xref: /openbsd-src/usr.bin/ssh/sshkey.c (revision 6c6408334dbede3a2c0dcd9ff9c489157df0c856)
1 /* $OpenBSD: sshkey.c,v 1.63 2018/03/02 02:08:03 djm Exp $ */
2 /*
3  * Copyright (c) 2000, 2001 Markus Friedl.  All rights reserved.
4  * Copyright (c) 2008 Alexander von Gernler.  All rights reserved.
5  * Copyright (c) 2010,2011 Damien Miller.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 #include <sys/types.h>
29 #include <netinet/in.h>
30 
31 #ifdef WITH_OPENSSL
32 #include <openssl/evp.h>
33 #include <openssl/err.h>
34 #include <openssl/pem.h>
35 #endif
36 
37 #include "crypto_api.h"
38 
39 #include <errno.h>
40 #include <stdio.h>
41 #include <string.h>
42 #include <util.h>
43 #include <limits.h>
44 #include <resolv.h>
45 
46 #include "ssh2.h"
47 #include "ssherr.h"
48 #include "misc.h"
49 #include "sshbuf.h"
50 #include "cipher.h"
51 #include "digest.h"
52 #define SSHKEY_INTERNAL
53 #include "sshkey.h"
54 #include "sshkey-xmss.h"
55 #include "match.h"
56 
57 #include "xmss_fast.h"
58 
59 /* openssh private key file format */
60 #define MARK_BEGIN		"-----BEGIN OPENSSH PRIVATE KEY-----\n"
61 #define MARK_END		"-----END OPENSSH PRIVATE KEY-----\n"
62 #define MARK_BEGIN_LEN		(sizeof(MARK_BEGIN) - 1)
63 #define MARK_END_LEN		(sizeof(MARK_END) - 1)
64 #define KDFNAME			"bcrypt"
65 #define AUTH_MAGIC		"openssh-key-v1"
66 #define SALT_LEN		16
67 #define DEFAULT_CIPHERNAME	"aes256-ctr"
68 #define	DEFAULT_ROUNDS		16
69 
70 /* Version identification string for SSH v1 identity files. */
71 #define LEGACY_BEGIN		"SSH PRIVATE KEY FILE FORMAT 1.1\n"
72 
73 int	sshkey_private_serialize_opt(const struct sshkey *key,
74     struct sshbuf *buf, enum sshkey_serialize_rep);
75 static int sshkey_from_blob_internal(struct sshbuf *buf,
76     struct sshkey **keyp, int allow_cert);
77 
78 /* Supported key types */
79 struct keytype {
80 	const char *name;
81 	const char *shortname;
82 	int type;
83 	int nid;
84 	int cert;
85 	int sigonly;
86 };
87 static const struct keytype keytypes[] = {
88 	{ "ssh-ed25519", "ED25519", KEY_ED25519, 0, 0, 0 },
89 	{ "ssh-ed25519-cert-v01@openssh.com", "ED25519-CERT",
90 	    KEY_ED25519_CERT, 0, 1, 0 },
91 #ifdef WITH_XMSS
92 	{ "ssh-xmss@openssh.com", "XMSS", KEY_XMSS, 0, 0, 0 },
93 	{ "ssh-xmss-cert-v01@openssh.com", "XMSS-CERT",
94 	    KEY_XMSS_CERT, 0, 1, 0 },
95 #endif /* WITH_XMSS */
96 #ifdef WITH_OPENSSL
97 	{ "ssh-rsa", "RSA", KEY_RSA, 0, 0, 0 },
98 	{ "rsa-sha2-256", "RSA", KEY_RSA, 0, 0, 1 },
99 	{ "rsa-sha2-512", "RSA", KEY_RSA, 0, 0, 1 },
100 	{ "ssh-dss", "DSA", KEY_DSA, 0, 0, 0 },
101 	{ "ecdsa-sha2-nistp256", "ECDSA", KEY_ECDSA, NID_X9_62_prime256v1, 0, 0 },
102 	{ "ecdsa-sha2-nistp384", "ECDSA", KEY_ECDSA, NID_secp384r1, 0, 0 },
103 	{ "ecdsa-sha2-nistp521", "ECDSA", KEY_ECDSA, NID_secp521r1, 0, 0 },
104 	{ "ssh-rsa-cert-v01@openssh.com", "RSA-CERT", KEY_RSA_CERT, 0, 1, 0 },
105 	{ "ssh-dss-cert-v01@openssh.com", "DSA-CERT", KEY_DSA_CERT, 0, 1, 0 },
106 	{ "ecdsa-sha2-nistp256-cert-v01@openssh.com", "ECDSA-CERT",
107 	    KEY_ECDSA_CERT, NID_X9_62_prime256v1, 1, 0 },
108 	{ "ecdsa-sha2-nistp384-cert-v01@openssh.com", "ECDSA-CERT",
109 	    KEY_ECDSA_CERT, NID_secp384r1, 1, 0 },
110 	{ "ecdsa-sha2-nistp521-cert-v01@openssh.com", "ECDSA-CERT",
111 	    KEY_ECDSA_CERT, NID_secp521r1, 1, 0 },
112 #endif /* WITH_OPENSSL */
113 	{ NULL, NULL, -1, -1, 0, 0 }
114 };
115 
116 const char *
117 sshkey_type(const struct sshkey *k)
118 {
119 	const struct keytype *kt;
120 
121 	for (kt = keytypes; kt->type != -1; kt++) {
122 		if (kt->type == k->type)
123 			return kt->shortname;
124 	}
125 	return "unknown";
126 }
127 
128 static const char *
129 sshkey_ssh_name_from_type_nid(int type, int nid)
130 {
131 	const struct keytype *kt;
132 
133 	for (kt = keytypes; kt->type != -1; kt++) {
134 		if (kt->type == type && (kt->nid == 0 || kt->nid == nid))
135 			return kt->name;
136 	}
137 	return "ssh-unknown";
138 }
139 
140 int
141 sshkey_type_is_cert(int type)
142 {
143 	const struct keytype *kt;
144 
145 	for (kt = keytypes; kt->type != -1; kt++) {
146 		if (kt->type == type)
147 			return kt->cert;
148 	}
149 	return 0;
150 }
151 
152 const char *
153 sshkey_ssh_name(const struct sshkey *k)
154 {
155 	return sshkey_ssh_name_from_type_nid(k->type, k->ecdsa_nid);
156 }
157 
158 const char *
159 sshkey_ssh_name_plain(const struct sshkey *k)
160 {
161 	return sshkey_ssh_name_from_type_nid(sshkey_type_plain(k->type),
162 	    k->ecdsa_nid);
163 }
164 
165 int
166 sshkey_type_from_name(const char *name)
167 {
168 	const struct keytype *kt;
169 
170 	for (kt = keytypes; kt->type != -1; kt++) {
171 		/* Only allow shortname matches for plain key types */
172 		if ((kt->name != NULL && strcmp(name, kt->name) == 0) ||
173 		    (!kt->cert && strcasecmp(kt->shortname, name) == 0))
174 			return kt->type;
175 	}
176 	return KEY_UNSPEC;
177 }
178 
179 int
180 sshkey_ecdsa_nid_from_name(const char *name)
181 {
182 	const struct keytype *kt;
183 
184 	for (kt = keytypes; kt->type != -1; kt++) {
185 		if (kt->type != KEY_ECDSA && kt->type != KEY_ECDSA_CERT)
186 			continue;
187 		if (kt->name != NULL && strcmp(name, kt->name) == 0)
188 			return kt->nid;
189 	}
190 	return -1;
191 }
192 
193 char *
194 sshkey_alg_list(int certs_only, int plain_only, int include_sigonly, char sep)
195 {
196 	char *tmp, *ret = NULL;
197 	size_t nlen, rlen = 0;
198 	const struct keytype *kt;
199 
200 	for (kt = keytypes; kt->type != -1; kt++) {
201 		if (kt->name == NULL)
202 			continue;
203 		if (!include_sigonly && kt->sigonly)
204 			continue;
205 		if ((certs_only && !kt->cert) || (plain_only && kt->cert))
206 			continue;
207 		if (ret != NULL)
208 			ret[rlen++] = sep;
209 		nlen = strlen(kt->name);
210 		if ((tmp = realloc(ret, rlen + nlen + 2)) == NULL) {
211 			free(ret);
212 			return NULL;
213 		}
214 		ret = tmp;
215 		memcpy(ret + rlen, kt->name, nlen + 1);
216 		rlen += nlen;
217 	}
218 	return ret;
219 }
220 
221 int
222 sshkey_names_valid2(const char *names, int allow_wildcard)
223 {
224 	char *s, *cp, *p;
225 	const struct keytype *kt;
226 	int type;
227 
228 	if (names == NULL || strcmp(names, "") == 0)
229 		return 0;
230 	if ((s = cp = strdup(names)) == NULL)
231 		return 0;
232 	for ((p = strsep(&cp, ",")); p && *p != '\0';
233 	    (p = strsep(&cp, ","))) {
234 		type = sshkey_type_from_name(p);
235 		if (type == KEY_UNSPEC) {
236 			if (allow_wildcard) {
237 				/*
238 				 * Try matching key types against the string.
239 				 * If any has a positive or negative match then
240 				 * the component is accepted.
241 				 */
242 				for (kt = keytypes; kt->type != -1; kt++) {
243 					if (match_pattern_list(kt->name,
244 					    p, 0) != 0)
245 						break;
246 				}
247 				if (kt->type != -1)
248 					continue;
249 			}
250 			free(s);
251 			return 0;
252 		}
253 	}
254 	free(s);
255 	return 1;
256 }
257 
258 u_int
259 sshkey_size(const struct sshkey *k)
260 {
261 	switch (k->type) {
262 #ifdef WITH_OPENSSL
263 	case KEY_RSA:
264 	case KEY_RSA_CERT:
265 		return BN_num_bits(k->rsa->n);
266 	case KEY_DSA:
267 	case KEY_DSA_CERT:
268 		return BN_num_bits(k->dsa->p);
269 	case KEY_ECDSA:
270 	case KEY_ECDSA_CERT:
271 		return sshkey_curve_nid_to_bits(k->ecdsa_nid);
272 #endif /* WITH_OPENSSL */
273 	case KEY_ED25519:
274 	case KEY_ED25519_CERT:
275 	case KEY_XMSS:
276 	case KEY_XMSS_CERT:
277 		return 256;	/* XXX */
278 	}
279 	return 0;
280 }
281 
282 static int
283 sshkey_type_is_valid_ca(int type)
284 {
285 	switch (type) {
286 	case KEY_RSA:
287 	case KEY_DSA:
288 	case KEY_ECDSA:
289 	case KEY_ED25519:
290 	case KEY_XMSS:
291 		return 1;
292 	default:
293 		return 0;
294 	}
295 }
296 
297 int
298 sshkey_is_cert(const struct sshkey *k)
299 {
300 	if (k == NULL)
301 		return 0;
302 	return sshkey_type_is_cert(k->type);
303 }
304 
305 /* Return the cert-less equivalent to a certified key type */
306 int
307 sshkey_type_plain(int type)
308 {
309 	switch (type) {
310 	case KEY_RSA_CERT:
311 		return KEY_RSA;
312 	case KEY_DSA_CERT:
313 		return KEY_DSA;
314 	case KEY_ECDSA_CERT:
315 		return KEY_ECDSA;
316 	case KEY_ED25519_CERT:
317 		return KEY_ED25519;
318 	case KEY_XMSS_CERT:
319 		return KEY_XMSS;
320 	default:
321 		return type;
322 	}
323 }
324 
325 #ifdef WITH_OPENSSL
326 /* XXX: these are really begging for a table-driven approach */
327 int
328 sshkey_curve_name_to_nid(const char *name)
329 {
330 	if (strcmp(name, "nistp256") == 0)
331 		return NID_X9_62_prime256v1;
332 	else if (strcmp(name, "nistp384") == 0)
333 		return NID_secp384r1;
334 	else if (strcmp(name, "nistp521") == 0)
335 		return NID_secp521r1;
336 	else
337 		return -1;
338 }
339 
340 u_int
341 sshkey_curve_nid_to_bits(int nid)
342 {
343 	switch (nid) {
344 	case NID_X9_62_prime256v1:
345 		return 256;
346 	case NID_secp384r1:
347 		return 384;
348 	case NID_secp521r1:
349 		return 521;
350 	default:
351 		return 0;
352 	}
353 }
354 
355 int
356 sshkey_ecdsa_bits_to_nid(int bits)
357 {
358 	switch (bits) {
359 	case 256:
360 		return NID_X9_62_prime256v1;
361 	case 384:
362 		return NID_secp384r1;
363 	case 521:
364 		return NID_secp521r1;
365 	default:
366 		return -1;
367 	}
368 }
369 
370 const char *
371 sshkey_curve_nid_to_name(int nid)
372 {
373 	switch (nid) {
374 	case NID_X9_62_prime256v1:
375 		return "nistp256";
376 	case NID_secp384r1:
377 		return "nistp384";
378 	case NID_secp521r1:
379 		return "nistp521";
380 	default:
381 		return NULL;
382 	}
383 }
384 
385 int
386 sshkey_ec_nid_to_hash_alg(int nid)
387 {
388 	int kbits = sshkey_curve_nid_to_bits(nid);
389 
390 	if (kbits <= 0)
391 		return -1;
392 
393 	/* RFC5656 section 6.2.1 */
394 	if (kbits <= 256)
395 		return SSH_DIGEST_SHA256;
396 	else if (kbits <= 384)
397 		return SSH_DIGEST_SHA384;
398 	else
399 		return SSH_DIGEST_SHA512;
400 }
401 #endif /* WITH_OPENSSL */
402 
403 static void
404 cert_free(struct sshkey_cert *cert)
405 {
406 	u_int i;
407 
408 	if (cert == NULL)
409 		return;
410 	sshbuf_free(cert->certblob);
411 	sshbuf_free(cert->critical);
412 	sshbuf_free(cert->extensions);
413 	free(cert->key_id);
414 	for (i = 0; i < cert->nprincipals; i++)
415 		free(cert->principals[i]);
416 	free(cert->principals);
417 	sshkey_free(cert->signature_key);
418 	freezero(cert, sizeof(*cert));
419 }
420 
421 static struct sshkey_cert *
422 cert_new(void)
423 {
424 	struct sshkey_cert *cert;
425 
426 	if ((cert = calloc(1, sizeof(*cert))) == NULL)
427 		return NULL;
428 	if ((cert->certblob = sshbuf_new()) == NULL ||
429 	    (cert->critical = sshbuf_new()) == NULL ||
430 	    (cert->extensions = sshbuf_new()) == NULL) {
431 		cert_free(cert);
432 		return NULL;
433 	}
434 	cert->key_id = NULL;
435 	cert->principals = NULL;
436 	cert->signature_key = NULL;
437 	return cert;
438 }
439 
440 struct sshkey *
441 sshkey_new(int type)
442 {
443 	struct sshkey *k;
444 #ifdef WITH_OPENSSL
445 	RSA *rsa;
446 	DSA *dsa;
447 #endif /* WITH_OPENSSL */
448 
449 	if ((k = calloc(1, sizeof(*k))) == NULL)
450 		return NULL;
451 	k->type = type;
452 	k->ecdsa = NULL;
453 	k->ecdsa_nid = -1;
454 	k->dsa = NULL;
455 	k->rsa = NULL;
456 	k->cert = NULL;
457 	k->ed25519_sk = NULL;
458 	k->ed25519_pk = NULL;
459 	k->xmss_sk = NULL;
460 	k->xmss_pk = NULL;
461 	switch (k->type) {
462 #ifdef WITH_OPENSSL
463 	case KEY_RSA:
464 	case KEY_RSA_CERT:
465 		if ((rsa = RSA_new()) == NULL ||
466 		    (rsa->n = BN_new()) == NULL ||
467 		    (rsa->e = BN_new()) == NULL) {
468 			RSA_free(rsa);
469 			free(k);
470 			return NULL;
471 		}
472 		k->rsa = rsa;
473 		break;
474 	case KEY_DSA:
475 	case KEY_DSA_CERT:
476 		if ((dsa = DSA_new()) == NULL ||
477 		    (dsa->p = BN_new()) == NULL ||
478 		    (dsa->q = BN_new()) == NULL ||
479 		    (dsa->g = BN_new()) == NULL ||
480 		    (dsa->pub_key = BN_new()) == NULL) {
481 			DSA_free(dsa);
482 			free(k);
483 			return NULL;
484 		}
485 		k->dsa = dsa;
486 		break;
487 	case KEY_ECDSA:
488 	case KEY_ECDSA_CERT:
489 		/* Cannot do anything until we know the group */
490 		break;
491 #endif /* WITH_OPENSSL */
492 	case KEY_ED25519:
493 	case KEY_ED25519_CERT:
494 	case KEY_XMSS:
495 	case KEY_XMSS_CERT:
496 		/* no need to prealloc */
497 		break;
498 	case KEY_UNSPEC:
499 		break;
500 	default:
501 		free(k);
502 		return NULL;
503 	}
504 
505 	if (sshkey_is_cert(k)) {
506 		if ((k->cert = cert_new()) == NULL) {
507 			sshkey_free(k);
508 			return NULL;
509 		}
510 	}
511 
512 	return k;
513 }
514 
515 int
516 sshkey_add_private(struct sshkey *k)
517 {
518 	switch (k->type) {
519 #ifdef WITH_OPENSSL
520 	case KEY_RSA:
521 	case KEY_RSA_CERT:
522 #define bn_maybe_alloc_failed(p) (p == NULL && (p = BN_new()) == NULL)
523 		if (bn_maybe_alloc_failed(k->rsa->d) ||
524 		    bn_maybe_alloc_failed(k->rsa->iqmp) ||
525 		    bn_maybe_alloc_failed(k->rsa->q) ||
526 		    bn_maybe_alloc_failed(k->rsa->p) ||
527 		    bn_maybe_alloc_failed(k->rsa->dmq1) ||
528 		    bn_maybe_alloc_failed(k->rsa->dmp1))
529 			return SSH_ERR_ALLOC_FAIL;
530 		break;
531 	case KEY_DSA:
532 	case KEY_DSA_CERT:
533 		if (bn_maybe_alloc_failed(k->dsa->priv_key))
534 			return SSH_ERR_ALLOC_FAIL;
535 		break;
536 #undef bn_maybe_alloc_failed
537 	case KEY_ECDSA:
538 	case KEY_ECDSA_CERT:
539 		/* Cannot do anything until we know the group */
540 		break;
541 #endif /* WITH_OPENSSL */
542 	case KEY_ED25519:
543 	case KEY_ED25519_CERT:
544 	case KEY_XMSS:
545 	case KEY_XMSS_CERT:
546 		/* no need to prealloc */
547 		break;
548 	case KEY_UNSPEC:
549 		break;
550 	default:
551 		return SSH_ERR_INVALID_ARGUMENT;
552 	}
553 	return 0;
554 }
555 
556 struct sshkey *
557 sshkey_new_private(int type)
558 {
559 	struct sshkey *k = sshkey_new(type);
560 
561 	if (k == NULL)
562 		return NULL;
563 	if (sshkey_add_private(k) != 0) {
564 		sshkey_free(k);
565 		return NULL;
566 	}
567 	return k;
568 }
569 
570 void
571 sshkey_free(struct sshkey *k)
572 {
573 	if (k == NULL)
574 		return;
575 	switch (k->type) {
576 #ifdef WITH_OPENSSL
577 	case KEY_RSA:
578 	case KEY_RSA_CERT:
579 		RSA_free(k->rsa);
580 		k->rsa = NULL;
581 		break;
582 	case KEY_DSA:
583 	case KEY_DSA_CERT:
584 		DSA_free(k->dsa);
585 		k->dsa = NULL;
586 		break;
587 	case KEY_ECDSA:
588 	case KEY_ECDSA_CERT:
589 		EC_KEY_free(k->ecdsa);
590 		k->ecdsa = NULL;
591 		break;
592 #endif /* WITH_OPENSSL */
593 	case KEY_ED25519:
594 	case KEY_ED25519_CERT:
595 		freezero(k->ed25519_pk, ED25519_PK_SZ);
596 		k->ed25519_pk = NULL;
597 		freezero(k->ed25519_sk, ED25519_SK_SZ);
598 		k->ed25519_sk = NULL;
599 		break;
600 #ifdef WITH_XMSS
601 	case KEY_XMSS:
602 	case KEY_XMSS_CERT:
603 		freezero(k->xmss_pk, sshkey_xmss_pklen(k));
604 		k->xmss_pk = NULL;
605 		freezero(k->xmss_sk, sshkey_xmss_sklen(k));
606 		k->xmss_sk = NULL;
607 		sshkey_xmss_free_state(k);
608 		free(k->xmss_name);
609 		k->xmss_name = NULL;
610 		free(k->xmss_filename);
611 		k->xmss_filename = NULL;
612 		break;
613 #endif /* WITH_XMSS */
614 	case KEY_UNSPEC:
615 		break;
616 	default:
617 		break;
618 	}
619 	if (sshkey_is_cert(k))
620 		cert_free(k->cert);
621 	freezero(k, sizeof(*k));
622 }
623 
624 static int
625 cert_compare(struct sshkey_cert *a, struct sshkey_cert *b)
626 {
627 	if (a == NULL && b == NULL)
628 		return 1;
629 	if (a == NULL || b == NULL)
630 		return 0;
631 	if (sshbuf_len(a->certblob) != sshbuf_len(b->certblob))
632 		return 0;
633 	if (timingsafe_bcmp(sshbuf_ptr(a->certblob), sshbuf_ptr(b->certblob),
634 	    sshbuf_len(a->certblob)) != 0)
635 		return 0;
636 	return 1;
637 }
638 
639 /*
640  * Compare public portions of key only, allowing comparisons between
641  * certificates and plain keys too.
