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dsynth - Make dummy /usr/packages directory for pkg compatibility
[dragonfly.git] / crypto / openssh / sshkey.c
blobd4356e72cd61dca1c663cc02bcb458657844088d
1 /* $OpenBSD: sshkey.c,v 1.142 2024/01/11 01:45:36 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 "includes.h"
29
30 #include <sys/types.h>
31 #include <netinet/in.h>
32
33 #ifdef WITH_OPENSSL
34 #include <openssl/evp.h>
35 #include <openssl/err.h>
36 #include <openssl/pem.h>
37 #endif
38
39 #include "crypto_api.h"
40
41 #include <errno.h>
42 #include <limits.h>
43 #include <stdio.h>
44 #include <stdlib.h>
45 #include <string.h>
46 #include <resolv.h>
47 #include <time.h>
48 #ifdef HAVE_UTIL_H
49 #include <util.h>
50 #endif /* HAVE_UTIL_H */
51
52 #include "ssh2.h"
53 #include "ssherr.h"
54 #include "misc.h"
55 #include "sshbuf.h"
56 #include "cipher.h"
57 #include "digest.h"
58 #define SSHKEY_INTERNAL
59 #include "sshkey.h"
60 #include "match.h"
61 #include "ssh-sk.h"
62
63 #ifdef WITH_XMSS
64 #include "sshkey-xmss.h"
65 #include "xmss_fast.h"
66 #endif
67
68 #include "openbsd-compat/openssl-compat.h"
69
70 /* openssh private key file format */
71 #define MARK_BEGIN "-----BEGIN OPENSSH PRIVATE KEY-----\n"
72 #define MARK_END "-----END OPENSSH PRIVATE KEY-----\n"
73 #define MARK_BEGIN_LEN (sizeof(MARK_BEGIN) - 1)
74 #define MARK_END_LEN (sizeof(MARK_END) - 1)
75 #define KDFNAME "bcrypt"
76 #define AUTH_MAGIC "openssh-key-v1"
77 #define SALT_LEN 16
78 #define DEFAULT_CIPHERNAME "aes256-ctr"
79 #define DEFAULT_ROUNDS 24
80
81 /* Version identification string for SSH v1 identity files. */
82 #define LEGACY_BEGIN "SSH PRIVATE KEY FILE FORMAT 1.1\n"
83
84 /*
85 * Constants relating to "shielding" support; protection of keys expected
86 * to remain in memory for long durations
87 */
88 #define SSHKEY_SHIELD_PREKEY_LEN (16 * 1024)
89 #define SSHKEY_SHIELD_CIPHER "aes256-ctr" /* XXX want AES-EME* */
90 #define SSHKEY_SHIELD_PREKEY_HASH SSH_DIGEST_SHA512
91
92 int sshkey_private_serialize_opt(struct sshkey *key,
93 struct sshbuf *buf, enum sshkey_serialize_rep);
94 static int sshkey_from_blob_internal(struct sshbuf *buf,
95 struct sshkey **keyp, int allow_cert);
96
97 /* Supported key types */
98 extern const struct sshkey_impl sshkey_ed25519_impl;
99 extern const struct sshkey_impl sshkey_ed25519_cert_impl;
100 extern const struct sshkey_impl sshkey_ed25519_sk_impl;
101 extern const struct sshkey_impl sshkey_ed25519_sk_cert_impl;
102 #ifdef WITH_OPENSSL
103 # ifdef OPENSSL_HAS_ECC
104 # ifdef ENABLE_SK
105 extern const struct sshkey_impl sshkey_ecdsa_sk_impl;
106 extern const struct sshkey_impl sshkey_ecdsa_sk_cert_impl;
107 extern const struct sshkey_impl sshkey_ecdsa_sk_webauthn_impl;
108 # endif /* ENABLE_SK */
109 extern const struct sshkey_impl sshkey_ecdsa_nistp256_impl;
110 extern const struct sshkey_impl sshkey_ecdsa_nistp256_cert_impl;
111 extern const struct sshkey_impl sshkey_ecdsa_nistp384_impl;
112 extern const struct sshkey_impl sshkey_ecdsa_nistp384_cert_impl;
113 # ifdef OPENSSL_HAS_NISTP521
114 extern const struct sshkey_impl sshkey_ecdsa_nistp521_impl;
115 extern const struct sshkey_impl sshkey_ecdsa_nistp521_cert_impl;
116 # endif /* OPENSSL_HAS_NISTP521 */
117 # endif /* OPENSSL_HAS_ECC */
118 extern const struct sshkey_impl sshkey_rsa_impl;
119 extern const struct sshkey_impl sshkey_rsa_cert_impl;
120 extern const struct sshkey_impl sshkey_rsa_sha256_impl;
121 extern const struct sshkey_impl sshkey_rsa_sha256_cert_impl;
122 extern const struct sshkey_impl sshkey_rsa_sha512_impl;
123 extern const struct sshkey_impl sshkey_rsa_sha512_cert_impl;
124 # ifdef WITH_DSA
125 extern const struct sshkey_impl sshkey_dss_impl;
126 extern const struct sshkey_impl sshkey_dsa_cert_impl;
127 # endif
128 #endif /* WITH_OPENSSL */
129 #ifdef WITH_XMSS
130 extern const struct sshkey_impl sshkey_xmss_impl;
131 extern const struct sshkey_impl sshkey_xmss_cert_impl;
132 #endif
133
134 const struct sshkey_impl * const keyimpls[] = {
135 &sshkey_ed25519_impl,
136 &sshkey_ed25519_cert_impl,
137 #ifdef ENABLE_SK
138 &sshkey_ed25519_sk_impl,
139 &sshkey_ed25519_sk_cert_impl,
140 #endif
141 #ifdef WITH_OPENSSL
142 # ifdef OPENSSL_HAS_ECC
143 &sshkey_ecdsa_nistp256_impl,
144 &sshkey_ecdsa_nistp256_cert_impl,
145 &sshkey_ecdsa_nistp384_impl,
146 &sshkey_ecdsa_nistp384_cert_impl,
147 # ifdef OPENSSL_HAS_NISTP521
148 &sshkey_ecdsa_nistp521_impl,
149 &sshkey_ecdsa_nistp521_cert_impl,
150 # endif /* OPENSSL_HAS_NISTP521 */
151 # ifdef ENABLE_SK
152 &sshkey_ecdsa_sk_impl,
153 &sshkey_ecdsa_sk_cert_impl,
154 &sshkey_ecdsa_sk_webauthn_impl,
155 # endif /* ENABLE_SK */
156 # endif /* OPENSSL_HAS_ECC */
157 # ifdef WITH_DSA
158 &sshkey_dss_impl,
159 &sshkey_dsa_cert_impl,
160 # endif
161 &sshkey_rsa_impl,
162 &sshkey_rsa_cert_impl,
163 &sshkey_rsa_sha256_impl,
164 &sshkey_rsa_sha256_cert_impl,
165 &sshkey_rsa_sha512_impl,
166 &sshkey_rsa_sha512_cert_impl,
167 #endif /* WITH_OPENSSL */
168 #ifdef WITH_XMSS
169 &sshkey_xmss_impl,
170 &sshkey_xmss_cert_impl,
171 #endif
172 NULL
173 };
174
175 static const struct sshkey_impl *
176 sshkey_impl_from_type(int type)
177 {
178 int i;
179
180 for (i = 0; keyimpls[i] != NULL; i++) {
181 if (keyimpls[i]->type == type)
182 return keyimpls[i];
183 }
184 return NULL;
185 }
186
187 static const struct sshkey_impl *
188 sshkey_impl_from_type_nid(int type, int nid)
189 {
190 int i;
191
192 for (i = 0; keyimpls[i] != NULL; i++) {
193 if (keyimpls[i]->type == type &&
194 (keyimpls[i]->nid == 0 || keyimpls[i]->nid == nid))
195 return keyimpls[i];
196 }
197 return NULL;
198 }
199
200 static const struct sshkey_impl *
201 sshkey_impl_from_key(const struct sshkey *k)
202 {
203 if (k == NULL)
204 return NULL;
205 return sshkey_impl_from_type_nid(k->type, k->ecdsa_nid);
206 }
207
208 const char *
209 sshkey_type(const struct sshkey *k)
210 {
211 const struct sshkey_impl *impl;
212
213 if ((impl = sshkey_impl_from_key(k)) == NULL)
214 return "unknown";
215 return impl->shortname;
216 }
217
218 static const char *
219 sshkey_ssh_name_from_type_nid(int type, int nid)
220 {
221 const struct sshkey_impl *impl;
222
223 if ((impl = sshkey_impl_from_type_nid(type, nid)) == NULL)
224 return "ssh-unknown";
225 return impl->name;
226 }
227
228 int
229 sshkey_type_is_cert(int type)
230 {
231 const struct sshkey_impl *impl;
232
233 if ((impl = sshkey_impl_from_type(type)) == NULL)
234 return 0;
235 return impl->cert;
236 }
237
238 const char *
239 sshkey_ssh_name(const struct sshkey *k)
240 {
241 return sshkey_ssh_name_from_type_nid(k->type, k->ecdsa_nid);
242 }
243
244 const char *
245 sshkey_ssh_name_plain(const struct sshkey *k)
246 {
247 return sshkey_ssh_name_from_type_nid(sshkey_type_plain(k->type),
248 k->ecdsa_nid);
249 }
250
251 int
252 sshkey_type_from_name(const char *name)
253 {
254 int i;
255 const struct sshkey_impl *impl;
256
257 for (i = 0; keyimpls[i] != NULL; i++) {
258 impl = keyimpls[i];
259 /* Only allow shortname matches for plain key types */
260 if ((impl->name != NULL && strcmp(name, impl->name) == 0) ||
261 (!impl->cert && strcasecmp(impl->shortname, name) == 0))
262 return impl->type;
263 }
264 return KEY_UNSPEC;
265 }
266
267 static int
268 key_type_is_ecdsa_variant(int type)
269 {
270 switch (type) {
271 case KEY_ECDSA:
272 case KEY_ECDSA_CERT:
273 case KEY_ECDSA_SK:
274 case KEY_ECDSA_SK_CERT:
275 return 1;
276 }
277 return 0;
278 }
279
280 int
281 sshkey_ecdsa_nid_from_name(const char *name)
282 {
283 int i;
284
285 for (i = 0; keyimpls[i] != NULL; i++) {
286 if (!key_type_is_ecdsa_variant(keyimpls[i]->type))
287 continue;
288 if (keyimpls[i]->name != NULL &&
289 strcmp(name, keyimpls[i]->name) == 0)
290 return keyimpls[i]->nid;
291 }
292 return -1;
293 }
294
295 int
296 sshkey_match_keyname_to_sigalgs(const char *keyname, const char *sigalgs)
297 {
298 int ktype;
299
300 if (sigalgs == NULL || *sigalgs == '\0' ||
301 (ktype = sshkey_type_from_name(keyname)) == KEY_UNSPEC)
302 return 0;
303 else if (ktype == KEY_RSA) {
304 return match_pattern_list("ssh-rsa", sigalgs, 0) == 1 ||
305 match_pattern_list("rsa-sha2-256", sigalgs, 0) == 1 ||
306 match_pattern_list("rsa-sha2-512", sigalgs, 0) == 1;
307 } else if (ktype == KEY_RSA_CERT) {
308 return match_pattern_list("ssh-rsa-cert-v01@openssh.com",
309 sigalgs, 0) == 1 ||
310 match_pattern_list("rsa-sha2-256-cert-v01@openssh.com",
311 sigalgs, 0) == 1 ||
312 match_pattern_list("rsa-sha2-512-cert-v01@openssh.com",
313 sigalgs, 0) == 1;
314 } else
315 return match_pattern_list(keyname, sigalgs, 0) == 1;
316 }
317
318 char *
319 sshkey_alg_list(int certs_only, int plain_only, int include_sigonly, char sep)
320 {
321 char *tmp, *ret = NULL;
322 size_t i, nlen, rlen = 0;
323 const struct sshkey_impl *impl;
324
325 for (i = 0; keyimpls[i] != NULL; i++) {
326 impl = keyimpls[i];
327 if (impl->name == NULL)
328 continue;
329 if (!include_sigonly && impl->sigonly)
330 continue;
331 if ((certs_only && !impl->cert) || (plain_only && impl->cert))
332 continue;
333 if (ret != NULL)
334 ret[rlen++] = sep;
335 nlen = strlen(impl->name);
336 if ((tmp = realloc(ret, rlen + nlen + 2)) == NULL) {
337 free(ret);
338 return NULL;
339 }
340 ret = tmp;
341 memcpy(ret + rlen, impl->name, nlen + 1);
342 rlen += nlen;
343 }
344 return ret;
345 }
346
347 int
348 sshkey_names_valid2(const char *names, int allow_wildcard, int plain_only)
349 {
350 char *s, *cp, *p;
351 const struct sshkey_impl *impl;
352 int i, type;
353
354 if (names == NULL || strcmp(names, "") == 0)
355 return 0;
356 if ((s = cp = strdup(names)) == NULL)
357 return 0;
358 for ((p = strsep(&cp, ",")); p && *p != '\0';
359 (p = strsep(&cp, ","))) {
360 type = sshkey_type_from_name(p);
361 if (type == KEY_UNSPEC) {
362 if (allow_wildcard) {
363 /*
364 * Try matching key types against the string.
365 * If any has a positive or negative match then
366 * the component is accepted.
