1 /* $OpenBSD: ssh-add.c,v 1.91 2009/08/27 17:44:52 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 <sys/param.h>
39 #include <sys/stat.h>
40 
41 #include <openssl/evp.h>
42 
43 #include <fcntl.h>
44 #include <pwd.h>
45 #include <stdio.h>
46 #include <stdlib.h>
47 #include <string.h>
48 #include <unistd.h>
49 
50 #include "xmalloc.h"
51 #include "ssh.h"
52 #include "rsa.h"
53 #include "log.h"
54 #include "key.h"
55 #include "buffer.h"
56 #include "authfd.h"
57 #include "authfile.h"
58 #include "pathnames.h"
59 #include "misc.h"
60 
61 __RCSID("$MirOS: src/usr.bin/ssh/ssh-add.c,v 1.8 2009/10/04 14:29:09 tg Exp $");
62 
63 /* argv0 */
64 extern char *__progname;
65 
66 /* Default files to add */
67 static const char *default_files[] = {
68 	_PATH_SSH_CLIENT_ID_RSA,
69 	_PATH_SSH_CLIENT_ID_DSA,
70 	_PATH_SSH_CLIENT_IDENTITY,
71 	NULL
72 };
73 
74 /* Default lifetime (0 == forever) */
75 static int lifetime = 0;
76 
77 /* User has to confirm key use */
78 static int confirm = 0;
79 
80 /* we keep a cache of one passphrases */
81 static char *pass = NULL;
82 static void
clear_pass(void)83 clear_pass(void)
84 {
85 	if (pass) {
86 		memset(pass, 0, strlen(pass));
87 		xfree(pass);
88 		pass = NULL;
89 	}
90 }
91 
92 static int
delete_file(AuthenticationConnection * ac,const char * filename)93 delete_file(AuthenticationConnection *ac, const char *filename)
94 {
95 	Key *public;
96 	char *comment = NULL;
97 	int ret = -1;
98 
99 	public = key_load_public(filename, &comment);
100 	if (public == NULL) {
101 		printf("Bad key file %s\n", filename);
102 		return -1;
103 	}
104 	if (ssh_remove_identity(ac, public)) {
105 		fprintf(stderr, "Identity removed: %s (%s)\n", filename, comment);
106 		ret = 0;
107 	} else
108 		fprintf(stderr, "Could not remove identity: %s\n", filename);
109 
110 	key_free(public);
111 	xfree(comment);
112 
113 	return ret;
114 }
115 
116 /* Send a request to remove all identities. */
117 static int
delete_all(AuthenticationConnection * ac)118 delete_all(AuthenticationConnection *ac)
119 {
120 	int ret = -1;
121 
122 	if (ssh_remove_all_identities(ac, 1))
123 		ret = 0;
124 	/* ignore error-code for ssh2 */
125 	ssh_remove_all_identities(ac, 2);
126 
127 	if (ret == 0)
128 		fprintf(stderr, "All identities removed.\n");
129 	else
130 		fprintf(stderr, "Failed to remove all identities.\n");
131 
132 	return ret;
133 }
134 
135 static int
add_file(AuthenticationConnection * ac,const char * filename)136 add_file(AuthenticationConnection *ac, const char *filename)
137 {
138 	Key *private;
139 	char *comment = NULL;
140 	char msg[1024];
141 	int fd, perms_ok, ret = -1;
142 
143 	if ((fd = open(filename, O_RDONLY)) < 0) {
144 		perror(filename);
145 		return -1;
146 	}
147 
148 	/*
149 	 * Since we'll try to load a keyfile multiple times, permission errors
150 	 * will occur multiple times, so check perms first and bail if wrong.
