1 /* $OpenBSD: ssh-add.c,v 1.123 2015/07/03 03:43:18 djm 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 * Adds an identity to the authentication server, or removes an identity.
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, 2001 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/stat.h>
42
43 #include <openssl/evp.h>
44 #include "openbsd-compat/openssl-compat.h"
45
46 #include <errno.h>
47 #include <fcntl.h>
48 #include <pwd.h>
49 #include <stdarg.h>
50 #include <stdio.h>
51 #include <stdlib.h>
52 #include <string.h>
53 #include <unistd.h>
54 #include <limits.h>
55
56 #include "xmalloc.h"
57 #include "ssh.h"
58 #include "rsa.h"
59 #include "log.h"
60 #include "sshkey.h"
61 #include "sshbuf.h"
62 #include "authfd.h"
63 #include "authfile.h"
64 #include "pathnames.h"
65 #include "misc.h"
66 #include "ssherr.h"
67 #include "digest.h"
68
69 /* argv0 */
70 extern char *__progname;
71
72 /* Default files to add */
73 static char *default_files[] = {
74 #ifdef WITH_OPENSSL
75 _PATH_SSH_CLIENT_ID_RSA,
76 _PATH_SSH_CLIENT_ID_DSA,
77 #ifdef OPENSSL_HAS_ECC
78 _PATH_SSH_CLIENT_ID_ECDSA,
79 #endif
80 #endif /* WITH_OPENSSL */
81 _PATH_SSH_CLIENT_ID_ED25519,
82 #ifdef WITH_SSH1
83 _PATH_SSH_CLIENT_IDENTITY,
84 #endif
85 NULL
86 };
87
88 static int fingerprint_hash = SSH_FP_HASH_DEFAULT;
89
90 /* Default lifetime (0 == forever) */
91 static int lifetime = 0;
92
93 /* User has to confirm key use */
94 static int confirm = 0;
95
96 /* we keep a cache of one passphrases */
97 static char *pass = NULL;
98 static void
clear_pass(void)99 clear_pass(void)
100 {
101 if (pass) {
102 explicit_bzero(pass, strlen(pass));
103 free(pass);
104 pass = NULL;
105 }
106 }
107
108 static int
delete_file(int agent_fd,const char * filename,int key_only)109 delete_file(int agent_fd, const char *filename, int key_only)
110 {
111 struct sshkey *public, *cert = NULL;
112 char *certpath = NULL, *comment = NULL;
113 int r, ret = -1;
114
115 if ((r = sshkey_load_public(filename, &public, &comment)) != 0) {
116 printf("Bad key file %s: %s\n", filename, ssh_err(r));
117 return -1;
118 }
119 if ((r = ssh_remove_identity(agent_fd, public)) == 0) {
120 fprintf(stderr, "Identity removed: %s (%s)\n", filename, comment);
121 ret = 0;
122 } else
123 fprintf(stderr, "Could not remove identity \"%s\": %s\n",
124 filename, ssh_err(r));
125
126 if (key_only)
127 goto out;
128
129 /* Now try to delete the corresponding certificate too */
130 free(comment);
131 comment = NULL;
132 xasprintf(&certpath, "%s-cert.pub", filename);
133 if ((r = sshkey_load_public(certpath, &cert, &comment)) != 0) {
134 if (r != SSH_ERR_SYSTEM_ERROR || errno != ENOENT)
135 error("Failed to load certificate \"%s\": %s",
136 certpath, ssh_err(r));
137 goto out;
138 }
139
140 if (!sshkey_equal_public(cert, public))
141 fatal("Certificate %s does not match private key %s",
142 certpath, filename);
143
144 if ((r = ssh_remove_identity(agent_fd, cert)) == 0) {
145 fprintf(stderr, "Identity removed: %s (%s)\n", certpath,
146 comment);
147 ret = 0;
148 } else
149 fprintf(stderr, "Could not remove identity \"%s\": %s\n",
150 certpath, ssh_err(r));
151
152 out:
153 if (cert != NULL)
