/*
* SSLv3/TLSv1 shared 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.
*/
/*
* The SSL 3.0 specification was drafted by Netscape in 1996,
* and became an IETF standard in 1999.
*
* http://wp.netscape.com/eng/ssl3/
* http://www.ietf.org/rfc/rfc2246.txt
* http://www.ietf.org/rfc/rfc4346.txt
*/
#include "polarssl/config.h"
#if defined(POLARSSL_SSL_TLS_C)
#include "polarssl/aes.h"
#include "polarssl/arc4.h"
#include "polarssl/camellia.h"
#include "polarssl/des.h"
#include "polarssl/debug.h"
#include "polarssl/ssl.h"
#include <string.h>
#include <stdlib.h>
#include <time.h>
/*
* Key material generation
*/
static int tls1_prf( unsigned char *secret, int slen, char *label,
unsigned char *random, int rlen,
unsigned char *dstbuf, int dlen )
{
int nb, hs;
int i, j, k;
unsigned char *S1, *S2;
unsigned char tmp[128];
unsigned char h_i[20];
if( sizeof( tmp ) < 20 + strlen( label ) + rlen )
return( POLARSSL_ERR_SSL_BAD_INPUT_DATA );
hs = ( slen + 1 ) / 2;
S1 = secret;
S2 = secret + slen - hs;
nb = strlen( label );
memcpy( tmp + 20, label, nb );
memcpy( tmp + 20 + nb, random, rlen );
nb += rlen;
/*
* First compute P_md5(secret,label+random)[0..dlen]
*/
md5_hmac( S1, hs, tmp + 20, nb, 4 + tmp );
for( i = 0; i < dlen; i += 16 )
{
md5_hmac( S1, hs, 4 + tmp, 16 + nb, h_i );
md5_hmac( S1, hs, 4 + tmp, 16, 4 + tmp );
k = ( i + 16 > dlen ) ? dlen % 16 : 16;
for( j = 0; j < k; j++ )
dstbuf[i + j] = h_i[j];
}
/*
* XOR out with P_sha1(secret,label+random)[0..dlen]
*/
sha1_hmac( S2, hs, tmp + 20, nb, tmp );
for( i = 0; i < dlen; i += 20 )
{
sha1_hmac( S2, hs, tmp, 20 + nb, h_i );
sha1_hmac( S2, hs, tmp, 20, tmp );
k = ( i + 20 > dlen ) ? dlen % 20 : 20;
for( j = 0; j < k; j++ )
dstbuf[i + j] = (unsigned char)( dstbuf[i + j] ^ h_i[j] );
}
memset( tmp, 0, sizeof( tmp ) );
memset( h_i, 0, sizeof( h_i ) );
return( 0 );
}
int ssl_derive_keys( ssl_context *ssl )
{
int i;
md5_context md5;
sha1_context sha1;
unsigned char tmp[64];
unsigned char padding[16];
unsigned char sha1sum[20];
unsigned char keyblk[256];
unsigned char *key1;
unsigned char *key2;
SSL_DEBUG_MSG( 2, ( "=> derive keys" ) );
/*
* SSLv3:
* master =
* MD5( premaster + SHA1( 'A' + premaster + randbytes ) ) +
* MD5( premaster + SHA1( 'BB' + premaster + randbytes ) ) +
* MD5( premaster + SHA1( 'CCC' + premaster + randbytes ) )
*
* TLSv1:
* master = PRF( premaster, "master secret", randbytes )[0..47]
*/
if( ssl->resume == 0 )
{
int len = ssl->pmslen;
SSL_DEBUG_BUF( 3, "premaster secret", ssl->premaster, len );
if( ssl->minor_ver == SSL_MINOR_VERSION_0 )
{
for( i = 0; i < 3; i++ )
{
memset( padding, 'A' + i, 1 + i );
sha1_starts( &sha1 );
sha1_update( &sha1, padding, 1 + i );
sha1_update( &sha1, ssl->premaster, len );
sha1_update( &sha1, ssl->randbytes, 64 );
sha1_finish( &sha1, sha1sum );
md5_starts( &md5 );
md5_update( &md5, ssl->premaster, len );
md5_update( &md5, sha1sum, 20 );
md5_finish( &md5, ssl->session->master + i * 16 );
}
}
else
tls1_prf( ssl->premaster, len, "master secret",
ssl->randbytes, 64, ssl->session->master, 48 );
memset( ssl->premaster, 0, sizeof( ssl->premaster ) );
}
else
SSL_DEBUG_MSG( 3, ( "no premaster (session resumed)" ) );
/*
* Swap the client and server random values.
*/
memcpy( tmp, ssl->randbytes, 64 );
memcpy( ssl->randbytes, tmp + 32, 32 );
memcpy( ssl->randbytes + 32, tmp, 32 );
memset( tmp, 0, sizeof( tmp ) );
/*
* SSLv3:
* key block =
* MD5( master + SHA1( 'A' + master + randbytes ) ) +
* MD5( master + SHA1( 'BB' + master + randbytes ) ) +
* MD5( master + SHA1( 'CCC' + master + randbytes ) ) +
* MD5( master + SHA1( 'DDDD' + master + randbytes ) ) +
* ...
*
* TLSv1:
* key block = PRF( master, "key expansion", randbytes )
*/
if( ssl->minor_ver == SSL_MINOR_VERSION_0 )
{
for( i = 0; i < 16; i++ )
{
memset( padding, 'A' + i, 1 + i );
sha1_starts( &sha1 );
sha1_update( &sha1, padding, 1 + i );
sha1_update( &sha1, ssl->session->master, 48 );
sha1_update( &sha1, ssl->randbytes, 64 );
sha1_finish( &sha1, sha1sum );
md5_starts( &md5 );
md5_update( &md5, ssl->session->master, 48 );
md5_update( &md5, sha1sum, 20 );
md5_finish( &md5, keyblk + i * 16 );
}
memset( &md5, 0, sizeof( md5 ) );
memset( &sha1, 0, sizeof( sha1 ) );
memset( padding, 0, sizeof( padding ) );
memset( sha1sum, 0, sizeof( sha1sum ) );
}
else
tls1_prf( ssl->session->master, 48, "key expansion",
ssl->randbytes, 64, keyblk, 256 );
SSL_DEBUG_MSG( 3, ( "cipher = %s", ssl_get_cipher( ssl ) ) );
SSL_DEBUG_BUF( 3, "master secret", ssl->session->master, 48 );
SSL_DEBUG_BUF( 4, "random bytes", ssl->randbytes, 64 );
SSL_DEBUG_BUF( 4, "key block", keyblk, 256 );
memset( ssl->randbytes, 0, sizeof( ssl->randbytes ) );
/*
* Determine the appropriate key, IV and MAC length.
*/
switch( ssl->session->cipher )
{
#if defined(POLARSSL_ARC4_C)
case SSL_RSA_RC4_128_MD5:
ssl->keylen = 16; ssl->minlen = 16;
ssl->ivlen = 0; ssl->maclen = 16;
break;
case SSL_RSA_RC4_128_SHA:
ssl->keylen = 16; ssl->minlen = 20;
ssl->ivlen = 0; ssl->maclen = 20;
break;
#endif
#if defined(POLARSSL_DES_C)
case SSL_RSA_DES_168_SHA:
case SSL_EDH_RSA_DES_168_SHA:
ssl->keylen = 24; ssl->minlen = 24;
ssl->ivlen = 8; ssl->maclen = 20;
break;
#endif
#if defined(POLARSSL_AES_C)
case SSL_RSA_AES_128_SHA:
ssl->keylen = 16; ssl->minlen = 32;
ssl->ivlen = 16; ssl->maclen = 20;
break;
case SSL_RSA_AES_256_SHA:
case SSL_EDH_RSA_AES_256_SHA:
ssl->keylen = 32; ssl->minlen = 32;
ssl->ivlen = 16; ssl->maclen = 20;
break;
#endif
#if defined(POLARSSL_CAMELLIA_C)
case SSL_RSA_CAMELLIA_128_SHA:
ssl->keylen = 16; ssl->minlen = 32;
ssl->ivlen = 16; ssl->maclen = 20;
break;
case SSL_RSA_CAMELLIA_256_SHA:
case SSL_EDH_RSA_CAMELLIA_256_SHA:
ssl->keylen = 32; ssl->minlen = 32;
ssl->ivlen = 16; ssl->maclen = 20;
break;
#endif
default:
SSL_DEBUG_MSG( 1, ( "cipher %s is not available",
ssl_get_cipher( ssl ) ) );
return( POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE );
}
SSL_DEBUG_MSG( 3, ( "keylen: %d, minlen: %d, ivlen: %d, maclen: %d",
ssl->keylen, ssl->minlen, ssl->ivlen, ssl->maclen ) );
/*
* Finally setup the cipher contexts, IVs and MAC secrets.
