xref: /netbsd-src/crypto/external/bsd/openssh/dist/authfd.c (revision 479d8f7d843cc1b22d497efdf1f27a50ee8418d4)
1 /*	$NetBSD: authfd.c,v 1.12 2016/12/25 00:07:46 christos Exp $	*/
2 /* $OpenBSD: authfd.c,v 1.100 2015/12/04 16:41:28 markus Exp $ */
3 
4 /*
5  * Author: Tatu Ylonen <ylo@cs.hut.fi>
6  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
7  *                    All rights reserved
8  * Functions for connecting the local authentication agent.
9  *
10  * As far as I am concerned, the code I have written for this software
11  * can be used freely for any purpose.  Any derived versions of this
12  * software must be clearly marked as such, and if the derived work is
13  * incompatible with the protocol description in the RFC file, it must be
14  * called by a name other than "ssh" or "Secure Shell".
15  *
16  * SSH2 implementation,
17  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
18  *
19  * Redistribution and use in source and binary forms, with or without
20  * modification, are permitted provided that the following conditions
21  * are met:
22  * 1. Redistributions of source code must retain the above copyright
23  *    notice, this list of conditions and the following disclaimer.
24  * 2. Redistributions in binary form must reproduce the above copyright
25  *    notice, this list of conditions and the following disclaimer in the
26  *    documentation and/or other materials provided with the distribution.
27  *
28  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
29  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
30  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
31  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
32  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
33  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
37  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
38  */
39 
40 #include "includes.h"
41 __RCSID("$NetBSD: authfd.c,v 1.12 2016/12/25 00:07:46 christos Exp $");
42 #include <sys/types.h>
43 #include <sys/un.h>
44 #include <sys/socket.h>
45 
46 #include <fcntl.h>
47 #include <stdlib.h>
48 #include <signal.h>
49 #include <string.h>
50 #include <unistd.h>
51 #include <errno.h>
52 
53 #include "xmalloc.h"
54 #include "ssh.h"
55 #include "rsa.h"
56 #include "sshbuf.h"
57 #include "sshkey.h"
58 #include "authfd.h"
59 #include "cipher.h"
60 #include "compat.h"
61 #include "log.h"
62 #include "atomicio.h"
63 #include "misc.h"
64 #include "ssherr.h"
65 
66 #define MAX_AGENT_IDENTITIES	2048		/* Max keys in agent reply */
67 #define MAX_AGENT_REPLY_LEN	(256 * 1024) 	/* Max bytes in agent reply */
68 
69 /* macro to check for "agent failure" message */
70 #define agent_failed(x) \
71     ((x == SSH_AGENT_FAILURE) || \
72     (x == SSH_COM_AGENT2_FAILURE) || \
73     (x == SSH2_AGENT_FAILURE))
74 
75 /* Convert success/failure response from agent to a err.h status */
76 static int
77 decode_reply(u_char type)
78 {
