5 Author: Pekka Riikonen <priikone@poseidon.pspt.fi>
7 Copyright (C) 1997 - 2001 Pekka Riikonen
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 2 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
21 /* This file includes the private message sending and receiving routines
22 and private message key handling routines. */
24 #include "clientlibincludes.h"
25 #include "client_internal.h"
27 /* Sends private message to remote client. If private message key has
28 not been set with this client then the message will be encrypted using
29 normal session keys. Private messages are special packets in SILC
30 network hence we need this own function for them. This is similiar
31 to silc_client_packet_send_to_channel except that we send private
32 message. The `data' is the private message. If the `force_send' is
33 TRUE the packet is sent immediately. */
35 void silc_client_send_private_message(SilcClient client,
36 SilcClientConnection conn,
37 SilcClientEntry client_entry,
38 SilcMessageFlags flags,
43 SilcSocketConnection sock = conn->sock;
45 SilcPacketContext packetdata;
50 SILC_LOG_DEBUG(("Sending private message"));
52 /* Encode private message payload */
53 buffer = silc_private_message_payload_encode(flags,
55 client_entry->send_key);
57 /* If we don't have private message specific key then private messages
58 are just as any normal packet thus call normal packet sending. If
59 the key exist then the encryption process is a bit different and
60 will be done in the rest of this function. */
61 if (!client_entry->send_key) {
62 silc_client_packet_send(client, sock, SILC_PACKET_PRIVATE_MESSAGE,
63 client_entry->id, SILC_ID_CLIENT, NULL, NULL,
64 buffer->data, buffer->len, force_send);
68 /* We have private message specific key */
70 /* Get data used in the encryption */
71 cipher = client_entry->send_key;
72 hmac = conn->hmac_send;
73 block_len = silc_cipher_get_block_len(cipher);
75 /* Set the packet context pointers. */
76 packetdata.flags = SILC_PACKET_FLAG_PRIVMSG_KEY;
77 packetdata.type = SILC_PACKET_PRIVATE_MESSAGE;
78 packetdata.src_id = conn->local_id_data;
79 packetdata.src_id_len = silc_id_get_len(conn->local_id, SILC_ID_CLIENT);
80 packetdata.src_id_type = SILC_ID_CLIENT;
81 packetdata.dst_id = silc_id_id2str(client_entry->id, SILC_ID_CLIENT);
82 packetdata.dst_id_len = silc_id_get_len(client_entry->id, SILC_ID_CLIENT);
83 packetdata.dst_id_type = SILC_ID_CLIENT;
84 packetdata.truelen = buffer->len + SILC_PACKET_HEADER_LEN +
85 packetdata.src_id_len + packetdata.dst_id_len;
86 packetdata.padlen = SILC_PACKET_PADLEN((SILC_PACKET_HEADER_LEN +
87 packetdata.src_id_len +
88 packetdata.dst_id_len), block_len);
90 /* Prepare outgoing data buffer for packet sending */
91 silc_packet_send_prepare(sock,
92 SILC_PACKET_HEADER_LEN +
93 packetdata.src_id_len +
94 packetdata.dst_id_len,
98 packetdata.buffer = sock->outbuf;
100 /* Put the actual encrypted message payload data into the buffer. */
101 silc_buffer_put(sock->outbuf, buffer->data, buffer->len);
103 /* Create the outgoing packet */
104 silc_packet_assemble(&packetdata, cipher);
106 /* Encrypt the header and padding of the packet. */
107 cipher = conn->send_key;
108 silc_packet_encrypt(cipher, hmac, conn->psn_send++,
109 sock->outbuf, SILC_PACKET_HEADER_LEN +
110 packetdata.src_id_len + packetdata.dst_id_len +
113 SILC_LOG_HEXDUMP(("Private message packet, len %d", sock->outbuf->len),
114 sock->outbuf->data, sock->outbuf->len);
116 /* Now actually send the packet */
117 silc_client_packet_send_real(client, sock, force_send);
118 silc_free(packetdata.dst_id);
121 silc_buffer_free(buffer);
124 static void silc_client_private_message_cb(SilcClient client,
125 SilcClientConnection conn,
126 SilcClientEntry *clients,
127 uint32 clients_count,
130 SilcPacketContext *packet = (SilcPacketContext *)context;
133 silc_packet_context_free(packet);
137 silc_client_private_message(client, conn->sock, packet);
138 silc_packet_context_free(packet);
141 /* Private message received. This processes the private message and
142 finally displays it on the screen. */