*/
if( ssl->endpoint == SSL_IS_CLIENT )
{
key1 = keyblk + ssl->maclen * 2;
key2 = keyblk + ssl->maclen * 2 + ssl->keylen;
memcpy( ssl->mac_enc, keyblk, ssl->maclen );
memcpy( ssl->mac_dec, keyblk + ssl->maclen, ssl->maclen );
memcpy( ssl->iv_enc, key2 + ssl->keylen, ssl->ivlen );
memcpy( ssl->iv_dec, key2 + ssl->keylen + ssl->ivlen,
ssl->ivlen );
}
else
{
key1 = keyblk + ssl->maclen * 2 + ssl->keylen;
key2 = keyblk + ssl->maclen * 2;
memcpy( ssl->mac_dec, keyblk, ssl->maclen );
memcpy( ssl->mac_enc, keyblk + ssl->maclen, ssl->maclen );
memcpy( ssl->iv_dec, key1 + ssl->keylen, ssl->ivlen );
memcpy( ssl->iv_enc, key1 + ssl->keylen + ssl->ivlen,
ssl->ivlen );
}
switch( ssl->session->cipher )
{
#if defined(POLARSSL_ARC4_C)
case SSL_RSA_RC4_128_MD5:
case SSL_RSA_RC4_128_SHA:
arc4_setup( (arc4_context *) ssl->ctx_enc, key1, ssl->keylen );
arc4_setup( (arc4_context *) ssl->ctx_dec, key2, ssl->keylen );
break;
#endif
#if defined(POLARSSL_DES_C)
case SSL_RSA_DES_168_SHA:
case SSL_EDH_RSA_DES_168_SHA:
des3_set3key_enc( (des3_context *) ssl->ctx_enc, key1 );
des3_set3key_dec( (des3_context *) ssl->ctx_dec, key2 );
break;
#endif
#if defined(POLARSSL_AES_C)
case SSL_RSA_AES_128_SHA:
aes_setkey_enc( (aes_context *) ssl->ctx_enc, key1, 128 );
aes_setkey_dec( (aes_context *) ssl->ctx_dec, key2, 128 );
break;
case SSL_RSA_AES_256_SHA:
case SSL_EDH_RSA_AES_256_SHA:
aes_setkey_enc( (aes_context *) ssl->ctx_enc, key1, 256 );
aes_setkey_dec( (aes_context *) ssl->ctx_dec, key2, 256 );
break;
#endif
#if defined(POLARSSL_CAMELLIA_C)
case SSL_RSA_CAMELLIA_128_SHA:
camellia_setkey_enc( (camellia_context *) ssl->ctx_enc, key1, 128 );
camellia_setkey_dec( (camellia_context *) ssl->ctx_dec, key2, 128 );
break;
case SSL_RSA_CAMELLIA_256_SHA:
case SSL_EDH_RSA_CAMELLIA_256_SHA:
camellia_setkey_enc( (camellia_context *) ssl->ctx_enc, key1, 256 );
camellia_setkey_dec( (camellia_context *) ssl->ctx_dec, key2, 256 );
break;
#endif
default:
return( POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE );
}
memset( keyblk, 0, sizeof( keyblk ) );
SSL_DEBUG_MSG( 2, ( "<= derive keys" ) );
return( 0 );
}
void ssl_calc_verify( ssl_context *ssl, unsigned char hash[36] )
{
md5_context md5;
sha1_context sha1;
unsigned char pad_1[48];
unsigned char pad_2[48];
SSL_DEBUG_MSG( 2, ( "=> calc verify" ) );
memcpy( &md5 , &ssl->fin_md5 , sizeof( md5_context ) );
memcpy( &sha1, &ssl->fin_sha1, sizeof( sha1_context ) );
if( ssl->minor_ver == SSL_MINOR_VERSION_0 )
{
memset( pad_1, 0x36, 48 );
memset( pad_2, 0x5C, 48 );
md5_update( &md5, ssl->session->master, 48 );
md5_update( &md5, pad_1, 48 );
md5_finish( &md5, hash );
md5_starts( &md5 );
md5_update( &md5, ssl->session->master, 48 );
md5_update( &md5, pad_2, 48 );
md5_update( &md5, hash, 16 );
md5_finish( &md5, hash );
sha1_update( &sha1, ssl->session->master, 48 );
sha1_update( &sha1, pad_1, 40 );
sha1_finish( &sha1, hash + 16 );
sha1_starts( &sha1 );
sha1_update( &sha1, ssl->session->master, 48 );
sha1_update( &sha1, pad_2, 40 );
sha1_update( &sha1, hash + 16, 20 );
sha1_finish( &sha1, hash + 16 );
}
else /* TLSv1 */
{
md5_finish( &md5, hash );
sha1_finish( &sha1, hash + 16 );
}
SSL_DEBUG_BUF( 3, "calculated verify result", hash, 36 );
SSL_DEBUG_MSG( 2, ( "<= calc verify" ) );
return;
}
/*
* SSLv3.0 MAC functions
*/
static void ssl_mac_md5( unsigned char *secret,
unsigned char *buf, int len,
unsigned char *ctr, int type )
{
unsigned char header[11];
unsigned char padding[48];
md5_context md5;
memcpy( header, ctr, 8 );
header[ 8] = (unsigned char) type;
header[ 9] = (unsigned char)( len >> 8 );
header[10] = (unsigned char)( len );
memset( padding, 0x36, 48 );
md5_starts( &md5 );
md5_update( &md5, secret, 16 );
md5_update( &md5, padding, 48 );
md5_update( &md5, header, 11 );
md5_update( &md5, buf, len );
md5_finish( &md5, buf + len );
memset( padding, 0x5C, 48 );
md5_starts( &md5 );
md5_update( &md5, secret, 16 );
md5_update( &md5, padding, 48 );
md5_update( &md5, buf + len, 16 );
md5_finish( &md5, buf + len );
}
static void ssl_mac_sha1( unsigned char *secret,
unsigned char *buf, int len,
unsigned char *ctr, int type )
{
unsigned char header[11];
unsigned char padding[40];
sha1_context sha1;
memcpy( header, ctr, 8 );
header[ 8] = (unsigned char) type;
header[ 9] = (unsigned char)( len >> 8 );
header[10] = (unsigned char)( len );
memset( padding, 0x36, 40 );
sha1_starts( &sha1 );
sha1_update( &sha1, secret, 20 );
sha1_update( &sha1, padding, 40 );
sha1_update( &sha1, header, 11 );
sha1_update( &sha1, buf, len );
sha1_finish( &sha1, buf + len );
memset( padding, 0x5C, 40 );
sha1_starts( &sha1 );
sha1_update( &sha1, secret, 20 );
sha1_update( &sha1, padding, 40 );
sha1_update( &sha1, buf + len, 20 );
sha1_finish( &sha1, buf + len );
}
/*
* Encryption/decryption functions
*/
static int ssl_encrypt_buf( ssl_context *ssl )
{
int i, padlen;
SSL_DEBUG_MSG( 2, ( "=> encrypt buf" ) );
/*
* Add MAC then encrypt
*/
if( ssl->minor_ver == SSL_MINOR_VERSION_0 )
{
if( ssl->maclen == 16 )
ssl_mac_md5( ssl->mac_enc,
ssl->out_msg, ssl->out_msglen,
ssl->out_ctr, ssl->out_msgtype );
if( ssl->maclen == 20 )
ssl_mac_sha1( ssl->mac_enc,
ssl->out_msg, ssl->out_msglen,
ssl->out_ctr, ssl->out_msgtype );
}
else
{
if( ssl->maclen == 16 )
md5_hmac( ssl->mac_enc, 16,
ssl->out_ctr, ssl->out_msglen + 13,
ssl->out_msg + ssl->out_msglen );
if( ssl->maclen == 20 )
sha1_hmac( ssl->mac_enc, 20,
ssl->out_ctr, ssl->out_msglen + 13,
ssl->out_msg + ssl->out_msglen );
