bool stun_agent_init_response (StunAgent *agent, StunMessage *msg,
uint8_t *buffer, size_t buffer_len, const StunMessage *request)
{
StunTransactionId id;
if (stun_message_get_class (request) != STUN_REQUEST) {
return FALSE;
}
msg->buffer = buffer;
msg->buffer_len = buffer_len;
msg->agent = agent;
msg->key = request->key;
msg->key_len = request->key_len;
memmove (msg->long_term_key, request->long_term_key,
sizeof(msg->long_term_key));
msg->long_term_valid = request->long_term_valid;
stun_message_id (request, id);
if (stun_message_init (msg, STUN_RESPONSE,
stun_message_get_method (request), id)) {
if ((agent->compatibility == STUN_COMPATIBILITY_RFC5389 ||
agent->compatibility == STUN_COMPATIBILITY_WLM2009) &&
(agent->software_attribute != NULL ||
agent->usage_flags & STUN_AGENT_USAGE_ADD_SOFTWARE)) {
stun_message_append_software (msg, agent->software_attribute);
}
return TRUE;
}
return FALSE;
}
StunUsageTurnReturn stun_usage_turn_refresh_process (StunMessage *msg,
uint32_t *lifetime, StunUsageTurnCompatibility compatibility)
{
int code = -1;
StunUsageTurnReturn ret = STUN_USAGE_TURN_RETURN_RELAY_SUCCESS;
if (compatibility == STUN_USAGE_TURN_COMPATIBILITY_DRAFT9 ||
compatibility == STUN_USAGE_TURN_COMPATIBILITY_RFC5766) {
if (stun_message_get_method (msg) != STUN_REFRESH)
return STUN_USAGE_TURN_RETURN_INVALID;
} else {
if (stun_message_get_method (msg) != STUN_ALLOCATE)
return STUN_USAGE_TURN_RETURN_INVALID;
}
switch (stun_message_get_class (msg))
{
case STUN_REQUEST:
case STUN_INDICATION:
return STUN_USAGE_TURN_RETURN_INVALID;
case STUN_RESPONSE:
break;
case STUN_ERROR:
if (stun_message_find_error (msg, &code) != STUN_MESSAGE_RETURN_SUCCESS) {
/* missing ERROR-CODE: ignore message */
return STUN_USAGE_TURN_RETURN_INVALID;
}
return STUN_USAGE_TURN_RETURN_ERROR;
default:
/* Fall through. */
break;
}
stun_message_find32 (msg, STUN_ATTRIBUTE_LIFETIME, lifetime);
stun_debug ("TURN Refresh successful!\n");
return ret;
}
static int dgram_process (int sock, StunAgent *oldagent, StunAgent *newagent)
{
union {
struct sockaddr_storage storage;
struct sockaddr addr;
} addr;
socklen_t addr_len;
uint8_t buf[STUN_MAX_MESSAGE_SIZE];
size_t buf_len = 0;
size_t len = 0;
StunMessage request;
StunMessage response;
StunValidationStatus validation;
StunAgent *agent = NULL;
gint ret;
addr_len = sizeof (struct sockaddr_in);
recv_packet:
len = recvfrom (sock, buf, sizeof(buf), 0,
&addr.addr, &addr_len);
if (drop_stun_packets) {
g_debug ("Dropping STUN packet as requested");
return -1;
}
if (len == (size_t)-1) {
return -1;
}
validation = stun_agent_validate (newagent, &request, buf, len, NULL, 0);
if (validation == STUN_VALIDATION_SUCCESS) {
agent = newagent;
} else {
validation = stun_agent_validate (oldagent, &request, buf, len, NULL, 0);
agent = oldagent;
}
/* Unknown attributes */
if (validation == STUN_VALIDATION_UNKNOWN_REQUEST_ATTRIBUTE) {
buf_len = stun_agent_build_unknown_attributes_error (agent, &response, buf,
sizeof (buf), &request);
goto send_buf;
}
/* Mal-formatted packets */
if (validation != STUN_VALIDATION_SUCCESS ||
stun_message_get_class (&request) != STUN_REQUEST) {
goto recv_packet;
}
switch (stun_message_get_method (&request)) {
case STUN_BINDING:
stun_agent_init_response (agent, &response, buf, sizeof (buf), &request);
if (stun_message_has_cookie (&request))
stun_message_append_xor_addr (&response,
STUN_ATTRIBUTE_XOR_MAPPED_ADDRESS,
&addr.storage, addr_len);
else
stun_message_append_addr (&response, STUN_ATTRIBUTE_MAPPED_ADDRESS,
&addr.addr, addr_len);
break;
case STUN_SHARED_SECRET:
case STUN_ALLOCATE:
case STUN_SET_ACTIVE_DST:
case STUN_CONNECT:
case STUN_OLD_SET_ACTIVE_DST:
case STUN_IND_DATA:
case STUN_IND_CONNECT_STATUS:
case STUN_CHANNELBIND:
default:
if (!stun_agent_init_error (agent, &response, buf, sizeof (buf),
&request, STUN_ERROR_BAD_REQUEST)) {
g_debug ("STUN error message not initialized properly");
g_assert_not_reached();
}
}
buf_len = stun_agent_finish_message (agent, &response, NULL, 0);
send_buf:
g_cancellable_cancel (global_cancellable);
g_debug ("Ready to send a STUN response");
g_assert (g_mutex_trylock (stun_mutex_ptr));
got_stun_packet = TRUE;
while (send_stun) {
g_debug ("Waiting for signal. State is %d", global_lagent_state);
g_cond_wait (stun_signal_ptr, stun_mutex_ptr);
}
g_mutex_unlock (stun_mutex_ptr);
len = sendto (sock, buf, buf_len, 0,
&addr.addr, addr_len);
g_debug ("STUN response sent");
drop_stun_packets = TRUE;
ret = (len < buf_len) ? -1 : 0;
return ret;
}
StunValidationStatus stun_agent_validate (StunAgent *agent, StunMessage *msg,
const uint8_t *buffer, size_t buffer_len,
StunMessageIntegrityValidate validater, void * validater_data)
{
StunTransactionId msg_id;
uint32_t fpr;
uint32_t crc32;
int len;
uint8_t *username = NULL;
uint16_t username_len;
uint8_t *key = NULL;
size_t key_len;
uint8_t *hash;
uint8_t sha[20];
uint16_t hlen;
int sent_id_idx = -1;
uint16_t unknown;
int error_code;
int ignore_credentials = 0;
uint8_t long_term_key[16];
bool long_term_key_valid = FALSE;
len = stun_message_validate_buffer_length (buffer, buffer_len);
if (len == STUN_MESSAGE_BUFFER_INVALID) {
return STUN_VALIDATION_NOT_STUN;
} else if (len == STUN_MESSAGE_BUFFER_INCOMPLETE) {
return STUN_VALIDATION_INCOMPLETE_STUN;
} else if (len != (int) buffer_len) {
return STUN_VALIDATION_NOT_STUN;
}
msg->buffer = (uint8_t *) buffer;
msg->buffer_len = buffer_len;
msg->agent = agent;
msg->key = NULL;
msg->key_len = 0;
msg->long_term_valid = FALSE;
/* TODO: reject it or not ? */
if ((agent->compatibility == STUN_COMPATIBILITY_RFC5389 ||
agent->compatibility == STUN_COMPATIBILITY_WLM2009) &&
!stun_message_has_cookie (msg)) {
stun_debug ("STUN demux error: no cookie!\n");
return STUN_VALIDATION_BAD_REQUEST;
}
if ((agent->compatibility == STUN_COMPATIBILITY_RFC5389 ||
agent->compatibility == STUN_COMPATIBILITY_WLM2009) &&
agent->usage_flags & STUN_AGENT_USAGE_USE_FINGERPRINT) {
/* Looks for FINGERPRINT */
if (stun_message_find32 (msg, STUN_ATTRIBUTE_FINGERPRINT, &fpr) !=
STUN_MESSAGE_RETURN_SUCCESS) {
stun_debug ("STUN demux error: no FINGERPRINT attribute!\n");
return STUN_VALIDATION_BAD_REQUEST;
}
/* Checks FINGERPRINT */
crc32 = stun_fingerprint (msg->buffer, stun_message_length (msg),
agent->compatibility == STUN_COMPATIBILITY_WLM2009);
fpr = ntohl (fpr);
if (fpr != crc32) {
stun_debug ("STUN demux error: bad fingerprint: 0x%08x,"
" expected: 0x%08x!\n", fpr, crc32);
return STUN_VALIDATION_BAD_REQUEST;
}
stun_debug ("STUN demux: OK!\n");
}
if (stun_message_get_class (msg) == STUN_RESPONSE ||
