1/* $OpenBSD: ssh-add.c,v 1.172 2024/01/11 01:45:36 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
43#ifdef WITH_OPENSSL
44# include <openssl/evp.h>
45# include "openbsd-compat/openssl-compat.h"
46#endif
47
48#include <errno.h>
49#include <fcntl.h>
50#include <pwd.h>
51#include <stdarg.h>
52#include <stdio.h>
53#include <stdlib.h>
54#include <string.h>
55#include <unistd.h>
56#include <limits.h>
57
58#include "xmalloc.h"
59#include "ssh.h"
60#include "log.h"
61#include "sshkey.h"
62#include "sshbuf.h"
63#include "authfd.h"
64#include "authfile.h"
65#include "pathnames.h"
66#include "misc.h"
67#include "ssherr.h"
68#include "digest.h"
69#include "ssh-sk.h"
70#include "sk-api.h"
71#include "hostfile.h"
72
73/* argv0 */
74extern char *__progname;
75
76/* Default files to add */
77static char *default_files[] = {
78#ifdef WITH_OPENSSL
79	_PATH_SSH_CLIENT_ID_RSA,
80#ifdef OPENSSL_HAS_ECC
81	_PATH_SSH_CLIENT_ID_ECDSA,
82	_PATH_SSH_CLIENT_ID_ECDSA_SK,
83#endif
84#endif /* WITH_OPENSSL */
85	_PATH_SSH_CLIENT_ID_ED25519,
86	_PATH_SSH_CLIENT_ID_ED25519_SK,
87	_PATH_SSH_CLIENT_ID_XMSS,
88#ifdef WITH_DSA
89	_PATH_SSH_CLIENT_ID_DSA,
90#endif
91	NULL
92};
93
94static int fingerprint_hash = SSH_FP_HASH_DEFAULT;
95
96/* Default lifetime (0 == forever) */
97static int lifetime = 0;
98
99/* User has to confirm key use */
100static int confirm = 0;
101
102/* Maximum number of signatures (XMSS) */
103static u_int maxsign = 0;
104static u_int minleft = 0;
105
106/* we keep a cache of one passphrase */
107static char *pass = NULL;
108static void
109clear_pass(void)
110{
111	if (pass) {
112		freezero(pass, strlen(pass));
113		pass = NULL;
114	}
115}
116
117static int
118delete_one(int agent_fd, const struct sshkey *key, const char *comment,
119    const char *path, int qflag)
120{
121	int r;
122
123	if ((r = ssh_remove_identity(agent_fd, key)) != 0) {
124		fprintf(stderr, "Could not remove identity \"%s\": %s\n",
125		    path, ssh_err(r));
126		return r;
127	}
128	if (!qflag) {
129		fprintf(stderr, "Identity removed: %s %s (%s)\n", path,
130		    sshkey_type(key), comment ? comment : "no comment");
131	}
132	return 0;
133}
134
135static int
136delete_stdin(int agent_fd, int qflag, int key_only, int cert_only)
137{
138	char *line = NULL, *cp;
139	size_t linesize = 0;
140	struct sshkey *key = NULL;
141	int lnum = 0, r, ret = -1;
142
143	while (getline(&line, &linesize, stdin) != -1) {
144		lnum++;
145		sshkey_free(key);
146		key = NULL;
147		line[strcspn(line, "\n")] = '\0';
148		cp = line + strspn(line, " \t");
149		if (*cp == '#' || *cp == '\0')
150			continue;
151		if ((key = sshkey_new(KEY_UNSPEC)) == NULL)
152			fatal_f("sshkey_new");
153		if ((r = sshkey_read(key, &cp)) != 0) {
154			error_r(r, "(stdin):%d: invalid key", lnum);
155			continue;
156		}
157		if ((!key_only && !cert_only) ||
158		    (key_only && !sshkey_is_cert(key)) ||
159		    (cert_only && sshkey_is_cert(key))) {
160			if (delete_one(agent_fd, key, cp,
161			    "(stdin)", qflag) == 0)
162				ret = 0;
163		}
164	}
165	sshkey_free(key);
166	free(line);
167	return ret;
168}
169
170static int
171delete_file(int agent_fd, const char *filename, int key_only,
172    int cert_only, int qflag)
173{
174	struct sshkey *public, *cert = NULL;
175	char *certpath = NULL, *comment = NULL;
176	int r, ret = -1;
177
178	if (strcmp(filename, "-") == 0)
179		return delete_stdin(agent_fd, qflag, key_only, cert_only);
180
181	if ((r = sshkey_load_public(filename, &public,  &comment)) != 0) {
182		printf("Bad key file %s: %s\n", filename, ssh_err(r));
183		return -1;
184	}
