xref: /dragonfly/crypto/openssh/ssh-keygen.c (revision dcd37f7d)
1 /* $OpenBSD: ssh-keygen.c,v 1.174 2009/06/22 05:39:28 dtucker 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 "includes.h"
16 
17 #include <sys/types.h>
18 #include <sys/socket.h>
19 #include <sys/stat.h>
20 #include <sys/param.h>
21 
22 #include <openssl/evp.h>
23 #include <openssl/pem.h>
24 #include "openbsd-compat/openssl-compat.h"
25 
26 #include <errno.h>
27 #include <fcntl.h>
28 #include <netdb.h>
29 #ifdef HAVE_PATHS_H
30 # include <paths.h>
31 #endif
32 #include <pwd.h>
33 #include <stdarg.h>
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <string.h>
37 #include <unistd.h>
38 
39 #include "xmalloc.h"
40 #include "key.h"
41 #include "rsa.h"
42 #include "authfile.h"
43 #include "uuencode.h"
44 #include "buffer.h"
45 #include "pathnames.h"
46 #include "log.h"
47 #include "misc.h"
48 #include "match.h"
49 #include "hostfile.h"
50 #include "dns.h"
51 
52 #ifdef SMARTCARD
53 #include "scard.h"
54 #endif
55 
56 /* Number of bits in the RSA/DSA key.  This value can be set on the command line. */
57 #define DEFAULT_BITS		2048
58 #define DEFAULT_BITS_DSA	1024
59 u_int32_t bits = 0;
60 
61 /*
62  * Flag indicating that we just want to change the passphrase.  This can be
63  * set on the command line.
64  */
65 int change_passphrase = 0;
66 
67 /*
68  * Flag indicating that we just want to change the comment.  This can be set
69  * on the command line.
70  */
71 int change_comment = 0;
72 
73 int quiet = 0;
74 
75 int log_level = SYSLOG_LEVEL_INFO;
76 
77 /* Flag indicating that we want to hash a known_hosts file */
78 int hash_hosts = 0;
79 /* Flag indicating that we want lookup a host in known_hosts file */
80 int find_host = 0;
81 /* Flag indicating that we want to delete a host from a known_hosts file */
82 int delete_host = 0;
83 
84 /* Flag indicating that we just want to see the key fingerprint */
85 int print_fingerprint = 0;
86 int print_bubblebabble = 0;
87 
88 /* The identity file name, given on the command line or entered by the user. */
89 char identity_file[1024];
90 int have_identity = 0;
91 
92 /* This is set to the passphrase if given on the command line. */
93 char *identity_passphrase = NULL;
94 
95 /* This is set to the new passphrase if given on the command line. */
96 char *identity_new_passphrase = NULL;
97 
98 /* This is set to the new comment if given on the command line. */
99 char *identity_comment = NULL;
100 
101 /* Dump public key file in format used by real and the original SSH 2 */
102 int convert_to_ssh2 = 0;
103 int convert_from_ssh2 = 0;
104 int print_public = 0;
105 int print_generic = 0;
106 
107 char *key_type_name = NULL;
108 
109 /* argv0 */
110 extern char *__progname;
111 
112 char hostname[MAXHOSTNAMELEN];
113 
114 /* moduli.c */
115 int gen_candidates(FILE *, u_int32_t, u_int32_t, BIGNUM *);
116 int prime_test(FILE *, FILE *, u_int32_t, u_int32_t);
117 
118 static void
119 ask_filename(struct passwd *pw, const char *prompt)
120 {
121 	char buf[1024];
122 	char *name = NULL;
123 
124 	if (key_type_name == NULL)
125 		name = _PATH_SSH_CLIENT_ID_RSA;
126 	else {
127 		switch (key_type_from_name(key_type_name)) {
128 		case KEY_RSA1:
129 			name = _PATH_SSH_CLIENT_IDENTITY;
130 			break;
131 		case KEY_DSA:
132 			name = _PATH_SSH_CLIENT_ID_DSA;
133 			break;
134 		case KEY_RSA:
135 			name = _PATH_SSH_CLIENT_ID_RSA;
136 			break;
137 		default:
138 			fprintf(stderr, "bad key type\n");
139 			exit(1);
140 			break;
141 		}
142 	}
143 	snprintf(identity_file, sizeof(identity_file), "%s/%s", pw->pw_dir, name);
144 	fprintf(stderr, "%s (%s): ", prompt, identity_file);
145 	if (fgets(buf, sizeof(buf), stdin) == NULL)
146 		exit(1);
147 	buf[strcspn(buf, "\n")] = '\0';
148 	if (strcmp(buf, "") != 0)
149 		strlcpy(identity_file, buf, sizeof(identity_file));
150 	have_identity = 1;
151 }
152 
153 static Key *
154 load_identity(char *filename)
155 {
156 	char *pass;
157 	Key *prv;
158 
159 	prv = key_load_private(filename, "", NULL);
160 	if (prv == NULL) {
161 		if (identity_passphrase)
162 			pass = xstrdup(identity_passphrase);
163 		else
164 			pass = read_passphrase("Enter passphrase: ",
165 			    RP_ALLOW_STDIN);
166 		prv = key_load_private(filename, pass, NULL);
167 		memset(pass, 0, strlen(pass));
168 		xfree(pass);
169 	}
170 	return prv;
171 }
172 
173 #define SSH_COM_PUBLIC_BEGIN		"---- BEGIN SSH2 PUBLIC KEY ----"
174 #define SSH_COM_PUBLIC_END		"---- END SSH2 PUBLIC KEY ----"
175 #define SSH_COM_PRIVATE_BEGIN		"---- BEGIN SSH2 ENCRYPTED PRIVATE KEY ----"
176 #define	SSH_COM_PRIVATE_KEY_MAGIC	0x3f6ff9eb
177 
178 static void
179 do_convert_to_ssh2(struct passwd *pw)
180 {
181 	Key *k;
182 	u_int len;
183 	u_char *blob;
184 	struct stat st;
185 
186 	if (!have_identity)
187 		ask_filename(pw, "Enter file in which the key is");
188 	if (stat(identity_file, &st) < 0) {
189 		perror(identity_file);
190 		exit(1);
191 	}
192 	if ((k = key_load_public(identity_file, NULL)) == NULL) {
193 		if ((k = load_identity(identity_file)) == NULL) {
194 			fprintf(stderr, "load failed\n");
195 			exit(1);
196 		}
197 	}
198 	if (k->type == KEY_RSA1) {
199 		fprintf(stderr, "version 1 keys are not supported\n");
200 		exit(1);
201 	}
202 	if (key_to_blob(k, &blob, &len) <= 0) {
203 		fprintf(stderr, "key_to_blob failed\n");
204 		exit(1);
205 	}
206 	fprintf(stdout, "%s\n", SSH_COM_PUBLIC_BEGIN);
207 	fprintf(stdout,
208 	    "Comment: \"%u-bit %s, converted from OpenSSH by %s@%s\"\n",
