1 /*
2 
3   silcclient.h
4 
5   Author: Pekka Riikonen <priikone@silcnet.org>
6 
7   Copyright (C) 2000 - 2014 Pekka Riikonen
8 
9   The contents of this file are subject to one of the Licenses specified
10   in the COPYING file;  You may not use this file except in compliance
11   with the License.
12 
13   The software distributed under the License is distributed on an "AS IS"
14   basis, in the hope that it will be useful, but WITHOUT WARRANTY OF ANY
15   KIND, either expressed or implied.  See the COPYING file for more
16   information.
17 
18 */
19 
20 /****h* silcclient/Client Library Interface
21  *
22  * DESCRIPTION
23  *
24  * This interface defines the SILC Client Library API for the application.
25  * The Client Library is a full featured SILC client without user interface.
26  * A simple interface called SILC Client Operations (SilcClientOperations)
27  * is provided for applications to implmeent the necessary functions to use
28  * the client library.  The silcclient.h header file includes client library
29  * API, such as command handling and message sending.  The silcclient_entry.h
30  * header file includes entry handling, such as channel and user entry
31  * handling.
32  *
33  * Practically all functions in the Client Library API accepts SilcClient
34  * and SilcClientConnection as their first two argument.  The first argument
35  * is the actual SilcClient context and the second is the SilcClientConnection
36  * context of the connection in question.  Application may create and handle
37  * multiple connections in one SilcClient.  Connections can be created to
38  * servers and other clients.
39  *
40  * The Client Library support multiple threads and is threads safe if used
41  * correctly.  Messages can be sent from multiple threads without any
42  * locking.  Messages however are always received only in one thread unless
43  * message waiting (see silc_client_private_message_wait as an example) is
44  * used.  The threads can be turned on and off by giving a parameter to the
45  * SilcClient.  When turned on, each new connection to remote host is always
46  * executed in an own thread.  All tasks related to that connection are then
47  * executed in that thread.  This means that client operation callbacks for
48  * that connections may be called from threads and application will need to
49  * employ concurrency control if the callbacks need to access shared data
50  * in the application.  Messages are also received in that thread.
51  *
52  ***/
53 
54 #ifndef SILCCLIENT_H
55 #define SILCCLIENT_H
56 
57 #ifdef __cplusplus
58 extern "C" {
59 #endif
60 
61 #include "client.h"
62 #include "silcclient_entry.h"
63 
64 /* General definitions */
65 
66 /****d* silcclient/SilcClientAPI/SilcClientConnectionStatus
67  *
68  * NAME
69  *
70  *    typedef enum { ... } SilcClientConnectionStatus
71  *
72  * DESCRIPTION
73  *
74  *    This type is returned to the `connect' client operation to indicate
75  *    the status of the created connection.  It can indicate if it was
76  *    successful or whether an error occurred.
77  *
78  * SOURCE
79  */
80 typedef enum {
81   SILC_CLIENT_CONN_SUCCESS,	       /* Successfully connected */
82   SILC_CLIENT_CONN_SUCCESS_RESUME,     /* Successfully connected and
83 					  resumed old detached session */
84   SILC_CLIENT_CONN_DISCONNECTED,       /* Remote host disconnected */
85   SILC_CLIENT_CONN_ERROR,	       /* Error occurred during connecting */
86   SILC_CLIENT_CONN_ERROR_KE,	       /* Key Exchange failed */
87   SILC_CLIENT_CONN_ERROR_AUTH,	       /* Authentication failed */
88   SILC_CLIENT_CONN_ERROR_RESUME,       /* Resuming failed */
89   SILC_CLIENT_CONN_ERROR_TIMEOUT,      /* Timeout during connecting */
90 } SilcClientConnectionStatus;
91 /***/
92 
93 /****f* silcclient/SilcClientAPI/SilcClientRunning
94  *
95  * SYNOPSIS
96  *
97  *    typedef void (*SilcClientRunning)(SilcClient client, void *context);
98  *
99  * DESCRIPTION
100  *
101  *    The callback given as argument to silc_client_init function.  Once
102  *    this is called the client library is running and application may
103  *    start using the Client library API.
104  *
105  ***/
106 typedef void (*SilcClientRunning)(SilcClient client, void *context);
107 
108 /****f* silcclient/SilcClientAPI/SilcClientStopped
109  *
110  * SYNOPSIS
111  *
112  *    typedef void (*SilcClientStopped)(SilcClient client, void *context);
113  *
114  * DESCRIPTION
115  *
116  *    The callback given as argument to silc_client_stop.  Once this is
117  *    called the client library has stopped and can be freed by calling
118  *    silc_client_free.  Note that this won't be called if there are
119  *    active connections in the client.  Connections must first be closed
120  *    by calling silc_client_close_connection or by sending QUIT command to
121  *    the server connection.
122  *
123  ***/
124 typedef void (*SilcClientStopped)(SilcClient client, void *context);
125 
126 /****f* silcclient/SilcClientAPI/SilcClientConnectCallback
127  *
128  * SYNOPSIS
129  *
130  *    void (*SilcClientConnectCallback)(SilcClient client,
131  *                                      SilcClientConnection conn,
132  *                                      SilcClientConnectionStatus status,
133  *                                      SilcStatus error,
134  *                                      const char *message,
135  *                                      void *context);
136  *
137  * DESCRIPTION
138  *
139  *    Connect callbak given as argument to silc_client_connect_to_server,
140  *    silc_client_connect_to_client and silc_client_key_exchange functions.
141  *    It is called to indicate the status of the connection, indicated
142  *    by the `status'.  It is called after the connection has been
143  *    established to the remote host and when connection is disconnected
144  *    by the remote host.  The `context' is the context given as argument
145  *    to the connecting function.  If the `status' is an error the `error'
146  *    may indicate more detailed error.  If `error' is SILC_STATUS_OK no
147  *    detailed error message is available.
148  *
149  *    When the `status' is SILC_CLIENT_CONN_DISCONNECTED the `error' will
150  *    indicate the reason for disconnection.  If the `message' is non-NULL
151  *    it delivers error or disconnection message.
152  *
153  *    The `conn' is the connection to the remote host.  In case error
154  *    occurred the `conn' may be NULL, however, in some cases a valid `conn'
155  *    is returned even in error.  If `conn' is non-NULL the receiver is
156  *    responsible of closing the connection with silc_client_close_connection
157  *    function, except when SILC_CLINET_CONN_DISCONNECTED or some error
158  *    was received.  In these cases the library will close the connection.
159  *
160  ***/
161 typedef void (*SilcClientConnectCallback)(SilcClient client,
162 					  SilcClientConnection conn,
163 					  SilcClientConnectionStatus status,
164 					  SilcStatus error,
165 					  const char *message,
166 					  void *context);
167 
168 /****s* silcclient/SilcClientAPI/SilcClient
169  *
170  * NAME
171  *
172  *    typedef struct SilcClientStruct { ... } *SilcClient
173  *
174  * DESCRIPTION
175  *
176  *    This is the actual SILC Client structure which represents one
177  *    SILC Client.  It is allocated with the silc_client_alloc function
178  *    and given as argument to all SILC Client Library functions.  It
179  *    is initialized with silc_client_init function, and freed with
180  *    silc_client_free function.
181  *
182  *    This context represents the client.  Each connection to remote server
183  *    is represented by SilcClientConnection context.
184  *
185  * SOURCE
186  */
187 struct SilcClientStruct {
188   char *username;               /* Username */
189   char *hostname;               /* hostname */
190   char *realname;               /* Real name */
191   SilcSchedule schedule;	/* Client scheduler */
192   SilcRng rng;			/* Random number generator */
193   void *application;		/* Application specific context, set with
194 				   silc_client_alloc. */
195 
196   /* Internal data for client library.  Application cannot access this. */
197   SilcClientInternal internal;
198 };
199 /***/
200 
201 /****s* silcclient/SilcClientAPI/SilcClientConnection
202  *
203  * NAME
204  *
205  *    typedef struct SilcClientConnectionStruct { ... }
206  *                      *SilcClientConnection
207  *
208  * DESCRIPTION
209  *
210  *    This structure represents a connection.  It is allocated and freed by
211  *    the library.  It is returned to application in SilcClientConnectCallback.
212  *    It includes all the important data for the session such as local
213  *    client entry (which includes current nickname), local and remote IDs,
214  *    and other information.  All strings in the structure are UTF-8 encoded.
215  *
216  * SOURCE
217  */
218 struct SilcClientConnectionStruct {
219   SilcClientEntry local_entry;	       /* Our own Client Entry */
220   SilcClientID *local_id;	       /* Our current Client ID */
221 
222   char *remote_host;		       /* Remote host name */
223   int remote_port;		       /* Remote port */
224   SilcID remote_id;		       /* Remote ID */
225 
226   SilcChannelEntry current_channel;    /* Current joined channel */
227   SilcPublicKey public_key;	       /* Public key used in this connection */
228   SilcPrivateKey private_key;	       /* Private key */
229   SilcPacketStream stream;	       /* Connection to remote host */
230   SilcConnectionType type;	       /* Connection type */
231   SilcClientConnectCallback callback;  /* Connection callback */
232   void *callback_context;	       /* Connection context */
233   SilcClient client;		       /* Pointer back to SilcClient */
234 
235   /* Current say() or verify_public_key() operation associated context,
236      identifies the client, channel or server the operation is related to.
237      Application can use this information to target the operation better. */
238   union {
239     SilcClientEntry client_entry;
240     SilcChannelEntry channel_entry;
241     SilcServerEntry server_entry;
242   };
243   SilcIdType context_type;		/* Defines which pointer is set
244 					   in the union.  If SILC_ID_NONE
245 					   pointer is NULL. */
246 
247   /* Application specific data.  Application may set here whatever it wants. */
248   void *context;
249 
250   /* Internal data for client library.  Application cannot access this. */
251   SilcClientConnectionInternal internal;
252 };
253 /***/
254 
255 /****s* silcclient/SilcClientAPI/SilcChannelUser
256  *
257  * NAME
258  *
259  *    typedef struct SilcChannelUserStruct { ... } *SilcChannelUser
260  *
261  * DESCRIPTION
262  *
263  *    This structure represents a client that has joined to a channel.
264  *    It shows the client and the channel and the client's mode (channel
265  *    user mode) on the channel.
266  *
267  * SOURCE
268  */
269 struct SilcChannelUserStruct {
270   SilcClientEntry client;	             /* Client joined on channel */
271   SilcUInt32 mode;			     /* mode, ChannelUserModes */
272   SilcChannelEntry channel;		     /* The channel user has joined */
273 
274   /* Application specific data.  Application may set here whatever it wants. */
275   void *context;
276 };
277 /***/
278 
279 /****s* silcclient/SilcClientAPI/SilcClientStats
280  *
281  * NAME
282  *
283  *    typedef struct { ... } SilcClientStats;
284  *
285  * DESCRIPTION
286  *
287  *    This structure holds SILC network statistics returned by the
288  *    SILC_COMMAND_STATS command reply to the application.
289  *
290  * SOURCE
291  */
292 typedef struct SilcClientStatsStruct {
293   SilcUInt32 starttime;		/* SILC server start time */
294   SilcUInt32 uptime;		/* SILC server uptime*/
295   SilcUInt32 my_clients;	/* Number of clients in the server */
296   SilcUInt32 my_channels;	/* Number of channel in the server */
297   SilcUInt32 my_server_ops;	/* Number of server operators in the server */
298   SilcUInt32 my_router_ops;	/* Number of router operators in the router */
299   SilcUInt32 cell_clients;	/* Number of clients in the cell */
300   SilcUInt32 cell_channels;	/* Number of channels in the cell */
301   SilcUInt32 cell_servers;	/* Number of server in the cell */
302   SilcUInt32 clients;		/* All clients in SILC network */
303   SilcUInt32 channels;		/* All channels in SILC network */
304   SilcUInt32 servers;		/* All servers in SILC network */
305   SilcUInt32 routers;		/* All routers in SILC network */
306   SilcUInt32 server_ops;	/* All server operators in SILC network */
307   SilcUInt32 router_ops;	/* All router operators in SILC network */
308 } SilcClientStats;
309 /***/
310 
311 /****d* silcclient/SilcClientAPI/SilcKeyAgreementStatus
312  *
313  * NAME
314  *
315  *    typedef enum { ... } SilcKeyAgreementStatus;
316  *
317  * DESCRIPTION
318  *
319  *    Key agreement status types indicating the status of the key
320  *    agreement protocol.  These types are returned to the application
321  *    in the SilcKeyAgreementCallback callback function.
