xref: /freebsd/crypto/openssh/ssh-keygen.c (revision 4b2eaea43fec8e8792be611dea204071a10b655a)
1 /*
2  * Author: Tatu Ylonen <ylo@cs.hut.fi>
3  * Copyright (c) 1994 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
4  *                    All rights reserved
5  * Identity and host key generation and maintenance.
6  *
7  * As far as I am concerned, the code I have written for this software
8  * can be used freely for any purpose.  Any derived versions of this
9  * software must be clearly marked as such, and if the derived work is
10  * incompatible with the protocol description in the RFC file, it must be
11  * called by a name other than "ssh" or "Secure Shell".
12  */
13 
14 #include "includes.h"
15 RCSID("$OpenBSD: ssh-keygen.c,v 1.101 2002/06/23 09:39:55 deraadt Exp $");
16 
17 #include <openssl/evp.h>
18 #include <openssl/pem.h>
19 
20 #include "xmalloc.h"
21 #include "key.h"
22 #include "rsa.h"
23 #include "authfile.h"
24 #include "uuencode.h"
25 #include "buffer.h"
26 #include "bufaux.h"
27 #include "pathnames.h"
28 #include "log.h"
29 #include "readpass.h"
30 
31 #ifdef SMARTCARD
32 #include "scard.h"
33 #endif
34 
35 /* Number of bits in the RSA/DSA key.  This value can be changed on the command line. */
36 int bits = 1024;
37 
38 /*
39  * Flag indicating that we just want to change the passphrase.  This can be
40  * set on the command line.
41  */
42 int change_passphrase = 0;
43 
44 /*
45  * Flag indicating that we just want to change the comment.  This can be set
46  * on the command line.
47  */
48 int change_comment = 0;
49 
50 int quiet = 0;
51 
52 /* Flag indicating that we just want to see the key fingerprint */
53 int print_fingerprint = 0;
54 int print_bubblebabble = 0;
55 
56 /* The identity file name, given on the command line or entered by the user. */
57 char identity_file[1024];
58 int have_identity = 0;
59 
60 /* This is set to the passphrase if given on the command line. */
61 char *identity_passphrase = NULL;
62 
63 /* This is set to the new passphrase if given on the command line. */
64 char *identity_new_passphrase = NULL;
65 
66 /* This is set to the new comment if given on the command line. */
67 char *identity_comment = NULL;
68 
69 /* Dump public key file in format used by real and the original SSH 2 */
70 int convert_to_ssh2 = 0;
71 int convert_from_ssh2 = 0;
72 int print_public = 0;
73 
74 char *key_type_name = NULL;
75 
76 /* argv0 */
77 #ifdef HAVE___PROGNAME
78 extern char *__progname;
79 #else
80 char *__progname;
81 #endif
82 
83 char hostname[MAXHOSTNAMELEN];
84 
85 static void
86 ask_filename(struct passwd *pw, const char *prompt)
87 {
88 	char buf[1024];
89 	char *name = NULL;
90 
91 	if (key_type_name == NULL)
92 		name = _PATH_SSH_CLIENT_ID_RSA;
93 	else
94 		switch (key_type_from_name(key_type_name)) {
95 		case KEY_RSA1:
96 			name = _PATH_SSH_CLIENT_IDENTITY;
97 			break;
98 		case KEY_DSA:
99 			name = _PATH_SSH_CLIENT_ID_DSA;
100 			break;
101 		case KEY_RSA:
102 			name = _PATH_SSH_CLIENT_ID_RSA;
103 			break;
104 		default:
105 			fprintf(stderr, "bad key type");
106 			exit(1);
107 			break;
108 		}
109 
110 	snprintf(identity_file, sizeof(identity_file), "%s/%s", pw->pw_dir, name);
111 	fprintf(stderr, "%s (%s): ", prompt, identity_file);
112 	fflush(stderr);
113 	if (fgets(buf, sizeof(buf), stdin) == NULL)
114 		exit(1);
