int ssl3_record_layer_decoder( void* decoder_stack, NM_PacketDir dir,
u_char* data, uint32_t len, uint32_t* processed )
{
int rc = DSSL_E_UNSPECIFIED_ERROR;
uint32_t recLen = 0, totalRecLen = 0;
uint8_t record_type = 0;
dssl_decoder_stack* stack = (dssl_decoder_stack*) decoder_stack;
dssl_decoder* next_decoder = NULL;
int decrypt_buffer_aquired = 0;
int decompress_buffer_aquired = 0;
int i = 0;
char * data2 = NULL;
uint32_t recLen2 = 0;
int block_size = 0;
DEBUG_TRACE1("ssl_record_layer_decoder - start. len: %d\n", len);
_ASSERT( stack );
_ASSERT( processed );
_ASSERT( stack->sess );
/*
for (i=0; i < len; i++)
{
printf("0x%02X ", data[i]);
}
*/
if( stack->state > SS_Established )
{
#ifdef NM_TRACE_SSL_RECORD
DEBUG_TRACE1( "[!]Unexpected SSL record after %s",
( (stack->state == SS_FatalAlert) ? "fatal alert" : "close_notify alert") );
#endif
return NM_ERROR( DSSL_E_SSL_UNEXPECTED_TRANSMISSION );
}
/* special case for a first client hello */
DEBUG_TRACE1("ssl_record_layer_decoder - version: 0x%02X\n", stack->sess->version);
if( stack->sess->version == 0 )
{
_ASSERT( dir == ePacketDirFromClient );
rc = ssl_decode_first_client_hello( stack->sess, data, len, processed );
return rc;
}
if( len < SSL3_HEADER_LEN ) return NM_ERROR( DSSL_E_SSL_INVALID_RECORD_LENGTH );
if( data[1] != 3) return NM_ERROR( DSSL_E_SSL_PROTOCOL_ERROR );
/* Decode record type */
record_type = data[0];
totalRecLen = recLen = MAKE_UINT16( data[3], data[4] );
DEBUG_TRACE1("ssl_record_layer_decoder - record_type: %d\n", record_type);
DEBUG_TRACE1("ssl_record_layer_decoder - recLen: %d\n", recLen);
/*
for (i = 0; i < 128; i++)
{
printf("ssl_tls_record_layer_decoder - data before skip header size [%d]: %d\n", i, data[i]);
}
*/
data += SSL3_HEADER_LEN;
len -= SSL3_HEADER_LEN;
DEBUG_TRACE1("ssl_record_layer_decoder - len after header adjustments: %d\n", len);
/*
for (i=0; i < len; i++)
{
printf("0x%02X ", data[i]);
}
*/
#ifdef NM_TRACE_SSL_RECORD
DEBUG_TRACE2( "\n==>Decoding SSL v3 Record, type: %d, len: %d\n{\n", (int) record_type, (int) recLen );
#endif
rc = DSSL_RC_OK;
if( len < recLen )
{
rc = DSSL_RC_WOULD_BLOCK;
DEBUG_TRACE0("ssl_tls_record_layer_decoder - rc is DSSL_RC_WOULD_BLOCK\n");
}
if( rc == DSSL_RC_OK && stack->cipher )
{
rc = ssl_decrypt_record( stack, data, recLen, &data, &recLen, &decrypt_buffer_aquired,&block_size );
DEBUG_TRACE1("ssl_record_layer_decoder - ssl_decrypt_record ret: %d\n", rc);
}
/* check if the record length is still within bounds (failed decryption, etc) */
if( rc == DSSL_RC_OK && (recLen > RFC_2246_MAX_COMPRESSED_LENGTH ||
recLen > len || (stack->md && recLen < EVP_MD_size(stack->md))) )
{
