/* ========= ClientKeyExchange ========= */
int ssl3_decode_client_key_exchange( DSSL_Session* sess, u_char* data, uint32_t len )
{
EVP_PKEY *pk = NULL;
u_char* org_data = data;
uint32_t org_len = len;
int pms_len = 0;
int rc = DSSL_RC_OK;
if( sess->version < SSL3_VERSION || sess->version > TLS1_2_VERSION )
{
return NM_ERROR( DSSL_E_SSL_UNKNOWN_VERSION );
}
/*
TLS is different as it sends the record length, while SSL3 implementaions don't
(due to a bug in Netscape implementation)
*/
if( sess->version > SSL3_VERSION )
{
uint16_t recLen = 0;
if( !IS_ENOUGH_LENGTH( org_data, org_len, data, 2 ) )
{
return NM_ERROR( DSSL_E_SSL_INVALID_RECORD_LENGTH );
}
recLen = MAKE_UINT16( data[0], data[1] );
if( len != (uint32_t)recLen + 2 )
{
/*TODO: set an option to tolerate this bug?*/
return NM_ERROR( DSSL_E_SSL_INVALID_RECORD_LENGTH );
}
/* advance */
data += len - recLen;
len = recLen;
}
if( !IS_ENOUGH_LENGTH( org_data, org_len, data, SSL_MAX_MASTER_KEY_LENGTH ) )
{
return NM_ERROR( DSSL_E_SSL_INVALID_RECORD_LENGTH );
}
pk = ssls_get_session_private_key( sess );
/* if SSL server key is not found, try to find a matching one from the key pool */
if(pk == NULL)
{
_ASSERT( sess->last_packet);
pk = ssls_try_ssl_keys( sess, data, len );
/* if a matching key found, register it with the server IP:port */
if(pk != NULL)
{
if( ssls_register_ssl_key( sess, pk ) == DSSL_RC_OK)
{
/* ssls_register_ssl_key clones the key, query the key back */
pk = ssls_get_session_private_key( sess );
}
else
{
pk = NULL;
}
}
}
if(!pk)
{
ssls_register_missing_key_server( sess );
return NM_ERROR( DSSL_E_SSL_SERVER_KEY_UNKNOWN );
}
if(pk->type != EVP_PKEY_RSA) return NM_ERROR( DSSL_E_SSL_CANNOT_DECRYPT_NON_RSA );
pms_len = RSA_private_decrypt( len, data, sess->PMS, pk->pkey.rsa, RSA_PKCS1_PADDING );
if( pms_len != SSL_MAX_MASTER_KEY_LENGTH )
{
return NM_ERROR( DSSL_E_SSL_CORRUPTED_PMS );
}
if( MAKE_UINT16( sess->PMS[0], sess->PMS[1] ) != sess->client_version )
{
return NM_ERROR( DSSL_E_SSL_PMS_VERSION_ROLLBACK );
}
rc = ssls_decode_master_secret( sess );
OPENSSL_cleanse(sess->PMS, sizeof(sess->PMS) );
if( rc != DSSL_RC_OK ) return rc;
rc = ssls_generate_keys( sess );
if( rc == DSSL_RC_OK )
{
ssls_store_session( sess );
}
return rc;
}
/* ========== CLIENT-MASTER-KEY ========== */
static int ssl2_decode_client_master_key( DSSL_Session* sess, u_char* data, uint32_t len, uint32_t* processed )
{
int rc = DSSL_RC_OK;
uint16_t clearKeyLen = 0;
uint16_t encKeyLen = 0;
uint16_t keyArgLen = 0;
u_char* pClearKey = NULL;
u_char* pEncKey = NULL;
u_char* pKeyArg = NULL;
_ASSERT( processed && data && sess );
if( len < SSL20_CLIENT_MASTER_KEY_MIN_LEN ) { return NM_ERROR( DSSL_E_SSL_INVALID_RECORD_LENGTH ); }
/* CIPHER-KIND - convert to 2 byte DSSL_Session::cipher_suite */
rc = DSSL_ConvertSSL2CipherSuite( data, &sess->cipher_suite );
/* CLEAR-KEY-LENGTH, ENCRYPTED-KEY-LENGTH, KEY-ARG-LENGTH */
if( rc == DSSL_RC_OK )
{
clearKeyLen = MAKE_UINT16( data[3], data[4] );
encKeyLen = MAKE_UINT16( data[5], data[6] );
keyArgLen = MAKE_UINT16( data[7], data[8] );
if( len != (uint32_t)clearKeyLen + encKeyLen + keyArgLen + SSL20_CLIENT_MASTER_KEY_MIN_LEN )
{
rc = NM_ERROR( DSSL_E_SSL_INVALID_RECORD_LENGTH );
}
*processed = len;
}
/* reconstitute the master secret */
if( rc == DSSL_RC_OK )
{
EVP_PKEY *pk = NULL;
pClearKey = data + SSL20_CLIENT_MASTER_KEY_MIN_LEN;
pEncKey = pClearKey + clearKeyLen;
pKeyArg = pEncKey + encKeyLen;
if( clearKeyLen ) { memcpy( sess->master_secret, pClearKey, clearKeyLen ); }
pk = ssls_get_session_private_key( sess );
/* if SSL server key is not found, try to find a matching one from the key pool */
if(pk == NULL)
{
u_char buff[1024];
_ASSERT( sess->last_packet);
memcpy(buff, pEncKey, encKeyLen);
pk = ssls_try_ssl_keys( sess, pEncKey, encKeyLen );
/* if a matching key found, register it with the server IP:port */
if(pk != NULL)
{
if( ssls_register_ssl_key( sess, pk ) == DSSL_RC_OK)
{
/* ssls_register_ssl_key clones the key, query the key back */
//pk = ssls_get_session_private_key( sess );
}
else
{
pk = NULL;
}
}
}
if( pk )
{
uint32_t encLen2 = RSA_private_decrypt( encKeyLen, pEncKey,
sess->master_secret + clearKeyLen, pk->pkey.rsa, RSA_PKCS1_PADDING );
if( clearKeyLen + encLen2 >= sizeof( sess->master_secret ) )
{
rc = NM_ERROR( DSSL_E_SSL_PROTOCOL_ERROR );
}
sess->master_key_len = clearKeyLen + encLen2;
}
else
{
rc = NM_ERROR( DSSL_E_SSL_SERVER_KEY_UNKNOWN );
ssls_register_missing_key_server( sess );
}
}
/* generate session keys */
if( rc == DSSL_RC_OK )
{
rc = ssls2_generate_keys( sess, pKeyArg, keyArgLen );
}
/* turn on new ciphers */
if( rc == DSSL_RC_OK )
{
rc = dssl_decoder_stack_flip_cipher( &sess->c_dec );
if (rc == DSSL_RC_OK ) { rc = dssl_decoder_stack_flip_cipher( &sess->s_dec ); }
}
return rc;
}
