xref: /openbsd-src/usr.bin/ssh/ssh-keygen.c (revision cd1eb269cafb12c415be1749cd4a4b5422710415)
1 /* $OpenBSD: ssh-keygen.c,v 1.189 2010/04/23 22:48:31 djm Exp $ */
2 /*
3  * Author: Tatu Ylonen <ylo@cs.hut.fi>
4  * Copyright (c) 1994 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5  *                    All rights reserved
6  * Identity and host key generation and maintenance.
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 
15 #include <sys/types.h>
16 #include <sys/socket.h>
17 #include <sys/stat.h>
18 #include <sys/param.h>
19 
20 #include <openssl/evp.h>
21 #include <openssl/pem.h>
22 
23 #include <errno.h>
24 #include <fcntl.h>
25 #include <pwd.h>
26 #include <stdio.h>
27 #include <stdlib.h>
28 #include <string.h>
29 #include <unistd.h>
30 
31 #include "xmalloc.h"
32 #include "key.h"
33 #include "rsa.h"
34 #include "authfile.h"
35 #include "uuencode.h"
36 #include "buffer.h"
37 #include "pathnames.h"
38 #include "log.h"
39 #include "misc.h"
40 #include "match.h"
41 #include "hostfile.h"
42 #include "dns.h"
43 #include "ssh2.h"
44 
45 #ifdef ENABLE_PKCS11
46 #include "ssh-pkcs11.h"
47 #endif
48 
49 /* Number of bits in the RSA/DSA key.  This value can be set on the command line. */
50 #define DEFAULT_BITS		2048
51 #define DEFAULT_BITS_DSA	1024
52 u_int32_t bits = 0;
53 
54 /*
55  * Flag indicating that we just want to change the passphrase.  This can be
56  * set on the command line.
57  */
58 int change_passphrase = 0;
59 
60 /*
61  * Flag indicating that we just want to change the comment.  This can be set
62  * on the command line.
63  */
64 int change_comment = 0;
65 
66 int quiet = 0;
67 
68 int log_level = SYSLOG_LEVEL_INFO;
69 
70 /* Flag indicating that we want to hash a known_hosts file */
71 int hash_hosts = 0;
72 /* Flag indicating that we want lookup a host in known_hosts file */
73 int find_host = 0;
74 /* Flag indicating that we want to delete a host from a known_hosts file */
75 int delete_host = 0;
76 
77 /* Flag indicating that we want to show the contents of a certificate */
78 int show_cert = 0;
79 
80 /* Flag indicating that we just want to see the key fingerprint */
81 int print_fingerprint = 0;
82 int print_bubblebabble = 0;
83 
84 /* The identity file name, given on the command line or entered by the user. */
85 char identity_file[1024];
86 int have_identity = 0;
87 
88 /* This is set to the passphrase if given on the command line. */
89 char *identity_passphrase = NULL;
90 
91 /* This is set to the new passphrase if given on the command line. */
92 char *identity_new_passphrase = NULL;
93 
94 /* This is set to the new comment if given on the command line. */
95 char *identity_comment = NULL;
96 
97 /* Path to CA key when certifying keys. */
98 char *ca_key_path = NULL;
99 
100 /* Certificate serial number */
101 long long cert_serial = 0;
102 
103 /* Key type when certifying */
104 u_int cert_key_type = SSH2_CERT_TYPE_USER;
105 
106 /* "key ID" of signed key */
107 char *cert_key_id = NULL;
108 
109 /* Comma-separated list of principal names for certifying keys */
110 char *cert_principals = NULL;
111 
112 /* Validity period for certificates */
113 u_int64_t cert_valid_from = 0;
114 u_int64_t cert_valid_to = ~0ULL;
115 
116 /* Certificate options */
117 #define CRITOPT_X_FWD	(1)
118 #define CRITOPT_AGENT_FWD	(1<<1)
119 #define CRITOPT_PORT_FWD	(1<<2)
120 #define CRITOPT_PTY		(1<<3)
121 #define CRITOPT_USER_RC	(1<<4)
122 #define CRITOPT_DEFAULT	(CRITOPT_X_FWD|CRITOPT_AGENT_FWD| \
123 				CRITOPT_PORT_FWD|CRITOPT_PTY| \
124 				CRITOPT_USER_RC)
125 u_int32_t critical_flags = CRITOPT_DEFAULT;
126 char *critical_command = NULL;
127 char *critical_src_addr = NULL;
128 
129 /* Dump public key file in format used by real and the original SSH 2 */
130 int convert_to_ssh2 = 0;
131 int convert_from_ssh2 = 0;
132 int print_public = 0;
133 int print_generic = 0;
134 
135 char *key_type_name = NULL;
136 
137 /* argv0 */
138 extern char *__progname;
139 
140 char hostname[MAXHOSTNAMELEN];
141 
142 /* moduli.c */
143 int gen_candidates(FILE *, u_int32_t, u_int32_t, BIGNUM *);
144 int prime_test(FILE *, FILE *, u_int32_t, u_int32_t);
145 
146 static void
147 ask_filename(struct passwd *pw, const char *prompt)
148 {
149 	char buf[1024];
150 	char *name = NULL;
151 
152 	if (key_type_name == NULL)
153 		name = _PATH_SSH_CLIENT_ID_RSA;
154 	else {
155 		switch (key_type_from_name(key_type_name)) {
156 		case KEY_RSA1:
157 			name = _PATH_SSH_CLIENT_IDENTITY;
158 			break;
159 		case KEY_DSA_CERT:
160 		case KEY_DSA_CERT_V00:
161 		case KEY_DSA:
162 			name = _PATH_SSH_CLIENT_ID_DSA;
163 			break;
164 		case KEY_RSA_CERT:
165 		case KEY_RSA_CERT_V00:
166 		case KEY_RSA:
167 			name = _PATH_SSH_CLIENT_ID_RSA;
168 			break;
169 		default:
170 			fprintf(stderr, "bad key type\n");
171 			exit(1);
172 			break;
173 		}
174 	}
175 	snprintf(identity_file, sizeof(identity_file), "%s/%s", pw->pw_dir, name);
176 	fprintf(stderr, "%s (%s): ", prompt, identity_file);
177 	if (fgets(buf, sizeof(buf), stdin) == NULL)
178 		exit(1);
179 	buf[strcspn(buf, "\n")] = '\0';
180 	if (strcmp(buf, "") != 0)
181 		strlcpy(identity_file, buf, sizeof(identity_file));
182 	have_identity = 1;
183 }
184 
185 static Key *
186 load_identity(char *filename)
187 {
188 	char *pass;
189 	Key *prv;
190 
191 	prv = key_load_private(filename, "", NULL);
192 	if (prv == NULL) {
193 		if (identity_passphrase)
194 			pass = xstrdup(identity_passphrase);
195 		else
196 			pass = read_passphrase("Enter passphrase: ",
197 			    RP_ALLOW_STDIN);
198 		prv = key_load_private(filename, pass, NULL);
199 		memset(pass, 0, strlen(pass));
200 		xfree(pass);
201 	}
202 	return prv;
203 }
204 
205 #define SSH_COM_PUBLIC_BEGIN		"---- BEGIN SSH2 PUBLIC KEY ----"
206 #define SSH_COM_PUBLIC_END		"---- END SSH2 PUBLIC KEY ----"
207 #define SSH_COM_PRIVATE_BEGIN		"---- BEGIN SSH2 ENCRYPTED PRIVATE KEY ----"
208 #define	SSH_COM_PRIVATE_KEY_MAGIC	0x3f6ff9eb
209 
210 static void
211 do_convert_to_ssh2(struct passwd *pw)
212 {
213 	Key *k;
214 	u_int len;
215 	u_char *blob;
216 	char comment[61];
217 	struct stat st;
218 
219 	if (!have_identity)
220 		ask_filename(pw, "Enter file in which the key is");
221 	if (stat(identity_file, &st) < 0) {
222 		perror(identity_file);
223 		exit(1);
224 	}
225 	if ((k = key_load_public(identity_file, NULL)) == NULL) {
