xref: /openbsd-src/usr.bin/ssh/ssh-keygen.c (revision db3296cf5c1dd9058ceecc3a29fe4aaa0bd26000)
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 1.107 2003/07/28 09:49:56 djm 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 #include "moduli.h"
31 
32 #ifdef SMARTCARD
33 #include "scard.h"
34 #endif
35 #ifdef DNS
36 #include "dns.h"
37 #endif
38 
39 /* Number of bits in the RSA/DSA key.  This value can be changed on the command line. */
40 int bits = 1024;
41 
42 /*
43  * Flag indicating that we just want to change the passphrase.  This can be
44  * set on the command line.
45  */
46 int change_passphrase = 0;
47 
48 /*
49  * Flag indicating that we just want to change the comment.  This can be set
50  * on the command line.
51  */
52 int change_comment = 0;
53 
54 int quiet = 0;
55 
56 /* Flag indicating that we just want to see the key fingerprint */
57 int print_fingerprint = 0;
58 int print_bubblebabble = 0;
59 
60 /* The identity file name, given on the command line or entered by the user. */
61 char identity_file[1024];
62 int have_identity = 0;
63 
64 /* This is set to the passphrase if given on the command line. */
65 char *identity_passphrase = NULL;
66 
67 /* This is set to the new passphrase if given on the command line. */
68 char *identity_new_passphrase = NULL;
69 
70 /* This is set to the new comment if given on the command line. */
71 char *identity_comment = NULL;
72 
73 /* Dump public key file in format used by real and the original SSH 2 */
74 int convert_to_ssh2 = 0;
75 int convert_from_ssh2 = 0;
76 int print_public = 0;
77 int print_generic = 0;
78 
79 char *key_type_name = NULL;
80 
81 /* argv0 */
82 extern char *__progname;
83 
84 char hostname[MAXHOSTNAMELEN];
85 
86 static void
87 ask_filename(struct passwd *pw, const char *prompt)
88 {
89 	char buf[1024];
90 	char *name = NULL;
91 
92 	if (key_type_name == NULL)
93 		name = _PATH_SSH_CLIENT_ID_RSA;
94 	else
95 		switch (key_type_from_name(key_type_name)) {
96 		case KEY_RSA1:
97 			name = _PATH_SSH_CLIENT_IDENTITY;
98 			break;
99 		case KEY_DSA:
100 			name = _PATH_SSH_CLIENT_ID_DSA;
101 			break;
102 		case KEY_RSA:
103 			name = _PATH_SSH_CLIENT_ID_RSA;
104 			break;
105 		default:
106 			fprintf(stderr, "bad key type");
107 			exit(1);
108 			break;
109 		}
110 
111 	snprintf(identity_file, sizeof(identity_file), "%s/%s", pw->pw_dir, name);
112 	fprintf(stderr, "%s (%s): ", prompt, identity_file);
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 (k->type == KEY_RSA1) {
168 		fprintf(stderr, "version 1 keys are not supported\n");
169 		exit(1);
170 	}
171 	if (key_to_blob(k, &blob, &len) <= 0) {
172 		fprintf(stderr, "key_to_blob failed\n");
173 		exit(1);
174 	}
175 	fprintf(stdout, "%s\n", SSH_COM_PUBLIC_BEGIN);
176 	fprintf(stdout,
177 	    "Comment: \"%u-bit %s, converted from OpenSSH by %s@%s\"\n",
178 	    key_size(k), key_type(k),
179 	    pw->pw_name, hostname);
180 	dump_base64(stdout, blob, len);
181 	fprintf(stdout, "%s\n", SSH_COM_PUBLIC_END);
182 	key_free(k);
183 	xfree(blob);
184 	exit(0);
185 }
186 
187 static void
188 buffer_get_bignum_bits(Buffer *b, BIGNUM *value)
189 {
190 	int bits = buffer_get_int(b);
191 	int bytes = (bits + 7) / 8;
192 
193 	if (buffer_len(b) < bytes)
194 		fatal("buffer_get_bignum_bits: input buffer too small: "
195 		    "need %d have %d", bytes, buffer_len(b));
196 	BN_bin2bn(buffer_ptr(b), bytes, value);
197 	buffer_consume(b, bytes);
198 }
199 
200 static Key *
201 do_convert_private_ssh2_from_blob(u_char *blob, u_int blen)
202 {
203 	Buffer b;
204 	Key *key = NULL;
205 	char *type, *cipher;
206 	u_char *sig, data[] = "abcde12345";
207 	int magic, rlen, ktype, i1, i2, i3, i4;
208 	u_int slen;
209 	u_long e;
210 
211 	buffer_init(&b);
212 	buffer_append(&b, blob, blen);
213 
214 	magic  = buffer_get_int(&b);