79 	if (agent_failed(type))
80 		return SSH_ERR_AGENT_FAILURE;
81 	else if (type == SSH_AGENT_SUCCESS)
82 		return 0;
83 	else
84 		return SSH_ERR_INVALID_FORMAT;
85 }
86 
87 /* Returns the number of the authentication fd, or -1 if there is none. */
88 int
89 ssh_get_authentication_socket(int *fdp)
90 {
91 	const char *authsocket;
92 	int sock, oerrno;
93 	struct sockaddr_un sunaddr;
94 
95 	if (fdp != NULL)
96 		*fdp = -1;
97 
98 	authsocket = getenv(SSH_AUTHSOCKET_ENV_NAME);
99 	if (!authsocket)
100 		return SSH_ERR_AGENT_NOT_PRESENT;
101 
102 	memset(&sunaddr, 0, sizeof(sunaddr));
103 	sunaddr.sun_family = AF_UNIX;
104 	strlcpy(sunaddr.sun_path, authsocket, sizeof(sunaddr.sun_path));
105 
106 	if ((sock = socket(AF_UNIX, SOCK_STREAM, 0)) < 0)
107 		return SSH_ERR_SYSTEM_ERROR;
108 
109 	/* close on exec */
110 	if (fcntl(sock, F_SETFD, FD_CLOEXEC) == -1 ||
111 	    connect(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) < 0) {
112 		oerrno = errno;
113 		close(sock);
114 		errno = oerrno;
115 		return SSH_ERR_SYSTEM_ERROR;
116 	}
117 	if (fdp != NULL)
118 		*fdp = sock;
119 	else
120 		close(sock);
121 	return 0;
122 }
123 
124 /* Communicate with agent: send request and read reply */
125 static int
126 ssh_request_reply(int sock, struct sshbuf *request, struct sshbuf *reply)
127 {
128 	int r;
129 	size_t l, len;
130 	char buf[1024];
131 
132 	/* Get the length of the message, and format it in the buffer. */
133 	len = sshbuf_len(request);
134 	put_u32(buf, len);
135 
136 	/* Send the length and then the packet to the agent. */
137 	if (atomicio(vwrite, sock, buf, 4) != 4 ||
138 	    atomicio(vwrite, sock, __UNCONST(sshbuf_ptr(request)),
139 	    sshbuf_len(request)) != sshbuf_len(request))
140 		return SSH_ERR_AGENT_COMMUNICATION;
141 	/*
142 	 * Wait for response from the agent.  First read the length of the
143 	 * response packet.
144 	 */
145 	if (atomicio(read, sock, buf, 4) != 4)
146 	    return SSH_ERR_AGENT_COMMUNICATION;
147 
148 	/* Extract the length, and check it for sanity. */
149 	len = get_u32(buf);
150 	if (len > MAX_AGENT_REPLY_LEN)
151 		return SSH_ERR_INVALID_FORMAT;
152 
153 	/* Read the rest of the response in to the buffer. */
154 	sshbuf_reset(reply);
155 	while (len > 0) {
156 		l = len;
157 		if (l > sizeof(buf))
158 			l = sizeof(buf);
159 		if (atomicio(read, sock, buf, l) != l)
160 			return SSH_ERR_AGENT_COMMUNICATION;
161 		if ((r = sshbuf_put(reply, buf, l)) != 0)
162 			return r;
163 		len -= l;
164 	}
165 	return 0;
166 }
167 
168 /*
169  * Closes the agent socket if it should be closed (depends on how it was
170  * obtained).  The argument must have been returned by
171  * ssh_get_authentication_socket().
172  */
173 void
174 ssh_close_authentication_socket(int sock)
175 {
176 	if (getenv(SSH_AUTHSOCKET_ENV_NAME))
177 		close(sock);
178 }
179 
180 /* Lock/unlock agent */
181 int
182 ssh_lock_agent(int sock, int lock, const char *password)
