1 /* $OpenBSD: sshkey.c,v 1.138 2023/08/21 04:36:46 djm Exp $ */ 2 /* 3 * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved. 4 * Copyright (c) 2008 Alexander von Gernler. All rights reserved. 5 * Copyright (c) 2010,2011 Damien Miller. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 #include "includes.h" 29 30 #include <sys/types.h> 31 #include <netinet/in.h> 32 33 #ifdef WITH_OPENSSL 34 #include <openssl/evp.h> 35 #include <openssl/err.h> 36 #include <openssl/pem.h> 37 #endif 38 39 #include "crypto_api.h" 40 41 #include <errno.h> 42 #include <limits.h> 43 #include <stdio.h> 44 #include <stdlib.h> 45 #include <string.h> 46 #include <resolv.h> 47 #include <time.h> 48 #ifdef HAVE_UTIL_H 49 #include <util.h> 50 #endif /* HAVE_UTIL_H */ 51 52 #include "ssh2.h" 53 #include "ssherr.h" 54 #include "misc.h" 55 #include "sshbuf.h" 56 #include "cipher.h" 57 #include "digest.h" 58 #define SSHKEY_INTERNAL 59 #include "sshkey.h" 60 #include "match.h" 61 #include "ssh-sk.h" 62 63 #ifdef WITH_XMSS 64 #include "sshkey-xmss.h" 65 #include "xmss_fast.h" 66 #endif 67 68 #include "openbsd-compat/openssl-compat.h" 69 70 /* openssh private key file format */ 71 #define MARK_BEGIN "-----BEGIN OPENSSH PRIVATE KEY-----\n" 72 #define MARK_END "-----END OPENSSH PRIVATE KEY-----\n" 73 #define MARK_BEGIN_LEN (sizeof(MARK_BEGIN) - 1) 74 #define MARK_END_LEN (sizeof(MARK_END) - 1) 75 #define KDFNAME "bcrypt" 76 #define AUTH_MAGIC "openssh-key-v1" 77 #define SALT_LEN 16 78 #define DEFAULT_CIPHERNAME "aes256-ctr" 79 #define DEFAULT_ROUNDS 24 80 81 /* Version identification string for SSH v1 identity files. */ 82 #define LEGACY_BEGIN "SSH PRIVATE KEY FILE FORMAT 1.1\n" 83 84 /* 85 * Constants relating to "shielding" support; protection of keys expected 86 * to remain in memory for long durations 87 */ 88 #define SSHKEY_SHIELD_PREKEY_LEN (16 * 1024) 89 #define SSHKEY_SHIELD_CIPHER "aes256-ctr" /* XXX want AES-EME* */ 90 #define SSHKEY_SHIELD_PREKEY_HASH SSH_DIGEST_SHA512 91 92 int sshkey_private_serialize_opt(struct sshkey *key, 93 struct sshbuf *buf, enum sshkey_serialize_rep); 94 static int sshkey_from_blob_internal(struct sshbuf *buf, 95 struct sshkey **keyp, int allow_cert); 96 97 /* Supported key types */ 98 extern const struct sshkey_impl sshkey_ed25519_impl; 99 extern const struct sshkey_impl sshkey_ed25519_cert_impl; 100 extern const struct sshkey_impl sshkey_ed25519_sk_impl; 101 extern const struct sshkey_impl sshkey_ed25519_sk_cert_impl; 102 #ifdef WITH_OPENSSL 103 # ifdef OPENSSL_HAS_ECC 104 # ifdef ENABLE_SK 105 extern const struct sshkey_impl sshkey_ecdsa_sk_impl; 106 extern const struct sshkey_impl sshkey_ecdsa_sk_cert_impl; 107 extern const struct sshkey_impl sshkey_ecdsa_sk_webauthn_impl; 108 # endif /* ENABLE_SK */ 109 extern const struct sshkey_impl sshkey_ecdsa_nistp256_impl; 110 extern const struct sshkey_impl sshkey_ecdsa_nistp256_cert_impl; 111 extern const struct sshkey_impl sshkey_ecdsa_nistp384_impl; 112 extern const struct sshkey_impl sshkey_ecdsa_nistp384_cert_impl; 113 # ifdef OPENSSL_HAS_NISTP521 114 extern const struct sshkey_impl sshkey_ecdsa_nistp521_impl; 115 extern const struct sshkey_impl sshkey_ecdsa_nistp521_cert_impl; 116 # endif /* OPENSSL_HAS_NISTP521 */ 117 # endif /* OPENSSL_HAS_ECC */ 118 extern const struct sshkey_impl sshkey_rsa_impl; 119 extern const struct sshkey_impl sshkey_rsa_cert_impl; 120 extern const struct sshkey_impl sshkey_rsa_sha256_impl; 121 extern const struct sshkey_impl sshkey_rsa_sha256_cert_impl; 122 extern const struct sshkey_impl sshkey_rsa_sha512_impl; 123 extern const struct sshkey_impl sshkey_rsa_sha512_cert_impl; 124 extern const struct sshkey_impl sshkey_dss_impl; 125 extern const struct sshkey_impl sshkey_dsa_cert_impl; 126 #endif /* WITH_OPENSSL */ 127 #ifdef WITH_XMSS 128 extern const struct sshkey_impl sshkey_xmss_impl; 129 extern const struct sshkey_impl sshkey_xmss_cert_impl; 130 #endif 131 132 const struct sshkey_impl * const keyimpls[] = { 133 &sshkey_ed25519_impl, 134 &sshkey_ed25519_cert_impl, 135 #ifdef ENABLE_SK 136 &sshkey_ed25519_sk_impl, 137 &sshkey_ed25519_sk_cert_impl, 138 #endif 139 #ifdef WITH_OPENSSL 140 # ifdef OPENSSL_HAS_ECC 141 &sshkey_ecdsa_nistp256_impl, 142 &sshkey_ecdsa_nistp256_cert_impl, 143 &sshkey_ecdsa_nistp384_impl, 144 &sshkey_ecdsa_nistp384_cert_impl, 145 # ifdef OPENSSL_HAS_NISTP521 146 &sshkey_ecdsa_nistp521_impl, 147 &sshkey_ecdsa_nistp521_cert_impl, 148 # endif /* OPENSSL_HAS_NISTP521 */ 149 # ifdef ENABLE_SK 150 &sshkey_ecdsa_sk_impl, 151 &sshkey_ecdsa_sk_cert_impl, 152 &sshkey_ecdsa_sk_webauthn_impl, 153 # endif /* ENABLE_SK */ 154 # endif /* OPENSSL_HAS_ECC */ 155 &sshkey_dss_impl, 156 &sshkey_dsa_cert_impl, 157 &sshkey_rsa_impl, 158 &sshkey_rsa_cert_impl, 159 &sshkey_rsa_sha256_impl, 160 &sshkey_rsa_sha256_cert_impl, 161 &sshkey_rsa_sha512_impl, 162 &sshkey_rsa_sha512_cert_impl, 163 #endif /* WITH_OPENSSL */ 164 #ifdef WITH_XMSS 165 &sshkey_xmss_impl, 166 &sshkey_xmss_cert_impl, 167 #endif 168 NULL 169 }; 170 171 static const struct sshkey_impl * 172 sshkey_impl_from_type(int type) 173 { 174 int i; 175 176 for (i = 0; keyimpls[i] != NULL; i++) { 177 if (keyimpls[i]->type == type) 178 return keyimpls[i]; 179 } 180 return NULL; 181 } 182 183 static const struct sshkey_impl * 184 sshkey_impl_from_type_nid(int type, int nid) 185 { 186 int i; 187 188 for (i = 0; keyimpls[i] != NULL; i++) { 189 if (keyimpls[i]->type == type && 190 (keyimpls[i]->nid == 0 || keyimpls[i]->nid == nid)) 191 return keyimpls[i]; 192 } 193 return NULL; 194 } 195 196 static const struct sshkey_impl * 197 sshkey_impl_from_key(const struct sshkey *k) 198 { 199 if (k == NULL) 200 return NULL; 201 return sshkey_impl_from_type_nid(k->type, k->ecdsa_nid); 202 } 203 204 const char * 205 sshkey_type(const struct sshkey *k) 206 { 207 const struct sshkey_impl *impl; 208 209 if ((impl = sshkey_impl_from_key(k)) == NULL) 210 return "unknown"; 211 return impl->shortname; 212 } 213 214 static const char * 215 sshkey_ssh_name_from_type_nid(int type, int nid) 216 { 217 const struct sshkey_impl *impl; 218 219 if ((impl = sshkey_impl_from_type_nid(type, nid)) == NULL) 220 return "ssh-unknown"; 221 return impl->name; 222 } 223 224 int 225 sshkey_type_is_cert(int type) 226 { 227 const struct sshkey_impl *impl; 228 229 if ((impl = sshkey_impl_from_type(type)) == NULL) 230 return 0; 231 return impl->cert; 232 } 233 234 const char * 235 sshkey_ssh_name(const struct sshkey *k) 236 { 237 return sshkey_ssh_name_from_type_nid(k->type, k->ecdsa_nid); 238 } 239 240 const char * 241 sshkey_ssh_name_plain(const struct sshkey *k) 242 { 243 return sshkey_ssh_name_from_type_nid(sshkey_type_plain(k->type), 244 k->ecdsa_nid); 245 } 246 247 int 248 sshkey_type_from_name(const char *name) 249 { 250 int i; 251 const struct sshkey_impl *impl; 252 253 for (i = 0; keyimpls[i] != NULL; i++) { 254 impl = keyimpls[i]; 255 /* Only allow shortname matches for plain key types */ 256 if ((impl->name != NULL && strcmp(name, impl->name) == 0) || 257 (!impl->cert && strcasecmp(impl->shortname, name) == 0)) 258 return impl->type; 259 } 260 return KEY_UNSPEC; 261 } 262 263 static int 264 key_type_is_ecdsa_variant(int type) 265 { 266 switch (type) { 267 case KEY_ECDSA: 268 case KEY_ECDSA_CERT: 269 case KEY_ECDSA_SK: 270 case KEY_ECDSA_SK_CERT: 271 return 1; 272 } 273 return 0; 274 } 275 276 int 277 sshkey_ecdsa_nid_from_name(const char *name) 278 { 279 int i; 280 281 for (i = 0; keyimpls[i] != NULL; i++) { 