209 	    key_size(k), key_type(k),
210 	    pw->pw_name, hostname);
211 	dump_base64(stdout, blob, len);
212 	fprintf(stdout, "%s\n", SSH_COM_PUBLIC_END);
213 	key_free(k);
214 	xfree(blob);
215 	exit(0);
216 }
217 
218 static void
219 buffer_get_bignum_bits(Buffer *b, BIGNUM *value)
220 {
221 	u_int bignum_bits = buffer_get_int(b);
222 	u_int bytes = (bignum_bits + 7) / 8;
223 
224 	if (buffer_len(b) < bytes)
225 		fatal("buffer_get_bignum_bits: input buffer too small: "
226 		    "need %d have %d", bytes, buffer_len(b));
227 	if (BN_bin2bn(buffer_ptr(b), bytes, value) == NULL)
228 		fatal("buffer_get_bignum_bits: BN_bin2bn failed");
229 	buffer_consume(b, bytes);
230 }
231 
232 static Key *
233 do_convert_private_ssh2_from_blob(u_char *blob, u_int blen)
234 {
235 	Buffer b;
236 	Key *key = NULL;
237 	char *type, *cipher;
238 	u_char *sig, data[] = "abcde12345";
239 	int magic, rlen, ktype, i1, i2, i3, i4;
240 	u_int slen;
241 	u_long e;
242 
243 	buffer_init(&b);
244 	buffer_append(&b, blob, blen);
245 
246 	magic = buffer_get_int(&b);
247 	if (magic != SSH_COM_PRIVATE_KEY_MAGIC) {
248 		error("bad magic 0x%x != 0x%x", magic, SSH_COM_PRIVATE_KEY_MAGIC);
249 		buffer_free(&b);
250 		return NULL;
251 	}
252 	i1 = buffer_get_int(&b);
253 	type   = buffer_get_string(&b, NULL);
254 	cipher = buffer_get_string(&b, NULL);
255 	i2 = buffer_get_int(&b);
256 	i3 = buffer_get_int(&b);
257 	i4 = buffer_get_int(&b);
258 	debug("ignore (%d %d %d %d)", i1, i2, i3, i4);
259 	if (strcmp(cipher, "none") != 0) {
260 		error("unsupported cipher %s", cipher);
261 		xfree(cipher);
262 		buffer_free(&b);
263 		xfree(type);
264 		return NULL;
265 	}
266 	xfree(cipher);
267 
268 	if (strstr(type, "dsa")) {
269 		ktype = KEY_DSA;
270 	} else if (strstr(type, "rsa")) {
271 		ktype = KEY_RSA;
272 	} else {
273 		buffer_free(&b);
274 		xfree(type);
275 		return NULL;
276 	}
277 	key = key_new_private(ktype);
278 	xfree(type);
279 
280 	switch (key->type) {
281 	case KEY_DSA:
282 		buffer_get_bignum_bits(&b, key->dsa->p);
283 		buffer_get_bignum_bits(&b, key->dsa->g);
284 		buffer_get_bignum_bits(&b, key->dsa->q);
285 		buffer_get_bignum_bits(&b, key->dsa->pub_key);
286 		buffer_get_bignum_bits(&b, key->dsa->priv_key);
287 		break;
288 	case KEY_RSA:
289 		e = buffer_get_char(&b);
290 		debug("e %lx", e);
291 		if (e < 30) {
292 			e <<= 8;
293 			e += buffer_get_char(&b);
294 			debug("e %lx", e);
295 			e <<= 8;
296 			e += buffer_get_char(&b);
297 			debug("e %lx", e);
298 		}
299 		if (!BN_set_word(key->rsa->e, e)) {
300 			buffer_free(&b);
301 			key_free(key);
302 			return NULL;
303 		}
304 		buffer_get_bignum_bits(&b, key->rsa->d);
305 		buffer_get_bignum_bits(&b, key->rsa->n);
306 		buffer_get_bignum_bits(&b, key->rsa->iqmp);
307 		buffer_get_bignum_bits(&b, key->rsa->q);
308 		buffer_get_bignum_bits(&b, key->rsa->p);
309 		rsa_generate_additional_parameters(key->rsa);
310 		break;
311 	}
312 	rlen = buffer_len(&b);
313 	if (rlen != 0)
314 		error("do_convert_private_ssh2_from_blob: "
315 		    "remaining bytes in key blob %d", rlen);
316 	buffer_free(&b);
317 
318 	/* try the key */
319 	key_sign(key, &sig, &slen, data, sizeof(data));
320 	key_verify(key, sig, slen, data, sizeof(data));
321 	xfree(sig);
322 	return key;
323 }
324 
325 static int
326 get_line(FILE *fp, char *line, size_t len)
327 {
328 	int c;
329 	size_t pos = 0;
330 
331 	line[0] = '\0';
332 	while ((c = fgetc(fp)) != EOF) {
333 		if (pos >= len - 1) {
334 			fprintf(stderr, "input line too long.\n");
335 			exit(1);
336 		}
337 		switch (c) {
338 		case '\r':
339 			c = fgetc(fp);
340 			if (c != EOF && c != '\n' && ungetc(c, fp) == EOF) {
341 				fprintf(stderr, "unget: %s\n", strerror(errno));
342 				exit(1);
343 			}
344 			return pos;
345 		case '\n':
346 			return pos;
347 		}
348 		line[pos++] = c;
349 		line[pos] = '\0';
350 	}
351 	/* We reached EOF */
352 	return -1;
353 }
354 
355 static void
356 do_convert_from_ssh2(struct passwd *pw)
357 {
358 	Key *k;
359 	int blen;
360 	u_int len;
361 	char line[1024];
362 	u_char blob[8096];
363 	char encoded[8096];
364 	struct stat st;
365 	int escaped = 0, private = 0, ok;
366 	FILE *fp;
367 
368 	if (!have_identity)
369 		ask_filename(pw, "Enter file in which the key is");
370 	if (stat(identity_file, &st) < 0) {
371 		perror(identity_file);
372 		exit(1);
373 	}
374 	fp = fopen(identity_file, "r");
375 	if (fp == NULL) {
376 		perror(identity_file);
377 		exit(1);
378 	}
379 	encoded[0] = '\0';
380 	while ((blen = get_line(fp, line, sizeof(line))) != -1) {
381 		if (line[blen - 1] == '\\')
382 			escaped++;
383 		if (strncmp(line, "----", 4) == 0 ||
384 		    strstr(line, ": ") != NULL) {
385 			if (strstr(line, SSH_COM_PRIVATE_BEGIN) != NULL)
386 				private = 1;
387 			if (strstr(line, " END ") != NULL) {
388 				break;
389 			}
390 			/* fprintf(stderr, "ignore: %s", line); */
391 			continue;
392 		}
393 		if (escaped) {
394 			escaped--;
395 			/* fprintf(stderr, "escaped: %s", line); */
396 			continue;
397 		}
398 		strlcat(encoded, line, sizeof(encoded));
399 	}
400 	len = strlen(encoded);
401 	if (((len % 4) == 3) &&
402 	    (encoded[len-1] == '=') &&
403 	    (encoded[len-2] == '=') &&
404 	    (encoded[len-3] == '='))
405 		encoded[len-3] = '\0';
406 	blen = uudecode(encoded, blob, sizeof(blob));
407 	if (blen < 0) {
408 		fprintf(stderr, "uudecode failed.\n");
409 		exit(1);
410 	}
411 	k = private ?