642  */
643 int
644 sshkey_equal_public(const struct sshkey *a, const struct sshkey *b)
645 {
646 #ifdef WITH_OPENSSL
647 	BN_CTX *bnctx;
648 #endif /* WITH_OPENSSL */
649 
650 	if (a == NULL || b == NULL ||
651 	    sshkey_type_plain(a->type) != sshkey_type_plain(b->type))
652 		return 0;
653 
654 	switch (a->type) {
655 #ifdef WITH_OPENSSL
656 	case KEY_RSA_CERT:
657 	case KEY_RSA:
658 		return a->rsa != NULL && b->rsa != NULL &&
659 		    BN_cmp(a->rsa->e, b->rsa->e) == 0 &&
660 		    BN_cmp(a->rsa->n, b->rsa->n) == 0;
661 	case KEY_DSA_CERT:
662 	case KEY_DSA:
663 		return a->dsa != NULL && b->dsa != NULL &&
664 		    BN_cmp(a->dsa->p, b->dsa->p) == 0 &&
665 		    BN_cmp(a->dsa->q, b->dsa->q) == 0 &&
666 		    BN_cmp(a->dsa->g, b->dsa->g) == 0 &&
667 		    BN_cmp(a->dsa->pub_key, b->dsa->pub_key) == 0;
668 	case KEY_ECDSA_CERT:
669 	case KEY_ECDSA:
670 		if (a->ecdsa == NULL || b->ecdsa == NULL ||
671 		    EC_KEY_get0_public_key(a->ecdsa) == NULL ||
672 		    EC_KEY_get0_public_key(b->ecdsa) == NULL)
673 			return 0;
674 		if ((bnctx = BN_CTX_new()) == NULL)
675 			return 0;
676 		if (EC_GROUP_cmp(EC_KEY_get0_group(a->ecdsa),
677 		    EC_KEY_get0_group(b->ecdsa), bnctx) != 0 ||
678 		    EC_POINT_cmp(EC_KEY_get0_group(a->ecdsa),
679 		    EC_KEY_get0_public_key(a->ecdsa),
680 		    EC_KEY_get0_public_key(b->ecdsa), bnctx) != 0) {
681 			BN_CTX_free(bnctx);
682 			return 0;
683 		}
684 		BN_CTX_free(bnctx);
685 		return 1;
686 #endif /* WITH_OPENSSL */
687 	case KEY_ED25519:
688 	case KEY_ED25519_CERT:
689 		return a->ed25519_pk != NULL && b->ed25519_pk != NULL &&
690 		    memcmp(a->ed25519_pk, b->ed25519_pk, ED25519_PK_SZ) == 0;
691 #ifdef WITH_XMSS
692 	case KEY_XMSS:
693 	case KEY_XMSS_CERT:
694 		return a->xmss_pk != NULL && b->xmss_pk != NULL &&
695 		    sshkey_xmss_pklen(a) == sshkey_xmss_pklen(b) &&
696 		    memcmp(a->xmss_pk, b->xmss_pk, sshkey_xmss_pklen(a)) == 0;
697 #endif /* WITH_XMSS */
698 	default:
699 		return 0;
700 	}
701 	/* NOTREACHED */
702 }
703 
704 int
705 sshkey_equal(const struct sshkey *a, const struct sshkey *b)
706 {
707 	if (a == NULL || b == NULL || a->type != b->type)
708 		return 0;
709 	if (sshkey_is_cert(a)) {
710 		if (!cert_compare(a->cert, b->cert))
711 			return 0;
712 	}
713 	return sshkey_equal_public(a, b);
714 }
715 
716 static int
717 to_blob_buf(const struct sshkey *key, struct sshbuf *b, int force_plain,
718   enum sshkey_serialize_rep opts)
719 {
720 	int type, ret = SSH_ERR_INTERNAL_ERROR;
721 	const char *typename;
722 
723 	if (key == NULL)
724 		return SSH_ERR_INVALID_ARGUMENT;
725 
726 	if (sshkey_is_cert(key)) {
727 		if (key->cert == NULL)
728 			return SSH_ERR_EXPECTED_CERT;
729 		if (sshbuf_len(key->cert->certblob) == 0)
730 			return SSH_ERR_KEY_LACKS_CERTBLOB;
731 	}
732 	type = force_plain ? sshkey_type_plain(key->type) : key->type;
733 	typename = sshkey_ssh_name_from_type_nid(type, key->ecdsa_nid);
734 
735 	switch (type) {
736 #ifdef WITH_OPENSSL
737 	case KEY_DSA_CERT:
738 	case KEY_ECDSA_CERT:
739 	case KEY_RSA_CERT:
740 #endif /* WITH_OPENSSL */
741 	case KEY_ED25519_CERT:
742 #ifdef WITH_XMSS
743 	case KEY_XMSS_CERT:
744 #endif /* WITH_XMSS */
745 		/* Use the existing blob */
746 		/* XXX modified flag? */
747 		if ((ret = sshbuf_putb(b, key->cert->certblob)) != 0)
748 			return ret;
749 		break;
750 #ifdef WITH_OPENSSL
751 	case KEY_DSA:
752 		if (key->dsa == NULL)
753 			return SSH_ERR_INVALID_ARGUMENT;
754 		if ((ret = sshbuf_put_cstring(b, typename)) != 0 ||
755 		    (ret = sshbuf_put_bignum2(b, key->dsa->p)) != 0 ||
756 		    (ret = sshbuf_put_bignum2(b, key->dsa->q)) != 0 ||
757 		    (ret = sshbuf_put_bignum2(b, key->dsa->g)) != 0 ||
758 		    (ret = sshbuf_put_bignum2(b, key->dsa->pub_key)) != 0)
759 			return ret;
760 		break;
761 	case KEY_ECDSA:
762 		if (key->ecdsa == NULL)
763 			return SSH_ERR_INVALID_ARGUMENT;
764 		if ((ret = sshbuf_put_cstring(b, typename)) != 0 ||
765 		    (ret = sshbuf_put_cstring(b,
766 		    sshkey_curve_nid_to_name(key->ecdsa_nid))) != 0 ||
767 		    (ret = sshbuf_put_eckey(b, key->ecdsa)) != 0)
768 			return ret;
769 		break;
770 	case KEY_RSA:
771 		if (key->rsa == NULL)
772 			return SSH_ERR_INVALID_ARGUMENT;
773 		if ((ret = sshbuf_put_cstring(b, typename)) != 0 ||
774 		    (ret = sshbuf_put_bignum2(b, key->rsa->e)) != 0 ||
775 		    (ret = sshbuf_put_bignum2(b, key->rsa->n)) != 0)
776 			return ret;
777 		break;
778 #endif /* WITH_OPENSSL */
779 	case KEY_ED25519:
780 		if (key->ed25519_pk == NULL)
781 			return SSH_ERR_INVALID_ARGUMENT;
782 		if ((ret = sshbuf_put_cstring(b, typename)) != 0 ||
783 		    (ret = sshbuf_put_string(b,
784 		    key->ed25519_pk, ED25519_PK_SZ)) != 0)
785 			return ret;
786 		break;
787 #ifdef WITH_XMSS
788 	case KEY_XMSS:
789 		if (key->xmss_name == NULL || key->xmss_pk == NULL ||
790 		    sshkey_xmss_pklen(key) == 0)
791 			return SSH_ERR_INVALID_ARGUMENT;
792 		if ((ret = sshbuf_put_cstring(b, typename)) != 0 ||
793 		    (ret = sshbuf_put_cstring(b, key->xmss_name)) != 0 ||
794 		    (ret = sshbuf_put_string(b,
795 		    key->xmss_pk, sshkey_xmss_pklen(key))) != 0 ||
796 		    (ret = sshkey_xmss_serialize_pk_info(key, b, opts)) != 0)
797 			return ret;
798 		break;
799 #endif /* WITH_XMSS */
800 	default:
801 		return SSH_ERR_KEY_TYPE_UNKNOWN;
802 	}
803 	return 0;
804 }
805 
806 int
807 sshkey_putb(const struct sshkey *key, struct sshbuf *b)
808 {
809 	return to_blob_buf(key, b, 0, SSHKEY_SERIALIZE_DEFAULT);
810 }
811 
812 int
813 sshkey_puts_opts(const struct sshkey *key, struct sshbuf *b,
814     enum sshkey_serialize_rep opts)
815 {
816 	struct sshbuf *tmp;
817 	int r;
818 
819 	if ((tmp = sshbuf_new()) == NULL)
820 		return SSH_ERR_ALLOC_FAIL;
821 	r = to_blob_buf(key, tmp, 0, opts);
822 	if (r == 0)
823 		r = sshbuf_put_stringb(b, tmp);
824 	sshbuf_free(tmp);
825 	return r;
826 }
827 
828 int
829 sshkey_puts(const struct sshkey *key, struct sshbuf *b)
830 {
831 	return sshkey_puts_opts(key, b, SSHKEY_SERIALIZE_DEFAULT);
832 }
833 
834 int
835 sshkey_putb_plain(const struct sshkey *key, struct sshbuf *b)
836 {
837 	return to_blob_buf(key, b, 1, SSHKEY_SERIALIZE_DEFAULT);
838 }
839 
840 static int
841 to_blob(const struct sshkey *key, u_char **blobp, size_t *lenp, int force_plain,
842     enum sshkey_serialize_rep opts)
843 {
844 	int ret = SSH_ERR_INTERNAL_ERROR;
845 	size_t len;
846 	struct sshbuf *b = NULL;
847 
848 	if (lenp != NULL)
849 		*lenp = 0;
850 	if (blobp != NULL)
851 		*blobp = NULL;
852 	if ((b = sshbuf_new()) == NULL)
853 		return SSH_ERR_ALLOC_FAIL;
854 	if ((ret = to_blob_buf(key, b, force_plain, opts)) != 0)
855 		goto out;
856 	len = sshbuf_len(b);
857 	if (lenp != NULL)
858 		*lenp = len;
859 	if (blobp != NULL) {
860 		if ((*blobp = malloc(len)) == NULL) {
861 			ret = SSH_ERR_ALLOC_FAIL;
862 			goto out;
863 		}
864 		memcpy(*blobp, sshbuf_ptr(b), len);
865 	}
866 	ret = 0;
867  out:
868 	sshbuf_free(b);
869 	return ret;
870 }
871 
872 int
873 sshkey_to_blob(const struct sshkey *key, u_char **blobp, size_t *lenp)
874 {
875 	return to_blob(key, blobp, lenp, 0, SSHKEY_SERIALIZE_DEFAULT);
876 }
877 
878 int
879 sshkey_plain_to_blob(const struct sshkey *key, u_char **blobp, size_t *lenp)
880 {
881 	return to_blob(key, blobp, lenp, 1, SSHKEY_SERIALIZE_DEFAULT);
882 }
883 
884 int
885 sshkey_fingerprint_raw(const struct sshkey *k, int dgst_alg,
886     u_char **retp, size_t *lenp)
887 {
888 	u_char *blob = NULL, *ret = NULL;
889 	size_t blob_len = 0;
890 	int r = SSH_ERR_INTERNAL_ERROR;
891 
892 	if (retp != NULL)
893 		*retp = NULL;
894 	if (lenp != NULL)
895 		*lenp = 0;
896 	if (ssh_digest_bytes(dgst_alg) == 0) {
897 		r = SSH_ERR_INVALID_ARGUMENT;
898 		goto out;
899 	}
900 	if ((r = to_blob(k, &blob, &blob_len, 1, SSHKEY_SERIALIZE_DEFAULT))
901 	    != 0)
902 		goto out;
903 	if ((ret = calloc(1, SSH_DIGEST_MAX_LENGTH)) == NULL) {
904 		r = SSH_ERR_ALLOC_FAIL;
905 		goto out;
906 	}
907 	if ((r = ssh_digest_memory(dgst_alg, blob, blob_len,
908 	    ret, SSH_DIGEST_MAX_LENGTH)) != 0)
909 		goto out;
910 	/* success */
911 	if (retp != NULL) {
912 		*retp = ret;
913 		ret = NULL;
914 	}
915 	if (lenp != NULL)
916 		*lenp = ssh_digest_bytes(dgst_alg);
917 	r = 0;
918  out:
919 	free(ret);
920 	if (blob != NULL) {
921 		explicit_bzero(blob, blob_len);
922 		free(blob);
923 	}
924 	return r;
925 }
926 
927 static char *
928 fingerprint_b64(const char *alg, u_char *dgst_raw, size_t dgst_raw_len)
929 {
930 	char *ret;
931 	size_t plen = strlen(alg) + 1;
932 	size_t rlen = ((dgst_raw_len + 2) / 3) * 4 + plen + 1;
933 	int r;
934 
935 	if (dgst_raw_len > 65536 || (ret = calloc(1, rlen)) == NULL)
936 		return NULL;
937 	strlcpy(ret, alg, rlen);
938 	strlcat(ret, ":", rlen);
939 	if (dgst_raw_len == 0)
940 		return ret;
941 	if ((r = b64_ntop(dgst_raw, dgst_raw_len,
942 	    ret + plen, rlen - plen)) == -1) {
943 		freezero(ret, rlen);
944 		return NULL;
945 	}
946 	/* Trim padding characters from end */
947 	ret[strcspn(ret, "=")] = '\0';
948 	return ret;
949 }
950 
951 static char *
952 fingerprint_hex(const char *alg, u_char *dgst_raw, size_t dgst_raw_len)
953 {
954 	char *retval, hex[5];
955 	size_t i, rlen = dgst_raw_len * 3 + strlen(alg) + 2;
956 
957 	if (dgst_raw_len > 65536 || (retval = calloc(1, rlen)) == NULL)
958 		return NULL;
959 	strlcpy(retval, alg, rlen);
960 	strlcat(retval, ":", rlen);
961 	for (i = 0; i < dgst_raw_len; i++) {
962 		snprintf(hex, sizeof(hex), "%s%02x",
963 		    i > 0 ? ":" : "", dgst_raw[i]);
964 		strlcat(retval, hex, rlen);
965 	}
966 	return retval;
967 }
968 
969 static char *
970 fingerprint_bubblebabble(u_char *dgst_raw, size_t dgst_raw_len)
971 {
972 	char vowels[] = { 'a', 'e', 'i', 'o', 'u', 'y' };
973 	char consonants[] = { 'b', 'c', 'd', 'f', 'g', 'h', 'k', 'l', 'm',
974 	    'n', 'p', 'r', 's', 't', 'v', 'z', 'x' };
975 	u_int i, j = 0, rounds, seed = 1;
976 	char *retval;
977 
978 	rounds = (dgst_raw_len / 2) + 1;
979 	if ((retval = calloc(rounds, 6)) == NULL)
980 		return NULL;
981 	retval[j++] = 'x';
982 	for (i = 0; i < rounds; i++) {
983 		u_int idx0, idx1, idx2, idx3, idx4;
984 		if ((i + 1 < rounds) || (dgst_raw_len % 2 != 0)) {
985 			idx0 = (((((u_int)(dgst_raw[2 * i])) >> 6) & 3) +
986 			    seed) % 6;
987 			idx1 = (((u_int)(dgst_raw[2 * i])) >> 2) & 15;
988 			idx2 = ((((u_int)(dgst_raw[2 * i])) & 3) +
989 			    (seed / 6)) % 6;
990 			retval[j++] = vowels[idx0];
991 			retval[j++] = consonants[idx1];
992 			retval[j++] = vowels[idx2];
993 			if ((i + 1) < rounds) {
994 				idx3 = (((u_int)(dgst_raw[(2 * i) + 1])) >> 4) & 15;
995 				idx4 = (((u_int)(dgst_raw[(2 * i) + 1]))) & 15;
996 				retval[j++] = consonants[idx3];
997 				retval[j++] = '-';
998 				retval[j++] = consonants[idx4];
999 				seed = ((seed * 5) +
1000 				    ((((u_int)(dgst_raw[2 * i])) * 7) +
1001 				    ((u_int)(dgst_raw[(2 * i) + 1])))) % 36;
1002 			}
1003 		} else {
1004 			idx0 = seed % 6;
1005 			idx1 = 16;
1006 			idx2 = seed / 6;
1007 			retval[j++] = vowels[idx0];
1008 			retval[j++] = consonants[idx1];
1009 			retval[j++] = vowels[idx2];
1010 		}
1011 	}
1012 	retval[j++] = 'x';
1013 	retval[j++] = '\0';
1014 	return retval;
1015 }
1016 
1017 /*
1018  * Draw an ASCII-Art representing the fingerprint so human brain can
1019  * profit from its built-in pattern recognition ability.
1020  * This technique is called "random art" and can be found in some
1021  * scientific publications like this original paper:
1022  *
1023  * "Hash Visualization: a New Technique to improve Real-World Security",
1024  * Perrig A. and Song D., 1999, International Workshop on Cryptographic
1025  * Techniques and E-Commerce (CrypTEC '99)
1026  * sparrow.ece.cmu.edu/~adrian/projects/validation/validation.pdf
1027  *
1028  * The subject came up in a talk by Dan Kaminsky, too.
1029  *
1030  * If you see the picture is different, the key is different.
1031  * If the picture looks the same, you still know nothing.
1032  *
1033  * The algorithm used here is a worm crawling over a discrete plane,
1034  * leaving a trace (augmenting the field) everywhere it goes.
1035  * Movement is taken from dgst_raw 2bit-wise.  Bumping into walls
1036  * makes the respective movement vector be ignored for this turn.
1037  * Graphs are not unambiguous, because circles in graphs can be
1038  * walked in either direction.
1039  */
1040 
1041 /*
1042  * Field sizes for the random art.  Have to be odd, so the starting point
1043  * can be in the exact middle of the picture, and FLDBASE should be >=8 .
1044  * Else pictures would be too dense, and drawing the frame would
1045  * fail, too, because the key type would not fit in anymore.
1046  */
1047 #define	FLDBASE		8
1048 #define	FLDSIZE_Y	(FLDBASE + 1)
1049 #define	FLDSIZE_X	(FLDBASE * 2 + 1)
1050 static char *
1051 fingerprint_randomart(const char *alg, u_char *dgst_raw, size_t dgst_raw_len,
1052     const struct sshkey *k)
1053 {
1054 	/*
1055 	 * Chars to be used after each other every time the worm
1056 	 * intersects with itself.  Matter of taste.