151 	 */
152 	perms_ok = key_perm_ok(fd, filename);
153 	close(fd);
154 	if (!perms_ok)
155 		return -1;
156 
157 	/* At first, try empty passphrase */
158 	private = key_load_private(filename, "", &comment);
159 	if (comment == NULL)
160 		comment = xstrdup(filename);
161 	/* try last */
162 	if (private == NULL && pass != NULL)
163 		private = key_load_private(filename, pass, NULL);
164 	if (private == NULL) {
165 		/* clear passphrase since it did not work */
166 		clear_pass();
167 		snprintf(msg, sizeof msg, "Enter passphrase for %.200s: ",
168 		    comment);
169 		for (;;) {
170 			pass = read_passphrase(msg, RP_ALLOW_STDIN);
171 			if (strcmp(pass, "") == 0) {
172 				clear_pass();
173 				xfree(comment);
174 				return -1;
175 			}
176 			private = key_load_private(filename, pass, &comment);
177 			if (private != NULL)
178 				break;
179 			clear_pass();
180 			snprintf(msg, sizeof msg,
181 			    "Bad passphrase, try again for %.200s: ", comment);
182 		}
183 	}
184 
185 	if (ssh_add_identity_constrained(ac, private, comment, lifetime,
186 	    confirm)) {
187 		fprintf(stderr, "Identity added: %s (%s)\n", filename, comment);
188 		ret = 0;
189 		if (lifetime != 0)
190 			fprintf(stderr,
191 			    "Lifetime set to %d seconds\n", lifetime);
192 		if (confirm != 0)
193 			fprintf(stderr,
194 			    "The user has to confirm each use of the key\n");
195 	} else {
196 		fprintf(stderr, "Could not add identity: %s\n", filename);
197 	}
198 
199 	xfree(comment);
200 	key_free(private);
201 
202 	return ret;
203 }
204 
205 static int
update_card(AuthenticationConnection * ac,int add,const char * id)206 update_card(AuthenticationConnection *ac, int add, const char *id)
207 {
208 	char *pin;
209 	int ret = -1;
210 
211 	pin = read_passphrase("Enter passphrase for smartcard: ", RP_ALLOW_STDIN);
212 	if (pin == NULL)
213 		return -1;
214 
215 	if (ssh_update_card(ac, add, id, pin, lifetime, confirm)) {
216 		fprintf(stderr, "Card %s: %s\n",
217 		    add ? "added" : "removed", id);
218 		ret = 0;
219 	} else {
220 		fprintf(stderr, "Could not %s card: %s\n",
221 		    add ? "add" : "remove", id);
222 		ret = -1;
223 	}
224 	xfree(pin);
225 	return ret;
226 }
227 
228 static int
list_identities(AuthenticationConnection * ac,int do_fp)229 list_identities(AuthenticationConnection *ac, int do_fp)
230 {
231 	Key *key;
232 	char *comment, *fp;
233 	int had_identities = 0;
234 	int version;
235 
236 	for (version = 1; version <= 2; version++) {
237 		for (key = ssh_get_first_identity(ac, &comment, version);
238 		    key != NULL;
239 		    key = ssh_get_next_identity(ac, &comment, version)) {
240 			had_identities = 1;
241 			if (do_fp) {
242 				fp = key_fingerprint(key, SSH_FP_MD5,
243 				    SSH_FP_HEX);
244 				printf("%d %s %s (%s)\n",
245 				    key_size(key), fp, comment, key_type(key));
246 				xfree(fp);
247 			} else {
248 				if (!key_write(key, stdout))
249 					fprintf(stderr, "key_write failed");
250 				fprintf(stdout, " %s\n", comment);
251 			}
252 			key_free(key);
253 			xfree(comment);
254 		}
255 	}
256 	if (!had_identities) {
257 		printf("The agent has no identities.\n");
258 		return -1;
259 	}
260 	return 0;
261 }
262 
263 static int
lock_agent(AuthenticationConnection * ac,int lock)264 lock_agent(AuthenticationConnection *ac, int lock)
265 {
266 	char prompt[100], *p1, *p2;
267 	int passok = 1, ret = -1;
268 
269 	strlcpy(prompt, "Enter lock password: ", sizeof(prompt));
270 	p1 = read_passphrase(prompt, RP_ALLOW_STDIN);
271 	if (lock) {
272 		strlcpy(prompt, "Again: ", sizeof prompt);
273 		p2 = read_passphrase(prompt, RP_ALLOW_STDIN);
274 		if (strcmp(p1, p2) != 0) {
275 			fprintf(stderr, "Passwords do not match.\n");
276 			passok = 0;
277 		}
278 		memset(p2, 0, strlen(p2));
279 		xfree(p2);
280 	}
281 	if (passok && ssh_lock_agent(ac, lock, p1)) {
282 		fprintf(stderr, "Agent %slocked.\n", lock ? "" : "un");
283 		ret = 0;