183 {
184 	int r;
185 	u_char type = lock ? SSH_AGENTC_LOCK : SSH_AGENTC_UNLOCK;
186 	struct sshbuf *msg;
187 
188 	if ((msg = sshbuf_new()) == NULL)
189 		return SSH_ERR_ALLOC_FAIL;
190 	if ((r = sshbuf_put_u8(msg, type)) != 0 ||
191 	    (r = sshbuf_put_cstring(msg, password)) != 0)
192 		goto out;
193 	if ((r = ssh_request_reply(sock, msg, msg)) != 0)
194 		goto out;
195 	if ((r = sshbuf_get_u8(msg, &type)) != 0)
196 		goto out;
197 	r = decode_reply(type);
198  out:
199 	sshbuf_free(msg);
200 	return r;
201 }
202 
203 #ifdef WITH_SSH1
204 static int
205 deserialise_identity1(struct sshbuf *ids, struct sshkey **keyp, char **commentp)
206 {
207 	struct sshkey *key;
208 	int r, keybits;
209 	u_int32_t bits;
210 	char *comment = NULL;
211 
212 	if ((key = sshkey_new(KEY_RSA1)) == NULL)
213 		return SSH_ERR_ALLOC_FAIL;
214 	if ((r = sshbuf_get_u32(ids, &bits)) != 0 ||
215 	    (r = sshbuf_get_bignum1(ids, key->rsa->e)) != 0 ||
216 	    (r = sshbuf_get_bignum1(ids, key->rsa->n)) != 0 ||
217 	    (r = sshbuf_get_cstring(ids, &comment, NULL)) != 0)
218 		goto out;
219 	keybits = BN_num_bits(key->rsa->n);
220 	/* XXX previously we just warned here. I think we should be strict */
221 	if (keybits < 0 || bits != (u_int)keybits) {
222 		r = SSH_ERR_KEY_BITS_MISMATCH;
223 		goto out;
224 	}
225 	if (keyp != NULL) {
226 		*keyp = key;
227 		key = NULL;
228 	}
229 	if (commentp != NULL) {
230 		*commentp = comment;
231 		comment = NULL;
232 	}
233 	r = 0;
234  out:
235 	sshkey_free(key);
236 	free(comment);
237 	return r;
238 }
239 #endif
240 
241 static int
242 deserialise_identity2(struct sshbuf *ids, struct sshkey **keyp, char **commentp)
243 {
244 	int r;
245 	char *comment = NULL;
246 	const u_char *blob;
247 	size_t blen;
248 
249 	if ((r = sshbuf_get_string_direct(ids, &blob, &blen)) != 0 ||
250 	    (r = sshbuf_get_cstring(ids, &comment, NULL)) != 0)
251 		goto out;
252 	if ((r = sshkey_from_blob(blob, blen, keyp)) != 0)
253 		goto out;
254 	if (commentp != NULL) {
255 		*commentp = comment;
256 		comment = NULL;
257 	}
258 	r = 0;
259  out:
260 	free(comment);
261 	return r;
262 }
263 
264 /*
265  * Fetch list of identities held by the agent.
266  */
267 int
268 ssh_fetch_identitylist(int sock, int version, struct ssh_identitylist **idlp)
269 {
270 	u_char type, code1 = 0, code2 = 0;
271 	u_int32_t num, i;
272 	struct sshbuf *msg;
273 	struct ssh_identitylist *idl = NULL;
274 	int r;
275 
276 	/* Determine request and expected response types */
277 	switch (version) {
278 	case 1:
279 		code1 = SSH_AGENTC_REQUEST_RSA_IDENTITIES;
280 		code2 = SSH_AGENT_RSA_IDENTITIES_ANSWER;
281 		break;
282 	case 2:
283 		code1 = SSH2_AGENTC_REQUEST_IDENTITIES;
284 		code2 = SSH2_AGENT_IDENTITIES_ANSWER;
285 		break;
286 	default:
287 		return SSH_ERR_INVALID_ARGUMENT;
288 	}
289 
290 	/*
291 	 * Send a message to the agent requesting for a list of the
292 	 * identities it can represent.