226 		if ((k = load_identity(identity_file)) == NULL) {
227 			fprintf(stderr, "load failed\n");
228 			exit(1);
229 		}
230 	}
231 	if (k->type == KEY_RSA1) {
232 		fprintf(stderr, "version 1 keys are not supported\n");
233 		exit(1);
234 	}
235 	if (key_to_blob(k, &blob, &len) <= 0) {
236 		fprintf(stderr, "key_to_blob failed\n");
237 		exit(1);
238 	}
239 	/* Comment + surrounds must fit into 72 chars (RFC 4716 sec 3.3) */
240 	snprintf(comment, sizeof(comment),
241 	    "%u-bit %s, converted by %s@%s from OpenSSH",
242 	    key_size(k), key_type(k),
243 	    pw->pw_name, hostname);
244 
245 	fprintf(stdout, "%s\n", SSH_COM_PUBLIC_BEGIN);
246 	fprintf(stdout, "Comment: \"%s\"\n", comment);
247 	dump_base64(stdout, blob, len);
248 	fprintf(stdout, "%s\n", SSH_COM_PUBLIC_END);
249 	key_free(k);
250 	xfree(blob);
251 	exit(0);
252 }
253 
254 static void
255 buffer_get_bignum_bits(Buffer *b, BIGNUM *value)
256 {
257 	u_int bignum_bits = buffer_get_int(b);
258 	u_int bytes = (bignum_bits + 7) / 8;
259 
260 	if (buffer_len(b) < bytes)
261 		fatal("buffer_get_bignum_bits: input buffer too small: "
262 		    "need %d have %d", bytes, buffer_len(b));
263 	if (BN_bin2bn(buffer_ptr(b), bytes, value) == NULL)
264 		fatal("buffer_get_bignum_bits: BN_bin2bn failed");
265 	buffer_consume(b, bytes);
266 }
267 
268 static Key *
269 do_convert_private_ssh2_from_blob(u_char *blob, u_int blen)
270 {
271 	Buffer b;
272 	Key *key = NULL;
273 	char *type, *cipher;
274 	u_char *sig, data[] = "abcde12345";
275 	int magic, rlen, ktype, i1, i2, i3, i4;
276 	u_int slen;
277 	u_long e;
278 
279 	buffer_init(&b);
280 	buffer_append(&b, blob, blen);
281 
282 	magic = buffer_get_int(&b);
283 	if (magic != SSH_COM_PRIVATE_KEY_MAGIC) {
284 		error("bad magic 0x%x != 0x%x", magic, SSH_COM_PRIVATE_KEY_MAGIC);
285 		buffer_free(&b);
286 		return NULL;
287 	}
288 	i1 = buffer_get_int(&b);
289 	type   = buffer_get_string(&b, NULL);
290 	cipher = buffer_get_string(&b, NULL);
291 	i2 = buffer_get_int(&b);
292 	i3 = buffer_get_int(&b);
293 	i4 = buffer_get_int(&b);
294 	debug("ignore (%d %d %d %d)", i1, i2, i3, i4);
295 	if (strcmp(cipher, "none") != 0) {
296 		error("unsupported cipher %s", cipher);
297 		xfree(cipher);
298 		buffer_free(&b);
299 		xfree(type);
300 		return NULL;
301 	}
302 	xfree(cipher);
303 
304 	if (strstr(type, "dsa")) {
305 		ktype = KEY_DSA;
306 	} else if (strstr(type, "rsa")) {
307 		ktype = KEY_RSA;
308 	} else {
309 		buffer_free(&b);
310 		xfree(type);
311 		return NULL;
312 	}
313 	key = key_new_private(ktype);
314 	xfree(type);
315 
316 	switch (key->type) {
317 	case KEY_DSA:
318 		buffer_get_bignum_bits(&b, key->dsa->p);
319 		buffer_get_bignum_bits(&b, key->dsa->g);
320 		buffer_get_bignum_bits(&b, key->dsa->q);
321 		buffer_get_bignum_bits(&b, key->dsa->pub_key);
322 		buffer_get_bignum_bits(&b, key->dsa->priv_key);
323 		break;
324 	case KEY_RSA:
325 		e = buffer_get_char(&b);
326 		debug("e %lx", e);
327 		if (e < 30) {
328 			e <<= 8;
329 			e += buffer_get_char(&b);
330 			debug("e %lx", e);
331 			e <<= 8;
332 			e += buffer_get_char(&b);
333 			debug("e %lx", e);
334 		}
335 		if (!BN_set_word(key->rsa->e, e)) {
336 			buffer_free(&b);
337 			key_free(key);
338 			return NULL;
339 		}
340 		buffer_get_bignum_bits(&b, key->rsa->d);
341 		buffer_get_bignum_bits(&b, key->rsa->n);
342 		buffer_get_bignum_bits(&b, key->rsa->iqmp);
343 		buffer_get_bignum_bits(&b, key->rsa->q);
344 		buffer_get_bignum_bits(&b, key->rsa->p);
345 		rsa_generate_additional_parameters(key->rsa);
346 		break;
347 	}
348 	rlen = buffer_len(&b);
349 	if (rlen != 0)
350 		error("do_convert_private_ssh2_from_blob: "
351 		    "remaining bytes in key blob %d", rlen);
352 	buffer_free(&b);
353 
354 	/* try the key */
355 	key_sign(key, &sig, &slen, data, sizeof(data));
356 	key_verify(key, sig, slen, data, sizeof(data));
357 	xfree(sig);
358 	return key;
359 }
360 
361 static int
362 get_line(FILE *fp, char *line, size_t len)
363 {
364 	int c;
365 	size_t pos = 0;
366 
367 	line[0] = '\0';
368 	while ((c = fgetc(fp)) != EOF) {
369 		if (pos >= len - 1) {
370 			fprintf(stderr, "input line too long.\n");
371 			exit(1);
372 		}
373 		switch (c) {
374 		case '\r':
375 			c = fgetc(fp);
376 			if (c != EOF && c != '\n' && ungetc(c, fp) == EOF) {
377 				fprintf(stderr, "unget: %s\n", strerror(errno));
378 				exit(1);
379 			}
380 			return pos;
381 		case '\n':
382 			return pos;
383 		}
384 		line[pos++] = c;
385 		line[pos] = '\0';
386 	}
387 	/* We reached EOF */
388 	return -1;
389 }
390 
391 static void
392 do_convert_from_ssh2(struct passwd *pw)
393 {
394 	Key *k;
395 	int blen;
396 	u_int len;
397 	char line[1024];
398 	u_char blob[8096];
399 	char encoded[8096];
400 	struct stat st;
401 	int escaped = 0, private = 0, ok;
402 	FILE *fp;
403 
404 	if (!have_identity)
405 		ask_filename(pw, "Enter file in which the key is");
406 	if (stat(identity_file, &st) < 0) {
407 		perror(identity_file);
408 		exit(1);
409 	}
410 	fp = fopen(identity_file, "r");
411 	if (fp == NULL) {
412 		perror(identity_file);
413 		exit(1);
414 	}
415 	encoded[0] = '\0';
416 	while ((blen = get_line(fp, line, sizeof(line))) != -1) {
417 		if (line[blen - 1] == '\\')
418 			escaped++;
419 		if (strncmp(line, "----", 4) == 0 ||
420 		    strstr(line, ": ") != NULL) {
421 			if (strstr(line, SSH_COM_PRIVATE_BEGIN) != NULL)
422 				private = 1;
423 			if (strstr(line, " END ") != NULL) {
424 				break;
425 			}
426 			/* fprintf(stderr, "ignore: %s", line); */
427 			continue;
428 		}
429 		if (escaped) {
430 			escaped--;
431 			/* fprintf(stderr, "escaped: %s", line); */
432 			continue;
433 		}
434 		strlcat(encoded, line, sizeof(encoded));
435 	}
436 	len = strlen(encoded);
437 	if (((len % 4) == 3) &&
438 	    (encoded[len-1] == '=') &&
439 	    (encoded[len-2] == '=') &&
440 	    (encoded[len-3] == '='))
441 		encoded[len-3] = '\0';
442 	blen = uudecode(encoded, blob, sizeof(blob));
443 	if (blen < 0) {
444 		fprintf(stderr, "uudecode failed.\n");
445 		exit(1);
446 	}
447 	k = private ?
448 	    do_convert_private_ssh2_from_blob(blob, blen) :
449 	    key_from_blob(blob, blen);
450 	if (k == NULL) {
451 		fprintf(stderr, "decode blob failed.\n");
452 		exit(1);
453 	}
454 	ok = private ?
455 	    (k->type == KEY_DSA ?
