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 SilcClientID *remote_id = NULL;
151 SilcClientEntry remote_client;
152 SilcMessageFlags flags;
154 if (packet->src_id_type != SILC_ID_CLIENT)
157 remote_id = silc_id_str2id(packet->src_id, packet->src_id_len,
162 /* Check whether we know this client already */
163 remote_client = silc_client_get_client_by_id(client, conn, remote_id);
164 if (!remote_client || !remote_client->nickname) {
166 if (remote_client->status & SILC_CLIENT_STATUS_RESOLVING) {
167 remote_client->status &= ~SILC_CLIENT_STATUS_RESOLVING;
170 remote_client->status |= SILC_CLIENT_STATUS_RESOLVING;
173 /* Resolve the client info */
174 silc_client_get_client_by_id_resolve(client, conn, remote_id,
175 silc_client_private_message_cb,
176 silc_packet_context_dup(packet));
180 /* Parse the payload and decrypt it also if private message key is set */
181 payload = silc_private_message_payload_parse(packet->buffer->data,
183 remote_client->receive_key);
185 silc_free(remote_id);
189 flags = silc_private_message_get_flags(payload);
191 /* Pass the private message to application */
192 client->internal->ops->private_message(
193 client, conn, remote_client, flags,
194 silc_private_message_get_message(payload,
197 /* See if we are away (gone). If we are away we will reply to the
198 sender with the set away message. */
199 if (conn->away && conn->away->away && !(flags & SILC_MESSAGE_FLAG_NOREPLY)) {
200 /* If it's me, ignore */
201 if (SILC_ID_CLIENT_COMPARE(remote_id, conn->local_id))
204 /* Send the away message */
205 silc_client_send_private_message(client, conn, remote_client,
206 SILC_MESSAGE_FLAG_AUTOREPLY |
207 SILC_MESSAGE_FLAG_NOREPLY,
209 strlen(conn->away->away), TRUE);
214 silc_private_message_payload_free(payload);
215 silc_free(remote_id);
218 /* Function that actually employes the received private message key */
220 static void silc_client_private_message_key_cb(SilcClient client,
221 SilcClientConnection conn,
222 SilcClientEntry *clients,
223 uint32 clients_count,
226 SilcPacketContext *packet = (SilcPacketContext *)context;
229 unsigned char *cipher;
235 /* Parse the private message key payload */
236 ret = silc_buffer_unformat(packet->buffer,
237 SILC_STR_UI16_NSTRING(&key, &key_len),
238 SILC_STR_UI16_STRING(&cipher),
243 if (key_len > packet->buffer->len)
246 /* Now take the key in use */
247 if (!silc_client_add_private_message_key(client, conn, clients[0],
248 cipher, key, key_len, FALSE, TRUE))
251 /* Print some info for application */
252 client->internal->ops->say(
253 client, conn, SILC_CLIENT_MESSAGE_AUDIT,
254 "Received private message key from %s%s%s %s%s%s",
255 clients[0]->nickname,
256 clients[0]->server ? "@" : "",
257 clients[0]->server ? clients[0]->server : "",
258 clients[0]->username ? "(" : "",
259 clients[0]->username ? clients[0]->username : "",
260 clients[0]->username ? ")" : "");
263 silc_packet_context_free(packet);
266 /* Processes incoming Private Message Key payload. The libary always
267 accepts the key and takes it into use. */
269 void silc_client_private_message_key(SilcClient client,
270 SilcSocketConnection sock,
271 SilcPacketContext *packet)
273 SilcClientID *remote_id;
275 if (packet->src_id_type != SILC_ID_CLIENT)
278 remote_id = silc_id_str2id(packet->src_id, packet->src_id_len,
283 silc_client_get_client_by_id_resolve(client, sock->user_data, remote_id,
284 silc_client_private_message_key_cb,
285 silc_packet_context_dup(packet));
286 silc_free(remote_id);
289 /* Adds private message key to the client library. The key will be used to
290 encrypt all private message between the client and the remote client
291 indicated by the `client_entry'. If the `key' is NULL and the boolean
292 value `generate_key' is TRUE the library will generate random key.
293 The `key' maybe for example pre-shared-key, passphrase or similar.
294 The `cipher' MAY be provided but SHOULD be NULL to assure that the
295 requirements of the SILC protocol are met. The API, however, allows
296 to allocate any cipher.