367 */
368 impl = NULL;
369 for (i = 0; keyimpls[i] != NULL; i++) {
370 if (match_pattern_list(
371 keyimpls[i]->name, p, 0) != 0) {
372 impl = keyimpls[i];
373 break;
374 }
375 }
376 if (impl != NULL)
377 continue;
378 }
379 free(s);
380 return 0;
381 } else if (plain_only && sshkey_type_is_cert(type)) {
382 free(s);
383 return 0;
384 }
385 }
386 free(s);
387 return 1;
388 }
389
390 u_int
391 sshkey_size(const struct sshkey *k)
392 {
393 const struct sshkey_impl *impl;
394
395 if ((impl = sshkey_impl_from_key(k)) == NULL)
396 return 0;
397 if (impl->funcs->size != NULL)
398 return impl->funcs->size(k);
399 return impl->keybits;
400 }
401
402 static int
403 sshkey_type_is_valid_ca(int type)
404 {
405 const struct sshkey_impl *impl;
406
407 if ((impl = sshkey_impl_from_type(type)) == NULL)
408 return 0;
409 /* All non-certificate types may act as CAs */
410 return !impl->cert;
411 }
412
413 int
414 sshkey_is_cert(const struct sshkey *k)
415 {
416 if (k == NULL)
417 return 0;
418 return sshkey_type_is_cert(k->type);
419 }
420
421 int
422 sshkey_is_sk(const struct sshkey *k)
423 {
424 if (k == NULL)
425 return 0;
426 switch (sshkey_type_plain(k->type)) {
427 case KEY_ECDSA_SK:
428 case KEY_ED25519_SK:
429 return 1;
430 default:
431 return 0;
432 }
433 }
434
435 /* Return the cert-less equivalent to a certified key type */
436 int
437 sshkey_type_plain(int type)
438 {
439 switch (type) {
440 case KEY_RSA_CERT:
441 return KEY_RSA;
442 case KEY_DSA_CERT:
443 return KEY_DSA;
444 case KEY_ECDSA_CERT:
445 return KEY_ECDSA;
446 case KEY_ECDSA_SK_CERT:
447 return KEY_ECDSA_SK;
448 case KEY_ED25519_CERT:
449 return KEY_ED25519;
450 case KEY_ED25519_SK_CERT:
451 return KEY_ED25519_SK;
452 case KEY_XMSS_CERT:
453 return KEY_XMSS;
454 default:
455 return type;
456 }
457 }
458
459 /* Return the cert equivalent to a plain key type */
460 static int
461 sshkey_type_certified(int type)
462 {
463 switch (type) {
464 case KEY_RSA:
465 return KEY_RSA_CERT;
466 case KEY_DSA:
467 return KEY_DSA_CERT;
468 case KEY_ECDSA:
469 return KEY_ECDSA_CERT;
470 case KEY_ECDSA_SK:
471 return KEY_ECDSA_SK_CERT;
472 case KEY_ED25519:
473 return KEY_ED25519_CERT;
474 case KEY_ED25519_SK:
475 return KEY_ED25519_SK_CERT;
476 case KEY_XMSS:
477 return KEY_XMSS_CERT;
478 default:
479 return -1;
480 }
481 }
482
483 #ifdef WITH_OPENSSL
484 /* XXX: these are really begging for a table-driven approach */
485 int
486 sshkey_curve_name_to_nid(const char *name)
487 {
488 if (strcmp(name, "nistp256") == 0)
489 return NID_X9_62_prime256v1;
490 else if (strcmp(name, "nistp384") == 0)
491 return NID_secp384r1;
492 # ifdef OPENSSL_HAS_NISTP521
493 else if (strcmp(name, "nistp521") == 0)
494 return NID_secp521r1;
495 # endif /* OPENSSL_HAS_NISTP521 */
496 else
497 return -1;
498 }
499
500 u_int
501 sshkey_curve_nid_to_bits(int nid)
502 {
503 switch (nid) {
504 case NID_X9_62_prime256v1:
505 return 256;
506 case NID_secp384r1:
507 return 384;
508 # ifdef OPENSSL_HAS_NISTP521
509 case NID_secp521r1:
510 return 521;
511 # endif /* OPENSSL_HAS_NISTP521 */
512 default:
513 return 0;
514 }
515 }
516
517 int
518 sshkey_ecdsa_bits_to_nid(int bits)
519 {
520 switch (bits) {
521 case 256:
522 return NID_X9_62_prime256v1;
523 case 384:
524 return NID_secp384r1;
525 # ifdef OPENSSL_HAS_NISTP521
526 case 521:
527 return NID_secp521r1;
528 # endif /* OPENSSL_HAS_NISTP521 */
529 default:
530 return -1;
531 }
532 }
533
534 const char *
535 sshkey_curve_nid_to_name(int nid)
536 {
537 switch (nid) {
538 case NID_X9_62_prime256v1:
539 return "nistp256";
540 case NID_secp384r1:
541 return "nistp384";
542 # ifdef OPENSSL_HAS_NISTP521
543 case NID_secp521r1:
544 return "nistp521";
545 # endif /* OPENSSL_HAS_NISTP521 */
546 default:
547 return NULL;
548 }
549 }
550
551 int
552 sshkey_ec_nid_to_hash_alg(int nid)
553 {
554 int kbits = sshkey_curve_nid_to_bits(nid);
555
556 if (kbits <= 0)
557 return -1;
558
559 /* RFC5656 section 6.2.1 */
560 if (kbits <= 256)
561 return SSH_DIGEST_SHA256;
562 else if (kbits <= 384)
563 return SSH_DIGEST_SHA384;
564 else
565 return SSH_DIGEST_SHA512;
566 }
567 #endif /* WITH_OPENSSL */
568
569 static void
570 cert_free(struct sshkey_cert *cert)
571 {
572 u_int i;
573
574 if (cert == NULL)
575 return;
576 sshbuf_free(cert->certblob);
577 sshbuf_free(cert->critical);
578 sshbuf_free(cert->extensions);
579 free(cert->key_id);
580 for (i = 0; i < cert->nprincipals; i++)
581 free(cert->principals[i]);
582 free(cert->principals);
583 sshkey_free(cert->signature_key);
584 free(cert->signature_type);
585 freezero(cert, sizeof(*cert));
586 }
587
588 static struct sshkey_cert *
589 cert_new(void)
590 {
591 struct sshkey_cert *cert;
592
593 if ((cert = calloc(1, sizeof(*cert))) == NULL)
594 return NULL;
595 if ((cert->certblob = sshbuf_new()) == NULL ||
596 (cert->critical = sshbuf_new()) == NULL ||
597 (cert->extensions = sshbuf_new()) == NULL) {
598 cert_free(cert);
599 return NULL;
600 }
601 cert->key_id = NULL;
602 cert->principals = NULL;
603 cert->signature_key = NULL;
604 cert->signature_type = NULL;
605 return cert;
606 }
607
608 struct sshkey *
609 sshkey_new(int type)
610 {
611 struct sshkey *k;
612 const struct sshkey_impl *impl = NULL;
613
614 if (type != KEY_UNSPEC &&
615 (impl = sshkey_impl_from_type(type)) == NULL)
616 return NULL;
617
618 /* All non-certificate types may act as CAs */
619 if ((k = calloc(1, sizeof(*k))) == NULL)
620 return NULL;
621 k->type = type;
622 k->ecdsa_nid = -1;
623 if (impl != NULL && impl->funcs->alloc != NULL) {
624 if (impl->funcs->alloc(k) != 0) {
625 free(k);
626 return NULL;
627 }
628 }
629 if (sshkey_is_cert(k)) {
630 if ((k->cert = cert_new()) == NULL) {
631 sshkey_free(k);
632 return NULL;
633 }
634 }
635
636 return k;
637 }
638
639 /* Frees common FIDO fields */
640 void
641 sshkey_sk_cleanup(struct sshkey *k)
642 {
643 free(k->sk_application);
644 sshbuf_free(k->sk_key_handle);
645 sshbuf_free(k->sk_reserved);
646 k->sk_application = NULL;
647 k->sk_key_handle = k->sk_reserved = NULL;
648 }
649
650 static void
651 sshkey_free_contents(struct sshkey *k)
652 {
653 const struct sshkey_impl *impl;
654
655 if (k == NULL)
656 return;
657 if ((impl = sshkey_impl_from_type(k->type)) != NULL &&
658 impl->funcs->cleanup != NULL)
659 impl->funcs->cleanup(k);
660 if (sshkey_is_cert(k))
661 cert_free(k->cert);
662 freezero(k->shielded_private, k->shielded_len);
663 freezero(k->shield_prekey, k->shield_prekey_len);
664 }
665
666 void
667 sshkey_free(struct sshkey *k)
668 {
669 sshkey_free_contents(k);
670 freezero(k, sizeof(*k));
671 }
672
673 static int
674 cert_compare(struct sshkey_cert *a, struct sshkey_cert *b)
675 {
676 if (a == NULL && b == NULL)
677 return 1;
678 if (a == NULL || b == NULL)
679 return 0;
680 if (sshbuf_len(a->certblob) != sshbuf_len(b->certblob))
681 return 0;
682 if (timingsafe_bcmp(sshbuf_ptr(a->certblob), sshbuf_ptr(b->certblob),
683 sshbuf_len(a->certblob)) != 0)
684 return 0;
685 return 1;
686 }
687
688 /* Compares FIDO-specific pubkey fields only */
689 int
690 sshkey_sk_fields_equal(const struct sshkey *a, const struct sshkey *b)
691 {
692 if (a->sk_application == NULL || b->sk_application == NULL)
693 return 0;
694 if (strcmp(a->sk_application, b->sk_application) != 0)
695 return 0;
696 return 1;
697 }
698
699 /*
700 * Compare public portions of key only, allowing comparisons between
701 * certificates and plain keys too.
702 */
703 int
704 sshkey_equal_public(const struct sshkey *a, const struct sshkey *b)
705 {
706 const struct sshkey_impl *impl;
707
708 if (a == NULL || b == NULL ||
709 sshkey_type_plain(a->type) != sshkey_type_plain(b->type))
710 return 0;
711 if ((impl = sshkey_impl_from_type(a->type)) == NULL)
712 return 0;
713 return impl->funcs->equal(a, b);
714 }
715
716 int
717 sshkey_equal(const struct sshkey *a, const struct sshkey *b)
718 {
719 if (a == NULL || b == NULL || a->type != b->type)
720 return 0;
721 if (sshkey_is_cert(a)) {
722 if (!cert_compare(a->cert, b->cert))
723 return 0;
724 }
725 return sshkey_equal_public(a, b);
726 }
727
728
729 /* Serialise common FIDO key parts */
730 int
731 sshkey_serialize_sk(const struct sshkey *key, struct sshbuf *b)
732 {
733 int r;
734
735 if ((r = sshbuf_put_cstring(b, key->sk_application)) != 0)
736 return r;
737
738 return 0;
739 }
740
741 static int
742 to_blob_buf(const struct sshkey *key, struct sshbuf *b, int force_plain,
743 enum sshkey_serialize_rep opts)
744 {
745 int type, ret = SSH_ERR_INTERNAL_ERROR;
746 const char *typename;
747 const struct sshkey_impl *impl;
748
749 if (key == NULL)
750 return SSH_ERR_INVALID_ARGUMENT;
751
752 type = force_plain ? sshkey_type_plain(key->type) : key->type;
753
754 if (sshkey_type_is_cert(type)) {
755 if (key->cert == NULL)
756 return SSH_ERR_EXPECTED_CERT;
757 if (sshbuf_len(key->cert->certblob) == 0)
758 return SSH_ERR_KEY_LACKS_CERTBLOB;
759 /* Use the existing blob */
760 if ((ret = sshbuf_putb(b, key->cert->certblob)) != 0)
761 return ret;
762 return 0;
763 }
764 if ((impl = sshkey_impl_from_type(type)) == NULL)
765 return SSH_ERR_KEY_TYPE_UNKNOWN;
766
767 typename = sshkey_ssh_name_from_type_nid(type, key->ecdsa_nid);
768 if ((ret = sshbuf_put_cstring(b, typename)) != 0)
769 return ret;
770 return impl->funcs->serialize_public(key, b, opts);
771 }
772
773 int
774 sshkey_putb(const struct sshkey *key, struct sshbuf *b)
775 {
776 return to_blob_buf(key, b, 0, SSHKEY_SERIALIZE_DEFAULT);
777 }
778
779 int
780 sshkey_puts_opts(const struct sshkey *key, struct sshbuf *b,
781 enum sshkey_serialize_rep opts)
782 {
783 struct sshbuf *tmp;
784 int r;
785
786 if ((tmp = sshbuf_new()) == NULL)
787 return SSH_ERR_ALLOC_FAIL;
788 r = to_blob_buf(key, tmp, 0, opts);
789 if (r == 0)
790 r = sshbuf_put_stringb(b, tmp);
791 sshbuf_free(tmp);
792 return r;
793 }
794
795 int
796 sshkey_puts(const struct sshkey *key, struct sshbuf *b)
797 {
798 return sshkey_puts_opts(key, b, SSHKEY_SERIALIZE_DEFAULT);
799 }
800
801 int
802 sshkey_putb_plain(const struct sshkey *key, struct sshbuf *b)
803 {
804 return to_blob_buf(key, b, 1, SSHKEY_SERIALIZE_DEFAULT);
805 }
806
807 static int
808 to_blob(const struct sshkey *key, u_char **blobp, size_t *lenp, int force_plain,
809 enum sshkey_serialize_rep opts)
810 {
811 int ret = SSH_ERR_INTERNAL_ERROR;
812 size_t len;
813 struct sshbuf *b = NULL;
814
815 if (lenp != NULL)
816 *lenp = 0;
817 if (blobp != NULL)
818 *blobp = NULL;
819 if ((b = sshbuf_new()) == NULL)
820 return SSH_ERR_ALLOC_FAIL;
821 if ((ret = to_blob_buf(key, b, force_plain, opts)) != 0)
822 goto out;
823 len = sshbuf_len(b);
824 if (lenp != NULL)
825 *lenp = len;
826 if (blobp != NULL) {
827 if ((*blobp = malloc(len)) == NULL) {
828 ret = SSH_ERR_ALLOC_FAIL;
829 goto out;
830 }
831 memcpy(*blobp, sshbuf_ptr(b), len);
832 }
833 ret = 0;
834 out:
835 sshbuf_free(b);
836 return ret;
837 }
838
839 int
840 sshkey_to_blob(const struct sshkey *key, u_char **blobp, size_t *lenp)
841 {
842 return to_blob(key, blobp, lenp, 0, SSHKEY_SERIALIZE_DEFAULT);
843 }
844
845 int
846 sshkey_plain_to_blob(const struct sshkey *key, u_char **blobp, size_t *lenp)
847 {
848 return to_blob(key, blobp, lenp, 1, SSHKEY_SERIALIZE_DEFAULT);
849 }
850
851 int
852 sshkey_fingerprint_raw(const struct sshkey *k, int dgst_alg,
853 u_char **retp, size_t *lenp)
854 {
855 u_char *blob = NULL, *ret = NULL;
856 size_t blob_len = 0;
857 int r = SSH_ERR_INTERNAL_ERROR;
858
859 if (retp != NULL)
860 *retp = NULL;
861 if (lenp != NULL)
862 *lenp = 0;
863 if (ssh_digest_bytes(dgst_alg) == 0) {
864 r = SSH_ERR_INVALID_ARGUMENT;
865 goto out;
866 }
867 if ((r = to_blob(k, &blob, &blob_len, 1, SSHKEY_SERIALIZE_DEFAULT))
868 != 0)
869 goto out;
870 if ((ret = calloc(1, SSH_DIGEST_MAX_LENGTH)) == NULL) {
871 r = SSH_ERR_ALLOC_FAIL;
872 goto out;
873 }
874 if ((r = ssh_digest_memory(dgst_alg, blob, blob_len,
875 ret, SSH_DIGEST_MAX_LENGTH)) != 0)
876 goto out;
877 /* success */
878 if (retp != NULL) {
879 *retp = ret;
880 ret = NULL;
881 }
882 if (lenp != NULL)
883 *lenp = ssh_digest_bytes(dgst_alg);
884 r = 0;
885 out:
886 free(ret);
887 if (blob != NULL)
888 freezero(blob, blob_len);
889 return r;
890 }
891
892 static char *
893 fingerprint_b64(const char *alg, u_char *dgst_raw, size_t dgst_raw_len)
894 {
895 char *ret;
896 size_t plen = strlen(alg) + 1;
897 size_t rlen = ((dgst_raw_len + 2) / 3) * 4 + plen + 1;
898
899 if (dgst_raw_len > 65536 || (ret = calloc(1, rlen)) == NULL)
900 return NULL;
901 strlcpy(ret, alg, rlen);
902 strlcat(ret, ":", rlen);
903 if (dgst_raw_len == 0)
904 return ret;
905 if (b64_ntop(dgst_raw, dgst_raw_len, ret + plen, rlen - plen) == -1) {
906 freezero(ret, rlen);
907 return NULL;
908 }
909 /* Trim padding characters from end */
910 ret[strcspn(ret, "=")] = '\0';
911 return ret;
912 }
913
914 static char *
915 fingerprint_hex(const char *alg, u_char *dgst_raw, size_t dgst_raw_len)
916 {
917 char *retval, hex[5];
918 size_t i, rlen = dgst_raw_len * 3 + strlen(alg) + 2;
919
920 if (dgst_raw_len > 65536 || (retval = calloc(1, rlen)) == NULL)
921 return NULL;
922 strlcpy(retval, alg, rlen);
923 strlcat(retval, ":", rlen);
924 for (i = 0; i < dgst_raw_len; i++) {
925 snprintf(hex, sizeof(hex), "%s%02x",
926 i > 0 ? ":" : "", dgst_raw[i]);
927 strlcat(retval, hex, rlen);
928 }
929 return retval;
930 }
931
932 static char *
933 fingerprint_bubblebabble(u_char *dgst_raw, size_t dgst_raw_len)
934 {
935 char vowels[] = { 'a', 'e', 'i', 'o', 'u', 'y' };
936 char consonants[] = { 'b', 'c', 'd', 'f', 'g', 'h', 'k', 'l', 'm',
937 'n', 'p', 'r', 's', 't', 'v', 'z', 'x' };
938 u_int i, j = 0, rounds, seed = 1;
939 char *retval;
940
941 rounds = (dgst_raw_len / 2) + 1;
942 if ((retval = calloc(rounds, 6)) == NULL)
943 return NULL;
944 retval[j++] = 'x';
945 for (i = 0; i < rounds; i++) {
946 u_int idx0, idx1, idx2, idx3, idx4;
947 if ((i + 1 < rounds) || (dgst_raw_len % 2 != 0)) {
948 idx0 = (((((u_int)(dgst_raw[2 * i])) >> 6) & 3) +
949 seed) % 6;
950 idx1 = (((u_int)(dgst_raw[2 * i])) >> 2) & 15;
951 idx2 = ((((u_int)(dgst_raw[2 * i])) & 3) +
952 (seed / 6)) % 6;
953 retval[j++] = vowels[idx0];
954 retval[j++] = consonants[idx1];
955 retval[j++] = vowels[idx2];
956 if ((i + 1) < rounds) {
957 idx3 = (((u_int)(dgst_raw[(2 * i) + 1])) >> 4) & 15;
958 idx4 = (((u_int)(dgst_raw[(2 * i) + 1]))) & 15;
959 retval[j++] = consonants[idx3];
960 retval[j++] = '-';
961 retval[j++] = consonants[idx4];
962 seed = ((seed * 5) +
963 ((((u_int)(dgst_raw[2 * i])) * 7) +
964 ((u_int)(dgst_raw[(2 * i) + 1])))) % 36;
965 }
966 } else {
967 idx0 = seed % 6;
968 idx1 = 16;
969 idx2 = seed / 6;
970 retval[j++] = vowels[idx0];
971 retval[j++] = consonants[idx1];
972 retval[j++] = vowels[idx2];
973 }
974 }
975 retval[j++] = 'x';
976 retval[j++] = '\0';
977 return retval;
978 }
979
980 /*
981 * Draw an ASCII-Art representing the fingerprint so human brain can
982 * profit from its built-in pattern recognition ability.
983 * This technique is called "random art" and can be found in some
984 * scientific publications like this original paper:
985 *
986 * "Hash Visualization: a New Technique to improve Real-World Security",
987 * Perrig A. and Song D., 1999, International Workshop on Cryptographic
988 * Techniques and E-Commerce (CrypTEC '99)
989 * sparrow.ece.cmu.edu/~adrian/projects/validation/validation.pdf
990 *
991 * The subject came up in a talk by Dan Kaminsky, too.
992 *
993 * If you see the picture is different, the key is different.
994 * If the picture looks the same, you still know nothing.
995 *
996 * The algorithm used here is a worm crawling over a discrete plane,
997 * leaving a trace (augmenting the field) everywhere it goes.
998 * Movement is taken from dgst_raw 2bit-wise. Bumping into walls
999 * makes the respective movement vector be ignored for this turn.
1000 * Graphs are not unambiguous, because circles in graphs can be
1001 * walked in either direction.
1002 */
1003
1004 /*
1005 * Field sizes for the random art. Have to be odd, so the starting point
1006 * can be in the exact middle of the picture, and FLDBASE should be >=8 .
1007 * Else pictures would be too dense, and drawing the frame would
1008 * fail, too, because the key type would not fit in anymore.
1009 */
1010 #define FLDBASE 8
1011 #define FLDSIZE_Y (FLDBASE + 1)
1012 #define FLDSIZE_X (FLDBASE * 2 + 1)
1013 static char *
1014 fingerprint_randomart(const char *alg, u_char *dgst_raw, size_t dgst_raw_len,
1015 const struct sshkey *k)
1016 {
1017 /*
1018 * Chars to be used after each other every time the worm
1019 * intersects with itself. Matter of taste.
