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mbedtls/library/ssl_cli.c
Paul Bakker a70366317d Improve interop by not writing ext_len in ClientHello / ServerHello when 0 
The RFC also indicates that without any extensions, we should write a
struct {} (empty) not an array of length zero.
2014-04-30 10:16:16 +02:00

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/*
* SSLv3/TLSv1 client-side functions
*
* Copyright (C) 2006-2014, Brainspark B.V.
*
* This file is part of PolarSSL (http://www.polarssl.org)
* Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
*
* All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "polarssl/config.h"
#if defined(POLARSSL_SSL_CLI_C)
#include "polarssl/debug.h"
#include "polarssl/ssl.h"
#if defined(POLARSSL_PLATFORM_C)
#include "polarssl/platform.h"
#else
#define polarssl_malloc malloc
#define polarssl_free free
#endif
#include <stdlib.h>
#include <stdio.h>
#if defined(_MSC_VER) && !defined(EFIX64) && !defined(EFI32)
#include <basetsd.h>
typedef UINT32 uint32_t;
#else
#include <inttypes.h>
#endif
#if defined(POLARSSL_HAVE_TIME)
#include <time.h>
#endif
#if defined(POLARSSL_SSL_SERVER_NAME_INDICATION)
static void ssl_write_hostname_ext( ssl_context *ssl,
unsigned char *buf,
size_t *olen )
{
unsigned char *p = buf;
*olen = 0;
if ( ssl->hostname == NULL )
return;
SSL_DEBUG_MSG( 3, ( "client hello, adding server name extension: %s",
ssl->hostname ) );
/*
* 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)( ( TLS_EXT_SERVERNAME >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( TLS_EXT_SERVERNAME ) & 0xFF );
*p++ = (unsigned char)( ( (ssl->hostname_len + 5) >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( (ssl->hostname_len + 5) ) & 0xFF );
*p++ = (unsigned char)( ( (ssl->hostname_len + 3) >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( (ssl->hostname_len + 3) ) & 0xFF );
*p++ = (unsigned char)( ( TLS_EXT_SERVERNAME_HOSTNAME ) & 0xFF );
*p++ = (unsigned char)( ( ssl->hostname_len >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( ssl->hostname_len ) & 0xFF );
memcpy( p, ssl->hostname, ssl->hostname_len );
*olen = ssl->hostname_len + 9;
}
#endif /* POLARSSL_SSL_SERVER_NAME_INDICATION */
static void ssl_write_renegotiation_ext( ssl_context *ssl,
unsigned char *buf,
size_t *olen )
{
unsigned char *p = buf;
*olen = 0;
if( ssl->renegotiation != SSL_RENEGOTIATION )
return;
SSL_DEBUG_MSG( 3, ( "client hello, adding renegotiation extension" ) );
/*
* Secure renegotiation
*/
*p++ = (unsigned char)( ( TLS_EXT_RENEGOTIATION_INFO >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( 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;
}
#if defined(POLARSSL_SSL_PROTO_TLS1_2)
static void ssl_write_signature_algorithms_ext( ssl_context *ssl,
unsigned char *buf,
size_t *olen )
{
unsigned char *p = buf;
unsigned char *sig_alg_list = buf + 6;
size_t sig_alg_len = 0;
*olen = 0;
if( ssl->max_minor_ver != SSL_MINOR_VERSION_3 )
return;
SSL_DEBUG_MSG( 3, ( "client hello, adding signature_algorithms extension" ) );
/*
* Prepare signature_algorithms extension (TLS 1.2)
*/
#if defined(POLARSSL_RSA_C)
#if defined(POLARSSL_SHA512_C)
sig_alg_list[sig_alg_len++] = SSL_HASH_SHA512;
sig_alg_list[sig_alg_len++] = SSL_SIG_RSA;
sig_alg_list[sig_alg_len++] = SSL_HASH_SHA384;
sig_alg_list[sig_alg_len++] = SSL_SIG_RSA;
#endif
#if defined(POLARSSL_SHA256_C)
sig_alg_list[sig_alg_len++] = SSL_HASH_SHA256;
sig_alg_list[sig_alg_len++] = SSL_SIG_RSA;
sig_alg_list[sig_alg_len++] = SSL_HASH_SHA224;
sig_alg_list[sig_alg_len++] = SSL_SIG_RSA;
#endif
#if defined(POLARSSL_SHA1_C)
sig_alg_list[sig_alg_len++] = SSL_HASH_SHA1;
sig_alg_list[sig_alg_len++] = SSL_SIG_RSA;
#endif
#if defined(POLARSSL_MD5_C)
sig_alg_list[sig_alg_len++] = SSL_HASH_MD5;
sig_alg_list[sig_alg_len++] = SSL_SIG_RSA;
#endif
#endif /* POLARSSL_RSA_C */
#if defined(POLARSSL_ECDSA_C)
#if defined(POLARSSL_SHA512_C)
sig_alg_list[sig_alg_len++] = SSL_HASH_SHA512;
sig_alg_list[sig_alg_len++] = SSL_SIG_ECDSA;
sig_alg_list[sig_alg_len++] = SSL_HASH_SHA384;
sig_alg_list[sig_alg_len++] = SSL_SIG_ECDSA;
#endif
#if defined(POLARSSL_SHA256_C)
sig_alg_list[sig_alg_len++] = SSL_HASH_SHA256;
sig_alg_list[sig_alg_len++] = SSL_SIG_ECDSA;
sig_alg_list[sig_alg_len++] = SSL_HASH_SHA224;
sig_alg_list[sig_alg_len++] = SSL_SIG_ECDSA;
#endif
#if defined(POLARSSL_SHA1_C)
sig_alg_list[sig_alg_len++] = SSL_HASH_SHA1;
sig_alg_list[sig_alg_len++] = SSL_SIG_ECDSA;
#endif
#if defined(POLARSSL_MD5_C)
sig_alg_list[sig_alg_len++] = SSL_HASH_MD5;
sig_alg_list[sig_alg_len++] = SSL_SIG_ECDSA;
#endif
#endif /* POLARSSL_ECDSA_C */
/*
* 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)( ( TLS_EXT_SIG_ALG >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( 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;
}
#endif /* POLARSSL_SSL_PROTO_TLS1_2 */
#if defined(POLARSSL_ECDH_C) || defined(POLARSSL_ECDSA_C)
static void ssl_write_supported_elliptic_curves_ext( ssl_context *ssl,
unsigned char *buf,
size_t *olen )
{
unsigned char *p = buf;
unsigned char *elliptic_curve_list = p + 6;
size_t elliptic_curve_len = 0;
const ecp_curve_info *info;
#if defined(POLARSSL_SSL_SET_CURVES)
const ecp_group_id *grp_id;
#else
((void) ssl);
#endif
*olen = 0;
SSL_DEBUG_MSG( 3, ( "client hello, adding supported_elliptic_curves extension" ) );
#if defined(POLARSSL_SSL_SET_CURVES)
for( grp_id = ssl->curve_list; *grp_id != POLARSSL_ECP_DP_NONE; grp_id++ )
{
info = ecp_curve_info_from_grp_id( *grp_id );
#else
for( info = ecp_curve_list(); info->grp_id != POLARSSL_ECP_DP_NONE; info++ )
{
#endif
elliptic_curve_list[elliptic_curve_len++] = info->tls_id >> 8;
elliptic_curve_list[elliptic_curve_len++] = info->tls_id & 0xFF;
}
if( elliptic_curve_len == 0 )
return;
*p++ = (unsigned char)( ( TLS_EXT_SUPPORTED_ELLIPTIC_CURVES >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( 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;
}
static void ssl_write_supported_point_formats_ext( ssl_context *ssl,
unsigned char *buf,
size_t *olen )
{
unsigned char *p = buf;
((void) ssl);
*olen = 0;
SSL_DEBUG_MSG( 3, ( "client hello, adding supported_point_formats extension" ) );
*p++ = (unsigned char)( ( TLS_EXT_SUPPORTED_POINT_FORMATS >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( TLS_EXT_SUPPORTED_POINT_FORMATS ) & 0xFF );
*p++ = 0x00;
*p++ = 2;
*p++ = 1;
*p++ = POLARSSL_ECP_PF_UNCOMPRESSED;
*olen = 6;
}
#endif /* POLARSSL_ECDH_C || POLARSSL_ECDSA_C */
#if defined(POLARSSL_SSL_MAX_FRAGMENT_LENGTH)
static void ssl_write_max_fragment_length_ext( ssl_context *ssl,
unsigned char *buf,
size_t *olen )
{
unsigned char *p = buf;
if( ssl->mfl_code == SSL_MAX_FRAG_LEN_NONE ) {
*olen = 0;
return;
}
SSL_DEBUG_MSG( 3, ( "client hello, adding max_fragment_length extension" ) );
*p++ = (unsigned char)( ( TLS_EXT_MAX_FRAGMENT_LENGTH >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( TLS_EXT_MAX_FRAGMENT_LENGTH ) & 0xFF );
*p++ = 0x00;
*p++ = 1;
*p++ = ssl->mfl_code;
*olen = 5;
}
#endif /* POLARSSL_SSL_MAX_FRAGMENT_LENGTH */
#if defined(POLARSSL_SSL_TRUNCATED_HMAC)
static void ssl_write_truncated_hmac_ext( ssl_context *ssl,
unsigned char *buf, size_t *olen )
{
unsigned char *p = buf;
if( ssl->trunc_hmac == SSL_TRUNC_HMAC_DISABLED )
{
*olen = 0;
return;
}
SSL_DEBUG_MSG( 3, ( "client hello, adding truncated_hmac extension" ) );
*p++ = (unsigned char)( ( TLS_EXT_TRUNCATED_HMAC >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( TLS_EXT_TRUNCATED_HMAC ) & 0xFF );
*p++ = 0x00;
*p++ = 0x00;
*olen = 4;
}
#endif /* POLARSSL_SSL_TRUNCATED_HMAC */
#if defined(POLARSSL_SSL_SESSION_TICKETS)
static void ssl_write_session_ticket_ext( ssl_context *ssl,
unsigned char *buf, size_t *olen )
{
unsigned char *p = buf;
size_t tlen = ssl->session_negotiate->ticket_len;
if( ssl->session_tickets == SSL_SESSION_TICKETS_DISABLED )
{
*olen = 0;
return;
}
