xref: /freebsd/crypto/openssh/ssh-keygen.c (revision ee2ea5ceafed78a5bd9810beb9e3ca927180c226)
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 1.94 2002/02/25 16:33:27 markus 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 <sectok.h>
33 #include <openssl/engine.h>
34 #include "scard.h"
35 #endif
36 
37 /* Number of bits in the RSA/DSA key.  This value can be changed on the command line. */
38 int bits = 1024;
39 
40 /*
41  * Flag indicating that we just want to change the passphrase.  This can be
42  * set on the command line.
43  */
44 int change_passphrase = 0;
45 
46 /*
47  * Flag indicating that we just want to change the comment.  This can be set
48  * on the command line.
49  */
50 int change_comment = 0;
51 
52 int quiet = 0;
53 
54 /* Flag indicating that we just want to see the key fingerprint */
55 int print_fingerprint = 0;
56 int print_bubblebabble = 0;
57 
58 /* The identity file name, given on the command line or entered by the user. */
59 char identity_file[1024];
60 int have_identity = 0;
61 
62 /* This is set to the passphrase if given on the command line. */
63 char *identity_passphrase = NULL;
64 
65 /* This is set to the new passphrase if given on the command line. */
66 char *identity_new_passphrase = NULL;
67 
68 /* This is set to the new comment if given on the command line. */
69 char *identity_comment = NULL;
70 
71 /* Dump public key file in format used by real and the original SSH 2 */
72 int convert_to_ssh2 = 0;
73 int convert_from_ssh2 = 0;
74 int print_public = 0;
75 
76 char *key_type_name = NULL;
77 
78 /* argv0 */
79 extern char *__progname;
80 
81 char hostname[MAXHOSTNAMELEN];
82 
83 static void
84 ask_filename(struct passwd *pw, const char *prompt)
85 {
86 	char buf[1024];
87 	char *name = NULL;
88 
89 	if (key_type_name == NULL)
90 		name = _PATH_SSH_CLIENT_ID_RSA;
91 	else
92 		switch (key_type_from_name(key_type_name)) {
93 		case KEY_RSA1:
94 			name = _PATH_SSH_CLIENT_IDENTITY;
95 			break;
96 		case KEY_DSA:
97 			name = _PATH_SSH_CLIENT_ID_DSA;
98 			break;
99 		case KEY_RSA:
100 			name = _PATH_SSH_CLIENT_ID_RSA;
101 			break;
102 		default:
103 			fprintf(stderr, "bad key type");
104 			exit(1);
105 			break;
106 		}
107 
108 	snprintf(identity_file, sizeof(identity_file), "%s/%s", pw->pw_dir, name);
109 	fprintf(stderr, "%s (%s): ", prompt, identity_file);
110 	fflush(stderr);
111 	if (fgets(buf, sizeof(buf), stdin) == NULL)
112 		exit(1);
113 	if (strchr(buf, '\n'))
114 		*strchr(buf, '\n') = 0;
115 	if (strcmp(buf, "") != 0)
116 		strlcpy(identity_file, buf, sizeof(identity_file));
117 	have_identity = 1;
118 }
119 
120 static Key *
121 load_identity(char *filename)
122 {
123 	char *pass;
124 	Key *prv;
125 
126 	prv = key_load_private(filename, "", NULL);
127 	if (prv == NULL) {
128 		if (identity_passphrase)
129 			pass = xstrdup(identity_passphrase);
130 		else
131 			pass = read_passphrase("Enter passphrase: ",
132 			    RP_ALLOW_STDIN);
133 		prv = key_load_private(filename, pass, NULL);
134 		memset(pass, 0, strlen(pass));
135 		xfree(pass);
136 	}
137 	return prv;
138 }
139 
140 #define SSH_COM_PUBLIC_BEGIN		"---- BEGIN SSH2 PUBLIC KEY ----"
141 #define SSH_COM_PUBLIC_END  		"---- END SSH2 PUBLIC KEY ----"
142 #define SSH_COM_PRIVATE_BEGIN		"---- BEGIN SSH2 ENCRYPTED PRIVATE KEY ----"
143 #define	SSH_COM_PRIVATE_KEY_MAGIC	0x3f6ff9eb
144 
145 static void
146 do_convert_to_ssh2(struct passwd *pw)
147 {
148 	Key *k;
149 	u_int len;
150 	u_char *blob;
151 	struct stat st;
152 
153 	if (!have_identity)
154 		ask_filename(pw, "Enter file in which the key is");
155 	if (stat(identity_file, &st) < 0) {
156 		perror(identity_file);
157 		exit(1);
158 	}
159 	if ((k = key_load_public(identity_file, NULL)) == NULL) {
160 		if ((k = load_identity(identity_file)) == NULL) {
