5 Author: Pekka Riikonen <priikone@silcnet.org>
7 Copyright (C) 2005 - 2007 Pekka Riikonen
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; version 2 of the License.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
21 #include "silcconnauth.h"
23 /************************** Types and definitions ***************************/
25 static SilcBool silc_connauth_packet_receive(SilcPacketEngine engine,
26 SilcPacketStream stream,
28 void *callback_context,
31 /* Connection authentication context */
32 struct SilcConnAuthStruct {
35 SilcAsyncOperationStruct op;
36 SilcConnectionType conn_type;
37 SilcAuthMethod auth_method;
39 SilcUInt32 auth_data_len;
40 SilcConnAuthCompletion completion;
41 SilcConnAuthGetAuthData get_auth_data;
43 SilcDList public_keys;
44 SilcSKRStatus skr_status;
45 SilcUInt32 timeout_secs;
47 unsigned int aborted : 1;
48 unsigned int success : 1;
51 /* Packet stream callbacks */
52 static SilcPacketCallbacks silc_connauth_stream_cbs =
54 silc_connauth_packet_receive, NULL, NULL
58 /************************ Static utility functions **************************/
62 static SilcBool silc_connauth_packet_receive(SilcPacketEngine engine,
63 SilcPacketStream stream,
65 void *callback_context,
68 SilcConnAuth connauth = callback_context;
69 connauth->packet = packet;
70 silc_fsm_continue(connauth->fsm);
74 /* Async operation abortion callback */
76 static void silc_connauth_abort(SilcAsyncOperation op, void *context)
78 SilcConnAuth connauth = context;
79 connauth->aborted = TRUE;
82 /* Generates signature for public key based authentication */
84 static SilcBool silc_connauth_get_signature(SilcConnAuth connauth,
85 unsigned char **auth_data,
86 SilcUInt32 *auth_data_len)
90 SilcPrivateKey private_key;
93 SILC_LOG_DEBUG(("Compute signature"));
96 private_key = connauth->auth_data;
98 /* Make the authentication data. Protocol says it is HASH plus
100 len = ske->hash_len + silc_buffer_len(ske->start_payload_copy);
101 auth = silc_buffer_alloc_size(len);
104 silc_buffer_format(auth,
105 SILC_STR_UI_XNSTRING(ske->hash, ske->hash_len),
106 SILC_STR_UI_XNSTRING(
107 ske->start_payload_copy->data,
108 silc_buffer_len(ske->start_payload_copy)),
111 len = ((silc_pkcs_private_key_get_len(private_key) + 7) / 8) + 1;
112 *auth_data = silc_calloc(len, sizeof(**auth_data));
113 if (*auth_data == NULL) {
114 silc_buffer_free(auth);
118 /* Compute signature */
119 if (!silc_pkcs_sign(private_key, auth->data, silc_buffer_len(auth),
120 *auth_data, len, auth_data_len, TRUE, ske->prop->hash)) {
121 silc_free(*auth_data);
122 silc_buffer_free(auth);
126 silc_buffer_free(auth);
130 /* Verifies digital signature */
132 static SilcBool silc_connauth_verify_signature(SilcConnAuth connauth,
133 SilcPublicKey pub_key,
139 SilcSKE ske = connauth->ske;
141 if (!pub_key || !sign)
144 /* Make the authentication data. Protocol says it is HASH plus
146 len = ske->hash_len + silc_buffer_len(ske->start_payload_copy);
147 auth = silc_buffer_alloc_size(len);
150 silc_buffer_format(auth,
151 SILC_STR_UI_XNSTRING(ske->hash, ske->hash_len),
152 SILC_STR_UI_XNSTRING(
153 ske->start_payload_copy->data,
154 silc_buffer_len(ske->start_payload_copy)),
157 /* Verify signature */
158 if (!silc_pkcs_verify(pub_key, sign, sign_len, auth->data,
159 silc_buffer_len(auth), ske->prop->hash)) {
160 silc_buffer_free(auth);
164 silc_buffer_free(auth);
171 SILC_TASK_CALLBACK(silc_connauth_timeout)
173 SilcConnAuth connauth = context;
174 SILC_LOG_DEBUG(("Protocol timeout"));