SSL_DEBUG_MSG( 3, ( "client hello, adding session ticket extension" ) );
*p++ = (unsigned char)( ( TLS_EXT_SESSION_TICKET >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( TLS_EXT_SESSION_TICKET ) & 0xFF );
*p++ = (unsigned char)( ( tlen >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( tlen ) & 0xFF );
*olen = 4;
if( ssl->session_negotiate->ticket == NULL ||
ssl->session_negotiate->ticket_len == 0 )
{
return;
}
SSL_DEBUG_MSG( 3, ( "sending session ticket of length %d", tlen ) );
memcpy( p, ssl->session_negotiate->ticket, tlen );
*olen += tlen;
}
#endif /* POLARSSL_SSL_SESSION_TICKETS */
#if defined(POLARSSL_SSL_ALPN)
static void ssl_write_alpn_ext( ssl_context *ssl,
unsigned char *buf, size_t *olen )
{
unsigned char *p = buf;
const char **cur;
if( ssl->alpn_list == NULL )
{
*olen = 0;
return;
}
SSL_DEBUG_MSG( 3, ( "client hello, adding alpn extension" ) );
*p++ = (unsigned char)( ( TLS_EXT_ALPN >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( 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->alpn_list; *cur != NULL; cur++ )
{
*p = (unsigned char)( strlen( *cur ) & 0xFF );
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 );
}
#endif /* POLARSSL_SSL_ALPN */
static int ssl_write_client_hello( ssl_context *ssl )
{
int ret;
size_t i, n, olen, ext_len = 0;
unsigned char *buf;
unsigned char *p, *q;
#if defined(POLARSSL_HAVE_TIME)
time_t t;
#endif
const int *ciphersuites;
const ssl_ciphersuite_t *ciphersuite_info;
SSL_DEBUG_MSG( 2, ( "=> write client hello" ) );
if( ssl->f_rng == NULL )
{
SSL_DEBUG_MSG( 1, ( "no RNG provided") );
return( POLARSSL_ERR_SSL_NO_RNG );
}
if( ssl->renegotiation == SSL_INITIAL_HANDSHAKE )
{
ssl->major_ver = ssl->min_major_ver;
ssl->minor_ver = ssl->min_minor_ver;
}
if( ssl->max_major_ver == 0 && ssl->max_minor_ver == 0 )
{
ssl->max_major_ver = SSL_MAX_MAJOR_VERSION;
ssl->max_minor_ver = SSL_MAX_MINOR_VERSION;
}
/*
* 0 . 0 handshake type
* 1 . 3 handshake length
* 4 . 5 highest version supported
* 6 . 9 current UNIX time
* 10 . 37 random bytes
*/
buf = ssl->out_msg;
p = buf + 4;
*p++ = (unsigned char) ssl->max_major_ver;
*p++ = (unsigned char) ssl->max_minor_ver;
SSL_DEBUG_MSG( 3, ( "client hello, max version: [%d:%d]",
buf[4], buf[5] ) );
#if defined(POLARSSL_HAVE_TIME)
t = time( NULL );
*p++ = (unsigned char)( t >> 24 );
*p++ = (unsigned char)( t >> 16 );
*p++ = (unsigned char)( t >> 8 );
*p++ = (unsigned char)( t );
SSL_DEBUG_MSG( 3, ( "client hello, current time: %lu", t ) );
#else
if( ( ret = ssl->f_rng( ssl->p_rng, p, 4 ) ) != 0 )
return( ret );
p += 4;
#endif
if( ( ret = ssl->f_rng( ssl->p_rng, p, 28 ) ) != 0 )
return( ret );
p += 28;
memcpy( ssl->handshake->randbytes, buf + 6, 32 );
SSL_DEBUG_BUF( 3, "client hello, random bytes", buf + 6, 32 );
/*
* 38 . 38 session id length
* 39 . 39+n session id
* 40+n . 41+n ciphersuitelist length
* 42+n . .. ciphersuitelist
* .. . .. compression methods length
* .. . .. compression methods
* .. . .. extensions length
* .. . .. extensions
*/
n = ssl->session_negotiate->length;
if( ssl->renegotiation != SSL_INITIAL_HANDSHAKE || n < 16 || n > 32 ||
ssl->handshake->resume == 0 )
{
n = 0;
}
#if defined(POLARSSL_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( ssl->renegotiation == SSL_INITIAL_HANDSHAKE &&
ssl->session_negotiate->ticket != NULL &&
ssl->session_negotiate->ticket_len != 0 )
{
ret = ssl->f_rng( ssl->p_rng, ssl->session_negotiate->id, 32 );
if( ret != 0 )
return( ret );
ssl->session_negotiate->length = n = 32;
}
#endif /* POLARSSL_SSL_SESSION_TICKETS */
*p++ = (unsigned char) n;
for( i = 0; i < n; i++ )
*p++ = ssl->session_negotiate->id[i];
SSL_DEBUG_MSG( 3, ( "client hello, session id len.: %d", n ) );
SSL_DEBUG_BUF( 3, "client hello, session id", buf + 39, n );
ciphersuites = ssl->ciphersuite_list[ssl->minor_ver];
n = 0;
q = p;
// Skip writing ciphersuite length for now
p += 2;
/*
* Add TLS_EMPTY_RENEGOTIATION_INFO_SCSV
*/
if( ssl->renegotiation == SSL_INITIAL_HANDSHAKE )
{
*p++ = (unsigned char)( SSL_EMPTY_RENEGOTIATION_INFO >> 8 );
*p++ = (unsigned char)( SSL_EMPTY_RENEGOTIATION_INFO );
n++;
}
for( i = 0; ciphersuites[i] != 0; i++ )
{
ciphersuite_info = ssl_ciphersuite_from_id( ciphersuites[i] );
if( ciphersuite_info == NULL )
continue;
if( ciphersuite_info->min_minor_ver > ssl->max_minor_ver ||
ciphersuite_info->max_minor_ver < ssl->min_minor_ver )
continue;
SSL_DEBUG_MSG( 3, ( "client hello, add ciphersuite: %2d",
ciphersuites[i] ) );
n++;
*p++ = (unsigned char)( ciphersuites[i] >> 8 );
*p++ = (unsigned char)( ciphersuites[i] );
}
*q++ = (unsigned char)( n >> 7 );
*q++ = (unsigned char)( n << 1 );
SSL_DEBUG_MSG( 3, ( "client hello, got %d ciphersuites", n ) );
#if defined(POLARSSL_ZLIB_SUPPORT)
SSL_DEBUG_MSG( 3, ( "client hello, compress len.: %d", 2 ) );
SSL_DEBUG_MSG( 3, ( "client hello, compress alg.: %d %d",
SSL_COMPRESS_DEFLATE, SSL_COMPRESS_NULL ) );
*p++ = 2;
*p++ = SSL_COMPRESS_DEFLATE;
*p++ = SSL_COMPRESS_NULL;
#else
SSL_DEBUG_MSG( 3, ( "client hello, compress len.: %d", 1 ) );
SSL_DEBUG_MSG( 3, ( "client hello, compress alg.: %d", SSL_COMPRESS_NULL ) );
*p++ = 1;
*p++ = SSL_COMPRESS_NULL;
#endif
// First write extensions, then the total length
//
#if defined(POLARSSL_SSL_SERVER_NAME_INDICATION)
ssl_write_hostname_ext( ssl, p + 2 + ext_len, &olen );
ext_len += olen;
#endif
ssl_write_renegotiation_ext( ssl, p + 2 + ext_len, &olen );
ext_len += olen;
#if defined(POLARSSL_SSL_PROTO_TLS1_2)
ssl_write_signature_algorithms_ext( ssl, p + 2 + ext_len, &olen );
ext_len += olen;
#endif
#if defined(POLARSSL_ECDH_C) || defined(POLARSSL_ECDSA_C)
ssl_write_supported_elliptic_curves_ext( ssl, p + 2 + ext_len, &olen );
ext_len += olen;
ssl_write_supported_point_formats_ext( ssl, p + 2 + ext_len, &olen );
ext_len += olen;
#endif
#if defined(POLARSSL_SSL_MAX_FRAGMENT_LENGTH)
ssl_write_max_fragment_length_ext( ssl, p + 2 + ext_len, &olen );
ext_len += olen;
#endif
#if defined(POLARSSL_SSL_TRUNCATED_HMAC)
ssl_write_truncated_hmac_ext( ssl, p + 2 + ext_len, &olen );
ext_len += olen;
#endif
#if defined(POLARSSL_SSL_SESSION_TICKETS)
ssl_write_session_ticket_ext( ssl, p + 2 + ext_len, &olen );
ext_len += olen;
#endif
#if defined(POLARSSL_SSL_ALPN)
ssl_write_alpn_ext( ssl, p + 2 + ext_len, &olen );
ext_len += olen;
#endif
SSL_DEBUG_MSG( 3, ( "client 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;
}
ssl->out_msglen = p - buf;
ssl->out_msgtype = SSL_MSG_HANDSHAKE;
ssl->out_msg[0] = SSL_HS_CLIENT_HELLO;
ssl->state++;
if( ( ret = ssl_write_record( ssl ) ) != 0 )
{
SSL_DEBUG_RET( 1, "ssl_write_record", ret );
return( ret );
}
SSL_DEBUG_MSG( 2, ( "<= write client hello" ) );
return( 0 );
}
static int ssl_parse_renegotiation_info( ssl_context *ssl,
const unsigned char *buf,
size_t len )
{
int ret;
if( ssl->renegotiation == SSL_INITIAL_HANDSHAKE )
{
if( len != 1 || buf[0] != 0x0 )
{
SSL_DEBUG_MSG( 1, ( "non-zero length renegotiated connection field" ) );
if( ( ret = ssl_send_fatal_handshake_failure( ssl ) ) != 0 )
return( ret );
return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO );
}
ssl->secure_renegotiation = SSL_SECURE_RENEGOTIATION;
}
else
{
/* 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 ||
safer_memcmp( buf + 1,
ssl->own_verify_data, ssl->verify_data_len ) != 0 ||
safer_memcmp( buf + 1 + ssl->verify_data_len,
ssl->peer_verify_data, ssl->verify_data_len ) != 0 )
{
SSL_DEBUG_MSG( 1, ( "non-matching renegotiated connection field" ) );
if( ( ret = ssl_send_fatal_handshake_failure( ssl ) ) != 0 )
return( ret );
return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO );
}
}
return( 0 );
}
#if defined(POLARSSL_SSL_MAX_FRAGMENT_LENGTH)
static int ssl_parse_max_fragment_length_ext( 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->mfl_code == SSL_MAX_FRAG_LEN_NONE ||
len != 1 ||
buf[0] != ssl->mfl_code )
{
