1 /* $NetBSD: ssh-add.c,v 1.32 2024/09/24 21:32:19 christos Exp $ */
2 /* $OpenBSD: ssh-add.c,v 1.173 2024/09/06 02:30:44 djm 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 * Adds an identity to the authentication server, or removes an identity.
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, 2001 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: ssh-add.c,v 1.32 2024/09/24 21:32:19 christos Exp $");
42 #include <sys/types.h>
43 #include <sys/stat.h>
44
45 #ifdef WITH_OPENSSL
46 #include <openssl/evp.h>
47 #endif
48
49 #include <errno.h>
50 #include <fcntl.h>
51 #include <pwd.h>
52 #include <stdio.h>
53 #include <stdlib.h>
54 #include <string.h>
55 #include <stdarg.h>
56 #include <unistd.h>
57 #include <limits.h>
58
59 #include "xmalloc.h"
60 #include "ssh.h"
61 #include "log.h"
62 #include "sshkey.h"
63 #include "sshbuf.h"
64 #include "authfd.h"
65 #include "authfile.h"
66 #include "pathnames.h"
67 #include "misc.h"
68 #include "ssherr.h"
69 #include "digest.h"
70 #include "ssh-sk.h"
71 #include "sk-api.h"
72 #include "hostfile.h"
73
74 /* argv0 */
75 extern char *__progname;
76
77 /* Default files to add */
78 static const char *default_files[] = {
79 _PATH_SSH_CLIENT_ID_RSA,
80 _PATH_SSH_CLIENT_ID_ECDSA,
81 _PATH_SSH_CLIENT_ID_ECDSA_SK,
82 _PATH_SSH_CLIENT_ID_ED25519,
83 _PATH_SSH_CLIENT_ID_ED25519_SK,
84 _PATH_SSH_CLIENT_ID_XMSS,
85 #ifdef WITH_DSA
86 _PATH_SSH_CLIENT_ID_DSA,
87 #endif
88 NULL
89 };
90
91 static int fingerprint_hash = SSH_FP_HASH_DEFAULT;
92
93 /* Default lifetime (0 == forever) */
94 static int lifetime = 0;
95
96 /* User has to confirm key use */
97 static int confirm = 0;
98
99 /* Maximum number of signatures (XMSS) */
100 static u_int maxsign = 0;
101 static u_int minleft = 0;
102
103 /* we keep a cache of one passphrase */
104 static char *pass = NULL;
105 static void
clear_pass(void)106 clear_pass(void)
107 {
108 if (pass) {
109 freezero(pass, strlen(pass));
110 pass = NULL;
111 }
112 }
113
114 static int
delete_one(int agent_fd,const struct sshkey * key,const char * comment,const char * path,int qflag)115 delete_one(int agent_fd, const struct sshkey *key, const char *comment,
116 const char *path, int qflag)
117 {
118 int r;
119
120 if ((r = ssh_remove_identity(agent_fd, key)) != 0) {
121 fprintf(stderr, "Could not remove identity \"%s\": %s\n",
122 path, ssh_err(r));
123 return r;
124 }
125 if (!qflag) {
126 fprintf(stderr, "Identity removed: %s %s (%s)\n", path,
127 sshkey_type(key), comment ? comment : "no comment");
128 }
129 return 0;
130 }
131
132 static int
delete_stdin(int agent_fd,int qflag,int key_only,int cert_only)133 delete_stdin(int agent_fd, int qflag, int key_only, int cert_only)
134 {
135 char *line = NULL, *cp;
136 size_t linesize = 0;
137 struct sshkey *key = NULL;
138 int lnum = 0, r, ret = -1;
139
140 while (getline(&line, &linesize, stdin) != -1) {
141 lnum++;
142 sshkey_free(key);
143 key = NULL;
144 line[strcspn(line, "\n")] = '\0';
145 cp = line + strspn(line, " \t");
146 if (*cp == '#' || *cp == '\0')
147 continue;
148 if ((key = sshkey_new(KEY_UNSPEC)) == NULL)
149 fatal_f("sshkey_new");
150 if ((r = sshkey_read(key, &cp)) != 0) {
151 error_r(r, "(stdin):%d: invalid key", lnum);
152 continue;
153 }
154 if ((!key_only && !cert_only) ||
155 (key_only && !sshkey_is_cert(key)) ||