412 	    do_convert_private_ssh2_from_blob(blob, blen) :
413 	    key_from_blob(blob, blen);
414 	if (k == NULL) {
415 		fprintf(stderr, "decode blob failed.\n");
416 		exit(1);
417 	}
418 	ok = private ?
419 	    (k->type == KEY_DSA ?
420 		 PEM_write_DSAPrivateKey(stdout, k->dsa, NULL, NULL, 0, NULL, NULL) :
421 		 PEM_write_RSAPrivateKey(stdout, k->rsa, NULL, NULL, 0, NULL, NULL)) :
422 	    key_write(k, stdout);
423 	if (!ok) {
424 		fprintf(stderr, "key write failed\n");
425 		exit(1);
426 	}
427 	key_free(k);
428 	if (!private)
429 		fprintf(stdout, "\n");
430 	fclose(fp);
431 	exit(0);
432 }
433 
434 static void
435 do_print_public(struct passwd *pw)
436 {
437 	Key *prv;
438 	struct stat st;
439 
440 	if (!have_identity)
441 		ask_filename(pw, "Enter file in which the key is");
442 	if (stat(identity_file, &st) < 0) {
443 		perror(identity_file);
444 		exit(1);
445 	}
446 	prv = load_identity(identity_file);
447 	if (prv == NULL) {
448 		fprintf(stderr, "load failed\n");
449 		exit(1);
450 	}
451 	if (!key_write(prv, stdout))
452 		fprintf(stderr, "key_write failed");
453 	key_free(prv);
454 	fprintf(stdout, "\n");
455 	exit(0);
456 }
457 
458 #ifdef SMARTCARD
459 static void
460 do_upload(struct passwd *pw, const char *sc_reader_id)
461 {
462 	Key *prv = NULL;
463 	struct stat st;
464 	int ret;
465 
466 	if (!have_identity)
467 		ask_filename(pw, "Enter file in which the key is");
468 	if (stat(identity_file, &st) < 0) {
469 		perror(identity_file);
470 		exit(1);
471 	}
472 	prv = load_identity(identity_file);
473 	if (prv == NULL) {
474 		error("load failed");
475 		exit(1);
476 	}
477 	ret = sc_put_key(prv, sc_reader_id);
478 	key_free(prv);
479 	if (ret < 0)
480 		exit(1);
481 	logit("loading key done");
482 	exit(0);
483 }
484 
485 static void
486 do_download(struct passwd *pw, const char *sc_reader_id)
487 {
488 	Key **keys = NULL;
489 	int i;
490 
491 	keys = sc_get_keys(sc_reader_id, NULL);
492 	if (keys == NULL)
493 		fatal("cannot read public key from smartcard");
494 	for (i = 0; keys[i]; i++) {
495 		key_write(keys[i], stdout);
496 		key_free(keys[i]);
497 		fprintf(stdout, "\n");
498 	}
499 	xfree(keys);
500 	exit(0);
501 }
502 #endif /* SMARTCARD */
503 
504 static void
505 do_fingerprint(struct passwd *pw)
506 {
507 	FILE *f;
508 	Key *public;
509 	char *comment = NULL, *cp, *ep, line[16*1024], *fp, *ra;
510 	int i, skip = 0, num = 0, invalid = 1;
511 	enum fp_rep rep;
512 	enum fp_type fptype;
513 	struct stat st;
514 
515 	fptype = print_bubblebabble ? SSH_FP_SHA1 : SSH_FP_MD5;
516 	rep =    print_bubblebabble ? SSH_FP_BUBBLEBABBLE : SSH_FP_HEX;
517 
518 	if (!have_identity)
519 		ask_filename(pw, "Enter file in which the key is");
520 	if (stat(identity_file, &st) < 0) {
521 		perror(identity_file);
522 		exit(1);
523 	}
524 	public = key_load_public(identity_file, &comment);
525 	if (public != NULL) {
526 		fp = key_fingerprint(public, fptype, rep);
527 		ra = key_fingerprint(public, fptype, SSH_FP_RANDOMART);
528 		printf("%u %s %s (%s)\n", key_size(public), fp, comment,
529 		    key_type(public));
530 		if (log_level >= SYSLOG_LEVEL_VERBOSE)
531 			printf("%s\n", ra);
532 		key_free(public);
533 		xfree(comment);
534 		xfree(ra);
535 		xfree(fp);
536 		exit(0);
537 	}
538 	if (comment) {
539 		xfree(comment);
540 		comment = NULL;
541 	}
542 
543 	f = fopen(identity_file, "r");
544 	if (f != NULL) {
545 		while (fgets(line, sizeof(line), f)) {
546 			if ((cp = strchr(line, '\n')) == NULL) {
547 				error("line %d too long: %.40s...",
548 				    num + 1, line);
549 				skip = 1;
550 				continue;
551 			}
552 			num++;
553 			if (skip) {
554 				skip = 0;
555 				continue;
556 			}
557 			*cp = '\0';
558 
559 			/* Skip leading whitespace, empty and comment lines. */
560 			for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
561 				;
562 			if (!*cp || *cp == '\n' || *cp == '#')
563 				continue;
564 			i = strtol(cp, &ep, 10);
565 			if (i == 0 || ep == NULL || (*ep != ' ' && *ep != '\t')) {
566 				int quoted = 0;
567 				comment = cp;
568 				for (; *cp && (quoted || (*cp != ' ' &&
569 				    *cp != '\t')); cp++) {
570 					if (*cp == '\\' && cp[1] == '"')
571 						cp++;	/* Skip both */
572 					else if (*cp == '"')
573 						quoted = !quoted;
574 				}
575 				if (!*cp)
576 					continue;
577 				*cp++ = '\0';
578 			}
579 			ep = cp;
580 			public = key_new(KEY_RSA1);
581 			if (key_read(public, &cp) != 1) {
582 				cp = ep;
583 				key_free(public);
584 				public = key_new(KEY_UNSPEC);
585 				if (key_read(public, &cp) != 1) {
586 					key_free(public);
587 					continue;
588 				}
589 			}
590 			comment = *cp ? cp : comment;
591 			fp = key_fingerprint(public, fptype, rep);
592 			ra = key_fingerprint(public, fptype, SSH_FP_RANDOMART);
593 			printf("%u %s %s (%s)\n", key_size(public), fp,
594 			    comment ? comment : "no comment", key_type(public));
595 			if (log_level >= SYSLOG_LEVEL_VERBOSE)
596 				printf("%s\n", ra);
597 			xfree(ra);
598 			xfree(fp);
599 			key_free(public);
600 			invalid = 0;
601 		}
602 		fclose(f);
603 	}
604 	if (invalid) {
605 		printf("%s is not a public key file.\n", identity_file);
606 		exit(1);
607 	}
608 	exit(0);
609 }
610 
611 static void
612 print_host(FILE *f, const char *name, Key *public, int hash)
613 {
614 	if (print_fingerprint) {
615 		enum fp_rep rep;
616 		enum fp_type fptype;
617 		char *fp, *ra;
618 
619 		fptype = print_bubblebabble ? SSH_FP_SHA1 : SSH_FP_MD5;
620 		rep =    print_bubblebabble ? SSH_FP_BUBBLEBABBLE : SSH_FP_HEX;
621 		fp = key_fingerprint(public, fptype, rep);
622 		ra = key_fingerprint(public, fptype, SSH_FP_RANDOMART);
623 		printf("%u %s %s (%s)\n", key_size(public), fp, name,
624 		    key_type(public));
625 		if (log_level >= SYSLOG_LEVEL_VERBOSE)
626 			printf("%s\n", ra);
627 		xfree(ra);
628 		xfree(fp);
629 	} else {
