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;
49 SILC_LOG_DEBUG(("Sending private message"));
51 /* Encode private message payload */
52 buffer = silc_private_message_payload_encode(flags,
54 client_entry->send_key);
56 /* If we don't have private message specific key then private messages
57 are just as any normal packet thus call normal packet sending. If
58 the key exist then the encryption process is a bit different and
59 will be done in the rest of this function. */
60 if (!client_entry->send_key) {
61 silc_client_packet_send(client, sock, SILC_PACKET_PRIVATE_MESSAGE,
62 client_entry->id, SILC_ID_CLIENT, NULL, NULL,
63 buffer->data, buffer->len, force_send);
67 /* We have private message specific key */
69 /* Get data used in the encryption */
70 cipher = client_entry->send_key;
71 hmac = conn->hmac_send;
73 /* Set the packet context pointers. */
74 packetdata.flags = SILC_PACKET_FLAG_PRIVMSG_KEY;
75 packetdata.type = SILC_PACKET_PRIVATE_MESSAGE;
76 packetdata.src_id = conn->local_id_data;
77 packetdata.src_id_len = SILC_ID_CLIENT_LEN;
78 packetdata.src_id_type = SILC_ID_CLIENT;
79 packetdata.dst_id = silc_id_id2str(client_entry->id, SILC_ID_CLIENT);
80 packetdata.dst_id_len = SILC_ID_CLIENT_LEN;
81 packetdata.dst_id_type = SILC_ID_CLIENT;
82 packetdata.truelen = buffer->len + SILC_PACKET_HEADER_LEN +
83 packetdata.src_id_len + packetdata.dst_id_len;
84 packetdata.padlen = SILC_PACKET_PADLEN((SILC_PACKET_HEADER_LEN +
85 packetdata.src_id_len +
86 packetdata.dst_id_len));
88 /* Prepare outgoing data buffer for packet sending */
89 silc_packet_send_prepare(sock,
90 SILC_PACKET_HEADER_LEN +
91 packetdata.src_id_len +
92 packetdata.dst_id_len,
96 packetdata.buffer = sock->outbuf;
98 /* Put the actual encrypted message payload data into the buffer. */
99 silc_buffer_put(sock->outbuf, buffer->data, buffer->len);
101 /* Create the outgoing packet */
102 silc_packet_assemble(&packetdata);
104 /* Encrypt the header and padding of the packet. */
105 cipher = conn->send_key;
106 silc_packet_encrypt(cipher, hmac, sock->outbuf, SILC_PACKET_HEADER_LEN +
107 packetdata.src_id_len + packetdata.dst_id_len +
110 SILC_LOG_HEXDUMP(("Private message packet, len %d", sock->outbuf->len),
111 sock->outbuf->data, sock->outbuf->len);
113 /* Now actually send the packet */
114 silc_client_packet_send_real(client, sock, force_send, FALSE);
115 silc_free(packetdata.dst_id);
118 silc_buffer_free(buffer);
121 static void silc_client_private_message_cb(SilcClient client,
122 SilcClientConnection conn,
123 SilcClientEntry *clients,
124 uint32 clients_count,
127 SilcPacketContext *packet = (SilcPacketContext *)context;
129 silc_client_private_message(client, conn->sock, packet);
130 silc_packet_context_free(packet);
133 /* Private message received. This processes the private message and
134 finally displays it on the screen. */
136 void silc_client_private_message(SilcClient client,
137 SilcSocketConnection sock,
138 SilcPacketContext *packet)
140 SilcClientConnection conn = (SilcClientConnection)sock->user_data;
141 SilcPrivateMessagePayload payload = NULL;
142 SilcIDCacheEntry id_cache;
143 SilcClientID *remote_id = NULL;
144 SilcClientEntry remote_client;
146 if (packet->src_id_type != SILC_ID_CLIENT)
149 remote_id = silc_id_str2id(packet->src_id, packet->src_id_len,
154 /* Check whether we know this client already */
155 if (!silc_idcache_find_by_id_one(conn->client_cache, remote_id,
156 SILC_ID_CLIENT, &id_cache)) {
157 /* Resolve the client info */
158 silc_client_get_client_by_id_resolve(client, conn, remote_id,
159 silc_client_private_message_cb,
160 silc_packet_context_dup(packet));
164 remote_client = (SilcClientEntry)id_cache->context;
166 /* Parse the payload and decrypt it also if private message key is set */
167 payload = silc_private_message_payload_parse(packet->buffer,
168 remote_client->send_key);
170 silc_free(remote_id);
174 /* Pass the private message to application */
175 client->ops->private_message(client, conn, remote_client,
176 silc_private_message_get_flags(payload),
177 silc_private_message_get_message(payload,
180 /* See if we are away (gone). If we are away we will reply to the
181 sender with the set away message. */
182 if (conn->away && conn->away->away) {
183 /* If it's me, ignore */
184 if (!SILC_ID_CLIENT_COMPARE(remote_id, conn->local_id))
187 /* Send the away message */
188 silc_client_send_private_message(client, conn, remote_client,
189 SILC_MESSAGE_FLAG_AUTOREPLY,