156 (cert_only && sshkey_is_cert(key))) {
157 if (delete_one(agent_fd, key, cp,
158 "(stdin)", qflag) == 0)
159 ret = 0;
160 }
161 }
162 sshkey_free(key);
163 free(line);
164 return ret;
165 }
166
167 static int
delete_file(int agent_fd,const char * filename,int key_only,int cert_only,int qflag)168 delete_file(int agent_fd, const char *filename, int key_only,
169 int cert_only, int qflag)
170 {
171 struct sshkey *public, *cert = NULL;
172 char *certpath = NULL, *comment = NULL;
173 int r, ret = -1;
174
175 if (strcmp(filename, "-") == 0)
176 return delete_stdin(agent_fd, qflag, key_only, cert_only);
177
178 if ((r = sshkey_load_public(filename, &public, &comment)) != 0) {
179 printf("Bad key file %s: %s\n", filename, ssh_err(r));
180 return -1;
181 }
182 if ((!key_only && !cert_only) ||
183 (key_only && !sshkey_is_cert(public)) ||
184 (cert_only && sshkey_is_cert(public))) {
185 if (delete_one(agent_fd, public, comment, filename, qflag) == 0)
186 ret = 0;
187 }
188
189 if (key_only)
190 goto out;
191
192 /* Now try to delete the corresponding certificate too */
193 free(comment);
194 comment = NULL;
195 xasprintf(&certpath, "%s-cert.pub", filename);
196 if ((r = sshkey_load_public(certpath, &cert, &comment)) != 0) {
197 if (r != SSH_ERR_SYSTEM_ERROR || errno != ENOENT)
198 error_r(r, "Failed to load certificate \"%s\"", certpath);
199 goto out;
200 }
201
202 if (!sshkey_equal_public(cert, public))
203 fatal("Certificate %s does not match private key %s",
204 certpath, filename);
205
206 if (delete_one(agent_fd, cert, comment, certpath, qflag) == 0)
207 ret = 0;
208
209 out:
210 sshkey_free(cert);
211 sshkey_free(public);
212 free(certpath);
213 free(comment);
214
215 return ret;
216 }
217
218 /* Send a request to remove all identities. */
219 static int
delete_all(int agent_fd,int qflag)220 delete_all(int agent_fd, int qflag)
221 {
222 int ret = -1;
223
224 /*
225 * Since the agent might be forwarded, old or non-OpenSSH, when asked
226 * to remove all keys, attempt to remove both protocol v.1 and v.2
227 * keys.
228 */
229 if (ssh_remove_all_identities(agent_fd, 2) == 0)
230 ret = 0;
231 /* ignore error-code for ssh1 */
232 ssh_remove_all_identities(agent_fd, 1);
233
234 if (ret != 0)
235 fprintf(stderr, "Failed to remove all identities.\n");
236 else if (!qflag)
237 fprintf(stderr, "All identities removed.\n");
238
239 return ret;
240 }
241
242 static int
add_file(int agent_fd,const char * filename,int key_only,int cert_only,int qflag,const char * skprovider,struct dest_constraint ** dest_constraints,size_t ndest_constraints)243 add_file(int agent_fd, const char *filename, int key_only, int cert_only,
244 int qflag, const char *skprovider,
245 struct dest_constraint **dest_constraints,
246 size_t ndest_constraints)
247 {
248 struct sshkey *private, *cert;
249 char *comment = NULL;
250 char msg[1024], *certpath = NULL;
251 int r, fd, ret = -1;
252 size_t i;
253 u_int32_t left;
254 struct sshbuf *keyblob;
255 struct ssh_identitylist *idlist;
256
257 if (strcmp(filename, "-") == 0) {
258 fd = STDIN_FILENO;
259 filename = "(stdin)";
260 } else if ((fd = open(filename, O_RDONLY)) == -1) {
261 perror(filename);
262 return -1;
263 }
264
265 /*
266 * Since we'll try to load a keyfile multiple times, permission errors
267 * will occur multiple times, so check perms first and bail if wrong.