rc = NM_ERROR(DSSL_E_SSL_INVALID_RECORD_LENGTH);
}
if( rc == DSSL_RC_OK && stack->md )
{
u_char mac[EVP_MAX_MD_SIZE];
u_char* rec_mac = NULL;
DEBUG_TRACE1("ssl_record_layer_decoder - data using len: %d\n", len);
/*
for (i=0; i < len; i++)
{
printf("0x%02X ", data[i]);
}
*/
recLen -= EVP_MD_size( stack->md );
rec_mac = data+recLen;
memset(mac, 0, sizeof(mac) );
// Fix - skip iv for TLS 1.1
DEBUG_TRACE1("ssl_record_layer_decoder - stack->version: 0x%02X\n", stack->version);
DEBUG_TRACE1("ssl_record_layer_decoder - block_size: %d\n", block_size);
if (stack->version > TLS1_VERSION && block_size > 1)
{
DEBUG_TRACE0("ssl_record_layer_decoder - activated fix for TLS 1.1 (skip 16 bytes)\n");
data2 = data + block_size;
recLen2 = recLen - block_size;
rc = stack->sess->caclulate_mac_proc( stack, record_type, data2, recLen2, mac );
}
else
{
rc = stack->sess->caclulate_mac_proc( stack, record_type, data, recLen, mac );
}
DEBUG_TRACE1("ssl_record_layer_decoder - caclulate_mac_proc result: %d\n", rc);
if( rc == DSSL_RC_OK )
{
DEBUG_TRACE1("ssl_record_layer_decoder - caclulate_mac_proc memcmp size(i.e. EVP_MD_size(stack->md)): %d\n", EVP_MD_size(stack->md));
DEBUG_TRACE0("ssl_record_layer_decoder - mac vs. rec_mac:\n");
if (IsDebugEnabled())
{
for (i=0; i < EVP_MD_size(stack->md); i++)
{
DEBUG_TRACE2("0x%02X vs. 0x%02X\n", mac[i], rec_mac[i]);
}
}
rc = memcmp( mac, rec_mac, EVP_MD_size(stack->md) ) == 0 ? DSSL_RC_OK : NM_ERROR( DSSL_E_SSL_INVALID_MAC );
}
}
if( rc == DSSL_RC_OK && stack->compression_method != 0 )
{
rc = ssl_decompress_record( stack, data, recLen, &data, &recLen, &decompress_buffer_aquired );
DEBUG_TRACE1("ssl_record_layer_decoder - ssl_decompress_record call ended. rc: %d\n", rc);
}
if( rc == DSSL_RC_OK )
{
DEBUG_TRACE1("ssl_record_layer_decoder - record_type: %d\n", record_type);
switch( record_type )
{
case SSL3_RT_HANDSHAKE:
DEBUG_TRACE0("ssl_record_layer_decoder - SSL3_RT_HANDSHAKE\n");
next_decoder = &stack->dhandshake;
break;
case SSL3_RT_CHANGE_CIPHER_SPEC:
DEBUG_TRACE0("ssl_record_layer_decoder - SSL3_RT_CHANGE_CIPHER_SPEC\n");
next_decoder = &stack->dcss;
break;
case SSL3_RT_APPLICATION_DATA:
DEBUG_TRACE0("ssl_record_layer_decoder - SSL3_RT_APPLICATION_DATA\n");
next_decoder = &stack->dappdata;
break;
case SSL3_RT_ALERT:
DEBUG_TRACE0("ssl_record_layer_decoder - SSL3_RT_ALERT\n");
next_decoder = &stack->dalert;
break;
default:
DEBUG_TRACE0("ssl_record_layer_decoder - record_type not found\n");
rc = NM_ERROR( DSSL_E_SSL_PROTOCOL_ERROR );
}
}
if( rc == DSSL_RC_OK )
{
_ASSERT( next_decoder != NULL );
DEBUG_TRACE1("ssl_record_layer_decoder - calling dssl_decoder_process. handler is: %x\n", next_decoder->handler);