1057 	 */
1058 	char	*augmentation_string = " .o+=*BOX@%&#/^SE";
1059 	char	*retval, *p, title[FLDSIZE_X], hash[FLDSIZE_X];
1060 	u_char	 field[FLDSIZE_X][FLDSIZE_Y];
1061 	size_t	 i, tlen, hlen;
1062 	u_int	 b;
1063 	int	 x, y, r;
1064 	size_t	 len = strlen(augmentation_string) - 1;
1065 
1066 	if ((retval = calloc((FLDSIZE_X + 3), (FLDSIZE_Y + 2))) == NULL)
1067 		return NULL;
1068 
1069 	/* initialize field */
1070 	memset(field, 0, FLDSIZE_X * FLDSIZE_Y * sizeof(char));
1071 	x = FLDSIZE_X / 2;
1072 	y = FLDSIZE_Y / 2;
1073 
1074 	/* process raw key */
1075 	for (i = 0; i < dgst_raw_len; i++) {
1076 		int input;
1077 		/* each byte conveys four 2-bit move commands */
1078 		input = dgst_raw[i];
1079 		for (b = 0; b < 4; b++) {
1080 			/* evaluate 2 bit, rest is shifted later */
1081 			x += (input & 0x1) ? 1 : -1;
1082 			y += (input & 0x2) ? 1 : -1;
1083 
1084 			/* assure we are still in bounds */
1085 			x = MAXIMUM(x, 0);
1086 			y = MAXIMUM(y, 0);
1087 			x = MINIMUM(x, FLDSIZE_X - 1);
1088 			y = MINIMUM(y, FLDSIZE_Y - 1);
1089 
1090 			/* augment the field */
1091 			if (field[x][y] < len - 2)
1092 				field[x][y]++;
1093 			input = input >> 2;
1094 		}
1095 	}
1096 
1097 	/* mark starting point and end point*/
1098 	field[FLDSIZE_X / 2][FLDSIZE_Y / 2] = len - 1;
1099 	field[x][y] = len;
1100 
1101 	/* assemble title */
1102 	r = snprintf(title, sizeof(title), "[%s %u]",
1103 		sshkey_type(k), sshkey_size(k));
1104 	/* If [type size] won't fit, then try [type]; fits "[ED25519-CERT]" */
1105 	if (r < 0 || r > (int)sizeof(title))
1106 		r = snprintf(title, sizeof(title), "[%s]", sshkey_type(k));
1107 	tlen = (r <= 0) ? 0 : strlen(title);
1108 
1109 	/* assemble hash ID. */
1110 	r = snprintf(hash, sizeof(hash), "[%s]", alg);
1111 	hlen = (r <= 0) ? 0 : strlen(hash);
1112 
1113 	/* output upper border */
1114 	p = retval;
1115 	*p++ = '+';
1116 	for (i = 0; i < (FLDSIZE_X - tlen) / 2; i++)
1117 		*p++ = '-';
1118 	memcpy(p, title, tlen);
1119 	p += tlen;
1120 	for (i += tlen; i < FLDSIZE_X; i++)
1121 		*p++ = '-';
1122 	*p++ = '+';
1123 	*p++ = '\n';
1124 
1125 	/* output content */
1126 	for (y = 0; y < FLDSIZE_Y; y++) {
1127 		*p++ = '|';
1128 		for (x = 0; x < FLDSIZE_X; x++)
1129 			*p++ = augmentation_string[MINIMUM(field[x][y], len)];
1130 		*p++ = '|';
1131 		*p++ = '\n';
1132 	}
1133 
1134 	/* output lower border */
1135 	*p++ = '+';
1136 	for (i = 0; i < (FLDSIZE_X - hlen) / 2; i++)
1137 		*p++ = '-';
1138 	memcpy(p, hash, hlen);
1139 	p += hlen;
1140 	for (i += hlen; i < FLDSIZE_X; i++)
1141 		*p++ = '-';
1142 	*p++ = '+';
1143 
1144 	return retval;
1145 }
1146 
1147 char *
1148 sshkey_fingerprint(const struct sshkey *k, int dgst_alg,
1149     enum sshkey_fp_rep dgst_rep)
1150 {
1151 	char *retval = NULL;
1152 	u_char *dgst_raw;
1153 	size_t dgst_raw_len;
1154 
1155 	if (sshkey_fingerprint_raw(k, dgst_alg, &dgst_raw, &dgst_raw_len) != 0)
1156 		return NULL;
1157 	switch (dgst_rep) {
1158 	case SSH_FP_DEFAULT:
1159 		if (dgst_alg == SSH_DIGEST_MD5) {
1160 			retval = fingerprint_hex(ssh_digest_alg_name(dgst_alg),
1161 			    dgst_raw, dgst_raw_len);
1162 		} else {
1163 			retval = fingerprint_b64(ssh_digest_alg_name(dgst_alg),
1164 			    dgst_raw, dgst_raw_len);
1165 		}
1166 		break;
1167 	case SSH_FP_HEX:
1168 		retval = fingerprint_hex(ssh_digest_alg_name(dgst_alg),
1169 		    dgst_raw, dgst_raw_len);
1170 		break;
1171 	case SSH_FP_BASE64:
1172 		retval = fingerprint_b64(ssh_digest_alg_name(dgst_alg),
1173 		    dgst_raw, dgst_raw_len);
1174 		break;
1175 	case SSH_FP_BUBBLEBABBLE:
1176 		retval = fingerprint_bubblebabble(dgst_raw, dgst_raw_len);
1177 		break;
1178 	case SSH_FP_RANDOMART:
1179 		retval = fingerprint_randomart(ssh_digest_alg_name(dgst_alg),
1180 		    dgst_raw, dgst_raw_len, k);
1181 		break;
1182 	default:
1183 		explicit_bzero(dgst_raw, dgst_raw_len);
1184 		free(dgst_raw);
1185 		return NULL;
1186 	}
1187 	explicit_bzero(dgst_raw, dgst_raw_len);
1188 	free(dgst_raw);
1189 	return retval;
1190 }
1191 
1192 static int
1193 peek_type_nid(const char *s, size_t l, int *nid)
1194 {
1195 	const struct keytype *kt;
1196 
1197 	for (kt = keytypes; kt->type != -1; kt++) {
1198 		if (kt->name == NULL || strlen(kt->name) != l)
1199 			continue;
1200 		if (memcmp(s, kt->name, l) == 0) {
1201 			*nid = -1;
1202 			if (kt->type == KEY_ECDSA || kt->type == KEY_ECDSA_CERT)
1203 				*nid = kt->nid;
1204 			return kt->type;
1205 		}
1206 	}
1207 	return KEY_UNSPEC;
1208 }
1209 
1210 
1211 /* XXX this can now be made const char * */
1212 int
1213 sshkey_read(struct sshkey *ret, char **cpp)
1214 {
1215 	struct sshkey *k;
1216 	char *cp, *blobcopy;
1217 	size_t space;
1218 	int r, type, curve_nid = -1;
1219 	struct sshbuf *blob;
1220 
1221 	if (ret == NULL)
1222 		return SSH_ERR_INVALID_ARGUMENT;
1223 
1224 	switch (ret->type) {
1225 	case KEY_UNSPEC:
1226 	case KEY_RSA:
1227 	case KEY_DSA:
1228 	case KEY_ECDSA:
1229 	case KEY_ED25519:
1230 	case KEY_DSA_CERT:
1231 	case KEY_ECDSA_CERT:
1232 	case KEY_RSA_CERT:
1233 	case KEY_ED25519_CERT:
1234 #ifdef WITH_XMSS
1235 	case KEY_XMSS:
1236 	case KEY_XMSS_CERT:
1237 #endif /* WITH_XMSS */
1238 		break; /* ok */
1239 	default:
1240 		return SSH_ERR_INVALID_ARGUMENT;
1241 	}
1242 
1243 	/* Decode type */
1244 	cp = *cpp;
1245 	space = strcspn(cp, " \t");
1246 	if (space == strlen(cp))
1247 		return SSH_ERR_INVALID_FORMAT;
1248 	if ((type = peek_type_nid(cp, space, &curve_nid)) == KEY_UNSPEC)
1249 		return SSH_ERR_INVALID_FORMAT;
1250 
1251 	/* skip whitespace */
1252 	for (cp += space; *cp == ' ' || *cp == '\t'; cp++)
1253 		;
1254 	if (*cp == '\0')
1255 		return SSH_ERR_INVALID_FORMAT;
1256 	if (ret->type != KEY_UNSPEC && ret->type != type)
1257 		return SSH_ERR_KEY_TYPE_MISMATCH;
1258 	if ((blob = sshbuf_new()) == NULL)
1259 		return SSH_ERR_ALLOC_FAIL;
1260 
1261 	/* find end of keyblob and decode */
1262 	space = strcspn(cp, " \t");
1263 	if ((blobcopy = strndup(cp, space)) == NULL) {
1264 		sshbuf_free(blob);
1265 		return SSH_ERR_ALLOC_FAIL;
1266 	}
1267 	if ((r = sshbuf_b64tod(blob, blobcopy)) != 0) {
1268 		free(blobcopy);
1269 		sshbuf_free(blob);
1270 		return r;
1271 	}
1272 	free(blobcopy);
1273 	if ((r = sshkey_fromb(blob, &k)) != 0) {
1274 		sshbuf_free(blob);
1275 		return r;
1276 	}
1277 	sshbuf_free(blob);
1278 
1279 	/* skip whitespace and leave cp at start of comment */
1280 	for (cp += space; *cp == ' ' || *cp == '\t'; cp++)
1281 		;
1282 
1283 	/* ensure type of blob matches type at start of line */
1284 	if (k->type != type) {
1285 		sshkey_free(k);
1286 		return SSH_ERR_KEY_TYPE_MISMATCH;
1287 	}
1288 	if (sshkey_type_plain(type) == KEY_ECDSA && curve_nid != k->ecdsa_nid) {
1289 		sshkey_free(k);
1290 		return SSH_ERR_EC_CURVE_MISMATCH;
1291 	}
1292 
1293 	/* Fill in ret from parsed key */
1294 	ret->type = type;
1295 	if (sshkey_is_cert(ret)) {
1296 		if (!sshkey_is_cert(k)) {
1297 			sshkey_free(k);
1298 			return SSH_ERR_EXPECTED_CERT;
1299 		}
1300 		if (ret->cert != NULL)
1301 			cert_free(ret->cert);
1302 		ret->cert = k->cert;
1303 		k->cert = NULL;
1304 	}
1305 	switch (sshkey_type_plain(ret->type)) {
1306 #ifdef WITH_OPENSSL
1307 	case KEY_RSA:
1308 		RSA_free(ret->rsa);
1309 		ret->rsa = k->rsa;
1310 		k->rsa = NULL;
1311 #ifdef DEBUG_PK
1312 		RSA_print_fp(stderr, ret->rsa, 8);
1313 #endif
1314 		break;
1315 	case KEY_DSA:
1316 		DSA_free(ret->dsa);
1317 		ret->dsa = k->dsa;
1318 		k->dsa = NULL;
1319 #ifdef DEBUG_PK
1320 		DSA_print_fp(stderr, ret->dsa, 8);
1321 #endif
1322 		break;
1323 	case KEY_ECDSA:
1324 		EC_KEY_free(ret->ecdsa);
1325 		ret->ecdsa = k->ecdsa;
1326 		ret->ecdsa_nid = k->ecdsa_nid;
1327 		k->ecdsa = NULL;
1328 		k->ecdsa_nid = -1;
1329 #ifdef DEBUG_PK
1330 		sshkey_dump_ec_key(ret->ecdsa);
1331 #endif
1332 		break;
1333 #endif /* WITH_OPENSSL */
1334 	case KEY_ED25519:
1335 		freezero(ret->ed25519_pk, ED25519_PK_SZ);
1336 		ret->ed25519_pk = k->ed25519_pk;
1337 		k->ed25519_pk = NULL;
1338 #ifdef DEBUG_PK
1339 		/* XXX */
1340 #endif
1341 		break;
1342 #ifdef WITH_XMSS
1343 	case KEY_XMSS:
1344 		free(ret->xmss_pk);
1345 		ret->xmss_pk = k->xmss_pk;
1346 		k->xmss_pk = NULL;
1347 		free(ret->xmss_state);
1348 		ret->xmss_state = k->xmss_state;
1349 		k->xmss_state = NULL;
1350 		free(ret->xmss_name);
1351 		ret->xmss_name = k->xmss_name;
1352 		k->xmss_name = NULL;
1353 		free(ret->xmss_filename);
1354 		ret->xmss_filename = k->xmss_filename;
1355 		k->xmss_filename = NULL;
1356 #ifdef DEBUG_PK
1357 		/* XXX */
1358 #endif
1359 		break;
1360 #endif /* WITH_XMSS */
1361 	default:
1362 		sshkey_free(k);
1363 		return SSH_ERR_INTERNAL_ERROR;
1364 	}
1365 	sshkey_free(k);
1366 
1367 	/* success */
1368 	*cpp = cp;
1369 	return 0;
1370 }
1371 
1372 int
1373 sshkey_to_base64(const struct sshkey *key, char **b64p)
1374 {
1375 	int r = SSH_ERR_INTERNAL_ERROR;
1376 	struct sshbuf *b = NULL;
1377 	char *uu = NULL;
1378 
1379 	if (b64p != NULL)
1380 		*b64p = NULL;
1381 	if ((b = sshbuf_new()) == NULL)
1382 		return SSH_ERR_ALLOC_FAIL;
1383 	if ((r = sshkey_putb(key, b)) != 0)
1384 		goto out;
1385 	if ((uu = sshbuf_dtob64(b)) == NULL) {
1386 		r = SSH_ERR_ALLOC_FAIL;
1387 		goto out;
1388 	}
1389 	/* Success */
1390 	if (b64p != NULL) {
1391 		*b64p = uu;
1392 		uu = NULL;
1393 	}
1394 	r = 0;
1395  out:
1396 	sshbuf_free(b);
1397 	free(uu);
1398 	return r;
1399 }
1400 
1401 int
1402 sshkey_format_text(const struct sshkey *key, struct sshbuf *b)
1403 {
1404 	int r = SSH_ERR_INTERNAL_ERROR;
1405 	char *uu = NULL;
1406 
1407 	if ((r = sshkey_to_base64(key, &uu)) != 0)
1408 		goto out;
1409 	if ((r = sshbuf_putf(b, "%s %s",
1410 	    sshkey_ssh_name(key), uu)) != 0)
1411 		goto out;
1412 	r = 0;
1413  out:
1414 	free(uu);
1415 	return r;
1416 }
1417 
1418 int
1419 sshkey_write(const struct sshkey *key, FILE *f)
1420 {
1421 	struct sshbuf *b = NULL;
1422 	int r = SSH_ERR_INTERNAL_ERROR;
1423 
1424 	if ((b = sshbuf_new()) == NULL)
1425 		return SSH_ERR_ALLOC_FAIL;
1426 	if ((r = sshkey_format_text(key, b)) != 0)
1427 		goto out;
1428 	if (fwrite(sshbuf_ptr(b), sshbuf_len(b), 1, f) != 1) {
1429 		if (feof(f))
1430 			errno = EPIPE;
1431 		r = SSH_ERR_SYSTEM_ERROR;
1432 		goto out;
1433 	}
1434 	/* Success */
1435 	r = 0;
1436  out:
1437 	sshbuf_free(b);
1438 	return r;
1439 }
1440 
1441 const char *
1442 sshkey_cert_type(const struct sshkey *k)
1443 {
1444 	switch (k->cert->type) {
1445 	case SSH2_CERT_TYPE_USER:
1446 		return "user";
1447 	case SSH2_CERT_TYPE_HOST:
1448 		return "host";
1449 	default:
1450 		return "unknown";
1451 	}
1452 }
1453 
1454 #ifdef WITH_OPENSSL
1455 static int
1456 rsa_generate_private_key(u_int bits, RSA **rsap)
1457 {
1458 	RSA *private = NULL;
1459 	BIGNUM *f4 = NULL;
1460 	int ret = SSH_ERR_INTERNAL_ERROR;
1461 
1462 	if (rsap == NULL)
1463 		return SSH_ERR_INVALID_ARGUMENT;
1464 	if (bits < SSH_RSA_MINIMUM_MODULUS_SIZE ||
1465 	    bits > SSHBUF_MAX_BIGNUM * 8)
1466 		return SSH_ERR_KEY_LENGTH;
1467 	*rsap = NULL;
1468 	if ((private = RSA_new()) == NULL || (f4 = BN_new()) == NULL) {
1469 		ret = SSH_ERR_ALLOC_FAIL;
1470 		goto out;
1471 	}
1472 	if (!BN_set_word(f4, RSA_F4) ||
1473 	    !RSA_generate_key_ex(private, bits, f4, NULL)) {
1474 		ret = SSH_ERR_LIBCRYPTO_ERROR;
1475 		goto out;
1476 	}
1477 	*rsap = private;
1478 	private = NULL;
1479 	ret = 0;
1480  out:
1481 	RSA_free(private);
1482 	BN_free(f4);
1483 	return ret;
1484 }
1485 
1486 static int
1487 dsa_generate_private_key(u_int bits, DSA **dsap)
1488 {
1489 	DSA *private;
1490 	int ret = SSH_ERR_INTERNAL_ERROR;
1491 
1492 	if (dsap == NULL)
1493 		return SSH_ERR_INVALID_ARGUMENT;
1494 	if (bits != 1024)
1495 		return SSH_ERR_KEY_LENGTH;
1496 	if ((private = DSA_new()) == NULL) {
1497 		ret = SSH_ERR_ALLOC_FAIL;
1498 		goto out;
1499 	}
1500 	*dsap = NULL;
1501 	if (!DSA_generate_parameters_ex(private, bits, NULL, 0, NULL,
1502 	    NULL, NULL) || !DSA_generate_key(private)) {
1503 		ret = SSH_ERR_LIBCRYPTO_ERROR;
1504 		goto out;
1505 	}
1506 	*dsap = private;
1507 	private = NULL;
1508 	ret = 0;
1509  out:
1510 	DSA_free(private);
1511 	return ret;
1512 }
1513 
1514 int
1515 sshkey_ecdsa_key_to_nid(EC_KEY *k)
1516 {
1517 	EC_GROUP *eg;
1518 	int nids[] = {
1519 		NID_X9_62_prime256v1,
1520 		NID_secp384r1,
1521 		NID_secp521r1,
1522 		-1
1523 	};
1524 	int nid;
1525 	u_int i;
1526 	BN_CTX *bnctx;
1527 	const EC_GROUP *g = EC_KEY_get0_group(k);
1528 
1529 	/*
1530 	 * The group may be stored in a ASN.1 encoded private key in one of two
1531 	 * ways: as a "named group", which is reconstituted by ASN.1 object ID
1532 	 * or explicit group parameters encoded into the key blob. Only the
1533 	 * "named group" case sets the group NID for us, but we can figure
1534 	 * it out for the other case by comparing against all the groups that
1535 	 * are supported.