630 		if (hash && (name = host_hash(name, NULL, 0)) == NULL)
631 			fatal("hash_host failed");
632 		fprintf(f, "%s ", name);
633 		if (!key_write(public, f))
634 			fatal("key_write failed");
635 		fprintf(f, "\n");
636 	}
637 }
638 
639 static void
640 do_known_hosts(struct passwd *pw, const char *name)
641 {
642 	FILE *in, *out = stdout;
643 	Key *public;
644 	char *cp, *cp2, *kp, *kp2;
645 	char line[16*1024], tmp[MAXPATHLEN], old[MAXPATHLEN];
646 	int c, skip = 0, inplace = 0, num = 0, invalid = 0, has_unhashed = 0;
647 
648 	if (!have_identity) {
649 		cp = tilde_expand_filename(_PATH_SSH_USER_HOSTFILE, pw->pw_uid);
650 		if (strlcpy(identity_file, cp, sizeof(identity_file)) >=
651 		    sizeof(identity_file))
652 			fatal("Specified known hosts path too long");
653 		xfree(cp);
654 		have_identity = 1;
655 	}
656 	if ((in = fopen(identity_file, "r")) == NULL)
657 		fatal("fopen: %s", strerror(errno));
658 
659 	/*
660 	 * Find hosts goes to stdout, hash and deletions happen in-place
661 	 * A corner case is ssh-keygen -HF foo, which should go to stdout
662 	 */
663 	if (!find_host && (hash_hosts || delete_host)) {
664 		if (strlcpy(tmp, identity_file, sizeof(tmp)) >= sizeof(tmp) ||
665 		    strlcat(tmp, ".XXXXXXXXXX", sizeof(tmp)) >= sizeof(tmp) ||
666 		    strlcpy(old, identity_file, sizeof(old)) >= sizeof(old) ||
667 		    strlcat(old, ".old", sizeof(old)) >= sizeof(old))
668 			fatal("known_hosts path too long");
669 		umask(077);
670 		if ((c = mkstemp(tmp)) == -1)
671 			fatal("mkstemp: %s", strerror(errno));
672 		if ((out = fdopen(c, "w")) == NULL) {
673 			c = errno;
674 			unlink(tmp);
675 			fatal("fdopen: %s", strerror(c));
676 		}
677 		inplace = 1;
678 	}
679 
680 	while (fgets(line, sizeof(line), in)) {
681 		if ((cp = strchr(line, '\n')) == NULL) {
682 			error("line %d too long: %.40s...", num + 1, line);
683 			skip = 1;
684 			invalid = 1;
685 			continue;
686 		}
687 		num++;
688 		if (skip) {
689 			skip = 0;
690 			continue;
691 		}
692 		*cp = '\0';
693 
694 		/* Skip leading whitespace, empty and comment lines. */
695 		for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
696 			;
697 		if (!*cp || *cp == '\n' || *cp == '#') {
698 			if (inplace)
699 				fprintf(out, "%s\n", cp);
700 			continue;
701 		}
702 		/* Find the end of the host name portion. */
703 		for (kp = cp; *kp && *kp != ' ' && *kp != '\t'; kp++)
704 			;
705 		if (*kp == '\0' || *(kp + 1) == '\0') {
706 			error("line %d missing key: %.40s...",
707 			    num, line);
708 			invalid = 1;
709 			continue;
710 		}
711 		*kp++ = '\0';
712 		kp2 = kp;
713 
714 		public = key_new(KEY_RSA1);
715 		if (key_read(public, &kp) != 1) {
716 			kp = kp2;
717 			key_free(public);
718 			public = key_new(KEY_UNSPEC);
719 			if (key_read(public, &kp) != 1) {
720 				error("line %d invalid key: %.40s...",
721 				    num, line);
722 				key_free(public);
723 				invalid = 1;
724 				continue;
725 			}
726 		}
727 
728 		if (*cp == HASH_DELIM) {
729 			if (find_host || delete_host) {
730 				cp2 = host_hash(name, cp, strlen(cp));
731 				if (cp2 == NULL) {
732 					error("line %d: invalid hashed "
733 					    "name: %.64s...", num, line);
734 					invalid = 1;
735 					continue;
736 				}
737 				c = (strcmp(cp2, cp) == 0);
738 				if (find_host && c) {
739 					printf("# Host %s found: "
740 					    "line %d type %s\n", name,
741 					    num, key_type(public));
742 					print_host(out, cp, public, 0);
743 				}
744 				if (delete_host && !c)
745 					print_host(out, cp, public, 0);
746 			} else if (hash_hosts)
747 				print_host(out, cp, public, 0);
748 		} else {
749 			if (find_host || delete_host) {
750 				c = (match_hostname(name, cp,
751 				    strlen(cp)) == 1);
752 				if (find_host && c) {
753 					printf("# Host %s found: "
754 					    "line %d type %s\n", name,
755 					    num, key_type(public));
756 					print_host(out, name, public,
757 					    hash_hosts);
758 				}
759 				if (delete_host && !c)
760 					print_host(out, cp, public, 0);
761 			} else if (hash_hosts) {
762 				for (cp2 = strsep(&cp, ",");
763 				    cp2 != NULL && *cp2 != '\0';
764 				    cp2 = strsep(&cp, ",")) {
765 					if (strcspn(cp2, "*?!") != strlen(cp2))
766 						fprintf(stderr, "Warning: "
767 						    "ignoring host name with "
768 						    "metacharacters: %.64s\n",
769 						    cp2);
770 					else
771 						print_host(out, cp2, public, 1);
772 				}
773 				has_unhashed = 1;
774 			}
775 		}
776 		key_free(public);
777 	}
778 	fclose(in);
779 
780 	if (invalid) {
781 		fprintf(stderr, "%s is not a valid known_hosts file.\n",
782 		    identity_file);
783 		if (inplace) {
784 			fprintf(stderr, "Not replacing existing known_hosts "
785 			    "file because of errors\n");
786 			fclose(out);
787 			unlink(tmp);
788 		}
789 		exit(1);
790 	}
791 
792 	if (inplace) {
793 		fclose(out);
794 
795 		/* Backup existing file */
796 		if (unlink(old) == -1 && errno != ENOENT)
797 			fatal("unlink %.100s: %s", old, strerror(errno));
798 		if (link(identity_file, old) == -1)
799 			fatal("link %.100s to %.100s: %s", identity_file, old,
800 			    strerror(errno));
801 		/* Move new one into place */
802 		if (rename(tmp, identity_file) == -1) {
803 			error("rename\"%s\" to \"%s\": %s", tmp, identity_file,
804 			    strerror(errno));
805 			unlink(tmp);
806 			unlink(old);
807 			exit(1);
808 		}
809 
810 		fprintf(stderr, "%s updated.\n", identity_file);
811 		fprintf(stderr, "Original contents retained as %s\n", old);
812 		if (has_unhashed) {
813 			fprintf(stderr, "WARNING: %s contains unhashed "
814 			    "entries\n", old);
815 			fprintf(stderr, "Delete this file to ensure privacy "
816 			    "of hostnames\n");
817 		}
818 	}
819 
820 	exit(0);
821 }
822 
823 /*
824  * Perform changing a passphrase.  The argument is the passwd structure
825  * for the current user.