185	if ((!key_only && !cert_only) ||
186	    (key_only && !sshkey_is_cert(public)) ||
187	    (cert_only && sshkey_is_cert(public))) {
188		if (delete_one(agent_fd, public, comment, filename, qflag) == 0)
189			ret = 0;
190	}
191
192	if (key_only)
193		goto out;
194
195	/* Now try to delete the corresponding certificate too */
196	free(comment);
197	comment = NULL;
198	xasprintf(&certpath, "%s-cert.pub", filename);
199	if ((r = sshkey_load_public(certpath, &cert, &comment)) != 0) {
200		if (r != SSH_ERR_SYSTEM_ERROR || errno != ENOENT)
201			error_r(r, "Failed to load certificate \"%s\"", certpath);
202		goto out;
203	}
204
205	if (!sshkey_equal_public(cert, public))
206		fatal("Certificate %s does not match private key %s",
207		    certpath, filename);
208
209	if (delete_one(agent_fd, cert, comment, certpath, qflag) == 0)
210		ret = 0;
211
212 out:
213	sshkey_free(cert);
214	sshkey_free(public);
215	free(certpath);
216	free(comment);
217
218	return ret;
219}
220
221/* Send a request to remove all identities. */
222static int
223delete_all(int agent_fd, int qflag)
224{
225	int ret = -1;
226
227	/*
228	 * Since the agent might be forwarded, old or non-OpenSSH, when asked
229	 * to remove all keys, attempt to remove both protocol v.1 and v.2
230	 * keys.
231	 */
232	if (ssh_remove_all_identities(agent_fd, 2) == 0)
233		ret = 0;
234	/* ignore error-code for ssh1 */
235	ssh_remove_all_identities(agent_fd, 1);
236
237	if (ret != 0)
238		fprintf(stderr, "Failed to remove all identities.\n");
239	else if (!qflag)
240		fprintf(stderr, "All identities removed.\n");
241
242	return ret;
243}
244
245static int
246add_file(int agent_fd, const char *filename, int key_only, int cert_only,
247    int qflag, const char *skprovider,
248    struct dest_constraint **dest_constraints,
249    size_t ndest_constraints)
250{
251	struct sshkey *private, *cert;
252	char *comment = NULL;
253	char msg[1024], *certpath = NULL;
254	int r, fd, ret = -1;
255	size_t i;
256	u_int32_t left;
257	struct sshbuf *keyblob;
258	struct ssh_identitylist *idlist;
259
260	if (strcmp(filename, "-") == 0) {
261		fd = STDIN_FILENO;
262		filename = "(stdin)";
263	} else if ((fd = open(filename, O_RDONLY)) == -1) {
264		perror(filename);
265		return -1;
266	}
267
268	/*
269	 * Since we'll try to load a keyfile multiple times, permission errors
270	 * will occur multiple times, so check perms first and bail if wrong.
271	 */
272	if (fd != STDIN_FILENO) {
273		if (sshkey_perm_ok(fd, filename) != 0) {
274			close(fd);
275			return -1;
276		}
277	}
278	if ((r = sshbuf_load_fd(fd, &keyblob)) != 0) {
279		fprintf(stderr, "Error loading key \"%s\": %s\n",
280		    filename, ssh_err(r));
281		sshbuf_free(keyblob);
282		close(fd);
283		return -1;
284	}
285	close(fd);
286
287	/* At first, try empty passphrase */
288	if ((r = sshkey_parse_private_fileblob(keyblob, "", &private,
289	    &comment)) != 0 && r != SSH_ERR_KEY_WRONG_PASSPHRASE) {
290		fprintf(stderr, "Error loading key \"%s\": %s\n",
291		    filename, ssh_err(r));
292		goto fail_load;
293	}
294	/* try last */
295	if (private == NULL && pass != NULL) {
296		if ((r = sshkey_parse_private_fileblob(keyblob, pass, &private,
297		    &comment)) != 0 && r != SSH_ERR_KEY_WRONG_PASSPHRASE) {
298			fprintf(stderr, "Error loading key \"%s\": %s\n",
299			    filename, ssh_err(r));
300			goto fail_load;
301		}
302	}
303	if (private == NULL) {
304		/* clear passphrase since it did not work */
305		clear_pass();
306		snprintf(msg, sizeof msg, "Enter passphrase for %s%s: ",
307		    filename, confirm ? " (will confirm each use)" : "");
308		for (;;) {
