xref: /netbsd-src/crypto/external/bsd/openssh/dist/ssh-keygen.c (revision 9fd8799cb5ceb66c69f2eb1a6d26a1d587ba1f1e)
1 /*	$NetBSD: ssh-keygen.c,v 1.37 2020/12/04 18:42:50 christos Exp $	*/
2 /* $OpenBSD: ssh-keygen.c,v 1.420 2020/09/09 03:08:01 djm Exp $ */
3 
4 /*
5  * Author: Tatu Ylonen <ylo@cs.hut.fi>
6  * Copyright (c) 1994 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
7  *                    All rights reserved
8  * Identity and host key generation and maintenance.
9  *
10  * As far as I am concerned, the code I have written for this software
11  * can be used freely for any purpose.  Any derived versions of this
12  * software must be clearly marked as such, and if the derived work is
13  * incompatible with the protocol description in the RFC file, it must be
14  * called by a name other than "ssh" or "Secure Shell".
15  */
16 
17 #include "includes.h"
18 __RCSID("$NetBSD: ssh-keygen.c,v 1.37 2020/12/04 18:42:50 christos Exp $");
19 #include <sys/types.h>
20 #include <sys/socket.h>
21 #include <sys/stat.h>
22 
23 #ifdef WITH_OPENSSL
24 #include <openssl/evp.h>
25 #include <openssl/pem.h>
26 #endif
27 
28 #include <stdint.h>
29 #include <errno.h>
30 #include <fcntl.h>
31 #include <netdb.h>
32 #include <pwd.h>
33 #include <stdio.h>
34 #include <stdlib.h>
35 #include <string.h>
36 #include <stdarg.h>
37 #include <unistd.h>
38 #include <limits.h>
39 #include <locale.h>
40 
41 #include "xmalloc.h"
42 #include "sshkey.h"
43 #include "authfile.h"
44 #include "sshbuf.h"
45 #include "pathnames.h"
46 #include "log.h"
47 #include "misc.h"
48 #include "match.h"
49 #include "hostfile.h"
50 #include "dns.h"
51 #include "ssh.h"
52 #include "ssh2.h"
53 #include "ssherr.h"
54 #include "atomicio.h"
55 #include "krl.h"
56 #include "digest.h"
57 #include "utf8.h"
58 #include "authfd.h"
59 #include "sshsig.h"
60 #include "ssh-sk.h"
61 #include "sk-api.h" /* XXX for SSH_SK_USER_PRESENCE_REQD; remove */
62 
63 #ifdef ENABLE_PKCS11
64 #include "ssh-pkcs11.h"
65 #endif
66 
67 #ifdef WITH_OPENSSL
68 # define DEFAULT_KEY_TYPE_NAME "rsa"
69 #else
70 # define DEFAULT_KEY_TYPE_NAME "ed25519"
71 #endif
72 
73 /*
74  * Default number of bits in the RSA, DSA and ECDSA keys.  These value can be
75  * overridden on the command line.
76  *
77  * These values, with the exception of DSA, provide security equivalent to at
78  * least 128 bits of security according to NIST Special Publication 800-57:
79  * Recommendation for Key Management Part 1 rev 4 section 5.6.1.
80  * For DSA it (and FIPS-186-4 section 4.2) specifies that the only size for
81  * which a 160bit hash is acceptable is 1kbit, and since ssh-dss specifies only
82  * SHA1 we limit the DSA key size 1k bits.
83  */
84 #define DEFAULT_BITS		3072
85 #define DEFAULT_BITS_DSA	1024
86 #define DEFAULT_BITS_ECDSA	256
87 
88 static int quiet = 0;
89 
90 /* Flag indicating that we just want to see the key fingerprint */
91 static int print_fingerprint = 0;
92 static int print_bubblebabble = 0;
93 
94 /* Hash algorithm to use for fingerprints. */
95 static int fingerprint_hash = SSH_FP_HASH_DEFAULT;
96 
97 /* The identity file name, given on the command line or entered by the user. */
98 static char identity_file[PATH_MAX];
99 static int have_identity = 0;
100 
101 /* This is set to the passphrase if given on the command line. */
102 static char *identity_passphrase = NULL;
103 
104 /* This is set to the new passphrase if given on the command line. */
105 static char *identity_new_passphrase = NULL;
106 
107 /* Key type when certifying */
108 static u_int cert_key_type = SSH2_CERT_TYPE_USER;
109 
110 /* "key ID" of signed key */
111 static char *cert_key_id = NULL;
112 
113 /* Comma-separated list of principal names for certifying keys */
114 static char *cert_principals = NULL;
115 
116 /* Validity period for certificates */
117 static u_int64_t cert_valid_from = 0;
118 static u_int64_t cert_valid_to = ~0ULL;
119 
120 /* Certificate options */
121 #define CERTOPT_X_FWD				(1)
122 #define CERTOPT_AGENT_FWD			(1<<1)
123 #define CERTOPT_PORT_FWD			(1<<2)
124 #define CERTOPT_PTY				(1<<3)
125 #define CERTOPT_USER_RC				(1<<4)
126 #define CERTOPT_NO_REQUIRE_USER_PRESENCE	(1<<5)
127 #define CERTOPT_DEFAULT	(CERTOPT_X_FWD|CERTOPT_AGENT_FWD| \
128 			 CERTOPT_PORT_FWD|CERTOPT_PTY|CERTOPT_USER_RC)
129 static u_int32_t certflags_flags = CERTOPT_DEFAULT;
130 static char *certflags_command = NULL;
131 static char *certflags_src_addr = NULL;
132 
133 /* Arbitrary extensions specified by user */
134 struct cert_ext {
135 	char *key;
136 	char *val;
137 	int crit;
138 };
139 static struct cert_ext *cert_ext;
140 static size_t ncert_ext;
141 
142 /* Conversion to/from various formats */
143 enum {
144 	FMT_RFC4716,
145 	FMT_PKCS8,
146 	FMT_PEM
147 } convert_format = FMT_RFC4716;
148 
149 static const char *key_type_name = NULL;
150 
151 /* Load key from this PKCS#11 provider */
152 static char *pkcs11provider = NULL;
153 
154 /* FIDO/U2F provider to use */
155 static const char *sk_provider = NULL;
156 
157 /* Format for writing private keys */
158 static int private_key_format = SSHKEY_PRIVATE_OPENSSH;
159 
160 /* Cipher for new-format private keys */
161 static char *openssh_format_cipher = NULL;
162 
163 /* Number of KDF rounds to derive new format keys. */
164 static int rounds = 0;
165 
166 /* argv0 */
167 extern char *__progname;
168 
169 static char hostname[NI_MAXHOST];
170 
171 #ifdef WITH_OPENSSL
172 /* moduli.c */
173 int gen_candidates(FILE *, u_int32_t, u_int32_t, BIGNUM *);
174 int prime_test(FILE *, FILE *, u_int32_t, u_int32_t, char *, unsigned long,
175     unsigned long);
176 #endif
177 
178 static void
179 type_bits_valid(int type, const char *name, u_int32_t *bitsp)
180 {
181 	if (type == KEY_UNSPEC)
182 		fatal("unknown key type %s", key_type_name);
183 	if (*bitsp == 0) {
184 #ifdef WITH_OPENSSL
185 		u_int nid;
186 
187 		switch(type) {
188 		case KEY_DSA:
189 			*bitsp = DEFAULT_BITS_DSA;
190 			break;
191 		case KEY_ECDSA:
192 			if (name != NULL &&
193 			    (nid = sshkey_ecdsa_nid_from_name(name)) > 0)
194 				*bitsp = sshkey_curve_nid_to_bits(nid);
195 			if (*bitsp == 0)
196 				*bitsp = DEFAULT_BITS_ECDSA;
197 			break;
198 		case KEY_RSA:
199 			*bitsp = DEFAULT_BITS;
200 			break;
201 		}
202 #endif
203 	}
204 #ifdef WITH_OPENSSL
205 	switch (type) {
206 	case KEY_DSA:
207 		if (*bitsp != 1024)
208 			fatal("Invalid DSA key length: must be 1024 bits");
209 		break;
210 	case KEY_RSA:
211 		if (*bitsp < SSH_RSA_MINIMUM_MODULUS_SIZE)
212 			fatal("Invalid RSA key length: minimum is %d bits",
213 			    SSH_RSA_MINIMUM_MODULUS_SIZE);
214 		else if (*bitsp > OPENSSL_RSA_MAX_MODULUS_BITS)
215 			fatal("Invalid RSA key length: maximum is %d bits",
216 			    OPENSSL_RSA_MAX_MODULUS_BITS);
217 		break;
218 	case KEY_ECDSA:
219 		if (sshkey_ecdsa_bits_to_nid(*bitsp) == -1)
220 			fatal("Invalid ECDSA key length: valid lengths are "
221 			    "256, 384 or 521 bits");
222 	}
223 #endif
224 }
225 
226 /*
227  * Checks whether a file exists and, if so, asks the user whether they wish
228  * to overwrite it.
229  * Returns nonzero if the file does not already exist or if the user agrees to
230  * overwrite, or zero otherwise.
231  */
232 static int
233 confirm_overwrite(const char *filename)
234 {
235 	char yesno[3];
236 	struct stat st;
237 
238 	if (stat(filename, &st) != 0)
239 		return 1;
240 	printf("%s already exists.\n", filename);
241 	printf("Overwrite (y/n)? ");
242 	fflush(stdout);
243 	if (fgets(yesno, sizeof(yesno), stdin) == NULL)
244 		return 0;
245 	if (yesno[0] != 'y' && yesno[0] != 'Y')
246 		return 0;
247 	return 1;
248 }
249 
250 static void
251 ask_filename(struct passwd *pw, const char *prompt)
252 {
253 	char buf[1024];
254 	const char *name = NULL;
255 
256 	if (key_type_name == NULL)
257 		name = _PATH_SSH_CLIENT_ID_RSA;
258 	else {
259 		switch (sshkey_type_from_name(key_type_name)) {
260 		case KEY_DSA_CERT:
261 		case KEY_DSA:
262 			name = _PATH_SSH_CLIENT_ID_DSA;
263 			break;
264 		case KEY_ECDSA_CERT:
265 		case KEY_ECDSA:
266 			name = _PATH_SSH_CLIENT_ID_ECDSA;
267 			break;
268 		case KEY_ECDSA_SK_CERT:
269 		case KEY_ECDSA_SK:
270 			name = _PATH_SSH_CLIENT_ID_ECDSA_SK;
271 			break;
272 		case KEY_RSA_CERT:
273 		case KEY_RSA:
274 			name = _PATH_SSH_CLIENT_ID_RSA;
275 			break;
276 		case KEY_ED25519:
277 		case KEY_ED25519_CERT:
278 			name = _PATH_SSH_CLIENT_ID_ED25519;
279 			break;
280 		case KEY_ED25519_SK:
281 		case KEY_ED25519_SK_CERT:
282 			name = _PATH_SSH_CLIENT_ID_ED25519_SK;
283 			break;
284 		case KEY_XMSS:
285 		case KEY_XMSS_CERT:
286 			name = _PATH_SSH_CLIENT_ID_XMSS;
287 			break;
288 		default:
289 			fatal("bad key type");
290 		}
291 	}
292 	snprintf(identity_file, sizeof(identity_file),
293 	    "%s/%s", pw->pw_dir, name);
294 	printf("%s (%s): ", prompt, identity_file);
295 	fflush(stdout);
296 	if (fgets(buf, sizeof(buf), stdin) == NULL)
297 		exit(1);
298 	buf[strcspn(buf, "\n")] = '\0';
299 	if (strcmp(buf, "") != 0)
300 		strlcpy(identity_file, buf, sizeof(identity_file));
301 	have_identity = 1;
302 }
303 
304 static struct sshkey *
305 load_identity(const char *filename, char **commentp)
306 {
307 	char *pass;
308 	struct sshkey *prv;
309 	int r;
310 
311 	if (commentp != NULL)
312 		*commentp = NULL;
313 	if ((r = sshkey_load_private(filename, "", &prv, commentp)) == 0)
314 		return prv;
315 	if (r != SSH_ERR_KEY_WRONG_PASSPHRASE)
316 		fatal("Load key \"%s\": %s", filename, ssh_err(r));
317 	if (identity_passphrase)
318 		pass = xstrdup(identity_passphrase);
319 	else
320 		pass = read_passphrase("Enter passphrase: ", RP_ALLOW_STDIN);
321 	r = sshkey_load_private(filename, pass, &prv, commentp);
322 	freezero(pass, strlen(pass));
323 	if (r != 0)
324 		fatal("Load key \"%s\": %s", filename, ssh_err(r));
325 	return prv;
326 }
327 
328 #define SSH_COM_PUBLIC_BEGIN		"---- BEGIN SSH2 PUBLIC KEY ----"
329 #define SSH_COM_PUBLIC_END		"---- END SSH2 PUBLIC KEY ----"
330 #define SSH_COM_PRIVATE_BEGIN		"---- BEGIN SSH2 ENCRYPTED PRIVATE KEY ----"
331 #define	SSH_COM_PRIVATE_KEY_MAGIC	0x3f6ff9eb
332 
333 #ifdef WITH_OPENSSL
334 __dead static void
335 do_convert_to_ssh2(struct passwd *pw, struct sshkey *k)
336 {
337 	struct sshbuf *b;
338 	char comment[61], *b64;
339 	int r;
340 
341 	if ((b = sshbuf_new()) == NULL)
342 		fatal("%s: sshbuf_new failed", __func__);
343 	if ((r = sshkey_putb(k, b)) != 0)
344 		fatal("key_to_blob failed: %s", ssh_err(r));
345 	if ((b64 = sshbuf_dtob64_string(b, 1)) == NULL)
346 		fatal("%s: sshbuf_dtob64_string failed", __func__);
347 
348 	/* Comment + surrounds must fit into 72 chars (RFC 4716 sec 3.3) */
349 	snprintf(comment, sizeof(comment),
350 	    "%u-bit %s, converted by %s@%s from OpenSSH",
351 	    sshkey_size(k), sshkey_type(k),
352 	    pw->pw_name, hostname);
353 
354 	sshkey_free(k);
355 	sshbuf_free(b);
356 
357 	fprintf(stdout, "%s\n", SSH_COM_PUBLIC_BEGIN);
358 	fprintf(stdout, "Comment: \"%s\"\n%s", comment, b64);
359 	fprintf(stdout, "%s\n", SSH_COM_PUBLIC_END);
360 	free(b64);
361 	exit(0);
362 }
363 
364 __dead static void
365 do_convert_to_pkcs8(struct sshkey *k)
366 {
367 	switch (sshkey_type_plain(k->type)) {
368 	case KEY_RSA:
369 		if (!PEM_write_RSA_PUBKEY(stdout, k->rsa))
370 			fatal("PEM_write_RSA_PUBKEY failed");
371 		break;
372 	case KEY_DSA:
373 		if (!PEM_write_DSA_PUBKEY(stdout, k->dsa))
374 			fatal("PEM_write_DSA_PUBKEY failed");
375 		break;
376 	case KEY_ECDSA:
377 		if (!PEM_write_EC_PUBKEY(stdout, k->ecdsa))
378 			fatal("PEM_write_EC_PUBKEY failed");
379 		break;
380 	default:
381 		fatal("%s: unsupported key type %s", __func__, sshkey_type(k));
382 	}
383 	exit(0);
384 }
385 
386 __dead static void
387 do_convert_to_pem(struct sshkey *k)
388 {
389 	switch (sshkey_type_plain(k->type)) {
390 	case KEY_RSA:
391 		if (!PEM_write_RSAPublicKey(stdout, k->rsa))
392 			fatal("PEM_write_RSAPublicKey failed");
393 		break;
394 	case KEY_DSA:
395 		if (!PEM_write_DSA_PUBKEY(stdout, k->dsa))
396 			fatal("PEM_write_DSA_PUBKEY failed");
397 		break;
398 	case KEY_ECDSA:
399 		if (!PEM_write_EC_PUBKEY(stdout, k->ecdsa))
400 			fatal("PEM_write_EC_PUBKEY failed");
401 		break;
402 	default:
403 		fatal("%s: unsupported key type %s", __func__, sshkey_type(k));
404 	}
405 	exit(0);
406 }
407 
408 __dead static void
409 do_convert_to(struct passwd *pw)
410 {
411 	struct sshkey *k;
412 	struct stat st;
413 	int r;
414 
415 	if (!have_identity)
416 		ask_filename(pw, "Enter file in which the key is");
417 	if (stat(identity_file, &st) == -1)
418 		fatal("%s: %s: %s", __progname, identity_file, strerror(errno));
419 	if ((r = sshkey_load_public(identity_file, &k, NULL)) != 0)
420 		k = load_identity(identity_file, NULL);
421 	switch (convert_format) {
422 	case FMT_RFC4716:
423 		do_convert_to_ssh2(pw, k);
424 		break;
425 	case FMT_PKCS8:
426 		do_convert_to_pkcs8(k);
427 		break;
428 	case FMT_PEM:
429 		do_convert_to_pem(k);
430 		break;
431 	default:
432 		fatal("%s: unknown key format %d", __func__, convert_format);
433 	}
434 	exit(0);
435 }
436 
437 /*
438  * This is almost exactly the bignum1 encoding, but with 32 bit for length
439  * instead of 16.
