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mbedtls/library/ssl_srv.c

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/*
* SSLv3/TLSv1 server-side functions
*
* Based on XySSL: Copyright (C) 2006-2008 Christophe Devine
*
* Copyright (C) 2009 Paul Bakker <polarssl_maintainer at polarssl dot org>
*
* 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_SRV_C)
#include "polarssl/debug.h"
#include "polarssl/ssl.h"
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <time.h>
static int ssl_parse_client_hello( ssl_context *ssl )
{
int ret, i, j, n;
int ciph_len, sess_len;
int chal_len, comp_len;
unsigned char *buf, *p;
SSL_DEBUG_MSG( 2, ( "=> parse client hello" ) );
if( ( ret = ssl_fetch_input( ssl, 5 ) ) != 0 )
{
SSL_DEBUG_RET( 1, "ssl_fetch_input", ret );
return( ret );
}
buf = ssl->in_hdr;
if( ( buf[0] & 0x80 ) != 0 )
{
SSL_DEBUG_BUF( 4, "record header", buf, 5 );
SSL_DEBUG_MSG( 3, ( "client hello v2, message type: %d",
buf[2] ) );
SSL_DEBUG_MSG( 3, ( "client hello v2, message len.: %d",
( ( buf[0] & 0x7F ) << 8 ) | buf[1] ) );
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] != SSL_HS_CLIENT_HELLO ||
buf[3] != SSL_MAJOR_VERSION_3 )
{
SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
n = ( ( buf[0] << 8 ) | buf[1] ) & 0x7FFF;
if( n < 17 || n > 512 )
{
SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
ssl->max_major_ver = buf[3];
ssl->max_minor_ver = buf[4];
ssl->major_ver = SSL_MAJOR_VERSION_3;
ssl->minor_ver = ( buf[4] <= SSL_MINOR_VERSION_1 )
? buf[4] : SSL_MINOR_VERSION_1;
if( ( ret = ssl_fetch_input( ssl, 2 + n ) ) != 0 )
{
SSL_DEBUG_RET( 1, "ssl_fetch_input", ret );
return( ret );
}
md5_update( &ssl->fin_md5 , buf + 2, n );
sha1_update( &ssl->fin_sha1, buf + 2, n );
buf = ssl->in_msg;
n = ssl->in_left - 5;
/*
* 0 . 1 cipherlist length
* 2 . 3 session id length
* 4 . 5 challenge length
* 6 . .. cipherlist
* .. . .. session id
* .. . .. challenge
*/
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];
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 )
{
SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
if( sess_len < 0 || sess_len > 32 )
{
SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
if( chal_len < 8 || chal_len > 32 )
{
SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
if( n != 6 + ciph_len + sess_len + chal_len )
{
SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
SSL_DEBUG_BUF( 3, "client hello, cipherlist",
buf + 6, ciph_len );
SSL_DEBUG_BUF( 3, "client hello, session id",
buf + 6 + ciph_len, sess_len );
SSL_DEBUG_BUF( 3, "client hello, challenge",
buf + 6 + ciph_len + sess_len, chal_len );
p = buf + 6 + ciph_len;
ssl->session->length = sess_len;
memset( ssl->session->id, 0, sizeof( ssl->session->id ) );
memcpy( ssl->session->id, p, ssl->session->length );
p += sess_len;
memset( ssl->randbytes, 0, 64 );
memcpy( ssl->randbytes + 32 - chal_len, p, chal_len );
for( i = 0; ssl->ciphers[i] != 0; i++ )
{
for( j = 0, p = buf + 6; j < ciph_len; j += 3, p += 3 )
{
if( p[0] == 0 &&
p[1] == 0 &&
p[2] == ssl->ciphers[i] )
goto have_cipher;
}
}
}
else
{
SSL_DEBUG_BUF( 4, "record header", buf, 5 );
SSL_DEBUG_MSG( 3, ( "client hello v3, message type: %d",
buf[0] ) );
SSL_DEBUG_MSG( 3, ( "client hello v3, message len.: %d",
( buf[3] << 8 ) | buf[4] ) );
SSL_DEBUG_MSG( 3, ( "client hello v3, protocol ver: [%d:%d]",
buf[1], buf[2] ) );
/*
* SSLv3 Client Hello
*
* Record layer:
* 0 . 0 message type
* 1 . 2 protocol version
* 3 . 4 message length
*/
if( buf[0] != SSL_MSG_HANDSHAKE ||
buf[1] != SSL_MAJOR_VERSION_3 )
{
SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
n = ( buf[3] << 8 ) | buf[4];
if( n < 45 || n > 512 )
{
SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
if( ( ret = ssl_fetch_input( ssl, 5 + n ) ) != 0 )
{
SSL_DEBUG_RET( 1, "ssl_fetch_input", ret );
return( ret );
}
buf = ssl->in_msg;
n = ssl->in_left - 5;
md5_update( &ssl->fin_md5 , buf, n );
sha1_update( &ssl->fin_sha1, buf, n );
/*
* SSL layer:
* 0 . 0 handshake type
* 1 . 3 handshake length
* 4 . 5 protocol version
* 6 . 9 UNIX time()
* 10 . 37 random bytes
* 38 . 38 session id length
* 39 . 38+x session id
* 39+x . 40+x cipherlist length
* 41+x . .. cipherlist
* .. . .. compression alg.