return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO );
}
return( 0 );
}
#endif /* POLARSSL_SSL_MAX_FRAGMENT_LENGTH */
#if defined(POLARSSL_SSL_TRUNCATED_HMAC)
static int ssl_parse_truncated_hmac_ext( ssl_context *ssl,
const unsigned char *buf,
size_t len )
{
if( ssl->trunc_hmac == SSL_TRUNC_HMAC_DISABLED ||
len != 0 )
{
return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO );
}
((void) buf);
ssl->session_negotiate->trunc_hmac = SSL_TRUNC_HMAC_ENABLED;
return( 0 );
}
#endif /* POLARSSL_SSL_TRUNCATED_HMAC */
#if defined(POLARSSL_SSL_SESSION_TICKETS)
static int ssl_parse_session_ticket_ext( ssl_context *ssl,
const unsigned char *buf,
size_t len )
{
if( ssl->session_tickets == SSL_SESSION_TICKETS_DISABLED ||
len != 0 )
{
return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO );
}
((void) buf);
ssl->handshake->new_session_ticket = 1;
return( 0 );
}
#endif /* POLARSSL_SSL_SESSION_TICKETS */
#if defined(POLARSSL_ECDH_C) || defined(POLARSSL_ECDSA_C)
static int ssl_parse_supported_point_formats_ext( ssl_context *ssl,
const unsigned char *buf,
size_t len )
{
size_t list_size;
const unsigned char *p;
list_size = buf[0];
if( list_size + 1 != len )
{
SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO );
}
p = buf + 2;
while( list_size > 0 )
{
if( p[0] == POLARSSL_ECP_PF_UNCOMPRESSED ||
p[0] == POLARSSL_ECP_PF_COMPRESSED )
{
ssl->handshake->ecdh_ctx.point_format = p[0];
SSL_DEBUG_MSG( 4, ( "point format selected: %d", p[0] ) );
return( 0 );
}
list_size--;
p++;
}
return( 0 );
}
#endif /* POLARSSL_ECDH_C || POLARSSL_ECDSA_C */
#if defined(POLARSSL_SSL_ALPN)
static int ssl_parse_alpn_ext( 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->alpn_list == NULL )
return( POLARSSL_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 )
return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO );
list_len = ( buf[0] << 8 ) | buf[1];
if( list_len != len - 2 )
return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO );
name_len = buf[2];
if( name_len != list_len - 1 )
return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO );
/* Check that the server chosen protocol was in our list and save it */
for( p = ssl->alpn_list; *p != NULL; p++ )
{
if( name_len == strlen( *p ) &&
memcmp( buf + 3, *p, name_len ) == 0 )
{
ssl->alpn_chosen = *p;
return( 0 );
}
}
return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO );
}
#endif /* POLARSSL_SSL_ALPN */
static int ssl_parse_server_hello( ssl_context *ssl )
{
int ret, i, comp;
size_t n;
size_t ext_len = 0;
unsigned char *buf, *ext;
int renegotiation_info_seen = 0;
int handshake_failure = 0;
#if defined(POLARSSL_DEBUG_C)
uint32_t t;
#endif
SSL_DEBUG_MSG( 2, ( "=> parse server hello" ) );
/*
* 0 . 0 handshake type
* 1 . 3 handshake length
* 4 . 5 protocol version
* 6 . 9 UNIX time()
* 10 . 37 random bytes
*/
buf = ssl->in_msg;
if( ( ret = ssl_read_record( ssl ) ) != 0 )
{
SSL_DEBUG_RET( 1, "ssl_read_record", ret );
return( ret );
}
if( ssl->in_msgtype != SSL_MSG_HANDSHAKE )
{
SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
return( POLARSSL_ERR_SSL_UNEXPECTED_MESSAGE );
}
SSL_DEBUG_MSG( 3, ( "server hello, chosen version: [%d:%d]",
buf[4], buf[5] ) );
if( ssl->in_hslen < 42 ||
buf[0] != SSL_HS_SERVER_HELLO ||
buf[4] != SSL_MAJOR_VERSION_3 )
{
SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO );
}
if( buf[5] > ssl->max_minor_ver )
{
SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO );
}
ssl->minor_ver = buf[5];
if( ssl->minor_ver < ssl->min_minor_ver )
{
SSL_DEBUG_MSG( 1, ( "server only supports ssl smaller than minimum"
" [%d:%d] < [%d:%d]", ssl->major_ver, ssl->minor_ver,
buf[4], buf[5] ) );
ssl_send_alert_message( ssl, SSL_ALERT_LEVEL_FATAL,
SSL_ALERT_MSG_PROTOCOL_VERSION );
return( POLARSSL_ERR_SSL_BAD_HS_PROTOCOL_VERSION );
}
#if defined(POLARSSL_DEBUG_C)
t = ( (uint32_t) buf[6] << 24 )
| ( (uint32_t) buf[7] << 16 )
| ( (uint32_t) buf[8] << 8 )
| ( (uint32_t) buf[9] );
SSL_DEBUG_MSG( 3, ( "server hello, current time: %lu", t ) );
#endif
memcpy( ssl->handshake->randbytes + 32, buf + 6, 32 );
n = buf[38];
SSL_DEBUG_BUF( 3, "server hello, random bytes", buf + 6, 32 );
if( n > 32 )
{
SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO );
}
/*
* 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 . 44+n+m extensions
*/
if( ssl->in_hslen > 42 + n )
{
ext_len = ( ( buf[42 + n] << 8 )
| ( buf[43 + n] ) );
if( ( ext_len > 0 && ext_len < 4 ) ||
ssl->in_hslen != 44 + n + ext_len )
{
SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO );
}
}
i = ( buf[39 + n] << 8 ) | buf[40 + n];
comp = buf[41 + n];
/*
* Initialize update checksum functions
*/
ssl->transform_negotiate->ciphersuite_info = ssl_ciphersuite_from_id( i );
if( ssl->transform_negotiate->ciphersuite_info == NULL )
{
SSL_DEBUG_MSG( 1, ( "ciphersuite info for %04x not found", i ) );
return( POLARSSL_ERR_SSL_BAD_INPUT_DATA );
}
ssl_optimize_checksum( ssl, ssl->transform_negotiate->ciphersuite_info );
SSL_DEBUG_MSG( 3, ( "server hello, session id len.: %d", n ) );
SSL_DEBUG_BUF( 3, "server hello, session id", buf + 39, n );
/*
* Check if the session can be resumed
*/
if( ssl->renegotiation != SSL_INITIAL_HANDSHAKE ||
ssl->handshake->resume == 0 || n == 0 ||
ssl->session_negotiate->ciphersuite != i ||
ssl->session_negotiate->compression != comp ||
ssl->session_negotiate->length != n ||
memcmp( ssl->session_negotiate->id, buf + 39, n ) != 0 )
{
ssl->state++;
ssl->handshake->resume = 0;
#if defined(POLARSSL_HAVE_TIME)
ssl->session_negotiate->start = time( NULL );
#endif
ssl->session_negotiate->ciphersuite = i;
ssl->session_negotiate->compression = comp;
ssl->session_negotiate->length = n;
memcpy( ssl->session_negotiate->id, buf + 39, n );
}
else
{
ssl->state = SSL_SERVER_CHANGE_CIPHER_SPEC;
if( ( ret = ssl_derive_keys( ssl ) ) != 0 )
{
SSL_DEBUG_RET( 1, "ssl_derive_keys", ret );
return( ret );
}
}
SSL_DEBUG_MSG( 3, ( "%s session has been resumed",
ssl->handshake->resume ? "a" : "no" ) );
SSL_DEBUG_MSG( 3, ( "server hello, chosen ciphersuite: %d", i ) );
SSL_DEBUG_MSG( 3, ( "server hello, compress alg.: %d", buf[41 + n] ) );
i = 0;
while( 1 )
{
if( ssl->ciphersuite_list[ssl->minor_ver][i] == 0 )
{
SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO );
}
if( ssl->ciphersuite_list[ssl->minor_ver][i++] ==
ssl->session_negotiate->ciphersuite )
{
break;
}
}
if( comp != SSL_COMPRESS_NULL
#if defined(POLARSSL_ZLIB_SUPPORT)
&& comp != SSL_COMPRESS_DEFLATE
#endif
)
{
SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO );
}
ssl->session_negotiate->compression = comp;
ext = buf + 44 + n;
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 )
{
SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO );
}
switch( ext_id )
{
case TLS_EXT_RENEGOTIATION_INFO:
SSL_DEBUG_MSG( 3, ( "found renegotiation extension" ) );
renegotiation_info_seen = 1;
if( ( ret = ssl_parse_renegotiation_info( ssl, ext + 4, ext_size ) ) != 0 )
return( ret );
break;
#if defined(POLARSSL_SSL_MAX_FRAGMENT_LENGTH)
case TLS_EXT_MAX_FRAGMENT_LENGTH:
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 /* POLARSSL_SSL_MAX_FRAGMENT_LENGTH */
#if defined(POLARSSL_SSL_TRUNCATED_HMAC)
case TLS_EXT_TRUNCATED_HMAC:
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 /* POLARSSL_SSL_TRUNCATED_HMAC */
#if defined(POLARSSL_SSL_SESSION_TICKETS)
case TLS_EXT_SESSION_TICKET:
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 /* POLARSSL_SSL_SESSION_TICKETS */
#if defined(POLARSSL_ECDH_C) || defined(POLARSSL_ECDSA_C)
case TLS_EXT_SUPPORTED_POINT_FORMATS:
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 /* POLARSSL_ECDH_C || POLARSSL_ECDSA_C */
#if defined(POLARSSL_SSL_ALPN)
case TLS_EXT_ALPN:
SSL_DEBUG_MSG( 3, ( "found alpn extension" ) );
if( ( ret = ssl_parse_alpn_ext( ssl, ext + 4, ext_size ) ) != 0 )
return( ret );
break;
#endif /* POLARSSL_SSL_ALPN */
default:
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 )
{
SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO );
}
}
/*
* Renegotiation security checks
*/
if( ssl->secure_renegotiation == SSL_LEGACY_RENEGOTIATION &&
ssl->allow_legacy_renegotiation == SSL_LEGACY_BREAK_HANDSHAKE )
{
SSL_DEBUG_MSG( 1, ( "legacy renegotiation, breaking off handshake" ) );
handshake_failure = 1;
}
else if( ssl->renegotiation == SSL_RENEGOTIATION &&
ssl->secure_renegotiation == SSL_SECURE_RENEGOTIATION &&
renegotiation_info_seen == 0 )
{
SSL_DEBUG_MSG( 1, ( "renegotiation_info extension missing (secure)" ) );
handshake_failure = 1;
}
else if( ssl->renegotiation == SSL_RENEGOTIATION &&
ssl->secure_renegotiation == SSL_LEGACY_RENEGOTIATION &&
ssl->allow_legacy_renegotiation == SSL_LEGACY_NO_RENEGOTIATION )
{
SSL_DEBUG_MSG( 1, ( "legacy renegotiation not allowed" ) );
handshake_failure = 1;
}
else if( ssl->renegotiation == SSL_RENEGOTIATION &&
ssl->secure_renegotiation == SSL_LEGACY_RENEGOTIATION &&
renegotiation_info_seen == 1 )
{
SSL_DEBUG_MSG( 1, ( "renegotiation_info extension present (legacy)" ) );
handshake_failure = 1;
}
if( handshake_failure == 1 )
{
if( ( ret = ssl_send_fatal_handshake_failure( ssl ) ) != 0 )
return( ret );
return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO );
}
SSL_DEBUG_MSG( 2, ( "<= parse server hello" ) );
return( 0 );
}
#if defined(POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED) || \
defined(POLARSSL_KEY_EXCHANGE_DHE_PSK_ENABLED)
static int ssl_parse_server_dh_params( ssl_context *ssl, unsigned char **p,
unsigned char *end )
{
int ret = POLARSSL_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 = dhm_read_params( &ssl->handshake->dhm_ctx, p, end ) ) != 0 )
{
SSL_DEBUG_RET( 2, ( "dhm_read_params" ), ret );
return( ret );
}
if( ssl->handshake->dhm_ctx.len < 64 ||
ssl->handshake->dhm_ctx.len > 512 )
{
SSL_DEBUG_MSG( 1, ( "bad server key exchange message (DHM length)" ) );
return( POLARSSL_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
}
SSL_DEBUG_MPI( 3, "DHM: P ", &ssl->handshake->dhm_ctx.P );
SSL_DEBUG_MPI( 3, "DHM: G ", &ssl->handshake->dhm_ctx.G );
SSL_DEBUG_MPI( 3, "DHM: GY", &ssl->handshake->dhm_ctx.GY );
return( ret );
}
#endif /* POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED ||
POLARSSL_KEY_EXCHANGE_DHE_PSK_ENABLED */
#if defined(POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \
defined(POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) || \
defined(POLARSSL_KEY_EXCHANGE_ECDHE_PSK_ENABLED) || \
defined(POLARSSL_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \
defined(POLARSSL_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)
static int ssl_check_server_ecdh_params( const ssl_context *ssl )
{
const ecp_curve_info *curve_info;
curve_info = ecp_curve_info_from_grp_id( ssl->handshake->ecdh_ctx.grp.id );
if( curve_info == NULL )
{
SSL_DEBUG_MSG( 1, ( "Should never happen" ) );
return( -1 );
}
SSL_DEBUG_MSG( 2, ( "ECDH curve: %s", curve_info->name ) );
#if defined(POLARSSL_SSL_ECP_SET_CURVES)
if( ! ssl_curve_is_acceptable( ssl, ssl->handshake->ecdh_ctx.grp.id ) )
#else
if( ssl->handshake->ecdh_ctx.grp.nbits < 163 ||
ssl->handshake->ecdh_ctx.grp.nbits > 521 )
#endif
return( -1 );
SSL_DEBUG_ECP( 3, "ECDH: Qp", &ssl->handshake->ecdh_ctx.Qp );
return( 0 );
}
#endif
#if defined(POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \
defined(POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) || \
defined(POLARSSL_KEY_EXCHANGE_ECDHE_PSK_ENABLED)
static int ssl_parse_server_ecdh_params( ssl_context *ssl,
unsigned char **p,
unsigned char *end )
{
int ret = POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE;
/*
* Ephemeral ECDH parameters:
*
* struct {
* ECParameters curve_params;
* ECPoint public;
* } ServerECDHParams;
*/
if( ( ret = ecdh_read_params( &ssl->handshake->ecdh_ctx,
(const unsigned char **) p, end ) ) != 0 )
{
SSL_DEBUG_RET( 1, ( "ecdh_read_params" ), ret );
return( ret );
}
if( ssl_check_server_ecdh_params( ssl ) != 0 )
{
SSL_DEBUG_MSG( 1, ( "bad server key exchange message (ECDHE curve)" ) );
return( POLARSSL_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
}
return( ret );
}
#endif /* POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED ||
POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED ||
POLARSSL_KEY_EXCHANGE_ECDHE_PSK_ENABLED */
#if defined(POLARSSL_KEY_EXCHANGE__SOME__PSK_ENABLED)
static int ssl_parse_server_psk_hint( ssl_context *ssl,
unsigned char **p,
unsigned char *end )
{
int ret = POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE;
size_t len;
((void) ssl);
/*
* PSK parameters:
*
* opaque psk_identity_hint<0..2^16-1>;
*/
len = (*p)[0] << 8 | (*p)[1];
*p += 2;
if( (*p) + len > end )
{
SSL_DEBUG_MSG( 1, ( "bad server key exchange message (psk_identity_hint length)" ) );
return( POLARSSL_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
}
// TODO: Retrieve PSK identity hint and callback to app
//
*p += len;
ret = 0;
return( ret );
}
#endif /* POLARSSL_KEY_EXCHANGE__SOME__PSK_ENABLED */
#if defined(POLARSSL_KEY_EXCHANGE_RSA_ENABLED) || \
defined(POLARSSL_KEY_EXCHANGE_RSA_PSK_ENABLED)
/*
* Generate a pre-master secret and encrypt it with the server's RSA key
*/
static int ssl_write_encrypted_pms( ssl_context *ssl,
size_t offset, size_t *olen,
size_t pms_offset )
{
int ret;
size_t len_bytes = ssl->minor_ver == SSL_MINOR_VERSION_0 ? 0 : 2;
unsigned char *p = ssl->handshake->premaster + pms_offset;
/*
* Generate (part of) the pre-master as
* struct {
* ProtocolVersion client_version;
* opaque random[46];
* } PreMasterSecret;
*/
p[0] = (unsigned char) ssl->max_major_ver;
p[1] = (unsigned char) ssl->max_minor_ver;
if( ( ret = ssl->f_rng( ssl->p_rng, p + 2, 46 ) ) != 0 )
{
SSL_DEBUG_RET( 1, "f_rng", ret );
return( ret );
}
ssl->handshake->pmslen = 48;
/*
* Now write it out, encrypted
*/
if( ! pk_can_do( &ssl->session_negotiate->peer_cert->pk,
POLARSSL_PK_RSA ) )
{
SSL_DEBUG_MSG( 1, ( "certificate key type mismatch" ) );
return( POLARSSL_ERR_SSL_PK_TYPE_MISMATCH );
}
if( ( ret = pk_encrypt( &ssl->session_negotiate->peer_cert->pk,
p, ssl->handshake->pmslen,
ssl->out_msg + offset + len_bytes, olen,
SSL_MAX_CONTENT_LEN - offset - len_bytes,
ssl->f_rng, ssl->p_rng ) ) != 0 )
{
SSL_DEBUG_RET( 1, "rsa_pkcs1_encrypt", ret );
return( ret );
}
#if defined(POLARSSL_SSL_PROTO_TLS1) || defined(POLARSSL_SSL_PROTO_TLS1_1) || \
defined(POLARSSL_SSL_PROTO_TLS1_2)
if( len_bytes == 2 )
{
ssl->out_msg[offset+0] = (unsigned char)( *olen >> 8 );
ssl->out_msg[offset+1] = (unsigned char)( *olen );
*olen += 2;
}
#endif
return( 0 );
}
#endif /* POLARSSL_KEY_EXCHANGE_RSA_ENABLED ||
POLARSSL_KEY_EXCHANGE_RSA_PSK_ENABLED */
#if defined(POLARSSL_SSL_PROTO_TLS1_2)
#if defined(POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED) || \
defined(POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \
defined(POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
static int ssl_parse_signature_algorithm( ssl_context *ssl,
unsigned char **p,
unsigned char *end,
md_type_t *md_alg,
pk_type_t *pk_alg )
{
((void) ssl);
*md_alg = POLARSSL_MD_NONE;
*pk_alg = POLARSSL_PK_NONE;
/* Only in TLS 1.2 */
if( ssl->minor_ver != SSL_MINOR_VERSION_3 )
{
return( 0 );
}
if( (*p) + 2 > end )
return( POLARSSL_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
/*
* Get hash algorithm
*/
if( ( *md_alg = ssl_md_alg_from_hash( (*p)[0] ) ) == POLARSSL_MD_NONE )
{
SSL_DEBUG_MSG( 2, ( "Server used unsupported "
"HashAlgorithm %d", *(p)[0] ) );
return( POLARSSL_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
}
/*
* Get signature algorithm
*/
if( ( *pk_alg = ssl_pk_alg_from_sig( (*p)[1] ) ) == POLARSSL_PK_NONE )
{
SSL_DEBUG_MSG( 2, ( "server used unsupported "
"SignatureAlgorithm %d", (*p)[1] ) );
return( POLARSSL_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
}