282 if (!key_type_is_ecdsa_variant(keyimpls[i]->type)) 283 continue; 284 if (keyimpls[i]->name != NULL && 285 strcmp(name, keyimpls[i]->name) == 0) 286 return keyimpls[i]->nid; 287 } 288 return -1; 289 } 290 291 int 292 sshkey_match_keyname_to_sigalgs(const char *keyname, const char *sigalgs) 293 { 294 int ktype; 295 296 if (sigalgs == NULL || *sigalgs == '\0' || 297 (ktype = sshkey_type_from_name(keyname)) == KEY_UNSPEC) 298 return 0; 299 else if (ktype == KEY_RSA) { 300 return match_pattern_list("ssh-rsa", sigalgs, 0) == 1 || 301 match_pattern_list("rsa-sha2-256", sigalgs, 0) == 1 || 302 match_pattern_list("rsa-sha2-512", sigalgs, 0) == 1; 303 } else if (ktype == KEY_RSA_CERT) { 304 return match_pattern_list("ssh-rsa-cert-v01@openssh.com", 305 sigalgs, 0) == 1 || 306 match_pattern_list("rsa-sha2-256-cert-v01@openssh.com", 307 sigalgs, 0) == 1 || 308 match_pattern_list("rsa-sha2-512-cert-v01@openssh.com", 309 sigalgs, 0) == 1; 310 } else 311 return match_pattern_list(keyname, sigalgs, 0) == 1; 312 } 313 314 char * 315 sshkey_alg_list(int certs_only, int plain_only, int include_sigonly, char sep) 316 { 317 char *tmp, *ret = NULL; 318 size_t i, nlen, rlen = 0; 319 const struct sshkey_impl *impl; 320 321 for (i = 0; keyimpls[i] != NULL; i++) { 322 impl = keyimpls[i]; 323 if (impl->name == NULL) 324 continue; 325 if (!include_sigonly && impl->sigonly) 326 continue; 327 if ((certs_only && !impl->cert) || (plain_only && impl->cert)) 328 continue; 329 if (ret != NULL) 330 ret[rlen++] = sep; 331 nlen = strlen(impl->name); 332 if ((tmp = realloc(ret, rlen + nlen + 2)) == NULL) { 333 free(ret); 334 return NULL; 335 } 336 ret = tmp; 337 memcpy(ret + rlen, impl->name, nlen + 1); 338 rlen += nlen; 339 } 340 return ret; 341 } 342 343 int 344 sshkey_names_valid2(const char *names, int allow_wildcard, int plain_only) 345 { 346 char *s, *cp, *p; 347 const struct sshkey_impl *impl; 348 int i, type; 349 350 if (names == NULL || strcmp(names, "") == 0) 351 return 0; 352 if ((s = cp = strdup(names)) == NULL) 353 return 0; 354 for ((p = strsep(&cp, ",")); p && *p != '\0'; 355 (p = strsep(&cp, ","))) { 356 type = sshkey_type_from_name(p); 357 if (type == KEY_UNSPEC) { 358 if (allow_wildcard) { 359 /* 360 * Try matching key types against the string. 361 * If any has a positive or negative match then 362 * the component is accepted. 363 */ 364 impl = NULL; 365 for (i = 0; keyimpls[i] != NULL; i++) { 366 if (match_pattern_list( 367 keyimpls[i]->name, p, 0) != 0) { 368 impl = keyimpls[i]; 369 break; 370 } 371 } 372 if (impl != NULL) 373 continue; 374 } 375 free(s); 376 return 0; 377 } else if (plain_only && sshkey_type_is_cert(type)) { 378 free(s); 379 return 0; 380 } 381 } 382 free(s); 383 return 1; 384 } 385 386 u_int 387 sshkey_size(const struct sshkey *k) 388 { 389 const struct sshkey_impl *impl; 390 391 if ((impl = sshkey_impl_from_key(k)) == NULL) 392 return 0; 393 if (impl->funcs->size != NULL) 394 return impl->funcs->size(k); 395 return impl->keybits; 396 } 397 398 static int 399 sshkey_type_is_valid_ca(int type) 400 { 401 const struct sshkey_impl *impl; 402 403 if ((impl = sshkey_impl_from_type(type)) == NULL) 404 return 0; 405 /* All non-certificate types may act as CAs */ 406 return !impl->cert; 407 } 408 409 int 410 sshkey_is_cert(const struct sshkey *k) 411 { 412 if (k == NULL) 413 return 0; 414 return sshkey_type_is_cert(k->type); 415 } 416 417 int 418 sshkey_is_sk(const struct sshkey *k) 419 { 420 if (k == NULL) 421 return 0; 422 switch (sshkey_type_plain(k->type)) { 423 case KEY_ECDSA_SK: 424 case KEY_ED25519_SK: 425 return 1; 426 default: 427 return 0; 428 } 429 } 430 431 /* Return the cert-less equivalent to a certified key type */ 432 int 433 sshkey_type_plain(int type) 434 { 435 switch (type) { 436 case KEY_RSA_CERT: 437 return KEY_RSA; 438 case KEY_DSA_CERT: 439 return KEY_DSA; 440 case KEY_ECDSA_CERT: 441 return KEY_ECDSA; 442 case KEY_ECDSA_SK_CERT: 443 return KEY_ECDSA_SK; 444 case KEY_ED25519_CERT: 445 return KEY_ED25519; 446 case KEY_ED25519_SK_CERT: 447 return KEY_ED25519_SK; 448 case KEY_XMSS_CERT: 449 return KEY_XMSS; 450 default: 451 return type; 452 } 453 } 454 455 /* Return the cert equivalent to a plain key type */ 456 static int 457 sshkey_type_certified(int type) 458 { 459 switch (type) { 460 case KEY_RSA: 461 return KEY_RSA_CERT; 462 case KEY_DSA: 463 return KEY_DSA_CERT; 464 case KEY_ECDSA: 465 return KEY_ECDSA_CERT; 466 case KEY_ECDSA_SK: 467 return KEY_ECDSA_SK_CERT; 468 case KEY_ED25519: 469 return KEY_ED25519_CERT; 470 case KEY_ED25519_SK: 471 return KEY_ED25519_SK_CERT; 472 case KEY_XMSS: 473 return KEY_XMSS_CERT; 474 default: 475 return -1; 476 } 477 } 478 479 #ifdef WITH_OPENSSL 480 /* XXX: these are really begging for a table-driven approach */ 481 int 482 sshkey_curve_name_to_nid(const char *name) 483 { 484 if (strcmp(name, "nistp256") == 0) 485 return NID_X9_62_prime256v1; 486 else if (strcmp(name, "nistp384") == 0) 487 return NID_secp384r1; 488 # ifdef OPENSSL_HAS_NISTP521 489 else if (strcmp(name, "nistp521") == 0) 490 return NID_secp521r1; 491 # endif /* OPENSSL_HAS_NISTP521 */ 492 else 493 return -1; 494 } 495 496 u_int 497 sshkey_curve_nid_to_bits(int nid) 498 { 499 switch (nid) { 500 case NID_X9_62_prime256v1: 501 return 256; 502 case NID_secp384r1: 503 return 384; 504 # ifdef OPENSSL_HAS_NISTP521 505 case NID_secp521r1: 506 return 521; 507 # endif /* OPENSSL_HAS_NISTP521 */ 508 default: 509 return 0; 510 } 511 } 512 513 int 514 sshkey_ecdsa_bits_to_nid(int bits) 515 { 516 switch (bits) { 517 case 256: 518 return NID_X9_62_prime256v1; 519 case 384: 520 return NID_secp384r1; 521 # ifdef OPENSSL_HAS_NISTP521 522 case 521: 523 return NID_secp521r1; 524 # endif /* OPENSSL_HAS_NISTP521 */ 525 default: 526 return -1; 527 } 528 } 529 530 const char * 531 sshkey_curve_nid_to_name(int nid) 532 { 533 switch (nid) { 534 case NID_X9_62_prime256v1: 535 return "nistp256"; 536 case NID_secp384r1: 537 return "nistp384"; 538 # ifdef OPENSSL_HAS_NISTP521 539 case NID_secp521r1: 540 return "nistp521"; 541 # endif /* OPENSSL_HAS_NISTP521 */ 542 default: 543 return NULL; 544 } 545 } 546 547 int 548 sshkey_ec_nid_to_hash_alg(int nid) 549 { 550 int kbits = sshkey_curve_nid_to_bits(nid); 551 552 if (kbits <= 0) 553 return -1; 554 555 /* RFC5656 section 6.2.1 */ 556 if (kbits <= 256) 557 return SSH_DIGEST_SHA256; 558 else if (kbits <= 384) 559 return SSH_DIGEST_SHA384; 560 else 561 return SSH_DIGEST_SHA512; 562 } 563 #endif /* WITH_OPENSSL */ 564 565 static void 566 cert_free(struct sshkey_cert *cert) 567 { 568 u_int i; 569 570 if (cert == NULL) 571 return; 572 sshbuf_free(cert->certblob); 573 sshbuf_free(cert->critical); 574 sshbuf_free(cert->extensions); 575 free(cert->key_id); 576 for (i = 0; i < cert->nprincipals; i++) 577 free(cert->principals[i]); 578 free(cert->principals); 579 sshkey_free(cert->signature_key); 580 free(cert->signature_type); 581 freezero(cert, sizeof(*cert)); 582 } 583 584 static struct sshkey_cert * 585 cert_new(void) 586 { 587 struct sshkey_cert *cert; 588 589 if ((cert = calloc(1, sizeof(*cert))) == NULL) 590 return NULL; 591 if ((cert->certblob = sshbuf_new()) == NULL || 592 (cert->critical = sshbuf_new()) == NULL || 593 (cert->extensions = sshbuf_new()) == NULL) { 594 cert_free(cert); 595 return NULL; 596 } 597 cert->key_id = NULL; 598 cert->principals = NULL; 599 cert->signature_key = NULL; 600 cert->signature_type = NULL; 601 return cert; 602 } 603 604 