1 /* $OpenBSD: ssh-add.c,v 1.101 2011/05/04 21:15:29 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_IDENTITY,
77 NULL
78 };
79
80 /* Default lifetime (0 == forever) */
81 static int lifetime = 0;
82
83 /* User has to confirm key use */
84 static int confirm = 0;
85
86 /* we keep a cache of one passphrases */
87 static char *pass = NULL;
88 static void
clear_pass(void)89 clear_pass(void)
90 {
91 if (pass) {
92 memset(pass, 0, strlen(pass));
93 xfree(pass);
94 pass = NULL;
95 }
96 }
97
98 static int
delete_file(AuthenticationConnection * ac,const char * filename)99 delete_file(AuthenticationConnection *ac, const char *filename)
100 {
101 Key *public;
102 char *comment = NULL;
103 int ret = -1;
104
105 public = key_load_public(filename, &comment);
106 if (public == NULL) {
107 printf("Bad key file %s\n", filename);
108 return -1;
109 }
110 if (ssh_remove_identity(ac, public)) {
111 fprintf(stderr, "Identity removed: %s (%s)\n", filename, comment);
112 ret = 0;
113 } else
114 fprintf(stderr, "Could not remove identity: %s\n", filename);
115
116 key_free(public);
117 xfree(comment);
118
119 return ret;
120 }
121
122 /* Send a request to remove all identities. */
123 static int
delete_all(AuthenticationConnection * ac)124 delete_all(AuthenticationConnection *ac)
125 {
126 int ret = -1;
127
128 if (ssh_remove_all_identities(ac, 1))
129 ret = 0;
130 /* ignore error-code for ssh2 */
131 ssh_remove_all_identities(ac, 2);
132
133 if (ret == 0)
134 fprintf(stderr, "All identities removed.\n");
135 else
136 fprintf(stderr, "Failed to remove all identities.\n");
137
138 return ret;
139 }
140
141 static int
add_file(AuthenticationConnection * ac,const char * filename)142 add_file(AuthenticationConnection *ac, const char *filename)
143 {
144 Key *private, *cert;
145 char *comment = NULL;
146 char msg[1024], *certpath;
147 int fd, perms_ok, ret = -1;
148 Buffer keyblob;
149
150 if (strcmp(filename, "-") == 0) {
151 fd = STDIN_FILENO;
152 filename = "(stdin)";
153 } else if ((fd = open(filename, O_RDONLY)) < 0) {
154 perror(filename);
155 return -1;
156 }
157
158 /*
159 * Since we'll try to load a keyfile multiple times, permission errors
160 * will occur multiple times, so check perms first and bail if wrong.
161 */
162 if (fd != STDIN_FILENO) {
163 perms_ok = key_perm_ok(fd, filename);
164 if (!perms_ok) {
165 close(fd);
166 return -1;
167 }
168 }
169 buffer_init(&keyblob);
170 if (!key_load_file(fd, filename, &keyblob)) {
171 buffer_free(&keyblob);
172 close(fd);
173 return -1;
174 }
175 close(fd);
176
177 /* At first, try empty passphrase */
178 private = key_parse_private(&keyblob, filename, "", &comment);
179 if (comment == NULL)
180 comment = xstrdup(filename);
181 /* try last */
182 if (private == NULL && pass != NULL)
183 private = key_parse_private(&keyblob, filename, pass, NULL);
184 if (private == NULL) {
185 /* clear passphrase since it did not work */
186 clear_pass();
187 snprintf(msg, sizeof msg, "Enter passphrase for %.200s: ",
188 comment);
189 for (;;) {
190 pass = read_passphrase(msg, RP_ALLOW_STDIN);
191 if (strcmp(pass, "") == 0) {
192 clear_pass();
193 xfree(comment);
194 buffer_free(&keyblob);
195 return -1;
196 }
197 private = key_parse_private(&keyblob, filename, pass,
198 &comment);
199 if (private != NULL)
200 break;
201 clear_pass();
202 snprintf(msg, sizeof msg,
203 "Bad passphrase, try again for %.200s: ", comment);
204 }
205 }
206 buffer_free(&keyblob);
207
208 if (ssh_add_identity_constrained(ac, private, comment, lifetime,
209 confirm)) {
210 fprintf(stderr, "Identity added: %s (%s)\n", filename, comment);
211 ret = 0;
212 if (lifetime != 0)
