5 Author: Pekka Riikonen <priikone@silcnet.org>
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 /****h* silccore/SILC Channel Interface
25 * Implementations of the Channel Payload, Channel Message Payload and
26 * Channel Key Payload. The Channel Payload represents new channel and
27 * is used to distribute the information of the new channel. The Channel
28 * Message Payload is used to deliver messages to the channel. The routines
29 * for Channel Message Payload also handles the encryption and decryption
30 * of the payload. Last, the Channel Key Payload is used to distribute
31 * a new key to the channel. It is done for example every time someone
32 * joins a channel or the old key expires.
39 #include "silcdlist.h"
41 /****s* silccore/SilcChannelAPI/SilcChannelPayload
45 * typedef struct SilcChannelPayloadStruct *SilcChannelPayload;
49 * This context is the actual Channel Payload and is allocated
50 * by silc_channel_payload_parse and given as argument usually to
51 * all silc_channel_payload_* functions. It is freed by the
52 * silc_channel_payload_free function.
55 typedef struct SilcChannelPayloadStruct *SilcChannelPayload;
57 /****s* silccore/SilcChannelAPI/SilcChannelMessagePayload
62 * SilcChannelMessagePayloadStruct *SilcChannelMessagePayload;
66 * This context is the actual Channel Message Payload and is allocated
67 * by silc_channel_message_payload_parse and given as argument usually to
68 * all silc_channel_message_payload_* functions. It is freed by the
69 * silc_channel_message_payload_free function.
72 typedef struct SilcChannelMessagePayloadStruct *SilcChannelMessagePayload;
74 /****s* silccore/SilcChannelAPI/SilcChannelKeyPayload
78 * typedef struct SilcChannelKeyPayloadStruct *SilcChannelKeyPayload;
82 * This context is the actual Channel Key Payload and is allocated
83 * by silc_channel_key_payload_parse and given as argument usually to
84 * all silc_channel_key_payload_* functions. It is freed by the
85 * silc_channel_key_payload_free function.
88 typedef struct SilcChannelKeyPayloadStruct *SilcChannelKeyPayload;
90 /****d* silccore/SilcChannelAPI/SilcMessageFlags
94 * typedef SilcUInt16 SilcMessageFlags;
98 * The message flags type definition and the message flags. The
99 * message flags are used to indicate some status of the message.
100 * These flags are also used by the private message interfaces.
104 typedef SilcUInt16 SilcMessageFlags;
106 /* The message flags (shared by both channel and private messages) */
107 #define SILC_MESSAGE_FLAG_NONE 0x0000
108 #define SILC_MESSAGE_FLAG_AUTOREPLY 0x0001
109 #define SILC_MESSAGE_FLAG_NOREPLY 0x0002
110 #define SILC_MESSAGE_FLAG_ACTION 0x0004
111 #define SILC_MESSAGE_FLAG_NOTICE 0x0008
112 #define SILC_MESSAGE_FLAG_REQUEST 0x0010
113 #define SILC_MESSAGE_FLAG_SIGNED 0x0020
114 #define SILC_MESSAGE_FLAG_RESERVED 0x0040 /* to 0x0200 */
115 #define SILC_MESSAGE_FLAG_PRIVATE 0x0400 /* to 0x8000 */
120 /****f* silccore/SilcChannelAPI/silc_channel_payload_parse
125 * silc_channel_payload_parse(const unsigned char *payload,
126 * SilcUInt32 payload_len);
130 * Parses channel payload returning new channel payload structure. The
131 * `buffer' is the raw payload buffer.
134 SilcChannelPayload silc_channel_payload_parse(const unsigned char *payload,
135 SilcUInt32 payload_len);
137 /****f* silccore/SilcChannelAPI/silc_channel_payload_parse_list
142 * silc_channel_payload_parse_list(const unsigned char *payload,
143 * SilcUInt32 payload_len);
147 * Parses list of channel payloads returning list of payloads. This
148 * is equivalent to the silc_channel_payload_parse except that the `buffer'
149 * now includes multiple Channel Payloads one after the other.
152 SilcDList silc_channel_payload_parse_list(const unsigned char *payload,
153 SilcUInt32 payload_len);
155 /****f* silccore/SilcChannelAPI/silc_channel_payload_encode
159 * SilcBuffer silc_channel_payload_encode(const unsigned char *channel_name,
160 * SilcUInt16 channel_name_len,
161 * const unsigned char *channel_id,
162 * SilcUInt32 channel_id_len,
167 * Encode new channel payload and returns it as buffer.
170 SilcBuffer silc_channel_payload_encode(const unsigned char *channel_name,
171 SilcUInt16 channel_name_len,
172 const unsigned char *channel_id,
173 SilcUInt32 channel_id_len,
176 /****f* silccore/SilcChannelAPI/silc_channel_payload_free
180 * void silc_channel_payload_free(SilcChannelPayload payload);
184 * Frees Channel Payload and all data in it.