298 If `responder' is TRUE then the sending and receiving keys will be
299 set according the client being the receiver of the private key. If
300 FALSE the client is being the sender (or negotiator) of the private
303 It is not necessary to set key for normal private message usage. If the
304 key is not set then the private messages are encrypted using normal
305 session keys. Setting the private key, however, increases the security.
307 Returns FALSE if the key is already set for the `client_entry', TRUE
310 int silc_client_add_private_message_key(SilcClient client,
311 SilcClientConnection conn,
312 SilcClientEntry client_entry,
319 unsigned char private_key[32];
322 SilcSKEKeyMaterial *keymat;
324 assert(client_entry);
326 /* Return FALSE if key already set */
327 if (client_entry->send_key && client_entry->receive_key)
331 cipher = SILC_DEFAULT_CIPHER;
333 /* Check the requested cipher */
334 if (!silc_cipher_is_supported(cipher))
337 /* Generate key if not provided */
338 if (generate_key == TRUE) {
340 for (i = 0; i < len; i++) private_key[i] = silc_rng_get_byte(client->rng);
343 client_entry->generated = TRUE;
347 client_entry->key = silc_calloc(key_len, sizeof(*client_entry->key));
348 memcpy(client_entry->key, key, key_len);
349 client_entry->key_len = key_len;
351 /* Produce the key material as the protocol defines */
352 keymat = silc_calloc(1, sizeof(*keymat));
353 if (silc_ske_process_key_material_data(key, key_len, 16, 256, 16,
354 client->internal->md5hash, keymat)
355 != SILC_SKE_STATUS_OK)
358 /* Allocate the ciphers */
359 silc_cipher_alloc(cipher, &client_entry->send_key);
360 silc_cipher_alloc(cipher, &client_entry->receive_key);
363 if (responder == TRUE) {
364 silc_cipher_set_key(client_entry->send_key, keymat->receive_enc_key,
365 keymat->enc_key_len);
366 silc_cipher_set_iv(client_entry->send_key, keymat->receive_iv);
367 silc_cipher_set_key(client_entry->receive_key, keymat->send_enc_key,
368 keymat->enc_key_len);
369 silc_cipher_set_iv(client_entry->receive_key, keymat->send_iv);
371 silc_cipher_set_key(client_entry->send_key, keymat->send_enc_key,
372 keymat->enc_key_len);
373 silc_cipher_set_iv(client_entry->send_key, keymat->send_iv);
374 silc_cipher_set_key(client_entry->receive_key, keymat->receive_enc_key,
375 keymat->enc_key_len);
376 silc_cipher_set_iv(client_entry->receive_key, keymat->receive_iv);
379 /* Free the key material */
380 silc_ske_free_key_material(keymat);
385 /* Same as above but takes the key material from the SKE key material
386 structure. This structure is received if the application uses the
387 silc_client_send_key_agreement to negotiate the key material. The
388 `cipher' SHOULD be provided as it is negotiated also in the SKE
391 int silc_client_add_private_message_key_ske(SilcClient client,
392 SilcClientConnection conn,
393 SilcClientEntry client_entry,
395 SilcSKEKeyMaterial *key,
398 assert(client_entry);
400 /* Return FALSE if key already set */
401 if (client_entry->send_key && client_entry->receive_key)
405 cipher = SILC_DEFAULT_CIPHER;
407 /* Check the requested cipher */
408 if (!silc_cipher_is_supported(cipher))
411 /* Allocate the ciphers */
412 silc_cipher_alloc(cipher, &client_entry->send_key);
413 silc_cipher_alloc(cipher, &client_entry->receive_key);
416 if (responder == TRUE) {
417 silc_cipher_set_key(client_entry->send_key, key->receive_enc_key,
419 silc_cipher_set_iv(client_entry->send_key, key->receive_iv);
420 silc_cipher_set_key(client_entry->receive_key, key->send_enc_key,
422 silc_cipher_set_iv(client_entry->receive_key, key->send_iv);
424 silc_cipher_set_key(client_entry->send_key, key->send_enc_key,
426 silc_cipher_set_iv(client_entry->send_key, key->send_iv);
427 silc_cipher_set_key(client_entry->receive_key, key->receive_enc_key,
429 silc_cipher_set_iv(client_entry->receive_key, key->receive_iv);
435 /* Sends private message key payload to the remote client indicated by
436 the `client_entry'. If the `force_send' is TRUE the packet is sent
437 immediately. Returns FALSE if error occurs, TRUE otherwise. The
438 application should call this function after setting the key to the
441 Note that the key sent using this function is sent to the remote client