213 fprintf(stderr,
214 "Lifetime set to %d seconds\n", lifetime);
215 if (confirm != 0)
216 fprintf(stderr,
217 "The user must confirm each use of the key\n");
218 } else {
219 fprintf(stderr, "Could not add identity: %s\n", filename);
220 }
221
222
223 /* Now try to add the certificate flavour too */
224 xasprintf(&certpath, "%s-cert.pub", filename);
225 if ((cert = key_load_public(certpath, NULL)) == NULL)
226 goto out;
227
228 if (!key_equal_public(cert, private)) {
229 error("Certificate %s does not match private key %s",
230 certpath, filename);
231 key_free(cert);
232 goto out;
233 }
234
235 /* Graft with private bits */
236 if (key_to_certified(private, key_cert_is_legacy(cert)) != 0) {
237 error("%s: key_to_certified failed", __func__);
238 key_free(cert);
239 goto out;
240 }
241 key_cert_copy(cert, private);
242 key_free(cert);
243
244 if (!ssh_add_identity_constrained(ac, private, comment,
245 lifetime, confirm)) {
246 error("Certificate %s (%s) add failed", certpath,
247 private->cert->key_id);
248 }
249 fprintf(stderr, "Certificate added: %s (%s)\n", certpath,
250 private->cert->key_id);
251 if (lifetime != 0)
252 fprintf(stderr, "Lifetime set to %d seconds\n", lifetime);
253 if (confirm != 0)
254 fprintf(stderr, "The user must confirm each use of the key\n");
255 out:
256 xfree(certpath);
257 xfree(comment);
258 key_free(private);
259
260 return ret;
261 }
262
263 static int
update_card(AuthenticationConnection * ac,int add,const char * id)264 update_card(AuthenticationConnection *ac, int add, const char *id)
265 {
266 char *pin;
267 int ret = -1;
268
269 pin = read_passphrase("Enter passphrase for PKCS#11: ", RP_ALLOW_STDIN);
270 if (pin == NULL)
271 return -1;
272
273 if (ssh_update_card(ac, add, id, pin, lifetime, confirm)) {
274 fprintf(stderr, "Card %s: %s\n",
275 add ? "added" : "removed", id);
276 ret = 0;
277 } else {
278 fprintf(stderr, "Could not %s card: %s\n",
279 add ? "add" : "remove", id);
280 ret = -1;
281 }
282 xfree(pin);
283 return ret;
284 }
285
286 static int
list_identities(AuthenticationConnection * ac,int do_fp)287 list_identities(AuthenticationConnection *ac, int do_fp)
288 {
289 Key *key;
290 char *comment, *fp;
291 int had_identities = 0;
292 int version;
293
294 for (version = 1; version <= 2; version++) {
295 for (key = ssh_get_first_identity(ac, &comment, version);
296 key != NULL;
297 key = ssh_get_next_identity(ac, &comment, version)) {
298 had_identities = 1;
299 if (do_fp) {
300 fp = key_fingerprint(key, SSH_FP_MD5,
301 SSH_FP_HEX);
302 printf("%d %s %s (%s)\n",
303 key_size(key), fp, comment, key_type(key));
304 xfree(fp);
305 } else {
306 if (!key_write(key, stdout))
307 fprintf(stderr, "key_write failed");
308 fprintf(stdout, " %s\n", comment);
309 }
310 key_free(key);
311 xfree(comment);
312 }
313 }
314 if (!had_identities) {
315 printf("The agent has no identities.\n");
316 return -1;
317 }
318 return 0;
319 }
320
321 static int
lock_agent(AuthenticationConnection * ac,int lock)322 lock_agent(AuthenticationConnection *ac, int lock)
323 {
324 char prompt[100], *p1, *p2;
325 int passok = 1, ret = -1;
326
327 strlcpy(prompt, "Enter lock password: ", sizeof(prompt));
328 p1 = read_passphrase(prompt, RP_ALLOW_STDIN);
329 if (lock) {
330 strlcpy(prompt, "Again: ", sizeof prompt);
331 p2 = read_passphrase(prompt, RP_ALLOW_STDIN);
332 if (strcmp(p1, p2) != 0) {
333 fprintf(stderr, "Passwords do not match.\n");
334 passok = 0;
335 }
336 memset(p2, 0, strlen(p2));
337 xfree(p2);
338 }
339 if (passok && ssh_lock_agent(ac, lock, p1)) {
340 fprintf(stderr, "Agent %slocked.\n", lock ? "" : "un");
341 ret = 0;
342 } else
