xref: /freebsd/crypto/openssh/authfd.c (revision 586f63035fbe5e45cfc971037fd76375661ece26)
1 /* $OpenBSD: authfd.c,v 1.86 2011/07/06 18:09:21 tedu Exp $ */
2 /*
3  * Author: Tatu Ylonen <ylo@cs.hut.fi>
4  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5  *                    All rights reserved
6  * Functions for connecting the local authentication agent.
7  *
8  * As far as I am concerned, the code I have written for this software
9  * can be used freely for any purpose.  Any derived versions of this
10  * software must be clearly marked as such, and if the derived work is
11  * incompatible with the protocol description in the RFC file, it must be
12  * called by a name other than "ssh" or "Secure Shell".
13  *
14  * SSH2 implementation,
15  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
16  *
17  * Redistribution and use in source and binary forms, with or without
18  * modification, are permitted provided that the following conditions
19  * are met:
20  * 1. Redistributions of source code must retain the above copyright
21  *    notice, this list of conditions and the following disclaimer.
22  * 2. Redistributions in binary form must reproduce the above copyright
23  *    notice, this list of conditions and the following disclaimer in the
24  *    documentation and/or other materials provided with the distribution.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
27  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
28  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
29  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
30  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
31  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
32  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
33  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
35  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36  */
37 
38 #include "includes.h"
39 
40 #include <sys/types.h>
41 #include <sys/un.h>
42 #include <sys/socket.h>
43 
44 #include <openssl/evp.h>
45 
46 #include <openssl/crypto.h>
47 #include <fcntl.h>
48 #include <stdlib.h>
49 #include <signal.h>
50 #include <stdarg.h>
51 #include <string.h>
52 #include <unistd.h>
53 
54 #include "xmalloc.h"
55 #include "ssh.h"
56 #include "rsa.h"
57 #include "buffer.h"
58 #include "key.h"
59 #include "authfd.h"
60 #include "cipher.h"
61 #include "kex.h"
62 #include "compat.h"
63 #include "log.h"
64 #include "atomicio.h"
65 #include "misc.h"
66 
67 static int agent_present = 0;
68 
69 /* helper */
70 int	decode_reply(int type);
71 
72 /* macro to check for "agent failure" message */
73 #define agent_failed(x) \
74     ((x == SSH_AGENT_FAILURE) || (x == SSH_COM_AGENT2_FAILURE) || \
75     (x == SSH2_AGENT_FAILURE))
76 
77 int
78 ssh_agent_present(void)
79 {
80 	int authfd;
81 
82 	if (agent_present)
83 		return 1;
84 	if ((authfd = ssh_get_authentication_socket()) == -1)
85 		return 0;
86 	else {
87 		ssh_close_authentication_socket(authfd);
88 		return 1;
89 	}
90 }
91 
92 /* Returns the number of the authentication fd, or -1 if there is none. */
93 
94 int
95 ssh_get_authentication_socket(void)
96 {
97 	const char *authsocket;
98 	int sock;
99 	struct sockaddr_un sunaddr;
100 
101 	authsocket = getenv(SSH_AUTHSOCKET_ENV_NAME);
102 	if (!authsocket)
103 		return -1;
104 
105 	bzero(&sunaddr, sizeof(sunaddr));
106 	sunaddr.sun_family = AF_UNIX;
107 	strlcpy(sunaddr.sun_path, authsocket, sizeof(sunaddr.sun_path));
108 
109 	sock = socket(AF_UNIX, SOCK_STREAM, 0);
110 	if (sock < 0)
111 		return -1;
112 
113 	/* close on exec */
114 	if (fcntl(sock, F_SETFD, FD_CLOEXEC) == -1) {
115 		close(sock);
116 		return -1;
117 	}
118 	if (connect(sock, (struct sockaddr *)&sunaddr, sizeof sunaddr) < 0) {
119 		close(sock);
120 		return -1;
121 	}
122 	agent_present = 1;
123 	return sock;
124 }
125 
126 static int
127 ssh_request_reply(AuthenticationConnection *auth, Buffer *request, Buffer *reply)
128 {
129 	u_int l, len;
130 	char buf[1024];
131 
132 	/* Get the length of the message, and format it in the buffer. */
133 	len = buffer_len(request);
134 	put_u32(buf, len);
135 
136 	/* Send the length and then the packet to the agent. */
137 	if (atomicio(vwrite, auth->fd, buf, 4) != 4 ||
138 	    atomicio(vwrite, auth->fd, buffer_ptr(request),
139 	    buffer_len(request)) != buffer_len(request)) {
140 		error("Error writing to authentication socket.");
141 		return 0;
142 	}
143 	/*
144 	 * Wait for response from the agent.  First read the length of the
145 	 * response packet.
