THEN_MAC)
case MBEDTLS_TLS_EXT_ENCRYPT_THEN_MAC:
MBEDTLS_SSL_DEBUG_MSG( 3, ( "found encrypt then mac extension" ) );
ret = ssl_parse_encrypt_then_mac_ext( ssl, ext + 4, ext_size );
if( ret != 0 )
return( ret );
break;
#endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */
#if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
case MBEDTLS_TLS_EXT_EXTENDED_MASTER_SECRET:
MBEDTLS_SSL_DEBUG_MSG( 3, ( "found extended master secret extension" ) );
ret = ssl_parse_extended_ms_ext( ssl, ext + 4, ext_size );
if( ret != 0 )
return( ret );
break;
#endif /* MBEDTLS_SSL_EXTENDED_MASTER_SECRET */
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
case MBEDTLS_TLS_EXT_SESSION_TICKET:
MBEDTLS_SSL_DEBUG_MSG( 3, ( "found session ticket extension" ) );
ret = ssl_parse_session_ticket_ext( ssl, ext + 4, ext_size );
if( ret != 0 )
return( ret );
break;
#endif /* MBEDTLS_SSL_SESSION_TICKETS */
#if defined(MBEDTLS_SSL_ALPN)
case MBEDTLS_TLS_EXT_ALPN:
MBEDTLS_SSL_DEBUG_MSG( 3, ( "found alpn extension" ) );
ret = ssl_parse_alpn_ext( ssl, ext + 4, ext_size );
if( ret != 0 )
return( ret );
break;
#endif /* MBEDTLS_SSL_SESSION_TICKETS */
default:
MBEDTLS_SSL_DEBUG_MSG( 3, ( "unknown extension found: %d (ignoring)",
ext_id ) );
}
ext_len -= 4 + ext_size;
ext += 4 + ext_size;
if( ext_len > 0 && ext_len < 4 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
}
#if defined(MBEDTLS_SSL_PROTO_SSL3)
}
#endif
#if defined(MBEDTLS_SSL_FALLBACK_SCSV)
for( i = 0, p = buf + ciph_offset + 2; i < ciph_len; i += 2, p += 2 )
{
if( p[0] == (unsigned char)( ( MBEDTLS_SSL_FALLBACK_SCSV_VALUE >> 8 ) & 0xff ) &&
p[1] == (unsigned char)( ( MBEDTLS_SSL_FALLBACK_SCSV_VALUE ) & 0xff ) )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "received FALLBACK_SCSV" ) );
if( ssl->minor_ver < ssl->conf->max_minor_ver )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "inapropriate fallback" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_INAPROPRIATE_FALLBACK );
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
break;
}
}
#endif /* MBEDTLS_SSL_FALLBACK_SCSV */
#if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \
defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)
/*
* Try to fall back to default hash SHA1 if the client
* hasn't provided any preferred signature-hash combinations.
*/
if( sig_hash_alg_ext_present == 0 )
{
mbedtls_md_type_t md_default = MBEDTLS_MD_SHA1;
if( mbedtls_ssl_check_sig_hash( ssl, md_default ) != 0 )
md_default = MBEDTLS_MD_NONE;
mbedtls_ssl_sig_hash_set_const_hash( &ssl->handshake->hash_algs, md_default );
}
#endif /* MBEDTLS_SSL_PROTO_TLS1_2 &&
MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED */
/*
* Check for TLS_EMPTY_RENEGOTIATION_INFO_SCSV
*/
for( i = 0, p = buf + ciph_offset + 2; i < ciph_len; i += 2, p += 2 )
{
if( p[0] == 0 && p[1] == MBEDTLS_SSL_EMPTY_RENEGOTIATION_INFO )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "received TLS_EMPTY_RENEGOTIATION_INFO " ) );
#if defined(MBEDTLS_SSL_RENEGOTIATION)
if( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "received RENEGOTIATION SCSV "
"during renegotiation" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
#endif
ssl->secure_renegotiation = MBEDTLS_SSL_SECURE_RENEGOTIATION;
break;
}
}
/*
* Renegotiation security checks
*/
if( ssl->secure_renegotiation != MBEDTLS_SSL_SECURE_RENEGOTIATION &&
ssl->conf->allow_legacy_renegotiation == MBEDTLS_SSL_LEGACY_BREAK_HANDSHAKE )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "legacy renegotiation, breaking off handshake" ) );
handshake_failure = 1;
}
#if defined(MBEDTLS_SSL_RENEGOTIATION)
else if( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS &&
ssl->secure_renegotiation == MBEDTLS_SSL_SECURE_RENEGOTIATION &&
renegotiation_info_seen == 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "renegotiation_info extension missing (secure)" ) );
handshake_failure = 1;
}
else if( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS &&
ssl->secure_renegotiation == MBEDTLS_SSL_LEGACY_RENEGOTIATION &&
ssl->conf->allow_legacy_renegotiation == MBEDTLS_SSL_LEGACY_NO_RENEGOTIATION )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "legacy renegotiation not allowed" ) );
handshake_failure = 1;
}
else if( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS &&
ssl->secure_renegotiation == MBEDTLS_SSL_LEGACY_RENEGOTIATION &&
renegotiation_info_seen == 1 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "renegotiation_info extension present (legacy)" ) );
handshake_failure = 1;
}
#endif /* MBEDTLS_SSL_RENEGOTIATION */
if( handshake_failure == 1 )
{
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
/*
* Search for a matching ciphersuite
* (At the end because we need information from the EC-based extensions
* and certificate from the SNI callback triggered by the SNI extension.)
