xref: /freebsd/crypto/openssh/ssh-add.c (revision d056fa046c6a91b90cd98165face0e42a33a5173)
1 /*
2  * Author: Tatu Ylonen <ylo@cs.hut.fi>
3  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
4  *                    All rights reserved
5  * Adds an identity to the authentication server, or removes an identity.
6  *
7  * As far as I am concerned, the code I have written for this software
8  * can be used freely for any purpose.  Any derived versions of this
9  * software must be clearly marked as such, and if the derived work is
10  * incompatible with the protocol description in the RFC file, it must be
11  * called by a name other than "ssh" or "Secure Shell".
12  *
13  * SSH2 implementation,
14  * Copyright (c) 2000, 2001 Markus Friedl.  All rights reserved.
15  *
16  * Redistribution and use in source and binary forms, with or without
17  * modification, are permitted provided that the following conditions
18  * are met:
19  * 1. Redistributions of source code must retain the above copyright
20  *    notice, this list of conditions and the following disclaimer.
21  * 2. Redistributions in binary form must reproduce the above copyright
22  *    notice, this list of conditions and the following disclaimer in the
23  *    documentation and/or other materials provided with the distribution.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
26  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
27  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
28  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
29  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
30  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
31  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
32  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
33  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
34  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35  */
36 
37 #include "includes.h"
38 RCSID("$OpenBSD: ssh-add.c,v 1.74 2005/11/12 18:37:59 deraadt Exp $");
39 
40 #include <openssl/evp.h>
41 
42 #include "ssh.h"
43 #include "rsa.h"
44 #include "log.h"
45 #include "xmalloc.h"
46 #include "key.h"
47 #include "authfd.h"
48 #include "authfile.h"
49 #include "pathnames.h"
50 #include "misc.h"
51 
52 /* argv0 */
53 extern char *__progname;
54 
55 /* Default files to add */
56 static char *default_files[] = {
57 	_PATH_SSH_CLIENT_ID_RSA,
58 	_PATH_SSH_CLIENT_ID_DSA,
59 	_PATH_SSH_CLIENT_IDENTITY,
60 	NULL
61 };
62 
63 /* Default lifetime (0 == forever) */
64 static int lifetime = 0;
65 
66 /* User has to confirm key use */
67 static int confirm = 0;
68 
69 /* we keep a cache of one passphrases */
70 static char *pass = NULL;
71 static void
72 clear_pass(void)
73 {
74 	if (pass) {
75 		memset(pass, 0, strlen(pass));
76 		xfree(pass);
77 		pass = NULL;
78 	}
79 }
80 
81 static int
82 delete_file(AuthenticationConnection *ac, const char *filename)
83 {
84 	Key *public;
85 	char *comment = NULL;
86 	int ret = -1;
87 
88 	public = key_load_public(filename, &comment);
89 	if (public == NULL) {
90 		printf("Bad key file %s\n", filename);
91 		return -1;
92 	}
93 	if (ssh_remove_identity(ac, public)) {
94 		fprintf(stderr, "Identity removed: %s (%s)\n", filename, comment);
95 		ret = 0;
96 	} else
97 		fprintf(stderr, "Could not remove identity: %s\n", filename);
98 
99 	key_free(public);
100 	xfree(comment);
101 
102 	return ret;
103 }
104 
105 /* Send a request to remove all identities. */
106 static int
107 delete_all(AuthenticationConnection *ac)
108 {
109 	int ret = -1;
110 
111 	if (ssh_remove_all_identities(ac, 1))
112 		ret = 0;
113 	/* ignore error-code for ssh2 */
114 	ssh_remove_all_identities(ac, 2);
115 
116 	if (ret == 0)
117 		fprintf(stderr, "All identities removed.\n");
118 	else
119 		fprintf(stderr, "Failed to remove all identities.\n");
120 
121 	return ret;
122 }
123 
124 static int
125 add_file(AuthenticationConnection *ac, const char *filename)
126 {
127 	struct stat st;