440  */
441 static void
442 buffer_get_bignum_bits(struct sshbuf *b, BIGNUM *value)
443 {
444 	u_int bytes, bignum_bits;
445 	int r;
446 
447 	if ((r = sshbuf_get_u32(b, &bignum_bits)) != 0)
448 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
449 	bytes = (bignum_bits + 7) / 8;
450 	if (sshbuf_len(b) < bytes)
451 		fatal("%s: input buffer too small: need %d have %zu",
452 		    __func__, bytes, sshbuf_len(b));
453 	if (BN_bin2bn(sshbuf_ptr(b), bytes, value) == NULL)
454 		fatal("%s: BN_bin2bn failed", __func__);
455 	if ((r = sshbuf_consume(b, bytes)) != 0)
456 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
457 }
458 
459 static struct sshkey *
460 do_convert_private_ssh2(struct sshbuf *b)
461 {
462 	struct sshkey *key = NULL;
463 	char *type, *cipher;
464 	u_char e1, e2, e3, *sig = NULL, data[] = "abcde12345";
465 	int r, rlen, ktype;
466 	u_int magic, i1, i2, i3, i4;
467 	size_t slen;
468 	u_long e;
469 	BIGNUM *dsa_p = NULL, *dsa_q = NULL, *dsa_g = NULL;
470 	BIGNUM *dsa_pub_key = NULL, *dsa_priv_key = NULL;
471 	BIGNUM *rsa_n = NULL, *rsa_e = NULL, *rsa_d = NULL;
472 	BIGNUM *rsa_p = NULL, *rsa_q = NULL, *rsa_iqmp = NULL;
473 
474 	if ((r = sshbuf_get_u32(b, &magic)) != 0)
475 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
476 
477 	if (magic != SSH_COM_PRIVATE_KEY_MAGIC) {
478 		error("bad magic 0x%x != 0x%x", magic,
479 		    SSH_COM_PRIVATE_KEY_MAGIC);
480 		return NULL;
481 	}
482 	if ((r = sshbuf_get_u32(b, &i1)) != 0 ||
483 	    (r = sshbuf_get_cstring(b, &type, NULL)) != 0 ||
484 	    (r = sshbuf_get_cstring(b, &cipher, NULL)) != 0 ||
485 	    (r = sshbuf_get_u32(b, &i2)) != 0 ||
486 	    (r = sshbuf_get_u32(b, &i3)) != 0 ||
487 	    (r = sshbuf_get_u32(b, &i4)) != 0)
488 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
489 	debug("ignore (%d %d %d %d)", i1, i2, i3, i4);
490 	if (strcmp(cipher, "none") != 0) {
491 		error("unsupported cipher %s", cipher);
492 		free(cipher);
493 		free(type);
494 		return NULL;
495 	}
496 	free(cipher);
497 
498 	if (strstr(type, "dsa")) {
499 		ktype = KEY_DSA;
500 	} else if (strstr(type, "rsa")) {
501 		ktype = KEY_RSA;
502 	} else {
503 		free(type);
504 		return NULL;
505 	}
506 	if ((key = sshkey_new(ktype)) == NULL)
507 		fatal("sshkey_new failed");
508 	free(type);
509 
510 	switch (key->type) {
511 	case KEY_DSA:
512 		if ((dsa_p = BN_new()) == NULL ||
513 		    (dsa_q = BN_new()) == NULL ||
514 		    (dsa_g = BN_new()) == NULL ||
515 		    (dsa_pub_key = BN_new()) == NULL ||
516 		    (dsa_priv_key = BN_new()) == NULL)
517 			fatal("%s: BN_new", __func__);
518 		buffer_get_bignum_bits(b, dsa_p);
519 		buffer_get_bignum_bits(b, dsa_g);
520 		buffer_get_bignum_bits(b, dsa_q);
521 		buffer_get_bignum_bits(b, dsa_pub_key);
522 		buffer_get_bignum_bits(b, dsa_priv_key);
523 		if (!DSA_set0_pqg(key->dsa, dsa_p, dsa_q, dsa_g))
524 			fatal("%s: DSA_set0_pqg failed", __func__);
525 		dsa_p = dsa_q = dsa_g = NULL; /* transferred */
526 		if (!DSA_set0_key(key->dsa, dsa_pub_key, dsa_priv_key))
527 			fatal("%s: DSA_set0_key failed", __func__);
528 		dsa_pub_key = dsa_priv_key = NULL; /* transferred */
529 		break;
530 	case KEY_RSA:
531 		if ((r = sshbuf_get_u8(b, &e1)) != 0 ||
532 		    (e1 < 30 && (r = sshbuf_get_u8(b, &e2)) != 0) ||
533 		    (e1 < 30 && (r = sshbuf_get_u8(b, &e3)) != 0))
534 			fatal("%s: buffer error: %s", __func__, ssh_err(r));
535 		e = e1;
536 		debug("e %lx", e);
537 		if (e < 30) {
538 			e <<= 8;
539 			e += e2;
540 			debug("e %lx", e);
541 			e <<= 8;
542 			e += e3;
543 			debug("e %lx", e);
544 		}
545 		if ((rsa_e = BN_new()) == NULL)
546 			fatal("%s: BN_new", __func__);
547 		if (!BN_set_word(rsa_e, e)) {
548 			BN_clear_free(rsa_e);
549 			sshkey_free(key);
550 			return NULL;
551 		}
552 		if ((rsa_n = BN_new()) == NULL ||
553 		    (rsa_d = BN_new()) == NULL ||
554 		    (rsa_p = BN_new()) == NULL ||
555 		    (rsa_q = BN_new()) == NULL ||
556 		    (rsa_iqmp = BN_new()) == NULL)
557 			fatal("%s: BN_new", __func__);
558 		buffer_get_bignum_bits(b, rsa_d);
559 		buffer_get_bignum_bits(b, rsa_n);
560 		buffer_get_bignum_bits(b, rsa_iqmp);
561 		buffer_get_bignum_bits(b, rsa_q);
562 		buffer_get_bignum_bits(b, rsa_p);
563 		if (!RSA_set0_key(key->rsa, rsa_n, rsa_e, rsa_d))
564 			fatal("%s: RSA_set0_key failed", __func__);
565 		rsa_n = rsa_e = rsa_d = NULL; /* transferred */
566 		if (!RSA_set0_factors(key->rsa, rsa_p, rsa_q))
567 			fatal("%s: RSA_set0_factors failed", __func__);
568 		rsa_p = rsa_q = NULL; /* transferred */
569 		if ((r = ssh_rsa_complete_crt_parameters(key, rsa_iqmp)) != 0)
570 			fatal("generate RSA parameters failed: %s", ssh_err(r));
571 		BN_clear_free(rsa_iqmp);
572 		break;
573 	}
574 	rlen = sshbuf_len(b);
575 	if (rlen != 0)
576 		error("%s: remaining bytes in key blob %d", __func__, rlen);
577 
578 	/* try the key */
579 	if (sshkey_sign(key, &sig, &slen, data, sizeof(data),
580 	    NULL, NULL, NULL, 0) != 0 ||
581 	    sshkey_verify(key, sig, slen, data, sizeof(data),
582 	    NULL, 0, NULL) != 0) {
583 		sshkey_free(key);
584 		free(sig);
585 		return NULL;
586 	}
587 	free(sig);
588 	return key;
589 }
590 
591 static int
592 get_line(FILE *fp, char *line, size_t len)
593 {
594 	int c;
595 	size_t pos = 0;
596 
597 	line[0] = '\0';
598 	while ((c = fgetc(fp)) != EOF) {
599 		if (pos >= len - 1)
600 			fatal("input line too long.");
601 		switch (c) {
602 		case '\r':
603 			c = fgetc(fp);
604 			if (c != EOF && c != '\n' && ungetc(c, fp) == EOF)
605 				fatal("unget: %s", strerror(errno));
606 			return pos;
607 		case '\n':
608 			return pos;
609 		}
610 		line[pos++] = c;
611 		line[pos] = '\0';
612 	}
613 	/* We reached EOF */
614 	return -1;
615 }
616 
617 static void
618 do_convert_from_ssh2(struct passwd *pw, struct sshkey **k, int *private)
619 {
620 	int r, blen, escaped = 0;
621 	u_int len;
622 	char line[1024];
623 	struct sshbuf *buf;
624 	char encoded[8096];
625 	FILE *fp;
626 
627 	if ((buf = sshbuf_new()) == NULL)
628 		fatal("sshbuf_new failed");
629 	if ((fp = fopen(identity_file, "r")) == NULL)
630 		fatal("%s: %s: %s", __progname, identity_file, strerror(errno));
631 	encoded[0] = '\0';
632 	while ((blen = get_line(fp, line, sizeof(line))) != -1) {
633 		if (blen > 0 && line[blen - 1] == '\\')
634 			escaped++;
635 		if (strncmp(line, "----", 4) == 0 ||
636 		    strstr(line, ": ") != NULL) {
637 			if (strstr(line, SSH_COM_PRIVATE_BEGIN) != NULL)
638 				*private = 1;
639 			if (strstr(line, " END ") != NULL) {
640 				break;
641 			}
642 			/* fprintf(stderr, "ignore: %s", line); */
643 			continue;
644 		}
645 		if (escaped) {
646 			escaped--;
647 			/* fprintf(stderr, "escaped: %s", line); */
648 			continue;
649 		}
650 		strlcat(encoded, line, sizeof(encoded));
651 	}
652 	len = strlen(encoded);
653 	if (((len % 4) == 3) &&
654 	    (encoded[len-1] == '=') &&
655 	    (encoded[len-2] == '=') &&
656 	    (encoded[len-3] == '='))
657 		encoded[len-3] = '\0';
658 	if ((r = sshbuf_b64tod(buf, encoded)) != 0)
659 		fatal("%s: base64 decoding failed: %s", __func__, ssh_err(r));
660 	if (*private) {
661 		if ((*k = do_convert_private_ssh2(buf)) == NULL)
662 			fatal("%s: private key conversion failed", __func__);
663 	} else if ((r = sshkey_fromb(buf, k)) != 0)
664 		fatal("decode blob failed: %s", ssh_err(r));
665 	sshbuf_free(buf);
666 	fclose(fp);
667 }
668 
669 static void
670 do_convert_from_pkcs8(struct sshkey **k, int *private)
671 {
672 	EVP_PKEY *pubkey;
673 	FILE *fp;
674 
675 	if ((fp = fopen(identity_file, "r")) == NULL)
676 		fatal("%s: %s: %s", __progname, identity_file, strerror(errno));
677 	if ((pubkey = PEM_read_PUBKEY(fp, NULL, NULL, NULL)) == NULL) {
678 		fatal("%s: %s is not a recognised public key format", __func__,
679 		    identity_file);
680 	}
681 	fclose(fp);
682 	switch (EVP_PKEY_base_id(pubkey)) {
683 	case EVP_PKEY_RSA:
684 		if ((*k = sshkey_new(KEY_UNSPEC)) == NULL)
685 			fatal("sshkey_new failed");
686 		(*k)->type = KEY_RSA;
687 		(*k)->rsa = EVP_PKEY_get1_RSA(pubkey);
688 		break;
689 	case EVP_PKEY_DSA:
690 		if ((*k = sshkey_new(KEY_UNSPEC)) == NULL)
691 			fatal("sshkey_new failed");
692 		(*k)->type = KEY_DSA;
693 		(*k)->dsa = EVP_PKEY_get1_DSA(pubkey);
694 		break;
695 	case EVP_PKEY_EC:
696 		if ((*k = sshkey_new(KEY_UNSPEC)) == NULL)
697 			fatal("sshkey_new failed");
698 		(*k)->type = KEY_ECDSA;
699 		(*k)->ecdsa = EVP_PKEY_get1_EC_KEY(pubkey);
700 		(*k)->ecdsa_nid = sshkey_ecdsa_key_to_nid((*k)->ecdsa);
701 		break;
702 	default:
703 		fatal("%s: unsupported pubkey type %d", __func__,
704 		    EVP_PKEY_base_id(pubkey));
705 	}
706 	EVP_PKEY_free(pubkey);
707 	return;
708 }
709 
710 static void
711 do_convert_from_pem(struct sshkey **k, int *private)
712 {
713 	FILE *fp;
714 	RSA *rsa;
715 
716 	if ((fp = fopen(identity_file, "r")) == NULL)
717 		fatal("%s: %s: %s", __progname, identity_file, strerror(errno));
718 	if ((rsa = PEM_read_RSAPublicKey(fp, NULL, NULL, NULL)) != NULL) {
719 		if ((*k = sshkey_new(KEY_UNSPEC)) == NULL)
720 			fatal("sshkey_new failed");
721 		(*k)->type = KEY_RSA;
722 		(*k)->rsa = rsa;
723 		fclose(fp);
724 		return;
725 	}
726 	fatal("%s: unrecognised raw private key format", __func__);
727 }
728 
729 __dead static void
730 do_convert_from(struct passwd *pw)
731 {
732 	struct sshkey *k = NULL;
733 	int r, private = 0, ok = 0;
734 	struct stat st;
735 
736 	if (!have_identity)
737 		ask_filename(pw, "Enter file in which the key is");
738 	if (stat(identity_file, &st) == -1)
739 		fatal("%s: %s: %s", __progname, identity_file, strerror(errno));
740 
741 	switch (convert_format) {
742 	case FMT_RFC4716:
743 		do_convert_from_ssh2(pw, &k, &private);
744 		break;
745 	case FMT_PKCS8:
746 		do_convert_from_pkcs8(&k, &private);
747 		break;
748 	case FMT_PEM:
749 		do_convert_from_pem(&k, &private);
750 		break;
751 	default:
752 		fatal("%s: unknown key format %d", __func__, convert_format);
753 	}
754 
755 	if (!private) {
756 		if ((r = sshkey_write(k, stdout)) == 0)
757 			ok = 1;
758 		if (ok)
759 			fprintf(stdout, "\n");
760 	} else {
761 		switch (k->type) {
762 		case KEY_DSA:
763 			ok = PEM_write_DSAPrivateKey(stdout, k->dsa, NULL,
764 			    NULL, 0, NULL, NULL);
765 			break;
766 		case KEY_ECDSA:
767 			ok = PEM_write_ECPrivateKey(stdout, k->ecdsa, NULL,
768 			    NULL, 0, NULL, NULL);
769 			break;
770 		case KEY_RSA:
771 			ok = PEM_write_RSAPrivateKey(stdout, k->rsa, NULL,
772 			    NULL, 0, NULL, NULL);
773 			break;
774 		default:
775 			fatal("%s: unsupported key type %s", __func__,
776 			    sshkey_type(k));
777 		}
778 	}
779 
780 	if (!ok)
781 		fatal("key write failed");
782 	sshkey_free(k);
783 	exit(0);
784 }
785 #endif
786 
787 __dead static void
788 do_print_public(struct passwd *pw)
789 {
790 	struct sshkey *prv;
791 	struct stat st;
792 	int r;
793 	char *comment = NULL;
794 
795 	if (!have_identity)
796 		ask_filename(pw, "Enter file in which the key is");
797 	if (stat(identity_file, &st) == -1)
798 		fatal("%s: %s", identity_file, strerror(errno));
799 	prv = load_identity(identity_file, &comment);
800 	if ((r = sshkey_write(prv, stdout)) != 0)
801 		error("sshkey_write failed: %s", ssh_err(r));
802 	if (comment != NULL && *comment != '\0')
803 		fprintf(stdout, " %s", comment);
804 	fprintf(stdout, "\n");
805 	if (sshkey_is_sk(prv)) {
806 		debug("sk_application: \"%s\", sk_flags 0x%02x",
807 			prv->sk_application, prv->sk_flags);
808 	}
809 	sshkey_free(prv);
810 	free(comment);
811 	exit(0);
812 }
813 
814 __dead static void
815 do_download(struct passwd *pw)
816 {
817 #ifdef ENABLE_PKCS11
818 	struct sshkey **keys = NULL;
819 	int i, nkeys;
820 	enum sshkey_fp_rep rep;
821 	int fptype;
822 	char *fp, *ra, **comments = NULL;
823 
824 	fptype = print_bubblebabble ? SSH_DIGEST_SHA1 : fingerprint_hash;
825 	rep =    print_bubblebabble ? SSH_FP_BUBBLEBABBLE : SSH_FP_DEFAULT;
826 
827 	pkcs11_init(1);
828 	nkeys = pkcs11_add_provider(pkcs11provider, NULL, &keys, &comments);
829 	if (nkeys <= 0)
830 		fatal("cannot read public key from pkcs11");
831 	for (i = 0; i < nkeys; i++) {
832 		if (print_fingerprint) {
833 			fp = sshkey_fingerprint(keys[i], fptype, rep);
834 			ra = sshkey_fingerprint(keys[i], fingerprint_hash,
835 			    SSH_FP_RANDOMART);
836 			if (fp == NULL || ra == NULL)
837 				fatal("%s: sshkey_fingerprint fail", __func__);
838 			printf("%u %s %s (PKCS11 key)\n", sshkey_size(keys[i]),
839 			    fp, sshkey_type(keys[i]));
840 			if (log_level_get() >= SYSLOG_LEVEL_VERBOSE)
841 				printf("%s\n", ra);
842 			free(ra);
843 			free(fp);
844 		} else {
845 			(void) sshkey_write(keys[i], stdout); /* XXX check */
846 			fprintf(stdout, "%s%s\n",
847 			    *(comments[i]) == '\0' ? "" : " ", comments[i]);
848 		}
849 		free(comments[i]);
850 		sshkey_free(keys[i]);
851 	}
852 	free(comments);
853 	free(keys);
854 	pkcs11_terminate();
855 	exit(0);
856 #else
857 	fatal("no pkcs11 support");
858 #endif /* ENABLE_PKCS11 */
859 }
860 
861 static struct sshkey *
862 try_read_key(char **cpp)
863 {
864 	struct sshkey *ret;
865 	int r;
866 
867 	if ((ret = sshkey_new(KEY_UNSPEC)) == NULL)
868 		fatal("sshkey_new failed");
869 	if ((r = sshkey_read(ret, cpp)) == 0)
870 		return ret;
871 	/* Not a key */
872 	sshkey_free(ret);
873 	return NULL;
874 }
875 
876 static void
877 fingerprint_one_key(const struct sshkey *public, const char *comment)
878 {
879 	char *fp = NULL, *ra = NULL;
880 	enum sshkey_fp_rep rep;
881 	int fptype;
882 
883 	fptype = print_bubblebabble ? SSH_DIGEST_SHA1 : fingerprint_hash;
884 	rep =    print_bubblebabble ? SSH_FP_BUBBLEBABBLE : SSH_FP_DEFAULT;
885 	fp = sshkey_fingerprint(public, fptype, rep);
886 	ra = sshkey_fingerprint(public, fingerprint_hash, SSH_FP_RANDOMART);
887 	if (fp == NULL || ra == NULL)
888 		fatal("%s: sshkey_fingerprint failed", __func__);
889 	mprintf("%u %s %s (%s)\n", sshkey_size(public), fp,
890 	    comment ? comment : "no comment", sshkey_type(public));
891 	if (log_level_get() >= SYSLOG_LEVEL_VERBOSE)
892 		printf("%s\n", ra);
893 	free(ra);
894 	free(fp);
895 }
896 
897 static void
898 fingerprint_private(const char *path)
899 {
900 	struct stat st;
901 	char *comment = NULL;
902 	struct sshkey *privkey = NULL, *pubkey = NULL;
903 	int r;
904 
905 	if (stat(identity_file, &st) == -1)
906 		fatal("%s: %s", path, strerror(errno));
907 	if ((r = sshkey_load_public(path, &pubkey, &comment)) != 0)
908 		debug("load public \"%s\": %s", path, ssh_err(r));
909 	if (pubkey == NULL || comment == NULL || *comment == '\0') {
910 		free(comment);
911 		if ((r = sshkey_load_private(path, NULL,
912 		    &privkey, &comment)) != 0)
913 			debug("load private \"%s\": %s", path, ssh_err(r));
914 	}
915 	if (pubkey == NULL && privkey == NULL)
916 		fatal("%s is not a key file.", path);
917 
918 	fingerprint_one_key(pubkey == NULL ? privkey : pubkey, comment);
919 	sshkey_free(pubkey);
920 	sshkey_free(privkey);
921 	free(comment);
922 }
923 
924 __dead static void
925 do_fingerprint(struct passwd *pw)
926 {
927 	FILE *f;
928 	struct sshkey *public = NULL;
929 	char *comment = NULL, *cp, *ep, *line = NULL;
930 	size_t linesize = 0;
931 	int i, invalid = 1;
932 	const char *path;
933 	u_long lnum = 0;
934 
935 	if (!have_identity)
936 		ask_filename(pw, "Enter file in which the key is");
937 	path = identity_file;
938 
939 	if (strcmp(identity_file, "-") == 0) {
940 		f = stdin;
941 		path = "(stdin)";
942 	} else if ((f = fopen(path, "r")) == NULL)
943 		fatal("%s: %s: %s", __progname, path, strerror(errno));
944 
945 	while (getline(&line, &linesize, f) != -1) {
946 		lnum++;
947 		cp = line;
948 		cp[strcspn(cp, "\n")] = '\0';
949 		/* Trim leading space and comments */
950 		cp = line + strspn(line, " \t");
951 		if (*cp == '#' || *cp == '\0')
952 			continue;
953 
954 		/*
955 		 * Input may be plain keys, private keys, authorized_keys
956 		 * or known_hosts.
957 		 */
958 
959 		/*
960 		 * Try private keys first. Assume a key is private if
961 		 * "SSH PRIVATE KEY" appears on the first line and we're
962 		 * not reading from stdin (XXX support private keys on stdin).
963 		 */
964 		if (lnum == 1 && strcmp(identity_file, "-") != 0 &&
965 		    strstr(cp, "PRIVATE KEY") != NULL) {
966 			free(line);
967 			fclose(f);
968 			fingerprint_private(path);
969 			exit(0);
970 		}
971 
972 		/*
973 		 * If it's not a private key, then this must be prepared to
974 		 * accept a public key prefixed with a hostname or options.