SSL_DEBUG_MSG( 2, ( "Server used SignatureAlgorithm %d", (*p)[1] ) );
SSL_DEBUG_MSG( 2, ( "Server used HashAlgorithm %d", (*p)[0] ) );
*p += 2;
return( 0 );
}
#endif /* POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED ||
POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED ||
POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED */
#endif /* POLARSSL_SSL_PROTO_TLS1_2 */
#if defined(POLARSSL_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \
defined(POLARSSL_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)
static int ssl_get_ecdh_params_from_cert( ssl_context *ssl )
{
int ret;
const ecp_keypair *peer_key;
if( ! pk_can_do( &ssl->session_negotiate->peer_cert->pk,
POLARSSL_PK_ECKEY ) )
{
SSL_DEBUG_MSG( 1, ( "server key not ECDH capable" ) );
return( POLARSSL_ERR_SSL_PK_TYPE_MISMATCH );
}
peer_key = pk_ec( ssl->session_negotiate->peer_cert->pk );
if( ( ret = ecdh_get_params( &ssl->handshake->ecdh_ctx, peer_key,
POLARSSL_ECDH_THEIRS ) ) != 0 )
{
SSL_DEBUG_RET( 1, ( "ecdh_get_params" ), ret );
return( ret );
}
if( ssl_check_server_ecdh_params( ssl ) != 0 )
{
SSL_DEBUG_MSG( 1, ( "bad server certificate (ECDH curve)" ) );
return( POLARSSL_ERR_SSL_BAD_HS_CERTIFICATE );
}
return( ret );
}
#endif /* POLARSSL_KEY_EXCHANGE_ECDH_RSA_ENABLED) ||
POLARSSL_KEY_EXCHANGE_ECDH_ECDSA_ENABLED */
static int ssl_parse_server_key_exchange( ssl_context *ssl )
{
int ret;
const ssl_ciphersuite_t *ciphersuite_info = ssl->transform_negotiate->ciphersuite_info;
unsigned char *p, *end;
#if defined(POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED) || \
defined(POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \
defined(POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
size_t sig_len, params_len;
unsigned char hash[64];
md_type_t md_alg = POLARSSL_MD_NONE;
size_t hashlen;
pk_type_t pk_alg = POLARSSL_PK_NONE;
#endif
SSL_DEBUG_MSG( 2, ( "=> parse server key exchange" ) );
#if defined(POLARSSL_KEY_EXCHANGE_RSA_ENABLED)
if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_RSA )
{
SSL_DEBUG_MSG( 2, ( "<= skip parse server key exchange" ) );
ssl->state++;
return( 0 );
}
((void) p);
((void) end);
#endif
#if defined(POLARSSL_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \
defined(POLARSSL_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)
if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDH_RSA ||
ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDH_ECDSA )
{
if( ( ret = ssl_get_ecdh_params_from_cert( ssl ) ) != 0 )
{
SSL_DEBUG_RET( 1, "ssl_get_ecdh_params_from_cert", ret );
return( ret );
}
SSL_DEBUG_MSG( 2, ( "<= skip parse server key exchange" ) );
ssl->state++;
return( 0 );
}
((void) p);
((void) end);
#endif
if( ( ret = ssl_read_record( ssl ) ) != 0 )
{
SSL_DEBUG_RET( 1, "ssl_read_record", ret );
return( ret );
}
if( ssl->in_msgtype != SSL_MSG_HANDSHAKE )
{
SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
return( POLARSSL_ERR_SSL_UNEXPECTED_MESSAGE );
}
/*
* ServerKeyExchange may be skipped with PSK and RSA-PSK when the server
* doesn't use a psk_identity_hint
*/
if( ssl->in_msg[0] != SSL_HS_SERVER_KEY_EXCHANGE )
{
if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_PSK ||
ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_RSA_PSK )
{
ssl->record_read = 1;
goto exit;
}
SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
return( POLARSSL_ERR_SSL_UNEXPECTED_MESSAGE );
}
p = ssl->in_msg + 4;
end = ssl->in_msg + ssl->in_hslen;
SSL_DEBUG_BUF( 3, "server key exchange", p, ssl->in_hslen - 4 );
#if defined(POLARSSL_KEY_EXCHANGE__SOME__PSK_ENABLED)
if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_PSK ||
ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_RSA_PSK ||
ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_DHE_PSK ||
ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_PSK )
{
if( ssl_parse_server_psk_hint( ssl, &p, end ) != 0 )
{
SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
}
} /* FALLTROUGH */
#endif /* POLARSSL_KEY_EXCHANGE__SOME__PSK_ENABLED */
#if defined(POLARSSL_KEY_EXCHANGE_PSK_ENABLED) || \
defined(POLARSSL_KEY_EXCHANGE_RSA_PSK_ENABLED)
if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_PSK ||
ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_RSA_PSK )
; /* nothing more to do */
else
#endif /* POLARSSL_KEY_EXCHANGE_PSK_ENABLED ||
POLARSSL_KEY_EXCHANGE_RSA_PSK_ENABLED */
#if defined(POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED) || \
defined(POLARSSL_KEY_EXCHANGE_DHE_PSK_ENABLED)
if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_DHE_RSA ||
ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_DHE_PSK )
{
if( ssl_parse_server_dh_params( ssl, &p, end ) != 0 )
{
SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
}
}
else
#endif /* POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED ||
POLARSSL_KEY_EXCHANGE_DHE_PSK_ENABLED */
#if defined(POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \
defined(POLARSSL_KEY_EXCHANGE_ECDHE_PSK_ENABLED) || \
defined(POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_RSA ||
ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_PSK ||
ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA )
{
if( ssl_parse_server_ecdh_params( ssl, &p, end ) != 0 )
{
SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
}
}
else
#endif /* POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED ||
POLARSSL_KEY_EXCHANGE_ECDHE_PSK_ENABLED ||
POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED */
{
SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE );
}
#if defined(POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED) || \
defined(POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \
defined(POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_DHE_RSA ||
ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_RSA ||
ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA )
{
params_len = p - ( ssl->in_msg + 4 );
/*
* Handle the digitally-signed structure
*/
#if defined(POLARSSL_SSL_PROTO_TLS1_2)
if( ssl->minor_ver == SSL_MINOR_VERSION_3 )
{
if( ssl_parse_signature_algorithm( ssl, &p, end,
&md_alg, &pk_alg ) != 0 )
{
SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
}
if( pk_alg != ssl_get_ciphersuite_sig_pk_alg( ciphersuite_info ) )
{
SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
}
}
else
#endif
#if defined(POLARSSL_SSL_PROTO_SSL3) || defined(POLARSSL_SSL_PROTO_TLS1) || \
defined(POLARSSL_SSL_PROTO_TLS1_1)
if( ssl->minor_ver < SSL_MINOR_VERSION_3 )
{
pk_alg = ssl_get_ciphersuite_sig_pk_alg( ciphersuite_info );
/* Default hash for ECDSA is SHA-1 */
if( pk_alg == POLARSSL_PK_ECDSA && md_alg == POLARSSL_MD_NONE )
md_alg = POLARSSL_MD_SHA1;
}
else
#endif
{
SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE );
}
/*
* Read signature
*/
sig_len = ( p[0] << 8 ) | p[1];
p += 2;
if( end != p + sig_len )
{
SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
}
SSL_DEBUG_BUF( 3, "signature", p, sig_len );
/*
* Compute the hash that has been signed
*/
#if defined(POLARSSL_SSL_PROTO_SSL3) || defined(POLARSSL_SSL_PROTO_TLS1) || \
defined(POLARSSL_SSL_PROTO_TLS1_1)
if( md_alg == POLARSSL_MD_NONE )
{
md5_context md5;
sha1_context sha1;
hashlen = 36;
/*
* digitally-signed struct {
* opaque md5_hash[16];
* opaque sha_hash[20];
* };
*
* md5_hash
* MD5(ClientHello.random + ServerHello.random
* + ServerParams);
* sha_hash
* SHA(ClientHello.random + ServerHello.random
* + ServerParams);
*/
md5_starts( &md5 );
md5_update( &md5, ssl->handshake->randbytes, 64 );
md5_update( &md5, ssl->in_msg + 4, params_len );
md5_finish( &md5, hash );
sha1_starts( &sha1 );
sha1_update( &sha1, ssl->handshake->randbytes, 64 );
sha1_update( &sha1, ssl->in_msg + 4, params_len );
sha1_finish( &sha1, hash + 16 );
}
else
#endif /* POLARSSL_SSL_PROTO_SSL3 || POLARSSL_SSL_PROTO_TLS1 || \
POLARSSL_SSL_PROTO_TLS1_1 */