293 	 */
294 	if ((msg = sshbuf_new()) == NULL)
295 		return SSH_ERR_ALLOC_FAIL;
296 	if ((r = sshbuf_put_u8(msg, code1)) != 0)
297 		goto out;
298 
299 	if ((r = ssh_request_reply(sock, msg, msg)) != 0)
300 		goto out;
301 
302 	/* Get message type, and verify that we got a proper answer. */
303 	if ((r = sshbuf_get_u8(msg, &type)) != 0)
304 		goto out;
305 	if (agent_failed(type)) {
306 		r = SSH_ERR_AGENT_FAILURE;
307 		goto out;
308 	} else if (type != code2) {
309 		r = SSH_ERR_INVALID_FORMAT;
310 		goto out;
311 	}
312 
313 	/* Get the number of entries in the response and check it for sanity. */
314 	if ((r = sshbuf_get_u32(msg, &num)) != 0)
315 		goto out;
316 	if (num > MAX_AGENT_IDENTITIES) {
317 		r = SSH_ERR_INVALID_FORMAT;
318 		goto out;
319 	}
320 	if (num == 0) {
321 		r = SSH_ERR_AGENT_NO_IDENTITIES;
322 		goto out;
323 	}
324 
325 	/* Deserialise the response into a list of keys/comments */
326 	if ((idl = calloc(1, sizeof(*idl))) == NULL ||
327 	    (idl->keys = calloc(num, sizeof(*idl->keys))) == NULL ||
328 	    (idl->comments = calloc(num, sizeof(*idl->comments))) == NULL) {
329 		r = SSH_ERR_ALLOC_FAIL;
330 		goto out;
331 	}
332 	for (i = 0; i < num;) {
333 		switch (version) {
334 		case 1:
335 #ifdef WITH_SSH1
336 			if ((r = deserialise_identity1(msg,
337 			    &(idl->keys[i]), &(idl->comments[i]))) != 0)
338 				goto out;
339 #endif
340 			break;
341 		case 2:
342 			if ((r = deserialise_identity2(msg,
343 			    &(idl->keys[i]), &(idl->comments[i]))) != 0) {
344 				if (r == SSH_ERR_KEY_TYPE_UNKNOWN) {
345 					/* Gracefully skip unknown key types */
346 					num--;
347 					continue;
348 				} else
349 					goto out;
350 			}
351 			break;
352 		}
353 		i++;
354 	}
355 	idl->nkeys = num;
356 	*idlp = idl;
357 	idl = NULL;
358 	r = 0;
359  out:
360 	sshbuf_free(msg);
361 	if (idl != NULL)
362 		ssh_free_identitylist(idl);
363 	return r;
364 }
365 
366 void
367 ssh_free_identitylist(struct ssh_identitylist *idl)
368 {
369 	size_t i;
370 
371 	if (idl == NULL)
372 		return;
373 	for (i = 0; i < idl->nkeys; i++) {
374 		if (idl->keys != NULL)
375 			sshkey_free(idl->keys[i]);
376 		if (idl->comments != NULL)
377 			free(idl->comments[i]);
378 	}
379 	free(idl);
380 }
381 
382 /*
383  * Sends a challenge (typically from a server via ssh(1)) to the agent,
384  * and waits for a response from the agent.
385  * Returns true (non-zero) if the agent gave the correct answer, zero
386  * otherwise.
387  */
388 
389 #ifdef WITH_SSH1
390 int
391 ssh_decrypt_challenge(int sock, struct sshkey* key, BIGNUM *challenge,
392     u_char session_id[16], u_char response[16])
393 {
394 	struct sshbuf *msg;
395 	int r;
396 	u_char type;
397 
398 	if (key->type != KEY_RSA1)
399 		return SSH_ERR_INVALID_ARGUMENT;
400 	if ((msg = sshbuf_new()) == NULL)
401 		return SSH_ERR_ALLOC_FAIL;
402 	if ((r = sshbuf_put_u8(msg, SSH_AGENTC_RSA_CHALLENGE)) != 0 ||
403 	    (r = sshbuf_put_u32(msg, BN_num_bits(key->rsa->n))) != 0 ||
404 	    (r = sshbuf_put_bignum1(msg, key->rsa->e)) != 0 ||
