5 Author: Pekka Riikonen <priikone@poseidon.pspt.fi>
7 Copyright (C) 1997 - 2000 Pekka Riikonen
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 2 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
21 * Client side of the protocols.
25 #include "clientlibincludes.h"
27 SILC_TASK_CALLBACK(silc_client_protocol_connection_auth);
28 SILC_TASK_CALLBACK(silc_client_protocol_key_exchange);
30 extern char *silc_version_string;
33 * Key Exhange protocol functions
36 /* Function that is called when SKE protocol sends packets to network. */
38 static void silc_client_protocol_ke_send_packet(SilcSKE ske,
43 SilcProtocol protocol = (SilcProtocol)context;
44 SilcClientKEInternalContext *ctx =
45 (SilcClientKEInternalContext *)protocol->context;
46 SilcClient client = (SilcClient)ctx->client;
48 /* Send the packet immediately */
49 silc_client_packet_send(client, ske->sock, type, NULL, 0, NULL, NULL,
50 packet->data, packet->len, TRUE);
54 /* Callback that is called when we have received KE2 payload from
55 responder. We try to verify the public key now. */
58 silc_client_protocol_ke_verify_key(SilcSKE ske,
59 unsigned char *pk_data,
61 SilcSKEPKType pk_type,
64 SilcProtocol protocol = (SilcProtocol)context;
65 SilcClientKEInternalContext *ctx =
66 (SilcClientKEInternalContext *)protocol->context;
67 SilcClient client = (SilcClient)ctx->client;
69 SILC_LOG_DEBUG(("Start"));
71 /* Verify server key from user. */
72 if (!client->ops->verify_server_key(client, ctx->sock->user_data,
73 pk_data, pk_len, pk_type))
74 return SILC_SKE_STATUS_UNSUPPORTED_PUBLIC_KEY;
76 return SILC_SKE_STATUS_OK;
79 /* Sets the negotiated key material into use for particular connection. */
81 static void silc_client_protocol_ke_set_keys(SilcSKE ske,
82 SilcSocketConnection sock,
83 SilcSKEKeyMaterial *keymat,
88 SilcClientConnection conn = (SilcClientConnection)sock->user_data;
91 SILC_LOG_DEBUG(("Setting new keys into use"));
93 /* Allocate cipher to be used in the communication */
94 silc_cipher_alloc(cipher->cipher->name, &conn->send_key);
95 silc_cipher_alloc(cipher->cipher->name, &conn->receive_key);
97 conn->send_key->cipher->set_key(conn->send_key->context,
100 conn->send_key->set_iv(conn->send_key, keymat->send_iv);
101 conn->receive_key->cipher->set_key(conn->receive_key->context,
102 keymat->receive_enc_key,
103 keymat->enc_key_len);
104 conn->receive_key->set_iv(conn->receive_key, keymat->receive_iv);
106 /* Allocate PKCS to be used */
108 /* XXX Do we ever need to allocate PKCS for the connection??
109 If yes, we need to change KE protocol to get the initiators
111 silc_pkcs_alloc(pkcs->pkcs->name, &conn->public_Key);
112 silc_pkcs_set_public_key(conn->public_key, ske->ke2_payload->pk_data,
113 ske->ke2_payload->pk_len);
116 /* Save HMAC key to be used in the communication. */
117 silc_hash_alloc(hash->hash->name, &nhash);
118 silc_hmac_alloc(nhash, &conn->hmac);
119 silc_hmac_set_key(conn->hmac, keymat->hmac_key, keymat->hmac_key_len);
124 SilcSKEStatus silc_ske_check_version(SilcSKE ske, unsigned char *version,
127 return SILC_SKE_STATUS_OK;
130 /* Performs key exchange protocol. This is used for both initiator
131 and responder key exchange. This may be called recursively. */
133 SILC_TASK_CALLBACK(silc_client_protocol_key_exchange)
135 SilcProtocol protocol = (SilcProtocol)context;
136 SilcClientKEInternalContext *ctx =
137 (SilcClientKEInternalContext *)protocol->context;
138 SilcClient client = (SilcClient)ctx->client;
139 SilcClientConnection conn = ctx->sock->user_data;
140 SilcSKEStatus status = 0;
142 SILC_LOG_DEBUG(("Start"));
144 if (protocol->state == SILC_PROTOCOL_STATE_UNKNOWN)
145 protocol->state = SILC_PROTOCOL_STATE_START;
147 switch(protocol->state) {
148 case SILC_PROTOCOL_STATE_START:
155 /* Allocate Key Exchange object */
156 ske = silc_ske_alloc();
158 ske->rng = client->rng;
160 if (ctx->responder == TRUE) {
162 SilcBuffer start_payload;
165 /* Start the key exchange by processing the received security
166 properties packet from initiator. */
167 status = silc_ske_responder_start(ske, ctx->rng, ctx->sock,
169 silc_client_protocol_ke_send_packet,
173 SilcSKEStartPayload *start_payload;
175 /* Assemble security properties. */
176 silc_ske_assemble_security_properties(ske, SILC_SKE_SP_FLAG_NONE,