309			pass = read_passphrase(msg, RP_ALLOW_STDIN);
310			if (strcmp(pass, "") == 0)
311				goto fail_load;
312			if ((r = sshkey_parse_private_fileblob(keyblob, pass,
313			    &private, &comment)) == 0)
314				break;
315			else if (r != SSH_ERR_KEY_WRONG_PASSPHRASE) {
316				fprintf(stderr,
317				    "Error loading key \"%s\": %s\n",
318				    filename, ssh_err(r));
319 fail_load:
320				clear_pass();
321				sshbuf_free(keyblob);
322				return -1;
323			}
324			clear_pass();
325			snprintf(msg, sizeof msg,
326			    "Bad passphrase, try again for %s%s: ", filename,
327			    confirm ? " (will confirm each use)" : "");
328		}
329	}
330	if (comment == NULL || *comment == '\0')
331		comment = xstrdup(filename);
332	sshbuf_free(keyblob);
333
334	/* For XMSS */
335	if ((r = sshkey_set_filename(private, filename)) != 0) {
336		fprintf(stderr, "Could not add filename to private key: %s (%s)\n",
337		    filename, comment);
338		goto out;
339	}
340	if (maxsign && minleft &&
341	    (r = ssh_fetch_identitylist(agent_fd, &idlist)) == 0) {
342		for (i = 0; i < idlist->nkeys; i++) {
343			if (!sshkey_equal_public(idlist->keys[i], private))
344				continue;
345			left = sshkey_signatures_left(idlist->keys[i]);
346			if (left < minleft) {
347				fprintf(stderr,
348				    "Only %d signatures left.\n", left);
349				break;
350			}
351			fprintf(stderr, "Skipping update: ");
352			if (left == minleft) {
353				fprintf(stderr,
354				    "required signatures left (%d).\n", left);
355			} else {
356				fprintf(stderr,
357				    "more signatures left (%d) than"
358				    " required (%d).\n", left, minleft);
359			}
360			ssh_free_identitylist(idlist);
361			goto out;
362		}
363		ssh_free_identitylist(idlist);
364	}
365
366	if (sshkey_is_sk(private)) {
367		if (skprovider == NULL) {
368			fprintf(stderr, "Cannot load FIDO key %s "
369			    "without provider\n", filename);
370			goto out;
371		}
372	} else {
373		/* Don't send provider constraint for other keys */
374		skprovider = NULL;
375	}
376
377	if (!cert_only &&
378	    (r = ssh_add_identity_constrained(agent_fd, private, comment,
379	    lifetime, confirm, maxsign, skprovider,
380	    dest_constraints, ndest_constraints)) == 0) {
381		ret = 0;
382		if (!qflag) {
383			fprintf(stderr, "Identity added: %s (%s)\n",
384			    filename, comment);
385			if (lifetime != 0) {
386				fprintf(stderr,
387				    "Lifetime set to %d seconds\n", lifetime);
388			}
389			if (confirm != 0) {
390				fprintf(stderr, "The user must confirm "
391				    "each use of the key\n");
392			}
393		}
394	} else {
395		fprintf(stderr, "Could not add identity \"%s\": %s\n",
396		    filename, ssh_err(r));
397	}
398
399	/* Skip trying to load the cert if requested */
400	if (key_only)
401		goto out;
402
403	/* Now try to add the certificate flavour too */
404	xasprintf(&certpath, "%s-cert.pub", filename);
405	if ((r = sshkey_load_public(certpath, &cert, NULL)) != 0) {
406		if (r != SSH_ERR_SYSTEM_ERROR || errno != ENOENT)
407			error_r(r, "Failed to load certificate \"%s\"",
408			    certpath);
409		goto out;
410	}
411
412	if (!sshkey_equal_public(cert, private)) {
413		error("Certificate %s does not match private key %s",
414		    certpath, filename);
415		sshkey_free(cert);
416		goto out;
417	}
418
419	/* Graft with private bits */
420	if ((r = sshkey_to_certified(private)) != 0) {
421		error_fr(r, "sshkey_to_certified");
422		sshkey_free(cert);
423		goto out;
424	}
425	if ((r = sshkey_cert_copy(cert, private)) != 0) {
426		error_fr(r, "sshkey_cert_copy");
427		sshkey_free(cert);
428		goto out;
429	}