// Fix - for TLS 1.1 continue
if (data2 == NULL)
rc = dssl_decoder_process( next_decoder, dir, data, recLen );
else
rc = dssl_decoder_process( next_decoder, dir, data2, recLen2 );
DEBUG_TRACE1("ssl_record_layer_decoder - dssl_decoder_process ret: %d\n", rc);
}
if( rc == DSSL_RC_OK )
{
*processed = totalRecLen + SSL3_HEADER_LEN;
}
if( decrypt_buffer_aquired )
{
ssls_release_decrypt_buffer( stack->sess );
}
if( decompress_buffer_aquired )
{
ssls_release_decompress_buffer( stack->sess );
}
#ifdef NM_TRACE_SSL_RECORD
DEBUG_TRACE1( "\n} rc: %d\n", (int) rc);
#endif
if( stack->state == SS_SeenCloseNotify )
{
stack->sess->flags |= SSF_CLOSE_NOTIFY_RECEIVED;
} else if ( stack->state == SS_FatalAlert )
{
stack->sess->flags |= SSF_FATAL_ALERT_RECEIVED;
}
DEBUG_TRACE1("ssl_record_layer_decoder - end. rc = %d\n", rc);
return rc;
}
int ssl3_record_layer_decoder( void* decoder_stack, NM_PacketDir dir,
u_char* data, uint32_t len, uint32_t* processed )
{
int rc = DSSL_E_UNSPECIFIED_ERROR;
uint32_t recLen = 0, totalRecLen = 0;
uint8_t record_type = 0;
dssl_decoder_stack* stack = (dssl_decoder_stack*) decoder_stack;
dssl_decoder* next_decoder = NULL;
int decrypt_buffer_aquired = 0;
int decompress_buffer_aquired = 0;
_ASSERT( stack );
_ASSERT( processed );
_ASSERT( stack->sess );
if( stack->state > SS_Established )
{
#ifdef NM_TRACE_SSL_RECORD
DEBUG_TRACE1( "[!]Unexpected SSL record after %s",
( (stack->state == SS_FatalAlert) ? "fatal alert" : "close_notify alert") );
#endif
return NM_ERROR( DSSL_E_SSL_UNEXPECTED_TRANSMISSION );
}
/* special case for a first client hello */
if( stack->sess->version == 0 )
{
_ASSERT( dir == ePacketDirFromClient );
rc = ssl_decode_first_client_hello( stack->sess, data, len, processed );
return rc;
}
if( len < SSL3_HEADER_LEN ) return NM_ERROR( DSSL_E_SSL_INVALID_RECORD_LENGTH );
if( data[1] != 3) return NM_ERROR( DSSL_E_SSL_PROTOCOL_ERROR );
/* Decode record type */
record_type = data[0];
totalRecLen = recLen = MAKE_UINT16( data[3], data[4] );
data += SSL3_HEADER_LEN;
len -= SSL3_HEADER_LEN;
#ifdef NM_TRACE_SSL_RECORD
DEBUG_TRACE3( "\n==>Decoding SSL v3 Record from %s, type: %d, len: %d\n{\n", ((dir == ePacketDirFromClient)?"client":"server"), (int) record_type, (int) recLen );
#endif
rc = DSSL_RC_OK;
if( len < recLen ) { rc = DSSL_RC_WOULD_BLOCK; }
if( rc == DSSL_RC_OK && stack->cipher )
{
rc = ssl_decrypt_record( stack, data, recLen, &data, &recLen, &decrypt_buffer_aquired );
}
/* check if the record length is still within bounds (failed decryption, etc) */
if( rc == DSSL_RC_OK && (recLen > RFC_2246_MAX_COMPRESSED_LENGTH ||