322  *
323  * SOURCE
324  */
325 typedef enum {
326   SILC_KEY_AGREEMENT_OK,	       /* Everything is Ok */
327   SILC_KEY_AGREEMENT_ERROR,	       /* Unknown error occurred */
328   SILC_KEY_AGREEMENT_FAILURE,	       /* The protocol failed */
329   SILC_KEY_AGREEMENT_TIMEOUT,	       /* The protocol timeout */
330   SILC_KEY_AGREEMENT_ABORTED,	       /* The protocol aborted */
331   SILC_KEY_AGREEMENT_ALREADY_STARTED,  /* Already started */
332   SILC_KEY_AGREEMENT_SELF_DENIED,      /* Negotiationg with itself denied */
333   SILC_KEY_AGREEMENT_NO_MEMORY,        /* System out of memory */
334 } SilcKeyAgreementStatus;
335 /***/
336 
337 /****f* silcclient/SilcClientAPI/SilcKeyAgreementCallback
338  *
339  * SYNOPSIS
340  *
341  *    typedef void (*SilcKeyAgreementCallback)(SilcClient client,
342  *                                             SilcClientConnection conn,
343  *                                             SilcClientEntry client_entry,
344  *                                             SilcKeyAgreementStatus status,
345  *                                             SilcSKEKeyMaterial *key,
346  *                                             void *context);
347  *
348  * DESCRIPTION
349  *
350  *    Key agreement callback that is called after the key agreement protocol
351  *    has been performed. This is called also if error occurred during the
352  *    key agreement protocol. The `key' is the allocated key material and
353  *    the caller is responsible of freeing it. The `key' is NULL if error
354  *    has occurred. The application can freely use the `key' to whatever
355  *    purpose it needs. See lib/silcske/silcske.h for the definition of
356  *    the SilcSKEKeyMaterial structure.
357  *
358  ***/
359 typedef void (*SilcKeyAgreementCallback)(SilcClient client,
360 					 SilcClientConnection conn,
361 					 SilcClientEntry client_entry,
362 					 SilcKeyAgreementStatus status,
363 					 SilcSKEKeyMaterial key,
364 					 void *context);
365 
366 /****s* silcclient/SilcClientAPI/SilcPrivateMessageKeys
367  *
368  * NAME
369  *
370  *    typedef struct { ... } SilcPrivateMessageKeys;
371  *
372  * DESCRIPTION
373  *
374  *    Structure to hold the list of private message keys. The list of these
375  *    structures is returned by the silc_client_list_private_message_keys
376  *    function.
377  *
378  * SOURCE
379  */
380 typedef struct SilcPrivateMessageKeysStruct {
381   SilcClientEntry client_entry;       /* The remote client entry */
382   char *cipher;			      /* The cipher name */
383   unsigned char *key;		      /* The original key, If the appliation
384 					 provided it. This is NULL if
385 					 the SKE key material was used. */
386   SilcUInt32 key_len;		      /* The key length */
387 } *SilcPrivateMessageKeys;
388 /***/
389 
390 /****s* silcclient/SilcClientAPI/SilcChannelPrivateKey
391  *
392  * NAME
393  *
394  *    typedef struct SilcChannelPrivateKeyStruct { ... }
395  *                      *SilcChannelPrivateKey;
396  *
397  * DESCRIPTION
398  *
399  *    Structure to hold one channel private key. The array of this structure
400  *    is returned by silc_client_list_channel_private_keys function.
401  *
402  * SOURCE
403  */
404 struct SilcChannelPrivateKeyStruct {
405   char *name;			      /* Application given name */
406   SilcCipher send_key;		      /* The cipher and key */
407   SilcCipher receive_key;	      /* The cipher and key */
408   SilcHmac hmac;		      /* The HMAC and hmac key */
409 };
410 /***/
411 
412 /****f* silcclient/SilcClientAPI/SilcAskPassphrase
413  *
414  * SYNOPSIS
415  *
416  *    typedef void (*SilcAskPassphrase)(const unsigned char *passphrase,
417  *			                SilcUInt32 passphrase_len,
418  *			                void *context);
419  *
420  * DESCRIPTION
421  *
422  *    Ask passphrase callback. This is called by the application when the
423  *    library calls `ask_passphrase' client operation.  The callback delivers
424  *    the passphrase to the library.  The passphrases in SILC protocol
425  *    MUST be in UTF-8 encoding, therefore the `passphrase' SHOULD be UTF-8
426  *    encoded, and if it is not then library will attempt to encode it.
427  *
428  ***/
429 typedef void (*SilcAskPassphrase)(const unsigned char *passphrase,
430 				  SilcUInt32 passphrase_len,
431 				  void *context);
432 
433 /****f* silcclient/SilcClientAPI/SilcVerifyPublicKey
434  *
435  * SYNOPSIS
436  *
437  *    typedef void (*SilcVerifyPublicKey)(SilcBool success, void *context);
438  *
439  * DESCRIPTION
440  *
441  *    Public key (or certificate) verification callback. This is called
442  *    by the application to indicate that the public key verification was
443  *    either success or failure.
444  *
445  ***/
446 typedef void (*SilcVerifyPublicKey)(SilcBool success, void *context);
447 
448 /****f* silcclient/SilcClientAPI/SilcGetAuthMeth
449  *
450  * SYNOPSIS
451  *
452  *    typedef void (*SilcGetAuthMeth)(SilcAuthMethod auth_meth,
453  *                                    const void *auth, SilcUInt32 auth_len,
454  *                                    void *context);
455  *
456  * DESCRIPTION
457  *
458  *    Authentication data resolving callback. This is called by the
459  *    application to return the resolved authentication data. The client
460  *    library has called the get_auth_method client operation and given
461  *    this function pointer as argument. The `auth_meth' is the selected
462  *    authentication method. The `auth_data' and the `auth_data_len'
463  *    are the resolved authentication data. The `context' is the libary's
464  *    context sent to the get_auth_method client operation.
465  *
466  *    If the `auth_method' is SILC_AUTH_PASSWORD then `auth' and `auth_len'
467  *    is the passphrase and its length.  If it is SILC_AUTH_PUBLIC_KEY the
468  *    `auth' must be NULL.  The library will use the private key given as
469  *    argument to silc_client_connect_to_server, silc_client_connect_to_client
470  *    or silc_client_key_exchange.  If it is SILC_AUTH_NONE, both `auth' and
471  *    `auth_len' are ignored.
472  *
473  ***/
474 typedef void (*SilcGetAuthMeth)(SilcAuthMethod auth_meth,
475 				const void *auth, SilcUInt32 auth_len,
476 				void *context);
477 
478 /****d* silcclient/SilcClientAPI/SilcClientMessageType
479  *
480  * NAME
481  *
482  *    typedef enum { ... } SilcClientMessageType;
483  *
484  * DESCRIPTION
485  *
486  *    Different message types for `say' client operation.  The application
487  *    may filter the message sent by the library according this type.
488  *
489  * SOURCE
490  */
491 typedef enum {
492   SILC_CLIENT_MESSAGE_INFO,	       /* Informational */
493   SILC_CLIENT_MESSAGE_WARNING,	       /* Warning */
494   SILC_CLIENT_MESSAGE_ERROR,	       /* Error */
495   SILC_CLIENT_MESSAGE_COMMAND_ERROR,   /* Error during command */
496   SILC_CLIENT_MESSAGE_AUDIT,	       /* Auditable */
497 } SilcClientMessageType;
498 /***/
499 
500 /****s* silcclient/SilcClientAPI/SilcClientOperations
501  *
502  * NAME
503  *
504  *    typedef struct { ... } SilcClientOperations;
505  *
506  * DESCRIPTION
507  *
508  *    SILC Client Operations. These must be implemented by the application.
509  *    The Client library may call any of these routines at any time.  The
510  *    routines are used to deliver certain information to the application
511  *    or from the application to the client library.
512  *
513  * SOURCE
514  */
515 typedef struct SilcClientOperationsStruct {
516   /* Message sent to the application by library. `conn' associates the
517      message to a specific connection.  `conn', however, may be NULL.
518      The `type' indicates the type of the message sent by the library.
519      The application can for example filter the message according the
520      type.  The variable argument list is arguments to the formatted
521      message `msg'.  A SilcClientEntry, SilcChannelEntry or SilcServerEntry
522      can be associated with the message inside the SilcClientConnection
523      by the library, and application may use it to better target the
524      message. */
525   void (*say)(SilcClient client, SilcClientConnection conn,
526 	      SilcClientMessageType type, char *msg, ...);
527 
528   /* Message for a channel. The `sender' is the sender of the message
529      The `channel' is the channel. The `message' is the message.  Note
530      that `message' maybe NULL.  The `flags' indicates message flags
531      and it is used to determine how the message can be interpreted
532      (like it may tell the message is multimedia message).  The `payload'
533      may be used to retrieve all the details of the message. */
534   void (*channel_message)(SilcClient client, SilcClientConnection conn,
535 			  SilcClientEntry sender, SilcChannelEntry channel,
536 			  SilcMessagePayload payload,
537 			  SilcChannelPrivateKey key, SilcMessageFlags flags,
538 			  const unsigned char *message,
539 			  SilcUInt32 message_len);
540 
541   /* Private message to the client. The `sender' is the sender of the
542      message. The message is `message'and maybe NULL.  The `flags'
543      indicates message flags  and it is used to determine how the message
544      can be interpreted (like it may tell the message is multimedia
545      message).  The `payload' may be used to retrieve all the details of
546      the message. */
547   void (*private_message)(SilcClient client, SilcClientConnection conn,
548 			  SilcClientEntry sender, SilcMessagePayload payload,
549 			  SilcMessageFlags flags, const unsigned char *message,
550 			  SilcUInt32 message_len);
551 
552   /* Notify message to the client.  The arguments are notify `type' specific.
553      See separate documentation in the Toolkit Reference Manual for the notify
554      arguments. */
555   void (*notify)(SilcClient client, SilcClientConnection conn,
556 		 SilcNotifyType type, ...);
557 
558   /* Command handler. This function is called always after application has
559      called a command.  It will be called to indicate that the command
560      was processed.  It will also be called if error occurs while processing
561      the command.  The `success' indicates whether the command was sent
562      or if error occurred.  The `status' indicates the actual error.
563      The `argc' and `argv' are the command line arguments sent to the
564      command by application.  Note that, this is not reply to the command
565      from server, this is merely and indication to application that the
566      command was processed. */
567   void (*command)(SilcClient client, SilcClientConnection conn,
568 		  SilcBool success, SilcCommand command, SilcStatus status,
569 		  SilcUInt32 argc, unsigned char **argv);
570 
571   /* Command reply handler.  Delivers a reply to command that was sent
572      earlier.  The `conn' is the associated client connection.  The `command'
573      indicates the command reply type.  If the `status' other than
574      SILC_STATUS_OK an error occurred.  In this case the `error' will indicate
575      the error.  It is possible to receive list of command replies and list
576      of errors.  In this case the `status' will indicate it is an list entry
577      (the `status' is SILC_STATUS_LIST_START, SILC_STATUS_LIST_ITEM and/or
578      SILC_STATUS_LIST_END).
579 
580      The arguments received in `ap' are command specific.  See a separate
581      documentation in the Toolkit Reference Manual for the command reply
582      arguments. */
583   void (*command_reply)(SilcClient client, SilcClientConnection conn,
584 			SilcCommand command, SilcStatus status,
585 			SilcStatus error, va_list ap);
586 
587   /* Find authentication method and authentication data by hostname and
588      port. The hostname may be IP address as well. The `auth_method' is
589      the authentication method the remote connection requires.  It is
590      however possible that remote accepts also some other authentication
591      method.  Application should use the method that may have been
592      configured for this connection.  If none has been configured it should
593      use the required `auth_method'.  If the `auth_method' is
594      SILC_AUTH_NONE, server does not require any authentication or the
595      required authentication method is not known.  The `completion'
596      callback must be called to deliver the chosen authentication method
597      and data. The `conn' may be NULL. */
598   void (*get_auth_method)(SilcClient client, SilcClientConnection conn,
599 			  char *hostname, SilcUInt16 port,
600 			  SilcAuthMethod auth_method,
601 			  SilcGetAuthMeth completion, void *context);
602 
603   /* Called to verify received public key. The `conn_type' indicates which
604      entity (server or client) has sent the public key. If user decides to
605      trust the key the application may save the key as trusted public key for
606      later use. The `completion' must be called after the public key has
607      been verified.  A SilcClientEntry or SilcServerEntry can be associated
608      with this request inside the SilcClientConnection by the library, and
609      application may use it to better target the verification request. */
610   void (*verify_public_key)(SilcClient client, SilcClientConnection conn,
611 			    SilcConnectionType conn_type,
612 			    SilcPublicKey public_key,
613 			    SilcVerifyPublicKey completion, void *context);
614 
615   /* Ask from end user a passphrase or a password. The passphrase is
616      returned to the library by calling the `completion' callback with
617      the `context'. The returned passphrase SHOULD be in UTF-8 encoded,
618      if not then the library will attempt to encode. */
619   void (*ask_passphrase)(SilcClient client, SilcClientConnection conn,
620 			 SilcAskPassphrase completion, void *context);
621 
622   /* Called to indicate that incoming key agreement request has been
623      received.  If the application wants to perform key agreement it may
624      call silc_client_perform_key_agreement to initiate key agreement or
625      silc_client_send_key_agreement to provide connection point to the
626      remote client in case the `hostname' is NULL.  If key agreement is
627      not desired this request can be ignored.  The `protocol' is either
628      value 0 for TCP or value 1 for UDP. */
629   void (*key_agreement)(SilcClient client, SilcClientConnection conn,
630 			SilcClientEntry client_entry,
631 			const char *hostname, SilcUInt16 protocol,
632 			SilcUInt16 port);
633 
634   /* Notifies application that file transfer protocol session is being
635      requested by the remote client indicated by the `client_entry' from
636      the `hostname' and `port'. The `session_id' is the file transfer
637      session and it can be used to either accept or reject the file
638      transfer request, by calling the silc_client_file_receive or
639      silc_client_file_close, respectively. */
640   void (*ftp)(SilcClient client, SilcClientConnection conn,
641 	      SilcClientEntry client_entry, SilcUInt32 session_id,
642 	      const char *hostname, SilcUInt16 port);
643 } SilcClientOperations;
644 /***/
645 
646 /****s* silcclient/SilcClientAPI/SilcClientParams
647  *
648  * NAME
649  *
650  *    typedef struct { ... } SilcClientParams;
651  *
652  * DESCRIPTION
653  *
654  *    Client parameters. This can be filled with proper values and
655  *    given as argument to the silc_client_alloc function. The structure
656  *    hold various parameters which affects the function of the client.