* .. . .. extensions
*/
SSL_DEBUG_BUF( 4, "record contents", buf, n );
SSL_DEBUG_MSG( 3, ( "client hello v3, handshake type: %d",
buf[0] ) );
SSL_DEBUG_MSG( 3, ( "client hello v3, handshake len.: %d",
( buf[1] << 16 ) | ( buf[2] << 8 ) | buf[3] ) );
SSL_DEBUG_MSG( 3, ( "client hello v3, max. version: [%d:%d]",
buf[4], buf[5] ) );
/*
* Check the handshake type and protocol version
*/
if( buf[0] != SSL_HS_CLIENT_HELLO ||
buf[4] != SSL_MAJOR_VERSION_3 )
{
SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
ssl->major_ver = SSL_MAJOR_VERSION_3;
ssl->minor_ver = ( buf[5] <= SSL_MINOR_VERSION_1 )
? buf[5] : SSL_MINOR_VERSION_1;
ssl->max_major_ver = buf[4];
ssl->max_minor_ver = buf[5];
memcpy( ssl->randbytes, buf + 6, 32 );
/*
* Check the handshake message length
*/
if( buf[1] != 0 || n != 4 + ( ( buf[2] << 8 ) | buf[3] ) )
{
SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
/*
* Check the session length
*/
sess_len = buf[38];
if( sess_len < 0 || sess_len > 32 )
{
SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
ssl->session->length = sess_len;
memset( ssl->session->id, 0, sizeof( ssl->session->id ) );
memcpy( ssl->session->id, buf + 39 , ssl->session->length );
/*
* Check the cipherlist length
*/
ciph_len = ( buf[39 + sess_len] << 8 )
| ( buf[40 + sess_len] );
if( ciph_len < 2 || ciph_len > 256 || ( ciph_len % 2 ) != 0 )
{
SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
/*
* Check the compression algorithms length
*/
comp_len = buf[41 + sess_len + ciph_len];
if( comp_len < 1 || comp_len > 16 )
{
SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
SSL_DEBUG_BUF( 3, "client hello, random bytes",
buf + 6, 32 );
SSL_DEBUG_BUF( 3, "client hello, session id",
buf + 38, sess_len );
SSL_DEBUG_BUF( 3, "client hello, cipherlist",
buf + 41 + sess_len, ciph_len );
SSL_DEBUG_BUF( 3, "client hello, compression",
buf + 42 + sess_len + ciph_len, comp_len );
/*
* Search for a matching cipher
*/
for( i = 0; ssl->ciphers[i] != 0; i++ )
{
for( j = 0, p = buf + 41 + sess_len; j < ciph_len;
j += 2, p += 2 )
{
if( p[0] == 0 && p[1] == ssl->ciphers[i] )
goto have_cipher;
}
}
}
SSL_DEBUG_MSG( 1, ( "got no ciphers in common" ) );
return( POLARSSL_ERR_SSL_NO_CIPHER_CHOSEN );
have_cipher:
ssl->session->cipher = ssl->ciphers[i];
ssl->in_left = 0;
ssl->state++;
SSL_DEBUG_MSG( 2, ( "<= parse client hello" ) );
return( 0 );
}
static int ssl_write_server_hello( ssl_context *ssl )
{
time_t t;
