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 92int sshkey_private_serialize_opt(struct sshkey *key, 93 struct sshbuf *buf, enum sshkey_serialize_rep); 94static int sshkey_from_blob_internal(struct sshbuf *buf, 95 struct sshkey **keyp, int allow_cert); 96 97/* Supported key types */ 98extern const struct sshkey_impl sshkey_ed25519_impl; 99extern const struct sshkey_impl sshkey_ed25519_cert_impl; 100extern const struct sshkey_impl sshkey_ed25519_sk_impl; 101extern const struct sshkey_impl sshkey_ed25519_sk_cert_impl; 102#ifdef WITH_OPENSSL 103# ifdef OPENSSL_HAS_ECC 104# ifdef ENABLE_SK 105extern const struct sshkey_impl sshkey_ecdsa_sk_impl; 106extern const struct sshkey_impl sshkey_ecdsa_sk_cert_impl; 107extern const struct sshkey_impl sshkey_ecdsa_sk_webauthn_impl; 108# endif /* ENABLE_SK */ 109extern const struct sshkey_impl sshkey_ecdsa_nistp256_impl; 110extern const struct sshkey_impl sshkey_ecdsa_nistp256_cert_impl; 111extern const struct sshkey_impl sshkey_ecdsa_nistp384_impl; 112extern const struct sshkey_impl sshkey_ecdsa_nistp384_cert_impl; 113# ifdef OPENSSL_HAS_NISTP521 114extern const struct sshkey_impl sshkey_ecdsa_nistp521_impl; 115extern const struct sshkey_impl sshkey_ecdsa_nistp521_cert_impl; 116# endif /* OPENSSL_HAS_NISTP521 */ 117# endif /* OPENSSL_HAS_ECC */ 118extern const struct sshkey_impl sshkey_rsa_impl; 119extern const struct sshkey_impl sshkey_rsa_cert_impl; 120extern const struct sshkey_impl sshkey_rsa_sha256_impl; 121extern const struct sshkey_impl sshkey_rsa_sha256_cert_impl; 122extern const struct sshkey_impl sshkey_rsa_sha512_impl; 123extern const struct sshkey_impl sshkey_rsa_sha512_cert_impl; 124# ifdef WITH_DSA 125extern const struct sshkey_impl sshkey_dss_impl; 126extern const struct sshkey_impl sshkey_dsa_cert_impl; 127# endif 128#endif /* WITH_OPENSSL */ 129#ifdef WITH_XMSS 130extern const struct sshkey_impl sshkey_xmss_impl; 131extern const struct sshkey_impl sshkey_xmss_cert_impl; 132#endif 133 134const 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 175static const struct sshkey_impl * 176sshkey_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 187static const struct sshkey_impl * 188sshkey_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 200static const struct sshkey_impl * 201sshkey_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 208const char * 209sshkey_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 218static const char * 219sshkey_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 228int 229sshkey_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 238const char * 239sshkey_ssh_name(const struct sshkey *k) 240{ 241 return sshkey_ssh_name_from_type_nid(k->type, k->ecdsa_nid); 242} 243 244const char * 245sshkey_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 251int 252sshkey_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 267static int 268key_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 280int 281sshkey_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 295int 296sshkey_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 318char * 319sshkey_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 347int 348sshkey_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 390u_int 391sshkey_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 402static int 403sshkey_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 413int 414sshkey_is_cert(const struct sshkey *k) 415{ 416 if (k == NULL) 417 return 0; 418 return sshkey_type_is_cert(k->type); 419} 420 421int 422sshkey_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 */ 436int 437sshkey_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 */ 460static int 461sshkey_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 */ 485int 486sshkey_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 500u_int 501sshkey_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 517int 518sshkey_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 534const char * 535sshkey_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 551int 552sshkey_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 569static void 570cert_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 588static struct sshkey_cert * 589cert_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 608struct sshkey * 609sshkey_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 */ 640void 641sshkey_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 650static void 651sshkey_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 666void 667sshkey_free(struct sshkey *k) 668{ 669 sshkey_free_contents(k); 670 freezero(k, sizeof(*k)); 671} 672 673static int 674cert_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 */ 689int 690sshkey_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 */ 703int 704sshkey_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 716int 717sshkey_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 */ 730int 731sshkey_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 741static int 742to_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 773int 774sshkey_putb(const struct sshkey *key, struct sshbuf *b) 775{ 776 return to_blob_buf(key, b, 0, SSHKEY_SERIALIZE_DEFAULT); 777} 778 779int 780sshkey_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 795int 796sshkey_puts(const struct sshkey *key, struct sshbuf *b) 797{ 798 return sshkey_puts_opts(key, b, SSHKEY_SERIALIZE_DEFAULT); 799} 800 801int 802sshkey_putb_plain(const struct sshkey *key, struct sshbuf *b) 803{ 804 return to_blob_buf(key, b, 1, SSHKEY_SERIALIZE_DEFAULT); 805} 806 807static int 808to_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 839int 840sshkey_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 845int 846sshkey_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 851int 852sshkey_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 892static char * 893fingerprint_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 914static char * 