5 Author: Pekka Riikonen <priikone@poseidon.pspt.fi>
7 Copyright (C) 2000 - 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.
24 #include "clientlibincludes.h"
27 This file defines the SILC Client Library API for the application. The
28 client operations are defined first. These are callback functions that
29 the application MUST implement since the library may call the functions
30 at any time. At the end of file is the API for the application that
31 it can use from the library. This is the only file that the application
32 may include from the SIlC Client Library.
34 Please, refer to the README file in this directory for the directions
35 of how to use the SILC Client Library.
38 /* General definitions */
40 /* Key agreement status types indicating the status of the protocol. */
42 SILC_KEY_AGREEMENT_OK, /* Everything is Ok */
43 SILC_KEY_AGREEMENT_ERROR, /* Unknown error occured */
44 SILC_KEY_AGREEMENT_FAILURE, /* The protocol failed */
45 SILC_KEY_AGREEMENT_TIMEOUT, /* The protocol timeout */
46 } SilcKeyAgreementStatus;
48 /* Key agreement callback that is called after the key agreement protocol
49 has been performed. This is called also if error occured during the
50 key agreement protocol. The `key' is the allocated key material and
51 the caller is responsible of freeing it. The `key' is NULL if error
52 has occured. The application can freely use the `key' to whatever
53 purpose it needs. See lib/silcske/silcske.h for the definition of
54 the SilcSKEKeyMaterial structure. */
55 typedef void (*SilcKeyAgreementCallback)(SilcClient client,
56 SilcClientConnection conn,
57 SilcClientEntry client_entry,
58 SilcKeyAgreementStatus status,
59 SilcSKEKeyMaterial *key,
62 /* Structure to hold the list of private message keys. The array of this
63 structure is returned by the silc_client_list_private_message_keys
66 SilcClientEntry client_entry; /* The remote client entry */
67 char *cipher; /* The cipher name */
68 unsigned char *key; /* The original key, If the appliation
69 provided it. This is NULL if the
70 library generated the key or if
71 the SKE key material was used. */
72 unsigned int key_len; /* The key length */
73 } *SilcPrivateMessageKeys;
75 /******************************************************************************
77 SILC Client Operations
79 These functions must be implemented by the application calling the SILC
80 client library. The client library can call these functions at any time.
82 To use this structure: define a static SilcClientOperations variable,
83 fill it and pass its pointer to silc_client_alloc function.
85 ******************************************************************************/
87 /* SILC Client Operations. These must be implemented by the application. */
89 /* Message sent to the application by library. `conn' associates the
90 message to a specific connection. `conn', however, may be NULL. */
91 void (*say)(SilcClient client, SilcClientConnection conn, char *msg, ...);
93 /* Message for a channel. The `sender' is the sender of the message
94 The `channel' is the channel. */
95 void (*channel_message)(SilcClient client, SilcClientConnection conn,
96 SilcClientEntry sender, SilcChannelEntry channel,
97 SilcMessageFlags flags, char *msg);
99 /* Private message to the client. The `sender' is the sender of the
101 void (*private_message)(SilcClient client, SilcClientConnection conn,
102 SilcClientEntry sender, SilcMessageFlags flags,
105 /* Notify message to the client. The notify arguments are sent in the
106 same order as servers sends them. The arguments are same as received
107 from the server except for ID's. If ID is received application receives
108 the corresponding entry to the ID. For example, if Client ID is received
109 application receives SilcClientEntry. Also, if the notify type is
110 for channel the channel entry is sent to application (even if server
111 does not send it because client library gets the channel entry from
112 the Channel ID in the packet's header). */
113 void (*notify)(SilcClient client, SilcClientConnection conn,
114 SilcNotifyType type, ...);
116 /* Command handler. This function is called always in the command function.
117 If error occurs it will be called as well. `conn' is the associated
118 client connection. `cmd_context' is the command context that was
119 originally sent to the command. `success' is FALSE if error occured
120 during command. `command' is the command being processed. It must be
121 noted that this is not reply from server. This is merely called just
122 after application has called the command. Just to tell application
123 that the command really was processed. */
124 void (*command)(SilcClient client, SilcClientConnection conn,
125 SilcClientCommandContext cmd_context, int success,
126 SilcCommand command);
128 /* Command reply handler. This function is called always in the command reply
129 function. If error occurs it will be called as well. Normal scenario
130 is that it will be called after the received command data has been parsed
131 and processed. The function is used to pass the received command data to
134 `conn' is the associated client connection. `cmd_payload' is the command
135 payload data received from server and it can be ignored. It is provided
136 if the application would like to re-parse the received command data,
137 however, it must be noted that the data is parsed already by the library
138 thus the payload can be ignored. `success' is FALSE if error occured.