284 	} else
285 		fprintf(stderr, "Failed to %slock agent.\n", lock ? "" : "un");
286 	memset(p1, 0, strlen(p1));
287 	xfree(p1);
288 	return (ret);
289 }
290 
291 static int
do_file(AuthenticationConnection * ac,int deleting,char * file)292 do_file(AuthenticationConnection *ac, int deleting, char *file)
293 {
294 	if (deleting) {
295 		if (delete_file(ac, file) == -1)
296 			return -1;
297 	} else {
298 		if (add_file(ac, file) == -1)
299 			return -1;
300 	}
301 	return 0;
302 }
303 
304 static void
usage(void)305 usage(void)
306 {
307 	fprintf(stderr, "usage: %s [options] [file ...]\n", __progname);
308 	fprintf(stderr, "Options:\n");
309 	fprintf(stderr, "  -l          List fingerprints of all identities.\n");
310 	fprintf(stderr, "  -L          List public key parameters of all identities.\n");
311 	fprintf(stderr, "  -d          Delete identity.\n");
312 	fprintf(stderr, "  -D          Delete all identities.\n");
313 	fprintf(stderr, "  -x          Lock agent.\n");
314 	fprintf(stderr, "  -X          Unlock agent.\n");
315 	fprintf(stderr, "  -t life     Set lifetime (in seconds) when adding identities.\n");
316 	fprintf(stderr, "  -c          Require confirmation to sign using identities\n");
317 #ifdef SMARTCARD
318 	fprintf(stderr, "  -s reader   Add key in smartcard reader.\n");
319 	fprintf(stderr, "  -e reader   Remove key in smartcard reader.\n");
320 #endif
321 }
322 
323 int
main(int argc,char ** argv)324 main(int argc, char **argv)
325 {
326 	AuthenticationConnection *ac = NULL;
327 	char *sc_reader_id = NULL;
328 	int i, ch, deleting = 0, ret = 0;
329 
330 	/* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
331 	sanitise_stdfd();
332 
333 	SSLeay_add_all_algorithms();
334 
335 	/* At first, get a connection to the authentication agent. */
336 	ac = ssh_get_authentication_connection();
337 	if (ac == NULL) {
338 		fprintf(stderr,
339 		    "Could not open a connection to your authentication agent.\n");
340 		exit(2);
341 	}
342 	while ((ch = getopt(argc, argv, "lLcdDxXe:s:t:")) != -1) {
343 		switch (ch) {
344 		case 'l':
345 		case 'L':
346 			if (list_identities(ac, ch == 'l' ? 1 : 0) == -1)
347 				ret = 1;
348 			goto done;
349 		case 'x':
350 		case 'X':
351 			if (lock_agent(ac, ch == 'x' ? 1 : 0) == -1)
352 				ret = 1;
353 			goto done;
354 		case 'c':
355 			confirm = 1;
356 			break;
357 		case 'd':
358 			deleting = 1;
359 			break;
360 		case 'D':
361 			if (delete_all(ac) == -1)
362 				ret = 1;
363 			goto done;
364 		case 's':
365 			sc_reader_id = optarg;
366 			break;
367 		case 'e':
368 			deleting = 1;
369 			sc_reader_id = optarg;
370 			break;
371 		case 't':
372 			if ((lifetime = convtime(optarg)) == -1) {
373 				fprintf(stderr, "Invalid lifetime\n");
374 				ret = 1;
375 				goto done;
376 			}
377 			break;
378 		default:
379 			usage();
380 			ret = 1;
381 			goto done;
382 		}
383 	}
384 	argc -= optind;
385 	argv += optind;
386 	if (sc_reader_id != NULL) {
387 		if (update_card(ac, !deleting, sc_reader_id) == -1)
388 			ret = 1;
389 		goto done;
390 	}
391 	if (argc == 0) {
392 		char buf[MAXPATHLEN];
393 		struct passwd *pw;
394 		struct stat st;
395 		int count = 0;
396 
397 		if ((pw = getpwuid(getuid())) == NULL) {
398 			fprintf(stderr, "No user found with uid %u\n",
399 			    (u_int)getuid());
400 			ret = 1;
401 			goto done;
402 		}
403 
404 		for (i = 0; default_files[i]; i++) {
405 			snprintf(buf, sizeof(buf), "%s/%s", pw->pw_dir,
406 			    default_files[i]);
407 			if (stat(buf, &st) < 0)
408 				continue;
409 			if (do_file(ac, deleting, buf) == -1)
410 				ret = 1;
411 			else
412 				count++;
413 		}
414 		if (count == 0)
415 			ret = 1;
416 	} else {
417 		for (i = 0; i < argc; i++) {
418 			if (do_file(ac, deleting, argv[i]) == -1)
419 				ret = 1;
420 		}
421 	}
422 	clear_pass();
423 
424 done:
425 	ssh_close_authentication_connection(ac);
426 	return ret;
427 }
428