115 	if (strchr(buf, '\n'))
116 		*strchr(buf, '\n') = 0;
117 	if (strcmp(buf, "") != 0)
118 		strlcpy(identity_file, buf, sizeof(identity_file));
119 	have_identity = 1;
120 }
121 
122 static Key *
123 load_identity(char *filename)
124 {
125 	char *pass;
126 	Key *prv;
127 
128 	prv = key_load_private(filename, "", NULL);
129 	if (prv == NULL) {
130 		if (identity_passphrase)
131 			pass = xstrdup(identity_passphrase);
132 		else
133 			pass = read_passphrase("Enter passphrase: ",
134 			    RP_ALLOW_STDIN);
135 		prv = key_load_private(filename, pass, NULL);
136 		memset(pass, 0, strlen(pass));
137 		xfree(pass);
138 	}
139 	return prv;
140 }
141 
142 #define SSH_COM_PUBLIC_BEGIN		"---- BEGIN SSH2 PUBLIC KEY ----"
143 #define SSH_COM_PUBLIC_END		"---- END SSH2 PUBLIC KEY ----"
144 #define SSH_COM_PRIVATE_BEGIN		"---- BEGIN SSH2 ENCRYPTED PRIVATE KEY ----"
145 #define	SSH_COM_PRIVATE_KEY_MAGIC	0x3f6ff9eb
146 
147 static void
148 do_convert_to_ssh2(struct passwd *pw)
149 {
150 	Key *k;
151 	u_int len;
152 	u_char *blob;
153 	struct stat st;
154 
155 	if (!have_identity)
156 		ask_filename(pw, "Enter file in which the key is");
157 	if (stat(identity_file, &st) < 0) {
158 		perror(identity_file);
159 		exit(1);
160 	}
161 	if ((k = key_load_public(identity_file, NULL)) == NULL) {
162 		if ((k = load_identity(identity_file)) == NULL) {
163 			fprintf(stderr, "load failed\n");
164 			exit(1);
165 		}
166 	}
167 	if (key_to_blob(k, &blob, &len) <= 0) {
168 		fprintf(stderr, "key_to_blob failed\n");
169 		exit(1);
170 	}
171 	fprintf(stdout, "%s\n", SSH_COM_PUBLIC_BEGIN);
172 	fprintf(stdout,
173 	    "Comment: \"%u-bit %s, converted from OpenSSH by %s@%s\"\n",
174 	    key_size(k), key_type(k),
175 	    pw->pw_name, hostname);
176 	dump_base64(stdout, blob, len);
177 	fprintf(stdout, "%s\n", SSH_COM_PUBLIC_END);
178 	key_free(k);
179 	xfree(blob);
180 	exit(0);
181 }
182 
183 static void
184 buffer_get_bignum_bits(Buffer *b, BIGNUM *value)
185 {
186 	int bits = buffer_get_int(b);
187 	int bytes = (bits + 7) / 8;
188 
189 	if (buffer_len(b) < bytes)
190 		fatal("buffer_get_bignum_bits: input buffer too small: "
191 		    "need %d have %d", bytes, buffer_len(b));
192 	BN_bin2bn(buffer_ptr(b), bytes, value);
193 	buffer_consume(b, bytes);
194 }
195 
196 static Key *
197 do_convert_private_ssh2_from_blob(u_char *blob, u_int blen)
198 {
199 	Buffer b;
200 	Key *key = NULL;
201 	char *type, *cipher;
202 	u_char *sig, data[] = "abcde12345";
203 	int magic, rlen, ktype, i1, i2, i3, i4;
204 	u_int slen;
205 	u_long e;
206 
207 	buffer_init(&b);
208 	buffer_append(&b, blob, blen);
209 
210 	magic  = buffer_get_int(&b);
211 	if (magic != SSH_COM_PRIVATE_KEY_MAGIC) {
212 		error("bad magic 0x%x != 0x%x", magic, SSH_COM_PRIVATE_KEY_MAGIC);
213 		buffer_free(&b);
214 		return NULL;
215 	}
216 	i1 = buffer_get_int(&b);
217 	type   = buffer_get_string(&b, NULL);
218 	cipher = buffer_get_string(&b, NULL);
219 	i2 = buffer_get_int(&b);
220 	i3 = buffer_get_int(&b);
221 	i4 = buffer_get_int(&b);
222 	debug("ignore (%d %d %d %d)", i1,i2,i3,i4);
223 	if (strcmp(cipher, "none") != 0) {
224 		error("unsupported cipher %s", cipher);
225 		xfree(cipher);
226 		buffer_free(&b);
227 		xfree(type);
228 		return NULL;
229 	}
230 	xfree(cipher);
231 
232 	if (strstr(type, "dsa")) {
233 		ktype = KEY_DSA;
234 	} else if (strstr(type, "rsa")) {