128 	Key *private;
129 	char *comment = NULL;
130 	char msg[1024];
131 	int ret = -1;
132 
133 	if (stat(filename, &st) < 0) {
134 		perror(filename);
135 		return -1;
136 	}
137 	/* At first, try empty passphrase */
138 	private = key_load_private(filename, "", &comment);
139 	if (comment == NULL)
140 		comment = xstrdup(filename);
141 	/* try last */
142 	if (private == NULL && pass != NULL)
143 		private = key_load_private(filename, pass, NULL);
144 	if (private == NULL) {
145 		/* clear passphrase since it did not work */
146 		clear_pass();
147 		snprintf(msg, sizeof msg, "Enter passphrase for %.200s: ",
148 		    comment);
149 		for (;;) {
150 			pass = read_passphrase(msg, RP_ALLOW_STDIN);
151 			if (strcmp(pass, "") == 0) {
152 				clear_pass();
153 				xfree(comment);
154 				return -1;
155 			}
156 			private = key_load_private(filename, pass, &comment);
157 			if (private != NULL)
158 				break;
159 			clear_pass();
160 			snprintf(msg, sizeof msg,
161 			    "Bad passphrase, try again for %.200s: ", comment);
162 		}
163 	}
164 
165 	if (ssh_add_identity_constrained(ac, private, comment, lifetime,
166 	    confirm)) {
167 		fprintf(stderr, "Identity added: %s (%s)\n", filename, comment);
168 		ret = 0;
169 		if (lifetime != 0)
170 			fprintf(stderr,
171 			    "Lifetime set to %d seconds\n", lifetime);
172 		if (confirm != 0)
173 			fprintf(stderr,
174 			    "The user has to confirm each use of the key\n");
175 	} else if (ssh_add_identity(ac, private, comment)) {
176 		fprintf(stderr, "Identity added: %s (%s)\n", filename, comment);
177 		ret = 0;
178 	} else {
179 		fprintf(stderr, "Could not add identity: %s\n", filename);
180 	}
181 
182 	xfree(comment);
183 	key_free(private);
184 
185 	return ret;
186 }
187 
188 static int
189 update_card(AuthenticationConnection *ac, int add, const char *id)
190 {
191 	char *pin;
192 	int ret = -1;
193 
194 	pin = read_passphrase("Enter passphrase for smartcard: ", RP_ALLOW_STDIN);
195 	if (pin == NULL)
196 		return -1;
197 
198 	if (ssh_update_card(ac, add, id, pin, lifetime, confirm)) {
199 		fprintf(stderr, "Card %s: %s\n",
200 		    add ? "added" : "removed", id);
201 		ret = 0;
202 	} else {
203 		fprintf(stderr, "Could not %s card: %s\n",
204 		    add ? "add" : "remove", id);
205 		ret = -1;
206 	}
207 	xfree(pin);
208 	return ret;
209 }
210 
211 static int
212 list_identities(AuthenticationConnection *ac, int do_fp)
213 {
214 	Key *key;
215 	char *comment, *fp;
216 	int had_identities = 0;
217 	int version;
218 
219 	for (version = 1; version <= 2; version++) {
220 		for (key = ssh_get_first_identity(ac, &comment, version);
221 		    key != NULL;
222 		    key = ssh_get_next_identity(ac, &comment, version)) {
223 			had_identities = 1;
224 			if (do_fp) {
225 				fp = key_fingerprint(key, SSH_FP_MD5,
226 				    SSH_FP_HEX);
227 				printf("%d %s %s (%s)\n",
228 				    key_size(key), fp, comment, key_type(key));
229 				xfree(fp);
230 			} else {
231 				if (!key_write(key, stdout))
232 					fprintf(stderr, "key_write failed");
233 				fprintf(stdout, " %s\n", comment);
234 			}
235 			key_free(key);
236 			xfree(comment);
237 		}
238 	}
239 	if (!had_identities) {
240 		printf("The agent has no identities.\n");
241 		return -1;
242 	}
243 	return 0;
244 }
245 
246 static int
247 lock_agent(AuthenticationConnection *ac, int lock)
248 {
249 	char prompt[100], *p1, *p2;
250 	int passok = 1, ret = -1;
251 
252 	strlcpy(prompt, "Enter lock password: ", sizeof(prompt));
253 	p1 = read_passphrase(prompt, RP_ALLOW_STDIN);
254 	if (lock) {
255 		strlcpy(prompt, "Again: ", sizeof prompt);
256 		p2 = read_passphrase(prompt, RP_ALLOW_STDIN);
257 		if (strcmp(p1, p2) != 0) {
258 			fprintf(stderr, "Passwords do not match.\n");
259 			passok = 0;
260 		}
261 		memset(p2, 0, strlen(p2));
262 		xfree(p2);
263 	}
264 	if (passok && ssh_lock_agent(ac, lock, p1)) {
265 		fprintf(stderr, "Agent %slocked.\n", lock ? "" : "un");
266 		ret = 0;
267 	} else