1020 */
1021 char *augmentation_string = " .o+=*BOX@%&#/^SE";
1022 char *retval, *p, title[FLDSIZE_X], hash[FLDSIZE_X];
1023 u_char field[FLDSIZE_X][FLDSIZE_Y];
1024 size_t i, tlen, hlen;
1025 u_int b;
1026 int x, y, r;
1027 size_t len = strlen(augmentation_string) - 1;
1028
1029 if ((retval = calloc((FLDSIZE_X + 3), (FLDSIZE_Y + 2))) == NULL)
1030 return NULL;
1031
1032 /* initialize field */
1033 memset(field, 0, FLDSIZE_X * FLDSIZE_Y * sizeof(char));
1034 x = FLDSIZE_X / 2;
1035 y = FLDSIZE_Y / 2;
1036
1037 /* process raw key */
1038 for (i = 0; i < dgst_raw_len; i++) {
1039 int input;
1040 /* each byte conveys four 2-bit move commands */
1041 input = dgst_raw[i];
1042 for (b = 0; b < 4; b++) {
1043 /* evaluate 2 bit, rest is shifted later */
1044 x += (input & 0x1) ? 1 : -1;
1045 y += (input & 0x2) ? 1 : -1;
1046
1047 /* assure we are still in bounds */
1048 x = MAXIMUM(x, 0);
1049 y = MAXIMUM(y, 0);
1050 x = MINIMUM(x, FLDSIZE_X - 1);
1051 y = MINIMUM(y, FLDSIZE_Y - 1);
1052
1053 /* augment the field */
1054 if (field[x][y] < len - 2)
1055 field[x][y]++;
1056 input = input >> 2;
1057 }
1058 }
1059
1060 /* mark starting point and end point*/
1061 field[FLDSIZE_X / 2][FLDSIZE_Y / 2] = len - 1;
1062 field[x][y] = len;
1063
1064 /* assemble title */
1065 r = snprintf(title, sizeof(title), "[%s %u]",
1066 sshkey_type(k), sshkey_size(k));
1067 /* If [type size] won't fit, then try [type]; fits "[ED25519-CERT]" */
1068 if (r < 0 || r > (int)sizeof(title))
1069 r = snprintf(title, sizeof(title), "[%s]", sshkey_type(k));
1070 tlen = (r <= 0) ? 0 : strlen(title);
1071
1072 /* assemble hash ID. */
1073 r = snprintf(hash, sizeof(hash), "[%s]", alg);
1074 hlen = (r <= 0) ? 0 : strlen(hash);
1075
1076 /* output upper border */
1077 p = retval;
1078 *p++ = '+';
1079 for (i = 0; i < (FLDSIZE_X - tlen) / 2; i++)
1080 *p++ = '-';
1081 memcpy(p, title, tlen);
1082 p += tlen;
1083 for (i += tlen; i < FLDSIZE_X; i++)
1084 *p++ = '-';
1085 *p++ = '+';
1086 *p++ = '\n';
1087
1088 /* output content */
1089 for (y = 0; y < FLDSIZE_Y; y++) {
1090 *p++ = '|';
1091 for (x = 0; x < FLDSIZE_X; x++)
1092 *p++ = augmentation_string[MINIMUM(field[x][y], len)];
1093 *p++ = '|';
1094 *p++ = '\n';
1095 }
1096
1097 /* output lower border */
1098 *p++ = '+';
1099 for (i = 0; i < (FLDSIZE_X - hlen) / 2; i++)
1100 *p++ = '-';
1101 memcpy(p, hash, hlen);
1102 p += hlen;
1103 for (i += hlen; i < FLDSIZE_X; i++)
1104 *p++ = '-';
1105 *p++ = '+';
1106
1107 return retval;
1108 }
1109
1110 char *
1111 sshkey_fingerprint(const struct sshkey *k, int dgst_alg,
1112 enum sshkey_fp_rep dgst_rep)
1113 {
1114 char *retval = NULL;
1115 u_char *dgst_raw;
1116 size_t dgst_raw_len;
1117
1118 if (sshkey_fingerprint_raw(k, dgst_alg, &dgst_raw, &dgst_raw_len) != 0)
1119 return NULL;
1120 switch (dgst_rep) {
1121 case SSH_FP_DEFAULT:
1122 if (dgst_alg == SSH_DIGEST_MD5) {
1123 retval = fingerprint_hex(ssh_digest_alg_name(dgst_alg),
1124 dgst_raw, dgst_raw_len);
1125 } else {
1126 retval = fingerprint_b64(ssh_digest_alg_name(dgst_alg),
1127 dgst_raw, dgst_raw_len);
1128 }
1129 break;
1130 case SSH_FP_HEX:
1131 retval = fingerprint_hex(ssh_digest_alg_name(dgst_alg),
1132 dgst_raw, dgst_raw_len);
1133 break;
1134 case SSH_FP_BASE64:
1135 retval = fingerprint_b64(ssh_digest_alg_name(dgst_alg),
1136 dgst_raw, dgst_raw_len);
1137 break;
1138 case SSH_FP_BUBBLEBABBLE:
1139 retval = fingerprint_bubblebabble(dgst_raw, dgst_raw_len);
1140 break;
1141 case SSH_FP_RANDOMART:
1142 retval = fingerprint_randomart(ssh_digest_alg_name(dgst_alg),
1143 dgst_raw, dgst_raw_len, k);
1144 break;
1145 default:
1146 freezero(dgst_raw, dgst_raw_len);
1147 return NULL;
1148 }
1149 freezero(dgst_raw, dgst_raw_len);
1150 return retval;
1151 }
1152
1153 static int
1154 peek_type_nid(const char *s, size_t l, int *nid)
1155 {
1156 const struct sshkey_impl *impl;
1157 int i;
1158
1159 for (i = 0; keyimpls[i] != NULL; i++) {
1160 impl = keyimpls[i];
1161 if (impl->name == NULL || strlen(impl->name) != l)
1162 continue;
1163 if (memcmp(s, impl->name, l) == 0) {
1164 *nid = -1;
1165 if (key_type_is_ecdsa_variant(impl->type))
1166 *nid = impl->nid;
1167 return impl->type;
1168 }
1169 }
1170 return KEY_UNSPEC;
1171 }
1172
1173 /* XXX this can now be made const char * */
1174 int
1175 sshkey_read(struct sshkey *ret, char **cpp)
1176 {
1177 struct sshkey *k;
1178 char *cp, *blobcopy;
1179 size_t space;
1180 int r, type, curve_nid = -1;
1181 struct sshbuf *blob;
1182
1183 if (ret == NULL)
1184 return SSH_ERR_INVALID_ARGUMENT;
1185 if (ret->type != KEY_UNSPEC && sshkey_impl_from_type(ret->type) == NULL)
1186 return SSH_ERR_INVALID_ARGUMENT;
1187
1188 /* Decode type */
1189 cp = *cpp;
1190 space = strcspn(cp, " \t");
1191 if (space == strlen(cp))
1192 return SSH_ERR_INVALID_FORMAT;
1193 if ((type = peek_type_nid(cp, space, &curve_nid)) == KEY_UNSPEC)
1194 return SSH_ERR_INVALID_FORMAT;
1195
1196 /* skip whitespace */
1197 for (cp += space; *cp == ' ' || *cp == '\t'; cp++)
1198 ;
1199 if (*cp == '\0')
1200 return SSH_ERR_INVALID_FORMAT;
1201 if (ret->type != KEY_UNSPEC && ret->type != type)
1202 return SSH_ERR_KEY_TYPE_MISMATCH;
1203 if ((blob = sshbuf_new()) == NULL)
1204 return SSH_ERR_ALLOC_FAIL;
1205
1206 /* find end of keyblob and decode */
1207 space = strcspn(cp, " \t");
1208 if ((blobcopy = strndup(cp, space)) == NULL) {
1209 sshbuf_free(blob);
1210 return SSH_ERR_ALLOC_FAIL;
1211 }
1212 if ((r = sshbuf_b64tod(blob, blobcopy)) != 0) {
1213 free(blobcopy);
1214 sshbuf_free(blob);
1215 return r;
1216 }
1217 free(blobcopy);
1218 if ((r = sshkey_fromb(blob, &k)) != 0) {
1219 sshbuf_free(blob);
1220 return r;
1221 }
1222 sshbuf_free(blob);
1223
1224 /* skip whitespace and leave cp at start of comment */
1225 for (cp += space; *cp == ' ' || *cp == '\t'; cp++)
1226 ;
1227
1228 /* ensure type of blob matches type at start of line */
1229 if (k->type != type) {
1230 sshkey_free(k);
1231 return SSH_ERR_KEY_TYPE_MISMATCH;
1232 }
1233 if (key_type_is_ecdsa_variant(type) && curve_nid != k->ecdsa_nid) {
1234 sshkey_free(k);
1235 return SSH_ERR_EC_CURVE_MISMATCH;
1236 }
1237
1238 /* Fill in ret from parsed key */
1239 sshkey_free_contents(ret);
1240 *ret = *k;
1241 freezero(k, sizeof(*k));
1242
1243 /* success */
1244 *cpp = cp;
1245 return 0;
1246 }
1247
1248 int
1249 sshkey_to_base64(const struct sshkey *key, char **b64p)
1250 {
1251 int r = SSH_ERR_INTERNAL_ERROR;
1252 struct sshbuf *b = NULL;
1253 char *uu = NULL;
1254
1255 if (b64p != NULL)
1256 *b64p = NULL;
1257 if ((b = sshbuf_new()) == NULL)
1258 return SSH_ERR_ALLOC_FAIL;
1259 if ((r = sshkey_putb(key, b)) != 0)
1260 goto out;
1261 if ((uu = sshbuf_dtob64_string(b, 0)) == NULL) {
1262 r = SSH_ERR_ALLOC_FAIL;
1263 goto out;
1264 }
1265 /* Success */
1266 if (b64p != NULL) {
1267 *b64p = uu;
1268 uu = NULL;
1269 }
1270 r = 0;
1271 out:
1272 sshbuf_free(b);
1273 free(uu);
1274 return r;
1275 }
1276
1277 int
1278 sshkey_format_text(const struct sshkey *key, struct sshbuf *b)
1279 {
1280 int r = SSH_ERR_INTERNAL_ERROR;
1281 char *uu = NULL;
1282
1283 if ((r = sshkey_to_base64(key, &uu)) != 0)
1284 goto out;
1285 if ((r = sshbuf_putf(b, "%s %s",
1286 sshkey_ssh_name(key), uu)) != 0)
1287 goto out;
1288 r = 0;
1289 out:
1290 free(uu);
1291 return r;
1292 }
1293
1294 int
1295 sshkey_write(const struct sshkey *key, FILE *f)
1296 {
1297 struct sshbuf *b = NULL;
1298 int r = SSH_ERR_INTERNAL_ERROR;
1299
1300 if ((b = sshbuf_new()) == NULL)
1301 return SSH_ERR_ALLOC_FAIL;
1302 if ((r = sshkey_format_text(key, b)) != 0)
1303 goto out;
1304 if (fwrite(sshbuf_ptr(b), sshbuf_len(b), 1, f) != 1) {
1305 if (feof(f))
1306 errno = EPIPE;
1307 r = SSH_ERR_SYSTEM_ERROR;
1308 goto out;
1309 }
1310 /* Success */
1311 r = 0;
1312 out:
1313 sshbuf_free(b);
1314 return r;
1315 }
1316
1317 const char *
1318 sshkey_cert_type(const struct sshkey *k)
1319 {
1320 switch (k->cert->type) {
1321 case SSH2_CERT_TYPE_USER:
1322 return "user";
1323 case SSH2_CERT_TYPE_HOST:
1324 return "host";
1325 default:
1326 return "unknown";
1327 }
1328 }
1329
1330 int
1331 sshkey_check_rsa_length(const struct sshkey *k, int min_size)
1332 {
1333 #ifdef WITH_OPENSSL
1334 const BIGNUM *rsa_n;
1335 int nbits;
1336
1337 if (k == NULL || k->rsa == NULL ||
1338 (k->type != KEY_RSA && k->type != KEY_RSA_CERT))
1339 return 0;
1340 RSA_get0_key(k->rsa, &rsa_n, NULL, NULL);
1341 nbits = BN_num_bits(rsa_n);
1342 if (nbits < SSH_RSA_MINIMUM_MODULUS_SIZE ||
1343 (min_size > 0 && nbits < min_size))
1344 return SSH_ERR_KEY_LENGTH;
1345 #endif /* WITH_OPENSSL */
1346 return 0;
1347 }
1348
1349 #ifdef WITH_OPENSSL
1350 # ifdef OPENSSL_HAS_ECC
1351 int
1352 sshkey_ecdsa_key_to_nid(EC_KEY *k)
1353 {
1354 EC_GROUP *eg;
1355 int nids[] = {
1356 NID_X9_62_prime256v1,
1357 NID_secp384r1,
1358 # ifdef OPENSSL_HAS_NISTP521
1359 NID_secp521r1,
1360 # endif /* OPENSSL_HAS_NISTP521 */
1361 -1
1362 };
1363 int nid;
1364 u_int i;
1365 const EC_GROUP *g = EC_KEY_get0_group(k);
1366
1367 /*
1368 * The group may be stored in a ASN.1 encoded private key in one of two
1369 * ways: as a "named group", which is reconstituted by ASN.1 object ID
1370 * or explicit group parameters encoded into the key blob. Only the
1371 * "named group" case sets the group NID for us, but we can figure
1372 * it out for the other case by comparing against all the groups that
1373 * are supported.
1374 */
1375 if ((nid = EC_GROUP_get_curve_name(g)) > 0)
1376 return nid;
1377 for (i = 0; nids[i] != -1; i++) {
1378 if ((eg = EC_GROUP_new_by_curve_name(nids[i])) == NULL)
1379 return -1;
1380 if (EC_GROUP_cmp(g, eg, NULL) == 0)
1381 break;
1382 EC_GROUP_free(eg);
1383 }
1384 if (nids[i] != -1) {
1385 /* Use the group with the NID attached */
1386 EC_GROUP_set_asn1_flag(eg, OPENSSL_EC_NAMED_CURVE);
1387 if (EC_KEY_set_group(k, eg) != 1) {
1388 EC_GROUP_free(eg);
1389 return -1;
1390 }
1391 }
1392 return nids[i];
1393 }
1394 # endif /* OPENSSL_HAS_ECC */
1395 #endif /* WITH_OPENSSL */
1396
1397 int
1398 sshkey_generate(int type, u_int bits, struct sshkey **keyp)
1399 {
1400 struct sshkey *k;
1401 int ret = SSH_ERR_INTERNAL_ERROR;
1402 const struct sshkey_impl *impl;
1403
1404 if (keyp == NULL || sshkey_type_is_cert(type))
1405 return SSH_ERR_INVALID_ARGUMENT;
1406 *keyp = NULL;
1407 if ((impl = sshkey_impl_from_type(type)) == NULL)
1408 return SSH_ERR_KEY_TYPE_UNKNOWN;
1409 if (impl->funcs->generate == NULL)
1410 return SSH_ERR_FEATURE_UNSUPPORTED;
1411 if ((k = sshkey_new(KEY_UNSPEC)) == NULL)
1412 return SSH_ERR_ALLOC_FAIL;
1413 k->type = type;
1414 if ((ret = impl->funcs->generate(k, bits)) != 0) {
1415 sshkey_free(k);
1416 return ret;
1417 }
1418 /* success */
1419 *keyp = k;
1420 return 0;
1421 }
1422
1423 int
1424 sshkey_cert_copy(const struct sshkey *from_key, struct sshkey *to_key)
1425 {
1426 u_int i;
1427 const struct sshkey_cert *from;
1428 struct sshkey_cert *to;
1429 int r = SSH_ERR_INTERNAL_ERROR;
1430
1431 if (to_key == NULL || (from = from_key->cert) == NULL)
1432 return SSH_ERR_INVALID_ARGUMENT;
1433
1434 if ((to = cert_new()) == NULL)
1435 return SSH_ERR_ALLOC_FAIL;
1436
1437 if ((r = sshbuf_putb(to->certblob, from->certblob)) != 0 ||
1438 (r = sshbuf_putb(to->critical, from->critical)) != 0 ||
1439 (r = sshbuf_putb(to->extensions, from->extensions)) != 0)
1440 goto out;
1441
1442 to->serial = from->serial;
1443 to->type = from->type;
1444 if (from->key_id == NULL)
1445 to->key_id = NULL;
1446 else if ((to->key_id = strdup(from->key_id)) == NULL) {
1447 r = SSH_ERR_ALLOC_FAIL;
1448 goto out;
1449 }
1450 to->valid_after = from->valid_after;
1451 to->valid_before = from->valid_before;
1452 if (from->signature_key == NULL)
1453 to->signature_key = NULL;
1454 else if ((r = sshkey_from_private(from->signature_key,
1455 &to->signature_key)) != 0)
1456 goto out;
1457 if (from->signature_type != NULL &&
1458 (to->signature_type = strdup(from->signature_type)) == NULL) {
1459 r = SSH_ERR_ALLOC_FAIL;
1460 goto out;
1461 }
1462 if (from->nprincipals > SSHKEY_CERT_MAX_PRINCIPALS) {
1463 r = SSH_ERR_INVALID_ARGUMENT;
1464 goto out;
1465 }
1466 if (from->nprincipals > 0) {
1467 if ((to->principals = calloc(from->nprincipals,
1468 sizeof(*to->principals))) == NULL) {
1469 r = SSH_ERR_ALLOC_FAIL;
1470 goto out;
1471 }
1472 for (i = 0; i < from->nprincipals; i++) {
1473 to->principals[i] = strdup(from->principals[i]);
1474 if (to->principals[i] == NULL) {
1475 to->nprincipals = i;
1476 r = SSH_ERR_ALLOC_FAIL;
1477 goto out;
1478 }
1479 }
1480 }
1481 to->nprincipals = from->nprincipals;
1482
1483 /* success */
1484 cert_free(to_key->cert);
1485 to_key->cert = to;
1486 to = NULL;
1487 r = 0;
1488 out:
1489 cert_free(to);
1490 return r;
1491 }
1492
1493 int
1494 sshkey_copy_public_sk(const struct sshkey *from, struct sshkey *to)
1495 {
1496 /* Append security-key application string */
1497 if ((to->sk_application = strdup(from->sk_application)) == NULL)
1498 return SSH_ERR_ALLOC_FAIL;
1499 return 0;
1500 }
1501
1502 int
1503 sshkey_from_private(const struct sshkey *k, struct sshkey **pkp)
1504 {
1505 struct sshkey *n = NULL;
1506 int r = SSH_ERR_INTERNAL_ERROR;
1507 const struct sshkey_impl *impl;
1508
1509 *pkp = NULL;
1510 if ((impl = sshkey_impl_from_key(k)) == NULL)
1511 return SSH_ERR_KEY_TYPE_UNKNOWN;
1512 if ((n = sshkey_new(k->type)) == NULL) {
1513 r = SSH_ERR_ALLOC_FAIL;
1514 goto out;
1515 }
1516 if ((r = impl->funcs->copy_public(k, n)) != 0)
1517 goto out;
1518 if (sshkey_is_cert(k) && (r = sshkey_cert_copy(k, n)) != 0)
1519 goto out;
1520 /* success */
1521 *pkp = n;
1522 n = NULL;
1523 r = 0;
1524 out:
1525 sshkey_free(n);
1526 return r;
1527 }
1528
1529 int
1530 sshkey_is_shielded(struct sshkey *k)
1531 {
1532 return k != NULL && k->shielded_private != NULL;
1533 }
1534
1535 int
1536 sshkey_shield_private(struct sshkey *k)
1537 {
1538 struct sshbuf *prvbuf = NULL;
1539 u_char *prekey = NULL, *enc = NULL, keyiv[SSH_DIGEST_MAX_LENGTH];
1540 struct sshcipher_ctx *cctx = NULL;
1541 const struct sshcipher *cipher;
1542 size_t i, enclen = 0;
1543 struct sshkey *kswap = NULL, tmp;