235 		ktype = KEY_RSA;
236 	} else {
237 		xfree(type);
238 		return NULL;
239 	}
240 	key = key_new_private(ktype);
241 	xfree(type);
242 
243 	switch (key->type) {
244 	case KEY_DSA:
245 		buffer_get_bignum_bits(&b, key->dsa->p);
246 		buffer_get_bignum_bits(&b, key->dsa->g);
247 		buffer_get_bignum_bits(&b, key->dsa->q);
248 		buffer_get_bignum_bits(&b, key->dsa->pub_key);
249 		buffer_get_bignum_bits(&b, key->dsa->priv_key);
250 		break;
251 	case KEY_RSA:
252 		e  = buffer_get_char(&b);
253 		debug("e %lx", e);
254 		if (e < 30) {
255 			e <<= 8;
256 			e += buffer_get_char(&b);
257 			debug("e %lx", e);
258 			e <<= 8;
259 			e += buffer_get_char(&b);
260 			debug("e %lx", e);
261 		}
262 		if (!BN_set_word(key->rsa->e, e)) {
263 			buffer_free(&b);
264 			key_free(key);
265 			return NULL;
266 		}
267 		buffer_get_bignum_bits(&b, key->rsa->d);
268 		buffer_get_bignum_bits(&b, key->rsa->n);
269 		buffer_get_bignum_bits(&b, key->rsa->iqmp);
270 		buffer_get_bignum_bits(&b, key->rsa->q);
271 		buffer_get_bignum_bits(&b, key->rsa->p);
272 		rsa_generate_additional_parameters(key->rsa);
273 		break;
274 	}
275 	rlen = buffer_len(&b);
276 	if (rlen != 0)
277 		error("do_convert_private_ssh2_from_blob: "
278 		    "remaining bytes in key blob %d", rlen);
279 	buffer_free(&b);
280 
281 	/* try the key */
282 	key_sign(key, &sig, &slen, data, sizeof(data));
283 	key_verify(key, sig, slen, data, sizeof(data));
284 	xfree(sig);
285 	return key;
286 }
287 
288 static void
289 do_convert_from_ssh2(struct passwd *pw)
290 {
291 	Key *k;
292 	int blen;
293 	u_int len;
294 	char line[1024], *p;
295 	u_char blob[8096];
296 	char encoded[8096];
297 	struct stat st;
298 	int escaped = 0, private = 0, ok;
299 	FILE *fp;
300 
301 	if (!have_identity)
302 		ask_filename(pw, "Enter file in which the key is");
303 	if (stat(identity_file, &st) < 0) {
304 		perror(identity_file);
305 		exit(1);
306 	}
307 	fp = fopen(identity_file, "r");
308 	if (fp == NULL) {
309 		perror(identity_file);
310 		exit(1);
311 	}
312 	encoded[0] = '\0';
313 	while (fgets(line, sizeof(line), fp)) {
314 		if (!(p = strchr(line, '\n'))) {
315 			fprintf(stderr, "input line too long.\n");
316 			exit(1);
317 		}
318 		if (p > line && p[-1] == '\\')
319 			escaped++;
320 		if (strncmp(line, "----", 4) == 0 ||
321 		    strstr(line, ": ") != NULL) {
322 			if (strstr(line, SSH_COM_PRIVATE_BEGIN) != NULL)
323 				private = 1;
324 			if (strstr(line, " END ") != NULL) {
325 				break;
326 			}
327 			/* fprintf(stderr, "ignore: %s", line); */
328 			continue;
329 		}
330 		if (escaped) {
331 			escaped--;
332 			/* fprintf(stderr, "escaped: %s", line); */
333 			continue;
334 		}
335 		*p = '\0';
336 		strlcat(encoded, line, sizeof(encoded));
337 	}
338 	len = strlen(encoded);
339 	if (((len % 4) == 3) &&
340 	    (encoded[len-1] == '=') &&
341 	    (encoded[len-2] == '=') &&
342 	    (encoded[len-3] == '='))
343 		encoded[len-3] = '\0';
344 	blen = uudecode(encoded, blob, sizeof(blob));
345 	if (blen < 0) {
346 		fprintf(stderr, "uudecode failed.\n");
347 		exit(1);
348 	}
349 	k = private ?
350 	    do_convert_private_ssh2_from_blob(blob, blen) :
351 	    key_from_blob(blob, blen);
352 	if (k == NULL) {
353 		fprintf(stderr, "decode blob failed.\n");
354 		exit(1);
355 	}
356 	ok = private ?
357 	    (k->type == KEY_DSA ?