180 /* Start the key exchange by sending our security properties
181 to the remote end. */
182 status = silc_ske_initiator_start(ske, ctx->rng, ctx->sock,
184 silc_client_protocol_ke_send_packet,
188 if (status != SILC_SKE_STATUS_OK) {
189 SILC_LOG_WARNING(("Error (type %d) during Key Exchange protocol",
191 SILC_LOG_DEBUG(("Error (type %d) during Key Exchange protocol",
194 protocol->state = SILC_PROTOCOL_STATE_ERROR;
195 protocol->execute(client->timeout_queue, 0, protocol, fd, 0, 0);
199 /* Advance the state of the protocol. */
208 if (ctx->responder == TRUE) {
211 silc_ske_responder_phase_1(ctx->ske,
212 ctx->ske->start_payload,
213 silc_server_protocol_ke_send_packet,
217 /* Call Phase-1 function. This processes the Key Exchange Start
218 paylaod reply we just got from the responder. The callback
219 function will receive the processed payload where we will
221 status = silc_ske_initiator_phase_1(ctx->ske, ctx->packet->buffer,
225 if (status != SILC_SKE_STATUS_OK) {
226 SILC_LOG_WARNING(("Error (type %d) during Key Exchange protocol",
228 SILC_LOG_DEBUG(("Error (type %d) during Key Exchange protocol",
231 protocol->state = SILC_PROTOCOL_STATE_ERROR;
232 protocol->execute(client->timeout_queue, 0, protocol, fd, 0, 0);
236 /* Advance the state of the protocol and call the next state. */
238 protocol->execute(client->timeout_queue, 0, protocol, fd, 0, 0);
246 if (ctx->responder == TRUE) {
249 silc_ske_responder_phase_2(ctx->ske,
250 ctx->ske->start_payload,
251 silc_server_protocol_ke_send_packet,
255 /* Call the Phase-2 function. This creates Diffie Hellman
256 key exchange parameters and sends our public part inside
257 Key Exhange 1 Payload to the responder. */
259 silc_ske_initiator_phase_2(ctx->ske,
261 silc_client_protocol_ke_send_packet,
265 if (status != SILC_SKE_STATUS_OK) {
266 SILC_LOG_WARNING(("Error (type %d) during Key Exchange protocol",
268 SILC_LOG_DEBUG(("Error (type %d) during Key Exchange protocol",
271 protocol->state = SILC_PROTOCOL_STATE_ERROR;
272 protocol->execute(client->timeout_queue, 0, protocol, fd, 0, 0);
276 /* Advance the state of the protocol. */
285 if (ctx->responder == TRUE) {
289 silc_ske_responder_phase_2(ctx->ske,
290 ctx->ske->start_payload,
291 silc_server_protocol_ke_send_packet,
295 /* Finish the protocol. This verifies the Key Exchange 2 payload
296 sent by responder. */
297 status = silc_ske_initiator_finish(ctx->ske, ctx->packet->buffer,
298 silc_client_protocol_ke_verify_key,
299 context, NULL, NULL);
302 if (status != SILC_SKE_STATUS_OK) {
304 if (status == SILC_SKE_STATUS_UNSUPPORTED_PUBLIC_KEY) {
305 client->ops->say(client, conn,
306 "Received unsupported server %s public key",
307 ctx->sock->hostname);
309 client->ops->say(client, conn,
310 "Error during key exchange protocol with server %s",
311 ctx->sock->hostname);
313 protocol->state = SILC_PROTOCOL_STATE_ERROR;
314 protocol->execute(client->timeout_queue, 0, protocol, fd, 0, 0);
318 /* Send Ok to the other end. We will end the protocol as server
319 sends Ok to us when we will take the new keys into use. */
320 silc_ske_end(ctx->ske, silc_client_protocol_ke_send_packet, context);
322 /* End the protocol on the next round */
323 protocol->state = SILC_PROTOCOL_STATE_END;
327 case SILC_PROTOCOL_STATE_END:
332 SilcSKEKeyMaterial *keymat;
334 /* Process the key material */
335 keymat = silc_calloc(1, sizeof(*keymat));
336 silc_ske_process_key_material(ctx->ske, 16, (16 * 8), 16, keymat);
338 /* Take the negotiated keys into use. */
339 silc_client_protocol_ke_set_keys(ctx->ske, ctx->sock, keymat,
340 ctx->ske->prop->cipher,
341 ctx->ske->prop->pkcs,
342 ctx->ske->prop->hash);
344 /* Protocol has ended, call the final callback */
345 if (protocol->final_callback)
346 protocol->execute_final(client->timeout_queue, 0, protocol, fd);
348 silc_protocol_free(protocol);
352 case SILC_PROTOCOL_STATE_ERROR:
354 * Error during protocol
357 /* Send abort notification */
358 silc_ske_abort(ctx->ske, ctx->ske->status,
359 silc_client_protocol_ke_send_packet,
362 /* On error the final callback is always called. */
363 if (protocol->final_callback)
364 protocol->execute_final(client->timeout_queue, 0, protocol, fd);
366 silc_protocol_free(protocol);
369 case SILC_PROTOCOL_STATE_FAILURE:
371 * Received failure from remote.