*/
got_common_suite = 0;
ciphersuites = ssl->conf->ciphersuite_list[ssl->minor_ver];
ciphersuite_info = NULL;
#if defined(MBEDTLS_SSL_SRV_RESPECT_CLIENT_PREFERENCE)
for( j = 0, p = buf + ciph_offset + 2; j < ciph_len; j += 2, p += 2 )
for( i = 0; ciphersuites[i] != 0; i++ )
#else
for( i = 0; ciphersuites[i] != 0; i++ )
for( j = 0, p = buf + ciph_offset + 2; j < ciph_len; j += 2, p += 2 )
#endif
{
if( p[0] != ( ( ciphersuites[i] >> 8 ) & 0xFF ) ||
p[1] != ( ( ciphersuites[i] ) & 0xFF ) )
continue;
got_common_suite = 1;
if( ( ret = ssl_ciphersuite_match( ssl, ciphersuites[i],
&ciphersuite_info ) ) != 0 )
return( ret );
if( ciphersuite_info != NULL )
goto have_ciphersuite;
}
if( got_common_suite )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "got ciphersuites in common, "
"but none of them usable" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_NO_USABLE_CIPHERSUITE );
}
else
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "got no ciphersuites in common" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_NO_CIPHER_CHOSEN );
}
have_ciphersuite:
MBEDTLS_SSL_DEBUG_MSG( 2, ( "selected ciphersuite: %s", ciphersuite_info->name ) );
ssl->session_negotiate->ciphersuite = ciphersuites[i];
ssl->transform_negotiate->ciphersuite_info = ciphersuite_info;
ssl->state++;
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
mbedtls_ssl_recv_flight_completed( ssl );
#endif
/* Debugging-only output for testsuite */
#if defined(MBEDTLS_DEBUG_C) && \
defined(MBEDTLS_SSL_PROTO_TLS1_2) && \
defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)
if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 )
{
mbedtls_pk_type_t sig_alg = mbedtls_ssl_get_ciphersuite_sig_alg( ciphersuite_info );
if( sig_alg != MBEDTLS_PK_NONE )
{
mbedtls_md_type_t md_alg = mbedtls_ssl_sig_hash_set_find( &ssl->handshake->hash_algs,
sig_alg );
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello v3, signature_algorithm ext: %d",
mbedtls_ssl_hash_from_md_alg( md_alg ) ) );
}
else
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "no hash algorithm for signature algorithm "
"%d - should not happen", sig_alg ) );
}
}
#endif
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse client hello" ) );
return( 0 );
}
#if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
static void ssl_write_truncated_hmac_ext( mbedtls_ssl_context *ssl,
unsigned char *buf,
size_t *olen )
{
unsigned char *p = buf;
if( ssl->session_negotiate->trunc_hmac == MBEDTLS_SSL_TRUNC_HMAC_DISABLED )
{
*olen = 0;
return;
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, adding truncated hmac extension" ) );
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_TRUNCATED_HMAC >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_TRUNCATED_HMAC ) & 0xFF );
*p++ = 0x00;
*p++ = 0x00;
*olen = 4;
}
#endif /* MBEDTLS_SSL_TRUNCATED_HMAC */
#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
static void ssl_write_encrypt_then_mac_ext( mbedtls_ssl_context *ssl,
unsigned char *buf,
size_t *olen )
{
unsigned char *p = buf;
const mbedtls_ssl_ciphersuite_t *suite = NULL;
const mbedtls_cipher_info_t *cipher = NULL;
if( ssl->session_negotiate->encrypt_then_mac == MBEDTLS_SSL_ETM_DISABLED ||
ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 )
{
*olen = 0;
return;
}
/*
* RFC 7366: "If a server receives an encrypt-then-MAC request extension
* from a client and then selects a stream or Authenticated Encryption
* with Associated Data (AEAD) ciphersuite, it MUST NOT send an
* encrypt-then-MAC response extension back to the client."