stun_message_get_class (msg) == STUN_ERROR) {
stun_message_id (msg, msg_id);
for (sent_id_idx = 0; sent_id_idx < STUN_AGENT_MAX_SAVED_IDS; sent_id_idx++) {
if (agent->sent_ids[sent_id_idx].valid == TRUE &&
agent->sent_ids[sent_id_idx].method == stun_message_get_method (msg) &&
memcmp (msg_id, agent->sent_ids[sent_id_idx].id,
sizeof(StunTransactionId)) == 0) {
key = agent->sent_ids[sent_id_idx].key;
key_len = agent->sent_ids[sent_id_idx].key_len;
memcpy (long_term_key, agent->sent_ids[sent_id_idx].long_term_key,
sizeof(long_term_key));
long_term_key_valid = agent->sent_ids[sent_id_idx].long_term_valid;
break;
}
}
if (sent_id_idx == STUN_AGENT_MAX_SAVED_IDS) {
return STUN_VALIDATION_UNMATCHED_RESPONSE;
}
}
ignore_credentials =
(agent->usage_flags & STUN_AGENT_USAGE_IGNORE_CREDENTIALS) ||
(stun_message_get_class (msg) == STUN_ERROR &&
stun_message_find_error (msg, &error_code) ==
STUN_MESSAGE_RETURN_SUCCESS &&
(error_code == 400 || error_code == 401)) ||
(stun_message_get_class (msg) == STUN_INDICATION &&
(agent->usage_flags & STUN_AGENT_USAGE_NO_INDICATION_AUTH));
if (key == NULL &&
ignore_credentials == 0 &&
(stun_message_get_class (msg) == STUN_REQUEST ||
stun_message_get_class (msg) == STUN_INDICATION) &&
(((agent->usage_flags & STUN_AGENT_USAGE_SHORT_TERM_CREDENTIALS) &&
(!stun_message_has_attribute (msg, STUN_ATTRIBUTE_USERNAME) ||
!stun_message_has_attribute (msg, STUN_ATTRIBUTE_MESSAGE_INTEGRITY))) ||
((agent->usage_flags & STUN_AGENT_USAGE_LONG_TERM_CREDENTIALS) &&
stun_message_get_class (msg) == STUN_REQUEST &&
(!stun_message_has_attribute (msg, STUN_ATTRIBUTE_USERNAME) ||
!stun_message_has_attribute (msg, STUN_ATTRIBUTE_MESSAGE_INTEGRITY) ||
!stun_message_has_attribute (msg, STUN_ATTRIBUTE_NONCE) ||
!stun_message_has_attribute (msg, STUN_ATTRIBUTE_REALM))) ||
((agent->usage_flags & STUN_AGENT_USAGE_IGNORE_CREDENTIALS) == 0 &&
stun_message_has_attribute (msg, STUN_ATTRIBUTE_USERNAME) &&
!stun_message_has_attribute (msg, STUN_ATTRIBUTE_MESSAGE_INTEGRITY)))) {
return STUN_VALIDATION_UNAUTHORIZED_BAD_REQUEST;
}
if (stun_message_has_attribute (msg, STUN_ATTRIBUTE_MESSAGE_INTEGRITY) &&
((key == NULL && ignore_credentials == 0) ||
(agent->usage_flags & STUN_AGENT_USAGE_FORCE_VALIDATER))) {
username_len = 0;
username = (uint8_t *) stun_message_find (msg, STUN_ATTRIBUTE_USERNAME,
&username_len);
if (validater == NULL ||
validater (agent, msg, username, username_len,
&key, &key_len, validater_data) == FALSE) {
return STUN_VALIDATION_UNAUTHORIZED;
}
}
if (ignore_credentials == 0 && key != NULL && key_len > 0) {
hash = (uint8_t *) stun_message_find (msg,
STUN_ATTRIBUTE_MESSAGE_INTEGRITY, &hlen);
if (hash) {
/* We must give the size from start to the end of the attribute
because you might have a FINGERPRINT attribute after it... */
if (agent->usage_flags & STUN_AGENT_USAGE_LONG_TERM_CREDENTIALS) {
uint8_t *realm = NULL;
uint8_t *username = NULL;
uint16_t realm_len;
uint16_t username_len;
uint8_t md5[16];
if (long_term_key_valid) {
memcpy (md5, long_term_key, sizeof (md5));
} else {
realm = (uint8_t *) stun_message_find (msg, STUN_ATTRIBUTE_REALM, &realm_len);
username = (uint8_t *) stun_message_find (msg,
STUN_ATTRIBUTE_USERNAME, &username_len);
if (username == NULL || realm == NULL) {
return STUN_VALIDATION_UNAUTHORIZED;
}
stun_hash_creds (realm, realm_len,
username, username_len,
key, key_len, md5);
}
memcpy (msg->long_term_key, md5, sizeof(md5));
msg->long_term_valid = TRUE;
if (agent->compatibility == STUN_COMPATIBILITY_RFC3489) {
stun_sha1 (msg->buffer, hash + 20 - msg->buffer, hash - msg->buffer,
sha, md5, sizeof(md5), TRUE);
} else if (agent->compatibility == STUN_COMPATIBILITY_WLM2009) {
stun_sha1 (msg->buffer, hash + 20 - msg->buffer,
stun_message_length (msg) - 20, sha, md5, sizeof(md5), TRUE);
} else {
stun_sha1 (msg->buffer, hash + 20 - msg->buffer,
hash - msg->buffer, sha, md5, sizeof(md5), FALSE);
}
} else {
if (agent->compatibility == STUN_COMPATIBILITY_RFC3489) {
stun_sha1 (msg->buffer, hash + 20 - msg->buffer, hash - msg->buffer,
sha, key, key_len, TRUE);
} else if (agent->compatibility == STUN_COMPATIBILITY_WLM2009) {
stun_sha1 (msg->buffer, hash + 20 - msg->buffer,
stun_message_length (msg) - 20, sha, key, key_len, TRUE);
} else {
stun_sha1 (msg->buffer, hash + 20 - msg->buffer,
hash - msg->buffer, sha, key, key_len, FALSE);
}
}
stun_debug (" Message HMAC-SHA1 fingerprint:");
stun_debug ("\nkey : ");
stun_debug_bytes (key, key_len);
stun_debug ("\n expected: ");
stun_debug_bytes (sha, sizeof (sha));
stun_debug ("\n received: ");
stun_debug_bytes (hash, sizeof (sha));
stun_debug ("\n");
if (memcmp (sha, hash, sizeof (sha))) {
stun_debug ("STUN auth error: SHA1 fingerprint mismatch!\n");
return STUN_VALIDATION_UNAUTHORIZED;
}
stun_debug ("STUN auth: OK!\n");
msg->key = key;
msg->key_len = key_len;
} else if (!(stun_message_get_class (msg) == STUN_ERROR &&
stun_message_find_error (msg, &error_code) ==
STUN_MESSAGE_RETURN_SUCCESS &&
(error_code == 400 || error_code == 401))) {
stun_debug ("STUN auth error: No message integrity attribute!\n");
return STUN_VALIDATION_UNAUTHORIZED;
}
}
if (sent_id_idx != -1 && sent_id_idx < STUN_AGENT_MAX_SAVED_IDS) {
agent->sent_ids[sent_id_idx].valid = FALSE;
}
if (stun_agent_find_unknowns (agent, msg, &unknown, 1) > 0) {
if (stun_message_get_class (msg) == STUN_REQUEST)
return STUN_VALIDATION_UNKNOWN_REQUEST_ATTRIBUTE;
else
return STUN_VALIDATION_UNKNOWN_ATTRIBUTE;
}
return STUN_VALIDATION_SUCCESS;
}
size_t stun_agent_finish_message (StunAgent *agent, StunMessage *msg,
const uint8_t *key, size_t key_len)
{
uint8_t *ptr;
uint32_t fpr;
int saved_id_idx = 0;
uint8_t md5[16];
if (stun_message_get_class (msg) == STUN_REQUEST) {
for (saved_id_idx = 0; saved_id_idx < STUN_AGENT_MAX_SAVED_IDS; saved_id_idx++) {
if (agent->sent_ids[saved_id_idx].valid == FALSE) {
break;
}
}
}
if (saved_id_idx == STUN_AGENT_MAX_SAVED_IDS) {
stun_debug ("Saved ids full");
return 0;
}
if (msg->key != NULL) {
key = msg->key;
key_len = msg->key_len;
}
if (key != NULL) {
bool skip = FALSE;
if (msg->long_term_valid) {
memcpy (md5, msg->long_term_key, sizeof(msg->long_term_key));
} else if (agent->usage_flags & STUN_AGENT_USAGE_LONG_TERM_CREDENTIALS) {
uint8_t *realm = NULL;
uint8_t *username = NULL;
uint16_t realm_len;
uint16_t username_len;
realm = (uint8_t *) stun_message_find (msg,
STUN_ATTRIBUTE_REALM, &realm_len);
username = (uint8_t *) stun_message_find (msg,
STUN_ATTRIBUTE_USERNAME, &username_len);
if (username == NULL || realm == NULL) {
skip = TRUE;
} else {
stun_hash_creds (realm, realm_len,
username, username_len,