int ret, i, n;
unsigned char *buf, *p;
SSL_DEBUG_MSG( 2, ( "=> write server hello" ) );
/*
* 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;
*p++ = (unsigned char) ssl->major_ver;
*p++ = (unsigned char) ssl->minor_ver;
SSL_DEBUG_MSG( 3, ( "server hello, chosen version: [%d:%d]",
buf[4], buf[5] ) );
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, ( "server hello, current time: %lu", t ) );
for( i = 28; i > 0; i-- )
*p++ = (unsigned char) ssl->f_rng( ssl->p_rng );
memcpy( ssl->randbytes + 32, buf + 6, 32 );
SSL_DEBUG_BUF( 3, "server hello, random bytes", buf + 6, 32 );
/*
* 38 . 38 session id length
* 39 . 38+n session id
* 39+n . 40+n chosen cipher
* 41+n . 41+n chosen compression alg.
*/
ssl->session->length = n = 32;
*p++ = (unsigned char) ssl->session->length;
if( ssl->s_get == NULL ||
ssl->s_get( ssl ) != 0 )
{
/*
* Not found, create a new session id
*/
ssl->resume = 0;
ssl->state++;
for( i = 0; i < n; i++ )
ssl->session->id[i] =
(unsigned char) ssl->f_rng( ssl->p_rng );
}
else
{
/*
* Found a matching session, resume it
*/
ssl->resume = 1;
ssl->state = SSL_SERVER_CHANGE_CIPHER_SPEC;
ssl_derive_keys( ssl );
}
memcpy( p, ssl->session->id, ssl->session->length );
p += ssl->session->length;
SSL_DEBUG_MSG( 3, ( "server hello, session id len.: %d", n ) );
SSL_DEBUG_BUF( 3, "server hello, session id", buf + 39, n );
SSL_DEBUG_MSG( 3, ( "%s session has been resumed",
ssl->resume ? "a" : "no" ) );
*p++ = (unsigned char)( ssl->session->cipher >> 8 );
*p++ = (unsigned char)( ssl->session->cipher );
*p++ = SSL_COMPRESS_NULL;
SSL_DEBUG_MSG( 3, ( "server hello, chosen cipher: %d",
ssl->session->cipher ) );
SSL_DEBUG_MSG( 3, ( "server hello, compress alg.: %d", 0 ) );
ssl->out_msglen = p - buf;
ssl->out_msgtype = SSL_MSG_HANDSHAKE;
ssl->out_msg[0] = SSL_HS_SERVER_HELLO;
ret = ssl_write_record( ssl );
SSL_DEBUG_MSG( 2, ( "<= write server hello" ) );
return( ret );
}
static int ssl_write_certificate_request( ssl_context *ssl )
{
int ret, n;
unsigned char *buf, *p;
x509_cert *crt;
SSL_DEBUG_MSG( 2, ( "=> write certificate request" ) );
ssl->state++;
if( ssl->authmode == SSL_VERIFY_NONE )
{
SSL_DEBUG_MSG( 2, ( "<= skip write certificate request" ) );
return( 0 );
}
/*
* 0 . 0 handshake type
* 1 . 3 handshake length
* 4 . 4 cert type count
* 5 .. n-1 cert types
* n .. n+1 length of all DNs
* n+2 .. n+3 length of DN 1
* n+4 .. ... Distinguished Name #1
* ... .. ... length of DN 2, etc.
