xref: /freebsd/crypto/openssh/authfd.c (revision eb69d1f144a6fcc765d1b9d44a5ae8082353e70b)
1 /* $OpenBSD: authfd.c,v 1.100 2015/12/04 16:41:28 markus 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 <fcntl.h>
45 #include <stdlib.h>
46 #include <signal.h>
47 #include <stdarg.h>
48 #include <string.h>
49 #include <unistd.h>
50 #include <errno.h>
51 
52 #include "xmalloc.h"
53 #include "ssh.h"
54 #include "rsa.h"
55 #include "sshbuf.h"
56 #include "sshkey.h"
57 #include "authfd.h"
58 #include "cipher.h"
59 #include "compat.h"
60 #include "log.h"
61 #include "atomicio.h"
62 #include "misc.h"
63 #include "ssherr.h"
64 
65 #define MAX_AGENT_IDENTITIES	2048		/* Max keys in agent reply */
66 #define MAX_AGENT_REPLY_LEN	(256 * 1024) 	/* Max bytes in agent reply */
67 
68 /* macro to check for "agent failure" message */
69 #define agent_failed(x) \
70     ((x == SSH_AGENT_FAILURE) || \
71     (x == SSH_COM_AGENT2_FAILURE) || \
72     (x == SSH2_AGENT_FAILURE))
73 
74 /* Convert success/failure response from agent to a err.h status */
75 static int
76 decode_reply(u_char type)
77 {
78 	if (agent_failed(type))
79 		return SSH_ERR_AGENT_FAILURE;
80 	else if (type == SSH_AGENT_SUCCESS)
81 		return 0;
82 	else
83 		return SSH_ERR_INVALID_FORMAT;
84 }
85 
86 /* Returns the number of the authentication fd, or -1 if there is none. */
87 int
88 ssh_get_authentication_socket(int *fdp)
89 {
90 	const char *authsocket;
91 	int sock, oerrno;
92 	struct sockaddr_un sunaddr;
93 
94 	if (fdp != NULL)
95 		*fdp = -1;
96 
97 	authsocket = getenv(SSH_AUTHSOCKET_ENV_NAME);
98 	if (!authsocket)
99 		return SSH_ERR_AGENT_NOT_PRESENT;
100 
101 	memset(&sunaddr, 0, sizeof(sunaddr));
102 	sunaddr.sun_family = AF_UNIX;
103 	strlcpy(sunaddr.sun_path, authsocket, sizeof(sunaddr.sun_path));
104 
105 	if ((sock = socket(AF_UNIX, SOCK_STREAM, 0)) < 0)
106 		return SSH_ERR_SYSTEM_ERROR;
107 
108 	/* close on exec */
109 	if (fcntl(sock, F_SETFD, FD_CLOEXEC) == -1 ||
110 	    connect(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) < 0) {
111 		oerrno = errno;
112 		close(sock);
113 		errno = oerrno;
114 		return SSH_ERR_SYSTEM_ERROR;
115 	}
116 	if (fdp != NULL)
117 		*fdp = sock;
118 	else
119 		close(sock);
120 	return 0;
121 }
122 
123 /* Communicate with agent: send request and read reply */
124 static int
125 ssh_request_reply(int sock, struct sshbuf *request, struct sshbuf *reply)
126 {
127 	int r;
128 	size_t l, len;
129 	char buf[1024];
130 
131 	/* Get the length of the message, and format it in the buffer. */
132 	len = sshbuf_len(request);
133 	put_u32(buf, len);
134 
135 	/* Send the length and then the packet to the agent. */
136 	if (atomicio(vwrite, sock, buf, 4) != 4 ||
137 	    atomicio(vwrite, sock, (u_char *)sshbuf_ptr(request),
138 	    sshbuf_len(request)) != sshbuf_len(request))
139 		return SSH_ERR_AGENT_COMMUNICATION;
140 	/*
141 	 * Wait for response from the agent.  First read the length of the
142 	 * response packet.