268 */
269 if (fd != STDIN_FILENO) {
270 if (sshkey_perm_ok(fd, filename) != 0) {
271 close(fd);
272 return -1;
273 }
274 }
275 if ((r = sshbuf_load_fd(fd, &keyblob)) != 0) {
276 fprintf(stderr, "Error loading key \"%s\": %s\n",
277 filename, ssh_err(r));
278 sshbuf_free(keyblob);
279 close(fd);
280 return -1;
281 }
282 close(fd);
283
284 /* At first, try empty passphrase */
285 if ((r = sshkey_parse_private_fileblob(keyblob, "", &private,
286 &comment)) != 0 && r != SSH_ERR_KEY_WRONG_PASSPHRASE) {
287 fprintf(stderr, "Error loading key \"%s\": %s\n",
288 filename, ssh_err(r));
289 goto fail_load;
290 }
291 /* try last */
292 if (private == NULL && pass != NULL) {
293 if ((r = sshkey_parse_private_fileblob(keyblob, pass, &private,
294 &comment)) != 0 && r != SSH_ERR_KEY_WRONG_PASSPHRASE) {
295 fprintf(stderr, "Error loading key \"%s\": %s\n",
296 filename, ssh_err(r));
297 goto fail_load;
298 }
299 }
300 if (private == NULL) {
301 /* clear passphrase since it did not work */
302 clear_pass();
303 snprintf(msg, sizeof msg, "Enter passphrase for %s%s: ",
304 filename, confirm ? " (will confirm each use)" : "");
305 for (;;) {
306 pass = read_passphrase(msg, RP_ALLOW_STDIN);
307 if (strcmp(pass, "") == 0)
308 goto fail_load;
309 if ((r = sshkey_parse_private_fileblob(keyblob, pass,
310 &private, &comment)) == 0)
311 break;
312 else if (r != SSH_ERR_KEY_WRONG_PASSPHRASE) {
313 fprintf(stderr,
314 "Error loading key \"%s\": %s\n",
315 filename, ssh_err(r));
316 fail_load:
317 clear_pass();
318 sshbuf_free(keyblob);
319 return -1;
320 }
321 clear_pass();
322 snprintf(msg, sizeof msg,
323 "Bad passphrase, try again for %s%s: ", filename,
324 confirm ? " (will confirm each use)" : "");
325 }
326 }
327 if (comment == NULL || *comment == '\0')
328 comment = xstrdup(filename);
329 sshbuf_free(keyblob);
330
331 /* For XMSS */
332 if ((r = sshkey_set_filename(private, filename)) != 0) {
333 fprintf(stderr, "Could not add filename to private key: %s (%s)\n",
334 filename, comment);
335 goto out;
336 }
337 if (maxsign && minleft &&
338 (r = ssh_fetch_identitylist(agent_fd, &idlist)) == 0) {
339 for (i = 0; i < idlist->nkeys; i++) {
340 if (!sshkey_equal_public(idlist->keys[i], private))
341 continue;
342 left = sshkey_signatures_left(idlist->keys[i]);
343 if (left < minleft) {
344 fprintf(stderr,
345 "Only %d signatures left.\n", left);
346 break;
347 }
348 fprintf(stderr, "Skipping update: ");
349 if (left == minleft) {
350 fprintf(stderr,
351 "required signatures left (%d).\n", left);
352 } else {
353 fprintf(stderr,
354 "more signatures left (%d) than"
355 " required (%d).\n", left, minleft);
356 }
357 ssh_free_identitylist(idlist);
358 goto out;
359 }
360 ssh_free_identitylist(idlist);
361 }
362
363 if (sshkey_is_sk(private)) {
364 if (skprovider == NULL) {
365 fprintf(stderr, "Cannot load FIDO key %s "
366 "without provider\n", filename);
367 goto out;
368 }
369 } else {
370 /* Don't send provider constraint for other keys */
371 skprovider = NULL;
372 }
373
374 if (!cert_only &&
375 (r = ssh_add_identity_constrained(agent_fd, private, comment,
376 lifetime, confirm, maxsign, skprovider,
377 dest_constraints, ndest_constraints)) == 0) {
378 ret = 0;
379 if (!qflag) {
380 fprintf(stderr, "Identity added: %s (%s)\n",
381 filename, comment);
382 if (lifetime != 0) {
383 fprintf(stderr,
384 "Lifetime set to %d seconds\n", lifetime);
385 }
386 if (confirm != 0) {
387 fprintf(stderr, "The user must confirm "
388 "each use of the key\n");
389 }
390 }
391 } else {
392 fprintf(stderr, "Could not add identity \"%s\": %s\n",
393 filename, ssh_err(r));
394 }
395
396 /* Skip trying to load the cert if requested */
397 if (key_only)
398 goto out;
399
400 /* Now try to add the certificate flavour too */