215 	if (magic != SSH_COM_PRIVATE_KEY_MAGIC) {
216 		error("bad magic 0x%x != 0x%x", magic, SSH_COM_PRIVATE_KEY_MAGIC);
217 		buffer_free(&b);
218 		return NULL;
219 	}
220 	i1 = buffer_get_int(&b);
221 	type   = buffer_get_string(&b, NULL);
222 	cipher = buffer_get_string(&b, NULL);
223 	i2 = buffer_get_int(&b);
224 	i3 = buffer_get_int(&b);
225 	i4 = buffer_get_int(&b);
226 	debug("ignore (%d %d %d %d)", i1,i2,i3,i4);
227 	if (strcmp(cipher, "none") != 0) {
228 		error("unsupported cipher %s", cipher);
229 		xfree(cipher);
230 		buffer_free(&b);
231 		xfree(type);
232 		return NULL;
233 	}
234 	xfree(cipher);
235 
236 	if (strstr(type, "dsa")) {
237 		ktype = KEY_DSA;
238 	} else if (strstr(type, "rsa")) {
239 		ktype = KEY_RSA;
240 	} else {
241 		xfree(type);
242 		return NULL;
243 	}
244 	key = key_new_private(ktype);
245 	xfree(type);
246 
247 	switch (key->type) {
248 	case KEY_DSA:
249 		buffer_get_bignum_bits(&b, key->dsa->p);
250 		buffer_get_bignum_bits(&b, key->dsa->g);
251 		buffer_get_bignum_bits(&b, key->dsa->q);
252 		buffer_get_bignum_bits(&b, key->dsa->pub_key);
253 		buffer_get_bignum_bits(&b, key->dsa->priv_key);
254 		break;
255 	case KEY_RSA:
256 		e  = buffer_get_char(&b);
257 		debug("e %lx", e);
258 		if (e < 30) {
259 			e <<= 8;
260 			e += buffer_get_char(&b);
261 			debug("e %lx", e);
262 			e <<= 8;
263 			e += buffer_get_char(&b);
264 			debug("e %lx", e);
265 		}
266 		if (!BN_set_word(key->rsa->e, e)) {
267 			buffer_free(&b);
268 			key_free(key);
269 			return NULL;
270 		}
271 		buffer_get_bignum_bits(&b, key->rsa->d);
272 		buffer_get_bignum_bits(&b, key->rsa->n);
273 		buffer_get_bignum_bits(&b, key->rsa->iqmp);
274 		buffer_get_bignum_bits(&b, key->rsa->q);
275 		buffer_get_bignum_bits(&b, key->rsa->p);
276 		rsa_generate_additional_parameters(key->rsa);
277 		break;
278 	}
279 	rlen = buffer_len(&b);
280 	if (rlen != 0)
281 		error("do_convert_private_ssh2_from_blob: "
282 		    "remaining bytes in key blob %d", rlen);
283 	buffer_free(&b);
284 
285 	/* try the key */
286 	key_sign(key, &sig, &slen, data, sizeof(data));
287 	key_verify(key, sig, slen, data, sizeof(data));
288 	xfree(sig);
289 	return key;
290 }
291 
292 static void
293 do_convert_from_ssh2(struct passwd *pw)
294 {
295 	Key *k;
296 	int blen;
297 	u_int len;
298 	char line[1024], *p;
299 	u_char blob[8096];
300 	char encoded[8096];
301 	struct stat st;
302 	int escaped = 0, private = 0, ok;
303 	FILE *fp;
304 
305 	if (!have_identity)
306 		ask_filename(pw, "Enter file in which the key is");
307 	if (stat(identity_file, &st) < 0) {
308 		perror(identity_file);
309 		exit(1);
310 	}
311 	fp = fopen(identity_file, "r");
312 	if (fp == NULL) {
313 		perror(identity_file);
314 		exit(1);
315 	}
316 	encoded[0] = '\0';
317 	while (fgets(line, sizeof(line), fp)) {
318 		if (!(p = strchr(line, '\n'))) {
319 			fprintf(stderr, "input line too long.\n");
320 			exit(1);
321 		}
322 		if (p > line && p[-1] == '\\')
323 			escaped++;
324 		if (strncmp(line, "----", 4) == 0 ||
325 		    strstr(line, ": ") != NULL) {
326 			if (strstr(line, SSH_COM_PRIVATE_BEGIN) != NULL)
327 				private = 1;
328 			if (strstr(line, " END ") != NULL) {
329 				break;
330 			}
331 			/* fprintf(stderr, "ignore: %s", line); */
332 			continue;
333 		}
334 		if (escaped) {
335 			escaped--;
336 			/* fprintf(stderr, "escaped: %s", line); */
337 			continue;
338 		}
339 		*p = '\0';
340 		strlcat(encoded, line, sizeof(encoded));
341 	}
342 	len = strlen(encoded);
343 	if (((len % 4) == 3) &&
344 	    (encoded[len-1] == '=') &&
345 	    (encoded[len-2] == '=') &&
346 	    (encoded[len-3] == '='))
347 		encoded[len-3] = '\0';
348 	blen = uudecode(encoded, blob, sizeof(blob));
349 	if (blen < 0) {
350 		fprintf(stderr, "uudecode failed.\n");
351 		exit(1);
352 	}
353 	k = private ?