}
SSL_DEBUG_BUF( 4, "computed mac",
ssl->out_msg + ssl->out_msglen, ssl->maclen );
ssl->out_msglen += ssl->maclen;
for( i = 7; i >= 0; i-- )
if( ++ssl->out_ctr[i] != 0 )
break;
if( ssl->ivlen == 0 )
{
#if defined(POLARSSL_ARC4_C)
padlen = 0;
SSL_DEBUG_MSG( 3, ( "before encrypt: msglen = %d, "
"including %d bytes of padding",
ssl->out_msglen, 0 ) );
SSL_DEBUG_BUF( 4, "before encrypt: output payload",
ssl->out_msg, ssl->out_msglen );
arc4_crypt( (arc4_context *) ssl->ctx_enc,
ssl->out_msg, ssl->out_msglen );
#else
return( POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE );
#endif
}
else
{
padlen = ssl->ivlen - ( ssl->out_msglen + 1 ) % ssl->ivlen;
if( padlen == ssl->ivlen )
padlen = 0;
for( i = 0; i <= padlen; i++ )
ssl->out_msg[ssl->out_msglen + i] = (unsigned char) padlen;
ssl->out_msglen += padlen + 1;
SSL_DEBUG_MSG( 3, ( "before encrypt: msglen = %d, "
"including %d bytes of padding",
ssl->out_msglen, padlen + 1 ) );
SSL_DEBUG_BUF( 4, "before encrypt: output payload",
ssl->out_msg, ssl->out_msglen );
switch( ssl->ivlen )
{
case 8:
#if defined(POLARSSL_DES_C)
des3_crypt_cbc( (des3_context *) ssl->ctx_enc,
DES_ENCRYPT, ssl->out_msglen,
ssl->iv_enc, ssl->out_msg, ssl->out_msg );
break;
#endif
case 16:
#if defined(POLARSSL_AES_C)
if ( ssl->session->cipher == SSL_RSA_AES_128_SHA ||
ssl->session->cipher == SSL_RSA_AES_256_SHA ||
ssl->session->cipher == SSL_EDH_RSA_AES_256_SHA)
{
aes_crypt_cbc( (aes_context *) ssl->ctx_enc,
AES_ENCRYPT, ssl->out_msglen,
ssl->iv_enc, ssl->out_msg, ssl->out_msg );
break;
}
#endif
#if defined(POLARSSL_CAMELLIA_C)
if ( ssl->session->cipher == SSL_RSA_CAMELLIA_128_SHA ||
ssl->session->cipher == SSL_RSA_CAMELLIA_256_SHA ||
ssl->session->cipher == SSL_EDH_RSA_CAMELLIA_256_SHA)
{
camellia_crypt_cbc( (camellia_context *) ssl->ctx_enc,
CAMELLIA_ENCRYPT, ssl->out_msglen,
ssl->iv_enc, ssl->out_msg, ssl->out_msg );
break;
}
#endif
default:
return( POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE );
}
}
SSL_DEBUG_MSG( 2, ( "<= encrypt buf" ) );
return( 0 );
}
static int ssl_decrypt_buf( ssl_context *ssl )
{
int i, padlen;
unsigned char tmp[20];
SSL_DEBUG_MSG( 2, ( "=> decrypt buf" ) );
if( ssl->in_msglen < ssl->minlen )
{
SSL_DEBUG_MSG( 1, ( "in_msglen (%d) < minlen (%d)",
ssl->in_msglen, ssl->minlen ) );
return( POLARSSL_ERR_SSL_INVALID_MAC );
}
if( ssl->ivlen == 0 )
{
#if defined(POLARSSL_ARC4_C)
padlen = 0;
arc4_crypt( (arc4_context *) ssl->ctx_dec,
ssl->in_msg, ssl->in_msglen );
#else
return( POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE );
#endif
}
else
{
/*
* Decrypt and check the padding
*/
if( ssl->in_msglen % ssl->ivlen != 0 )
{
SSL_DEBUG_MSG( 1, ( "msglen (%d) %% ivlen (%d) != 0",
ssl->in_msglen, ssl->ivlen ) );
return( POLARSSL_ERR_SSL_INVALID_MAC );
}
switch( ssl->ivlen )
{
#if defined(POLARSSL_DES_C)
case 8:
des3_crypt_cbc( (des3_context *) ssl->ctx_dec,
DES_DECRYPT, ssl->in_msglen,
ssl->iv_dec, ssl->in_msg, ssl->in_msg );
break;
#endif
case 16:
#if defined(POLARSSL_AES_C)
if ( ssl->session->cipher == SSL_RSA_AES_128_SHA ||
ssl->session->cipher == SSL_RSA_AES_256_SHA ||
ssl->session->cipher == SSL_EDH_RSA_AES_256_SHA)
{
aes_crypt_cbc( (aes_context *) ssl->ctx_dec,
AES_DECRYPT, ssl->in_msglen,
ssl->iv_dec, ssl->in_msg, ssl->in_msg );
break;
}
#endif
#if defined(POLARSSL_CAMELLIA_C)
if ( ssl->session->cipher == SSL_RSA_CAMELLIA_128_SHA ||
ssl->session->cipher == SSL_RSA_CAMELLIA_256_SHA ||
ssl->session->cipher == SSL_EDH_RSA_CAMELLIA_256_SHA)
{
camellia_crypt_cbc( (camellia_context *) ssl->ctx_dec,
CAMELLIA_DECRYPT, ssl->in_msglen,
ssl->iv_dec, ssl->in_msg, ssl->in_msg );
break;
}
#endif
default:
return( POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE );
}
padlen = 1 + ssl->in_msg[ssl->in_msglen - 1];
if( ssl->minor_ver == SSL_MINOR_VERSION_0 )
{
if( padlen > ssl->ivlen )
{
SSL_DEBUG_MSG( 1, ( "bad padding length: is %d, "
"should be no more than %d",
padlen, ssl->ivlen ) );
padlen = 0;
}
}
else
{
/*
* TLSv1: always check the padding
*/
for( i = 1; i <= padlen; i++ )
{
if( ssl->in_msg[ssl->in_msglen - i] != padlen - 1 )
{
SSL_DEBUG_MSG( 1, ( "bad padding byte: should be "
"%02x, but is %02x", padlen - 1,
ssl->in_msg[ssl->in_msglen - i] ) );
padlen = 0;
}
}
}
}
SSL_DEBUG_BUF( 4, "raw buffer after decryption",
ssl->in_msg, ssl->in_msglen );
/*
* Always compute the MAC (RFC4346, CBCTIME).
*/
ssl->in_msglen -= ( ssl->maclen + padlen );
ssl->in_hdr[3] = (unsigned char)( ssl->in_msglen >> 8 );
ssl->in_hdr[4] = (unsigned char)( ssl->in_msglen );
memcpy( tmp, ssl->in_msg + ssl->in_msglen, 20 );
if( ssl->minor_ver == SSL_MINOR_VERSION_0 )
{
if( ssl->maclen == 16 )
ssl_mac_md5( ssl->mac_dec,
ssl->in_msg, ssl->in_msglen,
ssl->in_ctr, ssl->in_msgtype );
else
ssl_mac_sha1( ssl->mac_dec,
ssl->in_msg, ssl->in_msglen,
ssl->in_ctr, ssl->in_msgtype );
}
else
{
if( ssl->maclen == 16 )
md5_hmac( ssl->mac_dec, 16,
ssl->in_ctr, ssl->in_msglen + 13,
ssl->in_msg + ssl->in_msglen );
else
sha1_hmac( ssl->mac_dec, 20,
ssl->in_ctr, ssl->in_msglen + 13,
ssl->in_msg + ssl->in_msglen );
}
SSL_DEBUG_BUF( 4, "message mac", tmp, ssl->maclen );
SSL_DEBUG_BUF( 4, "computed mac", ssl->in_msg + ssl->in_msglen,
ssl->maclen );
if( memcmp( tmp, ssl->in_msg + ssl->in_msglen,
ssl->maclen ) != 0 )
{
SSL_DEBUG_MSG( 1, ( "message mac does not match" ) );
return( POLARSSL_ERR_SSL_INVALID_MAC );
}
/*
* Finally check the padding length; bad padding
* will produce the same error as an invalid MAC.