456 		 PEM_write_DSAPrivateKey(stdout, k->dsa, NULL, NULL, 0, NULL, NULL) :
457 		 PEM_write_RSAPrivateKey(stdout, k->rsa, NULL, NULL, 0, NULL, NULL)) :
458 	    key_write(k, stdout);
459 	if (!ok) {
460 		fprintf(stderr, "key write failed\n");
461 		exit(1);
462 	}
463 	key_free(k);
464 	if (!private)
465 		fprintf(stdout, "\n");
466 	fclose(fp);
467 	exit(0);
468 }
469 
470 static void
471 do_print_public(struct passwd *pw)
472 {
473 	Key *prv;
474 	struct stat st;
475 
476 	if (!have_identity)
477 		ask_filename(pw, "Enter file in which the key is");
478 	if (stat(identity_file, &st) < 0) {
479 		perror(identity_file);
480 		exit(1);
481 	}
482 	prv = load_identity(identity_file);
483 	if (prv == NULL) {
484 		fprintf(stderr, "load failed\n");
485 		exit(1);
486 	}
487 	if (!key_write(prv, stdout))
488 		fprintf(stderr, "key_write failed");
489 	key_free(prv);
490 	fprintf(stdout, "\n");
491 	exit(0);
492 }
493 
494 static void
495 do_download(struct passwd *pw, char *pkcs11provider)
496 {
497 #ifdef ENABLE_PKCS11
498 	Key **keys = NULL;
499 	int i, nkeys;
500 
501 	pkcs11_init(0);
502 	nkeys = pkcs11_add_provider(pkcs11provider, NULL, &keys);
503 	if (nkeys <= 0)
504 		fatal("cannot read public key from pkcs11");
505 	for (i = 0; i < nkeys; i++) {
506 		key_write(keys[i], stdout);
507 		key_free(keys[i]);
508 		fprintf(stdout, "\n");
509 	}
510 	xfree(keys);
511 	pkcs11_terminate();
512 	exit(0);
513 #else
514 	fatal("no pkcs11 support");
515 #endif /* ENABLE_PKCS11 */
516 }
517 
518 static void
519 do_fingerprint(struct passwd *pw)
520 {
521 	FILE *f;
522 	Key *public;
523 	char *comment = NULL, *cp, *ep, line[16*1024], *fp, *ra;
524 	int i, skip = 0, num = 0, invalid = 1;
525 	enum fp_rep rep;
526 	enum fp_type fptype;
527 	struct stat st;
528 
529 	fptype = print_bubblebabble ? SSH_FP_SHA1 : SSH_FP_MD5;
530 	rep =    print_bubblebabble ? SSH_FP_BUBBLEBABBLE : SSH_FP_HEX;
531 
532 	if (!have_identity)
533 		ask_filename(pw, "Enter file in which the key is");
534 	if (stat(identity_file, &st) < 0) {
535 		perror(identity_file);
536 		exit(1);
537 	}
538 	public = key_load_public(identity_file, &comment);
539 	if (public != NULL) {
540 		fp = key_fingerprint(public, fptype, rep);
541 		ra = key_fingerprint(public, SSH_FP_MD5, SSH_FP_RANDOMART);
542 		printf("%u %s %s (%s)\n", key_size(public), fp, comment,
543 		    key_type(public));
544 		if (log_level >= SYSLOG_LEVEL_VERBOSE)
545 			printf("%s\n", ra);
546 		key_free(public);
547 		xfree(comment);
548 		xfree(ra);
549 		xfree(fp);
550 		exit(0);
551 	}
552 	if (comment) {
553 		xfree(comment);
554 		comment = NULL;
555 	}
556 
557 	f = fopen(identity_file, "r");
558 	if (f != NULL) {
559 		while (fgets(line, sizeof(line), f)) {
560 			if ((cp = strchr(line, '\n')) == NULL) {
561 				error("line %d too long: %.40s...",
562 				    num + 1, line);
563 				skip = 1;
564 				continue;
565 			}
566 			num++;
567 			if (skip) {
568 				skip = 0;
569 				continue;
570 			}
571 			*cp = '\0';
572 
573 			/* Skip leading whitespace, empty and comment lines. */
574 			for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
575 				;
576 			if (!*cp || *cp == '\n' || *cp == '#')
577 				continue;
578 			i = strtol(cp, &ep, 10);
579 			if (i == 0 || ep == NULL || (*ep != ' ' && *ep != '\t')) {
580 				int quoted = 0;
581 				comment = cp;
582 				for (; *cp && (quoted || (*cp != ' ' &&
583 				    *cp != '\t')); cp++) {
584 					if (*cp == '\\' && cp[1] == '"')
585 						cp++;	/* Skip both */
586 					else if (*cp == '"')
587 						quoted = !quoted;
588 				}
589 				if (!*cp)
590 					continue;
591 				*cp++ = '\0';
592 			}
593 			ep = cp;
594 			public = key_new(KEY_RSA1);
595 			if (key_read(public, &cp) != 1) {
596 				cp = ep;
597 				key_free(public);
598 				public = key_new(KEY_UNSPEC);
599 				if (key_read(public, &cp) != 1) {
600 					key_free(public);
601 					continue;
602 				}
603 			}
604 			comment = *cp ? cp : comment;
605 			fp = key_fingerprint(public, fptype, rep);
606 			ra = key_fingerprint(public, SSH_FP_MD5, SSH_FP_RANDOMART);
607 			printf("%u %s %s (%s)\n", key_size(public), fp,
608 			    comment ? comment : "no comment", key_type(public));
609 			if (log_level >= SYSLOG_LEVEL_VERBOSE)
610 				printf("%s\n", ra);
611 			xfree(ra);
612 			xfree(fp);
613 			key_free(public);
614 			invalid = 0;
615 		}
616 		fclose(f);
617 	}
618 	if (invalid) {
619 		printf("%s is not a public key file.\n", identity_file);
620 		exit(1);
621 	}
622 	exit(0);
623 }
624 
625 static void
626 printhost(FILE *f, const char *name, Key *public, int ca, int hash)
627 {
628 	if (print_fingerprint) {
629 		enum fp_rep rep;
630 		enum fp_type fptype;
631 		char *fp, *ra;
632 
633 		fptype = print_bubblebabble ? SSH_FP_SHA1 : SSH_FP_MD5;
634 		rep =    print_bubblebabble ? SSH_FP_BUBBLEBABBLE : SSH_FP_HEX;
635 		fp = key_fingerprint(public, fptype, rep);
636 		ra = key_fingerprint(public, SSH_FP_MD5, SSH_FP_RANDOMART);
637 		printf("%u %s %s (%s)\n", key_size(public), fp, name,
638 		    key_type(public));
639 		if (log_level >= SYSLOG_LEVEL_VERBOSE)
640 			printf("%s\n", ra);
641 		xfree(ra);
642 		xfree(fp);
643 	} else {
644 		if (hash && (name = host_hash(name, NULL, 0)) == NULL)
645 			fatal("hash_host failed");
646 		fprintf(f, "%s%s%s ", ca ? CA_MARKER : "", ca ? " " : "", name);
647 		if (!key_write(public, f))
648 			fatal("key_write failed");
649 		fprintf(f, "\n");
650 	}
651 }
652 
653 static void
654 do_known_hosts(struct passwd *pw, const char *name)
655 {
656 	FILE *in, *out = stdout;
657 	Key *pub;
658 	char *cp, *cp2, *kp, *kp2;
659 	char line[16*1024], tmp[MAXPATHLEN], old[MAXPATHLEN];
660 	int c, skip = 0, inplace = 0, num = 0, invalid = 0, has_unhashed = 0;
661 	int ca;
662 
663 	if (!have_identity) {
664 		cp = tilde_expand_filename(_PATH_SSH_USER_HOSTFILE, pw->pw_uid);
665 		if (strlcpy(identity_file, cp, sizeof(identity_file)) >=
666 		    sizeof(identity_file))
667 			fatal("Specified known hosts path too long");
668 		xfree(cp);
669 		have_identity = 1;
670 	}
671 	if ((in = fopen(identity_file, "r")) == NULL)
672 		fatal("fopen: %s", strerror(errno));
673 
674 	/*
675 	 * Find hosts goes to stdout, hash and deletions happen in-place
676 	 * A corner case is ssh-keygen -HF foo, which should go to stdout
677 	 */
678 	if (!find_host && (hash_hosts || delete_host)) {
679 		if (strlcpy(tmp, identity_file, sizeof(tmp)) >= sizeof(tmp) ||
680 		    strlcat(tmp, ".XXXXXXXXXX", sizeof(tmp)) >= sizeof(tmp) ||
681 		    strlcpy(old, identity_file, sizeof(old)) >= sizeof(old) ||
682 		    strlcat(old, ".old", sizeof(old)) >= sizeof(old))
683 			fatal("known_hosts path too long");
684 		umask(077);
685 		if ((c = mkstemp(tmp)) == -1)
686 			fatal("mkstemp: %s", strerror(errno));
687 		if ((out = fdopen(c, "w")) == NULL) {
688 			c = errno;
689 			unlink(tmp);
690 			fatal("fdopen: %s", strerror(c));
691 		}
692 		inplace = 1;
693 	}
694 
695 	while (fgets(line, sizeof(line), in)) {
696 		if ((cp = strchr(line, '\n')) == NULL) {
697 			error("line %d too long: %.40s...", num + 1, line);
698 			skip = 1;
699 			invalid = 1;
700 			continue;
701 		}
702 		num++;
703 		if (skip) {
704 			skip = 0;
705 			continue;
706 		}
707 		*cp = '\0';
708 
709 		/* Skip leading whitespace, empty and comment lines. */
710 		for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
711 			;
712 		if (!*cp || *cp == '\n' || *cp == '#') {
713 			if (inplace)
714 				fprintf(out, "%s\n", cp);
715 			continue;
716 		}
717 		/* Check whether this is a CA key */
718 		if (strncasecmp(cp, CA_MARKER, sizeof(CA_MARKER) - 1) == 0 &&
719 		    (cp[sizeof(CA_MARKER) - 1] == ' ' ||
720 		    cp[sizeof(CA_MARKER) - 1] == '\t')) {
721 			ca = 1;
722 			cp += sizeof(CA_MARKER);
723 		} else
724 			ca = 0;
725 
726 		/* Find the end of the host name portion. */
727 		for (kp = cp; *kp && *kp != ' ' && *kp != '\t'; kp++)
728 			;
729 
730 		if (*kp == '\0' || *(kp + 1) == '\0') {
731 			error("line %d missing key: %.40s...",
732 			    num, line);
733 			invalid = 1;
734 			continue;
735 		}
736 		*kp++ = '\0';
737 		kp2 = kp;
738 
739 		pub = key_new(KEY_RSA1);
740 		if (key_read(pub, &kp) != 1) {
741 			kp = kp2;
742 			key_free(pub);
743 			pub = key_new(KEY_UNSPEC);
744 			if (key_read(pub, &kp) != 1) {
745 				error("line %d invalid key: %.40s...",
746 				    num, line);
747 				key_free(pub);
748 				invalid = 1;
749 				continue;
750 			}
751 		}
752 
753 		if (*cp == HASH_DELIM) {
754 			if (find_host || delete_host) {
755 				cp2 = host_hash(name, cp, strlen(cp));
756 				if (cp2 == NULL) {
757 					error("line %d: invalid hashed "
758 					    "name: %.64s...", num, line);
759 					invalid = 1;
760 					continue;
761 				}
762 				c = (strcmp(cp2, cp) == 0);
763 				if (find_host && c) {
764 					printf("# Host %s found: "
765 					    "line %d type %s%s\n", name,
766 					    num, key_type(pub),
767 					    ca ? " (CA key)" : "");
768 					printhost(out, cp, pub, ca, 0);
769 				}
770 				if (delete_host && !c && !ca)
771 					printhost(out, cp, pub, ca, 0);
772 			} else if (hash_hosts)
773 				printhost(out, cp, pub, ca, 0);
774 		} else {
775 			if (find_host || delete_host) {
776 				c = (match_hostname(name, cp,
777 				    strlen(cp)) == 1);
778 				if (find_host && c) {
779 					printf("# Host %s found: "
780 					    "line %d type %s%s\n", name,
781 					    num, key_type(pub),
782 					    ca ? " (CA key)" : "");
783 					printhost(out, name, pub,
784 					    ca, hash_hosts && !ca);
785 				}
786 				if (delete_host && !c && !ca)
787 					printhost(out, cp, pub, ca, 0);
788 			} else if (hash_hosts) {
789 				for (cp2 = strsep(&cp, ",");
790 				    cp2 != NULL && *cp2 != '\0';
791 				    cp2 = strsep(&cp, ",")) {
792 					if (ca) {
793 						fprintf(stderr, "Warning: "
794 						    "ignoring CA key for host: "
795 						    "%.64s\n", cp2);
796 						printhost(out, cp2, pub, ca, 0);
797 					} else if (strcspn(cp2, "*?!") !=
798 					    strlen(cp2)) {
799 						fprintf(stderr, "Warning: "
800 						    "ignoring host name with "
801 						    "metacharacters: %.64s\n",
802 						    cp2);
803 						printhost(out, cp2, pub, ca, 0);
804 					} else
805 						printhost(out, cp2, pub, ca, 1);
806 				}
807 				has_unhashed = 1;
808 			}
809 		}
810 		key_free(pub);
811 	}
812 	fclose(in);
813 
814 	if (invalid) {
815 		fprintf(stderr, "%s is not a valid known_hosts file.\n",
816 		    identity_file);
817 		if (inplace) {
818 			fprintf(stderr, "Not replacing existing known_hosts "
819 			    "file because of errors\n");
820 			fclose(out);
821 			unlink(tmp);
822 		}
823 		exit(1);
824 	}
825 
826 	if (inplace) {
827 		fclose(out);
828 
829 		/* Backup existing file */
830 		if (unlink(old) == -1 && errno != ENOENT)
831 			fatal("unlink %.100s: %s", old, strerror(errno));
832 		if (link(identity_file, old) == -1)
833 			fatal("link %.100s to %.100s: %s", identity_file, old,
834 			    strerror(errno));
835 		/* Move new one into place */
836 		if (rename(tmp, identity_file) == -1) {
837 			error("rename\"%s\" to \"%s\": %s", tmp, identity_file,
838 			    strerror(errno));
839 			unlink(tmp);
840 			unlink(old);
841 			exit(1);
842 		}
843 
844 		fprintf(stderr, "%s updated.\n", identity_file);
845 		fprintf(stderr, "Original contents retained as %s\n", old);
846 		if (has_unhashed) {
847 			fprintf(stderr, "WARNING: %s contains unhashed "
848 			    "entries\n", old);
849 			fprintf(stderr, "Delete this file to ensure privacy "
850 			    "of hostnames\n");
851 		}
852 	}
853 
854 	exit(0);
855 }
856 
857 /*
858  * Perform changing a passphrase.  The argument is the passwd structure
859  * for the current user.