826  */
827 static void
828 do_change_passphrase(struct passwd *pw)
829 {
830 	char *comment;
831 	char *old_passphrase, *passphrase1, *passphrase2;
832 	struct stat st;
833 	Key *private;
834 
835 	if (!have_identity)
836 		ask_filename(pw, "Enter file in which the key is");
837 	if (stat(identity_file, &st) < 0) {
838 		perror(identity_file);
839 		exit(1);
840 	}
841 	/* Try to load the file with empty passphrase. */
842 	private = key_load_private(identity_file, "", &comment);
843 	if (private == NULL) {
844 		if (identity_passphrase)
845 			old_passphrase = xstrdup(identity_passphrase);
846 		else
847 			old_passphrase =
848 			    read_passphrase("Enter old passphrase: ",
849 			    RP_ALLOW_STDIN);
850 		private = key_load_private(identity_file, old_passphrase,
851 		    &comment);
852 		memset(old_passphrase, 0, strlen(old_passphrase));
853 		xfree(old_passphrase);
854 		if (private == NULL) {
855 			printf("Bad passphrase.\n");
856 			exit(1);
857 		}
858 	}
859 	printf("Key has comment '%s'\n", comment);
860 
861 	/* Ask the new passphrase (twice). */
862 	if (identity_new_passphrase) {
863 		passphrase1 = xstrdup(identity_new_passphrase);
864 		passphrase2 = NULL;
865 	} else {
866 		passphrase1 =
867 			read_passphrase("Enter new passphrase (empty for no "
868 			    "passphrase): ", RP_ALLOW_STDIN);
869 		passphrase2 = read_passphrase("Enter same passphrase again: ",
870 		    RP_ALLOW_STDIN);
871 
872 		/* Verify that they are the same. */
873 		if (strcmp(passphrase1, passphrase2) != 0) {
874 			memset(passphrase1, 0, strlen(passphrase1));
875 			memset(passphrase2, 0, strlen(passphrase2));
876 			xfree(passphrase1);
877 			xfree(passphrase2);
878 			printf("Pass phrases do not match.  Try again.\n");
879 			exit(1);
880 		}
881 		/* Destroy the other copy. */
882 		memset(passphrase2, 0, strlen(passphrase2));
883 		xfree(passphrase2);
884 	}
885 
886 	/* Save the file using the new passphrase. */
887 	if (!key_save_private(private, identity_file, passphrase1, comment)) {
888 		printf("Saving the key failed: %s.\n", identity_file);
889 		memset(passphrase1, 0, strlen(passphrase1));
890 		xfree(passphrase1);
891 		key_free(private);
892 		xfree(comment);
893 		exit(1);
894 	}
895 	/* Destroy the passphrase and the copy of the key in memory. */
896 	memset(passphrase1, 0, strlen(passphrase1));
897 	xfree(passphrase1);
898 	key_free(private);		 /* Destroys contents */
899 	xfree(comment);
900 
901 	printf("Your identification has been saved with the new passphrase.\n");
902 	exit(0);
903 }
904 
905 /*
906  * Print the SSHFP RR.
907  */
908 static int
909 do_print_resource_record(struct passwd *pw, char *fname, char *hname)
910 {
911 	Key *public;
912 	char *comment = NULL;
913 	struct stat st;
914 
915 	if (fname == NULL)
916 		ask_filename(pw, "Enter file in which the key is");
917 	if (stat(fname, &st) < 0) {
918 		if (errno == ENOENT)
919 			return 0;
920 		perror(fname);
921 		exit(1);
922 	}
923 	public = key_load_public(fname, &comment);
924 	if (public != NULL) {
925 		export_dns_rr(hname, public, stdout, print_generic);
926 		key_free(public);
927 		xfree(comment);
928 		return 1;
929 	}
930 	if (comment)
931 		xfree(comment);
932 
933 	printf("failed to read v2 public key from %s.\n", fname);
934 	exit(1);
935 }
936 
937 /*
938  * Change the comment of a private key file.