139 In this case arguments are not sent to the application. The `status' is
140 the command reply status server returned. The `command' is the command
141 reply being processed. The function has variable argument list and each
142 command defines the number and type of arguments it passes to the
143 application (on error they are not sent). */
144 void (*command_reply)(SilcClient client, SilcClientConnection conn,
145 SilcCommandPayload cmd_payload, int success,
146 SilcCommand command, SilcCommandStatus status, ...);
148 /* Called to indicate that connection was either successfully established
149 or connecting failed. This is also the first time application receives
150 the SilcClientConnection objecet which it should save somewhere. */
151 void (*connect)(SilcClient client, SilcClientConnection conn, int success);
153 /* Called to indicate that connection was disconnected to the server. */
154 void (*disconnect)(SilcClient client, SilcClientConnection conn);
156 /* Find authentication method and authentication data by hostname and
157 port. The hostname may be IP address as well. The found authentication
158 method and authentication data is returned to `auth_meth', `auth_data'
159 and `auth_data_len'. The function returns TRUE if authentication method
160 is found and FALSE if not. `conn' may be NULL. */
161 int (*get_auth_method)(SilcClient client, SilcClientConnection conn,
162 char *hostname, unsigned short port,
163 SilcProtocolAuthMeth *auth_meth,
164 unsigned char **auth_data,
165 unsigned int *auth_data_len);
167 /* Verifies received public key. The `conn_type' indicates which entity
168 (server, client etc.) has sent the public key. If user decides to trust
169 the key may be saved as trusted public key for later use. If user does
170 not trust the key this returns FALSE. If everything is Ok this returns
172 int (*verify_public_key)(SilcClient client, SilcClientConnection conn,
173 SilcSocketType conn_type, unsigned char *pk,
174 unsigned int pk_len, SilcSKEPKType pk_type);
176 /* Ask (interact, that is) a passphrase from user. Returns the passphrase
178 unsigned char *(*ask_passphrase)(SilcClient client,
179 SilcClientConnection conn);
181 /* Notifies application that failure packet was received. This is called
182 if there is some protocol active in the client. The `protocol' is the
183 protocol context. The `failure' is opaque pointer to the failure
184 indication. Note, that the `failure' is protocol dependant and
185 application must explicitly cast it to correct type. Usually `failure'
186 is 32 bit failure type (see protocol specs for all protocol failure
188 void (*failure)(SilcClient client, SilcClientConnection conn,
189 SilcProtocol protocol, void *failure);
191 /* Asks whether the user would like to perform the key agreement protocol.
192 This is called after we have received an key agreement packet or an
193 reply to our key agreement packet. This returns TRUE if the user wants
194 the library to perform the key agreement protocol and FALSE if it is not
195 desired (application may start it later by calling the function
196 silc_client_perform_key_agreement). If TRUE is returned also the
197 `completion' and `context' arguments must be set by the application. */
198 int (*key_agreement)(SilcClient client, SilcClientConnection conn,
199 SilcClientEntry client_entry, char *hostname,
201 SilcKeyAgreementCallback *completion,
203 } SilcClientOperations;
207 /******************************************************************************
209 SILC Client Library API
211 This is the API that is published by the SILC Client Library for the
212 applications. These functions are implemented in the SILC Client Library.
213 Application may freely call these functions from the library.
215 ******************************************************************************/
217 /* Initialization functions (client.c) */
219 /* Allocates new client object. This has to be done before client may
220 work. After calling this one must call silc_client_init to initialize
221 the client. The `application' is application specific user data pointer
222 and caller must free it. */
223 SilcClient silc_client_alloc(SilcClientOperations *ops, void *application);
225 /* Frees client object and its internals. */
226 void silc_client_free(SilcClient client);
228 /* Initializes the client. This makes all the necessary steps to make
229 the client ready to be run. One must call silc_client_run to run the
230 client. Returns FALSE if error occured, TRUE otherwise. */
231 int silc_client_init(SilcClient client);
233 /* Runs the client. This starts the scheduler from the utility library.