915fingerprint_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 932static char * 933fingerprint_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) 1013static char * 1014fingerprint_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 1110char * 1111sshkey_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 1153static int 1154peek_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 * */ 1174int 1175sshkey_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 1248int 1249sshkey_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 1277int 1278sshkey_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 1294int 1295sshkey_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 1317const char * 1318sshkey_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 1330int 1331sshkey_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 1351int 1352sshkey_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 1397int 1398sshkey_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 1423int 1424sshkey_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 1493int 1494sshkey_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 1502int 1503sshkey_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 1529int 1530sshkey_is_shielded(struct sshkey *k) 1531{ 1532 return k != NULL && k->shielded_private != NULL; 1533} 1534 1535int 1536sshkey_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 */ 1648static int 1649private2_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 1672int 1673sshkey_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 1761static int 1762cert_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 1887int 1888sshkey_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 1896static int 1897sshkey_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 1963int 1964sshkey_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 1976int 1977sshkey_fromb(struct sshbuf *b, struct sshkey **keyp) 1978{ 1979 return sshkey_from_blob_internal(b, keyp, 1); 1980} 1981 1982int 1983sshkey_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 1995int 1996sshkey_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 */ 2027int 2028sshkey_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 */ 2044const char * 2045sshkey_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 */ 2068int 2069sshkey_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 2087int 2088sshkey_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 */ 2127int 2128sshkey_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 */ 2146int 2147sshkey_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 */ 2160int 2161sshkey_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. */ 2172int 2173sshkey_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 2283static int 2284default_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 2295int 2296sshkey_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 2303int 2304sshkey_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 2363int 2364sshkey_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 2379int 2380sshkey_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 2401size_t 2402sshkey_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 */ 2427int 2428sshkey_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 2441int 2442sshkey_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 2485int 2486sshkey_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 */ 2493int 2494sshkey_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 2510int 2511sshkey_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) 2588int 2589sshkey_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 2663int 2664sshkey_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 2697void 2698sshkey_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 2731void 2732sshkey_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 2747static int 2748sshkey_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 2873static int 2874private2_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 2948static int 2949private2_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 3095static int 3096sshkey_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 3155static int 3156sshkey_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 */ 3207static int 3208sshkey_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" */ 3301int 3302sshkey_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 3343static int 3344translate_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 3385static void 3386clear_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 */ 3396static int 3397convert_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 3409static int 3410pem_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 3423static int 3424sshkey_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 3565int 3566sshkey_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 3596int 3597sshkey_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 3609void 3610sshkey_sig_details_free(struct sshkey_sig_details *details) 3611{ 3612 freezero(details, sizeof(*details)); 3613} 3614 3615int 3616sshkey_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 */ 3634int 3635sshkey_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; 3650out: 3651 if ((rupdate = sshkey_xmss_update_state(k, printerror)) != 0) { 3652 if (r == 0) 3653 r = rupdate; 3654 } 3655 return r; 3656} 3657 3658u_int32_t 3659sshkey_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 3666int 3667sshkey_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 3674int 3675sshkey_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 3688int 3689sshkey_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 3695u_int32_t 3696sshkey_signatures_left(const struct sshkey *k) 3697{ 3698 return 0; 3699} 3700 3701int 3702sshkey_enable_maxsign(struct sshkey *k, u_int32_t maxsign) 3703{ 3704 return SSH_ERR_INVALID_ARGUMENT; 3705} 3706 3707int 3708sshkey_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 */ 3715