146 	 */
147 	if (atomicio(read, auth->fd, buf, 4) != 4) {
148 	    error("Error reading response length from authentication socket.");
149 	    return 0;
150 	}
151 
152 	/* Extract the length, and check it for sanity. */
153 	len = get_u32(buf);
154 	if (len > 256 * 1024)
155 		fatal("Authentication response too long: %u", len);
156 
157 	/* Read the rest of the response in to the buffer. */
158 	buffer_clear(reply);
159 	while (len > 0) {
160 		l = len;
161 		if (l > sizeof(buf))
162 			l = sizeof(buf);
163 		if (atomicio(read, auth->fd, buf, l) != l) {
164 			error("Error reading response from authentication socket.");
165 			return 0;
166 		}
167 		buffer_append(reply, buf, l);
168 		len -= l;
169 	}
170 	return 1;
171 }
172 
173 /*
174  * Closes the agent socket if it should be closed (depends on how it was
175  * obtained).  The argument must have been returned by
176  * ssh_get_authentication_socket().
177  */
178 
179 void
180 ssh_close_authentication_socket(int sock)
181 {
182 	if (getenv(SSH_AUTHSOCKET_ENV_NAME))
183 		close(sock);
184 }
185 
186 /*
187  * Opens and connects a private socket for communication with the
188  * authentication agent.  Returns the file descriptor (which must be
189  * shut down and closed by the caller when no longer needed).
190  * Returns NULL if an error occurred and the connection could not be
191  * opened.
192  */
193 
194 AuthenticationConnection *
195 ssh_get_authentication_connection(void)
196 {
197 	AuthenticationConnection *auth;
198 	int sock;
199 
200 	sock = ssh_get_authentication_socket();
201 
202 	/*
203 	 * Fail if we couldn't obtain a connection.  This happens if we
204 	 * exited due to a timeout.
205 	 */
206 	if (sock < 0)
207 		return NULL;
208 
209 	auth = xmalloc(sizeof(*auth));
210 	auth->fd = sock;
211 	buffer_init(&auth->identities);
212 	auth->howmany = 0;
213 
214 	return auth;
215 }
216 
217 /*
218  * Closes the connection to the authentication agent and frees any associated
219  * memory.
220  */
221 
222 void
223 ssh_close_authentication_connection(AuthenticationConnection *auth)
224 {
225 	buffer_free(&auth->identities);
226 	close(auth->fd);
227 	xfree(auth);
228 }
229 
230 /* Lock/unlock agent */
231 int
232 ssh_lock_agent(AuthenticationConnection *auth, int lock, const char *password)
233 {
234 	int type;
235 	Buffer msg;
236 
237 	buffer_init(&msg);
238 	buffer_put_char(&msg, lock ? SSH_AGENTC_LOCK : SSH_AGENTC_UNLOCK);
239 	buffer_put_cstring(&msg, password);
240 
241 	if (ssh_request_reply(auth, &msg, &msg) == 0) {
242 		buffer_free(&msg);
243 		return 0;
244 	}
245 	type = buffer_get_char(&msg);
246 	buffer_free(&msg);
247 	return decode_reply(type);
248 }
249 
250 /*
251  * Returns the first authentication identity held by the agent.
252  */
253 
254 int
255 ssh_get_num_identities(AuthenticationConnection *auth, int version)
256 {
257 	int type, code1 = 0, code2 = 0;
258 	Buffer request;
259 
260 	switch (version) {
261 	case 1:
262 		code1 = SSH_AGENTC_REQUEST_RSA_IDENTITIES;
263 		code2 = SSH_AGENT_RSA_IDENTITIES_ANSWER;
264 		break;
265 	case 2:
266 		code1 = SSH2_AGENTC_REQUEST_IDENTITIES;
267 		code2 = SSH2_AGENT_IDENTITIES_ANSWER;
268 		break;
269 	default:
270 		return 0;
271 	}
272 
273 	/*
274 	 * Send a message to the agent requesting for a list of the
275 	 * identities it can represent.