234 When this functions returns the execution of the appliation is over. */
235 void silc_client_run(SilcClient client);
237 /* Stops the client. This is called to stop the client and thus to stop
239 void silc_client_stop(SilcClient client);
242 /* Connecting functions (client.c) */
244 /* Connects to remote server. This is the main routine used to connect
245 to SILC server. Returns -1 on error and the created socket otherwise.
246 The `context' is user context that is saved into the SilcClientConnection
247 that is created after the connection is created. Note that application
248 may handle the connecting process outside the library. If this is the
249 case then this function is not used at all. When the connecting is
250 done the `connect' client operation is called. */
251 int silc_client_connect_to_server(SilcClient client, int port,
252 char *host, void *context);
254 /* Allocates and adds new connection to the client. This adds the allocated
255 connection to the connection table and returns a pointer to it. A client
256 can have multiple connections to multiple servers. Every connection must
257 be added to the client using this function. User data `context' may
258 be sent as argument. This function is normally used only if the
259 application performed the connecting outside the library. The library
260 however may use this internally. */
261 SilcClientConnection silc_client_add_connection(SilcClient client,
266 /* Removes connection from client. Frees all memory. */
267 void silc_client_del_connection(SilcClient client, SilcClientConnection conn);
269 /* Adds listener socket to the listener sockets table. This function is
270 used to add socket objects that are listeners to the client. This should
271 not be used to add other connection objects. */
272 void silc_client_add_socket(SilcClient client, SilcSocketConnection sock);
274 /* Deletes listener socket from the listener sockets table. */
275 void silc_client_del_socket(SilcClient client, SilcSocketConnection sock);
277 /* Start SILC Key Exchange (SKE) protocol to negotiate shared secret
278 key material between client and server. This function can be called
279 directly if application is performing its own connecting and does not
280 use the connecting provided by this library. This function is normally
281 used only if the application performed the connecting outside the library.
282 The library however may use this internally. */
283 int silc_client_start_key_exchange(SilcClient client,
284 SilcClientConnection conn,
287 /* Closes connection to remote end. Free's all allocated data except
288 for some information such as nickname etc. that are valid at all time. */
289 void silc_client_close_connection(SilcClient client,
290 SilcClientConnection conn);
293 /* Message sending functions (client_channel.c and client_prvmsg.c) */
295 /* Sends packet to the `channel'. Packet to channel is always encrypted
296 differently from "normal" packets. SILC header of the packet is
297 encrypted with the next receiver's key and the rest of the packet is
298 encrypted with the channel specific key. Padding and HMAC is computed
299 with the next receiver's key. The `data' is the channel message. If
300 the `force_send' is TRUE then the packet is sent immediately.
302 If `key' is provided then that private key is used to encrypt the
303 channel message. If it is not provided, private keys has not been
304 set at all, the normal channel key is used automatically. If private
305 keys are set then the first key (the key that was added first as
306 private key) is used. */
307 void silc_client_send_channel_message(SilcClient client,
308 SilcClientConnection conn,
309 SilcChannelEntry channel,
310 SilcChannelPrivateKey key,
311 SilcMessageFlags flags,
313 unsigned int data_len,
316 /* Sends private message to remote client. If private message key has
317 not been set with this client then the message will be encrypted using
318 normal session keys. Private messages are special packets in SILC
319 network hence we need this own function for them. This is similiar
320 to silc_client_packet_send_to_channel except that we send private
321 message. The `data' is the private message. If the `force_send' is
322 TRUE the packet is sent immediately. */
323 void silc_client_send_private_message(SilcClient client,
324 SilcClientConnection conn,
325 SilcClientEntry client_entry,
326 SilcMessageFlags flags,
328 unsigned int data_len,
332 /* Client and Channel entry retrieval (idlist.c) */
334 /* Callback function given to the silc_client_get_client function. The
335 found entries are allocated into the `clients' array. The array must
336 not be freed by the caller, the library will free it later. If the
337 `clients' is NULL, no such clients exist in the SILC Network. */
338 typedef void (*SilcGetClientCallback)(SilcClient client,
339 SilcClientConnection conn,
340 SilcClientEntry *clients,
341 unsigned int clients_count,
344 /* Finds client entry or entries by the `nickname' and `server'. The
345 completion callback will be called when the client entries has been found.