1536 	 */
1537 	if ((nid = EC_GROUP_get_curve_name(g)) > 0)
1538 		return nid;
1539 	if ((bnctx = BN_CTX_new()) == NULL)
1540 		return -1;
1541 	for (i = 0; nids[i] != -1; i++) {
1542 		if ((eg = EC_GROUP_new_by_curve_name(nids[i])) == NULL) {
1543 			BN_CTX_free(bnctx);
1544 			return -1;
1545 		}
1546 		if (EC_GROUP_cmp(g, eg, bnctx) == 0)
1547 			break;
1548 		EC_GROUP_free(eg);
1549 	}
1550 	BN_CTX_free(bnctx);
1551 	if (nids[i] != -1) {
1552 		/* Use the group with the NID attached */
1553 		EC_GROUP_set_asn1_flag(eg, OPENSSL_EC_NAMED_CURVE);
1554 		if (EC_KEY_set_group(k, eg) != 1) {
1555 			EC_GROUP_free(eg);
1556 			return -1;
1557 		}
1558 	}
1559 	return nids[i];
1560 }
1561 
1562 static int
1563 ecdsa_generate_private_key(u_int bits, int *nid, EC_KEY **ecdsap)
1564 {
1565 	EC_KEY *private;
1566 	int ret = SSH_ERR_INTERNAL_ERROR;
1567 
1568 	if (nid == NULL || ecdsap == NULL)
1569 		return SSH_ERR_INVALID_ARGUMENT;
1570 	if ((*nid = sshkey_ecdsa_bits_to_nid(bits)) == -1)
1571 		return SSH_ERR_KEY_LENGTH;
1572 	*ecdsap = NULL;
1573 	if ((private = EC_KEY_new_by_curve_name(*nid)) == NULL) {
1574 		ret = SSH_ERR_ALLOC_FAIL;
1575 		goto out;
1576 	}
1577 	if (EC_KEY_generate_key(private) != 1) {
1578 		ret = SSH_ERR_LIBCRYPTO_ERROR;
1579 		goto out;
1580 	}
1581 	EC_KEY_set_asn1_flag(private, OPENSSL_EC_NAMED_CURVE);
1582 	*ecdsap = private;
1583 	private = NULL;
1584 	ret = 0;
1585  out:
1586 	EC_KEY_free(private);
1587 	return ret;
1588 }
1589 #endif /* WITH_OPENSSL */
1590 
1591 int
1592 sshkey_generate(int type, u_int bits, struct sshkey **keyp)
1593 {
1594 	struct sshkey *k;
1595 	int ret = SSH_ERR_INTERNAL_ERROR;
1596 
1597 	if (keyp == NULL)
1598 		return SSH_ERR_INVALID_ARGUMENT;
1599 	*keyp = NULL;
1600 	if ((k = sshkey_new(KEY_UNSPEC)) == NULL)
1601 		return SSH_ERR_ALLOC_FAIL;
1602 	switch (type) {
1603 	case KEY_ED25519:
1604 		if ((k->ed25519_pk = malloc(ED25519_PK_SZ)) == NULL ||
1605 		    (k->ed25519_sk = malloc(ED25519_SK_SZ)) == NULL) {
1606 			ret = SSH_ERR_ALLOC_FAIL;
1607 			break;
1608 		}
1609 		crypto_sign_ed25519_keypair(k->ed25519_pk, k->ed25519_sk);
1610 		ret = 0;
1611 		break;
1612 #ifdef WITH_XMSS
1613 	case KEY_XMSS:
1614 		ret = sshkey_xmss_generate_private_key(k, bits);
1615 		break;
1616 #endif /* WITH_XMSS */
1617 #ifdef WITH_OPENSSL
1618 	case KEY_DSA:
1619 		ret = dsa_generate_private_key(bits, &k->dsa);
1620 		break;
1621 	case KEY_ECDSA:
1622 		ret = ecdsa_generate_private_key(bits, &k->ecdsa_nid,
1623 		    &k->ecdsa);
1624 		break;
1625 	case KEY_RSA:
1626 		ret = rsa_generate_private_key(bits, &k->rsa);
1627 		break;
1628 #endif /* WITH_OPENSSL */
1629 	default:
1630 		ret = SSH_ERR_INVALID_ARGUMENT;
1631 	}
1632 	if (ret == 0) {
1633 		k->type = type;
1634 		*keyp = k;
1635 	} else
1636 		sshkey_free(k);
1637 	return ret;
1638 }
1639 
1640 int
1641 sshkey_cert_copy(const struct sshkey *from_key, struct sshkey *to_key)
1642 {
1643 	u_int i;
1644 	const struct sshkey_cert *from;
1645 	struct sshkey_cert *to;
1646 	int ret = SSH_ERR_INTERNAL_ERROR;
1647 
1648 	if (to_key->cert != NULL) {
1649 		cert_free(to_key->cert);
1650 		to_key->cert = NULL;
1651 	}
1652 
1653 	if ((from = from_key->cert) == NULL)
1654 		return SSH_ERR_INVALID_ARGUMENT;
1655 
1656 	if ((to = to_key->cert = cert_new()) == NULL)
1657 		return SSH_ERR_ALLOC_FAIL;
1658 
1659 	if ((ret = sshbuf_putb(to->certblob, from->certblob)) != 0 ||
1660 	    (ret = sshbuf_putb(to->critical, from->critical)) != 0 ||
1661 	    (ret = sshbuf_putb(to->extensions, from->extensions)) != 0)
1662 		return ret;
1663 
1664 	to->serial = from->serial;
1665 	to->type = from->type;
1666 	if (from->key_id == NULL)
1667 		to->key_id = NULL;
1668 	else if ((to->key_id = strdup(from->key_id)) == NULL)
1669 		return SSH_ERR_ALLOC_FAIL;
1670 	to->valid_after = from->valid_after;
1671 	to->valid_before = from->valid_before;
1672 	if (from->signature_key == NULL)
1673 		to->signature_key = NULL;
1674 	else if ((ret = sshkey_from_private(from->signature_key,
1675 	    &to->signature_key)) != 0)
1676 		return ret;
1677 
1678 	if (from->nprincipals > SSHKEY_CERT_MAX_PRINCIPALS)
1679 		return SSH_ERR_INVALID_ARGUMENT;
1680 	if (from->nprincipals > 0) {
1681 		if ((to->principals = calloc(from->nprincipals,
1682 		    sizeof(*to->principals))) == NULL)
1683 			return SSH_ERR_ALLOC_FAIL;
1684 		for (i = 0; i < from->nprincipals; i++) {
1685 			to->principals[i] = strdup(from->principals[i]);
1686 			if (to->principals[i] == NULL) {
1687 				to->nprincipals = i;
1688 				return SSH_ERR_ALLOC_FAIL;
1689 			}
1690 		}
1691 	}
1692 	to->nprincipals = from->nprincipals;
1693 	return 0;
1694 }
1695 
1696 int
1697 sshkey_from_private(const struct sshkey *k, struct sshkey **pkp)
1698 {
1699 	struct sshkey *n = NULL;
1700 	int ret = SSH_ERR_INTERNAL_ERROR;
1701 
1702 	*pkp = NULL;
1703 	switch (k->type) {
1704 #ifdef WITH_OPENSSL
1705 	case KEY_DSA:
1706 	case KEY_DSA_CERT:
1707 		if ((n = sshkey_new(k->type)) == NULL)
1708 			return SSH_ERR_ALLOC_FAIL;
1709 		if ((BN_copy(n->dsa->p, k->dsa->p) == NULL) ||
1710 		    (BN_copy(n->dsa->q, k->dsa->q) == NULL) ||
1711 		    (BN_copy(n->dsa->g, k->dsa->g) == NULL) ||
1712 		    (BN_copy(n->dsa->pub_key, k->dsa->pub_key) == NULL)) {
1713 			sshkey_free(n);
1714 			return SSH_ERR_ALLOC_FAIL;
1715 		}
1716 		break;
1717 	case KEY_ECDSA:
1718 	case KEY_ECDSA_CERT:
1719 		if ((n = sshkey_new(k->type)) == NULL)
1720 			return SSH_ERR_ALLOC_FAIL;
1721 		n->ecdsa_nid = k->ecdsa_nid;
1722 		n->ecdsa = EC_KEY_new_by_curve_name(k->ecdsa_nid);
1723 		if (n->ecdsa == NULL) {
1724 			sshkey_free(n);
1725 			return SSH_ERR_ALLOC_FAIL;
1726 		}
1727 		if (EC_KEY_set_public_key(n->ecdsa,
1728 		    EC_KEY_get0_public_key(k->ecdsa)) != 1) {
1729 			sshkey_free(n);
1730 			return SSH_ERR_LIBCRYPTO_ERROR;
1731 		}
1732 		break;
1733 	case KEY_RSA:
1734 	case KEY_RSA_CERT:
1735 		if ((n = sshkey_new(k->type)) == NULL)
1736 			return SSH_ERR_ALLOC_FAIL;
1737 		if ((BN_copy(n->rsa->n, k->rsa->n) == NULL) ||
1738 		    (BN_copy(n->rsa->e, k->rsa->e) == NULL)) {
1739 			sshkey_free(n);
1740 			return SSH_ERR_ALLOC_FAIL;
1741 		}
1742 		break;
1743 #endif /* WITH_OPENSSL */
1744 	case KEY_ED25519:
1745 	case KEY_ED25519_CERT:
1746 		if ((n = sshkey_new(k->type)) == NULL)
1747 			return SSH_ERR_ALLOC_FAIL;
1748 		if (k->ed25519_pk != NULL) {
1749 			if ((n->ed25519_pk = malloc(ED25519_PK_SZ)) == NULL) {
1750 				sshkey_free(n);
1751 				return SSH_ERR_ALLOC_FAIL;
1752 			}
1753 			memcpy(n->ed25519_pk, k->ed25519_pk, ED25519_PK_SZ);
1754 		}
1755 		break;
1756 #ifdef WITH_XMSS
1757 	case KEY_XMSS:
1758 	case KEY_XMSS_CERT:
1759 		if ((n = sshkey_new(k->type)) == NULL)
1760 			return SSH_ERR_ALLOC_FAIL;
1761 		if ((ret = sshkey_xmss_init(n, k->xmss_name)) != 0) {
1762 			sshkey_free(n);
1763 			return ret;
1764 		}
1765 		if (k->xmss_pk != NULL) {
1766 			size_t pklen = sshkey_xmss_pklen(k);
1767 			if (pklen == 0 || sshkey_xmss_pklen(n) != pklen) {
1768 				sshkey_free(n);
1769 				return SSH_ERR_INTERNAL_ERROR;
1770 			}
1771 			if ((n->xmss_pk = malloc(pklen)) == NULL) {
1772 				sshkey_free(n);
1773 				return SSH_ERR_ALLOC_FAIL;
1774 			}
1775 			memcpy(n->xmss_pk, k->xmss_pk, pklen);
1776 		}
1777 		break;
1778 #endif /* WITH_XMSS */
1779 	default:
1780 		return SSH_ERR_KEY_TYPE_UNKNOWN;
1781 	}
1782 	if (sshkey_is_cert(k)) {
1783 		if ((ret = sshkey_cert_copy(k, n)) != 0) {
1784 			sshkey_free(n);
1785 			return ret;
1786 		}
1787 	}
1788 	*pkp = n;
1789 	return 0;
1790 }
1791 
1792 static int
1793 cert_parse(struct sshbuf *b, struct sshkey *key, struct sshbuf *certbuf)
1794 {
1795 	struct sshbuf *principals = NULL, *crit = NULL;
1796 	struct sshbuf *exts = NULL, *ca = NULL;
1797 	u_char *sig = NULL;
1798 	size_t signed_len = 0, slen = 0, kidlen = 0;
1799 	int ret = SSH_ERR_INTERNAL_ERROR;
1800 
1801 	/* Copy the entire key blob for verification and later serialisation */
1802 	if ((ret = sshbuf_putb(key->cert->certblob, certbuf)) != 0)
1803 		return ret;
1804 
1805 	/* Parse body of certificate up to signature */
1806 	if ((ret = sshbuf_get_u64(b, &key->cert->serial)) != 0 ||
1807 	    (ret = sshbuf_get_u32(b, &key->cert->type)) != 0 ||
1808 	    (ret = sshbuf_get_cstring(b, &key->cert->key_id, &kidlen)) != 0 ||
1809 	    (ret = sshbuf_froms(b, &principals)) != 0 ||
1810 	    (ret = sshbuf_get_u64(b, &key->cert->valid_after)) != 0 ||
1811 	    (ret = sshbuf_get_u64(b, &key->cert->valid_before)) != 0 ||
1812 	    (ret = sshbuf_froms(b, &crit)) != 0 ||
1813 	    (ret = sshbuf_froms(b, &exts)) != 0 ||
1814 	    (ret = sshbuf_get_string_direct(b, NULL, NULL)) != 0 ||
1815 	    (ret = sshbuf_froms(b, &ca)) != 0) {
1816 		/* XXX debug print error for ret */
1817 		ret = SSH_ERR_INVALID_FORMAT;
1818 		goto out;
1819 	}
1820 
1821 	/* Signature is left in the buffer so we can calculate this length */
1822 	signed_len = sshbuf_len(key->cert->certblob) - sshbuf_len(b);
1823 
1824 	if ((ret = sshbuf_get_string(b, &sig, &slen)) != 0) {
1825 		ret = SSH_ERR_INVALID_FORMAT;
1826 		goto out;
1827 	}
1828 
1829 	if (key->cert->type != SSH2_CERT_TYPE_USER &&
1830 	    key->cert->type != SSH2_CERT_TYPE_HOST) {
1831 		ret = SSH_ERR_KEY_CERT_UNKNOWN_TYPE;
1832 		goto out;
1833 	}
1834 
1835 	/* Parse principals section */
1836 	while (sshbuf_len(principals) > 0) {
1837 		char *principal = NULL;
1838 		char **oprincipals = NULL;
1839 
1840 		if (key->cert->nprincipals >= SSHKEY_CERT_MAX_PRINCIPALS) {
1841 			ret = SSH_ERR_INVALID_FORMAT;
1842 			goto out;
1843 		}
1844 		if ((ret = sshbuf_get_cstring(principals, &principal,
1845 		    NULL)) != 0) {
1846 			ret = SSH_ERR_INVALID_FORMAT;
1847 			goto out;
1848 		}
1849 		oprincipals = key->cert->principals;
1850 		key->cert->principals = recallocarray(key->cert->principals,
1851 		    key->cert->nprincipals, key->cert->nprincipals + 1,
1852 		    sizeof(*key->cert->principals));
1853 		if (key->cert->principals == NULL) {
1854 			free(principal);
1855 			key->cert->principals = oprincipals;
1856 			ret = SSH_ERR_ALLOC_FAIL;
1857 			goto out;
1858 		}
1859 		key->cert->principals[key->cert->nprincipals++] = principal;
1860 	}
1861 
1862 	/*
1863 	 * Stash a copies of the critical options and extensions sections
1864 	 * for later use.
1865 	 */
1866 	if ((ret = sshbuf_putb(key->cert->critical, crit)) != 0 ||
1867 	    (exts != NULL &&
1868 	    (ret = sshbuf_putb(key->cert->extensions, exts)) != 0))
1869 		goto out;
1870 
1871 	/*
1872 	 * Validate critical options and extensions sections format.
1873 	 */
1874 	while (sshbuf_len(crit) != 0) {
1875 		if ((ret = sshbuf_get_string_direct(crit, NULL, NULL)) != 0 ||
1876 		    (ret = sshbuf_get_string_direct(crit, NULL, NULL)) != 0) {
1877 			sshbuf_reset(key->cert->critical);
1878 			ret = SSH_ERR_INVALID_FORMAT;
1879 			goto out;
1880 		}
1881 	}
1882 	while (exts != NULL && sshbuf_len(exts) != 0) {
1883 		if ((ret = sshbuf_get_string_direct(exts, NULL, NULL)) != 0 ||
1884 		    (ret = sshbuf_get_string_direct(exts, NULL, NULL)) != 0) {
1885 			sshbuf_reset(key->cert->extensions);
1886 			ret = SSH_ERR_INVALID_FORMAT;
1887 			goto out;
1888 		}
1889 	}
1890 
1891 	/* Parse CA key and check signature */
1892 	if (sshkey_from_blob_internal(ca, &key->cert->signature_key, 0) != 0) {
1893 		ret = SSH_ERR_KEY_CERT_INVALID_SIGN_KEY;
1894 		goto out;
1895 	}
1896 	if (!sshkey_type_is_valid_ca(key->cert->signature_key->type)) {
1897 		ret = SSH_ERR_KEY_CERT_INVALID_SIGN_KEY;
1898 		goto out;
1899 	}
1900 	if ((ret = sshkey_verify(key->cert->signature_key, sig, slen,
1901 	    sshbuf_ptr(key->cert->certblob), signed_len, NULL, 0)) != 0)
1902 		goto out;
1903 
1904 	/* Success */
1905 	ret = 0;
1906  out:
1907 	sshbuf_free(ca);
1908 	sshbuf_free(crit);
1909 	sshbuf_free(exts);
1910 	sshbuf_free(principals);
1911 	free(sig);
1912 	return ret;
1913 }
1914 
1915 static int
1916 sshkey_from_blob_internal(struct sshbuf *b, struct sshkey **keyp,
1917     int allow_cert)
1918 {
1919 	int type, ret = SSH_ERR_INTERNAL_ERROR;
1920 	char *ktype = NULL, *curve = NULL, *xmss_name = NULL;
1921 	struct sshkey *key = NULL;
1922 	size_t len;
1923 	u_char *pk = NULL;
1924 	struct sshbuf *copy;
1925 #ifdef WITH_OPENSSL
1926 	EC_POINT *q = NULL;
1927 #endif /* WITH_OPENSSL */
1928 
1929 #ifdef DEBUG_PK /* XXX */
1930 	sshbuf_dump(b, stderr);
1931 #endif
1932 	if (keyp != NULL)
1933 		*keyp = NULL;
1934 	if ((copy = sshbuf_fromb(b)) == NULL) {
1935 		ret = SSH_ERR_ALLOC_FAIL;
1936 		goto out;
1937 	}
1938 	if (sshbuf_get_cstring(b, &ktype, NULL) != 0) {
1939 		ret = SSH_ERR_INVALID_FORMAT;
1940 		goto out;
1941 	}
1942 
1943 	type = sshkey_type_from_name(ktype);
1944 	if (!allow_cert && sshkey_type_is_cert(type)) {
1945 		ret = SSH_ERR_KEY_CERT_INVALID_SIGN_KEY;
1946 		goto out;
1947 	}
1948 	switch (type) {
1949 #ifdef WITH_OPENSSL
1950 	case KEY_RSA_CERT:
1951 		/* Skip nonce */
1952 		if (sshbuf_get_string_direct(b, NULL, NULL) != 0) {
1953 			ret = SSH_ERR_INVALID_FORMAT;
1954 			goto out;
1955 		}
1956 		/* FALLTHROUGH */
1957 	case KEY_RSA:
1958 		if ((key = sshkey_new(type)) == NULL) {
1959 			ret = SSH_ERR_ALLOC_FAIL;
1960 			goto out;
1961 		}
1962 		if (sshbuf_get_bignum2(b, key->rsa->e) != 0 ||
1963 		    sshbuf_get_bignum2(b, key->rsa->n) != 0) {
1964 			ret = SSH_ERR_INVALID_FORMAT;
1965 			goto out;
1966 		}
1967 		if (BN_num_bits(key->rsa->n) < SSH_RSA_MINIMUM_MODULUS_SIZE) {
1968 			ret = SSH_ERR_KEY_LENGTH;
1969 			goto out;
1970 		}
1971 #ifdef DEBUG_PK
1972 		RSA_print_fp(stderr, key->rsa, 8);
1973 #endif
1974 		break;
1975 	case KEY_DSA_CERT:
1976 		/* Skip nonce */
1977 		if (sshbuf_get_string_direct(b, NULL, NULL) != 0) {
1978 			ret = SSH_ERR_INVALID_FORMAT;
1979 			goto out;
1980 		}
1981 		/* FALLTHROUGH */
1982 	case KEY_DSA:
1983 		if ((key = sshkey_new(type)) == NULL) {
1984 			ret = SSH_ERR_ALLOC_FAIL;
1985 			goto out;
1986 		}
1987 		if (sshbuf_get_bignum2(b, key->dsa->p) != 0 ||
1988 		    sshbuf_get_bignum2(b, key->dsa->q) != 0 ||
1989 		    sshbuf_get_bignum2(b, key->dsa->g) != 0 ||
1990 		    sshbuf_get_bignum2(b, key->dsa->pub_key) != 0) {
1991 			ret = SSH_ERR_INVALID_FORMAT;
1992 			goto out;
1993 		}
1994 #ifdef DEBUG_PK
1995 		DSA_print_fp(stderr, key->dsa, 8);
1996 #endif
1997 		break;
1998 	case KEY_ECDSA_CERT:
1999 		/* Skip nonce */
2000 		if (sshbuf_get_string_direct(b, NULL, NULL) != 0) {
2001 			ret = SSH_ERR_INVALID_FORMAT;
2002 			goto out;
2003 		}
2004 		/* FALLTHROUGH */
2005 	case KEY_ECDSA:
2006 		if ((key = sshkey_new(type)) == NULL) {
2007 			ret = SSH_ERR_ALLOC_FAIL;
2008 			goto out;
2009 		}
2010 		key->ecdsa_nid = sshkey_ecdsa_nid_from_name(ktype);
2011 		if (sshbuf_get_cstring(b, &curve, NULL) != 0) {
2012 			ret = SSH_ERR_INVALID_FORMAT;
2013 			goto out;
2014 		}
2015 		if (key->ecdsa_nid != sshkey_curve_name_to_nid(curve)) {
2016 			ret = SSH_ERR_EC_CURVE_MISMATCH;
2017 			goto out;
2018 		}
2019 		EC_KEY_free(key->ecdsa);
2020 		if ((key->ecdsa = EC_KEY_new_by_curve_name(key->ecdsa_nid))
2021 		    == NULL) {
2022 			ret = SSH_ERR_EC_CURVE_INVALID;
2023 			goto out;
2024 		}
2025 		if ((q = EC_POINT_new(EC_KEY_get0_group(key->ecdsa))) == NULL) {
2026 			ret = SSH_ERR_ALLOC_FAIL;
2027 			goto out;
2028 		}
2029 		if (sshbuf_get_ec(b, q, EC_KEY_get0_group(key->ecdsa)) != 0) {
2030 			ret = SSH_ERR_INVALID_FORMAT;
2031 			goto out;
2032 		}
2033 		if (sshkey_ec_validate_public(EC_KEY_get0_group(key->ecdsa),
2034 		    q) != 0) {
2035 			ret = SSH_ERR_KEY_INVALID_EC_VALUE;
2036 			goto out;
2037 		}
2038 		if (EC_KEY_set_public_key(key->ecdsa, q) != 1) {
2039 			/* XXX assume it is a allocation error */
2040 			ret = SSH_ERR_ALLOC_FAIL;
2041 			goto out;
2042 		}
2043 #ifdef DEBUG_PK
2044 		sshkey_dump_ec_point(EC_KEY_get0_group(key->ecdsa), q);
2045 #endif
2046 		break;
2047 #endif /* WITH_OPENSSL */
2048 	case KEY_ED25519_CERT:
2049 		/* Skip nonce */
2050 		if (sshbuf_get_string_direct(b, NULL, NULL) != 0) {
2051 			ret = SSH_ERR_INVALID_FORMAT;
2052 			goto out;
2053 		}
2054 		/* FALLTHROUGH */
2055 	case KEY_ED25519:
2056 		if ((ret = sshbuf_get_string(b, &pk, &len)) != 0)
2057 			goto out;
2058 		if (len != ED25519_PK_SZ) {
2059 			ret = SSH_ERR_INVALID_FORMAT;
2060 			goto out;
2061 		}
2062 		if ((key = sshkey_new(type)) == NULL) {
2063 			ret = SSH_ERR_ALLOC_FAIL;
2064 			goto out;
2065 		}
2066 		key->ed25519_pk = pk;
2067 		pk = NULL;
2068 		break;
2069 #ifdef WITH_XMSS
2070 	case KEY_XMSS_CERT:
2071 		/* Skip nonce */
2072 		if (sshbuf_get_string_direct(b, NULL, NULL) != 0) {
2073 			ret = SSH_ERR_INVALID_FORMAT;
2074 			goto out;
2075 		}
2076 		/* FALLTHROUGH */
2077 	case KEY_XMSS:
2078 		if ((ret = sshbuf_get_cstring(b, &xmss_name, NULL)) != 0)
2079 			goto out;
2080 		if ((key = sshkey_new(type)) == NULL) {
2081 			ret = SSH_ERR_ALLOC_FAIL;
2082 			goto out;
2083 		}
2084 		if ((ret = sshkey_xmss_init(key, xmss_name)) != 0)
2085 			goto out;
2086 		if ((ret = sshbuf_get_string(b, &pk, &len)) != 0)
2087 			goto out;
2088 		if (len == 0 || len != sshkey_xmss_pklen(key)) {
2089 			ret = SSH_ERR_INVALID_FORMAT;
2090 			goto out;
2091 		}
2092 		key->xmss_pk = pk;
2093 		pk = NULL;
2094 		if (type != KEY_XMSS_CERT &&
2095 		    (ret = sshkey_xmss_deserialize_pk_info(key, b)) != 0)
2096 			goto out;
2097 		break;
2098 #endif /* WITH_XMSS */
2099 	case KEY_UNSPEC:
2100 	default:
2101 		ret = SSH_ERR_KEY_TYPE_UNKNOWN;
2102 		goto out;
2103 	}
2104 
2105 	/* Parse certificate potion */
2106 	if (sshkey_is_cert(key) && (ret = cert_parse(b, key, copy)) != 0)
2107 		goto out;
2108 
2109 	if (key != NULL && sshbuf_len(b) != 0) {
2110 		ret = SSH_ERR_INVALID_FORMAT;
2111 		goto out;
2112 	}
2113 	ret = 0;
2114 	if (keyp != NULL) {
2115 		*keyp = key;
2116 		key = NULL;
2117 	}
2118  out:
2119 	sshbuf_free(copy);
2120 	sshkey_free(key);
2121 	free(xmss_name);
2122 	free(ktype);
2123 	free(curve);
2124 	free(pk);
2125 #ifdef WITH_OPENSSL
2126 	EC_POINT_free(q);
2127 #endif /* WITH_OPENSSL */
2128 	return ret;
2129 }
2130 
2131 int
2132 sshkey_from_blob(const u_char *blob, size_t blen, struct sshkey **keyp)
2133 {
2134 	struct sshbuf *b;
2135 	int r;
2136 
2137 	if ((b = sshbuf_from(blob, blen)) == NULL)
2138 		return SSH_ERR_ALLOC_FAIL;
2139 	r = sshkey_from_blob_internal(b, keyp, 1);
2140 	sshbuf_free(b);
2141 	return r;
2142 }
2143 
2144 int
2145 sshkey_fromb(struct sshbuf *b, struct sshkey **keyp)
2146 {
2147 	return sshkey_from_blob_internal(b, keyp, 1);
2148 }
2149 
2150 int
2151 sshkey_froms(struct sshbuf *buf, struct sshkey **keyp)
2152 {
2153 	struct sshbuf *b;
2154 	int r;
2155 
2156 	if ((r = sshbuf_froms(buf, &b)) != 0)
2157 		return r;
2158 	r = sshkey_from_blob_internal(b, keyp, 1);
2159 	sshbuf_free(b);
2160 	return r;
2161 }
2162 
2163 int
2164 sshkey_sigtype(const u_char *sig, size_t siglen, char **sigtypep)
2165 {
2166 	int r;
2167 	struct sshbuf *b = NULL;
2168 	char *sigtype = NULL;
2169 
2170 	if (sigtypep != NULL)
2171 		*sigtypep = NULL;
2172 	if ((b = sshbuf_from(sig, siglen)) == NULL)
2173 		return SSH_ERR_ALLOC_FAIL;
2174 	if ((r = sshbuf_get_cstring(b, &sigtype, NULL)) != 0)
2175 		goto out;
2176 	/* success */
2177 	if (sigtypep != NULL) {
2178 		*sigtypep = sigtype;
2179 		sigtype = NULL;
2180 	}
2181 	r = 0;
2182  out:
2183 	free(sigtype);
2184 	sshbuf_free(b);
2185 	return r;
2186 }
2187 
2188 int
2189 sshkey_sign(const struct sshkey *key,
2190     u_char **sigp, size_t *lenp,
2191     const u_char *data, size_t datalen, const char *alg, u_int compat)
2192 {
2193 	if (sigp != NULL)
2194 		*sigp = NULL;
2195 	if (lenp != NULL)
2196 		*lenp = 0;
2197 	if (datalen > SSH_KEY_MAX_SIGN_DATA_SIZE)
2198 		return SSH_ERR_INVALID_ARGUMENT;
2199 	switch (key->type) {
2200 #ifdef WITH_OPENSSL
2201 	case KEY_DSA_CERT:
2202 	case KEY_DSA:
2203 		return ssh_dss_sign(key, sigp, lenp, data, datalen, compat);
2204 	case KEY_ECDSA_CERT:
2205 	case KEY_ECDSA:
2206 		return ssh_ecdsa_sign(key, sigp, lenp, data, datalen, compat);
2207 	case KEY_RSA_CERT:
2208 	case KEY_RSA:
2209 		return ssh_rsa_sign(key, sigp, lenp, data, datalen, alg);
2210 #endif /* WITH_OPENSSL */
2211 	case KEY_ED25519:
2212 	case KEY_ED25519_CERT:
2213 		return ssh_ed25519_sign(key, sigp, lenp, data, datalen, compat);
2214 #ifdef WITH_XMSS
2215 	case KEY_XMSS:
2216 	case KEY_XMSS_CERT:
2217 		return ssh_xmss_sign(key, sigp, lenp, data, datalen, compat);
2218 #endif /* WITH_XMSS */
2219 	default:
2220 		return SSH_ERR_KEY_TYPE_UNKNOWN;
2221 	}
2222 }
2223 
2224 /*
2225  * ssh_key_verify returns 0 for a correct signature  and < 0 on error.