860  */
861 static void
862 do_change_passphrase(struct passwd *pw)
863 {
864 	char *comment;
865 	char *old_passphrase, *passphrase1, *passphrase2;
866 	struct stat st;
867 	Key *private;
868 
869 	if (!have_identity)
870 		ask_filename(pw, "Enter file in which the key is");
871 	if (stat(identity_file, &st) < 0) {
872 		perror(identity_file);
873 		exit(1);
874 	}
875 	/* Try to load the file with empty passphrase. */
876 	private = key_load_private(identity_file, "", &comment);
877 	if (private == NULL) {
878 		if (identity_passphrase)
879 			old_passphrase = xstrdup(identity_passphrase);
880 		else
881 			old_passphrase =
882 			    read_passphrase("Enter old passphrase: ",
883 			    RP_ALLOW_STDIN);
884 		private = key_load_private(identity_file, old_passphrase,
885 		    &comment);
886 		memset(old_passphrase, 0, strlen(old_passphrase));
887 		xfree(old_passphrase);
888 		if (private == NULL) {
889 			printf("Bad passphrase.\n");
890 			exit(1);
891 		}
892 	}
893 	printf("Key has comment '%s'\n", comment);
894 
895 	/* Ask the new passphrase (twice). */
896 	if (identity_new_passphrase) {
897 		passphrase1 = xstrdup(identity_new_passphrase);
898 		passphrase2 = NULL;
899 	} else {
900 		passphrase1 =
901 			read_passphrase("Enter new passphrase (empty for no "
902 			    "passphrase): ", RP_ALLOW_STDIN);
903 		passphrase2 = read_passphrase("Enter same passphrase again: ",
904 		    RP_ALLOW_STDIN);
905 
906 		/* Verify that they are the same. */
907 		if (strcmp(passphrase1, passphrase2) != 0) {
908 			memset(passphrase1, 0, strlen(passphrase1));
909 			memset(passphrase2, 0, strlen(passphrase2));
910 			xfree(passphrase1);
911 			xfree(passphrase2);
912 			printf("Pass phrases do not match.  Try again.\n");
913 			exit(1);
914 		}
915 		/* Destroy the other copy. */
916 		memset(passphrase2, 0, strlen(passphrase2));
917 		xfree(passphrase2);
918 	}
919 
920 	/* Save the file using the new passphrase. */
921 	if (!key_save_private(private, identity_file, passphrase1, comment)) {
922 		printf("Saving the key failed: %s.\n", identity_file);
923 		memset(passphrase1, 0, strlen(passphrase1));
924 		xfree(passphrase1);
925 		key_free(private);
926 		xfree(comment);
927 		exit(1);
928 	}
929 	/* Destroy the passphrase and the copy of the key in memory. */
930 	memset(passphrase1, 0, strlen(passphrase1));
931 	xfree(passphrase1);
932 	key_free(private);		 /* Destroys contents */
933 	xfree(comment);
934 
935 	printf("Your identification has been saved with the new passphrase.\n");
936 	exit(0);
937 }
938 
939 /*
940  * Print the SSHFP RR.
941  */
942 static int
943 do_print_resource_record(struct passwd *pw, char *fname, char *hname)
944 {
945 	Key *public;
946 	char *comment = NULL;
947 	struct stat st;
948 
949 	if (fname == NULL)
950 		ask_filename(pw, "Enter file in which the key is");
951 	if (stat(fname, &st) < 0) {
952 		if (errno == ENOENT)
953 			return 0;
954 		perror(fname);
955 		exit(1);
956 	}
957 	public = key_load_public(fname, &comment);
958 	if (public != NULL) {
959 		export_dns_rr(hname, public, stdout, print_generic);
960 		key_free(public);
961 		xfree(comment);
962 		return 1;
963 	}
964 	if (comment)
965 		xfree(comment);
966 
967 	printf("failed to read v2 public key from %s.\n", fname);
968 	exit(1);
969 }
970 
971 /*
972  * Change the comment of a private key file.
973  */
974 static void
975 do_change_comment(struct passwd *pw)
976 {
977 	char new_comment[1024], *comment, *passphrase;
978 	Key *private;
979 	Key *public;
980 	struct stat st;
981 	FILE *f;
982 	int fd;
983 
984 	if (!have_identity)
985 		ask_filename(pw, "Enter file in which the key is");
986 	if (stat(identity_file, &st) < 0) {
987 		perror(identity_file);
988 		exit(1);
989 	}
990 	private = key_load_private(identity_file, "", &comment);
991 	if (private == NULL) {
992 		if (identity_passphrase)
993 			passphrase = xstrdup(identity_passphrase);
994 		else if (identity_new_passphrase)
995 			passphrase = xstrdup(identity_new_passphrase);
996 		else
997 			passphrase = read_passphrase("Enter passphrase: ",
998 			    RP_ALLOW_STDIN);
999 		/* Try to load using the passphrase. */
1000 		private = key_load_private(identity_file, passphrase, &comment);
1001 		if (private == NULL) {
1002 			memset(passphrase, 0, strlen(passphrase));
1003 			xfree(passphrase);
1004 			printf("Bad passphrase.\n");
1005 			exit(1);
1006 		}
1007 	} else {
1008 		passphrase = xstrdup("");
1009 	}
1010 	if (private->type != KEY_RSA1) {
1011 		fprintf(stderr, "Comments are only supported for RSA1 keys.\n");
1012 		key_free(private);
1013 		exit(1);
1014 	}
1015 	printf("Key now has comment '%s'\n", comment);
1016 
1017 	if (identity_comment) {
1018 		strlcpy(new_comment, identity_comment, sizeof(new_comment));
1019 	} else {
1020 		printf("Enter new comment: ");
1021 		fflush(stdout);
1022 		if (!fgets(new_comment, sizeof(new_comment), stdin)) {
1023 			memset(passphrase, 0, strlen(passphrase));
1024 			key_free(private);
1025 			exit(1);
1026 		}
1027 		new_comment[strcspn(new_comment, "\n")] = '\0';
1028 	}
1029 
1030 	/* Save the file using the new passphrase. */
1031 	if (!key_save_private(private, identity_file, passphrase, new_comment)) {
1032 		printf("Saving the key failed: %s.\n", identity_file);
1033 		memset(passphrase, 0, strlen(passphrase));
1034 		xfree(passphrase);
1035 		key_free(private);
1036 		xfree(comment);
1037 		exit(1);
1038 	}
1039 	memset(passphrase, 0, strlen(passphrase));
1040 	xfree(passphrase);
1041 	public = key_from_private(private);
1042 	key_free(private);
1043 
1044 	strlcat(identity_file, ".pub", sizeof(identity_file));
1045 	fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
1046 	if (fd == -1) {
1047 		printf("Could not save your public key in %s\n", identity_file);
1048 		exit(1);
1049 	}
1050 	f = fdopen(fd, "w");
1051 	if (f == NULL) {
1052 		printf("fdopen %s failed\n", identity_file);
1053 		exit(1);
1054 	}
1055 	if (!key_write(public, f))
1056 		fprintf(stderr, "write key failed\n");
1057 	key_free(public);
1058 	fprintf(f, " %s\n", new_comment);
1059 	fclose(f);
1060 
1061 	xfree(comment);
1062 
1063 	printf("The comment in your key file has been changed.\n");
1064 	exit(0);
1065 }
1066 
1067 static const char *
1068 fmt_validity(u_int64_t valid_from, u_int64_t valid_to)
1069 {
1070 	char from[32], to[32];
1071 	static char ret[64];
1072 	time_t tt;
1073 	struct tm *tm;
1074 
1075 	*from = *to = '\0';
1076 	if (valid_from == 0 && valid_to == 0xffffffffffffffffULL)
1077 		return "forever";
1078 
1079 	if (valid_from != 0) {
1080 		/* XXX revisit INT_MAX in 2038 :) */
1081 		tt = valid_from > INT_MAX ? INT_MAX : valid_from;
1082 		tm = localtime(&tt);
1083 		strftime(from, sizeof(from), "%Y-%m-%dT%H:%M:%S", tm);
1084 	}
1085 	if (valid_to != 0xffffffffffffffffULL) {
1086 		/* XXX revisit INT_MAX in 2038 :) */
1087 		tt = valid_to > INT_MAX ? INT_MAX : valid_to;
1088 		tm = localtime(&tt);
1089 		strftime(to, sizeof(to), "%Y-%m-%dT%H:%M:%S", tm);
1090 	}
1091 
1092 	if (valid_from == 0) {
1093 		snprintf(ret, sizeof(ret), "before %s", to);
