- Added proper support for TLS 1.2 signature_algorithm extension on server

side
 - Minor const changes to other extension parsing functions
This commit is contained in:
Paul Bakker 2012-09-28 14:15:14 +00:00
parent 1d29fb5e33
commit 23f3680898
4 changed files with 170 additions and 21 deletions

View File

@ -350,6 +350,7 @@ struct _ssl_handshake_params
/*
* Handshake specific crypto variables
*/
int sig_alg; /*!< Signature algorithm */
#if defined(POLARSSL_DHM_C)
dhm_context dhm_ctx; /*!< DHM key exchange */
#endif

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@ -701,7 +701,7 @@ static int ssl_parse_server_key_exchange( ssl_context *ssl )
{
if( p[1] != SSL_SIG_RSA )
{
SSL_DEBUG_MSG( 2, ( "Server used unsupported SignatureAlgorithm %d", p[1] ) );
SSL_DEBUG_MSG( 2, ( "server used unsupported SignatureAlgorithm %d", p[1] ) );
SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
}

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@ -35,12 +35,12 @@
#include <time.h>
static int ssl_parse_servername_ext( ssl_context *ssl,
unsigned char *buf,
const unsigned char *buf,
size_t len )
{
int ret;
size_t servername_list_size, hostname_len;
unsigned char *p;
const unsigned char *p;
servername_list_size = ( ( buf[0] << 8 ) | ( buf[1] ) );
if( servername_list_size + 2 != len )
@ -72,13 +72,20 @@ static int ssl_parse_servername_ext( ssl_context *ssl,
}
servername_list_size -= hostname_len + 3;
p += hostname_len + 3;
}
if( servername_list_size != 0 )
{
SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
return( 0 );
}
static int ssl_parse_renegotiation_info( ssl_context *ssl,
unsigned char *buf,
const unsigned char *buf,
size_t len )
{
int ret;
@ -115,6 +122,71 @@ static int ssl_parse_renegotiation_info( ssl_context *ssl,
return( 0 );
}
static int ssl_parse_signature_algorithms_ext( ssl_context *ssl,
const unsigned char *buf,
size_t len )
{
size_t sig_alg_list_size;
const unsigned char *p;
sig_alg_list_size = ( ( buf[0] << 8 ) | ( buf[1] ) );
if( sig_alg_list_size + 2 != len ||
sig_alg_list_size %2 != 0 )
{
SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
p = buf + 2;
while( sig_alg_list_size > 0 )
{
if( p[1] != SSL_SIG_RSA )
continue;
#if defined(POLARSSL_SHA4_C)
if( p[0] == SSL_HASH_SHA512 )
{
ssl->handshake->sig_alg = SSL_HASH_SHA512;
break;
}
if( p[0] == SSL_HASH_SHA384 )
{
ssl->handshake->sig_alg = SSL_HASH_SHA384;
break;
}
#endif
#if defined(POLARSSL_SHA2_C)
if( p[0] == SSL_HASH_SHA256 )
{
ssl->handshake->sig_alg = SSL_HASH_SHA256;
break;
}
if( p[0] == SSL_HASH_SHA224 )
{
ssl->handshake->sig_alg = SSL_HASH_SHA224;
break;
}
#endif
if( p[0] == SSL_HASH_SHA1 )
{
ssl->handshake->sig_alg = SSL_HASH_SHA1;
break;
}
if( p[0] == SSL_HASH_MD5 )
{
ssl->handshake->sig_alg = SSL_HASH_MD5;
break;
}
sig_alg_list_size -= 2;
p += 2;
}
SSL_DEBUG_MSG( 3, ( "client hello v3, signature_algorithm ext: %d",
ssl->handshake->sig_alg ) );
return( 0 );
}
static int ssl_parse_client_hello( ssl_context *ssl )
{
int ret;
@ -399,9 +471,19 @@ have_ciphersuite:
SSL_DEBUG_MSG( 3, ( "found renegotiation extension" ) );
renegotiation_info_seen = 1;
if( ( ret = ssl_parse_renegotiation_info( ssl, ext + 4, ext_size ) ) != 0 )
ret = ssl_parse_renegotiation_info( ssl, ext + 4, ext_size );
if( ret != 0 )
return( ret );
break;
case TLS_EXT_SIG_ALG:
SSL_DEBUG_MSG( 3, ( "found signature_algorithms extension" ) );