2226  * If "alg" specified, then the signature must use that algorithm.
2227  */
2228 int
2229 sshkey_verify(const struct sshkey *key,
2230     const u_char *sig, size_t siglen,
2231     const u_char *data, size_t dlen, const char *alg, u_int compat)
2232 {
2233 	if (siglen == 0 || dlen > SSH_KEY_MAX_SIGN_DATA_SIZE)
2234 		return SSH_ERR_INVALID_ARGUMENT;
2235 	switch (key->type) {
2236 #ifdef WITH_OPENSSL
2237 	case KEY_DSA_CERT:
2238 	case KEY_DSA:
2239 		return ssh_dss_verify(key, sig, siglen, data, dlen, compat);
2240 	case KEY_ECDSA_CERT:
2241 	case KEY_ECDSA:
2242 		return ssh_ecdsa_verify(key, sig, siglen, data, dlen, compat);
2243 	case KEY_RSA_CERT:
2244 	case KEY_RSA:
2245 		return ssh_rsa_verify(key, sig, siglen, data, dlen, alg);
2246 #endif /* WITH_OPENSSL */
2247 	case KEY_ED25519:
2248 	case KEY_ED25519_CERT:
2249 		return ssh_ed25519_verify(key, sig, siglen, data, dlen, compat);
2250 #ifdef WITH_XMSS
2251 	case KEY_XMSS:
2252 	case KEY_XMSS_CERT:
2253 		return ssh_xmss_verify(key, sig, siglen, data, dlen, compat);
2254 #endif /* WITH_XMSS */
2255 	default:
2256 		return SSH_ERR_KEY_TYPE_UNKNOWN;
2257 	}
2258 }
2259 
2260 /* Converts a private to a public key */
2261 int
2262 sshkey_demote(const struct sshkey *k, struct sshkey **dkp)
2263 {
2264 	struct sshkey *pk;
2265 	int ret = SSH_ERR_INTERNAL_ERROR;
2266 
2267 	*dkp = NULL;
2268 	if ((pk = calloc(1, sizeof(*pk))) == NULL)
2269 		return SSH_ERR_ALLOC_FAIL;
2270 	pk->type = k->type;
2271 	pk->flags = k->flags;
2272 	pk->ecdsa_nid = k->ecdsa_nid;
2273 	pk->dsa = NULL;
2274 	pk->ecdsa = NULL;
2275 	pk->rsa = NULL;
2276 	pk->ed25519_pk = NULL;
2277 	pk->ed25519_sk = NULL;
2278 	pk->xmss_pk = NULL;
2279 	pk->xmss_sk = NULL;
2280 
2281 	switch (k->type) {
2282 #ifdef WITH_OPENSSL
2283 	case KEY_RSA_CERT:
2284 		if ((ret = sshkey_cert_copy(k, pk)) != 0)
2285 			goto fail;
2286 		/* FALLTHROUGH */
2287 	case KEY_RSA:
2288 		if ((pk->rsa = RSA_new()) == NULL ||
2289 		    (pk->rsa->e = BN_dup(k->rsa->e)) == NULL ||
2290 		    (pk->rsa->n = BN_dup(k->rsa->n)) == NULL) {
2291 			ret = SSH_ERR_ALLOC_FAIL;
2292 			goto fail;
2293 			}
2294 		break;
2295 	case KEY_DSA_CERT:
2296 		if ((ret = sshkey_cert_copy(k, pk)) != 0)
2297 			goto fail;
2298 		/* FALLTHROUGH */
2299 	case KEY_DSA:
2300 		if ((pk->dsa = DSA_new()) == NULL ||
2301 		    (pk->dsa->p = BN_dup(k->dsa->p)) == NULL ||
2302 		    (pk->dsa->q = BN_dup(k->dsa->q)) == NULL ||
2303 		    (pk->dsa->g = BN_dup(k->dsa->g)) == NULL ||
2304 		    (pk->dsa->pub_key = BN_dup(k->dsa->pub_key)) == NULL) {
2305 			ret = SSH_ERR_ALLOC_FAIL;
2306 			goto fail;
2307 		}
2308 		break;
2309 	case KEY_ECDSA_CERT:
2310 		if ((ret = sshkey_cert_copy(k, pk)) != 0)
2311 			goto fail;
2312 		/* FALLTHROUGH */
2313 	case KEY_ECDSA:
2314 		pk->ecdsa = EC_KEY_new_by_curve_name(pk->ecdsa_nid);
2315 		if (pk->ecdsa == NULL) {
2316 			ret = SSH_ERR_ALLOC_FAIL;
2317 			goto fail;
2318 		}
2319 		if (EC_KEY_set_public_key(pk->ecdsa,
2320 		    EC_KEY_get0_public_key(k->ecdsa)) != 1) {
2321 			ret = SSH_ERR_LIBCRYPTO_ERROR;
2322 			goto fail;
2323 		}
2324 		break;
2325 #endif /* WITH_OPENSSL */
2326 	case KEY_ED25519_CERT:
2327 		if ((ret = sshkey_cert_copy(k, pk)) != 0)
2328 			goto fail;
2329 		/* FALLTHROUGH */
2330 	case KEY_ED25519:
2331 		if (k->ed25519_pk != NULL) {
2332 			if ((pk->ed25519_pk = malloc(ED25519_PK_SZ)) == NULL) {
2333 				ret = SSH_ERR_ALLOC_FAIL;
2334 				goto fail;
2335 			}
2336 			memcpy(pk->ed25519_pk, k->ed25519_pk, ED25519_PK_SZ);
2337 		}
2338 		break;
2339 #ifdef WITH_XMSS
2340 	case KEY_XMSS_CERT:
2341 		if ((ret = sshkey_cert_copy(k, pk)) != 0)
2342 			goto fail;
2343 		/* FALLTHROUGH */
2344 	case KEY_XMSS:
2345 		if ((ret = sshkey_xmss_init(pk, k->xmss_name)) != 0)
2346 			goto fail;
2347 		if (k->xmss_pk != NULL) {
2348 			size_t pklen = sshkey_xmss_pklen(k);
2349 
2350 			if (pklen == 0 || sshkey_xmss_pklen(pk) != pklen) {
2351 				ret = SSH_ERR_INTERNAL_ERROR;
2352 				goto fail;
2353 			}
2354 			if ((pk->xmss_pk = malloc(pklen)) == NULL) {
2355 				ret = SSH_ERR_ALLOC_FAIL;
2356 				goto fail;
2357 			}
2358 			memcpy(pk->xmss_pk, k->xmss_pk, pklen);
2359 		}
2360 		break;
2361 #endif /* WITH_XMSS */
2362 	default:
2363 		ret = SSH_ERR_KEY_TYPE_UNKNOWN;
2364  fail:
2365 		sshkey_free(pk);
2366 		return ret;
2367 	}
2368 	*dkp = pk;
2369 	return 0;
2370 }
2371 
2372 /* Convert a plain key to their _CERT equivalent */
2373 int
2374 sshkey_to_certified(struct sshkey *k)
2375 {
2376 	int newtype;
2377 
2378 	switch (k->type) {
2379 #ifdef WITH_OPENSSL
2380 	case KEY_RSA:
2381 		newtype = KEY_RSA_CERT;
2382 		break;
2383 	case KEY_DSA:
2384 		newtype = KEY_DSA_CERT;
2385 		break;
2386 	case KEY_ECDSA:
2387 		newtype = KEY_ECDSA_CERT;
2388 		break;
2389 #endif /* WITH_OPENSSL */
2390 	case KEY_ED25519:
2391 		newtype = KEY_ED25519_CERT;
2392 		break;
2393 #ifdef WITH_XMSS
2394 	case KEY_XMSS:
2395 		newtype = KEY_XMSS_CERT;
2396 		break;
2397 #endif /* WITH_XMSS */
2398 	default:
2399 		return SSH_ERR_INVALID_ARGUMENT;
2400 	}
2401 	if ((k->cert = cert_new()) == NULL)
2402 		return SSH_ERR_ALLOC_FAIL;
2403 	k->type = newtype;
2404 	return 0;
2405 }
2406 
2407 /* Convert a certificate to its raw key equivalent */
2408 int
2409 sshkey_drop_cert(struct sshkey *k)
2410 {
2411 	if (!sshkey_type_is_cert(k->type))
2412 		return SSH_ERR_KEY_TYPE_UNKNOWN;
2413 	cert_free(k->cert);
2414 	k->cert = NULL;
2415 	k->type = sshkey_type_plain(k->type);
2416 	return 0;
2417 }
2418 
2419 /* Sign a certified key, (re-)generating the signed certblob. */
2420 int
2421 sshkey_certify_custom(struct sshkey *k, struct sshkey *ca, const char *alg,
2422     sshkey_certify_signer *signer, void *signer_ctx)
2423 {
2424 	struct sshbuf *principals = NULL;
2425 	u_char *ca_blob = NULL, *sig_blob = NULL, nonce[32];
2426 	size_t i, ca_len, sig_len;
2427 	int ret = SSH_ERR_INTERNAL_ERROR;
2428 	struct sshbuf *cert;
2429 
2430 	if (k == NULL || k->cert == NULL ||
2431 	    k->cert->certblob == NULL || ca == NULL)
2432 		return SSH_ERR_INVALID_ARGUMENT;
2433 	if (!sshkey_is_cert(k))
2434 		return SSH_ERR_KEY_TYPE_UNKNOWN;
2435 	if (!sshkey_type_is_valid_ca(ca->type))
2436 		return SSH_ERR_KEY_CERT_INVALID_SIGN_KEY;
2437 
2438 	if ((ret = sshkey_to_blob(ca, &ca_blob, &ca_len)) != 0)
2439 		return SSH_ERR_KEY_CERT_INVALID_SIGN_KEY;
2440 
2441 	cert = k->cert->certblob; /* for readability */
2442 	sshbuf_reset(cert);
2443 	if ((ret = sshbuf_put_cstring(cert, sshkey_ssh_name(k))) != 0)
2444 		goto out;
2445 
2446 	/* -v01 certs put nonce first */
2447 	arc4random_buf(&nonce, sizeof(nonce));
2448 	if ((ret = sshbuf_put_string(cert, nonce, sizeof(nonce))) != 0)
2449 		goto out;
2450 
2451 	/* XXX this substantially duplicates to_blob(); refactor */
2452 	switch (k->type) {
2453 #ifdef WITH_OPENSSL
2454 	case KEY_DSA_CERT:
2455 		if ((ret = sshbuf_put_bignum2(cert, k->dsa->p)) != 0 ||
2456 		    (ret = sshbuf_put_bignum2(cert, k->dsa->q)) != 0 ||
2457 		    (ret = sshbuf_put_bignum2(cert, k->dsa->g)) != 0 ||
2458 		    (ret = sshbuf_put_bignum2(cert, k->dsa->pub_key)) != 0)
2459 			goto out;
2460 		break;
2461 	case KEY_ECDSA_CERT:
2462 		if ((ret = sshbuf_put_cstring(cert,
2463 		    sshkey_curve_nid_to_name(k->ecdsa_nid))) != 0 ||
2464 		    (ret = sshbuf_put_ec(cert,
2465 		    EC_KEY_get0_public_key(k->ecdsa),
2466 		    EC_KEY_get0_group(k->ecdsa))) != 0)
2467 			goto out;
2468 		break;
2469 	case KEY_RSA_CERT:
2470 		if ((ret = sshbuf_put_bignum2(cert, k->rsa->e)) != 0 ||
2471 		    (ret = sshbuf_put_bignum2(cert, k->rsa->n)) != 0)
2472 			goto out;
2473 		break;
2474 #endif /* WITH_OPENSSL */
2475 	case KEY_ED25519_CERT:
2476 		if ((ret = sshbuf_put_string(cert,
2477 		    k->ed25519_pk, ED25519_PK_SZ)) != 0)
2478 			goto out;
2479 		break;
2480 #ifdef WITH_XMSS
2481 	case KEY_XMSS_CERT:
2482 		if (k->xmss_name == NULL) {
2483 			ret = SSH_ERR_INVALID_ARGUMENT;
2484 			goto out;
2485 		}
2486 		if ((ret = sshbuf_put_cstring(cert, k->xmss_name)) ||
2487 		    (ret = sshbuf_put_string(cert,
2488 		    k->xmss_pk, sshkey_xmss_pklen(k))) != 0)
2489 			goto out;
2490 		break;
2491 #endif /* WITH_XMSS */
2492 	default:
2493 		ret = SSH_ERR_INVALID_ARGUMENT;
2494 		goto out;
2495 	}
2496 
2497 	if ((ret = sshbuf_put_u64(cert, k->cert->serial)) != 0 ||
2498 	    (ret = sshbuf_put_u32(cert, k->cert->type)) != 0 ||
2499 	    (ret = sshbuf_put_cstring(cert, k->cert->key_id)) != 0)
2500 		goto out;
2501 
2502 	if ((principals = sshbuf_new()) == NULL) {
2503 		ret = SSH_ERR_ALLOC_FAIL;
2504 		goto out;
2505 	}
2506 	for (i = 0; i < k->cert->nprincipals; i++) {
2507 		if ((ret = sshbuf_put_cstring(principals,
2508 		    k->cert->principals[i])) != 0)
2509 			goto out;
2510 	}
2511 	if ((ret = sshbuf_put_stringb(cert, principals)) != 0 ||
2512 	    (ret = sshbuf_put_u64(cert, k->cert->valid_after)) != 0 ||
2513 	    (ret = sshbuf_put_u64(cert, k->cert->valid_before)) != 0 ||
2514 	    (ret = sshbuf_put_stringb(cert, k->cert->critical)) != 0 ||
2515 	    (ret = sshbuf_put_stringb(cert, k->cert->extensions)) != 0 ||
2516 	    (ret = sshbuf_put_string(cert, NULL, 0)) != 0 || /* Reserved */
2517 	    (ret = sshbuf_put_string(cert, ca_blob, ca_len)) != 0)
2518 		goto out;
2519 
2520 	/* Sign the whole mess */
2521 	if ((ret = signer(ca, &sig_blob, &sig_len, sshbuf_ptr(cert),
2522 	    sshbuf_len(cert), alg, 0, signer_ctx)) != 0)
2523 		goto out;
2524 
2525 	/* Append signature and we are done */
2526 	if ((ret = sshbuf_put_string(cert, sig_blob, sig_len)) != 0)
2527 		goto out;
2528 	ret = 0;
2529  out:
2530 	if (ret != 0)
2531 		sshbuf_reset(cert);
2532 	free(sig_blob);
2533 	free(ca_blob);
2534 	sshbuf_free(principals);
2535 	return ret;
2536 }
2537 
2538 static int
2539 default_key_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,
2540     const u_char *data, size_t datalen,
2541     const char *alg, u_int compat, void *ctx)
2542 {
2543 	if (ctx != NULL)
2544 		return SSH_ERR_INVALID_ARGUMENT;
2545 	return sshkey_sign(key, sigp, lenp, data, datalen, alg, compat);
2546 }
2547 
2548 int
2549 sshkey_certify(struct sshkey *k, struct sshkey *ca, const char *alg)
2550 {
2551 	return sshkey_certify_custom(k, ca, alg, default_key_sign, NULL);
2552 }
2553 
2554 int
2555 sshkey_cert_check_authority(const struct sshkey *k,
2556     int want_host, int require_principal,
2557     const char *name, const char **reason)
2558 {
2559 	u_int i, principal_matches;
2560 	time_t now = time(NULL);
2561 
2562 	if (reason != NULL)
2563 		*reason = NULL;
2564 
2565 	if (want_host) {
2566 		if (k->cert->type != SSH2_CERT_TYPE_HOST) {
2567 			*reason = "Certificate invalid: not a host certificate";
2568 			return SSH_ERR_KEY_CERT_INVALID;
2569 		}
2570 	} else {
2571 		if (k->cert->type != SSH2_CERT_TYPE_USER) {
2572 			*reason = "Certificate invalid: not a user certificate";
2573 			return SSH_ERR_KEY_CERT_INVALID;
2574 		}
2575 	}
2576 	if (now < 0) {
2577 		/* yikes - system clock before epoch! */
2578 		*reason = "Certificate invalid: not yet valid";
2579 		return SSH_ERR_KEY_CERT_INVALID;
2580 	}
2581 	if ((u_int64_t)now < k->cert->valid_after) {
2582 		*reason = "Certificate invalid: not yet valid";
2583 		return SSH_ERR_KEY_CERT_INVALID;
2584 	}
2585 	if ((u_int64_t)now >= k->cert->valid_before) {
2586 		*reason = "Certificate invalid: expired";
2587 		return SSH_ERR_KEY_CERT_INVALID;
2588 	}
2589 	if (k->cert->nprincipals == 0) {
2590 		if (require_principal) {
2591 			*reason = "Certificate lacks principal list";
2592 			return SSH_ERR_KEY_CERT_INVALID;
2593 		}
2594 	} else if (name != NULL) {
2595 		principal_matches = 0;
2596 		for (i = 0; i < k->cert->nprincipals; i++) {
2597 			if (strcmp(name, k->cert->principals[i]) == 0) {
2598 				principal_matches = 1;
2599 				break;
2600 			}
2601 		}
2602 		if (!principal_matches) {
2603 			*reason = "Certificate invalid: name is not a listed "
2604 			    "principal";
2605 			return SSH_ERR_KEY_CERT_INVALID;
2606 		}
2607 	}
2608 	return 0;
2609 }
2610 
2611 size_t
2612 sshkey_format_cert_validity(const struct sshkey_cert *cert, char *s, size_t l)
2613 {
2614 	char from[32], to[32], ret[64];
2615 	time_t tt;
2616 	struct tm *tm;
2617 
2618 	*from = *to = '\0';
2619 	if (cert->valid_after == 0 &&
2620 	    cert->valid_before == 0xffffffffffffffffULL)
2621 		return strlcpy(s, "forever", l);
2622 
2623 	if (cert->valid_after != 0) {
2624 		/* XXX revisit INT_MAX in 2038 :) */
2625 		tt = cert->valid_after > INT_MAX ?
