int DSSL_SessionProcessData( DSSL_Session* sess, NM_PacketDir dir, u_char* data, uint32_t len )
{
int rc = DSSL_RC_OK;
dssl_decoder_stack* dec = NULL;
if( dir == ePacketDirInvalid ) return NM_ERROR( DSSL_E_INVALID_PARAMETER );
dec = (dir == ePacketDirFromClient) ? &sess->c_dec : &sess->s_dec;
if( !sslc_is_decoder_stack_set( dec ) )
{
uint16_t ver = 0;
int is_client = (dir == ePacketDirFromClient);
if( is_client )
{
rc = ssl_detect_client_hello_version( data, len, &ver );
}
else
{
rc = ssl_detect_server_hello_version( data, len, &ver );
/* update the client decoder after the server have declared the actual version
of the session */
DEBUG_TRACE2("DSSL_SessionProcessData - sess->version: 0x%02X, ver is: 0x%02X\n", sess->version, ver);
if( rc == DSSL_RC_OK && sess->version != ver )
{
sess->c_dec.version = ver;
rc = dssl_decoder_stack_set( &sess->c_dec, sess, ver, 1 );
}
ssls_set_session_version( sess, ver );
}
if( rc == DSSL_RC_OK )
{
dec->version = ver;
rc = dssl_decoder_stack_set( dec, sess, ver, is_client );
}
}
if( rc == DSSL_RC_OK ) rc = dssl_decoder_stack_process( dec, dir, data, len );
/* check if a session with a first-time automapped key failed */
if( NM_IS_FAILED( rc ) && sess->flags & SSF_TEST_SSL_KEY )
{
if(sess->event_callback)
{
(*sess->event_callback)( sess->user_data, eSslMappedKeyFailed, sess->ssl_si );
}
DSSL_MoveServerToMissingKeyList( sess->env, sess->ssl_si );
sess->ssl_si = NULL;
}
if( NM_IS_FAILED( rc ) && sess->error_callback && rc != DSSL_E_SSL_SERVER_KEY_UNKNOWN )
{
sess->error_callback( sess->user_data, rc );
}
return rc;
}
static int ssl3_decode_server_hello( DSSL_Session* sess, u_char* data, uint32_t len )
{
uint16_t server_version = 0;
u_char* org_data = data;
uint16_t session_id_len = 0;
int session_id_match = 0;
if( data[0] != 3 || data[1] > 3) return NM_ERROR( DSSL_E_SSL_UNKNOWN_VERSION );
if( len < SSL3_SERVER_HELLO_MIN_LEN ) return NM_ERROR( DSSL_E_SSL_INVALID_RECORD_LENGTH );
/* Server Version */
server_version = MAKE_UINT16( data[0], data[1] );
if( sess->version == 0 || server_version < sess->version )
{
ssls_set_session_version( sess, server_version );
}
data+= 2;
/* ServerRandom */
_ASSERT_STATIC( sizeof(sess->server_random) == 32 );
memcpy( sess->server_random, data, sizeof( sess->server_random ) );
data+= 32;
DEBUG_TRACE_BUF("server_random", sess->server_random, 32);
/* session ID */
_ASSERT_STATIC( sizeof(sess->session_id) == 32 );
session_id_len = data[0];
data++;
if( session_id_len > 0 )
{
if ( session_id_len > 32 ) return NM_ERROR( DSSL_E_SSL_PROTOCOL_ERROR );
if( !IS_ENOUGH_LENGTH( org_data, len, data, session_id_len ) )
{
return NM_ERROR( DSSL_E_SSL_INVALID_RECORD_LENGTH );
}
if( sess->flags & SSF_CLIENT_SESSION_ID_SET
&& memcmp( sess->session_id, data, session_id_len ) == 0 )
{
session_id_match = 1;
}
else
{
sess->flags &= ~SSF_CLIENT_SESSION_ID_SET;
memcpy( sess->session_id, data, session_id_len );
}
data += session_id_len;
}
/* Cipher Suite and Compression */
if( !IS_ENOUGH_LENGTH( org_data, len, data, 3 ) )
{
return NM_ERROR( DSSL_E_SSL_INVALID_RECORD_LENGTH );
}
sess->cipher_suite = MAKE_UINT16( data[0], data[1] );
sess->compression_method = data[2];
data += 3;
sess->flags &= ~SSF_TLS_SERVER_SESSION_TICKET; /* clear server side TLS Session Ticket flag */