347 Note: this function is always asynchronous and resolves the client
348 information from the server. Thus, if you already know the client
349 information then use the silc_client_get_client_by_id function to
350 get the client entry since this function may be very slow and should
351 be used only to initially get the client entries. */
352 void silc_client_get_clients(SilcClient client,
353 SilcClientConnection conn,
356 SilcGetClientCallback completion,
359 /* Same as above function but does not resolve anything from the server.
360 This checks local cache and returns all clients from the cache. */
361 SilcClientEntry *silc_client_get_clients_local(SilcClient client,
362 SilcClientConnection conn,
365 unsigned int *clients_count);
367 /* Gets client entries by the list of client ID's `client_id_list'. This
368 always resolves those client ID's it does not know yet from the server
369 so this function might take a while. The `client_id_list' is a list
370 of ID Payloads added one after other. JOIN command reply and USERS
371 command reply for example returns this sort of list. The `completion'
372 will be called after the entries are available. */
373 void silc_client_get_clients_by_list(SilcClient client,
374 SilcClientConnection conn,
375 unsigned int list_count,
376 SilcBuffer client_id_list,
377 SilcGetClientCallback completion,
380 /* Find entry for client by the client's ID. Returns the entry or NULL
381 if the entry was not found. */
382 SilcClientEntry silc_client_get_client_by_id(SilcClient client,
383 SilcClientConnection conn,
384 SilcClientID *client_id);
386 /* Same as above but will always resolve the information from the server.
387 Use this only if you know that you don't have the entry and the only
388 thing you know about the client is its ID. */
389 void silc_client_get_client_by_id_resolve(SilcClient client,
390 SilcClientConnection conn,
391 SilcClientID *client_id,
392 SilcGetClientCallback completion,
395 /* Finds entry for channel by the channel name. Returns the entry or NULL
396 if the entry was not found. It is found only if the client is joined
398 SilcChannelEntry silc_client_get_channel(SilcClient client,
399 SilcClientConnection conn,
403 /* Command management (command.c) */
405 /* Allocate Command Context. The context is defined in `command.h' file.
406 The context is used by the library commands and applications should use
407 it as well. However, application may choose to use some own context
408 for its local commands. All library commands, however, must use this
410 SilcClientCommandContext silc_client_command_alloc();
412 /* Free command context and its internals */
413 void silc_client_command_free(SilcClientCommandContext ctx);
415 /* Duplicate Command Context by adding reference counter. The context won't
416 be free'd untill it hits zero. */
417 SilcClientCommandContext silc_client_command_dup(SilcClientCommandContext ctx);
419 /* Finds and returns a pointer to the command list. Return NULL if the
420 command is not found. See the `command.[ch]' for the command list. */
421 SilcClientCommand *silc_client_command_find(const char *name);
423 /* Generic function to send any command. The arguments must be sent already
424 encoded into correct form and in correct order. */
425 void silc_client_send_command(SilcClient client, SilcClientConnection conn,
426 SilcCommand command, unsigned short ident,
427 unsigned int argc, ...);
429 /* Pending Command callback destructor. This is called after calling the
430 pending callback or if error occurs while processing the pending command.
431 If error occurs then the callback won't be called at all, and only this
432 destructor is called. The `context' is the context given for the function
433 silc_client_command_pending. */
434 typedef void (*SilcClientPendingDestructor)(void *context);
436 /* Add new pending command to be executed when reply to a command has been
437 received. The `reply_cmd' is the command that will call the `callback'
438 with `context' when reply has been received. If `ident is non-zero
439 the `callback' will be executed when received reply with command
440 identifier `ident'. */
441 void silc_client_command_pending(SilcClientConnection conn,
442 SilcCommand reply_cmd,
443 unsigned short ident,
444 SilcClientPendingDestructor destructor,
445 SilcCommandCb callback,
449 /* Private Message key management (client_prvmsg.c) */
451 /* Adds private message key to the client library. The key will be used to
452 encrypt all private message between the client and the remote client
453 indicated by the `client_entry'. If the `key' is NULL and the boolean
454 value `generate_key' is TRUE the library will generate random key.
455 The `key' maybe for example pre-shared-key, passphrase or similar.
456 The `cipher' MAY be provided but SHOULD be NULL to assure that the
457 requirements of the SILC protocol are met. The API, however, allows
458 to allocate any cipher.
460 It is not necessary to set key for normal private message usage. If the
461 key is not set then the private messages are encrypted using normal
462 session keys. Setting the private key, however, increases the security.