*/
buf = ssl->out_msg;
p = buf + 4;
/*
* At the moment, only RSA certificates are supported
*/
*p++ = 1;
*p++ = 1;
p += 2;
crt = ssl->ca_chain;
while( crt != NULL && crt->next != NULL )
{
if( p - buf > 4096 )
break;
n = crt->subject_raw.len;
*p++ = (unsigned char)( n >> 8 );
*p++ = (unsigned char)( n );
memcpy( p, crt->subject_raw.p, n );
SSL_DEBUG_BUF( 3, "requested DN", p, n );
p += n; crt = crt->next;
}
ssl->out_msglen = n = p - buf;
ssl->out_msgtype = SSL_MSG_HANDSHAKE;
ssl->out_msg[0] = SSL_HS_CERTIFICATE_REQUEST;
ssl->out_msg[6] = (unsigned char)( ( n - 8 ) >> 8 );
ssl->out_msg[7] = (unsigned char)( ( n - 8 ) );
ret = ssl_write_record( ssl );
SSL_DEBUG_MSG( 2, ( "<= write certificate request" ) );
return( ret );
}
static int ssl_write_server_key_exchange( ssl_context *ssl )
{
int ret, n;
unsigned char hash[36];
md5_context md5;
sha1_context sha1;
SSL_DEBUG_MSG( 2, ( "=> write server key exchange" ) );
if( ssl->session->cipher != SSL_EDH_RSA_DES_168_SHA &&
ssl->session->cipher != SSL_EDH_RSA_AES_256_SHA &&
ssl->session->cipher != SSL_EDH_RSA_CAMELLIA_256_SHA)
{
SSL_DEBUG_MSG( 2, ( "<= skip write server key exchange" ) );
ssl->state++;
return( 0 );
}
#if !defined(POLARSSL_DHM_C)
SSL_DEBUG_MSG( 1, ( "support for dhm is not available" ) );
return( POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE );
#else
/*
* 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_make_params( &ssl->dhm_ctx, 256, ssl->out_msg + 4,
&n, ssl->f_rng, ssl->p_rng ) ) != 0 )
{
SSL_DEBUG_RET( 1, "dhm_make_params", ret );
return( ret );
}
SSL_DEBUG_MPI( 3, "DHM: X ", &ssl->dhm_ctx.X );
SSL_DEBUG_MPI( 3, "DHM: P ", &ssl->dhm_ctx.P );
SSL_DEBUG_MPI( 3, "DHM: G ", &ssl->dhm_ctx.G );
SSL_DEBUG_MPI( 3, "DHM: GX", &ssl->dhm_ctx.GX );
/*
* 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->randbytes, 64 );
md5_update( &md5, ssl->out_msg + 4, n );
md5_finish( &md5, hash );
sha1_starts( &sha1 );
sha1_update( &sha1, ssl->randbytes, 64 );
sha1_update( &sha1, ssl->out_msg + 4, n );
sha1_finish( &sha1, hash + 16 );
SSL_DEBUG_BUF( 3, "parameters hash", hash, 36 );
ssl->out_msg[4 + n] = (unsigned char)( ssl->rsa_key->len >> 8 );
ssl->out_msg[5 + n] = (unsigned char)( ssl->rsa_key->len );
ret = rsa_pkcs1_sign( ssl->rsa_key, RSA_PRIVATE,
RSA_RAW, 36, hash, ssl->out_msg + 6 + n );
if( ret != 0 )
{
SSL_DEBUG_RET( 1, "rsa_pkcs1_sign", ret );
return( ret );
}
SSL_DEBUG_BUF( 3, "my RSA sig", ssl->out_msg + 6 + n,
ssl->rsa_key->len );
ssl->out_msglen = 6 + n + ssl->rsa_key->len;
ssl->out_msgtype = SSL_MSG_HANDSHAKE;
ssl->out_msg[0] = SSL_HS_SERVER_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 server key exchange" ) );
return( 0 );
#endif
}
static int ssl_write_server_hello_done( ssl_context *ssl )
{
int ret;