143 	 */
144 	if (atomicio(read, sock, buf, 4) != 4)
145 	    return SSH_ERR_AGENT_COMMUNICATION;
146 
147 	/* Extract the length, and check it for sanity. */
148 	len = get_u32(buf);
149 	if (len > MAX_AGENT_REPLY_LEN)
150 		return SSH_ERR_INVALID_FORMAT;
151 
152 	/* Read the rest of the response in to the buffer. */
153 	sshbuf_reset(reply);
154 	while (len > 0) {
155 		l = len;
156 		if (l > sizeof(buf))
157 			l = sizeof(buf);
158 		if (atomicio(read, sock, buf, l) != l)
159 			return SSH_ERR_AGENT_COMMUNICATION;
160 		if ((r = sshbuf_put(reply, buf, l)) != 0)
161 			return r;
162 		len -= l;
163 	}
164 	return 0;
165 }
166 
167 /*
168  * Closes the agent socket if it should be closed (depends on how it was
169  * obtained).  The argument must have been returned by
170  * ssh_get_authentication_socket().
171  */
172 void
173 ssh_close_authentication_socket(int sock)
174 {
175 	if (getenv(SSH_AUTHSOCKET_ENV_NAME))
176 		close(sock);
177 }
178 
179 /* Lock/unlock agent */
180 int
181 ssh_lock_agent(int sock, int lock, const char *password)
182 {
183 	int r;
184 	u_char type = lock ? SSH_AGENTC_LOCK : SSH_AGENTC_UNLOCK;
185 	struct sshbuf *msg;
186 
187 	if ((msg = sshbuf_new()) == NULL)
188 		return SSH_ERR_ALLOC_FAIL;
189 	if ((r = sshbuf_put_u8(msg, type)) != 0 ||
190 	    (r = sshbuf_put_cstring(msg, password)) != 0)
191 		goto out;
192 	if ((r = ssh_request_reply(sock, msg, msg)) != 0)
193 		goto out;
194 	if ((r = sshbuf_get_u8(msg, &type)) != 0)
195 		goto out;
196 	r = decode_reply(type);
197  out:
198 	sshbuf_free(msg);
199 	return r;
200 }
201 
202 #ifdef WITH_SSH1
203 static int
204 deserialise_identity1(struct sshbuf *ids, struct sshkey **keyp, char **commentp)
205 {
206 	struct sshkey *key;
207 	int r, keybits;
208 	u_int32_t bits;
209 	char *comment = NULL;
210 
211 	if ((key = sshkey_new(KEY_RSA1)) == NULL)
212 		return SSH_ERR_ALLOC_FAIL;
213 	if ((r = sshbuf_get_u32(ids, &bits)) != 0 ||
214 	    (r = sshbuf_get_bignum1(ids, key->rsa->e)) != 0 ||
215 	    (r = sshbuf_get_bignum1(ids, key->rsa->n)) != 0 ||
216 	    (r = sshbuf_get_cstring(ids, &comment, NULL)) != 0)
217 		goto out;
218 	keybits = BN_num_bits(key->rsa->n);
219 	/* XXX previously we just warned here. I think we should be strict */
220 	if (keybits < 0 || bits != (u_int)keybits) {
221 		r = SSH_ERR_KEY_BITS_MISMATCH;
222 		goto out;
223 	}
224 	if (keyp != NULL) {
225 		*keyp = key;
226 		key = NULL;
227 	}
228 	if (commentp != NULL) {
229 		*commentp = comment;
230 		comment = NULL;
231 	}
232 	r = 0;
233  out:
234 	sshkey_free(key);
235 	free(comment);
236 	return r;
237 }
238 #endif
239 
240 static int
241 deserialise_identity2(struct sshbuf *ids, struct sshkey **keyp, char **commentp)
242 {
243 	int r;
244 	char *comment = NULL;
245 	const u_char *blob;
246 	size_t blen;
247 
248 	if ((r = sshbuf_get_string_direct(ids, &blob, &blen)) != 0 ||
249 	    (r = sshbuf_get_cstring(ids, &comment, NULL)) != 0)
250 		goto out;
251 	if ((r = sshkey_from_blob(blob, blen, keyp)) != 0)
252 		goto out;
253 	if (commentp != NULL) {
254 		*commentp = comment;
255 		comment = NULL;
256 	}
257 	r = 0;
258  out:
259 	free(comment);
260 	return r;
261 }
262 
263 /*
264  * Fetch list of identities held by the agent.