975 		 * Try a bare key first, otherwise skip the leading stuff.
976 		 */
977 		if ((public = try_read_key(&cp)) == NULL) {
978 			i = strtol(cp, &ep, 10);
979 			if (i == 0 || ep == NULL ||
980 			    (*ep != ' ' && *ep != '\t')) {
981 				int quoted = 0;
982 
983 				comment = cp;
984 				for (; *cp && (quoted || (*cp != ' ' &&
985 				    *cp != '\t')); cp++) {
986 					if (*cp == '\\' && cp[1] == '"')
987 						cp++;	/* Skip both */
988 					else if (*cp == '"')
989 						quoted = !quoted;
990 				}
991 				if (!*cp)
992 					continue;
993 				*cp++ = '\0';
994 			}
995 		}
996 		/* Retry after parsing leading hostname/key options */
997 		if (public == NULL && (public = try_read_key(&cp)) == NULL) {
998 			debug("%s:%lu: not a public key", path, lnum);
999 			continue;
1000 		}
1001 
1002 		/* Find trailing comment, if any */
1003 		for (; *cp == ' ' || *cp == '\t'; cp++)
1004 			;
1005 		if (*cp != '\0' && *cp != '#')
1006 			comment = cp;
1007 
1008 		fingerprint_one_key(public, comment);
1009 		sshkey_free(public);
1010 		invalid = 0; /* One good key in the file is sufficient */
1011 	}
1012 	fclose(f);
1013 	free(line);
1014 
1015 	if (invalid)
1016 		fatal("%s is not a public key file.", path);
1017 	exit(0);
1018 }
1019 
1020 static void
1021 do_gen_all_hostkeys(struct passwd *pw)
1022 {
1023 	struct {
1024 		const char *key_type;
1025 		const char *key_type_display;
1026 		const char *path;
1027 	} key_types[] = {
1028 #ifdef WITH_OPENSSL
1029 		{ "rsa", "RSA" ,_PATH_HOST_RSA_KEY_FILE },
1030 		{ "dsa", "DSA", _PATH_HOST_DSA_KEY_FILE },
1031 		{ "ecdsa", "ECDSA",_PATH_HOST_ECDSA_KEY_FILE },
1032 #endif /* WITH_OPENSSL */
1033 		{ "ed25519", "ED25519",_PATH_HOST_ED25519_KEY_FILE },
1034 #ifdef WITH_XMSS
1035 		{ "xmss", "XMSS",_PATH_HOST_XMSS_KEY_FILE },
1036 #endif /* WITH_XMSS */
1037 		{ NULL, NULL, NULL }
1038 	};
1039 
1040 	u_int32_t bits = 0;
1041 	int first = 0;
1042 	struct stat st;
1043 	struct sshkey *private, *public;
1044 	char comment[1024], *prv_tmp, *pub_tmp, *prv_file, *pub_file;
1045 	int i, type, fd, r;
1046 
1047 	for (i = 0; key_types[i].key_type; i++) {
1048 		public = private = NULL;
1049 		prv_tmp = pub_tmp = prv_file = pub_file = NULL;
1050 
1051 		xasprintf(&prv_file, "%s%s",
1052 		    identity_file, key_types[i].path);
1053 
1054 		/* Check whether private key exists and is not zero-length */
1055 		if (stat(prv_file, &st) == 0) {
1056 			if (st.st_size != 0)
1057 				goto next;
1058 		} else if (errno != ENOENT) {
1059 			error("Could not stat %s: %s", key_types[i].path,
1060 			    strerror(errno));
1061 			goto failnext;
1062 		}
1063 
1064 		/*
1065 		 * Private key doesn't exist or is invalid; proceed with
1066 		 * key generation.
1067 		 */
1068 		xasprintf(&prv_tmp, "%s%s.XXXXXXXXXX",
1069 		    identity_file, key_types[i].path);
1070 		xasprintf(&pub_tmp, "%s%s.pub.XXXXXXXXXX",
1071 		    identity_file, key_types[i].path);
1072 		xasprintf(&pub_file, "%s%s.pub",
1073 		    identity_file, key_types[i].path);
1074 
1075 		if (first == 0) {
1076 			first = 1;
1077 			printf("%s: generating new host keys: ", __progname);
1078 		}
1079 		printf("%s ", key_types[i].key_type_display);
1080 		fflush(stdout);
1081 		type = sshkey_type_from_name(key_types[i].key_type);
1082 		if ((fd = mkstemp(prv_tmp)) == -1) {
1083 			error("Could not save your private key in %s: %s",
1084 			    prv_tmp, strerror(errno));
1085 			goto failnext;
1086 		}
1087 		(void)close(fd); /* just using mkstemp() to reserve a name */
1088 		bits = 0;
1089 		type_bits_valid(type, NULL, &bits);
1090 		if ((r = sshkey_generate(type, bits, &private)) != 0) {
1091 			error("sshkey_generate failed: %s", ssh_err(r));
1092 			goto failnext;
1093 		}
1094 		if ((r = sshkey_from_private(private, &public)) != 0)
1095 			fatal("sshkey_from_private failed: %s", ssh_err(r));
1096 		snprintf(comment, sizeof comment, "%s@%s", pw->pw_name,
1097 		    hostname);
1098 		if ((r = sshkey_save_private(private, prv_tmp, "",
1099 		    comment, private_key_format, openssh_format_cipher,
1100 		    rounds)) != 0) {
1101 			error("Saving key \"%s\" failed: %s",
1102 			    prv_tmp, ssh_err(r));
1103 			goto failnext;
1104 		}
1105 		if ((fd = mkstemp(pub_tmp)) == -1) {
1106 			error("Could not save your public key in %s: %s",
1107 			    pub_tmp, strerror(errno));
1108 			goto failnext;
1109 		}
1110 		(void)fchmod(fd, 0644);
1111 		(void)close(fd);
1112 		if ((r = sshkey_save_public(public, pub_tmp, comment)) != 0) {
1113 			fatal("Unable to save public key to %s: %s",
1114 			    identity_file, ssh_err(r));
1115 			goto failnext;
1116 		}
1117 
1118 		/* Rename temporary files to their permanent locations. */
1119 		if (rename(pub_tmp, pub_file) != 0) {
1120 			error("Unable to move %s into position: %s",
1121 			    pub_file, strerror(errno));
1122 			goto failnext;
1123 		}
1124 		if (rename(prv_tmp, prv_file) != 0) {
1125 			error("Unable to move %s into position: %s",
1126 			    key_types[i].path, strerror(errno));
1127  failnext:
1128 			first = 0;
1129 			goto next;
1130 		}
1131  next:
1132 		sshkey_free(private);
1133 		sshkey_free(public);
1134 		free(prv_tmp);
1135 		free(pub_tmp);
1136 		free(prv_file);
1137 		free(pub_file);
1138 	}
1139 	if (first != 0)
1140 		printf("\n");
1141 }
1142 
1143 struct known_hosts_ctx {
1144 	const char *host;	/* Hostname searched for in find/delete case */
1145 	FILE *out;		/* Output file, stdout for find_hosts case */
1146 	int has_unhashed;	/* When hashing, original had unhashed hosts */
1147 	int found_key;		/* For find/delete, host was found */
1148 	int invalid;		/* File contained invalid items; don't delete */
1149 	int hash_hosts;		/* Hash hostnames as we go */
1150 	int find_host;		/* Search for specific hostname */
1151 	int delete_host;	/* Delete host from known_hosts */
1152 };
1153 
1154 static int
1155 known_hosts_hash(struct hostkey_foreach_line *l, void *_ctx)
1156 {
1157 	struct known_hosts_ctx *ctx = (struct known_hosts_ctx *)_ctx;
1158 	char *hashed, *cp, *hosts, *ohosts;
1159 	int has_wild = l->hosts && strcspn(l->hosts, "*?!") != strlen(l->hosts);
1160 	int was_hashed = l->hosts && l->hosts[0] == HASH_DELIM;
1161 
1162 	switch (l->status) {
1163 	case HKF_STATUS_OK:
1164 	case HKF_STATUS_MATCHED:
1165 		/*
1166 		 * Don't hash hosts already already hashed, with wildcard
1167 		 * characters or a CA/revocation marker.
1168 		 */
1169 		if (was_hashed || has_wild || l->marker != MRK_NONE) {
1170 			fprintf(ctx->out, "%s\n", l->line);
1171 			if (has_wild && !ctx->find_host) {
1172 				logit("%s:%lu: ignoring host name "
1173 				    "with wildcard: %.64s", l->path,
1174 				    l->linenum, l->hosts);
1175 			}
1176 			return 0;
1177 		}
1178 		/*
1179 		 * Split any comma-separated hostnames from the host list,
1180 		 * hash and store separately.
1181 		 */
1182 		ohosts = hosts = xstrdup(l->hosts);
1183 		while ((cp = strsep(&hosts, ",")) != NULL && *cp != '\0') {
1184 			lowercase(cp);
1185 			if ((hashed = host_hash(cp, NULL, 0)) == NULL)
1186 				fatal("hash_host failed");
1187 			fprintf(ctx->out, "%s %s\n", hashed, l->rawkey);
1188 			ctx->has_unhashed = 1;
1189 		}
1190 		free(ohosts);
1191 		return 0;
1192 	case HKF_STATUS_INVALID:
1193 		/* Retain invalid lines, but mark file as invalid. */
1194 		ctx->invalid = 1;
1195 		logit("%s:%lu: invalid line", l->path, l->linenum);
1196 		/* FALLTHROUGH */
1197 	default:
1198 		fprintf(ctx->out, "%s\n", l->line);
1199 		return 0;
1200 	}
1201 	/* NOTREACHED */
1202 	return -1;
1203 }
1204 
1205 static int
1206 known_hosts_find_delete(struct hostkey_foreach_line *l, void *_ctx)
1207 {
1208 	struct known_hosts_ctx *ctx = (struct known_hosts_ctx *)_ctx;
1209 	enum sshkey_fp_rep rep;
1210 	int fptype;
1211 	char *fp = NULL, *ra = NULL;
1212 
1213 	fptype = print_bubblebabble ? SSH_DIGEST_SHA1 : fingerprint_hash;
1214 	rep =    print_bubblebabble ? SSH_FP_BUBBLEBABBLE : SSH_FP_DEFAULT;
1215 
1216 	if (l->status == HKF_STATUS_MATCHED) {
1217 		if (ctx->delete_host) {
1218 			if (l->marker != MRK_NONE) {
1219 				/* Don't remove CA and revocation lines */
1220 				fprintf(ctx->out, "%s\n", l->line);
1221 			} else {
1222 				/*
1223 				 * Hostname matches and has no CA/revoke
1224 				 * marker, delete it by *not* writing the
1225 				 * line to ctx->out.
1226 				 */
1227 				ctx->found_key = 1;
1228 				if (!quiet)
1229 					printf("# Host %s found: line %lu\n",
1230 					    ctx->host, l->linenum);
1231 			}
1232 			return 0;
1233 		} else if (ctx->find_host) {
1234 			ctx->found_key = 1;
1235 			if (!quiet) {
1236 				printf("# Host %s found: line %lu %s\n",
1237 				    ctx->host,
1238 				    l->linenum, l->marker == MRK_CA ? "CA" :
1239 				    (l->marker == MRK_REVOKE ? "REVOKED" : ""));
1240 			}
1241 			if (ctx->hash_hosts)
1242 				known_hosts_hash(l, ctx);
1243 			else if (print_fingerprint) {
1244 				fp = sshkey_fingerprint(l->key, fptype, rep);
1245 				ra = sshkey_fingerprint(l->key,
1246 				    fingerprint_hash, SSH_FP_RANDOMART);
1247 				if (fp == NULL || ra == NULL)
1248 					fatal("%s: sshkey_fingerprint failed",
1249 					    __func__);
1250 				mprintf("%s %s %s%s%s\n", ctx->host,
1251 				    sshkey_type(l->key), fp,
1252 				    l->comment[0] ? " " : "",
1253 				    l->comment);
1254 				if (log_level_get() >= SYSLOG_LEVEL_VERBOSE)
1255 					printf("%s\n", ra);
1256 				free(ra);
1257 				free(fp);
1258 			} else
1259 				fprintf(ctx->out, "%s\n", l->line);
1260 			return 0;
1261 		}
1262 	} else if (ctx->delete_host) {
1263 		/* Retain non-matching hosts when deleting */
1264 		if (l->status == HKF_STATUS_INVALID) {
1265 			ctx->invalid = 1;
1266 			logit("%s:%lu: invalid line", l->path, l->linenum);
1267 		}
1268 		fprintf(ctx->out, "%s\n", l->line);
1269 	}
1270 	return 0;
1271 }
1272 
1273 __dead static void
1274 do_known_hosts(struct passwd *pw, const char *name, int find_host,
1275     int delete_host, int hash_hosts)
1276 {
1277 	char *cp, tmp[PATH_MAX], old[PATH_MAX];
1278 	int r, fd, oerrno, inplace = 0;
1279 	struct known_hosts_ctx ctx;
1280 	u_int foreach_options;
1281 	struct stat sb;
1282 
1283 	if (!have_identity) {
1284 		cp = tilde_expand_filename(_PATH_SSH_USER_HOSTFILE, pw->pw_uid);
1285 		if (strlcpy(identity_file, cp, sizeof(identity_file)) >=
1286 		    sizeof(identity_file))
1287 			fatal("Specified known hosts path too long");
1288 		free(cp);
1289 		have_identity = 1;
1290 	}
1291 	if (stat(identity_file, &sb) != 0)
1292 		fatal("Cannot stat %s: %s", identity_file, strerror(errno));
1293 
1294 	memset(&ctx, 0, sizeof(ctx));
1295 	ctx.out = stdout;
1296 	ctx.host = name;
1297 	ctx.hash_hosts = hash_hosts;
1298 	ctx.find_host = find_host;
1299 	ctx.delete_host = delete_host;
1300 
1301 	/*
1302 	 * Find hosts goes to stdout, hash and deletions happen in-place
1303 	 * A corner case is ssh-keygen -HF foo, which should go to stdout
1304 	 */
1305 	if (!find_host && (hash_hosts || delete_host)) {
1306 		if (strlcpy(tmp, identity_file, sizeof(tmp)) >= sizeof(tmp) ||
1307 		    strlcat(tmp, ".XXXXXXXXXX", sizeof(tmp)) >= sizeof(tmp) ||
1308 		    strlcpy(old, identity_file, sizeof(old)) >= sizeof(old) ||
1309 		    strlcat(old, ".old", sizeof(old)) >= sizeof(old))
1310 			fatal("known_hosts path too long");
1311 		umask(077);
1312 		if ((fd = mkstemp(tmp)) == -1)
1313 			fatal("mkstemp: %s", strerror(errno));
1314 		if ((ctx.out = fdopen(fd, "w")) == NULL) {
1315 			oerrno = errno;
1316 			unlink(tmp);
1317 			fatal("fdopen: %s", strerror(oerrno));
1318 		}
1319 		fchmod(fd, sb.st_mode & 0644);
1320 		inplace = 1;
1321 	}
1322 	/* XXX support identity_file == "-" for stdin */
1323 	foreach_options = find_host ? HKF_WANT_MATCH : 0;
1324 	foreach_options |= print_fingerprint ? HKF_WANT_PARSE_KEY : 0;
1325 	if ((r = hostkeys_foreach(identity_file, (find_host || !hash_hosts) ?
1326 	    known_hosts_find_delete : known_hosts_hash, &ctx, name, NULL,
1327 	    foreach_options)) != 0) {
1328 		if (inplace)
1329 			unlink(tmp);
1330 		fatal("%s: hostkeys_foreach failed: %s", __func__, ssh_err(r));
1331 	}
1332 
1333 	if (inplace)
1334 		fclose(ctx.out);
1335 
1336 	if (ctx.invalid) {
1337 		error("%s is not a valid known_hosts file.", identity_file);
1338 		if (inplace) {
1339 			error("Not replacing existing known_hosts "
1340 			    "file because of errors");
1341 			unlink(tmp);
1342 		}
1343 		exit(1);
1344 	} else if (delete_host && !ctx.found_key) {
1345 		logit("Host %s not found in %s", name, identity_file);
1346 		if (inplace)
1347 			unlink(tmp);
1348 	} else if (inplace) {
1349 		/* Backup existing file */
1350 		if (unlink(old) == -1 && errno != ENOENT)
1351 			fatal("unlink %.100s: %s", old, strerror(errno));
1352 		if (link(identity_file, old) == -1)
1353 			fatal("link %.100s to %.100s: %s", identity_file, old,
1354 			    strerror(errno));
1355 		/* Move new one into place */
1356 		if (rename(tmp, identity_file) == -1) {
1357 			error("rename\"%s\" to \"%s\": %s", tmp, identity_file,
1358 			    strerror(errno));
1359 			unlink(tmp);
1360 			unlink(old);
1361 			exit(1);
1362 		}
1363 
1364 		printf("%s updated.\n", identity_file);
1365 		printf("Original contents retained as %s\n", old);
1366 		if (ctx.has_unhashed) {
1367 			logit("WARNING: %s contains unhashed entries", old);
1368 			logit("Delete this file to ensure privacy "
1369 			    "of hostnames");
1370 		}
1371 	}
1372 
1373 	exit (find_host && !ctx.found_key);
1374 }
1375 
1376 /*
1377  * Perform changing a passphrase.  The argument is the passwd structure
1378  * for the current user.
1379  */
1380 __dead static void
1381 do_change_passphrase(struct passwd *pw)
1382 {
1383 	char *comment;
1384 	char *old_passphrase, *passphrase1, *passphrase2;
1385 	struct stat st;
1386 	struct sshkey *private;
1387 	int r;
1388 
1389 	if (!have_identity)
1390 		ask_filename(pw, "Enter file in which the key is");
1391 	if (stat(identity_file, &st) == -1)
1392 		fatal("%s: %s", identity_file, strerror(errno));
1393 	/* Try to load the file with empty passphrase. */
1394 	r = sshkey_load_private(identity_file, "", &private, &comment);
1395 	if (r == SSH_ERR_KEY_WRONG_PASSPHRASE) {
1396 		if (identity_passphrase)
1397 			old_passphrase = xstrdup(identity_passphrase);
1398 		else
1399 			old_passphrase =
1400 			    read_passphrase("Enter old passphrase: ",
1401 			    RP_ALLOW_STDIN);
1402 		r = sshkey_load_private(identity_file, old_passphrase,
1403 		    &private, &comment);
1404 		freezero(old_passphrase, strlen(old_passphrase));
1405 		if (r != 0)
1406 			goto badkey;
1407 	} else if (r != 0) {
1408  badkey:
1409 		fatal("Failed to load key %s: %s", identity_file, ssh_err(r));
1410 	}
1411 	if (comment)
1412 		mprintf("Key has comment '%s'\n", comment);
1413 
1414 	/* Ask the new passphrase (twice). */
1415 	if (identity_new_passphrase) {
1416 		passphrase1 = xstrdup(identity_new_passphrase);
1417 		passphrase2 = NULL;
1418 	} else {
1419 		passphrase1 =
1420 			read_passphrase("Enter new passphrase (empty for no "
1421 			    "passphrase): ", RP_ALLOW_STDIN);
1422 		passphrase2 = read_passphrase("Enter same passphrase again: ",
1423 		    RP_ALLOW_STDIN);
1424 
1425 		/* Verify that they are the same. */
1426 		if (strcmp(passphrase1, passphrase2) != 0) {
1427 			explicit_bzero(passphrase1, strlen(passphrase1));
1428 			explicit_bzero(passphrase2, strlen(passphrase2));
1429 			free(passphrase1);
1430 			free(passphrase2);
1431 			printf("Pass phrases do not match.  Try again.\n");
1432 			exit(1);
1433 		}
1434 		/* Destroy the other copy. */
1435 		freezero(passphrase2, strlen(passphrase2));
1436 	}
1437 
1438 	/* Save the file using the new passphrase. */
1439 	if ((r = sshkey_save_private(private, identity_file, passphrase1,
1440 	    comment, private_key_format, openssh_format_cipher, rounds)) != 0) {
1441 		error("Saving key \"%s\" failed: %s.",
1442 		    identity_file, ssh_err(r));
1443 		freezero(passphrase1, strlen(passphrase1));
1444 		sshkey_free(private);
1445 		free(comment);
1446 		exit(1);
1447 	}
1448 	/* Destroy the passphrase and the copy of the key in memory. */
1449 	freezero(passphrase1, strlen(passphrase1));
1450 	sshkey_free(private);		 /* Destroys contents */
1451 	free(comment);
1452 
1453 	printf("Your identification has been saved with the new passphrase.\n");
1454 	exit(0);
1455 }
1456 
1457 /*
1458  * Print the SSHFP RR.
