5 Author: Pekka Riikonen <priikone@silcnet.org>
7 Copyright (C) 1997 - 2005 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; version 2 of the License.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
20 /****h* silccore/SILC Message Interface
24 * This interface includes the implementation of the Message Payload that
25 * is used to send private messages and channel messages.
27 * This interface defines also the SILC_MESSAGE_FLAG_SIGNED Payload,
28 * which defines how channel messages and private messages can be digitally
29 * signed. This interface provides the payload parsing, encoding,
30 * signature computing and signature verification routines.
37 /****s* silccore/SilcMessageAPI/SilcMessagePayload
41 * typedef struct SilcMessagePayloadStruct *SilcMessagePayload;
46 * This context is the actual Message Payload and is allocated
47 * by silc_message_payload_parse and given as argument usually
48 * to all silc_message_* functions. It is freed by the
49 * silc_message_payload_free function.
52 typedef struct SilcMessagePayloadStruct *SilcMessagePayload;
54 /****s* silccore/SilcMessageAPI/SilcMessageSignedPayload
58 * typedef struct SilcMessageSignedPayloadStruct *SilcMessageSignedPayload;
63 * This context represents the SILC_MESSAGE_FLAG_SIGNED Payload which
64 * is used with channel messages and private messages to indicate that
65 * the message is digitally signed. This payload may include the
66 * message sender's public key and it includes the digital signature.
67 * This payload MUST NOT be used in any other context except with
68 * channel and private message sending and reception.
71 typedef struct SilcMessageSignedPayloadStruct *SilcMessageSignedPayload;
73 /****d* silccore/SilcMessageAPI/SilcMessageFlags
77 * typedef SilcUInt16 SilcMessageFlags;
81 * The message flags type definition and the message flags. The
82 * message flags are used to indicate some status of the message.
86 typedef SilcUInt16 SilcMessageFlags;
88 /* The message flags */
89 #define SILC_MESSAGE_FLAG_NONE 0x0000 /* No flags */
90 #define SILC_MESSAGE_FLAG_AUTOREPLY 0x0001 /* Automatically replied */
91 #define SILC_MESSAGE_FLAG_NOREPLY 0x0002 /* Send no reply to this */
92 #define SILC_MESSAGE_FLAG_ACTION 0x0004 /* Action message */
93 #define SILC_MESSAGE_FLAG_NOTICE 0x0008 /* Notice message */
94 #define SILC_MESSAGE_FLAG_REQUEST 0x0010 /* A request */
95 #define SILC_MESSAGE_FLAG_SIGNED 0x0020 /* Message is signed */
96 #define SILC_MESSAGE_FLAG_REPLY 0x0040 /* A reply */
97 #define SILC_MESSAGE_FLAG_DATA 0x0080 /* MIME object */
98 #define SILC_MESSAGE_FLAG_UTF8 0x0100 /* UTF-8 string */
99 #define SILC_MESSAGE_FLAG_ACK 0x0200 /* ACK messages */
100 #define SILC_MESSAGE_FLAG_STOP 0x0400 /* Stop indication */
101 #define SILC_MESSAGE_FLAG_RESERVED 0x0800 /* to 0x1000 */
102 #define SILC_MESSAGE_FLAG_PRIVATE 0x2000 /* to 0x8000 */
105 /****f* silccore/SilcMessageAPI/silc_message_payload_decrypt
109 * SilcBool silc_message_payload_decrypt(unsigned char *data,
111 * SilcBool private_message,
112 * SilcBool static_key,
115 * SilcBool check_mac);
119 * Decrypt Message Payload indicated by `data'. If the payload is
120 * channel message then `private_message' is FALSE, and if it is
121 * private message it is TRUE. If the private message key is static
122 * (pre-shared key) then protocol dictates that the IV is present
123 * and `static_key' must be set to TRUE. If the key is not static
124 * (Key Agreement was done for the key) then it MUST be FALSE. For
125 * channel messages the `static_key' is ignored.
127 * This is usually used by the Message Payload interface itself but can
128 * be called by the appliation if separate decryption process is required.
129 * For example server might need to call this directly in some
130 * circumstances. The `cipher' is used to decrypt the payload. If
131 * `check_mac' is FALSE then MAC is not verified.
134 SilcBool silc_message_payload_decrypt(unsigned char *data,
136 SilcBool private_message,
142 /****f* silccore/SilcMessageAPI/silc_message_payload_parse
147 * silc_message_payload_parse(unsigned char *payload,
148 * SilcUInt32 payload_len,
149 * SilcBool private_message,
150 * SilcBool static_key,
156 * Parses Message Payload returning new payload structure. This also
157 * decrypts the payload and checks the MAC. If the payload is
158 * channel message then `private_message' is FALSE, and if it is
159 * private message it is TRUE. If the private message key is static
160 * (pre-shared key) then protocol dictates that the IV is present
161 * and `static_key' must be set to TRUE. If the key is not static
162 * (Key Agreement was done for the key) then it MUST be FALSE. For
163 * channel messages the `static_key' is ignored.