401 xasprintf(&certpath, "%s-cert.pub", filename);
402 if ((r = sshkey_load_public(certpath, &cert, NULL)) != 0) {
403 if (r != SSH_ERR_SYSTEM_ERROR || errno != ENOENT)
404 error_r(r, "Failed to load certificate \"%s\"",
405 certpath);
406 goto out;
407 }
408
409 if (!sshkey_equal_public(cert, private)) {
410 error("Certificate %s does not match private key %s",
411 certpath, filename);
412 sshkey_free(cert);
413 goto out;
414 }
415
416 /* Graft with private bits */
417 if ((r = sshkey_to_certified(private)) != 0) {
418 error_fr(r, "sshkey_to_certified");
419 sshkey_free(cert);
420 goto out;
421 }
422 if ((r = sshkey_cert_copy(cert, private)) != 0) {
423 error_fr(r, "sshkey_cert_copy");
424 sshkey_free(cert);
425 goto out;
426 }
427 sshkey_free(cert);
428
429 if ((r = ssh_add_identity_constrained(agent_fd, private, comment,
430 lifetime, confirm, maxsign, skprovider,
431 dest_constraints, ndest_constraints)) != 0) {
432 error_r(r, "Certificate %s (%s) add failed", certpath,
433 private->cert->key_id);
434 goto out;
435 }
436 /* success */
437 if (!qflag) {
438 fprintf(stderr, "Certificate added: %s (%s)\n", certpath,
439 private->cert->key_id);
440 if (lifetime != 0) {
441 fprintf(stderr, "Lifetime set to %d seconds\n",
442 lifetime);
443 }
444 if (confirm != 0) {
445 fprintf(stderr, "The user must confirm each use "
446 "of the key\n");
447 }
448 }
449
450 out:
451 free(certpath);
452 free(comment);
453 sshkey_free(private);
454
455 return ret;
456 }
457
458 static int
update_card(int agent_fd,int add,const char * id,int qflag,int key_only,int cert_only,struct dest_constraint ** dest_constraints,size_t ndest_constraints,struct sshkey ** certs,size_t ncerts)459 update_card(int agent_fd, int add, const char *id, int qflag,
460 int key_only, int cert_only,
461 struct dest_constraint **dest_constraints, size_t ndest_constraints,
462 struct sshkey **certs, size_t ncerts)
463 {
464 char *pin = NULL;
465 int r, ret = -1;
466
467 if (key_only)
468 ncerts = 0;
469
470 if (add) {
471 if ((pin = read_passphrase("Enter passphrase for PKCS#11: ",
472 RP_ALLOW_STDIN)) == NULL)
473 return -1;
474 }
475
476 if ((r = ssh_update_card(agent_fd, add, id, pin == NULL ? "" : pin,
477 lifetime, confirm, dest_constraints, ndest_constraints,
478 cert_only, certs, ncerts)) == 0) {
479 ret = 0;
480 if (!qflag) {
481 fprintf(stderr, "Card %s: %s\n",
482 add ? "added" : "removed", id);
483 }
484 } else {
485 fprintf(stderr, "Could not %s card \"%s\": %s\n",
486 add ? "add" : "remove", id, ssh_err(r));
487 ret = -1;
488 }
489 free(pin);
490 return ret;
491 }
492
493 static int
test_key(int agent_fd,const char * filename)494 test_key(int agent_fd, const char *filename)
495 {
496 struct sshkey *key = NULL;
497 u_char *sig = NULL;
498 const char *alg = NULL;
499 size_t slen = 0;
500 int r, ret = -1;
501 u_char data[1024];
502
503 if ((r = sshkey_load_public(filename, &key, NULL)) != 0) {
504 error_r(r, "Couldn't read public key %s", filename);
505 return -1;
506 }
507 if (sshkey_type_plain(key->type) == KEY_RSA)
508 alg = "rsa-sha2-256";
509 arc4random_buf(data, sizeof(data));
510 if ((r = ssh_agent_sign(agent_fd, key, &sig, &slen, data, sizeof(data),
511 alg, 0)) != 0) {
512 error_r(r, "Agent signature failed for %s", filename);
513 goto done;
514 }
515 if ((r = sshkey_verify(key, sig, slen, data, sizeof(data),
516 alg, 0, NULL)) != 0) {
517 error_r(r, "Signature verification failed for %s", filename);
518 goto done;
519 }
520 /* success */
521 ret = 0;
522 done:
523 free(sig);
524 sshkey_free(key);
525 return ret;
526 }
527
528 static int
list_identities(int agent_fd,int do_fp)529 list_identities(int agent_fd, int do_fp)
530 {
531 char *fp;
532 int r;
533 struct ssh_identitylist *idlist;
534 u_int32_t left;
535 size_t i;