358 		 PEM_write_DSAPrivateKey(stdout, k->dsa, NULL, NULL, 0, NULL, NULL) :
359 		 PEM_write_RSAPrivateKey(stdout, k->rsa, NULL, NULL, 0, NULL, NULL)) :
360 	    key_write(k, stdout);
361 	if (!ok) {
362 		fprintf(stderr, "key write failed");
363 		exit(1);
364 	}
365 	key_free(k);
366 	if (!private)
367 		fprintf(stdout, "\n");
368 	fclose(fp);
369 	exit(0);
370 }
371 
372 static void
373 do_print_public(struct passwd *pw)
374 {
375 	Key *prv;
376 	struct stat st;
377 
378 	if (!have_identity)
379 		ask_filename(pw, "Enter file in which the key is");
380 	if (stat(identity_file, &st) < 0) {
381 		perror(identity_file);
382 		exit(1);
383 	}
384 	prv = load_identity(identity_file);
385 	if (prv == NULL) {
386 		fprintf(stderr, "load failed\n");
387 		exit(1);
388 	}
389 	if (!key_write(prv, stdout))
390 		fprintf(stderr, "key_write failed");
391 	key_free(prv);
392 	fprintf(stdout, "\n");
393 	exit(0);
394 }
395 
396 #ifdef SMARTCARD
397 static void
398 do_upload(struct passwd *pw, const char *sc_reader_id)
399 {
400 	Key *prv = NULL;
401 	struct stat st;
402 	int ret;
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 	prv = load_identity(identity_file);
411 	if (prv == NULL) {
412 		error("load failed");
413 		exit(1);
414 	}
415 	ret = sc_put_key(prv, sc_reader_id);
416 	key_free(prv);
417 	if (ret < 0)
418 		exit(1);
419 	log("loading key done");
420 	exit(0);
421 }
422 
423 static void
424 do_download(struct passwd *pw, const char *sc_reader_id)
425 {
426 	Key **keys = NULL;
427 	int i;
428 
429 	keys = sc_get_keys(sc_reader_id, NULL);
430 	if (keys == NULL)
431 		fatal("cannot read public key from smartcard");
432 	for (i = 0; keys[i]; i++) {
433 		key_write(keys[i], stdout);
434 		key_free(keys[i]);
435 		fprintf(stdout, "\n");
436 	}
437 	xfree(keys);
438 	exit(0);
439 }
440 #endif /* SMARTCARD */
441 
442 static void
443 do_fingerprint(struct passwd *pw)
444 {
445 	FILE *f;
446 	Key *public;
447 	char *comment = NULL, *cp, *ep, line[16*1024], *fp;
448 	int i, skip = 0, num = 1, invalid = 1;
449 	enum fp_rep rep;
450 	enum fp_type fptype;
451 	struct stat st;
452 
453 	fptype = print_bubblebabble ? SSH_FP_SHA1 : SSH_FP_MD5;
454 	rep =    print_bubblebabble ? SSH_FP_BUBBLEBABBLE : SSH_FP_HEX;
455 
456 	if (!have_identity)
457 		ask_filename(pw, "Enter file in which the key is");
458 	if (stat(identity_file, &st) < 0) {
459 		perror(identity_file);
460 		exit(1);
461 	}
462 	public = key_load_public(identity_file, &comment);
463 	if (public != NULL) {
464 		fp = key_fingerprint(public, fptype, rep);
465 		printf("%u %s %s\n", key_size(public), fp, comment);
466 		key_free(public);
467 		xfree(comment);
468 		xfree(fp);
469 		exit(0);
470 	}
471 	if (comment)
472 		xfree(comment);
473 
474 	f = fopen(identity_file, "r");
475 	if (f != NULL) {
476 		while (fgets(line, sizeof(line), f)) {
477 			i = strlen(line) - 1;
478 			if (line[i] != '\n') {
479 				error("line %d too long: %.40s...", num, line);
480 				skip = 1;
481 				continue;
482 			}
483 			num++;
484 			if (skip) {
485 				skip = 0;
486 				continue;
487 			}
488 			line[i] = '\0';
489 
490 			/* Skip leading whitespace, empty and comment lines. */
491 			for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
492 				;
493 			if (!*cp || *cp == '\n' || *cp == '#')
494 				continue ;
495 			i = strtol(cp, &ep, 10);
496 			if (i == 0 || ep == NULL || (*ep != ' ' && *ep != '\t')) {
497 				int quoted = 0;
498 				comment = cp;
499 				for (; *cp && (quoted || (*cp != ' ' &&
500 				    *cp != '\t')); cp++) {
501 					if (*cp == '\\' && cp[1] == '"')
502 						cp++;	/* Skip both */
503 					else if (*cp == '"')
504 						quoted = !quoted;
505 				}
506 				if (!*cp)
507 					continue;
508 				*cp++ = '\0';
509 			}
510 			ep = cp;
511 			public = key_new(KEY_RSA1);
512 			if (key_read(public, &cp) != 1) {
513 				cp = ep;
514 				key_free(public);
515 				public = key_new(KEY_UNSPEC);
516 				if (key_read(public, &cp) != 1) {
517 					key_free(public);
518 					continue;
519 				}
520 			}
521 			comment = *cp ? cp : comment;
522 			fp = key_fingerprint(public, fptype, rep);
523 			printf("%u %s %s\n", key_size(public), fp,
524 			    comment ? comment : "no comment");
525 			xfree(fp);
526 			key_free(public);
527 			invalid = 0;
528 		}
529 		fclose(f);
530 	}
531 	if (invalid) {
532 		printf("%s is not a public key file.\n", identity_file);
533 		exit(1);
534 	}
535 	exit(0);
536 }
537 
538 /*
539  * Perform changing a passphrase.  The argument is the passwd structure
540  * for the current user.