1094 		return ret;
1095 	}
1096 	if (valid_to == 0xffffffffffffffffULL) {
1097 		snprintf(ret, sizeof(ret), "after %s", from);
1098 		return ret;
1099 	}
1100 
1101 	snprintf(ret, sizeof(ret), "from %s to %s", from, to);
1102 	return ret;
1103 }
1104 
1105 static void
1106 add_flag_option(Buffer *c, const char *name)
1107 {
1108 	debug3("%s: %s", __func__, name);
1109 	buffer_put_cstring(c, name);
1110 	buffer_put_string(c, NULL, 0);
1111 }
1112 
1113 static void
1114 add_string_option(Buffer *c, const char *name, const char *value)
1115 {
1116 	Buffer b;
1117 
1118 	debug3("%s: %s=%s", __func__, name, value);
1119 	buffer_init(&b);
1120 	buffer_put_cstring(&b, value);
1121 
1122 	buffer_put_cstring(c, name);
1123 	buffer_put_string(c, buffer_ptr(&b), buffer_len(&b));
1124 
1125 	buffer_free(&b);
1126 }
1127 
1128 static void
1129 prepare_options_buf(Buffer *c)
1130 {
1131 	buffer_clear(c);
1132 	if ((critical_flags & CRITOPT_X_FWD) != 0)
1133 		add_flag_option(c, "permit-X11-forwarding");
1134 	if ((critical_flags & CRITOPT_AGENT_FWD) != 0)
1135 		add_flag_option(c, "permit-agent-forwarding");
1136 	if ((critical_flags & CRITOPT_PORT_FWD) != 0)
1137 		add_flag_option(c, "permit-port-forwarding");
1138 	if ((critical_flags & CRITOPT_PTY) != 0)
1139 		add_flag_option(c, "permit-pty");
1140 	if ((critical_flags & CRITOPT_USER_RC) != 0)
1141 		add_flag_option(c, "permit-user-rc");
1142 	if (critical_command != NULL)
1143 		add_string_option(c, "force-command", critical_command);
1144 	if (critical_src_addr != NULL)
1145 		add_string_option(c, "source-address", critical_src_addr);
1146 }
1147 
1148 static void
1149 do_ca_sign(struct passwd *pw, int argc, char **argv)
1150 {
1151 	int i, fd;
1152 	u_int n;
1153 	Key *ca, *public;
1154 	char *otmp, *tmp, *cp, *out, *comment, **plist = NULL;
1155 	FILE *f;
1156 	int v00 = 0; /* legacy keys */
1157 
1158 	tmp = tilde_expand_filename(ca_key_path, pw->pw_uid);
1159 	if ((ca = load_identity(tmp)) == NULL)
1160 		fatal("Couldn't load CA key \"%s\"", tmp);
1161 	xfree(tmp);
1162 
1163 	if (key_type_name != NULL) {
1164 		switch (key_type_from_name(key_type_name)) {
1165 		case KEY_RSA_CERT_V00:
1166 		case KEY_DSA_CERT_V00:
1167 			v00 = 1;
1168 			break;
1169 		case KEY_UNSPEC:
1170 			if (strcasecmp(key_type_name, "v00") == 0) {
1171 				v00 = 1;
1172 				break;
1173 			} else if (strcasecmp(key_type_name, "v01") == 0)
1174 				break;
1175 			/* FALLTHROUGH */
1176 		default:
1177 			fprintf(stderr, "unknown key type %s\n", key_type_name);
1178 			exit(1);
1179 		}
1180 	}
1181 
1182 	for (i = 0; i < argc; i++) {
1183 		/* Split list of principals */
1184 		n = 0;
1185 		if (cert_principals != NULL) {
1186 			otmp = tmp = xstrdup(cert_principals);
1187 			plist = NULL;
1188 			for (; (cp = strsep(&tmp, ",")) != NULL; n++) {
1189 				plist = xrealloc(plist, n + 1, sizeof(*plist));
1190 				if (*(plist[n] = xstrdup(cp)) == '\0')
1191 					fatal("Empty principal name");
1192 			}
1193 			xfree(otmp);
1194 		}
1195 
1196 		tmp = tilde_expand_filename(argv[i], pw->pw_uid);
1197 		if ((public = key_load_public(tmp, &comment)) == NULL)
1198 			fatal("%s: unable to open \"%s\"", __func__, tmp);
1199 		if (public->type != KEY_RSA && public->type != KEY_DSA)
1200 			fatal("%s: key \"%s\" type %s cannot be certified",
1201 			    __func__, tmp, key_type(public));
1202 
1203 		/* Prepare certificate to sign */
1204 		if (key_to_certified(public, v00) != 0)
1205 			fatal("Could not upgrade key %s to certificate", tmp);
1206 		public->cert->type = cert_key_type;
1207 		public->cert->serial = (u_int64_t)cert_serial;
1208 		public->cert->key_id = xstrdup(cert_key_id);
1209 		public->cert->nprincipals = n;
1210 		public->cert->principals = plist;
1211 		public->cert->valid_after = cert_valid_from;
1212 		public->cert->valid_before = cert_valid_to;
1213 		prepare_options_buf(&public->cert->critical);
1214 		public->cert->signature_key = key_from_private(ca);
1215 
1216 		if (key_certify(public, ca) != 0)
1217 			fatal("Couldn't not certify key %s", tmp);
1218 
1219 		if ((cp = strrchr(tmp, '.')) != NULL && strcmp(cp, ".pub") == 0)
1220 			*cp = '\0';
1221 		xasprintf(&out, "%s-cert.pub", tmp);
1222 		xfree(tmp);
1223 
1224 		if ((fd = open(out, O_WRONLY|O_CREAT|O_TRUNC, 0644)) == -1)
1225 			fatal("Could not open \"%s\" for writing: %s", out,
1226 			    strerror(errno));
1227 		if ((f = fdopen(fd, "w")) == NULL)
1228 			fatal("%s: fdopen: %s", __func__, strerror(errno));
1229 		if (!key_write(public, f))
1230 			fatal("Could not write certified key to %s", out);
1231 		fprintf(f, " %s\n", comment);
1232 		fclose(f);
1233 
1234 		if (!quiet) {
1235 			logit("Signed %s key %s: id \"%s\" serial %llu%s%s "
1236 			    "valid %s", key_cert_type(public),
1237 			    out, public->cert->key_id, public->cert->serial,
1238 			    cert_principals != NULL ? " for " : "",
1239 			    cert_principals != NULL ? cert_principals : "",
1240 			    fmt_validity(cert_valid_from, cert_valid_to));
1241 		}
1242 
1243 		key_free(public);
1244 		xfree(out);
1245 	}
1246 	exit(0);
1247 }
1248 
1249 static u_int64_t
1250 parse_relative_time(const char *s, time_t now)
1251 {
1252 	int64_t mul, secs;
1253 
1254 	mul = *s == '-' ? -1 : 1;
1255 
1256 	if ((secs = convtime(s + 1)) == -1)
1257 		fatal("Invalid relative certificate time %s", s);
1258 	if (mul == -1 && secs > now)
1259 		fatal("Certificate time %s cannot be represented", s);
1260 	return now + (u_int64_t)(secs * mul);
1261 }
1262 
1263 static u_int64_t
1264 parse_absolute_time(const char *s)
1265 {
1266 	struct tm tm;
1267 	time_t tt;
1268 	char buf[32], *fmt;
1269 
1270 	/*
1271 	 * POSIX strptime says "The application shall ensure that there
1272 	 * is white-space or other non-alphanumeric characters between
1273 	 * any two conversion specifications" so arrange things this way.
1274 	 */
1275 	switch (strlen(s)) {
1276 	case 8:
1277 		fmt = "%Y-%m-%d";
1278 		snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2s", s, s + 4, s + 6);
1279 		break;
1280 	case 14:
1281 		fmt = "%Y-%m-%dT%H:%M:%S";
1282 		snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2sT%.2s:%.2s:%.2s",
1283 		    s, s + 4, s + 6, s + 8, s + 10, s + 12);
1284 		break;
1285 	default:
1286 		fatal("Invalid certificate time format %s", s);
1287 	}
1288 
1289 	bzero(&tm, sizeof(tm));
1290 	if (strptime(buf, fmt, &tm) == NULL)
1291 		fatal("Invalid certificate time %s", s);
1292 	if ((tt = mktime(&tm)) < 0)
1293 		fatal("Certificate time %s cannot be represented", s);
1294 	return (u_int64_t)tt;
1295 }
1296 
1297 static void
1298 parse_cert_times(char *timespec)
1299 {
1300 	char *from, *to;
1301 	time_t now = time(NULL);
1302 	int64_t secs;
1303 
1304 	/* +timespec relative to now */
1305 	if (*timespec == '+' && strchr(timespec, ':') == NULL) {
1306 		if ((secs = convtime(timespec + 1)) == -1)
1307 			fatal("Invalid relative certificate life %s", timespec);
1308 		cert_valid_to = now + secs;
1309 		/*
1310 		 * Backdate certificate one minute to avoid problems on hosts
1311 		 * with poorly-synchronised clocks.