939  */
940 static void
941 do_change_comment(struct passwd *pw)
942 {
943 	char new_comment[1024], *comment, *passphrase;
944 	Key *private;
945 	Key *public;
946 	struct stat st;
947 	FILE *f;
948 	int fd;
949 
950 	if (!have_identity)
951 		ask_filename(pw, "Enter file in which the key is");
952 	if (stat(identity_file, &st) < 0) {
953 		perror(identity_file);
954 		exit(1);
955 	}
956 	private = key_load_private(identity_file, "", &comment);
957 	if (private == NULL) {
958 		if (identity_passphrase)
959 			passphrase = xstrdup(identity_passphrase);
960 		else if (identity_new_passphrase)
961 			passphrase = xstrdup(identity_new_passphrase);
962 		else
963 			passphrase = read_passphrase("Enter passphrase: ",
964 			    RP_ALLOW_STDIN);
965 		/* Try to load using the passphrase. */
966 		private = key_load_private(identity_file, passphrase, &comment);
967 		if (private == NULL) {
968 			memset(passphrase, 0, strlen(passphrase));
969 			xfree(passphrase);
970 			printf("Bad passphrase.\n");
971 			exit(1);
972 		}
973 	} else {
974 		passphrase = xstrdup("");
975 	}
976 	if (private->type != KEY_RSA1) {
977 		fprintf(stderr, "Comments are only supported for RSA1 keys.\n");
978 		key_free(private);
979 		exit(1);
980 	}
981 	printf("Key now has comment '%s'\n", comment);
982 
983 	if (identity_comment) {
984 		strlcpy(new_comment, identity_comment, sizeof(new_comment));
985 	} else {
986 		printf("Enter new comment: ");
987 		fflush(stdout);
988 		if (!fgets(new_comment, sizeof(new_comment), stdin)) {
989 			memset(passphrase, 0, strlen(passphrase));
990 			key_free(private);
991 			exit(1);
992 		}
993 		new_comment[strcspn(new_comment, "\n")] = '\0';
994 	}
995 
996 	/* Save the file using the new passphrase. */
997 	if (!key_save_private(private, identity_file, passphrase, new_comment)) {
998 		printf("Saving the key failed: %s.\n", identity_file);
999 		memset(passphrase, 0, strlen(passphrase));
1000 		xfree(passphrase);
1001 		key_free(private);
1002 		xfree(comment);
1003 		exit(1);
1004 	}
1005 	memset(passphrase, 0, strlen(passphrase));
1006 	xfree(passphrase);
1007 	public = key_from_private(private);
1008 	key_free(private);
1009 
1010 	strlcat(identity_file, ".pub", sizeof(identity_file));
1011 	fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
1012 	if (fd == -1) {
1013 		printf("Could not save your public key in %s\n", identity_file);
1014 		exit(1);
1015 	}
1016 	f = fdopen(fd, "w");
1017 	if (f == NULL) {
1018 		printf("fdopen %s failed\n", identity_file);
1019 		exit(1);
1020 	}
1021 	if (!key_write(public, f))
1022 		fprintf(stderr, "write key failed\n");
1023 	key_free(public);
1024 	fprintf(f, " %s\n", new_comment);
1025 	fclose(f);
1026 
1027 	xfree(comment);
1028 
1029 	printf("The comment in your key file has been changed.\n");
1030 	exit(0);
1031 }
1032 
1033 static void
1034 usage(void)
1035 {
1036 	fprintf(stderr, "usage: %s [options]\n", __progname);
1037 	fprintf(stderr, "Options:\n");
1038 	fprintf(stderr, "  -a trials   Number of trials for screening DH-GEX moduli.\n");
1039 	fprintf(stderr, "  -B          Show bubblebabble digest of key file.\n");
1040 	fprintf(stderr, "  -b bits     Number of bits in the key to create.\n");
1041 	fprintf(stderr, "  -C comment  Provide new comment.\n");
1042 	fprintf(stderr, "  -c          Change comment in private and public key files.\n");
1043 #ifdef SMARTCARD
1044 	fprintf(stderr, "  -D reader   Download public key from smartcard.\n");
1045 #endif /* SMARTCARD */
1046 	fprintf(stderr, "  -e          Convert OpenSSH to RFC 4716 key file.\n");
1047 	fprintf(stderr, "  -F hostname Find hostname in known hosts file.\n");
1048 	fprintf(stderr, "  -f filename Filename of the key file.\n");
1049 	fprintf(stderr, "  -G file     Generate candidates for DH-GEX moduli.\n");
1050 	fprintf(stderr, "  -g          Use generic DNS resource record format.\n");
1051 	fprintf(stderr, "  -H          Hash names in known_hosts file.\n");
1052 	fprintf(stderr, "  -i          Convert RFC 4716 to OpenSSH key file.\n");
1053 	fprintf(stderr, "  -l          Show fingerprint of key file.\n");
1054 	fprintf(stderr, "  -M memory   Amount of memory (MB) to use for generating DH-GEX moduli.\n");
1055 	fprintf(stderr, "  -N phrase   Provide new passphrase.\n");
1056 	fprintf(stderr, "  -P phrase   Provide old passphrase.\n");
1057 	fprintf(stderr, "  -p          Change passphrase of private key file.\n");
1058 	fprintf(stderr, "  -q          Quiet.\n");
1059 	fprintf(stderr, "  -R hostname Remove host from known_hosts file.\n");
1060 	fprintf(stderr, "  -r hostname Print DNS resource record.\n");
1061 	fprintf(stderr, "  -S start    Start point (hex) for generating DH-GEX moduli.\n");
1062 	fprintf(stderr, "  -T file     Screen candidates for DH-GEX moduli.\n");
1063 	fprintf(stderr, "  -t type     Specify type of key to create.\n");
1064 #ifdef SMARTCARD
1065 	fprintf(stderr, "  -U reader   Upload private key to smartcard.\n");
1066 #endif /* SMARTCARD */
1067 	fprintf(stderr, "  -v          Verbose.\n");
1068 	fprintf(stderr, "  -W gen      Generator to use for generating DH-GEX moduli.\n");
1069 	fprintf(stderr, "  -y          Read private key file and print public key.\n");
1070 
1071 	exit(1);
1072 }
1073 
1074 /*
1075  * Main program for key management.