144 void silc_client_private_message(SilcClient client,
145 SilcSocketConnection sock,
146 SilcPacketContext *packet)
148 SilcClientConnection conn = (SilcClientConnection)sock->user_data;
149 SilcPrivateMessagePayload payload = NULL;
150 SilcIDCacheEntry id_cache;
151 SilcClientID *remote_id = NULL;
152 SilcClientEntry remote_client;
153 SilcMessageFlags flags;
155 if (packet->src_id_type != SILC_ID_CLIENT)
158 remote_id = silc_id_str2id(packet->src_id, packet->src_id_len,
163 /* Check whether we know this client already */
164 if (!silc_idcache_find_by_id_one_ext(conn->client_cache, (void *)remote_id,
166 silc_hash_client_id_compare, NULL,
168 /* Resolve the client info */
169 silc_client_get_client_by_id_resolve(client, conn, remote_id,
170 silc_client_private_message_cb,
171 silc_packet_context_dup(packet));
175 remote_client = (SilcClientEntry)id_cache->context;
177 /* Parse the payload and decrypt it also if private message key is set */
178 payload = silc_private_message_payload_parse(packet->buffer,
179 remote_client->receive_key);
181 silc_free(remote_id);
185 flags = silc_private_message_get_flags(payload);
187 /* Pass the private message to application */
188 client->ops->private_message(client, conn, remote_client, flags,
189 silc_private_message_get_message(payload,
192 /* See if we are away (gone). If we are away we will reply to the
193 sender with the set away message. */
194 if (conn->away && conn->away->away && !(flags & SILC_MESSAGE_FLAG_NOREPLY)) {
195 /* If it's me, ignore */
196 if (SILC_ID_CLIENT_COMPARE(remote_id, conn->local_id))
199 /* Send the away message */
200 silc_client_send_private_message(client, conn, remote_client,
201 SILC_MESSAGE_FLAG_AUTOREPLY |
202 SILC_MESSAGE_FLAG_NOREPLY,
204 strlen(conn->away->away), TRUE);
209 silc_private_message_payload_free(payload);
211 silc_free(remote_id);
214 /* Function that actually employes the received private message key */
216 static void silc_client_private_message_key_cb(SilcClient client,
217 SilcClientConnection conn,
218 SilcClientEntry *clients,
219 uint32 clients_count,
222 SilcPacketContext *packet = (SilcPacketContext *)context;
225 unsigned char *cipher;
231 /* Parse the private message key payload */
232 ret = silc_buffer_unformat(packet->buffer,
233 SILC_STR_UI16_NSTRING(&key, &key_len),
234 SILC_STR_UI16_STRING(&cipher),
239 if (key_len > packet->buffer->len)
242 /* Now take the key in use */
243 if (!silc_client_add_private_message_key(client, conn, clients[0],
244 cipher, key, key_len, FALSE, TRUE))
247 /* Print some info for application */
248 client->ops->say(client, conn, SILC_CLIENT_MESSAGE_AUDIT,
249 "Received private message key from %s%s%s %s%s%s",
250 clients[0]->nickname,
251 clients[0]->server ? "@" : "",
252 clients[0]->server ? clients[0]->server : "",
253 clients[0]->username ? "(" : "",
254 clients[0]->username ? clients[0]->username : "",
255 clients[0]->username ? ")" : "");
258 silc_packet_context_free(packet);
261 /* Processes incoming Private Message Key payload. The libary always
262 accepts the key and takes it into use. */
264 void silc_client_private_message_key(SilcClient client,
265 SilcSocketConnection sock,
266 SilcPacketContext *packet)
268 SilcClientID *remote_id;
270 if (packet->src_id_type != SILC_ID_CLIENT)
273 remote_id = silc_id_str2id(packet->src_id, packet->src_id_len,
278 silc_client_get_client_by_id_resolve(client, sock->user_data, remote_id,
279 silc_client_private_message_key_cb,
280 silc_packet_context_dup(packet));
281 silc_free(remote_id);
284 /* Adds private message key to the client library. The key will be used to
285 encrypt all private message between the client and the remote client
286 indicated by the `client_entry'. If the `key' is NULL and the boolean
287 value `generate_key' is TRUE the library will generate random key.
288 The `key' maybe for example pre-shared-key, passphrase or similar.
289 The `cipher' MAY be provided but SHOULD be NULL to assure that the
290 requirements of the SILC protocol are met. The API, however, allows
291 to allocate any cipher.