struct sshkey * 605 sshkey_new(int type) 606 { 607 struct sshkey *k; 608 const struct sshkey_impl *impl = NULL; 609 610 if (type != KEY_UNSPEC && 611 (impl = sshkey_impl_from_type(type)) == NULL) 612 return NULL; 613 614 /* All non-certificate types may act as CAs */ 615 if ((k = calloc(1, sizeof(*k))) == NULL) 616 return NULL; 617 k->type = type; 618 k->ecdsa_nid = -1; 619 if (impl != NULL && impl->funcs->alloc != NULL) { 620 if (impl->funcs->alloc(k) != 0) { 621 free(k); 622 return NULL; 623 } 624 } 625 if (sshkey_is_cert(k)) { 626 if ((k->cert = cert_new()) == NULL) { 627 sshkey_free(k); 628 return NULL; 629 } 630 } 631 632 return k; 633 } 634 635 /* Frees common FIDO fields */ 636 void 637 sshkey_sk_cleanup(struct sshkey *k) 638 { 639 free(k->sk_application); 640 sshbuf_free(k->sk_key_handle); 641 sshbuf_free(k->sk_reserved); 642 k->sk_application = NULL; 643 k->sk_key_handle = k->sk_reserved = NULL; 644 } 645 646 static void 647 sshkey_free_contents(struct sshkey *k) 648 { 649 const struct sshkey_impl *impl; 650 651 if (k == NULL) 652 return; 653 if ((impl = sshkey_impl_from_type(k->type)) != NULL && 654 impl->funcs->cleanup != NULL) 655 impl->funcs->cleanup(k); 656 if (sshkey_is_cert(k)) 657 cert_free(k->cert); 658 freezero(k->shielded_private, k->shielded_len); 659 freezero(k->shield_prekey, k->shield_prekey_len); 660 } 661 662 void 663 sshkey_free(struct sshkey *k) 664 { 665 sshkey_free_contents(k); 666 freezero(k, sizeof(*k)); 667 } 668 669 static int 670 cert_compare(struct sshkey_cert *a, struct sshkey_cert *b) 671 { 672 if (a == NULL && b == NULL) 673 return 1; 674 if (a == NULL || b == NULL) 675 return 0; 676 if (sshbuf_len(a->certblob) != sshbuf_len(b->certblob)) 677 return 0; 678 if (timingsafe_bcmp(sshbuf_ptr(a->certblob), sshbuf_ptr(b->certblob), 679 sshbuf_len(a->certblob)) != 0) 680 return 0; 681 return 1; 682 } 683 684 /* Compares FIDO-specific pubkey fields only */ 685 int 686 sshkey_sk_fields_equal(const struct sshkey *a, const struct sshkey *b) 687 { 688 if (a->sk_application == NULL || b->sk_application == NULL) 689 return 0; 690 if (strcmp(a->sk_application, b->sk_application) != 0) 691 return 0; 692 return 1; 693 } 694 695 /* 696 * Compare public portions of key only, allowing comparisons between 697 * certificates and plain keys too. 698 */ 699 int 700 sshkey_equal_public(const struct sshkey *a, const struct sshkey *b) 701 { 702 const struct sshkey_impl *impl; 703 704 if (a == NULL || b == NULL || 705 sshkey_type_plain(a->type) != sshkey_type_plain(b->type)) 706 return 0; 707 if ((impl = sshkey_impl_from_type(a->type)) == NULL) 708 return 0; 709 return impl->funcs->equal(a, b); 710 } 711 712 int 713 sshkey_equal(const struct sshkey *a, const struct sshkey *b) 714 { 715 if (a == NULL || b == NULL || a->type != b->type) 716 return 0; 717 if (sshkey_is_cert(a)) { 718 if (!cert_compare(a->cert, b->cert)) 719 return 0; 720 } 721 return sshkey_equal_public(a, b); 722 } 723 724 725 /* Serialise common FIDO key parts */ 726 int 727 sshkey_serialize_sk(const struct sshkey *key, struct sshbuf *b) 728 { 729 int r; 730 731 if ((r = sshbuf_put_cstring(b, key->sk_application)) != 0) 732 return r; 733 734 return 0; 735 } 736 737 static int 738 to_blob_buf(const struct sshkey *key, struct sshbuf *b, int force_plain, 739 enum sshkey_serialize_rep opts) 740 { 741 int type, ret = SSH_ERR_INTERNAL_ERROR; 742 const char *typename; 743 const struct sshkey_impl *impl; 744 745 if (key == NULL) 746 return SSH_ERR_INVALID_ARGUMENT; 747 748 type = force_plain ? sshkey_type_plain(key->type) : key->type; 749 750 if (sshkey_type_is_cert(type)) { 751 if (key->cert == NULL) 752 return SSH_ERR_EXPECTED_CERT; 753 if (sshbuf_len(key->cert->certblob) == 0) 754 return SSH_ERR_KEY_LACKS_CERTBLOB; 755 /* Use the existing blob */ 756 if ((ret = sshbuf_putb(b, key->cert->certblob)) != 0) 757 return ret; 758 return 0; 759 } 760 if ((impl = sshkey_impl_from_type(type)) == NULL) 761 return SSH_ERR_KEY_TYPE_UNKNOWN; 762 763 typename = sshkey_ssh_name_from_type_nid(type, key->ecdsa_nid); 764 if ((ret = sshbuf_put_cstring(b, typename)) != 0) 765 return ret; 766 return impl->funcs->serialize_public(key, b, opts); 767 } 768 769 int 770 sshkey_putb(const struct sshkey *key, struct sshbuf *b) 771 { 772 return to_blob_buf(key, b, 0, SSHKEY_SERIALIZE_DEFAULT); 773 } 774 775 int 776 sshkey_puts_opts(const struct sshkey *key, struct sshbuf *b, 777 enum sshkey_serialize_rep opts) 778 { 779 struct sshbuf *tmp; 780 int r; 781 782 if ((tmp = sshbuf_new()) == NULL) 783 return SSH_ERR_ALLOC_FAIL; 784 r = to_blob_buf(key, tmp, 0, opts); 785 if (r == 0) 786 r = sshbuf_put_stringb(b, tmp); 787 sshbuf_free(tmp); 788 return r; 789 } 790 791 int 792 sshkey_puts(const struct sshkey *key, struct sshbuf *b) 793 { 794 return sshkey_puts_opts(key, b, SSHKEY_SERIALIZE_DEFAULT); 795 } 796 797 int 798 sshkey_putb_plain(const struct sshkey *key, struct sshbuf *b) 799 { 800 return to_blob_buf(key, b, 1, SSHKEY_SERIALIZE_DEFAULT); 801 } 802 803 static int 804 to_blob(const struct sshkey *key, u_char **blobp, size_t *lenp, int force_plain, 805 enum sshkey_serialize_rep opts) 806 { 807 int ret = SSH_ERR_INTERNAL_ERROR; 808 size_t len; 809 struct sshbuf *b = NULL; 810 811 if (lenp != NULL) 812 *lenp = 0; 813 if (blobp != NULL) 814 *blobp = NULL; 815 if ((b = sshbuf_new()) == NULL) 816 return SSH_ERR_ALLOC_FAIL; 817 if ((ret = to_blob_buf(key, b, force_plain, opts)) != 0) 818 goto out; 819 len = sshbuf_len(b); 820 if (lenp != NULL) 821 *lenp = len; 822 if (blobp != NULL) { 823 if ((*blobp = malloc(len)) == NULL) { 824 ret = SSH_ERR_ALLOC_FAIL; 825 goto out; 826 } 827 memcpy(*blobp, sshbuf_ptr(b), len); 828 } 829 ret = 0; 830 out: 831 sshbuf_free(b); 832 return ret; 833 } 834 835 int 836 sshkey_to_blob(const struct sshkey *key, u_char **blobp, size_t *lenp) 837 { 838 return to_blob(key, blobp, lenp, 0, SSHKEY_SERIALIZE_DEFAULT); 839 } 840 841 int 842 sshkey_plain_to_blob(const struct sshkey *key, u_char **blobp, size_t *lenp) 843 { 844 return to_blob(key, blobp, lenp, 1, SSHKEY_SERIALIZE_DEFAULT); 845 } 846 847 int 848 sshkey_fingerprint_raw(const struct sshkey *k, int dgst_alg, 849 u_char **retp, size_t *lenp) 850 { 851 u_char *blob = NULL, *ret = NULL; 852 size_t blob_len = 0; 853 int r = SSH_ERR_INTERNAL_ERROR; 854 855 if (retp != NULL) 856 *retp = NULL; 857 if (lenp != NULL) 858 *lenp = 0; 859 if (ssh_digest_bytes(dgst_alg) == 0) { 860 r = SSH_ERR_INVALID_ARGUMENT; 861 goto out; 862 } 863 if ((r = to_blob(k, &blob, &blob_len, 1, SSHKEY_SERIALIZE_DEFAULT)) 864 != 0) 865 goto out; 866 if ((ret = calloc(1, SSH_DIGEST_MAX_LENGTH)) == NULL) { 867 r = SSH_ERR_ALLOC_FAIL; 868 goto out; 869 } 870 if ((r = ssh_digest_memory(dgst_alg, blob, blob_len, 871 ret, SSH_DIGEST_MAX_LENGTH)) != 0) 872 goto out; 873 /* success */ 874 if (retp != NULL) { 875 *retp = ret; 876 ret = NULL; 877 } 878 if (lenp != NULL) 879 *lenp = ssh_digest_bytes(dgst_alg); 880 r = 0; 881 out: 882 free(ret); 883 if (blob != NULL) 884 freezero(blob, blob_len); 885 return r; 886 } 887 888 static char * 889 fingerprint_b64(const char *alg, u_char *dgst_raw, size_t dgst_raw_len) 890 { 891 char *ret; 892 size_t plen = strlen(alg) + 1; 893 size_t rlen = ((dgst_raw_len + 2) / 3) * 4 + plen + 1; 894 895 if (dgst_raw_len > 65536 || (ret = calloc(1, rlen)) == NULL) 896 return NULL; 897 strlcpy(ret, alg, rlen); 898 strlcat(ret, ":", rlen); 899 if (dgst_raw_len == 0) 900 return ret; 901 if (b64_ntop(dgst_raw, dgst_raw_len, ret + plen, rlen - plen) == -1) { 902 freezero(ret, rlen); 903 return NULL; 904 } 905 /* Trim padding characters from end */ 906 ret[strcspn(ret, "=")] = '\0'; 907 return ret; 908 } 909 910 static char * 911 fingerprint_hex(const char *alg, u_char *dgst_raw, size_t dgst_raw_len) 912 { 913 char *retval, hex[5]; 914 size_t i, rlen = dgst_raw_len * 3 + strlen(alg) + 2; 915 916 if (dgst_raw_len > 65536 || (retval = calloc(1, rlen)) == NULL) 917 return NULL; 918 strlcpy(retval, alg, rlen); 919 strlcat(retval, ":", rlen); 920 for (i = 0; i < dgst_raw_len; i++) { 921 snprintf(hex, sizeof(hex), "%s%02x", 922 i > 0 ? ":" : "", dgst_raw[i]); 923 strlcat(retval, hex, rlen); 924 } 925 return retval; 926 } 927 928 static char * 929 fingerprint_bubblebabble(u_char *dgst_raw, size_t dgst_raw_len) 930 { 931 char vowels[] = { 'a', 'e', 'i', 'o', 'u', 'y' }; 932 char consonants[] = { 'b', 'c', 'd', 'f', 'g', 'h', 'k', 'l', 'm', 933 'n', 'p', 'r', 's', 't', 'v', 'z', 'x' }; 934 u_int i, j = 0, rounds, seed = 1; 935 char *retval; 936 937 rounds = (dgst_raw_len / 2) + 1; 938 if ((retval = calloc(rounds, 6)) == NULL) 939 return NULL; 940 retval[j++] = 'x'; 941 for (i = 0; i < rounds; i++) { 942 u_int idx0, idx1, idx2, idx3, idx4; 943 if ((i + 1 < rounds) || (dgst_raw_len % 2 != 0)) { 944 idx0 = (((((u_int)(dgst_raw[2 * i])) >> 6) & 3) + 945 seed) % 6; 946 idx1 = (((u_int)(dgst_raw[2 * i])) >> 2) & 15; 947 idx2 = ((((u_int)(dgst_raw[2 * i])) & 3) + 948 (seed / 6)) % 6; 949 retval[j++] = vowels[idx0]; 950 retval[j++] = consonants[idx1]; 951 retval[j++] = vowels[idx2]; 952 if ((i + 1) < rounds) { 953 idx3 = (((u_int)(dgst_raw[(2 * i) + 1])) >> 4) & 15; 954 idx4 = (((u_int)(dgst_raw[(2 * i) + 1]))) & 15; 955 retval[j++] = consonants[idx3]; 956 retval[j++] = '-'; 957 retval[j++] = consonants[idx4]; 958 seed = ((seed * 5) + 959 ((((u_int)(dgst_raw[2 * i])) * 7) + 960 ((u_int)(dgst_raw[(2 * i) + 1])))) % 36; 961 } 962 } else { 963 idx0 = seed % 6; 964 idx1 = 16; 965 idx2 = seed / 6; 966 retval[j++] = vowels[idx0]; 967 retval[j++] = consonants[idx1]; 968 retval[j++] = vowels[idx2]; 969 } 970 } 971 retval[j++] = 'x'; 972 retval[j++] = '\0'; 973 return retval; 974 } 975 976 /* 977 * Draw an ASCII-Art representing the fingerprint so human brain can 978 * profit from its built-in pattern recognition ability. 979 * This technique is called "random art" and can be found in some 980 * scientific publications like this original paper: 981 * 982 * "Hash Visualization: a New Technique to improve Real-World Security", 983 * Perrig A. and Song D., 1999, International Workshop on Cryptographic 984 * Techniques and E-Commerce (CrypTEC '99) 985 * sparrow.ece.cmu.edu/~adrian/projects/validation/validation.pdf 986 * 987 * The subject came up in a talk by Dan Kaminsky, too. 988 * 989 * If you see the picture is different, the key is different. 990 * If the picture looks the same, you still know nothing. 991 * 992 * The algorithm used here is a worm crawling over a discrete plane, 993 * leaving a trace (augmenting the field) everywhere it goes. 994 * Movement is taken from dgst_raw 2bit-wise. Bumping into walls 995 * makes the respective movement vector be ignored for this turn. 996 * Graphs are not unambiguous, because circles in graphs can be 997 * walked in either direction. 998 */ 999 1000 /* 1001 * Field sizes for the random art. Have to be odd, so the starting point 1002 * can be in the exact middle of the picture, and FLDBASE should be >=8 . 1003 * Else pictures would be too dense, and drawing the frame would 1004 * fail, too, because the key type would not fit in anymore. 1005 */ 1006 #define FLDBASE 8 1007 #define FLDSIZE_Y (FLDBASE + 1) 1008 #define FLDSIZE_X (FLDBASE * 2 + 1) 1009 static char * 1010 fingerprint_randomart(const char *alg, u_char *dgst_raw, size_t dgst_raw_len, 1011 const struct sshkey *k) 1012 { 1013 /* 1014 * Chars to be used after each other every time the worm 1015 * intersects with itself. Matter of taste. 1016 */ 1017 char *augmentation_string = " .o+=*BOX@%&#/^SE"; 1018 char *retval, *p, title[FLDSIZE_X], hash[FLDSIZE_X]; 1019 u_char field[FLDSIZE_X][FLDSIZE_Y]; 1020 size_t i, tlen, hlen; 1021 u_int b; 1022 int x, y, r; 1023 size_t len = strlen(augmentation_string) - 1; 1024 1025 if ((retval = calloc((FLDSIZE_X + 3), (FLDSIZE_Y + 2))) == NULL) 1026 return NULL; 1027 1028 /* initialize field */ 1029 memset(field, 0, FLDSIZE_X * FLDSIZE_Y * sizeof(char)); 1030 x = FLDSIZE_X / 2; 1031 y = FLDSIZE_Y / 2; 1032 1033 /* process raw key */ 1034 for (i = 0; i < dgst_raw_len; i++) { 1035 int input; 1036 /* each byte conveys four 2-bit move commands */ 1037 input = dgst_raw[i]; 1038 for (b = 0; b < 4; b++) { 1039 /* evaluate 2 bit, rest is shifted later */ 1040 x += (input & 0x1) ? 1 : -1; 1041 y += (input & 0x2) ? 1 : -1; 1042 1043 /* assure we are still in bounds */ 1044 x = MAXIMUM(x, 0); 1045 y = MAXIMUM(y, 0); 1046 x = MINIMUM(x, FLDSIZE_X - 1); 1047 y = MINIMUM(y, FLDSIZE_Y - 1); 1048 1049 /* augment the field */ 1050 if (field[x][y] < len - 2) 1051 field[x][y]++; 1052 input = input >> 2; 1053 } 1054 } 1055 1056 /* mark starting point and end point*/ 1057 field[FLDSIZE_X / 2][FLDSIZE_Y / 2] = len - 1; 1058 field[x][y] = len; 1059 1060 /* assemble title */ 1061 r = snprintf(title, sizeof(title), "[%s %u]", 1062 sshkey_type(k), sshkey_size(k)); 1063 /* If [type size] won't fit, then try [type]; fits "[ED25519-CERT]" */ 1064 if (r < 0 || r > (int)sizeof(title)) 1065 r = snprintf(title, sizeof(title), "[%s]", sshkey_type(k)); 1066 tlen = (r <= 0) ? 0 : strlen(title); 1067 1068 /* assemble hash ID. */ 1069 r = snprintf(hash, sizeof(hash), "[%s]", alg); 1070 hlen = (r <= 0) ? 0 : strlen(hash); 1071 1072 /* output upper border */ 1073 p = retval; 1074 *p++ = '+'; 1075 for (i = 0; i < (FLDSIZE_X - tlen) / 2; i++) 1076 *p++ = '-'; 1077 memcpy(p, title, tlen); 1078 p += tlen; 1079 for (i += tlen; i < FLDSIZE_X; i++) 1080 *p++ = '-'; 1081 *p++ = '+'; 1082 *p++ = '\n'; 1083 1084 /* output content */ 1085 for (y = 0; y < FLDSIZE_Y; y++) { 1086 *p++ = '|'; 1087 for (x = 0; x < FLDSIZE_X; x++) 1088 *p++ = augmentation_string[MINIMUM(field[x][y], len)]; 1089 *p++ = '|'; 1090 *p++ = '\n'; 1091 } 1092 1093 /* output lower border */ 1094 *p++ = '+'; 1095 for (i = 0; i < (FLDSIZE_X - hlen) / 2; i++) 1096 *p++ = '-'; 1097 memcpy(p, hash, hlen); 1098 p += hlen; 1099 for (i += hlen; i < FLDSIZE_X; i++) 1100 *p++ = '-'; 1101 *p++ = '+'; 1102 1103 return retval; 1104 } 1105 1106 char * 1107 sshkey_fingerprint(const struct sshkey *k, int dgst_alg, 1108 enum sshkey_fp_rep dgst_rep) 1109 { 1110 char *retval = NULL; 1111 u_char *dgst_raw; 1112 size_t dgst_raw_len; 1113 1114 if (sshkey_fingerprint_raw(k, dgst_alg, &dgst_raw, &dgst_raw_len) != 0) 1115 return NULL; 1116 switch (dgst_rep) { 1117 case SSH_FP_DEFAULT: 1118 if (dgst_alg == SSH_DIGEST_MD5) { 1119 retval = fingerprint_hex(ssh_digest_alg_name(dgst_alg), 1120 dgst_raw, dgst_raw_len); 1121 } else { 1122 retval = fingerprint_b64(ssh_digest_alg_name(dgst_alg), 1123 dgst_raw, dgst_raw_len); 1124 } 1125 break; 1126 case SSH_FP_HEX: 1127 retval = fingerprint_hex(ssh_digest_alg_name(dgst_alg), 1128 dgst_raw, dgst_raw_len); 1129 break; 1130 case SSH_FP_BASE64: 1131 retval = fingerprint_b64(ssh_digest_alg_name(dgst_alg), 1132 dgst_raw, dgst_raw_len); 1133 break; 1134 case SSH_FP_BUBBLEBABBLE: 1135 retval = fingerprint_bubblebabble(dgst_raw, dgst_raw_len); 1136 break; 1137 case