175 connauth->aborted = TRUE;
176 silc_fsm_continue_sync(connauth->fsm);
181 static void silc_connauth_skr_callback(SilcSKR skr, SilcSKRFind find,
182 SilcSKRStatus status,
183 SilcDList results, void *context)
185 SilcConnAuth connauth = context;
187 silc_skr_find_free(find);
189 connauth->public_keys = results;
190 connauth->skr_status = status;
192 SILC_FSM_CALL_CONTINUE(connauth->fsm);
197 static void silc_connauth_fsm_destructor(SilcFSM fsm, void *fsm_context,
198 void *destructor_context)
204 /******************************* Protocol API *******************************/
206 /* Allocate connection authentication context */
208 SilcConnAuth silc_connauth_alloc(SilcSchedule schedule,
210 SilcUInt32 timeout_secs)
212 SilcConnAuth connauth;
214 if (!schedule || !ske)
217 connauth = silc_calloc(1, sizeof(*connauth));
221 connauth->fsm = silc_fsm_alloc(connauth, silc_connauth_fsm_destructor,
223 if (!connauth->fsm) {
224 silc_connauth_free(connauth);
228 connauth->timeout_secs = timeout_secs;
235 /* Free connection authentication context */
237 void silc_connauth_free(SilcConnAuth connauth)
239 if (connauth->public_keys)
240 silc_dlist_uninit(connauth->public_keys);
243 silc_ske_free(connauth->ske);
248 /* Return associated SKE context */
250 SilcSKE silc_connauth_get_ske(SilcConnAuth connauth)
252 return connauth->ske;
256 /******************************** Initiator *********************************/
258 SILC_FSM_STATE(silc_connauth_st_initiator_start);
259 SILC_FSM_STATE(silc_connauth_st_initiator_result);
260 SILC_FSM_STATE(silc_connauth_st_initiator_failure);
262 SILC_FSM_STATE(silc_connauth_st_initiator_start)
264 SilcConnAuth connauth = fsm_context;
267 unsigned char *auth_data = NULL;
268 SilcUInt32 auth_data_len = 0;
269 SilcPacketFlags flags = 0;
271 SILC_LOG_DEBUG(("Start"));
273 if (connauth->aborted) {
275 silc_fsm_next(fsm, silc_connauth_st_initiator_failure);
276 return SILC_FSM_CONTINUE;
280 if (connauth->timeout_secs)
281 silc_schedule_task_add_timeout(silc_fsm_get_schedule(fsm),
282 silc_connauth_timeout, connauth,
283 connauth->timeout_secs, 0);
285 switch (connauth->auth_method) {
287 /* No authentication required */
290 case SILC_AUTH_PASSWORD:
291 auth_data = silc_memdup(connauth->auth_data, connauth->auth_data_len);
294 silc_fsm_next(fsm, silc_connauth_st_initiator_failure);
295 return SILC_FSM_CONTINUE;
297 auth_data_len = connauth->auth_data_len;
298 flags = SILC_PACKET_FLAG_LONG_PAD;
301 case SILC_AUTH_PUBLIC_KEY:
302 if (!silc_connauth_get_signature(connauth, &auth_data, &auth_data_len)) {
303 /** Error computing signature */
304 silc_fsm_next(fsm, silc_connauth_st_initiator_failure);
305 return SILC_FSM_CONTINUE;
310 payload_len = 4 + auth_data_len;
311 packet = silc_buffer_alloc_size(payload_len);
314 silc_fsm_next(fsm, silc_connauth_st_initiator_failure);
315 return SILC_FSM_CONTINUE;
318 silc_buffer_format(packet,
319 SILC_STR_UI_SHORT(payload_len),
320 SILC_STR_UI_SHORT(connauth->conn_type),
321 SILC_STR_UI_XNSTRING(auth_data, auth_data_len),
324 /* Send the packet */
325 if (!silc_packet_send(connauth->ske->stream, SILC_PACKET_CONNECTION_AUTH,
326 flags, packet->data, silc_buffer_len(packet))) {
327 /** Error sending packet */
328 silc_fsm_next(fsm, silc_connauth_st_initiator_failure);
329 return SILC_FSM_CONTINUE;
333 memset(auth_data, 0, auth_data_len);
334 silc_free(auth_data);
336 silc_buffer_free(packet);
338 /** Wait for responder */
339 silc_fsm_next(fsm, silc_connauth_st_initiator_result);