276 	 */
277 	buffer_init(&request);
278 	buffer_put_char(&request, code1);
279 
280 	buffer_clear(&auth->identities);
281 	if (ssh_request_reply(auth, &request, &auth->identities) == 0) {
282 		buffer_free(&request);
283 		return 0;
284 	}
285 	buffer_free(&request);
286 
287 	/* Get message type, and verify that we got a proper answer. */
288 	type = buffer_get_char(&auth->identities);
289 	if (agent_failed(type)) {
290 		return 0;
291 	} else if (type != code2) {
292 		fatal("Bad authentication reply message type: %d", type);
293 	}
294 
295 	/* Get the number of entries in the response and check it for sanity. */
296 	auth->howmany = buffer_get_int(&auth->identities);
297 	if ((u_int)auth->howmany > 1024)
298 		fatal("Too many identities in authentication reply: %d",
299 		    auth->howmany);
300 
301 	return auth->howmany;
302 }
303 
304 Key *
305 ssh_get_first_identity(AuthenticationConnection *auth, char **comment, int version)
306 {
307 	/* get number of identities and return the first entry (if any). */
308 	if (ssh_get_num_identities(auth, version) > 0)
309 		return ssh_get_next_identity(auth, comment, version);
310 	return NULL;
311 }
312 
313 Key *
314 ssh_get_next_identity(AuthenticationConnection *auth, char **comment, int version)
315 {
316 	int keybits;
317 	u_int bits;
318 	u_char *blob;
319 	u_int blen;
320 	Key *key = NULL;
321 
322 	/* Return failure if no more entries. */
323 	if (auth->howmany <= 0)
324 		return NULL;
325 
326 	/*
327 	 * Get the next entry from the packet.  These will abort with a fatal
328 	 * error if the packet is too short or contains corrupt data.
329 	 */
330 	switch (version) {
331 	case 1:
332 		key = key_new(KEY_RSA1);
333 		bits = buffer_get_int(&auth->identities);
334 		buffer_get_bignum(&auth->identities, key->rsa->e);
335 		buffer_get_bignum(&auth->identities, key->rsa->n);
336 		*comment = buffer_get_string(&auth->identities, NULL);
337 		keybits = BN_num_bits(key->rsa->n);
338 		if (keybits < 0 || bits != (u_int)keybits)
339 			logit("Warning: identity keysize mismatch: actual %d, announced %u",
340 			    BN_num_bits(key->rsa->n), bits);
341 		break;
342 	case 2:
343 		blob = buffer_get_string(&auth->identities, &blen);
344 		*comment = buffer_get_string(&auth->identities, NULL);
345 		key = key_from_blob(blob, blen);
346 		xfree(blob);
347 		break;
348 	default:
349 		return NULL;
350 	}
351 	/* Decrement the number of remaining entries. */
352 	auth->howmany--;
353 	return key;
354 }
355 
356 /*
357  * Generates a random challenge, sends it to the agent, and waits for
358  * response from the agent.  Returns true (non-zero) if the agent gave the
359  * correct answer, zero otherwise.  Response type selects the style of
360  * response desired, with 0 corresponding to protocol version 1.0 (no longer
361  * supported) and 1 corresponding to protocol version 1.1.
362  */
363 
364 int
365 ssh_decrypt_challenge(AuthenticationConnection *auth,
366     Key* key, BIGNUM *challenge,
367     u_char session_id[16],
368     u_int response_type,
369     u_char response[16])
370 {
371 	Buffer buffer;
372 	int success = 0;
373 	int i;
374 	int type;
375 
376 	if (key->type != KEY_RSA1)
377 		return 0;
378 	if (response_type == 0) {
379 		logit("Compatibility with ssh protocol version 1.0 no longer supported.");
380 		return 0;
381 	}
382 	buffer_init(&buffer);
383 	buffer_put_char(&buffer, SSH_AGENTC_RSA_CHALLENGE);
384 	buffer_put_int(&buffer, BN_num_bits(key->rsa->n));
385 	buffer_put_bignum(&buffer, key->rsa->e);
386 	buffer_put_bignum(&buffer, key->rsa->n);
387 	buffer_put_bignum(&buffer, challenge);
388 	buffer_append(&buffer, session_id, 16);
389 	buffer_put_int(&buffer, response_type);
390 
391 	if (ssh_request_reply(auth, &buffer, &buffer) == 0) {
392 		buffer_free(&buffer);
393 		return 0;
394 	}
395 	type = buffer_get_char(&buffer);
396 
397 	if (agent_failed(type)) {
398 		logit("Agent admitted failure to authenticate using the key.");
399 	} else if (type != SSH_AGENT_RSA_RESPONSE) {
400 		fatal("Bad authentication response: %d", type);
401 	} else {
402 		success = 1;
403 		/*
404 		 * Get the response from the packet.  This will abort with a
405 		 * fatal error if the packet is corrupt.