1076  */
1077 int
1078 main(int argc, char **argv)
1079 {
1080 	char dotsshdir[MAXPATHLEN], comment[1024], *passphrase1, *passphrase2;
1081 	char out_file[MAXPATHLEN], *reader_id = NULL;
1082 	char *rr_hostname = NULL;
1083 	Key *private, *public;
1084 	struct passwd *pw;
1085 	struct stat st;
1086 	int opt, type, fd, download = 0;
1087 	u_int32_t memory = 0, generator_wanted = 0, trials = 100;
1088 	int do_gen_candidates = 0, do_screen_candidates = 0;
1089 	BIGNUM *start = NULL;
1090 	FILE *f;
1091 	const char *errstr;
1092 
1093 	extern int optind;
1094 	extern char *optarg;
1095 
1096 	/* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1097 	sanitise_stdfd();
1098 
1099 	__progname = ssh_get_progname(argv[0]);
1100 
1101 	SSLeay_add_all_algorithms();
1102 	log_init(argv[0], SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_USER, 1);
1103 
1104 	init_rng();
1105 	seed_rng();
1106 
1107 	/* we need this for the home * directory.  */
1108 	pw = getpwuid(getuid());
1109 	if (!pw) {
1110 		printf("You don't exist, go away!\n");
1111 		exit(1);
1112 	}
1113 	if (gethostname(hostname, sizeof(hostname)) < 0) {
1114 		perror("gethostname");
1115 		exit(1);
1116 	}
1117 
1118 	while ((opt = getopt(argc, argv,
1119 	    "degiqpclBHvxXyF:b:f:t:U:D:P:N:C:r:g:R:T:G:M:S:a:W:")) != -1) {
1120 		switch (opt) {
1121 		case 'b':
1122 			bits = (u_int32_t)strtonum(optarg, 768, 32768, &errstr);
1123 			if (errstr)
1124 				fatal("Bits has bad value %s (%s)",
1125 					optarg, errstr);
1126 			break;
1127 		case 'F':
1128 			find_host = 1;
1129 			rr_hostname = optarg;
1130 			break;
1131 		case 'H':
1132 			hash_hosts = 1;
1133 			break;
1134 		case 'R':
1135 			delete_host = 1;
1136 			rr_hostname = optarg;
1137 			break;
1138 		case 'l':
1139 			print_fingerprint = 1;
1140 			break;
1141 		case 'B':
1142 			print_bubblebabble = 1;
1143 			break;
1144 		case 'p':
1145 			change_passphrase = 1;
1146 			break;
1147 		case 'c':
1148 			change_comment = 1;
1149 			break;
1150 		case 'f':
1151 			if (strlcpy(identity_file, optarg, sizeof(identity_file)) >=
1152 			    sizeof(identity_file))
1153 				fatal("Identity filename too long");
1154 			have_identity = 1;
1155 			break;
1156 		case 'g':
1157 			print_generic = 1;
1158 			break;
1159 		case 'P':
1160 			identity_passphrase = optarg;
1161 			break;
1162 		case 'N':
1163 			identity_new_passphrase = optarg;
1164 			break;
1165 		case 'C':
1166 			identity_comment = optarg;
1167 			break;
1168 		case 'q':
1169 			quiet = 1;
1170 			break;
1171 		case 'e':
1172 		case 'x':
1173 			/* export key */
1174 			convert_to_ssh2 = 1;
1175 			break;
1176 		case 'i':
1177 		case 'X':
1178 			/* import key */
1179 			convert_from_ssh2 = 1;
1180 			break;
1181 		case 'y':
1182 			print_public = 1;
1183 			break;
1184 		case 'd':
1185 			key_type_name = "dsa";
1186 			break;
1187 		case 't':
1188 			key_type_name = optarg;
1189 			break;
1190 		case 'D':
1191 			download = 1;
1192 			/*FALLTHROUGH*/
1193 		case 'U':
1194 			reader_id = optarg;
1195 			break;
1196 		case 'v':
1197 			if (log_level == SYSLOG_LEVEL_INFO)
1198 				log_level = SYSLOG_LEVEL_DEBUG1;
1199 			else {
1200 				if (log_level >= SYSLOG_LEVEL_DEBUG1 &&
1201 				    log_level < SYSLOG_LEVEL_DEBUG3)
1202 					log_level++;
1203 			}
1204 			break;
1205 		case 'r':
1206 			rr_hostname = optarg;
1207 			break;
1208 		case 'W':
1209 			generator_wanted = (u_int32_t)strtonum(optarg, 1,
1210 			    UINT_MAX, &errstr);
1211 			if (errstr)
1212 				fatal("Desired generator has bad value: %s (%s)",
1213 					optarg, errstr);
1214 			break;
1215 		case 'a':
1216 			trials = (u_int32_t)strtonum(optarg, 1, UINT_MAX, &errstr);
1217 			if (errstr)
1218 				fatal("Invalid number of trials: %s (%s)",
1219 					optarg, errstr);
1220 			break;
1221 		case 'M':
1222 			memory = (u_int32_t)strtonum(optarg, 1, UINT_MAX, &errstr);
1223 			if (errstr) {
1224 				fatal("Memory limit is %s: %s", errstr, optarg);
1225 			}
1226 			break;
1227 		case 'G':
1228 			do_gen_candidates = 1;
1229 			if (strlcpy(out_file, optarg, sizeof(out_file)) >=
1230 			    sizeof(out_file))
1231 				fatal("Output filename too long");
1232 			break;
1233 		case 'T':
1234 			do_screen_candidates = 1;
1235 			if (strlcpy(out_file, optarg, sizeof(out_file)) >=
1236 			    sizeof(out_file))
1237 				fatal("Output filename too long");
1238 			break;
1239 		case 'S':
1240 			/* XXX - also compare length against bits */
1241 			if (BN_hex2bn(&start, optarg) == 0)
1242 				fatal("Invalid start point.");
1243 			break;
1244 		case '?':
1245 		default:
1246 			usage();
1247 		}
1248 	}
1249 
1250 	/* reinit */
1251 	log_init(argv[0], log_level, SYSLOG_FACILITY_USER, 1);
1252 
1253 	if (optind < argc) {
1254 		printf("Too many arguments.\n");
1255 		usage();
1256 	}
1257 	if (change_passphrase && change_comment) {
1258 		printf("Can only have one of -p and -c.\n");
1259 		usage();
1260 	}
1261 	if (print_fingerprint && (delete_host || hash_hosts)) {
1262 		printf("Cannot use -l with -D or -R.\n");
1263 		usage();
1264 	}
1265 	if (delete_host || hash_hosts || find_host)
1266 		do_known_hosts(pw, rr_hostname);
1267 	if (print_fingerprint || print_bubblebabble)
1268 		do_fingerprint(pw);
1269 	if (change_passphrase)
1270 		do_change_passphrase(pw);
1271 	if (change_comment)
1272 		do_change_comment(pw);
1273 	if (convert_to_ssh2)
1274 		do_convert_to_ssh2(pw);
1275 	if (convert_from_ssh2)
1276 		do_convert_from_ssh2(pw);
1277 	if (print_public)
1278 		do_print_public(pw);
1279 	if (rr_hostname != NULL) {
1280 		unsigned int n = 0;
1281 
1282 		if (have_identity) {
1283 			n = do_print_resource_record(pw,
1284 			    identity_file, rr_hostname);
1285 			if (n == 0) {
1286 				perror(identity_file);
1287 				exit(1);
1288 			}
1289 			exit(0);
1290 		} else {
1291 
1292 			n += do_print_resource_record(pw,
1293 			    _PATH_HOST_RSA_KEY_FILE, rr_hostname);
1294 			n += do_print_resource_record(pw,
1295 			    _PATH_HOST_DSA_KEY_FILE, rr_hostname);
1296 
1297 			if (n == 0)