354 	    do_convert_private_ssh2_from_blob(blob, blen) :
355 	    key_from_blob(blob, blen);
356 	if (k == NULL) {
357 		fprintf(stderr, "decode blob failed.\n");
358 		exit(1);
359 	}
360 	ok = private ?
361 	    (k->type == KEY_DSA ?
362 		 PEM_write_DSAPrivateKey(stdout, k->dsa, NULL, NULL, 0, NULL, NULL) :
363 		 PEM_write_RSAPrivateKey(stdout, k->rsa, NULL, NULL, 0, NULL, NULL)) :
364 	    key_write(k, stdout);
365 	if (!ok) {
366 		fprintf(stderr, "key write failed");
367 		exit(1);
368 	}
369 	key_free(k);
370 	if (!private)
371 		fprintf(stdout, "\n");
372 	fclose(fp);
373 	exit(0);
374 }
375 
376 static void
377 do_print_public(struct passwd *pw)
378 {
379 	Key *prv;
380 	struct stat st;
381 
382 	if (!have_identity)
383 		ask_filename(pw, "Enter file in which the key is");
384 	if (stat(identity_file, &st) < 0) {
385 		perror(identity_file);
386 		exit(1);
387 	}
388 	prv = load_identity(identity_file);
389 	if (prv == NULL) {
390 		fprintf(stderr, "load failed\n");
391 		exit(1);
392 	}
393 	if (!key_write(prv, stdout))
394 		fprintf(stderr, "key_write failed");
395 	key_free(prv);
396 	fprintf(stdout, "\n");
397 	exit(0);
398 }
399 
400 #ifdef SMARTCARD
401 static void
402 do_upload(struct passwd *pw, const char *sc_reader_id)
403 {
404 	Key *prv = NULL;
405 	struct stat st;
406 	int ret;
407 
408 	if (!have_identity)
409 		ask_filename(pw, "Enter file in which the key is");
410 	if (stat(identity_file, &st) < 0) {
411 		perror(identity_file);
412 		exit(1);
413 	}
414 	prv = load_identity(identity_file);
415 	if (prv == NULL) {
416 		error("load failed");
417 		exit(1);
418 	}
419 	ret = sc_put_key(prv, sc_reader_id);
420 	key_free(prv);
421 	if (ret < 0)
422 		exit(1);
423 	logit("loading key done");
424 	exit(0);
425 }
426 
427 static void
428 do_download(struct passwd *pw, const char *sc_reader_id)
429 {
430 	Key **keys = NULL;
431 	int i;
432 
433 	keys = sc_get_keys(sc_reader_id, NULL);
434 	if (keys == NULL)
435 		fatal("cannot read public key from smartcard");
436 	for (i = 0; keys[i]; i++) {
437 		key_write(keys[i], stdout);
438 		key_free(keys[i]);
439 		fprintf(stdout, "\n");
440 	}
441 	xfree(keys);
442 	exit(0);
443 }
444 #endif /* SMARTCARD */
445 
446 static void
447 do_fingerprint(struct passwd *pw)
448 {
449 	FILE *f;
450 	Key *public;
451 	char *comment = NULL, *cp, *ep, line[16*1024], *fp;
452 	int i, skip = 0, num = 1, invalid = 1;
453 	enum fp_rep rep;
454 	enum fp_type fptype;
455 	struct stat st;
456 
457 	fptype = print_bubblebabble ? SSH_FP_SHA1 : SSH_FP_MD5;
458 	rep =    print_bubblebabble ? SSH_FP_BUBBLEBABBLE : SSH_FP_HEX;
459 
460 	if (!have_identity)
461 		ask_filename(pw, "Enter file in which the key is");
462 	if (stat(identity_file, &st) < 0) {
463 		perror(identity_file);
464 		exit(1);
465 	}
466 	public = key_load_public(identity_file, &comment);
467 	if (public != NULL) {
468 		fp = key_fingerprint(public, fptype, rep);
469 		printf("%u %s %s\n", key_size(public), fp, comment);
470 		key_free(public);
471 		xfree(comment);
472 		xfree(fp);
473 		exit(0);
474 	}
475 	if (comment)
476 		xfree(comment);
477 
478 	f = fopen(identity_file, "r");
479 	if (f != NULL) {
480 		while (fgets(line, sizeof(line), f)) {
481 			i = strlen(line) - 1;
482 			if (line[i] != '\n') {
483 				error("line %d too long: %.40s...", num, line);
484 				skip = 1;
485 				continue;
486 			}
487 			num++;
488 			if (skip) {
489 				skip = 0;
490 				continue;
491 			}
492 			line[i] = '\0';
493 
494 			/* Skip leading whitespace, empty and comment lines. */
495 			for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
496 				;
497 			if (!*cp || *cp == '\n' || *cp == '#')
498 				continue ;
499 			i = strtol(cp, &ep, 10);
500 			if (i == 0 || ep == NULL || (*ep != ' ' && *ep != '\t')) {