191 strlen(conn->away->away), TRUE);
196 silc_private_message_payload_free(payload);
198 silc_free(remote_id);
201 /* Function that actually employes the received private message key */
203 static void silc_client_private_message_key_cb(SilcClient client,
204 SilcClientConnection conn,
205 SilcClientEntry *clients,
206 uint32 clients_count,
209 SilcPacketContext *packet = (SilcPacketContext *)context;
212 unsigned char *cipher;
218 /* Parse the private message key payload */
219 ret = silc_buffer_unformat(packet->buffer,
220 SILC_STR_UI16_NSTRING(&key, &key_len),
221 SILC_STR_UI16_STRING(&cipher),
226 if (key_len > packet->buffer->len)
229 /* Now take the key in use */
230 if (!silc_client_add_private_message_key(client, conn, clients[0],
231 cipher, key, key_len, FALSE))
234 /* Print some info for application */
235 client->ops->say(client, conn,
236 "Received private message key from %s%s%s %s%s%s",
237 clients[0]->nickname,
238 clients[0]->server ? "@" : "",
239 clients[0]->server ? clients[0]->server : "",
240 clients[0]->username ? "(" : "",
241 clients[0]->username ? clients[0]->username : "",
242 clients[0]->username ? ")" : "");
245 silc_packet_context_free(packet);
248 /* Processes incoming Private Message Key payload. The libary always
249 accepts the key and takes it into use. */
251 void silc_client_private_message_key(SilcClient client,
252 SilcSocketConnection sock,
253 SilcPacketContext *packet)
255 SilcClientID *remote_id;
257 if (packet->src_id_type != SILC_ID_CLIENT)
260 remote_id = silc_id_str2id(packet->src_id, packet->src_id_len,
265 silc_client_get_client_by_id_resolve(client, sock->user_data, remote_id,
266 silc_client_private_message_key_cb,
267 silc_packet_context_dup(packet));
268 silc_free(remote_id);
271 /* Adds private message key to the client library. The key will be used to
272 encrypt all private message between the client and the remote client
273 indicated by the `client_entry'. If the `key' is NULL and the boolean
274 value `generate_key' is TRUE the library will generate random key.
275 The `key' maybe for example pre-shared-key, passphrase or similar.
276 The `cipher' MAY be provided but SHOULD be NULL to assure that the
277 requirements of the SILC protocol are met. The API, however, allows
278 to allocate any cipher.
280 It is not necessary to set key for normal private message usage. If the
281 key is not set then the private messages are encrypted using normal
282 session keys. Setting the private key, however, increases the security.
284 Returns FALSE if the key is already set for the `client_entry', TRUE
287 int silc_client_add_private_message_key(SilcClient client,
288 SilcClientConnection conn,
289 SilcClientEntry client_entry,
295 unsigned char private_key[32];
298 SilcSKEKeyMaterial *keymat;
300 assert(client_entry);
302 /* Return FALSE if key already set */
303 if (client_entry->send_key && client_entry->receive_key)
307 cipher = "aes-256-cbc";
309 /* Check the requested cipher */
310 if (!silc_cipher_is_supported(cipher))
313 /* Generate key if not provided */
314 if (generate_key == TRUE) {
316 for (i = 0; i < len; i++) private_key[i] = silc_rng_get_byte(client->rng);
319 client_entry->generated = TRUE;
323 client_entry->key = silc_calloc(key_len, sizeof(*client_entry->key));
324 memcpy(client_entry->key, key, key_len);
325 client_entry->key_len = key_len;
327 /* Produce the key material as the protocol defines */
328 keymat = silc_calloc(1, sizeof(*keymat));
329 if (silc_ske_process_key_material_data(key, key_len, 16, 256, 16,
330 client->md5hash, keymat)
331 != SILC_SKE_STATUS_OK)
334 /* Allocate the ciphers */
335 silc_cipher_alloc(cipher, &client_entry->send_key);
336 silc_cipher_alloc(cipher, &client_entry->receive_key);
339 silc_cipher_set_key(client_entry->send_key, keymat->send_enc_key,
340 keymat->enc_key_len);
341 silc_cipher_set_iv(client_entry->send_key, keymat->send_iv);
342 silc_cipher_set_key(client_entry->receive_key, keymat->receive_enc_key,
343 keymat->enc_key_len);
344 silc_cipher_set_iv(client_entry->receive_key, keymat->receive_iv);
346 /* Free the key material */
347 silc_ske_free_key_material(keymat);
352 /* Same as above but takes the key material from the SKE key material
353 structure. This structure is received if the application uses the
354 silc_client_send_key_agreement to negotiate the key material. The
355 `cipher' SHOULD be provided as it is negotiated also in the SKE
358 int silc_client_add_private_message_key_ske(SilcClient client,