2626 		    INT_MAX : cert->valid_after;
2627 		tm = localtime(&tt);
2628 		strftime(from, sizeof(from), "%Y-%m-%dT%H:%M:%S", tm);
2629 	}
2630 	if (cert->valid_before != 0xffffffffffffffffULL) {
2631 		/* XXX revisit INT_MAX in 2038 :) */
2632 		tt = cert->valid_before > INT_MAX ?
2633 		    INT_MAX : cert->valid_before;
2634 		tm = localtime(&tt);
2635 		strftime(to, sizeof(to), "%Y-%m-%dT%H:%M:%S", tm);
2636 	}
2637 
2638 	if (cert->valid_after == 0)
2639 		snprintf(ret, sizeof(ret), "before %s", to);
2640 	else if (cert->valid_before == 0xffffffffffffffffULL)
2641 		snprintf(ret, sizeof(ret), "after %s", from);
2642 	else
2643 		snprintf(ret, sizeof(ret), "from %s to %s", from, to);
2644 
2645 	return strlcpy(s, ret, l);
2646 }
2647 
2648 int
2649 sshkey_private_serialize_opt(const struct sshkey *key, struct sshbuf *b,
2650     enum sshkey_serialize_rep opts)
2651 {
2652 	int r = SSH_ERR_INTERNAL_ERROR;
2653 
2654 	if ((r = sshbuf_put_cstring(b, sshkey_ssh_name(key))) != 0)
2655 		goto out;
2656 	switch (key->type) {
2657 #ifdef WITH_OPENSSL
2658 	case KEY_RSA:
2659 		if ((r = sshbuf_put_bignum2(b, key->rsa->n)) != 0 ||
2660 		    (r = sshbuf_put_bignum2(b, key->rsa->e)) != 0 ||
2661 		    (r = sshbuf_put_bignum2(b, key->rsa->d)) != 0 ||
2662 		    (r = sshbuf_put_bignum2(b, key->rsa->iqmp)) != 0 ||
2663 		    (r = sshbuf_put_bignum2(b, key->rsa->p)) != 0 ||
2664 		    (r = sshbuf_put_bignum2(b, key->rsa->q)) != 0)
2665 			goto out;
2666 		break;
2667 	case KEY_RSA_CERT:
2668 		if (key->cert == NULL || sshbuf_len(key->cert->certblob) == 0) {
2669 			r = SSH_ERR_INVALID_ARGUMENT;
2670 			goto out;
2671 		}
2672 		if ((r = sshbuf_put_stringb(b, key->cert->certblob)) != 0 ||
2673 		    (r = sshbuf_put_bignum2(b, key->rsa->d)) != 0 ||
2674 		    (r = sshbuf_put_bignum2(b, key->rsa->iqmp)) != 0 ||
2675 		    (r = sshbuf_put_bignum2(b, key->rsa->p)) != 0 ||
2676 		    (r = sshbuf_put_bignum2(b, key->rsa->q)) != 0)
2677 			goto out;
2678 		break;
2679 	case KEY_DSA:
2680 		if ((r = sshbuf_put_bignum2(b, key->dsa->p)) != 0 ||
2681 		    (r = sshbuf_put_bignum2(b, key->dsa->q)) != 0 ||
2682 		    (r = sshbuf_put_bignum2(b, key->dsa->g)) != 0 ||
2683 		    (r = sshbuf_put_bignum2(b, key->dsa->pub_key)) != 0 ||
2684 		    (r = sshbuf_put_bignum2(b, key->dsa->priv_key)) != 0)
2685 			goto out;
2686 		break;
2687 	case KEY_DSA_CERT:
2688 		if (key->cert == NULL || sshbuf_len(key->cert->certblob) == 0) {
2689 			r = SSH_ERR_INVALID_ARGUMENT;
2690 			goto out;
2691 		}
2692 		if ((r = sshbuf_put_stringb(b, key->cert->certblob)) != 0 ||
2693 		    (r = sshbuf_put_bignum2(b, key->dsa->priv_key)) != 0)
2694 			goto out;
2695 		break;
2696 	case KEY_ECDSA:
2697 		if ((r = sshbuf_put_cstring(b,
2698 		    sshkey_curve_nid_to_name(key->ecdsa_nid))) != 0 ||
2699 		    (r = sshbuf_put_eckey(b, key->ecdsa)) != 0 ||
2700 		    (r = sshbuf_put_bignum2(b,
2701 		    EC_KEY_get0_private_key(key->ecdsa))) != 0)
2702 			goto out;
2703 		break;
2704 	case KEY_ECDSA_CERT:
2705 		if (key->cert == NULL || sshbuf_len(key->cert->certblob) == 0) {
2706 			r = SSH_ERR_INVALID_ARGUMENT;
2707 			goto out;
2708 		}
2709 		if ((r = sshbuf_put_stringb(b, key->cert->certblob)) != 0 ||
2710 		    (r = sshbuf_put_bignum2(b,
2711 		    EC_KEY_get0_private_key(key->ecdsa))) != 0)
2712 			goto out;
2713 		break;
2714 #endif /* WITH_OPENSSL */
2715 	case KEY_ED25519:
2716 		if ((r = sshbuf_put_string(b, key->ed25519_pk,
2717 		    ED25519_PK_SZ)) != 0 ||
2718 		    (r = sshbuf_put_string(b, key->ed25519_sk,
2719 		    ED25519_SK_SZ)) != 0)
2720 			goto out;
2721 		break;
2722 	case KEY_ED25519_CERT:
2723 		if (key->cert == NULL || sshbuf_len(key->cert->certblob) == 0) {
2724 			r = SSH_ERR_INVALID_ARGUMENT;
2725 			goto out;
2726 		}
2727 		if ((r = sshbuf_put_stringb(b, key->cert->certblob)) != 0 ||
2728 		    (r = sshbuf_put_string(b, key->ed25519_pk,
2729 		    ED25519_PK_SZ)) != 0 ||
2730 		    (r = sshbuf_put_string(b, key->ed25519_sk,
2731 		    ED25519_SK_SZ)) != 0)
2732 			goto out;
2733 		break;
2734 #ifdef WITH_XMSS
2735 	case KEY_XMSS:
2736 		if (key->xmss_name == NULL) {
2737 			r = SSH_ERR_INVALID_ARGUMENT;
2738 			goto out;
2739 		}
2740 		if ((r = sshbuf_put_cstring(b, key->xmss_name)) != 0 ||
2741 		    (r = sshbuf_put_string(b, key->xmss_pk,
2742 		    sshkey_xmss_pklen(key))) != 0 ||
2743 		    (r = sshbuf_put_string(b, key->xmss_sk,
2744 		    sshkey_xmss_sklen(key))) != 0 ||
2745 		    (r = sshkey_xmss_serialize_state_opt(key, b, opts)) != 0)
2746 			goto out;
2747 		break;
2748 	case KEY_XMSS_CERT:
2749 		if (key->cert == NULL || sshbuf_len(key->cert->certblob) == 0 ||
2750 		    key->xmss_name == NULL) {
2751 			r = SSH_ERR_INVALID_ARGUMENT;
2752 			goto out;
2753 		}
2754 		if ((r = sshbuf_put_stringb(b, key->cert->certblob)) != 0 ||
2755 		    (r = sshbuf_put_cstring(b, key->xmss_name)) != 0 ||
2756 		    (r = sshbuf_put_string(b, key->xmss_pk,
2757 		    sshkey_xmss_pklen(key))) != 0 ||
2758 		    (r = sshbuf_put_string(b, key->xmss_sk,
2759 		    sshkey_xmss_sklen(key))) != 0 ||
2760 		    (r = sshkey_xmss_serialize_state_opt(key, b, opts)) != 0)
2761 			goto out;
2762 		break;
2763 #endif /* WITH_XMSS */
2764 	default:
2765 		r = SSH_ERR_INVALID_ARGUMENT;
2766 		goto out;
2767 	}
2768 	/* success */
2769 	r = 0;
2770  out:
2771 	return r;
2772 }
2773 
2774 int
2775 sshkey_private_serialize(const struct sshkey *key, struct sshbuf *b)
2776 {
2777 	return sshkey_private_serialize_opt(key, b,
2778 	    SSHKEY_SERIALIZE_DEFAULT);
2779 }
2780 
2781 int
2782 sshkey_private_deserialize(struct sshbuf *buf, struct sshkey **kp)
2783 {
2784 	char *tname = NULL, *curve = NULL, *xmss_name = NULL;
2785 	struct sshkey *k = NULL;
2786 	size_t pklen = 0, sklen = 0;
2787 	int type, r = SSH_ERR_INTERNAL_ERROR;
2788 	u_char *ed25519_pk = NULL, *ed25519_sk = NULL;
2789 	u_char *xmss_pk = NULL, *xmss_sk = NULL;
2790 #ifdef WITH_OPENSSL
2791 	BIGNUM *exponent = NULL;
2792 #endif /* WITH_OPENSSL */
2793 
2794 	if (kp != NULL)
2795 		*kp = NULL;
2796 	if ((r = sshbuf_get_cstring(buf, &tname, NULL)) != 0)
2797 		goto out;
2798 	type = sshkey_type_from_name(tname);
2799 	switch (type) {
2800 #ifdef WITH_OPENSSL
2801 	case KEY_DSA:
2802 		if ((k = sshkey_new_private(type)) == NULL) {
2803 			r = SSH_ERR_ALLOC_FAIL;
2804 			goto out;
2805 		}
2806 		if ((r = sshbuf_get_bignum2(buf, k->dsa->p)) != 0 ||
2807 		    (r = sshbuf_get_bignum2(buf, k->dsa->q)) != 0 ||
2808 		    (r = sshbuf_get_bignum2(buf, k->dsa->g)) != 0 ||
2809 		    (r = sshbuf_get_bignum2(buf, k->dsa->pub_key)) != 0 ||
2810 		    (r = sshbuf_get_bignum2(buf, k->dsa->priv_key)) != 0)
2811 			goto out;
2812 		break;
2813 	case KEY_DSA_CERT:
2814 		if ((r = sshkey_froms(buf, &k)) != 0 ||
2815 		    (r = sshkey_add_private(k)) != 0 ||
2816 		    (r = sshbuf_get_bignum2(buf, k->dsa->priv_key)) != 0)
2817 			goto out;
2818 		break;
2819 	case KEY_ECDSA:
2820 		if ((k = sshkey_new_private(type)) == NULL) {
2821 			r = SSH_ERR_ALLOC_FAIL;
2822 			goto out;
2823 		}
2824 		if ((k->ecdsa_nid = sshkey_ecdsa_nid_from_name(tname)) == -1) {
2825 			r = SSH_ERR_INVALID_ARGUMENT;
2826 			goto out;
2827 		}
2828 		if ((r = sshbuf_get_cstring(buf, &curve, NULL)) != 0)
2829 			goto out;
2830 		if (k->ecdsa_nid != sshkey_curve_name_to_nid(curve)) {
2831 			r = SSH_ERR_EC_CURVE_MISMATCH;
2832 			goto out;
2833 		}
2834 		k->ecdsa = EC_KEY_new_by_curve_name(k->ecdsa_nid);
2835 		if (k->ecdsa  == NULL || (exponent = BN_new()) == NULL) {
2836 			r = SSH_ERR_LIBCRYPTO_ERROR;
2837 			goto out;
2838 		}
2839 		if ((r = sshbuf_get_eckey(buf, k->ecdsa)) != 0 ||
2840 		    (r = sshbuf_get_bignum2(buf, exponent)))
2841 			goto out;
2842 		if (EC_KEY_set_private_key(k->ecdsa, exponent) != 1) {
2843 			r = SSH_ERR_LIBCRYPTO_ERROR;
2844 			goto out;
2845 		}
2846 		if ((r = sshkey_ec_validate_public(EC_KEY_get0_group(k->ecdsa),
2847 		    EC_KEY_get0_public_key(k->ecdsa))) != 0 ||
2848 		    (r = sshkey_ec_validate_private(k->ecdsa)) != 0)
2849 			goto out;
2850 		break;
2851 	case KEY_ECDSA_CERT:
2852 		if ((exponent = BN_new()) == NULL) {
2853 			r = SSH_ERR_LIBCRYPTO_ERROR;
2854 			goto out;
2855 		}
2856 		if ((r = sshkey_froms(buf, &k)) != 0 ||
2857 		    (r = sshkey_add_private(k)) != 0 ||
2858 		    (r = sshbuf_get_bignum2(buf, exponent)) != 0)
2859 			goto out;
2860 		if (EC_KEY_set_private_key(k->ecdsa, exponent) != 1) {
2861 			r = SSH_ERR_LIBCRYPTO_ERROR;
2862 			goto out;
2863 		}
2864 		if ((r = sshkey_ec_validate_public(EC_KEY_get0_group(k->ecdsa),
2865 		    EC_KEY_get0_public_key(k->ecdsa))) != 0 ||
2866 		    (r = sshkey_ec_validate_private(k->ecdsa)) != 0)
2867 			goto out;
2868 		break;
2869 	case KEY_RSA:
2870 		if ((k = sshkey_new_private(type)) == NULL) {
2871 			r = SSH_ERR_ALLOC_FAIL;
2872 			goto out;
2873 		}
2874 		if ((r = sshbuf_get_bignum2(buf, k->rsa->n)) != 0 ||
2875 		    (r = sshbuf_get_bignum2(buf, k->rsa->e)) != 0 ||
2876 		    (r = sshbuf_get_bignum2(buf, k->rsa->d)) != 0 ||
2877 		    (r = sshbuf_get_bignum2(buf, k->rsa->iqmp)) != 0 ||
2878 		    (r = sshbuf_get_bignum2(buf, k->rsa->p)) != 0 ||
2879 		    (r = sshbuf_get_bignum2(buf, k->rsa->q)) != 0 ||
2880 		    (r = ssh_rsa_generate_additional_parameters(k)) != 0)
2881 			goto out;
2882 		if (BN_num_bits(k->rsa->n) < SSH_RSA_MINIMUM_MODULUS_SIZE) {
2883 			r = SSH_ERR_KEY_LENGTH;
2884 			goto out;
2885 		}
2886 		break;
2887 	case KEY_RSA_CERT:
2888 		if ((r = sshkey_froms(buf, &k)) != 0 ||
2889 		    (r = sshkey_add_private(k)) != 0 ||
2890 		    (r = sshbuf_get_bignum2(buf, k->rsa->d)) != 0 ||
2891 		    (r = sshbuf_get_bignum2(buf, k->rsa->iqmp)) != 0 ||
2892 		    (r = sshbuf_get_bignum2(buf, k->rsa->p)) != 0 ||
2893 		    (r = sshbuf_get_bignum2(buf, k->rsa->q)) != 0 ||
2894 		    (r = ssh_rsa_generate_additional_parameters(k)) != 0)
2895 			goto out;
2896 		if (BN_num_bits(k->rsa->n) < SSH_RSA_MINIMUM_MODULUS_SIZE) {
2897 			r = SSH_ERR_KEY_LENGTH;
2898 			goto out;
2899 		}
2900 		break;
2901 #endif /* WITH_OPENSSL */
2902 	case KEY_ED25519:
2903 		if ((k = sshkey_new_private(type)) == NULL) {
2904 			r = SSH_ERR_ALLOC_FAIL;
2905 			goto out;
2906 		}
2907 		if ((r = sshbuf_get_string(buf, &ed25519_pk, &pklen)) != 0 ||
2908 		    (r = sshbuf_get_string(buf, &ed25519_sk, &sklen)) != 0)
2909 			goto out;
2910 		if (pklen != ED25519_PK_SZ || sklen != ED25519_SK_SZ) {
2911 			r = SSH_ERR_INVALID_FORMAT;
2912 			goto out;
2913 		}
2914 		k->ed25519_pk = ed25519_pk;
2915 		k->ed25519_sk = ed25519_sk;
2916 		ed25519_pk = ed25519_sk = NULL;
2917 		break;
2918 	case KEY_ED25519_CERT:
2919 		if ((r = sshkey_froms(buf, &k)) != 0 ||
2920 		    (r = sshkey_add_private(k)) != 0 ||
2921 		    (r = sshbuf_get_string(buf, &ed25519_pk, &pklen)) != 0 ||
2922 		    (r = sshbuf_get_string(buf, &ed25519_sk, &sklen)) != 0)
2923 			goto out;
2924 		if (pklen != ED25519_PK_SZ || sklen != ED25519_SK_SZ) {
2925 			r = SSH_ERR_INVALID_FORMAT;
2926 			goto out;
2927 		}
2928 		k->ed25519_pk = ed25519_pk;
2929 		k->ed25519_sk = ed25519_sk;
2930 		ed25519_pk = ed25519_sk = NULL;
2931 		break;
2932 #ifdef WITH_XMSS
2933 	case KEY_XMSS:
2934 		if ((k = sshkey_new_private(type)) == NULL) {
2935 			r = SSH_ERR_ALLOC_FAIL;
2936 			goto out;
2937 		}
2938 		if ((r = sshbuf_get_cstring(buf, &xmss_name, NULL)) != 0 ||
2939 		    (r = sshkey_xmss_init(k, xmss_name)) != 0 ||
2940 		    (r = sshbuf_get_string(buf, &xmss_pk, &pklen)) != 0 ||
2941 		    (r = sshbuf_get_string(buf, &xmss_sk, &sklen)) != 0)
2942 			goto out;
2943 		if (pklen != sshkey_xmss_pklen(k) ||
2944 		    sklen != sshkey_xmss_sklen(k)) {
2945 			r = SSH_ERR_INVALID_FORMAT;
2946 			goto out;
2947 		}
2948 		k->xmss_pk = xmss_pk;
2949 		k->xmss_sk = xmss_sk;
2950 		xmss_pk = xmss_sk = NULL;
2951 		/* optional internal state */
2952 		if ((r = sshkey_xmss_deserialize_state_opt(k, buf)) != 0)
2953 			goto out;
2954 		break;
2955 	case KEY_XMSS_CERT:
2956 		if ((r = sshkey_froms(buf, &k)) != 0 ||
2957 		    (r = sshkey_add_private(k)) != 0 ||
2958 		    (r = sshbuf_get_string(buf, &xmss_pk, &pklen)) != 0 ||
2959 		    (r = sshbuf_get_string(buf, &xmss_sk, &sklen)) != 0)
2960 			goto out;
2961 		if (pklen != sshkey_xmss_pklen(k) ||
2962 		    sklen != sshkey_xmss_sklen(k)) {
2963 			r = SSH_ERR_INVALID_FORMAT;
2964 			goto out;
2965 		}
2966 		k->xmss_pk = xmss_pk;
2967 		k->xmss_sk = xmss_sk;
2968 		xmss_pk = xmss_sk = NULL;
2969 		/* optional internal state */
2970 		if ((r = sshkey_xmss_deserialize_state_opt(k, buf)) != 0)
2971 			goto out;
2972 		break;
2973 #endif /* WITH_XMSS */
2974 	default:
2975 		r = SSH_ERR_KEY_TYPE_UNKNOWN;
2976 		goto out;
2977 	}
2978 #ifdef WITH_OPENSSL
2979 	/* enable blinding */
2980 	switch (k->type) {
2981 	case KEY_RSA:
2982 	case KEY_RSA_CERT:
2983 		if (RSA_blinding_on(k->rsa, NULL) != 1) {
2984 			r = SSH_ERR_LIBCRYPTO_ERROR;
2985 			goto out;
2986 		}
2987 		break;
2988 	}
2989 #endif /* WITH_OPENSSL */
2990 	/* success */
2991 	r = 0;
2992 	if (kp != NULL) {
2993 		*kp = k;
2994 		k = NULL;
2995 	}
2996  out:
2997 	free(tname);
2998 	free(curve);
2999 #ifdef WITH_OPENSSL
3000 	BN_clear_free(exponent);
3001 #endif /* WITH_OPENSSL */
3002 	sshkey_free(k);
3003 	freezero(ed25519_pk, pklen);
3004 	freezero(ed25519_sk, sklen);
3005 	free(xmss_name);
3006 	freezero(xmss_pk, pklen);
3007 	freezero(xmss_sk, sklen);
3008 	return r;
3009 }
3010 
3011 #ifdef WITH_OPENSSL
3012 int
3013 sshkey_ec_validate_public(const EC_GROUP *group, const EC_POINT *public)
3014 {
3015 	BN_CTX *bnctx;
3016 	EC_POINT *nq = NULL;
3017 	BIGNUM *order, *x, *y, *tmp;
3018 	int ret = SSH_ERR_KEY_INVALID_EC_VALUE;
3019 
3020 	/*
3021 	 * NB. This assumes OpenSSL has already verified that the public
3022 	 * point lies on the curve. This is done by EC_POINT_oct2point()
3023 	 * implicitly calling EC_POINT_is_on_curve(). If this code is ever
3024 	 * reachable with public points not unmarshalled using
3025 	 * EC_POINT_oct2point then the caller will need to explicitly check.