*/
if( ssl->ivlen != 0 && padlen == 0 )
return( POLARSSL_ERR_SSL_INVALID_MAC );
if( ssl->in_msglen == 0 )
{
ssl->nb_zero++;
/*
* Three or more empty messages may be a DoS attack
* (excessive CPU consumption).
*/
if( ssl->nb_zero > 3 )
{
SSL_DEBUG_MSG( 1, ( "received four consecutive empty "
"messages, possible DoS attack" ) );
return( POLARSSL_ERR_SSL_INVALID_MAC );
}
}
else
ssl->nb_zero = 0;
for( i = 7; i >= 0; i-- )
if( ++ssl->in_ctr[i] != 0 )
break;
SSL_DEBUG_MSG( 2, ( "<= decrypt buf" ) );
return( 0 );
}
/*
* Fill the input message buffer
*/
int ssl_fetch_input( ssl_context *ssl, int nb_want )
{
int ret, len;
SSL_DEBUG_MSG( 2, ( "=> fetch input" ) );
while( ssl->in_left < nb_want )
{
len = nb_want - ssl->in_left;
ret = ssl->f_recv( ssl->p_recv, ssl->in_hdr + ssl->in_left, len );
SSL_DEBUG_MSG( 2, ( "in_left: %d, nb_want: %d",
ssl->in_left, nb_want ) );
SSL_DEBUG_RET( 2, "ssl->f_recv", ret );
if( ret < 0 )
return( ret );
ssl->in_left += ret;
}
SSL_DEBUG_MSG( 2, ( "<= fetch input" ) );
return( 0 );
}
/*
* Flush any data not yet written
*/
int ssl_flush_output( ssl_context *ssl )
{
int ret;
unsigned char *buf;
SSL_DEBUG_MSG( 2, ( "=> flush output" ) );
while( ssl->out_left > 0 )
{
SSL_DEBUG_MSG( 2, ( "message length: %d, out_left: %d",
5 + ssl->out_msglen, ssl->out_left ) );
buf = ssl->out_hdr + 5 + ssl->out_msglen - ssl->out_left;
ret = ssl->f_send( ssl->p_send, buf, ssl->out_left );
SSL_DEBUG_RET( 2, "ssl->f_send", ret );
if( ret <= 0 )
return( ret );
ssl->out_left -= ret;
}
SSL_DEBUG_MSG( 2, ( "<= flush output" ) );
return( 0 );
}
/*
* Record layer functions
*/
int ssl_write_record( ssl_context *ssl )
{
int ret, len = ssl->out_msglen;
SSL_DEBUG_MSG( 2, ( "=> write record" ) );
ssl->out_hdr[0] = (unsigned char) ssl->out_msgtype;
ssl->out_hdr[1] = (unsigned char) ssl->major_ver;
ssl->out_hdr[2] = (unsigned char) ssl->minor_ver;
ssl->out_hdr[3] = (unsigned char)( len >> 8 );
ssl->out_hdr[4] = (unsigned char)( len );
if( ssl->out_msgtype == SSL_MSG_HANDSHAKE )
{
ssl->out_msg[1] = (unsigned char)( ( len - 4 ) >> 16 );
ssl->out_msg[2] = (unsigned char)( ( len - 4 ) >> 8 );
ssl->out_msg[3] = (unsigned char)( ( len - 4 ) );
md5_update( &ssl->fin_md5 , ssl->out_msg, len );
sha1_update( &ssl->fin_sha1, ssl->out_msg, len );
}
if( ssl->do_crypt != 0 )
{
if( ( ret = ssl_encrypt_buf( ssl ) ) != 0 )
{
SSL_DEBUG_RET( 1, "ssl_encrypt_buf", ret );
return( ret );
}
len = ssl->out_msglen;
ssl->out_hdr[3] = (unsigned char)( len >> 8 );
ssl->out_hdr[4] = (unsigned char)( len );
}
ssl->out_left = 5 + ssl->out_msglen;
SSL_DEBUG_MSG( 3, ( "output record: msgtype = %d, "
"version = [%d:%d], msglen = %d",
ssl->out_hdr[0], ssl->out_hdr[1], ssl->out_hdr[2],
( ssl->out_hdr[3] << 8 ) | ssl->out_hdr[4] ) );
SSL_DEBUG_BUF( 4, "output record sent to network",
ssl->out_hdr, 5 + ssl->out_msglen );
if( ( ret = ssl_flush_output( ssl ) ) != 0 )
{
SSL_DEBUG_RET( 1, "ssl_flush_output", ret );
return( ret );
}
SSL_DEBUG_MSG( 2, ( "<= write record" ) );
return( 0 );
}
int ssl_read_record( ssl_context *ssl )
{
int ret;
SSL_DEBUG_MSG( 2, ( "=> read record" ) );
if( ssl->in_hslen != 0 &&
ssl->in_hslen < ssl->in_msglen )
{
/*
* Get next Handshake message in the current record
*/
ssl->in_msglen -= ssl->in_hslen;
memcpy( ssl->in_msg, ssl->in_msg + ssl->in_hslen,
ssl->in_msglen );
ssl->in_hslen = 4;
ssl->in_hslen += ( ssl->in_msg[2] << 8 ) | ssl->in_msg[3];
SSL_DEBUG_MSG( 3, ( "handshake message: msglen ="
" %d, type = %d, hslen = %d",
ssl->in_msglen, ssl->in_msg[0], ssl->in_hslen ) );
if( ssl->in_msglen < 4 || ssl->in_msg[1] != 0 )
{
SSL_DEBUG_MSG( 1, ( "bad handshake length" ) );
return( POLARSSL_ERR_SSL_INVALID_RECORD );
}
if( ssl->in_msglen < ssl->in_hslen )
{
SSL_DEBUG_MSG( 1, ( "bad handshake length" ) );
return( POLARSSL_ERR_SSL_INVALID_RECORD );
}
md5_update( &ssl->fin_md5 , ssl->in_msg, ssl->in_hslen );
sha1_update( &ssl->fin_sha1, ssl->in_msg, ssl->in_hslen );
return( 0 );
}
ssl->in_hslen = 0;
/*
* Read the record header and validate it
*/
if( ( ret = ssl_fetch_input( ssl, 5 ) ) != 0 )
{
SSL_DEBUG_RET( 1, "ssl_fetch_input", ret );
return( ret );
}
ssl->in_msgtype = ssl->in_hdr[0];
ssl->in_msglen = ( ssl->in_hdr[3] << 8 ) | ssl->in_hdr[4];
SSL_DEBUG_MSG( 3, ( "input record: msgtype = %d, "
"version = [%d:%d], msglen = %d",