430	sshkey_free(cert);
431
432	if ((r = ssh_add_identity_constrained(agent_fd, private, comment,
433	    lifetime, confirm, maxsign, skprovider,
434	    dest_constraints, ndest_constraints)) != 0) {
435		error_r(r, "Certificate %s (%s) add failed", certpath,
436		    private->cert->key_id);
437		goto out;
438	}
439	/* success */
440	if (!qflag) {
441		fprintf(stderr, "Certificate added: %s (%s)\n", certpath,
442		    private->cert->key_id);
443		if (lifetime != 0) {
444			fprintf(stderr, "Lifetime set to %d seconds\n",
445			    lifetime);
446		}
447		if (confirm != 0) {
448			fprintf(stderr, "The user must confirm each use "
449			    "of the key\n");
450		}
451	}
452
453 out:
454	free(certpath);
455	free(comment);
456	sshkey_free(private);
457
458	return ret;
459}
460
461static int
462update_card(int agent_fd, int add, const char *id, int qflag,
463    int key_only, int cert_only,
464    struct dest_constraint **dest_constraints, size_t ndest_constraints,
465    struct sshkey **certs, size_t ncerts)
466{
467	char *pin = NULL;
468	int r, ret = -1;
469
470	if (key_only)
471		ncerts = 0;
472
473	if (add) {
474		if ((pin = read_passphrase("Enter passphrase for PKCS#11: ",
475		    RP_ALLOW_STDIN)) == NULL)
476			return -1;
477	}
478
479	if ((r = ssh_update_card(agent_fd, add, id, pin == NULL ? "" : pin,
480	    lifetime, confirm, dest_constraints, ndest_constraints,
481	    cert_only, certs, ncerts)) == 0) {
482		ret = 0;
483		if (!qflag) {
484			fprintf(stderr, "Card %s: %s\n",
485			    add ? "added" : "removed", id);
486		}
487	} else {
488		fprintf(stderr, "Could not %s card \"%s\": %s\n",
489		    add ? "add" : "remove", id, ssh_err(r));
490		ret = -1;
491	}
492	free(pin);
493	return ret;
494}
495
496static int
497test_key(int agent_fd, const char *filename)
498{
499	struct sshkey *key = NULL;
500	u_char *sig = NULL;
501	const char *alg = NULL;
502	size_t slen = 0;
503	int r, ret = -1;
504	char data[1024];
505
506	if ((r = sshkey_load_public(filename, &key, NULL)) != 0) {
507		error_r(r, "Couldn't read public key %s", filename);
508		return -1;
509	}
510	if (sshkey_type_plain(key->type) == KEY_RSA)
511		alg = "rsa-sha2-256";
512	arc4random_buf(data, sizeof(data));
513	if ((r = ssh_agent_sign(agent_fd, key, &sig, &slen, data, sizeof(data),
514	    alg, 0)) != 0) {
515		error_r(r, "Agent signature failed for %s", filename);
516		goto done;
517	}
518	if ((r = sshkey_verify(key, sig, slen, data, sizeof(data),
519	    alg, 0, NULL)) != 0) {
520		error_r(r, "Signature verification failed for %s", filename);
521		goto done;
522	}
523	/* success */
524	ret = 0;
525 done:
526	free(sig);
527	sshkey_free(key);
528	return ret;
529}
530
531static int
532list_identities(int agent_fd, int do_fp)
533{
534	char *fp;
535	int r;
536	struct ssh_identitylist *idlist;
537	u_int32_t left;
538	size_t i;
539
540	if ((r = ssh_fetch_identitylist(agent_fd, &idlist)) != 0) {
541		if (r != SSH_ERR_AGENT_NO_IDENTITIES)
542			fprintf(stderr, "error fetching identities: %s\n",
543			    ssh_err(r));
544		else
545			printf("The agent has no identities.\n");
546		return -1;
547	}
548	for (i = 0; i < idlist->nkeys; i++) {
549		if (do_fp) {
550			fp = sshkey_fingerprint(idlist->keys[i],
551			    fingerprint_hash, SSH_FP_DEFAULT);
552			printf("%u %s %s (%s)\n", sshkey_size(idlist->keys[i]),
553			    fp == NULL ? "(null)" : fp, idlist->comments[i],
554			    sshkey_type(idlist->keys[i]));
555			free(fp);
556		} else {
557			if ((r = sshkey_write(idlist->keys[i], stdout)) != 0) {
558				fprintf(stderr, "sshkey_write: %s\n",
559				    ssh_err(r));
560				continue;
