1 /* $OpenBSD: ssh-add.c,v 1.109 2014/02/02 03:44:31 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 #include <sys/param.h>
43
44 #include <openssl/evp.h>
45 #include "openbsd-compat/openssl-compat.h"
46
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
55 #include "xmalloc.h"
56 #include "ssh.h"
57 #include "rsa.h"
58 #include "log.h"
59 #include "key.h"
60 #include "buffer.h"
61 #include "authfd.h"
62 #include "authfile.h"
63 #include "pathnames.h"
64 #include "misc.h"
65
66 /* argv0 */
67 extern char *__progname;
68
69 /* Default files to add */
70 static char *default_files[] = {
71 _PATH_SSH_CLIENT_ID_RSA,
72 _PATH_SSH_CLIENT_ID_DSA,
73 #ifdef OPENSSL_HAS_ECC
74 _PATH_SSH_CLIENT_ID_ECDSA,
75 #endif
76 _PATH_SSH_CLIENT_ID_ED25519,
77 _PATH_SSH_CLIENT_IDENTITY,
78 NULL
79 };
80
81 /* Default lifetime (0 == forever) */
82 static int lifetime = 0;
83
84 /* User has to confirm key use */
85 static int confirm = 0;
86
87 /* we keep a cache of one passphrases */
88 static char *pass = NULL;
89 static void
clear_pass(void)90 clear_pass(void)
91 {
92 if (pass) {
93 explicit_bzero(pass, strlen(pass));
94 free(pass);
95 pass = NULL;
96 }
97 }
98
99 static int
delete_file(AuthenticationConnection * ac,const char * filename,int key_only)100 delete_file(AuthenticationConnection *ac, const char *filename, int key_only)
101 {
102 Key *public = NULL, *cert = NULL;
103 char *certpath = NULL, *comment = NULL;
104 int ret = -1;
105
106 public = key_load_public(filename, &comment);
107 if (public == NULL) {
108 printf("Bad key file %s\n", filename);
109 return -1;
110 }
111 if (ssh_remove_identity(ac, public)) {
112 fprintf(stderr, "Identity removed: %s (%s)\n", filename, comment);
113 ret = 0;
114 } else
115 fprintf(stderr, "Could not remove identity: %s\n", filename);
116
117 if (key_only)
118 goto out;
119
120 /* Now try to delete the corresponding certificate too */
121 free(comment);
122 comment = NULL;
123 xasprintf(&certpath, "%s-cert.pub", filename);
124 if ((cert = key_load_public(certpath, &comment)) == NULL)
125 goto out;
126 if (!key_equal_public(cert, public))
127 fatal("Certificate %s does not match private key %s",
128 certpath, filename);
129
130 if (ssh_remove_identity(ac, cert)) {
131 fprintf(stderr, "Identity removed: %s (%s)\n", certpath,
132 comment);
133 ret = 0;
134 } else
135 fprintf(stderr, "Could not remove identity: %s\n", certpath);
136
137 out:
138 if (cert != NULL)
139 key_free(cert);
140 if (public != NULL)
141 key_free(public);
142 free(certpath);
143 free(comment);
144
145 return ret;
146 }
147
148 /* Send a request to remove all identities. */
149 static int
delete_all(AuthenticationConnection * ac)150 delete_all(AuthenticationConnection *ac)
151 {
152 int ret = -1;
153
154 if (ssh_remove_all_identities(ac, 1))
155 ret = 0;
156 /* ignore error-code for ssh2 */
157 ssh_remove_all_identities(ac, 2);
158
159 if (ret == 0)
160 fprintf(stderr, "All identities removed.\n");
161 else
162 fprintf(stderr, "Failed to remove all identities.\n");
163
164 return ret;
165 }
166
167 static int
add_file(AuthenticationConnection * ac,const char * filename,int key_only)168 add_file(AuthenticationConnection *ac, const char *filename, int key_only)
169 {
170 Key *private, *cert;
171 char *comment = NULL;
172 char msg[1024], *certpath = NULL;
173 int fd, perms_ok, ret = -1;
174 Buffer keyblob;
175
176 if (strcmp(filename, "-") == 0) {
177 fd = STDIN_FILENO;
178 filename = "(stdin)";
179 } else if ((fd = open(filename, O_RDONLY)) < 0) {
180 perror(filename);
181 return -1;
182 }
183
184 /*
185 * Since we'll try to load a keyfile multiple times, permission errors
186 * will occur multiple times, so check perms first and bail if wrong.