1459  */
1460 static int
1461 do_print_resource_record(struct passwd *pw, const char *fname,
1462     const char *hname, int print_generic)
1463 {
1464 	struct sshkey *public;
1465 	char *comment = NULL;
1466 	struct stat st;
1467 	int r;
1468 
1469 	if (fname == NULL)
1470 		fatal("%s: no filename", __func__);
1471 	if (stat(fname, &st) == -1) {
1472 		if (errno == ENOENT)
1473 			return 0;
1474 		fatal("%s: %s", fname, strerror(errno));
1475 	}
1476 	if ((r = sshkey_load_public(fname, &public, &comment)) != 0)
1477 		fatal("Failed to read v2 public key from \"%s\": %s.",
1478 		    fname, ssh_err(r));
1479 	export_dns_rr(hname, public, stdout, print_generic);
1480 	sshkey_free(public);
1481 	free(comment);
1482 	return 1;
1483 }
1484 
1485 /*
1486  * Change the comment of a private key file.
1487  */
1488 __dead static void
1489 do_change_comment(struct passwd *pw, const char *identity_comment)
1490 {
1491 	char new_comment[1024], *comment, *passphrase;
1492 	struct sshkey *private;
1493 	struct sshkey *public;
1494 	struct stat st;
1495 	int r;
1496 
1497 	if (!have_identity)
1498 		ask_filename(pw, "Enter file in which the key is");
1499 	if (stat(identity_file, &st) == -1)
1500 		fatal("%s: %s", identity_file, strerror(errno));
1501 	if ((r = sshkey_load_private(identity_file, "",
1502 	    &private, &comment)) == 0)
1503 		passphrase = xstrdup("");
1504 	else if (r != SSH_ERR_KEY_WRONG_PASSPHRASE)
1505 		fatal("Cannot load private key \"%s\": %s.",
1506 		    identity_file, ssh_err(r));
1507 	else {
1508 		if (identity_passphrase)
1509 			passphrase = xstrdup(identity_passphrase);
1510 		else if (identity_new_passphrase)
1511 			passphrase = xstrdup(identity_new_passphrase);
1512 		else
1513 			passphrase = read_passphrase("Enter passphrase: ",
1514 			    RP_ALLOW_STDIN);
1515 		/* Try to load using the passphrase. */
1516 		if ((r = sshkey_load_private(identity_file, passphrase,
1517 		    &private, &comment)) != 0) {
1518 			freezero(passphrase, strlen(passphrase));
1519 			fatal("Cannot load private key \"%s\": %s.",
1520 			    identity_file, ssh_err(r));
1521 		}
1522 	}
1523 
1524 	if (private->type != KEY_ED25519 && private->type != KEY_XMSS &&
1525 	    private_key_format != SSHKEY_PRIVATE_OPENSSH) {
1526 		error("Comments are only supported for keys stored in "
1527 		    "the new format (-o).");
1528 		explicit_bzero(passphrase, strlen(passphrase));
1529 		sshkey_free(private);
1530 		exit(1);
1531 	}
1532 	if (comment)
1533 		printf("Old comment: %s\n", comment);
1534 	else
1535 		printf("No existing comment\n");
1536 
1537 	if (identity_comment) {
1538 		strlcpy(new_comment, identity_comment, sizeof(new_comment));
1539 	} else {
1540 		printf("New comment: ");
1541 		fflush(stdout);
1542 		if (!fgets(new_comment, sizeof(new_comment), stdin)) {
1543 			explicit_bzero(passphrase, strlen(passphrase));
1544 			sshkey_free(private);
1545 			exit(1);
1546 		}
1547 		new_comment[strcspn(new_comment, "\n")] = '\0';
1548 	}
1549 	if (comment != NULL && strcmp(comment, new_comment) == 0) {
1550 		printf("No change to comment\n");
1551 		free(passphrase);
1552 		sshkey_free(private);
1553 		free(comment);
1554 		exit(0);
1555 	}
1556 
1557 	/* Save the file using the new passphrase. */
1558 	if ((r = sshkey_save_private(private, identity_file, passphrase,
1559 	    new_comment, private_key_format, openssh_format_cipher,
1560 	    rounds)) != 0) {
1561 		error("Saving key \"%s\" failed: %s",
1562 		    identity_file, ssh_err(r));
1563 		freezero(passphrase, strlen(passphrase));
1564 		sshkey_free(private);
1565 		free(comment);
1566 		exit(1);
1567 	}
1568 	freezero(passphrase, strlen(passphrase));
1569 	if ((r = sshkey_from_private(private, &public)) != 0)
1570 		fatal("sshkey_from_private failed: %s", ssh_err(r));
1571 	sshkey_free(private);
1572 
1573 	strlcat(identity_file, ".pub", sizeof(identity_file));
1574 	if ((r = sshkey_save_public(public, identity_file, new_comment)) != 0) {
1575 		fatal("Unable to save public key to %s: %s",
1576 		    identity_file, ssh_err(r));
1577 	}
1578 	sshkey_free(public);
1579 	free(comment);
1580 
1581 	if (strlen(new_comment) > 0)
1582 		printf("Comment '%s' applied\n", new_comment);
1583 	else
1584 		printf("Comment removed\n");
1585 
1586 	exit(0);
1587 }
1588 
1589 static void
1590 cert_ext_add(const char *key, const char *value, int iscrit)
1591 {
1592 	cert_ext = xreallocarray(cert_ext, ncert_ext + 1, sizeof(*cert_ext));
1593 	cert_ext[ncert_ext].key = xstrdup(key);
1594 	cert_ext[ncert_ext].val = value == NULL ? NULL : xstrdup(value);
1595 	cert_ext[ncert_ext].crit = iscrit;
1596 	ncert_ext++;
1597 }
1598 
1599 /* qsort(3) comparison function for certificate extensions */
1600 static int
1601 cert_ext_cmp(const void *_a, const void *_b)
1602 {
1603 	const struct cert_ext *a = (const struct cert_ext *)_a;
1604 	const struct cert_ext *b = (const struct cert_ext *)_b;
1605 	int r;
1606 
1607 	if (a->crit != b->crit)
1608 		return (a->crit < b->crit) ? -1 : 1;
1609 	if ((r = strcmp(a->key, b->key)) != 0)
1610 		return r;
1611 	if ((a->val == NULL) != (b->val == NULL))
1612 		return (a->val == NULL) ? -1 : 1;
1613 	if (a->val != NULL && (r = strcmp(a->val, b->val)) != 0)
1614 		return r;
1615 	return 0;
1616 }
1617 
1618 #define OPTIONS_CRITICAL	1
1619 #define OPTIONS_EXTENSIONS	2
1620 static void
1621 prepare_options_buf(struct sshbuf *c, int which)
1622 {
1623 	struct sshbuf *b;
1624 	size_t i;
1625 	int r;
1626 	const struct cert_ext *ext;
1627 
1628 	if ((b = sshbuf_new()) == NULL)
1629 		fatal("%s: sshbuf_new failed", __func__);
1630 	sshbuf_reset(c);
1631 	for (i = 0; i < ncert_ext; i++) {
1632 		ext = &cert_ext[i];
1633 		if ((ext->crit && (which & OPTIONS_EXTENSIONS)) ||
1634 		    (!ext->crit && (which & OPTIONS_CRITICAL)))
1635 			continue;
1636 		if (ext->val == NULL) {
1637 			/* flag option */
1638 			debug3("%s: %s", __func__, ext->key);
1639 			if ((r = sshbuf_put_cstring(c, ext->key)) != 0 ||
1640 			    (r = sshbuf_put_string(c, NULL, 0)) != 0)
1641 				fatal("%s: buffer: %s", __func__, ssh_err(r));
1642 		} else {
1643 			/* key/value option */
1644 			debug3("%s: %s=%s", __func__, ext->key, ext->val);
1645 			sshbuf_reset(b);
1646 			if ((r = sshbuf_put_cstring(c, ext->key)) != 0 ||
1647 			    (r = sshbuf_put_cstring(b, ext->val)) != 0 ||
1648 			    (r = sshbuf_put_stringb(c, b)) != 0)
1649 				fatal("%s: buffer: %s", __func__, ssh_err(r));
1650 		}
1651 	}
1652 	sshbuf_free(b);
1653 }
1654 
1655 static void
1656 finalise_cert_exts(void)
1657 {
1658 	/* critical options */
1659 	if (certflags_command != NULL)
1660 		cert_ext_add("force-command", certflags_command, 1);
1661 	if (certflags_src_addr != NULL)
1662 		cert_ext_add("source-address", certflags_src_addr, 1);
1663 	/* extensions */
1664 	if ((certflags_flags & CERTOPT_X_FWD) != 0)
1665 		cert_ext_add("permit-X11-forwarding", NULL, 0);
1666 	if ((certflags_flags & CERTOPT_AGENT_FWD) != 0)
1667 		cert_ext_add("permit-agent-forwarding", NULL, 0);
1668 	if ((certflags_flags & CERTOPT_PORT_FWD) != 0)
1669 		cert_ext_add("permit-port-forwarding", NULL, 0);
1670 	if ((certflags_flags & CERTOPT_PTY) != 0)
1671 		cert_ext_add("permit-pty", NULL, 0);
1672 	if ((certflags_flags & CERTOPT_USER_RC) != 0)
1673 		cert_ext_add("permit-user-rc", NULL, 0);
1674 	if ((certflags_flags & CERTOPT_NO_REQUIRE_USER_PRESENCE) != 0)
1675 		cert_ext_add("no-touch-required", NULL, 0);
1676 	/* order lexically by key */
1677 	if (ncert_ext > 0)
1678 		qsort(cert_ext, ncert_ext, sizeof(*cert_ext), cert_ext_cmp);
1679 }
1680 
1681 static struct sshkey *
1682 load_pkcs11_key(char *path)
1683 {
1684 #ifdef ENABLE_PKCS11
1685 	struct sshkey **keys = NULL, *public, *private = NULL;
1686 	int r, i, nkeys;
1687 
1688 	if ((r = sshkey_load_public(path, &public, NULL)) != 0)
1689 		fatal("Couldn't load CA public key \"%s\": %s",
1690 		    path, ssh_err(r));
1691 
1692 	nkeys = pkcs11_add_provider(pkcs11provider, identity_passphrase,
1693 	    &keys, NULL);
1694 	debug3("%s: %d keys", __func__, nkeys);
1695 	if (nkeys <= 0)
1696 		fatal("cannot read public key from pkcs11");
1697 	for (i = 0; i < nkeys; i++) {
1698 		if (sshkey_equal_public(public, keys[i])) {
1699 			private = keys[i];
1700 			continue;
1701 		}
1702 		sshkey_free(keys[i]);
1703 	}
1704 	free(keys);
1705 	sshkey_free(public);
1706 	return private;
1707 #else
1708 	fatal("no pkcs11 support");
1709 #endif /* ENABLE_PKCS11 */
1710 }
1711 
1712 /* Signer for sshkey_certify_custom that uses the agent */
1713 static int
1714 agent_signer(struct sshkey *key, u_char **sigp, size_t *lenp,
1715     const u_char *data, size_t datalen,
1716     const char *alg, const char *provider, const char *pin,
1717     u_int compat, void *ctx)
1718 {
1719 	int *agent_fdp = (int *)ctx;
1720 
1721 	return ssh_agent_sign(*agent_fdp, key, sigp, lenp,
1722 	    data, datalen, alg, compat);
1723 }
1724 
1725 __dead static void
1726 do_ca_sign(struct passwd *pw, const char *ca_key_path, int prefer_agent,
1727     unsigned long long cert_serial, int cert_serial_autoinc,
1728     int argc, char **argv)
1729 {
1730 	int r, i, found, agent_fd = -1;
1731 	u_int n;
1732 	struct sshkey *ca, *public;
1733 	char valid[64], *otmp, *tmp, *cp, *out, *comment;
1734 	char *ca_fp = NULL, **plist = NULL, *pin = NULL;
1735 	struct ssh_identitylist *agent_ids;
1736 	size_t j;
1737 	struct notifier_ctx *notifier = NULL;
1738 
1739 #ifdef ENABLE_PKCS11
1740 	pkcs11_init(1);
1741 #endif
1742 	tmp = tilde_expand_filename(ca_key_path, pw->pw_uid);
1743 	if (pkcs11provider != NULL) {
1744 		/* If a PKCS#11 token was specified then try to use it */
1745 		if ((ca = load_pkcs11_key(tmp)) == NULL)
1746 			fatal("No PKCS#11 key matching %s found", ca_key_path);
1747 	} else if (prefer_agent) {
1748 		/*
1749 		 * Agent signature requested. Try to use agent after making
1750 		 * sure the public key specified is actually present in the
1751 		 * agent.
1752 		 */
1753 		if ((r = sshkey_load_public(tmp, &ca, NULL)) != 0)
1754 			fatal("Cannot load CA public key %s: %s",
1755 			    tmp, ssh_err(r));
1756 		if ((r = ssh_get_authentication_socket(&agent_fd)) != 0)
1757 			fatal("Cannot use public key for CA signature: %s",
1758 			    ssh_err(r));
1759 		if ((r = ssh_fetch_identitylist(agent_fd, &agent_ids)) != 0)
1760 			fatal("Retrieve agent key list: %s", ssh_err(r));
1761 		found = 0;
1762 		for (j = 0; j < agent_ids->nkeys; j++) {
1763 			if (sshkey_equal(ca, agent_ids->keys[j])) {
1764 				found = 1;
1765 				break;
1766 			}
1767 		}
1768 		if (!found)
1769 			fatal("CA key %s not found in agent", tmp);
1770 		ssh_free_identitylist(agent_ids);
1771 		ca->flags |= SSHKEY_FLAG_EXT;
1772 	} else {
1773 		/* CA key is assumed to be a private key on the filesystem */
1774 		ca = load_identity(tmp, NULL);
1775 		if (sshkey_is_sk(ca) &&
1776 		    (ca->sk_flags & SSH_SK_USER_VERIFICATION_REQD)) {
1777 			if ((pin = read_passphrase("Enter PIN for CA key: ",
1778 			    RP_ALLOW_STDIN)) == NULL)
1779 				fatal("%s: couldn't read PIN", __func__);
1780 		}
1781 	}
1782 	free(tmp);
1783 
1784 	if (key_type_name != NULL) {
1785 		if (sshkey_type_from_name(key_type_name) != ca->type) {
1786 			fatal("CA key type %s doesn't match specified %s",
1787 			    sshkey_ssh_name(ca), key_type_name);
1788 		}
1789 	} else if (ca->type == KEY_RSA) {
1790 		/* Default to a good signature algorithm */
1791 		key_type_name = "rsa-sha2-512";
1792 	}
1793 	ca_fp = sshkey_fingerprint(ca, fingerprint_hash, SSH_FP_DEFAULT);
1794 
1795 	finalise_cert_exts();
1796 	for (i = 0; i < argc; i++) {
1797 		/* Split list of principals */
1798 		n = 0;
1799 		if (cert_principals != NULL) {
1800 			otmp = tmp = xstrdup(cert_principals);
1801 			plist = NULL;
1802 			for (; (cp = strsep(&tmp, ",")) != NULL; n++) {
1803 				plist = xreallocarray(plist, n + 1, sizeof(*plist));
1804 				if (*(plist[n] = xstrdup(cp)) == '\0')
1805 					fatal("Empty principal name");
1806 			}
1807 			free(otmp);
1808 		}
1809 		if (n > SSHKEY_CERT_MAX_PRINCIPALS)
1810 			fatal("Too many certificate principals specified");
1811 
1812 		tmp = tilde_expand_filename(argv[i], pw->pw_uid);
1813 		if ((r = sshkey_load_public(tmp, &public, &comment)) != 0)
1814 			fatal("%s: unable to open \"%s\": %s",
1815 			    __func__, tmp, ssh_err(r));
1816 		if (sshkey_is_cert(public))
1817 			fatal("%s: key \"%s\" type %s cannot be certified",
1818 			    __func__, tmp, sshkey_type(public));
1819 
1820 		/* Prepare certificate to sign */
1821 		if ((r = sshkey_to_certified(public)) != 0)
1822 			fatal("Could not upgrade key %s to certificate: %s",
1823 			    tmp, ssh_err(r));
1824 		public->cert->type = cert_key_type;
1825 		public->cert->serial = (u_int64_t)cert_serial;
1826 		public->cert->key_id = xstrdup(cert_key_id);
1827 		public->cert->nprincipals = n;
1828 		public->cert->principals = plist;
1829 		public->cert->valid_after = cert_valid_from;
1830 		public->cert->valid_before = cert_valid_to;
1831 		prepare_options_buf(public->cert->critical, OPTIONS_CRITICAL);
1832 		prepare_options_buf(public->cert->extensions,
1833 		    OPTIONS_EXTENSIONS);
1834 		if ((r = sshkey_from_private(ca,
1835 		    &public->cert->signature_key)) != 0)
1836 			fatal("sshkey_from_private (ca key): %s", ssh_err(r));
1837 
1838 		if (agent_fd != -1 && (ca->flags & SSHKEY_FLAG_EXT) != 0) {
1839 			if ((r = sshkey_certify_custom(public, ca,
1840 			    key_type_name, sk_provider, NULL, agent_signer,
1841 			    &agent_fd)) != 0)
1842 				fatal("Couldn't certify key %s via agent: %s",
1843 				    tmp, ssh_err(r));
1844 		} else {
1845 			if (sshkey_is_sk(ca) &&
1846 			    (ca->sk_flags & SSH_SK_USER_PRESENCE_REQD)) {
1847 				notifier = notify_start(0,
1848 				    "Confirm user presence for key %s %s",
1849 				    sshkey_type(ca), ca_fp);
1850 			}
1851 			r = sshkey_certify(public, ca, key_type_name,
1852 			    sk_provider, pin);
1853 			notify_complete(notifier);
1854 			if (r != 0)
1855 				fatal("Couldn't certify key %s: %s",
1856 				    tmp, ssh_err(r));
1857 		}
1858 
1859 		if ((cp = strrchr(tmp, '.')) != NULL && strcmp(cp, ".pub") == 0)
1860 			*cp = '\0';
1861 		xasprintf(&out, "%s-cert.pub", tmp);
1862 		free(tmp);
1863 
1864 		if ((r = sshkey_save_public(public, out, comment)) != 0) {
1865 			fatal("Unable to save public key to %s: %s",
1866 			    identity_file, ssh_err(r));
1867 		}
1868 
1869 		if (!quiet) {
1870 			sshkey_format_cert_validity(public->cert,
1871 			    valid, sizeof(valid));
1872 			logit("Signed %s key %s: id \"%s\" serial %llu%s%s "
1873 			    "valid %s", sshkey_cert_type(public),
1874 			    out, public->cert->key_id,
1875 			    (unsigned long long)public->cert->serial,
1876 			    cert_principals != NULL ? " for " : "",
1877 			    cert_principals != NULL ? cert_principals : "",
1878 			    valid);
1879 		}
1880 
1881 		sshkey_free(public);
1882 		free(out);
1883 		if (cert_serial_autoinc)
1884 			cert_serial++;
1885 	}
1886 	if (pin != NULL)
1887 		freezero(pin, strlen(pin));
1888 	free(ca_fp);
1889 #ifdef ENABLE_PKCS11
1890 	pkcs11_terminate();
1891 #endif
1892 	exit(0);
1893 }
1894 
1895 static u_int64_t
1896 parse_relative_time(const char *s, time_t now)
1897 {
1898 	int64_t mul, secs;
1899 
1900 	mul = *s == '-' ? -1 : 1;
1901 
1902 	if ((secs = convtime(s + 1)) == -1)
1903 		fatal("Invalid relative certificate time %s", s);
1904 	if (mul == -1 && secs > now)
1905 		fatal("Certificate time %s cannot be represented", s);
1906 	return now + (u_int64_t)(secs * mul);
1907 }
1908 
1909 static void
1910 parse_cert_times(char *timespec)
1911 {
1912 	char *from, *to;
1913 	time_t now = time(NULL);
1914 	int64_t secs;
1915 
1916 	/* +timespec relative to now */
1917 	if (*timespec == '+' && strchr(timespec, ':') == NULL) {
1918 		if ((secs = convtime(timespec + 1)) == -1)
1919 			fatal("Invalid relative certificate life %s", timespec);
1920 		cert_valid_to = now + secs;
1921 		/*
1922 		 * Backdate certificate one minute to avoid problems on hosts
1923 		 * with poorly-synchronised clocks.