561			}
562			fprintf(stdout, " %s", idlist->comments[i]);
563			left = sshkey_signatures_left(idlist->keys[i]);
564			if (left > 0)
565				fprintf(stdout,
566				    " [signatures left %d]", left);
567			fprintf(stdout, "\n");
568		}
569	}
570	ssh_free_identitylist(idlist);
571	return 0;
572}
573
574static int
575lock_agent(int agent_fd, int lock)
576{
577	char prompt[100], *p1, *p2;
578	int r, passok = 1, ret = -1;
579
580	strlcpy(prompt, "Enter lock password: ", sizeof(prompt));
581	p1 = read_passphrase(prompt, RP_ALLOW_STDIN);
582	if (lock) {
583		strlcpy(prompt, "Again: ", sizeof prompt);
584		p2 = read_passphrase(prompt, RP_ALLOW_STDIN);
585		if (strcmp(p1, p2) != 0) {
586			fprintf(stderr, "Passwords do not match.\n");
587			passok = 0;
588		}
589		freezero(p2, strlen(p2));
590	}
591	if (passok) {
592		if ((r = ssh_lock_agent(agent_fd, lock, p1)) == 0) {
593			fprintf(stderr, "Agent %slocked.\n", lock ? "" : "un");
594			ret = 0;
595		} else {
596			fprintf(stderr, "Failed to %slock agent: %s\n",
597			    lock ? "" : "un", ssh_err(r));
598		}
599	}
600	freezero(p1, strlen(p1));
601	return (ret);
602}
603
604static int
605load_resident_keys(int agent_fd, const char *skprovider, int qflag,
606    struct dest_constraint **dest_constraints, size_t ndest_constraints)
607{
608	struct sshsk_resident_key **srks;
609	size_t nsrks, i;
610	struct sshkey *key;
611	int r, ok = 0;
612	char *fp;
613
614	pass = read_passphrase("Enter PIN for authenticator: ", RP_ALLOW_STDIN);
615	if ((r = sshsk_load_resident(skprovider, NULL, pass, 0,
616	    &srks, &nsrks)) != 0) {
617		error_r(r, "Unable to load resident keys");
618		return r;
619	}
620	for (i = 0; i < nsrks; i++) {
621		key = srks[i]->key;
622		if ((fp = sshkey_fingerprint(key,
623		    fingerprint_hash, SSH_FP_DEFAULT)) == NULL)
624			fatal_f("sshkey_fingerprint failed");
625		if ((r = ssh_add_identity_constrained(agent_fd, key, "",
626		    lifetime, confirm, maxsign, skprovider,
627		    dest_constraints, ndest_constraints)) != 0) {
628			error("Unable to add key %s %s",
629			    sshkey_type(key), fp);
630			free(fp);
631			ok = r;
632			continue;
633		}
634		if (ok == 0)
635			ok = 1;
636		if (!qflag) {
637			fprintf(stderr, "Resident identity added: %s %s\n",
638			    sshkey_type(key), fp);
639			if (lifetime != 0) {
640				fprintf(stderr,
641				    "Lifetime set to %d seconds\n", lifetime);
642			}
643			if (confirm != 0) {
644				fprintf(stderr, "The user must confirm "
645				    "each use of the key\n");
646			}
647		}
648		free(fp);
649	}
650	sshsk_free_resident_keys(srks, nsrks);
651	if (nsrks == 0)
652		return SSH_ERR_KEY_NOT_FOUND;
653	return ok == 1 ? 0 : ok;
654}
655
656static int
657do_file(int agent_fd, int deleting, int key_only, int cert_only,
658    char *file, int qflag, const char *skprovider,
659    struct dest_constraint **dest_constraints, size_t ndest_constraints)
660{
661	if (deleting) {
662		if (delete_file(agent_fd, file, key_only,
663		    cert_only, qflag) == -1)
664			return -1;
665	} else {
666		if (add_file(agent_fd, file, key_only, cert_only, qflag,
667		    skprovider, dest_constraints, ndest_constraints) == -1)
668			return -1;
669	}
670	return 0;
671}
672
673/* Append string 's' to a NULL-terminated array of strings */
674static void
675stringlist_append(char ***listp, const char *s)
676{
677	size_t i = 0;
678
679	if (*listp == NULL)
680		*listp = xcalloc(2, sizeof(**listp));
681	else {
682		for (i = 0; (*listp)[i] != NULL; i++)
683			; /* count */
684		*listp = xrecallocarray(*listp, i + 1, i + 2, sizeof(**listp));
685	}