1544 int r = SSH_ERR_INTERNAL_ERROR;
1545
1546 #ifdef DEBUG_PK
1547 fprintf(stderr, "%s: entering for %s\n", __func__, sshkey_ssh_name(k));
1548 #endif
1549 if ((cipher = cipher_by_name(SSHKEY_SHIELD_CIPHER)) == NULL) {
1550 r = SSH_ERR_INVALID_ARGUMENT;
1551 goto out;
1552 }
1553 if (cipher_keylen(cipher) + cipher_ivlen(cipher) >
1554 ssh_digest_bytes(SSHKEY_SHIELD_PREKEY_HASH)) {
1555 r = SSH_ERR_INTERNAL_ERROR;
1556 goto out;
1557 }
1558
1559 /* Prepare a random pre-key, and from it an ephemeral key */
1560 if ((prekey = malloc(SSHKEY_SHIELD_PREKEY_LEN)) == NULL) {
1561 r = SSH_ERR_ALLOC_FAIL;
1562 goto out;
1563 }
1564 arc4random_buf(prekey, SSHKEY_SHIELD_PREKEY_LEN);
1565 if ((r = ssh_digest_memory(SSHKEY_SHIELD_PREKEY_HASH,
1566 prekey, SSHKEY_SHIELD_PREKEY_LEN,
1567 keyiv, SSH_DIGEST_MAX_LENGTH)) != 0)
1568 goto out;
1569 #ifdef DEBUG_PK
1570 fprintf(stderr, "%s: key+iv\n", __func__);
1571 sshbuf_dump_data(keyiv, ssh_digest_bytes(SSHKEY_SHIELD_PREKEY_HASH),
1572 stderr);
1573 #endif
1574 if ((r = cipher_init(&cctx, cipher, keyiv, cipher_keylen(cipher),
1575 keyiv + cipher_keylen(cipher), cipher_ivlen(cipher), 1)) != 0)
1576 goto out;
1577
1578 /* Serialise and encrypt the private key using the ephemeral key */
1579 if ((prvbuf = sshbuf_new()) == NULL) {
1580 r = SSH_ERR_ALLOC_FAIL;
1581 goto out;
1582 }
1583 if (sshkey_is_shielded(k) && (r = sshkey_unshield_private(k)) != 0)
1584 goto out;
1585 if ((r = sshkey_private_serialize_opt(k, prvbuf,
1586 SSHKEY_SERIALIZE_SHIELD)) != 0)
1587 goto out;
1588 /* pad to cipher blocksize */
1589 i = 0;
1590 while (sshbuf_len(prvbuf) % cipher_blocksize(cipher)) {
1591 if ((r = sshbuf_put_u8(prvbuf, ++i & 0xff)) != 0)
1592 goto out;
1593 }
1594 #ifdef DEBUG_PK
1595 fprintf(stderr, "%s: serialised\n", __func__);
1596 sshbuf_dump(prvbuf, stderr);
1597 #endif
1598 /* encrypt */
1599 enclen = sshbuf_len(prvbuf);
1600 if ((enc = malloc(enclen)) == NULL) {
1601 r = SSH_ERR_ALLOC_FAIL;
1602 goto out;
1603 }
1604 if ((r = cipher_crypt(cctx, 0, enc,
1605 sshbuf_ptr(prvbuf), sshbuf_len(prvbuf), 0, 0)) != 0)
1606 goto out;
1607 #ifdef DEBUG_PK
1608 fprintf(stderr, "%s: encrypted\n", __func__);
1609 sshbuf_dump_data(enc, enclen, stderr);
1610 #endif
1611
1612 /* Make a scrubbed, public-only copy of our private key argument */
1613 if ((r = sshkey_from_private(k, &kswap)) != 0)
1614 goto out;
1615
1616 /* Swap the private key out (it will be destroyed below) */
1617 tmp = *kswap;
1618 *kswap = *k;
1619 *k = tmp;
1620
1621 /* Insert the shielded key into our argument */
1622 k->shielded_private = enc;
1623 k->shielded_len = enclen;
1624 k->shield_prekey = prekey;
1625 k->shield_prekey_len = SSHKEY_SHIELD_PREKEY_LEN;
1626 enc = prekey = NULL; /* transferred */
1627 enclen = 0;
1628
1629 /* preserve key fields that are required for correct operation */
1630 k->sk_flags = kswap->sk_flags;
1631
1632 /* success */
1633 r = 0;
1634
1635 out:
1636 /* XXX behaviour on error - invalidate original private key? */
1637 cipher_free(cctx);
1638 explicit_bzero(keyiv, sizeof(keyiv));
1639 explicit_bzero(&tmp, sizeof(tmp));
1640 freezero(enc, enclen);
1641 freezero(prekey, SSHKEY_SHIELD_PREKEY_LEN);
1642 sshkey_free(kswap);
1643 sshbuf_free(prvbuf);
1644 return r;
1645 }
1646
1647 /* Check deterministic padding after private key */
1648 static int
1649 private2_check_padding(struct sshbuf *decrypted)
1650 {
1651 u_char pad;
1652 size_t i;
1653 int r;
1654
1655 i = 0;
1656 while (sshbuf_len(decrypted)) {
1657 if ((r = sshbuf_get_u8(decrypted, &pad)) != 0)
1658 goto out;
1659 if (pad != (++i & 0xff)) {
1660 r = SSH_ERR_INVALID_FORMAT;
1661 goto out;
1662 }
1663 }
1664 /* success */
1665 r = 0;
1666 out:
1667 explicit_bzero(&pad, sizeof(pad));
1668 explicit_bzero(&i, sizeof(i));
1669 return r;
1670 }
1671
1672 int
1673 sshkey_unshield_private(struct sshkey *k)
1674 {
1675 struct sshbuf *prvbuf = NULL;
1676 u_char *cp, keyiv[SSH_DIGEST_MAX_LENGTH];
1677 struct sshcipher_ctx *cctx = NULL;
1678 const struct sshcipher *cipher;
1679 struct sshkey *kswap = NULL, tmp;
1680 int r = SSH_ERR_INTERNAL_ERROR;
1681
1682 #ifdef DEBUG_PK
1683 fprintf(stderr, "%s: entering for %s\n", __func__, sshkey_ssh_name(k));
1684 #endif
1685 if (!sshkey_is_shielded(k))
1686 return 0; /* nothing to do */
1687
1688 if ((cipher = cipher_by_name(SSHKEY_SHIELD_CIPHER)) == NULL) {
1689 r = SSH_ERR_INVALID_ARGUMENT;
1690 goto out;
1691 }
1692 if (cipher_keylen(cipher) + cipher_ivlen(cipher) >
1693 ssh_digest_bytes(SSHKEY_SHIELD_PREKEY_HASH)) {
1694 r = SSH_ERR_INTERNAL_ERROR;
1695 goto out;
1696 }
1697 /* check size of shielded key blob */
1698 if (k->shielded_len < cipher_blocksize(cipher) ||
1699 (k->shielded_len % cipher_blocksize(cipher)) != 0) {
1700 r = SSH_ERR_INVALID_FORMAT;
1701 goto out;
1702 }
1703
1704 /* Calculate the ephemeral key from the prekey */
1705 if ((r = ssh_digest_memory(SSHKEY_SHIELD_PREKEY_HASH,
1706 k->shield_prekey, k->shield_prekey_len,
1707 keyiv, SSH_DIGEST_MAX_LENGTH)) != 0)
1708 goto out;
1709 if ((r = cipher_init(&cctx, cipher, keyiv, cipher_keylen(cipher),
1710 keyiv + cipher_keylen(cipher), cipher_ivlen(cipher), 0)) != 0)
1711 goto out;
1712 #ifdef DEBUG_PK
1713 fprintf(stderr, "%s: key+iv\n", __func__);
1714 sshbuf_dump_data(keyiv, ssh_digest_bytes(SSHKEY_SHIELD_PREKEY_HASH),
1715 stderr);
1716 #endif
1717
1718 /* Decrypt and parse the shielded private key using the ephemeral key */
1719 if ((prvbuf = sshbuf_new()) == NULL) {
1720 r = SSH_ERR_ALLOC_FAIL;
1721 goto out;
1722 }
1723 if ((r = sshbuf_reserve(prvbuf, k->shielded_len, &cp)) != 0)
1724 goto out;
1725 /* decrypt */
1726 #ifdef DEBUG_PK
1727 fprintf(stderr, "%s: encrypted\n", __func__);
1728 sshbuf_dump_data(k->shielded_private, k->shielded_len, stderr);
1729 #endif
1730 if ((r = cipher_crypt(cctx, 0, cp,
1731 k->shielded_private, k->shielded_len, 0, 0)) != 0)
1732 goto out;
1733 #ifdef DEBUG_PK
1734 fprintf(stderr, "%s: serialised\n", __func__);
1735 sshbuf_dump(prvbuf, stderr);
1736 #endif
1737 /* Parse private key */
1738 if ((r = sshkey_private_deserialize(prvbuf, &kswap)) != 0)
1739 goto out;
1740
1741 if ((r = private2_check_padding(prvbuf)) != 0)
1742 goto out;
1743
1744 /* Swap the parsed key back into place */
1745 tmp = *kswap;
1746 *kswap = *k;
1747 *k = tmp;
1748
1749 /* success */
1750 r = 0;
1751
1752 out:
1753 cipher_free(cctx);
1754 explicit_bzero(keyiv, sizeof(keyiv));
1755 explicit_bzero(&tmp, sizeof(tmp));
1756 sshkey_free(kswap);
1757 sshbuf_free(prvbuf);
1758 return r;
1759 }
1760
1761 static int
1762 cert_parse(struct sshbuf *b, struct sshkey *key, struct sshbuf *certbuf)
1763 {
1764 struct sshbuf *principals = NULL, *crit = NULL;
1765 struct sshbuf *exts = NULL, *ca = NULL;
1766 u_char *sig = NULL;
1767 size_t signed_len = 0, slen = 0, kidlen = 0;
1768 int ret = SSH_ERR_INTERNAL_ERROR;
1769
1770 /* Copy the entire key blob for verification and later serialisation */
1771 if ((ret = sshbuf_putb(key->cert->certblob, certbuf)) != 0)
1772 return ret;
1773
1774 /* Parse body of certificate up to signature */
1775 if ((ret = sshbuf_get_u64(b, &key->cert->serial)) != 0 ||
1776 (ret = sshbuf_get_u32(b, &key->cert->type)) != 0 ||
1777 (ret = sshbuf_get_cstring(b, &key->cert->key_id, &kidlen)) != 0 ||
1778 (ret = sshbuf_froms(b, &principals)) != 0 ||
1779 (ret = sshbuf_get_u64(b, &key->cert->valid_after)) != 0 ||
1780 (ret = sshbuf_get_u64(b, &key->cert->valid_before)) != 0 ||
1781 (ret = sshbuf_froms(b, &crit)) != 0 ||
1782 (ret = sshbuf_froms(b, &exts)) != 0 ||
1783 (ret = sshbuf_get_string_direct(b, NULL, NULL)) != 0 ||
1784 (ret = sshbuf_froms(b, &ca)) != 0) {
1785 /* XXX debug print error for ret */
1786 ret = SSH_ERR_INVALID_FORMAT;
1787 goto out;
1788 }
1789
1790 /* Signature is left in the buffer so we can calculate this length */
1791 signed_len = sshbuf_len(key->cert->certblob) - sshbuf_len(b);
1792
1793 if ((ret = sshbuf_get_string(b, &sig, &slen)) != 0) {
1794 ret = SSH_ERR_INVALID_FORMAT;
1795 goto out;
1796 }
1797
1798 if (key->cert->type != SSH2_CERT_TYPE_USER &&
1799 key->cert->type != SSH2_CERT_TYPE_HOST) {
1800 ret = SSH_ERR_KEY_CERT_UNKNOWN_TYPE;
1801 goto out;
1802 }
1803
1804 /* Parse principals section */
1805 while (sshbuf_len(principals) > 0) {
1806 char *principal = NULL;
1807 char **oprincipals = NULL;
1808
1809 if (key->cert->nprincipals >= SSHKEY_CERT_MAX_PRINCIPALS) {
1810 ret = SSH_ERR_INVALID_FORMAT;
1811 goto out;
1812 }
1813 if ((ret = sshbuf_get_cstring(principals, &principal,
1814 NULL)) != 0) {
1815 ret = SSH_ERR_INVALID_FORMAT;
1816 goto out;
1817 }
1818 oprincipals = key->cert->principals;
1819 key->cert->principals = recallocarray(key->cert->principals,
1820 key->cert->nprincipals, key->cert->nprincipals + 1,
1821 sizeof(*key->cert->principals));
1822 if (key->cert->principals == NULL) {
1823 free(principal);
1824 key->cert->principals = oprincipals;
1825 ret = SSH_ERR_ALLOC_FAIL;
1826 goto out;
1827 }
1828 key->cert->principals[key->cert->nprincipals++] = principal;
1829 }
1830
1831 /*
1832 * Stash a copies of the critical options and extensions sections
1833 * for later use.
1834 */
1835 if ((ret = sshbuf_putb(key->cert->critical, crit)) != 0 ||
1836 (exts != NULL &&
1837 (ret = sshbuf_putb(key->cert->extensions, exts)) != 0))
1838 goto out;
1839
1840 /*
1841 * Validate critical options and extensions sections format.
1842 */
1843 while (sshbuf_len(crit) != 0) {
1844 if ((ret = sshbuf_get_string_direct(crit, NULL, NULL)) != 0 ||
1845 (ret = sshbuf_get_string_direct(crit, NULL, NULL)) != 0) {
1846 sshbuf_reset(key->cert->critical);
1847 ret = SSH_ERR_INVALID_FORMAT;
1848 goto out;
1849 }
1850 }
1851 while (exts != NULL && sshbuf_len(exts) != 0) {
1852 if ((ret = sshbuf_get_string_direct(exts, NULL, NULL)) != 0 ||
1853 (ret = sshbuf_get_string_direct(exts, NULL, NULL)) != 0) {
1854 sshbuf_reset(key->cert->extensions);
1855 ret = SSH_ERR_INVALID_FORMAT;
1856 goto out;
1857 }
1858 }
1859
1860 /* Parse CA key and check signature */
1861 if (sshkey_from_blob_internal(ca, &key->cert->signature_key, 0) != 0) {
1862 ret = SSH_ERR_KEY_CERT_INVALID_SIGN_KEY;
1863 goto out;
1864 }
1865 if (!sshkey_type_is_valid_ca(key->cert->signature_key->type)) {
1866 ret = SSH_ERR_KEY_CERT_INVALID_SIGN_KEY;
1867 goto out;
1868 }
1869 if ((ret = sshkey_verify(key->cert->signature_key, sig, slen,
1870 sshbuf_ptr(key->cert->certblob), signed_len, NULL, 0, NULL)) != 0)
1871 goto out;
1872 if ((ret = sshkey_get_sigtype(sig, slen,
1873 &key->cert->signature_type)) != 0)
1874 goto out;
1875
1876 /* Success */
1877 ret = 0;
1878 out:
1879 sshbuf_free(ca);
1880 sshbuf_free(crit);
1881 sshbuf_free(exts);
1882 sshbuf_free(principals);
1883 free(sig);
1884 return ret;
1885 }
1886
1887 int
1888 sshkey_deserialize_sk(struct sshbuf *b, struct sshkey *key)
1889 {
1890 /* Parse additional security-key application string */
1891 if (sshbuf_get_cstring(b, &key->sk_application, NULL) != 0)
1892 return SSH_ERR_INVALID_FORMAT;
1893 return 0;
1894 }
1895
1896 static int
1897 sshkey_from_blob_internal(struct sshbuf *b, struct sshkey **keyp,
1898 int allow_cert)
1899 {
1900 int type, ret = SSH_ERR_INTERNAL_ERROR;
1901 char *ktype = NULL;
1902 struct sshkey *key = NULL;
1903 struct sshbuf *copy;
1904 const struct sshkey_impl *impl;
1905
1906 #ifdef DEBUG_PK /* XXX */
1907 sshbuf_dump(b, stderr);
1908 #endif
1909 if (keyp != NULL)
1910 *keyp = NULL;
1911 if ((copy = sshbuf_fromb(b)) == NULL) {
1912 ret = SSH_ERR_ALLOC_FAIL;
1913 goto out;
1914 }
1915 if (sshbuf_get_cstring(b, &ktype, NULL) != 0) {
1916 ret = SSH_ERR_INVALID_FORMAT;
1917 goto out;
1918 }
1919
1920 type = sshkey_type_from_name(ktype);
1921 if (!allow_cert && sshkey_type_is_cert(type)) {
1922 ret = SSH_ERR_KEY_CERT_INVALID_SIGN_KEY;
1923 goto out;
1924 }
1925 if ((impl = sshkey_impl_from_type(type)) == NULL) {
1926 ret = SSH_ERR_KEY_TYPE_UNKNOWN;
1927 goto out;
1928 }
1929 if ((key = sshkey_new(type)) == NULL) {
1930 ret = SSH_ERR_ALLOC_FAIL;
1931 goto out;
1932 }
1933 if (sshkey_type_is_cert(type)) {
1934 /* Skip nonce that precedes all certificates */
1935 if (sshbuf_get_string_direct(b, NULL, NULL) != 0) {
1936 ret = SSH_ERR_INVALID_FORMAT;
1937 goto out;
1938 }
1939 }
1940 if ((ret = impl->funcs->deserialize_public(ktype, b, key)) != 0)
1941 goto out;
1942
1943 /* Parse certificate potion */
1944 if (sshkey_is_cert(key) && (ret = cert_parse(b, key, copy)) != 0)
1945 goto out;
1946
1947 if (key != NULL && sshbuf_len(b) != 0) {
1948 ret = SSH_ERR_INVALID_FORMAT;
1949 goto out;
1950 }
1951 ret = 0;
1952 if (keyp != NULL) {
1953 *keyp = key;
1954 key = NULL;
1955 }
1956 out:
1957 sshbuf_free(copy);
1958 sshkey_free(key);
1959 free(ktype);
1960 return ret;
1961 }
1962
1963 int
1964 sshkey_from_blob(const u_char *blob, size_t blen, struct sshkey **keyp)
1965 {
1966 struct sshbuf *b;
1967 int r;
1968
1969 if ((b = sshbuf_from(blob, blen)) == NULL)
1970 return SSH_ERR_ALLOC_FAIL;
1971 r = sshkey_from_blob_internal(b, keyp, 1);
1972 sshbuf_free(b);
1973 return r;
1974 }
1975
1976 int
1977 sshkey_fromb(struct sshbuf *b, struct sshkey **keyp)
1978 {
1979 return sshkey_from_blob_internal(b, keyp, 1);
1980 }
1981
1982 int
1983 sshkey_froms(struct sshbuf *buf, struct sshkey **keyp)
1984 {
1985 struct sshbuf *b;
1986 int r;
1987
1988 if ((r = sshbuf_froms(buf, &b)) != 0)
1989 return r;
1990 r = sshkey_from_blob_internal(b, keyp, 1);
1991 sshbuf_free(b);
1992 return r;
1993 }
1994
1995 int
1996 sshkey_get_sigtype(const u_char *sig, size_t siglen, char **sigtypep)
1997 {
1998 int r;
1999 struct sshbuf *b = NULL;
2000 char *sigtype = NULL;
2001
2002 if (sigtypep != NULL)
2003 *sigtypep = NULL;
2004 if ((b = sshbuf_from(sig, siglen)) == NULL)
2005 return SSH_ERR_ALLOC_FAIL;
2006 if ((r = sshbuf_get_cstring(b, &sigtype, NULL)) != 0)
2007 goto out;
2008 /* success */
2009 if (sigtypep != NULL) {
2010 *sigtypep = sigtype;
2011 sigtype = NULL;
2012 }
2013 r = 0;
2014 out:
2015 free(sigtype);
2016 sshbuf_free(b);
2017 return r;
2018 }
2019
2020 /*
2021 *
2022 * Checks whether a certificate's signature type is allowed.