374 /* On error the final callback is always called. */
375 if (protocol->final_callback)
376 protocol->execute_final(client->timeout_queue, 0, protocol, fd);
378 silc_protocol_free(protocol);
380 case SILC_PROTOCOL_STATE_UNKNOWN:
386 * Connection Authentication protocol functions
389 SILC_TASK_CALLBACK(silc_client_protocol_connection_auth)
391 SilcProtocol protocol = (SilcProtocol)context;
392 SilcClientConnAuthInternalContext *ctx =
393 (SilcClientConnAuthInternalContext *)protocol->context;
394 SilcClient client = (SilcClient)ctx->client;
395 SilcClientConnection conn = ctx->sock->user_data;
397 SILC_LOG_DEBUG(("Start"));
399 if (protocol->state == SILC_PROTOCOL_STATE_UNKNOWN)
400 protocol->state = SILC_PROTOCOL_STATE_START;
402 switch(protocol->state) {
403 case SILC_PROTOCOL_STATE_START:
406 * Start protocol. We send authentication data to the server
407 * to be authenticated.
411 unsigned char *auth_data = NULL;
412 unsigned int auth_data_len = 0;
414 switch(ctx->auth_meth) {
415 case SILC_PROTOCOL_CONN_AUTH_NONE:
416 /* No authentication required */
419 case SILC_PROTOCOL_CONN_AUTH_PASSWORD:
420 /* Password authentication */
421 if (ctx->auth_data && ctx->auth_data_len) {
422 auth_data = ctx->auth_data;
423 auth_data_len = ctx->auth_data_len;
427 client->ops->say(client, conn,
428 "Password authentication required by server %s",
429 ctx->sock->hostname);
430 auth_data = client->ops->ask_passphrase(client, conn);
431 auth_data_len = strlen(auth_data);
434 case SILC_PROTOCOL_CONN_AUTH_PUBLIC_KEY:
439 payload_len = 4 + auth_data_len;
440 packet = silc_buffer_alloc(payload_len);
441 silc_buffer_pull_tail(packet, SILC_BUFFER_END(packet));
442 silc_buffer_format(packet,
443 SILC_STR_UI_SHORT(payload_len),
444 SILC_STR_UI_SHORT(SILC_SOCKET_TYPE_CLIENT),
445 SILC_STR_UI_XNSTRING(auth_data, auth_data_len),
448 /* Send the packet to server */
449 silc_client_packet_send(client, ctx->sock,
450 SILC_PACKET_CONNECTION_AUTH,
452 packet->data, packet->len, TRUE);
455 memset(auth_data, 0, auth_data_len);
456 silc_free(auth_data);
458 silc_buffer_free(packet);
460 /* Next state is end of protocol */
461 protocol->state = SILC_PROTOCOL_STATE_END;
465 case SILC_PROTOCOL_STATE_END:
468 * End protocol. Nothing special to be done here.
471 /* Protocol has ended, call the final callback */
472 if (protocol->final_callback)
473 protocol->execute_final(client->timeout_queue, 0, protocol, fd);
475 silc_protocol_free(protocol);
479 case SILC_PROTOCOL_STATE_ERROR:
482 * Error. Send notify to remote.
484 unsigned char error[4];
486 SILC_PUT32_MSB(SILC_CONN_AUTH_FAILED, error);
488 /* Error in protocol. Send FAILURE packet. Although I don't think
489 this could ever happen on client side. */
490 silc_client_packet_send(client, ctx->sock, SILC_PACKET_FAILURE,
491 NULL, 0, NULL, NULL, error, 4, TRUE);
493 /* On error the final callback is always called. */
494 if (protocol->final_callback)
495 protocol->execute_final(client->timeout_queue, 0, protocol, fd);
497 silc_protocol_free(protocol);
500 case SILC_PROTOCOL_STATE_FAILURE:
502 * Received failure from remote.
505 /* On error the final callback is always called. */
506 if (protocol->final_callback)
507 protocol->execute_final(client->timeout_queue, 0, protocol, fd);
509 silc_protocol_free(protocol);
512 case SILC_PROTOCOL_STATE_UNKNOWN:
517 /* Registers protocols used in client */
519 void silc_client_protocols_register(void)
521 silc_protocol_register(SILC_PROTOCOL_CLIENT_CONNECTION_AUTH,
522 silc_client_protocol_connection_auth);
523 silc_protocol_register(SILC_PROTOCOL_CLIENT_KEY_EXCHANGE,
524 silc_client_protocol_key_exchange);
527 /* Unregisters protocols */
529 void silc_client_protocols_unregister(void)
531 silc_protocol_unregister(SILC_PROTOCOL_CLIENT_CONNECTION_AUTH,
532 silc_client_protocol_connection_auth);
533 silc_protocol_unregister(SILC_PROTOCOL_CLIENT_KEY_EXCHANGE,
534 silc_client_protocol_key_exchange);