406 		 */
407 		for (i = 0; i < 16; i++)
408 			response[i] = (u_char)buffer_get_char(&buffer);
409 	}
410 	buffer_free(&buffer);
411 	return success;
412 }
413 
414 /* ask agent to sign data, returns -1 on error, 0 on success */
415 int
416 ssh_agent_sign(AuthenticationConnection *auth,
417     Key *key,
418     u_char **sigp, u_int *lenp,
419     u_char *data, u_int datalen)
420 {
421 	extern int datafellows;
422 	Buffer msg;
423 	u_char *blob;
424 	u_int blen;
425 	int type, flags = 0;
426 	int ret = -1;
427 
428 	if (key_to_blob(key, &blob, &blen) == 0)
429 		return -1;
430 
431 	if (datafellows & SSH_BUG_SIGBLOB)
432 		flags = SSH_AGENT_OLD_SIGNATURE;
433 
434 	buffer_init(&msg);
435 	buffer_put_char(&msg, SSH2_AGENTC_SIGN_REQUEST);
436 	buffer_put_string(&msg, blob, blen);
437 	buffer_put_string(&msg, data, datalen);
438 	buffer_put_int(&msg, flags);
439 	xfree(blob);
440 
441 	if (ssh_request_reply(auth, &msg, &msg) == 0) {
442 		buffer_free(&msg);
443 		return -1;
444 	}
445 	type = buffer_get_char(&msg);
446 	if (agent_failed(type)) {
447 		logit("Agent admitted failure to sign using the key.");
448 	} else if (type != SSH2_AGENT_SIGN_RESPONSE) {
449 		fatal("Bad authentication response: %d", type);
450 	} else {
451 		ret = 0;
452 		*sigp = buffer_get_string(&msg, lenp);
453 	}
454 	buffer_free(&msg);
455 	return ret;
456 }
457 
458 /* Encode key for a message to the agent. */
459 
460 static void
461 ssh_encode_identity_rsa1(Buffer *b, RSA *key, const char *comment)
462 {
463 	buffer_put_int(b, BN_num_bits(key->n));
464 	buffer_put_bignum(b, key->n);
465 	buffer_put_bignum(b, key->e);
466 	buffer_put_bignum(b, key->d);
467 	/* To keep within the protocol: p < q for ssh. in SSL p > q */
468 	buffer_put_bignum(b, key->iqmp);	/* ssh key->u */
469 	buffer_put_bignum(b, key->q);	/* ssh key->p, SSL key->q */
470 	buffer_put_bignum(b, key->p);	/* ssh key->q, SSL key->p */
471 	buffer_put_cstring(b, comment);
472 }
473 
474 static void
475 ssh_encode_identity_ssh2(Buffer *b, Key *key, const char *comment)
476 {
477 	buffer_put_cstring(b, key_ssh_name(key));
478 	switch (key->type) {
479 	case KEY_RSA:
480 		buffer_put_bignum2(b, key->rsa->n);
481 		buffer_put_bignum2(b, key->rsa->e);
482 		buffer_put_bignum2(b, key->rsa->d);
483 		buffer_put_bignum2(b, key->rsa->iqmp);
484 		buffer_put_bignum2(b, key->rsa->p);
485 		buffer_put_bignum2(b, key->rsa->q);
486 		break;
487 	case KEY_RSA_CERT_V00:
488 	case KEY_RSA_CERT:
489 		if (key->cert == NULL || buffer_len(&key->cert->certblob) == 0)
490 			fatal("%s: no cert/certblob", __func__);
491 		buffer_put_string(b, buffer_ptr(&key->cert->certblob),
492 		    buffer_len(&key->cert->certblob));
493 		buffer_put_bignum2(b, key->rsa->d);
494 		buffer_put_bignum2(b, key->rsa->iqmp);
495 		buffer_put_bignum2(b, key->rsa->p);
496 		buffer_put_bignum2(b, key->rsa->q);
497 		break;
498 	case KEY_DSA:
499 		buffer_put_bignum2(b, key->dsa->p);