541  */
542 static void
543 do_change_passphrase(struct passwd *pw)
544 {
545 	char *comment;
546 	char *old_passphrase, *passphrase1, *passphrase2;
547 	struct stat st;
548 	Key *private;
549 
550 	if (!have_identity)
551 		ask_filename(pw, "Enter file in which the key is");
552 	if (stat(identity_file, &st) < 0) {
553 		perror(identity_file);
554 		exit(1);
555 	}
556 	/* Try to load the file with empty passphrase. */
557 	private = key_load_private(identity_file, "", &comment);
558 	if (private == NULL) {
559 		if (identity_passphrase)
560 			old_passphrase = xstrdup(identity_passphrase);
561 		else
562 			old_passphrase =
563 			    read_passphrase("Enter old passphrase: ",
564 			    RP_ALLOW_STDIN);
565 		private = key_load_private(identity_file, old_passphrase,
566 		    &comment);
567 		memset(old_passphrase, 0, strlen(old_passphrase));
568 		xfree(old_passphrase);
569 		if (private == NULL) {
570 			printf("Bad passphrase.\n");
571 			exit(1);
572 		}
573 	}
574 	printf("Key has comment '%s'\n", comment);
575 
576 	/* Ask the new passphrase (twice). */
577 	if (identity_new_passphrase) {
578 		passphrase1 = xstrdup(identity_new_passphrase);
579 		passphrase2 = NULL;
580 	} else {
581 		passphrase1 =
582 			read_passphrase("Enter new passphrase (empty for no "
583 			    "passphrase): ", RP_ALLOW_STDIN);
584 		passphrase2 = read_passphrase("Enter same passphrase again: ",
585 		    RP_ALLOW_STDIN);
586 
587 		/* Verify that they are the same. */
588 		if (strcmp(passphrase1, passphrase2) != 0) {
589 			memset(passphrase1, 0, strlen(passphrase1));
590 			memset(passphrase2, 0, strlen(passphrase2));
591 			xfree(passphrase1);
592 			xfree(passphrase2);
593 			printf("Pass phrases do not match.  Try again.\n");
594 			exit(1);
595 		}
596 		/* Destroy the other copy. */
597 		memset(passphrase2, 0, strlen(passphrase2));
598 		xfree(passphrase2);
599 	}
600 
601 	/* Save the file using the new passphrase. */
602 	if (!key_save_private(private, identity_file, passphrase1, comment)) {
603 		printf("Saving the key failed: %s.\n", identity_file);
604 		memset(passphrase1, 0, strlen(passphrase1));
605 		xfree(passphrase1);
606 		key_free(private);
607 		xfree(comment);
608 		exit(1);
609 	}
610 	/* Destroy the passphrase and the copy of the key in memory. */
611 	memset(passphrase1, 0, strlen(passphrase1));
612 	xfree(passphrase1);
613 	key_free(private);		 /* Destroys contents */
614 	xfree(comment);
615 
616 	printf("Your identification has been saved with the new passphrase.\n");
617 	exit(0);
618 }
619 
620 /*
621  * Change the comment of a private key file.