187 void silc_channel_payload_free(SilcChannelPayload payload);
189 /****f* silccore/SilcChannelAPI/silc_channel_payload_list_free
193 * void silc_channel_payload_list_free(SilcDList list);
197 * Frees list of Channel Payloads and all data in them.
200 void silc_channel_payload_list_free(SilcDList list);
202 /****f* silccore/SilcChannelAPI/silc_channel_get_name
206 * unsigned char *silc_channel_get_name(SilcChannelPayload payload,
207 * SilcUInt32 *channel_name_len);
211 * Return the channel name from the payload. The caller must not free it.
214 unsigned char *silc_channel_get_name(SilcChannelPayload payload,
215 SilcUInt32 *channel_name_len);
217 /****f* silccore/SilcChannelAPI/silc_channel_get_id
221 * unsigned char *silc_channel_get_id(SilcChannelPayload payload,
222 * SilcUInt32 *channel_id_len);
226 * Return the Channel ID data from the payload. The caller must not free it.
229 unsigned char *silc_channel_get_id(SilcChannelPayload payload,
230 SilcUInt32 *channel_id_len);
232 /****f* silccore/SilcChannelAPI/silc_channel_get_id_parse
236 * SilcChannelID *silc_channel_get_id_parse(SilcChannelPayload payload);
240 * Return the Channel ID as parsed ID. This is equivalent to the
241 * silc_channel_get_id execpt that the ID is already parsed. The caller
242 * must free the parsed Channel ID.
245 SilcChannelID *silc_channel_get_id_parse(SilcChannelPayload payload);
247 /****f* silccore/SilcChannelAPI/silc_channel_get_mode
251 * SilcUInt32 silc_channel_get_mode(SilcChannelPayload payload);
255 * Return the mode. The mode is arbitrary. It can be the mode of the
256 * channel or perhaps the mode of the client on the channel. The protocol
257 * dictates what the usage of the mode is in different circumstances.
260 SilcUInt32 silc_channel_get_mode(SilcChannelPayload payload);
262 /****f* silccore/SilcChannelAPI/silc_channel_message_payload_decrypt
266 * bool silc_channel_message_payload_decrypt(unsigned char *data,
273 * Decrypt the channel message. First push the IV out of the packet `data'.
274 * The IV is used in the decryption process. Then decrypt the message.
275 * After decryption, take the MAC from the decrypted packet, compute MAC
276 * and compare the MACs. If they match, the decryption was successful
277 * and we have the channel message ready to be displayed.
279 * This is usually used by the Channel Message interface itself but can
280 * be called by the appliation if separate decryption process is required.
281 * For example server might need to call this directly in some
282 * circumstances. The `cipher' is used to decrypt the payload.
284 * If the `hmac' is no provided then the MAC of the channel message is
288 bool silc_channel_message_payload_decrypt(unsigned char *data,
293 /****f* silccore/SilcChannelAPI/silc_channel_message_payload_parse
297 * SilcChannelMessagePayload
298 * silc_channel_message_payload_parse(const unsigned char *payload,
299 * SilcUInt32 payload_len,
305 * Parses channel message payload returning new channel payload structure.
306 * This also decrypts it and checks the MAC. The `cipher's is used to
307 * decrypt the payload.
309 * If the `hmac' is no provided then the MAC of the channel message is
313 SilcChannelMessagePayload
314 silc_channel_message_payload_parse(unsigned char *payload,
315 SilcUInt32 payload_len,
319 /****f* silccore/SilcChannelAPI/silc_channel_message_payload_encrypt
323 * bool silc_channel_message_payload_encrypt(unsigned char *data,
324 * SilcUInt32 data_len,
325 * SilcUInt32 true_len,
333 * This function is used to encrypt the Channel Messsage Payload which is
334 * the `data' and `data_len'. The `data_len' is the data length which is
335 * used to create MAC out of. The `true_len' is the true length of `data'
336 * message payload and is used assemble rest of the packet after MAC
337 * creation. The `true_len' length packet will then be encrypted.
339 * This is usually used by the Channel Message interface itself but can
340 * be called by the appliation if separate encryption process is required.
341 * For example server might need to call this directly in some
342 * circumstances. The `cipher' is used to encrypt the payload.