265  */
266 int
267 ssh_fetch_identitylist(int sock, int version, struct ssh_identitylist **idlp)
268 {
269 	u_char type, code1 = 0, code2 = 0;
270 	u_int32_t num, i;
271 	struct sshbuf *msg;
272 	struct ssh_identitylist *idl = NULL;
273 	int r;
274 
275 	/* Determine request and expected response types */
276 	switch (version) {
277 	case 1:
278 		code1 = SSH_AGENTC_REQUEST_RSA_IDENTITIES;
279 		code2 = SSH_AGENT_RSA_IDENTITIES_ANSWER;
280 		break;
281 	case 2:
282 		code1 = SSH2_AGENTC_REQUEST_IDENTITIES;
283 		code2 = SSH2_AGENT_IDENTITIES_ANSWER;
284 		break;
285 	default:
286 		return SSH_ERR_INVALID_ARGUMENT;
287 	}
288 
289 	/*
290 	 * Send a message to the agent requesting for a list of the
291 	 * identities it can represent.
292 	 */
293 	if ((msg = sshbuf_new()) == NULL)
294 		return SSH_ERR_ALLOC_FAIL;
295 	if ((r = sshbuf_put_u8(msg, code1)) != 0)
296 		goto out;
297 
298 	if ((r = ssh_request_reply(sock, msg, msg)) != 0)
299 		goto out;
300 
301 	/* Get message type, and verify that we got a proper answer. */
302 	if ((r = sshbuf_get_u8(msg, &type)) != 0)
303 		goto out;
304 	if (agent_failed(type)) {
305 		r = SSH_ERR_AGENT_FAILURE;
306 		goto out;
307 	} else if (type != code2) {
308 		r = SSH_ERR_INVALID_FORMAT;
309 		goto out;
310 	}
311 
312 	/* Get the number of entries in the response and check it for sanity. */
313 	if ((r = sshbuf_get_u32(msg, &num)) != 0)
314 		goto out;
315 	if (num > MAX_AGENT_IDENTITIES) {
316 		r = SSH_ERR_INVALID_FORMAT;
317 		goto out;
318 	}
319 	if (num == 0) {
320 		r = SSH_ERR_AGENT_NO_IDENTITIES;
321 		goto out;
322 	}
323 
324 	/* Deserialise the response into a list of keys/comments */
325 	if ((idl = calloc(1, sizeof(*idl))) == NULL ||
326 	    (idl->keys = calloc(num, sizeof(*idl->keys))) == NULL ||
327 	    (idl->comments = calloc(num, sizeof(*idl->comments))) == NULL) {
328 		r = SSH_ERR_ALLOC_FAIL;
329 		goto out;
330 	}
331 	for (i = 0; i < num;) {
332 		switch (version) {
333 		case 1:
334 #ifdef WITH_SSH1
335 			if ((r = deserialise_identity1(msg,
336 			    &(idl->keys[i]), &(idl->comments[i]))) != 0)
337 				goto out;
338 #endif
339 			break;
340 		case 2:
341 			if ((r = deserialise_identity2(msg,
342 			    &(idl->keys[i]), &(idl->comments[i]))) != 0) {
343 				if (r == SSH_ERR_KEY_TYPE_UNKNOWN) {
344 					/* Gracefully skip unknown key types */
345 					num--;
346 					continue;
347 				} else
348 					goto out;
349 			}
350 			break;
351 		}
352 		i++;
353 	}
354 	idl->nkeys = num;
355 	*idlp = idl;
356 	idl = NULL;
357 	r = 0;
358  out:
359 	sshbuf_free(msg);
360 	if (idl != NULL)
361 		ssh_free_identitylist(idl);
362 	return r;
363 }
364 
365 void
366 ssh_free_identitylist(struct ssh_identitylist *idl)
367 {
368 	size_t i;
369 
370 	if (idl == NULL)
371 		return;
372 	for (i = 0; i < idl->nkeys; i++) {
373 		if (idl->keys != NULL)
374 			sshkey_free(idl->keys[i]);
375 		if (idl->comments != NULL)
376 			free(idl->comments[i]);
377 	}
378 	free(idl);
379 }
380 
381 /*
382  * Sends a challenge (typically from a server via ssh(1)) to the agent,
383  * and waits for a response from the agent.
384  * Returns true (non-zero) if the agent gave the correct answer, zero
385  * otherwise.