#if defined(POLARSSL_SSL_PROTO_TLS1) || defined(POLARSSL_SSL_PROTO_TLS1_1) || \
defined(POLARSSL_SSL_PROTO_TLS1_2)
if( md_alg != POLARSSL_MD_NONE )
{
md_context_t ctx;
/* Info from md_alg will be used instead */
hashlen = 0;
/*
* digitally-signed struct {
* opaque client_random[32];
* opaque server_random[32];
* ServerDHParams params;
* };
*/
if( ( ret = md_init_ctx( &ctx, md_info_from_type( md_alg ) ) ) != 0 )
{
SSL_DEBUG_RET( 1, "md_init_ctx", ret );
return( ret );
}
md_starts( &ctx );
md_update( &ctx, ssl->handshake->randbytes, 64 );
md_update( &ctx, ssl->in_msg + 4, params_len );
md_finish( &ctx, hash );
md_free_ctx( &ctx );
}
else
#endif /* POLARSSL_SSL_PROTO_TLS1 || POLARSSL_SSL_PROTO_TLS1_1 || \
POLARSSL_SSL_PROTO_TLS1_2 */
{
SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE );
}
SSL_DEBUG_BUF( 3, "parameters hash", hash, hashlen != 0 ? hashlen :
(unsigned int) ( md_info_from_type( md_alg ) )->size );
/*
* Verify signature
*/
if( ! pk_can_do( &ssl->session_negotiate->peer_cert->pk, pk_alg ) )
{
SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
return( POLARSSL_ERR_SSL_PK_TYPE_MISMATCH );
}
if( ( ret = pk_verify( &ssl->session_negotiate->peer_cert->pk,
md_alg, hash, hashlen, p, sig_len ) ) != 0 )
{
SSL_DEBUG_RET( 1, "pk_verify", ret );
return( ret );
}
}
#endif /* POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED ||
POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED ||
POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED */
exit:
ssl->state++;
SSL_DEBUG_MSG( 2, ( "<= parse server key exchange" ) );
return( 0 );
}
#if !defined(POLARSSL_KEY_EXCHANGE_RSA_ENABLED) && \
!defined(POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED) && \
!defined(POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED) && \
!defined(POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
static int ssl_parse_certificate_request( ssl_context *ssl )
{
int ret = POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE;
const ssl_ciphersuite_t *ciphersuite_info = ssl->transform_negotiate->ciphersuite_info;
SSL_DEBUG_MSG( 2, ( "=> parse certificate request" ) );
if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_PSK ||
ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_RSA_PSK ||
ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_DHE_PSK ||
ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_PSK )
{
SSL_DEBUG_MSG( 2, ( "<= skip parse certificate request" ) );
ssl->state++;
return( 0 );
}
SSL_DEBUG_MSG( 1, ( "should not happen" ) );
return( ret );
}
#else
static int ssl_parse_certificate_request( ssl_context *ssl )
{
int ret;
unsigned char *buf, *p;
size_t n = 0, m = 0;
size_t cert_type_len = 0, dn_len = 0;
const ssl_ciphersuite_t *ciphersuite_info = ssl->transform_negotiate->ciphersuite_info;
SSL_DEBUG_MSG( 2, ( "=> parse certificate request" ) );
if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_PSK ||
ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_RSA_PSK ||
ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_DHE_PSK ||
ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_PSK )
{
SSL_DEBUG_MSG( 2, ( "<= skip parse certificate request" ) );
ssl->state++;
return( 0 );
}
/*
* 0 . 0 handshake type
* 1 . 3 handshake length
* 4 . 4 cert type count
* 5 .. m-1 cert types
* m .. m+1 sig alg length (TLS 1.2 only)
* m+1 .. n-1 SignatureAndHashAlgorithms (TLS 1.2 only)
* n .. n+1 length of all DNs
* n+2 .. n+3 length of DN 1
* n+4 .. ... Distinguished Name #1
* ... .. ... length of DN 2, etc.
*/
if( ssl->record_read == 0 )
{
if( ( ret = ssl_read_record( ssl ) ) != 0 )
{
SSL_DEBUG_RET( 1, "ssl_read_record", ret );
return( ret );
}
if( ssl->in_msgtype != SSL_MSG_HANDSHAKE )
{
SSL_DEBUG_MSG( 1, ( "bad certificate request message" ) );
return( POLARSSL_ERR_SSL_UNEXPECTED_MESSAGE );
}
ssl->record_read = 1;
}
ssl->client_auth = 0;
ssl->state++;
if( ssl->in_msg[0] == SSL_HS_CERTIFICATE_REQUEST )
ssl->client_auth++;
SSL_DEBUG_MSG( 3, ( "got %s certificate request",
ssl->client_auth ? "a" : "no" ) );
if( ssl->client_auth == 0 )
goto exit;
ssl->record_read = 0;
// TODO: handshake_failure alert for an anonymous server to request
// client authentication
buf = ssl->in_msg;
// Retrieve cert types
//
cert_type_len = buf[4];
n = cert_type_len;
if( ssl->in_hslen < 6 + n )
{
SSL_DEBUG_MSG( 1, ( "bad certificate request message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_CERTIFICATE_REQUEST );
}
p = buf + 5;
while( cert_type_len > 0 )
{
#if defined(POLARSSL_RSA_C)
if( *p == SSL_CERT_TYPE_RSA_SIGN &&
pk_can_do( ssl_own_key( ssl ), POLARSSL_PK_RSA ) )
{
ssl->handshake->cert_type = SSL_CERT_TYPE_RSA_SIGN;
break;
}
else
#endif
#if defined(POLARSSL_ECDSA_C)
if( *p == SSL_CERT_TYPE_ECDSA_SIGN &&
pk_can_do( ssl_own_key( ssl ), POLARSSL_PK_ECDSA ) )
{
ssl->handshake->cert_type = SSL_CERT_TYPE_ECDSA_SIGN;
break;
}
else
#endif
{
; /* Unsupported cert type, ignore */
}
cert_type_len--;
p++;
}
#if defined(POLARSSL_SSL_PROTO_TLS1_2)
if( ssl->minor_ver == SSL_MINOR_VERSION_3 )
{
/* Ignored, see comments about hash in write_certificate_verify */
// TODO: should check the signature part against our pk_key though
size_t sig_alg_len = ( ( buf[5 + n] << 8 )
| ( buf[6 + n] ) );
p = buf + 7 + n;
m += 2;
n += sig_alg_len;
if( ssl->in_hslen < 6 + n )
{
SSL_DEBUG_MSG( 1, ( "bad certificate request message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_CERTIFICATE_REQUEST );
}
}
#endif /* POLARSSL_SSL_PROTO_TLS1_2 */
/* Ignore certificate_authorities, we only have one cert anyway */
// TODO: should not send cert if no CA matches
dn_len = ( ( buf[5 + m + n] << 8 )
| ( buf[6 + m + n] ) );
n += dn_len;
if( ssl->in_hslen != 7 + m + n )
{
SSL_DEBUG_MSG( 1, ( "bad certificate request message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_CERTIFICATE_REQUEST );
}
exit:
SSL_DEBUG_MSG( 2, ( "<= parse certificate request" ) );
return( 0 );
}
#endif /* !POLARSSL_KEY_EXCHANGE_RSA_ENABLED &&
!POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED &&
!POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED &&
!POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED */
static int ssl_parse_server_hello_done( ssl_context *ssl )
{
int ret;
SSL_DEBUG_MSG( 2, ( "=> parse server hello done" ) );
if( ssl->record_read == 0 )
{
if( ( ret = ssl_read_record( ssl ) ) != 0 )
{
SSL_DEBUG_RET( 1, "ssl_read_record", ret );
return( ret );
}
if( ssl->in_msgtype != SSL_MSG_HANDSHAKE )
{
SSL_DEBUG_MSG( 1, ( "bad server hello done message" ) );
return( POLARSSL_ERR_SSL_UNEXPECTED_MESSAGE );
}
}
ssl->record_read = 0;
if( ssl->in_hslen != 4 ||
ssl->in_msg[0] != SSL_HS_SERVER_HELLO_DONE )
{
SSL_DEBUG_MSG( 1, ( "bad server hello done message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO_DONE );
}
ssl->state++;
SSL_DEBUG_MSG( 2, ( "<= parse server hello done" ) );
return( 0 );
}
static int ssl_write_client_key_exchange( ssl_context *ssl )
{
int ret;
size_t i, n;
const ssl_ciphersuite_t *ciphersuite_info = ssl->transform_negotiate->ciphersuite_info;
SSL_DEBUG_MSG( 2, ( "=> write client key exchange" ) );
#if defined(POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED)
if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_DHE_RSA )
{
/*
* DHM key exchange -- send G^X mod P
*/
n = ssl->handshake->dhm_ctx.len;
ssl->out_msg[4] = (unsigned char)( n >> 8 );
ssl->out_msg[5] = (unsigned char)( n );
i = 6;
ret = dhm_make_public( &ssl->handshake->dhm_ctx,
(int) mpi_size( &ssl->handshake->dhm_ctx.P ),
&ssl->out_msg[i], n,
ssl->f_rng, ssl->p_rng );
if( ret != 0 )
{
SSL_DEBUG_RET( 1, "dhm_make_public", ret );
return( ret );
}
SSL_DEBUG_MPI( 3, "DHM: X ", &ssl->handshake->dhm_ctx.X );
SSL_DEBUG_MPI( 3, "DHM: GX", &ssl->handshake->dhm_ctx.GX );
ssl->handshake->pmslen = ssl->handshake->dhm_ctx.len;
if( ( ret = dhm_calc_secret( &ssl->handshake->dhm_ctx,
ssl->handshake->premaster,
&ssl->handshake->pmslen,