*/
if( ( suite = mbedtls_ssl_ciphersuite_from_id(
ssl->session_negotiate->ciphersuite ) ) == NULL ||
( cipher = mbedtls_cipher_info_from_type( suite->cipher ) ) == NULL ||
cipher->mode != MBEDTLS_MODE_CBC )
{
*olen = 0;
return;
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, adding encrypt then mac extension" ) );
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_ENCRYPT_THEN_MAC >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_ENCRYPT_THEN_MAC ) & 0xFF );
*p++ = 0x00;
*p++ = 0x00;
*olen = 4;
}
#endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */
#if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
static void ssl_write_extended_ms_ext( mbedtls_ssl_context *ssl,
unsigned char *buf,
size_t *olen )
{
unsigned char *p = buf;
if( ssl->handshake->extended_ms == MBEDTLS_SSL_EXTENDED_MS_DISABLED ||
ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 )
{
*olen = 0;
return;
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, adding extended master secret "
"extension" ) );
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_EXTENDED_MASTER_SECRET >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_EXTENDED_MASTER_SECRET ) & 0xFF );
*p++ = 0x00;
*p++ = 0x00;
*olen = 4;
}
#endif /* MBEDTLS_SSL_EXTENDED_MASTER_SECRET */
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
static void ssl_write_session_ticket_ext( mbedtls_ssl_context *ssl,
unsigned char *buf,
size_t *olen )
{
unsigned char *p = buf;
if( ssl->handshake->new_session_ticket == 0 )
{
*olen = 0;
return;
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, adding session ticket extension" ) );
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SESSION_TICKET >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SESSION_TICKET ) & 0xFF );
*p++ = 0x00;
*p++ = 0x00;
*olen = 4;
}
#endif /* MBEDTLS_SSL_SESSION_TICKETS */
static void ssl_write_renegotiation_ext( mbedtls_ssl_context *ssl,
unsigned char *buf,
size_t *olen )
{
unsigned char *p = buf;
if( ssl->secure_renegotiation != MBEDTLS_SSL_SECURE_RENEGOTIATION )
{
*olen = 0;
return;
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, secure renegotiation extension" ) );
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_RENEGOTIATION_INFO >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_RENEGOTIATION_INFO ) & 0xFF );
#if defined(MBEDTLS_SSL_RENEGOTIATION)
if( ssl->renego_status != MBEDTLS_SSL_INITIAL_HANDSHAKE )
{
*p++ = 0x00;
*p++ = ( ssl->verify_data_len * 2 + 1 ) & 0xFF;
*p++ = ssl->verify_data_len * 2 & 0xFF;
memcpy( p, ssl->peer_verify_data, ssl->verify_data_len );
p += ssl->verify_data_len;
memcpy( p, ssl->own_verify_data, ssl->verify_data_len );
p += ssl->verify_data_len;
}
else
#endif /* MBEDTLS_SSL_RENEGOTIATION */
{
*p++ = 0x00;
*p++ = 0x01;
*p++ = 0x00;
}
*olen = p - buf;
}
#if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
static void ssl_write_max_fragment_length_ext( mbedtls_ssl_context *ssl,
unsigned char *buf,
size_t *olen )
{
unsigned char *p = buf;
if( ssl->session_negotiate->mfl_code == MBEDTLS_SSL_MAX_FRAG_LEN_NONE )
{
*olen = 0;
return;
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, max_fragment_length extension" ) );
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_MAX_FRAGMENT_LENGTH >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_MAX_FRAGMENT_LENGTH ) & 0xFF );
*p++ = 0x00;
*p++ = 1;
*p++ = ssl->session_negotiate->mfl_code;
*olen = 5;
}
#endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */
#if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \
defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
static void ssl_write_supported_point_formats_ext( mbedtls_ssl_context *ssl,
unsigned char *buf,
size_t *olen )
{
unsigned char *p = buf;
((void) ssl);
if( ( ssl->handshake->cli_exts &
MBEDTLS_TLS_EXT_SUPPORTED_POINT_FORMATS_PRESENT ) == 0 )
{
*olen = 0;
return;
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, supported_point_formats extension" ) );