165 * If the `hmac' is no provided then the MAC of the channel message is
166 * not verified. If the message is private message and `cipher' is NULL
167 * then this assumes that the packet was decrypted with session keys
168 * (no private message key) and this merely decodes the payload.
172 silc_message_payload_parse(unsigned char *payload,
173 SilcUInt32 payload_len,
174 SilcBool private_message,
179 /****f* silccore/SilcMessageAPI/silc_message_payload_encrypt
183 * SilcBool silc_message_payload_encrypt(unsigned char *data,
184 * SilcUInt32 data_len,
185 * SilcUInt32 true_len,
193 * This function is used to encrypt the Messsage Payload which is
194 * the `data' and `data_len'. The `data_len' is the data length which
195 * is used to create MAC out of. The `data' MUST have additional space
196 * after `true_len' bytes for the MAC which is appended to the data.
198 * This is usually used by the Message Payload interface itself but can
199 * be called by the appliation if separate encryption process is required.
200 * For example server might need to call this directly in some
201 * circumstances. The `cipher' is used to encrypt the payload and `hmac'
202 * to compute the MAC for the payload.
205 SilcBool silc_message_payload_encrypt(unsigned char *data,
213 /****f* silccore/SilcMessageAPI/silc_message_payload_encode
217 * SilcBuffer silc_message_payload_encode(SilcMessageFlags flags,
218 * const unsigned char *data,
219 * SilcUInt32 data_len,
220 * SilcBool generate_iv,
221 * SilcBool private_message,
225 * SilcPublicKey public_key,
226 * SilcPrivateKey private_key,
231 * Encodes a Message Payload into a buffer and returns it. This is
232 * used to encode channel messages and private messages into a packet.
233 * If `private_message' is FALSE then this encodes channel message, if
234 * it is TRUE this encodes private message. If `private_message' is
235 * TRUE then `generate_iv' MUST be FALSE if the private message key
236 * `cipher' is not static key (pre-shared key). If it is static key
237 * then protocol dictates that IV must be present in the Message Payload
238 * and `generate_iv' must be TRUE. The caller must know whether the key
239 * is static or not for private messages. If the key was generated with
240 * Key Agreement protocol then `generate_iv' is always FALSE. For
241 * channel messages `generate_iv' is always set to TRUE value.
243 * The `cipher' is the cipher used to encrypt the message and `hmac'
244 * is used to compute the MAC for the payload. If encoding private
245 * message that will be encrypted with session keys (no private message
246 * key) then `cipher' and `hmac' is NULL and this merely encodes the
247 * payload buffer, and the caller must encrypt the packet later.
248 * If `rng' is NULL then global RNG is used, if non-NULL then the
249 * `rng' is used (for IV and padding generation).
251 * The `public_key', `private_key' and `hash' are provided only if the
252 * flags includes SILC_MESSAGE_FLAG_SIGNED, in which case the message
253 * will be digitally signed. If `public_key' is non-NULL then it will
254 * be included in the message. The `private_message' and `hash' MUST
255 * be provided. The `hash' SHOULD be SHA1.
258 SilcBuffer silc_message_payload_encode(SilcMessageFlags flags,
259 const unsigned char *data,
261 SilcBool generate_iv,
262 SilcBool private_message,
266 SilcPublicKey public_key,
267 SilcPrivateKey private_key,
270 /****f* silccore/SilcMessageAPI/silc_message_payload_free
274 * void silc_message_payload_free(SilcMessagePayload payload);
278 * Free's Message Payload and all data in it.
281 void silc_message_payload_free(SilcMessagePayload payload);
283 /****f* silccore/SilcMessageAPI/silc_message_get_flags
287 * SilcMessageFlags silc_message_get_flags(SilcMessagePayload payload);
291 * Returns the message flags from the payload.
294 SilcMessageFlags silc_message_get_flags(SilcMessagePayload payload);
296 /****f* silccore/SilcMessageAPI/silc_message_get_data
301 * silc_message_get_data(SilcMessagePayload payload,
302 * SilcUInt32 *data_len);
306 * Return the data in the payload, that is, the actual message data.
307 * The caller must not free it.
310 unsigned char *silc_message_get_data(SilcMessagePayload payload,
311 SilcUInt32 *data_len);
313 /****f* silccore/SilcMessageAPI/silc_message_get_mac
318 * silc_message_get_mac(SilcMessagePayload payload);
322 * Return the MAC of the payload. The caller must already know the
323 * length of the MAC. The caller must not free the MAC.