1924 		 */
1925 		cert_valid_from = ((now - 59)/ 60) * 60;
1926 		return;
1927 	}
1928 
1929 	/*
1930 	 * from:to, where
1931 	 * from := [+-]timespec | YYYYMMDD | YYYYMMDDHHMMSS | "always"
1932 	 *   to := [+-]timespec | YYYYMMDD | YYYYMMDDHHMMSS | "forever"
1933 	 */
1934 	from = xstrdup(timespec);
1935 	to = strchr(from, ':');
1936 	if (to == NULL || from == to || *(to + 1) == '\0')
1937 		fatal("Invalid certificate life specification %s", timespec);
1938 	*to++ = '\0';
1939 
1940 	if (*from == '-' || *from == '+')
1941 		cert_valid_from = parse_relative_time(from, now);
1942 	else if (strcmp(from, "always") == 0)
1943 		cert_valid_from = 0;
1944 	else if (parse_absolute_time(from, &cert_valid_from) != 0)
1945 		fatal("Invalid from time \"%s\"", from);
1946 
1947 	if (*to == '-' || *to == '+')
1948 		cert_valid_to = parse_relative_time(to, now);
1949 	else if (strcmp(to, "forever") == 0)
1950 		cert_valid_to = ~(u_int64_t)0;
1951 	else if (parse_absolute_time(to, &cert_valid_to) != 0)
1952 		fatal("Invalid to time \"%s\"", to);
1953 
1954 	if (cert_valid_to <= cert_valid_from)
1955 		fatal("Empty certificate validity interval");
1956 	free(from);
1957 }
1958 
1959 static void
1960 add_cert_option(char *opt)
1961 {
1962 	char *val, *cp;
1963 	int iscrit = 0;
1964 
1965 	if (strcasecmp(opt, "clear") == 0)
1966 		certflags_flags = 0;
1967 	else if (strcasecmp(opt, "no-x11-forwarding") == 0)
1968 		certflags_flags &= ~CERTOPT_X_FWD;
1969 	else if (strcasecmp(opt, "permit-x11-forwarding") == 0)
1970 		certflags_flags |= CERTOPT_X_FWD;
1971 	else if (strcasecmp(opt, "no-agent-forwarding") == 0)
1972 		certflags_flags &= ~CERTOPT_AGENT_FWD;
1973 	else if (strcasecmp(opt, "permit-agent-forwarding") == 0)
1974 		certflags_flags |= CERTOPT_AGENT_FWD;
1975 	else if (strcasecmp(opt, "no-port-forwarding") == 0)
1976 		certflags_flags &= ~CERTOPT_PORT_FWD;
1977 	else if (strcasecmp(opt, "permit-port-forwarding") == 0)
1978 		certflags_flags |= CERTOPT_PORT_FWD;
1979 	else if (strcasecmp(opt, "no-pty") == 0)
1980 		certflags_flags &= ~CERTOPT_PTY;
1981 	else if (strcasecmp(opt, "permit-pty") == 0)
1982 		certflags_flags |= CERTOPT_PTY;
1983 	else if (strcasecmp(opt, "no-user-rc") == 0)
1984 		certflags_flags &= ~CERTOPT_USER_RC;
1985 	else if (strcasecmp(opt, "permit-user-rc") == 0)
1986 		certflags_flags |= CERTOPT_USER_RC;
1987 	else if (strcasecmp(opt, "touch-required") == 0)
1988 		certflags_flags &= ~CERTOPT_NO_REQUIRE_USER_PRESENCE;
1989 	else if (strcasecmp(opt, "no-touch-required") == 0)
1990 		certflags_flags |= CERTOPT_NO_REQUIRE_USER_PRESENCE;
1991 	else if (strncasecmp(opt, "force-command=", 14) == 0) {
1992 		val = opt + 14;
1993 		if (*val == '\0')
1994 			fatal("Empty force-command option");
1995 		if (certflags_command != NULL)
1996 			fatal("force-command already specified");
1997 		certflags_command = xstrdup(val);
1998 	} else if (strncasecmp(opt, "source-address=", 15) == 0) {
1999 		val = opt + 15;
2000 		if (*val == '\0')
2001 			fatal("Empty source-address option");
2002 		if (certflags_src_addr != NULL)
2003 			fatal("source-address already specified");
2004 		if (addr_match_cidr_list(NULL, val) != 0)
2005 			fatal("Invalid source-address list");
2006 		certflags_src_addr = xstrdup(val);
2007 	} else if (strncasecmp(opt, "extension:", 10) == 0 ||
2008 		   (iscrit = (strncasecmp(opt, "critical:", 9) == 0))) {
2009 		val = xstrdup(strchr(opt, ':') + 1);
2010 		if ((cp = strchr(val, '=')) != NULL)
2011 			*cp++ = '\0';
2012 		cert_ext_add(val, cp, iscrit);
2013 		free(val);
2014 	} else
2015 		fatal("Unsupported certificate option \"%s\"", opt);
2016 }
2017 
2018 static void
2019 show_options(struct sshbuf *optbuf, int in_critical)
2020 {
2021 	char *name, *arg, *hex;
2022 	struct sshbuf *options, *option = NULL;
2023 	int r;
2024 
2025 	if ((options = sshbuf_fromb(optbuf)) == NULL)
2026 		fatal("%s: sshbuf_fromb failed", __func__);
2027 	while (sshbuf_len(options) != 0) {
2028 		sshbuf_free(option);
2029 		option = NULL;
2030 		if ((r = sshbuf_get_cstring(options, &name, NULL)) != 0 ||
2031 		    (r = sshbuf_froms(options, &option)) != 0)
2032 			fatal("%s: buffer error: %s", __func__, ssh_err(r));
2033 		printf("                %s", name);
2034 		if (!in_critical &&
2035 		    (strcmp(name, "permit-X11-forwarding") == 0 ||
2036 		    strcmp(name, "permit-agent-forwarding") == 0 ||
2037 		    strcmp(name, "permit-port-forwarding") == 0 ||
2038 		    strcmp(name, "permit-pty") == 0 ||
2039 		    strcmp(name, "permit-user-rc") == 0 ||
2040 		    strcmp(name, "no-touch-required") == 0)) {
2041 			printf("\n");
2042 		} else if (in_critical &&
2043 		    (strcmp(name, "force-command") == 0 ||
2044 		    strcmp(name, "source-address") == 0)) {
2045 			if ((r = sshbuf_get_cstring(option, &arg, NULL)) != 0)
2046 				fatal("%s: buffer error: %s",
2047 				    __func__, ssh_err(r));
2048 			printf(" %s\n", arg);
2049 			free(arg);
2050 		} else if (sshbuf_len(option) > 0) {
2051 			hex = sshbuf_dtob16(option);
2052 			printf(" UNKNOWN OPTION: %s (len %zu)\n",
2053 			    hex, sshbuf_len(option));
2054 			sshbuf_reset(option);
2055 			free(hex);
2056 		} else
2057 			printf(" UNKNOWN FLAG OPTION\n");
2058 		free(name);
2059 		if (sshbuf_len(option) != 0)
2060 			fatal("Option corrupt: extra data at end");
2061 	}
2062 	sshbuf_free(option);
2063 	sshbuf_free(options);
2064 }
2065 
2066 static void
2067 print_cert(struct sshkey *key)
2068 {
2069 	char valid[64], *key_fp, *ca_fp;
2070 	u_int i;
2071 
2072 	key_fp = sshkey_fingerprint(key, fingerprint_hash, SSH_FP_DEFAULT);
2073 	ca_fp = sshkey_fingerprint(key->cert->signature_key,
2074 	    fingerprint_hash, SSH_FP_DEFAULT);
2075 	if (key_fp == NULL || ca_fp == NULL)
2076 		fatal("%s: sshkey_fingerprint fail", __func__);
2077 	sshkey_format_cert_validity(key->cert, valid, sizeof(valid));
2078 
2079 	printf("        Type: %s %s certificate\n", sshkey_ssh_name(key),
2080 	    sshkey_cert_type(key));
2081 	printf("        Public key: %s %s\n", sshkey_type(key), key_fp);
2082 	printf("        Signing CA: %s %s (using %s)\n",
2083 	    sshkey_type(key->cert->signature_key), ca_fp,
2084 	    key->cert->signature_type);
2085 	printf("        Key ID: \"%s\"\n", key->cert->key_id);
2086 	printf("        Serial: %llu\n", (unsigned long long)key->cert->serial);
2087 	printf("        Valid: %s\n", valid);
2088 	printf("        Principals: ");
2089 	if (key->cert->nprincipals == 0)
2090 		printf("(none)\n");
2091 	else {
2092 		for (i = 0; i < key->cert->nprincipals; i++)
2093 			printf("\n                %s",
2094 			    key->cert->principals[i]);
2095 		printf("\n");
2096 	}
2097 	printf("        Critical Options: ");
2098 	if (sshbuf_len(key->cert->critical) == 0)
2099 		printf("(none)\n");
2100 	else {
2101 		printf("\n");
2102 		show_options(key->cert->critical, 1);
2103 	}
2104 	printf("        Extensions: ");
2105 	if (sshbuf_len(key->cert->extensions) == 0)
2106 		printf("(none)\n");
2107 	else {
2108 		printf("\n");
2109 		show_options(key->cert->extensions, 0);
2110 	}
2111 }
2112 
2113 __dead static void
2114 do_show_cert(struct passwd *pw)
2115 {
2116 	struct sshkey *key = NULL;
2117 	struct stat st;
2118 	int r, is_stdin = 0, ok = 0;
2119 	FILE *f;
2120 	char *cp, *line = NULL;
2121 	const char *path;
2122 	size_t linesize = 0;
2123 	u_long lnum = 0;
2124 
2125 	if (!have_identity)
2126 		ask_filename(pw, "Enter file in which the key is");
2127 	if (strcmp(identity_file, "-") != 0 && stat(identity_file, &st) == -1)
2128 		fatal("%s: %s: %s", __progname, identity_file, strerror(errno));
2129 
2130 	path = identity_file;
2131 	if (strcmp(path, "-") == 0) {
2132 		f = stdin;
2133 		path = "(stdin)";
2134 		is_stdin = 1;
2135 	} else if ((f = fopen(identity_file, "r")) == NULL)
2136 		fatal("fopen %s: %s", identity_file, strerror(errno));
2137 
2138 	while (getline(&line, &linesize, f) != -1) {
2139 		lnum++;
2140 		sshkey_free(key);
2141 		key = NULL;
2142 		/* Trim leading space and comments */
2143 		cp = line + strspn(line, " \t");
2144 		if (*cp == '#' || *cp == '\0')
2145 			continue;
2146 		if ((key = sshkey_new(KEY_UNSPEC)) == NULL)
2147 			fatal("sshkey_new");
2148 		if ((r = sshkey_read(key, &cp)) != 0) {
2149 			error("%s:%lu: invalid key: %s", path,
2150 			    lnum, ssh_err(r));
2151 			continue;
2152 		}
2153 		if (!sshkey_is_cert(key)) {
2154 			error("%s:%lu is not a certificate", path, lnum);
2155 			continue;
2156 		}
2157 		ok = 1;
2158 		if (!is_stdin && lnum == 1)
2159 			printf("%s:\n", path);
2160 		else
2161 			printf("%s:%lu:\n", path, lnum);
2162 		print_cert(key);
2163 	}
2164 	free(line);
2165 	sshkey_free(key);
2166 	fclose(f);
2167 	exit(ok ? 0 : 1);
2168 }
2169 
2170 static void
2171 load_krl(const char *path, struct ssh_krl **krlp)
2172 {
2173 	struct sshbuf *krlbuf;
2174 	int r;
2175 
2176 	if ((r = sshbuf_load_file(path, &krlbuf)) != 0)
2177 		fatal("Unable to load KRL: %s", ssh_err(r));
2178 	/* XXX check sigs */
2179 	if ((r = ssh_krl_from_blob(krlbuf, krlp, NULL, 0)) != 0 ||
2180 	    *krlp == NULL)
2181 		fatal("Invalid KRL file: %s", ssh_err(r));
2182 	sshbuf_free(krlbuf);
2183 }
2184 
2185 static void
2186 hash_to_blob(const char *cp, u_char **blobp, size_t *lenp,
2187     const char *file, u_long lnum)
2188 {
2189 	char *tmp;
2190 	size_t tlen;
2191 	struct sshbuf *b;
2192 	int r;
2193 
2194 	if (strncmp(cp, "SHA256:", 7) != 0)
2195 		fatal("%s:%lu: unsupported hash algorithm", file, lnum);
2196 	cp += 7;
2197 
2198 	/*
2199 	 * OpenSSH base64 hashes omit trailing '='
2200 	 * characters; put them back for decode.
2201 	 */
2202 	tlen = strlen(cp);
2203 	tmp = xmalloc(tlen + 4 + 1);
2204 	strlcpy(tmp, cp, tlen + 1);
2205 	while ((tlen % 4) != 0) {
2206 		tmp[tlen++] = '=';
2207 		tmp[tlen] = '\0';
2208 	}
2209 	if ((b = sshbuf_new()) == NULL)
2210 		fatal("%s: sshbuf_new failed", __func__);
2211 	if ((r = sshbuf_b64tod(b, tmp)) != 0)
2212 		fatal("%s:%lu: decode hash failed: %s", file, lnum, ssh_err(r));
2213 	free(tmp);
2214 	*lenp = sshbuf_len(b);
2215 	*blobp = xmalloc(*lenp);
2216 	memcpy(*blobp, sshbuf_ptr(b), *lenp);
2217 	sshbuf_free(b);
2218 }
2219 
2220 static void
2221 update_krl_from_file(struct passwd *pw, const char *file, int wild_ca,
2222     const struct sshkey *ca, struct ssh_krl *krl)
2223 {
2224 	struct sshkey *key = NULL;
2225 	u_long lnum = 0;
2226 	char *path, *cp, *ep, *line = NULL;
2227 	u_char *blob = NULL;
2228 	size_t blen = 0, linesize = 0;
2229 	unsigned long long serial, serial2;
2230 	int i, was_explicit_key, was_sha1, was_sha256, was_hash, r;
2231 	FILE *krl_spec;
2232 
2233 	path = tilde_expand_filename(file, pw->pw_uid);
2234 	if (strcmp(path, "-") == 0) {
2235 		krl_spec = stdin;
2236 		free(path);
2237 		path = xstrdup("(standard input)");
2238 	} else if ((krl_spec = fopen(path, "r")) == NULL)
2239 		fatal("fopen %s: %s", path, strerror(errno));
2240 
2241 	if (!quiet)
2242 		printf("Revoking from %s\n", path);
2243 	while (getline(&line, &linesize, krl_spec) != -1) {
2244 		lnum++;
2245 		was_explicit_key = was_sha1 = was_sha256 = was_hash = 0;
2246 		cp = line + strspn(line, " \t");
2247 		/* Trim trailing space, comments and strip \n */
2248 		for (i = 0, r = -1; cp[i] != '\0'; i++) {
2249 			if (cp[i] == '#' || cp[i] == '\n') {
2250 				cp[i] = '\0';
2251 				break;
2252 			}
2253 			if (cp[i] == ' ' || cp[i] == '\t') {
2254 				/* Remember the start of a span of whitespace */
2255 				if (r == -1)
2256 					r = i;
2257 			} else
2258 				r = -1;
2259 		}
2260 		if (r != -1)
2261 			cp[r] = '\0';
2262 		if (*cp == '\0')
2263 			continue;
2264 		if (strncasecmp(cp, "serial:", 7) == 0) {
2265 			if (ca == NULL && !wild_ca) {
2266 				fatal("revoking certificates by serial number "
2267 				    "requires specification of a CA key");
2268 			}
2269 			cp += 7;
2270 			cp = cp + strspn(cp, " \t");
2271 			errno = 0;
2272 			serial = strtoull(cp, &ep, 0);
2273 			if (*cp == '\0' || (*ep != '\0' && *ep != '-'))
2274 				fatal("%s:%lu: invalid serial \"%s\"",
2275 				    path, lnum, cp);
2276 			if (errno == ERANGE && serial == ULLONG_MAX)
2277 				fatal("%s:%lu: serial out of range",
2278 				    path, lnum);
2279 			serial2 = serial;
2280 			if (*ep == '-') {
2281 				cp = ep + 1;
2282 				errno = 0;
2283 				serial2 = strtoull(cp, &ep, 0);
2284 				if (*cp == '\0' || *ep != '\0')
2285 					fatal("%s:%lu: invalid serial \"%s\"",
2286 					    path, lnum, cp);
2287 				if (errno == ERANGE && serial2 == ULLONG_MAX)
2288 					fatal("%s:%lu: serial out of range",
2289 					    path, lnum);
2290 				if (serial2 <= serial)
2291 					fatal("%s:%lu: invalid serial range "
2292 					    "%llu:%llu", path, lnum,
2293 					    (unsigned long long)serial,
2294 					    (unsigned long long)serial2);
2295 			}
2296 			if (ssh_krl_revoke_cert_by_serial_range(krl,
2297 			    ca, serial, serial2) != 0) {
2298 				fatal("%s: revoke serial failed",
2299 				    __func__);
2300 			}
2301 		} else if (strncasecmp(cp, "id:", 3) == 0) {
2302 			if (ca == NULL && !wild_ca) {
2303 				fatal("revoking certificates by key ID "
2304 				    "requires specification of a CA key");
2305 			}
2306 			cp += 3;
2307 			cp = cp + strspn(cp, " \t");
2308 			if (ssh_krl_revoke_cert_by_key_id(krl, ca, cp) != 0)
2309 				fatal("%s: revoke key ID failed", __func__);
2310 		} else if (strncasecmp(cp, "hash:", 5) == 0) {
2311 			cp += 5;
2312 			cp = cp + strspn(cp, " \t");
2313 			hash_to_blob(cp, &blob, &blen, file, lnum);
2314 			r = ssh_krl_revoke_key_sha256(krl, blob, blen);
2315 			if (r != 0)
2316 				fatal("%s: revoke key failed: %s",
2317 				    __func__, ssh_err(r));
2318 		} else {
2319 			if (strncasecmp(cp, "key:", 4) == 0) {
2320 				cp += 4;
2321 				cp = cp + strspn(cp, " \t");
2322 				was_explicit_key = 1;
2323 			} else if (strncasecmp(cp, "sha1:", 5) == 0) {
2324 				cp += 5;
2325 				cp = cp + strspn(cp, " \t");
2326 				was_sha1 = 1;
2327 			} else if (strncasecmp(cp, "sha256:", 7) == 0) {
2328 				cp += 7;
2329 				cp = cp + strspn(cp, " \t");
2330 				was_sha256 = 1;
2331 				/*
2332 				 * Just try to process the line as a key.