386  */
387 
388 #ifdef WITH_SSH1
389 int
390 ssh_decrypt_challenge(int sock, struct sshkey* key, BIGNUM *challenge,
391     u_char session_id[16], u_char response[16])
392 {
393 	struct sshbuf *msg;
394 	int r;
395 	u_char type;
396 
397 	if (key->type != KEY_RSA1)
398 		return SSH_ERR_INVALID_ARGUMENT;
399 	if ((msg = sshbuf_new()) == NULL)
400 		return SSH_ERR_ALLOC_FAIL;
401 	if ((r = sshbuf_put_u8(msg, SSH_AGENTC_RSA_CHALLENGE)) != 0 ||
402 	    (r = sshbuf_put_u32(msg, BN_num_bits(key->rsa->n))) != 0 ||
403 	    (r = sshbuf_put_bignum1(msg, key->rsa->e)) != 0 ||
404 	    (r = sshbuf_put_bignum1(msg, key->rsa->n)) != 0 ||
405 	    (r = sshbuf_put_bignum1(msg, challenge)) != 0 ||
406 	    (r = sshbuf_put(msg, session_id, 16)) != 0 ||
407 	    (r = sshbuf_put_u32(msg, 1)) != 0) /* Response type for proto 1.1 */
408 		goto out;
409 	if ((r = ssh_request_reply(sock, msg, msg)) != 0)
410 		goto out;
411 	if ((r = sshbuf_get_u8(msg, &type)) != 0)
412 		goto out;
413 	if (agent_failed(type)) {
414 		r = SSH_ERR_AGENT_FAILURE;
415 		goto out;
416 	} else if (type != SSH_AGENT_RSA_RESPONSE) {
417 		r = SSH_ERR_INVALID_FORMAT;
418 		goto out;
419 	}
420 	if ((r = sshbuf_get(msg, response, 16)) != 0)
421 		goto out;
422 	r = 0;
423  out:
424 	sshbuf_free(msg);
425 	return r;
426 }
427 #endif
428 
429 /* encode signature algoritm in flag bits, so we can keep the msg format */
430 static u_int
431 agent_encode_alg(struct sshkey *key, const char *alg)
432 {
433 	if (alg != NULL && key->type == KEY_RSA) {
434 		if (strcmp(alg, "rsa-sha2-256") == 0)
435 			return SSH_AGENT_RSA_SHA2_256;
436 		else if (strcmp(alg, "rsa-sha2-512") == 0)
437 			return SSH_AGENT_RSA_SHA2_512;
438 	}
439 	return 0;
440 }
441 
442 /* ask agent to sign data, returns err.h code on error, 0 on success */
443 int
444 ssh_agent_sign(int sock, struct sshkey *key,
445     u_char **sigp, size_t *lenp,
446     const u_char *data, size_t datalen, const char *alg, u_int compat)
447 {
448 	struct sshbuf *msg;
449 	u_char *blob = NULL, type;
450 	size_t blen = 0, len = 0;
451 	u_int flags = 0;
452 	int r = SSH_ERR_INTERNAL_ERROR;
453 
454 	*sigp = NULL;
455 	*lenp = 0;
456 
457 	if (datalen > SSH_KEY_MAX_SIGN_DATA_SIZE)
458 		return SSH_ERR_INVALID_ARGUMENT;
459 	if (compat & SSH_BUG_SIGBLOB)
460 		flags |= SSH_AGENT_OLD_SIGNATURE;
461 	if ((msg = sshbuf_new()) == NULL)
462 		return SSH_ERR_ALLOC_FAIL;
463 	if ((r = sshkey_to_blob(key, &blob, &blen)) != 0)
464 		goto out;
465 	flags |= agent_encode_alg(key, alg);
466 	if ((r = sshbuf_put_u8(msg, SSH2_AGENTC_SIGN_REQUEST)) != 0 ||
467 	    (r = sshbuf_put_string(msg, blob, blen)) != 0 ||
468 	    (r = sshbuf_put_string(msg, data, datalen)) != 0 ||
469 	    (r = sshbuf_put_u32(msg, flags)) != 0)
470 		goto out;
471 	if ((r = ssh_request_reply(sock, msg, msg)) != 0)
472 		goto out;
473 	if ((r = sshbuf_get_u8(msg, &type)) != 0)
474 		goto out;
475 	if (agent_failed(type)) {
476 		r = SSH_ERR_AGENT_FAILURE;
477 		goto out;
478 	} else if (type != SSH2_AGENT_SIGN_RESPONSE) {
479 		r = SSH_ERR_INVALID_FORMAT;
480 		goto out;
481 	}
482 	if ((r = sshbuf_get_string(msg, sigp, &len)) != 0)
483 		goto out;
484 	*lenp = len;
485 	r = 0;
486  out:
487 	if (blob != NULL) {
488 		explicit_bzero(blob, blen);