161 			fprintf(stderr, "load failed\n");
162 			exit(1);
163 		}
164 	}
165 	if (key_to_blob(k, &blob, &len) <= 0) {
166 		fprintf(stderr, "key_to_blob failed\n");
167 		exit(1);
168 	}
169 	fprintf(stdout, "%s\n", SSH_COM_PUBLIC_BEGIN);
170 	fprintf(stdout,
171 	    "Comment: \"%d-bit %s, converted from OpenSSH by %s@%s\"\n",
172 	    key_size(k), key_type(k),
173 	    pw->pw_name, hostname);
174 	dump_base64(stdout, blob, len);
175 	fprintf(stdout, "%s\n", SSH_COM_PUBLIC_END);
176 	key_free(k);
177 	xfree(blob);
178 	exit(0);
179 }
180 
181 static void
182 buffer_get_bignum_bits(Buffer *b, BIGNUM *value)
183 {
184 	int bits = buffer_get_int(b);
185 	int bytes = (bits + 7) / 8;
186 
187 	if (buffer_len(b) < bytes)
188 		fatal("buffer_get_bignum_bits: input buffer too small: "
189 		    "need %d have %d", bytes, buffer_len(b));
190 	BN_bin2bn(buffer_ptr(b), bytes, value);
191 	buffer_consume(b, bytes);
192 }
193 
194 static Key *
195 do_convert_private_ssh2_from_blob(u_char *blob, u_int blen)
196 {
197 	Buffer b;
198 	Key *key = NULL;
199 	char *type, *cipher;
200 	u_char *sig, data[] = "abcde12345";
201 	int magic, rlen, ktype, i1, i2, i3, i4;
202 	u_int slen;
203 	u_long e;
204 
205 	buffer_init(&b);
206 	buffer_append(&b, blob, blen);
207 
208 	magic  = buffer_get_int(&b);
209 	if (magic != SSH_COM_PRIVATE_KEY_MAGIC) {
210 		error("bad magic 0x%x != 0x%x", magic, SSH_COM_PRIVATE_KEY_MAGIC);
211 		buffer_free(&b);
212 		return NULL;
213 	}
214 	i1 = buffer_get_int(&b);
215 	type   = buffer_get_string(&b, NULL);
216 	cipher = buffer_get_string(&b, NULL);
217 	i2 = buffer_get_int(&b);
218 	i3 = buffer_get_int(&b);
219 	i4 = buffer_get_int(&b);
220 	debug("ignore (%d %d %d %d)", i1,i2,i3,i4);
221 	if (strcmp(cipher, "none") != 0) {
222 		error("unsupported cipher %s", cipher);
223 		xfree(cipher);
224 		buffer_free(&b);
225 		xfree(type);
226 		return NULL;
227 	}
228 	xfree(cipher);
229 
230 	if (strstr(type, "dsa")) {
231 		ktype = KEY_DSA;
232 	} else if (strstr(type, "rsa")) {
233 		ktype = KEY_RSA;
234 	} else {
235 		xfree(type);
236 		return NULL;
237 	}
238 	key = key_new_private(ktype);
239 	xfree(type);
240 
241 	switch (key->type) {
242 	case KEY_DSA:
243 		buffer_get_bignum_bits(&b, key->dsa->p);
244 		buffer_get_bignum_bits(&b, key->dsa->g);
245 		buffer_get_bignum_bits(&b, key->dsa->q);
246 		buffer_get_bignum_bits(&b, key->dsa->pub_key);
247 		buffer_get_bignum_bits(&b, key->dsa->priv_key);
248 		break;
249 	case KEY_RSA:
250 		e  = buffer_get_char(&b);
251 		debug("e %lx", e);
252 		if (e < 30) {
253 			e <<= 8;
254 			e += buffer_get_char(&b);
255 			debug("e %lx", e);
256 			e <<= 8;
257 			e += buffer_get_char(&b);
258 			debug("e %lx", e);
259 		}
260 		if (!BN_set_word(key->rsa->e, e)) {
261 			buffer_free(&b);
262 			key_free(key);
263 			return NULL;
264 		}
265 		buffer_get_bignum_bits(&b, key->rsa->d);
266 		buffer_get_bignum_bits(&b, key->rsa->n);
267 		buffer_get_bignum_bits(&b, key->rsa->iqmp);
268 		buffer_get_bignum_bits(&b, key->rsa->q);
269 		buffer_get_bignum_bits(&b, key->rsa->p);
270 		rsa_generate_additional_parameters(key->rsa);
271 		break;
272 	}
273 	rlen = buffer_len(&b);
274 	if (rlen != 0)
275 		error("do_convert_private_ssh2_from_blob: "
276 		    "remaining bytes in key blob %d", rlen);
277 	buffer_free(&b);
278 
279 	/* try the key */
280 	key_sign(key, &sig, &slen, data, sizeof(data));
281 	key_verify(key, sig, slen, data, sizeof(data));
282 	xfree(sig);
283 	return key;
284 }
285 
286 static void
287 do_convert_from_ssh2(struct passwd *pw)
288 {
289 	Key *k;
290 	int blen;
291 	char line[1024], *p;
292 	u_char blob[8096];
293 	char encoded[8096];
294 	struct stat st;
295 	int escaped = 0, private = 0, ok;
296 	FILE *fp;
297 