326 unsigned char *silc_message_get_mac(SilcMessagePayload payload);
328 /****f* silccore/SilcMessageAPI/silc_message_get_iv
333 * silc_message_get_iv(SilcMessagePayload payload);
337 * Return the IV of the payload. The caller must already know the
338 * length of the IV. The caller must not free the IV.
341 unsigned char *silc_message_get_iv(SilcMessagePayload payload);
343 /****f* silccore/SilcMessageAPI/silc_message_get_signature
347 * SilcMessageSignedPayload
348 * silc_message_get_signature(SilcMessagePayload payload);
352 * Returns the pointer to the signature of the message if the
353 * SILC_MESSAGE_FLAG_SIGNED was set. If the flag is set and this
354 * function returns NULL then error had occurred and the signature
355 * could not be retrieved from the message.
357 * The caller SHOULD verify the signature by calling the
358 * silc_message_signed_verify function. Caller must not free the
359 * returned payload pointer.
362 SilcMessageSignedPayload
363 silc_message_get_signature(SilcMessagePayload payload);
365 /****f* silccore/SilcMessageAPI/silc_message_signed_payload_parse
369 * SilcMessageSignedPayload
370 * silc_message_signed_payload_parse(const unsigned char *data,
371 * SilcUInt32 data_len);
375 * Parses the SilcMessageSignedPayload Payload from the `data' of
376 * length of `data_len' bytes. The `data' must be payload without
377 * the actual message payload. Returns the parsed payload or NULL
378 * on error. Caller must free the returned payload. Application
379 * usually does not need to call this since the function
380 * silc_message_payload_parse calls this automatically for signed
384 SilcMessageSignedPayload
385 silc_message_signed_payload_parse(const unsigned char *data,
386 SilcUInt32 data_len);
388 /****f* silccore/SilcMessageAPI/silc_message_signed_payload_encode
393 * silc_message_signed_payload_encode(const unsigned char *message_payload,
394 * SilcUInt32 message_payload_len,
395 * SilcPublicKey public_key,
396 * SilcPrivateKey private_key,
401 * Encodes the SilcMessageSignedPayload Payload and computes the
402 * digital signature. The `message_payload' is the message data that
403 * is used in the signature computation. The encoding of the buffer
404 * is specified in the SILC protocol. If `public_key' is provided
405 * then the public key included in the payload. The `private_key'
406 * is used to produce the signature. This function returns the encoded
407 * payload with the signature or NULL on error. Caller must free the
408 * returned buffer. The `hash' SHOULD be SHA-1 hash function.
410 * Application usually does not need to call this since the function
411 * silc_message_payload_encode calls this automatically if the caller
412 * wants to sign the message.
416 silc_message_signed_payload_encode(const unsigned char *message_payload,
417 SilcUInt32 message_payload_len,
418 SilcPublicKey public_key,
419 SilcPrivateKey private_key,
422 /****f* silccore/SilcMessageAPI/silc_message_signed_payload_free
426 * void silc_message_signed_payload_free(SilcMessageSignedPayload sig);
430 * Frees the SilcMessageSignedPayload Payload.
433 void silc_message_signed_payload_free(SilcMessageSignedPayload sig);
435 /****f* silccore/SilcMessageAPI/silc_message_signed_verify
439 * int silc_message_signed_verify(SilcMessageSignedPayload sig,
440 * SilcMessagePayload message,
441 * SilcPublicKey remote_public_key,
446 * This routine can be used to verify the signature found in
447 * SilcMessageSignedPayload Payload. This returns SILC_AUTH_OK if the
448 * signature verification was successful.
451 int silc_message_signed_verify(SilcMessageSignedPayload sig,
452 SilcMessagePayload message,
453 SilcPublicKey remote_public_key,
456 /****f* silccore/SilcMessageAPI/silc_message_signed_get_public_key
461 * silc_message_signed_get_public_key(SilcMessageSignedPayload sig,
462 * const unsigned char **pk_data,
463 * SilcUInt32 *pk_data_len);
467 * Returns the decoded SilcPublicKey from the SilcMessageSignedPayload
468 * Payload or NULL if it does not include public key. The caller must
469 * free the returned public key pointer. This also returns the raw
470 * public key (before decoding) into `pk_data' and `pk_data_len' if
471 * they are provided. The caller must not free these pointers.
475 silc_message_signed_get_public_key(SilcMessageSignedPayload sig,
476 const unsigned char **pk_data,
477 SilcUInt32 *pk_data_len);
479 #endif /* SILCMESSAGE_H */