187 */
188 if (fd != STDIN_FILENO) {
189 perms_ok = key_perm_ok(fd, filename);
190 if (!perms_ok) {
191 close(fd);
192 return -1;
193 }
194 }
195 buffer_init(&keyblob);
196 if (!key_load_file(fd, filename, &keyblob)) {
197 buffer_free(&keyblob);
198 close(fd);
199 return -1;
200 }
201 close(fd);
202
203 /* At first, try empty passphrase */
204 private = key_parse_private(&keyblob, filename, "", &comment);
205 if (comment == NULL)
206 comment = xstrdup(filename);
207 /* try last */
208 if (private == NULL && pass != NULL)
209 private = key_parse_private(&keyblob, filename, pass, NULL);
210 if (private == NULL) {
211 /* clear passphrase since it did not work */
212 clear_pass();
213 snprintf(msg, sizeof msg, "Enter passphrase for %.200s: ",
214 comment);
215 for (;;) {
216 pass = read_passphrase(msg, RP_ALLOW_STDIN);
217 if (strcmp(pass, "") == 0) {
218 clear_pass();
219 free(comment);
220 buffer_free(&keyblob);
221 return -1;
222 }
223 private = key_parse_private(&keyblob, filename, pass,
224 &comment);
225 if (private != NULL)
226 break;
227 clear_pass();
228 snprintf(msg, sizeof msg,
229 "Bad passphrase, try again for %.200s: ", comment);
230 }
231 }
232 buffer_free(&keyblob);
233
234 if (ssh_add_identity_constrained(ac, private, comment, lifetime,
235 confirm)) {
236 fprintf(stderr, "Identity added: %s (%s)\n", filename, comment);
237 ret = 0;
238 if (lifetime != 0)
239 fprintf(stderr,
240 "Lifetime set to %d seconds\n", lifetime);
241 if (confirm != 0)
242 fprintf(stderr,
243 "The user must confirm each use of the key\n");
244 } else {
245 fprintf(stderr, "Could not add identity: %s\n", filename);
246 }
247
248 /* Skip trying to load the cert if requested */
249 if (key_only)
250 goto out;
251
252 /* Now try to add the certificate flavour too */
253 xasprintf(&certpath, "%s-cert.pub", filename);
254 if ((cert = key_load_public(certpath, NULL)) == NULL)
255 goto out;
256
257 if (!key_equal_public(cert, private)) {
258 error("Certificate %s does not match private key %s",
259 certpath, filename);
260 key_free(cert);
261 goto out;
262 }
263
264 /* Graft with private bits */
265 if (key_to_certified(private, key_cert_is_legacy(cert)) != 0) {
266 error("%s: key_to_certified failed", __func__);
267 key_free(cert);
268 goto out;
269 }
270 key_cert_copy(cert, private);
271 key_free(cert);
272
273 if (!ssh_add_identity_constrained(ac, private, comment,
274 lifetime, confirm)) {
275 error("Certificate %s (%s) add failed", certpath,
276 private->cert->key_id);
277 }
278 fprintf(stderr, "Certificate added: %s (%s)\n", certpath,
279 private->cert->key_id);
280 if (lifetime != 0)
281 fprintf(stderr, "Lifetime set to %d seconds\n", lifetime);
282 if (confirm != 0)
283 fprintf(stderr, "The user must confirm each use of the key\n");
284 out:
285 if (certpath != NULL)
286 free(certpath);
287 free(comment);
288 key_free(private);
289
290 return ret;
291 }
292
293 static int
update_card(AuthenticationConnection * ac,int add,const char * id)294 update_card(AuthenticationConnection *ac, int add, const char *id)