2333 				 * Parsing will fail if it isn't.
2334 				 */
2335 			}
2336 			if ((key = sshkey_new(KEY_UNSPEC)) == NULL)
2337 				fatal("sshkey_new");
2338 			if ((r = sshkey_read(key, &cp)) != 0)
2339 				fatal("%s:%lu: invalid key: %s",
2340 				    path, lnum, ssh_err(r));
2341 			if (was_explicit_key)
2342 				r = ssh_krl_revoke_key_explicit(krl, key);
2343 			else if (was_sha1) {
2344 				if (sshkey_fingerprint_raw(key,
2345 				    SSH_DIGEST_SHA1, &blob, &blen) != 0) {
2346 					fatal("%s:%lu: fingerprint failed",
2347 					    file, lnum);
2348 				}
2349 				r = ssh_krl_revoke_key_sha1(krl, blob, blen);
2350 			} else if (was_sha256) {
2351 				if (sshkey_fingerprint_raw(key,
2352 				    SSH_DIGEST_SHA256, &blob, &blen) != 0) {
2353 					fatal("%s:%lu: fingerprint failed",
2354 					    file, lnum);
2355 				}
2356 				r = ssh_krl_revoke_key_sha256(krl, blob, blen);
2357 			} else
2358 				r = ssh_krl_revoke_key(krl, key);
2359 			if (r != 0)
2360 				fatal("%s: revoke key failed: %s",
2361 				    __func__, ssh_err(r));
2362 			freezero(blob, blen);
2363 			blob = NULL;
2364 			blen = 0;
2365 			sshkey_free(key);
2366 		}
2367 	}
2368 	if (strcmp(path, "-") != 0)
2369 		fclose(krl_spec);
2370 	free(line);
2371 	free(path);
2372 }
2373 
2374 static void
2375 do_gen_krl(struct passwd *pw, int updating, const char *ca_key_path,
2376     unsigned long long krl_version, const char *krl_comment,
2377     int argc, char **argv)
2378 {
2379 	struct ssh_krl *krl;
2380 	struct stat sb;
2381 	struct sshkey *ca = NULL;
2382 	int i, r, wild_ca = 0;
2383 	char *tmp;
2384 	struct sshbuf *kbuf;
2385 
2386 	if (*identity_file == '\0')
2387 		fatal("KRL generation requires an output file");
2388 	if (stat(identity_file, &sb) == -1) {
2389 		if (errno != ENOENT)
2390 			fatal("Cannot access KRL \"%s\": %s",
2391 			    identity_file, strerror(errno));
2392 		if (updating)
2393 			fatal("KRL \"%s\" does not exist", identity_file);
2394 	}
2395 	if (ca_key_path != NULL) {
2396 		if (strcasecmp(ca_key_path, "none") == 0)
2397 			wild_ca = 1;
2398 		else {
2399 			tmp = tilde_expand_filename(ca_key_path, pw->pw_uid);
2400 			if ((r = sshkey_load_public(tmp, &ca, NULL)) != 0)
2401 				fatal("Cannot load CA public key %s: %s",
2402 				    tmp, ssh_err(r));
2403 			free(tmp);
2404 		}
2405 	}
2406 
2407 	if (updating)
2408 		load_krl(identity_file, &krl);
2409 	else if ((krl = ssh_krl_init()) == NULL)
2410 		fatal("couldn't create KRL");
2411 
2412 	if (krl_version != 0)
2413 		ssh_krl_set_version(krl, krl_version);
2414 	if (krl_comment != NULL)
2415 		ssh_krl_set_comment(krl, krl_comment);
2416 
2417 	for (i = 0; i < argc; i++)
2418 		update_krl_from_file(pw, argv[i], wild_ca, ca, krl);
2419 
2420 	if ((kbuf = sshbuf_new()) == NULL)
2421 		fatal("sshbuf_new failed");
2422 	if (ssh_krl_to_blob(krl, kbuf, NULL, 0) != 0)
2423 		fatal("Couldn't generate KRL");
2424 	if ((r = sshbuf_write_file(identity_file, kbuf)) != 0)
2425 		fatal("write %s: %s", identity_file, strerror(errno));
2426 	sshbuf_free(kbuf);
2427 	ssh_krl_free(krl);
2428 	sshkey_free(ca);
2429 }
2430 
2431 __dead static void
2432 do_check_krl(struct passwd *pw, int print_krl, int argc, char **argv)
2433 {
2434 	int i, r, ret = 0;
2435 	char *comment;
2436 	struct ssh_krl *krl;
2437 	struct sshkey *k;
2438 
2439 	if (*identity_file == '\0')
2440 		fatal("KRL checking requires an input file");
2441 	load_krl(identity_file, &krl);
2442 	if (print_krl)
2443 		krl_dump(krl, stdout);
2444 	for (i = 0; i < argc; i++) {
2445 		if ((r = sshkey_load_public(argv[i], &k, &comment)) != 0)
2446 			fatal("Cannot load public key %s: %s",
2447 			    argv[i], ssh_err(r));
2448 		r = ssh_krl_check_key(krl, k);
2449 		printf("%s%s%s%s: %s\n", argv[i],
2450 		    *comment ? " (" : "", comment, *comment ? ")" : "",
2451 		    r == 0 ? "ok" : "REVOKED");
2452 		if (r != 0)
2453 			ret = 1;
2454 		sshkey_free(k);
2455 		free(comment);
2456 	}
2457 	ssh_krl_free(krl);
2458 	exit(ret);
2459 }
2460 
2461 static struct sshkey *
2462 load_sign_key(const char *keypath, const struct sshkey *pubkey)
2463 {
2464 	size_t i, slen, plen = strlen(keypath);
2465 	char *privpath = xstrdup(keypath);
2466 	const char *suffixes[] = { "-cert.pub", ".pub", NULL };
2467 	struct sshkey *ret = NULL, *privkey = NULL;
2468 	int r;
2469 
2470 	/*
2471 	 * If passed a public key filename, then try to locate the corresponding
2472 	 * private key. This lets us specify certificates on the command-line
2473 	 * and have ssh-keygen find the appropriate private key.
2474 	 */
2475 	for (i = 0; suffixes[i]; i++) {
2476 		slen = strlen(suffixes[i]);
2477 		if (plen <= slen ||
2478 		    strcmp(privpath + plen - slen, suffixes[i]) != 0)
2479 			continue;
2480 		privpath[plen - slen] = '\0';
2481 		debug("%s: %s looks like a public key, using private key "
2482 		    "path %s instead", __func__, keypath, privpath);
2483 	}
2484 	if ((privkey = load_identity(privpath, NULL)) == NULL) {
2485 		error("Couldn't load identity %s", keypath);
2486 		goto done;
2487 	}
2488 	if (!sshkey_equal_public(pubkey, privkey)) {
2489 		error("Public key %s doesn't match private %s",
2490 		    keypath, privpath);
2491 		goto done;
2492 	}
2493 	if (sshkey_is_cert(pubkey) && !sshkey_is_cert(privkey)) {
2494 		/*
2495 		 * Graft the certificate onto the private key to make
2496 		 * it capable of signing.
2497 		 */
2498 		if ((r = sshkey_to_certified(privkey)) != 0) {
2499 			error("%s: sshkey_to_certified: %s", __func__,
2500 			    ssh_err(r));
2501 			goto done;
2502 		}
2503 		if ((r = sshkey_cert_copy(pubkey, privkey)) != 0) {
2504 			error("%s: sshkey_cert_copy: %s", __func__, ssh_err(r));
2505 			goto done;
2506 		}
2507 	}
2508 	/* success */
2509 	ret = privkey;
2510 	privkey = NULL;
2511  done:
2512 	sshkey_free(privkey);
2513 	free(privpath);
2514 	return ret;
2515 }
2516 
2517 static int
2518 sign_one(struct sshkey *signkey, const char *filename, int fd,
2519     const char *sig_namespace, sshsig_signer *signer, void *signer_ctx)
2520 {
2521 	struct sshbuf *sigbuf = NULL, *abuf = NULL;
2522 	int r = SSH_ERR_INTERNAL_ERROR, wfd = -1, oerrno;
2523 	char *wfile = NULL, *asig = NULL, *fp = NULL;
2524 	char *pin = NULL, *prompt = NULL;
2525 
2526 	if (!quiet) {
2527 		if (fd == STDIN_FILENO)
2528 			fprintf(stderr, "Signing data on standard input\n");
2529 		else
2530 			fprintf(stderr, "Signing file %s\n", filename);
2531 	}
2532 	if (signer == NULL && sshkey_is_sk(signkey)) {
2533 		if ((signkey->sk_flags & SSH_SK_USER_VERIFICATION_REQD)) {
2534 			xasprintf(&prompt, "Enter PIN for %s key: ",
2535 			    sshkey_type(signkey));
2536 			if ((pin = read_passphrase(prompt,
2537 			    RP_ALLOW_STDIN)) == NULL)
2538 				fatal("%s: couldn't read PIN", __func__);
2539 		}
2540 		if ((signkey->sk_flags & SSH_SK_USER_PRESENCE_REQD)) {
2541 			if ((fp = sshkey_fingerprint(signkey, fingerprint_hash,
2542 			    SSH_FP_DEFAULT)) == NULL)
2543 				fatal("%s: fingerprint failed", __func__);
2544 			fprintf(stderr, "Confirm user presence for key %s %s\n",
2545 			    sshkey_type(signkey), fp);
2546 			free(fp);
2547 		}
2548 	}
2549 	if ((r = sshsig_sign_fd(signkey, NULL, sk_provider, pin,
2550 	    fd, sig_namespace, &sigbuf, signer, signer_ctx)) != 0) {
2551 		error("Signing %s failed: %s", filename, ssh_err(r));
2552 		goto out;
2553 	}
2554 	if ((r = sshsig_armor(sigbuf, &abuf)) != 0) {
2555 		error("%s: sshsig_armor: %s", __func__, ssh_err(r));
2556 		goto out;
2557 	}
2558 	if ((asig = sshbuf_dup_string(abuf)) == NULL) {
2559 		error("%s: buffer error", __func__);
2560 		r = SSH_ERR_ALLOC_FAIL;
2561 		goto out;
2562 	}
2563 
2564 	if (fd == STDIN_FILENO) {
2565 		fputs(asig, stdout);
2566 		fflush(stdout);
2567 	} else {
2568 		xasprintf(&wfile, "%s.sig", filename);
2569 		if (confirm_overwrite(wfile)) {
2570 			if ((wfd = open(wfile, O_WRONLY|O_CREAT|O_TRUNC,
2571 			    0666)) == -1) {
2572 				oerrno = errno;
2573 				error("Cannot open %s: %s",
2574 				    wfile, strerror(errno));
2575 				errno = oerrno;
2576 				r = SSH_ERR_SYSTEM_ERROR;
2577 				goto out;
2578 			}
2579 			if (atomicio(vwrite, wfd, asig,
2580 			    strlen(asig)) != strlen(asig)) {
2581 				oerrno = errno;
2582 				error("Cannot write to %s: %s",
2583 				    wfile, strerror(errno));
2584 				errno = oerrno;
2585 				r = SSH_ERR_SYSTEM_ERROR;
2586 				goto out;
2587 			}
2588 			if (!quiet) {
2589 				fprintf(stderr, "Write signature to %s\n",
2590 				    wfile);
2591 			}
2592 		}
2593 	}
2594 	/* success */
2595 	r = 0;
2596  out:
2597 	free(wfile);
2598 	free(prompt);
2599 	free(asig);
2600 	if (pin != NULL)
2601 		freezero(pin, strlen(pin));
2602 	sshbuf_free(abuf);
2603 	sshbuf_free(sigbuf);
2604 	if (wfd != -1)
2605 		close(wfd);
2606 	return r;
2607 }
2608 
2609 static int
2610 sig_sign(const char *keypath, const char *sig_namespace, int argc, char **argv)
2611 {
2612 	int i, fd = -1, r, ret = -1;
2613 	int agent_fd = -1;
2614 	struct sshkey *pubkey = NULL, *privkey = NULL, *signkey = NULL;
2615 	sshsig_signer *signer = NULL;
2616 
2617 	/* Check file arguments. */
2618 	for (i = 0; i < argc; i++) {
2619 		if (strcmp(argv[i], "-") != 0)
2620 			continue;
2621 		if (i > 0 || argc > 1)
2622 			fatal("Cannot sign mix of paths and standard input");
2623 	}
2624 
2625 	if ((r = sshkey_load_public(keypath, &pubkey, NULL)) != 0) {
2626 		error("Couldn't load public key %s: %s", keypath, ssh_err(r));
2627 		goto done;
2628 	}
2629 
2630 	if ((r = ssh_get_authentication_socket(&agent_fd)) != 0)
2631 		debug("Couldn't get agent socket: %s", ssh_err(r));
2632 	else {
2633 		if ((r = ssh_agent_has_key(agent_fd, pubkey)) == 0)
2634 			signer = agent_signer;
2635 		else
2636 			debug("Couldn't find key in agent: %s", ssh_err(r));
2637 	}
2638 
2639 	if (signer == NULL) {
2640 		/* Not using agent - try to load private key */
2641 		if ((privkey = load_sign_key(keypath, pubkey)) == NULL)
2642 			goto done;
2643 		signkey = privkey;
2644 	} else {
2645 		/* Will use key in agent */
2646 		signkey = pubkey;
2647 	}
2648 
2649 	if (argc == 0) {
2650 		if ((r = sign_one(signkey, "(stdin)", STDIN_FILENO,
2651 		    sig_namespace, signer, &agent_fd)) != 0)
2652 			goto done;
2653 	} else {
2654 		for (i = 0; i < argc; i++) {
2655 			if (strcmp(argv[i], "-") == 0)
2656 				fd = STDIN_FILENO;
2657 			else if ((fd = open(argv[i], O_RDONLY)) == -1) {
2658 				error("Cannot open %s for signing: %s",
2659 				    argv[i], strerror(errno));
2660 				goto done;
2661 			}
2662 			if ((r = sign_one(signkey, argv[i], fd, sig_namespace,
2663 			    signer, &agent_fd)) != 0)
2664 				goto done;
2665 			if (fd != STDIN_FILENO)
2666 				close(fd);
2667 			fd = -1;
2668 		}
2669 	}
2670 
2671 	ret = 0;
2672 done:
2673 	if (fd != -1 && fd != STDIN_FILENO)
2674 		close(fd);
2675 	sshkey_free(pubkey);
2676 	sshkey_free(privkey);
2677 	return ret;
2678 }
2679 
2680 static int
2681 sig_verify(const char *signature, const char *sig_namespace,
2682     const char *principal, const char *allowed_keys, const char *revoked_keys)
2683 {
2684 	int r, ret = -1;
2685 	struct sshbuf *sigbuf = NULL, *abuf = NULL;
2686 	struct sshkey *sign_key = NULL;
2687 	char *fp = NULL;
2688 	struct sshkey_sig_details *sig_details = NULL;
2689 
2690 	memset(&sig_details, 0, sizeof(sig_details));
2691 	if ((r = sshbuf_load_file(signature, &abuf)) != 0) {
2692 		error("Couldn't read signature file: %s", ssh_err(r));
2693 		goto done;
2694 	}
2695 
2696 	if ((r = sshsig_dearmor(abuf, &sigbuf)) != 0) {
2697 		error("%s: sshsig_armor: %s", __func__, ssh_err(r));
2698 		goto done;
2699 	}
2700 	if ((r = sshsig_verify_fd(sigbuf, STDIN_FILENO, sig_namespace,
2701 	    &sign_key, &sig_details)) != 0)
2702 		goto done; /* sshsig_verify() prints error */
2703 
2704 	if ((fp = sshkey_fingerprint(sign_key, fingerprint_hash,
2705 	    SSH_FP_DEFAULT)) == NULL)
2706 		fatal("%s: sshkey_fingerprint failed", __func__);
2707 	debug("Valid (unverified) signature from key %s", fp);
2708 	if (sig_details != NULL) {
2709 		debug2("%s: signature details: counter = %u, flags = 0x%02x",
2710 		    __func__, sig_details->sk_counter, sig_details->sk_flags);
2711 	}
2712 	free(fp);
2713 	fp = NULL;
2714 
2715 	if (revoked_keys != NULL) {
2716 		if ((r = sshkey_check_revoked(sign_key, revoked_keys)) != 0) {
2717 			debug3("sshkey_check_revoked failed: %s", ssh_err(r));
2718 			goto done;
2719 		}
2720 	}
2721 
2722 	if (allowed_keys != NULL &&
2723 	    (r = sshsig_check_allowed_keys(allowed_keys, sign_key,
2724 					   principal, sig_namespace)) != 0) {
2725 		debug3("sshsig_check_allowed_keys failed: %s", ssh_err(r));
2726 		goto done;
2727 	}
2728 	/* success */
2729 	ret = 0;
2730 done:
2731 	if (!quiet) {
2732 		if (ret == 0) {
2733 			if ((fp = sshkey_fingerprint(sign_key, fingerprint_hash,
2734 			    SSH_FP_DEFAULT)) == NULL) {
2735 				fatal("%s: sshkey_fingerprint failed",
2736 				    __func__);
2737 			}
2738 			if (principal == NULL) {
2739 				printf("Good \"%s\" signature with %s key %s\n",
2740 				       sig_namespace, sshkey_type(sign_key), fp);
2741 
2742 			} else {
2743 				printf("Good \"%s\" signature for %s with %s key %s\n",