ssl->in_hdr[0], ssl->in_hdr[1], ssl->in_hdr[2],
( ssl->in_hdr[3] << 8 ) | ssl->in_hdr[4] ) );
if( ssl->in_hdr[1] != ssl->major_ver )
{
SSL_DEBUG_MSG( 1, ( "major version mismatch" ) );
return( POLARSSL_ERR_SSL_INVALID_RECORD );
}
if( ssl->in_hdr[2] != SSL_MINOR_VERSION_0 &&
ssl->in_hdr[2] != SSL_MINOR_VERSION_1 )
{
SSL_DEBUG_MSG( 1, ( "minor version mismatch" ) );
return( POLARSSL_ERR_SSL_INVALID_RECORD );
}
/*
* Make sure the message length is acceptable
*/
if( ssl->do_crypt == 0 )
{
if( ssl->in_msglen < 1 ||
ssl->in_msglen > SSL_MAX_CONTENT_LEN )
{
SSL_DEBUG_MSG( 1, ( "bad message length" ) );
return( POLARSSL_ERR_SSL_INVALID_RECORD );
}
}
else
{
if( ssl->in_msglen < ssl->minlen )
{
SSL_DEBUG_MSG( 1, ( "bad message length" ) );
return( POLARSSL_ERR_SSL_INVALID_RECORD );
}
if( ssl->minor_ver == SSL_MINOR_VERSION_0 &&
ssl->in_msglen > ssl->minlen + SSL_MAX_CONTENT_LEN )
{
SSL_DEBUG_MSG( 1, ( "bad message length" ) );
return( POLARSSL_ERR_SSL_INVALID_RECORD );
}
/*
* TLS encrypted messages can have up to 256 bytes of padding
*/
if( ssl->minor_ver == SSL_MINOR_VERSION_1 &&
ssl->in_msglen > ssl->minlen + SSL_MAX_CONTENT_LEN + 256 )
{
SSL_DEBUG_MSG( 1, ( "bad message length" ) );
return( POLARSSL_ERR_SSL_INVALID_RECORD );
}
}
/*
* Read and optionally decrypt the message contents
*/
if( ( ret = ssl_fetch_input( ssl, 5 + ssl->in_msglen ) ) != 0 )
{
SSL_DEBUG_RET( 1, "ssl_fetch_input", ret );
return( ret );
}
SSL_DEBUG_BUF( 4, "input record from network",
ssl->in_hdr, 5 + ssl->in_msglen );
if( ssl->do_crypt != 0 )
{
if( ( ret = ssl_decrypt_buf( ssl ) ) != 0 )
{
SSL_DEBUG_RET( 1, "ssl_decrypt_buf", ret );
return( ret );
}
SSL_DEBUG_BUF( 4, "input payload after decrypt",
ssl->in_msg, ssl->in_msglen );
if( ssl->in_msglen > SSL_MAX_CONTENT_LEN )
{
SSL_DEBUG_MSG( 1, ( "bad message length" ) );
return( POLARSSL_ERR_SSL_INVALID_RECORD );
}
}
if( ssl->in_msgtype == SSL_MSG_HANDSHAKE )
{
ssl->in_hslen = 4;
ssl->in_hslen += ( ssl->in_msg[2] << 8 ) | ssl->in_msg[3];
SSL_DEBUG_MSG( 3, ( "handshake message: msglen ="
" %d, type = %d, hslen = %d",
ssl->in_msglen, ssl->in_msg[0], ssl->in_hslen ) );
/*
* Additional checks to validate the handshake header
*/
if( ssl->in_msglen < 4 || ssl->in_msg[1] != 0 )
{
SSL_DEBUG_MSG( 1, ( "bad handshake length" ) );
return( POLARSSL_ERR_SSL_INVALID_RECORD );
}
if( ssl->in_msglen < ssl->in_hslen )
{
SSL_DEBUG_MSG( 1, ( "bad handshake length" ) );
return( POLARSSL_ERR_SSL_INVALID_RECORD );
}
md5_update( &ssl->fin_md5 , ssl->in_msg, ssl->in_hslen );
sha1_update( &ssl->fin_sha1, ssl->in_msg, ssl->in_hslen );
}
if( ssl->in_msgtype == SSL_MSG_ALERT )
{
SSL_DEBUG_MSG( 2, ( "got an alert message, type: [%d:%d]",
ssl->in_msg[0], ssl->in_msg[1] ) );
/*
* Ignore non-fatal alerts, except close_notify
*/
if( ssl->in_msg[0] == SSL_ALERT_FATAL )
{
SSL_DEBUG_MSG( 1, ( "is a fatal alert message" ) );
return( POLARSSL_ERR_SSL_FATAL_ALERT_MESSAGE | ssl->in_msg[1] );
}
if( ssl->in_msg[0] == SSL_ALERT_WARNING &&
ssl->in_msg[1] == SSL_ALERT_CLOSE_NOTIFY )
{
SSL_DEBUG_MSG( 2, ( "is a close notify message" ) );
return( POLARSSL_ERR_SSL_PEER_CLOSE_NOTIFY );
}
}
ssl->in_left = 0;
SSL_DEBUG_MSG( 2, ( "<= read record" ) );
return( 0 );
}
/*
* Handshake functions
*/
int ssl_write_certificate( ssl_context *ssl )
{
int ret, i, n;
x509_cert *crt;
SSL_DEBUG_MSG( 2, ( "=> write certificate" ) );
if( ssl->endpoint == SSL_IS_CLIENT )
{
if( ssl->client_auth == 0 )
{
SSL_DEBUG_MSG( 2, ( "<= skip write certificate" ) );
ssl->state++;
return( 0 );
}
/*
* If using SSLv3 and got no cert, send an Alert message
* (otherwise an empty Certificate message will be sent).
*/
if( ssl->own_cert == NULL &&
ssl->minor_ver == SSL_MINOR_VERSION_0 )
{
ssl->out_msglen = 2;
ssl->out_msgtype = SSL_MSG_ALERT;
ssl->out_msg[0] = SSL_ALERT_WARNING;
ssl->out_msg[1] = SSL_ALERT_NO_CERTIFICATE;
SSL_DEBUG_MSG( 2, ( "got no certificate to send" ) );
goto write_msg;
}
}
else /* SSL_IS_SERVER */
{
if( ssl->own_cert == NULL )
{
SSL_DEBUG_MSG( 1, ( "got no certificate to send" ) );
return( POLARSSL_ERR_SSL_CERTIFICATE_REQUIRED );
}
}
SSL_DEBUG_CRT( 3, "own certificate", ssl->own_cert );
/*
* 0 . 0 handshake type
* 1 . 3 handshake length
* 4 . 6 length of all certs
* 7 . 9 length of cert. 1
* 10 . n-1 peer certificate
* n . n+2 length of cert. 2
* n+3 . ... upper level cert, etc.