2023 * Returns 0 (success) if the certificate signature type appears in the
2024 * "allowed" pattern-list, or the key is not a certificate to begin with.
2025 * Otherwise returns a ssherr.h code.
2026 */
2027 int
2028 sshkey_check_cert_sigtype(const struct sshkey *key, const char *allowed)
2029 {
2030 if (key == NULL || allowed == NULL)
2031 return SSH_ERR_INVALID_ARGUMENT;
2032 if (!sshkey_type_is_cert(key->type))
2033 return 0;
2034 if (key->cert == NULL || key->cert->signature_type == NULL)
2035 return SSH_ERR_INVALID_ARGUMENT;
2036 if (match_pattern_list(key->cert->signature_type, allowed, 0) != 1)
2037 return SSH_ERR_SIGN_ALG_UNSUPPORTED;
2038 return 0;
2039 }
2040
2041 /*
2042 * Returns the expected signature algorithm for a given public key algorithm.
2043 */
2044 const char *
2045 sshkey_sigalg_by_name(const char *name)
2046 {
2047 const struct sshkey_impl *impl;
2048 int i;
2049
2050 for (i = 0; keyimpls[i] != NULL; i++) {
2051 impl = keyimpls[i];
2052 if (strcmp(impl->name, name) != 0)
2053 continue;
2054 if (impl->sigalg != NULL)
2055 return impl->sigalg;
2056 if (!impl->cert)
2057 return impl->name;
2058 return sshkey_ssh_name_from_type_nid(
2059 sshkey_type_plain(impl->type), impl->nid);
2060 }
2061 return NULL;
2062 }
2063
2064 /*
2065 * Verifies that the signature algorithm appearing inside the signature blob
2066 * matches that which was requested.
2067 */
2068 int
2069 sshkey_check_sigtype(const u_char *sig, size_t siglen,
2070 const char *requested_alg)
2071 {
2072 const char *expected_alg;
2073 char *sigtype = NULL;
2074 int r;
2075
2076 if (requested_alg == NULL)
2077 return 0;
2078 if ((expected_alg = sshkey_sigalg_by_name(requested_alg)) == NULL)
2079 return SSH_ERR_INVALID_ARGUMENT;
2080 if ((r = sshkey_get_sigtype(sig, siglen, &sigtype)) != 0)
2081 return r;
2082 r = strcmp(expected_alg, sigtype) == 0;
2083 free(sigtype);
2084 return r ? 0 : SSH_ERR_SIGN_ALG_UNSUPPORTED;
2085 }
2086
2087 int
2088 sshkey_sign(struct sshkey *key,
2089 u_char **sigp, size_t *lenp,
2090 const u_char *data, size_t datalen,
2091 const char *alg, const char *sk_provider, const char *sk_pin, u_int compat)
2092 {
2093 int was_shielded = sshkey_is_shielded(key);
2094 int r2, r = SSH_ERR_INTERNAL_ERROR;
2095 const struct sshkey_impl *impl;
2096
2097 if (sigp != NULL)
2098 *sigp = NULL;
2099 if (lenp != NULL)
2100 *lenp = 0;
2101 if (datalen > SSH_KEY_MAX_SIGN_DATA_SIZE)
2102 return SSH_ERR_INVALID_ARGUMENT;
2103 if ((impl = sshkey_impl_from_key(key)) == NULL)
2104 return SSH_ERR_KEY_TYPE_UNKNOWN;
2105 if ((r = sshkey_unshield_private(key)) != 0)
2106 return r;
2107 if (sshkey_is_sk(key)) {
2108 r = sshsk_sign(sk_provider, key, sigp, lenp, data,
2109 datalen, compat, sk_pin);
2110 } else {
2111 if (impl->funcs->sign == NULL)
2112 r = SSH_ERR_SIGN_ALG_UNSUPPORTED;
2113 else {
2114 r = impl->funcs->sign(key, sigp, lenp, data, datalen,
2115 alg, sk_provider, sk_pin, compat);
2116 }
2117 }
2118 if (was_shielded && (r2 = sshkey_shield_private(key)) != 0)
2119 return r2;
2120 return r;
2121 }
2122
2123 /*
2124 * ssh_key_verify returns 0 for a correct signature and < 0 on error.
2125 * If "alg" specified, then the signature must use that algorithm.
2126 */
2127 int
2128 sshkey_verify(const struct sshkey *key,
2129 const u_char *sig, size_t siglen,
2130 const u_char *data, size_t dlen, const char *alg, u_int compat,
2131 struct sshkey_sig_details **detailsp)
2132 {
2133 const struct sshkey_impl *impl;
2134
2135 if (detailsp != NULL)
2136 *detailsp = NULL;
2137 if (siglen == 0 || dlen > SSH_KEY_MAX_SIGN_DATA_SIZE)
2138 return SSH_ERR_INVALID_ARGUMENT;
2139 if ((impl = sshkey_impl_from_key(key)) == NULL)
2140 return SSH_ERR_KEY_TYPE_UNKNOWN;
2141 return impl->funcs->verify(key, sig, siglen, data, dlen,
2142 alg, compat, detailsp);
2143 }
2144
2145 /* Convert a plain key to their _CERT equivalent */
2146 int
2147 sshkey_to_certified(struct sshkey *k)
2148 {
2149 int newtype;
2150
2151 if ((newtype = sshkey_type_certified(k->type)) == -1)
2152 return SSH_ERR_INVALID_ARGUMENT;
2153 if ((k->cert = cert_new()) == NULL)
2154 return SSH_ERR_ALLOC_FAIL;
2155 k->type = newtype;
2156 return 0;
2157 }
2158
2159 /* Convert a certificate to its raw key equivalent */
2160 int
2161 sshkey_drop_cert(struct sshkey *k)
2162 {
2163 if (!sshkey_type_is_cert(k->type))
2164 return SSH_ERR_KEY_TYPE_UNKNOWN;
2165 cert_free(k->cert);
2166 k->cert = NULL;
2167 k->type = sshkey_type_plain(k->type);
2168 return 0;
2169 }
2170
2171 /* Sign a certified key, (re-)generating the signed certblob. */
2172 int
2173 sshkey_certify_custom(struct sshkey *k, struct sshkey *ca, const char *alg,
2174 const char *sk_provider, const char *sk_pin,
2175 sshkey_certify_signer *signer, void *signer_ctx)
2176 {
2177 const struct sshkey_impl *impl;
2178 struct sshbuf *principals = NULL;
2179 u_char *ca_blob = NULL, *sig_blob = NULL, nonce[32];
2180 size_t i, ca_len, sig_len;
2181 int ret = SSH_ERR_INTERNAL_ERROR;
2182 struct sshbuf *cert = NULL;
2183 char *sigtype = NULL;
2184
2185 if (k == NULL || k->cert == NULL ||
2186 k->cert->certblob == NULL || ca == NULL)
2187 return SSH_ERR_INVALID_ARGUMENT;
2188 if (!sshkey_is_cert(k))
2189 return SSH_ERR_KEY_TYPE_UNKNOWN;
2190 if (!sshkey_type_is_valid_ca(ca->type))
2191 return SSH_ERR_KEY_CERT_INVALID_SIGN_KEY;
2192 if ((impl = sshkey_impl_from_key(k)) == NULL)
2193 return SSH_ERR_INTERNAL_ERROR;
2194
2195 /*
2196 * If no alg specified as argument but a signature_type was set,
2197 * then prefer that. If both were specified, then they must match.
2198 */
2199 if (alg == NULL)
2200 alg = k->cert->signature_type;
2201 else if (k->cert->signature_type != NULL &&
2202 strcmp(alg, k->cert->signature_type) != 0)
2203 return SSH_ERR_INVALID_ARGUMENT;
2204
2205 /*
2206 * If no signing algorithm or signature_type was specified and we're
2207 * using a RSA key, then default to a good signature algorithm.
2208 */
2209 if (alg == NULL && ca->type == KEY_RSA)
2210 alg = "rsa-sha2-512";
2211
2212 if ((ret = sshkey_to_blob(ca, &ca_blob, &ca_len)) != 0)
2213 return SSH_ERR_KEY_CERT_INVALID_SIGN_KEY;
2214
2215 cert = k->cert->certblob; /* for readability */
2216 sshbuf_reset(cert);
2217 if ((ret = sshbuf_put_cstring(cert, sshkey_ssh_name(k))) != 0)
2218 goto out;
2219
2220 /* -v01 certs put nonce first */
2221 arc4random_buf(&nonce, sizeof(nonce));
2222 if ((ret = sshbuf_put_string(cert, nonce, sizeof(nonce))) != 0)
2223 goto out;
2224
2225 /* Public key next */
2226 if ((ret = impl->funcs->serialize_public(k, cert,
2227 SSHKEY_SERIALIZE_DEFAULT)) != 0)
2228 goto out;
2229
2230 /* Then remaining cert fields */
2231 if ((ret = sshbuf_put_u64(cert, k->cert->serial)) != 0 ||
2232 (ret = sshbuf_put_u32(cert, k->cert->type)) != 0 ||
2233 (ret = sshbuf_put_cstring(cert, k->cert->key_id)) != 0)
2234 goto out;
2235
2236 if ((principals = sshbuf_new()) == NULL) {
2237 ret = SSH_ERR_ALLOC_FAIL;
2238 goto out;
2239 }
2240 for (i = 0; i < k->cert->nprincipals; i++) {
2241 if ((ret = sshbuf_put_cstring(principals,
2242 k->cert->principals[i])) != 0)
2243 goto out;
2244 }
2245 if ((ret = sshbuf_put_stringb(cert, principals)) != 0 ||
2246 (ret = sshbuf_put_u64(cert, k->cert->valid_after)) != 0 ||
2247 (ret = sshbuf_put_u64(cert, k->cert->valid_before)) != 0 ||
2248 (ret = sshbuf_put_stringb(cert, k->cert->critical)) != 0 ||
2249 (ret = sshbuf_put_stringb(cert, k->cert->extensions)) != 0 ||
2250 (ret = sshbuf_put_string(cert, NULL, 0)) != 0 || /* Reserved */
2251 (ret = sshbuf_put_string(cert, ca_blob, ca_len)) != 0)
2252 goto out;
2253
2254 /* Sign the whole mess */
2255 if ((ret = signer(ca, &sig_blob, &sig_len, sshbuf_ptr(cert),
2256 sshbuf_len(cert), alg, sk_provider, sk_pin, 0, signer_ctx)) != 0)
2257 goto out;
2258 /* Check and update signature_type against what was actually used */
2259 if ((ret = sshkey_get_sigtype(sig_blob, sig_len, &sigtype)) != 0)
2260 goto out;
2261 if (alg != NULL && strcmp(alg, sigtype) != 0) {
2262 ret = SSH_ERR_SIGN_ALG_UNSUPPORTED;
2263 goto out;
2264 }
2265 if (k->cert->signature_type == NULL) {
2266 k->cert->signature_type = sigtype;
2267 sigtype = NULL;
2268 }
2269 /* Append signature and we are done */
2270 if ((ret = sshbuf_put_string(cert, sig_blob, sig_len)) != 0)
2271 goto out;
2272 ret = 0;
2273 out:
2274 if (ret != 0)
2275 sshbuf_reset(cert);
2276 free(sig_blob);
2277 free(ca_blob);
2278 free(sigtype);
2279 sshbuf_free(principals);
2280 return ret;
2281 }
2282
2283 static int
2284 default_key_sign(struct sshkey *key, u_char **sigp, size_t *lenp,
2285 const u_char *data, size_t datalen,
2286 const char *alg, const char *sk_provider, const char *sk_pin,
2287 u_int compat, void *ctx)
2288 {
2289 if (ctx != NULL)
2290 return SSH_ERR_INVALID_ARGUMENT;
2291 return sshkey_sign(key, sigp, lenp, data, datalen, alg,
2292 sk_provider, sk_pin, compat);
2293 }
2294
2295 int
2296 sshkey_certify(struct sshkey *k, struct sshkey *ca, const char *alg,
2297 const char *sk_provider, const char *sk_pin)
2298 {
2299 return sshkey_certify_custom(k, ca, alg, sk_provider, sk_pin,
2300 default_key_sign, NULL);
2301 }
2302
2303 int
2304 sshkey_cert_check_authority(const struct sshkey *k,
2305 int want_host, int require_principal, int wildcard_pattern,
2306 uint64_t verify_time, const char *name, const char **reason)
2307 {
2308 u_int i, principal_matches;
2309
2310 if (reason == NULL)
2311 return SSH_ERR_INVALID_ARGUMENT;
2312 if (!sshkey_is_cert(k)) {
2313 *reason = "Key is not a certificate";
2314 return SSH_ERR_KEY_CERT_INVALID;
2315 }
2316 if (want_host) {
2317 if (k->cert->type != SSH2_CERT_TYPE_HOST) {
2318 *reason = "Certificate invalid: not a host certificate";
2319 return SSH_ERR_KEY_CERT_INVALID;
2320 }
2321 } else {
2322 if (k->cert->type != SSH2_CERT_TYPE_USER) {
2323 *reason = "Certificate invalid: not a user certificate";
2324 return SSH_ERR_KEY_CERT_INVALID;
2325 }
2326 }
2327 if (verify_time < k->cert->valid_after) {
2328 *reason = "Certificate invalid: not yet valid";
2329 return SSH_ERR_KEY_CERT_INVALID;
2330 }
2331 if (verify_time >= k->cert->valid_before) {
2332 *reason = "Certificate invalid: expired";
2333 return SSH_ERR_KEY_CERT_INVALID;
2334 }
2335 if (k->cert->nprincipals == 0) {
2336 if (require_principal) {
2337 *reason = "Certificate lacks principal list";
2338 return SSH_ERR_KEY_CERT_INVALID;
2339 }
2340 } else if (name != NULL) {
2341 principal_matches = 0;
2342 for (i = 0; i < k->cert->nprincipals; i++) {
2343 if (wildcard_pattern) {
2344 if (match_pattern(k->cert->principals[i],
2345 name)) {
2346 principal_matches = 1;
2347 break;
2348 }
2349 } else if (strcmp(name, k->cert->principals[i]) == 0) {
2350 principal_matches = 1;
2351 break;
2352 }
2353 }
2354 if (!principal_matches) {
2355 *reason = "Certificate invalid: name is not a listed "
2356 "principal";
2357 return SSH_ERR_KEY_CERT_INVALID;
2358 }
2359 }
2360 return 0;
2361 }
2362
2363 int
2364 sshkey_cert_check_authority_now(const struct sshkey *k,
2365 int want_host, int require_principal, int wildcard_pattern,
2366 const char *name, const char **reason)
2367 {
2368 time_t now;
2369
2370 if ((now = time(NULL)) < 0) {
2371 /* yikes - system clock before epoch! */
2372 *reason = "Certificate invalid: not yet valid";
2373 return SSH_ERR_KEY_CERT_INVALID;
2374 }
2375 return sshkey_cert_check_authority(k, want_host, require_principal,
2376 wildcard_pattern, (uint64_t)now, name, reason);
2377 }
2378
2379 int
2380 sshkey_cert_check_host(const struct sshkey *key, const char *host,
2381 int wildcard_principals, const char *ca_sign_algorithms,
2382 const char **reason)
2383 {
2384 int r;
2385
2386 if ((r = sshkey_cert_check_authority_now(key, 1, 0, wildcard_principals,
2387 host, reason)) != 0)
2388 return r;
2389 if (sshbuf_len(key->cert->critical) != 0) {
2390 *reason = "Certificate contains unsupported critical options";
2391 return SSH_ERR_KEY_CERT_INVALID;
2392 }
2393 if (ca_sign_algorithms != NULL &&
2394 (r = sshkey_check_cert_sigtype(key, ca_sign_algorithms)) != 0) {
2395 *reason = "Certificate signed with disallowed algorithm";
2396 return SSH_ERR_KEY_CERT_INVALID;
2397 }
2398 return 0;
2399 }
2400
2401 size_t
2402 sshkey_format_cert_validity(const struct sshkey_cert *cert, char *s, size_t l)
2403 {
2404 char from[32], to[32], ret[128];
2405
2406 *from = *to = '\0';
2407 if (cert->valid_after == 0 &&
2408 cert->valid_before == 0xffffffffffffffffULL)
2409 return strlcpy(s, "forever", l);
2410
2411 if (cert->valid_after != 0)
2412 format_absolute_time(cert->valid_after, from, sizeof(from));
2413 if (cert->valid_before != 0xffffffffffffffffULL)
2414 format_absolute_time(cert->valid_before, to, sizeof(to));
2415
2416 if (cert->valid_after == 0)
2417 snprintf(ret, sizeof(ret), "before %s", to);
2418 else if (cert->valid_before == 0xffffffffffffffffULL)
2419 snprintf(ret, sizeof(ret), "after %s", from);
2420 else
2421 snprintf(ret, sizeof(ret), "from %s to %s", from, to);
2422
2423 return strlcpy(s, ret, l);
2424 }
2425
2426 /* Common serialization for FIDO private keys */
2427 int
2428 sshkey_serialize_private_sk(const struct sshkey *key, struct sshbuf *b)
2429 {
2430 int r;
2431
2432 if ((r = sshbuf_put_cstring(b, key->sk_application)) != 0 ||
2433 (r = sshbuf_put_u8(b, key->sk_flags)) != 0 ||
2434 (r = sshbuf_put_stringb(b, key->sk_key_handle)) != 0 ||
2435 (r = sshbuf_put_stringb(b, key->sk_reserved)) != 0)
2436 return r;
2437
2438 return 0;
2439 }
2440
2441 int
2442 sshkey_private_serialize_opt(struct sshkey *key, struct sshbuf *buf,
2443 enum sshkey_serialize_rep opts)
2444 {
2445 int r = SSH_ERR_INTERNAL_ERROR;
2446 int was_shielded = sshkey_is_shielded(key);
2447 struct sshbuf *b = NULL;