536
537 if ((r = ssh_fetch_identitylist(agent_fd, &idlist)) != 0) {
538 if (r != SSH_ERR_AGENT_NO_IDENTITIES)
539 fprintf(stderr, "error fetching identities: %s\n",
540 ssh_err(r));
541 else
542 printf("The agent has no identities.\n");
543 return -1;
544 }
545 for (i = 0; i < idlist->nkeys; i++) {
546 if (do_fp) {
547 fp = sshkey_fingerprint(idlist->keys[i],
548 fingerprint_hash, SSH_FP_DEFAULT);
549 printf("%u %s %s (%s)\n", sshkey_size(idlist->keys[i]),
550 fp == NULL ? "(null)" : fp, idlist->comments[i],
551 sshkey_type(idlist->keys[i]));
552 free(fp);
553 } else {
554 if ((r = sshkey_write(idlist->keys[i], stdout)) != 0) {
555 fprintf(stderr, "sshkey_write: %s\n",
556 ssh_err(r));
557 continue;
558 }
559 fprintf(stdout, " %s", idlist->comments[i]);
560 left = sshkey_signatures_left(idlist->keys[i]);
561 if (left > 0)
562 fprintf(stdout,
563 " [signatures left %d]", left);
564 fprintf(stdout, "\n");
565 }
566 }
567 ssh_free_identitylist(idlist);
568 return 0;
569 }
570
571 static int
lock_agent(int agent_fd,int lock)572 lock_agent(int agent_fd, int lock)
573 {
574 char prompt[100], *p1, *p2;
575 int r, passok = 1, ret = -1;
576
577 strlcpy(prompt, "Enter lock password: ", sizeof(prompt));
578 p1 = read_passphrase(prompt, RP_ALLOW_STDIN);
579 if (lock) {
580 strlcpy(prompt, "Again: ", sizeof prompt);
581 p2 = read_passphrase(prompt, RP_ALLOW_STDIN);
582 if (strcmp(p1, p2) != 0) {
583 fprintf(stderr, "Passwords do not match.\n");
584 passok = 0;
585 }
586 freezero(p2, strlen(p2));
587 }
588 if (passok) {
589 if ((r = ssh_lock_agent(agent_fd, lock, p1)) == 0) {
590 fprintf(stderr, "Agent %slocked.\n", lock ? "" : "un");
591 ret = 0;
592 } else {
593 fprintf(stderr, "Failed to %slock agent: %s\n",
594 lock ? "" : "un", ssh_err(r));
595 }
596 }
597 freezero(p1, strlen(p1));
598 return (ret);
599 }
600
601 static int
load_resident_keys(int agent_fd,const char * skprovider,int qflag,struct dest_constraint ** dest_constraints,size_t ndest_constraints)602 load_resident_keys(int agent_fd, const char *skprovider, int qflag,
603 struct dest_constraint **dest_constraints, size_t ndest_constraints)
604 {
605 struct sshsk_resident_key **srks;
606 size_t nsrks, i;
607 struct sshkey *key;
608 int r, ok = 0;
609 char *fp;
610
611 pass = read_passphrase("Enter PIN for authenticator: ", RP_ALLOW_STDIN);
612 if ((r = sshsk_load_resident(skprovider, NULL, pass, 0,
613 &srks, &nsrks)) != 0) {
614 error_r(r, "Unable to load resident keys");
615 return r;
616 }
617 for (i = 0; i < nsrks; i++) {
618 key = srks[i]->key;
619 if ((fp = sshkey_fingerprint(key,
620 fingerprint_hash, SSH_FP_DEFAULT)) == NULL)
621 fatal_f("sshkey_fingerprint failed");
622 if ((r = ssh_add_identity_constrained(agent_fd, key, "",
623 lifetime, confirm, maxsign, skprovider,
624 dest_constraints, ndest_constraints)) != 0) {
625 error("Unable to add key %s %s",
626 sshkey_type(key), fp);
627 free(fp);
628 ok = r;
629 continue;
630 }
631 if (ok == 0)
632 ok = 1;
633 if (!qflag) {
634 fprintf(stderr, "Resident identity added: %s %s\n",
635 sshkey_type(key), fp);
636 if (lifetime != 0) {
637 fprintf(stderr,
638 "Lifetime set to %d seconds\n", lifetime);
639 }
640 if (confirm != 0) {
641 fprintf(stderr, "The user must confirm "
642 "each use of the key\n");
643 }
644 }
645 free(fp);
646 }
647 sshsk_free_resident_keys(srks, nsrks);
648 if (nsrks == 0)
649 return SSH_ERR_KEY_NOT_FOUND;
650 return ok == 1 ? 0 : ok;
651 }
652
653 static int
do_file(int agent_fd,int deleting,int key_only,int cert_only,char * file,int qflag,const char * skprovider,struct dest_constraint ** dest_constraints,size_t ndest_constraints)654 do_file(int agent_fd, int deleting, int key_only, int cert_only,
655 char *file, int qflag, const char *skprovider,
