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);
}
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);
}