622  */
623 static void
624 do_change_comment(struct passwd *pw)
625 {
626 	char new_comment[1024], *comment, *passphrase;
627 	Key *private;
628 	Key *public;
629 	struct stat st;
630 	FILE *f;
631 	int fd;
632 
633 	if (!have_identity)
634 		ask_filename(pw, "Enter file in which the key is");
635 	if (stat(identity_file, &st) < 0) {
636 		perror(identity_file);
637 		exit(1);
638 	}
639 	private = key_load_private(identity_file, "", &comment);
640 	if (private == NULL) {
641 		if (identity_passphrase)
642 			passphrase = xstrdup(identity_passphrase);
643 		else if (identity_new_passphrase)
644 			passphrase = xstrdup(identity_new_passphrase);
645 		else
646 			passphrase = read_passphrase("Enter passphrase: ",
647 			    RP_ALLOW_STDIN);
648 		/* Try to load using the passphrase. */
649 		private = key_load_private(identity_file, passphrase, &comment);
650 		if (private == NULL) {
651 			memset(passphrase, 0, strlen(passphrase));
652 			xfree(passphrase);
653 			printf("Bad passphrase.\n");
654 			exit(1);
655 		}
656 	} else {
657 		passphrase = xstrdup("");
658 	}
659 	if (private->type != KEY_RSA1) {
660 		fprintf(stderr, "Comments are only supported for RSA1 keys.\n");
661 		key_free(private);
662 		exit(1);
663 	}
664 	printf("Key now has comment '%s'\n", comment);
665 
666 	if (identity_comment) {
667 		strlcpy(new_comment, identity_comment, sizeof(new_comment));
668 	} else {
669 		printf("Enter new comment: ");
670 		fflush(stdout);
671 		if (!fgets(new_comment, sizeof(new_comment), stdin)) {
672 			memset(passphrase, 0, strlen(passphrase));
673 			key_free(private);
674 			exit(1);
675 		}
676 		if (strchr(new_comment, '\n'))
677 			*strchr(new_comment, '\n') = 0;
678 	}
679 
680 	/* Save the file using the new passphrase. */
681 	if (!key_save_private(private, identity_file, passphrase, new_comment)) {
682 		printf("Saving the key failed: %s.\n", identity_file);
683 		memset(passphrase, 0, strlen(passphrase));
684 		xfree(passphrase);
685 		key_free(private);
686 		xfree(comment);
687 		exit(1);
688 	}
689 	memset(passphrase, 0, strlen(passphrase));
690 	xfree(passphrase);
691 	public = key_from_private(private);
692 	key_free(private);
693 
694 	strlcat(identity_file, ".pub", sizeof(identity_file));
695 	fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
696 	if (fd == -1) {
697 		printf("Could not save your public key in %s\n", identity_file);
698 		exit(1);
699 	}
700 	f = fdopen(fd, "w");
701 	if (f == NULL) {
702 		printf("fdopen %s failed", identity_file);
703 		exit(1);
704 	}
705 	if (!key_write(public, f))
706 		fprintf(stderr, "write key failed");
707 	key_free(public);
708 	fprintf(f, " %s\n", new_comment);
709 	fclose(f);
710 
711 	xfree(comment);
712 
713 	printf("The comment in your key file has been changed.\n");
714 	exit(0);
715 }
716 
717 static void
718 usage(void)
719 {
720 	fprintf(stderr, "Usage: %s [options]\n", __progname);
721 	fprintf(stderr, "Options:\n");
722 	fprintf(stderr, "  -b bits     Number of bits in the key to create.\n");
723 	fprintf(stderr, "  -c          Change comment in private and public key files.\n");
724 	fprintf(stderr, "  -e          Convert OpenSSH to IETF SECSH key file.\n");
725 	fprintf(stderr, "  -f filename Filename of the key file.\n");
726 	fprintf(stderr, "  -i          Convert IETF SECSH to OpenSSH key file.\n");
727 	fprintf(stderr, "  -l          Show fingerprint of key file.\n");
728 	fprintf(stderr, "  -p          Change passphrase of private key file.\n");
729 	fprintf(stderr, "  -q          Quiet.\n");
730 	fprintf(stderr, "  -y          Read private key file and print public key.\n");
731 	fprintf(stderr, "  -t type     Specify type of key to create.\n");
732 	fprintf(stderr, "  -B          Show bubblebabble digest of key file.\n");
733 	fprintf(stderr, "  -C comment  Provide new comment.\n");
734 	fprintf(stderr, "  -N phrase   Provide new passphrase.\n");
735 	fprintf(stderr, "  -P phrase   Provide old passphrase.\n");
736 #ifdef SMARTCARD
737 	fprintf(stderr, "  -D reader   Download public key from smartcard.\n");
738 	fprintf(stderr, "  -U reader   Upload private key to smartcard.\n");
739 #endif /* SMARTCARD */
740 
741 	exit(1);
742 }
743 
744 /*
745  * Main program for key management.
