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 */
67extern char *__progname;
68
69/* Default files to add */
70static 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) */
81static int lifetime = 0;
82
83/* User has to confirm key use */
84static int confirm = 0;
85
86/* we keep a cache of one passphrases */
87static char *pass = NULL;
88static void
89clear_pass(void)
90{
91	if (pass) {
92		memset(pass, 0, strlen(pass));
93		xfree(pass);
94		pass = NULL;
95	}
96}
97
98static int
99delete_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. */
123static int
124delete_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
141static int
142add_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
263static int
264update_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
286static int
287list_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
321static int
322lock_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
349static int
350do_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
362static void
363usage(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
379int
380main(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
485done:
486	ssh_close_authentication_connection(ac);
487	return ret;
488}
489