key, key_len, md5);
}
memcpy (msg->long_term_key, md5, sizeof(msg->long_term_key));
msg->long_term_valid = TRUE;
}
/* If no realm/username and long term credentials,
then don't send the message integrity */
if (skip == FALSE) {
ptr = stun_message_append (msg, STUN_ATTRIBUTE_MESSAGE_INTEGRITY, 20);
if (ptr == NULL) {
return 0;
}
if (agent->usage_flags & STUN_AGENT_USAGE_LONG_TERM_CREDENTIALS) {
if (agent->compatibility == STUN_COMPATIBILITY_RFC3489) {
stun_sha1 (msg->buffer, stun_message_length (msg),
stun_message_length (msg) - 20, ptr, md5, sizeof(md5), TRUE);
} else if (agent->compatibility == STUN_COMPATIBILITY_WLM2009) {
size_t minus = 20;
if (agent->usage_flags & STUN_AGENT_USAGE_USE_FINGERPRINT)
minus -= 8;
stun_sha1 (msg->buffer, stun_message_length (msg),
stun_message_length (msg) - minus, ptr, md5, sizeof(md5), TRUE);
} else {
stun_sha1 (msg->buffer, stun_message_length (msg),
stun_message_length (msg) - 20, ptr, md5, sizeof(md5), FALSE);
}
} else {
if (agent->compatibility == STUN_COMPATIBILITY_RFC3489) {
stun_sha1 (msg->buffer, stun_message_length (msg),
stun_message_length (msg) - 20, ptr, key, key_len, TRUE);
} else if (agent->compatibility == STUN_COMPATIBILITY_WLM2009) {
size_t minus = 20;
if (agent->usage_flags & STUN_AGENT_USAGE_USE_FINGERPRINT)
minus -= 8;
stun_sha1 (msg->buffer, stun_message_length (msg),
stun_message_length (msg) - minus, ptr, key, key_len, TRUE);
} else {
stun_sha1 (msg->buffer, stun_message_length (msg),
stun_message_length (msg) - 20, ptr, key, key_len, FALSE);
}
}
stun_debug (" Message HMAC-SHA1 message integrity:"
"\n key : ");
stun_debug_bytes (key, key_len);
stun_debug ("\n sent : ");
stun_debug_bytes (ptr, 20);
stun_debug ("\n");
}
}
if ((agent->compatibility == STUN_COMPATIBILITY_RFC5389 ||
agent->compatibility == STUN_COMPATIBILITY_WLM2009) &&
agent->usage_flags & STUN_AGENT_USAGE_USE_FINGERPRINT) {
ptr = stun_message_append (msg, STUN_ATTRIBUTE_FINGERPRINT, 4);
if (ptr == NULL) {
return 0;
}
fpr = stun_fingerprint (msg->buffer, stun_message_length (msg),
agent->compatibility == STUN_COMPATIBILITY_WLM2009);
memcpy (ptr, &fpr, sizeof (fpr));
stun_debug (" Message HMAC-SHA1 fingerprint: ");
stun_debug_bytes (ptr, 4);
stun_debug ("\n");
}
if (stun_message_get_class (msg) == STUN_REQUEST) {
stun_message_id (msg, agent->sent_ids[saved_id_idx].id);
agent->sent_ids[saved_id_idx].method = stun_message_get_method (msg);
agent->sent_ids[saved_id_idx].key = (uint8_t *) key;
agent->sent_ids[saved_id_idx].key_len = key_len;
memcpy (agent->sent_ids[saved_id_idx].long_term_key, msg->long_term_key,
sizeof(msg->long_term_key));
agent->sent_ids[saved_id_idx].long_term_valid = msg->long_term_valid;
agent->sent_ids[saved_id_idx].valid = TRUE;
}
msg->key = (uint8_t *) key;
msg->key_len = key_len;
return stun_message_length (msg);
}
StunUsageTurnReturn stun_usage_turn_process (StunMessage *msg,
struct sockaddr *relay_addr, socklen_t *relay_addrlen,
struct sockaddr *addr, socklen_t *addrlen,
struct sockaddr *alternate_server, socklen_t *alternate_server_len,
uint32_t *bandwidth, uint32_t *lifetime,
StunUsageTurnCompatibility compatibility)
{
int val, code = -1;
StunUsageTurnReturn ret = STUN_USAGE_TURN_RETURN_RELAY_SUCCESS;
if (stun_message_get_method (msg) != STUN_ALLOCATE)
return STUN_USAGE_TURN_RETURN_INVALID;
switch (stun_message_get_class (msg))
{
case STUN_REQUEST:
case STUN_INDICATION:
return STUN_USAGE_TURN_RETURN_INVALID;
case STUN_RESPONSE:
break;
case STUN_ERROR:
if (stun_message_find_error (msg, &code) != STUN_MESSAGE_RETURN_SUCCESS) {
/* missing ERROR-CODE: ignore message */
return STUN_USAGE_TURN_RETURN_INVALID;
}
/* NOTE: currently we ignore unauthenticated messages if the context
* is authenticated, for security reasons. */
stun_debug (" STUN error message received (code: %d)\n", code);
/* ALTERNATE-SERVER mechanism */
if ((code / 100) == 3) {
if (alternate_server && alternate_server_len) {
if (stun_message_find_addr (msg, STUN_ATTRIBUTE_ALTERNATE_SERVER,
alternate_server, alternate_server_len) !=
STUN_MESSAGE_RETURN_SUCCESS) {
stun_debug (" Unexpectedly missing ALTERNATE-SERVER attribute\n");
return STUN_USAGE_TURN_RETURN_ERROR;
}
} else {
if (!stun_message_has_attribute (msg,
STUN_ATTRIBUTE_ALTERNATE_SERVER)) {
stun_debug (" Unexpectedly missing ALTERNATE-SERVER attribute\n");
return STUN_USAGE_TURN_RETURN_ERROR;
}
}
stun_debug ("Found alternate server\n");
return STUN_USAGE_TURN_RETURN_ALTERNATE_SERVER;
}
return STUN_USAGE_TURN_RETURN_ERROR;
}
stun_debug ("Received %u-bytes STUN message\n", stun_message_length (msg));
if (compatibility == STUN_USAGE_TURN_COMPATIBILITY_DRAFT9) {
val = stun_message_find_xor_addr (msg,
STUN_ATTRIBUTE_XOR_MAPPED_ADDRESS, addr, addrlen);
if (val == STUN_MESSAGE_RETURN_SUCCESS)
ret = STUN_USAGE_TURN_RETURN_MAPPED_SUCCESS;
val = stun_message_find_xor_addr (msg,
STUN_ATTRIBUTE_RELAY_ADDRESS, relay_addr, relay_addrlen);
if (val != STUN_MESSAGE_RETURN_SUCCESS) {
stun_debug (" No RELAYED-ADDRESS: %d\n", val);
return STUN_USAGE_TURN_RETURN_ERROR;
}
} else if (compatibility == STUN_USAGE_TURN_COMPATIBILITY_GOOGLE) {
val = stun_message_find_addr (msg,
STUN_ATTRIBUTE_MAPPED_ADDRESS, relay_addr, relay_addrlen);
if (val != STUN_MESSAGE_RETURN_SUCCESS) {
stun_debug (" No MAPPED-ADDRESS: %d\n", val);
return STUN_USAGE_TURN_RETURN_ERROR;
}
} else if (compatibility == STUN_USAGE_TURN_COMPATIBILITY_MSN) {
val = stun_message_find_addr (msg,
STUN_ATTRIBUTE_MSN_MAPPED_ADDRESS, addr, addrlen);
if (val == STUN_MESSAGE_RETURN_SUCCESS)
ret = STUN_USAGE_TURN_RETURN_MAPPED_SUCCESS;
val = stun_message_find_addr (msg,
STUN_ATTRIBUTE_MAPPED_ADDRESS, relay_addr, relay_addrlen);
if (val != STUN_MESSAGE_RETURN_SUCCESS) {
stun_debug (" No MAPPED-ADDRESS: %d\n", val);
return STUN_USAGE_TURN_RETURN_ERROR;
}
}
stun_message_find32 (msg, STUN_ATTRIBUTE_LIFETIME, lifetime);
stun_message_find32 (msg, STUN_ATTRIBUTE_BANDWIDTH, bandwidth);
stun_debug (" Mapped address found!\n");
return ret;
}
size_t stun_agent_finish_message (StunAgent *agent, StunMessage *msg,
const uint8_t *key, size_t key_len)
{
uint8_t *ptr;
uint32_t fpr;
int saved_id_idx = 0;
uint8_t md5[16];
bool remember_transaction;
remember_transaction = (stun_message_get_class (msg) == STUN_REQUEST);
if (agent->compatibility == STUN_COMPATIBILITY_OC2007 &&
stun_message_get_method (msg) == STUN_SEND) {
/* As per [MS-TURN] Section 2.2.1, the TURN server doesn't send responses to
* STUN_SEND requests, so don't bother waiting for them. More details at
* https://msdn.microsoft.com/en-us/library/dd946797%28v=office.12%29.aspx.