*/
i = 7;
crt = ssl->own_cert;
while( crt != NULL && crt->next != NULL )
{
n = crt->raw.len;
if( i + 3 + n > SSL_MAX_CONTENT_LEN )
{
SSL_DEBUG_MSG( 1, ( "certificate too large, %d > %d",
i + 3 + n, SSL_MAX_CONTENT_LEN ) );
return( POLARSSL_ERR_SSL_CERTIFICATE_TOO_LARGE );
}
ssl->out_msg[i ] = (unsigned char)( n >> 16 );
ssl->out_msg[i + 1] = (unsigned char)( n >> 8 );
ssl->out_msg[i + 2] = (unsigned char)( n );
i += 3; memcpy( ssl->out_msg + i, crt->raw.p, n );
i += n; crt = crt->next;
}
ssl->out_msg[4] = (unsigned char)( ( i - 7 ) >> 16 );
ssl->out_msg[5] = (unsigned char)( ( i - 7 ) >> 8 );
ssl->out_msg[6] = (unsigned char)( ( i - 7 ) );
ssl->out_msglen = i;
ssl->out_msgtype = SSL_MSG_HANDSHAKE;
ssl->out_msg[0] = SSL_HS_CERTIFICATE;
write_msg:
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" ) );
return( 0 );
}
int ssl_parse_certificate( ssl_context *ssl )
{
int ret, i, n;
SSL_DEBUG_MSG( 2, ( "=> parse certificate" ) );
if( ssl->endpoint == SSL_IS_SERVER &&
ssl->authmode == SSL_VERIFY_NONE )
{
SSL_DEBUG_MSG( 2, ( "<= skip parse certificate" ) );
ssl->state++;
return( 0 );
}
if( ( ret = ssl_read_record( ssl ) ) != 0 )
{
SSL_DEBUG_RET( 1, "ssl_read_record", ret );
return( ret );
}
ssl->state++;
/*
* Check if the client sent an empty certificate
*/
if( ssl->endpoint == SSL_IS_SERVER &&
ssl->minor_ver == SSL_MINOR_VERSION_0 )
{
if( ssl->in_msglen == 2 &&
ssl->in_msgtype == SSL_MSG_ALERT &&
ssl->in_msg[0] == SSL_ALERT_WARNING &&
ssl->in_msg[1] == SSL_ALERT_NO_CERTIFICATE )
{
SSL_DEBUG_MSG( 1, ( "SSLv3 client has no certificate" ) );
if( ssl->authmode == SSL_VERIFY_OPTIONAL )
return( 0 );
else
return( POLARSSL_ERR_SSL_NO_CLIENT_CERTIFICATE );
}
}
if( ssl->endpoint == SSL_IS_SERVER &&
ssl->minor_ver != SSL_MINOR_VERSION_0 )
{
if( ssl->in_hslen == 7 &&
ssl->in_msgtype == SSL_MSG_HANDSHAKE &&
ssl->in_msg[0] == SSL_HS_CERTIFICATE &&
memcmp( ssl->in_msg + 4, "\0\0\0", 3 ) == 0 )
{
SSL_DEBUG_MSG( 1, ( "TLSv1 client has no certificate" ) );
if( ssl->authmode == SSL_VERIFY_REQUIRED )
return( POLARSSL_ERR_SSL_NO_CLIENT_CERTIFICATE );
else
return( 0 );
}
}
if( ssl->in_msgtype != SSL_MSG_HANDSHAKE )
{
SSL_DEBUG_MSG( 1, ( "bad certificate message" ) );
return( POLARSSL_ERR_SSL_UNEXPECTED_MESSAGE );
}
if( ssl->in_msg[0] != SSL_HS_CERTIFICATE || ssl->in_hslen < 10 )
{
SSL_DEBUG_MSG( 1, ( "bad certificate message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_CERTIFICATE );
}
/*
* Same message structure as in ssl_write_certificate()
*/
n = ( ssl->in_msg[5] << 8 ) | ssl->in_msg[6];
if( ssl->in_msg[4] != 0 || ssl->in_hslen != 7 + n )
{
SSL_DEBUG_MSG( 1, ( "bad certificate message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_CERTIFICATE );
}
if( ( ssl->peer_cert = (x509_cert *) malloc(
sizeof( x509_cert ) ) ) == NULL )
{
SSL_DEBUG_MSG( 1, ( "malloc(%d bytes) failed",
sizeof( x509_cert ) ) );
return( 1 );
}
memset( ssl->peer_cert, 0, sizeof( x509_cert ) );
i = 7;
while( i < ssl->in_hslen )
{
if( ssl->in_msg[i] != 0 )
{
SSL_DEBUG_MSG( 1, ( "bad certificate message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_CERTIFICATE );
}
n = ( (unsigned int) ssl->in_msg[i + 1] << 8 )
| (unsigned int) ssl->in_msg[i + 2];
i += 3;
if( n < 128 || i + n > ssl->in_hslen )
{
SSL_DEBUG_MSG( 1, ( "bad certificate message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_CERTIFICATE );
}
ret = x509parse_crt( ssl->peer_cert, ssl->in_msg + i, n );
if( ret != 0 )
{
SSL_DEBUG_RET( 1, " x509parse_crt", ret );
return( ret );
}
i += n;
}
SSL_DEBUG_CRT( 3, "peer certificate", ssl->peer_cert );
if( ssl->authmode != SSL_VERIFY_NONE )
{
if( ssl->ca_chain == NULL )
{
SSL_DEBUG_MSG( 1, ( "got no CA chain" ) );
return( POLARSSL_ERR_SSL_CA_CHAIN_REQUIRED );
}
ret = x509parse_verify( ssl->peer_cert, ssl->ca_chain,
ssl->peer_cn, &ssl->verify_result );
if( ret != 0 )
SSL_DEBUG_RET( 1, "x509_verify_cert", ret );
if( ssl->authmode != SSL_VERIFY_REQUIRED )
ret = 0;
}
SSL_DEBUG_MSG( 2, ( "<= parse certificate" ) );
return( ret );
}
int ssl_write_change_cipher_spec( ssl_context *ssl )
{
int ret;
SSL_DEBUG_MSG( 2, ( "=> write change cipher spec" ) );
ssl->out_msgtype = SSL_MSG_CHANGE_CIPHER_SPEC;
ssl->out_msglen = 1;
ssl->out_msg[0] = 1;
ssl->do_crypt = 0;
ssl->state++;
if( ( ret = ssl_write_record( ssl ) ) != 0 )
{
SSL_DEBUG_RET( 1, "ssl_write_record", ret );
return( ret );
}
SSL_DEBUG_MSG( 2, ( "<= write change cipher spec" ) );
return( 0 );
}
int ssl_parse_change_cipher_spec( ssl_context *ssl )
{
int ret;
SSL_DEBUG_MSG( 2, ( "=> parse change cipher spec" ) );
ssl->do_crypt = 0;
if( ( ret = ssl_read_record( ssl ) ) != 0 )
{
SSL_DEBUG_RET( 1, "ssl_read_record", ret );
return( ret );
}
if( ssl->in_msgtype != SSL_MSG_CHANGE_CIPHER_SPEC )
{
SSL_DEBUG_MSG( 1, ( "bad change cipher spec message" ) );
return( POLARSSL_ERR_SSL_UNEXPECTED_MESSAGE );
}
if( ssl->in_msglen != 1 || ssl->in_msg[0] != 1 )
{
SSL_DEBUG_MSG( 1, ( "bad change cipher spec message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_CHANGE_CIPHER_SPEC );
}
ssl->state++;
SSL_DEBUG_MSG( 2, ( "<= parse change cipher spec" ) );
return( 0 );
}
static void ssl_calc_finished(
ssl_context *ssl, unsigned char *buf, int from,
md5_context *md5, sha1_context *sha1 )
{
int len = 12;
char *sender;
unsigned char padbuf[48];
unsigned char md5sum[16];
unsigned char sha1sum[20];
SSL_DEBUG_MSG( 2, ( "=> calc finished" ) );
/*
* SSLv3:
* hash =
* MD5( master + pad2 +
* MD5( handshake + sender + master + pad1 ) )
* + SHA1( master + pad2 +
* SHA1( handshake + sender + master + pad1 ) )
*
* TLSv1:
* hash = PRF( master, finished_label,
* MD5( handshake ) + SHA1( handshake ) )[0..11]
*/
SSL_DEBUG_BUF( 4, "finished md5 state", (unsigned char *)
md5->state, sizeof( md5->state ) );
SSL_DEBUG_BUF( 4, "finished sha1 state", (unsigned char *)
sha1->state, sizeof( sha1->state ) );
if( ssl->minor_ver == SSL_MINOR_VERSION_0 )
{
sender = ( from == SSL_IS_CLIENT ) ? (char *) "CLNT"
: (char *) "SRVR";
memset( padbuf, 0x36, 48 );
md5_update( md5, (unsigned char *) sender, 4 );
md5_update( md5, ssl->session->master, 48 );
md5_update( md5, padbuf, 48 );
md5_finish( md5, md5sum );
sha1_update( sha1, (unsigned char *) sender, 4 );
sha1_update( sha1, ssl->session->master, 48 );
sha1_update( sha1, padbuf, 40 );
sha1_finish( sha1, sha1sum );
memset( padbuf, 0x5C, 48 );
md5_starts( md5 );
md5_update( md5, ssl->session->master, 48 );
md5_update( md5, padbuf, 48 );
md5_update( md5, md5sum, 16 );
md5_finish( md5, buf );
sha1_starts( sha1 );
sha1_update( sha1, ssl->session->master, 48 );
sha1_update( sha1, padbuf , 40 );
sha1_update( sha1, sha1sum, 20 );
sha1_finish( sha1, buf + 16 );
len += 24;
}
else
{
sender = ( from == SSL_IS_CLIENT )
? (char *) "client finished"
: (char *) "server finished";
md5_finish( md5, padbuf );
sha1_finish( sha1, padbuf + 16 );
tls1_prf( ssl->session->master, 48, sender,
padbuf, 36, buf, len );
}
SSL_DEBUG_BUF( 3, "calc finished result", buf, len );
memset( md5, 0, sizeof( md5_context ) );
memset( sha1, 0, sizeof( sha1_context ) );
memset( padbuf, 0, sizeof( padbuf ) );
memset( md5sum, 0, sizeof( md5sum ) );
memset( sha1sum, 0, sizeof( sha1sum ) );
SSL_DEBUG_MSG( 2, ( "<= calc finished" ) );
}
int ssl_write_finished( ssl_context *ssl )
{
int ret, hash_len;
md5_context md5;
sha1_context sha1;
SSL_DEBUG_MSG( 2, ( "=> write finished" ) );
memcpy( &md5 , &ssl->fin_md5 , sizeof( md5_context ) );
memcpy( &sha1, &ssl->fin_sha1, sizeof( sha1_context ) );
ssl_calc_finished( ssl, ssl->out_msg + 4,
ssl->endpoint, &md5, &sha1 );
hash_len = ( ssl->minor_ver == SSL_MINOR_VERSION_0 ) ? 36 : 12;
ssl->out_msglen = 4 + hash_len;
ssl->out_msgtype = SSL_MSG_HANDSHAKE;
ssl->out_msg[0] = SSL_HS_FINISHED;
/*
* In case of session resuming, invert the client and server
* ChangeCipherSpec messages order.