489 		free(blob);
490 	}
491 	sshbuf_free(msg);
492 	return r;
493 }
494 
495 /* Encode key for a message to the agent. */
496 
497 #ifdef WITH_SSH1
498 static int
499 ssh_encode_identity_rsa1(struct sshbuf *b, RSA *key, const char *comment)
500 {
501 	int r;
502 
503 	/* To keep within the protocol: p < q for ssh. in SSL p > q */
504 	if ((r = sshbuf_put_u32(b, BN_num_bits(key->n))) != 0 ||
505 	    (r = sshbuf_put_bignum1(b, key->n)) != 0 ||
506 	    (r = sshbuf_put_bignum1(b, key->e)) != 0 ||
507 	    (r = sshbuf_put_bignum1(b, key->d)) != 0 ||
508 	    (r = sshbuf_put_bignum1(b, key->iqmp)) != 0 ||
509 	    (r = sshbuf_put_bignum1(b, key->q)) != 0 ||
510 	    (r = sshbuf_put_bignum1(b, key->p)) != 0 ||
511 	    (r = sshbuf_put_cstring(b, comment)) != 0)
512 		return r;
513 	return 0;
514 }
515 #endif
516 
517 static int
518 ssh_encode_identity_ssh2(struct sshbuf *b, struct sshkey *key,
519     const char *comment)
520 {
521 	int r;
522 
523 	if ((r = sshkey_private_serialize(key, b)) != 0 ||
524 	    (r = sshbuf_put_cstring(b, comment)) != 0)
525 		return r;
526 	return 0;
527 }
528 
529 static int
530 encode_constraints(struct sshbuf *m, u_int life, u_int confirm)
531 {
532 	int r;
533 
534 	if (life != 0) {
535 		if ((r = sshbuf_put_u8(m, SSH_AGENT_CONSTRAIN_LIFETIME)) != 0 ||
536 		    (r = sshbuf_put_u32(m, life)) != 0)
537 			goto out;
538 	}
539 	if (confirm != 0) {
540 		if ((r = sshbuf_put_u8(m, SSH_AGENT_CONSTRAIN_CONFIRM)) != 0)
541 			goto out;
542 	}
543 	r = 0;
544  out:
545 	return r;
546 }
547 
548 /*
549  * Adds an identity to the authentication server.
550  * This call is intended only for use by ssh-add(1) and like applications.
551  */
552 int
553 ssh_add_identity_constrained(int sock, struct sshkey *key, const char *comment,
554     u_int life, u_int confirm)
555 {
556 	struct sshbuf *msg;
557 	int r, constrained = (life || confirm);
558 	u_char type;
559 
560 	if ((msg = sshbuf_new()) == NULL)
561 		return SSH_ERR_ALLOC_FAIL;
562 
563 	switch (key->type) {
564 #ifdef WITH_SSH1
565 	case KEY_RSA1:
566 		type = constrained ?
567 		    SSH_AGENTC_ADD_RSA_ID_CONSTRAINED :
568 		    SSH_AGENTC_ADD_RSA_IDENTITY;
569 		if ((r = sshbuf_put_u8(msg, type)) != 0 ||
570 		    (r = ssh_encode_identity_rsa1(msg, key->rsa, comment)) != 0)
571 			goto out;
572 		break;
573 #endif
574 #ifdef WITH_OPENSSL
575 	case KEY_RSA:
576 	case KEY_RSA_CERT:
577 	case KEY_DSA:
578 	case KEY_DSA_CERT:
579 	case KEY_ECDSA:
580 	case KEY_ECDSA_CERT:
581 #endif
582 	case KEY_ED25519:
583 	case KEY_ED25519_CERT:
584 		type = constrained ?
585 		    SSH2_AGENTC_ADD_ID_CONSTRAINED :
586 		    SSH2_AGENTC_ADD_IDENTITY;
587 		if ((r = sshbuf_put_u8(msg, type)) != 0 ||
588 		    (r = ssh_encode_identity_ssh2(msg, key, comment)) != 0)
589 			goto out;
590 		break;
591 	default:
592 		r = SSH_ERR_INVALID_ARGUMENT;
593 		goto out;
594 	}
595 	if (constrained &&
596 	    (r = encode_constraints(msg, life, confirm)) != 0)
597 		goto out;
598 	if ((r = ssh_request_reply(sock, msg, msg)) != 0)
599 		goto out;
600 	if ((r = sshbuf_get_u8(msg, &type)) != 0)
601 		goto out;
602 	r = decode_reply(type);
603  out:
604 	sshbuf_free(msg);
605 	return r;
606 }
607 
608 /*
609  * Removes an identity from the authentication server.