2744 				       sig_namespace, principal,
2745 				       sshkey_type(sign_key), fp);
2746 			}
2747 		} else {
2748 			printf("Could not verify signature.\n");
2749 		}
2750 	}
2751 	sshbuf_free(sigbuf);
2752 	sshbuf_free(abuf);
2753 	sshkey_free(sign_key);
2754 	sshkey_sig_details_free(sig_details);
2755 	free(fp);
2756 	return ret;
2757 }
2758 
2759 static int
2760 sig_find_principals(const char *signature, const char *allowed_keys) {
2761 	int r, ret = -1;
2762 	struct sshbuf *sigbuf = NULL, *abuf = NULL;
2763 	struct sshkey *sign_key = NULL;
2764 	char *principals = NULL, *cp, *tmp;
2765 
2766 	if ((r = sshbuf_load_file(signature, &abuf)) != 0) {
2767 		error("Couldn't read signature file: %s", ssh_err(r));
2768 		goto done;
2769 	}
2770 	if ((r = sshsig_dearmor(abuf, &sigbuf)) != 0) {
2771 		error("%s: sshsig_armor: %s", __func__, ssh_err(r));
2772 		goto done;
2773 	}
2774 	if ((r = sshsig_get_pubkey(sigbuf, &sign_key)) != 0) {
2775 		error("%s: sshsig_get_pubkey: %s",
2776 		    __func__, ssh_err(r));
2777 		goto done;
2778 	}
2779 	if ((r = sshsig_find_principals(allowed_keys, sign_key,
2780 	    &principals)) != 0) {
2781 		error("%s: sshsig_get_principal: %s",
2782 		      __func__, ssh_err(r));
2783 		goto done;
2784 	}
2785 	ret = 0;
2786 done:
2787 	if (ret == 0 ) {
2788 		/* Emit matching principals one per line */
2789 		tmp = principals;
2790 		while ((cp = strsep(&tmp, ",")) != NULL && *cp != '\0')
2791 			puts(cp);
2792 	} else {
2793 		fprintf(stderr, "No principal matched.\n");
2794 	}
2795 	sshbuf_free(sigbuf);
2796 	sshbuf_free(abuf);
2797 	sshkey_free(sign_key);
2798 	free(principals);
2799 	return ret;
2800 }
2801 
2802 static void
2803 do_moduli_gen(const char *out_file, char **opts, size_t nopts)
2804 {
2805 #ifdef WITH_OPENSSL
2806 	/* Moduli generation/screening */
2807 	u_int32_t memory = 0;
2808 	BIGNUM *start = NULL;
2809 	int moduli_bits = 0;
2810 	FILE *out;
2811 	size_t i;
2812 	const char *errstr;
2813 
2814 	/* Parse options */
2815 	for (i = 0; i < nopts; i++) {
2816 		if (strncmp(opts[i], "memory=", 7) == 0) {
2817 			memory = (u_int32_t)strtonum(opts[i]+7, 1,
2818 			    UINT_MAX, &errstr);
2819 			if (errstr) {
2820 				fatal("Memory limit is %s: %s",
2821 				    errstr, opts[i]+7);
2822 			}
2823 		} else if (strncmp(opts[i], "start=", 6) == 0) {
2824 			/* XXX - also compare length against bits */
2825 			if (BN_hex2bn(&start, opts[i]+6) == 0)
2826 				fatal("Invalid start point.");
2827 		} else if (strncmp(opts[i], "bits=", 5) == 0) {
2828 			moduli_bits = (int)strtonum(opts[i]+5, 1,
2829 			    INT_MAX, &errstr);
2830 			if (errstr) {
2831 				fatal("Invalid number: %s (%s)",
2832 					opts[i]+12, errstr);
2833 			}
2834 		} else {
2835 			fatal("Option \"%s\" is unsupported for moduli "
2836 			    "generation", opts[i]);
2837 		}
2838 	}
2839 
2840 	if ((out = fopen(out_file, "w")) == NULL) {
2841 		fatal("Couldn't open modulus candidate file \"%s\": %s",
2842 		    out_file, strerror(errno));
2843 	}
2844 	setvbuf(out, NULL, _IOLBF, 0);
2845 
2846 	if (moduli_bits == 0)
2847 		moduli_bits = DEFAULT_BITS;
2848 	if (gen_candidates(out, memory, moduli_bits, start) != 0)
2849 		fatal("modulus candidate generation failed");
2850 #else /* WITH_OPENSSL */
2851 	fatal("Moduli generation is not supported");
2852 #endif /* WITH_OPENSSL */
2853 }
2854 
2855 static void
2856 do_moduli_screen(const char *out_file, char **opts, size_t nopts)
2857 {
2858 #ifdef WITH_OPENSSL
2859 	/* Moduli generation/screening */
2860 	char *checkpoint = NULL;
2861 	u_int32_t generator_wanted = 0;
2862 	unsigned long start_lineno = 0, lines_to_process = 0;
2863 	int prime_tests = 0;
2864 	FILE *out, *in = stdin;
2865 	size_t i;
2866 	const char *errstr;
2867 
2868 	/* Parse options */
2869 	for (i = 0; i < nopts; i++) {
2870 		if (strncmp(opts[i], "lines=", 6) == 0) {
2871 			lines_to_process = strtoul(opts[i]+6, NULL, 10);
2872 		} else if (strncmp(opts[i], "start-line=", 11) == 0) {
2873 			start_lineno = strtoul(opts[i]+11, NULL, 10);
2874 		} else if (strncmp(opts[i], "checkpoint=", 11) == 0) {
2875 			checkpoint = xstrdup(opts[i]+11);
2876 		} else if (strncmp(opts[i], "generator=", 10) == 0) {
2877 			generator_wanted = (u_int32_t)strtonum(
2878 			    opts[i]+10, 1, UINT_MAX, &errstr);
2879 			if (errstr != NULL) {
2880 				fatal("Generator invalid: %s (%s)",
2881 				    opts[i]+10, errstr);
2882 			}
2883 		} else if (strncmp(opts[i], "prime-tests=", 12) == 0) {
2884 			prime_tests = (int)strtonum(opts[i]+12, 1,
2885 			    INT_MAX, &errstr);
2886 			if (errstr) {
2887 				fatal("Invalid number: %s (%s)",
2888 					opts[i]+12, errstr);
2889 			}
2890 		} else {
2891 			fatal("Option \"%s\" is unsupported for moduli "
2892 			    "screening", opts[i]);
2893 		}
2894 	}
2895 
2896 	if (have_identity && strcmp(identity_file, "-") != 0) {
2897 		if ((in = fopen(identity_file, "r")) == NULL) {
2898 			fatal("Couldn't open modulus candidate "
2899 			    "file \"%s\": %s", identity_file,
2900 			    strerror(errno));
2901 		}
2902 	}
2903 
2904 	if ((out = fopen(out_file, "a")) == NULL) {
2905 		fatal("Couldn't open moduli file \"%s\": %s",
2906 		    out_file, strerror(errno));
2907 	}
2908 	setvbuf(out, NULL, _IOLBF, 0);
2909 	if (prime_test(in, out, prime_tests == 0 ? 100 : prime_tests,
2910 	    generator_wanted, checkpoint,
2911 	    start_lineno, lines_to_process) != 0)
2912 		fatal("modulus screening failed");
2913 #else /* WITH_OPENSSL */
2914 	fatal("Moduli screening is not supported");
2915 #endif /* WITH_OPENSSL */
2916 }
2917 
2918 static char *
2919 private_key_passphrase(void)
2920 {
2921 	char *passphrase1, *passphrase2;
2922 
2923 	/* Ask for a passphrase (twice). */
2924 	if (identity_passphrase)
2925 		passphrase1 = xstrdup(identity_passphrase);
2926 	else if (identity_new_passphrase)
2927 		passphrase1 = xstrdup(identity_new_passphrase);
2928 	else {
2929 passphrase_again:
2930 		passphrase1 =
2931 			read_passphrase("Enter passphrase (empty for no "
2932 			    "passphrase): ", RP_ALLOW_STDIN);
2933 		passphrase2 = read_passphrase("Enter same passphrase again: ",
2934 		    RP_ALLOW_STDIN);
2935 		if (strcmp(passphrase1, passphrase2) != 0) {
2936 			/*
2937 			 * The passphrases do not match.  Clear them and
2938 			 * retry.
2939 			 */
2940 			freezero(passphrase1, strlen(passphrase1));
2941 			freezero(passphrase2, strlen(passphrase2));
2942 			printf("Passphrases do not match.  Try again.\n");
2943 			goto passphrase_again;
2944 		}
2945 		/* Clear the other copy of the passphrase. */
2946 		freezero(passphrase2, strlen(passphrase2));
2947 	}
2948 	return passphrase1;
2949 }
2950 
2951 static const char *
2952 skip_ssh_url_preamble(const char *s)
2953 {
2954 	if (strncmp(s, "ssh://", 6) == 0)
2955 		return s + 6;
2956 	else if (strncmp(s, "ssh:", 4) == 0)
2957 		return s + 4;
2958 	return s;
2959 }
2960 
2961 static int
2962 do_download_sk(const char *skprovider, const char *device)
2963 {
2964 	struct sshkey **keys;
2965 	size_t nkeys, i;
2966 	int r, ret = -1;
2967 	char *fp, *pin = NULL, *pass = NULL, *path, *pubpath;
2968 	const char *ext;
2969 
2970 	if (skprovider == NULL)
2971 		fatal("Cannot download keys without provider");
2972 
2973 	pin = read_passphrase("Enter PIN for authenticator: ", RP_ALLOW_STDIN);
2974 	if (!quiet) {
2975 		printf("You may need to touch your authenticator "
2976 		    "to authorize key download.\n");
2977 	}
2978 	if ((r = sshsk_load_resident(skprovider, device, pin,
2979 	    &keys, &nkeys)) != 0) {
2980 		if (pin != NULL)
2981 			freezero(pin, strlen(pin));
2982 		error("Unable to load resident keys: %s", ssh_err(r));
2983 		return -1;
2984 	}
2985 	if (nkeys == 0)
2986 		logit("No keys to download");
2987 	if (pin != NULL)
2988 		freezero(pin, strlen(pin));
2989 
2990 	for (i = 0; i < nkeys; i++) {
2991 		if (keys[i]->type != KEY_ECDSA_SK &&
2992 		    keys[i]->type != KEY_ED25519_SK) {
2993 			error("Unsupported key type %s (%d)",
2994 			    sshkey_type(keys[i]), keys[i]->type);
2995 			continue;
2996 		}
2997 		if ((fp = sshkey_fingerprint(keys[i],
2998 		    fingerprint_hash, SSH_FP_DEFAULT)) == NULL)
2999 			fatal("%s: sshkey_fingerprint failed", __func__);
3000 		debug("%s: key %zu: %s %s %s (flags 0x%02x)", __func__, i,
3001 		    sshkey_type(keys[i]), fp, keys[i]->sk_application,
3002 		    keys[i]->sk_flags);
3003 		ext = skip_ssh_url_preamble(keys[i]->sk_application);
3004 		xasprintf(&path, "id_%s_rk%s%s",
3005 		    keys[i]->type == KEY_ECDSA_SK ? "ecdsa_sk" : "ed25519_sk",
3006 		    *ext == '\0' ? "" : "_", ext);
3007 
3008 		/* If the file already exists, ask the user to confirm. */
3009 		if (!confirm_overwrite(path)) {
3010 			free(path);
3011 			break;
3012 		}
3013 
3014 		/* Save the key with the application string as the comment */
3015 		if (pass == NULL)
3016 			pass = private_key_passphrase();
3017 		if ((r = sshkey_save_private(keys[i], path, pass,
3018 		    keys[i]->sk_application, private_key_format,
3019 		    openssh_format_cipher, rounds)) != 0) {
3020 			error("Saving key \"%s\" failed: %s",
3021 			    path, ssh_err(r));
3022 			free(path);
3023 			break;
3024 		}
3025 		if (!quiet) {
3026 			printf("Saved %s key%s%s to %s\n",
3027 			    sshkey_type(keys[i]),
3028 			    *ext != '\0' ? " " : "",
3029 			    *ext != '\0' ? keys[i]->sk_application : "",
3030 			    path);
3031 		}
3032 
3033 		/* Save public key too */
3034 		xasprintf(&pubpath, "%s.pub", path);
3035 		free(path);
3036 		if ((r = sshkey_save_public(keys[i], pubpath,
3037 		    keys[i]->sk_application)) != 0) {
3038 			error("Saving public key \"%s\" failed: %s",
3039 			    pubpath, ssh_err(r));
3040 			free(pubpath);
3041 			break;
3042 		}
3043 		free(pubpath);
3044 	}
3045 
3046 	if (i >= nkeys)
3047 		ret = 0; /* success */
3048 	if (pass != NULL)
3049 		freezero(pass, strlen(pass));
3050 	for (i = 0; i < nkeys; i++)
3051 		sshkey_free(keys[i]);
3052 	free(keys);
3053 	return ret;
3054 }
3055 
3056 static void
3057 save_attestation(struct sshbuf *attest, const char *path)
3058 {
3059 	mode_t omask;
3060 	int r;
3061 
3062 	if (path == NULL)
3063 		return; /* nothing to do */
3064 	if (attest == NULL || sshbuf_len(attest) == 0)
3065 		fatal("Enrollment did not return attestation data");
3066 	omask = umask(077);
3067 	r = sshbuf_write_file(path, attest);
3068 	umask(omask);
3069 	if (r != 0)
3070 		fatal("Unable to write attestation data \"%s\": %s", path,
3071 		    ssh_err(r));
3072 	if (!quiet)
3073 		printf("Your FIDO attestation certificate has been saved in "
3074 		    "%s\n", path);
3075 }
3076 
3077 __dead static void
3078 usage(void)
3079 {
3080 	fprintf(stderr,
3081 	    "usage: ssh-keygen [-q] [-a rounds] [-b bits] [-C comment] [-f output_keyfile]\n"
3082 	    "                  [-m format] [-N new_passphrase] [-O option]\n"
3083 	    "                  [-t dsa | ecdsa | ecdsa-sk | ed25519 | ed25519-sk | rsa]\n"
3084 	    "                  [-w provider]\n"
3085 	    "       ssh-keygen -p [-a rounds] [-f keyfile] [-m format] [-N new_passphrase]\n"
3086 	    "                   [-P old_passphrase]\n"
3087 	    "       ssh-keygen -i [-f input_keyfile] [-m key_format]\n"
3088 	    "       ssh-keygen -e [-f input_keyfile] [-m key_format]\n"
3089 	    "       ssh-keygen -y [-f input_keyfile]\n"
3090 	    "       ssh-keygen -c [-a rounds] [-C comment] [-f keyfile] [-P passphrase]\n"
3091 	    "       ssh-keygen -l [-v] [-E fingerprint_hash] [-f input_keyfile]\n"
3092 	    "       ssh-keygen -B [-f input_keyfile]\n");
3093 #ifdef ENABLE_PKCS11
3094 	fprintf(stderr,
3095 	    "       ssh-keygen -D pkcs11\n");
3096 #endif
3097 	fprintf(stderr,
3098 	    "       ssh-keygen -F hostname [-lv] [-f known_hosts_file]\n"
3099 	    "       ssh-keygen -H [-f known_hosts_file]\n"
3100 	    "       ssh-keygen -K [-a rounds] [-w provider]\n"
3101 	    "       ssh-keygen -R hostname [-f known_hosts_file]\n"
3102 	    "       ssh-keygen -r hostname [-g] [-f input_keyfile]\n"
3103 #ifdef WITH_OPENSSL
3104 	    "       ssh-keygen -M generate [-O option] output_file\n"
3105 	    "       ssh-keygen -M screen [-f input_file] [-O option] output_file\n"
3106 #endif
3107 	    "       ssh-keygen -I certificate_identity -s ca_key [-hU] [-D pkcs11_provider]\n"
3108 	    "                  [-n principals] [-O option] [-V validity_interval]\n"
3109 	    "                  [-z serial_number] file ...\n"
3110 	    "       ssh-keygen -L [-f input_keyfile]\n"
3111 	    "       ssh-keygen -A [-a rounds] [-f prefix_path]\n"
3112 	    "       ssh-keygen -k -f krl_file [-u] [-s ca_public] [-z version_number]\n"
3113 	    "                  file ...\n"
3114 	    "       ssh-keygen -Q [-l] -f krl_file [file ...]\n"
3115 	    "       ssh-keygen -Y find-principals -s signature_file -f allowed_signers_file\n"
3116 	    "       ssh-keygen -Y check-novalidate -n namespace -s signature_file\n"
3117 	    "       ssh-keygen -Y sign -f key_file -n namespace file ...\n"
3118 	    "       ssh-keygen -Y verify -f allowed_signers_file -I signer_identity\n"
3119 	    "       		-n namespace -s signature_file [-r revocation_file]\n");
3120 	exit(1);
3121 }
3122 
3123 /*
3124  * Main program for key management.