*/
if( ssl->resume != 0 )
{
if( ssl->endpoint == SSL_IS_CLIENT )
ssl->state = SSL_HANDSHAKE_OVER;
else
ssl->state = SSL_CLIENT_CHANGE_CIPHER_SPEC;
}
else
ssl->state++;
ssl->do_crypt = 1;
if( ( ret = ssl_write_record( ssl ) ) != 0 )
{
SSL_DEBUG_RET( 1, "ssl_write_record", ret );
return( ret );
}
SSL_DEBUG_MSG( 2, ( "<= write finished" ) );
return( 0 );
}
int ssl_parse_finished( ssl_context *ssl )
{
int ret, hash_len;
md5_context md5;
sha1_context sha1;
unsigned char buf[36];
SSL_DEBUG_MSG( 2, ( "=> parse finished" ) );
memcpy( &md5 , &ssl->fin_md5 , sizeof( md5_context ) );
memcpy( &sha1, &ssl->fin_sha1, sizeof( sha1_context ) );
ssl->do_crypt = 1;
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 finished message" ) );
return( POLARSSL_ERR_SSL_UNEXPECTED_MESSAGE );
}
hash_len = ( ssl->minor_ver == SSL_MINOR_VERSION_0 ) ? 36 : 12;
if( ssl->in_msg[0] != SSL_HS_FINISHED ||
ssl->in_hslen != 4 + hash_len )
{
SSL_DEBUG_MSG( 1, ( "bad finished message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_FINISHED );
}
ssl_calc_finished( ssl, buf, ssl->endpoint ^ 1, &md5, &sha1 );
if( memcmp( ssl->in_msg + 4, buf, hash_len ) != 0 )
{
SSL_DEBUG_MSG( 1, ( "bad finished message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_FINISHED );
}
if( ssl->resume != 0 )
{
if( ssl->endpoint == SSL_IS_CLIENT )
ssl->state = SSL_CLIENT_CHANGE_CIPHER_SPEC;
if( ssl->endpoint == SSL_IS_SERVER )
ssl->state = SSL_HANDSHAKE_OVER;
}
else
ssl->state++;
SSL_DEBUG_MSG( 2, ( "<= parse finished" ) );
return( 0 );
}
/*
* Initialize an SSL context
*/
int ssl_init( ssl_context *ssl )
{
int len = SSL_BUFFER_LEN;
memset( ssl, 0, sizeof( ssl_context ) );
ssl->in_ctr = (unsigned char *) malloc( len );
ssl->in_hdr = ssl->in_ctr + 8;
ssl->in_msg = ssl->in_ctr + 13;
if( ssl->in_ctr == NULL )
{
SSL_DEBUG_MSG( 1, ( "malloc(%d bytes) failed", len ) );
return( 1 );
}
ssl->out_ctr = (unsigned char *) malloc( len );
ssl->out_hdr = ssl->out_ctr + 8;
ssl->out_msg = ssl->out_ctr + 13;
if( ssl->out_ctr == NULL )
{
SSL_DEBUG_MSG( 1, ( "malloc(%d bytes) failed", len ) );
free( ssl-> in_ctr );
return( 1 );
}
memset( ssl-> in_ctr, 0, SSL_BUFFER_LEN );
memset( ssl->out_ctr, 0, SSL_BUFFER_LEN );
ssl->hostname = NULL;
ssl->hostname_len = 0;
md5_starts( &ssl->fin_md5 );
sha1_starts( &ssl->fin_sha1 );
return( 0 );
}
/*
* SSL set accessors
*/
void ssl_set_endpoint( ssl_context *ssl, int endpoint )
{
ssl->endpoint = endpoint;
}
void ssl_set_authmode( ssl_context *ssl, int authmode )
{
ssl->authmode = authmode;
}
void ssl_set_rng( ssl_context *ssl,
int (*f_rng)(void *),
void *p_rng )
{
ssl->f_rng = f_rng;
ssl->p_rng = p_rng;
}
void ssl_set_dbg( ssl_context *ssl,
void (*f_dbg)(void *, int, char *),
void *p_dbg )
{
ssl->f_dbg = f_dbg;
ssl->p_dbg = p_dbg;
}
void ssl_set_bio( ssl_context *ssl,
int (*f_recv)(void *, unsigned char *, int), void *p_recv,
int (*f_send)(void *, unsigned char *, int), void *p_send )
{
ssl->f_recv = f_recv;
ssl->f_send = f_send;
ssl->p_recv = p_recv;
ssl->p_send = p_send;
}
void ssl_set_scb( ssl_context *ssl,
int (*s_get)(ssl_context *),
int (*s_set)(ssl_context *) )
{
ssl->s_get = s_get;
ssl->s_set = s_set;
}
void ssl_set_session( ssl_context *ssl, int resume, int timeout,
ssl_session *session )
{
ssl->resume = resume;
ssl->timeout = timeout;
ssl->session = session;
}
void ssl_set_ciphers( ssl_context *ssl, int *ciphers )
{
ssl->ciphers = ciphers;
}
void ssl_set_ca_chain( ssl_context *ssl, x509_cert *ca_chain,
char *peer_cn )
{
ssl->ca_chain = ca_chain;
ssl->peer_cn = peer_cn;
}
void ssl_set_own_cert( ssl_context *ssl, x509_cert *own_cert,
rsa_context *rsa_key )
{
ssl->own_cert = own_cert;
ssl->rsa_key = rsa_key;
}
int ssl_set_dh_param( ssl_context *ssl, char *dhm_P, char *dhm_G )
{
int ret;
if( ( ret = mpi_read_string( &ssl->dhm_ctx.P, 16, dhm_P ) ) != 0 )
{
SSL_DEBUG_RET( 1, "mpi_read_string", ret );
return( ret );
}
if( ( ret = mpi_read_string( &ssl->dhm_ctx.G, 16, dhm_G ) ) != 0 )
{
SSL_DEBUG_RET( 1, "mpi_read_string", ret );
return( ret );
}
return( 0 );
}
int ssl_set_hostname( ssl_context *ssl, char *hostname )
{
if( hostname == NULL )
return( POLARSSL_ERR_SSL_BAD_INPUT_DATA );
ssl->hostname_len = strlen( hostname );
ssl->hostname = (unsigned char *) malloc( ssl->hostname_len );
memcpy( ssl->hostname, (unsigned char *) hostname,
ssl->hostname_len );
return( 0 );
}
/*
* SSL get accessors
*/
int ssl_get_bytes_avail( ssl_context *ssl )
{
return( ssl->in_offt == NULL ? 0 : ssl->in_msglen );
}
int ssl_get_verify_result( ssl_context *ssl )
{
return( ssl->verify_result );
}
char *ssl_get_cipher( ssl_context *ssl )
{
switch( ssl->session->cipher )
{
#if defined(POLARSSL_ARC4_C)
case SSL_RSA_RC4_128_MD5:
return( "SSL_RSA_RC4_128_MD5" );
case SSL_RSA_RC4_128_SHA:
return( "SSL_RSA_RC4_128_SHA" );
#endif
#if defined(POLARSSL_DES_C)
case SSL_RSA_DES_168_SHA:
return( "SSL_RSA_DES_168_SHA" );
case SSL_EDH_RSA_DES_168_SHA:
return( "SSL_EDH_RSA_DES_168_SHA" );
#endif