if( ssl->renegotiation == SSL_RENEGOTIATION )
break;
ret = ssl_parse_signature_algorithms_ext( ssl, ext + 4, ext_size );
if( ret != 0 )
return( ret );
break;
default:
@ -671,9 +753,7 @@ static int ssl_write_server_key_exchange( ssl_context *ssl )
#if defined(POLARSSL_DHM_C)
int ret;
size_t n, rsa_key_len = 0;
unsigned char hash[48];
md5_context md5;
sha1_context sha1;
unsigned char hash[64];
int hash_id;
unsigned int hashlen;
#endif
@ -741,6 +821,9 @@ static int ssl_write_server_key_exchange( ssl_context *ssl )
if( ssl->minor_ver != SSL_MINOR_VERSION_3 )
{
md5_context md5;
sha1_context sha1;
/*
* digitally-signed struct {
* opaque md5_hash[16];
@ -776,17 +859,82 @@ static int ssl_write_server_key_exchange( ssl_context *ssl )
* ServerDHParams params;
* };
*/
/* TODO TLS1.2 Get a supported hash algorithm from the
* signature_algorithms extension, Otherwise SHA1 + RSA!
*/
sha1_starts( &sha1 );
sha1_update( &sha1, ssl->handshake->randbytes, 64 );
sha1_update( &sha1, ssl->out_msg + 4, n );
sha1_finish( &sha1, hash );
#if defined(POLARSSL_SHA4_C)
if( ssl->handshake->sig_alg == SSL_HASH_SHA512 )
{
sha4_context sha4;
hashlen = 20;
hash_id = SIG_RSA_SHA1;
sha4_starts( &sha4, 0 );
sha4_update( &sha4, ssl->handshake->randbytes, 64 );
sha4_update( &sha4, ssl->out_msg + 4, n );
sha4_finish( &sha4, hash );
hashlen = 64;
hash_id = SIG_RSA_SHA512;
}
if( ssl->handshake->sig_alg == SSL_HASH_SHA384 )
{
sha4_context sha4;
sha4_starts( &sha4, 1 );
sha4_update( &sha4, ssl->handshake->randbytes, 64 );
sha4_update( &sha4, ssl->out_msg + 4, n );
sha4_finish( &sha4, hash );
hashlen = 48;
hash_id = SIG_RSA_SHA384;
}
#endif
#if defined(POLARSSL_SHA2_C)
if( ssl->handshake->sig_alg == SSL_HASH_SHA256 )
{
sha2_context sha2;
sha2_starts( &sha2, 0 );
sha2_update( &sha2, ssl->handshake->randbytes, 64 );
sha2_update( &sha2, ssl->out_msg + 4, n );
sha2_finish( &sha2, hash );
hashlen = 32;
hash_id = SIG_RSA_SHA256;
}
if( ssl->handshake->sig_alg == SSL_HASH_SHA224 )
{
sha2_context sha2;
sha2_starts( &sha2, 1 );
sha2_update( &sha2, ssl->handshake->randbytes, 64 );
sha2_update( &sha2, ssl->out_msg + 4, n );
sha2_finish( &sha2, hash );
hashlen = 24;
hash_id = SIG_RSA_SHA224;
}
#endif
if( ssl->handshake->sig_alg == SSL_HASH_SHA1 )
{
sha1_context sha1;
sha1_starts( &sha1 );
sha1_update( &sha1, ssl->handshake->randbytes, 64 );
sha1_update( &sha1, ssl->out_msg + 4, n );
sha1_finish( &sha1, hash );
hashlen = 20;
hash_id = SIG_RSA_SHA1;
}
if( ssl->handshake->sig_alg == SSL_HASH_MD5 )
{
md5_context md5;
md5_starts( &md5 );
md5_update( &md5, ssl->handshake->randbytes, 64 );
md5_update( &md5, ssl->out_msg + 4, n );
md5_finish( &md5, hash );
hashlen = 16;
hash_id = SIG_RSA_MD5;
}
}
SSL_DEBUG_BUF( 3, "parameters hash", hash, hashlen );
@ -796,8 +944,7 @@ static int ssl_write_server_key_exchange( ssl_context *ssl )
if( ssl->minor_ver == SSL_MINOR_VERSION_3 )
{
// TODO TLS1.2 Base on selection above (SHA1 + RSA is default choice)
ssl->out_msg[4 + n] = SSL_HASH_SHA1;
ssl->out_msg[4 + n] = ssl->handshake->sig_alg;
ssl->out_msg[5 + n] = SSL_SIG_RSA;
n += 2;

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@ -2834,7 +2834,8 @@ int ssl_handshake_init( ssl_context *ssl )
sha4_starts( &ssl->handshake->fin_sha4, 1 );
ssl->handshake->update_checksum = ssl_update_checksum_start;
ssl->handshake->sig_alg = SSL_HASH_SHA1;
return( 0 );
}