SSL_DEBUG_MSG( 2, ( "=> write server hello done" ) );
ssl->out_msglen = 4;
ssl->out_msgtype = SSL_MSG_HANDSHAKE;
ssl->out_msg[0] = SSL_HS_SERVER_HELLO_DONE;
ssl->state++;
if( ( ret = ssl_write_record( ssl ) ) != 0 )
{
SSL_DEBUG_RET( 1, "ssl_write_record", ret );
return( ret );
}
SSL_DEBUG_MSG( 2, ( "<= write server hello done" ) );
return( 0 );
}
static int ssl_parse_client_key_exchange( ssl_context *ssl )
{
int ret, i, n;
SSL_DEBUG_MSG( 2, ( "=> parse client key exchange" ) );
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 client key exchange message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE );
}
if( ssl->in_msg[0] != SSL_HS_CLIENT_KEY_EXCHANGE )
{
SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE );
}
if( ssl->session->cipher == SSL_EDH_RSA_DES_168_SHA ||
ssl->session->cipher == SSL_EDH_RSA_AES_256_SHA ||
ssl->session->cipher == SSL_EDH_RSA_CAMELLIA_256_SHA)
{
#if !defined(POLARSSL_DHM_C)
SSL_DEBUG_MSG( 1, ( "support for dhm is not available" ) );
return( POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE );
#else
/*
* Receive G^Y mod P, premaster = (G^Y)^X mod P
*/
n = ( ssl->in_msg[4] << 8 ) | ssl->in_msg[5];
if( n < 1 || n > ssl->dhm_ctx.len ||
n + 6 != ssl->in_hslen )
{
SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE );
}
if( ( ret = dhm_read_public( &ssl->dhm_ctx,
ssl->in_msg + 6, n ) ) != 0 )
{
SSL_DEBUG_RET( 1, "dhm_read_public", ret );
return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE | ret );
}
SSL_DEBUG_MPI( 3, "DHM: GY", &ssl->dhm_ctx.GY );
ssl->pmslen = ssl->dhm_ctx.len;
if( ( ret = dhm_calc_secret( &ssl->dhm_ctx,
ssl->premaster, &ssl->pmslen ) ) != 0 )
{
SSL_DEBUG_RET( 1, "dhm_calc_secret", ret );
return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE | ret );
}
SSL_DEBUG_MPI( 3, "DHM: K ", &ssl->dhm_ctx.K );
#endif
}
else
{
/*
* Decrypt the premaster using own private RSA key
*/
i = 4;
n = ssl->rsa_key->len;
ssl->pmslen = 48;
if( ssl->minor_ver != SSL_MINOR_VERSION_0 )
{
i += 2;
if( ssl->in_msg[4] != ( ( n >> 8 ) & 0xFF ) ||
ssl->in_msg[5] != ( ( n ) & 0xFF ) )
{
SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE );
}
}
if( ssl->in_hslen != i + n )
{
SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE );
}
ret = rsa_pkcs1_decrypt( ssl->rsa_key, RSA_PRIVATE, &ssl->pmslen,
ssl->in_msg + i, ssl->premaster,
sizeof(ssl->premaster) );
if( ret != 0 || ssl->pmslen != 48 ||
ssl->premaster[0] != ssl->max_major_ver ||
ssl->premaster[1] != ssl->max_minor_ver )
{
SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) );
/*
* Protection against Bleichenbacher's attack:
* invalid PKCS#1 v1.5 padding must not cause
* the connection to end immediately; instead,
* send a bad_record_mac later in the handshake.