501 				int quoted = 0;
502 				comment = cp;
503 				for (; *cp && (quoted || (*cp != ' ' &&
504 				    *cp != '\t')); cp++) {
505 					if (*cp == '\\' && cp[1] == '"')
506 						cp++;	/* Skip both */
507 					else if (*cp == '"')
508 						quoted = !quoted;
509 				}
510 				if (!*cp)
511 					continue;
512 				*cp++ = '\0';
513 			}
514 			ep = cp;
515 			public = key_new(KEY_RSA1);
516 			if (key_read(public, &cp) != 1) {
517 				cp = ep;
518 				key_free(public);
519 				public = key_new(KEY_UNSPEC);
520 				if (key_read(public, &cp) != 1) {
521 					key_free(public);
522 					continue;
523 				}
524 			}
525 			comment = *cp ? cp : comment;
526 			fp = key_fingerprint(public, fptype, rep);
527 			printf("%u %s %s\n", key_size(public), fp,
528 			    comment ? comment : "no comment");
529 			xfree(fp);
530 			key_free(public);
531 			invalid = 0;
532 		}
533 		fclose(f);
534 	}
535 	if (invalid) {
536 		printf("%s is not a public key file.\n", identity_file);
537 		exit(1);
538 	}
539 	exit(0);
540 }
541 
542 /*
543  * Perform changing a passphrase.  The argument is the passwd structure
544  * for the current user.
545  */
546 static void
547 do_change_passphrase(struct passwd *pw)
548 {
549 	char *comment;
550 	char *old_passphrase, *passphrase1, *passphrase2;
551 	struct stat st;
552 	Key *private;
553 
554 	if (!have_identity)
555 		ask_filename(pw, "Enter file in which the key is");
556 	if (stat(identity_file, &st) < 0) {
557 		perror(identity_file);
558 		exit(1);
559 	}
560 	/* Try to load the file with empty passphrase. */
561 	private = key_load_private(identity_file, "", &comment);
562 	if (private == NULL) {
563 		if (identity_passphrase)
564 			old_passphrase = xstrdup(identity_passphrase);
565 		else
566 			old_passphrase =
567 			    read_passphrase("Enter old passphrase: ",
568 			    RP_ALLOW_STDIN);
569 		private = key_load_private(identity_file, old_passphrase,
570 		    &comment);
571 		memset(old_passphrase, 0, strlen(old_passphrase));
572 		xfree(old_passphrase);
573 		if (private == NULL) {
574 			printf("Bad passphrase.\n");
575 			exit(1);
576 		}
577 	}
578 	printf("Key has comment '%s'\n", comment);
579 
580 	/* Ask the new passphrase (twice). */
581 	if (identity_new_passphrase) {
582 		passphrase1 = xstrdup(identity_new_passphrase);
583 		passphrase2 = NULL;
584 	} else {
585 		passphrase1 =
586 			read_passphrase("Enter new passphrase (empty for no "
587 			    "passphrase): ", RP_ALLOW_STDIN);
588 		passphrase2 = read_passphrase("Enter same passphrase again: ",
589 		    RP_ALLOW_STDIN);
590 
591 		/* Verify that they are the same. */
592 		if (strcmp(passphrase1, passphrase2) != 0) {
593 			memset(passphrase1, 0, strlen(passphrase1));
594 			memset(passphrase2, 0, strlen(passphrase2));
595 			xfree(passphrase1);
596 			xfree(passphrase2);
597 			printf("Pass phrases do not match.  Try again.\n");
598 			exit(1);
599 		}
600 		/* Destroy the other copy. */
601 		memset(passphrase2, 0, strlen(passphrase2));
602 		xfree(passphrase2);
603 	}
604 
605 	/* Save the file using the new passphrase. */
606 	if (!key_save_private(private, identity_file, passphrase1, comment)) {
607 		printf("Saving the key failed: %s.\n", identity_file);
608 		memset(passphrase1, 0, strlen(passphrase1));
609 		xfree(passphrase1);
610 		key_free(private);
611 		xfree(comment);
612 		exit(1);
613 	}
614 	/* Destroy the passphrase and the copy of the key in memory. */
615 	memset(passphrase1, 0, strlen(passphrase1));
616 	xfree(passphrase1);
617 	key_free(private);		 /* Destroys contents */
618 	xfree(comment);
619 
620 	printf("Your identification has been saved with the new passphrase.\n");
621 	exit(0);
622 }
623 
624 #ifdef DNS
625 /*
626  * Print the SSHFP RR.