ssl->f_rng, ssl->p_rng ) ) != 0 )
{
SSL_DEBUG_RET( 1, "dhm_calc_secret", ret );
return( ret );
}
SSL_DEBUG_MPI( 3, "DHM: K ", &ssl->handshake->dhm_ctx.K );
}
else
#endif /* POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED */
#if defined(POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \
defined(POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) || \
defined(POLARSSL_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \
defined(POLARSSL_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)
if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_RSA ||
ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA ||
ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDH_RSA ||
ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDH_ECDSA )
{
/*
* ECDH key exchange -- send client public value
*/
i = 4;
ret = ecdh_make_public( &ssl->handshake->ecdh_ctx,
&n,
&ssl->out_msg[i], 1000,
ssl->f_rng, ssl->p_rng );
if( ret != 0 )
{
SSL_DEBUG_RET( 1, "ecdh_make_public", ret );
return( ret );
}
SSL_DEBUG_ECP( 3, "ECDH: Q", &ssl->handshake->ecdh_ctx.Q );
if( ( ret = ecdh_calc_secret( &ssl->handshake->ecdh_ctx,
&ssl->handshake->pmslen,
ssl->handshake->premaster,
POLARSSL_MPI_MAX_SIZE,
ssl->f_rng, ssl->p_rng ) ) != 0 )
{
SSL_DEBUG_RET( 1, "ecdh_calc_secret", ret );
return( ret );
}
SSL_DEBUG_MPI( 3, "ECDH: z", &ssl->handshake->ecdh_ctx.z );
}
else
#endif /* POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED ||
POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED ||
POLARSSL_KEY_EXCHANGE_ECDH_RSA_ENABLED ||
POLARSSL_KEY_EXCHANGE_ECDH_ECDSA_ENABLED */
#if defined(POLARSSL_KEY_EXCHANGE__SOME__PSK_ENABLED)
if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_PSK ||
ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_RSA_PSK ||
ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_DHE_PSK ||
ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_PSK )
{
/*
* opaque psk_identity<0..2^16-1>;
*/
if( ssl->psk == NULL || ssl->psk_identity == NULL )
return( POLARSSL_ERR_SSL_PRIVATE_KEY_REQUIRED );
i = 4;
n = ssl->psk_identity_len;
ssl->out_msg[i++] = (unsigned char)( n >> 8 );
ssl->out_msg[i++] = (unsigned char)( n );
memcpy( ssl->out_msg + i, ssl->psk_identity, ssl->psk_identity_len );
i += ssl->psk_identity_len;
#if defined(POLARSSL_KEY_EXCHANGE_PSK_ENABLED)
if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_PSK )
{
n = 0;
}
else
#endif
#if defined(POLARSSL_KEY_EXCHANGE_RSA_PSK_ENABLED)
if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_RSA_PSK )
{
if( ( ret = ssl_write_encrypted_pms( ssl, i, &n, 2 ) ) != 0 )
return( ret );
}
else
#endif
#if defined(POLARSSL_KEY_EXCHANGE_DHE_PSK_ENABLED)
if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_DHE_PSK )
{
/*
* ClientDiffieHellmanPublic public (DHM send G^X mod P)
*/
n = ssl->handshake->dhm_ctx.len;
ssl->out_msg[i++] = (unsigned char)( n >> 8 );
ssl->out_msg[i++] = (unsigned char)( n );
ret = dhm_make_public( &ssl->handshake->dhm_ctx,
(int) mpi_size( &ssl->handshake->dhm_ctx.P ),
&ssl->out_msg[i], n,
ssl->f_rng, ssl->p_rng );
if( ret != 0 )
{
SSL_DEBUG_RET( 1, "dhm_make_public", ret );
return( ret );
}
}
else
#endif /* POLARSSL_KEY_EXCHANGE_DHE_PSK_ENABLED */
#if defined(POLARSSL_KEY_EXCHANGE_ECDHE_PSK_ENABLED)
if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_PSK )
{
/*
* ClientECDiffieHellmanPublic public;
*/
ret = ecdh_make_public( &ssl->handshake->ecdh_ctx, &n,
&ssl->out_msg[i], SSL_MAX_CONTENT_LEN - i,
ssl->f_rng, ssl->p_rng );
if( ret != 0 )
{
SSL_DEBUG_RET( 1, "ecdh_make_public", ret );
return( ret );
}
SSL_DEBUG_ECP( 3, "ECDH: Q", &ssl->handshake->ecdh_ctx.Q );
}
else
#endif /* POLARSSL_KEY_EXCHANGE_ECDHE_PSK_ENABLED */
{
SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE );
}
if( ( ret = ssl_psk_derive_premaster( ssl,
ciphersuite_info->key_exchange ) ) != 0 )
{
SSL_DEBUG_RET( 1, "ssl_psk_derive_premaster", ret );
return( ret );
}
}
else
#endif /* POLARSSL_KEY_EXCHANGE__SOME__PSK_ENABLED */
#if defined(POLARSSL_KEY_EXCHANGE_RSA_ENABLED)
if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_RSA )
{
i = 4;
if( ( ret = ssl_write_encrypted_pms( ssl, i, &n, 0 ) ) != 0 )
return( ret );
}
else
#endif /* POLARSSL_KEY_EXCHANGE_RSA_ENABLED */
{
((void) ciphersuite_info);
SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE );
}
if( ( ret = ssl_derive_keys( ssl ) ) != 0 )
{
SSL_DEBUG_RET( 1, "ssl_derive_keys", ret );
return( ret );
}
ssl->out_msglen = i + n;
ssl->out_msgtype = SSL_MSG_HANDSHAKE;
ssl->out_msg[0] = SSL_HS_CLIENT_KEY_EXCHANGE;
ssl->state++;
if( ( ret = ssl_write_record( ssl ) ) != 0 )
{
SSL_DEBUG_RET( 1, "ssl_write_record", ret );
return( ret );
}
SSL_DEBUG_MSG( 2, ( "<= write client key exchange" ) );
return( 0 );
}
#if !defined(POLARSSL_KEY_EXCHANGE_RSA_ENABLED) && \
!defined(POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED) && \
!defined(POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED) && \
!defined(POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
static int ssl_write_certificate_verify( ssl_context *ssl )
{
int ret = POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE;
const ssl_ciphersuite_t *ciphersuite_info = ssl->transform_negotiate->ciphersuite_info;
SSL_DEBUG_MSG( 2, ( "=> write certificate verify" ) );
if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_PSK ||
ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_RSA_PSK ||
ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_PSK ||
ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_DHE_PSK )
{
SSL_DEBUG_MSG( 2, ( "<= skip write certificate verify" ) );
ssl->state++;
return( 0 );
}
SSL_DEBUG_MSG( 1, ( "should not happen" ) );
return( ret );
}
#else
static int ssl_write_certificate_verify( ssl_context *ssl )
{
int ret = POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE;
const ssl_ciphersuite_t *ciphersuite_info = ssl->transform_negotiate->ciphersuite_info;
size_t n = 0, offset = 0;
unsigned char hash[48];
unsigned char *hash_start = hash;
md_type_t md_alg = POLARSSL_MD_NONE;
unsigned int hashlen;
SSL_DEBUG_MSG( 2, ( "=> write certificate verify" ) );
if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_PSK ||
ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_RSA_PSK ||
ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_PSK ||
ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_DHE_PSK )
{
SSL_DEBUG_MSG( 2, ( "<= skip write certificate verify" ) );
ssl->state++;
return( 0 );
}
if( ssl->client_auth == 0 || ssl_own_cert( ssl ) == NULL )
{
SSL_DEBUG_MSG( 2, ( "<= skip write certificate verify" ) );
ssl->state++;
return( 0 );
}
if( ssl_own_key( ssl ) == NULL )
{
SSL_DEBUG_MSG( 1, ( "got no private key" ) );
return( POLARSSL_ERR_SSL_PRIVATE_KEY_REQUIRED );
}
/*
* Make an RSA signature of the handshake digests
*/
ssl->handshake->calc_verify( ssl, hash );
#if defined(POLARSSL_SSL_PROTO_SSL3) || defined(POLARSSL_SSL_PROTO_TLS1) || \
defined(POLARSSL_SSL_PROTO_TLS1_1)
if( ssl->minor_ver != SSL_MINOR_VERSION_3 )
{
/*
* digitally-signed struct {
* opaque md5_hash[16];
* opaque sha_hash[20];
* };
*
* md5_hash
* MD5(handshake_messages);
*
* sha_hash
* SHA(handshake_messages);
*/
hashlen = 36;
md_alg = POLARSSL_MD_NONE;
/*
* For ECDSA, default hash is SHA-1 only
*/
if( pk_can_do( ssl_own_key( ssl ), POLARSSL_PK_ECDSA ) )
{
hash_start += 16;
hashlen -= 16;
md_alg = POLARSSL_MD_SHA1;
}
}
else
#endif /* POLARSSL_SSL_PROTO_SSL3 || POLARSSL_SSL_PROTO_TLS1 || \
POLARSSL_SSL_PROTO_TLS1_1 */
#if defined(POLARSSL_SSL_PROTO_TLS1_2)
if( ssl->minor_ver == SSL_MINOR_VERSION_3 )
{
/*
* digitally-signed struct {
* opaque handshake_messages[handshake_messages_length];
* };
*
* Taking shortcut here. We assume that the server always allows the
* PRF Hash function and has sent it in the allowed signature
* algorithms list received in the Certificate Request message.