154 sshkey_free(cert);
155 if (public != NULL)
156 sshkey_free(public);
157 free(certpath);
158 free(comment);
159
160 return ret;
161 }
162
163 /* Send a request to remove all identities. */
164 static int
delete_all(int agent_fd)165 delete_all(int agent_fd)
166 {
167 int ret = -1;
168
169 if (ssh_remove_all_identities(agent_fd, 2) == 0)
170 ret = 0;
171 /* ignore error-code for ssh1 */
172 ssh_remove_all_identities(agent_fd, 1);
173
174 if (ret == 0)
175 fprintf(stderr, "All identities removed.\n");
176 else
177 fprintf(stderr, "Failed to remove all identities.\n");
178
179 return ret;
180 }
181
182 static int
add_file(int agent_fd,const char * filename,int key_only)183 add_file(int agent_fd, const char *filename, int key_only)
184 {
185 struct sshkey *private, *cert;
186 char *comment = NULL;
187 char msg[1024], *certpath = NULL;
188 int r, fd, ret = -1;
189 struct sshbuf *keyblob;
190
191 if (strcmp(filename, "-") == 0) {
192 fd = STDIN_FILENO;
193 filename = "(stdin)";
194 } else if ((fd = open(filename, O_RDONLY)) < 0) {
195 perror(filename);
196 return -1;
197 }
198
199 /*
200 * Since we'll try to load a keyfile multiple times, permission errors
201 * will occur multiple times, so check perms first and bail if wrong.
202 */
203 if (fd != STDIN_FILENO) {
204 if (sshkey_perm_ok(fd, filename) != 0) {
205 close(fd);
206 return -1;
207 }
208 }
209 if ((keyblob = sshbuf_new()) == NULL)
210 fatal("%s: sshbuf_new failed", __func__);
211 if ((r = sshkey_load_file(fd, keyblob)) != 0) {
212 fprintf(stderr, "Error loading key \"%s\": %s\n",
213 filename, ssh_err(r));
214 sshbuf_free(keyblob);
215 close(fd);
216 return -1;
217 }
218 close(fd);
219
220 /* At first, try empty passphrase */
221 if ((r = sshkey_parse_private_fileblob(keyblob, "", filename,
222 &private, &comment)) != 0 && r != SSH_ERR_KEY_WRONG_PASSPHRASE) {
223 fprintf(stderr, "Error loading key \"%s\": %s\n",
224 filename, ssh_err(r));
225 goto fail_load;
226 }
227 /* try last */
228 if (private == NULL && pass != NULL) {
229 if ((r = sshkey_parse_private_fileblob(keyblob, pass, filename,
230 &private, &comment)) != 0 &&
231 r != SSH_ERR_KEY_WRONG_PASSPHRASE) {
232 fprintf(stderr, "Error loading key \"%s\": %s\n",
233 filename, ssh_err(r));
234 goto fail_load;
235 }
236 }
237 if (comment == NULL)
238 comment = xstrdup(filename);
239 if (private == NULL) {
240 /* clear passphrase since it did not work */
241 clear_pass();
242 snprintf(msg, sizeof msg, "Enter passphrase for %.200s%s: ",
243 comment, confirm ? " (will confirm each use)" : "");
244 for (;;) {
245 pass = read_passphrase(msg, RP_ALLOW_STDIN);
246 if (strcmp(pass, "") == 0)
247 goto fail_load;
248 if ((r = sshkey_parse_private_fileblob(keyblob, pass,
249 filename, &private, NULL)) == 0)
250 break;
251 else if (r != SSH_ERR_KEY_WRONG_PASSPHRASE) {
252 fprintf(stderr,
253 "Error loading key \"%s\": %s\n",
254 filename, ssh_err(r));
255 fail_load:
256 clear_pass();
257 free(comment);
258 sshbuf_free(keyblob);
259 return -1;
260 }
261 clear_pass();
262 snprintf(msg, sizeof msg,
263 "Bad passphrase, try again for %.200s%s: ", comment,
264 confirm ? " (will confirm each use)" : "");
265 }
266 }