686	(*listp)[i] = xstrdup(s);
687}
688
689static void
690parse_dest_constraint_hop(const char *s, struct dest_constraint_hop *dch,
691    char **hostkey_files)
692{
693	char *user = NULL, *host, *os, *path;
694	size_t i;
695	struct hostkeys *hostkeys;
696	const struct hostkey_entry *hke;
697	int r, want_ca;
698
699	memset(dch, '\0', sizeof(*dch));
700	os = xstrdup(s);
701	if ((host = strchr(os, '@')) == NULL)
702		host = os;
703	else {
704		*host++ = '\0';
705		user = os;
706	}
707	cleanhostname(host);
708	/* Trivial case: username@ (all hosts) */
709	if (*host == '\0') {
710		if (user == NULL) {
711			fatal("Invalid key destination constraint \"%s\": "
712			    "does not specify user or host", s);
713		}
714		dch->user = xstrdup(user);
715		/* other fields left blank */
716		free(os);
717		return;
718	}
719	if (hostkey_files == NULL)
720		fatal_f("no hostkey files");
721	/* Otherwise we need to look up the keys for this hostname */
722	hostkeys = init_hostkeys();
723	for (i = 0; hostkey_files[i]; i++) {
724		path = tilde_expand_filename(hostkey_files[i], getuid());
725		debug2_f("looking up host keys for \"%s\" in %s", host, path);
726                load_hostkeys(hostkeys, host, path, 0);
727		free(path);
728	}
729	dch->user = user == NULL ? NULL : xstrdup(user);
730	dch->hostname = xstrdup(host);
731	for (i = 0; i < hostkeys->num_entries; i++) {
732		hke = hostkeys->entries + i;
733		want_ca = hke->marker == MRK_CA;
734		if (hke->marker != MRK_NONE && !want_ca)
735			continue;
736		debug3_f("%s%s%s: adding %s %skey from %s:%lu as key %u",
737		    user == NULL ? "": user, user == NULL ? "" : "@",
738		    host, sshkey_type(hke->key), want_ca ? "CA " : "",
739		    hke->file, hke->line, dch->nkeys);
740		dch->keys = xrecallocarray(dch->keys, dch->nkeys,
741		    dch->nkeys + 1, sizeof(*dch->keys));
742		dch->key_is_ca = xrecallocarray(dch->key_is_ca, dch->nkeys,
743		    dch->nkeys + 1, sizeof(*dch->key_is_ca));
744		if ((r = sshkey_from_private(hke->key,
745		    &(dch->keys[dch->nkeys]))) != 0)
746			fatal_fr(r, "sshkey_from_private");
747		dch->key_is_ca[dch->nkeys] = want_ca;
748		dch->nkeys++;
749	}
750	if (dch->nkeys == 0)
751		fatal("No host keys found for destination \"%s\"", host);
752	free_hostkeys(hostkeys);
753	free(os);
754	return;
755}
756
757static void
758parse_dest_constraint(const char *s, struct dest_constraint ***dcp,
759    size_t *ndcp, char **hostkey_files)
760{
761	struct dest_constraint *dc;
762	char *os, *cp;
763
764	dc = xcalloc(1, sizeof(*dc));
765	os = xstrdup(s);
766	if ((cp = strchr(os, '>')) == NULL) {
767		/* initial hop; no 'from' hop specified */
768		parse_dest_constraint_hop(os, &dc->to, hostkey_files);
769	} else {
770		/* two hops specified */
771		*(cp++) = '\0';
772		parse_dest_constraint_hop(os, &dc->from, hostkey_files);
773		parse_dest_constraint_hop(cp, &dc->to, hostkey_files);
774		if (dc->from.user != NULL) {
775			fatal("Invalid key constraint %s: cannot specify "
776			    "user on 'from' host", os);
777		}
778	}
779	/* XXX eliminate or error on duplicates */
780	debug2_f("constraint %zu: %s%s%s (%u keys) > %s%s%s (%u keys)", *ndcp,
781	    dc->from.user ? dc->from.user : "", dc->from.user ? "@" : "",
782	    dc->from.hostname ? dc->from.hostname : "(ORIGIN)", dc->from.nkeys,
783	    dc->to.user ? dc->to.user : "", dc->to.user ? "@" : "",
784	    dc->to.hostname ? dc->to.hostname : "(ANY)", dc->to.nkeys);
785	*dcp = xrecallocarray(*dcp, *ndcp, *ndcp + 1, sizeof(**dcp));
786	(*dcp)[(*ndcp)++] = dc;
787	free(os);
788}
789
790
791static void
792usage(void)
793{
794	fprintf(stderr,