293 If `responder' is TRUE then the sending and receiving keys will be
294 set according the client being the receiver of the private key. If
295 FALSE the client is being the sender (or negotiator) of the private
298 It is not necessary to set key for normal private message usage. If the
299 key is not set then the private messages are encrypted using normal
300 session keys. Setting the private key, however, increases the security.
302 Returns FALSE if the key is already set for the `client_entry', TRUE
305 int silc_client_add_private_message_key(SilcClient client,
306 SilcClientConnection conn,
307 SilcClientEntry client_entry,
314 unsigned char private_key[32];
317 SilcSKEKeyMaterial *keymat;
319 assert(client_entry);
321 /* Return FALSE if key already set */
322 if (client_entry->send_key && client_entry->receive_key)
326 cipher = SILC_DEFAULT_CIPHER;
328 /* Check the requested cipher */
329 if (!silc_cipher_is_supported(cipher))
332 /* Generate key if not provided */
333 if (generate_key == TRUE) {
335 for (i = 0; i < len; i++) private_key[i] = silc_rng_get_byte(client->rng);
338 client_entry->generated = TRUE;
342 client_entry->key = silc_calloc(key_len, sizeof(*client_entry->key));
343 memcpy(client_entry->key, key, key_len);
344 client_entry->key_len = key_len;
346 /* Produce the key material as the protocol defines */
347 keymat = silc_calloc(1, sizeof(*keymat));
348 if (silc_ske_process_key_material_data(key, key_len, 16, 256, 16,
349 client->md5hash, keymat)
350 != SILC_SKE_STATUS_OK)
353 /* Allocate the ciphers */
354 silc_cipher_alloc(cipher, &client_entry->send_key);
355 silc_cipher_alloc(cipher, &client_entry->receive_key);
358 if (responder == TRUE) {
359 silc_cipher_set_key(client_entry->send_key, keymat->receive_enc_key,
360 keymat->enc_key_len);
361 silc_cipher_set_iv(client_entry->send_key, keymat->receive_iv);
362 silc_cipher_set_key(client_entry->receive_key, keymat->send_enc_key,
363 keymat->enc_key_len);
364 silc_cipher_set_iv(client_entry->receive_key, keymat->send_iv);
366 silc_cipher_set_key(client_entry->send_key, keymat->send_enc_key,
367 keymat->enc_key_len);
368 silc_cipher_set_iv(client_entry->send_key, keymat->send_iv);
369 silc_cipher_set_key(client_entry->receive_key, keymat->receive_enc_key,
370 keymat->enc_key_len);
371 silc_cipher_set_iv(client_entry->receive_key, keymat->receive_iv);
374 /* Free the key material */
375 silc_ske_free_key_material(keymat);
380 /* Same as above but takes the key material from the SKE key material
381 structure. This structure is received if the application uses the
382 silc_client_send_key_agreement to negotiate the key material. The
383 `cipher' SHOULD be provided as it is negotiated also in the SKE
386 int silc_client_add_private_message_key_ske(SilcClient client,
387 SilcClientConnection conn,
388 SilcClientEntry client_entry,
390 SilcSKEKeyMaterial *key,
393 assert(client_entry);
395 /* Return FALSE if key already set */
396 if (client_entry->send_key && client_entry->receive_key)
400 cipher = SILC_DEFAULT_CIPHER;
402 /* Check the requested cipher */
403 if (!silc_cipher_is_supported(cipher))
406 /* Allocate the ciphers */
407 silc_cipher_alloc(cipher, &client_entry->send_key);
408 silc_cipher_alloc(cipher, &client_entry->receive_key);
411 if (responder == TRUE) {
412 silc_cipher_set_key(client_entry->send_key, key->receive_enc_key,
414 silc_cipher_set_iv(client_entry->send_key, key->receive_iv);
415 silc_cipher_set_key(client_entry->receive_key, key->send_enc_key,
417 silc_cipher_set_iv(client_entry->receive_key, key->send_iv);
419 silc_cipher_set_key(client_entry->send_key, key->send_enc_key,
421 silc_cipher_set_iv(client_entry->send_key, key->send_iv);
422 silc_cipher_set_key(client_entry->receive_key, key->receive_enc_key,
424 silc_cipher_set_iv(client_entry->receive_key, key->receive_iv);
430 /* Sends private message key payload to the remote client indicated by
431 the `client_entry'. If the `force_send' is TRUE the packet is sent
432 immediately. Returns FALSE if error occurs, TRUE otherwise. The
433 application should call this function after setting the key to the
436 Note that the key sent using this function is sent to the remote client