*/
remember_transaction = FALSE;
}
if (remember_transaction) {
for (saved_id_idx = 0; saved_id_idx < STUN_AGENT_MAX_SAVED_IDS; saved_id_idx++) {
if (agent->sent_ids[saved_id_idx].valid == FALSE) {
break;
}
}
}
if (saved_id_idx == STUN_AGENT_MAX_SAVED_IDS) {
stun_debug ("WARNING: Saved IDs full. STUN message dropped.");
return 0;
}
if (msg->key != NULL) {
key = msg->key;
key_len = msg->key_len;
}
if (key != NULL) {
bool skip = FALSE;
if (msg->long_term_valid) {
memcpy (md5, msg->long_term_key, sizeof(msg->long_term_key));
} else if (agent->usage_flags & STUN_AGENT_USAGE_LONG_TERM_CREDENTIALS) {
uint8_t *realm = NULL;
uint8_t *username = NULL;
uint16_t realm_len;
uint16_t username_len;
realm = (uint8_t *) stun_message_find (msg,
STUN_ATTRIBUTE_REALM, &realm_len);
username = (uint8_t *) stun_message_find (msg,
STUN_ATTRIBUTE_USERNAME, &username_len);
if (username == NULL || realm == NULL) {
skip = TRUE;
} else {
stun_hash_creds (realm, realm_len,
username, username_len,
key, key_len, md5);
memcpy (msg->long_term_key, md5, sizeof(msg->long_term_key));
msg->long_term_valid = TRUE;
}
}
/* If no realm/username and long term credentials,
then don't send the message integrity */
if (skip == FALSE) {
ptr = stun_message_append (msg, STUN_ATTRIBUTE_MESSAGE_INTEGRITY, 20);
if (ptr == NULL) {
return 0;
}
if (agent->usage_flags & STUN_AGENT_USAGE_LONG_TERM_CREDENTIALS) {
if (agent->compatibility == STUN_COMPATIBILITY_RFC3489 ||
agent->compatibility == STUN_COMPATIBILITY_OC2007) {
stun_sha1 (msg->buffer, stun_message_length (msg),
stun_message_length (msg) - 20, ptr, md5, sizeof(md5), TRUE);
} else if (agent->compatibility == STUN_COMPATIBILITY_WLM2009) {
size_t minus = 20;
if (agent->usage_flags & STUN_AGENT_USAGE_USE_FINGERPRINT)
minus -= 8;
stun_sha1 (msg->buffer, stun_message_length (msg),
stun_message_length (msg) - minus, ptr, md5, sizeof(md5), TRUE);
} else {
stun_sha1 (msg->buffer, stun_message_length (msg),
stun_message_length (msg) - 20, ptr, md5, sizeof(md5), FALSE);
}
} else {
if (agent->compatibility == STUN_COMPATIBILITY_RFC3489 ||
agent->compatibility == STUN_COMPATIBILITY_OC2007) {
stun_sha1 (msg->buffer, stun_message_length (msg),
stun_message_length (msg) - 20, ptr, key, key_len, TRUE);
} else if (agent->compatibility == STUN_COMPATIBILITY_WLM2009) {
size_t minus = 20;
if (agent->usage_flags & STUN_AGENT_USAGE_USE_FINGERPRINT)
minus -= 8;
stun_sha1 (msg->buffer, stun_message_length (msg),
stun_message_length (msg) - minus, ptr, key, key_len, TRUE);
} else {
stun_sha1 (msg->buffer, stun_message_length (msg),
stun_message_length (msg) - 20, ptr, key, key_len, FALSE);
}
}
stun_debug (" Message HMAC-SHA1 message integrity:");
stun_debug_bytes (" key : ", key, key_len);
stun_debug_bytes (" sent : ", ptr, 20);
}
}
if ((agent->compatibility == STUN_COMPATIBILITY_RFC5389 ||
agent->compatibility == STUN_COMPATIBILITY_WLM2009) &&
agent->usage_flags & STUN_AGENT_USAGE_USE_FINGERPRINT) {
ptr = stun_message_append (msg, STUN_ATTRIBUTE_FINGERPRINT, 4);
if (ptr == NULL) {
return 0;
}
fpr = stun_fingerprint (msg->buffer, stun_message_length (msg),
agent->compatibility == STUN_COMPATIBILITY_WLM2009);
memcpy (ptr, &fpr, sizeof (fpr));
stun_debug_bytes (" Message HMAC-SHA1 fingerprint: ", ptr, 4);
}
if (remember_transaction) {
stun_message_id (msg, agent->sent_ids[saved_id_idx].id);
agent->sent_ids[saved_id_idx].method = stun_message_get_method (msg);
agent->sent_ids[saved_id_idx].key = (uint8_t *) key;
agent->sent_ids[saved_id_idx].key_len = key_len;
memcpy (agent->sent_ids[saved_id_idx].long_term_key, msg->long_term_key,
sizeof(msg->long_term_key));
agent->sent_ids[saved_id_idx].long_term_valid = msg->long_term_valid;
agent->sent_ids[saved_id_idx].valid = TRUE;
}
msg->key = (uint8_t *) key;
msg->key_len = key_len;
return stun_message_length (msg);
}
StunUsageIceReturn
stun_usage_ice_conncheck_create_reply (StunAgent *agent, StunMessage *req,
StunMessage *msg, uint8_t *buf, size_t *plen,
const struct sockaddr *src, socklen_t srclen,
bool *control, uint64_t tie,
StunUsageIceCompatibility compatibility)
{
const char *username = NULL;
uint16_t username_len;
size_t len = *plen;
uint64_t q;
StunMessageReturn val = STUN_MESSAGE_RETURN_SUCCESS;
StunUsageIceReturn ret = STUN_USAGE_ICE_RETURN_SUCCESS;
#define err( code ) \
stun_bind_error (agent, msg, buf, &len, req, code); \
*plen = len
*plen = 0;
stun_debug ("STUN Reply (buffer size = %u)...\n", (unsigned)len);
if (stun_message_get_class (req) != STUN_REQUEST)
{
stun_debug (" Unhandled non-request (class %u) message.\n",
stun_message_get_class (req));
return STUN_USAGE_ICE_RETURN_INVALID_REQUEST;
}
if (stun_message_get_method (req) != STUN_BINDING)
{
stun_debug (" Bad request (method %u) message.\n",
stun_message_get_method (req));
err (STUN_ERROR_BAD_REQUEST);
return STUN_USAGE_ICE_RETURN_INVALID_METHOD;
}
/* Role conflict handling */
assert (control != NULL);
if (stun_message_find64 (req, *control ? STUN_ATTRIBUTE_ICE_CONTROLLING
: STUN_ATTRIBUTE_ICE_CONTROLLED, &q) == STUN_MESSAGE_RETURN_SUCCESS)
{
stun_debug ("STUN Role Conflict detected:\n");
if (tie < q)
{
stun_debug (" switching role from \"controll%s\" to \"controll%s\"\n",
*control ? "ing" : "ed", *control ? "ed" : "ing");
*control = !*control;
ret = STUN_USAGE_ICE_RETURN_ROLE_CONFLICT;
}
else
{
stun_debug (" staying \"controll%s\" (sending error)\n",
*control ? "ing" : "ed");
err (STUN_ERROR_ROLE_CONFLICT);
return STUN_USAGE_ICE_RETURN_SUCCESS;
}
} else {
stun_debug ("STUN Role not specified by peer!\n");
}
if (stun_agent_init_response (agent, msg, buf, len, req) == FALSE) {
stun_debug ("Unable to create response\n");
goto failure;
}
if (compatibility == STUN_USAGE_ICE_COMPATIBILITY_MSN) {
StunTransactionId transid;
uint32_t magic_cookie;
stun_message_id (msg, transid);
magic_cookie = *((uint32_t *) transid);
val = stun_message_append_xor_addr_full (msg, STUN_ATTRIBUTE_XOR_MAPPED_ADDRESS,
src, srclen, htonl (magic_cookie));
} else if (stun_message_has_cookie (msg)) {
val = stun_message_append_xor_addr (msg, STUN_ATTRIBUTE_XOR_MAPPED_ADDRESS,
src, srclen);
} else {
val = stun_message_append_addr (msg, STUN_ATTRIBUTE_MAPPED_ADDRESS,