359 SilcClientConnection conn,
360 SilcClientEntry client_entry,
362 SilcSKEKeyMaterial *key)
364 assert(client_entry);
366 /* Return FALSE if key already set */
367 if (client_entry->send_key && client_entry->receive_key)
371 cipher = "aes-256-cbc";
373 /* Check the requested cipher */
374 if (!silc_cipher_is_supported(cipher))
377 /* Allocate the ciphers */
378 silc_cipher_alloc(cipher, &client_entry->send_key);
379 silc_cipher_alloc(cipher, &client_entry->receive_key);
382 silc_cipher_set_key(client_entry->send_key, key->send_enc_key,
384 silc_cipher_set_iv(client_entry->send_key, key->send_iv);
385 silc_cipher_set_key(client_entry->receive_key, key->receive_enc_key,
387 silc_cipher_set_iv(client_entry->receive_key, key->receive_iv);
392 /* Sends private message key payload to the remote client indicated by
393 the `client_entry'. If the `force_send' is TRUE the packet is sent
394 immediately. Returns FALSE if error occurs, TRUE otherwise. The
395 application should call this function after setting the key to the
398 Note that the key sent using this function is sent to the remote client
399 through the SILC network. The packet is protected using normal session
402 int silc_client_send_private_message_key(SilcClient client,
403 SilcClientConnection conn,
404 SilcClientEntry client_entry,
407 SilcSocketConnection sock = conn->sock;
411 if (!client_entry->send_key || !client_entry->key)
414 SILC_LOG_DEBUG(("Sending private message key"));
416 cipher_len = strlen(client_entry->send_key->cipher->name);
418 /* Create private message key payload */
419 buffer = silc_buffer_alloc(2 + client_entry->key_len);
420 silc_buffer_pull_tail(buffer, SILC_BUFFER_END(buffer));
421 silc_buffer_format(buffer,
422 SILC_STR_UI_SHORT(client_entry->key_len),
423 SILC_STR_UI_XNSTRING(client_entry->key,
424 client_entry->key_len),
425 SILC_STR_UI_SHORT(cipher_len),
426 SILC_STR_UI_XNSTRING(client_entry->send_key->cipher->name,
430 /* Send the packet */
431 silc_client_packet_send(client, sock, SILC_PACKET_PRIVATE_MESSAGE_KEY,
432 client_entry->id, SILC_ID_CLIENT, NULL, NULL,
433 buffer->data, buffer->len, force_send);
439 /* Removes the private message from the library. The key won't be used
440 after this to protect the private messages with the remote `client_entry'
441 client. Returns FALSE on error, TRUE otherwise. */
443 int silc_client_del_private_message_key(SilcClient client,
444 SilcClientConnection conn,
445 SilcClientEntry client_entry)
447 assert(client_entry);
449 if (!client_entry->send_key && !client_entry->receive_key)
452 silc_cipher_free(client_entry->send_key);
453 silc_cipher_free(client_entry->receive_key);
455 if (client_entry->key) {
456 memset(client_entry->key, 0, client_entry->key_len);
457 silc_free(client_entry->key);
460 client_entry->send_key = NULL;
461 client_entry->receive_key = NULL;
462 client_entry->key = NULL;
467 /* Returns array of set private message keys associated to the connection
468 `conn'. Returns allocated SilcPrivateMessageKeys array and the array
469 count to the `key_count' argument. The array must be freed by the caller
470 by calling the silc_client_free_private_message_keys function. Note:
471 the keys returned in the array is in raw format. It might not be desired
472 to show the keys as is. The application might choose not to show the keys
473 at all or to show the fingerprints of the keys. */
475 SilcPrivateMessageKeys
476 silc_client_list_private_message_keys(SilcClient client,
477 SilcClientConnection conn,
480 SilcPrivateMessageKeys keys;
482 SilcIDCacheEntry id_cache;
483 SilcIDCacheList list;
484 SilcClientEntry entry;
486 if (!silc_idcache_find_by_id(conn->client_cache, SILC_ID_CACHE_ANY,
487 SILC_ID_CLIENT, &list))
490 if (!silc_idcache_list_count(list)) {
491 silc_idcache_list_free(list);
495 keys = silc_calloc(silc_idcache_list_count(list), sizeof(*keys));
497 silc_idcache_list_first(list, &id_cache);
499 entry = (SilcClientEntry)id_cache->context;
501 if (entry->send_key) {
502 keys[count].client_entry = entry;
503 keys[count].cipher = entry->send_key->cipher->name;
504 keys[count].key = entry->generated == FALSE ? entry->key : NULL;
505 keys[count].key_len = entry->generated == FALSE ? entry->key_len : 0;
509 if (!silc_idcache_list_next(list, &id_cache))
519 /* Frees the SilcPrivateMessageKeys array returned by the function
520 silc_client_list_private_message_keys. */
522 void silc_client_free_private_message_keys(SilcPrivateMessageKeys keys,