405 	    (r = sshbuf_put_bignum1(msg, key->rsa->n)) != 0 ||
406 	    (r = sshbuf_put_bignum1(msg, challenge)) != 0 ||
407 	    (r = sshbuf_put(msg, session_id, 16)) != 0 ||
408 	    (r = sshbuf_put_u32(msg, 1)) != 0) /* Response type for proto 1.1 */
409 		goto out;
410 	if ((r = ssh_request_reply(sock, msg, msg)) != 0)
411 		goto out;
412 	if ((r = sshbuf_get_u8(msg, &type)) != 0)
413 		goto out;
414 	if (agent_failed(type)) {
415 		r = SSH_ERR_AGENT_FAILURE;
416 		goto out;
417 	} else if (type != SSH_AGENT_RSA_RESPONSE) {
418 		r = SSH_ERR_INVALID_FORMAT;
419 		goto out;
420 	}
421 	if ((r = sshbuf_get(msg, response, 16)) != 0)
422 		goto out;
423 	r = 0;
424  out:
425 	sshbuf_free(msg);
426 	return r;
427 }
428 #endif
429 
430 /* encode signature algoritm in flag bits, so we can keep the msg format */
431 static u_int
432 agent_encode_alg(struct sshkey *key, const char *alg)
433 {
434 	if (alg != NULL && key->type == KEY_RSA) {
435 		if (strcmp(alg, "rsa-sha2-256") == 0)
436 			return SSH_AGENT_RSA_SHA2_256;
437 		else if (strcmp(alg, "rsa-sha2-512") == 0)
438 			return SSH_AGENT_RSA_SHA2_512;
439 	}
440 	return 0;
441 }
442 
443 /* ask agent to sign data, returns err.h code on error, 0 on success */
444 int
445 ssh_agent_sign(int sock, struct sshkey *key,
446     u_char **sigp, size_t *lenp,
447     const u_char *data, size_t datalen, const char *alg, u_int compat)
448 {
449 	struct sshbuf *msg;
450 	u_char *blob = NULL, type;
451 	size_t blen = 0, len = 0;
452 	u_int flags = 0;
453 	int r = SSH_ERR_INTERNAL_ERROR;
454 
455 	*sigp = NULL;
456 	*lenp = 0;
457 
458 	if (datalen > SSH_KEY_MAX_SIGN_DATA_SIZE)
459 		return SSH_ERR_INVALID_ARGUMENT;
460 	if (compat & SSH_BUG_SIGBLOB)
461 		flags |= SSH_AGENT_OLD_SIGNATURE;
462 	if ((msg = sshbuf_new()) == NULL)
463 		return SSH_ERR_ALLOC_FAIL;
464 	if ((r = sshkey_to_blob(key, &blob, &blen)) != 0)
465 		goto out;
466 	flags |= agent_encode_alg(key, alg);
467 	if ((r = sshbuf_put_u8(msg, SSH2_AGENTC_SIGN_REQUEST)) != 0 ||
468 	    (r = sshbuf_put_string(msg, blob, blen)) != 0 ||
469 	    (r = sshbuf_put_string(msg, data, datalen)) != 0 ||
470 	    (r = sshbuf_put_u32(msg, flags)) != 0)
471 		goto out;
472 	if ((r = ssh_request_reply(sock, msg, msg)) != 0)
473 		goto out;
474 	if ((r = sshbuf_get_u8(msg, &type)) != 0)
475 		goto out;
476 	if (agent_failed(type)) {
477 		r = SSH_ERR_AGENT_FAILURE;
478 		goto out;
479 	} else if (type != SSH2_AGENT_SIGN_RESPONSE) {
480 		r = SSH_ERR_INVALID_FORMAT;
481 		goto out;
482 	}
483 	if ((r = sshbuf_get_string(msg, sigp, &len)) != 0)
484 		goto out;
485 	*lenp = len;
486 	r = 0;
487  out:
488 	if (blob != NULL) {
489 		explicit_bzero(blob, blen);
490 		free(blob);
491 	}
492 	sshbuf_free(msg);
493 	return r;
494 }
495 
496 /* Encode key for a message to the agent. */
497 
498 #ifdef WITH_SSH1
499 static int
500 ssh_encode_identity_rsa1(struct sshbuf *b, RSA *key, const char *comment)
501 {
502 	int r;
503 
504 	/* To keep within the protocol: p < q for ssh. in SSL p > q */