295 {
296 char *pin = NULL;
297 int ret = -1;
298
299 if (add) {
300 if ((pin = read_passphrase("Enter passphrase for PKCS#11: ",
301 RP_ALLOW_STDIN)) == NULL)
302 return -1;
303 }
304
305 if (ssh_update_card(ac, add, id, pin == NULL ? "" : pin,
306 lifetime, confirm)) {
307 fprintf(stderr, "Card %s: %s\n",
308 add ? "added" : "removed", id);
309 ret = 0;
310 } else {
311 fprintf(stderr, "Could not %s card: %s\n",
312 add ? "add" : "remove", id);
313 ret = -1;
314 }
315 free(pin);
316 return ret;
317 }
318
319 static int
list_identities(AuthenticationConnection * ac,int do_fp)320 list_identities(AuthenticationConnection *ac, int do_fp)
321 {
322 Key *key;
323 char *comment, *fp;
324 int had_identities = 0;
325 int version;
326
327 for (version = 1; version <= 2; version++) {
328 for (key = ssh_get_first_identity(ac, &comment, version);
329 key != NULL;
330 key = ssh_get_next_identity(ac, &comment, version)) {
331 had_identities = 1;
332 if (do_fp) {
333 fp = key_fingerprint(key, SSH_FP_MD5,
334 SSH_FP_HEX);
335 printf("%d %s %s (%s)\n",
336 key_size(key), fp, comment, key_type(key));
337 free(fp);
338 } else {
339 if (!key_write(key, stdout))
340 fprintf(stderr, "key_write failed");
341 fprintf(stdout, " %s\n", comment);
342 }
343 key_free(key);
344 free(comment);
345 }
346 }
347 if (!had_identities) {
348 printf("The agent has no identities.\n");
349 return -1;
350 }
351 return 0;
352 }
353
354 static int
lock_agent(AuthenticationConnection * ac,int lock)355 lock_agent(AuthenticationConnection *ac, int lock)
356 {
357 char prompt[100], *p1, *p2;
358 int passok = 1, ret = -1;
359
360 strlcpy(prompt, "Enter lock password: ", sizeof(prompt));
361 p1 = read_passphrase(prompt, RP_ALLOW_STDIN);
362 if (lock) {
363 strlcpy(prompt, "Again: ", sizeof prompt);
364 p2 = read_passphrase(prompt, RP_ALLOW_STDIN);
365 if (strcmp(p1, p2) != 0) {
366 fprintf(stderr, "Passwords do not match.\n");
367 passok = 0;
368 }
369 explicit_bzero(p2, strlen(p2));
370 free(p2);
371 }
372 if (passok && ssh_lock_agent(ac, lock, p1)) {
373 fprintf(stderr, "Agent %slocked.\n", lock ? "" : "un");
374 ret = 0;
375 } else
376 fprintf(stderr, "Failed to %slock agent.\n", lock ? "" : "un");
377 explicit_bzero(p1, strlen(p1));
378 free(p1);
379 return (ret);
380 }
381
382 static int
do_file(AuthenticationConnection * ac,int deleting,int key_only,char * file)383 do_file(AuthenticationConnection *ac, int deleting, int key_only, char *file)
384 {
385 if (deleting) {
386 if (delete_file(ac, file, key_only) == -1)
387 return -1;
388 } else {
389 if (add_file(ac, file, key_only) == -1)
390 return -1;
391 }
392 return 0;
393 }
394
395 static void
usage(void)396 usage(void)
397 {
398 fprintf(stderr, "usage: %s [options] [file ...]\n", __progname);
399 fprintf(stderr, "Options:\n");
400 fprintf(stderr, " -l List fingerprints of all identities.\n");
401 fprintf(stderr, " -L List public key parameters of all identities.\n");