345 bool silc_channel_message_payload_encrypt(unsigned char *data,
353 /****f* silccore/SilcChannelAPI/silc_channel_message_payload_encode
357 * SilcBuffer silc_channel_message_payload_encode(SilcUInt16 flags,
358 * SilcUInt16 data_len,
359 * const unsigned char *data,
368 * Encodes channel message payload into a buffer and returns it. This
369 * is used to add channel message payload into a packet. As the channel
370 * payload is encrypted separately from other parts of the packet padding
371 * must be applied to the payload. The function generates the padding
372 * automatically from random data. The `cipher' is the cipher used
373 * encrypt the payload and `hmac' is used to compute the MAC for the
374 * payload. If `rng' is NULL then global RNG is used, if non-NULL then
378 SilcBuffer silc_channel_message_payload_encode(SilcUInt16 flags,
380 const unsigned char *data,
387 /****f* silccore/SilcChannelAPI/silc_channel_message_payload_free
392 * silc_channel_message_payload_free(SilcChannelMessagePayload payload);
396 * Free's Channel Message Payload and all data in it.
399 void silc_channel_message_payload_free(SilcChannelMessagePayload payload);
401 /****f* silccore/SilcChannelAPI/silc_channel_message_get_flags
406 * silc_channel_message_get_flags(SilcChannelMessagePayload payload);
410 * Returns the message flags from the payload.
414 silc_channel_message_get_flags(SilcChannelMessagePayload payload);
416 /****f* silccore/SilcChannelAPI/silc_channel_message_get_data
421 * silc_channel_message_get_data(SilcChannelMessagePayload payload,
422 * SilcUInt32 *data_len);
426 * Return the data in the payload, that is, the actual channel message.
427 * The caller must not free it.
430 unsigned char *silc_channel_message_get_data(SilcChannelMessagePayload payload,
431 SilcUInt32 *data_len);
433 /****f* silccore/SilcChannelAPI/silc_channel_message_get_mac
438 * silc_channel_message_get_mac(SilcChannelMessagePayload payload);
442 * Return the MAC of the payload. The caller must already know the
443 * length of the MAC. The caller must not free the MAC.
446 unsigned char *silc_channel_message_get_mac(SilcChannelMessagePayload payload);
448 /****f* silccore/SilcChannelAPI/silc_channel_message_get_iv
453 * silc_channel_message_get_iv(SilcChannelMessagePayload payload);
457 * Return the IV of the payload. The caller must already know the
458 * length of the IV. The caller must not free the IV.
461 unsigned char *silc_channel_message_get_iv(SilcChannelMessagePayload payload);
463 /****f* silccore/SilcChannelAPI/silc_channel_key_payload_parse
467 * SilcChannelKeyPayload
468 * silc_channel_key_payload_parse(const unsigned char *payload,
469 * uin32 payload_len);
473 * Parses channel key payload returning new channel key payload
477 SilcChannelKeyPayload
478 silc_channel_key_payload_parse(const unsigned char *payload,
479 SilcUInt32 payload_len);
481 /****f* silccore/SilcChannelAPI/silc_channel_key_payload_encode
485 * SilcBuffer silc_channel_key_payload_encode(SilcUInt16 id_len,
486 * const unsigned char *id,
487 * SilcUInt16 cipher_len,
488 * const unsigned char *cipher,
489 * SilcUInt16 key_len,
490 * const unsigned char *key);
494 * Encodes channel key payload into a buffer and returns it. This is used
495 * to add channel key payload into a packet.
498 SilcBuffer silc_channel_key_payload_encode(SilcUInt16 id_len,
499 const unsigned char *id,
500 SilcUInt16 cipher_len,
501 const unsigned char *cipher,
503 const unsigned char *key);
505 /****f* silccore/SilcChannelAPI/silc_channel_key_payload_free
509 * void silc_channel_key_payload_free(SilcChannelKeyPayload payload);
513 * Frees the Channel Key Payload and all data in it.
516 void silc_channel_key_payload_free(SilcChannelKeyPayload payload);
518 /****f* silccore/SilcChannelAPI/silc_channel_key_get_id
522 * unsigned char *silc_channel_key_get_id(SilcChannelKeyPayload payload,
523 * SilcUInt32 *id_len);
527 * Return the Channel ID data from the payload. The caller must not
531 unsigned char *silc_channel_key_get_id(SilcChannelKeyPayload payload,
534 /****f* silccore/SilcChannelAPI/silc_channel_key_get_cipher
538 * unsigned char *silc_channel_key_get_cipher(SilcChannelKeyPayload payload,
539 * SilcUInt32 *cipher_len);
543 * Return the name of the cipher from the payload. The caller must not
547 unsigned char *silc_channel_key_get_cipher(SilcChannelKeyPayload payload,
548 SilcUInt32 *cipher_len);
550 /****f* silccore/SilcChannelAPI/silc_channel_key_get_key
554 * unsigned char *silc_channel_key_get_key(SilcChannelKeyPayload payload,
555 * SilcUInt32 *key_len);
559 * Return the raw key material from the payload. The caller must not
563 unsigned char *silc_channel_key_get_key(SilcChannelKeyPayload payload,
564 SilcUInt32 *key_len);