746  */
747 int
748 main(int ac, char **av)
749 {
750 	char dotsshdir[MAXPATHLEN], comment[1024], *passphrase1, *passphrase2;
751 	char *reader_id = NULL;
752 	Key *private, *public;
753 	struct passwd *pw;
754 	struct stat st;
755 	int opt, type, fd, download = 0;
756 	FILE *f;
757 
758 	extern int optind;
759 	extern char *optarg;
760 
761 	__progname = get_progname(av[0]);
762 
763 	SSLeay_add_all_algorithms();
764 	init_rng();
765 	seed_rng();
766 
767 	/* we need this for the home * directory.  */
768 	pw = getpwuid(getuid());
769 	if (!pw) {
770 		printf("You don't exist, go away!\n");
771 		exit(1);
772 	}
773 	if (gethostname(hostname, sizeof(hostname)) < 0) {
774 		perror("gethostname");
775 		exit(1);
776 	}
777 
778 	while ((opt = getopt(ac, av, "deiqpclBRxXyb:f:t:U:D:P:N:C:")) != -1) {
779 		switch (opt) {
780 		case 'b':
781 			bits = atoi(optarg);
782 			if (bits < 512 || bits > 32768) {
783 				printf("Bits has bad value.\n");
784 				exit(1);
785 			}
786 			break;
787 		case 'l':
788 			print_fingerprint = 1;
789 			break;
790 		case 'B':
791 			print_bubblebabble = 1;
792 			break;
793 		case 'p':
794 			change_passphrase = 1;
795 			break;
796 		case 'c':
797 			change_comment = 1;
798 			break;
799 		case 'f':
800 			strlcpy(identity_file, optarg, sizeof(identity_file));
801 			have_identity = 1;
802 			break;
803 		case 'P':
804 			identity_passphrase = optarg;
805 			break;
806 		case 'N':
807 			identity_new_passphrase = optarg;
808 			break;
809 		case 'C':
810 			identity_comment = optarg;
811 			break;
812 		case 'q':
813 			quiet = 1;
814 			break;
815 		case 'R':
816 			/* unused */
817 			exit(0);
818 			break;
819 		case 'e':
820 		case 'x':
821 			/* export key */
822 			convert_to_ssh2 = 1;
823 			break;
824 		case 'i':
825 		case 'X':
826 			/* import key */
827 			convert_from_ssh2 = 1;
828 			break;
829 		case 'y':
830 			print_public = 1;
831 			break;
832 		case 'd':
833 			key_type_name = "dsa";
834 			break;
835 		case 't':
836 			key_type_name = optarg;
837 			break;
838 		case 'D':
839 			download = 1;
840 		case 'U':
841 			reader_id = optarg;
842 			break;
843 		case '?':
844 		default:
845 			usage();
846 		}
847 	}
848 	if (optind < ac) {
849 		printf("Too many arguments.\n");
850 		usage();
851 	}
852 	if (change_passphrase && change_comment) {
853 		printf("Can only have one of -p and -c.\n");
854 		usage();
855 	}
856 	if (print_fingerprint || print_bubblebabble)
857 		do_fingerprint(pw);
858 	if (change_passphrase)
859 		do_change_passphrase(pw);
860 	if (change_comment)
861 		do_change_comment(pw);
862 	if (convert_to_ssh2)
863 		do_convert_to_ssh2(pw);
864 	if (convert_from_ssh2)
865 		do_convert_from_ssh2(pw);
866 	if (print_public)
867 		do_print_public(pw);
868 	if (reader_id != NULL) {
869 #ifdef SMARTCARD
870 		if (download)
871 			do_download(pw, reader_id);
872 		else
873 			do_upload(pw, reader_id);
874 #else /* SMARTCARD */
875 		fatal("no support for smartcards.");
876 #endif /* SMARTCARD */
877 	}
878 
879 	arc4random_stir();
880 
881 	if (key_type_name == NULL) {
882 		printf("You must specify a key type (-t).\n");
883 		usage();
884 	}
885 	type = key_type_from_name(key_type_name);
886 	if (type == KEY_UNSPEC) {
887 		fprintf(stderr, "unknown key type %s\n", key_type_name);
888 		exit(1);
889 	}
890 	if (!quiet)
891 		printf("Generating public/private %s key pair.\n", key_type_name);
892 	private = key_generate(type, bits);
893 	if (private == NULL) {
894 		fprintf(stderr, "key_generate failed");
895 		exit(1);
896 	}
897 	public  = key_from_private(private);