src, srclen);
}
if (val != STUN_MESSAGE_RETURN_SUCCESS) {
stun_debug (" Mapped address problem: %d\n", val);
goto failure;
}
username = (const char *)stun_message_find (req,
STUN_ATTRIBUTE_USERNAME, &username_len);
if (username) {
val = stun_message_append_bytes (msg, STUN_ATTRIBUTE_USERNAME,
username, username_len);
}
if (val != STUN_MESSAGE_RETURN_SUCCESS) {
stun_debug ("Error appending username: %d\n", val);
goto failure;
}
/* the stun agent will automatically use the password of the request */
len = stun_agent_finish_message (agent, msg, NULL, 0);
if (len == 0)
goto failure;
*plen = len;
stun_debug (" All done (response size: %u)\n", (unsigned)len);
return ret;
failure:
assert (*plen == 0);
stun_debug (" Fatal error formatting Response: %d\n", val);
switch (val)
{
case STUN_MESSAGE_RETURN_NOT_ENOUGH_SPACE:
return STUN_USAGE_ICE_RETURN_MEMORY_ERROR;
case STUN_MESSAGE_RETURN_INVALID:
case STUN_MESSAGE_RETURN_UNSUPPORTED_ADDRESS:
return STUN_USAGE_ICE_RETURN_INVALID_ADDRESS;
default:
return STUN_USAGE_ICE_RETURN_ERROR;
}
}
StunUsageIceReturn stun_usage_ice_conncheck_process (StunMessage *msg,
struct sockaddr *addr, socklen_t *addrlen,
StunUsageIceCompatibility compatibility)
{
int code = -1;
StunMessageReturn val;
if (stun_message_get_method (msg) != STUN_BINDING)
return STUN_USAGE_ICE_RETURN_INVALID;
switch (stun_message_get_class (msg))
{
case STUN_REQUEST:
case STUN_INDICATION:
return STUN_USAGE_ICE_RETURN_INVALID;
case STUN_RESPONSE:
break;
case STUN_ERROR:
if (stun_message_find_error (msg, &code) != STUN_MESSAGE_RETURN_SUCCESS) {
/* missing ERROR-CODE: ignore message */
return STUN_USAGE_ICE_RETURN_INVALID;
}
if (code == STUN_ERROR_ROLE_CONFLICT)
return STUN_USAGE_ICE_RETURN_ROLE_CONFLICT;
/* NOTE: currently we ignore unauthenticated messages if the context
* is authenticated, for security reasons. */
stun_debug (" STUN error message received (code: %d)\n", code);
return STUN_USAGE_ICE_RETURN_ERROR;
}
stun_debug ("Received %u-bytes STUN message\n", stun_message_length (msg));
if (compatibility == STUN_USAGE_ICE_COMPATIBILITY_MSN) {
StunTransactionId transid;
uint32_t magic_cookie;
stun_message_id (msg, transid);
magic_cookie = *((uint32_t *) transid);
val = stun_message_find_xor_addr_full (msg,
STUN_ATTRIBUTE_XOR_MAPPED_ADDRESS, addr, addrlen, htonl (magic_cookie));
} else {
val = stun_message_find_xor_addr (msg,
STUN_ATTRIBUTE_XOR_MAPPED_ADDRESS, addr, addrlen);
}
if (val != STUN_MESSAGE_RETURN_SUCCESS)
{
stun_debug (" No XOR-MAPPED-ADDRESS: %d\n", val);
val = stun_message_find_addr (msg,
STUN_ATTRIBUTE_MAPPED_ADDRESS, addr, addrlen);
if (val != STUN_MESSAGE_RETURN_SUCCESS)
{
stun_debug (" No MAPPED-ADDRESS: %d\n", val);
return STUN_USAGE_ICE_RETURN_NO_MAPPED_ADDRESS;
}
}
stun_debug ("Mapped address found!\n");
return STUN_USAGE_ICE_RETURN_SUCCESS;
}
static int dgram_process (int sock, StunAgent *oldagent, StunAgent *newagent)
{
union {
struct sockaddr_storage storage;
struct sockaddr addr;
} addr;
socklen_t addr_len;
uint8_t buf[STUN_MAX_MESSAGE_SIZE];
size_t buf_len = 0;
size_t len = 0;
StunMessage request;
StunMessage response;
StunValidationStatus validation;
StunAgent *agent = NULL;
addr_len = sizeof (struct sockaddr_in);
len = recvfrom (sock, buf, sizeof(buf), 0, &addr.addr, &addr_len);
if (len == (size_t)-1)
return -1;
validation = stun_agent_validate (newagent, &request, buf, len, NULL, 0);
if (validation == STUN_VALIDATION_SUCCESS) {
agent = newagent;
}
else {
validation = stun_agent_validate (oldagent, &request, buf, len, NULL, 0);
agent = oldagent;
}
/* Unknown attributes */
if (validation == STUN_VALIDATION_UNKNOWN_REQUEST_ATTRIBUTE)
{
buf_len = stun_agent_build_unknown_attributes_error (agent, &response, buf,
sizeof (buf), &request);
goto send_buf;
}
/* Mal-formatted packets */
if (validation != STUN_VALIDATION_SUCCESS ||
stun_message_get_class (&request) != STUN_REQUEST) {
return -1;
}
switch (stun_message_get_method (&request))
{
case STUN_BINDING:
stun_agent_init_response (agent, &response, buf, sizeof (buf), &request);
if (stun_message_has_cookie (&request))
stun_message_append_xor_addr (&response,
STUN_ATTRIBUTE_XOR_MAPPED_ADDRESS, &addr.addr, addr_len);
else
stun_message_append_addr (&response, STUN_ATTRIBUTE_MAPPED_ADDRESS,
&addr.addr, addr_len);
break;
case STUN_SHARED_SECRET:
case STUN_ALLOCATE:
case STUN_SEND:
case STUN_CONNECT:
case STUN_IND_SEND:
case STUN_IND_DATA:
case STUN_CREATEPERMISSION:
case STUN_CHANNELBIND:
default:
if (!stun_agent_init_error (agent, &response, buf, sizeof (buf),
&request, STUN_ERROR_BAD_REQUEST))
return -1;
}
buf_len = stun_agent_finish_message (agent, &response, NULL, 0);
send_buf:
len = sendto (sock, buf, buf_len, 0, &addr.addr, addr_len);
return (len < buf_len) ? -1 : 0;
}
static int dgram_process (int sock, StunAgent *oldagent, StunAgent *newagent)
{
struct sockaddr_storage addr;
uint8_t buf[STUN_MAX_MESSAGE_SIZE];
char ctlbuf[CMSG_SPACE (sizeof (struct in6_pktinfo))];
struct iovec iov = { buf, sizeof (buf) };
StunMessage request;
StunMessage response;
StunValidationStatus validation;
StunAgent *agent = NULL;
struct msghdr mh =
{
.msg_name = (struct sockaddr *)&addr,
.msg_namelen = sizeof (addr),
.msg_iov = &iov,
.msg_iovlen = 1,
.msg_control = ctlbuf,
.msg_controllen = sizeof (ctlbuf)
};
size_t len = recv_safe (sock, &mh);
if (len == (size_t)-1)
return -1;
validation = stun_agent_validate (newagent, &request, buf, len, NULL, 0);
if (validation == STUN_VALIDATION_SUCCESS) {
agent = newagent;
}
else {
validation = stun_agent_validate (oldagent, &request, buf, len, NULL, 0);
agent = oldagent;
}
/* Unknown attributes */
if (validation == STUN_VALIDATION_UNKNOWN_REQUEST_ATTRIBUTE)
{
stun_agent_build_unknown_attributes_error (agent, &response, buf,
sizeof (buf), &request);
goto send_buf;
}
/* Mal-formatted packets */
if (validation != STUN_VALIDATION_SUCCESS ||
stun_message_get_class (&request) != STUN_REQUEST) {
return -1;
}
switch (stun_message_get_method (&request))
{
case STUN_BINDING:
stun_agent_init_response (agent, &response, buf, sizeof (buf), &request);
if (stun_message_has_cookie (&request))