/* Process SSL Extensions, if present */
if(IS_ENOUGH_LENGTH( org_data, len, data, 2 ))
{
int t_len = MAKE_UINT16(data[0], data[1]);
data += 2;
if(!IS_ENOUGH_LENGTH( org_data, len, data, t_len))
return NM_ERROR(DSSL_E_SSL_INVALID_RECORD_LENGTH);
/* cycle through extension records */
while(t_len >= 4)
{
int ext_type = MAKE_UINT16(data[0], data[1]); /* extension type */
int ext_len = MAKE_UINT16(data[2], data[3]);
#ifdef NM_TRACE_SSL_HANDSHAKE
DEBUG_TRACE2( "\nSSL extension: %s len: %d", SSL3_ExtensionTypeToString( ext_type ), ext_len );
#endif
/* TLS Session Ticket extension found, set the flag */
if( ext_type == 0x0023)
{
sess->flags |= SSF_TLS_SERVER_SESSION_TICKET;
}
data += ext_len + 4;
if(data > org_data + len) return NM_ERROR(DSSL_E_SSL_INVALID_RECORD_LENGTH);
t_len -= ext_len + 4;
}
}
if( session_id_match )
{
if( sess->flags & SSF_TLS_SESSION_TICKET_SET)
{
int rc = ssls_init_from_tls_ticket( sess );
if( NM_IS_FAILED( rc ) )
return rc;
}
else
{
/* lookup session from the cache for stateful SSL renegotiation */
int rc = ssls_lookup_session( sess );
if( NM_IS_FAILED( rc ) )
return rc;
}
}
if( sess->flags & SSF_CLIENT_SESSION_ID_SET )
{
int rc = ssls_generate_keys( sess );
if( NM_IS_FAILED( rc ) ) return rc;
}
return DSSL_RC_OK;
}
static int ssl3_decode_client_hello( DSSL_Session* sess, u_char* data, uint32_t len )
{
u_char* org_data = data;
int t_len = 0;
/* record the handshake start time */
sess->handshake_start = sess->last_packet->pcap_header.ts;
if( data[0] != 3 || data[1] > 3) return NM_ERROR( DSSL_E_SSL_UNKNOWN_VERSION );
/* 2 bytes client version */
sess->client_version = MAKE_UINT16( data[0], data[1] );
ssls_set_session_version( sess, MAKE_UINT16( data[0], data[1] ) );
data+= 2;
/* make sure */
if( data + 32 > org_data + len ) return NM_ERROR( DSSL_E_SSL_INVALID_RECORD_LENGTH );
/* 32 bytes ClientRandom */
memcpy( sess->client_random, data, 32 );
data+= 32;
DEBUG_TRACE_BUF("client_random", sess->client_random, 32);
/* check session ID length */
if( data[0] > 32 ) return NM_ERROR( DSSL_E_SSL_PROTOCOL_ERROR );
if( data[0] > 0 )
{
/* Session ID set */
if( data + data[0] > org_data + len )
return NM_ERROR( DSSL_E_SSL_INVALID_RECORD_LENGTH );
memcpy( sess->session_id, data+1, data[0] );
sess->flags |= SSF_CLIENT_SESSION_ID_SET;
data += data[0] + 1;
}
else
{
/* no Session ID */
sess->flags &= ~SSF_CLIENT_SESSION_ID_SET;
++data;
}
/* Cypher Suites */
if(data + 1 >= org_data + len) return NM_ERROR( DSSL_E_SSL_INVALID_RECORD_LENGTH );
t_len = MAKE_UINT16(data[0], data[1]) + 2; /* cypher suites + cypher sute length size */
data += t_len; /* skip cypher suites */
/* Compression Method */
if(data >= org_data + len) return NM_ERROR( DSSL_E_SSL_INVALID_RECORD_LENGTH );
if(data + data[0] + 1 > org_data + len) return NM_ERROR( DSSL_E_SSL_INVALID_RECORD_LENGTH );
t_len = data[0] + 1;
data += t_len; /* skip compression methods */
/* Extensions */
/* clear all previous extension fields */
ssls_free_extension_data(sess);
if(data >= org_data + len) return DSSL_RC_OK;
if(data + 2 > org_data + len) return NM_ERROR( DSSL_E_SSL_INVALID_RECORD_LENGTH );
t_len = MAKE_UINT16(data[0], data[1]);
data += 2; /* positon at the beginning of the first extension record, if any*/