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SUPPORTED_POINT_FORMATS >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SUPPORTED_POINT_FORMATS ) & 0xFF );
*p++ = 0x00;
*p++ = 2;
*p++ = 1;
*p++ = MBEDTLS_ECP_PF_UNCOMPRESSED;
*olen = 6;
}
#endif /* MBEDTLS_ECDH_C || MBEDTLS_ECDSA_C || MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
#if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
static void ssl_write_ecjpake_kkpp_ext( mbedtls_ssl_context *ssl,
unsigned char *buf,
size_t *olen )
{
int ret;
unsigned char *p = buf;
const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN;
size_t kkpp_len;
*olen = 0;
/* Skip costly computation if not needed */
if( ssl->transform_negotiate->ciphersuite_info->key_exchange !=
MBEDTLS_KEY_EXCHANGE_ECJPAKE )
return;
MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, ecjpake kkpp extension" ) );
if( end - p < 4 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
return;
}
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_ECJPAKE_KKPP >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_ECJPAKE_KKPP ) & 0xFF );
ret = mbedtls_ecjpake_write_round_one( &ssl->handshake->ecjpake_ctx,
p + 2, end - p - 2, &kkpp_len,
ssl->conf->f_rng, ssl->conf->p_rng );
if( ret != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1 , "mbedtls_ecjpake_write_round_one", ret );
return;
}
*p++ = (unsigned char)( ( kkpp_len >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( kkpp_len ) & 0xFF );
*olen = kkpp_len + 4;
}
#endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
#if defined(MBEDTLS_SSL_ALPN )
static void ssl_write_alpn_ext( mbedtls_ssl_context *ssl,
unsigned char *buf, size_t *olen )
{
if( ssl->alpn_chosen == NULL )
{
*olen = 0;
return;
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, adding alpn extension" ) );
/*
* 0 . 1 ext identifier
* 2 . 3 ext length
* 4 . 5 protocol list length
* 6 . 6 protocol name length
* 7 . 7+n protocol name
*/
buf[0] = (unsigned char)( ( MBEDTLS_TLS_EXT_ALPN >> 8 ) & 0xFF );
buf[1] = (unsigned char)( ( MBEDTLS_TLS_EXT_ALPN ) & 0xFF );
*olen = 7 + strlen( ssl->alpn_chosen );
buf[2] = (unsigned char)( ( ( *olen - 4 ) >> 8 ) & 0xFF );
buf[3] = (unsigned char)( ( ( *olen - 4 ) ) & 0xFF );
buf[4] = (unsigned char)( ( ( *olen - 6 ) >> 8 ) & 0xFF );
buf[5] = (unsigned char)( ( ( *olen - 6 ) ) & 0xFF );
buf[6] = (unsigned char)( ( ( *olen - 7 ) ) & 0xFF );
memcpy( buf + 7, ssl->alpn_chosen, *olen - 7 );
}
#endif /* MBEDTLS_ECDH_C || MBEDTLS_ECDSA_C */
#if defined(MBEDTLS_SSL_DTLS_HELLO_VERIFY)
static int ssl_write_hello_verify_request( mbedtls_ssl_context *ssl )
{
int ret;
unsigned char *p = ssl->out_msg + 4;
unsigned char *cookie_len_byte;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write hello verify request" ) );
/*
* struct {
* ProtocolVersion server_version;
* opaque cookie<0..2^8-1>;
* } HelloVerifyRequest;
*/
/* The RFC is not clear on this point, but sending the actual negotiated
* version looks like the most interoperable thing to do. */
mbedtls_ssl_write_version( ssl->major_ver, ssl->minor_ver,
ssl->conf->transport, p );
MBEDTLS_SSL_DEBUG_BUF( 3, "server version", p, 2 );
p += 2;
/* If we get here, f_cookie_check is not null */
if( ssl->conf->f_cookie_write == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "inconsistent cookie callbacks" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
/* Skip length byte until we know the length */
cookie_len_byte = p++;
if( ( ret = ssl->conf->f_cookie_write( ssl->conf->p_cookie,
&p, ssl->out_buf + MBEDTLS_SSL_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_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_RSA_ENABLED) && \
!defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED) && \
!defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) && \
!defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) && \
!defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)&& \
!defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
static int ssl_write_certificate_request( mbedtls_ssl_context *ssl )