1298 				fatal("no keys found.");
1299 			exit(0);
1300 		}
1301 	}
1302 	if (reader_id != NULL) {
1303 #ifdef SMARTCARD
1304 		if (download)
1305 			do_download(pw, reader_id);
1306 		else
1307 			do_upload(pw, reader_id);
1308 #else /* SMARTCARD */
1309 		fatal("no support for smartcards.");
1310 #endif /* SMARTCARD */
1311 	}
1312 
1313 	if (do_gen_candidates) {
1314 		FILE *out = fopen(out_file, "w");
1315 
1316 		if (out == NULL) {
1317 			error("Couldn't open modulus candidate file \"%s\": %s",
1318 			    out_file, strerror(errno));
1319 			return (1);
1320 		}
1321 		if (bits == 0)
1322 			bits = DEFAULT_BITS;
1323 		if (gen_candidates(out, memory, bits, start) != 0)
1324 			fatal("modulus candidate generation failed");
1325 
1326 		return (0);
1327 	}
1328 
1329 	if (do_screen_candidates) {
1330 		FILE *in;
1331 		FILE *out = fopen(out_file, "w");
1332 
1333 		if (have_identity && strcmp(identity_file, "-") != 0) {
1334 			if ((in = fopen(identity_file, "r")) == NULL) {
1335 				fatal("Couldn't open modulus candidate "
1336 				    "file \"%s\": %s", identity_file,
1337 				    strerror(errno));
1338 			}
1339 		} else
1340 			in = stdin;
1341 
1342 		if (out == NULL) {
1343 			fatal("Couldn't open moduli file \"%s\": %s",
1344 			    out_file, strerror(errno));
1345 		}
1346 		if (prime_test(in, out, trials, generator_wanted) != 0)
1347 			fatal("modulus screening failed");
1348 		return (0);
1349 	}
1350 
1351 	arc4random_stir();
1352 
1353 	if (key_type_name == NULL)
1354 		key_type_name = "rsa";
1355 
1356 	type = key_type_from_name(key_type_name);
1357 	if (type == KEY_UNSPEC) {
1358 		fprintf(stderr, "unknown key type %s\n", key_type_name);
1359 		exit(1);
1360 	}
1361 	if (bits == 0)
1362 		bits = (type == KEY_DSA) ? DEFAULT_BITS_DSA : DEFAULT_BITS;
1363 	if (type == KEY_DSA && bits != 1024)
1364 		fatal("DSA keys must be 1024 bits");
1365 	if (!quiet)
1366 		printf("Generating public/private %s key pair.\n", key_type_name);
1367 	private = key_generate(type, bits);
1368 	if (private == NULL) {
1369 		fprintf(stderr, "key_generate failed\n");
1370 		exit(1);
1371 	}
1372 	public  = key_from_private(private);
1373 
1374 	if (!have_identity)
1375 		ask_filename(pw, "Enter file in which to save the key");
1376 
1377 	/* Create ~/.ssh directory if it doesn't already exist. */
1378 	snprintf(dotsshdir, sizeof dotsshdir, "%s/%s", pw->pw_dir, _PATH_SSH_USER_DIR);
1379 	if (strstr(identity_file, dotsshdir) != NULL &&
1380 	    stat(dotsshdir, &st) < 0) {
1381 		if (mkdir(dotsshdir, 0700) < 0)
1382 			error("Could not create directory '%s'.", dotsshdir);
1383 		else if (!quiet)
1384 			printf("Created directory '%s'.\n", dotsshdir);
1385 	}
1386 	/* If the file already exists, ask the user to confirm. */
1387 	if (stat(identity_file, &st) >= 0) {
1388 		char yesno[3];
1389 		printf("%s already exists.\n", identity_file);
1390 		printf("Overwrite (y/n)? ");
1391 		fflush(stdout);
1392 		if (fgets(yesno, sizeof(yesno), stdin) == NULL)
1393 			exit(1);
1394 		if (yesno[0] != 'y' && yesno[0] != 'Y')
1395 			exit(1);
1396 	}
1397 	/* Ask for a passphrase (twice). */
1398 	if (identity_passphrase)
1399 		passphrase1 = xstrdup(identity_passphrase);
1400 	else if (identity_new_passphrase)
1401 		passphrase1 = xstrdup(identity_new_passphrase);
1402 	else {
1403 passphrase_again:
1404 		passphrase1 =
1405 			read_passphrase("Enter passphrase (empty for no "
1406 			    "passphrase): ", RP_ALLOW_STDIN);
1407 		passphrase2 = read_passphrase("Enter same passphrase again: ",
1408 		    RP_ALLOW_STDIN);
1409 		if (strcmp(passphrase1, passphrase2) != 0) {
1410 			/*
1411 			 * The passphrases do not match.  Clear them and
1412 			 * retry.
1413 			 */
1414 			memset(passphrase1, 0, strlen(passphrase1));
1415 			memset(passphrase2, 0, strlen(passphrase2));
1416 			xfree(passphrase1);
1417 			xfree(passphrase2);
1418 			printf("Passphrases do not match.  Try again.\n");
1419 			goto passphrase_again;
1420 		}
1421 		/* Clear the other copy of the passphrase. */
1422 		memset(passphrase2, 0, strlen(passphrase2));
1423 		xfree(passphrase2);
1424 	}
1425 
1426 	if (identity_comment) {
1427 		strlcpy(comment, identity_comment, sizeof(comment));
1428 	} else {
1429 		/* Create default comment field for the passphrase. */
1430 		snprintf(comment, sizeof comment, "%s@%s", pw->pw_name, hostname);
1431 	}
1432 
1433 	/* Save the key with the given passphrase and comment. */
1434 	if (!key_save_private(private, identity_file, passphrase1, comment)) {
1435 		printf("Saving the key failed: %s.\n", identity_file);
1436 		memset(passphrase1, 0, strlen(passphrase1));
1437 		xfree(passphrase1);
1438 		exit(1);
1439 	}
1440 	/* Clear the passphrase. */
1441 	memset(passphrase1, 0, strlen(passphrase1));
1442 	xfree(passphrase1);
1443 
1444 	/* Clear the private key and the random number generator. */
1445 	key_free(private);
1446 	arc4random_stir();
1447 
1448 	if (!quiet)
1449 		printf("Your identification has been saved in %s.\n", identity_file);
1450 
1451 	strlcat(identity_file, ".pub", sizeof(identity_file));
1452 	fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
1453 	if (fd == -1) {
1454 		printf("Could not save your public key in %s\n", identity_file);
1455 		exit(1);
1456 	}
1457 	f = fdopen(fd, "w");
1458 	if (f == NULL) {
1459 		printf("fdopen %s failed\n", identity_file);
1460 		exit(1);
1461 	}
1462 	if (!key_write(public, f))
1463 		fprintf(stderr, "write key failed\n");
1464 	fprintf(f, " %s\n", comment);
1465 	fclose(f);
1466 
1467 	if (!quiet) {
1468 		char *fp = key_fingerprint(public, SSH_FP_MD5, SSH_FP_HEX);
1469 		char *ra = key_fingerprint(public, SSH_FP_MD5,
1470 		    SSH_FP_RANDOMART);
1471 		printf("Your public key has been saved in %s.\n",
1472 		    identity_file);
1473 		printf("The key fingerprint is:\n");
1474 		printf("%s %s\n", fp, comment);
1475 		printf("The key's randomart image is:\n");
1476 		printf("%s\n", ra);
1477 		xfree(ra);
1478 		xfree(fp);
1479 	}
1480 
1481 	key_free(public);
1482 	exit(0);
1483 }
1484