2448 const struct sshkey_impl *impl;
2449
2450 if ((impl = sshkey_impl_from_key(key)) == NULL)
2451 return SSH_ERR_INTERNAL_ERROR;
2452 if ((r = sshkey_unshield_private(key)) != 0)
2453 return r;
2454 if ((b = sshbuf_new()) == NULL)
2455 return SSH_ERR_ALLOC_FAIL;
2456 if ((r = sshbuf_put_cstring(b, sshkey_ssh_name(key))) != 0)
2457 goto out;
2458 if (sshkey_is_cert(key)) {
2459 if (key->cert == NULL ||
2460 sshbuf_len(key->cert->certblob) == 0) {
2461 r = SSH_ERR_INVALID_ARGUMENT;
2462 goto out;
2463 }
2464 if ((r = sshbuf_put_stringb(b, key->cert->certblob)) != 0)
2465 goto out;
2466 }
2467 if ((r = impl->funcs->serialize_private(key, b, opts)) != 0)
2468 goto out;
2469
2470 /*
2471 * success (but we still need to append the output to buf after
2472 * possibly re-shielding the private key)
2473 */
2474 r = 0;
2475 out:
2476 if (was_shielded)
2477 r = sshkey_shield_private(key);
2478 if (r == 0)
2479 r = sshbuf_putb(buf, b);
2480 sshbuf_free(b);
2481
2482 return r;
2483 }
2484
2485 int
2486 sshkey_private_serialize(struct sshkey *key, struct sshbuf *b)
2487 {
2488 return sshkey_private_serialize_opt(key, b,
2489 SSHKEY_SERIALIZE_DEFAULT);
2490 }
2491
2492 /* Shared deserialization of FIDO private key components */
2493 int
2494 sshkey_private_deserialize_sk(struct sshbuf *buf, struct sshkey *k)
2495 {
2496 int r;
2497
2498 if ((k->sk_key_handle = sshbuf_new()) == NULL ||
2499 (k->sk_reserved = sshbuf_new()) == NULL)
2500 return SSH_ERR_ALLOC_FAIL;
2501 if ((r = sshbuf_get_cstring(buf, &k->sk_application, NULL)) != 0 ||
2502 (r = sshbuf_get_u8(buf, &k->sk_flags)) != 0 ||
2503 (r = sshbuf_get_stringb(buf, k->sk_key_handle)) != 0 ||
2504 (r = sshbuf_get_stringb(buf, k->sk_reserved)) != 0)
2505 return r;
2506
2507 return 0;
2508 }
2509
2510 int
2511 sshkey_private_deserialize(struct sshbuf *buf, struct sshkey **kp)
2512 {
2513 const struct sshkey_impl *impl;
2514 char *tname = NULL;
2515 char *expect_sk_application = NULL;
2516 u_char *expect_ed25519_pk = NULL;
2517 struct sshkey *k = NULL;
2518 int type, r = SSH_ERR_INTERNAL_ERROR;
2519
2520 if (kp != NULL)
2521 *kp = NULL;
2522 if ((r = sshbuf_get_cstring(buf, &tname, NULL)) != 0)
2523 goto out;
2524 type = sshkey_type_from_name(tname);
2525 if (sshkey_type_is_cert(type)) {
2526 /*
2527 * Certificate key private keys begin with the certificate
2528 * itself. Make sure this matches the type of the enclosing
2529 * private key.
2530 */
2531 if ((r = sshkey_froms(buf, &k)) != 0)
2532 goto out;
2533 if (k->type != type) {
2534 r = SSH_ERR_KEY_CERT_MISMATCH;
2535 goto out;
2536 }
2537 /* For ECDSA keys, the group must match too */
2538 if (k->type == KEY_ECDSA &&
2539 k->ecdsa_nid != sshkey_ecdsa_nid_from_name(tname)) {
2540 r = SSH_ERR_KEY_CERT_MISMATCH;
2541 goto out;
2542 }
2543 /*
2544 * Several fields are redundant between certificate and
2545 * private key body, we require these to match.
2546 */
2547 expect_sk_application = k->sk_application;
2548 expect_ed25519_pk = k->ed25519_pk;
2549 k->sk_application = NULL;
2550 k->ed25519_pk = NULL;
2551 /* XXX xmss too or refactor */
2552 } else {
2553 if ((k = sshkey_new(type)) == NULL) {
2554 r = SSH_ERR_ALLOC_FAIL;
2555 goto out;
2556 }
2557 }
2558 if ((impl = sshkey_impl_from_type(type)) == NULL) {
2559 r = SSH_ERR_INTERNAL_ERROR;
2560 goto out;
2561 }
2562 if ((r = impl->funcs->deserialize_private(tname, buf, k)) != 0)
2563 goto out;
2564
2565 /* XXX xmss too or refactor */
2566 if ((expect_sk_application != NULL && (k->sk_application == NULL ||
2567 strcmp(expect_sk_application, k->sk_application) != 0)) ||
2568 (expect_ed25519_pk != NULL && (k->ed25519_pk == NULL ||
2569 memcmp(expect_ed25519_pk, k->ed25519_pk, ED25519_PK_SZ) != 0))) {
2570 r = SSH_ERR_KEY_CERT_MISMATCH;
2571 goto out;
2572 }
2573 /* success */
2574 r = 0;
2575 if (kp != NULL) {
2576 *kp = k;
2577 k = NULL;
2578 }
2579 out:
2580 free(tname);
2581 sshkey_free(k);
2582 free(expect_sk_application);
2583 free(expect_ed25519_pk);
2584 return r;
2585 }
2586
2587 #if defined(WITH_OPENSSL) && defined(OPENSSL_HAS_ECC)
2588 int
2589 sshkey_ec_validate_public(const EC_GROUP *group, const EC_POINT *public)
2590 {
2591 EC_POINT *nq = NULL;
2592 BIGNUM *order = NULL, *x = NULL, *y = NULL, *tmp = NULL;
2593 int ret = SSH_ERR_KEY_INVALID_EC_VALUE;
2594
2595 /*
2596 * NB. This assumes OpenSSL has already verified that the public
2597 * point lies on the curve. This is done by EC_POINT_oct2point()
2598 * implicitly calling EC_POINT_is_on_curve(). If this code is ever
2599 * reachable with public points not unmarshalled using
2600 * EC_POINT_oct2point then the caller will need to explicitly check.
2601 */
2602
2603 /*
2604 * We shouldn't ever hit this case because bignum_get_ecpoint()
2605 * refuses to load GF2m points.
2606 */
2607 if (EC_METHOD_get_field_type(EC_GROUP_method_of(group)) !=
2608 NID_X9_62_prime_field)
2609 goto out;
2610
2611 /* Q != infinity */
2612 if (EC_POINT_is_at_infinity(group, public))
2613 goto out;
2614
2615 if ((x = BN_new()) == NULL ||
2616 (y = BN_new()) == NULL ||
2617 (order = BN_new()) == NULL ||
2618 (tmp = BN_new()) == NULL) {
2619 ret = SSH_ERR_ALLOC_FAIL;
2620 goto out;
2621 }
2622
2623 /* log2(x) > log2(order)/2, log2(y) > log2(order)/2 */
2624 if (EC_GROUP_get_order(group, order, NULL) != 1 ||
2625 EC_POINT_get_affine_coordinates_GFp(group, public,
2626 x, y, NULL) != 1) {
2627 ret = SSH_ERR_LIBCRYPTO_ERROR;
2628 goto out;
2629 }
2630 if (BN_num_bits(x) <= BN_num_bits(order) / 2 ||
2631 BN_num_bits(y) <= BN_num_bits(order) / 2)
2632 goto out;
2633
2634 /* nQ == infinity (n == order of subgroup) */
2635 if ((nq = EC_POINT_new(group)) == NULL) {
2636 ret = SSH_ERR_ALLOC_FAIL;
2637 goto out;
2638 }
2639 if (EC_POINT_mul(group, nq, NULL, public, order, NULL) != 1) {
2640 ret = SSH_ERR_LIBCRYPTO_ERROR;
2641 goto out;
2642 }
2643 if (EC_POINT_is_at_infinity(group, nq) != 1)
2644 goto out;
2645
2646 /* x < order - 1, y < order - 1 */
2647 if (!BN_sub(tmp, order, BN_value_one())) {
2648 ret = SSH_ERR_LIBCRYPTO_ERROR;
2649 goto out;
2650 }
2651 if (BN_cmp(x, tmp) >= 0 || BN_cmp(y, tmp) >= 0)
2652 goto out;
2653 ret = 0;
2654 out:
2655 BN_clear_free(x);
2656 BN_clear_free(y);
2657 BN_clear_free(order);
2658 BN_clear_free(tmp);
2659 EC_POINT_free(nq);
2660 return ret;
2661 }
2662
2663 int
2664 sshkey_ec_validate_private(const EC_KEY *key)
2665 {
2666 BIGNUM *order = NULL, *tmp = NULL;
2667 int ret = SSH_ERR_KEY_INVALID_EC_VALUE;
2668
2669 if ((order = BN_new()) == NULL || (tmp = BN_new()) == NULL) {
2670 ret = SSH_ERR_ALLOC_FAIL;
2671 goto out;
2672 }
2673
2674 /* log2(private) > log2(order)/2 */
2675 if (EC_GROUP_get_order(EC_KEY_get0_group(key), order, NULL) != 1) {
2676 ret = SSH_ERR_LIBCRYPTO_ERROR;
2677 goto out;
2678 }
2679 if (BN_num_bits(EC_KEY_get0_private_key(key)) <=
2680 BN_num_bits(order) / 2)
2681 goto out;
2682
2683 /* private < order - 1 */
2684 if (!BN_sub(tmp, order, BN_value_one())) {
2685 ret = SSH_ERR_LIBCRYPTO_ERROR;
2686 goto out;
2687 }
2688 if (BN_cmp(EC_KEY_get0_private_key(key), tmp) >= 0)
2689 goto out;
2690 ret = 0;
2691 out:
2692 BN_clear_free(order);
2693 BN_clear_free(tmp);
2694 return ret;
2695 }
2696
2697 void
2698 sshkey_dump_ec_point(const EC_GROUP *group, const EC_POINT *point)
2699 {
2700 BIGNUM *x = NULL, *y = NULL;
2701
2702 if (point == NULL) {
2703 fputs("point=(NULL)\n", stderr);
2704 return;
2705 }
2706 if ((x = BN_new()) == NULL || (y = BN_new()) == NULL) {
2707 fprintf(stderr, "%s: BN_new failed\n", __func__);
2708 goto out;
2709 }
2710 if (EC_METHOD_get_field_type(EC_GROUP_method_of(group)) !=
2711 NID_X9_62_prime_field) {
2712 fprintf(stderr, "%s: group is not a prime field\n", __func__);
2713 goto out;
2714 }
2715 if (EC_POINT_get_affine_coordinates_GFp(group, point,
2716 x, y, NULL) != 1) {
2717 fprintf(stderr, "%s: EC_POINT_get_affine_coordinates_GFp\n",
2718 __func__);
2719 goto out;
2720 }
2721 fputs("x=", stderr);
2722 BN_print_fp(stderr, x);
2723 fputs("\ny=", stderr);
2724 BN_print_fp(stderr, y);
2725 fputs("\n", stderr);
2726 out:
2727 BN_clear_free(x);
2728 BN_clear_free(y);
2729 }
2730
2731 void
2732 sshkey_dump_ec_key(const EC_KEY *key)
2733 {
2734 const BIGNUM *exponent;
2735
2736 sshkey_dump_ec_point(EC_KEY_get0_group(key),
2737 EC_KEY_get0_public_key(key));
2738 fputs("exponent=", stderr);
2739 if ((exponent = EC_KEY_get0_private_key(key)) == NULL)
2740 fputs("(NULL)", stderr);
2741 else
2742 BN_print_fp(stderr, EC_KEY_get0_private_key(key));
2743 fputs("\n", stderr);
2744 }
2745 #endif /* WITH_OPENSSL && OPENSSL_HAS_ECC */
2746
2747 static int
2748 sshkey_private_to_blob2(struct sshkey *prv, struct sshbuf *blob,
2749 const char *passphrase, const char *comment, const char *ciphername,
2750 int rounds)
2751 {
2752 u_char *cp, *key = NULL, *pubkeyblob = NULL;
2753 u_char salt[SALT_LEN];
2754 size_t i, pubkeylen, keylen, ivlen, blocksize, authlen;
2755 u_int check;
2756 int r = SSH_ERR_INTERNAL_ERROR;
2757 struct sshcipher_ctx *ciphercontext = NULL;
2758 const struct sshcipher *cipher;
2759 const char *kdfname = KDFNAME;
2760 struct sshbuf *encoded = NULL, *encrypted = NULL, *kdf = NULL;
2761
2762 if (rounds <= 0)
2763 rounds = DEFAULT_ROUNDS;
2764 if (passphrase == NULL || !strlen(passphrase)) {
2765 ciphername = "none";
2766 kdfname = "none";
2767 } else if (ciphername == NULL)
2768 ciphername = DEFAULT_CIPHERNAME;
2769 if ((cipher = cipher_by_name(ciphername)) == NULL) {
2770 r = SSH_ERR_INVALID_ARGUMENT;
2771 goto out;
2772 }
2773
2774 if ((kdf = sshbuf_new()) == NULL ||
2775 (encoded = sshbuf_new()) == NULL ||
2776 (encrypted = sshbuf_new()) == NULL) {
2777 r = SSH_ERR_ALLOC_FAIL;
2778 goto out;
2779 }
2780 blocksize = cipher_blocksize(cipher);
2781 keylen = cipher_keylen(cipher);
2782 ivlen = cipher_ivlen(cipher);
2783 authlen = cipher_authlen(cipher);
2784 if ((key = calloc(1, keylen + ivlen)) == NULL) {
2785 r = SSH_ERR_ALLOC_FAIL;
2786 goto out;
2787 }
2788 if (strcmp(kdfname, "bcrypt") == 0) {
2789 arc4random_buf(salt, SALT_LEN);
2790 if (bcrypt_pbkdf(passphrase, strlen(passphrase),
2791 salt, SALT_LEN, key, keylen + ivlen, rounds) < 0) {
2792 r = SSH_ERR_INVALID_ARGUMENT;
2793 goto out;
2794 }
2795 if ((r = sshbuf_put_string(kdf, salt, SALT_LEN)) != 0 ||
2796 (r = sshbuf_put_u32(kdf, rounds)) != 0)
2797 goto out;
2798 } else if (strcmp(kdfname, "none") != 0) {
2799 /* Unsupported KDF type */
2800 r = SSH_ERR_KEY_UNKNOWN_CIPHER;
2801 goto out;
2802 }
2803 if ((r = cipher_init(&ciphercontext, cipher, key, keylen,
2804 key + keylen, ivlen, 1)) != 0)
2805 goto out;
2806
2807 if ((r = sshbuf_put(encoded, AUTH_MAGIC, sizeof(AUTH_MAGIC))) != 0 ||
2808 (r = sshbuf_put_cstring(encoded, ciphername)) != 0 ||
2809 (r = sshbuf_put_cstring(encoded, kdfname)) != 0 ||
2810 (r = sshbuf_put_stringb(encoded, kdf)) != 0 ||
2811 (r = sshbuf_put_u32(encoded, 1)) != 0 || /* number of keys */
2812 (r = sshkey_to_blob(prv, &pubkeyblob, &pubkeylen)) != 0 ||
2813 (r = sshbuf_put_string(encoded, pubkeyblob, pubkeylen)) != 0)
2814 goto out;
2815
2816 /* set up the buffer that will be encrypted */
2817
2818 /* Random check bytes */
2819 check = arc4random();
2820 if ((r = sshbuf_put_u32(encrypted, check)) != 0 ||
2821 (r = sshbuf_put_u32(encrypted, check)) != 0)
2822 goto out;
2823
2824 /* append private key and comment*/
2825 if ((r = sshkey_private_serialize_opt(prv, encrypted,
2826 SSHKEY_SERIALIZE_FULL)) != 0 ||
2827 (r = sshbuf_put_cstring(encrypted, comment)) != 0)
2828 goto out;
2829
2830 /* padding */
2831 i = 0;
2832 while (sshbuf_len(encrypted) % blocksize) {
2833 if ((r = sshbuf_put_u8(encrypted, ++i & 0xff)) != 0)
2834 goto out;
2835 }
2836
2837 /* length in destination buffer */
2838 if ((r = sshbuf_put_u32(encoded, sshbuf_len(encrypted))) != 0)
2839 goto out;
2840
2841 /* encrypt */
2842 if ((r = sshbuf_reserve(encoded,
2843 sshbuf_len(encrypted) + authlen, &cp)) != 0)
2844 goto out;
2845 if ((r = cipher_crypt(ciphercontext, 0, cp,
2846 sshbuf_ptr(encrypted), sshbuf_len(encrypted), 0, authlen)) != 0)
2847 goto out;
2848
2849 sshbuf_reset(blob);
2850
2851 /* assemble uuencoded key */
2852 if ((r = sshbuf_put(blob, MARK_BEGIN, MARK_BEGIN_LEN)) != 0 ||
2853 (r = sshbuf_dtob64(encoded, blob, 1)) != 0 ||
2854 (r = sshbuf_put(blob, MARK_END, MARK_END_LEN)) != 0)
2855 goto out;
2856
2857 /* success */
2858 r = 0;
2859
2860 out:
2861 sshbuf_free(kdf);
2862 sshbuf_free(encoded);
2863 sshbuf_free(encrypted);
2864 cipher_free(ciphercontext);
2865 explicit_bzero(salt, sizeof(salt));
2866 if (key != NULL)
2867 freezero(key, keylen + ivlen);
2868 if (pubkeyblob != NULL)
2869 freezero(pubkeyblob, pubkeylen);
2870 return r;
2871 }
2872
2873 static int
2874 private2_uudecode(struct sshbuf *blob, struct sshbuf **decodedp)
2875 {
2876 const u_char *cp;
2877 size_t encoded_len;
2878 int r;
2879 u_char last;
2880 struct sshbuf *encoded = NULL, *decoded = NULL;
2881
2882 if (blob == NULL || decodedp == NULL)
2883 return SSH_ERR_INVALID_ARGUMENT;
2884
2885 *decodedp = NULL;
2886
2887 if ((encoded = sshbuf_new()) == NULL ||
2888 (decoded = sshbuf_new()) == NULL) {
2889 r = SSH_ERR_ALLOC_FAIL;
2890 goto out;
2891 }
2892
2893 /* check preamble */
2894 cp = sshbuf_ptr(blob);
2895 encoded_len = sshbuf_len(blob);
2896 if (encoded_len < (MARK_BEGIN_LEN + MARK_END_LEN) ||
2897 memcmp(cp, MARK_BEGIN, MARK_BEGIN_LEN) != 0) {
2898 r = SSH_ERR_INVALID_FORMAT;
2899 goto out;
2900 }
2901 cp += MARK_BEGIN_LEN;
2902 encoded_len -= MARK_BEGIN_LEN;
2903
2904 /* Look for end marker, removing whitespace as we go */
2905 while (encoded_len > 0) {
2906 if (*cp != '\n' && *cp != '\r') {
2907 if ((r = sshbuf_put_u8(encoded, *cp)) != 0)
2908 goto out;
2909 }