298 	if (!have_identity)
299 		ask_filename(pw, "Enter file in which the key is");
300 	if (stat(identity_file, &st) < 0) {
301 		perror(identity_file);
302 		exit(1);
303 	}
304 	fp = fopen(identity_file, "r");
305 	if (fp == NULL) {
306 		perror(identity_file);
307 		exit(1);
308 	}
309 	encoded[0] = '\0';
310 	while (fgets(line, sizeof(line), fp)) {
311 		if (!(p = strchr(line, '\n'))) {
312 			fprintf(stderr, "input line too long.\n");
313 			exit(1);
314 		}
315 		if (p > line && p[-1] == '\\')
316 			escaped++;
317 		if (strncmp(line, "----", 4) == 0 ||
318 		    strstr(line, ": ") != NULL) {
319 			if (strstr(line, SSH_COM_PRIVATE_BEGIN) != NULL)
320 				private = 1;
321 			if (strstr(line, " END ") != NULL) {
322 				break;
323 			}
324 			/* fprintf(stderr, "ignore: %s", line); */
325 			continue;
326 		}
327 		if (escaped) {
328 			escaped--;
329 			/* fprintf(stderr, "escaped: %s", line); */
330 			continue;
331 		}
332 		*p = '\0';
333 		strlcat(encoded, line, sizeof(encoded));
334 	}
335 	blen = uudecode(encoded, blob, sizeof(blob));
336 	if (blen < 0) {
337 		fprintf(stderr, "uudecode failed.\n");
338 		exit(1);
339 	}
340 	k = private ?
341 	    do_convert_private_ssh2_from_blob(blob, blen) :
342 	    key_from_blob(blob, blen);
343 	if (k == NULL) {
344 		fprintf(stderr, "decode blob failed.\n");
345 		exit(1);
346 	}
347 	ok = private ?
348 	    (k->type == KEY_DSA ?
349 		 PEM_write_DSAPrivateKey(stdout, k->dsa, NULL, NULL, 0, NULL, NULL) :
350 		 PEM_write_RSAPrivateKey(stdout, k->rsa, NULL, NULL, 0, NULL, NULL)) :
351 	    key_write(k, stdout);
352 	if (!ok) {
353 		fprintf(stderr, "key write failed");
354 		exit(1);
355 	}
356 	key_free(k);
357 	if (!private)
358 		fprintf(stdout, "\n");
359 	fclose(fp);
360 	exit(0);
361 }
362 
363 static void
364 do_print_public(struct passwd *pw)
365 {
366 	Key *prv;
367 	struct stat st;
368 
369 	if (!have_identity)
370 		ask_filename(pw, "Enter file in which the key is");
371 	if (stat(identity_file, &st) < 0) {
372 		perror(identity_file);
373 		exit(1);
374 	}
375 	prv = load_identity(identity_file);
376 	if (prv == NULL) {
377 		fprintf(stderr, "load failed\n");
378 		exit(1);
379 	}
380 	if (!key_write(prv, stdout))
381 		fprintf(stderr, "key_write failed");
382 	key_free(prv);
383 	fprintf(stdout, "\n");
384 	exit(0);
385 }
386 
387 #ifdef SMARTCARD
388 #define NUM_RSA_KEY_ELEMENTS 5+1
389 #define COPY_RSA_KEY(x, i) \
390 	do { \
391 		len = BN_num_bytes(prv->rsa->x); \
392 		elements[i] = xmalloc(len); \
393 		debug("#bytes %d", len); \
394 		if (BN_bn2bin(prv->rsa->x, elements[i]) < 0) \
395 			goto done; \
396 	} while (0)
397 
398 static int
399 get_AUT0(char *aut0)
400 {
401 	EVP_MD *evp_md = EVP_sha1();
402 	EVP_MD_CTX md;
403 	char *pass;
404 
405 	pass = read_passphrase("Enter passphrase for smartcard: ", RP_ALLOW_STDIN);
406 	if (pass == NULL)
407 		return -1;
408 	EVP_DigestInit(&md, evp_md);
409 	EVP_DigestUpdate(&md, pass, strlen(pass));
410 	EVP_DigestFinal(&md, aut0, NULL);
411 	memset(pass, 0, strlen(pass));
412 	xfree(pass);
413 	return 0;
414 }
415 
416 static void
417 do_upload(struct passwd *pw, const char *sc_reader_id)
418 {
419 	Key *prv = NULL;
420 	struct stat st;
421 	u_char *elements[NUM_RSA_KEY_ELEMENTS];
422 	u_char key_fid[2];
423 	u_char DEFAUT0[] = {0xad, 0x9f, 0x61, 0xfe, 0xfa, 0x20, 0xce, 0x63};
424 	u_char AUT0[EVP_MAX_MD_SIZE];
425 	int len, status = 1, i, fd = -1, ret;
426 	int sw = 0, cla = 0x00;
427 
428 	for (i = 0; i < NUM_RSA_KEY_ELEMENTS; i++)
429 		elements[i] = NULL;
430 	if (!have_identity)
431 		ask_filename(pw, "Enter file in which the key is");
432 	if (stat(identity_file, &st) < 0) {
433 		perror(identity_file);
434 		goto done;
435 	}
436 	prv = load_identity(identity_file);
437 	if (prv == NULL) {