3026 	 */
3027 
3028 	if ((bnctx = BN_CTX_new()) == NULL)
3029 		return SSH_ERR_ALLOC_FAIL;
3030 	BN_CTX_start(bnctx);
3031 
3032 	/*
3033 	 * We shouldn't ever hit this case because bignum_get_ecpoint()
3034 	 * refuses to load GF2m points.
3035 	 */
3036 	if (EC_METHOD_get_field_type(EC_GROUP_method_of(group)) !=
3037 	    NID_X9_62_prime_field)
3038 		goto out;
3039 
3040 	/* Q != infinity */
3041 	if (EC_POINT_is_at_infinity(group, public))
3042 		goto out;
3043 
3044 	if ((x = BN_CTX_get(bnctx)) == NULL ||
3045 	    (y = BN_CTX_get(bnctx)) == NULL ||
3046 	    (order = BN_CTX_get(bnctx)) == NULL ||
3047 	    (tmp = BN_CTX_get(bnctx)) == NULL) {
3048 		ret = SSH_ERR_ALLOC_FAIL;
3049 		goto out;
3050 	}
3051 
3052 	/* log2(x) > log2(order)/2, log2(y) > log2(order)/2 */
3053 	if (EC_GROUP_get_order(group, order, bnctx) != 1 ||
3054 	    EC_POINT_get_affine_coordinates_GFp(group, public,
3055 	    x, y, bnctx) != 1) {
3056 		ret = SSH_ERR_LIBCRYPTO_ERROR;
3057 		goto out;
3058 	}
3059 	if (BN_num_bits(x) <= BN_num_bits(order) / 2 ||
3060 	    BN_num_bits(y) <= BN_num_bits(order) / 2)
3061 		goto out;
3062 
3063 	/* nQ == infinity (n == order of subgroup) */
3064 	if ((nq = EC_POINT_new(group)) == NULL) {
3065 		ret = SSH_ERR_ALLOC_FAIL;
3066 		goto out;
3067 	}
3068 	if (EC_POINT_mul(group, nq, NULL, public, order, bnctx) != 1) {
3069 		ret = SSH_ERR_LIBCRYPTO_ERROR;
3070 		goto out;
3071 	}
3072 	if (EC_POINT_is_at_infinity(group, nq) != 1)
3073 		goto out;
3074 
3075 	/* x < order - 1, y < order - 1 */
3076 	if (!BN_sub(tmp, order, BN_value_one())) {
3077 		ret = SSH_ERR_LIBCRYPTO_ERROR;
3078 		goto out;
3079 	}
3080 	if (BN_cmp(x, tmp) >= 0 || BN_cmp(y, tmp) >= 0)
3081 		goto out;
3082 	ret = 0;
3083  out:
3084 	BN_CTX_free(bnctx);
3085 	EC_POINT_free(nq);
3086 	return ret;
3087 }
3088 
3089 int
3090 sshkey_ec_validate_private(const EC_KEY *key)
3091 {
3092 	BN_CTX *bnctx;
3093 	BIGNUM *order, *tmp;
3094 	int ret = SSH_ERR_KEY_INVALID_EC_VALUE;
3095 
3096 	if ((bnctx = BN_CTX_new()) == NULL)
3097 		return SSH_ERR_ALLOC_FAIL;
3098 	BN_CTX_start(bnctx);
3099 
3100 	if ((order = BN_CTX_get(bnctx)) == NULL ||
3101 	    (tmp = BN_CTX_get(bnctx)) == NULL) {
3102 		ret = SSH_ERR_ALLOC_FAIL;
3103 		goto out;
3104 	}
3105 
3106 	/* log2(private) > log2(order)/2 */
3107 	if (EC_GROUP_get_order(EC_KEY_get0_group(key), order, bnctx) != 1) {
3108 		ret = SSH_ERR_LIBCRYPTO_ERROR;
3109 		goto out;
3110 	}
3111 	if (BN_num_bits(EC_KEY_get0_private_key(key)) <=
3112 	    BN_num_bits(order) / 2)
3113 		goto out;
3114 
3115 	/* private < order - 1 */
3116 	if (!BN_sub(tmp, order, BN_value_one())) {
3117 		ret = SSH_ERR_LIBCRYPTO_ERROR;
3118 		goto out;
3119 	}
3120 	if (BN_cmp(EC_KEY_get0_private_key(key), tmp) >= 0)
3121 		goto out;
3122 	ret = 0;
3123  out:
3124 	BN_CTX_free(bnctx);
3125 	return ret;
3126 }
3127 
3128 void
3129 sshkey_dump_ec_point(const EC_GROUP *group, const EC_POINT *point)
3130 {
3131 	BIGNUM *x, *y;
3132 	BN_CTX *bnctx;
3133 
3134 	if (point == NULL) {
3135 		fputs("point=(NULL)\n", stderr);
3136 		return;
3137 	}
3138 	if ((bnctx = BN_CTX_new()) == NULL) {
3139 		fprintf(stderr, "%s: BN_CTX_new failed\n", __func__);
3140 		return;
3141 	}
3142 	BN_CTX_start(bnctx);
3143 	if ((x = BN_CTX_get(bnctx)) == NULL ||
3144 	    (y = BN_CTX_get(bnctx)) == NULL) {
3145 		fprintf(stderr, "%s: BN_CTX_get failed\n", __func__);
3146 		return;
3147 	}
3148 	if (EC_METHOD_get_field_type(EC_GROUP_method_of(group)) !=
3149 	    NID_X9_62_prime_field) {
3150 		fprintf(stderr, "%s: group is not a prime field\n", __func__);
3151 		return;
3152 	}
3153 	if (EC_POINT_get_affine_coordinates_GFp(group, point, x, y,
3154 	    bnctx) != 1) {
3155 		fprintf(stderr, "%s: EC_POINT_get_affine_coordinates_GFp\n",
3156 		    __func__);
3157 		return;
3158 	}
3159 	fputs("x=", stderr);
3160 	BN_print_fp(stderr, x);
3161 	fputs("\ny=", stderr);
3162 	BN_print_fp(stderr, y);
3163 	fputs("\n", stderr);
3164 	BN_CTX_free(bnctx);
3165 }
3166 
3167 void
3168 sshkey_dump_ec_key(const EC_KEY *key)
3169 {
3170 	const BIGNUM *exponent;
3171 
3172 	sshkey_dump_ec_point(EC_KEY_get0_group(key),
3173 	    EC_KEY_get0_public_key(key));
3174 	fputs("exponent=", stderr);
3175 	if ((exponent = EC_KEY_get0_private_key(key)) == NULL)
3176 		fputs("(NULL)", stderr);
3177 	else
3178 		BN_print_fp(stderr, EC_KEY_get0_private_key(key));
3179 	fputs("\n", stderr);
3180 }
3181 #endif /* WITH_OPENSSL */
3182 
3183 static int
3184 sshkey_private_to_blob2(const struct sshkey *prv, struct sshbuf *blob,
3185     const char *passphrase, const char *comment, const char *ciphername,
3186     int rounds)
3187 {
3188 	u_char *cp, *key = NULL, *pubkeyblob = NULL;
3189 	u_char salt[SALT_LEN];
3190 	char *b64 = NULL;
3191 	size_t i, pubkeylen, keylen, ivlen, blocksize, authlen;
3192 	u_int check;
3193 	int r = SSH_ERR_INTERNAL_ERROR;
3194 	struct sshcipher_ctx *ciphercontext = NULL;
3195 	const struct sshcipher *cipher;
3196 	const char *kdfname = KDFNAME;
3197 	struct sshbuf *encoded = NULL, *encrypted = NULL, *kdf = NULL;
3198 
3199 	if (rounds <= 0)
3200 		rounds = DEFAULT_ROUNDS;
3201 	if (passphrase == NULL || !strlen(passphrase)) {
3202 		ciphername = "none";
3203 		kdfname = "none";
3204 	} else if (ciphername == NULL)
3205 		ciphername = DEFAULT_CIPHERNAME;
3206 	if ((cipher = cipher_by_name(ciphername)) == NULL) {
3207 		r = SSH_ERR_INVALID_ARGUMENT;
3208 		goto out;
3209 	}
3210 
3211 	if ((kdf = sshbuf_new()) == NULL ||
3212 	    (encoded = sshbuf_new()) == NULL ||
3213 	    (encrypted = sshbuf_new()) == NULL) {
3214 		r = SSH_ERR_ALLOC_FAIL;
3215 		goto out;
3216 	}
3217 	blocksize = cipher_blocksize(cipher);
3218 	keylen = cipher_keylen(cipher);
3219 	ivlen = cipher_ivlen(cipher);
3220 	authlen = cipher_authlen(cipher);
3221 	if ((key = calloc(1, keylen + ivlen)) == NULL) {
3222 		r = SSH_ERR_ALLOC_FAIL;
3223 		goto out;
3224 	}
3225 	if (strcmp(kdfname, "bcrypt") == 0) {
3226 		arc4random_buf(salt, SALT_LEN);
3227 		if (bcrypt_pbkdf(passphrase, strlen(passphrase),
3228 		    salt, SALT_LEN, key, keylen + ivlen, rounds) < 0) {
3229 			r = SSH_ERR_INVALID_ARGUMENT;
3230 			goto out;
3231 		}
3232 		if ((r = sshbuf_put_string(kdf, salt, SALT_LEN)) != 0 ||
3233 		    (r = sshbuf_put_u32(kdf, rounds)) != 0)
3234 			goto out;
3235 	} else if (strcmp(kdfname, "none") != 0) {
3236 		/* Unsupported KDF type */
3237 		r = SSH_ERR_KEY_UNKNOWN_CIPHER;
3238 		goto out;
3239 	}
3240 	if ((r = cipher_init(&ciphercontext, cipher, key, keylen,
3241 	    key + keylen, ivlen, 1)) != 0)
3242 		goto out;
3243 
3244 	if ((r = sshbuf_put(encoded, AUTH_MAGIC, sizeof(AUTH_MAGIC))) != 0 ||
3245 	    (r = sshbuf_put_cstring(encoded, ciphername)) != 0 ||
3246 	    (r = sshbuf_put_cstring(encoded, kdfname)) != 0 ||
3247 	    (r = sshbuf_put_stringb(encoded, kdf)) != 0 ||
3248 	    (r = sshbuf_put_u32(encoded, 1)) != 0 ||	/* number of keys */
3249 	    (r = sshkey_to_blob(prv, &pubkeyblob, &pubkeylen)) != 0 ||
3250 	    (r = sshbuf_put_string(encoded, pubkeyblob, pubkeylen)) != 0)
3251 		goto out;
3252 
3253 	/* set up the buffer that will be encrypted */
3254 
3255 	/* Random check bytes */
3256 	check = arc4random();
3257 	if ((r = sshbuf_put_u32(encrypted, check)) != 0 ||
3258 	    (r = sshbuf_put_u32(encrypted, check)) != 0)
3259 		goto out;
3260 
3261 	/* append private key and comment*/
3262 	if ((r = sshkey_private_serialize_opt(prv, encrypted,
3263 	     SSHKEY_SERIALIZE_FULL)) != 0 ||
3264 	    (r = sshbuf_put_cstring(encrypted, comment)) != 0)
3265 		goto out;
3266 
3267 	/* padding */
3268 	i = 0;
3269 	while (sshbuf_len(encrypted) % blocksize) {
3270 		if ((r = sshbuf_put_u8(encrypted, ++i & 0xff)) != 0)
3271 			goto out;
3272 	}
3273 
3274 	/* length in destination buffer */
3275 	if ((r = sshbuf_put_u32(encoded, sshbuf_len(encrypted))) != 0)
3276 		goto out;
3277 
3278 	/* encrypt */
3279 	if ((r = sshbuf_reserve(encoded,
3280 	    sshbuf_len(encrypted) + authlen, &cp)) != 0)
3281 		goto out;
3282 	if ((r = cipher_crypt(ciphercontext, 0, cp,
3283 	    sshbuf_ptr(encrypted), sshbuf_len(encrypted), 0, authlen)) != 0)
3284 		goto out;
3285 
3286 	/* uuencode */
3287 	if ((b64 = sshbuf_dtob64(encoded)) == NULL) {
3288 		r = SSH_ERR_ALLOC_FAIL;
3289 		goto out;
3290 	}
3291 
3292 	sshbuf_reset(blob);
3293 	if ((r = sshbuf_put(blob, MARK_BEGIN, MARK_BEGIN_LEN)) != 0)
3294 		goto out;
3295 	for (i = 0; i < strlen(b64); i++) {
3296 		if ((r = sshbuf_put_u8(blob, b64[i])) != 0)
3297 			goto out;
3298 		/* insert line breaks */
3299 		if (i % 70 == 69 && (r = sshbuf_put_u8(blob, '\n')) != 0)
3300 			goto out;
3301 	}
3302 	if (i % 70 != 69 && (r = sshbuf_put_u8(blob, '\n')) != 0)
3303 		goto out;
3304 	if ((r = sshbuf_put(blob, MARK_END, MARK_END_LEN)) != 0)
3305 		goto out;
3306 
3307 	/* success */
3308 	r = 0;
3309 
3310  out:
3311 	sshbuf_free(kdf);
3312 	sshbuf_free(encoded);
3313 	sshbuf_free(encrypted);
3314 	cipher_free(ciphercontext);
3315 	explicit_bzero(salt, sizeof(salt));
3316 	if (key != NULL) {
3317 		explicit_bzero(key, keylen + ivlen);
3318 		free(key);
3319 	}
3320 	if (pubkeyblob != NULL) {
3321 		explicit_bzero(pubkeyblob, pubkeylen);
3322 		free(pubkeyblob);
3323 	}
3324 	if (b64 != NULL) {
3325 		explicit_bzero(b64, strlen(b64));
3326 		free(b64);
3327 	}
3328 	return r;
3329 }
3330 
3331 static int
3332 sshkey_parse_private2(struct sshbuf *blob, int type, const char *passphrase,
3333     struct sshkey **keyp, char **commentp)
3334 {
3335 	char *comment = NULL, *ciphername = NULL, *kdfname = NULL;
3336 	const struct sshcipher *cipher = NULL;
3337 	const u_char *cp;
3338 	int r = SSH_ERR_INTERNAL_ERROR;
3339 	size_t encoded_len;
3340 	size_t i, keylen = 0, ivlen = 0, authlen = 0, slen = 0;
3341 	struct sshbuf *encoded = NULL, *decoded = NULL;
3342 	struct sshbuf *kdf = NULL, *decrypted = NULL;
3343 	struct sshcipher_ctx *ciphercontext = NULL;
3344 	struct sshkey *k = NULL;
3345 	u_char *key = NULL, *salt = NULL, *dp, pad, last;
3346 	u_int blocksize, rounds, nkeys, encrypted_len, check1, check2;
3347 
3348 	if (keyp != NULL)
3349 		*keyp = NULL;
3350 	if (commentp != NULL)
3351 		*commentp = NULL;
3352 
3353 	if ((encoded = sshbuf_new()) == NULL ||
3354 	    (decoded = sshbuf_new()) == NULL ||
3355 	    (decrypted = sshbuf_new()) == NULL) {
3356 		r = SSH_ERR_ALLOC_FAIL;
3357 		goto out;
3358 	}
3359 
3360 	/* check preamble */
3361 	cp = sshbuf_ptr(blob);
3362 	encoded_len = sshbuf_len(blob);
3363 	if (encoded_len < (MARK_BEGIN_LEN + MARK_END_LEN) ||
3364 	    memcmp(cp, MARK_BEGIN, MARK_BEGIN_LEN) != 0) {
3365 		r = SSH_ERR_INVALID_FORMAT;
3366 		goto out;
3367 	}
3368 	cp += MARK_BEGIN_LEN;
3369 	encoded_len -= MARK_BEGIN_LEN;
3370 
3371 	/* Look for end marker, removing whitespace as we go */
3372 	while (encoded_len > 0) {
3373 		if (*cp != '\n' && *cp != '\r') {
3374 			if ((r = sshbuf_put_u8(encoded, *cp)) != 0)
3375 				goto out;
3376 		}
3377 		last = *cp;
3378 		encoded_len--;
3379 		cp++;
3380 		if (last == '\n') {
3381 			if (encoded_len >= MARK_END_LEN &&
3382 			    memcmp(cp, MARK_END, MARK_END_LEN) == 0) {
3383 				/* \0 terminate */
3384 				if ((r = sshbuf_put_u8(encoded, 0)) != 0)
3385 					goto out;
3386 				break;
3387 			}
3388 		}
3389 	}
3390 	if (encoded_len == 0) {
3391 		r = SSH_ERR_INVALID_FORMAT;
3392 		goto out;
3393 	}
3394 
3395 	/* decode base64 */
3396 	if ((r = sshbuf_b64tod(decoded, (char *)sshbuf_ptr(encoded))) != 0)
3397 		goto out;
3398 
3399 	/* check magic */
3400 	if (sshbuf_len(decoded) < sizeof(AUTH_MAGIC) ||
3401 	    memcmp(sshbuf_ptr(decoded), AUTH_MAGIC, sizeof(AUTH_MAGIC))) {
3402 		r = SSH_ERR_INVALID_FORMAT;
3403 		goto out;
3404 	}
3405 	/* parse public portion of key */
3406 	if ((r = sshbuf_consume(decoded, sizeof(AUTH_MAGIC))) != 0 ||
3407 	    (r = sshbuf_get_cstring(decoded, &ciphername, NULL)) != 0 ||
3408 	    (r = sshbuf_get_cstring(decoded, &kdfname, NULL)) != 0 ||
3409 	    (r = sshbuf_froms(decoded, &kdf)) != 0 ||
3410 	    (r = sshbuf_get_u32(decoded, &nkeys)) != 0 ||
3411 	    (r = sshbuf_skip_string(decoded)) != 0 || /* pubkey */
3412 	    (r = sshbuf_get_u32(decoded, &encrypted_len)) != 0)
3413 		goto out;
3414 
3415 	if ((cipher = cipher_by_name(ciphername)) == NULL) {
3416 		r = SSH_ERR_KEY_UNKNOWN_CIPHER;
3417 		goto out;
3418 	}
3419 	if ((passphrase == NULL || strlen(passphrase) == 0) &&
3420 	    strcmp(ciphername, "none") != 0) {
3421 		/* passphrase required */
3422 		r = SSH_ERR_KEY_WRONG_PASSPHRASE;
3423 		goto out;
3424 	}
3425 	if (strcmp(kdfname, "none") != 0 && strcmp(kdfname, "bcrypt") != 0) {
3426 		r = SSH_ERR_KEY_UNKNOWN_CIPHER;
3427 		goto out;
3428 	}
3429 	if (!strcmp(kdfname, "none") && strcmp(ciphername, "none") != 0) {
3430 		r = SSH_ERR_INVALID_FORMAT;
3431 		goto out;
3432 	}
3433 	if (nkeys != 1) {
3434 		/* XXX only one key supported */
3435 		r = SSH_ERR_INVALID_FORMAT;
3436 		goto out;
3437 	}
3438 
3439 	/* check size of encrypted key blob */
3440 	blocksize = cipher_blocksize(cipher);
3441 	if (encrypted_len < blocksize || (encrypted_len % blocksize) != 0) {
3442 		r = SSH_ERR_INVALID_FORMAT;
3443 		goto out;
3444 	}
3445 
3446 	/* setup key */
3447 	keylen = cipher_keylen(cipher);
3448 	ivlen = cipher_ivlen(cipher);
3449 	authlen = cipher_authlen(cipher);
3450 	if ((key = calloc(1, keylen + ivlen)) == NULL) {
3451 		r = SSH_ERR_ALLOC_FAIL;
3452 		goto out;
3453 	}
3454 	if (strcmp(kdfname, "bcrypt") == 0) {
3455 		if ((r = sshbuf_get_string(kdf, &salt, &slen)) != 0 ||
3456 		    (r = sshbuf_get_u32(kdf, &rounds)) != 0)