610  * This call is intended only for use by ssh-add(1) and like applications.
611  */
612 int
613 ssh_remove_identity(int sock, struct sshkey *key)
614 {
615 	struct sshbuf *msg;
616 	int r;
617 	u_char type, *blob = NULL;
618 	size_t blen;
619 
620 	if ((msg = sshbuf_new()) == NULL)
621 		return SSH_ERR_ALLOC_FAIL;
622 
623 #ifdef WITH_SSH1
624 	if (key->type == KEY_RSA1) {
625 		if ((r = sshbuf_put_u8(msg,
626 		    SSH_AGENTC_REMOVE_RSA_IDENTITY)) != 0 ||
627 		    (r = sshbuf_put_u32(msg, BN_num_bits(key->rsa->n))) != 0 ||
628 		    (r = sshbuf_put_bignum1(msg, key->rsa->e)) != 0 ||
629 		    (r = sshbuf_put_bignum1(msg, key->rsa->n)) != 0)
630 			goto out;
631 	} else
632 #endif
633 	if (key->type != KEY_UNSPEC) {
634 		if ((r = sshkey_to_blob(key, &blob, &blen)) != 0)
635 			goto out;
636 		if ((r = sshbuf_put_u8(msg,
637 		    SSH2_AGENTC_REMOVE_IDENTITY)) != 0 ||
638 		    (r = sshbuf_put_string(msg, blob, blen)) != 0)
639 			goto out;
640 	} else {
641 		r = SSH_ERR_INVALID_ARGUMENT;
642 		goto out;
643 	}
644 	if ((r = ssh_request_reply(sock, msg, msg)) != 0)
645 		goto out;
646 	if ((r = sshbuf_get_u8(msg, &type)) != 0)
647 		goto out;
648 	r = decode_reply(type);
649  out:
650 	if (blob != NULL) {
651 		explicit_bzero(blob, blen);
652 		free(blob);
653 	}
654 	sshbuf_free(msg);
655 	return r;
656 }
657 
658 /*
659  * Add/remove an token-based identity from the authentication server.
660  * This call is intended only for use by ssh-add(1) and like applications.
661  */
662 int
663 ssh_update_card(int sock, int add, const char *reader_id, const char *pin,
664     u_int life, u_int confirm)
665 {
666 	struct sshbuf *msg;
667 	int r, constrained = (life || confirm);
668 	u_char type;
669 
670 	if (add) {
671 		type = constrained ?
672 		    SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED :
673 		    SSH_AGENTC_ADD_SMARTCARD_KEY;
674 	} else
675 		type = SSH_AGENTC_REMOVE_SMARTCARD_KEY;
676 
677 	if ((msg = sshbuf_new()) == NULL)
678 		return SSH_ERR_ALLOC_FAIL;
679 	if ((r = sshbuf_put_u8(msg, type)) != 0 ||
680 	    (r = sshbuf_put_cstring(msg, reader_id)) != 0 ||
681 	    (r = sshbuf_put_cstring(msg, pin)) != 0)
682 		goto out;
683 	if (constrained &&
684 	    (r = encode_constraints(msg, life, confirm)) != 0)
685 		goto out;
686 	if ((r = ssh_request_reply(sock, msg, msg)) != 0)
687 		goto out;
688 	if ((r = sshbuf_get_u8(msg, &type)) != 0)
689 		goto out;
690 	r = decode_reply(type);
691  out:
692 	sshbuf_free(msg);
693 	return r;
694 }
695 
696 /*
697  * Removes all identities from the agent.
698  * This call is intended only for use by ssh-add(1) and like applications.
699  */
700 int
701 ssh_remove_all_identities(int sock, int version)
702 {
703 	struct sshbuf *msg;
704 	u_char type = (version == 1) ?
705 	    SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES :
706 	    SSH2_AGENTC_REMOVE_ALL_IDENTITIES;
707 	int r;
708 
709 	if ((msg = sshbuf_new()) == NULL)
710 		return SSH_ERR_ALLOC_FAIL;
711 	if ((r = sshbuf_put_u8(msg, type)) != 0)
712 		goto out;
713 	if ((r = ssh_request_reply(sock, msg, msg)) != 0)
714 		goto out;
715 	if ((r = sshbuf_get_u8(msg, &type)) != 0)
716 		goto out;
717 	r = decode_reply(type);
718  out:
719 	sshbuf_free(msg);
720 	return r;
721 }
722