438 		error("load failed");
439 		goto done;
440 	}
441 	COPY_RSA_KEY(q, 0);
442 	COPY_RSA_KEY(p, 1);
443 	COPY_RSA_KEY(iqmp, 2);
444 	COPY_RSA_KEY(dmq1, 3);
445 	COPY_RSA_KEY(dmp1, 4);
446 	COPY_RSA_KEY(n, 5);
447 	len = BN_num_bytes(prv->rsa->n);
448 	fd = sectok_friendly_open(sc_reader_id, STONOWAIT, &sw);
449 	if (fd < 0) {
450 		error("sectok_open failed: %s", sectok_get_sw(sw));
451 		goto done;
452 	}
453 	if (! sectok_cardpresent(fd)) {
454 		error("smartcard in reader %s not present",
455 		    sc_reader_id);
456 		goto done;
457 	}
458 	ret = sectok_reset(fd, 0, NULL, &sw);
459 	if (ret <= 0) {
460 		error("sectok_reset failed: %s", sectok_get_sw(sw));
461 		goto done;
462 	}
463 	if ((cla = cyberflex_inq_class(fd)) < 0) {
464 		error("cyberflex_inq_class failed");
465 		goto done;
466 	}
467 	memcpy(AUT0, DEFAUT0, sizeof(DEFAUT0));
468 	if (cyberflex_verify_AUT0(fd, cla, AUT0, sizeof(DEFAUT0)) < 0) {
469 		if (get_AUT0(AUT0) < 0 ||
470 		    cyberflex_verify_AUT0(fd, cla, AUT0, sizeof(DEFAUT0)) < 0) {
471 			error("cyberflex_verify_AUT0 failed");
472 			goto done;
473 		}
474 	}
475 	key_fid[0] = 0x00;
476 	key_fid[1] = 0x12;
477 	if (cyberflex_load_rsa_priv(fd, cla, key_fid, 5, 8*len, elements,
478 	    &sw) < 0) {
479 		error("cyberflex_load_rsa_priv failed: %s", sectok_get_sw(sw));
480 		goto done;
481 	}
482 	if (!sectok_swOK(sw))
483 		goto done;
484 	log("cyberflex_load_rsa_priv done");
485 	key_fid[0] = 0x73;
486 	key_fid[1] = 0x68;
487 	if (cyberflex_load_rsa_pub(fd, cla, key_fid, len, elements[5],
488 	    &sw) < 0) {
489 		error("cyberflex_load_rsa_pub failed: %s", sectok_get_sw(sw));
490 		goto done;
491 	}
492 	if (!sectok_swOK(sw))
493 		goto done;
494 	log("cyberflex_load_rsa_pub done");
495 	status = 0;
496 	log("loading key done");
497 done:
498 
499 	memset(elements[0], '\0', BN_num_bytes(prv->rsa->q));
500 	memset(elements[1], '\0', BN_num_bytes(prv->rsa->p));
501 	memset(elements[2], '\0', BN_num_bytes(prv->rsa->iqmp));
502 	memset(elements[3], '\0', BN_num_bytes(prv->rsa->dmq1));
503 	memset(elements[4], '\0', BN_num_bytes(prv->rsa->dmp1));
504 	memset(elements[5], '\0', BN_num_bytes(prv->rsa->n));
505 
506 	if (prv)
507 		key_free(prv);
508 	for (i = 0; i < NUM_RSA_KEY_ELEMENTS; i++)
509 		if (elements[i])
510 			xfree(elements[i]);
511 	if (fd != -1)
512 		sectok_close(fd);
513 	exit(status);
514 }
515 
516 static void
517 do_download(struct passwd *pw, const char *sc_reader_id)
518 {
519 	Key *pub = NULL;
520 
521 	pub = sc_get_key(sc_reader_id);
522 	if (pub == NULL)
523 		fatal("cannot read public key from smartcard");
524 	key_write(pub, stdout);
525 	key_free(pub);
526 	fprintf(stdout, "\n");
527 	exit(0);
528 }
529 #endif /* SMARTCARD */
530 
531 static void
532 do_fingerprint(struct passwd *pw)
533 {
534 	FILE *f;
535 	Key *public;
536 	char *comment = NULL, *cp, *ep, line[16*1024], *fp;
537 	int i, skip = 0, num = 1, invalid = 1;
538 	enum fp_rep rep;
539 	enum fp_type fptype;
540 	struct stat st;
541 
542 	fptype = print_bubblebabble ? SSH_FP_SHA1 : SSH_FP_MD5;
543 	rep =    print_bubblebabble ? SSH_FP_BUBBLEBABBLE : SSH_FP_HEX;
544 
545 	if (!have_identity)
546 		ask_filename(pw, "Enter file in which the key is");
547 	if (stat(identity_file, &st) < 0) {
548 		perror(identity_file);
549 		exit(1);
550 	}
551 	public = key_load_public(identity_file, &comment);
552 	if (public != NULL) {
553 		fp = key_fingerprint(public, fptype, rep);
554 		printf("%d %s %s\n", key_size(public), fp, comment);
555 		key_free(public);
556 		xfree(comment);
557 		xfree(fp);
558 		exit(0);
559 	}
560 	if (comment)
561 		xfree(comment);
562 
563 	f = fopen(identity_file, "r");
564 	if (f != NULL) {
565 		while (fgets(line, sizeof(line), f)) {
566 			i = strlen(line) - 1;
567 			if (line[i] != '\n') {