402 fprintf(stderr, " -k Load only keys and not certificates.\n");
403 fprintf(stderr, " -c Require confirmation to sign using identities\n");
404 fprintf(stderr, " -t life Set lifetime (in seconds) when adding identities.\n");
405 fprintf(stderr, " -d Delete identity.\n");
406 fprintf(stderr, " -D Delete all identities.\n");
407 fprintf(stderr, " -x Lock agent.\n");
408 fprintf(stderr, " -X Unlock agent.\n");
409 fprintf(stderr, " -s pkcs11 Add keys from PKCS#11 provider.\n");
410 fprintf(stderr, " -e pkcs11 Remove keys provided by PKCS#11 provider.\n");
411 }
412
413 int
main(int argc,char ** argv)414 main(int argc, char **argv)
415 {
416 extern char *optarg;
417 extern int optind;
418 AuthenticationConnection *ac = NULL;
419 char *pkcs11provider = NULL;
420 int i, ch, deleting = 0, ret = 0, key_only = 0;
421
422 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
423 sanitise_stdfd();
424
425 __progname = ssh_get_progname(argv[0]);
426 seed_rng();
427
428 OpenSSL_add_all_algorithms();
429
430 /* At first, get a connection to the authentication agent. */
431 ac = ssh_get_authentication_connection();
432 if (ac == NULL) {
433 fprintf(stderr,
434 "Could not open a connection to your authentication agent.\n");
435 exit(2);
436 }
437 while ((ch = getopt(argc, argv, "klLcdDxXe:s:t:")) != -1) {
438 switch (ch) {
439 case 'k':
440 key_only = 1;
441 break;
442 case 'l':
443 case 'L':
444 if (list_identities(ac, ch == 'l' ? 1 : 0) == -1)
445 ret = 1;
446 goto done;
447 case 'x':
448 case 'X':
449 if (lock_agent(ac, ch == 'x' ? 1 : 0) == -1)
450 ret = 1;
451 goto done;
452 case 'c':
453 confirm = 1;
454 break;
455 case 'd':
456 deleting = 1;
457 break;
458 case 'D':
459 if (delete_all(ac) == -1)
460 ret = 1;
461 goto done;
462 case 's':
463 pkcs11provider = optarg;
464 break;
465 case 'e':
466 deleting = 1;
467 pkcs11provider = optarg;
468 break;
469 case 't':
470 if ((lifetime = convtime(optarg)) == -1) {
471 fprintf(stderr, "Invalid lifetime\n");
472 ret = 1;
473 goto done;
474 }
475 break;
476 default:
477 usage();
478 ret = 1;
479 goto done;
480 }
481 }
482 argc -= optind;
483 argv += optind;
484 if (pkcs11provider != NULL) {
485 if (update_card(ac, !deleting, pkcs11provider) == -1)
486 ret = 1;
487 goto done;
488 }
489 if (argc == 0) {
490 char buf[MAXPATHLEN];
491 struct passwd *pw;
492 struct stat st;
493 int count = 0;
494
495 if ((pw = getpwuid(getuid())) == NULL) {
496 fprintf(stderr, "No user found with uid %u\n",
497 (u_int)getuid());
498 ret = 1;
499 goto done;
500 }
501
502 for (i = 0; default_files[i]; i++) {
503 snprintf(buf, sizeof(buf), "%s/%s", pw->pw_dir,
504 default_files[i]);
505 if (stat(buf, &st) < 0)
506 continue;
507 if (do_file(ac, deleting, key_only, buf) == -1)
508 ret = 1;
509 else
510 count++;
511 }
512 if (count == 0)
513 ret = 1;
514 } else {
515 for (i = 0; i < argc; i++) {
516 if (do_file(ac, deleting, key_only, argv[i]) == -1)
517 ret = 1;
518 }
519 }
520 clear_pass();
521
522 done:
523 ssh_close_authentication_connection(ac);
524 return ret;
525 }
526