stun_message_append_xor_addr (&response,
STUN_ATTRIBUTE_XOR_MAPPED_ADDRESS,
mh.msg_name, mh.msg_namelen);
else
stun_message_append_addr (&response, STUN_ATTRIBUTE_MAPPED_ADDRESS,
mh.msg_name, mh.msg_namelen);
break;
default:
stun_agent_init_error (agent, &response, buf, sizeof (buf),
&request, STUN_ERROR_BAD_REQUEST);
}
iov.iov_len = stun_agent_finish_message (agent, &response, NULL, 0);
send_buf:
len = send_safe (sock, &mh);
return (len < iov.iov_len) ? -1 : 0;
}
static int run (int family, int protocol, unsigned port)
{
StunAgent oldagent;
StunAgent newagent;
int sock = listen_socket (family, SOCK_DGRAM, protocol, port);
if (sock == -1)
return -1;
stun_agent_init (&oldagent, known_attributes,
STUN_COMPATIBILITY_RFC3489, 0);
stun_agent_init (&newagent, known_attributes,
STUN_COMPATIBILITY_RFC5389, STUN_AGENT_USAGE_USE_FINGERPRINT);
for (;;)
dgram_process (sock, &oldagent, &newagent);
}
StunUsageBindReturn stun_usage_bind_process (StunMessage *msg,
struct sockaddr *addr, socklen_t *addrlen,
struct sockaddr *alternate_server, socklen_t *alternate_server_len)
{
int code = -1;
StunMessageReturn val;
if (stun_message_get_method (msg) != STUN_BINDING)
return STUN_USAGE_BIND_RETURN_INVALID;
switch (stun_message_get_class (msg))
{
case STUN_REQUEST:
case STUN_INDICATION:
return STUN_USAGE_BIND_RETURN_INVALID;
case STUN_RESPONSE:
break;
case STUN_ERROR:
if (stun_message_find_error (msg, &code) != STUN_MESSAGE_RETURN_SUCCESS) {
/* missing ERROR-CODE: ignore message */
return STUN_USAGE_BIND_RETURN_INVALID;
}
/* NOTE: currently we ignore unauthenticated messages if the context
* is authenticated, for security reasons. */
stun_debug (" STUN error message received (code: %d)", code);
/* ALTERNATE-SERVER mechanism */
if ((code / 100) == 3) {
if (alternate_server && alternate_server_len) {
if (stun_message_find_addr (msg, STUN_ATTRIBUTE_ALTERNATE_SERVER,
(struct sockaddr_storage *) alternate_server,
alternate_server_len) != STUN_MESSAGE_RETURN_SUCCESS) {
stun_debug (" Unexpectedly missing ALTERNATE-SERVER attribute");
return STUN_USAGE_BIND_RETURN_ERROR;
}
} else {
if (!stun_message_has_attribute (msg, STUN_ATTRIBUTE_ALTERNATE_SERVER)) {
stun_debug (" Unexpectedly missing ALTERNATE-SERVER attribute");
return STUN_USAGE_BIND_RETURN_ERROR;
}
}
stun_debug ("Found alternate server");
return STUN_USAGE_BIND_RETURN_ALTERNATE_SERVER;
}
return STUN_USAGE_BIND_RETURN_ERROR;
default:
/* Fall through. */
break;
}
stun_debug ("Received %u-bytes STUN message", stun_message_length (msg));
val = stun_message_find_xor_addr (msg,
STUN_ATTRIBUTE_XOR_MAPPED_ADDRESS, (struct sockaddr_storage *)addr,
addrlen);
if (val != STUN_MESSAGE_RETURN_SUCCESS)
{
stun_debug (" No XOR-MAPPED-ADDRESS: %d", val);
val = stun_message_find_addr (msg,
STUN_ATTRIBUTE_MAPPED_ADDRESS, (struct sockaddr_storage *)addr,
addrlen);
if (val != STUN_MESSAGE_RETURN_SUCCESS)
{
stun_debug (" No MAPPED-ADDRESS: %d", val);
return STUN_USAGE_BIND_RETURN_ERROR;
}
}
stun_debug (" Mapped address found!");
return STUN_USAGE_BIND_RETURN_SUCCESS;
}
StunUsageIceReturn
stun_usage_ice_conncheck_create_reply (StunAgent *agent, StunMessage *req,
StunMessage *msg, uint8_t *buf, size_t *plen,
const struct sockaddr_storage *src, socklen_t srclen,
bool *control, uint64_t tie,
StunUsageIceCompatibility compatibility)
{
const char *username = NULL;
uint16_t username_len;
size_t len = *plen;
uint64_t q;
StunMessageReturn val = STUN_MESSAGE_RETURN_SUCCESS;
StunUsageIceReturn ret = STUN_USAGE_ICE_RETURN_SUCCESS;
#define err( code ) \
stun_bind_error (agent, msg, buf, &len, req, code); \
*plen = len
*plen = 0;
stun_debug ("STUN Reply (buffer size = %u)...", (unsigned)len);
if (stun_message_get_class (req) != STUN_REQUEST)
{
stun_debug (" Unhandled non-request (class %u) message.",
stun_message_get_class (req));
return STUN_USAGE_ICE_RETURN_INVALID_REQUEST;
}
if (stun_message_get_method (req) != STUN_BINDING)
{
stun_debug (" Bad request (method %u) message.",
stun_message_get_method (req));
err (STUN_ERROR_BAD_REQUEST);
return STUN_USAGE_ICE_RETURN_INVALID_METHOD;
}
/* Role conflict handling */
assert (control != NULL);
if (stun_message_find64 (req, *control ? STUN_ATTRIBUTE_ICE_CONTROLLING
: STUN_ATTRIBUTE_ICE_CONTROLLED, &q) == STUN_MESSAGE_RETURN_SUCCESS)
{
/* we have the ice-controlling/controlled attribute,
* and there's a role conflict
*/
stun_debug ("STUN Role Conflict detected:");
/* According to ICE RFC 5245, section 7.2.1.1, we consider the four
* possible cases when a role conflict is detected: two cases are
* resolved by switching role locally, and the two other cases are
* handled by responding with a STUN error.
*/
if ((tie < q && *control) || (tie >= q && !*control))
{
stun_debug (" switching role from \"controll%s\" to \"controll%s\"",
*control ? "ing" : "ed", *control ? "ed" : "ing");
*control = !*control;
ret = STUN_USAGE_ICE_RETURN_ROLE_CONFLICT;
}
else
{
stun_debug (" staying \"controll%s\" (sending error)",
*control ? "ing" : "ed");
err (STUN_ERROR_ROLE_CONFLICT);
return STUN_USAGE_ICE_RETURN_ROLE_CONFLICT;
}
} else {
if (stun_message_find64 (req, *control ? STUN_ATTRIBUTE_ICE_CONTROLLED
: STUN_ATTRIBUTE_ICE_CONTROLLING, &q) != STUN_MESSAGE_RETURN_SUCCESS)
{
/* we don't have the expected ice-controlling/controlled
* attribute
*/
if (compatibility == STUN_USAGE_ICE_COMPATIBILITY_RFC5245 ||
compatibility == STUN_USAGE_ICE_COMPATIBILITY_MSICE2)
{
stun_debug ("STUN Role not specified by peer!");
}
}
}
if (stun_agent_init_response (agent, msg, buf, len, req) == FALSE) {
stun_debug ("Unable to create response");
goto failure;
}
if (compatibility == STUN_USAGE_ICE_COMPATIBILITY_MSN) {
union {
StunTransactionId transid;
uint32_t magic_cookie;
} conv;
stun_message_id (msg, conv.transid);
val = stun_message_append_xor_addr_full (msg, STUN_ATTRIBUTE_XOR_MAPPED_ADDRESS,
src, srclen, htonl (conv.magic_cookie));
} else if (stun_message_has_cookie (msg) &&
compatibility != STUN_USAGE_ICE_COMPATIBILITY_GOOGLE) {
val = stun_message_append_xor_addr (msg, STUN_ATTRIBUTE_XOR_MAPPED_ADDRESS,
src, srclen);
} else {
val = stun_message_append_addr (msg, STUN_ATTRIBUTE_MAPPED_ADDRESS,
(struct sockaddr *) src, srclen);