795"usage: ssh-add [-CcDdKkLlqvXx] [-E fingerprint_hash] [-H hostkey_file]\n"
796"               [-h destination_constraint] [-S provider] [-t life]\n"
797#ifdef WITH_XMSS
798"               [-M maxsign] [-m minleft]\n"
799#endif
800"               [file ...]\n"
801"       ssh-add -s pkcs11 [-Cv] [certificate ...]\n"
802"       ssh-add -e pkcs11\n"
803"       ssh-add -T pubkey ...\n"
804	);
805}
806
807int
808main(int argc, char **argv)
809{
810	extern char *optarg;
811	extern int optind;
812	int agent_fd;
813	char *pkcs11provider = NULL, *skprovider = NULL;
814	char **dest_constraint_strings = NULL, **hostkey_files = NULL;
815	int r, i, ch, deleting = 0, ret = 0, key_only = 0, cert_only = 0;
816	int do_download = 0, xflag = 0, lflag = 0, Dflag = 0;
817	int qflag = 0, Tflag = 0;
818	SyslogFacility log_facility = SYSLOG_FACILITY_AUTH;
819	LogLevel log_level = SYSLOG_LEVEL_INFO;
820	struct sshkey *k, **certs = NULL;
821	struct dest_constraint **dest_constraints = NULL;
822	size_t ndest_constraints = 0, ncerts = 0;
823
824	/* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
825	sanitise_stdfd();
826
827	__progname = ssh_get_progname(argv[0]);
828	seed_rng();
829
830	log_init(__progname, log_level, log_facility, 1);
831
832	setvbuf(stdout, NULL, _IOLBF, 0);
833
834	/* First, get a connection to the authentication agent. */
835	switch (r = ssh_get_authentication_socket(&agent_fd)) {
836	case 0:
837		break;
838	case SSH_ERR_AGENT_NOT_PRESENT:
839		fprintf(stderr, "Could not open a connection to your "
840		    "authentication agent.\n");
841		exit(2);
842	default:
843		fprintf(stderr, "Error connecting to agent: %s\n", ssh_err(r));
844		exit(2);
845	}
846
847	skprovider = getenv("SSH_SK_PROVIDER");
848
849	while ((ch = getopt(argc, argv, "vkKlLCcdDTxXE:e:h:H:M:m:qs:S:t:")) != -1) {
850		switch (ch) {
851		case 'v':
852			if (log_level == SYSLOG_LEVEL_INFO)
853				log_level = SYSLOG_LEVEL_DEBUG1;
854			else if (log_level < SYSLOG_LEVEL_DEBUG3)
855				log_level++;
856			break;
857		case 'E':
858			fingerprint_hash = ssh_digest_alg_by_name(optarg);
859			if (fingerprint_hash == -1)
860				fatal("Invalid hash algorithm \"%s\"", optarg);
861			break;
862		case 'H':
863			stringlist_append(&hostkey_files, optarg);
864			break;
865		case 'h':
866			stringlist_append(&dest_constraint_strings, optarg);
867			break;
868		case 'k':
869			key_only = 1;
870			break;
871		case 'C':
872			cert_only = 1;
873			break;
874		case 'K':
875			do_download = 1;
876			break;
877		case 'l':
878		case 'L':
879			if (lflag != 0)
880				fatal("-%c flag already specified", lflag);
881			lflag = ch;
882			break;
883		case 'x':
884		case 'X':
885			if (xflag != 0)
886				fatal("-%c flag already specified", xflag);
887			xflag = ch;
888			break;
889		case 'c':
890			confirm = 1;
891			break;
892		case 'm':
893			minleft = (u_int)strtonum(optarg, 1, UINT_MAX, NULL);
894			if (minleft == 0) {
895				usage();
896				ret = 1;
897				goto done;
898			}
899			break;
900		case 'M':
901			maxsign = (u_int)strtonum(optarg, 1, UINT_MAX, NULL);
902			if (maxsign == 0) {
903				usage();
904				ret = 1;
905				goto done;
906			}
907			break;
908		case 'd':
909			deleting = 1;
910			break;
911		case 'D':
912			Dflag = 1;
913			break;
914		case 's':
915			pkcs11provider = optarg;
916			break;
917		case 'S':
918			skprovider = optarg;
919			break;
920		case 'e':
921			deleting = 1;
922			pkcs11provider = optarg;
923			break;
924		case 't':
925			if ((lifetime = convtime(optarg)) == -1 ||
926			    lifetime < 0 || (u_long)lifetime > UINT32_MAX) {
927				fprintf(stderr, "Invalid lifetime\n");