627  */
628 static void
629 do_print_resource_record(struct passwd *pw, char *hostname)
630 {
631 	Key *public;
632 	char *comment = NULL;
633 	struct stat st;
634 
635 	if (!have_identity)
636 		ask_filename(pw, "Enter file in which the key is");
637 	if (stat(identity_file, &st) < 0) {
638 		perror(identity_file);
639 		exit(1);
640 	}
641 	public = key_load_public(identity_file, &comment);
642 	if (public != NULL) {
643 		export_dns_rr(hostname, public, stdout, print_generic);
644 		key_free(public);
645 		xfree(comment);
646 		exit(0);
647 	}
648 	if (comment)
649 		xfree(comment);
650 
651 	printf("failed to read v2 public key from %s.\n", identity_file);
652 	exit(1);
653 }
654 #endif /* DNS */
655 
656 /*
657  * Change the comment of a private key file.
658  */
659 static void
660 do_change_comment(struct passwd *pw)
661 {
662 	char new_comment[1024], *comment, *passphrase;
663 	Key *private;
664 	Key *public;
665 	struct stat st;
666 	FILE *f;
667 	int fd;
668 
669 	if (!have_identity)
670 		ask_filename(pw, "Enter file in which the key is");
671 	if (stat(identity_file, &st) < 0) {
672 		perror(identity_file);
673 		exit(1);
674 	}
675 	private = key_load_private(identity_file, "", &comment);
676 	if (private == NULL) {
677 		if (identity_passphrase)
678 			passphrase = xstrdup(identity_passphrase);
679 		else if (identity_new_passphrase)
680 			passphrase = xstrdup(identity_new_passphrase);
681 		else
682 			passphrase = read_passphrase("Enter passphrase: ",
683 			    RP_ALLOW_STDIN);
684 		/* Try to load using the passphrase. */
685 		private = key_load_private(identity_file, passphrase, &comment);
686 		if (private == NULL) {
687 			memset(passphrase, 0, strlen(passphrase));
688 			xfree(passphrase);
689 			printf("Bad passphrase.\n");
690 			exit(1);
691 		}
692 	} else {
693 		passphrase = xstrdup("");
694 	}
695 	if (private->type != KEY_RSA1) {
696 		fprintf(stderr, "Comments are only supported for RSA1 keys.\n");
697 		key_free(private);
698 		exit(1);
699 	}
700 	printf("Key now has comment '%s'\n", comment);
701 
702 	if (identity_comment) {
703 		strlcpy(new_comment, identity_comment, sizeof(new_comment));
704 	} else {
705 		printf("Enter new comment: ");
706 		fflush(stdout);
707 		if (!fgets(new_comment, sizeof(new_comment), stdin)) {
708 			memset(passphrase, 0, strlen(passphrase));
709 			key_free(private);
710 			exit(1);
711 		}
712 		if (strchr(new_comment, '\n'))
713 			*strchr(new_comment, '\n') = 0;
714 	}
715 
716 	/* Save the file using the new passphrase. */
717 	if (!key_save_private(private, identity_file, passphrase, new_comment)) {
718 		printf("Saving the key failed: %s.\n", identity_file);
719 		memset(passphrase, 0, strlen(passphrase));
720 		xfree(passphrase);
721 		key_free(private);
722 		xfree(comment);
723 		exit(1);
724 	}
725 	memset(passphrase, 0, strlen(passphrase));
726 	xfree(passphrase);
727 	public = key_from_private(private);
728 	key_free(private);
729 
730 	strlcat(identity_file, ".pub", sizeof(identity_file));
731 	fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
732 	if (fd == -1) {
733 		printf("Could not save your public key in %s\n", identity_file);
734 		exit(1);
735 	}
736 	f = fdopen(fd, "w");
737 	if (f == NULL) {
738 		printf("fdopen %s failed", identity_file);
739 		exit(1);
740 	}
741 	if (!key_write(public, f))
742 		fprintf(stderr, "write key failed");
743 	key_free(public);
744 	fprintf(f, " %s\n", new_comment);
745 	fclose(f);
746 
747 	xfree(comment);
748 
749 	printf("The comment in your key file has been changed.\n");
750 	exit(0);
751 }
752 
753 static void
754 usage(void)
755 {
756 	fprintf(stderr, "Usage: %s [options]\n", __progname);
757 	fprintf(stderr, "Options:\n");
758 	fprintf(stderr, "  -b bits     Number of bits in the key to create.\n");