267 sshbuf_free(keyblob);
268
269 if ((r = ssh_add_identity_constrained(agent_fd, private, comment,
270 lifetime, confirm)) == 0) {
271 fprintf(stderr, "Identity added: %s (%s)\n", filename, comment);
272 ret = 0;
273 if (lifetime != 0)
274 fprintf(stderr,
275 "Lifetime set to %d seconds\n", lifetime);
276 if (confirm != 0)
277 fprintf(stderr,
278 "The user must confirm each use of the key\n");
279 } else {
280 fprintf(stderr, "Could not add identity \"%s\": %s\n",
281 filename, ssh_err(r));
282 }
283
284 /* Skip trying to load the cert if requested */
285 if (key_only)
286 goto out;
287
288 /* Now try to add the certificate flavour too */
289 xasprintf(&certpath, "%s-cert.pub", filename);
290 if ((r = sshkey_load_public(certpath, &cert, NULL)) != 0) {
291 if (r != SSH_ERR_SYSTEM_ERROR || errno != ENOENT)
292 error("Failed to load certificate \"%s\": %s",
293 certpath, ssh_err(r));
294 goto out;
295 }
296
297 if (!sshkey_equal_public(cert, private)) {
298 error("Certificate %s does not match private key %s",
299 certpath, filename);
300 sshkey_free(cert);
301 goto out;
302 }
303
304 /* Graft with private bits */
305 if ((r = sshkey_to_certified(private)) != 0) {
306 error("%s: sshkey_to_certified: %s", __func__, ssh_err(r));
307 sshkey_free(cert);
308 goto out;
309 }
310 if ((r = sshkey_cert_copy(cert, private)) != 0) {
311 error("%s: key_cert_copy: %s", __func__, ssh_err(r));
312 sshkey_free(cert);
313 goto out;
314 }
315 sshkey_free(cert);
316
317 if ((r = ssh_add_identity_constrained(agent_fd, private, comment,
318 lifetime, confirm)) != 0) {
319 error("Certificate %s (%s) add failed: %s", certpath,
320 private->cert->key_id, ssh_err(r));
321 goto out;
322 }
323 fprintf(stderr, "Certificate added: %s (%s)\n", certpath,
324 private->cert->key_id);
325 if (lifetime != 0)
326 fprintf(stderr, "Lifetime set to %d seconds\n", lifetime);
327 if (confirm != 0)
328 fprintf(stderr, "The user must confirm each use of the key\n");
329 out:
330 free(certpath);
331 free(comment);
332 sshkey_free(private);
333
334 return ret;
335 }
336
337 static int
update_card(int agent_fd,int add,const char * id)338 update_card(int agent_fd, int add, const char *id)
339 {
340 char *pin = NULL;
341 int r, ret = -1;
342
343 if (add) {
344 if ((pin = read_passphrase("Enter passphrase for PKCS#11: ",
345 RP_ALLOW_STDIN)) == NULL)
346 return -1;
347 }
348
349 if ((r = ssh_update_card(agent_fd, add, id, pin == NULL ? "" : pin,
350 lifetime, confirm)) == 0) {
351 fprintf(stderr, "Card %s: %s\n",
352 add ? "added" : "removed", id);
353 ret = 0;
354 } else {
355 fprintf(stderr, "Could not %s card \"%s\": %s\n",
356 add ? "add" : "remove", id, ssh_err(r));
357 ret = -1;
358 }
359 free(pin);
360 return ret;
361 }
362
363 static int
list_identities(int agent_fd,int do_fp)364 list_identities(int agent_fd, int do_fp)
365 {
366 char *fp;
367 int r, had_identities = 0;
368 struct ssh_identitylist *idlist;
369 size_t i;
370 #ifdef WITH_SSH1
371 int version = 1;
372 #else
373 int version = 2;
374 #endif
375
376 for (; version <= 2; version++) {
377 if ((r = ssh_fetch_identitylist(agent_fd, version,
378 &idlist)) != 0) {
379 if (r != SSH_ERR_AGENT_NO_IDENTITIES)