657  *
658  * SOURCE
659  */
660 typedef struct SilcClientParamsStruct {
661   /* If this boolean is set to TRUE then the client library will use
662      threads.  Any of the callback functions in the SilcClientOperations
663      and other callbacks may be called at any time in a thread.  The
664      application may need to employ appropriate concurrency control
665      in the callbacks to protect application specific data. */
666   SilcBool threads;
667 
668   /* Nickname format string. This can be used to order the client library
669      to save the nicknames in the library in a certain format. Since
670      nicknames are not unique in SILC it is possible to have multiple same
671      nicknames. Using this format string it is possible to order the library
672      to separate the multiple same nicknames from each other. If this is
673      empty then default format is used which is the default nickname
674      without anything else. The string MUST be NULL terminated.
675 
676      Following format types are available:
677 
678      %n  nickname      - the real nickname returned by the server (mandatory)
679      %a  number        - ascending number in case there are several
680                          same nicknames (fe. nick#2 and nick#3)
681      %h  hostname      - the stripped hostname of the client
682      %H  full hostname - the full hostname of the client
683 
684      Example format strings: "%n#%a"     (fe. nick#2, nick#3)
685                              "%n#%h%a"   (fe. nick#host, nick#host2)
686                              "%a!%n#%h"  (fe. nick#host, 2!nick#host)
687 
688      Note that there must always be some separator characters around '%n'
689      format.  It is not possible to put format characters before or after
690      '%n' without separators (such ash '#').  Also note that the separator
691      character should be a character that cannot be part of normal nickname.
692      Note that, using '@' as a separator is not recommended as the nickname
693      string may contain it to separate a server name from the nickname (eg.
694      nickname@silcnet.org).
695   */
696   char nickname_format[32];
697 
698   /* If this is set to TRUE then the `nickname_format' is employed to all
699      saved nicknames even if there are no multiple same nicknames in the
700      cache. By default this is FALSE, which means that the `nickname_format'
701      is employed only if the library will receive a nickname that is
702      already saved in the cache. It is recommended to leave this to FALSE
703      value. */
704   SilcBool nickname_force_format;
705 
706   /* If this is set to TRUE then all nickname strings returned by the library
707      and stored by the library are in the format of 'nickname@server', eg.
708      nickname@silcnet.org.  If this is FALSE then the server name of the
709      nickname is available only from the SilcClientEntry structure.  When this
710      is TRUE the server name is still parsed to SilcClientEntry. */
711   SilcBool full_nicknames;
712 
713   /* If this is set to TRUE then all channel name strings returned by the
714      library and stored by the library are in the format of 'channel@server',
715      eg. silc@silcnet.org.  If this is FALSE then the server name of the
716      channel is available only from the SilcChannelEntry structure.  When this
717      is TRUE the server name is still parsed to SilcChannelEntry.  Note that,
718      not all SILC server versions return such channel name strings. */
719   SilcBool full_channel_names;
720 
721   /* If this is set to TRUE, the silcclient library will not register and
722      deregister the cipher, pkcs, hash and hmac algorithms. The application
723      itself will need to handle that. */
724   SilcBool dont_register_crypto_library;
725 
726   /* If this is set to TRUE, the silcclient library will not automatically
727      negotiate private message keys using SKE over the SILC network but will
728      use normal session keys to protect private messages. */
729   SilcBool dont_autoneg_prvmsg_keys;
730 } SilcClientParams;
731 /***/
732 
733 
734 /* Initialization functions (client.c) */
735 
736 /****f* silcclient/SilcClientAPI/silc_client_alloc
737  *
738  * SYNOPSIS
739  *
740  *    SilcClient silc_client_alloc(SilcClientOperations *ops,
741  *                                 SilcClientParams *params,
742  *                                 void *application,
743  *                                 const char *silc_version);
744  *
745  * DESCRIPTION
746  *
747  *    Allocates new client object. This has to be done before client may
748  *    work. After calling this one must call silc_client_init to initialize
749  *    the client. The `application' is application specific user data pointer
750  *    and caller must free it. The `silc_version' is the application version
751  *    that will be used to compare against remote host's (usually a server)
752  *    version string.  The `application' context is accessible by the
753  *    application by client->application, client being SilcClient.
754  *
755  ***/
756 SilcClient silc_client_alloc(SilcClientOperations *ops,
757 			     SilcClientParams *params,
758 			     void *application,
759 			     const char *version_string);
760 
761 /****f* silcclient/SilcClientAPI/silc_client_free
762  *
763  * SYNOPSIS
764  *
765  *    void silc_client_free(SilcClient client);
766  *
767  * DESCRIPTION
768  *
769  *    Frees client object and its internals.  The execution of the client
770  *    should be stopped with silc_client_stop function before calling
771  *    this function.
772  *
773  ***/
774 void silc_client_free(SilcClient client);
775 
776 /****f* silcclient/SilcClientAPI/silc_client_init
777  *
778  * SYNOPSIS
779  *
780  *    SilcBool silc_client_init(SilcClient client, const char *username,
781  *                              const char *hostname, const char *realname,
782  *                              SilcClientRunning running, void *context);
783  *
784  * DESCRIPTION
785  *
786  *    Initializes the client. This makes all the necessary steps to make
787  *    the client ready to be run. One must call silc_client_run to run the
788  *    client. Returns FALSE if error occurred, TRUE otherwise.
789  *
790  *    The `username' and `hostname' strings must be given and they must be
791  *    UTF-8 encoded.  The `username' is the client's username in the
792  *    operating system, `hostname' is the client's host name and the
793  *    `realname' is the user's real name.
794  *
795  *    The `running' callback with `context' is called after the client is
796  *    running after silc_client_run or silc_client_run_one has been called.
797  *    Application may start using the Client library API after that.  Setting
798  *    the callback is optional, but highly recommended.
799  *
800  ***/
801 SilcBool silc_client_init(SilcClient client, const char *username,
802 			  const char *hostname, const char *realname,
803 			  SilcClientRunning running, void *context);
804 
805 /****f* silcclient/SilcClientAPI/silc_client_run
806  *
807  * SYNOPSIS
808  *
809  *    void silc_client_run(SilcClient client);
810  *
811  * DESCRIPTION
812  *
813  *    Runs the client.  This starts the scheduler from the utility library.
814  *    When this functions returns the execution of the application is over.
815  *    The client must be initialized before calling this.
816  *
817  ***/
818 void silc_client_run(SilcClient client);
819 
820 /****f* silcclient/SilcClientAPI/silc_client_run_one
821  *
822  * SYNOPSIS
823  *
824  *    void silc_client_run_one(SilcClient client);
825  *
826  * DESCRIPTION
827  *
828  *    Runs the client and returns immeadiately. This function is used when
829  *    the SILC Client object indicated by the `client' is run under some
830  *    other scheduler, or event loop or main loop.  On GUI applications,
831  *    for example this may be desired to used to run the client under the
832  *    GUI application's main loop.  Typically the GUI application would
833  *    register an idle task that calls this function multiple times in
834  *    a second to quickly process the SILC specific data.
835  *
836  ***/
837 void silc_client_run_one(SilcClient client);
838 
839 /****f* silcclient/SilcClientAPI/silc_client_stop
840  *
841  * SYNOPSIS
842  *
843  *    void silc_client_stop(SilcClient client, SilcClientStopped stopped,
844  *                          void *context);
845  *
846  * DESCRIPTION
847  *
848  *    Stops the client. This is called to stop the client and thus to stop
849  *    the program.  The client context must be freed with the silc_client_free
850  *    function.  All connections that exist in this client must be closed
851  *    before calling this function.  Connections can be closed by calling
852  *    silc_client_close_connection.
853  *
854  *    The `stopped' will be called once the client and all connections have
855  *    finished.  The client may be freed after that.  Note that the `stopped'
856  *    won't be called before all connections have finished.  Setting the
857  *    callback is optional.
858  *
859  ***/
860 void silc_client_stop(SilcClient client, SilcClientStopped stopped,
861 		      void *context);
862 
863 /* Connecting functions */
864 
865 /****s* silcclient/SilcClientAPI/SilcClientConnectionParams
866  *
867  * NAME
868  *
869  *    typedef struct { ... } SilcClientConnectionParams;
870  *
871  * DESCRIPTION
872  *
873  *    Client connection parameters.  This can be filled by the application
874  *    and given as argument to silc_client_connect_to_server,
875  *    silc_client_connect_to_client, silc_client_key_exchange or
876  *    silc_client_send_key_agreement.
877  *
878  * SOURCE
879  */
880 typedef struct SilcClientConnectionParamsStruct {
881   /* If this is provided the user's nickname in the network will be the
882      string given here.  If it is given, it must be UTF-8 encoded.  If this
883      string is not given, the user's username by default is used as nickname.
884      The nickname may later be changed by using NICK command.  The maximum
885      length for the nickname string is 128 bytes. */
886   char *nickname;
887 
888   /* If this key repository pointer is non-NULL then public key received in
889      the key exchange protocol will be verified from this repository.  If
890      this is not provided then the `verify_public_key' client operation will
891      be called back to application.  If the boolean `verify_notfound' is set
892      to TRUE then the `verify_public_key' client operation will be called
893      in case the public key is not found in `repository'.  Only public keys
894      added with at least SILC_SKR_USAGE_KEY_AGREEMENT in the repository will
895      be checked, other keys will be ignored. */
896   SilcSKR repository;
897   SilcBool verify_notfound;
898 
899   /* Authentication data.  Application may set here the authentication data
900      and authentication method to be used in connecting.  If `auth_set'
901      boolean is TRUE then authentication data is provided by application.
902      If the authentication method is public key authentication then the key
903      pair given as argument when connecting will be used and `auth' field
904      is NULL.  If it is passphrase authentication, it can be provided in
905      `auth' and `auth_len' fields.  If `auth_set' is FALSE
906      the `get_auth_method' client operation will be called to get the
907      authentication method and data from application. */
908   SilcBool auth_set;
909   SilcAuthMethod auth_method;
910   void *auth;
911   SilcUInt32 auth_len;
912 
913   /* If this boolean is set to TRUE then the connection will use UDP instead
914      of TCP.  If UDP is set then also the next `local_ip' and `local_port'
915      must be set. */
916   SilcBool udp;
917 
918   /* The `local_ip' specifies the local IP address used with the connection.
919      It must be non-NULL if `udp' boolean is TRUE.  If the `local_port' is
920      non-zero it will be used as local port with UDP connection.  The remote
921      host will also send packets to the specified address and port.  If the
922      `bind_ip' is non-NULL a listener is bound to that address instead of
923      `local_ip'. */
924   char *local_ip;
925   char *bind_ip;
926   int local_port;
927 
928   /* If this boolean is set to TRUE then the key exchange is done with
929      perfect forward secrecy. */
930   SilcBool pfs;
931 
932   /* If this boolean is set to TRUE then connection authentication protocol
933      is not performed during connecting.  Only key exchange protocol is
934      performed.  This usually must be set to TRUE when connecting to another
935      client, but must be FALSE with server connections. */
936   SilcBool no_authentication;
937 
938   /* The SILC session detachment data that was returned in the `command_reply'
939      client operation for SILC_COMMAND_DETACH command.  If this is provided
940      here the client library will attempt to resume the session in the network.
941      After the connection is created and the session has been resumed the
942      client will receive SILC_COMMAND_NICK command_reply for the client's
943      nickname in the network and SILC_COMMAND_JOIN command reply for all the
944      channels that the client has joined in the network.  It may also receive
945      SILC_COMMAND_UMODE command reply to set user's mode on the network. */
946   unsigned char *detach_data;
947   SilcUInt32 detach_data_len;
948 
949   /* Connection timeout.  If non-zero, the connection will timeout unless
950      the SILC connection is completed in the specified amount of time. */
951   SilcUInt32 timeout_secs;
952 
953   /* Rekey timeout in seconds.  The client will perform rekey in this
954      time interval.  If set to zero, the default value will be used
955      (3600 seconds, 1 hour). */
956   SilcUInt32 rekey_secs;
957 
958   /* If this is set to TRUE then the client will ignore all incoming
959      Requested Attributes queries and does not reply anything back.  This
960      usually leads into situation where server does not anymore send
961      the queries after seeing that client does not reply anything back.