268 		fprintf(stderr, "Failed to %slock agent.\n", lock ? "" : "un");
269 	memset(p1, 0, strlen(p1));
270 	xfree(p1);
271 	return (ret);
272 }
273 
274 static int
275 do_file(AuthenticationConnection *ac, int deleting, char *file)
276 {
277 	if (deleting) {
278 		if (delete_file(ac, file) == -1)
279 			return -1;
280 	} else {
281 		if (add_file(ac, file) == -1)
282 			return -1;
283 	}
284 	return 0;
285 }
286 
287 static void
288 usage(void)
289 {
290 	fprintf(stderr, "Usage: %s [options]\n", __progname);
291 	fprintf(stderr, "Options:\n");
292 	fprintf(stderr, "  -l          List fingerprints of all identities.\n");
293 	fprintf(stderr, "  -L          List public key parameters of all identities.\n");
294 	fprintf(stderr, "  -d          Delete identity.\n");
295 	fprintf(stderr, "  -D          Delete all identities.\n");
296 	fprintf(stderr, "  -x          Lock agent.\n");
297 	fprintf(stderr, "  -X          Unlock agent.\n");
298 	fprintf(stderr, "  -t life     Set lifetime (in seconds) when adding identities.\n");
299 	fprintf(stderr, "  -c          Require confirmation to sign using identities\n");
300 #ifdef SMARTCARD
301 	fprintf(stderr, "  -s reader   Add key in smartcard reader.\n");
302 	fprintf(stderr, "  -e reader   Remove key in smartcard reader.\n");
303 #endif
304 }
305 
306 int
307 main(int argc, char **argv)
308 {
309 	extern char *optarg;
310 	extern int optind;
311 	AuthenticationConnection *ac = NULL;
312 	char *sc_reader_id = NULL;
313 	int i, ch, deleting = 0, ret = 0;
314 
315 	/* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
316 	sanitise_stdfd();
317 
318 	__progname = ssh_get_progname(argv[0]);
319 	init_rng();
320 	seed_rng();
321 
322 	SSLeay_add_all_algorithms();
323 
324 	/* At first, get a connection to the authentication agent. */
325 	ac = ssh_get_authentication_connection();
326 	if (ac == NULL) {
327 		fprintf(stderr,
328 		    "Could not open a connection to your authentication agent.\n");
329 		exit(2);
330 	}
331 	while ((ch = getopt(argc, argv, "lLcdDxXe:s:t:")) != -1) {
332 		switch (ch) {
333 		case 'l':
334 		case 'L':
335 			if (list_identities(ac, ch == 'l' ? 1 : 0) == -1)
336 				ret = 1;
337 			goto done;
338 			break;
339 		case 'x':
340 		case 'X':
341 			if (lock_agent(ac, ch == 'x' ? 1 : 0) == -1)
342 				ret = 1;
343 			goto done;
344 			break;
345 		case 'c':
346 			confirm = 1;
347 			break;
348 		case 'd':
349 			deleting = 1;
350 			break;
351 		case 'D':
352 			if (delete_all(ac) == -1)
353 				ret = 1;
354 			goto done;
355 			break;
356 		case 's':
357 			sc_reader_id = optarg;
358 			break;
359 		case 'e':
360 			deleting = 1;
361 			sc_reader_id = optarg;
362 			break;
363 		case 't':
364 			if ((lifetime = convtime(optarg)) == -1) {
365 				fprintf(stderr, "Invalid lifetime\n");
366 				ret = 1;
367 				goto done;
368 			}
369 			break;
370 		default:
371 			usage();
372 			ret = 1;
373 			goto done;
374 		}
375 	}
376 	argc -= optind;
377 	argv += optind;
378 	if (sc_reader_id != NULL) {
379 		if (update_card(ac, !deleting, sc_reader_id) == -1)
380 			ret = 1;
381 		goto done;
382 	}
383 	if (argc == 0) {
384 		char buf[MAXPATHLEN];
385 		struct passwd *pw;
386 		struct stat st;
387 		int count = 0;
388 
389 		if ((pw = getpwuid(getuid())) == NULL) {
390 			fprintf(stderr, "No user found with uid %u\n",
391 			    (u_int)getuid());
392 			ret = 1;
393 			goto done;
394 		}
395 
396 		for (i = 0; default_files[i]; i++) {
397 			snprintf(buf, sizeof(buf), "%s/%s", pw->pw_dir,
398 			    default_files[i]);
399 			if (stat(buf, &st) < 0)
400 				continue;
401 			if (do_file(ac, deleting, buf) == -1)
402 				ret = 1;
403 			else
404 				count++;
405 		}
406 		if (count == 0)
407 			ret = 1;
408 	} else {
409 		for (i = 0; i < argc; i++) {
410 			if (do_file(ac, deleting, argv[i]) == -1)
411 				ret = 1;
412 		}
413 	}
414 	clear_pass();
415 
416 done:
417 	ssh_close_authentication_connection(ac);
418 	return ret;
419 }
420