3125  */
3126 int
3127 main(int argc, char **argv)
3128 {
3129 	char comment[1024], *passphrase;
3130 	char *rr_hostname = NULL, *ep, *fp, *ra;
3131 	struct sshkey *private, *public;
3132 	struct passwd *pw;
3133 	int r, opt, type;
3134 	int change_passphrase = 0, change_comment = 0, show_cert = 0;
3135 	int find_host = 0, delete_host = 0, hash_hosts = 0;
3136 	int gen_all_hostkeys = 0, gen_krl = 0, update_krl = 0, check_krl = 0;
3137 	int prefer_agent = 0, convert_to = 0, convert_from = 0;
3138 	int print_public = 0, print_generic = 0, cert_serial_autoinc = 0;
3139 	int do_gen_candidates = 0, do_screen_candidates = 0, download_sk = 0;
3140 	unsigned long long cert_serial = 0;
3141 	char *identity_comment = NULL, *ca_key_path = NULL, **opts = NULL;
3142 	char *sk_application = NULL, *sk_device = NULL, *sk_user = NULL;
3143 	char *sk_attestation_path = NULL;
3144 	struct sshbuf *challenge = NULL, *attest = NULL;
3145 	size_t i, nopts = 0;
3146 	u_int32_t bits = 0;
3147 	uint8_t sk_flags = SSH_SK_USER_PRESENCE_REQD;
3148 	const char *errstr;
3149 	int log_level = SYSLOG_LEVEL_INFO;
3150 	char *sign_op = NULL;
3151 
3152 	extern int optind;
3153 	extern char *optarg;
3154 
3155 	/* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
3156 	sanitise_stdfd();
3157 
3158 #ifdef WITH_OPENSSL
3159 	OpenSSL_add_all_algorithms();
3160 #endif
3161 	log_init(argv[0], SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_USER, 1);
3162 
3163 	setlocale(LC_CTYPE, "");
3164 
3165 	/* we need this for the home * directory.  */
3166 	pw = getpwuid(getuid());
3167 	if (!pw)
3168 		fatal("No user exists for uid %lu", (u_long)getuid());
3169 	if (gethostname(hostname, sizeof(hostname)) == -1)
3170 		fatal("gethostname: %s", strerror(errno));
3171 
3172 	sk_provider = getenv("SSH_SK_PROVIDER");
3173 
3174 	/* Remaining characters: dGjJSTWx */
3175 	while ((opt = getopt(argc, argv, "ABHKLQUXceghiklopquvy"
3176 	    "C:D:E:F:I:M:N:O:P:R:V:Y:Z:"
3177 	    "a:b:f:g:m:n:r:s:t:w:z:")) != -1) {
3178 		switch (opt) {
3179 		case 'A':
3180 			gen_all_hostkeys = 1;
3181 			break;
3182 		case 'b':
3183 			bits = (u_int32_t)strtonum(optarg, 1, UINT32_MAX,
3184 			    &errstr);
3185 			if (errstr)
3186 				fatal("Bits has bad value %s (%s)",
3187 					optarg, errstr);
3188 			break;
3189 		case 'E':
3190 			fingerprint_hash = ssh_digest_alg_by_name(optarg);
3191 			if (fingerprint_hash == -1)
3192 				fatal("Invalid hash algorithm \"%s\"", optarg);
3193 			break;
3194 		case 'F':
3195 			find_host = 1;
3196 			rr_hostname = optarg;
3197 			break;
3198 		case 'H':
3199 			hash_hosts = 1;
3200 			break;
3201 		case 'I':
3202 			cert_key_id = optarg;
3203 			break;
3204 		case 'R':
3205 			delete_host = 1;
3206 			rr_hostname = optarg;
3207 			break;
3208 		case 'L':
3209 			show_cert = 1;
3210 			break;
3211 		case 'l':
3212 			print_fingerprint = 1;
3213 			break;
3214 		case 'B':
3215 			print_bubblebabble = 1;
3216 			break;
3217 		case 'm':
3218 			if (strcasecmp(optarg, "RFC4716") == 0 ||
3219 			    strcasecmp(optarg, "ssh2") == 0) {
3220 				convert_format = FMT_RFC4716;
3221 				break;
3222 			}
3223 			if (strcasecmp(optarg, "PKCS8") == 0) {
3224 				convert_format = FMT_PKCS8;
3225 				private_key_format = SSHKEY_PRIVATE_PKCS8;
3226 				break;
3227 			}
3228 			if (strcasecmp(optarg, "PEM") == 0) {
3229 				convert_format = FMT_PEM;
3230 				private_key_format = SSHKEY_PRIVATE_PEM;
3231 				break;
3232 			}
3233 			fatal("Unsupported conversion format \"%s\"", optarg);
3234 		case 'n':
3235 			cert_principals = optarg;
3236 			break;
3237 		case 'o':
3238 			/* no-op; new format is already the default */
3239 			break;
3240 		case 'p':
3241 			change_passphrase = 1;
3242 			break;
3243 		case 'c':
3244 			change_comment = 1;
3245 			break;
3246 		case 'f':
3247 			if (strlcpy(identity_file, optarg,
3248 			    sizeof(identity_file)) >= sizeof(identity_file))
3249 				fatal("Identity filename too long");
3250 			have_identity = 1;
3251 			break;
3252 		case 'g':
3253 			print_generic = 1;
3254 			break;
3255 		case 'K':
3256 			download_sk = 1;
3257 			break;
3258 		case 'P':
3259 			identity_passphrase = optarg;
3260 			break;
3261 		case 'N':
3262 			identity_new_passphrase = optarg;
3263 			break;
3264 		case 'Q':
3265 			check_krl = 1;
3266 			break;
3267 		case 'O':
3268 			opts = xrecallocarray(opts, nopts, nopts + 1,
3269 			    sizeof(*opts));
3270 			opts[nopts++] = xstrdup(optarg);
3271 			break;
3272 		case 'Z':
3273 			openssh_format_cipher = optarg;
3274 			break;
3275 		case 'C':
3276 			identity_comment = optarg;
3277 			break;
3278 		case 'q':
3279 			quiet = 1;
3280 			break;
3281 		case 'e':
3282 			/* export key */
3283 			convert_to = 1;
3284 			break;
3285 		case 'h':
3286 			cert_key_type = SSH2_CERT_TYPE_HOST;
3287 			certflags_flags = 0;
3288 			break;
3289 		case 'k':
3290 			gen_krl = 1;
3291 			break;
3292 		case 'i':
3293 		case 'X':
3294 			/* import key */
3295 			convert_from = 1;
3296 			break;
3297 		case 'y':
3298 			print_public = 1;
3299 			break;
3300 		case 's':
3301 			ca_key_path = optarg;
3302 			break;
3303 		case 't':
3304 			key_type_name = optarg;
3305 			break;
3306 		case 'D':
3307 			pkcs11provider = optarg;
3308 			break;
3309 		case 'U':
3310 			prefer_agent = 1;
3311 			break;
3312 		case 'u':
3313 			update_krl = 1;
3314 			break;
3315 		case 'v':
3316 			if (log_level == SYSLOG_LEVEL_INFO)
3317 				log_level = SYSLOG_LEVEL_DEBUG1;
3318 			else {
3319 				if (log_level >= SYSLOG_LEVEL_DEBUG1 &&
3320 				    log_level < SYSLOG_LEVEL_DEBUG3)
3321 					log_level++;
3322 			}
3323 			break;
3324 		case 'r':
3325 			rr_hostname = optarg;
3326 			break;
3327 		case 'a':
3328 			rounds = (int)strtonum(optarg, 1, INT_MAX, &errstr);
3329 			if (errstr)
3330 				fatal("Invalid number: %s (%s)",
3331 					optarg, errstr);
3332 			break;
3333 		case 'V':
3334 			parse_cert_times(optarg);
3335 			break;
3336 		case 'Y':
3337 			sign_op = optarg;
3338 			break;
3339 		case 'w':
3340 			sk_provider = optarg;
3341 			break;
3342 		case 'z':
3343 			errno = 0;
3344 			if (*optarg == '+') {
3345 				cert_serial_autoinc = 1;
3346 				optarg++;
3347 			}
3348 			cert_serial = strtoull(optarg, &ep, 10);
3349 			if (*optarg < '0' || *optarg > '9' || *ep != '\0' ||
3350 			    (errno == ERANGE && cert_serial == ULLONG_MAX))
3351 				fatal("Invalid serial number \"%s\"", optarg);
3352 			break;
3353 		case 'M':
3354 			if (strcmp(optarg, "generate") == 0)
3355 				do_gen_candidates = 1;
3356 			else if (strcmp(optarg, "screen") == 0)
3357 				do_screen_candidates = 1;
3358 			else
3359 				fatal("Unsupported moduli option %s", optarg);
3360 			break;
3361 		case '?':
3362 		default:
3363 			usage();
3364 		}
3365 	}
3366 
3367 	if (sk_provider == NULL)
3368 		sk_provider = "internal";
3369 
3370 	/* reinit */
3371 	log_init(argv[0], log_level, SYSLOG_FACILITY_USER, 1);
3372 
3373 	argv += optind;
3374 	argc -= optind;
3375 
3376 	if (sign_op != NULL) {
3377 		if (strncmp(sign_op, "find-principals", 15) == 0) {
3378 			if (ca_key_path == NULL) {
3379 				error("Too few arguments for find-principals:"
3380 				      "missing signature file");
3381 				exit(1);
3382 			}
3383 			if (!have_identity) {
3384 				error("Too few arguments for find-principals:"
3385 				      "missing allowed keys file");
3386 				exit(1);
3387 			}
3388 			return sig_find_principals(ca_key_path, identity_file);
3389 		} else if (strncmp(sign_op, "sign", 4) == 0) {
3390 			if (cert_principals == NULL ||
3391 			    *cert_principals == '\0') {
3392 				error("Too few arguments for sign: "
3393 				    "missing namespace");
3394 				exit(1);
3395 			}
3396 			if (!have_identity) {
3397 				error("Too few arguments for sign: "
3398 				    "missing key");
3399 				exit(1);
3400 			}
3401 			return sig_sign(identity_file, cert_principals,
3402 			    argc, argv);
3403 		} else if (strncmp(sign_op, "check-novalidate", 16) == 0) {
3404 			if (ca_key_path == NULL) {
3405 				error("Too few arguments for check-novalidate: "
3406 				      "missing signature file");
3407 				exit(1);
3408 			}
3409 			return sig_verify(ca_key_path, cert_principals,
3410 			    NULL, NULL, NULL);
3411 		} else if (strncmp(sign_op, "verify", 6) == 0) {
3412 			if (cert_principals == NULL ||
3413 			    *cert_principals == '\0') {
3414 				error("Too few arguments for verify: "
3415 				    "missing namespace");
3416 				exit(1);
3417 			}
3418 			if (ca_key_path == NULL) {
3419 				error("Too few arguments for verify: "
3420 				    "missing signature file");
3421 				exit(1);
3422 			}
3423 			if (!have_identity) {
3424 				error("Too few arguments for sign: "
3425 				    "missing allowed keys file");
3426 				exit(1);
3427 			}
3428 			if (cert_key_id == NULL) {
3429 				error("Too few arguments for verify: "
3430 				    "missing principal ID");
3431 				exit(1);
3432 			}
3433 			return sig_verify(ca_key_path, cert_principals,
3434 			    cert_key_id, identity_file, rr_hostname);
3435 		}
3436 		error("Unsupported operation for -Y: \"%s\"", sign_op);
3437 		usage();
3438 		/* NOTREACHED */
3439 	}
3440 
3441 	if (ca_key_path != NULL) {
3442 		if (argc < 1 && !gen_krl) {
3443 			error("Too few arguments.");
3444 			usage();
3445 		}
3446 	} else if (argc > 0 && !gen_krl && !check_krl &&
3447 	    !do_gen_candidates && !do_screen_candidates) {
3448 		error("Too many arguments.");
3449 		usage();
3450 	}
3451 	if (change_passphrase && change_comment) {
3452 		error("Can only have one of -p and -c.");
3453 		usage();
3454 	}
3455 	if (print_fingerprint && (delete_host || hash_hosts)) {
3456 		error("Cannot use -l with -H or -R.");
3457 		usage();
3458 	}
3459 	if (gen_krl) {
3460 		do_gen_krl(pw, update_krl, ca_key_path,
3461 		    cert_serial, identity_comment, argc, argv);
3462 		return (0);
3463 	}
3464 	if (check_krl) {
3465 		do_check_krl(pw, print_fingerprint, argc, argv);
3466 		return (0);
3467 	}
3468 	if (ca_key_path != NULL) {
3469 		if (cert_key_id == NULL)
3470 			fatal("Must specify key id (-I) when certifying");
3471 		for (i = 0; i < nopts; i++)
3472 			add_cert_option(opts[i]);
3473 		do_ca_sign(pw, ca_key_path, prefer_agent,
3474 		    cert_serial, cert_serial_autoinc, argc, argv);
3475 	}
3476 	if (show_cert)
3477 		do_show_cert(pw);
3478 	if (delete_host || hash_hosts || find_host) {
3479 		do_known_hosts(pw, rr_hostname, find_host,
3480 		    delete_host, hash_hosts);
3481 	}
3482 	if (pkcs11provider != NULL)
3483 		do_download(pw);
3484 	if (download_sk) {
3485 		for (i = 0; i < nopts; i++) {
3486 			if (strncasecmp(opts[i], "device=", 7) == 0) {
3487 				sk_device = xstrdup(opts[i] + 7);
3488 			} else {
3489 				fatal("Option \"%s\" is unsupported for "
3490 				    "FIDO authenticator download", opts[i]);
3491 			}
3492 		}
3493 		return do_download_sk(sk_provider, sk_device);
3494 	}
3495 	if (print_fingerprint || print_bubblebabble)
3496 		do_fingerprint(pw);
3497 	if (change_passphrase)
3498 		do_change_passphrase(pw);
3499 	if (change_comment)
3500 		do_change_comment(pw, identity_comment);
3501 #ifdef WITH_OPENSSL
3502 	if (convert_to)
3503 		do_convert_to(pw);
3504 	if (convert_from)
3505 		do_convert_from(pw);
3506 #else /* WITH_OPENSSL */
3507 	if (convert_to || convert_from)
3508 		fatal("key conversion disabled at compile time");
3509 #endif /* WITH_OPENSSL */
3510 	if (print_public)
3511 		do_print_public(pw);
3512 	if (rr_hostname != NULL) {
3513 		unsigned int n = 0;
3514 
3515 		if (have_identity) {
3516 			n = do_print_resource_record(pw, identity_file,
3517 			    rr_hostname, print_generic);
3518 			if (n == 0)
3519 				fatal("%s: %s", identity_file, strerror(errno));
3520 			exit(0);
3521 		} else {
3522 
3523 			n += do_print_resource_record(pw,
3524 			    _PATH_HOST_RSA_KEY_FILE, rr_hostname,
3525 			    print_generic);
3526 			n += do_print_resource_record(pw,
3527 			    _PATH_HOST_DSA_KEY_FILE, rr_hostname,
3528 			    print_generic);
3529 			n += do_print_resource_record(pw,
3530 			    _PATH_HOST_ECDSA_KEY_FILE, rr_hostname,
3531 			    print_generic);
3532 			n += do_print_resource_record(pw,
3533 			    _PATH_HOST_ED25519_KEY_FILE, rr_hostname,
3534 			    print_generic);
3535 			n += do_print_resource_record(pw,
3536 			    _PATH_HOST_XMSS_KEY_FILE, rr_hostname,
3537 			    print_generic);
3538 			if (n == 0)
3539 				fatal("no keys found.");
3540 			exit(0);
3541 		}
3542 	}
3543 
3544 	if (do_gen_candidates || do_screen_candidates) {
3545 		if (argc <= 0)
3546 			fatal("No output file specified");
3547 		else if (argc > 1)
3548 			fatal("Too many output files specified");
3549 	}
3550 	if (do_gen_candidates) {
3551 		do_moduli_gen(argv[0], opts, nopts);
3552 		return 0;
3553 	}
3554 	if (do_screen_candidates) {
3555 		do_moduli_screen(argv[0], opts, nopts);
3556 		return 0;
3557 	}
3558 
3559 	if (gen_all_hostkeys) {
3560 		do_gen_all_hostkeys(pw);
3561 		return (0);
3562 	}
3563 
3564 	if (key_type_name == NULL)
3565 		key_type_name = DEFAULT_KEY_TYPE_NAME;
3566 
3567 	type = sshkey_type_from_name(key_type_name);
3568 	type_bits_valid(type, key_type_name, &bits);
3569 
3570 	if (!quiet)
3571 		printf("Generating public/private %s key pair.\n",
3572 		    key_type_name);
3573 	switch (type) {
3574 	case KEY_ECDSA_SK:
3575 	case KEY_ED25519_SK:
3576 		for (i = 0; i < nopts; i++) {
3577 			if (strcasecmp(opts[i], "no-touch-required") == 0) {
3578 				sk_flags &= ~SSH_SK_USER_PRESENCE_REQD;
3579 			} else if (strcasecmp(opts[i], "verify-required") == 0) {
3580 				sk_flags |= SSH_SK_USER_VERIFICATION_REQD;
3581 			} else if (strcasecmp(opts[i], "resident") == 0) {
3582 				sk_flags |= SSH_SK_RESIDENT_KEY;
3583 			} else if (strncasecmp(opts[i], "device=", 7) == 0) {
3584 				sk_device = xstrdup(opts[i] + 7);
3585 			} else if (strncasecmp(opts[i], "user=", 5) == 0) {
3586 				sk_user = xstrdup(opts[i] + 5);
3587 			} else if (strncasecmp(opts[i], "challenge=", 10) == 0) {
3588 				if ((r = sshbuf_load_file(opts[i] + 10,
3589 				    &challenge)) != 0) {
3590 					fatal("Unable to load FIDO enrollment "
3591 					    "challenge \"%s\": %s",
3592 					    opts[i] + 10, ssh_err(r));
3593 				}
3594 			} else if (strncasecmp(opts[i],
3595 			    "write-attestation=", 18) == 0) {
3596 				sk_attestation_path = opts[i] + 18;
3597 			} else if (strncasecmp(opts[i],
3598 			    "application=", 12) == 0) {
3599 				sk_application = xstrdup(opts[i] + 12);
3600 				if (strncmp(sk_application, "ssh:", 4) != 0) {
3601 					fatal("FIDO application string must "
3602 					    "begin with \"ssh:\"");
3603 				}
3604 			} else {
3605 				fatal("Option \"%s\" is unsupported for "
3606 				    "FIDO authenticator enrollment", opts[i]);
3607 			}
3608 		}
3609 		if (!quiet) {
3610 			printf("You may need to touch your authenticator "
3611 			    "to authorize key generation.\n");
3612 		}
3613 		if ((attest = sshbuf_new()) == NULL)
3614 			fatal("sshbuf_new failed");
3615 		if ((sk_flags &
3616 		    (SSH_SK_USER_VERIFICATION_REQD|SSH_SK_RESIDENT_KEY))) {
3617 			passphrase = read_passphrase("Enter PIN for "
3618 			    "authenticator: ", RP_ALLOW_STDIN);
3619 		} else {
3620 			passphrase = NULL;
3621 		}
3622 		for (i = 0 ; ; i++) {
3623 			fflush(stdout);
3624 			r = sshsk_enroll(type, sk_provider, sk_device,
3625 			    sk_application == NULL ? "ssh:" : sk_application,
3626 			    sk_user, sk_flags, passphrase, challenge,
3627 			    &private, attest);
3628 			if (r == 0)
3629 				break;
3630 			if (r != SSH_ERR_KEY_WRONG_PASSPHRASE)
3631 				fatal("Key enrollment failed: %s", ssh_err(r));
3632 			else if (passphrase != NULL) {
3633 				error("PIN incorrect");
3634 				freezero(passphrase, strlen(passphrase));
3635 				passphrase = NULL;
3636 			}
3637 			if (i >= 3)
3638 				fatal("Too many incorrect PINs");
3639 			passphrase = read_passphrase("Enter PIN for "
3640 			    "authenticator: ", RP_ALLOW_STDIN);
3641 			if (!quiet) {
3642 				printf("You may need to touch your "
3643 				    "authenticator (again) to authorize "
3644 				    "key generation.\n");
3645 			}
3646 		}
3647 		if (passphrase != NULL) {
3648 			freezero(passphrase, strlen(passphrase));
3649 			passphrase = NULL;
3650 		}
3651 		break;
3652 	default:
3653 		if ((r = sshkey_generate(type, bits, &private)) != 0)
3654 			fatal("sshkey_generate failed");
3655 		break;
3656 	}
3657 	if ((r = sshkey_from_private(private, &public)) != 0)
3658 		fatal("sshkey_from_private failed: %s\n", ssh_err(r));
3659 
3660 	if (!have_identity)
3661 		ask_filename(pw, "Enter file in which to save the key");
3662 
3663 	/* Create ~/.ssh directory if it doesn't already exist. */
3664 	hostfile_create_user_ssh_dir(identity_file, !quiet);
3665 
3666 	/* If the file already exists, ask the user to confirm. */
3667 	if (!confirm_overwrite(identity_file))
3668 		exit(1);
3669 
3670 	/* Determine the passphrase for the private key */
3671 	passphrase = private_key_passphrase();
3672 	if (identity_comment) {
3673 		strlcpy(comment, identity_comment, sizeof(comment));
3674 	} else {
3675 		/* Create default comment field for the passphrase. */
3676 		snprintf(comment, sizeof comment, "%s@%s", pw->pw_name, hostname);
3677 	}
3678 
3679 	/* Save the key with the given passphrase and comment. */
3680 	if ((r = sshkey_save_private(private, identity_file, passphrase,
3681 	    comment, private_key_format, openssh_format_cipher, rounds)) != 0) {
3682 		error("Saving key \"%s\" failed: %s",
3683 		    identity_file, ssh_err(r));
3684 		freezero(passphrase, strlen(passphrase));
3685 		exit(1);
3686 	}
3687 	freezero(passphrase, strlen(passphrase));
3688 	sshkey_free(private);
3689 
3690 	if (!quiet) {
3691 		printf("Your identification has been saved in %s\n",
3692 		    identity_file);
3693 	}
3694 
3695 	strlcat(identity_file, ".pub", sizeof(identity_file));
3696 	if ((r = sshkey_save_public(public, identity_file, comment)) != 0) {
3697 		fatal("Unable to save public key to %s: %s",
3698 		    identity_file, ssh_err(r));
3699 	}
3700 
3701 	if (!quiet) {
3702 		fp = sshkey_fingerprint(public, fingerprint_hash,
3703 		    SSH_FP_DEFAULT);
3704 		ra = sshkey_fingerprint(public, fingerprint_hash,
3705 		    SSH_FP_RANDOMART);
3706 		if (fp == NULL || ra == NULL)
3707 			fatal("sshkey_fingerprint failed");
3708 		printf("Your public key has been saved in %s\n",
3709 		    identity_file);
3710 		printf("The key fingerprint is:\n");
3711 		printf("%s %s\n", fp, comment);
3712 		printf("The key's randomart image is:\n");
3713 		printf("%s\n", ra);
3714 		free(ra);
3715 		free(fp);
3716 	}
3717 
3718 	if (sk_attestation_path != NULL)
3719 		save_attestation(attest, sk_attestation_path);
3720 
3721 	sshbuf_free(attest);
3722 	sshkey_free(public);
3723 
3724 	exit(0);
3725 }
3726