962      If your application does not support Requested Attributes or you do
963      not want to use them set this to TRUE.  See SilcAttribute and
964      silc_client_attribute_add for more information on attributes. */
965   SilcBool ignore_requested_attributes;
966 
967   /* User context for SilcClientConnection.  If non-NULL this context is
968      set to the 'context' field in SilcClientConnection when the connection
969      context is created. */
970   void *context;
971 } SilcClientConnectionParams;
972 /***/
973 
974 /****f* silcclient/SilcClientAPI/silc_client_connect_to_server
975  *
976  * SYNOPSIS
977  *
978  *    SilcAsyncOperation
979  *    silc_client_connect_to_server(SilcClient client,
980  *                                  SilcClientConnectionParams *params,
981  *                                  SilcPublicKey public_key,
982  *                                  SilcPrivateKey private_key,
983  *                                  char *remote_host, int port,
984  *                                  SilcClientConnectCallback callback,
985  *                                  void *context);
986  *
987  * DESCRIPTION
988  *
989  *    Connects to remote server `remote_host' at port `port'.  This function
990  *    can be used to create connection to remote SILC server and start
991  *    SILC session in the SILC network.  The `params' may be provided
992  *    to provide various connection parameters.  The `public_key' and the
993  *    `private_key' is your identity used in this connection.  When
994  *    authentication method is based on digital signatures, this key pair
995  *    will be used.  The `callback' with `context' will be called after the
996  *    connection has been created.  It will also be called later when remote
997  *    host disconnects.
998  *
999  *    If application wishes to create the network connection itself, use
1000  *    the silc_client_key_exchange after creating the connection to start
1001  *    key exchange and authentication with the server.
1002  *
1003  *    Returns SilcAsyncOperation which can be used to cancel the connecting,
1004  *    or NULL on error.  Note that the returned pointer becomes invalid
1005  *    after the `callback' is called.
1006  *
1007  ***/
1008 SilcAsyncOperation
1009 silc_client_connect_to_server(SilcClient client,
1010 			      SilcClientConnectionParams *params,
1011 			      SilcPublicKey public_key,
1012 			      SilcPrivateKey private_key,
1013 			      char *remote_host, int port,
1014 			      SilcClientConnectCallback callback,
1015 			      void *context);
1016 
1017 /****f* silcclient/SilcClientAPI/silc_client_connect_to_client
1018  *
1019  * SYNOPSIS
1020  *
1021  *    SilcAsyncOperation
1022  *    silc_client_connect_to_client(SilcClient client,
1023  *                                  SilcClientConnectionParams *params,
1024  *                                  SilcPublicKey public_key,
1025  *                                  SilcPrivateKey private_key,
1026  *                                  char *remote_host, int port,
1027  *                                  SilcClientConnectCallback callback,
1028  *                                  void *context);
1029  *
1030  * DESCRIPTION
1031  *
1032  *    Connects to remote client `remote_host' at port `port'.  This function
1033  *    can be used to create peer-to-peer connection to another SILC client,
1034  *    for example, for direct conferencing, or file transfer or for other
1035  *    purposes.  The `params' may be provided to provide various connection
1036  *    parameters.  The `public_key' and the `private_key' is your identity
1037  *    used in this connection.  The `callback' with `context' will be called
1038  *    after the connection has been created.  It will also be called later
1039  *    when remote host disconnects.
1040  *
1041  *    If application wishes to create the network connection itself, use
1042  *    the silc_client_key_exchange after creating the connection to start
1043  *    key exchange with the client.
1044  *
1045  *    Returns SilcAsyncOperation which can be used to cancel the connecting,
1046  *    or NULL on error.  Note that the returned pointer becomes invalid
1047  *    after the `callback' is called.
1048  *
1049  ***/
1050 SilcAsyncOperation
1051 silc_client_connect_to_client(SilcClient client,
1052 			      SilcClientConnectionParams *params,
1053 			      SilcPublicKey public_key,
1054 			      SilcPrivateKey private_key,
1055 			      char *remote_host, int port,
1056 			      SilcClientConnectCallback callback,
1057 			      void *context);
1058 
1059 /****f* silcclient/SilcClientAPI/silc_client_key_exchange
1060  *
1061  * SYNOPSIS
1062  *
1063  *    SilcAsyncOperation
1064  *    silc_client_key_exchange(SilcClient client,
1065  *                             SilcClientConnectionParams *params,
1066  *                             SilcPublicKey public_key,
1067  *                             SilcPrivateKey private_key,
1068  *                             SilcStream stream,
1069  *                             SilcConnectionType conn_type,
1070  *                             SilcClientConnectCallback callback,
1071  *                             void *context);
1072  *
1073  * DESCRIPTION
1074  *
1075  *    Starts key exchange protocol and authentication protocol in the
1076  *    connection indicated by `stream'.  This function can be be used to
1077  *    start SILC session with remote host (usually server) when the caller
1078  *    has itself created the connection, instead of calling the function
1079  *    silc_client_connect_to_server or silc_client_connect_to_client.  If
1080  *    one of those functions was used this function must not be called as
1081  *    in that case the key exchange is performed automatically.
1082  *
1083  *    Use this function only if you have created the connection by yourself.
1084  *    After creating the connection the socket must be wrapped into a
1085  *    socket stream.  See silcsocketstream.h for more information.  Note that
1086  *    the `stream' must have valid remote IP address (and optionally also
1087  *    hostname) and port set.
1088  *
1089  *    The `params' may be provided to provide various connection parameters.
1090  *    The `public_key' and the `private_key' is your identity used in this
1091  *    session.  The `callback' with `context' will be called after the session
1092  *    has been set up.  It will also be called later when remote host
1093  *    disconnects.  The `conn_type' is the type of session this is going to
1094  *    be.  If the remote is SILC server it is SILC_CONN_SERVER or if it is
1095  *    SILC client it is SILC_CONN_CLIENT.
1096  *
1097  *    Returns SilcAsyncOperation which can be used to cancel the connecting,
1098  *    or NULL on error.  Note that the returned pointer becomes invalid
1099  *    after the `callback' is called.
1100  *
1101  * EXAMPLE
1102  *
1103  *    int sock;
1104  *
1105  *    // Create remote connection stream.  Resolve hostname and IP also.
1106  *    sock = create_connection(remote_host, port);
1107  *    silc_socket_tcp_stream_create(sock, TRUE, FALSE, schedule,
1108  *                                  stream_create_cb, app);
1109  *
1110  *    // Stream callback delivers our new SilcStream context
1111  *    void stream_create_cb(SilcSocketStreamStatus status, SilcStream stream,
1112  *                          void *context)
1113  *    {
1114  *      ...
1115  *      if (status != SILC_SOCKET_OK)
1116  *        error(status);
1117  *
1118  *      // Start key exchange
1119  *      silc_client_key_exchange(client, NULL, public_key, private_key,
1120  *                               stream, SILC_CONN_SERVER, connection_cb, app);
1121  *      ...
1122  *    }
1123  *
1124  ***/
1125 SilcAsyncOperation
1126 silc_client_key_exchange(SilcClient client,
1127 			 SilcClientConnectionParams *params,
1128 			 SilcPublicKey public_key,
1129 			 SilcPrivateKey private_key,
1130 			 SilcStream stream,
1131 			 SilcConnectionType conn_type,
1132 			 SilcClientConnectCallback callback,
1133 			 void *context);
1134 
1135 /****f* silcclient/SilcClientAPI/silc_client_close_connection
1136  *
1137  * SYNOPSIS
1138  *
1139  *    void silc_client_close_connection(SilcClient client,
1140  *                                      SilcClientConnection conn);
1141  *
1142  * DESCRIPTION
1143  *
1144  *    Closes the remote connection `conn'.  The `conn' will become invalid
1145  *    after this call.  Usually this function is called only when explicitly
1146  *    closing connection for example in case of error, or when the remote
1147  *    connection was created by the application or when the remote is client
1148  *    connection.  Server connections are usually closed by sending QUIT
1149  *    command to the server.  However, this call may also be used.
1150  *
1151  ***/
1152 void silc_client_close_connection(SilcClient client,
1153 				  SilcClientConnection conn);
1154 
1155 /* Message sending functions */
1156 
1157 /****f* silcclient/SilcClientAPI/silc_client_send_channel_message
1158  *
1159  * SYNOPSIS
1160  *
1161  *    SilcBool silc_client_send_channel_message(SilcClient client,
1162  *                                              SilcClientConnection conn,
1163  *                                              SilcChannelEntry channel,
1164  *                                              SilcChannelPrivateKey key,
1165  *                                              SilcMessageFlags flags,
1166  *                                              SilcHash hash,
1167  *                                              unsigned char *data,
1168  *                                              SilcUInt32 data_len);
1169  *
1170  * DESCRIPTION
1171  *
1172  *    Sends encrypted message to the `channel'.  The plaintext message is
1173  *    the `data' of `data_len' bytes in length.
1174  *
1175  *    If `key' is provided then that private channel message key is used to
1176  *    encrypt the message.  If it is not provided and the `channel' does not
1177  *    have SILC_CHANNEL_MODE_PRIVKEY set, the curent channel key is used
1178  *    instead.  If the mode is set but `key' is NULL the key that was added
1179  *    first as private channel message key will be used.
1180  *
1181  *    If the `flags' includes SILC_MESSAGE_FLAG_SIGNED the message will be
1182  *    digitally signed with the SILC key pair associated with the `conn'.
1183  *    In this case the `hash' pointer must be provided as well.
1184  *
1185  *    Returns TRUE if the message was sent, and FALSE if error occurred or
1186  *    the sending is not allowed due to channel modes (like sending is
1187  *    blocked).  This function is thread safe and channel messages can be
1188  *    sent from multiple threads.
1189  *
1190  ***/
1191 SilcBool silc_client_send_channel_message(SilcClient client,
1192 					  SilcClientConnection conn,
1193 					  SilcChannelEntry channel,
1194 					  SilcChannelPrivateKey key,
1195 					  SilcMessageFlags flags,
1196 					  SilcHash hash,
1197 					  unsigned char *data,
1198 					  SilcUInt32 data_len);
1199 
1200 /****f* silcclient/SilcClientAPI/silc_client_send_private_message
1201  *
1202  * SYNOPSIS
1203  *
1204  *    SilcBool silc_client_send_private_message(SilcClient client,
1205  *                                              SilcClientConnection conn,
1206  *                                              SilcClientEntry client_entry,
1207  *                                              SilcMessageFlags flags,
1208  *                                              SilcHash hash,
1209  *                                              unsigned char *data,
1210  *                                              SilcUInt32 data_len);
1211  *
1212  * DESCRIPTION
1213  *
1214  *    Sends private message to remote client. If private message key has
1215  *    not been set with this client then the message will be encrypted using
1216  *    the session keys used in `conn' connection.  If the `flags' includes
1217  *    SILC_MESSAGE_FLAG_SIGNED the message will be digitally signed with the
1218  *    SILC key pair associated with `conn'.  In this case the caller must also
1219  *    provide the `hash' pointer.
1220  *
1221  *    Returns TRUE if the message was sent, and FALSE if error occurred.
1222  *    This function is thread safe and private messages can be sent from
1223  *    multiple threads.
1224  *
1225  ***/
1226 SilcBool silc_client_send_private_message(SilcClient client,
1227 					  SilcClientConnection conn,
1228 					  SilcClientEntry client_entry,
1229 					  SilcMessageFlags flags,
1230 					  SilcHash hash,
1231 					  unsigned char *data,
1232 					  SilcUInt32 data_len);
1233 
1234 /****f* silcclient/SilcClientAPI/silc_client_private_message_wait_init
1235  *
1236  * SYNOPSIS
1237  *
1238  *    SilcBool
1239  *    silc_client_private_message_wait_init(SilcClient client,
1240  *                                          SilcClientConnection conn,
1241  *                                          SilcClientEntry client_entry);
1242  *
1243  * DESCRIPTION
1244  *
1245  *    Initializes private message waiting functionality for the client
1246  *    indicated by `client_entry'.  Once this is called private message
1247  *    from remote connection indicated by `conn' for `client_entry' may
1248  *    be waiter for, for example in a thread.  The function
1249  *    silc_client_private_message_wait is used to block the current thread
1250  *    until a private message is received from a specified client entry.
1251  *    Return FALSE in case an internal error occurred.
1252  *
1253  ***/
1254 SilcBool silc_client_private_message_wait_init(SilcClient client,
1255 					       SilcClientConnection conn,
1256 					       SilcClientEntry client_entry);
1257 
1258 /****f* silcclient/SilcClientAPI/silc_client_private_message_wait_uninit
1259  *
1260  * SYNOPSIS
1261  *
1262  *    void
1263  *    silc_client_private_message_wait_uninit(SilcClient client,
1264  *                                            SilcClientConnection conn,
1265  *                                            SilcClientEntry client_entry);
1266  *
1267  * DESCRIPTION
1268  *
1269  *    Unintializes private message waiting for client indicated by
1270  *    `client_entry'.  After this call private message cannot be waited
1271  *    anymore and silc_client_private_message_wait will return with FALSE
1272  *    value.