380 fprintf(stderr, "error fetching identities for "
381 "protocol %d: %s\n", version, ssh_err(r));
382 continue;
383 }
384 for (i = 0; i < idlist->nkeys; i++) {
385 had_identities = 1;
386 if (do_fp) {
387 fp = sshkey_fingerprint(idlist->keys[i],
388 fingerprint_hash, SSH_FP_DEFAULT);
389 printf("%d %s %s (%s)\n",
390 sshkey_size(idlist->keys[i]),
391 fp == NULL ? "(null)" : fp,
392 idlist->comments[i],
393 sshkey_type(idlist->keys[i]));
394 free(fp);
395 } else {
396 if ((r = sshkey_write(idlist->keys[i],
397 stdout)) != 0) {
398 fprintf(stderr, "sshkey_write: %s\n",
399 ssh_err(r));
400 continue;
401 }
402 fprintf(stdout, " %s\n", idlist->comments[i]);
403 }
404 }
405 ssh_free_identitylist(idlist);
406 }
407 if (!had_identities) {
408 printf("The agent has no identities.\n");
409 return -1;
410 }
411 return 0;
412 }
413
414 static int
lock_agent(int agent_fd,int lock)415 lock_agent(int agent_fd, int lock)
416 {
417 char prompt[100], *p1, *p2;
418 int r, passok = 1, ret = -1;
419
420 strlcpy(prompt, "Enter lock password: ", sizeof(prompt));
421 p1 = read_passphrase(prompt, RP_ALLOW_STDIN);
422 if (lock) {
423 strlcpy(prompt, "Again: ", sizeof prompt);
424 p2 = read_passphrase(prompt, RP_ALLOW_STDIN);
425 if (strcmp(p1, p2) != 0) {
426 fprintf(stderr, "Passwords do not match.\n");
427 passok = 0;
428 }
429 explicit_bzero(p2, strlen(p2));
430 free(p2);
431 }
432 if (passok) {
433 if ((r = ssh_lock_agent(agent_fd, lock, p1)) == 0) {
434 fprintf(stderr, "Agent %slocked.\n", lock ? "" : "un");
435 ret = 0;
436 } else {
437 fprintf(stderr, "Failed to %slock agent: %s\n",
438 lock ? "" : "un", ssh_err(r));
439 }
440 }
441 explicit_bzero(p1, strlen(p1));
442 free(p1);
443 return (ret);
444 }
445
446 static int
do_file(int agent_fd,int deleting,int key_only,char * file)447 do_file(int agent_fd, int deleting, int key_only, char *file)
448 {
449 if (deleting) {
450 if (delete_file(agent_fd, file, key_only) == -1)
451 return -1;
452 } else {
453 if (add_file(agent_fd, file, key_only) == -1)
454 return -1;
455 }
456 return 0;
457 }
458
459 static void
usage(void)460 usage(void)
461 {
462 fprintf(stderr, "usage: %s [options] [file ...]\n", __progname);
463 fprintf(stderr, "Options:\n");
464 fprintf(stderr, " -l List fingerprints of all identities.\n");
465 fprintf(stderr, " -E hash Specify hash algorithm used for fingerprints.\n");
466 fprintf(stderr, " -L List public key parameters of all identities.\n");
467 fprintf(stderr, " -k Load only keys and not certificates.\n");
468 fprintf(stderr, " -c Require confirmation to sign using identities\n");
469 fprintf(stderr, " -t life Set lifetime (in seconds) when adding identities.\n");
470 fprintf(stderr, " -d Delete identity.\n");
471 fprintf(stderr, " -D Delete all identities.\n");
472 fprintf(stderr, " -x Lock agent.\n");
473 fprintf(stderr, " -X Unlock agent.\n");
474 fprintf(stderr, " -s pkcs11 Add keys from PKCS#11 provider.\n");
475 fprintf(stderr, " -e pkcs11 Remove keys provided by PKCS#11 provider.\n");
476 }
477
478 int
main(int argc,char ** argv)479 main(int argc, char **argv)
480 {
481 extern char *optarg;
482 extern int optind;
483 int agent_fd;