568 				error("line %d too long: %.40s...", num, line);
569 				skip = 1;
570 				continue;
571 			}
572 			num++;
573 			if (skip) {
574 				skip = 0;
575 				continue;
576 			}
577 			line[i] = '\0';
578 
579 			/* Skip leading whitespace, empty and comment lines. */
580 			for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
581 				;
582 			if (!*cp || *cp == '\n' || *cp == '#')
583 				continue ;
584 			i = strtol(cp, &ep, 10);
585 			if (i == 0 || ep == NULL || (*ep != ' ' && *ep != '\t')) {
586 				int quoted = 0;
587 				comment = cp;
588 				for (; *cp && (quoted || (*cp != ' ' && *cp != '\t')); cp++) {
589 					if (*cp == '\\' && cp[1] == '"')
590 						cp++;	/* Skip both */
591 					else if (*cp == '"')
592 						quoted = !quoted;
593 				}
594 				if (!*cp)
595 					continue;
596 				*cp++ = '\0';
597 			}
598 			ep = cp;
599 			public = key_new(KEY_RSA1);
600 			if (key_read(public, &cp) != 1) {
601 				cp = ep;
602 				key_free(public);
603 				public = key_new(KEY_UNSPEC);
604 				if (key_read(public, &cp) != 1) {
605 					key_free(public);
606 					continue;
607 				}
608 			}
609 			comment = *cp ? cp : comment;
610 			fp = key_fingerprint(public, fptype, rep);
611 			printf("%d %s %s\n", key_size(public), fp,
612 			    comment ? comment : "no comment");
613 			xfree(fp);
614 			key_free(public);
615 			invalid = 0;
616 		}
617 		fclose(f);
618 	}
619 	if (invalid) {
620 		printf("%s is not a public key file.\n", identity_file);
621 		exit(1);
622 	}
623 	exit(0);
624 }
625 
626 /*
627  * Perform changing a passphrase.  The argument is the passwd structure
628  * for the current user.
629  */
630 static void
631 do_change_passphrase(struct passwd *pw)
632 {
633 	char *comment;
634 	char *old_passphrase, *passphrase1, *passphrase2;
635 	struct stat st;
636 	Key *private;
637 
638 	if (!have_identity)
639 		ask_filename(pw, "Enter file in which the key is");
640 	if (stat(identity_file, &st) < 0) {
641 		perror(identity_file);
642 		exit(1);
643 	}
644 	/* Try to load the file with empty passphrase. */
645 	private = key_load_private(identity_file, "", &comment);
646 	if (private == NULL) {
647 		if (identity_passphrase)
648 			old_passphrase = xstrdup(identity_passphrase);
649 		else
650 			old_passphrase =
651 			    read_passphrase("Enter old passphrase: ",
652 			    RP_ALLOW_STDIN);
653 		private = key_load_private(identity_file, old_passphrase,
654 		    &comment);
655 		memset(old_passphrase, 0, strlen(old_passphrase));
656 		xfree(old_passphrase);
657 		if (private == NULL) {
658 			printf("Bad passphrase.\n");
659 			exit(1);
660 		}
661 	}
662 	printf("Key has comment '%s'\n", comment);
663 
664 	/* Ask the new passphrase (twice). */
665 	if (identity_new_passphrase) {
666 		passphrase1 = xstrdup(identity_new_passphrase);
667 		passphrase2 = NULL;
668 	} else {
669 		passphrase1 =
670 			read_passphrase("Enter new passphrase (empty for no "
671 			    "passphrase): ", RP_ALLOW_STDIN);
672 		passphrase2 = read_passphrase("Enter same passphrase again: ",
673 		    RP_ALLOW_STDIN);
674 
675 		/* Verify that they are the same. */
676 		if (strcmp(passphrase1, passphrase2) != 0) {
677 			memset(passphrase1, 0, strlen(passphrase1));
678 			memset(passphrase2, 0, strlen(passphrase2));
679 			xfree(passphrase1);
680 			xfree(passphrase2);
681 			printf("Pass phrases do not match.  Try again.\n");
682 			exit(1);
683 		}
684 		/* Destroy the other copy. */
685 		memset(passphrase2, 0, strlen(passphrase2));
686 		xfree(passphrase2);
687 	}
688 
689 	/* Save the file using the new passphrase. */
690 	if (!key_save_private(private, identity_file, passphrase1, comment)) {
691 		printf("Saving the key failed: %s.\n", identity_file);
692 		memset(passphrase1, 0, strlen(passphrase1));