1273  *
1274  ***/
1275 void silc_client_private_message_wait_uninit(SilcClient client,
1276 					     SilcClientConnection conn,
1277 					     SilcClientEntry client_entry);
1278 
1279 /****f* silcclient/SilcClientAPI/silc_client_private_message_wait
1280  *
1281  * SYNOPSIS
1282  *
1283  *    SilcBool
1284  *    silc_client_private_message_wait(SilcClient client,
1285  *                                     SilcClientConnection conn,
1286  *                                     SilcClientEntry client_entry,
1287  *                                     SilcMessagePayload *payload);
1288  *
1289  * DESCRIPTION
1290  *
1291  *    Blocks current thread or process until a private message has been
1292  *    received from the remote client indicated by `client_entry'.  Before
1293  *    private messages can be waited the silc_client_private_message_wait_init
1294  *    must be called.  This function can be used from a thread to wait for
1295  *    private message from the specified client.  Multiple threads can be
1296  *    created to wait messages from multiple clients.  Any other private
1297  *    message received from the connection indicated by `conn' will be
1298  *    forwarded to the normal `private_message' client operation callback.
1299  *    The private messages from `client_entry' will not be delivered to the
1300  *    `private_message' client operation callback.
1301  *
1302  *    Returns TRUE and the received private message into `payload'.  The caller
1303  *    must free the returned SilcMessagePayload.  If this function returns
1304  *    FALSE the private messages cannot be waited anymore.  This happens
1305  *    when some other thread calls silc_client_private_message_wait_uninit.
1306  *    This returns FALSE also if silc_client_private_message_wait_init has
1307  *    not been called.
1308  *
1309  ***/
1310 SilcBool silc_client_private_message_wait(SilcClient client,
1311 					  SilcClientConnection conn,
1312 					  SilcClientEntry client_entry,
1313 					  SilcMessagePayload *payload);
1314 
1315 /****f* silcclient/SilcClientAPI/silc_client_on_channel
1316  *
1317  * SYNOPSIS
1318  *
1319  *    SilcChannelUser silc_client_on_channel(SilcChannelEntry channel,
1320  *                                           SilcClientEntry client_entry);
1321  *
1322  * DESCRIPTION
1323  *
1324  *    Returns the SilcChannelUser entry if the `client_entry' is joined on the
1325  *    channel indicated by the `channel'. NULL if client is not joined on
1326  *    the channel.
1327  *
1328  ***/
1329 SilcChannelUser silc_client_on_channel(SilcChannelEntry channel,
1330 				       SilcClientEntry client_entry);
1331 
1332 
1333 /* Command management */
1334 
1335 /****f* silcclient/SilcClientAPI/silc_client_command_call
1336  *
1337  * SYNOPSIS
1338  *
1339  *    SilcUInt16 silc_client_command_call(SilcClient client,
1340  *                                        SilcClientConnection conn,
1341  *                                        const char *command_line, ...);
1342  *
1343  * DESCRIPTION
1344  *
1345  *    Calls and executes the command indicated by the `command_name'.
1346  *    The `command_line' is a string which includes the command's name and
1347  *    its arguments separated with whitespaces (' ').  If `command_line'
1348  *    is non-NULL then all variable arguments are ignored by default.
1349  *
1350  *    If `command_line' is NULL, then the variable arguments define the
1351  *    command's name and its arguments.  The first variable argument must
1352  *    be the command name.  The variable argument list must be terminated
1353  *    with NULL.
1354  *
1355  *    Returns command identifier for this sent command.  It can be used
1356  *    to additionally attach to the command reply using the function
1357  *    silc_client_command_pending, if needed.  Returns 0 on error.
1358  *
1359  *    The `command' client operation callback will be called when the
1360  *    command is executed to indicate whether or not the command executed
1361  *    successfully.
1362  *
1363  *    The `command_reply' client operation callbak will be called when reply
1364  *    is received from the server to the command.  Application may also use
1365  *    the silc_client_command_pending to attach to the command reply.
1366  *    The command identifier for silc_client_command_pending function after
1367  *    this function call is conn->cmd_ident, which application may use.
1368  *
1369  * EXAMPLE
1370  *
1371  *    silc_client_command_call(client, conn, NULL, "PING", "silc.silcnet.org",
1372  *                             NULL);
1373  *    silc_client_command_call(client, conn, "PING silc.silcnet.org");
1374  *
1375  * NOTES
1376  *
1377  *    This command executes the commands implemented inside the client
1378  *    library.  These commands are designed for command line applications,
1379  *    but GUI application may call them too if needed.  Alternatively
1380  *    application may override the library and use silc_client_command_send
1381  *    function instead.
1382  *
1383  ***/
1384 SilcUInt16 silc_client_command_call(SilcClient client,
1385 				    SilcClientConnection conn,
1386 				    const char *command_line, ...);
1387 
1388 /****f* silcclient/SilcClientAPI/SilcClientCommandReply
1389  *
1390  * SYNOPSIS
1391  *
1392  *    typedef SilcBool (*SilcClientCommandReply)(SilcClient client,
1393  *                                               SilcClientConnection conn,
1394  *                                               SilcCommand command,
1395  *                                               SilcStatus status,
1396  *                                               SilcStatus error,
1397  *                                               void *context,
1398  *                                               va_list ap);
1399  *
1400  * DESCRIPTION
1401  *
1402  *    The command reply callback function given as argument to functions
1403  *    silc_client_command_send and silc_client_command_pending.  This is
1404  *    called to deliver the command replies to the caller.  Each command
1405  *    reply received from the server to the `command' will be delivered
1406  *    separately to the caller by calling this callback.  The `status' will
1407  *    indicate whether there is only one reply or multiple replies.  The
1408  *    `error' will indicate if an error occurred.  The `ap' will include
1409  *    command reply arguments.  They are the same arguments as for
1410  *    `command_reply' client operation callback in SilcClientOperations.
1411  *
1412  *    If `status' is SILC_STATUS_OK only one reply was received and error
1413  *    did not occur.  If it is SILC_STATUS_LIST_START, SILC_STATUS_LIST_ITEM
1414  *    or SILC_STATUS_LIST_END, there are will be two or more replies.  The
1415  *    first reply is SILC_STATUS_LIST_START and last one SILC_STATUS_LIST_END.
1416  *
1417  *    If FALSE is returned in this function this callback will not be called
1418  *    again for `command' even if there are more comand replies.  By returning
1419  *    FALSE the caller my stop the command reply handling when needed.
1420  *
1421  ***/
1422 typedef SilcBool (*SilcClientCommandReply)(SilcClient client,
1423 					   SilcClientConnection conn,
1424 					   SilcCommand command,
1425 					   SilcStatus status,
1426 					   SilcStatus error,
1427 					   void *context,
1428 					   va_list ap);
1429 
1430 /****f* silcclient/SilcClientAPI/silc_client_command_send
1431  *
1432  * SYNOPSIS
1433  *
1434  *    SilcUInt16 silc_client_command_send(SilcClient client,
1435  *                                        SilcClientConnection conn,
1436  *                                        SilcCommand command,
1437  *                                        SilcClientCommandReply reply,
1438  *                                        void *reply_context,
1439  *                                        SilcUInt32 argc, ...);
1440  *
1441  * DESCRIPTION
1442  *
1443  *    Generic function to send any command.  The arguments must be given
1444  *    already encoded into correct format and in correct order. If application
1445  *    wants to perform the commands by itself, it can do so and send the data
1446  *    directly to the server using this function.  If application is using
1447  *    the silc_client_command_call, this function is usually not used.
1448  *    Programmer should get familiar with the SILC protocol commands
1449  *    specification when using this function, as the arguments needs to
1450  *    be encoded as specified in the protocol.
1451  *
1452  *    The variable arguments are a set of { type, data, data_length },
1453  *    and the `argc' is the number of these sets.
1454  *
1455  *    The `reply' callback must be provided, and it is called when the
1456  *    command reply is received from the server.  Note that, when using this
1457  *    function the default `command_reply' client operation callback will not
1458  *    be called when reply is received.
1459  *
1460  *    Returns command identifier for this sent command.  It can be used
1461  *    to additionally attach to the command reply using the function
1462  *    silc_client_command_pending, if needed.  Returns 0 on error.
1463  *
1464  * EXAMPLE
1465  *
1466  *    silc_client_command_send(client, conn, SILC_COMMAND_WHOIS,
1467  *                             my_whois_command_reply, cmd_ctx,
1468  *                             1, 1, nickname, strlen(nickname));
1469  *
1470  ***/
1471 SilcUInt16 silc_client_command_send(SilcClient client,
1472 				    SilcClientConnection conn,
1473 				    SilcCommand command,
1474 				    SilcClientCommandReply reply,
1475 				    void *reply_context,
1476 				    SilcUInt32 argc, ...);
1477 
1478 /****f* silcclient/SilcClientAPI/silc_client_command_pending
1479  *
1480  * SYNOPSIS
1481  *
1482  *    void silc_client_command_pending(SilcClientConnection conn,
1483  *                                     SilcCommand command,
1484  *                                     SilcUInt16 cmd_ident,
1485  *                                     SilcClientCommandReply reply,
1486  *                                     void *context);
1487  *
1488  * DESCRIPTION
1489  *
1490  *    This function can be used to add pending command callback to be
1491  *    called when an command reply is received to an earlier sent command.
1492  *    The `command' is the command that must be received in order for
1493  *    the pending command callback indicated by `callback' to be called.
1494  *
1495  *    The `cmd_ident' is a command identifier which was set for the earlier
1496  *    sent command.  The command reply will include the same identifier
1497  *    and pending command callback will be called when the reply is
1498  *    received with the same command identifier.  It is possible to
1499  *    add multiple pending command callbacks for same command and for
1500  *    same identifier.
1501  *
1502  *    Application may use this function to add its own command reply
1503  *    handlers if it wishes not to use the standard `command_reply'
1504  *    client operation.
1505  *
1506  *    Note also that the application is notified about the received command
1507  *    reply through the `command_reply' client operation before calling
1508  *    the `callback` pending command callback.  That is the normal
1509  *    command reply handling, and is called regardless whether pending
1510  *    command callbacks are used or not.
1511  *
1512  * EXAMPLE
1513  *
1514  *    SilcUInt16 cmd_ident;
1515  *    cmd_ident = silc_client_command_call(client, conn,
1516  *                                         "PING silc.silcnet.org");
1517  *    silc_client_command_pending(conn, SILC_COMMAND_PING, cmd_ident,
1518  *                                my_ping_handler, my_ping_context);
1519  *
1520  ***/
1521 SilcBool silc_client_command_pending(SilcClientConnection conn,
1522 				     SilcCommand command,
1523 				     SilcUInt16 cmd_ident,
1524 				     SilcClientCommandReply reply,
1525 				     void *context);
1526 
1527 
1528 /* Private Message key management */
1529 
1530 /****f* silcclient/SilcClientAPI/silc_client_add_private_message_key
1531  *
1532  * SYNOPSIS
1533  *
1534  *    SilcBool
1535  *    silc_client_add_private_message_key(SilcClient client,
1536  *                                        SilcClientConnection conn,
1537  *                                        SilcClientEntry client_entry,
1538  *                                        const char *cipher,
1539  *                                        const char *hmac,
1540  *                                        unsigned char *key,
1541  *                                        SilcUInt32 key_len);
1542  *
1543  * DESCRIPTION
1544  *
1545  *    Adds a static private message key to the client library.  The key
1546  *    will be used to encrypt all private message between the client and
1547  *    the remote client indicated by the `client_entry'.  The `key' can
1548  *    be for example a pre-shared-key, passphrase or similar shared secret
1549  *    string.  The `cipher' and `hmac' MAY be provided but SHOULD be NULL
1550  *    to assure that the requirements of the SILC protocol are met. The
1551  *    API, however, allows to allocate any cipher and HMAC.
1552  *
1553  *    If the private message key is added to client without first receiving
1554  *    a request for it from the remote `client_entry' this function will
1555  *    send the request to `client_entry'.  Note that, the actual key is
1556  *    not sent to the network.
1557  *
1558  *    It is not necessary to set key for normal private message usage. If the
1559  *    key is not set then the private messages are encrypted using normal
1560  *    session keys.  Setting the private key, however, increases security.
1561  *
1562  *    Returns FALSE if the key is already set for the `client_entry', TRUE
1563  *    otherwise.
1564  *
1565  ***/
1566 SilcBool silc_client_add_private_message_key(SilcClient client,
1567 					     SilcClientConnection conn,
1568 					     SilcClientEntry client_entry,
1569 					     const char *cipher,
1570 					     const char *hmac,
1571 					     unsigned char *key,
1572 					     SilcUInt32 key_len);
1573 
1574 /****f* silcclient/SilcClientAPI/silc_client_add_private_message_key_ske
1575  *
1576  * SYNOPSIS
1577  *
1578  *    SilcBool
1579  *    silc_client_add_private_message_key_ske(SilcClient client,
1580  *                                            SilcClientConnection conn,
1581  *                                            SilcClientEntry client_entry,
1582  *                                            const char *cipher,
1583  *                                            const char *hmac,
1584  *                                            SilcSKEKeyMaterial key);
1585  *
1586  * DESCRIPTION
1587  *
1588  *    Same as silc_client_add_private_message_key but takes the key material
1589  *    from the SKE key material structure.  This structure is received if
1590  *    the application uses the silc_client_send_key_agreement to negotiate
1591  *    the key material.  The `cipher' and `hmac' SHOULD be provided as it is
1592  *    negotiated also in the SKE protocol.