759 	fprintf(stderr, "  -c          Change comment in private and public key files.\n");
760 	fprintf(stderr, "  -e          Convert OpenSSH to IETF SECSH key file.\n");
761 	fprintf(stderr, "  -f filename Filename of the key file.\n");
762 	fprintf(stderr, "  -g          Use generic DNS resource record format.\n");
763 	fprintf(stderr, "  -i          Convert IETF SECSH to OpenSSH key file.\n");
764 	fprintf(stderr, "  -l          Show fingerprint of key file.\n");
765 	fprintf(stderr, "  -p          Change passphrase of private key file.\n");
766 	fprintf(stderr, "  -q          Quiet.\n");
767 	fprintf(stderr, "  -y          Read private key file and print public key.\n");
768 	fprintf(stderr, "  -t type     Specify type of key to create.\n");
769 	fprintf(stderr, "  -B          Show bubblebabble digest of key file.\n");
770 	fprintf(stderr, "  -C comment  Provide new comment.\n");
771 	fprintf(stderr, "  -N phrase   Provide new passphrase.\n");
772 	fprintf(stderr, "  -P phrase   Provide old passphrase.\n");
773 #ifdef DNS
774 	fprintf(stderr, "  -r hostname Print DNS resource record.\n");
775 #endif /* DNS */
776 #ifdef SMARTCARD
777 	fprintf(stderr, "  -D reader   Download public key from smartcard.\n");
778 	fprintf(stderr, "  -U reader   Upload private key to smartcard.\n");
779 #endif /* SMARTCARD */
780 
781 	fprintf(stderr, "  -G file     Generate candidates for DH-GEX moduli\n");
782 	fprintf(stderr, "  -T file     Screen candidates for DH-GEX moduli\n");
783 
784 	exit(1);
785 }
786 
787 /*
788  * Main program for key management.
789  */
790 int
791 main(int ac, char **av)
792 {
793 	char dotsshdir[MAXPATHLEN], comment[1024], *passphrase1, *passphrase2;
794 	char out_file[PATH_MAX], *reader_id = NULL;
795 	char *resource_record_hostname = NULL;
796 	Key *private, *public;
797 	struct passwd *pw;
798 	struct stat st;
799 	int opt, type, fd, download = 0, memory = 0;
800 	int generator_wanted = 0, trials = 100;
801 	int do_gen_candidates = 0, do_screen_candidates = 0;
802 	BIGNUM *start = NULL;
803 	FILE *f;
804 
805 	extern int optind;
806 	extern char *optarg;
807 
808 	SSLeay_add_all_algorithms();
809 	log_init(av[0], SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_USER, 1);
810 
811 	/* we need this for the home * directory.  */
812 	pw = getpwuid(getuid());
813 	if (!pw) {
814 		printf("You don't exist, go away!\n");
815 		exit(1);
816 	}
817 	if (gethostname(hostname, sizeof(hostname)) < 0) {
818 		perror("gethostname");
819 		exit(1);
820 	}
821 
822 	while ((opt = getopt(ac, av,
823 	    "degiqpclBRxXyb:f:t:U:D:P:N:C:r:g:T:G:M:S:a:W:")) != -1) {
824 		switch (opt) {
825 		case 'b':
826 			bits = atoi(optarg);
827 			if (bits < 512 || bits > 32768) {
828 				printf("Bits has bad value.\n");
829 				exit(1);
830 			}
831 			break;
832 		case 'l':
833 			print_fingerprint = 1;
834 			break;
835 		case 'B':
836 			print_bubblebabble = 1;
837 			break;
838 		case 'p':
839 			change_passphrase = 1;
840 			break;
841 		case 'c':
842 			change_comment = 1;
843 			break;
844 		case 'f':
845 			strlcpy(identity_file, optarg, sizeof(identity_file));
846 			have_identity = 1;
847 			break;
848 		case 'g':
849 			print_generic = 1;
850 			break;
851 		case 'P':
852 			identity_passphrase = optarg;
853 			break;
854 		case 'N':
855 			identity_new_passphrase = optarg;
856 			break;
857 		case 'C':
858 			identity_comment = optarg;
859 			break;
860 		case 'q':
861 			quiet = 1;
862 			break;
863 		case 'R':
864 			/* unused */
865 			exit(0);
866 			break;
867 		case 'e':
868 		case 'x':
869 			/* export key */
870 			convert_to_ssh2 = 1;
871 			break;
872 		case 'i':
873 		case 'X':
874 			/* import key */
875 			convert_from_ssh2 = 1;
876 			break;
877 		case 'y':
878 			print_public = 1;
879 			break;
880 		case 'd':
881 			key_type_name = "dsa";