928				ret = 1;
929				goto done;
930			}
931			break;
932		case 'q':
933			qflag = 1;
934			break;
935		case 'T':
936			Tflag = 1;
937			break;
938		default:
939			usage();
940			ret = 1;
941			goto done;
942		}
943	}
944	log_init(__progname, log_level, log_facility, 1);
945
946	if ((xflag != 0) + (lflag != 0) + (Dflag != 0) > 1)
947		fatal("Invalid combination of actions");
948	else if (xflag) {
949		if (lock_agent(agent_fd, xflag == 'x' ? 1 : 0) == -1)
950			ret = 1;
951		goto done;
952	} else if (lflag) {
953		if (list_identities(agent_fd, lflag == 'l' ? 1 : 0) == -1)
954			ret = 1;
955		goto done;
956	} else if (Dflag) {
957		if (delete_all(agent_fd, qflag) == -1)
958			ret = 1;
959		goto done;
960	}
961
962#ifdef ENABLE_SK_INTERNAL
963	if (skprovider == NULL)
964		skprovider = "internal";
965#endif
966
967	if (hostkey_files == NULL) {
968		/* use defaults from readconf.c */
969		stringlist_append(&hostkey_files, _PATH_SSH_USER_HOSTFILE);
970		stringlist_append(&hostkey_files, _PATH_SSH_USER_HOSTFILE2);
971		stringlist_append(&hostkey_files, _PATH_SSH_SYSTEM_HOSTFILE);
972		stringlist_append(&hostkey_files, _PATH_SSH_SYSTEM_HOSTFILE2);
973	}
974	if (dest_constraint_strings != NULL) {
975		for (i = 0; dest_constraint_strings[i] != NULL; i++) {
976			parse_dest_constraint(dest_constraint_strings[i],
977			  &dest_constraints, &ndest_constraints, hostkey_files);
978		}
979	}
980
981	argc -= optind;
982	argv += optind;
983	if (Tflag) {
984		if (argc <= 0)
985			fatal("no keys to test");
986		for (r = i = 0; i < argc; i++)
987			r |= test_key(agent_fd, argv[i]);
988		ret = r == 0 ? 0 : 1;
989		goto done;
990	}
991	if (pkcs11provider != NULL) {
992		for (i = 0; i < argc; i++) {
993			if ((r = sshkey_load_public(argv[i], &k, NULL)) != 0)
994				fatal_fr(r, "load certificate %s", argv[i]);
995			certs = xrecallocarray(certs, ncerts, ncerts + 1,
996			    sizeof(*certs));
997			debug2("%s: %s", argv[i], sshkey_ssh_name(k));
998			certs[ncerts++] = k;
999		}
1000		debug2_f("loaded %zu certificates", ncerts);
1001		if (update_card(agent_fd, !deleting, pkcs11provider,
1002		    qflag, key_only, cert_only,
1003		    dest_constraints, ndest_constraints,
1004		    certs, ncerts) == -1)
1005			ret = 1;
1006		goto done;
1007	}
1008	if (do_download) {
1009		if (skprovider == NULL)
1010			fatal("Cannot download keys without provider");
1011		if (load_resident_keys(agent_fd, skprovider, qflag,
1012		    dest_constraints, ndest_constraints) != 0)
1013			ret = 1;
1014		goto done;
1015	}
1016	if (argc == 0) {
1017		char buf[PATH_MAX];
1018		struct passwd *pw;
1019		struct stat st;
1020		int count = 0;
1021
1022		if ((pw = getpwuid(getuid())) == NULL) {
1023			fprintf(stderr, "No user found with uid %u\n",
1024			    (u_int)getuid());
1025			ret = 1;
1026			goto done;
1027		}
1028
1029		for (i = 0; default_files[i]; i++) {
1030			snprintf(buf, sizeof(buf), "%s/%s", pw->pw_dir,
1031			    default_files[i]);
1032			if (stat(buf, &st) == -1)
1033				continue;
1034			if (do_file(agent_fd, deleting, key_only, cert_only,
1035			    buf, qflag, skprovider,
1036			    dest_constraints, ndest_constraints) == -1)
1037				ret = 1;
1038			else
1039				count++;
1040		}
1041		if (count == 0)
1042			ret = 1;
1043	} else {
1044		for (i = 0; i < argc; i++) {
1045			if (do_file(agent_fd, deleting, key_only, cert_only,
1046			    argv[i], qflag, skprovider,
1047			    dest_constraints, ndest_constraints) == -1)
1048				ret = 1;
1049		}
1050	}
1051done:
1052	clear_pass();
1053	ssh_close_authentication_socket(agent_fd);
1054	return ret;
1055}
1056