340 return SILC_FSM_WAIT;
343 SILC_FSM_STATE(silc_connauth_st_initiator_result)
345 SilcConnAuth connauth = fsm_context;
347 SILC_LOG_DEBUG(("Start"));
349 if (connauth->aborted) {
351 silc_fsm_next(fsm, silc_connauth_st_initiator_failure);
352 return SILC_FSM_CONTINUE;
355 /* Check the status of authentication */
356 if (connauth->packet->type == SILC_PACKET_SUCCESS) {
357 SILC_LOG_DEBUG(("Authentication successful"));
358 connauth->success = TRUE;
360 SILC_LOG_DEBUG(("Authentication failed"));
361 connauth->success = FALSE;
363 silc_packet_free(connauth->packet);
365 silc_packet_stream_unlink(connauth->ske->stream,
366 &silc_connauth_stream_cbs, connauth);
367 silc_schedule_task_del_by_context(silc_fsm_get_schedule(fsm), connauth);
369 /* Call completion callback */
370 connauth->completion(connauth, connauth->success, connauth->context);
372 return SILC_FSM_FINISH;
375 SILC_FSM_STATE(silc_connauth_st_initiator_failure)
377 SilcConnAuth connauth = fsm_context;
378 unsigned char error[4];
380 SILC_LOG_DEBUG(("Start"));
382 if (!connauth->aborted) {
383 /* Send FAILURE packet */
384 SILC_PUT32_MSB(SILC_AUTH_FAILED, error);
385 silc_packet_send(connauth->ske->stream, SILC_PACKET_FAILURE, 0, error, 4);
387 /* Call completion callback */
388 connauth->completion(connauth, FALSE, connauth->context);
391 silc_packet_stream_unlink(connauth->ske->stream,
392 &silc_connauth_stream_cbs, connauth);
393 silc_schedule_task_del_by_context(silc_fsm_get_schedule(fsm), connauth);
395 return SILC_FSM_FINISH;
399 silc_connauth_initiator(SilcConnAuth connauth,
400 SilcConnectionType conn_type,
401 SilcAuthMethod auth_method, void *auth_data,
402 SilcUInt32 auth_data_len,
403 SilcConnAuthCompletion completion,
406 SILC_LOG_DEBUG(("Connection authentication as initiator"));
408 if (auth_method == SILC_AUTH_PASSWORD && !auth_data) {
409 completion(connauth, FALSE, context);
413 if (auth_method == SILC_AUTH_PUBLIC_KEY && !auth_data) {
414 completion(connauth, FALSE, context);
418 connauth->conn_type = conn_type;
419 connauth->auth_method = auth_method;
420 connauth->auth_data = auth_data;
421 connauth->auth_data_len = auth_data_len;
422 connauth->completion = completion;
423 connauth->context = context;
425 /* Link to packet stream to get packets */
426 silc_packet_stream_link(connauth->ske->stream,
427 &silc_connauth_stream_cbs, connauth, 1000000,
429 SILC_PACKET_FAILURE, -1);
431 /* Start the protocol */
432 silc_async_init(&connauth->op, silc_connauth_abort, NULL, connauth);
433 silc_fsm_start(connauth->fsm, silc_connauth_st_initiator_start);
435 return &connauth->op;
439 /******************************** Responder *********************************/
441 SILC_FSM_STATE(silc_connauth_st_responder_start);
442 SILC_FSM_STATE(silc_connauth_st_responder_authenticate);
443 SILC_FSM_STATE(silc_connauth_st_responder_authenticate_pk);
444 SILC_FSM_STATE(silc_connauth_st_responder_success);
445 SILC_FSM_STATE(silc_connauth_st_responder_failure);
447 SILC_FSM_STATE(silc_connauth_st_responder_start)
449 SilcConnAuth connauth = fsm_context;
451 SILC_LOG_DEBUG(("Start"));
453 if (connauth->aborted) {
455 silc_fsm_next(fsm, silc_connauth_st_responder_failure);
456 return SILC_FSM_CONTINUE;
460 if (connauth->timeout_secs)
461 silc_schedule_task_add_timeout(silc_fsm_get_schedule(fsm),
462 silc_connauth_timeout, connauth,
463 connauth->timeout_secs, 0);
465 /** Wait for initiator */
466 silc_fsm_next(fsm, silc_connauth_st_responder_authenticate);