recLen > len || (stack->sess->version < TLS1_2_VERSION && stack->md && recLen < EVP_MD_size(stack->md))) )
{
rc = NM_ERROR(DSSL_E_SSL_INVALID_RECORD_LENGTH);
}
if( rc == DSSL_RC_OK && stack->md )
{
u_char mac[EVP_MAX_MD_SIZE*2];
u_char* rec_mac = NULL;
int l = EVP_MD_size( stack->md );
int ivl = EVP_CIPHER_iv_length( stack->cipher->cipher );
if ( EVP_CIPH_CBC_MODE == stack->sess->cipher_mode || EVP_CIPH_STREAM_CIPHER == stack->sess->cipher_mode )
recLen -= l;
rec_mac = data+recLen;
memset(mac, 0, sizeof(mac) );
/* TLS 1.1 and later: remove explicit IV for non-stream ciphers */
if ( EVP_CIPH_CBC_MODE == stack->sess->cipher_mode )
{
if (stack->sess->version >= TLS1_1_VERSION )
{
if (ivl <= recLen) {
recLen -= ivl;
data += ivl;
}
}
}
/* AEAD ciphers have no mac */
if ( EVP_CIPH_CBC_MODE == stack->sess->cipher_mode || EVP_CIPH_STREAM_CIPHER == stack->sess->cipher_mode )
{
rc = stack->sess->caclulate_mac_proc( stack, record_type, data, recLen, mac );
if( rc == DSSL_RC_OK )
{
rc = memcmp( mac, rec_mac, l ) == 0 ? DSSL_RC_OK : NM_ERROR( DSSL_E_SSL_INVALID_MAC );
}
}
}
if( rc == DSSL_RC_OK && stack->compression_method != 0 )
{
rc = ssl_decompress_record( stack, data, recLen, &data, &recLen, &decompress_buffer_aquired );
}
DEBUG_TRACE_BUF("decompressed", data, recLen);
if( rc == DSSL_RC_OK )
{
switch( record_type )
{
case SSL3_RT_HANDSHAKE:
next_decoder = &stack->dhandshake;
break;
case SSL3_RT_CHANGE_CIPHER_SPEC:
next_decoder = &stack->dcss;
break;
case SSL3_RT_APPLICATION_DATA:
next_decoder = &stack->dappdata;
break;
case SSL3_RT_ALERT:
next_decoder = &stack->dalert;
break;
default:
rc = NM_ERROR( DSSL_E_SSL_PROTOCOL_ERROR );
}
}
if( rc == DSSL_RC_OK )
{
_ASSERT( next_decoder != NULL );
rc = dssl_decoder_process( next_decoder, dir, data, recLen );
}
if( rc == DSSL_RC_OK )
{
*processed = totalRecLen + SSL3_HEADER_LEN;
}
if( decrypt_buffer_aquired )
{
ssls_release_decrypt_buffer( stack->sess );
}
if( decompress_buffer_aquired )
{
ssls_release_decompress_buffer( stack->sess );
}
#ifdef NM_TRACE_SSL_RECORD
DEBUG_TRACE1( "\n} rc: %d\n", (int) rc);
#endif
if( stack->state == SS_SeenCloseNotify )
{
stack->sess->flags |= SSF_CLOSE_NOTIFY_RECEIVED;
} else if ( stack->state == SS_FatalAlert )
{
stack->sess->flags |= SSF_FATAL_ALERT_RECEIVED;
}
return rc;
}
/* ========== Handshake decoding function ========== */
int ssl3_decode_handshake_record( dssl_decoder_stack* stack, NM_PacketDir dir,
u_char* data, uint32_t len, uint32_t* processed )
{
int rc = DSSL_E_UNSPECIFIED_ERROR;
uint32_t recLen = 0;
u_char hs_type = 0;
u_char* org_data = data;
DSSL_Session* sess = stack->sess;
_ASSERT( processed != NULL );
_ASSERT((sess->flags & SSF_SSLV2_CHALLENGE) == 0);