1312 		 */
1313 		cert_valid_from = ((now - 59)/ 60) * 60;
1314 		return;
1315 	}
1316 
1317 	/*
1318 	 * from:to, where
1319 	 * from := [+-]timespec | YYYYMMDD | YYYYMMDDHHMMSS
1320 	 *   to := [+-]timespec | YYYYMMDD | YYYYMMDDHHMMSS
1321 	 */
1322 	from = xstrdup(timespec);
1323 	to = strchr(from, ':');
1324 	if (to == NULL || from == to || *(to + 1) == '\0')
1325 		fatal("Invalid certificate life specification %s", timespec);
1326 	*to++ = '\0';
1327 
1328 	if (*from == '-' || *from == '+')
1329 		cert_valid_from = parse_relative_time(from, now);
1330 	else
1331 		cert_valid_from = parse_absolute_time(from);
1332 
1333 	if (*to == '-' || *to == '+')
1334 		cert_valid_to = parse_relative_time(to, cert_valid_from);
1335 	else
1336 		cert_valid_to = parse_absolute_time(to);
1337 
1338 	if (cert_valid_to <= cert_valid_from)
1339 		fatal("Empty certificate validity interval");
1340 	xfree(from);
1341 }
1342 
1343 static void
1344 add_cert_option(char *opt)
1345 {
1346 	char *val;
1347 
1348 	if (strcmp(opt, "clear") == 0)
1349 		critical_flags = 0;
1350 	else if (strcasecmp(opt, "no-x11-forwarding") == 0)
1351 		critical_flags &= ~CRITOPT_X_FWD;
1352 	else if (strcasecmp(opt, "permit-x11-forwarding") == 0)
1353 		critical_flags |= CRITOPT_X_FWD;
1354 	else if (strcasecmp(opt, "no-agent-forwarding") == 0)
1355 		critical_flags &= ~CRITOPT_AGENT_FWD;
1356 	else if (strcasecmp(opt, "permit-agent-forwarding") == 0)
1357 		critical_flags |= CRITOPT_AGENT_FWD;
1358 	else if (strcasecmp(opt, "no-port-forwarding") == 0)
1359 		critical_flags &= ~CRITOPT_PORT_FWD;
1360 	else if (strcasecmp(opt, "permit-port-forwarding") == 0)
1361 		critical_flags |= CRITOPT_PORT_FWD;
1362 	else if (strcasecmp(opt, "no-pty") == 0)
1363 		critical_flags &= ~CRITOPT_PTY;
1364 	else if (strcasecmp(opt, "permit-pty") == 0)
1365 		critical_flags |= CRITOPT_PTY;
1366 	else if (strcasecmp(opt, "no-user-rc") == 0)
1367 		critical_flags &= ~CRITOPT_USER_RC;
1368 	else if (strcasecmp(opt, "permit-user-rc") == 0)
1369 		critical_flags |= CRITOPT_USER_RC;
1370 	else if (strncasecmp(opt, "force-command=", 14) == 0) {
1371 		val = opt + 14;
1372 		if (*val == '\0')
1373 			fatal("Empty force-command option");
1374 		if (critical_command != NULL)
1375 			fatal("force-command already specified");
1376 		critical_command = xstrdup(val);
1377 	} else if (strncasecmp(opt, "source-address=", 15) == 0) {
1378 		val = opt + 15;
1379 		if (*val == '\0')
1380 			fatal("Empty source-address option");
1381 		if (critical_src_addr != NULL)
1382 			fatal("source-address already specified");
1383 		if (addr_match_cidr_list(NULL, val) != 0)
1384 			fatal("Invalid source-address list");
1385 		critical_src_addr = xstrdup(val);
1386 	} else
1387 		fatal("Unsupported certificate option \"%s\"", opt);
1388 }
1389 
1390 static void
1391 do_show_cert(struct passwd *pw)
1392 {
1393 	Key *key;
1394 	struct stat st;
1395 	char *key_fp, *ca_fp;
1396 	Buffer options, option;
1397 	u_char *name, *data;
1398 	u_int i, dlen, v00;
1399 
1400 	if (!have_identity)
1401 		ask_filename(pw, "Enter file in which the key is");
1402 	if (stat(identity_file, &st) < 0) {
1403 		perror(identity_file);
1404 		exit(1);
1405 	}
1406 	if ((key = key_load_public(identity_file, NULL)) == NULL)
1407 		fatal("%s is not a public key", identity_file);
1408 	if (!key_is_cert(key))
1409 		fatal("%s is not a certificate", identity_file);
1410 	v00 = key->type == KEY_RSA_CERT_V00 || key->type == KEY_DSA_CERT_V00;
1411 
1412 	key_fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX);
1413 	ca_fp = key_fingerprint(key->cert->signature_key,
1414 	    SSH_FP_MD5, SSH_FP_HEX);
1415 
1416 	printf("%s:\n", identity_file);
1417 	printf("        Type: %s %s certificate\n", key_ssh_name(key),
1418 	    key_cert_type(key));
1419 	printf("        Public key: %s %s\n", key_type(key), key_fp);
1420 	printf("        Signing CA: %s %s\n",
1421 	    key_type(key->cert->signature_key), ca_fp);
1422 	printf("        Key ID: \"%s\"\n", key->cert->key_id);
1423 	if (!v00)
1424 		printf("        Serial: %llu\n", key->cert->serial);
1425 	printf("        Valid: %s\n",
1426 	    fmt_validity(key->cert->valid_after, key->cert->valid_before));
1427 	printf("        Principals: ");
1428 	if (key->cert->nprincipals == 0)
1429 		printf("(none)\n");
1430 	else {
1431 		for (i = 0; i < key->cert->nprincipals; i++)
1432 			printf("\n                %s",
1433 			    key->cert->principals[i]);
1434 		printf("\n");
1435 	}
1436 	printf("        Critical Options: ");
1437 	if (buffer_len(&key->cert->critical) == 0)
1438 		printf("(none)\n");
1439 	else {
1440 		printf("\n");
1441 		buffer_init(&options);
1442 		buffer_append(&options,
1443 		    buffer_ptr(&key->cert->critical),
1444 		    buffer_len(&key->cert->critical));
1445 		buffer_init(&option);
1446 		while (buffer_len(&options) != 0) {
1447 			name = buffer_get_string(&options, NULL);
1448 			data = buffer_get_string_ptr(&options, &dlen);
1449 			buffer_append(&option, data, dlen);
1450 			printf("                %s", name);
1451 			if (strcmp(name, "permit-X11-forwarding") == 0 ||
1452 			    strcmp(name, "permit-agent-forwarding") == 0 ||
1453 			    strcmp(name, "permit-port-forwarding") == 0 ||
1454 			    strcmp(name, "permit-pty") == 0 ||
1455 			    strcmp(name, "permit-user-rc") == 0)
1456 				printf("\n");
1457 			else if (strcmp(name, "force-command") == 0 ||
1458 			    strcmp(name, "source-address") == 0) {
1459 				data = buffer_get_string(&option, NULL);
1460 				printf(" %s\n", data);
1461 				xfree(data);
1462 			} else {
1463 				printf(" UNKNOWN OPTION (len %u)\n",
1464 				    buffer_len(&option));
1465 				buffer_clear(&option);
1466 			}
1467 			xfree(name);
1468 			if (buffer_len(&option) != 0)
1469 				fatal("Option corrupt: extra data at end");
1470 		}
1471 		buffer_free(&option);
1472 		buffer_free(&options);
1473 	}
1474 	if (!v00) {
1475 		printf("        Extensions: ");
1476 		if (buffer_len(&key->cert->extensions) == 0)
1477 			printf("(none)\n");
1478 		else {
1479 			printf("\n");
1480 			buffer_init(&options);
1481 			buffer_append(&options,
1482 			    buffer_ptr(&key->cert->extensions),
1483 			    buffer_len(&key->cert->extensions));
1484 			buffer_init(&option);
1485 			while (buffer_len(&options) != 0) {
1486 				name = buffer_get_string(&options, NULL);
1487 				(void)buffer_get_string_ptr(&options, &dlen);
1488 				printf("                %s UNKNOWN OPTION "
1489 				    "(len %u)\n", name, dlen);
1490 				xfree(name);
1491 			}
1492 			buffer_free(&option);
1493 			buffer_free(&options);
1494 		}
1495 	}
1496 	exit(0);
1497 }
1498 
1499 static void
1500 usage(void)
1501 {
1502 	fprintf(stderr, "usage: %s [options]\n", __progname);
1503 	fprintf(stderr, "Options:\n");
1504 	fprintf(stderr, "  -a trials   Number of trials for screening DH-GEX moduli.\n");
1505 	fprintf(stderr, "  -B          Show bubblebabble digest of key file.\n");
1506 	fprintf(stderr, "  -b bits     Number of bits in the key to create.\n");
1507 	fprintf(stderr, "  -C comment  Provide new comment.\n");
1508 	fprintf(stderr, "  -c          Change comment in private and public key files.\n");
1509 #ifdef ENABLE_PKCS11
1510 	fprintf(stderr, "  -D pkcs11   Download public key from pkcs11 token.\n");
1511 #endif
1512 	fprintf(stderr, "  -e          Convert OpenSSH to RFC 4716 key file.\n");
1513 	fprintf(stderr, "  -F hostname Find hostname in known hosts file.\n");
1514 	fprintf(stderr, "  -f filename Filename of the key file.\n");
1515 	fprintf(stderr, "  -G file     Generate candidates for DH-GEX moduli.\n");
1516 	fprintf(stderr, "  -g          Use generic DNS resource record format.\n");
1517 	fprintf(stderr, "  -H          Hash names in known_hosts file.\n");
1518 	fprintf(stderr, "  -h          Generate host certificate instead of a user certificate.\n");
1519 	fprintf(stderr, "  -I key_id   Key identifier to include in certificate.\n");
1520 	fprintf(stderr, "  -i          Convert RFC 4716 to OpenSSH key file.\n");
1521 	fprintf(stderr, "  -L          Print the contents of a certificate.\n");
1522 	fprintf(stderr, "  -l          Show fingerprint of key file.\n");
1523 	fprintf(stderr, "  -M memory   Amount of memory (MB) to use for generating DH-GEX moduli.\n");
1524 	fprintf(stderr, "  -n name,... User/host principal names to include in certificate\n");
1525 	fprintf(stderr, "  -N phrase   Provide new passphrase.\n");
1526 	fprintf(stderr, "  -O option   Specify a certificate option.\n");
1527 	fprintf(stderr, "  -P phrase   Provide old passphrase.\n");
1528 	fprintf(stderr, "  -p          Change passphrase of private key file.\n");
1529 	fprintf(stderr, "  -q          Quiet.\n");
1530 	fprintf(stderr, "  -R hostname Remove host from known_hosts file.\n");
1531 	fprintf(stderr, "  -r hostname Print DNS resource record.\n");
1532 	fprintf(stderr, "  -s ca_key   Certify keys with CA key.\n");
1533 	fprintf(stderr, "  -S start    Start point (hex) for generating DH-GEX moduli.\n");
1534 	fprintf(stderr, "  -T file     Screen candidates for DH-GEX moduli.\n");
1535 	fprintf(stderr, "  -t type     Specify type of key to create.\n");
1536 	fprintf(stderr, "  -V from:to  Specify certificate validity interval.\n");
1537 	fprintf(stderr, "  -v          Verbose.\n");
1538 	fprintf(stderr, "  -W gen      Generator to use for generating DH-GEX moduli.\n");
1539 	fprintf(stderr, "  -y          Read private key file and print public key.\n");
1540 	fprintf(stderr, "  -z serial   Specify a serial number.\n");
1541 
1542 	exit(1);
1543 }
1544 
1545 /*
1546  * Main program for key management.