656 struct dest_constraint **dest_constraints, size_t ndest_constraints)
657 {
658 if (deleting) {
659 if (delete_file(agent_fd, file, key_only,
660 cert_only, qflag) == -1)
661 return -1;
662 } else {
663 if (add_file(agent_fd, file, key_only, cert_only, qflag,
664 skprovider, dest_constraints, ndest_constraints) == -1)
665 return -1;
666 }
667 return 0;
668 }
669
670 /* Append string 's' to a NULL-terminated array of strings */
671 static void
stringlist_append(char *** listp,const char * s)672 stringlist_append(char ***listp, const char *s)
673 {
674 size_t i = 0;
675
676 if (*listp == NULL)
677 *listp = xcalloc(2, sizeof(**listp));
678 else {
679 for (i = 0; (*listp)[i] != NULL; i++)
680 ; /* count */
681 *listp = xrecallocarray(*listp, i + 1, i + 2, sizeof(**listp));
682 }
683 (*listp)[i] = xstrdup(s);
684 }
685
686 static void
parse_dest_constraint_hop(const char * s,struct dest_constraint_hop * dch,char ** hostkey_files)687 parse_dest_constraint_hop(const char *s, struct dest_constraint_hop *dch,
688 char **hostkey_files)
689 {
690 char *user = NULL, *host, *os, *path;
691 size_t i;
692 struct hostkeys *hostkeys;
693 const struct hostkey_entry *hke;
694 int r, want_ca;
695
696 memset(dch, '\0', sizeof(*dch));
697 os = xstrdup(s);
698 if ((host = strrchr(os, '@')) == NULL)
699 host = os;
700 else {
701 *host++ = '\0';
702 user = os;
703 }
704 cleanhostname(host);
705 /* Trivial case: username@ (all hosts) */
706 if (*host == '\0') {
707 if (user == NULL) {
708 fatal("Invalid key destination constraint \"%s\": "
709 "does not specify user or host", s);
710 }
711 dch->user = xstrdup(user);
712 /* other fields left blank */
713 free(os);
714 return;
715 }
716 if (hostkey_files == NULL)
717 fatal_f("no hostkey files");
718 /* Otherwise we need to look up the keys for this hostname */
719 hostkeys = init_hostkeys();
720 for (i = 0; hostkey_files[i]; i++) {
721 path = tilde_expand_filename(hostkey_files[i], getuid());
722 debug2_f("looking up host keys for \"%s\" in %s", host, path);
723 load_hostkeys(hostkeys, host, path, 0);
724 free(path);
725 }
726 dch->user = user == NULL ? NULL : xstrdup(user);
727 dch->hostname = xstrdup(host);
728 for (i = 0; i < hostkeys->num_entries; i++) {
729 hke = hostkeys->entries + i;
730 want_ca = hke->marker == MRK_CA;
731 if (hke->marker != MRK_NONE && !want_ca)
732 continue;
733 debug3_f("%s%s%s: adding %s %skey from %s:%lu as key %u",
734 user == NULL ? "": user, user == NULL ? "" : "@",
735 host, sshkey_type(hke->key), want_ca ? "CA " : "",
736 hke->file, hke->line, dch->nkeys);
737 dch->keys = xrecallocarray(dch->keys, dch->nkeys,
738 dch->nkeys + 1, sizeof(*dch->keys));
739 dch->key_is_ca = xrecallocarray(dch->key_is_ca, dch->nkeys,
740 dch->nkeys + 1, sizeof(*dch->key_is_ca));
741 if ((r = sshkey_from_private(hke->key,
742 &(dch->keys[dch->nkeys]))) != 0)
743 fatal_fr(r, "sshkey_from_private");
744 dch->key_is_ca[dch->nkeys] = want_ca;
745 dch->nkeys++;
746 }
747 if (dch->nkeys == 0)
748 fatal("No host keys found for destination \"%s\"", host);
749 free_hostkeys(hostkeys);
750 free(os);
751 return;
752 }
753
754 static void
parse_dest_constraint(const char * s,struct dest_constraint *** dcp,size_t * ndcp,char ** hostkey_files)755 parse_dest_constraint(const char *s, struct dest_constraint ***dcp,
756 size_t *ndcp, char **hostkey_files)
757 {
758 struct dest_constraint *dc;
759 char *os, *cp;
760
761 dc = xcalloc(1, sizeof(*dc));
762 os = xstrdup(s);
763 if ((cp = strchr(os, '>')) == NULL) {
764 /* initial hop; no 'from' hop specified */
765 parse_dest_constraint_hop(os, &dc->to, hostkey_files);
766 } else {
767 /* two hops specified */
768 *(cp++) = '\0';
769 parse_dest_constraint_hop(os, &dc->from, hostkey_files);
770 parse_dest_constraint_hop(cp, &dc->to, hostkey_files);