SSH_FP_RANDOMART: 1138 retval = fingerprint_randomart(ssh_digest_alg_name(dgst_alg), 1139 dgst_raw, dgst_raw_len, k); 1140 break; 1141 default: 1142 freezero(dgst_raw, dgst_raw_len); 1143 return NULL; 1144 } 1145 freezero(dgst_raw, dgst_raw_len); 1146 return retval; 1147 } 1148 1149 static int 1150 peek_type_nid(const char *s, size_t l, int *nid) 1151 { 1152 const struct sshkey_impl *impl; 1153 int i; 1154 1155 for (i = 0; keyimpls[i] != NULL; i++) { 1156 impl = keyimpls[i]; 1157 if (impl->name == NULL || strlen(impl->name) != l) 1158 continue; 1159 if (memcmp(s, impl->name, l) == 0) { 1160 *nid = -1; 1161 if (key_type_is_ecdsa_variant(impl->type)) 1162 *nid = impl->nid; 1163 return impl->type; 1164 } 1165 } 1166 return KEY_UNSPEC; 1167 } 1168 1169 /* XXX this can now be made const char * */ 1170 int 1171 sshkey_read(struct sshkey *ret, char **cpp) 1172 { 1173 struct sshkey *k; 1174 char *cp, *blobcopy; 1175 size_t space; 1176 int r, type, curve_nid = -1; 1177 struct sshbuf *blob; 1178 1179 if (ret == NULL) 1180 return SSH_ERR_INVALID_ARGUMENT; 1181 if (ret->type != KEY_UNSPEC && sshkey_impl_from_type(ret->type) == NULL) 1182 return SSH_ERR_INVALID_ARGUMENT; 1183 1184 /* Decode type */ 1185 cp = *cpp; 1186 space = strcspn(cp, " \t"); 1187 if (space == strlen(cp)) 1188 return SSH_ERR_INVALID_FORMAT; 1189 if ((type = peek_type_nid(cp, space, &curve_nid)) == KEY_UNSPEC) 1190 return SSH_ERR_INVALID_FORMAT; 1191 1192 /* skip whitespace */ 1193 for (cp += space; *cp == ' ' || *cp == '\t'; cp++) 1194 ; 1195 if (*cp == '\0') 1196 return SSH_ERR_INVALID_FORMAT; 1197 if (ret->type != KEY_UNSPEC && ret->type != type) 1198 return SSH_ERR_KEY_TYPE_MISMATCH; 1199 if ((blob = sshbuf_new()) == NULL) 1200 return SSH_ERR_ALLOC_FAIL; 1201 1202 /* find end of keyblob and decode */ 1203 space = strcspn(cp, " \t"); 1204 if ((blobcopy = strndup(cp, space)) == NULL) { 1205 sshbuf_free(blob); 1206 return SSH_ERR_ALLOC_FAIL; 1207 } 1208 if ((r = sshbuf_b64tod(blob, blobcopy)) != 0) { 1209 free(blobcopy); 1210 sshbuf_free(blob); 1211 return r; 1212 } 1213 free(blobcopy); 1214 if ((r = sshkey_fromb(blob, &k)) != 0) { 1215 sshbuf_free(blob); 1216 return r; 1217 } 1218 sshbuf_free(blob); 1219 1220 /* skip whitespace and leave cp at start of comment */ 1221 for (cp += space; *cp == ' ' || *cp == '\t'; cp++) 1222 ; 1223 1224 /* ensure type of blob matches type at start of line */ 1225 if (k->type != type) { 1226 sshkey_free(k); 1227 return SSH_ERR_KEY_TYPE_MISMATCH; 1228 } 1229 if (key_type_is_ecdsa_variant(type) && curve_nid != k->ecdsa_nid) { 1230 sshkey_free(k); 1231 return SSH_ERR_EC_CURVE_MISMATCH; 1232 } 1233 1234 /* Fill in ret from parsed key */ 1235 sshkey_free_contents(ret); 1236 *ret = *k; 1237 freezero(k, sizeof(*k)); 1238 1239 /* success */ 1240 *cpp = cp; 1241 return 0; 1242 } 1243 1244 int 1245 sshkey_to_base64(const struct sshkey *key, char **b64p) 1246 { 1247 int r = SSH_ERR_INTERNAL_ERROR; 1248 struct sshbuf *b = NULL; 1249 char *uu = NULL; 1250 1251 if (b64p != NULL) 1252 *b64p = NULL; 1253 if ((b = sshbuf_new()) == NULL) 1254 return SSH_ERR_ALLOC_FAIL; 1255 if ((r = sshkey_putb(key, b)) != 0) 1256 goto out; 1257 if ((uu = sshbuf_dtob64_string(b, 0)) == NULL) { 1258 r = SSH_ERR_ALLOC_FAIL; 1259 goto out; 1260 } 1261 /* Success */ 1262 if (b64p != NULL) { 1263 *b64p = uu; 1264 uu = NULL; 1265 } 1266 r = 0; 1267 out: 1268 sshbuf_free(b); 1269 free(uu); 1270 return r; 1271 } 1272 1273 int 1274 sshkey_format_text(const struct sshkey *key, struct sshbuf *b) 1275 { 1276 int r = SSH_ERR_INTERNAL_ERROR; 1277 char *uu = NULL; 1278 1279 if ((r = sshkey_to_base64(key, &uu)) != 0) 1280 goto out; 1281 if ((r = sshbuf_putf(b, "%s %s", 1282 sshkey_ssh_name(key), uu)) != 0) 1283 goto out; 1284 r = 0; 1285 out: 1286 free(uu); 1287 return r; 1288 } 1289 1290 int 1291 sshkey_write(const struct sshkey *key, FILE *f) 1292 { 1293 struct sshbuf *b = NULL; 1294 int r = SSH_ERR_INTERNAL_ERROR; 1295 1296 if ((b = sshbuf_new()) == NULL) 1297 return SSH_ERR_ALLOC_FAIL; 1298 if ((r = sshkey_format_text(key, b)) != 0) 1299 goto out; 1300 if (fwrite(sshbuf_ptr(b), sshbuf_len(b), 1, f) != 1) { 1301 if (feof(f)) 1302 errno = EPIPE; 1303 r = SSH_ERR_SYSTEM_ERROR; 1304 goto out; 1305 } 1306 /* Success */ 1307 r = 0; 1308 out: 1309 sshbuf_free(b); 1310 return r; 1311 } 1312 1313 const char * 1314 sshkey_cert_type(const struct sshkey *k) 1315 { 1316 switch (k->cert->type) { 1317 case SSH2_CERT_TYPE_USER: 1318 return "user"; 1319 case SSH2_CERT_TYPE_HOST: 1320 return "host"; 1321 default: 1322 return "unknown"; 1323 } 1324 } 1325 1326 int 1327 sshkey_check_rsa_length(const struct sshkey *k, int min_size) 1328 { 1329 #ifdef WITH_OPENSSL 1330 const BIGNUM *rsa_n; 1331 int nbits; 1332 1333 if (k == NULL || k->rsa == NULL || 1334 (k->type != KEY_RSA && k->type != KEY_RSA_CERT)) 1335 return 0; 1336 RSA_get0_key(k->rsa, &rsa_n, NULL, NULL); 1337 nbits = BN_num_bits(rsa_n); 1338 if (nbits < SSH_RSA_MINIMUM_MODULUS_SIZE || 1339 (min_size > 0 && nbits < min_size)) 1340 return SSH_ERR_KEY_LENGTH; 1341 #endif /* WITH_OPENSSL */ 1342 return 0; 1343 } 1344 1345 #ifdef WITH_OPENSSL 1346 # ifdef OPENSSL_HAS_ECC 1347 int 1348 sshkey_ecdsa_key_to_nid(EC_KEY *k) 1349 { 1350 EC_GROUP *eg; 1351 int nids[] = { 1352 NID_X9_62_prime256v1, 1353 NID_secp384r1, 1354 # ifdef OPENSSL_HAS_NISTP521 1355 NID_secp521r1, 1356 # endif /* OPENSSL_HAS_NISTP521 */ 1357 -1 1358 }; 1359 int nid; 1360 u_int i; 1361 const EC_GROUP *g = EC_KEY_get0_group(k); 1362 1363 /* 1364 * The group may be stored in a ASN.1 encoded private key in one of two 1365 * ways: as a "named group", which is reconstituted by ASN.1 object ID 1366 * or explicit group parameters encoded into the key blob. Only the 1367 * "named group" case sets the group NID for us, but we can figure 1368 * it out for the other case by comparing against all the groups that 1369 * are supported. 1370 */ 1371 if ((nid = EC_GROUP_get_curve_name(g)) > 0) 1372 return nid; 1373 for (i = 0; nids[i] != -1; i++) { 1374 if ((eg = EC_GROUP_new_by_curve_name(nids[i])) == NULL) 1375 return -1; 1376 if (EC_GROUP_cmp(g, eg, NULL) == 0) 1377 break; 1378 EC_GROUP_free(eg); 1379 } 1380 if (nids[i] != -1) { 1381 /* Use the group with the NID attached */ 1382 EC_GROUP_set_asn1_flag(eg, OPENSSL_EC_NAMED_CURVE); 1383 if (EC_KEY_set_group(k, eg) != 1) { 1384 EC_GROUP_free(eg); 1385 return -1; 1386 } 1387 } 1388 return nids[i]; 1389 } 1390 # endif /* OPENSSL_HAS_ECC */ 1391 #endif /* WITH_OPENSSL */ 1392 1393 int 1394 sshkey_generate(int type, u_int bits, struct sshkey **keyp) 1395 { 1396 struct sshkey *k; 1397 int ret = SSH_ERR_INTERNAL_ERROR; 1398 const struct sshkey_impl *impl; 1399 1400 if (keyp == NULL || sshkey_type_is_cert(type)) 1401 return SSH_ERR_INVALID_ARGUMENT; 1402 *keyp = NULL; 1403 if ((impl = sshkey_impl_from_type(type)) == NULL) 1404 return SSH_ERR_KEY_TYPE_UNKNOWN; 1405 if (impl->funcs->generate == NULL) 1406 return SSH_ERR_FEATURE_UNSUPPORTED; 1407 if ((k = sshkey_new(KEY_UNSPEC)) == NULL) 1408 return SSH_ERR_ALLOC_FAIL; 1409 k->type = type; 1410 if ((ret = impl->funcs->generate(k, bits)) != 0) { 1411 sshkey_free(k); 1412 return ret; 1413 } 1414 /* success */ 1415 *keyp = k; 1416 return 0; 1417 } 1418 1419 int 1420 sshkey_cert_copy(const struct sshkey *from_key, struct sshkey *to_key) 1421 { 1422 u_int i; 1423 const struct sshkey_cert *from; 1424 struct sshkey_cert *to; 1425 int r = SSH_ERR_INTERNAL_ERROR; 1426 1427 if (to_key == NULL || (from = from_key->cert) == NULL) 1428 return SSH_ERR_INVALID_ARGUMENT; 1429 1430 if ((to = cert_new()) == NULL) 1431 return SSH_ERR_ALLOC_FAIL; 1432 1433 if ((r = sshbuf_putb(to->certblob, from->certblob)) != 0 || 1434 (r = sshbuf_putb(to->critical, from->critical)) != 0 || 1435 (r = sshbuf_putb(to->extensions, from->extensions)) != 0) 1436 goto out; 1437 1438 to->serial = from->serial; 1439 to->type = from->type; 1440 if (from->key_id == NULL) 1441 to->key_id = NULL; 1442 else if ((to->key_id = strdup(from->key_id)) == NULL) { 1443 r = SSH_ERR_ALLOC_FAIL; 1444 goto out; 1445 } 1446 to->valid_after = from->valid_after; 1447 to->valid_before = from->valid_before; 1448 if (from->signature_key == NULL) 1449 to->signature_key = NULL; 1450 else if ((r = sshkey_from_private(from->signature_key, 1451 &to->signature_key)) != 0) 1452 goto out; 1453 if (from->signature_type != NULL && 1454 (to->signature_type = strdup(from->signature_type)) == NULL) { 1455 r = SSH_ERR_ALLOC_FAIL; 1456 goto out; 1457 } 1458 if (from->nprincipals > SSHKEY_CERT_MAX_PRINCIPALS) { 1459 r = SSH_ERR_INVALID_ARGUMENT; 1460 goto out; 1461 } 1462 if (from->nprincipals > 0) { 1463 if ((to->principals = calloc(from->nprincipals, 1464 sizeof(*to->principals))) == NULL) { 1465 r = SSH_ERR_ALLOC_FAIL; 1466 goto out; 1467 } 1468 for (i = 0; i < from->nprincipals; i++) { 1469 to->principals[i] = strdup(from->principals[i]); 1470 if (to->principals[i] == NULL) { 1471 to->nprincipals = i; 1472 r = SSH_ERR_ALLOC_FAIL; 1473 goto out; 1474 } 1475 } 1476 } 1477 to->nprincipals = from->nprincipals; 1478 1479 /* success */ 1480 cert_free(to_key->cert); 1481 to_key->cert = to; 1482 to = NULL; 1483 r = 0; 1484 out: 1485 cert_free(to); 1486 return r; 1487 } 1488 1489 int 1490 sshkey_copy_public_sk(const struct sshkey *from, struct sshkey *to) 1491 { 1492 /* Append security-key application string */ 1493 if ((to->sk_application = strdup(from->sk_application)) == NULL) 1494 return SSH_ERR_ALLOC_FAIL; 1495 return 0; 1496 } 1497 1498 int 1499 sshkey_from_private(const struct sshkey *k, struct sshkey **pkp) 1500 { 1501 struct sshkey *n = NULL; 1502 int r = SSH_ERR_INTERNAL_ERROR; 1503 const struct sshkey_impl *impl; 1504 1505 *pkp = NULL; 1506 if ((impl = sshkey_impl_from_key(k)) == NULL) 1507 return SSH_ERR_KEY_TYPE_UNKNOWN; 1508 if ((n = sshkey_new(k->type)) == NULL) { 1509 r = SSH_ERR_ALLOC_FAIL; 1510 goto out; 1511 } 1512 if ((r = impl->funcs->copy_public(k, n)) != 0) 1513 goto out; 1514 if (sshkey_is_cert(k) && (r = sshkey_cert_copy(k, n)) != 0) 1515 goto out; 1516 /* success */ 1517 *pkp = n; 1518 n = NULL; 1519 r = 0; 1520 out: 1521 sshkey_free(n); 1522 return r; 1523 } 1524 1525 int 1526 sshkey_is_shielded(struct sshkey *k) 1527 { 1528 return k != NULL && k->shielded_private != NULL; 1529 } 1530 1531 int 1532 sshkey_shield_private(struct sshkey *k) 1533 { 1534 struct sshbuf *prvbuf = NULL; 1535 u_char *prekey = NULL, *enc = NULL, keyiv[SSH_DIGEST_MAX_LENGTH]; 1536 struct sshcipher_ctx *cctx = NULL; 1537 const struct sshcipher *cipher; 1538 size_t i, enclen = 0; 1539 struct sshkey *kswap = NULL, tmp; 1540 int r = SSH_ERR_INTERNAL_ERROR; 1541 1542 #ifdef DEBUG_PK 1543 fprintf(stderr, "%s: entering for %s\n", __func__, sshkey_ssh_name(k)); 1544 #endif 1545 if ((cipher = cipher_by_name(SSHKEY_SHIELD_CIPHER)) == NULL) { 1546 r = SSH_ERR_INVALID_ARGUMENT; 1547 goto out; 1548 } 1549 if (cipher_keylen(cipher) + cipher_ivlen(cipher) > 1550 ssh_digest_bytes(SSHKEY_SHIELD_PREKEY_HASH)) { 1551 r = SSH_ERR_INTERNAL_ERROR; 1552 goto out; 1553 } 1554 1555 /* Prepare a random pre-key, and from it an ephemeral key */ 1556 if ((prekey = malloc(SSHKEY_SHIELD_PREKEY_LEN)) == NULL) { 1557 r = SSH_ERR_ALLOC_FAIL; 1558 goto out; 1559 } 1560 arc4random_buf(prekey, SSHKEY_SHIELD_PREKEY_LEN); 1561 if ((r = ssh_digest_memory(SSHKEY_SHIELD_PREKEY_HASH, 1562 prekey, SSHKEY_SHIELD_PREKEY_LEN, 1563 keyiv, SSH_DIGEST_MAX_LENGTH)) != 0) 1564 goto out; 1565 #ifdef DEBUG_PK 1566 fprintf(stderr, "%s: key+iv\n", __func__); 1567 sshbuf_dump_data(keyiv, ssh_digest_bytes(SSHKEY_SHIELD_PREKEY_HASH), 1568 stderr); 1569 #endif 1570 if ((r = cipher_init(&cctx, cipher, keyiv, cipher_keylen(cipher), 1571 keyiv + cipher_keylen(cipher), cipher_ivlen(cipher), 1)) != 0) 1572 goto out; 1573 1574 /* Serialise and encrypt the private key using the ephemeral key */ 1575 if ((prvbuf = sshbuf_new()) == NULL) { 1576 r = SSH_ERR_ALLOC_FAIL; 1577 goto out; 1578 } 1579 if (sshkey_is_shielded(k) && (r = sshkey_unshield_private(k)) != 0) 1580 goto out; 1581 if ((r = sshkey_private_serialize_opt(k, prvbuf, 1582 SSHKEY_SERIALIZE_SHIELD)) != 0) 1583 goto out; 1584 /* pad to cipher blocksize */ 1585 i = 0; 1586 while (sshbuf_len(prvbuf) % cipher_blocksize(cipher)) { 1587 if ((r = sshbuf_put_u8(prvbuf, ++i & 0xff)) != 0) 1588 goto out; 1589 } 1590 #ifdef DEBUG_PK 1591 fprintf(stderr, "%s: serialised\n", __func__); 1592 sshbuf_dump(prvbuf, stderr); 1593 #endif 1594 /* encrypt */ 1595 enclen = sshbuf_len(prvbuf); 1596 if ((enc = malloc(enclen)) == NULL) { 1597 r = SSH_ERR_ALLOC_FAIL; 1598 goto out; 1599 } 1600 if ((r = cipher_crypt(cctx, 0, enc, 1601 sshbuf_ptr(prvbuf), sshbuf_len(prvbuf), 0, 0)) != 0) 1602 goto out; 1603 #ifdef DEBUG_PK 1604 fprintf(stderr, "%s: encrypted\n", __func__); 1605 sshbuf_dump_data(enc, enclen, stderr); 1606 #endif 1607 1608 /* Make a scrubbed, public-only copy of our private key argument */ 1609 if ((r = sshkey_from_private(k, &kswap)) != 0) 1610 goto out; 1611 1612 /* Swap the private key out (it will be destroyed below) */ 1613 tmp = *kswap; 1614 *kswap = *k; 1615 *k = tmp; 1616 1617 /* Insert the shielded key into our argument */ 1618 k->shielded_private = enc; 1619 k->shielded_len = enclen; 1620 k->shield_prekey = prekey; 1621 k->shield_prekey_len = SSHKEY_SHIELD_PREKEY_LEN; 1622 enc = prekey = NULL; /* transferred */ 1623 enclen = 0; 1624 1625 /* preserve key fields that are required for correct operation */ 1626 k->sk_flags = kswap->sk_flags; 1627 1628 /* success */ 1629 r = 0; 1630 1631 out: 1632 /* XXX behaviour on error - invalidate original private key? */ 1633 cipher_free(cctx); 1634 explicit_bzero(keyiv, sizeof(keyiv)); 1635 explicit_bzero(&tmp, sizeof(tmp)); 1636 freezero(enc, enclen); 1637 freezero(prekey, SSHKEY_SHIELD_PREKEY_LEN); 1638 sshkey_free(kswap); 1639 sshbuf_free(prvbuf); 1640 return r; 1641 } 1642 1643 /* Check deterministic padding after private key */ 1644 static int 1645 private2_check_padding(struct sshbuf *decrypted) 1646 { 1647 u_char pad; 1648 size_t i; 1649 int r; 1650 1651 i = 0; 1652 while (sshbuf_len(decrypted)) { 1653 if ((r = sshbuf_get_u8(decrypted, &pad)) != 0) 1654 goto out; 1655 if (pad != (++i & 0xff)) { 1656 r = SSH_ERR_INVALID_FORMAT; 1657 goto out; 1658 } 1659 } 1660 /* success */ 1661 r = 0; 1662 out: 1663 explicit_bzero(&pad, sizeof(pad)); 1664 explicit_bzero(&i, sizeof(i)); 1665 return r; 1666 } 1667 1668 int 1669 sshkey_unshield_private(struct sshkey *k) 1670 { 1671 struct sshbuf *prvbuf = NULL; 1672 u_char *cp, keyiv[SSH_DIGEST_MAX_LENGTH]; 1673 struct sshcipher_ctx *cctx = NULL; 1674 const struct sshcipher *cipher; 1675 struct sshkey *kswap = NULL, tmp; 1676 int r = SSH_ERR_INTERNAL_ERROR; 1677 1678 #ifdef DEBUG_PK 1679 fprintf(stderr, "%s: entering for %s\n", __func__, sshkey_ssh_name(k)); 1680 #endif 1681 if (!sshkey_is_shielded(k)) 1682 return 0; /* nothing to do */ 1683 1684 if ((cipher = cipher_by_name(SSHKEY_SHIELD_CIPHER)) == NULL) { 