if( sess->version == 0 )
{
return ssl_decode_first_client_hello( sess, data, len, processed );
}
if( len < SSL3_HANDSHAKE_HEADER_LEN ) return NM_ERROR( DSSL_E_SSL_INVALID_RECORD_LENGTH );
DEBUG_TRACE_BUF("handshake", data, len);
recLen = (((int32_t)data[1]) << 16) | (((int32_t)data[2]) << 8) | data[3];
hs_type = data[0];
data += SSL3_HANDSHAKE_HEADER_LEN;
len -= SSL3_HANDSHAKE_HEADER_LEN;
if( len < recLen )return NM_ERROR( DSSL_E_SSL_INVALID_RECORD_LENGTH );
#ifdef NM_TRACE_SSL_HANDSHAKE
DEBUG_TRACE2( "===>Decoding SSL v3 handshake: %s len: %d...", SSL3_HandshakeTypeToString( hs_type ), (int) recLen );
#endif
switch( hs_type )
{
case SSL3_MT_HELLO_REQUEST:
rc = ssl3_decode_dummy( sess, data, recLen );
break;
case SSL3_MT_CLIENT_HELLO:
rc = ssl3_decode_client_hello( sess, data, recLen );
break;
case SSL3_MT_SERVER_HELLO:
stack->state = SS_SeenServerHello;
rc = ssl3_decode_server_hello( sess, data, recLen );
break;
case SSL3_MT_CERTIFICATE:
if( dir == ePacketDirFromServer )
{
rc = ssl3_decode_server_certificate( sess, data, recLen );
}
else
{
rc = ssl3_decode_dummy( sess, data, recLen );
}
break;
case SSL3_MT_SERVER_DONE:
rc = ssl3_decode_dummy( sess, data, recLen );
break;
case SSL3_MT_CLIENT_KEY_EXCHANGE:
rc = ssl3_decode_client_key_exchange( sess, data, recLen );
break;
case SSL3_MT_FINISHED:
rc = (*sess->decode_finished_proc)( sess, dir, data, recLen );
if( rc == DSSL_RC_OK ) {
stack->state = SS_Established;
ssls_handshake_done( sess );
}
break;
case SSL3_MT_CERTIFICATE_STATUS:
rc = ssl3_decode_dummy( sess, data, recLen );
break;
case SSL3_MT_SERVER_KEY_EXCHANGE:
/*at this point it is clear that the session is not decryptable due to ephemeral keys usage.*/
rc = NM_ERROR( DSSL_E_SSL_CANNOT_DECRYPT_EPHEMERAL );
break;
case SSL3_MT_CERTIFICATE_REQUEST:
/* TODO: track CertificateRequest- client certificate / certificate verify */
rc = ssl3_decode_dummy( sess, data, recLen );
break;
case SSL3_MT_CERTIFICATE_VERIFY:
/* TODO: track CertificateRequest- client certificate / certificate verify */
rc = ssl3_decode_dummy( sess, data, recLen );
break;
case SSL3_MT_NEWSESSION_TICKET:
rc = ssl3_decode_new_session_ticket( sess, data, recLen );
break;
default:
rc = NM_ERROR( DSSL_E_SSL_PROTOCOL_ERROR );
break;
}
if( rc == DSSL_RC_OK )
{
*processed = recLen + SSL3_HANDSHAKE_HEADER_LEN;
if( hs_type == SSL3_MT_CLIENT_HELLO )
{
ssl3_init_handshake_digests( sess );
}
if( hs_type != SSL3_MT_HELLO_REQUEST )
{
ssl3_update_handshake_digests( sess, org_data, *processed );
}
}
#ifdef NM_TRACE_SSL_HANDSHAKE
if( rc == DSSL_RC_OK )
{
DEBUG_TRACE0( "OK\n" );
}
else
{
DEBUG_TRACE1( "Error! (%d)\n", (int)rc );
}
#endif
return rc;
}