1593  *
1594  ***/
1595 SilcBool silc_client_add_private_message_key_ske(SilcClient client,
1596 						 SilcClientConnection conn,
1597 						 SilcClientEntry client_entry,
1598 						 const char *cipher,
1599 						 const char *hmac,
1600 						 SilcSKEKeyMaterial key);
1601 
1602 /****f* silcclient/SilcClientAPI/silc_client_del_private_message_key
1603  *
1604  * SYNOPSIS
1605  *
1606  *    SilcBool
1607  *    silc_client_del_private_message_key(SilcClient client,
1608  *                                        SilcClientConnection conn,
1609  *                                        SilcClientEntry client_entry);
1610  *
1611  * DESCRIPTION
1612  *
1613  *    Removes the private message from the library. The key won't be used
1614  *    after this to protect the private messages with the remote `client_entry'
1615  *    client. Returns FALSE on error, TRUE otherwise.
1616  *
1617  ***/
1618 SilcBool silc_client_del_private_message_key(SilcClient client,
1619 					     SilcClientConnection conn,
1620 					     SilcClientEntry client_entry);
1621 
1622 /****f* silcclient/SilcClientAPI/silc_client_list_private_message_keys
1623  *
1624  * SYNOPSIS
1625  *
1626  *    SilcPrivateMessageKeys
1627  *    silc_client_list_private_message_keys(SilcClient client,
1628  *                                          SilcClientConnection conn,
1629  *                                          SilcUInt32 *key_count);
1630  *
1631  * DESCRIPTION
1632  *
1633  *    Returns array of set private message keys associated to the connection
1634  *    `conn'. Returns allocated SilcPrivateMessageKeys array and the array
1635  *    count to the `key_count' argument. The array must be freed by the caller
1636  *    by calling the silc_client_free_private_message_keys function. Note:
1637  *    the keys returned in the array is in raw format. It might not be desired
1638  *    to show the keys as is. The application might choose not to show the keys
1639  *    at all or to show the fingerprints of the keys.
1640  *
1641  ***/
1642 SilcPrivateMessageKeys
1643 silc_client_list_private_message_keys(SilcClient client,
1644 				      SilcClientConnection conn,
1645 				      SilcUInt32 *key_count);
1646 
1647 /****f* silcclient/SilcClientAPI/silc_client_free_private_message_keys
1648  *
1649  * SYNOPSIS
1650  *
1651  *    void silc_client_free_private_message_keys(SilcPrivateMessageKeys keys,
1652  *                                               SilcUInt32 key_count);
1653  *
1654  * DESCRIPTION
1655  *
1656  *    Frees the SilcPrivateMessageKeys array returned by the function
1657  *    silc_client_list_private_message_keys.
1658  *
1659  ***/
1660 void silc_client_free_private_message_keys(SilcPrivateMessageKeys keys,
1661 					   SilcUInt32 key_count);
1662 
1663 /****f* silcclient/SilcClientAPI/silc_client_private_message_key_is_set
1664  *
1665  * SYNOPSIS
1666  *
1667  *    SilcBool
1668  *    silc_client_private_message_key_is_set(SilcClient client,
1669  *                                           SilcClientConnection conn,
1670  *                                           SilcClientEntry client_entry);
1671  *
1672  * DESCRIPTION
1673  *
1674  *    Returns TRUE if the private message key has been set for the client
1675  *    entry indicated by `client_entry'.
1676  *
1677  ***/
1678 SilcBool
1679 silc_client_private_message_key_is_set(SilcClient client,
1680 				       SilcClientConnection conn,
1681 				       SilcClientEntry client_entry);
1682 
1683 
1684 /* Channel private key management */
1685 
1686 /****f* silcclient/SilcClientAPI/silc_client_add_channel_private_key
1687  *
1688  * SYNOPSIS
1689  *
1690  *    SilcBool
1691  *    silc_client_add_channel_private_key(SilcClient client,
1692  *                                        SilcClientConnection conn,
1693  *                                        SilcChannelEntry channel,
1694  *                                        const char *name,
1695  *                                        char *cipher,
1696  *                                        char *hmac,
1697  *                                        unsigned char *key,
1698  *                                        SilcUInt32 key_len,
1699  *                                        SilcChannelPrivateKey *ret_key);
1700  *
1701  * DESCRIPTION
1702  *
1703  *    Adds private key for channel. When channel has private key then the
1704  *    messages are encrypted using that key. All clients on the channel
1705  *    must also know the key in order to decrypt the messages. However,
1706  *    it is possible to have several private keys per one channel. In this
1707  *    case only some of the clients on the channel may know the one key
1708  *    and only some the other key.  The `name' can be application given
1709  *    name for the key.  This returns the created key to the 'ret_key'
1710  *    pointer if it is non-NULL;
1711  *
1712  *    If `cipher' and/or `hmac' is NULL then default values will be used
1713  *    (aes-256-cbc for cipher and hmac-sha1-96 for hmac).
1714  *
1715  *    The private key for channel is optional. If it is not set then the
1716  *    channel messages are encrypted using the channel key generated by the
1717  *    server. However, setting the private key (or keys) for the channel
1718  *    significantly adds security. If more than one key is set the library
1719  *    will automatically try all keys at the message decryption phase. Note:
1720  *    setting many keys slows down the decryption phase as all keys has to
1721  *    be tried in order to find the correct decryption key. However, setting
1722  *    a few keys does not have big impact to the decryption performace.
1723  *
1724  * NOTES
1725  *
1726  *    NOTE: This is entirely local setting. The key set using this function
1727  *    is not sent to the network at any phase.
1728  *
1729  *    NOTE: If the key material was originated by the SKE protocol (using
1730  *    silc_client_send_key_agreement) then the `key' MUST be the
1731  *    key->send_enc_key as this is dictated by the SILC protocol. However,
1732  *    currently it is not expected that the SKE key material would be used
1733  *    as channel private key. However, this API allows it.
1734  *
1735  ***/
1736 SilcBool silc_client_add_channel_private_key(SilcClient client,
1737 					     SilcClientConnection conn,
1738 					     SilcChannelEntry channel,
1739 					     const char *name,
1740 					     char *cipher,
1741 					     char *hmac,
1742 					     unsigned char *key,
1743 					     SilcUInt32 key_len,
1744 					     SilcChannelPrivateKey *ret_key);
1745 
1746 /****f* silcclient/SilcClientAPI/silc_client_del_channel_private_keys
1747  *
1748  * SYNOPSIS
1749  *
1750  *    SilcBool silc_client_del_channel_private_keys(SilcClient client,
1751  *                                                  SilcClientConnection conn,
1752  *                                                  SilcChannelEntry channel);
1753  *
1754  * DESCRIPTION
1755  *
1756  *    Removes all private keys from the `channel'. The old channel key is used
1757  *    after calling this to protect the channel messages. Returns FALSE on
1758  *    on error, TRUE otherwise.
1759  *
1760  ***/
1761 SilcBool silc_client_del_channel_private_keys(SilcClient client,
1762 					      SilcClientConnection conn,
1763 					      SilcChannelEntry channel);
1764 
1765 /****f* silcclient/SilcClientAPI/silc_client_del_channel_private_key
1766  *
1767  * SYNOPSIS
1768  *
1769  *    SilcBool silc_client_del_channel_private_key(SilcClient client,
1770  *                                                 SilcClientConnection conn,
1771  *                                                 SilcChannelEntry channel,
1772  *                                                 SilcChannelPrivateKey key);
1773  *
1774  * DESCRIPTION
1775  *
1776  *    Removes and frees private key `key' from the channel `channel'.
1777  *    The `key' is retrieved by calling the function
1778  *    silc_client_list_channel_private_keys. The key is not used after
1779  *    this. If the key was last private key then the old channel key is
1780  *    used hereafter to protect the channel messages. This returns FALSE
1781  *    on error, TRUE otherwise.
1782  *
1783  ***/
1784 SilcBool silc_client_del_channel_private_key(SilcClient client,
1785 					     SilcClientConnection conn,
1786 					     SilcChannelEntry channel,
1787 					     SilcChannelPrivateKey key);
1788 
1789 /****f* silcclient/SilcClientAPI/silc_client_list_channel_private_keys
1790  *
1791  * SYNOPSIS
1792  *
1793  *    SilcDList
1794  *    silc_client_list_channel_private_keys(SilcClient client,
1795  *                                          SilcClientConnection conn,
1796  *                                          SilcChannelEntry channel);
1797  *
1798  * DESCRIPTION
1799  *
1800  *    Returns list of private keys associated to the `channel'.  The caller
1801  *    must free the returned list with silc_dlist_uninit.  The pointers in
1802  *    the list may be used to delete the specific key by giving the pointer
1803  *    as argument to the function silc_client_del_channel_private_key.  Each
1804  *    entry in the list is SilcChannelPrivateKey.
1805  *
1806  ***/
1807 SilcDList silc_client_list_channel_private_keys(SilcClient client,
1808 						SilcClientConnection conn,
1809 						SilcChannelEntry channel);
1810 
1811 /****f* silcclient/SilcClientAPI/silc_client_current_channel_private_key
1812  *
1813  * SYNOPSIS
1814  *
1815  *    void silc_client_current_channel_private_key(SilcClient client,
1816  *                                                 SilcClientConnection conn,
1817  *                                                 SilcChannelEntry channel,
1818  *                                                 SilcChannelPrivateKey key);
1819  *
1820  * DESCRIPTION
1821  *
1822  *    Sets the `key' to be used as current channel private key on the
1823  *    `channel'.  Packet sent after calling this function will be secured
1824  *    with `key'.
1825  *
1826  ***/
1827 void silc_client_current_channel_private_key(SilcClient client,
1828 					     SilcClientConnection conn,
1829 					     SilcChannelEntry channel,
1830 					     SilcChannelPrivateKey key);
1831 
1832 
1833 /* Key Agreement routines */
1834 
1835 /****f* silcclient/SilcClientAPI/silc_client_send_key_agreement
1836  *
1837  * SYNOPSIS
1838  *
1839  *    void silc_client_send_key_agreement(SilcClient client,
1840  *                                        SilcClientConnection conn,
1841  *                                        SilcClientEntry client_entry,
1842  *                                        SilcClientConnectionParams *params,
1843  *                                        SilcPublicKey public_key,
1844  *                                        SilcPrivateKey private_key,
1845  *                                        SilcKeyAgreementCallback completion,
1846  *                                        void *context);
1847  *
1848  * DESCRIPTION
1849  *
1850  *    Sends key agreement request to the remote client indicated by the
1851  *    `client_entry'.
1852  *
1853  *    If `params' is non-NULL and it has the `local_ip' and `local_port' set
1854  *    the caller will provide the connection endpoint for the key agreement
1855  *    connection.  The `bind_ip' can be used to bind to that IP instead of
1856  *    `local_ip'.  If the `udp' is set to TRUE the connection will be UDP
1857  *    instead of TCP.  Caller may also set the `repository', `verify_notfound'
1858  *    and `timeout_secs' fields in `params'.  Other fields are ignored.
1859  *    If `params' is NULL, then the `client_entry' is expected to provide
1860  *    the connection endpoint for us.  It is recommended the `timeout_secs'
1861  *    is specified in case the remote client does not reply anything to
1862  *    the request.
1863  *
1864  *    The `public_key' and `private_key' is our identity in the key agreement.
1865  *
1866  *    In case we do not provide the connection endpoint, we will receive
1867  *    the `key_agreement' client operation when the remote send its own
1868  *    key agreement request packet.  We may then there start the key
1869  *    agreement with silc_client_perform_key_agreement.  If we provided the
1870  *    the connection endpoint, the client operation will not be called.
1871  *
1872  *    There can be only one active key agreement for `client_entry'.  Old
1873  *    key agreement may be aborted by calling silc_client_abort_key_agreement.
1874  *
1875  * EXAMPLE
1876  *
1877  *    // Send key agreement request (we don't provide connection endpoint)
1878  *    silc_client_send_key_agreement(client, conn, remote_client,
1879  *                                   NULL, public_key, private_key,
1880  *                                   my_keyagr_completion, my_context);
1881  *
1882  *    // Another example where we provide connection endpoint (TCP).