693 		xfree(passphrase1);
694 		key_free(private);
695 		xfree(comment);
696 		exit(1);
697 	}
698 	/* Destroy the passphrase and the copy of the key in memory. */
699 	memset(passphrase1, 0, strlen(passphrase1));
700 	xfree(passphrase1);
701 	key_free(private);		 /* Destroys contents */
702 	xfree(comment);
703 
704 	printf("Your identification has been saved with the new passphrase.\n");
705 	exit(0);
706 }
707 
708 /*
709  * Change the comment of a private key file.
710  */
711 static void
712 do_change_comment(struct passwd *pw)
713 {
714 	char new_comment[1024], *comment, *passphrase;
715 	Key *private;
716 	Key *public;
717 	struct stat st;
718 	FILE *f;
719 	int fd;
720 
721 	if (!have_identity)
722 		ask_filename(pw, "Enter file in which the key is");
723 	if (stat(identity_file, &st) < 0) {
724 		perror(identity_file);
725 		exit(1);
726 	}
727 	private = key_load_private(identity_file, "", &comment);
728 	if (private == NULL) {
729 		if (identity_passphrase)
730 			passphrase = xstrdup(identity_passphrase);
731 		else if (identity_new_passphrase)
732 			passphrase = xstrdup(identity_new_passphrase);
733 		else
734 			passphrase = read_passphrase("Enter passphrase: ",
735 			    RP_ALLOW_STDIN);
736 		/* Try to load using the passphrase. */
737 		private = key_load_private(identity_file, passphrase, &comment);
738 		if (private == NULL) {
739 			memset(passphrase, 0, strlen(passphrase));
740 			xfree(passphrase);
741 			printf("Bad passphrase.\n");
742 			exit(1);
743 		}
744 	} else {
745 		passphrase = xstrdup("");
746 	}
747 	if (private->type != KEY_RSA1) {
748 		fprintf(stderr, "Comments are only supported for RSA1 keys.\n");
749 		key_free(private);
750 		exit(1);
751 	}
752 	printf("Key now has comment '%s'\n", comment);
753 
754 	if (identity_comment) {
755 		strlcpy(new_comment, identity_comment, sizeof(new_comment));
756 	} else {
757 		printf("Enter new comment: ");
758 		fflush(stdout);
759 		if (!fgets(new_comment, sizeof(new_comment), stdin)) {
760 			memset(passphrase, 0, strlen(passphrase));
761 			key_free(private);
762 			exit(1);
763 		}
764 		if (strchr(new_comment, '\n'))
765 			*strchr(new_comment, '\n') = 0;
766 	}
767 
768 	/* Save the file using the new passphrase. */
769 	if (!key_save_private(private, identity_file, passphrase, new_comment)) {
770 		printf("Saving the key failed: %s.\n", identity_file);
771 		memset(passphrase, 0, strlen(passphrase));
772 		xfree(passphrase);
773 		key_free(private);
774 		xfree(comment);
775 		exit(1);
776 	}
777 	memset(passphrase, 0, strlen(passphrase));
778 	xfree(passphrase);
779 	public = key_from_private(private);
780 	key_free(private);
781 
782 	strlcat(identity_file, ".pub", sizeof(identity_file));
783 	fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
784 	if (fd == -1) {
785 		printf("Could not save your public key in %s\n", identity_file);
786 		exit(1);
787 	}
788 	f = fdopen(fd, "w");
789 	if (f == NULL) {
790 		printf("fdopen %s failed", identity_file);
791 		exit(1);
792 	}
793 	if (!key_write(public, f))
794 		fprintf(stderr, "write key failed");
795 	key_free(public);
796 	fprintf(f, " %s\n", new_comment);
797 	fclose(f);
798 
799 	xfree(comment);
800 
801 	printf("The comment in your key file has been changed.\n");
802 	exit(0);
803 }
804 
805 static void
806 usage(void)
807 {
808 	fprintf(stderr, "Usage: %s [options]\n", __progname);
809 	fprintf(stderr, "Options:\n");
810 	fprintf(stderr, "  -b bits     Number of bits in the key to create.\n");
811 	fprintf(stderr, "  -c          Change comment in private and public key files.\n");
812 	fprintf(stderr, "  -e          Convert OpenSSH to IETF SECSH key file.\n");
813 	fprintf(stderr, "  -f filename Filename of the key file.\n");