}
if (val != STUN_MESSAGE_RETURN_SUCCESS) {
stun_debug (" Mapped address problem: %d", val);
goto failure;
}
username = (const char *)stun_message_find (req,
STUN_ATTRIBUTE_USERNAME, &username_len);
if (username) {
val = stun_message_append_bytes (msg, STUN_ATTRIBUTE_USERNAME,
username, username_len);
}
if (val != STUN_MESSAGE_RETURN_SUCCESS) {
stun_debug ("Error appending username: %d", val);
goto failure;
}
if (compatibility == STUN_USAGE_ICE_COMPATIBILITY_MSICE2) {
val = stun_message_append32 (msg,
STUN_ATTRIBUTE_MS_IMPLEMENTATION_VERSION, 2);
if (val != STUN_MESSAGE_RETURN_SUCCESS) {
stun_debug ("Error appending implementation version: %d", val);
goto failure;
}
}
/* the stun agent will automatically use the password of the request */
len = stun_agent_finish_message (agent, msg, NULL, 0);
if (len == 0)
goto failure;
*plen = len;
stun_debug (" All done (response size: %u)", (unsigned)len);
return ret;
failure:
assert (*plen == 0);
stun_debug (" Fatal error formatting Response: %d", val);
switch (val)
{
case STUN_MESSAGE_RETURN_NOT_ENOUGH_SPACE:
return STUN_USAGE_ICE_RETURN_MEMORY_ERROR;
case STUN_MESSAGE_RETURN_INVALID:
case STUN_MESSAGE_RETURN_UNSUPPORTED_ADDRESS:
return STUN_USAGE_ICE_RETURN_INVALID_ADDRESS;
case STUN_MESSAGE_RETURN_SUCCESS:
assert (0); /* shouldn’t be reached */
case STUN_MESSAGE_RETURN_NOT_FOUND:
default:
return STUN_USAGE_ICE_RETURN_ERROR;
}
}
int handle_stun(udp_conn* c, uint8_t *packet, size_t len) {
StunAgent agent;
StunValidationStatus status;
StunAgentUsageFlags flags;
StunMessage request;
StunMessage response;
int ret;
size_t output_size;
uint8_t output[1024];
flags = STUN_AGENT_USAGE_IGNORE_CREDENTIALS; // | STUN_AGENT_USAGE_USE_FINGERPRINT;
static const uint16_t attr[] = {
STUN_ATTRIBUTE_MAPPED_ADDRESS,
STUN_ATTRIBUTE_RESPONSE_ADDRESS,
STUN_ATTRIBUTE_CHANGE_REQUEST,
STUN_ATTRIBUTE_SOURCE_ADDRESS,
STUN_ATTRIBUTE_CHANGED_ADDRESS,
STUN_ATTRIBUTE_USERNAME,
STUN_ATTRIBUTE_PASSWORD,
STUN_ATTRIBUTE_MESSAGE_INTEGRITY,
STUN_ATTRIBUTE_ERROR_CODE,
STUN_ATTRIBUTE_UNKNOWN_ATTRIBUTES,
STUN_ATTRIBUTE_REFLECTED_FROM,
STUN_ATTRIBUTE_CHANNEL_NUMBER,
STUN_ATTRIBUTE_LIFETIME,
STUN_ATTRIBUTE_MS_ALTERNATE_SERVER,
STUN_ATTRIBUTE_MAGIC_COOKIE,
STUN_ATTRIBUTE_BANDWIDTH,
STUN_ATTRIBUTE_DESTINATION_ADDRESS,
STUN_ATTRIBUTE_REMOTE_ADDRESS,
STUN_ATTRIBUTE_PEER_ADDRESS,
STUN_ATTRIBUTE_XOR_PEER_ADDRESS,
STUN_ATTRIBUTE_DATA,
STUN_ATTRIBUTE_REALM,
STUN_ATTRIBUTE_NONCE,
STUN_ATTRIBUTE_RELAY_ADDRESS,
STUN_ATTRIBUTE_RELAYED_ADDRESS,
STUN_ATTRIBUTE_XOR_RELAYED_ADDRESS,
STUN_ATTRIBUTE_REQUESTED_ADDRESS_TYPE,
STUN_ATTRIBUTE_REQUESTED_PORT_PROPS,
STUN_ATTRIBUTE_REQUESTED_PROPS,
STUN_ATTRIBUTE_EVEN_PORT,
STUN_ATTRIBUTE_REQUESTED_TRANSPORT,
STUN_ATTRIBUTE_DONT_FRAGMENT,
STUN_ATTRIBUTE_XOR_MAPPED_ADDRESS,
STUN_ATTRIBUTE_TIMER_VAL,
STUN_ATTRIBUTE_REQUESTED_IP,
STUN_ATTRIBUTE_RESERVATION_TOKEN,
STUN_ATTRIBUTE_CONNECT_STAT,
STUN_ATTRIBUTE_PRIORITY,
STUN_ATTRIBUTE_USE_CANDIDATE,
STUN_ATTRIBUTE_OPTIONS,
STUN_ATTRIBUTE_MS_VERSION,
STUN_ATTRIBUTE_SOFTWARE,
STUN_ATTRIBUTE_ALTERNATE_SERVER,
STUN_ATTRIBUTE_FINGERPRINT,
STUN_ATTRIBUTE_ICE_CONTROLLED,
STUN_ATTRIBUTE_ICE_CONTROLLING,
STUN_ATTRIBUTE_MS_SEQUENCE_NUMBER,
STUN_ATTRIBUTE_CANDIDATE_IDENTIFIER
};
/* initialize our agent to be compatible with RFC5389 (= with TLS support) */
output_size = 0;
memset(output, 0, sizeof(output));
stun_agent_init(&agent, attr, STUN_COMPATIBILITY_RFC5389, flags);
/* validate the request */
status = stun_agent_validate(&agent, &request, packet, len, NULL, NULL);
print_stun_validation_status(status);
/* check the class */
StunClass request_class = stun_message_get_class(&request);
print_stun_class(request_class);
if(request_class == STUN_ERROR) {
printf("Error: request stun class failed.\n");
exit(0);
}
/* what stun method? */
StunMethod request_method = stun_message_get_method(&request);
print_stun_method(request_method);
/* initialize the response */
ret = stun_agent_init_response(&agent, &response, output, 1024, &request);
printf("Stun agent_init_response ret: %d\n", ret);
/* add xor-mapped-address */
uint32_t magic_cookie = 0;
uint8_t* cookie_ptr = NULL;
StunTransactionId transid;
socklen_t sock_len = 0;
char client_ip[16] = { 0 } ;
StunMessageReturn stun_ret = STUN_MESSAGE_RETURN_INVALID;
stun_message_id(&response, transid);
magic_cookie = *((uint32_t*)transid);
sock_len = sizeof(c->client);
cookie_ptr = (uint8_t*) &magic_cookie;
inet_ntop(AF_INET, &c->client.sin_addr.s_addr, client_ip, sizeof(client_ip));
stun_ret = stun_message_append_xor_addr(&response, STUN_ATTRIBUTE_XOR_MAPPED_ADDRESS, (const struct sockaddr*)&c->client, sock_len);
print_stun_message_return(stun_ret);
printf("Received data from: %s\n", client_ip);
printf("Magic cookie: %02X %02X %02X %02X\n", cookie_ptr[0], cookie_ptr[1], cookie_ptr[2], cookie_ptr[3]);
// username
// --------
const char* username = NULL;
uint16_t username_len = 0;
username = (const char*)stun_message_find(&request, STUN_ATTRIBUTE_USERNAME, &username_len);
printf("Username: %s, len: %d\n", username, (int)username_len);
#if 0
if(username) {
StunMessageReturn username_res = stun_message_append_bytes(&response, STUN_ATTRIBUTE_USERNAME, username, username_len);
print_stun_message_return(username_res);
}
uint32_t fingerprint = 0;
if(stun_message_find32(&request, STUN_ATTRIBUTE_FINGERPRINT, &fingerprint) == STUN_MESSAGE_RETURN_SUCCESS) {
printf("Got fingerprint: %d\n", fingerprint);
if(stun_message_append32(&response, STUN_ATTRIBUTE_FINGERPRINT, fingerprint) != STUN_MESSAGE_RETURN_SUCCESS) {
printf("Error while adding the fingerprint.\n");
}
}
#endif
// password
const char* password = ucon_ptr->stun_pw; // "94ccca06d14fb48c135bdaff30560c4d";
uint16_t password_len = strlen(password) + 1;
output_size = stun_agent_finish_message(&agent, &response, (const uint8_t*) password, password_len);
// answer to the connection
krx_udp_send(c, output, output_size);
print_buffer(output, output_size);
return 0;
}
/* Tests for generic message validation routines */
static void test_message (void)
{
static const uint8_t extra_garbage[] =
{0x15, 0x55, 0x00, 0x00,
0x21, 0x12, 0xA4, 0x42, // cookie
0x76, 0x54, 0x32, 0x10,