484 char *pkcs11provider = NULL;
485 int r, i, ch, deleting = 0, ret = 0, key_only = 0;
486 int xflag = 0, lflag = 0, Dflag = 0;
487
488 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
489 sanitise_stdfd();
490
491 __progname = ssh_get_progname(argv[0]);
492 seed_rng();
493
494 #ifdef WITH_OPENSSL
495 OpenSSL_add_all_algorithms();
496 #endif
497
498 setvbuf(stdout, NULL, _IOLBF, 0);
499
500 /* First, get a connection to the authentication agent. */
501 switch (r = ssh_get_authentication_socket(&agent_fd)) {
502 case 0:
503 break;
504 case SSH_ERR_AGENT_NOT_PRESENT:
505 fprintf(stderr, "Could not open a connection to your "
506 "authentication agent.\n");
507 exit(2);
508 default:
509 fprintf(stderr, "Error connecting to agent: %s\n", ssh_err(r));
510 exit(2);
511 }
512
513 while ((ch = getopt(argc, argv, "klLcdDxXE:e:s:t:")) != -1) {
514 switch (ch) {
515 case 'E':
516 fingerprint_hash = ssh_digest_alg_by_name(optarg);
517 if (fingerprint_hash == -1)
518 fatal("Invalid hash algorithm \"%s\"", optarg);
519 break;
520 case 'k':
521 key_only = 1;
522 break;
523 case 'l':
524 case 'L':
525 if (lflag != 0)
526 fatal("-%c flag already specified", lflag);
527 lflag = ch;
528 break;
529 case 'x':
530 case 'X':
531 if (xflag != 0)
532 fatal("-%c flag already specified", xflag);
533 xflag = ch;
534 break;
535 case 'c':
536 confirm = 1;
537 break;
538 case 'd':
539 deleting = 1;
540 break;
541 case 'D':
542 Dflag = 1;
543 break;
544 case 's':
545 pkcs11provider = optarg;
546 break;
547 case 'e':
548 deleting = 1;
549 pkcs11provider = optarg;
550 break;
551 case 't':
552 if ((lifetime = convtime(optarg)) == -1) {
553 fprintf(stderr, "Invalid lifetime\n");
554 ret = 1;
555 goto done;
556 }
557 break;
558 default:
559 usage();
560 ret = 1;
561 goto done;
562 }
563 }
564
565 if ((xflag != 0) + (lflag != 0) + (Dflag != 0) > 1)
566 fatal("Invalid combination of actions");
567 else if (xflag) {
568 if (lock_agent(agent_fd, xflag == 'x' ? 1 : 0) == -1)
569 ret = 1;
570 goto done;
571 } else if (lflag) {
572 if (list_identities(agent_fd, lflag == 'l' ? 1 : 0) == -1)
573 ret = 1;
574 goto done;
575 } else if (Dflag) {
576 if (delete_all(agent_fd) == -1)
577 ret = 1;
578 goto done;
579 }
580
581 argc -= optind;
582 argv += optind;
583 if (pkcs11provider != NULL) {
584 if (update_card(agent_fd, !deleting, pkcs11provider) == -1)
585 ret = 1;
586 goto done;
587 }
588 if (argc == 0) {
589 char buf[PATH_MAX];
590 struct passwd *pw;
591 struct stat st;
592 int count = 0;
593
594 if ((pw = getpwuid(getuid())) == NULL) {
595 fprintf(stderr, "No user found with uid %u\n",
596 (u_int)getuid());
597 ret = 1;
598 goto done;
599 }
600
601 for (i = 0; default_files[i]; i++) {
602 snprintf(buf, sizeof(buf), "%s/%s", pw->pw_dir,
603 default_files[i]);
604 if (stat(buf, &st) < 0)
605 continue;
606 if (do_file(agent_fd, deleting, key_only, buf) == -1)
607 ret = 1;
608 else
609 count++;
610 }
611 if (count == 0)
612 ret = 1;
613 } else {
614 for (i = 0; i < argc; i++) {
615 if (do_file(agent_fd, deleting, key_only,
616 argv[i]) == -1)
617 ret = 1;
618 }
619 }
620 clear_pass();
621
622 done:
623 ssh_close_authentication_socket(agent_fd);
624 return ret;
625 }
626