771 if (dc->from.user != NULL) {
772 fatal("Invalid key constraint %s: cannot specify "
773 "user on 'from' host", os);
774 }
775 }
776 /* XXX eliminate or error on duplicates */
777 debug2_f("constraint %zu: %s%s%s (%u keys) > %s%s%s (%u keys)", *ndcp,
778 dc->from.user ? dc->from.user : "", dc->from.user ? "@" : "",
779 dc->from.hostname ? dc->from.hostname : "(ORIGIN)", dc->from.nkeys,
780 dc->to.user ? dc->to.user : "", dc->to.user ? "@" : "",
781 dc->to.hostname ? dc->to.hostname : "(ANY)", dc->to.nkeys);
782 *dcp = xrecallocarray(*dcp, *ndcp, *ndcp + 1, sizeof(**dcp));
783 (*dcp)[(*ndcp)++] = dc;
784 free(os);
785 }
786
787
788 static void
usage(void)789 usage(void)
790 {
791 fprintf(stderr,
792 "usage: ssh-add [-CcDdKkLlqvXx] [-E fingerprint_hash] [-H hostkey_file]\n"
793 " [-h destination_constraint] [-S provider] [-t life]\n"
794 #ifdef WITH_XMSS
795 " [-M maxsign] [-m minleft]\n"
796 #endif
797 " [file ...]\n"
798 " ssh-add -s pkcs11 [-Cv] [certificate ...]\n"
799 " ssh-add -e pkcs11\n"
800 " ssh-add -T pubkey ...\n"
801 );
802 }
803
804 int
main(int argc,char ** argv)805 main(int argc, char **argv)
806 {
807 extern char *optarg;
808 extern int optind;
809 int agent_fd;
810 char *pkcs11provider = NULL;
811 const char *skprovider = NULL;
812 char **dest_constraint_strings = NULL, **hostkey_files = NULL;
813 int r, i, ch, deleting = 0, ret = 0, key_only = 0, cert_only = 0;
814 int do_download = 0, xflag = 0, lflag = 0, Dflag = 0;
815 int qflag = 0, Tflag = 0;
816 SyslogFacility log_facility = SYSLOG_FACILITY_AUTH;
817 LogLevel log_level = SYSLOG_LEVEL_INFO;
818 struct sshkey *k, **certs = NULL;
819 struct dest_constraint **dest_constraints = NULL;
820 size_t ndest_constraints = 0, ncerts = 0;
821
822 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
823 sanitise_stdfd();
824
825 #ifdef WITH_OPENSSL
826 OpenSSL_add_all_algorithms();
827 #endif
828 log_init(__progname, log_level, log_facility, 1);
829
830 setvbuf(stdout, NULL, _IOLBF, 0);
831
832 /* First, get a connection to the authentication agent. */
833 switch (r = ssh_get_authentication_socket(&agent_fd)) {
834 case 0:
835 break;
836 case SSH_ERR_AGENT_NOT_PRESENT:
837 fprintf(stderr, "Could not open a connection to your "
838 "authentication agent.\n");
839 exit(2);
840 default:
841 fprintf(stderr, "Error connecting to agent: %s\n", ssh_err(r));
842 exit(2);
843 }
844
845 skprovider = getenv("SSH_SK_PROVIDER");
846
847 while ((ch = getopt(argc, argv, "vkKlLCcdDTxXE:e:h:H:M:m:qs:S:t:")) != -1) {
848 switch (ch) {
849 case 'v':
850 if (log_level == SYSLOG_LEVEL_INFO)
851 log_level = SYSLOG_LEVEL_DEBUG1;
852 else if (log_level < SYSLOG_LEVEL_DEBUG3)
853 log_level++;
854 break;
855 case 'E':
856 fingerprint_hash = ssh_digest_alg_by_name(optarg);
857 if (fingerprint_hash == -1)
858 fatal("Invalid hash algorithm \"%s\"", optarg);
859 break;
860 case 'H':
861 stringlist_append(&hostkey_files, optarg);
862 break;
863 case 'h':
864 stringlist_append(&dest_constraint_strings, optarg);
865 break;
866 case 'k':
867 key_only = 1;
868 break;
869 case 'C':
870 cert_only = 1;
871 break;
872 case 'K':
873 do_download = 1;
874 break;
875 case 'l':
876 case 'L':
877 if (lflag != 0)
878 fatal("-%c flag already specified", lflag);
879 lflag = ch;
880 break;
881 case 'x':
882 case 'X':
883 if (xflag != 0)
884 fatal("-%c flag already specified", xflag);
885 xflag = ch;
886 break;
887 case 'c':
888 confirm = 1;
889 break;
890 case 'm':
891 minleft = (u_int)strtonum(optarg, 1, UINT_MAX, NULL);
892 if (minleft == 0) {
893 usage();
894 ret = 1;
895 goto done;
896 }
897 break;
898 case 'M':
899 maxsign = (u_int)strtonum(optarg, 1, UINT_MAX, NULL);
900 if (maxsign == 0) {
901 usage();
902 ret = 1;
903 goto done;
904 }
905 break;