464 Returns FALSE if the key is already set for the `client_entry', TRUE
466 int silc_client_add_private_message_key(SilcClient client,
467 SilcClientConnection conn,
468 SilcClientEntry client_entry,
471 unsigned int key_len,
474 /* Same as above but takes the key material from the SKE key material
475 structure. This structure is received if the application uses the
476 silc_client_send_key_agreement to negotiate the key material. The
477 `cipher' SHOULD be provided as it is negotiated also in the SKE
479 int silc_client_add_private_message_key_ske(SilcClient client,
480 SilcClientConnection conn,
481 SilcClientEntry client_entry,
483 SilcSKEKeyMaterial *key);
485 /* Sends private message key payload to the remote client indicated by
486 the `client_entry'. If the `force_send' is TRUE the packet is sent
487 immediately. Returns FALSE if error occurs, TRUE otherwise. The
488 application should call this function after setting the key to the
491 Note that the key sent using this function is sent to the remote client
492 through the SILC network. The packet is protected using normal session
494 int silc_client_send_private_message_key(SilcClient client,
495 SilcClientConnection conn,
496 SilcClientEntry client_entry,
499 /* Removes the private message from the library. The key won't be used
500 after this to protect the private messages with the remote `client_entry'
501 client. Returns FALSE on error, TRUE otherwise. */
502 int silc_client_del_private_message_key(SilcClient client,
503 SilcClientConnection conn,
504 SilcClientEntry client_entry);
506 /* Returns array of set private message keys associated to the connection
507 `conn'. Returns allocated SilcPrivateMessageKeys array and the array
508 count to the `key_count' argument. The array must be freed by the caller
509 by calling the silc_client_free_private_message_keys function. Note:
510 the keys returned in the array is in raw format. It might not be desired
511 to show the keys as is. The application might choose not to show the keys
512 at all or to show the fingerprints of the keys. */
513 SilcPrivateMessageKeys
514 silc_client_list_private_message_keys(SilcClient client,
515 SilcClientConnection conn,
516 unsigned int *key_count);
518 /* Frees the SilcPrivateMessageKeys array returned by the function
519 silc_client_list_private_message_keys. */
520 void silc_client_free_private_message_keys(SilcPrivateMessageKeys keys,
521 unsigned int key_count);
524 /* Channel private key management (client_channel.c,
525 SilcChannelPrivateKey is defined in idlist.h) */
527 /* Adds private key for channel. This may be set only if the channel's mode
528 mask includes the SILC_CHANNEL_MODE_PRIVKEY. This returns FALSE if the
529 mode is not set. When channel has private key then the messages are
530 encrypted using that key. All clients on the channel must also know the
531 key in order to decrypt the messages. However, it is possible to have
532 several private keys per one channel. In this case only some of the
533 clients on the channel may know the one key and only some the other key.
535 The private key for channel is optional. If it is not set then the
536 channel messages are encrypted using the channel key generated by the
537 server. However, setting the private key (or keys) for the channel
538 significantly adds security. If more than one key is set the library
539 will automatically try all keys at the message decryption phase. Note:
540 setting many keys slows down the decryption phase as all keys has to
541 be tried in order to find the correct decryption key. However, setting
542 a few keys does not have big impact to the decryption performace.
544 NOTE: that this is entirely local setting. The key set using this function
545 is not sent to the network at any phase.
547 NOTE: If the key material was originated by the SKE protocol (using
548 silc_client_send_key_agreement) then the `key' MUST be the
549 key->send_enc_key as this is dictated by the SILC protocol. However,
550 currently it is not expected that the SKE key material would be used
551 as channel private key. However, this API allows it. */
552 int silc_client_add_channel_private_key(SilcClient client,
553 SilcClientConnection conn,
554 SilcChannelEntry channel,
558 unsigned int key_len);
560 /* Removes all private keys from the `channel'. The old channel key is used
561 after calling this to protect the channel messages. Returns FALSE on
562 on error, TRUE otherwise. */
563 int silc_client_del_channel_private_keys(SilcClient client,
564 SilcClientConnection conn,
565 SilcChannelEntry channel);
567 /* Removes and frees private key `key' from the channel `channel'. The `key'
568 is retrieved by calling the function silc_client_list_channel_private_keys.
569 The key is not used after this. If the key was last private key then the
570 old channel key is used hereafter to protect the channel messages. This
571 returns FALSE on error, TRUE otherwise. */
572 int silc_client_del_channel_private_key(SilcClient client,
573 SilcClientConnection conn,
574 SilcChannelEntry channel,
575 SilcChannelPrivateKey key);
577 /* Returns array (pointers) of private keys associated to the `channel'.