while(t_len >= 4)
{
int ext_type = MAKE_UINT16(data[0], data[1]); /* extension type */
int ext_len = MAKE_UINT16(data[2], data[3]);
#ifdef NM_TRACE_SSL_HANDSHAKE
DEBUG_TRACE2( "\nSSL extension: %s len: %d", SSL3_ExtensionTypeToString( ext_type ), ext_len );
#endif
/* TLS Session Ticket */
if( ext_type == 0x0023)
{
/* non empty ticket passed, store it */
if(ext_len > 0)
{
sess->flags |= SSF_TLS_SESSION_TICKET_SET;
sess->session_ticket = (u_char*) malloc(ext_len);
if(sess->session_ticket == NULL) return NM_ERROR(DSSL_E_OUT_OF_MEMORY);
memcpy(sess->session_ticket, data+4, ext_len);
sess->session_ticket_len = ext_len;
}
}
data += ext_len + 4;
if(data > org_data + len) return NM_ERROR(DSSL_E_SSL_INVALID_RECORD_LENGTH);
t_len -= ext_len + 4;
}
return DSSL_RC_OK;
}
/* ========== CLIENT-HELLO ========== */
static int ssl2_decode_client_hello( DSSL_Session* sess, u_char* data, uint32_t len, uint32_t* processed )
{
int rc = DSSL_RC_OK;
uint32_t sessionIdLen = 0, challengeLen = 0, cipherSpecLen = 0;
_ASSERT( processed && data && sess );
/* record the handshake start time */
sess->handshake_start = sess->last_packet->pcap_header.ts;
if( len < SSL20_CLIENT_HELLO_MIN_LEN ) return NM_ERROR( DSSL_E_SSL_INVALID_RECORD_LENGTH );
if( data[0] == 0 && data[1] == 2 )
{
sess->client_version = SSL2_VERSION;
rc = ssls_set_session_version( sess, SSL2_VERSION );
}
else if( data[0] == 3 )
{
/* SSLv3 or TLS1 in a v2 header */
sess->client_version = MAKE_UINT16(data[0], data[1]);
rc = ssls_set_session_version( sess, MAKE_UINT16(data[0], data[1]) );
}
else
{
rc = NM_ERROR( DSSL_E_SSL_UNKNOWN_VERSION );
}
/* validate the record format */
if( rc == DSSL_RC_OK )
{
/* CIPHER-SPECS-LENGTH */
cipherSpecLen = MAKE_UINT16( data[2], data[3] );
/* SESSION-ID-LENGTH */
sessionIdLen = MAKE_UINT16( data[4], data[5] );
/* CHALLENGE-LENGTH */
challengeLen = MAKE_UINT16( data[6], data[7] );
if( challengeLen + sessionIdLen + cipherSpecLen + SSL20_CLIENT_HELLO_MIN_LEN != len )
{
rc = NM_ERROR( DSSL_E_SSL_INVALID_RECORD_LENGTH );
}
}
/* validate and set the session ID */
if( rc == DSSL_RC_OK )
{
if( sessionIdLen == 16 )
{
u_char* sessionId = data + SSL20_CLIENT_HELLO_MIN_LEN + cipherSpecLen;
_ASSERT( sessionIdLen <= sizeof( sess->session_id ) );
memset( sess->session_id, 0, sizeof( sess->session_id ) );
memcpy( sess->session_id, sessionId, sessionIdLen );
sess->flags |= SSF_CLIENT_SESSION_ID_SET;
}
else
{
sess->flags &= ~SSF_CLIENT_SESSION_ID_SET;
if (sessionIdLen != 0 )
{
/* session ID length must be either 16 or 0 for SSL v2 */
rc = NM_ERROR( DSSL_E_SSL_PROTOCOL_ERROR );
}
}
}
/* validate and set the client random aka Challenge */
if( rc == DSSL_RC_OK )
{
if( challengeLen < 16 || challengeLen > 32 )
{
rc = NM_ERROR( DSSL_E_SSL_PROTOCOL_ERROR );
}
else
{
u_char* challenge = data + SSL20_CLIENT_HELLO_MIN_LEN + cipherSpecLen + sessionIdLen;
_ASSERT( challengeLen <= sizeof( sess->client_random ) );
memset( sess->client_random, 0, sizeof( sess->client_random ) );
memcpy( sess->client_random, challenge, challengeLen );
sess->client_challenge_len = challengeLen;
/* may need this flag later to convert CHALLENGE to SSL v3 CLIENT_RANDOM */
sess->flags |= SSF_SSLV2_CHALLENGE;
}
}
if( rc == DSSL_RC_OK ) { *processed = len; }
return rc;
}