1685 r = SSH_ERR_INVALID_ARGUMENT; 1686 goto out; 1687 } 1688 if (cipher_keylen(cipher) + cipher_ivlen(cipher) > 1689 ssh_digest_bytes(SSHKEY_SHIELD_PREKEY_HASH)) { 1690 r = SSH_ERR_INTERNAL_ERROR; 1691 goto out; 1692 } 1693 /* check size of shielded key blob */ 1694 if (k->shielded_len < cipher_blocksize(cipher) || 1695 (k->shielded_len % cipher_blocksize(cipher)) != 0) { 1696 r = SSH_ERR_INVALID_FORMAT; 1697 goto out; 1698 } 1699 1700 /* Calculate the ephemeral key from the prekey */ 1701 if ((r = ssh_digest_memory(SSHKEY_SHIELD_PREKEY_HASH, 1702 k->shield_prekey, k->shield_prekey_len, 1703 keyiv, SSH_DIGEST_MAX_LENGTH)) != 0) 1704 goto out; 1705 if ((r = cipher_init(&cctx, cipher, keyiv, cipher_keylen(cipher), 1706 keyiv + cipher_keylen(cipher), cipher_ivlen(cipher), 0)) != 0) 1707 goto out; 1708 #ifdef DEBUG_PK 1709 fprintf(stderr, "%s: key+iv\n", __func__); 1710 sshbuf_dump_data(keyiv, ssh_digest_bytes(SSHKEY_SHIELD_PREKEY_HASH), 1711 stderr); 1712 #endif 1713 1714 /* Decrypt and parse the shielded private key using the ephemeral key */ 1715 if ((prvbuf = sshbuf_new()) == NULL) { 1716 r = SSH_ERR_ALLOC_FAIL; 1717 goto out; 1718 } 1719 if ((r = sshbuf_reserve(prvbuf, k->shielded_len, &cp)) != 0) 1720 goto out; 1721 /* decrypt */ 1722 #ifdef DEBUG_PK 1723 fprintf(stderr, "%s: encrypted\n", __func__); 1724 sshbuf_dump_data(k->shielded_private, k->shielded_len, stderr); 1725 #endif 1726 if ((r = cipher_crypt(cctx, 0, cp, 1727 k->shielded_private, k->shielded_len, 0, 0)) != 0) 1728 goto out; 1729 #ifdef DEBUG_PK 1730 fprintf(stderr, "%s: serialised\n", __func__); 1731 sshbuf_dump(prvbuf, stderr); 1732 #endif 1733 /* Parse private key */ 1734 if ((r = sshkey_private_deserialize(prvbuf, &kswap)) != 0) 1735 goto out; 1736 1737 if ((r = private2_check_padding(prvbuf)) != 0) 1738 goto out; 1739 1740 /* Swap the parsed key back into place */ 1741 tmp = *kswap; 1742 *kswap = *k; 1743 *k = tmp; 1744 1745 /* success */ 1746 r = 0; 1747 1748 out: 1749 cipher_free(cctx); 1750 explicit_bzero(keyiv, sizeof(keyiv)); 1751 explicit_bzero(&tmp, sizeof(tmp)); 1752 sshkey_free(kswap); 1753 sshbuf_free(prvbuf); 1754 return r; 1755 } 1756 1757 static int 1758 cert_parse(struct sshbuf *b, struct sshkey *key, struct sshbuf *certbuf) 1759 { 1760 struct sshbuf *principals = NULL, *crit = NULL; 1761 struct sshbuf *exts = NULL, *ca = NULL; 1762 u_char *sig = NULL; 1763 size_t signed_len = 0, slen = 0, kidlen = 0; 1764 int ret = SSH_ERR_INTERNAL_ERROR; 1765 1766 /* Copy the entire key blob for verification and later serialisation */ 1767 if ((ret = sshbuf_putb(key->cert->certblob, certbuf)) != 0) 1768 return ret; 1769 1770 /* Parse body of certificate up to signature */ 1771 if ((ret = sshbuf_get_u64(b, &key->cert->serial)) != 0 || 1772 (ret = sshbuf_get_u32(b, &key->cert->type)) != 0 || 1773 (ret = sshbuf_get_cstring(b, &key->cert->key_id, &kidlen)) != 0 || 1774 (ret = sshbuf_froms(b, &principals)) != 0 || 1775 (ret = sshbuf_get_u64(b, &key->cert->valid_after)) != 0 || 1776 (ret = sshbuf_get_u64(b, &key->cert->valid_before)) != 0 || 1777 (ret = sshbuf_froms(b, &crit)) != 0 || 1778 (ret = sshbuf_froms(b, &exts)) != 0 || 1779 (ret = sshbuf_get_string_direct(b, NULL, NULL)) != 0 || 1780 (ret = sshbuf_froms(b, &ca)) != 0) { 1781 /* XXX debug print error for ret */ 1782 ret = SSH_ERR_INVALID_FORMAT; 1783 goto out; 1784 } 1785 1786 /* Signature is left in the buffer so we can calculate this length */ 1787 signed_len = sshbuf_len(key->cert->certblob) - sshbuf_len(b); 1788 1789 if ((ret = sshbuf_get_string(b, &sig, &slen)) != 0) { 1790 ret = SSH_ERR_INVALID_FORMAT; 1791 goto out; 1792 } 1793 1794 if (key->cert->type != SSH2_CERT_TYPE_USER && 1795 key->cert->type != SSH2_CERT_TYPE_HOST) { 1796 ret = SSH_ERR_KEY_CERT_UNKNOWN_TYPE; 1797 goto out; 1798 } 1799 1800 /* Parse principals section */ 1801 while (sshbuf_len(principals) > 0) { 1802 char *principal = NULL; 1803 char **oprincipals = NULL; 1804 1805 if (key->cert->nprincipals >= SSHKEY_CERT_MAX_PRINCIPALS) { 1806 ret = SSH_ERR_INVALID_FORMAT; 1807 goto out; 1808 } 1809 if ((ret = sshbuf_get_cstring(principals, &principal, 1810 NULL)) != 0) { 1811 ret = SSH_ERR_INVALID_FORMAT; 1812 goto out; 1813 } 1814 oprincipals = key->cert->principals; 1815 key->cert->principals = recallocarray(key->cert->principals, 1816 key->cert->nprincipals, key->cert->nprincipals + 1, 1817 sizeof(*key->cert->principals)); 1818 if (key->cert->principals == NULL) { 1819 free(principal); 1820 key->cert->principals = oprincipals; 1821 ret = SSH_ERR_ALLOC_FAIL; 1822 goto out; 1823 } 1824 key->cert->principals[key->cert->nprincipals++] = principal; 1825 } 1826 1827 /* 1828 * Stash a copies of the critical options and extensions sections 1829 * for later use. 1830 */ 1831 if ((ret = sshbuf_putb(key->cert->critical, crit)) != 0 || 1832 (exts != NULL && 1833 (ret = sshbuf_putb(key->cert->extensions, exts)) != 0)) 1834 goto out; 1835 1836 /* 1837 * Validate critical options and extensions sections format. 1838 */ 1839 while (sshbuf_len(crit) != 0) { 1840 if ((ret = sshbuf_get_string_direct(crit, NULL, NULL)) != 0 || 1841 (ret = sshbuf_get_string_direct(crit, NULL, NULL)) != 0) { 1842 sshbuf_reset(key->cert->critical); 1843 ret = SSH_ERR_INVALID_FORMAT; 1844 goto out; 1845 } 1846 } 1847 while (exts != NULL && sshbuf_len(exts) != 0) { 1848 if ((ret = sshbuf_get_string_direct(exts, NULL, NULL)) != 0 || 1849 (ret = sshbuf_get_string_direct(exts, NULL, NULL)) != 0) { 1850 sshbuf_reset(key->cert->extensions); 1851 ret = SSH_ERR_INVALID_FORMAT; 1852 goto out; 1853 } 1854 } 1855 1856 /* Parse CA key and check signature */ 1857 if (sshkey_from_blob_internal(ca, &key->cert->signature_key, 0) != 0) { 1858 ret = SSH_ERR_KEY_CERT_INVALID_SIGN_KEY; 1859 goto out; 1860 } 1861 if (!sshkey_type_is_valid_ca(key->cert->signature_key->type)) { 1862 ret = SSH_ERR_KEY_CERT_INVALID_SIGN_KEY; 1863 goto out; 1864 } 1865 if ((ret = sshkey_verify(key->cert->signature_key, sig, slen, 1866 sshbuf_ptr(key->cert->certblob), signed_len, NULL, 0, NULL)) != 0) 1867 goto out; 1868 if ((ret = sshkey_get_sigtype(sig, slen, 1869 &key->cert->signature_type)) != 0) 1870 goto out; 1871 1872 /* Success */ 1873 ret = 0; 1874 out: 1875 sshbuf_free(ca); 1876 sshbuf_free(crit); 1877 sshbuf_free(exts); 1878 sshbuf_free(principals); 1879 free(sig); 1880 return ret; 1881 } 1882 1883 int 1884 sshkey_deserialize_sk(struct sshbuf *b, struct sshkey *key) 1885 { 1886 /* Parse additional security-key application string */ 1887 if (sshbuf_get_cstring(b, &key->sk_application, NULL) != 0) 1888 return SSH_ERR_INVALID_FORMAT; 1889 return 0; 1890 } 1891 1892 static int 1893 sshkey_from_blob_internal(struct sshbuf *b, struct sshkey **keyp, 1894 int allow_cert) 1895 { 1896 int type, ret = SSH_ERR_INTERNAL_ERROR; 1897 char *ktype = NULL; 1898 struct sshkey *key = NULL; 1899 struct sshbuf *copy; 1900 const struct sshkey_impl *impl; 1901 1902 #ifdef DEBUG_PK /* XXX */ 1903 sshbuf_dump(b, stderr); 1904 #endif 1905 if (keyp != NULL) 1906 *keyp = NULL; 1907 if ((copy = sshbuf_fromb(b)) == NULL) { 1908 ret = SSH_ERR_ALLOC_FAIL; 1909 goto out; 1910 } 1911 if (sshbuf_get_cstring(b, &ktype, NULL) != 0) { 1912 ret = SSH_ERR_INVALID_FORMAT; 1913 goto out; 1914 } 1915 1916 type = sshkey_type_from_name(ktype); 1917 if (!allow_cert && sshkey_type_is_cert(type)) { 1918 ret = SSH_ERR_KEY_CERT_INVALID_SIGN_KEY; 1919 goto out; 1920 } 1921 if ((impl = sshkey_impl_from_type(type)) == NULL) { 