500 		buffer_put_bignum2(b, key->dsa->q);
501 		buffer_put_bignum2(b, key->dsa->g);
502 		buffer_put_bignum2(b, key->dsa->pub_key);
503 		buffer_put_bignum2(b, key->dsa->priv_key);
504 		break;
505 	case KEY_DSA_CERT_V00:
506 	case KEY_DSA_CERT:
507 		if (key->cert == NULL || buffer_len(&key->cert->certblob) == 0)
508 			fatal("%s: no cert/certblob", __func__);
509 		buffer_put_string(b, buffer_ptr(&key->cert->certblob),
510 		    buffer_len(&key->cert->certblob));
511 		buffer_put_bignum2(b, key->dsa->priv_key);
512 		break;
513 #ifdef OPENSSL_HAS_ECC
514 	case KEY_ECDSA:
515 		buffer_put_cstring(b, key_curve_nid_to_name(key->ecdsa_nid));
516 		buffer_put_ecpoint(b, EC_KEY_get0_group(key->ecdsa),
517 		    EC_KEY_get0_public_key(key->ecdsa));
518 		buffer_put_bignum2(b, EC_KEY_get0_private_key(key->ecdsa));
519 		break;
520 	case KEY_ECDSA_CERT:
521 		if (key->cert == NULL || buffer_len(&key->cert->certblob) == 0)
522 			fatal("%s: no cert/certblob", __func__);
523 		buffer_put_string(b, buffer_ptr(&key->cert->certblob),
524 		    buffer_len(&key->cert->certblob));
525 		buffer_put_bignum2(b, EC_KEY_get0_private_key(key->ecdsa));
526 		break;
527 #endif
528 	}
529 	buffer_put_cstring(b, comment);
530 }
531 
532 /*
533  * Adds an identity to the authentication server.  This call is not meant to
534  * be used by normal applications.
535  */
536 
537 int
538 ssh_add_identity_constrained(AuthenticationConnection *auth, Key *key,
539     const char *comment, u_int life, u_int confirm)
540 {
541 	Buffer msg;
542 	int type, constrained = (life || confirm);
543 
544 	buffer_init(&msg);
545 
546 	switch (key->type) {
547 	case KEY_RSA1:
548 		type = constrained ?
549 		    SSH_AGENTC_ADD_RSA_ID_CONSTRAINED :
550 		    SSH_AGENTC_ADD_RSA_IDENTITY;
551 		buffer_put_char(&msg, type);
552 		ssh_encode_identity_rsa1(&msg, key->rsa, comment);
553 		break;
554 	case KEY_RSA:
555 	case KEY_RSA_CERT:
556 	case KEY_RSA_CERT_V00:
557 	case KEY_DSA:
558 	case KEY_DSA_CERT:
559 	case KEY_DSA_CERT_V00:
560 	case KEY_ECDSA:
561 	case KEY_ECDSA_CERT:
562 		type = constrained ?
563 		    SSH2_AGENTC_ADD_ID_CONSTRAINED :
564 		    SSH2_AGENTC_ADD_IDENTITY;
565 		buffer_put_char(&msg, type);
566 		ssh_encode_identity_ssh2(&msg, key, comment);
567 		break;
568 	default:
569 		buffer_free(&msg);
570 		return 0;
571 	}
572 	if (constrained) {
573 		if (life != 0) {
574 			buffer_put_char(&msg, SSH_AGENT_CONSTRAIN_LIFETIME);
575 			buffer_put_int(&msg, life);
576 		}
577 		if (confirm != 0)
578 			buffer_put_char(&msg, SSH_AGENT_CONSTRAIN_CONFIRM);
579 	}
580 	if (ssh_request_reply(auth, &msg, &msg) == 0) {
581 		buffer_free(&msg);
582 		return 0;
583 	}
584 	type = buffer_get_char(&msg);
585 	buffer_free(&msg);
586 	return decode_reply(type);
587 }
588 
589 /*
590  * Removes an identity from the authentication server.  This call is not
591  * meant to be used by normal applications.