814 	fprintf(stderr, "  -i          Convert IETF SECSH to OpenSSH key file.\n");
815 	fprintf(stderr, "  -l          Show fingerprint of key file.\n");
816 	fprintf(stderr, "  -p          Change passphrase of private key file.\n");
817 	fprintf(stderr, "  -q          Quiet.\n");
818 	fprintf(stderr, "  -y          Read private key file and print public key.\n");
819 	fprintf(stderr, "  -t type     Specify type of key to create.\n");
820 	fprintf(stderr, "  -B          Show bubblebabble digest of key file.\n");
821 	fprintf(stderr, "  -C comment  Provide new comment.\n");
822 	fprintf(stderr, "  -N phrase   Provide new passphrase.\n");
823 	fprintf(stderr, "  -P phrase   Provide old passphrase.\n");
824 #ifdef SMARTCARD
825 	fprintf(stderr, "  -D reader   Download public key from smartcard.\n");
826 	fprintf(stderr, "  -U reader   Upload private key to smartcard.\n");
827 #endif /* SMARTCARD */
828 
829 	exit(1);
830 }
831 
832 /*
833  * Main program for key management.
834  */
835 int
836 main(int ac, char **av)
837 {
838 	char dotsshdir[MAXPATHLEN], comment[1024], *passphrase1, *passphrase2;
839 	char *reader_id = NULL;
840 	Key *private, *public;
841 	struct passwd *pw;
842 	struct stat st;
843 	int opt, type, fd, download = 0;
844 	FILE *f;
845 
846 	extern int optind;
847 	extern char *optarg;
848 
849 	SSLeay_add_all_algorithms();
850 
851 	/* we need this for the home * directory.  */
852 	pw = getpwuid(getuid());
853 	if (!pw) {
854 		printf("You don't exist, go away!\n");
855 		exit(1);
856 	}
857 	if (gethostname(hostname, sizeof(hostname)) < 0) {
858 		perror("gethostname");
859 		exit(1);
860 	}
861 
862 	while ((opt = getopt(ac, av, "deiqpclBRxXyb:f:t:U:D:P:N:C:")) != -1) {
863 		switch (opt) {
864 		case 'b':
865 			bits = atoi(optarg);
866 			if (bits < 512 || bits > 32768) {
867 				printf("Bits has bad value.\n");
868 				exit(1);
869 			}
870 			break;
871 		case 'l':
872 			print_fingerprint = 1;
873 			break;
874 		case 'B':
875 			print_bubblebabble = 1;
876 			break;
877 		case 'p':
878 			change_passphrase = 1;
879 			break;
880 		case 'c':
881 			change_comment = 1;
882 			break;
883 		case 'f':
884 			strlcpy(identity_file, optarg, sizeof(identity_file));
885 			have_identity = 1;
886 			break;
887 		case 'P':
888 			identity_passphrase = optarg;
889 			break;
890 		case 'N':
891 			identity_new_passphrase = optarg;
892 			break;
893 		case 'C':
894 			identity_comment = optarg;
895 			break;
896 		case 'q':
897 			quiet = 1;
898 			break;
899 		case 'R':
900 			/* unused */
901 			exit(0);
902 			break;
903 		case 'e':
904 		case 'x':
905 			/* export key */
906 			convert_to_ssh2 = 1;
907 			break;
908 		case 'i':
909 		case 'X':
910 			/* import key */
911 			convert_from_ssh2 = 1;
912 			break;
913 		case 'y':
914 			print_public = 1;
915 			break;
916 		case 'd':
917 			key_type_name = "dsa";
918 			break;
919 		case 't':
920 			key_type_name = optarg;
921 			break;
922 		case 'D':
923 			download = 1;
924 		case 'U':
925 			reader_id = optarg;
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 (reader_id != NULL) {
953 #ifdef SMARTCARD
954 		if (download)
955 			do_download(pw, reader_id);
956 		else
957 			do_upload(pw, reader_id);
958 #else /* SMARTCARD */
959 		fatal("no support for smartcards.");
960 #endif /* SMARTCARD */
961 	}
962 
963 	arc4random_stir();
964 
965 	if (key_type_name == NULL) {
966 		printf("You must specify a key type (-t).\n");
967 		usage();
968 	}
969 	type = key_type_from_name(key_type_name);
970 	if (type == KEY_UNSPEC) {
971 		fprintf(stderr, "unknown key type %s\n", key_type_name);
972 		exit(1);
973 	}
974 	if (!quiet)
975 		printf("Generating public/private %s key pair.\n", key_type_name);
976 	private = key_generate(type, bits);
977 	if (private == NULL) {