3457 			goto out;
3458 		if (bcrypt_pbkdf(passphrase, strlen(passphrase), salt, slen,
3459 		    key, keylen + ivlen, rounds) < 0) {
3460 			r = SSH_ERR_INVALID_FORMAT;
3461 			goto out;
3462 		}
3463 	}
3464 
3465 	/* check that an appropriate amount of auth data is present */
3466 	if (sshbuf_len(decoded) < encrypted_len + authlen) {
3467 		r = SSH_ERR_INVALID_FORMAT;
3468 		goto out;
3469 	}
3470 
3471 	/* decrypt private portion of key */
3472 	if ((r = sshbuf_reserve(decrypted, encrypted_len, &dp)) != 0 ||
3473 	    (r = cipher_init(&ciphercontext, cipher, key, keylen,
3474 	    key + keylen, ivlen, 0)) != 0)
3475 		goto out;
3476 	if ((r = cipher_crypt(ciphercontext, 0, dp, sshbuf_ptr(decoded),
3477 	    encrypted_len, 0, authlen)) != 0) {
3478 		/* an integrity error here indicates an incorrect passphrase */
3479 		if (r == SSH_ERR_MAC_INVALID)
3480 			r = SSH_ERR_KEY_WRONG_PASSPHRASE;
3481 		goto out;
3482 	}
3483 	if ((r = sshbuf_consume(decoded, encrypted_len + authlen)) != 0)
3484 		goto out;
3485 	/* there should be no trailing data */
3486 	if (sshbuf_len(decoded) != 0) {
3487 		r = SSH_ERR_INVALID_FORMAT;
3488 		goto out;
3489 	}
3490 
3491 	/* check check bytes */
3492 	if ((r = sshbuf_get_u32(decrypted, &check1)) != 0 ||
3493 	    (r = sshbuf_get_u32(decrypted, &check2)) != 0)
3494 		goto out;
3495 	if (check1 != check2) {
3496 		r = SSH_ERR_KEY_WRONG_PASSPHRASE;
3497 		goto out;
3498 	}
3499 
3500 	/* Load the private key and comment */
3501 	if ((r = sshkey_private_deserialize(decrypted, &k)) != 0 ||
3502 	    (r = sshbuf_get_cstring(decrypted, &comment, NULL)) != 0)
3503 		goto out;
3504 
3505 	/* Check deterministic padding */
3506 	i = 0;
3507 	while (sshbuf_len(decrypted)) {
3508 		if ((r = sshbuf_get_u8(decrypted, &pad)) != 0)
3509 			goto out;
3510 		if (pad != (++i & 0xff)) {
3511 			r = SSH_ERR_INVALID_FORMAT;
3512 			goto out;
3513 		}
3514 	}
3515 
3516 	/* XXX decode pubkey and check against private */
3517 
3518 	/* success */
3519 	r = 0;
3520 	if (keyp != NULL) {
3521 		*keyp = k;
3522 		k = NULL;
3523 	}
3524 	if (commentp != NULL) {
3525 		*commentp = comment;
3526 		comment = NULL;
3527 	}
3528  out:
3529 	pad = 0;
3530 	cipher_free(ciphercontext);
3531 	free(ciphername);
3532 	free(kdfname);
3533 	free(comment);
3534 	if (salt != NULL) {
3535 		explicit_bzero(salt, slen);
3536 		free(salt);
3537 	}
3538 	if (key != NULL) {
3539 		explicit_bzero(key, keylen + ivlen);
3540 		free(key);
3541 	}
3542 	sshbuf_free(encoded);
3543 	sshbuf_free(decoded);
3544 	sshbuf_free(kdf);
3545 	sshbuf_free(decrypted);
3546 	sshkey_free(k);
3547 	return r;
3548 }
3549 
3550 
3551 #ifdef WITH_OPENSSL
3552 /* convert SSH v2 key in OpenSSL PEM format */
3553 static int
3554 sshkey_private_pem_to_blob(struct sshkey *key, struct sshbuf *blob,
3555     const char *_passphrase, const char *comment)
3556 {
3557 	int success, r;
3558 	int blen, len = strlen(_passphrase);
3559 	u_char *passphrase = (len > 0) ? (u_char *)_passphrase : NULL;
3560 	const EVP_CIPHER *cipher = (len > 0) ? EVP_aes_128_cbc() : NULL;
3561 	char *bptr;
3562 	BIO *bio = NULL;
3563 
3564 	if (len > 0 && len <= 4)
3565 		return SSH_ERR_PASSPHRASE_TOO_SHORT;
3566 	if ((bio = BIO_new(BIO_s_mem())) == NULL)
3567 		return SSH_ERR_ALLOC_FAIL;
3568 
3569 	switch (key->type) {
3570 	case KEY_DSA:
3571 		success = PEM_write_bio_DSAPrivateKey(bio, key->dsa,
3572 		    cipher, passphrase, len, NULL, NULL);
3573 		break;
3574 	case KEY_ECDSA:
3575 		success = PEM_write_bio_ECPrivateKey(bio, key->ecdsa,
3576 		    cipher, passphrase, len, NULL, NULL);
3577 		break;
3578 	case KEY_RSA:
3579 		success = PEM_write_bio_RSAPrivateKey(bio, key->rsa,
3580 		    cipher, passphrase, len, NULL, NULL);
3581 		break;
3582 	default:
3583 		success = 0;
3584 		break;
3585 	}
3586 	if (success == 0) {
3587 		r = SSH_ERR_LIBCRYPTO_ERROR;
3588 		goto out;
3589 	}
3590 	if ((blen = BIO_get_mem_data(bio, &bptr)) <= 0) {
3591 		r = SSH_ERR_INTERNAL_ERROR;
3592 		goto out;
3593 	}
3594 	if ((r = sshbuf_put(blob, bptr, blen)) != 0)
3595 		goto out;
3596 	r = 0;
3597  out:
3598 	BIO_free(bio);
3599 	return r;
3600 }
3601 #endif /* WITH_OPENSSL */
3602 
3603 /* Serialise "key" to buffer "blob" */
3604 int
3605 sshkey_private_to_fileblob(struct sshkey *key, struct sshbuf *blob,
3606     const char *passphrase, const char *comment,
3607     int force_new_format, const char *new_format_cipher, int new_format_rounds)
3608 {
3609 	switch (key->type) {
3610 #ifdef WITH_OPENSSL
3611 	case KEY_DSA:
3612 	case KEY_ECDSA:
3613 	case KEY_RSA:
3614 		if (force_new_format) {
3615 			return sshkey_private_to_blob2(key, blob, passphrase,
3616 			    comment, new_format_cipher, new_format_rounds);
3617 		}
3618 		return sshkey_private_pem_to_blob(key, blob,
3619 		    passphrase, comment);
3620 #endif /* WITH_OPENSSL */
3621 	case KEY_ED25519:
3622 #ifdef WITH_XMSS
3623 	case KEY_XMSS:
3624 #endif /* WITH_XMSS */
3625 		return sshkey_private_to_blob2(key, blob, passphrase,
3626 		    comment, new_format_cipher, new_format_rounds);
3627 	default:
3628 		return SSH_ERR_KEY_TYPE_UNKNOWN;
3629 	}
3630 }
3631 
3632 
3633 #ifdef WITH_OPENSSL
3634 static int
3635 translate_libcrypto_error(unsigned long pem_err)
3636 {
3637 	int pem_reason = ERR_GET_REASON(pem_err);
3638 
3639 	switch (ERR_GET_LIB(pem_err)) {
3640 	case ERR_LIB_PEM:
3641 		switch (pem_reason) {
3642 		case PEM_R_BAD_PASSWORD_READ:
3643 		case PEM_R_PROBLEMS_GETTING_PASSWORD:
3644 		case PEM_R_BAD_DECRYPT:
3645 			return SSH_ERR_KEY_WRONG_PASSPHRASE;
3646 		default:
3647 			return SSH_ERR_INVALID_FORMAT;
3648 		}
3649 	case ERR_LIB_EVP:
3650 		switch (pem_reason) {
3651 		case EVP_R_BAD_DECRYPT:
3652 			return SSH_ERR_KEY_WRONG_PASSPHRASE;
3653 		case EVP_R_BN_DECODE_ERROR:
3654 		case EVP_R_DECODE_ERROR:
3655 #ifdef EVP_R_PRIVATE_KEY_DECODE_ERROR
3656 		case EVP_R_PRIVATE_KEY_DECODE_ERROR:
3657 #endif
3658 			return SSH_ERR_INVALID_FORMAT;
3659 		default:
3660 			return SSH_ERR_LIBCRYPTO_ERROR;
3661 		}
3662 	case ERR_LIB_ASN1:
3663 		return SSH_ERR_INVALID_FORMAT;
3664 	}
3665 	return SSH_ERR_LIBCRYPTO_ERROR;
3666 }
3667 
3668 static void
3669 clear_libcrypto_errors(void)
3670 {
3671 	while (ERR_get_error() != 0)
3672 		;
3673 }
3674 
3675 /*
3676  * Translate OpenSSL error codes to determine whether
3677  * passphrase is required/incorrect.
3678  */
3679 static int
3680 convert_libcrypto_error(void)
3681 {
3682 	/*
3683 	 * Some password errors are reported at the beginning
3684 	 * of the error queue.
3685 	 */
3686 	if (translate_libcrypto_error(ERR_peek_error()) ==
3687 	    SSH_ERR_KEY_WRONG_PASSPHRASE)
3688 		return SSH_ERR_KEY_WRONG_PASSPHRASE;
3689 	return translate_libcrypto_error(ERR_peek_last_error());
3690 }
3691 
3692 static int
3693 sshkey_parse_private_pem_fileblob(struct sshbuf *blob, int type,
3694     const char *passphrase, struct sshkey **keyp)
3695 {
3696 	EVP_PKEY *pk = NULL;
3697 	struct sshkey *prv = NULL;
3698 	BIO *bio = NULL;
3699 	int r;
3700 
3701 	if (keyp != NULL)
3702 		*keyp = NULL;
3703 
3704 	if ((bio = BIO_new(BIO_s_mem())) == NULL || sshbuf_len(blob) > INT_MAX)
3705 		return SSH_ERR_ALLOC_FAIL;
3706 	if (BIO_write(bio, sshbuf_ptr(blob), sshbuf_len(blob)) !=
3707 	    (int)sshbuf_len(blob)) {
3708 		r = SSH_ERR_ALLOC_FAIL;
3709 		goto out;
3710 	}
3711 
3712 	clear_libcrypto_errors();
3713 	if ((pk = PEM_read_bio_PrivateKey(bio, NULL, NULL,
3714 	    (char *)passphrase)) == NULL) {
3715 		r = convert_libcrypto_error();
3716 		goto out;
3717 	}
3718 	if (pk->type == EVP_PKEY_RSA &&
3719 	    (type == KEY_UNSPEC || type == KEY_RSA)) {
3720 		if ((prv = sshkey_new(KEY_UNSPEC)) == NULL) {
3721 			r = SSH_ERR_ALLOC_FAIL;
3722 			goto out;
3723 		}
3724 		prv->rsa = EVP_PKEY_get1_RSA(pk);
3725 		prv->type = KEY_RSA;
3726 #ifdef DEBUG_PK
3727 		RSA_print_fp(stderr, prv->rsa, 8);
3728 #endif
3729 		if (RSA_blinding_on(prv->rsa, NULL) != 1) {
3730 			r = SSH_ERR_LIBCRYPTO_ERROR;
3731 			goto out;
3732 		}
3733 		if (BN_num_bits(prv->rsa->n) < SSH_RSA_MINIMUM_MODULUS_SIZE) {
3734 			r = SSH_ERR_KEY_LENGTH;
3735 			goto out;
3736 		}
3737 	} else if (pk->type == EVP_PKEY_DSA &&
3738 	    (type == KEY_UNSPEC || type == KEY_DSA)) {
3739 		if ((prv = sshkey_new(KEY_UNSPEC)) == NULL) {
3740 			r = SSH_ERR_ALLOC_FAIL;
3741 			goto out;
3742 		}
3743 		prv->dsa = EVP_PKEY_get1_DSA(pk);
3744 		prv->type = KEY_DSA;
3745 #ifdef DEBUG_PK
3746 		DSA_print_fp(stderr, prv->dsa, 8);
3747 #endif
3748 	} else if (pk->type == EVP_PKEY_EC &&
3749 	    (type == KEY_UNSPEC || type == KEY_ECDSA)) {
3750 		if ((prv = sshkey_new(KEY_UNSPEC)) == NULL) {
3751 			r = SSH_ERR_ALLOC_FAIL;
3752 			goto out;
3753 		}
3754 		prv->ecdsa = EVP_PKEY_get1_EC_KEY(pk);
3755 		prv->type = KEY_ECDSA;
3756 		prv->ecdsa_nid = sshkey_ecdsa_key_to_nid(prv->ecdsa);
3757 		if (prv->ecdsa_nid == -1 ||
3758 		    sshkey_curve_nid_to_name(prv->ecdsa_nid) == NULL ||
3759 		    sshkey_ec_validate_public(EC_KEY_get0_group(prv->ecdsa),
3760 		    EC_KEY_get0_public_key(prv->ecdsa)) != 0 ||
3761 		    sshkey_ec_validate_private(prv->ecdsa) != 0) {
3762 			r = SSH_ERR_INVALID_FORMAT;
3763 			goto out;
3764 		}
3765 #ifdef DEBUG_PK
3766 		if (prv != NULL && prv->ecdsa != NULL)
3767 			sshkey_dump_ec_key(prv->ecdsa);
3768 #endif
3769 	} else {
3770 		r = SSH_ERR_INVALID_FORMAT;
3771 		goto out;
3772 	}
3773 	r = 0;
3774 	if (keyp != NULL) {
3775 		*keyp = prv;
3776 		prv = NULL;
3777 	}
3778  out:
3779 	BIO_free(bio);
3780 	EVP_PKEY_free(pk);
3781 	sshkey_free(prv);
3782 	return r;
3783 }
3784 #endif /* WITH_OPENSSL */
3785 
3786 int
3787 sshkey_parse_private_fileblob_type(struct sshbuf *blob, int type,
3788     const char *passphrase, struct sshkey **keyp, char **commentp)
3789 {
3790 	int r = SSH_ERR_INTERNAL_ERROR;
3791 
3792 	if (keyp != NULL)
3793 		*keyp = NULL;
3794 	if (commentp != NULL)
3795 		*commentp = NULL;
3796 
3797 	switch (type) {
3798 #ifdef WITH_OPENSSL
3799 	case KEY_DSA:
3800 	case KEY_ECDSA:
3801 	case KEY_RSA:
3802 		return sshkey_parse_private_pem_fileblob(blob, type,
3803 		    passphrase, keyp);
3804 #endif /* WITH_OPENSSL */
3805 	case KEY_ED25519:
3806 #ifdef WITH_XMSS
3807 	case KEY_XMSS:
3808 #endif /* WITH_XMSS */
3809 		return sshkey_parse_private2(blob, type, passphrase,
3810 		    keyp, commentp);
3811 	case KEY_UNSPEC:
3812 		r = sshkey_parse_private2(blob, type, passphrase, keyp,
3813 		    commentp);
3814 		/* Do not fallback to PEM parser if only passphrase is wrong. */
3815 		if (r == 0 || r == SSH_ERR_KEY_WRONG_PASSPHRASE)
3816 			return r;
3817 #ifdef WITH_OPENSSL
3818 		return sshkey_parse_private_pem_fileblob(blob, type,
3819 		    passphrase, keyp);
3820 #else
3821 		return SSH_ERR_INVALID_FORMAT;
3822 #endif /* WITH_OPENSSL */
3823 	default:
3824 		return SSH_ERR_KEY_TYPE_UNKNOWN;
3825 	}
3826 }
3827 
3828 int
3829 sshkey_parse_private_fileblob(struct sshbuf *buffer, const char *passphrase,
3830     struct sshkey **keyp, char **commentp)
3831 {
3832 	if (keyp != NULL)
3833 		*keyp = NULL;
3834 	if (commentp != NULL)
3835 		*commentp = NULL;
3836 
3837 	return sshkey_parse_private_fileblob_type(buffer, KEY_UNSPEC,
3838 	    passphrase, keyp, commentp);
3839 }
3840 
3841 #ifdef WITH_XMSS
3842 /*
3843  * serialize the key with the current state and forward the state
3844  * maxsign times.
3845  */
3846 int
3847 sshkey_private_serialize_maxsign(const struct sshkey *k, struct sshbuf *b,
3848     u_int32_t maxsign, sshkey_printfn *pr)
3849 {
3850 	int r, rupdate;
3851 
3852 	if (maxsign == 0 ||
3853 	    sshkey_type_plain(k->type) != KEY_XMSS)
3854 		return sshkey_private_serialize_opt(k, b,
3855 		    SSHKEY_SERIALIZE_DEFAULT);
3856 	if ((r = sshkey_xmss_get_state(k, pr)) != 0 ||
3857 	    (r = sshkey_private_serialize_opt(k, b,
3858 	    SSHKEY_SERIALIZE_STATE)) != 0 ||
3859 	    (r = sshkey_xmss_forward_state(k, maxsign)) != 0)
3860 		goto out;
3861 	r = 0;
3862 out:
3863 	if ((rupdate = sshkey_xmss_update_state(k, pr)) != 0) {
3864 		if (r == 0)
3865 			r = rupdate;
3866 	}
3867 	return r;
3868 }
3869 
3870 u_int32_t
3871 sshkey_signatures_left(const struct sshkey *k)
3872 {
3873 	if (sshkey_type_plain(k->type) == KEY_XMSS)
3874 		return sshkey_xmss_signatures_left(k);
3875 	return 0;
3876 }
3877 
3878 int
3879 sshkey_enable_maxsign(struct sshkey *k, u_int32_t maxsign)
3880 {
3881 	if (sshkey_type_plain(k->type) != KEY_XMSS)
3882 		return SSH_ERR_INVALID_ARGUMENT;
3883 	return sshkey_xmss_enable_maxsign(k, maxsign);
3884 }
3885 
3886 int
3887 sshkey_set_filename(struct sshkey *k, const char *filename)
3888 {
3889 	if (k == NULL)
3890 		return SSH_ERR_INVALID_ARGUMENT;
3891 	if (sshkey_type_plain(k->type) != KEY_XMSS)
3892 		return 0;
3893 	if (filename == NULL)
3894 		return SSH_ERR_INVALID_ARGUMENT;
3895 	if ((k->xmss_filename = strdup(filename)) == NULL)
3896 		return SSH_ERR_ALLOC_FAIL;
3897 	return 0;
3898 }
3899 #else
3900 int
3901 sshkey_private_serialize_maxsign(const struct sshkey *k, struct sshbuf *b,
3902     u_int32_t maxsign, sshkey_printfn *pr)
3903 {
3904 	return sshkey_private_serialize_opt(k, b, SSHKEY_SERIALIZE_DEFAULT);
3905 }
3906 
3907 u_int32_t
3908 sshkey_signatures_left(const struct sshkey *k)
3909 {
3910 	return 0;
3911 }
3912 
3913 int
3914 sshkey_enable_maxsign(struct sshkey *k, u_int32_t maxsign)
3915 {
3916 	return SSH_ERR_INVALID_ARGUMENT;
3917 }
3918 
3919 int
3920 sshkey_set_filename(struct sshkey *k, const char *filename)
3921 {
3922 	if (k == NULL)
3923 		return SSH_ERR_INVALID_ARGUMENT;
3924 	return 0;
3925 }
3926 #endif /* WITH_XMSS */
3927