578 The caller must free the array by calling the function
579 silc_client_free_channel_private_keys. The pointers in the array may be
580 used to delete the specific key by giving the pointer as argument to the
581 function silc_client_del_channel_private_key. */
582 SilcChannelPrivateKey *
583 silc_client_list_channel_private_keys(SilcClient client,
584 SilcClientConnection conn,
585 SilcChannelEntry channel,
586 unsigned int *key_count);
588 /* Frees the SilcChannelPrivateKey array. */
589 void silc_client_free_channel_private_keys(SilcChannelPrivateKey *keys,
590 unsigned int key_count);
593 /* Key Agreement routines (client_keyagr.c) */
595 /* Sends key agreement request to the remote client indicated by the
596 `client_entry'. If the caller provides the `hostname' and the `port'
597 arguments then the library will bind the client to that hostname and
598 that port for the key agreement protocol. It also sends the `hostname'
599 and the `port' in the key agreement packet to the remote client. This
600 would indicate that the remote client may initiate the key agreement
601 protocol to the `hostname' on the `port'. If port is zero then the
602 bound port is undefined (the operating system defines it).
604 If the `hostname' and `port' is not provided then empty key agreement
605 packet is sent to the remote client. The remote client may reply with
606 the same packet including its hostname and port. If the library receives
607 the reply from the remote client the `key_agreement' client operation
608 callback will be called to verify whether the user wants to perform the
609 key agreement or not.
611 NOTE: If the application provided the `hostname' and the `port' and the
612 remote side initiates the key agreement protocol it is not verified
613 from the user anymore whether the protocol should be executed or not.
614 By setting the `hostname' and `port' the user gives permission to
615 perform the protocol (we are responder in this case).
617 NOTE: If the remote side decides not to initiate the key agreement
618 or decides not to reply with the key agreement packet then we cannot
619 perform the key agreement at all. If the key agreement protocol is
620 performed the `completion' callback with the `context' will be called.
621 If remote side decides to ignore the request the `completion' will be
622 called after the specified timeout, `timeout_secs'.
624 NOTE: There can be only one active key agreement for one client entry.
625 Before setting new one, the old one must be finished (it is finished
626 after calling the completion callback) or the function
627 silc_client_abort_key_agreement must be called. */
628 void silc_client_send_key_agreement(SilcClient client,
629 SilcClientConnection conn,
630 SilcClientEntry client_entry,
633 unsigned long timeout_secs,
634 SilcKeyAgreementCallback completion,
637 /* Performs the actual key agreement protocol. Application may use this
638 to initiate the key agreement protocol. This can be called for example
639 after the application has received the `key_agreement' client operation,
640 and did not return TRUE from it.
642 The `hostname' is the remote hostname (or IP address) and the `port'
643 is the remote port. The `completion' callback with the `context' will
644 be called after the key agreement protocol.
646 NOTE: If the application returns TRUE in the `key_agreement' client
647 operation the library will automatically start the key agreement. In this
648 case the application must not call this function. However, application
649 may choose to just ignore the `key_agreement' client operation (and
650 merely just print information about it on the screen) and call this
651 function when the user whishes to do so (by, for example, giving some
652 specific command). Thus, the API provides both, automatic and manual
653 initiation of the key agreement. Calling this function is the manual
654 initiation and returning TRUE in the `key_agreement' client operation
655 is the automatic initiation. */
656 void silc_client_perform_key_agreement(SilcClient client,
657 SilcClientConnection conn,
658 SilcClientEntry client_entry,
661 SilcKeyAgreementCallback completion,
664 /* Same as above but application has created already the connection to
665 the remote host. The `sock' is the socket to the remote connection.
666 Application can use this function if it does not want the client library
667 to create the connection. */
668 void silc_client_perform_key_agreement_fd(SilcClient client,
669 SilcClientConnection conn,
670 SilcClientEntry client_entry,
673 SilcKeyAgreementCallback completion,
676 /* This function can be called to unbind the hostname and the port for
677 the key agreement protocol. However, this function has effect only
678 before the key agreement protocol has been performed. After it has
679 been performed the library will automatically unbind the port. The
680 `client_entry' is the client to which we sent the key agreement
682 void silc_client_abort_key_agreement(SilcClient client,
683 SilcClientConnection conn,
684 SilcClientEntry client_entry);