1883  *    SilcClientConnectionParams params;
1884  *    memset(&params, 0, sizeof(params));
1885  *    params.local_ip = local_ip;
1886  *    params.local_port = local_port;
1887  *    params.timeout_secs = 60;
1888  *    silc_client_send_key_agreement(client, conn, remote_client,
1889  *                                   &params, public_key, private_key,
1890  *                                   my_keyagr_completion, my_context);
1891  *
1892  ***/
1893 void silc_client_send_key_agreement(SilcClient client,
1894 				    SilcClientConnection conn,
1895 				    SilcClientEntry client_entry,
1896 				    SilcClientConnectionParams *params,
1897 				    SilcPublicKey public_key,
1898 				    SilcPrivateKey private_key,
1899 				    SilcKeyAgreementCallback completion,
1900 				    void *context);
1901 
1902 /****f* silcclient/SilcClientAPI/silc_client_perform_key_agreement
1903  *
1904  * SYNOPSIS
1905  *
1906  *    void
1907  *    silc_client_perform_key_agreement(SilcClient client,
1908  *                                      SilcClientConnection conn,
1909  *                                      SilcClientEntry client_entry,
1910  *                                      SilcClientConnectionParams *params,
1911  *                                      SilcPublicKey public_key,
1912  *                                      SilcPrivateKey private_key,
1913  *                                      char *hostname, int port,
1914  *                                      SilcKeyAgreementCallback completion,
1915  *                                      void *context);
1916  *
1917  * DESCRIPTION
1918  *
1919  *    Performs the key agreement protocol.  Application may use this to
1920  *    initiate the key agreement protocol.  Usually this is called after
1921  *    receiving the `key_agreement' client operation.
1922  *
1923  *    The `hostname' is the remote hostname (or IP address) and the `port'
1924  *    is the remote port.  The `completion' callback with the `context' will
1925  *    be called after the key agreement protocol.
1926  *
1927  *    The `params' is connection parameters and it may be used to define
1928  *    the key agreement connection related parameters.  It may be NULL.
1929  *
1930  ***/
1931 void silc_client_perform_key_agreement(SilcClient client,
1932 				       SilcClientConnection conn,
1933 				       SilcClientEntry client_entry,
1934 				       SilcClientConnectionParams *params,
1935 				       SilcPublicKey public_key,
1936 				       SilcPrivateKey private_key,
1937 				       char *hostname, int port,
1938 				       SilcKeyAgreementCallback completion,
1939 				       void *context);
1940 
1941 /****f* silcclient/SilcClientAPI/silc_client_perform_key_agreement_stream
1942  *
1943  * SYNOPSIS
1944  *
1945  *    void
1946  *    silc_client_perform_key_agreement_stream(
1947  *                                      SilcClient client,
1948  *                                      SilcClientConnection conn,
1949  *                                      SilcClientEntry client_entry,
1950  *                                      SilcClientConnectionParams *params,
1951  *                                      SilcPublicKey public_key,
1952  *                                      SilcPrivateKey private_key,
1953  *                                      SilcStream stream,
1954  *                                      SilcKeyAgreementCallback completion,
1955  *                                      void *context);
1956  *
1957  * DESCRIPTION
1958  *
1959  *    Same as silc_client_perform_key_agreement but the caller has created
1960  *    the connection to remote client.  The `stream' is the created
1961  *    connection.
1962  *
1963  ***/
1964 void
1965 silc_client_perform_key_agreement_stream(SilcClient client,
1966 					 SilcClientConnection conn,
1967 					 SilcClientEntry client_entry,
1968 					 SilcClientConnectionParams *params,
1969 					 SilcPublicKey public_key,
1970 					 SilcPrivateKey private_key,
1971 					 SilcStream stream,
1972 					 SilcKeyAgreementCallback completion,
1973 					 void *context);
1974 
1975 /****f* silcclient/SilcClientAPI/silc_client_abort_key_agreement
1976  *
1977  * SYNOPSIS
1978  *
1979  *    void silc_client_abort_key_agreement(SilcClient client,
1980  *                                         SilcClientConnection conn,
1981  *                                         SilcClientEntry client_entry);
1982  *
1983  * DESCRIPTION
1984  *
1985  *    This function can be called to unbind the hostname and the port for
1986  *    the key agreement protocol. However, this function has effect only
1987  *    before the key agreement protocol has been performed. After it has
1988  *    been performed the library will automatically unbind the port. The
1989  *    `client_entry' is the client to which we sent the key agreement
1990  *    request.  The key agreement completion callback will be called
1991  *    with SILC_KEY_AGREEMENT_ABORTED status.
1992  *
1993  ***/
1994 void silc_client_abort_key_agreement(SilcClient client,
1995 				     SilcClientConnection conn,
1996 				     SilcClientEntry client_entry);
1997 
1998 
1999 /* Misc functions */
2000 
2001 /****f* silcclient/SilcClientAPI/silc_client_set_away_message
2002  *
2003  * SYNOPSIS
2004  *
2005  *    SilcBool silc_client_set_away_message(SilcClient client,
2006  *                                          SilcClientConnection conn,
2007  *                                          char *message);
2008  *
2009  * DESCRIPTION
2010  *
2011  *    Sets away `message'.  The away message may be set when the client's
2012  *    mode is changed to SILC_UMODE_GONE and the client whishes to reply
2013  *    to anyone who sends private message.  The `message' will be sent
2014  *    automatically back to the the client who send private message.  If
2015  *    away message is already set this replaces the old message with the
2016  *    new one.  If `message' is NULL the old away message is removed.
2017  *    The sender may freely free the memory of the `message'.  Returns
2018  *    FALSE on error.
2019  *
2020  ***/
2021 SilcBool silc_client_set_away_message(SilcClient client,
2022 				      SilcClientConnection conn,
2023 				      char *message);
2024 
2025 /****d* silcclient/SilcClientAPI/SilcClientMonitorStatus
2026  *
2027  * NAME
2028  *
2029  *    typedef enum { ... } SilcClientMonitorStatus;
2030  *
2031  * DESCRIPTION
2032  *
2033  *    File transmission session status types.  These will indicate
2034  *    the status of the file transmission session.
2035  *
2036  *    The SILC_CLIENT_FILE_MONITOR_KEY_AGREEMENT is called when session
2037  *    is key exchange phase.
2038  *
2039  *    The SILC_CLIENT_FILE_MONITOR_SEND is called when data is being sent
2040  *    to remote client.
2041  *
2042  *    The SILC_CLIENT_FILE_MONITOR_RECEIVE is called when data is being
2043  *    recieved from remote client.
2044  *
2045  *    The SILC_CLIENT_FILE_MONITOR_CLOSED will be called when the user
2046  *    issues silc_client_file_close.  If needed, it may be ignored in the
2047  *    monitor callback.
2048  *
2049  *    The SILC_CLIENT_FILE_MONITOR_DISCONNECT will be called if remote
2050  *    disconnects the session connection.  The silc_client_file_close must
2051  *    be called when this status is received.  The session is over when
2052  *    this is received.
2053  *
2054  *    The SILC_CLIENLT_FILE_MONITOR_ERROR is called in case some error
2055  *    occured.  The SilcClientFileError will indicate more detailed error
2056  *    condition.  The silc_client_file_close must be called when this status
2057  *    is received.  The session is over when this is received.
2058  *
2059  * SOURCE
2060  */
2061 typedef enum {
2062   SILC_CLIENT_FILE_MONITOR_KEY_AGREEMENT,    /* In key agreemenet phase */
2063   SILC_CLIENT_FILE_MONITOR_SEND,	     /* Sending file */
2064   SILC_CLIENT_FILE_MONITOR_RECEIVE,	     /* Receiving file */
2065   SILC_CLIENT_FILE_MONITOR_GET,		     /* Unsupported */
2066   SILC_CLIENT_FILE_MONITOR_PUT,		     /* Unsupported */
2067   SILC_CLIENT_FILE_MONITOR_CLOSED,	     /* Session closed */
2068   SILC_CLIENT_FILE_MONITOR_DISCONNECT,	     /* Session disconnected */
2069   SILC_CLIENT_FILE_MONITOR_ERROR,	     /* Error during session */
2070 } SilcClientMonitorStatus;
2071 /***/
2072 
2073 /****d* silcclient/SilcClientAPI/SilcClientFileError
2074  *
2075  * NAME
2076  *
2077  *    typedef enum { ... } SilcClientFileError;
2078  *
2079  * DESCRIPTION
2080  *
2081  *    File transmission error types.  These types are returned by
2082  *    some of the file transmission functions, and by the monitor
2083  *    callback to indicate error.
2084  *
2085  * SOURCE
2086  */
2087 typedef enum {
2088   SILC_CLIENT_FILE_OK,
2089   SILC_CLIENT_FILE_ERROR,	             /* Generic error */
2090   SILC_CLIENT_FILE_UNKNOWN_SESSION,	     /* Unknown session ID */
2091   SILC_CLIENT_FILE_ALREADY_STARTED,	     /* Session already started */
2092   SILC_CLIENT_FILE_NO_SUCH_FILE,	     /* No such file */
2093   SILC_CLIENT_FILE_PERMISSION_DENIED,	     /* Permission denied */
2094   SILC_CLIENT_FILE_KEY_AGREEMENT_FAILED,     /* Key exchange failed */
2095   SILC_CLIENT_FILE_CONNECT_FAILED,	     /* Error during connecting */
2096   SILC_CLIENT_FILE_TIMEOUT,	             /* Connecting timedout */
2097   SILC_CLIENT_FILE_NO_MEMORY,		     /* System out of memory */
2098 } SilcClientFileError;
2099 /***/
2100 
2101 /****f* silcclient/SilcClientAPI/SilcClientFileMonitor
2102  *
2103  * SYNOPSIS
2104  *
2105  *    typedef void (*SilcClientFileMonitor)(SilcClient client,
2106  *                                          SilcClientConnection conn,
2107  *                                          SilcClientMonitorStatus status,
2108  *                                          SilcClientFileError error,
2109  *                                          SilcUInt64 offset,
2110  *                                          SilcUInt64 filesize,
2111  *                                          SilcClientEntry client_entry,
2112  *                                          SilcUInt32 session_id,
2113  *                                          const char *filepath,
2114  *                                          void *context);
2115  *
2116  * DESCRIPTION
2117  *
2118  *    Monitor callback that is called during the file transmission to
2119  *    monitor the transmission process.  The `status' indicates the current
2120  *    monitoring process.  The `error' will indicate the error type
2121  *    if `status' is SILC_CLIENT_FILE_MONITOR_ERROR.  The `offset' is the
2122  *    currently transmitted amount of total `filesize'.  The `client_entry'
2123  *    indicates the remote client, and the transmission session ID is the
2124  *    `session_id'.  The filename being transmitted is indicated by the
2125  *    `filepath'.  The `conn' is NULL if the connection to remote client
2126  *    does not exist yet.
2127  *
2128  ***/
2129 typedef void (*SilcClientFileMonitor)(SilcClient client,
2130 				      SilcClientConnection conn,
2131 				      SilcClientMonitorStatus status,
2132 				      SilcClientFileError error,
2133 				      SilcUInt64 offset,
2134 				      SilcUInt64 filesize,
2135 				      SilcClientEntry client_entry,
2136 				      SilcUInt32 session_id,
2137 				      const char *filepath,
2138 				      void *context);
2139 
2140 /****f* silcclient/SilcClientAPI/SilcClientFileName
2141  *
2142  * SYNOPSIS
2143  *
2144  *    typedef void (*SilcClientFileName)(const char *filepath,
2145  *                                       void *context);
2146  *
2147  * DESCRIPTION
2148  *
2149  *    Completion callback for the SilcClientFileAskName callback function.
2150  *    Application calls this to deliver the filepath and filename where
2151  *    the downloaded file is to be saved.
2152  *
2153  ***/
2154 typedef void (*SilcClientFileName)(const char *filepath,
2155 				   void *context);
2156 
2157 /****f* silcclient/SilcClientAPI/SilcClientFileAskName
2158  *
2159  * SYNOPSIS
2160  *
2161  *    typedef void (*SilcClientFileAskName)(SilcClient client,
2162  *                                          SilcClientConnection conn,
2163  *                                          SilcUInt32 session_id,
2164  *                                          const char *remote_filename,
2165  *                                          SilcClientFileName completion,
2166  *                                          void *completion_context,
2167  *                                          void *context);
2168  *
2169  * DESCRIPTION
2170  *
2171  *    File name asking callback that is called if it is given to the
2172  *    silc_client_file_receive and the path given to that as argument was
2173  *    NULL.  The library calls this to ask the filename and filepath to
2174  *    where the file is to be saved.  The 'remote_filename' is the file
2175  *    that is being downloaded.  Application must call the 'completion'
2176  *    with 'completion_context' to continue with the file downloading.
2177  *    It is not mandatory to provide this to the silc_client_file_receive.
2178  *
2179  ***/
2180 typedef void (*SilcClientFileAskName)(SilcClient client,
2181 				      SilcClientConnection conn,
2182 				      SilcUInt32 session_id,
2183 				      const char *remote_filename,
2184 				      SilcClientFileName completion,
2185 				      void *completion_context,
2186 				      void *context);
2187 
2188 /****f* silcclient/SilcClientAPI/silc_client_file_send
2189  *
2190  * SYNOPSIS
2191  *
2192  *    SilcClientFileError
2193  *    silc_client_file_send(SilcClient client,
2194  *                          SilcClientConnection conn,
2195  *                          SilcClientEntry client_entry,
2196  *                          SilcClientConnectionParams *params,
2197  *                          SilcPublicKey public_key,
2198  *                          SilcPrivateKey private_key,
2199  *                          SilcClientFileMonitor monitor,
2200  *                          void *monitor_context,
2201  *                          const char *filepath,
2202  *                          SilcUInt32 *session_id);
2203  *
2204  * DESCRIPTION
2205  *
2206  *    Sends a file indicated by the `filepath' to the remote client
2207  *    indicated by the `client_entry'.  This will negotiate a secret key
2208  *    with the remote client before actually starting the transmission of
2209  *    the file.  The `monitor' callback will be called to monitor the
2210  *    transmission of the file.