*
* Until we encounter a server that does not, we will take this
* shortcut.
*
* Reason: Otherwise we should have running hashes for SHA512 and SHA224
* in order to satisfy 'weird' needs from the server side.
*/
if( ssl->transform_negotiate->ciphersuite_info->mac ==
POLARSSL_MD_SHA384 )
{
md_alg = POLARSSL_MD_SHA384;
ssl->out_msg[4] = SSL_HASH_SHA384;
}
else
{
md_alg = POLARSSL_MD_SHA256;
ssl->out_msg[4] = SSL_HASH_SHA256;
}
ssl->out_msg[5] = ssl_sig_from_pk( ssl_own_key( ssl ) );
/* Info from md_alg will be used instead */
hashlen = 0;
offset = 2;
}
else
#endif /* POLARSSL_SSL_PROTO_TLS1_2 */
{
SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE );
}
if( ( ret = pk_sign( ssl_own_key( ssl ), md_alg, hash_start, hashlen,
ssl->out_msg + 6 + offset, &n,
ssl->f_rng, ssl->p_rng ) ) != 0 )
{
SSL_DEBUG_RET( 1, "pk_sign", ret );
return( ret );
}
ssl->out_msg[4 + offset] = (unsigned char)( n >> 8 );
ssl->out_msg[5 + offset] = (unsigned char)( n );
ssl->out_msglen = 6 + n + offset;
ssl->out_msgtype = SSL_MSG_HANDSHAKE;
ssl->out_msg[0] = SSL_HS_CERTIFICATE_VERIFY;
ssl->state++;
if( ( ret = ssl_write_record( ssl ) ) != 0 )
{
SSL_DEBUG_RET( 1, "ssl_write_record", ret );
return( ret );
}
SSL_DEBUG_MSG( 2, ( "<= write certificate verify" ) );
return( ret );
}
#endif /* !POLARSSL_KEY_EXCHANGE_RSA_ENABLED &&
!POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED &&
!POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED */
#if defined(POLARSSL_SSL_SESSION_TICKETS)
static int ssl_parse_new_session_ticket( ssl_context *ssl )
{
int ret;
uint32_t lifetime;
size_t ticket_len;
unsigned char *ticket;
SSL_DEBUG_MSG( 2, ( "=> parse new session ticket" ) );
if( ( ret = ssl_read_record( ssl ) ) != 0 )
{
SSL_DEBUG_RET( 1, "ssl_read_record", ret );
return( ret );
}
if( ssl->in_msgtype != SSL_MSG_HANDSHAKE )
{
SSL_DEBUG_MSG( 1, ( "bad new session ticket message" ) );
return( POLARSSL_ERR_SSL_UNEXPECTED_MESSAGE );
}
/*
* struct {
* uint32 ticket_lifetime_hint;
* opaque ticket<0..2^16-1>;
* } NewSessionTicket;
*
* 0 . 0 handshake message type
* 1 . 3 handshake message length
* 4 . 7 ticket_lifetime_hint
* 8 . 9 ticket_len (n)
* 10 . 9+n ticket content
*/
if( ssl->in_msg[0] != SSL_HS_NEW_SESSION_TICKET ||
ssl->in_hslen < 10 )
{
SSL_DEBUG_MSG( 1, ( "bad new session ticket message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_NEW_SESSION_TICKET );
}
lifetime = ( ssl->in_msg[4] << 24 ) | ( ssl->in_msg[5] << 16 ) |
( ssl->in_msg[6] << 8 ) | ( ssl->in_msg[7] );
ticket_len = ( ssl->in_msg[8] << 8 ) | ( ssl->in_msg[9] );
if( ticket_len + 10 != ssl->in_hslen )
{
SSL_DEBUG_MSG( 1, ( "bad new session ticket message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_NEW_SESSION_TICKET );
}
SSL_DEBUG_MSG( 3, ( "ticket length: %d", ticket_len ) );
/* We're not waiting for a NewSessionTicket message any more */
ssl->handshake->new_session_ticket = 0;
/*
* Zero-length ticket means the server changed his mind and doesn't want
* to send a ticket after all, so just forget it
*/
if( ticket_len == 0)
return( 0 );
polarssl_free( ssl->session_negotiate->ticket );
ssl->session_negotiate->ticket = NULL;
ssl->session_negotiate->ticket_len = 0;
if( ( ticket = polarssl_malloc( ticket_len ) ) == NULL )
{
SSL_DEBUG_MSG( 1, ( "ticket malloc failed" ) );
return( POLARSSL_ERR_SSL_MALLOC_FAILED );
}
memcpy( ticket, ssl->in_msg + 10, ticket_len );
ssl->session_negotiate->ticket = ticket;
ssl->session_negotiate->ticket_len = ticket_len;
ssl->session_negotiate->ticket_lifetime = lifetime;
/*
* RFC 5077 section 3.4:
* "If the client receives a session ticket from the server, then it
* discards any Session ID that was sent in the ServerHello."
*/
SSL_DEBUG_MSG( 3, ( "ticket in use, discarding session id" ) );
ssl->session_negotiate->length = 0;
SSL_DEBUG_MSG( 2, ( "<= parse new session ticket" ) );
return( 0 );
}
#endif /* POLARSSL_SSL_SESSION_TICKETS */
/*
* SSL handshake -- client side -- single step
*/
int ssl_handshake_client_step( ssl_context *ssl )
{
int ret = 0;
if( ssl->state == SSL_HANDSHAKE_OVER )
return( POLARSSL_ERR_SSL_BAD_INPUT_DATA );
SSL_DEBUG_MSG( 2, ( "client state: %d", ssl->state ) );
if( ( ret = ssl_flush_output( ssl ) ) != 0 )
return( ret );
switch( ssl->state )
{
case SSL_HELLO_REQUEST:
ssl->state = SSL_CLIENT_HELLO;
break;
/*
* ==> ClientHello
*/
case SSL_CLIENT_HELLO:
ret = ssl_write_client_hello( ssl );
break;
/*
* <== ServerHello
* Certificate
* ( ServerKeyExchange )
* ( CertificateRequest )
* ServerHelloDone
*/
case SSL_SERVER_HELLO:
ret = ssl_parse_server_hello( ssl );
break;
case SSL_SERVER_CERTIFICATE:
ret = ssl_parse_certificate( ssl );
break;
case SSL_SERVER_KEY_EXCHANGE:
ret = ssl_parse_server_key_exchange( ssl );
break;
case SSL_CERTIFICATE_REQUEST:
ret = ssl_parse_certificate_request( ssl );
break;
case SSL_SERVER_HELLO_DONE:
ret = ssl_parse_server_hello_done( ssl );
break;
/*
* ==> ( Certificate/Alert )
* ClientKeyExchange
* ( CertificateVerify )
* ChangeCipherSpec
* Finished
*/
case SSL_CLIENT_CERTIFICATE:
ret = ssl_write_certificate( ssl );
break;
case SSL_CLIENT_KEY_EXCHANGE:
ret = ssl_write_client_key_exchange( ssl );
break;
case SSL_CERTIFICATE_VERIFY:
ret = ssl_write_certificate_verify( ssl );
break;
case SSL_CLIENT_CHANGE_CIPHER_SPEC:
ret = ssl_write_change_cipher_spec( ssl );
break;
case SSL_CLIENT_FINISHED:
ret = ssl_write_finished( ssl );
break;
/*
* <== ( NewSessionTicket )
* ChangeCipherSpec
* Finished
*/
case SSL_SERVER_CHANGE_CIPHER_SPEC:
#if defined(POLARSSL_SSL_SESSION_TICKETS)
if( ssl->handshake->new_session_ticket != 0 )
ret = ssl_parse_new_session_ticket( ssl );
else
#endif
ret = ssl_parse_change_cipher_spec( ssl );
break;
case SSL_SERVER_FINISHED:
ret = ssl_parse_finished( ssl );
break;
case SSL_FLUSH_BUFFERS:
SSL_DEBUG_MSG( 2, ( "handshake: done" ) );
ssl->state = SSL_HANDSHAKE_WRAPUP;
break;
case SSL_HANDSHAKE_WRAPUP:
ssl_handshake_wrapup( ssl );
break;
default:
SSL_DEBUG_MSG( 1, ( "invalid state %d", ssl->state ) );
return( POLARSSL_ERR_SSL_BAD_INPUT_DATA );
}
return( ret );
}
#endif
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