505 	if ((r = sshbuf_put_u32(b, BN_num_bits(key->n))) != 0 ||
506 	    (r = sshbuf_put_bignum1(b, key->n)) != 0 ||
507 	    (r = sshbuf_put_bignum1(b, key->e)) != 0 ||
508 	    (r = sshbuf_put_bignum1(b, key->d)) != 0 ||
509 	    (r = sshbuf_put_bignum1(b, key->iqmp)) != 0 ||
510 	    (r = sshbuf_put_bignum1(b, key->q)) != 0 ||
511 	    (r = sshbuf_put_bignum1(b, key->p)) != 0 ||
512 	    (r = sshbuf_put_cstring(b, comment)) != 0)
513 		return r;
514 	return 0;
515 }
516 #endif
517 
518 static int
519 ssh_encode_identity_ssh2(struct sshbuf *b, struct sshkey *key,
520     const char *comment)
521 {
522 	int r;
523 
524 	if ((r = sshkey_private_serialize(key, b)) != 0 ||
525 	    (r = sshbuf_put_cstring(b, comment)) != 0)
526 		return r;
527 	return 0;
528 }
529 
530 static int
531 encode_constraints(struct sshbuf *m, u_int life, u_int confirm)
532 {
533 	int r;
534 
535 	if (life != 0) {
536 		if ((r = sshbuf_put_u8(m, SSH_AGENT_CONSTRAIN_LIFETIME)) != 0 ||
537 		    (r = sshbuf_put_u32(m, life)) != 0)
538 			goto out;
539 	}
540 	if (confirm != 0) {
541 		if ((r = sshbuf_put_u8(m, SSH_AGENT_CONSTRAIN_CONFIRM)) != 0)
542 			goto out;
543 	}
544 	r = 0;
545  out:
546 	return r;
547 }
548 
549 /*
550  * Adds an identity to the authentication server.
551  * This call is intended only for use by ssh-add(1) and like applications.
552  */
553 int
554 ssh_add_identity_constrained(int sock, struct sshkey *key, const char *comment,
555     u_int life, u_int confirm)
556 {
557 	struct sshbuf *msg;
558 	int r, constrained = (life || confirm);
559 	u_char type;
560 
561 	if ((msg = sshbuf_new()) == NULL)
562 		return SSH_ERR_ALLOC_FAIL;
563 
564 	switch (key->type) {
565 #ifdef WITH_SSH1
566 	case KEY_RSA1:
567 		type = constrained ?
568 		    SSH_AGENTC_ADD_RSA_ID_CONSTRAINED :
569 		    SSH_AGENTC_ADD_RSA_IDENTITY;
570 		if ((r = sshbuf_put_u8(msg, type)) != 0 ||
571 		    (r = ssh_encode_identity_rsa1(msg, key->rsa, comment)) != 0)
572 			goto out;
573 		break;
574 #endif
575 #ifdef WITH_OPENSSL
576 	case KEY_RSA:
577 	case KEY_RSA_CERT:
578 	case KEY_DSA:
579 	case KEY_DSA_CERT:
580 	case KEY_ECDSA:
581 	case KEY_ECDSA_CERT:
582 #endif
583 	case KEY_ED25519:
584 	case KEY_ED25519_CERT:
585 		type = constrained ?
586 		    SSH2_AGENTC_ADD_ID_CONSTRAINED :
587 		    SSH2_AGENTC_ADD_IDENTITY;
588 		if ((r = sshbuf_put_u8(msg, type)) != 0 ||
589 		    (r = ssh_encode_identity_ssh2(msg, key, comment)) != 0)
590 			goto out;
591 		break;
592 	default:
593 		r = SSH_ERR_INVALID_ARGUMENT;
594 		goto out;
595 	}
596 	if (constrained &&
597 	    (r = encode_constraints(msg, life, confirm)) != 0)
598 		goto out;
599 	if ((r = ssh_request_reply(sock, msg, msg)) != 0)
600 		goto out;
601 	if ((r = sshbuf_get_u8(msg, &type)) != 0)
602 		goto out;
603 	r = decode_reply(type);
604  out:
605 	sshbuf_free(msg);
606 	return r;
607 }
608 
609 /*
610  * Removes an identity from the authentication server.
611  * This call is intended only for use by ssh-add(1) and like applications.