906 case 'd':
907 deleting = 1;
908 break;
909 case 'D':
910 Dflag = 1;
911 break;
912 case 's':
913 pkcs11provider = optarg;
914 break;
915 case 'S':
916 skprovider = optarg;
917 break;
918 case 'e':
919 deleting = 1;
920 pkcs11provider = optarg;
921 break;
922 case 't':
923 if ((lifetime = convtime(optarg)) == -1 ||
924 lifetime < 0 || (u_long)lifetime > UINT32_MAX) {
925 fprintf(stderr, "Invalid lifetime\n");
926 ret = 1;
927 goto done;
928 }
929 break;
930 case 'q':
931 qflag = 1;
932 break;
933 case 'T':
934 Tflag = 1;
935 break;
936 default:
937 usage();
938 ret = 1;
939 goto done;
940 }
941 }
942 log_init(__progname, log_level, log_facility, 1);
943
944 if ((xflag != 0) + (lflag != 0) + (Dflag != 0) > 1)
945 fatal("Invalid combination of actions");
946 else if (xflag) {
947 if (lock_agent(agent_fd, xflag == 'x' ? 1 : 0) == -1)
948 ret = 1;
949 goto done;
950 } else if (lflag) {
951 if (list_identities(agent_fd, lflag == 'l' ? 1 : 0) == -1)
952 ret = 1;
953 goto done;
954 } else if (Dflag) {
955 if (delete_all(agent_fd, qflag) == -1)
956 ret = 1;
957 goto done;
958 }
959
960 if (skprovider == NULL)
961 skprovider = "internal";
962 if (hostkey_files == NULL) {
963 /* use defaults from readconf.c */
964 stringlist_append(&hostkey_files, _PATH_SSH_USER_HOSTFILE);
965 stringlist_append(&hostkey_files, _PATH_SSH_USER_HOSTFILE2);
966 stringlist_append(&hostkey_files, _PATH_SSH_SYSTEM_HOSTFILE);
967 stringlist_append(&hostkey_files, _PATH_SSH_SYSTEM_HOSTFILE2);
968 }
969 if (dest_constraint_strings != NULL) {
970 for (i = 0; dest_constraint_strings[i] != NULL; i++) {
971 parse_dest_constraint(dest_constraint_strings[i],
972 &dest_constraints, &ndest_constraints, hostkey_files);
973 }
974 }
975
976 argc -= optind;
977 argv += optind;
978 if (Tflag) {
979 if (argc <= 0)
980 fatal("no keys to test");
981 for (r = i = 0; i < argc; i++)
982 r |= test_key(agent_fd, argv[i]);
983 ret = r == 0 ? 0 : 1;
984 goto done;
985 }
986 if (pkcs11provider != NULL) {
987 for (i = 0; i < argc; i++) {
988 if ((r = sshkey_load_public(argv[i], &k, NULL)) != 0)
989 fatal_fr(r, "load certificate %s", argv[i]);
990 certs = xrecallocarray(certs, ncerts, ncerts + 1,
991 sizeof(*certs));
992 debug2("%s: %s", argv[i], sshkey_ssh_name(k));
993 certs[ncerts++] = k;
994 }
995 debug2_f("loaded %zu certificates", ncerts);
996 if (update_card(agent_fd, !deleting, pkcs11provider,
997 qflag, key_only, cert_only,
998 dest_constraints, ndest_constraints,
999 certs, ncerts) == -1)
1000 ret = 1;
1001 goto done;
1002 }
1003 if (do_download) {
1004 if (skprovider == NULL)
1005 fatal("Cannot download keys without provider");
1006 if (load_resident_keys(agent_fd, skprovider, qflag,
1007 dest_constraints, ndest_constraints) != 0)
1008 ret = 1;
1009 goto done;
1010 }
1011 if (argc == 0) {
1012 char buf[PATH_MAX];
1013 struct passwd *pw;
1014 struct stat st;
1015 int count = 0;
1016
1017 if ((pw = getpwuid(getuid())) == NULL) {
1018 fprintf(stderr, "No user found with uid %u\n",
1019 (u_int)getuid());
1020 ret = 1;
1021 goto done;
1022 }
1023
1024 for (i = 0; default_files[i]; i++) {
1025 snprintf(buf, sizeof(buf), "%s/%s", pw->pw_dir,
1026 default_files[i]);
1027 if (stat(buf, &st) == -1)
1028 continue;
1029 if (do_file(agent_fd, deleting, key_only, cert_only,
1030 buf, qflag, skprovider,
1031 dest_constraints, ndest_constraints) == -1)
1032 ret = 1;
1033 else
1034 count++;
1035 }
1036 if (count == 0)
1037 ret = 1;
1038 } else {
1039 for (i = 0; i < argc; i++) {
1040 if (do_file(agent_fd, deleting, key_only, cert_only,
1041 argv[i], qflag, skprovider,
1042 dest_constraints, ndest_constraints) == -1)
1043 ret = 1;
1044 }
1045 }
1046 done:
1047 clear_pass();
1048 ssh_close_authentication_socket(agent_fd);
1049 return ret;
1050 }
1051