#if defined(POLARSSL_AES_C)
case SSL_RSA_AES_128_SHA:
return( "SSL_RSA_AES_128_SHA" );
case SSL_RSA_AES_256_SHA:
return( "SSL_RSA_AES_256_SHA" );
case SSL_EDH_RSA_AES_256_SHA:
return( "SSL_EDH_RSA_AES_256_SHA" );
#endif
#if defined(POLARSSL_CAMELLIA_C)
case SSL_RSA_CAMELLIA_128_SHA:
return( "SSL_RSA_CAMELLIA_128_SHA" );
case SSL_RSA_CAMELLIA_256_SHA:
return( "SSL_RSA_CAMELLIA_256_SHA" );
case SSL_EDH_RSA_CAMELLIA_256_SHA:
return( "SSL_EDH_RSA_CAMELLIA_256_SHA" );
#endif
default:
break;
}
return( "unknown" );
}
int ssl_default_ciphers[] =
{
#if defined(POLARSSL_DHM_C)
#if defined(POLARSSL_AES_C)
SSL_EDH_RSA_AES_256_SHA,
#endif
#if defined(POLARSSL_CAMELLIA_C)
SSL_EDH_RSA_CAMELLIA_256_SHA,
#endif
#if defined(POLARSSL_DES_C)
SSL_EDH_RSA_DES_168_SHA,
#endif
#endif
#if defined(POLARSSL_AES_C)
SSL_RSA_AES_256_SHA,
#endif
#if defined(POLARSSL_CAMELLIA_C)
SSL_RSA_CAMELLIA_256_SHA,
#endif
#if defined(POLARSSL_AES_C)
SSL_RSA_AES_128_SHA,
#endif
#if defined(POLARSSL_CAMELLIA_C)
SSL_RSA_CAMELLIA_128_SHA,
#endif
#if defined(POLARSSL_DES_C)
SSL_RSA_DES_168_SHA,
#endif
#if defined(POLARSSL_ARC4_C)
SSL_RSA_RC4_128_SHA,
SSL_RSA_RC4_128_MD5,
#endif
0
};
/*
* Perform the SSL handshake
*/
int ssl_handshake( ssl_context *ssl )
{
int ret = POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE;
SSL_DEBUG_MSG( 2, ( "=> handshake" ) );
#if defined(POLARSSL_SSL_CLI_C)
if( ssl->endpoint == SSL_IS_CLIENT )
ret = ssl_handshake_client( ssl );
#endif
#if defined(POLARSSL_SSL_SRV_C)
if( ssl->endpoint == SSL_IS_SERVER )
ret = ssl_handshake_server( ssl );
#endif
SSL_DEBUG_MSG( 2, ( "<= handshake" ) );
return( ret );
}
/*
* Receive application data decrypted from the SSL layer
*/
int ssl_read( ssl_context *ssl, unsigned char *buf, int len )
{
int ret, n;
SSL_DEBUG_MSG( 2, ( "=> read" ) );
if( ssl->state != SSL_HANDSHAKE_OVER )
{
if( ( ret = ssl_handshake( ssl ) ) != 0 )
{
SSL_DEBUG_RET( 1, "ssl_handshake", ret );
return( ret );
}
}
if( ssl->in_offt == NULL )
{
if( ( ret = ssl_read_record( ssl ) ) != 0 )
{
SSL_DEBUG_RET( 1, "ssl_read_record", ret );
return( ret );
}
if( ssl->in_msglen == 0 &&
ssl->in_msgtype == SSL_MSG_APPLICATION_DATA )
{
/*
* OpenSSL sends empty messages to randomize the IV
*/
if( ( ret = ssl_read_record( ssl ) ) != 0 )
{
SSL_DEBUG_RET( 1, "ssl_read_record", ret );
return( ret );
}
}
if( ssl->in_msgtype != SSL_MSG_APPLICATION_DATA )
{
SSL_DEBUG_MSG( 1, ( "bad application data message" ) );
return( POLARSSL_ERR_SSL_UNEXPECTED_MESSAGE );
}
ssl->in_offt = ssl->in_msg;
}
n = ( len < ssl->in_msglen )
? len : ssl->in_msglen;
memcpy( buf, ssl->in_offt, n );
ssl->in_msglen -= n;
if( ssl->in_msglen == 0 )
/* all bytes consumed */
ssl->in_offt = NULL;
else
/* more data available */
ssl->in_offt += n;
SSL_DEBUG_MSG( 2, ( "<= read" ) );
return( n );
}
/*
* Send application data to be encrypted by the SSL layer
*/
int ssl_write( ssl_context *ssl, unsigned char *buf, int len )
{
int ret, n;
SSL_DEBUG_MSG( 2, ( "=> write" ) );
if( ssl->state != SSL_HANDSHAKE_OVER )
{
if( ( ret = ssl_handshake( ssl ) ) != 0 )
{
SSL_DEBUG_RET( 1, "ssl_handshake", ret );
return( ret );
}
}
n = ( len < SSL_MAX_CONTENT_LEN )
? len : SSL_MAX_CONTENT_LEN;
if( ssl->out_left != 0 )
{
if( ( ret = ssl_flush_output( ssl ) ) != 0 )
{
SSL_DEBUG_RET( 1, "ssl_flush_output", ret );
return( ret );
}
}
else
{
ssl->out_msglen = n;
ssl->out_msgtype = SSL_MSG_APPLICATION_DATA;
memcpy( ssl->out_msg, buf, n );
if( ( ret = ssl_write_record( ssl ) ) != 0 )
{
SSL_DEBUG_RET( 1, "ssl_write_record", ret );
return( ret );
}
}
SSL_DEBUG_MSG( 2, ( "<= write" ) );
return( n );
}
/*
* Notify the peer that the connection is being closed
*/
int ssl_close_notify( ssl_context *ssl )
{
int ret;
SSL_DEBUG_MSG( 2, ( "=> write close notify" ) );
if( ( ret = ssl_flush_output( ssl ) ) != 0 )
{
SSL_DEBUG_RET( 1, "ssl_flush_output", ret );
return( ret );
}
if( ssl->state == SSL_HANDSHAKE_OVER )
{
ssl->out_msgtype = SSL_MSG_ALERT;
ssl->out_msglen = 2;
ssl->out_msg[0] = SSL_ALERT_WARNING;
ssl->out_msg[1] = SSL_ALERT_CLOSE_NOTIFY;
if( ( ret = ssl_write_record( ssl ) ) != 0 )
{
SSL_DEBUG_RET( 1, "ssl_write_record", ret );
return( ret );
}
}
SSL_DEBUG_MSG( 2, ( "<= write close notify" ) );
return( ret );
}
/*
* Free an SSL context
*/
void ssl_free( ssl_context *ssl )
{
SSL_DEBUG_MSG( 2, ( "=> free" ) );
if( ssl->peer_cert != NULL )
{
x509_free( ssl->peer_cert );
memset( ssl->peer_cert, 0, sizeof( x509_cert ) );
free( ssl->peer_cert );
}
if( ssl->out_ctr != NULL )
{
memset( ssl->out_ctr, 0, SSL_BUFFER_LEN );
free( ssl->out_ctr );
}
if( ssl->in_ctr != NULL )
{
memset( ssl->in_ctr, 0, SSL_BUFFER_LEN );
free( ssl->in_ctr );
}
#if defined(POLARSSL_DHM_C)
dhm_free( &ssl->dhm_ctx );
#endif
if ( ssl->hostname != NULL)
{
memset( ssl->hostname, 0, ssl->hostname_len );
free( ssl->hostname );
ssl->hostname_len = 0;
}
SSL_DEBUG_MSG( 2, ( "<= free" ) );
/* Actually free after last debug message */
memset( ssl, 0, sizeof( ssl_context ) );
}
#endif