882 			break;
883 		case 't':
884 			key_type_name = optarg;
885 			break;
886 		case 'D':
887 			download = 1;
888 		case 'U':
889 			reader_id = optarg;
890 			break;
891 		case 'r':
892 			resource_record_hostname = optarg;
893 			break;
894 		case 'W':
895 			generator_wanted = atoi(optarg);
896 			if (generator_wanted < 1)
897 				fatal("Desired generator has bad value.");
898 			break;
899 		case 'a':
900 			trials = atoi(optarg);
901 			if (trials < TRIAL_MINIMUM) {
902 				fatal("Minimum primality trials is %d",
903 				    TRIAL_MINIMUM);
904 			}
905 			break;
906 		case 'M':
907 			memory = atoi(optarg);
908 			if (memory != 0 &&
909 			   (memory < LARGE_MINIMUM || memory > LARGE_MAXIMUM)) {
910 				fatal("Invalid memory amount (min %ld, max %ld)",
911 				    LARGE_MINIMUM, LARGE_MAXIMUM);
912 			}
913 			break;
914 		case 'G':
915 			do_gen_candidates = 1;
916 			strlcpy(out_file, optarg, sizeof(out_file));
917 			break;
918 		case 'T':
919 			do_screen_candidates = 1;
920 			strlcpy(out_file, optarg, sizeof(out_file));
921 			break;
922 		case 'S':
923 			/* XXX - also compare length against bits */
924 			if (BN_hex2bn(&start, optarg) == 0)
925 				fatal("Invalid start point.");
926 			break;
927 		case '?':
928 		default:
929 			usage();
930 		}
931 	}
932 	if (optind < ac) {
933 		printf("Too many arguments.\n");
934 		usage();
935 	}
936 	if (change_passphrase && change_comment) {
937 		printf("Can only have one of -p and -c.\n");
938 		usage();
939 	}
940 	if (print_fingerprint || print_bubblebabble)
941 		do_fingerprint(pw);
942 	if (change_passphrase)
943 		do_change_passphrase(pw);
944 	if (change_comment)
945 		do_change_comment(pw);
946 	if (convert_to_ssh2)
947 		do_convert_to_ssh2(pw);
948 	if (convert_from_ssh2)
949 		do_convert_from_ssh2(pw);
950 	if (print_public)
951 		do_print_public(pw);
952 	if (resource_record_hostname != NULL) {
953 #ifdef DNS
954 		do_print_resource_record(pw, resource_record_hostname);
955 #else /* DNS */
956 		fatal("no DNS support.");
957 #endif /* DNS */
958 	}
959 	if (reader_id != NULL) {
960 #ifdef SMARTCARD
961 		if (download)
962 			do_download(pw, reader_id);
963 		else
964 			do_upload(pw, reader_id);
965 #else /* SMARTCARD */
966 		fatal("no support for smartcards.");
967 #endif /* SMARTCARD */
968 	}
969 
970 	if (do_gen_candidates) {
971 		FILE *out = fopen(out_file, "w");
972 
973 		if (out == NULL) {
974 			error("Couldn't open modulus candidate file \"%s\": %s",
975 			    out_file, strerror(errno));
976 			return (1);
977 		}
978 		if (gen_candidates(out, memory, bits, start) != 0)
979 			fatal("modulus candidate generation failed\n");
980 
981 		return (0);
982 	}
983 
984 	if (do_screen_candidates) {
985 		FILE *in;
986 		FILE *out = fopen(out_file, "w");
987 
988 		if (have_identity && strcmp(identity_file, "-") != 0) {
989 			if ((in = fopen(identity_file, "r")) == NULL) {
990 				fatal("Couldn't open modulus candidate "
991 				    "file \"%s\": %s", identity_file,
992 				    strerror(errno));
993 			}
994 		} else
995 			in = stdin;
996 
997 		if (out == NULL) {
998 			fatal("Couldn't open moduli file \"%s\": %s",
999 			    out_file, strerror(errno));
1000 		}
1001 		if (prime_test(in, out, trials, generator_wanted) != 0)
1002 			fatal("modulus screening failed\n");
1003 	}
1004 
1005 	arc4random_stir();
1006 
1007 	if (key_type_name == NULL) {
1008 		printf("You must specify a key type (-t).\n");
1009 		usage();
1010 	}
1011 	type = key_type_from_name(key_type_name);
1012 	if (type == KEY_UNSPEC) {
1013 		fprintf(stderr, "unknown key type %s\n", key_type_name);
1014 		exit(1);
1015 	}
1016 	if (!quiet)
1017 		printf("Generating public/private %s key pair.\n", key_type_name);
1018 	private = key_generate(type, bits);
1019 	if (private == NULL) {