*/
ssl->pmslen = 48;
for( i = 0; i < ssl->pmslen; i++ )
ssl->premaster[i] = (unsigned char) ssl->f_rng( ssl->p_rng );
}
}
ssl_derive_keys( ssl );
if( ssl->s_set != NULL )
ssl->s_set( ssl );
ssl->state++;
SSL_DEBUG_MSG( 2, ( "<= parse client key exchange" ) );
return( 0 );
}
static int ssl_parse_certificate_verify( ssl_context *ssl )
{
int n1, n2, ret;
unsigned char hash[36];
SSL_DEBUG_MSG( 2, ( "=> parse certificate verify" ) );
if( ssl->peer_cert == NULL )
{
SSL_DEBUG_MSG( 2, ( "<= skip parse certificate verify" ) );
ssl->state++;
return( 0 );
}
ssl_calc_verify( ssl, hash );
if( ( ret = ssl_read_record( ssl ) ) != 0 )
{
SSL_DEBUG_RET( 1, "ssl_read_record", ret );
return( ret );
}
ssl->state++;
if( ssl->in_msgtype != SSL_MSG_HANDSHAKE )
{
SSL_DEBUG_MSG( 1, ( "bad certificate verify message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_CERTIFICATE_VERIFY );
}
if( ssl->in_msg[0] != SSL_HS_CERTIFICATE_VERIFY )
{
SSL_DEBUG_MSG( 1, ( "bad certificate verify message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_CERTIFICATE_VERIFY );
}
n1 = ssl->peer_cert->rsa.len;
n2 = ( ssl->in_msg[4] << 8 ) | ssl->in_msg[5];
if( n1 + 6 != ssl->in_hslen || n1 != n2 )
{
SSL_DEBUG_MSG( 1, ( "bad certificate verify message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_CERTIFICATE_VERIFY );
}
ret = rsa_pkcs1_verify( &ssl->peer_cert->rsa, RSA_PUBLIC,
RSA_RAW, 36, hash, ssl->in_msg + 6 );
if( ret != 0 )
{
SSL_DEBUG_RET( 1, "rsa_pkcs1_verify", ret );
return( ret );
}
SSL_DEBUG_MSG( 2, ( "<= parse certificate verify" ) );
return( 0 );
}
/*
* SSL handshake -- server side
*/
int ssl_handshake_server( ssl_context *ssl )
{
int ret = 0;
SSL_DEBUG_MSG( 2, ( "=> handshake server" ) );
while( ssl->state != SSL_HANDSHAKE_OVER )
{
SSL_DEBUG_MSG( 2, ( "server state: %d", ssl->state ) );
if( ( ret = ssl_flush_output( ssl ) ) != 0 )
break;
switch( ssl->state )
{
case SSL_HELLO_REQUEST:
ssl->state = SSL_CLIENT_HELLO;
break;
/*
* <== ClientHello
*/
case SSL_CLIENT_HELLO:
ret = ssl_parse_client_hello( ssl );
break;
/*
* ==> ServerHello
* Certificate
* ( ServerKeyExchange )
* ( CertificateRequest )
* ServerHelloDone
*/
case SSL_SERVER_HELLO:
ret = ssl_write_server_hello( ssl );
break;
case SSL_SERVER_CERTIFICATE:
ret = ssl_write_certificate( ssl );
break;
case SSL_SERVER_KEY_EXCHANGE:
ret = ssl_write_server_key_exchange( ssl );
break;
case SSL_CERTIFICATE_REQUEST:
ret = ssl_write_certificate_request( ssl );
break;
case SSL_SERVER_HELLO_DONE:
ret = ssl_write_server_hello_done( ssl );
break;
/*
* <== ( Certificate/Alert )
* ClientKeyExchange
* ( CertificateVerify )
* ChangeCipherSpec
* Finished
*/
case SSL_CLIENT_CERTIFICATE:
ret = ssl_parse_certificate( ssl );
break;
case SSL_CLIENT_KEY_EXCHANGE:
ret = ssl_parse_client_key_exchange( ssl );
break;
case SSL_CERTIFICATE_VERIFY:
ret = ssl_parse_certificate_verify( ssl );
break;
case SSL_CLIENT_CHANGE_CIPHER_SPEC:
ret = ssl_parse_change_cipher_spec( ssl );
break;
case SSL_CLIENT_FINISHED:
ret = ssl_parse_finished( ssl );
break;
/*
* ==> ChangeCipherSpec
* Finished
*/
case SSL_SERVER_CHANGE_CIPHER_SPEC:
ret = ssl_write_change_cipher_spec( ssl );
break;
case SSL_SERVER_FINISHED:
ret = ssl_write_finished( ssl );
break;
case SSL_FLUSH_BUFFERS:
SSL_DEBUG_MSG( 2, ( "handshake: done" ) );
ssl->state = SSL_HANDSHAKE_OVER;
break;
default:
SSL_DEBUG_MSG( 1, ( "invalid state %d", ssl->state ) );
return( POLARSSL_ERR_SSL_BAD_INPUT_DATA );
}
if( ret != 0 )
break;
}
SSL_DEBUG_MSG( 2, ( "<= handshake server" ) );
return( ret );
}
#endif
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