1547  */
1548 int
1549 main(int argc, char **argv)
1550 {
1551 	char dotsshdir[MAXPATHLEN], comment[1024], *passphrase1, *passphrase2;
1552 	char out_file[MAXPATHLEN], *pkcs11provider = NULL;
1553 	char *rr_hostname = NULL;
1554 	Key *private, *public;
1555 	struct passwd *pw;
1556 	struct stat st;
1557 	int opt, type, fd;
1558 	u_int maxbits;
1559 	u_int32_t memory = 0, generator_wanted = 0, trials = 100;
1560 	int do_gen_candidates = 0, do_screen_candidates = 0;
1561 	BIGNUM *start = NULL;
1562 	FILE *f;
1563 	const char *errstr;
1564 
1565 	extern int optind;
1566 	extern char *optarg;
1567 
1568 	/* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1569 	sanitise_stdfd();
1570 
1571 	SSLeay_add_all_algorithms();
1572 	log_init(argv[0], SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_USER, 1);
1573 
1574 	/* we need this for the home * directory.  */
1575 	pw = getpwuid(getuid());
1576 	if (!pw) {
1577 		printf("You don't exist, go away!\n");
1578 		exit(1);
1579 	}
1580 	if (gethostname(hostname, sizeof(hostname)) < 0) {
1581 		perror("gethostname");
1582 		exit(1);
1583 	}
1584 
1585 	while ((opt = getopt(argc, argv, "degiqpclBHLhvxXyF:b:f:t:D:I:P:N:n:"
1586 	    "O:C:r:g:R:T:G:M:S:s:a:V:W:z:")) != -1) {
1587 		switch (opt) {
1588 		case 'b':
1589 			bits = (u_int32_t)strtonum(optarg, 768, 32768, &errstr);
1590 			if (errstr)
1591 				fatal("Bits has bad value %s (%s)",
1592 					optarg, errstr);
1593 			break;
1594 		case 'F':
1595 			find_host = 1;
1596 			rr_hostname = optarg;
1597 			break;
1598 		case 'H':
1599 			hash_hosts = 1;
1600 			break;
1601 		case 'I':
1602 			cert_key_id = optarg;
1603 			break;
1604 		case 'R':
1605 			delete_host = 1;
1606 			rr_hostname = optarg;
1607 			break;
1608 		case 'L':
1609 			show_cert = 1;
1610 			break;
1611 		case 'l':
1612 			print_fingerprint = 1;
1613 			break;
1614 		case 'B':
1615 			print_bubblebabble = 1;
1616 			break;
1617 		case 'n':
1618 			cert_principals = optarg;
1619 			break;
1620 		case 'p':
1621 			change_passphrase = 1;
1622 			break;
1623 		case 'c':
1624 			change_comment = 1;
1625 			break;
1626 		case 'f':
1627 			if (strlcpy(identity_file, optarg, sizeof(identity_file)) >=
1628 			    sizeof(identity_file))
1629 				fatal("Identity filename too long");
1630 			have_identity = 1;
1631 			break;
1632 		case 'g':
1633 			print_generic = 1;
1634 			break;
1635 		case 'P':
1636 			identity_passphrase = optarg;
1637 			break;
1638 		case 'N':
1639 			identity_new_passphrase = optarg;
1640 			break;
1641 		case 'O':
1642 			add_cert_option(optarg);
1643 			break;
1644 		case 'C':
1645 			identity_comment = optarg;
1646 			break;
1647 		case 'q':
1648 			quiet = 1;
1649 			break;
1650 		case 'e':
1651 		case 'x':
1652 			/* export key */
1653 			convert_to_ssh2 = 1;
1654 			break;
1655 		case 'h':
1656 			cert_key_type = SSH2_CERT_TYPE_HOST;
1657 			critical_flags = 0;
1658 			break;
1659 		case 'i':
1660 		case 'X':
1661 			/* import key */
1662 			convert_from_ssh2 = 1;
1663 			break;
1664 		case 'y':
1665 			print_public = 1;
1666 			break;
1667 		case 'd':
1668 			key_type_name = "dsa";
1669 			break;
1670 		case 's':
1671 			ca_key_path = optarg;
1672 			break;
1673 		case 't':
1674 			key_type_name = optarg;
1675 			break;
1676 		case 'D':
1677 			pkcs11provider = optarg;
1678 			break;
1679 		case 'v':
1680 			if (log_level == SYSLOG_LEVEL_INFO)
1681 				log_level = SYSLOG_LEVEL_DEBUG1;
1682 			else {
1683 				if (log_level >= SYSLOG_LEVEL_DEBUG1 &&
1684 				    log_level < SYSLOG_LEVEL_DEBUG3)
1685 					log_level++;
1686 			}
1687 			break;
1688 		case 'r':
1689 			rr_hostname = optarg;
1690 			break;
1691 		case 'W':
1692 			generator_wanted = (u_int32_t)strtonum(optarg, 1,
1693 			    UINT_MAX, &errstr);
1694 			if (errstr)
1695 				fatal("Desired generator has bad value: %s (%s)",
1696 					optarg, errstr);
1697 			break;
1698 		case 'a':
1699 			trials = (u_int32_t)strtonum(optarg, 1, UINT_MAX, &errstr);
1700 			if (errstr)
1701 				fatal("Invalid number of trials: %s (%s)",
1702 					optarg, errstr);
1703 			break;
1704 		case 'M':
1705 			memory = (u_int32_t)strtonum(optarg, 1, UINT_MAX, &errstr);
1706 			if (errstr)
1707 				fatal("Memory limit is %s: %s", errstr, optarg);
1708 			break;
1709 		case 'G':
1710 			do_gen_candidates = 1;
1711 			if (strlcpy(out_file, optarg, sizeof(out_file)) >=
1712 			    sizeof(out_file))
1713 				fatal("Output filename too long");
1714 			break;
1715 		case 'T':
1716 			do_screen_candidates = 1;
1717 			if (strlcpy(out_file, optarg, sizeof(out_file)) >=
1718 			    sizeof(out_file))
1719 				fatal("Output filename too long");
1720 			break;
1721 		case 'S':
1722 			/* XXX - also compare length against bits */
1723 			if (BN_hex2bn(&start, optarg) == 0)
1724 				fatal("Invalid start point.");
1725 			break;
1726 		case 'V':
1727 			parse_cert_times(optarg);
1728 			break;
1729 		case 'z':
1730 			cert_serial = strtonum(optarg, 0, LLONG_MAX, &errstr);
1731 			if (errstr)
1732 				fatal("Invalid serial number: %s", errstr);
1733 			break;
1734 		case '?':
1735 		default:
1736 			usage();
1737 		}
1738 	}
1739 
1740 	/* reinit */
1741 	log_init(argv[0], log_level, SYSLOG_FACILITY_USER, 1);
1742 
1743 	argv += optind;
1744 	argc -= optind;
1745 
1746 	if (ca_key_path != NULL) {
1747 		if (argc < 1) {
1748 			printf("Too few arguments.\n");
1749 			usage();
1750 		}
1751 	} else if (argc > 0) {
1752 		printf("Too many arguments.\n");
1753 		usage();
1754 	}
1755 	if (change_passphrase && change_comment) {
1756 		printf("Can only have one of -p and -c.\n");
1757 		usage();
1758 	}
1759 	if (print_fingerprint && (delete_host || hash_hosts)) {
1760 		printf("Cannot use -l with -D or -R.\n");
1761 		usage();
1762 	}
1763 	if (ca_key_path != NULL) {
1764 		if (cert_key_id == NULL)
1765 			fatal("Must specify key id (-I) when certifying");
1766 		do_ca_sign(pw, argc, argv);
1767 	}
1768 	if (show_cert)
1769 		do_show_cert(pw);
1770 	if (delete_host || hash_hosts || find_host)
1771 		do_known_hosts(pw, rr_hostname);
1772 	if (print_fingerprint || print_bubblebabble)
1773 		do_fingerprint(pw);
1774 	if (change_passphrase)
1775 		do_change_passphrase(pw);
1776 	if (change_comment)
1777 		do_change_comment(pw);
1778 	if (convert_to_ssh2)
1779 		do_convert_to_ssh2(pw);
1780 	if (convert_from_ssh2)
1781 		do_convert_from_ssh2(pw);
1782 	if (print_public)
1783 		do_print_public(pw);
1784 	if (rr_hostname != NULL) {
1785 		unsigned int n = 0;
1786 
1787 		if (have_identity) {
1788 			n = do_print_resource_record(pw,
1789 			    identity_file, rr_hostname);