2910 last = *cp;
2911 encoded_len--;
2912 cp++;
2913 if (last == '\n') {
2914 if (encoded_len >= MARK_END_LEN &&
2915 memcmp(cp, MARK_END, MARK_END_LEN) == 0) {
2916 /* \0 terminate */
2917 if ((r = sshbuf_put_u8(encoded, 0)) != 0)
2918 goto out;
2919 break;
2920 }
2921 }
2922 }
2923 if (encoded_len == 0) {
2924 r = SSH_ERR_INVALID_FORMAT;
2925 goto out;
2926 }
2927
2928 /* decode base64 */
2929 if ((r = sshbuf_b64tod(decoded, (char *)sshbuf_ptr(encoded))) != 0)
2930 goto out;
2931
2932 /* check magic */
2933 if (sshbuf_len(decoded) < sizeof(AUTH_MAGIC) ||
2934 memcmp(sshbuf_ptr(decoded), AUTH_MAGIC, sizeof(AUTH_MAGIC))) {
2935 r = SSH_ERR_INVALID_FORMAT;
2936 goto out;
2937 }
2938 /* success */
2939 *decodedp = decoded;
2940 decoded = NULL;
2941 r = 0;
2942 out:
2943 sshbuf_free(encoded);
2944 sshbuf_free(decoded);
2945 return r;
2946 }
2947
2948 static int
2949 private2_decrypt(struct sshbuf *decoded, const char *passphrase,
2950 struct sshbuf **decryptedp, struct sshkey **pubkeyp)
2951 {
2952 char *ciphername = NULL, *kdfname = NULL;
2953 const struct sshcipher *cipher = NULL;
2954 int r = SSH_ERR_INTERNAL_ERROR;
2955 size_t keylen = 0, ivlen = 0, authlen = 0, slen = 0;
2956 struct sshbuf *kdf = NULL, *decrypted = NULL;
2957 struct sshcipher_ctx *ciphercontext = NULL;
2958 struct sshkey *pubkey = NULL;
2959 u_char *key = NULL, *salt = NULL, *dp;
2960 u_int blocksize, rounds, nkeys, encrypted_len, check1, check2;
2961
2962 if (decoded == NULL || decryptedp == NULL || pubkeyp == NULL)
2963 return SSH_ERR_INVALID_ARGUMENT;
2964
2965 *decryptedp = NULL;
2966 *pubkeyp = NULL;
2967
2968 if ((decrypted = sshbuf_new()) == NULL) {
2969 r = SSH_ERR_ALLOC_FAIL;
2970 goto out;
2971 }
2972
2973 /* parse public portion of key */
2974 if ((r = sshbuf_consume(decoded, sizeof(AUTH_MAGIC))) != 0 ||
2975 (r = sshbuf_get_cstring(decoded, &ciphername, NULL)) != 0 ||
2976 (r = sshbuf_get_cstring(decoded, &kdfname, NULL)) != 0 ||
2977 (r = sshbuf_froms(decoded, &kdf)) != 0 ||
2978 (r = sshbuf_get_u32(decoded, &nkeys)) != 0)
2979 goto out;
2980
2981 if (nkeys != 1) {
2982 /* XXX only one key supported at present */
2983 r = SSH_ERR_INVALID_FORMAT;
2984 goto out;
2985 }
2986
2987 if ((r = sshkey_froms(decoded, &pubkey)) != 0 ||
2988 (r = sshbuf_get_u32(decoded, &encrypted_len)) != 0)
2989 goto out;
2990
2991 if ((cipher = cipher_by_name(ciphername)) == NULL) {
2992 r = SSH_ERR_KEY_UNKNOWN_CIPHER;
2993 goto out;
2994 }
2995 if (strcmp(kdfname, "none") != 0 && strcmp(kdfname, "bcrypt") != 0) {
2996 r = SSH_ERR_KEY_UNKNOWN_CIPHER;
2997 goto out;
2998 }
2999 if (strcmp(kdfname, "none") == 0 && strcmp(ciphername, "none") != 0) {
3000 r = SSH_ERR_INVALID_FORMAT;
3001 goto out;
3002 }
3003 if ((passphrase == NULL || strlen(passphrase) == 0) &&
3004 strcmp(kdfname, "none") != 0) {
3005 /* passphrase required */
3006 r = SSH_ERR_KEY_WRONG_PASSPHRASE;
3007 goto out;
3008 }
3009
3010 /* check size of encrypted key blob */
3011 blocksize = cipher_blocksize(cipher);
3012 if (encrypted_len < blocksize || (encrypted_len % blocksize) != 0) {
3013 r = SSH_ERR_INVALID_FORMAT;
3014 goto out;
3015 }
3016
3017 /* setup key */
3018 keylen = cipher_keylen(cipher);
3019 ivlen = cipher_ivlen(cipher);
3020 authlen = cipher_authlen(cipher);
3021 if ((key = calloc(1, keylen + ivlen)) == NULL) {
3022 r = SSH_ERR_ALLOC_FAIL;
3023 goto out;
3024 }
3025 if (strcmp(kdfname, "bcrypt") == 0) {
3026 if ((r = sshbuf_get_string(kdf, &salt, &slen)) != 0 ||
3027 (r = sshbuf_get_u32(kdf, &rounds)) != 0)
3028 goto out;
3029 if (bcrypt_pbkdf(passphrase, strlen(passphrase), salt, slen,
3030 key, keylen + ivlen, rounds) < 0) {
3031 r = SSH_ERR_INVALID_FORMAT;
3032 goto out;
3033 }
3034 }
3035
3036 /* check that an appropriate amount of auth data is present */
3037 if (sshbuf_len(decoded) < authlen ||
3038 sshbuf_len(decoded) - authlen < encrypted_len) {
3039 r = SSH_ERR_INVALID_FORMAT;
3040 goto out;
3041 }
3042
3043 /* decrypt private portion of key */
3044 if ((r = sshbuf_reserve(decrypted, encrypted_len, &dp)) != 0 ||
3045 (r = cipher_init(&ciphercontext, cipher, key, keylen,
3046 key + keylen, ivlen, 0)) != 0)
3047 goto out;
3048 if ((r = cipher_crypt(ciphercontext, 0, dp, sshbuf_ptr(decoded),
3049 encrypted_len, 0, authlen)) != 0) {
3050 /* an integrity error here indicates an incorrect passphrase */
3051 if (r == SSH_ERR_MAC_INVALID)
3052 r = SSH_ERR_KEY_WRONG_PASSPHRASE;
3053 goto out;
3054 }
3055 if ((r = sshbuf_consume(decoded, encrypted_len + authlen)) != 0)
3056 goto out;
3057 /* there should be no trailing data */
3058 if (sshbuf_len(decoded) != 0) {
3059 r = SSH_ERR_INVALID_FORMAT;
3060 goto out;
3061 }
3062
3063 /* check check bytes */
3064 if ((r = sshbuf_get_u32(decrypted, &check1)) != 0 ||
3065 (r = sshbuf_get_u32(decrypted, &check2)) != 0)
3066 goto out;
3067 if (check1 != check2) {
3068 r = SSH_ERR_KEY_WRONG_PASSPHRASE;
3069 goto out;
3070 }
3071 /* success */
3072 *decryptedp = decrypted;
3073 decrypted = NULL;
3074 *pubkeyp = pubkey;
3075 pubkey = NULL;
3076 r = 0;
3077 out:
3078 cipher_free(ciphercontext);
3079 free(ciphername);
3080 free(kdfname);
3081 sshkey_free(pubkey);
3082 if (salt != NULL) {
3083 explicit_bzero(salt, slen);
3084 free(salt);
3085 }
3086 if (key != NULL) {
3087 explicit_bzero(key, keylen + ivlen);
3088 free(key);
3089 }
3090 sshbuf_free(kdf);
3091 sshbuf_free(decrypted);
3092 return r;
3093 }
3094
3095 static int
3096 sshkey_parse_private2(struct sshbuf *blob, int type, const char *passphrase,
3097 struct sshkey **keyp, char **commentp)
3098 {
3099 char *comment = NULL;
3100 int r = SSH_ERR_INTERNAL_ERROR;
3101 struct sshbuf *decoded = NULL, *decrypted = NULL;
3102 struct sshkey *k = NULL, *pubkey = NULL;
3103
3104 if (keyp != NULL)
3105 *keyp = NULL;
3106 if (commentp != NULL)
3107 *commentp = NULL;
3108
3109 /* Undo base64 encoding and decrypt the private section */
3110 if ((r = private2_uudecode(blob, &decoded)) != 0 ||
3111 (r = private2_decrypt(decoded, passphrase,
3112 &decrypted, &pubkey)) != 0)
3113 goto out;
3114
3115 if (type != KEY_UNSPEC &&
3116 sshkey_type_plain(type) != sshkey_type_plain(pubkey->type)) {
3117 r = SSH_ERR_KEY_TYPE_MISMATCH;
3118 goto out;
3119 }
3120
3121 /* Load the private key and comment */
3122 if ((r = sshkey_private_deserialize(decrypted, &k)) != 0 ||
3123 (r = sshbuf_get_cstring(decrypted, &comment, NULL)) != 0)
3124 goto out;
3125
3126 /* Check deterministic padding after private section */
3127 if ((r = private2_check_padding(decrypted)) != 0)
3128 goto out;
3129
3130 /* Check that the public key in the envelope matches the private key */
3131 if (!sshkey_equal(pubkey, k)) {
3132 r = SSH_ERR_INVALID_FORMAT;
3133 goto out;
3134 }
3135
3136 /* success */
3137 r = 0;
3138 if (keyp != NULL) {
3139 *keyp = k;
3140 k = NULL;
3141 }
3142 if (commentp != NULL) {
3143 *commentp = comment;
3144 comment = NULL;
3145 }
3146 out:
3147 free(comment);
3148 sshbuf_free(decoded);
3149 sshbuf_free(decrypted);
3150 sshkey_free(k);
3151 sshkey_free(pubkey);
3152 return r;
3153 }
3154
3155 static int
3156 sshkey_parse_private2_pubkey(struct sshbuf *blob, int type,
3157 struct sshkey **keyp)
3158 {
3159 int r = SSH_ERR_INTERNAL_ERROR;
3160 struct sshbuf *decoded = NULL;
3161 struct sshkey *pubkey = NULL;
3162 u_int nkeys = 0;
3163
3164 if (keyp != NULL)
3165 *keyp = NULL;
3166
3167 if ((r = private2_uudecode(blob, &decoded)) != 0)
3168 goto out;
3169 /* parse public key from unencrypted envelope */
3170 if ((r = sshbuf_consume(decoded, sizeof(AUTH_MAGIC))) != 0 ||
3171 (r = sshbuf_skip_string(decoded)) != 0 || /* cipher */
3172 (r = sshbuf_skip_string(decoded)) != 0 || /* KDF alg */
3173 (r = sshbuf_skip_string(decoded)) != 0 || /* KDF hint */
3174 (r = sshbuf_get_u32(decoded, &nkeys)) != 0)
3175 goto out;
3176
3177 if (nkeys != 1) {
3178 /* XXX only one key supported at present */
3179 r = SSH_ERR_INVALID_FORMAT;
3180 goto out;
3181 }
3182
3183 /* Parse the public key */
3184 if ((r = sshkey_froms(decoded, &pubkey)) != 0)
3185 goto out;
3186
3187 if (type != KEY_UNSPEC &&
3188 sshkey_type_plain(type) != sshkey_type_plain(pubkey->type)) {
3189 r = SSH_ERR_KEY_TYPE_MISMATCH;
3190 goto out;
3191 }
3192
3193 /* success */
3194 r = 0;
3195 if (keyp != NULL) {
3196 *keyp = pubkey;
3197 pubkey = NULL;
3198 }
3199 out:
3200 sshbuf_free(decoded);
3201 sshkey_free(pubkey);
3202 return r;
3203 }
3204
3205 #ifdef WITH_OPENSSL
3206 /* convert SSH v2 key to PEM or PKCS#8 format */
3207 static int
3208 sshkey_private_to_blob_pem_pkcs8(struct sshkey *key, struct sshbuf *buf,
3209 int format, const char *_passphrase, const char *comment)
3210 {
3211 int was_shielded = sshkey_is_shielded(key);
3212 int success, r;
3213 int blen, len = strlen(_passphrase);
3214 u_char *passphrase = (len > 0) ? (u_char *)_passphrase : NULL;
3215 const EVP_CIPHER *cipher = (len > 0) ? EVP_aes_128_cbc() : NULL;
3216 char *bptr;
3217 BIO *bio = NULL;
3218 struct sshbuf *blob;
3219 EVP_PKEY *pkey = NULL;
3220
3221 if (len > 0 && len <= 4)
3222 return SSH_ERR_PASSPHRASE_TOO_SHORT;
3223 if ((blob = sshbuf_new()) == NULL)
3224 return SSH_ERR_ALLOC_FAIL;
3225 if ((bio = BIO_new(BIO_s_mem())) == NULL) {
3226 r = SSH_ERR_ALLOC_FAIL;
3227 goto out;
3228 }
3229 if (format == SSHKEY_PRIVATE_PKCS8 && (pkey = EVP_PKEY_new()) == NULL) {
3230 r = SSH_ERR_ALLOC_FAIL;
3231 goto out;
3232 }
3233 if ((r = sshkey_unshield_private(key)) != 0)
3234 goto out;
3235
3236 switch (key->type) {
3237 #ifdef WITH_DSA
3238 case KEY_DSA:
3239 if (format == SSHKEY_PRIVATE_PEM) {
3240 success = PEM_write_bio_DSAPrivateKey(bio, key->dsa,
3241 cipher, passphrase, len, NULL, NULL);
3242 } else {
3243 success = EVP_PKEY_set1_DSA(pkey, key->dsa);
3244 }
3245 break;
3246 #endif
3247 #ifdef OPENSSL_HAS_ECC
3248 case KEY_ECDSA:
3249 if (format == SSHKEY_PRIVATE_PEM) {
3250 success = PEM_write_bio_ECPrivateKey(bio, key->ecdsa,
3251 cipher, passphrase, len, NULL, NULL);
3252 } else {
3253 success = EVP_PKEY_set1_EC_KEY(pkey, key->ecdsa);
3254 }
3255 break;
3256 #endif
3257 case KEY_RSA:
3258 if (format == SSHKEY_PRIVATE_PEM) {
3259 success = PEM_write_bio_RSAPrivateKey(bio, key->rsa,
3260 cipher, passphrase, len, NULL, NULL);
3261 } else {
3262 success = EVP_PKEY_set1_RSA(pkey, key->rsa);
3263 }
3264 break;
3265 default:
3266 success = 0;
3267 break;
3268 }
3269 if (success == 0) {
3270 r = SSH_ERR_LIBCRYPTO_ERROR;
3271 goto out;
3272 }
3273 if (format == SSHKEY_PRIVATE_PKCS8) {
3274 if ((success = PEM_write_bio_PrivateKey(bio, pkey, cipher,
3275 passphrase, len, NULL, NULL)) == 0) {
3276 r = SSH_ERR_LIBCRYPTO_ERROR;
3277 goto out;
3278 }
3279 }
3280 if ((blen = BIO_get_mem_data(bio, &bptr)) <= 0) {
3281 r = SSH_ERR_INTERNAL_ERROR;
3282 goto out;
3283 }
3284 if ((r = sshbuf_put(blob, bptr, blen)) != 0)
3285 goto out;
3286 r = 0;
3287 out:
3288 if (was_shielded)
3289 r = sshkey_shield_private(key);
3290 if (r == 0)
3291 r = sshbuf_putb(buf, blob);
3292
3293 EVP_PKEY_free(pkey);
3294 sshbuf_free(blob);
3295 BIO_free(bio);
3296 return r;
3297 }
3298 #endif /* WITH_OPENSSL */
3299
3300 /* Serialise "key" to buffer "blob" */
3301 int
3302 sshkey_private_to_fileblob(struct sshkey *key, struct sshbuf *blob,
3303 const char *passphrase, const char *comment,
3304 int format, const char *openssh_format_cipher, int openssh_format_rounds)
3305 {
3306 switch (key->type) {
3307 #ifdef WITH_OPENSSL
3308 case KEY_DSA:
3309 case KEY_ECDSA:
3310 case KEY_RSA:
3311 break; /* see below */
3312 #endif /* WITH_OPENSSL */
3313 case KEY_ED25519:
3314 case KEY_ED25519_SK:
3315 #ifdef WITH_XMSS
3316 case KEY_XMSS:
3317 #endif /* WITH_XMSS */
3318 #ifdef WITH_OPENSSL
3319 case KEY_ECDSA_SK:
3320 #endif /* WITH_OPENSSL */
3321 return sshkey_private_to_blob2(key, blob, passphrase,
3322 comment, openssh_format_cipher, openssh_format_rounds);
3323 default:
3324 return SSH_ERR_KEY_TYPE_UNKNOWN;
3325 }
3326
3327 #ifdef WITH_OPENSSL
3328 switch (format) {
3329 case SSHKEY_PRIVATE_OPENSSH:
3330 return sshkey_private_to_blob2(key, blob, passphrase,
3331 comment, openssh_format_cipher, openssh_format_rounds);
3332 case SSHKEY_PRIVATE_PEM:
3333 case SSHKEY_PRIVATE_PKCS8:
3334 return sshkey_private_to_blob_pem_pkcs8(key, blob,
3335 format, passphrase, comment);
3336 default:
3337 return SSH_ERR_INVALID_ARGUMENT;
3338 }
3339 #endif /* WITH_OPENSSL */
3340 }
3341
3342 #ifdef WITH_OPENSSL
3343 static int
3344 translate_libcrypto_error(unsigned long pem_err)
3345 {
3346 int pem_reason = ERR_GET_REASON(pem_err);
3347
3348 switch (ERR_GET_LIB(pem_err)) {
3349 case ERR_LIB_PEM:
3350 switch (pem_reason) {
3351 case PEM_R_BAD_PASSWORD_READ:
3352 #ifdef PEM_R_PROBLEMS_GETTING_PASSWORD
3353 case PEM_R_PROBLEMS_GETTING_PASSWORD:
3354 #endif
3355 #ifdef PEM_R_BAD_DECRYPT
3356 case PEM_R_BAD_DECRYPT:
3357 #endif
3358 return SSH_ERR_KEY_WRONG_PASSPHRASE;
3359 default:
3360 return SSH_ERR_INVALID_FORMAT;
3361 }
3362 case ERR_LIB_EVP:
3363 switch (pem_reason) {
3364 #ifdef EVP_R_BAD_DECRYPT
3365 case EVP_R_BAD_DECRYPT:
3366 return SSH_ERR_KEY_WRONG_PASSPHRASE;
3367 #endif
3368 #ifdef EVP_R_BN_DECODE_ERROR
3369 case EVP_R_BN_DECODE_ERROR:
3370 #endif
3371 case EVP_R_DECODE_ERROR:
3372 #ifdef EVP_R_PRIVATE_KEY_DECODE_ERROR
3373 case EVP_R_PRIVATE_KEY_DECODE_ERROR:
3374 #endif
3375 return SSH_ERR_INVALID_FORMAT;
3376 default:
3377 return SSH_ERR_LIBCRYPTO_ERROR;
3378 }
3379 case ERR_LIB_ASN1:
3380 return SSH_ERR_INVALID_FORMAT;
3381 }
3382 return SSH_ERR_LIBCRYPTO_ERROR;
3383 }
3384
3385 static void
3386 clear_libcrypto_errors(void)
3387 {
3388 while (ERR_get_error() != 0)
3389 ;
3390 }
3391
3392 /*
3393 * Translate OpenSSL error codes to determine whether
3394 * passphrase is required/incorrect.