467 return SILC_FSM_WAIT;
470 SILC_FSM_STATE(silc_connauth_st_responder_authenticate)
472 SilcConnAuth connauth = fsm_context;
473 SilcUInt16 payload_len;
474 SilcUInt16 conn_type;
475 unsigned char *auth_data = NULL, *passphrase = NULL;
476 SilcUInt32 passphrase_len;
477 SilcSKR repository = NULL;
480 SILC_LOG_DEBUG(("Start"));
482 if (connauth->aborted) {
484 silc_packet_free(connauth->packet);
485 silc_fsm_next(fsm, silc_connauth_st_responder_failure);
486 return SILC_FSM_CONTINUE;
489 if (connauth->packet->type != SILC_PACKET_CONNECTION_AUTH) {
490 /** Protocol failure */
491 silc_packet_free(connauth->packet);
492 silc_fsm_next(fsm, silc_connauth_st_responder_failure);
493 return SILC_FSM_CONTINUE;
496 /* Parse the received authentication data packet. The received
497 payload is Connection Auth Payload. */
498 ret = silc_buffer_unformat(&connauth->packet->buffer,
499 SILC_STR_UI_SHORT(&payload_len),
500 SILC_STR_UI_SHORT(&conn_type),
504 SILC_LOG_ERROR(("Bad payload in authentication packet"));
505 silc_packet_free(connauth->packet);
506 silc_fsm_next(fsm, silc_connauth_st_responder_failure);
507 return SILC_FSM_CONTINUE;
510 if (payload_len != silc_buffer_len(&connauth->packet->buffer)) {
511 /** Bad payload length */
512 SILC_LOG_ERROR(("Bad payload length in authentication packet"));
513 silc_packet_free(connauth->packet);
514 silc_fsm_next(fsm, silc_connauth_st_responder_failure);
515 return SILC_FSM_CONTINUE;
520 if (conn_type < SILC_CONN_CLIENT || conn_type > SILC_CONN_ROUTER) {
521 /** Bad connection type */
522 SILC_LOG_ERROR(("Bad connection type (%d) in authentication packet",
524 silc_packet_free(connauth->packet);
525 silc_fsm_next(fsm, silc_connauth_st_responder_failure);
526 return SILC_FSM_CONTINUE;
529 if (payload_len > 0) {
530 /* Get authentication data */
531 ret = silc_buffer_unformat(&connauth->packet->buffer,
533 SILC_STR_UI_XNSTRING(&auth_data,
538 SILC_LOG_DEBUG(("Bad payload in authentication payload"));
539 silc_packet_free(connauth->packet);
540 silc_fsm_next(fsm, silc_connauth_st_responder_failure);
541 return SILC_FSM_CONTINUE;
544 silc_packet_free(connauth->packet);
546 SILC_LOG_DEBUG(("Remote connection type %d", conn_type));
548 /* Get authentication data */
549 if (!connauth->get_auth_data(connauth, conn_type, &passphrase,
550 &passphrase_len, &repository,
551 connauth->context)) {
552 /** Connection not configured */
553 SILC_LOG_ERROR(("Remote connection not configured"));
554 silc_fsm_next(fsm, silc_connauth_st_responder_failure);
555 return SILC_FSM_CONTINUE;
560 /* Passphrase authentication */
561 if (passphrase && passphrase_len) {
562 SILC_LOG_DEBUG(("Passphrase authentication"));
563 if (!memcmp(auth_data, passphrase, passphrase_len)) {
564 /** Authentication failed */
565 silc_fsm_next(fsm, silc_connauth_st_responder_failure);
566 return SILC_FSM_CONTINUE;
568 } else if (repository) {
569 /* Digital signature */
572 SILC_LOG_DEBUG(("Digital signature authentication"));
574 connauth->auth_data = silc_memdup(auth_data, payload_len);
575 connauth->auth_data_len = payload_len;
577 /* Allocate search constraints for finding the key */
578 find = silc_skr_find_alloc();
580 if (!find || !connauth->auth_data) {
582 silc_fsm_next(fsm, silc_connauth_st_responder_failure);
583 return SILC_FSM_CONTINUE;
586 silc_skr_find_set_pkcs_type(find, connauth->ske->pk_type);
587 silc_skr_find_set_public_key(find, connauth->ske->public_key);
588 silc_skr_find_set_usage(find, (SILC_SKR_USAGE_AUTH |