978 		fprintf(stderr, "key_generate failed");
979 		exit(1);
980 	}
981 	public  = key_from_private(private);
982 
983 	if (!have_identity)
984 		ask_filename(pw, "Enter file in which to save the key");
985 
986 	/* Create ~/.ssh directory if it doesn\'t already exist. */
987 	snprintf(dotsshdir, sizeof dotsshdir, "%s/%s", pw->pw_dir, _PATH_SSH_USER_DIR);
988 	if (strstr(identity_file, dotsshdir) != NULL &&
989 	    stat(dotsshdir, &st) < 0) {
990 		if (mkdir(dotsshdir, 0700) < 0)
991 			error("Could not create directory '%s'.", dotsshdir);
992 		else if (!quiet)
993 			printf("Created directory '%s'.\n", dotsshdir);
994 	}
995 	/* If the file already exists, ask the user to confirm. */
996 	if (stat(identity_file, &st) >= 0) {
997 		char yesno[3];
998 		printf("%s already exists.\n", identity_file);
999 		printf("Overwrite (y/n)? ");
1000 		fflush(stdout);
1001 		if (fgets(yesno, sizeof(yesno), stdin) == NULL)
1002 			exit(1);
1003 		if (yesno[0] != 'y' && yesno[0] != 'Y')
1004 			exit(1);
1005 	}
1006 	/* Ask for a passphrase (twice). */
1007 	if (identity_passphrase)
1008 		passphrase1 = xstrdup(identity_passphrase);
1009 	else if (identity_new_passphrase)
1010 		passphrase1 = xstrdup(identity_new_passphrase);
1011 	else {
1012 passphrase_again:
1013 		passphrase1 =
1014 			read_passphrase("Enter passphrase (empty for no "
1015 			    "passphrase): ", RP_ALLOW_STDIN);
1016 		passphrase2 = read_passphrase("Enter same passphrase again: ",
1017 		    RP_ALLOW_STDIN);
1018 		if (strcmp(passphrase1, passphrase2) != 0) {
1019 			/*
1020 			 * The passphrases do not match.  Clear them and
1021 			 * retry.
1022 			 */
1023 			memset(passphrase1, 0, strlen(passphrase1));
1024 			memset(passphrase2, 0, strlen(passphrase2));
1025 			xfree(passphrase1);
1026 			xfree(passphrase2);
1027 			printf("Passphrases do not match.  Try again.\n");
1028 			goto passphrase_again;
1029 		}
1030 		/* Clear the other copy of the passphrase. */
1031 		memset(passphrase2, 0, strlen(passphrase2));
1032 		xfree(passphrase2);
1033 	}
1034 
1035 	if (identity_comment) {
1036 		strlcpy(comment, identity_comment, sizeof(comment));
1037 	} else {
1038 		/* Create default commend field for the passphrase. */
1039 		snprintf(comment, sizeof comment, "%s@%s", pw->pw_name, hostname);
1040 	}
1041 
1042 	/* Save the key with the given passphrase and comment. */
1043 	if (!key_save_private(private, identity_file, passphrase1, comment)) {
1044 		printf("Saving the key failed: %s.\n", identity_file);
1045 		memset(passphrase1, 0, strlen(passphrase1));
1046 		xfree(passphrase1);
1047 		exit(1);
1048 	}
1049 	/* Clear the passphrase. */
1050 	memset(passphrase1, 0, strlen(passphrase1));
1051 	xfree(passphrase1);
1052 
1053 	/* Clear the private key and the random number generator. */
1054 	key_free(private);
1055 	arc4random_stir();
1056 
1057 	if (!quiet)
1058 		printf("Your identification has been saved in %s.\n", identity_file);
1059 
1060 	strlcat(identity_file, ".pub", sizeof(identity_file));
1061 	fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
1062 	if (fd == -1) {
1063 		printf("Could not save your public key in %s\n", identity_file);
1064 		exit(1);
1065 	}
1066 	f = fdopen(fd, "w");
1067 	if (f == NULL) {
1068 		printf("fdopen %s failed", identity_file);
1069 		exit(1);
1070 	}
1071 	if (!key_write(public, f))
1072 		fprintf(stderr, "write key failed");
1073 	fprintf(f, " %s\n", comment);
1074 	fclose(f);
1075 
1076 	if (!quiet) {
1077 		char *fp = key_fingerprint(public, SSH_FP_MD5, SSH_FP_HEX);
1078 		printf("Your public key has been saved in %s.\n",
1079 		    identity_file);
1080 		printf("The key fingerprint is:\n");
1081 		printf("%s %s\n", fp, comment);
1082 		xfree(fp);
1083 	}
1084 
1085 	key_free(public);
1086 	exit(0);
1087 }
1088