898 
899 	if (!have_identity)
900 		ask_filename(pw, "Enter file in which to save the key");
901 
902 	/* Create ~/.ssh directory if it doesn\'t already exist. */
903 	snprintf(dotsshdir, sizeof dotsshdir, "%s/%s", pw->pw_dir, _PATH_SSH_USER_DIR);
904 	if (strstr(identity_file, dotsshdir) != NULL &&
905 	    stat(dotsshdir, &st) < 0) {
906 		if (mkdir(dotsshdir, 0700) < 0)
907 			error("Could not create directory '%s'.", dotsshdir);
908 		else if (!quiet)
909 			printf("Created directory '%s'.\n", dotsshdir);
910 	}
911 	/* If the file already exists, ask the user to confirm. */
912 	if (stat(identity_file, &st) >= 0) {
913 		char yesno[3];
914 		printf("%s already exists.\n", identity_file);
915 		printf("Overwrite (y/n)? ");
916 		fflush(stdout);
917 		if (fgets(yesno, sizeof(yesno), stdin) == NULL)
918 			exit(1);
919 		if (yesno[0] != 'y' && yesno[0] != 'Y')
920 			exit(1);
921 	}
922 	/* Ask for a passphrase (twice). */
923 	if (identity_passphrase)
924 		passphrase1 = xstrdup(identity_passphrase);
925 	else if (identity_new_passphrase)
926 		passphrase1 = xstrdup(identity_new_passphrase);
927 	else {
928 passphrase_again:
929 		passphrase1 =
930 			read_passphrase("Enter passphrase (empty for no "
931 			    "passphrase): ", RP_ALLOW_STDIN);
932 		passphrase2 = read_passphrase("Enter same passphrase again: ",
933 		    RP_ALLOW_STDIN);
934 		if (strcmp(passphrase1, passphrase2) != 0) {
935 			/*
936 			 * The passphrases do not match.  Clear them and
937 			 * retry.
938 			 */
939 			memset(passphrase1, 0, strlen(passphrase1));
940 			memset(passphrase2, 0, strlen(passphrase2));
941 			xfree(passphrase1);
942 			xfree(passphrase2);
943 			printf("Passphrases do not match.  Try again.\n");
944 			goto passphrase_again;
945 		}
946 		/* Clear the other copy of the passphrase. */
947 		memset(passphrase2, 0, strlen(passphrase2));
948 		xfree(passphrase2);
949 	}
950 
951 	if (identity_comment) {
952 		strlcpy(comment, identity_comment, sizeof(comment));
953 	} else {
954 		/* Create default commend field for the passphrase. */
955 		snprintf(comment, sizeof comment, "%s@%s", pw->pw_name, hostname);
956 	}
957 
958 	/* Save the key with the given passphrase and comment. */
959 	if (!key_save_private(private, identity_file, passphrase1, comment)) {
960 		printf("Saving the key failed: %s.\n", identity_file);
961 		memset(passphrase1, 0, strlen(passphrase1));
962 		xfree(passphrase1);
963 		exit(1);
964 	}
965 	/* Clear the passphrase. */
966 	memset(passphrase1, 0, strlen(passphrase1));
967 	xfree(passphrase1);
968 
969 	/* Clear the private key and the random number generator. */
970 	key_free(private);
971 	arc4random_stir();
972 
973 	if (!quiet)
974 		printf("Your identification has been saved in %s.\n", identity_file);
975 
976 	strlcat(identity_file, ".pub", sizeof(identity_file));
977 	fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
978 	if (fd == -1) {
979 		printf("Could not save your public key in %s\n", identity_file);
980 		exit(1);
981 	}
982 	f = fdopen(fd, "w");
983 	if (f == NULL) {
984 		printf("fdopen %s failed", identity_file);
985 		exit(1);
986 	}
987 	if (!key_write(public, f))
988 		fprintf(stderr, "write key failed");
989 	fprintf(f, " %s\n", comment);
990 	fclose(f);
991 
992 	if (!quiet) {
993 		char *fp = key_fingerprint(public, SSH_FP_MD5, SSH_FP_HEX);
994 		printf("Your public key has been saved in %s.\n",
995 		    identity_file);
996 		printf("The key fingerprint is:\n");
997 		printf("%s %s\n", fp, comment);
998 		xfree(fp);
999 	}
1000 
1001 	key_free(public);
1002 	exit(0);
1003 }
1004