2211  *
2212  *    This returns a file session ID for the file transmission to the
2213  *    `session_id' pointer.  It can be used to close the session (and
2214  *    abort the file transmission) by calling the silc_client_file_close
2215  *    function.  The session ID is also returned in the `monitor' callback.
2216  *
2217  *    If `params' is non-NULL and it has the `local_ip' and `local_port' set
2218  *    the caller will provide the connection endpoint for the key agreement
2219  *    connection.  The `bind_ip' can be used to bind to that IP instead of
2220  *    `local_ip'.  Caller may also set the `repository', `verify_notfound'
2221  *    and `timeout_secs' fields in `params'.  Other fields are ignored.
2222  *    If `params' is NULL, then the `client_entry' is expected to provide
2223  *    the connection endpoint for us.  It is recommended the `timeout_secs'
2224  *    is specified in case the remote client does not reply anything to
2225  *    the request.
2226  *
2227  *    The `public_key' and `private_key' is our identity in the key agreement.
2228  *
2229  *    If error will occur during the file transfer process the error status
2230  *    will be returned in the monitor callback.  In this case the application
2231  *    must call silc_client_file_close to close the session.
2232  *
2233  ***/
2234 SilcClientFileError
2235 silc_client_file_send(SilcClient client,
2236 		      SilcClientConnection conn,
2237 		      SilcClientEntry client_entry,
2238 		      SilcClientConnectionParams *params,
2239 		      SilcPublicKey public_key,
2240 		      SilcPrivateKey private_key,
2241 		      SilcClientFileMonitor monitor,
2242 		      void *monitor_context,
2243 		      const char *filepath,
2244 		      SilcUInt32 *session_id);
2245 
2246 /****f* silcclient/SilcClientAPI/silc_client_file_receive
2247  *
2248  * SYNOPSIS
2249  *
2250  *    SilcClientFileError
2251  *    silc_client_file_receive(SilcClient client,
2252  *                             SilcClientConnection conn,
2253  *                             SilcClientConnectionParams *params,
2254  *                             SilcPublicKey public_key,
2255  *                             SilcPrivateKey private_key,
2256  *                             SilcClientFileMonitor monitor,
2257  *                             void *monitor_context,
2258  *                             const char *path,
2259  *                             SilcUInt32 session_id,
2260  *                             SilcClientFileAskName ask_name,
2261  *                             void *ask_name_context);
2262  *
2263  * DESCRIPTION
2264  *
2265  *    Receives a file from a client indicated by the `client_entry'.  The
2266  *    `session_id' indicates the file transmission session and it has been
2267  *    received in the `ftp' client operation callback.  This will actually
2268  *    perform the key agreement protocol with the remote client before
2269  *    actually starting the file transmission.  The `monitor' callback
2270  *    will be called to monitor the transmission.  If `path' is non-NULL
2271  *    the file will be saved into that directory.  If NULL the file is
2272  *    saved in the current working directory, unless the 'ask_name'
2273  *    callback is non-NULL.  In this case the callback is called to ask
2274  *    the path and filename from application.
2275  *
2276  *    The `params' is the connection related parameters.  If the remote client
2277  *    provided connection point the `params' will be used when creating
2278  *    connection to the remote client.  If remote client did not provide
2279  *    connection point the `params' is used to provide connection point
2280  *    locally for the remote client.  See silc_client_file_send for more
2281  *    information on providing connection point for remote client.
2282  *
2283  *    The `public_key' and `private_key' is our identity in the key agreement.
2284  *
2285  *    If error will occur during the file transfer process the error status
2286  *    will be returned in the monitor callback.  In this case the application
2287  *    must call silc_client_file_close to close the session.
2288  *
2289  ***/
2290 SilcClientFileError
2291 silc_client_file_receive(SilcClient client,
2292 			 SilcClientConnection conn,
2293 			 SilcClientConnectionParams *params,
2294 			 SilcPublicKey public_key,
2295 			 SilcPrivateKey private_key,
2296 			 SilcClientFileMonitor monitor,
2297 			 void *monitor_context,
2298 			 const char *path,
2299 			 SilcUInt32 session_id,
2300 			 SilcClientFileAskName ask_name,
2301 			 void *ask_name_context);
2302 
2303 /****f* silcclient/SilcClientAPI/silc_client_file_close
2304  *
2305  * SYNOPSIS
2306  *
2307  *    SilcClientFileError silc_client_file_close(SilcClient client,
2308  *                                               SilcClientConnection conn,
2309  *                                               SilcUInt32 session_id);
2310  *
2311  * DESCRIPTION
2312  *
2313  *    Closes file transmission session indicated by the `session_id'.
2314  *    If file transmission is being conducted it will be aborted
2315  *    automatically. This function is also used to close the session
2316  *    after successful file transmission. This function can be used
2317  *    also to reject incoming file transmission request.  If the
2318  *    session was already started and the monitor callback was set
2319  *    the monitor callback will be called with the monitor status
2320  *    SILC_CLIENT_FILE_MONITOR_CLOSED.
2321  *
2322  ***/
2323 SilcClientFileError silc_client_file_close(SilcClient client,
2324 					   SilcClientConnection conn,
2325 					   SilcUInt32 session_id);
2326 
2327 /****f* silcclient/SilcClientAPI/silc_client_attribute_add
2328  *
2329  * SYNOPSIS
2330  *
2331  *    SilcAttributePayload
2332  *    silc_client_attribute_add(SilcClient client,
2333  *                              SilcClientConnection conn,
2334  *                              SilcAttribute attribute,
2335  *                              void *object,
2336  *                              SilcUInt32 object_size);
2337  *
2338  * DESCRIPTION
2339  *
2340  *    Add new Requsted Attribute for WHOIS command to the client library.
2341  *    The `attribute' object indicated by `object' is added and allocated
2342  *    SilcAttributePayload is returned.  The `object' must be of correct
2343  *    type and of correct size.  See the SilcAttribute for object types
2344  *    for different attributes.  You may also get all added attributes
2345  *    from the client with silc_client_attributes_get function.
2346  *
2347  *    Requested Attributes are different personal information about the
2348  *    user, status information and other information which other users
2349  *    may query with WHOIS command.  Application may set these so that
2350  *    if someone sends WHOIS query these attributes will be replied back
2351  *    to the sender.  The library always puts the public key to the
2352  *    Requested Attributes, but if application wishes to add additional
2353  *    public keys (or certificates) it can be done with this interface.
2354  *    Library also always computes digital signature of the attributes
2355  *    automatically, so application does not need to do that.
2356  *
2357  ***/
2358 SilcAttributePayload silc_client_attribute_add(SilcClient client,
2359 					       SilcClientConnection conn,
2360 					       SilcAttribute attribute,
2361 					       void *object,
2362 					       SilcUInt32 object_size);
2363 
2364 /****f* silcclient/SilcClientAPI/silc_client_attribute_del
2365  *
2366  * SYNOPSIS
2367  *
2368  *    SilcBool silc_client_attribute_del(SilcClient client,
2369  *                                   SilcClientConnection conn,
2370  *                                   SilcAttribute attribute,
2371  *                                   SilcAttributePayload attr);
2372  *
2373  * DESCRIPTION
2374  *
2375  *    Delete a Requested Attribute from the client.  If the `attribute'
2376  *    is non-zero then all attributes of that type are deleted and the
2377  *    `attr' is ignored.  If `attr' is non-NULL then that specific
2378  *    attribute is deleted and `attribute' is ignored.
2379  *
2380  *    You may get all added attributes with the function
2381  *    silc_client_attributes_get and to get the SilcAttributePayload.
2382  *    This function Returns TRUE if the attribute was found and deleted.
2383  *
2384  ***/
2385 SilcBool silc_client_attribute_del(SilcClient client,
2386 				   SilcClientConnection conn,
2387 				   SilcAttribute attribute,
2388 				   SilcAttributePayload attr);
2389 
2390 /****f* silcclient/SilcClientAPI/silc_client_attributes_get
2391  *
2392  * SYNOPSIS
2393  *
2394  *    const SilcHashTable
2395  *    silc_client_attributes_get(SilcClient client,
2396  *                               SilcClientConnection conn);
2397  *
2398  * DESCRIPTION
2399  *
2400  *    Returns pointer to the SilcHashTable which includes all the added
2401  *    Requested Attributes.  The caller must not free the hash table.
2402  *    The caller may use SilcHashTableList and silc_hash_table_list to
2403  *    traverse the table.  Each entry in the hash table is one added
2404  *    SilcAttributePayload.  It is possible to delete a attribute
2405  *    payload while traversing the table.
2406  *
2407  ***/
2408 SilcHashTable silc_client_attributes_get(SilcClient client,
2409 					 SilcClientConnection conn);
2410 
2411 /****f* silcclient/SilcClientAPI/silc_client_attributes_request
2412  *
2413  * SYNOPSIS
2414  *
2415  *    SilcBuffer silc_client_attributes_request(SilcAttribute attribute, ...);
2416  *
2417  * DESCRIPTION
2418  *
2419  *    Constructs a Requested Attributes buffer. If the `attribute' is zero (0)
2420  *    then all attributes are requested.  Alternatively, `attribute' and
2421  *    all variable arguments can each be requested attribute.  In this case
2422  *    the last must be set to zero (0) to complete the variable list of
2423  *    requested attributes.  See SilcAttribute for all attributes.
2424  *    You can give the returned buffer as argument to for example
2425  *    silc_client_get_client_by_id_resolve function.
2426  *
2427  * EXAMPLE
2428  *
2429  *    Request all attributes
2430  *    buffer = silc_client_attributes_request(0);
2431  *
2432  *    Request only the following attributes
2433  *    buffer = silc_client_attributes_request(SILC_ATTRIBUTE_USER_INFO,
2434  *                                            SILC_ATTRIBUTE_SERVICE,
2435  *                                            SILC_ATTRIBUTE_MOOD, 0);
2436  *
2437  ***/
2438 SilcBuffer silc_client_attributes_request(SilcAttribute attribute, ...);
2439 
2440 /****f* silcclient/SilcClientAPI/silc_client_nickname_format
2441  *
2442  * SYNOPSIS
2443  *
2444  *    SilcClientEntry
2445  *    silc_client_nickname_format(SilcClient client,
2446  *                                SilcClientConnection conn,
2447  *                                SilcClientEntry client_entry,
2448  *                                SilcBool priority);
2449  *
2450  * DESCRIPTION
2451  *
2452  *    Formats the nickname of `client_entry' according to the nickname
2453  *    formatting rules set in SilcClientParams.  If the `priority' is TRUE
2454  *    then the `client_entry' will always get the unformatted nickname.
2455  *    If FALSE and there are more than one same nicknames in the client
2456  *    the nickname will be formatted.
2457  *
2458  *    This returns NULL on error.  Otherwise, the client entry that was
2459  *    formatted is returned.  If `priority' is FALSE this always returns
2460  *    the `client_entry'.  If it is TRUE, this may return the client entry
2461  *    that was formatted after giving the `client_entry' the unformatted
2462  *    nickname.
2463  *
2464  *    Usually application does not need to call this function, as the library
2465  *    automatically formats nicknames.  However, if application wants to
2466  *    for example force the `client_entry' to always have the unformatted
2467  *    nickname it may call this function to do so.
2468  *
2469  ***/
2470 SilcClientEntry silc_client_nickname_format(SilcClient client,
2471 					    SilcClientConnection conn,
2472 					    SilcClientEntry client_entry,
2473 					    SilcBool priority);
2474 
2475 /****f* silcclient/SilcClientAPI/silc_client_nickname_parse
2476  *
2477  * SYNOPSIS
2478  *
2479  *    SilcBool silc_client_nickname_parse(SilcClient client,
2480  *                                        SilcClientConnection conn,
2481  *                                        char *nickname,
2482  *                                        char **ret_nick);
2483  *
2484  * DESCRIPTION
2485  *
2486  *    Parses the `nickname' according to the format string given in the
2487  *    SilcClientParams.  Returns the parsed nickname into the `ret_nick'.
2488  *    The caller must free the returned pointer.  Returns FALSE if error
2489  *    occurred during parsing.  Returns TRUE if the nickname was parsed,
2490  *    it was not formatted or if the format string has not been specified
2491  *    in SilcClientParams.
2492  *
2493  ***/
2494 SilcBool silc_client_nickname_parse(SilcClient client,
2495 				    SilcClientConnection conn,
2496 				    char *nickname,
2497 				    char **ret_nick);
2498 
2499 #ifdef __cplusplus
2500 }
2501 #endif
2502 
2503 #endif /* SILCCLIENT_H */
2504