1790 			if (n == 0) {
1791 				perror(identity_file);
1792 				exit(1);
1793 			}
1794 			exit(0);
1795 		} else {
1796 
1797 			n += do_print_resource_record(pw,
1798 			    _PATH_HOST_RSA_KEY_FILE, rr_hostname);
1799 			n += do_print_resource_record(pw,
1800 			    _PATH_HOST_DSA_KEY_FILE, rr_hostname);
1801 
1802 			if (n == 0)
1803 				fatal("no keys found.");
1804 			exit(0);
1805 		}
1806 	}
1807 	if (pkcs11provider != NULL)
1808 		do_download(pw, pkcs11provider);
1809 
1810 	if (do_gen_candidates) {
1811 		FILE *out = fopen(out_file, "w");
1812 
1813 		if (out == NULL) {
1814 			error("Couldn't open modulus candidate file \"%s\": %s",
1815 			    out_file, strerror(errno));
1816 			return (1);
1817 		}
1818 		if (bits == 0)
1819 			bits = DEFAULT_BITS;
1820 		if (gen_candidates(out, memory, bits, start) != 0)
1821 			fatal("modulus candidate generation failed");
1822 
1823 		return (0);
1824 	}
1825 
1826 	if (do_screen_candidates) {
1827 		FILE *in;
1828 		FILE *out = fopen(out_file, "w");
1829 
1830 		if (have_identity && strcmp(identity_file, "-") != 0) {
1831 			if ((in = fopen(identity_file, "r")) == NULL) {
1832 				fatal("Couldn't open modulus candidate "
1833 				    "file \"%s\": %s", identity_file,
1834 				    strerror(errno));
1835 			}
1836 		} else
1837 			in = stdin;
1838 
1839 		if (out == NULL) {
1840 			fatal("Couldn't open moduli file \"%s\": %s",
1841 			    out_file, strerror(errno));
1842 		}
1843 		if (prime_test(in, out, trials, generator_wanted) != 0)
1844 			fatal("modulus screening failed");
1845 		return (0);
1846 	}
1847 
1848 	arc4random_stir();
1849 
1850 	if (key_type_name == NULL)
1851 		key_type_name = "rsa";
1852 
1853 	type = key_type_from_name(key_type_name);
1854 	if (type == KEY_UNSPEC) {
1855 		fprintf(stderr, "unknown key type %s\n", key_type_name);
1856 		exit(1);
1857 	}
1858 	if (bits == 0)
1859 		bits = (type == KEY_DSA) ? DEFAULT_BITS_DSA : DEFAULT_BITS;
1860 	maxbits = (type == KEY_DSA) ?
1861 	    OPENSSL_DSA_MAX_MODULUS_BITS : OPENSSL_RSA_MAX_MODULUS_BITS;
1862 	if (bits > maxbits) {
1863 		fprintf(stderr, "key bits exceeds maximum %d\n", maxbits);
1864 		exit(1);
1865 	}
1866 	if (type == KEY_DSA && bits != 1024)
1867 		fatal("DSA keys must be 1024 bits");
1868 	if (!quiet)
1869 		printf("Generating public/private %s key pair.\n", key_type_name);
1870 	private = key_generate(type, bits);
1871 	if (private == NULL) {
1872 		fprintf(stderr, "key_generate failed\n");
1873 		exit(1);
1874 	}
1875 	public  = key_from_private(private);
1876 
1877 	if (!have_identity)
1878 		ask_filename(pw, "Enter file in which to save the key");
1879 
1880 	/* Create ~/.ssh directory if it doesn't already exist. */
1881 	snprintf(dotsshdir, sizeof dotsshdir, "%s/%s",
1882 	    pw->pw_dir, _PATH_SSH_USER_DIR);
1883 	if (strstr(identity_file, dotsshdir) != NULL) {
1884 		if (stat(dotsshdir, &st) < 0) {
1885 			if (errno != ENOENT) {
1886 				error("Could not stat %s: %s", dotsshdir,
1887 				    strerror(errno));
1888 			} else if (mkdir(dotsshdir, 0700) < 0) {
1889 				error("Could not create directory '%s': %s",
1890 				    dotsshdir, strerror(errno));
1891 			} else if (!quiet)
1892 				printf("Created directory '%s'.\n", dotsshdir);
1893 		}
1894 	}
1895 	/* If the file already exists, ask the user to confirm. */
1896 	if (stat(identity_file, &st) >= 0) {
1897 		char yesno[3];
1898 		printf("%s already exists.\n", identity_file);
1899 		printf("Overwrite (y/n)? ");
1900 		fflush(stdout);
1901 		if (fgets(yesno, sizeof(yesno), stdin) == NULL)
1902 			exit(1);
1903 		if (yesno[0] != 'y' && yesno[0] != 'Y')
1904 			exit(1);
1905 	}
1906 	/* Ask for a passphrase (twice). */
1907 	if (identity_passphrase)
1908 		passphrase1 = xstrdup(identity_passphrase);
1909 	else if (identity_new_passphrase)
1910 		passphrase1 = xstrdup(identity_new_passphrase);
1911 	else {
1912 passphrase_again:
1913 		passphrase1 =
1914 			read_passphrase("Enter passphrase (empty for no "
1915 			    "passphrase): ", RP_ALLOW_STDIN);
1916 		passphrase2 = read_passphrase("Enter same passphrase again: ",
1917 		    RP_ALLOW_STDIN);
1918 		if (strcmp(passphrase1, passphrase2) != 0) {
1919 			/*
1920 			 * The passphrases do not match.  Clear them and
1921 			 * retry.
1922 			 */
1923 			memset(passphrase1, 0, strlen(passphrase1));
1924 			memset(passphrase2, 0, strlen(passphrase2));
1925 			xfree(passphrase1);
1926 			xfree(passphrase2);
1927 			printf("Passphrases do not match.  Try again.\n");
1928 			goto passphrase_again;
1929 		}
1930 		/* Clear the other copy of the passphrase. */
1931 		memset(passphrase2, 0, strlen(passphrase2));
1932 		xfree(passphrase2);
1933 	}
1934 
1935 	if (identity_comment) {
1936 		strlcpy(comment, identity_comment, sizeof(comment));
1937 	} else {
1938 		/* Create default comment field for the passphrase. */
1939 		snprintf(comment, sizeof comment, "%s@%s", pw->pw_name, hostname);
1940 	}
1941 
1942 	/* Save the key with the given passphrase and comment. */
1943 	if (!key_save_private(private, identity_file, passphrase1, comment)) {
1944 		printf("Saving the key failed: %s.\n", identity_file);
1945 		memset(passphrase1, 0, strlen(passphrase1));
1946 		xfree(passphrase1);
1947 		exit(1);
1948 	}
1949 	/* Clear the passphrase. */
1950 	memset(passphrase1, 0, strlen(passphrase1));
1951 	xfree(passphrase1);
1952 
1953 	/* Clear the private key and the random number generator. */
1954 	key_free(private);
1955 	arc4random_stir();
1956 
1957 	if (!quiet)
1958 		printf("Your identification has been saved in %s.\n", identity_file);
1959 
1960 	strlcat(identity_file, ".pub", sizeof(identity_file));
1961 	fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
1962 	if (fd == -1) {
1963 		printf("Could not save your public key in %s\n", identity_file);
1964 		exit(1);
1965 	}
1966 	f = fdopen(fd, "w");
1967 	if (f == NULL) {
1968 		printf("fdopen %s failed\n", identity_file);
1969 		exit(1);
1970 	}
1971 	if (!key_write(public, f))
1972 		fprintf(stderr, "write key failed\n");
1973 	fprintf(f, " %s\n", comment);
1974 	fclose(f);
1975 
1976 	if (!quiet) {
1977 		char *fp = key_fingerprint(public, SSH_FP_MD5, SSH_FP_HEX);
1978 		char *ra = key_fingerprint(public, SSH_FP_MD5,
1979 		    SSH_FP_RANDOMART);
1980 		printf("Your public key has been saved in %s.\n",
1981 		    identity_file);
1982 		printf("The key fingerprint is:\n");
1983 		printf("%s %s\n", fp, comment);
1984 		printf("The key's randomart image is:\n");
1985 		printf("%s\n", ra);
1986 		xfree(ra);
1987 		xfree(fp);
1988 	}
1989 
1990 	key_free(public);
1991 	exit(0);
1992 }
1993