437 through the SILC network. The packet is protected using normal session
440 int silc_client_send_private_message_key(SilcClient client,
441 SilcClientConnection conn,
442 SilcClientEntry client_entry,
445 SilcSocketConnection sock = conn->sock;
449 if (!client_entry->send_key || !client_entry->key)
452 SILC_LOG_DEBUG(("Sending private message key"));
454 cipher_len = strlen(client_entry->send_key->cipher->name);
456 /* Create private message key payload */
457 buffer = silc_buffer_alloc(2 + client_entry->key_len);
458 silc_buffer_pull_tail(buffer, SILC_BUFFER_END(buffer));
459 silc_buffer_format(buffer,
460 SILC_STR_UI_SHORT(client_entry->key_len),
461 SILC_STR_UI_XNSTRING(client_entry->key,
462 client_entry->key_len),
463 SILC_STR_UI_SHORT(cipher_len),
464 SILC_STR_UI_XNSTRING(client_entry->send_key->cipher->name,
468 /* Send the packet */
469 silc_client_packet_send(client, sock, SILC_PACKET_PRIVATE_MESSAGE_KEY,
470 client_entry->id, SILC_ID_CLIENT, NULL, NULL,
471 buffer->data, buffer->len, force_send);
477 /* Removes the private message from the library. The key won't be used
478 after this to protect the private messages with the remote `client_entry'
479 client. Returns FALSE on error, TRUE otherwise. */
481 int silc_client_del_private_message_key(SilcClient client,
482 SilcClientConnection conn,
483 SilcClientEntry client_entry)
485 assert(client_entry);
487 if (!client_entry->send_key && !client_entry->receive_key)
490 silc_cipher_free(client_entry->send_key);
491 silc_cipher_free(client_entry->receive_key);
493 if (client_entry->key) {
494 memset(client_entry->key, 0, client_entry->key_len);
495 silc_free(client_entry->key);
498 client_entry->send_key = NULL;
499 client_entry->receive_key = NULL;
500 client_entry->key = NULL;
505 /* Returns array of set private message keys associated to the connection
506 `conn'. Returns allocated SilcPrivateMessageKeys array and the array
507 count to the `key_count' argument. The array must be freed by the caller
508 by calling the silc_client_free_private_message_keys function. Note:
509 the keys returned in the array is in raw format. It might not be desired
510 to show the keys as is. The application might choose not to show the keys
511 at all or to show the fingerprints of the keys. */
513 SilcPrivateMessageKeys
514 silc_client_list_private_message_keys(SilcClient client,
515 SilcClientConnection conn,
518 SilcPrivateMessageKeys keys;
520 SilcIDCacheEntry id_cache;
521 SilcIDCacheList list;
522 SilcClientEntry entry;
524 if (!silc_idcache_get_all(conn->client_cache, &list))
527 if (!silc_idcache_list_count(list)) {
528 silc_idcache_list_free(list);
532 keys = silc_calloc(silc_idcache_list_count(list), sizeof(*keys));
534 silc_idcache_list_first(list, &id_cache);
536 entry = (SilcClientEntry)id_cache->context;
538 if (entry->send_key) {
539 keys[count].client_entry = entry;
540 keys[count].cipher = entry->send_key->cipher->name;
541 keys[count].key = entry->generated == FALSE ? entry->key : NULL;
542 keys[count].key_len = entry->generated == FALSE ? entry->key_len : 0;
546 if (!silc_idcache_list_next(list, &id_cache))
556 /* Frees the SilcPrivateMessageKeys array returned by the function
557 silc_client_list_private_message_keys. */
559 void silc_client_free_private_message_keys(SilcPrivateMessageKeys keys,
565 /* Sets away `message'. The away message may be set when the client's
566 mode is changed to SILC_UMODE_GONE and the client whishes to reply
567 to anyone who sends private message. The `message' will be sent
568 automatically back to the the client who send private message. If
569 away message is already set this replaces the old message with the
570 new one. If `message' is NULL the old away message is removed.
571 The sender may freely free the memory of the `message'. */
573 void silc_client_set_away_message(SilcClient client,
574 SilcClientConnection conn,
577 if (!message && conn->away) {
578 silc_free(conn->away->away);
579 silc_free(conn->away);
585 conn->away = silc_calloc(1, sizeof(*conn->away));
586 if (conn->away->away)
587 silc_free(conn->away->away);
588 conn->away->away = strdup(message);