1020 		fprintf(stderr, "key_generate failed");
1021 		exit(1);
1022 	}
1023 	public  = key_from_private(private);
1024 
1025 	if (!have_identity)
1026 		ask_filename(pw, "Enter file in which to save the key");
1027 
1028 	/* Create ~/.ssh directory if it doesn\'t already exist. */
1029 	snprintf(dotsshdir, sizeof dotsshdir, "%s/%s", pw->pw_dir, _PATH_SSH_USER_DIR);
1030 	if (strstr(identity_file, dotsshdir) != NULL &&
1031 	    stat(dotsshdir, &st) < 0) {
1032 		if (mkdir(dotsshdir, 0700) < 0)
1033 			error("Could not create directory '%s'.", dotsshdir);
1034 		else if (!quiet)
1035 			printf("Created directory '%s'.\n", dotsshdir);
1036 	}
1037 	/* If the file already exists, ask the user to confirm. */
1038 	if (stat(identity_file, &st) >= 0) {
1039 		char yesno[3];
1040 		printf("%s already exists.\n", identity_file);
1041 		printf("Overwrite (y/n)? ");
1042 		fflush(stdout);
1043 		if (fgets(yesno, sizeof(yesno), stdin) == NULL)
1044 			exit(1);
1045 		if (yesno[0] != 'y' && yesno[0] != 'Y')
1046 			exit(1);
1047 	}
1048 	/* Ask for a passphrase (twice). */
1049 	if (identity_passphrase)
1050 		passphrase1 = xstrdup(identity_passphrase);
1051 	else if (identity_new_passphrase)
1052 		passphrase1 = xstrdup(identity_new_passphrase);
1053 	else {
1054 passphrase_again:
1055 		passphrase1 =
1056 			read_passphrase("Enter passphrase (empty for no "
1057 			    "passphrase): ", RP_ALLOW_STDIN);
1058 		passphrase2 = read_passphrase("Enter same passphrase again: ",
1059 		    RP_ALLOW_STDIN);
1060 		if (strcmp(passphrase1, passphrase2) != 0) {
1061 			/*
1062 			 * The passphrases do not match.  Clear them and
1063 			 * retry.
1064 			 */
1065 			memset(passphrase1, 0, strlen(passphrase1));
1066 			memset(passphrase2, 0, strlen(passphrase2));
1067 			xfree(passphrase1);
1068 			xfree(passphrase2);
1069 			printf("Passphrases do not match.  Try again.\n");
1070 			goto passphrase_again;
1071 		}
1072 		/* Clear the other copy of the passphrase. */
1073 		memset(passphrase2, 0, strlen(passphrase2));
1074 		xfree(passphrase2);
1075 	}
1076 
1077 	if (identity_comment) {
1078 		strlcpy(comment, identity_comment, sizeof(comment));
1079 	} else {
1080 		/* Create default commend field for the passphrase. */
1081 		snprintf(comment, sizeof comment, "%s@%s", pw->pw_name, hostname);
1082 	}
1083 
1084 	/* Save the key with the given passphrase and comment. */
1085 	if (!key_save_private(private, identity_file, passphrase1, comment)) {
1086 		printf("Saving the key failed: %s.\n", identity_file);
1087 		memset(passphrase1, 0, strlen(passphrase1));
1088 		xfree(passphrase1);
1089 		exit(1);
1090 	}
1091 	/* Clear the passphrase. */
1092 	memset(passphrase1, 0, strlen(passphrase1));
1093 	xfree(passphrase1);
1094 
1095 	/* Clear the private key and the random number generator. */
1096 	key_free(private);
1097 	arc4random_stir();
1098 
1099 	if (!quiet)
1100 		printf("Your identification has been saved in %s.\n", identity_file);
1101 
1102 	strlcat(identity_file, ".pub", sizeof(identity_file));
1103 	fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
1104 	if (fd == -1) {
1105 		printf("Could not save your public key in %s\n", identity_file);
1106 		exit(1);
1107 	}
1108 	f = fdopen(fd, "w");
1109 	if (f == NULL) {
1110 		printf("fdopen %s failed", identity_file);
1111 		exit(1);
1112 	}
1113 	if (!key_write(public, f))
1114 		fprintf(stderr, "write key failed");
1115 	fprintf(f, " %s\n", comment);
1116 	fclose(f);
1117 
1118 	if (!quiet) {
1119 		char *fp = key_fingerprint(public, SSH_FP_MD5, SSH_FP_HEX);
1120 		printf("Your public key has been saved in %s.\n",
1121 		    identity_file);
1122 		printf("The key fingerprint is:\n");
1123 		printf("%s %s\n", fp, comment);
1124 		xfree(fp);
1125 	}
1126 
1127 	key_free(public);
1128 	exit(0);
1129 }
1130