589 SILC_SKR_USAGE_KEY_AGREEMENT));
591 /** Find public key */
592 silc_fsm_next(fsm, silc_connauth_st_responder_authenticate_pk);
593 SILC_FSM_CALL(silc_skr_find(repository, find, silc_connauth_skr_callback,
598 /* Passphrase auth Ok, or no authentication required */
600 /** Authentication successful */
601 silc_fsm_next(fsm, silc_connauth_st_responder_success);
602 return SILC_FSM_CONTINUE;
605 SILC_FSM_STATE(silc_connauth_st_responder_authenticate_pk)
607 SilcConnAuth connauth = fsm_context;
610 if (connauth->aborted) {
612 silc_fsm_next(fsm, silc_connauth_st_responder_failure);
613 return SILC_FSM_CONTINUE;
616 if (connauth->skr_status != SILC_SKR_OK) {
617 /** Public key not found */
618 SILC_LOG_DEBUG(("Public key not found, error %d", connauth->skr_status));
619 silc_fsm_next(fsm, silc_connauth_st_responder_failure);
620 return SILC_FSM_CONTINUE;
623 SILC_LOG_DEBUG(("Found %d public keys",
624 silc_dlist_count(connauth->public_keys)));
626 /* Verify signature */
627 key = silc_dlist_get(connauth->public_keys);
628 if (!silc_connauth_verify_signature(connauth, key->key,
630 connauth->auth_data_len)) {
631 /** Invalid signature */
632 SILC_LOG_DEBUG(("Invalid signature"));
633 silc_free(connauth->auth_data);
634 silc_fsm_next(fsm, silc_connauth_st_responder_failure);
635 return SILC_FSM_CONTINUE;
638 silc_free(connauth->auth_data);
640 /** Authentication successful */
641 silc_fsm_next(fsm, silc_connauth_st_responder_success);
642 return SILC_FSM_CONTINUE;
645 SILC_FSM_STATE(silc_connauth_st_responder_success)
647 SilcConnAuth connauth = fsm_context;
648 unsigned char tmp[4];
650 SILC_LOG_DEBUG(("Authentication successful"));
652 /* Send FAILURE packet */
653 SILC_PUT32_MSB(SILC_AUTH_OK, tmp);
654 silc_packet_send(connauth->ske->stream, SILC_PACKET_SUCCESS, 0, tmp, 4);
656 /* Call completion callback */
657 connauth->completion(connauth, TRUE, connauth->context);
659 silc_packet_stream_unlink(connauth->ske->stream,
660 &silc_connauth_stream_cbs, connauth);
661 silc_schedule_task_del_by_context(silc_fsm_get_schedule(fsm), connauth);
663 return SILC_FSM_FINISH;
666 SILC_FSM_STATE(silc_connauth_st_responder_failure)
668 SilcConnAuth connauth = fsm_context;
669 unsigned char error[4];
671 SILC_LOG_ERROR(("Authentication failed"));
673 if (!connauth->aborted) {
674 /* Send FAILURE packet */
675 SILC_PUT32_MSB(SILC_AUTH_FAILED, error);
676 silc_packet_send(connauth->ske->stream, SILC_PACKET_FAILURE, 0, error, 4);
678 /* Call completion callback */
679 connauth->completion(connauth, FALSE, connauth->context);
682 silc_packet_stream_unlink(connauth->ske->stream,
683 &silc_connauth_stream_cbs, connauth);
684 silc_schedule_task_del_by_context(silc_fsm_get_schedule(fsm), connauth);
686 return SILC_FSM_FINISH;
690 silc_connauth_responder(SilcConnAuth connauth,
691 SilcConnAuthGetAuthData get_auth_data,
692 SilcConnAuthCompletion completion,
695 SILC_LOG_DEBUG(("Connection authentication as responder"));
697 connauth->get_auth_data = get_auth_data;
698 connauth->completion = completion;
699 connauth->context = context;
701 /* Link to packet stream to get packets */
702 silc_packet_stream_link(connauth->ske->stream,
703 &silc_connauth_stream_cbs, connauth, 1000000,
704 SILC_PACKET_CONNECTION_AUTH,
705 SILC_PACKET_FAILURE, -1);
707 /* Start the protocol */
708 silc_async_init(&connauth->op, silc_connauth_abort, NULL, connauth);
709 silc_fsm_start(connauth->fsm, silc_connauth_st_responder_start);
711 return &connauth->op;