3395 */
3396 static int
3397 convert_libcrypto_error(void)
3398 {
3399 /*
3400 * Some password errors are reported at the beginning
3401 * of the error queue.
3402 */
3403 if (translate_libcrypto_error(ERR_peek_error()) ==
3404 SSH_ERR_KEY_WRONG_PASSPHRASE)
3405 return SSH_ERR_KEY_WRONG_PASSPHRASE;
3406 return translate_libcrypto_error(ERR_peek_last_error());
3407 }
3408
3409 static int
3410 pem_passphrase_cb(char *buf, int size, int rwflag, void *u)
3411 {
3412 char *p = (char *)u;
3413 size_t len;
3414
3415 if (p == NULL || (len = strlen(p)) == 0)
3416 return -1;
3417 if (size < 0 || len > (size_t)size)
3418 return -1;
3419 memcpy(buf, p, len);
3420 return (int)len;
3421 }
3422
3423 static int
3424 sshkey_parse_private_pem_fileblob(struct sshbuf *blob, int type,
3425 const char *passphrase, struct sshkey **keyp)
3426 {
3427 EVP_PKEY *pk = NULL;
3428 struct sshkey *prv = NULL;
3429 BIO *bio = NULL;
3430 int r;
3431
3432 if (keyp != NULL)
3433 *keyp = NULL;
3434
3435 if ((bio = BIO_new(BIO_s_mem())) == NULL || sshbuf_len(blob) > INT_MAX)
3436 return SSH_ERR_ALLOC_FAIL;
3437 if (BIO_write(bio, sshbuf_ptr(blob), sshbuf_len(blob)) !=
3438 (int)sshbuf_len(blob)) {
3439 r = SSH_ERR_ALLOC_FAIL;
3440 goto out;
3441 }
3442
3443 clear_libcrypto_errors();
3444 if ((pk = PEM_read_bio_PrivateKey(bio, NULL, pem_passphrase_cb,
3445 (char *)passphrase)) == NULL) {
3446 /*
3447 * libcrypto may return various ASN.1 errors when attempting
3448 * to parse a key with an incorrect passphrase.
3449 * Treat all format errors as "incorrect passphrase" if a
3450 * passphrase was supplied.
3451 */
3452 if (passphrase != NULL && *passphrase != '\0')
3453 r = SSH_ERR_KEY_WRONG_PASSPHRASE;
3454 else
3455 r = convert_libcrypto_error();
3456 goto out;
3457 }
3458 if (EVP_PKEY_base_id(pk) == EVP_PKEY_RSA &&
3459 (type == KEY_UNSPEC || type == KEY_RSA)) {
3460 if ((prv = sshkey_new(KEY_UNSPEC)) == NULL) {
3461 r = SSH_ERR_ALLOC_FAIL;
3462 goto out;
3463 }
3464 prv->rsa = EVP_PKEY_get1_RSA(pk);
3465 prv->type = KEY_RSA;
3466 #ifdef DEBUG_PK
3467 RSA_print_fp(stderr, prv->rsa, 8);
3468 #endif
3469 if (RSA_blinding_on(prv->rsa, NULL) != 1) {
3470 r = SSH_ERR_LIBCRYPTO_ERROR;
3471 goto out;
3472 }
3473 if ((r = sshkey_check_rsa_length(prv, 0)) != 0)
3474 goto out;
3475 #ifdef WITH_DSA
3476 } else if (EVP_PKEY_base_id(pk) == EVP_PKEY_DSA &&
3477 (type == KEY_UNSPEC || type == KEY_DSA)) {
3478 if ((prv = sshkey_new(KEY_UNSPEC)) == NULL) {
3479 r = SSH_ERR_ALLOC_FAIL;
3480 goto out;
3481 }
3482 prv->dsa = EVP_PKEY_get1_DSA(pk);
3483 prv->type = KEY_DSA;
3484 #ifdef DEBUG_PK
3485 DSA_print_fp(stderr, prv->dsa, 8);
3486 #endif
3487 #endif
3488 #ifdef OPENSSL_HAS_ECC
3489 } else if (EVP_PKEY_base_id(pk) == EVP_PKEY_EC &&
3490 (type == KEY_UNSPEC || type == KEY_ECDSA)) {
3491 if ((prv = sshkey_new(KEY_UNSPEC)) == NULL) {
3492 r = SSH_ERR_ALLOC_FAIL;
3493 goto out;
3494 }
3495 prv->ecdsa = EVP_PKEY_get1_EC_KEY(pk);
3496 prv->type = KEY_ECDSA;
3497 prv->ecdsa_nid = sshkey_ecdsa_key_to_nid(prv->ecdsa);
3498 if (prv->ecdsa_nid == -1 ||
3499 sshkey_curve_nid_to_name(prv->ecdsa_nid) == NULL ||
3500 sshkey_ec_validate_public(EC_KEY_get0_group(prv->ecdsa),
3501 EC_KEY_get0_public_key(prv->ecdsa)) != 0 ||
3502 sshkey_ec_validate_private(prv->ecdsa) != 0) {
3503 r = SSH_ERR_INVALID_FORMAT;
3504 goto out;
3505 }
3506 # ifdef DEBUG_PK
3507 if (prv != NULL && prv->ecdsa != NULL)
3508 sshkey_dump_ec_key(prv->ecdsa);
3509 # endif
3510 #endif /* OPENSSL_HAS_ECC */
3511 #ifdef OPENSSL_HAS_ED25519
3512 } else if (EVP_PKEY_base_id(pk) == EVP_PKEY_ED25519 &&
3513 (type == KEY_UNSPEC || type == KEY_ED25519)) {
3514 size_t len;
3515
3516 if ((prv = sshkey_new(KEY_UNSPEC)) == NULL ||
3517 (prv->ed25519_sk = calloc(1, ED25519_SK_SZ)) == NULL ||
3518 (prv->ed25519_pk = calloc(1, ED25519_PK_SZ)) == NULL) {
3519 r = SSH_ERR_ALLOC_FAIL;
3520 goto out;
3521 }
3522 prv->type = KEY_ED25519;
3523 len = ED25519_PK_SZ;
3524 if (!EVP_PKEY_get_raw_public_key(pk, prv->ed25519_pk, &len)) {
3525 r = SSH_ERR_LIBCRYPTO_ERROR;
3526 goto out;
3527 }
3528 if (len != ED25519_PK_SZ) {
3529 r = SSH_ERR_INVALID_FORMAT;
3530 goto out;
3531 }
3532 len = ED25519_SK_SZ - ED25519_PK_SZ;
3533 if (!EVP_PKEY_get_raw_private_key(pk, prv->ed25519_sk, &len)) {
3534 r = SSH_ERR_LIBCRYPTO_ERROR;
3535 goto out;
3536 }
3537 if (len != ED25519_SK_SZ - ED25519_PK_SZ) {
3538 r = SSH_ERR_INVALID_FORMAT;
3539 goto out;
3540 }
3541 /* Append the public key to our private key */
3542 memcpy(prv->ed25519_sk + (ED25519_SK_SZ - ED25519_PK_SZ),
3543 prv->ed25519_pk, ED25519_PK_SZ);
3544 # ifdef DEBUG_PK
3545 sshbuf_dump_data(prv->ed25519_sk, ED25519_SK_SZ, stderr);
3546 # endif
3547 #endif /* OPENSSL_HAS_ED25519 */
3548 } else {
3549 r = SSH_ERR_INVALID_FORMAT;
3550 goto out;
3551 }
3552 r = 0;
3553 if (keyp != NULL) {
3554 *keyp = prv;
3555 prv = NULL;
3556 }
3557 out:
3558 BIO_free(bio);
3559 EVP_PKEY_free(pk);
3560 sshkey_free(prv);
3561 return r;
3562 }
3563 #endif /* WITH_OPENSSL */
3564
3565 int
3566 sshkey_parse_private_fileblob_type(struct sshbuf *blob, int type,
3567 const char *passphrase, struct sshkey **keyp, char **commentp)
3568 {
3569 int r = SSH_ERR_INTERNAL_ERROR;
3570
3571 if (keyp != NULL)
3572 *keyp = NULL;
3573 if (commentp != NULL)
3574 *commentp = NULL;
3575
3576 switch (type) {
3577 case KEY_XMSS:
3578 /* No fallback for new-format-only keys */
3579 return sshkey_parse_private2(blob, type, passphrase,
3580 keyp, commentp);
3581 default:
3582 r = sshkey_parse_private2(blob, type, passphrase, keyp,
3583 commentp);
3584 /* Only fallback to PEM parser if a format error occurred. */
3585 if (r != SSH_ERR_INVALID_FORMAT)
3586 return r;
3587 #ifdef WITH_OPENSSL
3588 return sshkey_parse_private_pem_fileblob(blob, type,
3589 passphrase, keyp);
3590 #else
3591 return SSH_ERR_INVALID_FORMAT;
3592 #endif /* WITH_OPENSSL */
3593 }
3594 }
3595
3596 int
3597 sshkey_parse_private_fileblob(struct sshbuf *buffer, const char *passphrase,
3598 struct sshkey **keyp, char **commentp)
3599 {
3600 if (keyp != NULL)
3601 *keyp = NULL;
3602 if (commentp != NULL)
3603 *commentp = NULL;
3604
3605 return sshkey_parse_private_fileblob_type(buffer, KEY_UNSPEC,
3606 passphrase, keyp, commentp);
3607 }
3608
3609 void
3610 sshkey_sig_details_free(struct sshkey_sig_details *details)
3611 {
3612 freezero(details, sizeof(*details));
3613 }
3614
3615 int
3616 sshkey_parse_pubkey_from_private_fileblob_type(struct sshbuf *blob, int type,
3617 struct sshkey **pubkeyp)
3618 {
3619 int r = SSH_ERR_INTERNAL_ERROR;
3620
3621 if (pubkeyp != NULL)
3622 *pubkeyp = NULL;
3623 /* only new-format private keys bundle a public key inside */
3624 if ((r = sshkey_parse_private2_pubkey(blob, type, pubkeyp)) != 0)
3625 return r;
3626 return 0;
3627 }
3628
3629 #ifdef WITH_XMSS
3630 /*
3631 * serialize the key with the current state and forward the state
3632 * maxsign times.
3633 */
3634 int
3635 sshkey_private_serialize_maxsign(struct sshkey *k, struct sshbuf *b,
3636 u_int32_t maxsign, int printerror)
3637 {
3638 int r, rupdate;
3639
3640 if (maxsign == 0 ||
3641 sshkey_type_plain(k->type) != KEY_XMSS)
3642 return sshkey_private_serialize_opt(k, b,
3643 SSHKEY_SERIALIZE_DEFAULT);
3644 if ((r = sshkey_xmss_get_state(k, printerror)) != 0 ||
3645 (r = sshkey_private_serialize_opt(k, b,
3646 SSHKEY_SERIALIZE_STATE)) != 0 ||
3647 (r = sshkey_xmss_forward_state(k, maxsign)) != 0)
3648 goto out;
3649 r = 0;
3650 out:
3651 if ((rupdate = sshkey_xmss_update_state(k, printerror)) != 0) {
3652 if (r == 0)
3653 r = rupdate;
3654 }
3655 return r;
3656 }
3657
3658 u_int32_t
3659 sshkey_signatures_left(const struct sshkey *k)
3660 {
3661 if (sshkey_type_plain(k->type) == KEY_XMSS)
3662 return sshkey_xmss_signatures_left(k);
3663 return 0;
3664 }
3665
3666 int
3667 sshkey_enable_maxsign(struct sshkey *k, u_int32_t maxsign)
3668 {
3669 if (sshkey_type_plain(k->type) != KEY_XMSS)
3670 return SSH_ERR_INVALID_ARGUMENT;
3671 return sshkey_xmss_enable_maxsign(k, maxsign);
3672 }
3673
3674 int
3675 sshkey_set_filename(struct sshkey *k, const char *filename)
3676 {
3677 if (k == NULL)
3678 return SSH_ERR_INVALID_ARGUMENT;
3679 if (sshkey_type_plain(k->type) != KEY_XMSS)
3680 return 0;
3681 if (filename == NULL)
3682 return SSH_ERR_INVALID_ARGUMENT;
3683 if ((k->xmss_filename = strdup(filename)) == NULL)
3684 return SSH_ERR_ALLOC_FAIL;
3685 return 0;
3686 }
3687 #else
3688 int
3689 sshkey_private_serialize_maxsign(struct sshkey *k, struct sshbuf *b,
3690 u_int32_t maxsign, int printerror)
3691 {
3692 return sshkey_private_serialize_opt(k, b, SSHKEY_SERIALIZE_DEFAULT);
3693 }
3694
3695 u_int32_t
3696 sshkey_signatures_left(const struct sshkey *k)
3697 {
3698 return 0;
3699 }
3700
3701 int
3702 sshkey_enable_maxsign(struct sshkey *k, u_int32_t maxsign)
3703 {
3704 return SSH_ERR_INVALID_ARGUMENT;
3705 }
3706
3707 int
3708 sshkey_set_filename(struct sshkey *k, const char *filename)
3709 {
3710 if (k == NULL)
3711 return SSH_ERR_INVALID_ARGUMENT;
3712 return 0;
3713 }
3714 #endif /* WITH_XMSS */
DragonFly BSD