612  */
613 int
614 ssh_remove_identity(int sock, struct sshkey *key)
615 {
616 	struct sshbuf *msg;
617 	int r;
618 	u_char type, *blob = NULL;
619 	size_t blen;
620 
621 	if ((msg = sshbuf_new()) == NULL)
622 		return SSH_ERR_ALLOC_FAIL;
623 
624 #ifdef WITH_SSH1
625 	if (key->type == KEY_RSA1) {
626 		if ((r = sshbuf_put_u8(msg,
627 		    SSH_AGENTC_REMOVE_RSA_IDENTITY)) != 0 ||
628 		    (r = sshbuf_put_u32(msg, BN_num_bits(key->rsa->n))) != 0 ||
629 		    (r = sshbuf_put_bignum1(msg, key->rsa->e)) != 0 ||
630 		    (r = sshbuf_put_bignum1(msg, key->rsa->n)) != 0)
631 			goto out;
632 	} else
633 #endif
634 	if (key->type != KEY_UNSPEC) {
635 		if ((r = sshkey_to_blob(key, &blob, &blen)) != 0)
636 			goto out;
637 		if ((r = sshbuf_put_u8(msg,
638 		    SSH2_AGENTC_REMOVE_IDENTITY)) != 0 ||
639 		    (r = sshbuf_put_string(msg, blob, blen)) != 0)
640 			goto out;
641 	} else {
642 		r = SSH_ERR_INVALID_ARGUMENT;
643 		goto out;
644 	}
645 	if ((r = ssh_request_reply(sock, msg, msg)) != 0)
646 		goto out;
647 	if ((r = sshbuf_get_u8(msg, &type)) != 0)
648 		goto out;
649 	r = decode_reply(type);
650  out:
651 	if (blob != NULL) {
652 		explicit_bzero(blob, blen);
653 		free(blob);
654 	}
655 	sshbuf_free(msg);
656 	return r;
657 }
658 
659 /*
660  * Add/remove an token-based identity from the authentication server.
661  * This call is intended only for use by ssh-add(1) and like applications.
662  */
663 int
664 ssh_update_card(int sock, int add, const char *reader_id, const char *pin,
665     u_int life, u_int confirm)
666 {
667 	struct sshbuf *msg;
668 	int r, constrained = (life || confirm);
669 	u_char type;
670 
671 	if (add) {
672 		type = constrained ?
673 		    SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED :
674 		    SSH_AGENTC_ADD_SMARTCARD_KEY;
675 	} else
676 		type = SSH_AGENTC_REMOVE_SMARTCARD_KEY;
677 
678 	if ((msg = sshbuf_new()) == NULL)
679 		return SSH_ERR_ALLOC_FAIL;
680 	if ((r = sshbuf_put_u8(msg, type)) != 0 ||
681 	    (r = sshbuf_put_cstring(msg, reader_id)) != 0 ||
682 	    (r = sshbuf_put_cstring(msg, pin)) != 0)
683 		goto out;
684 	if (constrained &&
685 	    (r = encode_constraints(msg, life, confirm)) != 0)
686 		goto out;
687 	if ((r = ssh_request_reply(sock, msg, msg)) != 0)
688 		goto out;
689 	if ((r = sshbuf_get_u8(msg, &type)) != 0)
690 		goto out;
691 	r = decode_reply(type);
692  out:
693 	sshbuf_free(msg);
694 	return r;
695 }
696 
697 /*
698  * Removes all identities from the agent.
699  * This call is intended only for use by ssh-add(1) and like applications.
700  */
701 int
702 ssh_remove_all_identities(int sock, int version)
703 {
704 	struct sshbuf *msg;
705 	u_char type = (version == 1) ?
706 	    SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES :
707 	    SSH2_AGENTC_REMOVE_ALL_IDENTITIES;
708 	int r;
709 
710 	if ((msg = sshbuf_new()) == NULL)
711 		return SSH_ERR_ALLOC_FAIL;
712 	if ((r = sshbuf_put_u8(msg, type)) != 0)
713 		goto out;
714 	if ((r = ssh_request_reply(sock, msg, msg)) != 0)
715 		goto out;
716 	if ((r = sshbuf_get_u8(msg, &type)) != 0)
717 		goto out;
718 	r = decode_reply(type);
719  out:
720 	sshbuf_free(msg);
721 	return r;
722 }
723