442 through the SILC network. The packet is protected using normal session
445 int silc_client_send_private_message_key(SilcClient client,
446 SilcClientConnection conn,
447 SilcClientEntry client_entry,
450 SilcSocketConnection sock = conn->sock;
454 if (!client_entry->send_key || !client_entry->key)
457 SILC_LOG_DEBUG(("Sending private message key"));
459 cipher_len = strlen(client_entry->send_key->cipher->name);
461 /* Create private message key payload */
462 buffer = silc_buffer_alloc(2 + client_entry->key_len);
463 silc_buffer_pull_tail(buffer, SILC_BUFFER_END(buffer));
464 silc_buffer_format(buffer,
465 SILC_STR_UI_SHORT(client_entry->key_len),
466 SILC_STR_UI_XNSTRING(client_entry->key,
467 client_entry->key_len),
468 SILC_STR_UI_SHORT(cipher_len),
469 SILC_STR_UI_XNSTRING(client_entry->send_key->cipher->name,
473 /* Send the packet */
474 silc_client_packet_send(client, sock, SILC_PACKET_PRIVATE_MESSAGE_KEY,
475 client_entry->id, SILC_ID_CLIENT, NULL, NULL,
476 buffer->data, buffer->len, force_send);
482 /* Removes the private message from the library. The key won't be used
483 after this to protect the private messages with the remote `client_entry'
484 client. Returns FALSE on error, TRUE otherwise. */
486 int silc_client_del_private_message_key(SilcClient client,
487 SilcClientConnection conn,
488 SilcClientEntry client_entry)
490 assert(client_entry);
492 if (!client_entry->send_key && !client_entry->receive_key)
495 silc_cipher_free(client_entry->send_key);
496 silc_cipher_free(client_entry->receive_key);
498 if (client_entry->key) {
499 memset(client_entry->key, 0, client_entry->key_len);
500 silc_free(client_entry->key);
503 client_entry->send_key = NULL;
504 client_entry->receive_key = NULL;
505 client_entry->key = NULL;
510 /* Returns array of set private message keys associated to the connection
511 `conn'. Returns allocated SilcPrivateMessageKeys array and the array
512 count to the `key_count' argument. The array must be freed by the caller
513 by calling the silc_client_free_private_message_keys function. Note:
514 the keys returned in the array is in raw format. It might not be desired
515 to show the keys as is. The application might choose not to show the keys
516 at all or to show the fingerprints of the keys. */
518 SilcPrivateMessageKeys
519 silc_client_list_private_message_keys(SilcClient client,
520 SilcClientConnection conn,
523 SilcPrivateMessageKeys keys;
525 SilcIDCacheEntry id_cache;
526 SilcIDCacheList list;
527 SilcClientEntry entry;
529 if (!silc_idcache_get_all(conn->client_cache, &list))
532 if (!silc_idcache_list_count(list)) {
533 silc_idcache_list_free(list);
537 keys = silc_calloc(silc_idcache_list_count(list), sizeof(*keys));
539 silc_idcache_list_first(list, &id_cache);
541 entry = (SilcClientEntry)id_cache->context;
543 if (entry->send_key) {
544 keys[count].client_entry = entry;
545 keys[count].cipher = entry->send_key->cipher->name;
546 keys[count].key = entry->generated == FALSE ? entry->key : NULL;
547 keys[count].key_len = entry->generated == FALSE ? entry->key_len : 0;
551 if (!silc_idcache_list_next(list, &id_cache))
561 /* Frees the SilcPrivateMessageKeys array returned by the function
562 silc_client_list_private_message_keys. */
564 void silc_client_free_private_message_keys(SilcPrivateMessageKeys keys,
570 /* Sets away `message'. The away message may be set when the client's
571 mode is changed to SILC_UMODE_GONE and the client whishes to reply
572 to anyone who sends private message. The `message' will be sent
573 automatically back to the the client who send private message. If
574 away message is already set this replaces the old message with the
575 new one. If `message' is NULL the old away message is removed.
576 The sender may freely free the memory of the `message'. */
578 void silc_client_set_away_message(SilcClient client,
579 SilcClientConnection conn,
582 if (!message && conn->away) {
583 silc_free(conn->away->away);
584 silc_free(conn->away);
590 conn->away = silc_calloc(1, sizeof(*conn->away));
591 if (conn->away->away)
592 silc_free(conn->away->away);
593 conn->away->away = strdup(message);