0xfe, 0xdc, 0xba, 0x98,
0x76, 0x54, 0x32, 0x10,
0xaa, 0xbb, 0xcc, 0xdd}; //extra garbage
static const uint8_t simple_resp[] =
{0x15, 0x55, 0x00, 0x00,
0x21, 0x12, 0xA4, 0x42, // cookie
0x76, 0x54, 0x32, 0x10,
0xfe, 0xdc, 0xba, 0x98,
0x76, 0x54, 0x32, 0x10};
static const uint8_t old_ind[] =
{0x14, 0x55, 0x00, 0x00,
0xfe, 0xdc, 0xba, 0x98, // NO cookie
0x76, 0x54, 0x32, 0x10,
0xfe, 0xdc, 0xba, 0x98,
0x76, 0x54, 0x32, 0x10};
static const uint8_t fpr_resp[] =
{0x15, 0x55, 0x00, 0x10,
0x21, 0x12, 0xA4, 0x42, // cookie
0x76, 0x54, 0x32, 0x10,
0xfe, 0xdc, 0xba, 0x98,
0x76, 0x54, 0x32, 0x10,
0x00, 0x06, 0x00, 0x04, // dummy USERNAME header
0x41, 0x42, 0x43, 0x44,
0x80, 0x28, 0x00, 0x04, // FINGERPRINT header
0xdc, 0x8d, 0xa7, 0x74}; // CRC32;
static const uint8_t bad1[32] =
{0x15, 0x55, 0x00, 0x08,
0x21, 0x12, 0xA4, 0x42, // cookie
0x76, 0x54, 0x32, 0x10,
0xfe, 0xdc, 0xba, 0x98,
0x76, 0x54, 0x32, 0x10,
0x00, 0x06, 0x00, 0x05, // too big attribute for message
0x11, 0x22, 0x33, 0x44,
0x55, 0x66, 0x77, 0x88};
static const uint8_t bad2[24] =
{0x15, 0x55, 0x00, 0x05, // invalid message length
0x21, 0x12, 0xA4, 0x42,
0x76, 0x54, 0x32, 0x10,
0xfe, 0xdc, 0xba, 0x98,
0x76, 0x54, 0x32, 0x10,
0x00, 0x06, 0x00, 0x01};
static const uint8_t bad3[27] =
{0x15, 0x55, 0x00, 0x08,
0x21, 0x12, 0xA4, 0x42,
0x76, 0x54, 0x32, 0x10,
0xfe, 0xdc, 0xba, 0x98,
0x76, 0x54, 0x32, 0x10,
0x00, 0x06, 0x00, 0x03,
0x11, 0x22, 0x33}; // missing padding
static const uint8_t bad_crc[] =
{0x15, 0x55, 0x00, 0x08,
0x21, 0x12, 0xA4, 0x42,
0x76, 0x54, 0x32, 0x10,
0xfe, 0xdc, 0xba, 0x98,
0x76, 0x54, 0x32, 0x10,
0x80, 0x28, 0x00, 0x04, // FINGERPRINT header
0x04, 0x91, 0xcd, 0x78}; // CRC32
static uint8_t bad_crc_offset[] =
{0x15, 0x55, 0x00, 0x10,
0x21, 0x12, 0xA4, 0x42,
0x76, 0x54, 0x32, 0x10,
0xfe, 0xdc, 0xba, 0x98,
0x20, 0x67, 0xc4, 0x09,
0x80, 0x28, 0x00, 0x04, // FINGERPRINT header
0x00, 0x00, 0x00, 0x00,
0x00, 0x06, 0x00, 0x04,
0x41, 0x42, 0x43, 0x44};
static unsigned char req[] =
{0x00, 0x01, 0x00, 0x00,
0x8b, 0x45, 0x9b, 0xc3,
0xe7, 0x7a, 0x05, 0xb3,
0xe4, 0xfe, 0x01, 0xf0,
0xaf, 0x83, 0xe1, 0x9e};
static uint8_t binding_error_resp[] =
{0x01, 0x11, 0x00, 0x84,
0x8b, 0x45, 0x9b, 0xc3,
0xe7, 0x7a, 0x05, 0xb3,
0xe4, 0xfe, 0x01, 0xf0,
0xaf, 0x83, 0xe1, 0x9e,
0x00, 0x06, 0x00, 0x48, // USERNAME
0x92, 0x6b, 0x2b, 0x3e,
0x6a, 0xa5, 0x43, 0x58,
0xa8, 0x51, 0x25, 0xa6,
0xf7, 0x9c, 0x0a, 0xe7,
0xd8, 0x86, 0xf7, 0x76,
0xf9, 0xcd, 0x8a, 0x2e,
0x45, 0xd7, 0xcb, 0xbb,
0xae, 0xe5, 0x03, 0xc3,
0x3a, 0x32, 0x3a, 0xa9,
0x9e, 0xb7, 0x7b, 0x32,
0xe3, 0xf3, 0xa6, 0xc0,
0xe8, 0x54, 0x4b, 0xef,
0x52, 0xd2, 0xe2, 0xc0,
0x43, 0xc2, 0x4c, 0xbc,
0xaf, 0xd9, 0xf2, 0xfa,
0x48, 0x8b, 0x8c, 0xe6,
0x62, 0x14, 0x64, 0x3a,
0x32, 0x00, 0x00, 0x00,
0x00, 0x09, 0x00, 0x1c, // ERROR-CODE
0x00, 0x00, 0x04, 0x1f,
0x49, 0x6e, 0x74, 0x65,
0x67, 0x72, 0x69, 0x74,
0x79, 0x20, 0x43, 0x68,
0x65, 0x63, 0x6b, 0x20,
0x46, 0x61, 0x69, 0x6c,
0x75, 0x72, 0x65, 0x2e,
0x00, 0x08, 0x00, 0x14, // MESSAGE-INTEGRITY
0xf7, 0x46, 0x81, 0xc4,
0x6f, 0x4c, 0x21, 0x5c,
0xf6, 0x8e, 0xc0, 0x81,
0x0e, 0x20, 0x3f, 0xb1,
0xb1, 0xad, 0xa4, 0x8a};
StunAgent agent;
StunAgent agent2;
StunMessage msg;
uint16_t known_attributes[] = {STUN_ATTRIBUTE_USERNAME,
STUN_ATTRIBUTE_ERROR_CODE,
STUN_ATTRIBUTE_MESSAGE_INTEGRITY};
uint8_t username_v[] = {0x92, 0x6b, 0x2b, 0x3e, 0x6a, 0xa5, 0x43, 0x58,
0xa8, 0x51, 0x25, 0xa6, 0xf7, 0x9c, 0x0a, 0xe7,
0xd8, 0x86, 0xf7, 0x76, 0xf9, 0xcd, 0x8a, 0x2e,
0x45, 0xd7, 0xcb, 0xbb, 0xae, 0xe5, 0x03, 0xc3,
0x3a, 0x32, 0x3a, 0xa9, 0x9e, 0xb7, 0x7b, 0x32,
0xe3, 0xf3, 0xa6, 0xc0, 0xe8, 0x54, 0x4b, 0xef,
0x52, 0xd2, 0xe2, 0xc0, 0x43, 0xc2, 0x4c, 0xbc,
0xaf, 0xd9, 0xf2, 0xfa, 0x48, 0x8b, 0x8c, 0xe6,
0x62, 0x14, 0x64, 0x3a, 0x32, 0x00, 0x00, 0x00};
uint8_t password_v[] = {0x77, 0xd9, 0x7a, 0xe9, 0xcf, 0xe0, 0x3e, 0xa2,
0x28, 0xa0, 0x5d, 0xec, 0xcf, 0x36, 0xe8, 0x49};
StunDefaultValidaterData v = {username_v, 72, password_v, 16};
stun_agent_init (&agent, known_attributes,
STUN_COMPATIBILITY_RFC5389, STUN_AGENT_USAGE_USE_FINGERPRINT);
stun_agent_init (&agent2, known_attributes,
STUN_COMPATIBILITY_RFC3489, STUN_AGENT_USAGE_SHORT_TERM_CREDENTIALS);
stun_agent_validate (&agent2, &msg, req, sizeof(req), NULL, NULL);
stun_agent_finish_message (&agent2, &msg, NULL, 0);
if (stun_agent_validate (&agent2, &msg, binding_error_resp,
sizeof(binding_error_resp),
stun_agent_default_validater, &v) != STUN_VALIDATION_SUCCESS)
fatal ("Binding Error Response failed");
if (stun_message_validate_buffer_length (NULL, 0, TRUE) !=
STUN_MESSAGE_BUFFER_INVALID)
fatal ("0 bytes test failed");
if (stun_message_validate_buffer_length ((uint8_t *)"\xf0", 1, TRUE) >= 0)
fatal ("1 byte test failed");
if (stun_message_validate_buffer_length (bad1, sizeof (bad1), TRUE) >= 0)
fatal ("Badness 1 test failed");
if (stun_message_validate_buffer_length (bad2, sizeof (bad2), TRUE) >= 0)
fatal ("Badness 2 test failed");
if (stun_message_validate_buffer_length (bad3, sizeof (bad3), TRUE) != 0)
fatal ("Badness 3 test failed");
validate (simple_resp, 20);
validate (old_ind, 20);
validate (fpr_resp, 36);
if (stun_agent_validate (&agent, &msg, extra_garbage, sizeof(extra_garbage),
NULL, NULL) != STUN_VALIDATION_NOT_STUN)
fatal ("Extra garbage test failed");
if (stun_agent_validate (&agent, &msg, simple_resp, sizeof(simple_resp),
NULL, NULL) != STUN_VALIDATION_BAD_REQUEST)
fatal ("Missing CRC test failed");
if (stun_agent_validate (&agent, &msg, old_ind, sizeof(old_ind),
NULL, NULL) != STUN_VALIDATION_BAD_REQUEST)
fatal ("Missing cookie test failed");
if (stun_agent_validate (&agent, &msg, bad_crc, sizeof(bad_crc),
NULL, NULL) != STUN_VALIDATION_BAD_REQUEST)
fatal ("Bad CRC test failed");
if (stun_agent_validate (&agent, &msg, bad_crc_offset, sizeof(bad_crc_offset),
NULL, NULL) != STUN_VALIDATION_BAD_REQUEST)
fatal ("Bad CRC offset test failed");
if (stun_agent_validate (&agent, &msg, fpr_resp, sizeof(fpr_resp),
NULL, NULL) != STUN_VALIDATION_UNMATCHED_RESPONSE)
fatal ("Good CRC test failed");
if (stun_message_get_class (&msg) != 3)
fatal ("Class test failed");
if (stun_message_get_method (&msg) != 0x525)
fatal ("Method test failed");
}