592  */
593 
594 int
595 ssh_remove_identity(AuthenticationConnection *auth, Key *key)
596 {
597 	Buffer msg;
598 	int type;
599 	u_char *blob;
600 	u_int blen;
601 
602 	buffer_init(&msg);
603 
604 	if (key->type == KEY_RSA1) {
605 		buffer_put_char(&msg, SSH_AGENTC_REMOVE_RSA_IDENTITY);
606 		buffer_put_int(&msg, BN_num_bits(key->rsa->n));
607 		buffer_put_bignum(&msg, key->rsa->e);
608 		buffer_put_bignum(&msg, key->rsa->n);
609 	} else if (key_type_plain(key->type) == KEY_DSA ||
610 	    key_type_plain(key->type) == KEY_RSA ||
611 	    key_type_plain(key->type) == KEY_ECDSA) {
612 		key_to_blob(key, &blob, &blen);
613 		buffer_put_char(&msg, SSH2_AGENTC_REMOVE_IDENTITY);
614 		buffer_put_string(&msg, blob, blen);
615 		xfree(blob);
616 	} else {
617 		buffer_free(&msg);
618 		return 0;
619 	}
620 	if (ssh_request_reply(auth, &msg, &msg) == 0) {
621 		buffer_free(&msg);
622 		return 0;
623 	}
624 	type = buffer_get_char(&msg);
625 	buffer_free(&msg);
626 	return decode_reply(type);
627 }
628 
629 int
630 ssh_update_card(AuthenticationConnection *auth, int add,
631     const char *reader_id, const char *pin, u_int life, u_int confirm)
632 {
633 	Buffer msg;
634 	int type, constrained = (life || confirm);
635 
636 	if (add) {
637 		type = constrained ?
638 		    SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED :
639 		    SSH_AGENTC_ADD_SMARTCARD_KEY;
640 	} else
641 		type = SSH_AGENTC_REMOVE_SMARTCARD_KEY;
642 
643 	buffer_init(&msg);
644 	buffer_put_char(&msg, type);
645 	buffer_put_cstring(&msg, reader_id);
646 	buffer_put_cstring(&msg, pin);
647 
648 	if (constrained) {
649 		if (life != 0) {
650 			buffer_put_char(&msg, SSH_AGENT_CONSTRAIN_LIFETIME);
651 			buffer_put_int(&msg, life);
652 		}
653 		if (confirm != 0)
654 			buffer_put_char(&msg, SSH_AGENT_CONSTRAIN_CONFIRM);
655 	}
656 
657 	if (ssh_request_reply(auth, &msg, &msg) == 0) {
658 		buffer_free(&msg);
659 		return 0;
660 	}
661 	type = buffer_get_char(&msg);
662 	buffer_free(&msg);
663 	return decode_reply(type);
664 }
665 
666 /*
667  * Removes all identities from the agent.  This call is not meant to be used
668  * by normal applications.
669  */
670 
671 int
672 ssh_remove_all_identities(AuthenticationConnection *auth, int version)
673 {
674 	Buffer msg;
675 	int type;
676 	int code = (version==1) ?
677 		SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES :
678 		SSH2_AGENTC_REMOVE_ALL_IDENTITIES;
679 
680 	buffer_init(&msg);
681 	buffer_put_char(&msg, code);
682 
683 	if (ssh_request_reply(auth, &msg, &msg) == 0) {
684 		buffer_free(&msg);
685 		return 0;
686 	}
687 	type = buffer_get_char(&msg);
688 	buffer_free(&msg);
689 	return decode_reply(type);
690 }
691 
692 int
693 decode_reply(int type)
694 {
695 	switch (type) {
696 	case SSH_AGENT_FAILURE:
697 	case SSH_COM_AGENT2_FAILURE:
698 	case SSH2_AGENT_FAILURE:
699 		logit("SSH_AGENT_FAILURE");
700 		return 0;
701 	case SSH_AGENT_SUCCESS:
702 		return 1;
703 	default:
704 		fatal("Bad response from authentication agent: %d", type);
705 	}
706 	/* NOTREACHED */
707 	return 0;
708 }
709