343 fprintf(stderr, "Failed to %slock agent.\n", lock ? "" : "un");
344 memset(p1, 0, strlen(p1));
345 xfree(p1);
346 return (ret);
347 }
348
349 static int
do_file(AuthenticationConnection * ac,int deleting,char * file)350 do_file(AuthenticationConnection *ac, int deleting, char *file)
351 {
352 if (deleting) {
353 if (delete_file(ac, file) == -1)
354 return -1;
355 } else {
356 if (add_file(ac, file) == -1)
357 return -1;
358 }
359 return 0;
360 }
361
362 static void
usage(void)363 usage(void)
364 {
365 fprintf(stderr, "usage: %s [options] [file ...]\n", __progname);
366 fprintf(stderr, "Options:\n");
367 fprintf(stderr, " -l List fingerprints of all identities.\n");
368 fprintf(stderr, " -L List public key parameters of all identities.\n");
369 fprintf(stderr, " -d Delete identity.\n");
370 fprintf(stderr, " -D Delete all identities.\n");
371 fprintf(stderr, " -x Lock agent.\n");
372 fprintf(stderr, " -X Unlock agent.\n");
373 fprintf(stderr, " -t life Set lifetime (in seconds) when adding identities.\n");
374 fprintf(stderr, " -c Require confirmation to sign using identities\n");
375 fprintf(stderr, " -s pkcs11 Add keys from PKCS#11 provider.\n");
376 fprintf(stderr, " -e pkcs11 Remove keys provided by PKCS#11 provider.\n");
377 }
378
379 int
main(int argc,char ** argv)380 main(int argc, char **argv)
381 {
382 extern char *optarg;
383 extern int optind;
384 AuthenticationConnection *ac = NULL;
385 char *pkcs11provider = NULL;
386 int i, ch, deleting = 0, ret = 0;
387
388 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
389 sanitise_stdfd();
390
391 __progname = ssh_get_progname(argv[0]);
392 seed_rng();
393
394 OpenSSL_add_all_algorithms();
395
396 /* At first, get a connection to the authentication agent. */
397 ac = ssh_get_authentication_connection();
398 if (ac == NULL) {
399 fprintf(stderr,
400 "Could not open a connection to your authentication agent.\n");
401 exit(2);
402 }
403 while ((ch = getopt(argc, argv, "lLcdDxXe:s:t:")) != -1) {
404 switch (ch) {
405 case 'l':
406 case 'L':
407 if (list_identities(ac, ch == 'l' ? 1 : 0) == -1)
408 ret = 1;
409 goto done;
410 case 'x':
411 case 'X':
412 if (lock_agent(ac, ch == 'x' ? 1 : 0) == -1)
413 ret = 1;
414 goto done;
415 case 'c':
416 confirm = 1;
417 break;
418 case 'd':
419 deleting = 1;
420 break;
421 case 'D':
422 if (delete_all(ac) == -1)
423 ret = 1;
424 goto done;
425 case 's':
426 pkcs11provider = optarg;
427 break;
428 case 'e':
429 deleting = 1;
430 pkcs11provider = optarg;
431 break;
432 case 't':
433 if ((lifetime = convtime(optarg)) == -1) {
434 fprintf(stderr, "Invalid lifetime\n");
435 ret = 1;
436 goto done;
437 }
438 break;
439 default:
440 usage();
441 ret = 1;
442 goto done;
443 }
444 }
445 argc -= optind;
446 argv += optind;
447 if (pkcs11provider != NULL) {
448 if (update_card(ac, !deleting, pkcs11provider) == -1)
449 ret = 1;
450 goto done;
451 }
452 if (argc == 0) {
453 char buf[MAXPATHLEN];
454 struct passwd *pw;
455 struct stat st;
456 int count = 0;
457
458 if ((pw = getpwuid(getuid())) == NULL) {
459 fprintf(stderr, "No user found with uid %u\n",
460 (u_int)getuid());
461 ret = 1;
462 goto done;
463 }
464
465 for (i = 0; default_files[i]; i++) {
466 snprintf(buf, sizeof(buf), "%s/%s", pw->pw_dir,
467 default_files[i]);
468 if (stat(buf, &st) < 0)
469 continue;
470 if (do_file(ac, deleting, buf) == -1)
471 ret = 1;
472 else
473 count++;
474 }
475 if (count == 0)
476 ret = 1;
477 } else {
478 for (i = 0; i < argc; i++) {
479 if (do_file(ac, deleting, argv[i]) == -1)
480 ret = 1;
481 }
482 }
483 clear_pass();
484
485 done:
486 ssh_close_authentication_connection(ac);
487 return ret;
488 }
489