1922 ret = SSH_ERR_KEY_TYPE_UNKNOWN; 1923 goto out; 1924 } 1925 if ((key = sshkey_new(type)) == NULL) { 1926 ret = SSH_ERR_ALLOC_FAIL; 1927 goto out; 1928 } 1929 if (sshkey_type_is_cert(type)) { 1930 /* Skip nonce that preceeds all certificates */ 1931 if (sshbuf_get_string_direct(b, NULL, NULL) != 0) { 1932 ret = SSH_ERR_INVALID_FORMAT; 1933 goto out; 1934 } 1935 } 1936 if ((ret = impl->funcs->deserialize_public(ktype, b, key)) != 0) 1937 goto out; 1938 1939 /* Parse certificate potion */ 1940 if (sshkey_is_cert(key) && (ret = cert_parse(b, key, copy)) != 0) 1941 goto out; 1942 1943 if (key != NULL && sshbuf_len(b) != 0) { 1944 ret = SSH_ERR_INVALID_FORMAT; 1945 goto out; 1946 } 1947 ret = 0; 1948 if (keyp != NULL) { 1949 *keyp = key; 1950 key = NULL; 1951 } 1952 out: 1953 sshbuf_free(copy); 1954 sshkey_free(key); 1955 free(ktype); 1956 return ret; 1957 } 1958 1959 int 1960 sshkey_from_blob(const u_char *blob, size_t blen, struct sshkey **keyp) 1961 { 1962 struct sshbuf *b; 1963 int r; 1964 1965 if ((b = sshbuf_from(blob, blen)) == NULL) 1966 return SSH_ERR_ALLOC_FAIL; 1967 r = sshkey_from_blob_internal(b, keyp, 1); 1968 sshbuf_free(b); 1969 return r; 1970 } 1971 1972 int 1973 sshkey_fromb(struct sshbuf *b, struct sshkey **keyp) 1974 { 1975 return sshkey_from_blob_internal(b, keyp, 1); 1976 } 1977 1978 int 1979 sshkey_froms(struct sshbuf *buf, struct sshkey **keyp) 1980 { 1981 struct sshbuf *b; 1982 int r; 1983 1984 if ((r = sshbuf_froms(buf, &b)) != 0) 1985 return r; 1986 r = sshkey_from_blob_internal(b, keyp, 1); 1987 sshbuf_free(b); 1988 return r; 1989 } 1990 1991 int 1992 sshkey_get_sigtype(const u_char *sig, size_t siglen, char **sigtypep) 1993 { 1994 int r; 1995 struct sshbuf *b = NULL; 1996 char *sigtype = NULL; 1997 1998 if (sigtypep != NULL) 1999 *sigtypep = NULL; 2000 if ((b = sshbuf_from(sig, siglen)) == NULL) 2001 return SSH_ERR_ALLOC_FAIL; 2002 if ((r = sshbuf_get_cstring(b, &sigtype, NULL)) != 0) 2003 goto out; 2004 /* success */ 2005 if (sigtypep != NULL) { 2006 *sigtypep = sigtype; 2007 sigtype = NULL; 2008 } 2009 r = 0; 2010 out: 2011 free(sigtype); 2012 sshbuf_free(b); 2013 return r; 2014 } 2015 2016 /* 2017 * 2018 * Checks whether a certificate's signature type is allowed. 2019 * Returns 0 (success) if the certificate signature type appears in the 2020 * "allowed" pattern-list, or the key is not a certificate to begin with. 2021 * Otherwise returns a ssherr.h code. 2022 */ 2023 int 2024 sshkey_check_cert_sigtype(const struct sshkey *key, const char *allowed) 2025 { 2026 if (key == NULL || allowed == NULL) 2027 return SSH_ERR_INVALID_ARGUMENT; 2028 if (!sshkey_type_is_cert(key->type)) 2029 return 0; 2030 if (key->cert == NULL || key->cert->signature_type == NULL) 2031 return SSH_ERR_INVALID_ARGUMENT; 2032 if (match_pattern_list(key->cert->signature_type, allowed, 0) != 1) 2033 return SSH_ERR_SIGN_ALG_UNSUPPORTED; 2034 return 0; 2035 } 2036 2037 /* 2038 * Returns the expected signature algorithm for a given public key algorithm. 2039 */ 2040 const char * 2041 sshkey_sigalg_by_name(const char *name) 2042 { 2043 const struct sshkey_impl *impl; 2044 int i; 2045 2046 for (i = 0; keyimpls[i] != NULL; i++) { 2047 impl = keyimpls[i]; 2048 if (strcmp(impl->name, name) != 0) 2049 continue; 2050 if (impl->sigalg != NULL) 2051 return impl->sigalg; 2052 if (!impl->cert) 2053 return impl->name; 2054 return sshkey_ssh_name_from_type_nid( 2055 sshkey_type_plain(impl->type), impl->nid); 2056 } 2057 return NULL; 2058 } 2059 2060 /* 2061 * Verifies that the signature algorithm appearing inside the signature blob 2062 * matches that which was requested. 2063 */ 2064 int 2065 sshkey_check_sigtype(const u_char *sig, size_t siglen, 2066 const char *requested_alg) 2067 { 2068 const char *expected_alg; 2069 char *sigtype = NULL; 2070 int r; 2071 2072 if (requested_alg == NULL) 2073 return 0; 2074 if ((expected_alg = sshkey_sigalg_by_name(requested_alg)) == NULL) 2075 return SSH_ERR_INVALID_ARGUMENT; 2076 if ((r = sshkey_get_sigtype(sig, siglen, &sigtype)) != 0) 2077 return r; 2078 r = strcmp(expected_alg, sigtype) == 0; 2079 free(sigtype); 2080 return r ? 0 : SSH_ERR_SIGN_ALG_UNSUPPORTED; 2081 } 2082 2083 int 2084 sshkey_sign(struct sshkey *key, 2085 u_char **sigp, size_t *lenp, 2086 const u_char *data, size_t datalen, 2087 const char *alg, const char *sk_provider, const char *sk_pin, u_int compat) 2088 { 2089 int was_shielded = sshkey_is_shielded(key); 2090 int r2, r = SSH_ERR_INTERNAL_ERROR; 2091 const struct sshkey_impl *impl; 2092 2093 if (sigp != NULL) 2094 *sigp = NULL; 2095 if (lenp != NULL) 2096 *lenp = 0; 2097 if (datalen > SSH_KEY_MAX_SIGN_DATA_SIZE) 2098 return SSH_ERR_INVALID_ARGUMENT; 2099 if ((impl = sshkey_impl_from_key(key)) == NULL) 2100 return SSH_ERR_KEY_TYPE_UNKNOWN; 2101 if ((r = sshkey_unshield_private(key)) != 0) 2102 return r; 2103 if (sshkey_is_sk(key)) { 2104 r = sshsk_sign(sk_provider, key, sigp, lenp, data, 2105 datalen, compat, sk_pin); 2106 } else { 2107 if (impl->funcs->sign == NULL) 2108 r = SSH_ERR_SIGN_ALG_UNSUPPORTED; 2109 else { 2110 r = impl->funcs->sign(key, sigp, lenp, data, datalen, 2111 alg, sk_provider, sk_pin, compat); 2112 } 2113 } 2114 if (was_shielded && (r2 = sshkey_shield_private(key)) != 0) 2115 return r2; 2116 return r; 2117 } 2118 2119 /* 2120 * ssh_key_verify returns 0 for a correct signature and < 0 on error. 2121 * If "alg" specified, then the signature must use that algorithm. 2122 */ 2123 int 2124 sshkey_verify(const struct sshkey *key, 2125 const u_char *sig, size_t siglen, 2126 const u_char *data, size_t dlen, const char *alg, u_int compat, 2127 struct sshkey_sig_details **detailsp) 2128 { 2129 const struct sshkey_impl *impl; 2130 2131 if (detailsp != NULL) 2132 *detailsp = NULL; 2133 if (siglen == 0 || dlen > SSH_KEY_MAX_SIGN_DATA_SIZE) 2134 return SSH_ERR_INVALID_ARGUMENT; 2135 if ((impl = sshkey_impl_from_key(key)) == NULL) 2136 return SSH_ERR_KEY_TYPE_UNKNOWN; 2137 return impl->funcs->verify(key, sig, siglen, data, dlen, 2138 alg, compat, detailsp); 2139 } 2140 2141 /* Convert a plain key to their _CERT equivalent */ 2142 int 2143 sshkey_to_certified(struct sshkey *k) 2144 { 2145 int newtype; 2146 2147 if ((newtype = sshkey_type_certified(k->type)) == -1) 2148 return SSH_ERR_INVALID_ARGUMENT; 2149 if ((k->cert = cert_new()) == NULL) 2150 return SSH_ERR_ALLOC_FAIL; 2151 k->type = newtype; 2152 return 0; 2153 } 2154 2155 /* Convert a certificate to its raw key equivalent */ 2156 int 2157 sshkey_drop_cert(struct sshkey *k) 2158 { 2159 if (!sshkey_type_is_cert(k->type)) 2160 return SSH_ERR_KEY_TYPE_UNKNOWN; 2161 cert_free(k->cert); 2162 k->cert = NULL; 2163 k->type = sshkey_type_plain(k->type); 2164 return 0; 2165 } 2166 2167 /* Sign a certified key, (re-)generating the signed certblob. */ 2168 int 2169 sshkey_certify_custom(struct sshkey *k, struct sshkey *ca, const char *alg, 2170 const char *sk_provider, const char *sk_pin, 2171 sshkey_certify_signer *signer, void *signer_ctx) 2172 { 2173 const struct sshkey_impl *impl; 2174 struct sshbuf *principals = NULL; 2175 u_char *ca_blob = NULL, *sig_blob = NULL, nonce[32]; 2176 size_t i, ca_len, sig_len; 2177 int ret = SSH_ERR_INTERNAL_ERROR; 2178 struct sshbuf *cert = NULL; 2179 char *sigtype = NULL; 2180 2181 if (k == NULL || k->cert == NULL || 2182 k->cert->certblob == NULL || ca == NULL) 2183 return SSH_ERR_INVALID_ARGUMENT; 2184 if (!sshkey_is_cert(k)) 2185 return SSH_ERR_KEY_TYPE_UNKNOWN; 2186 if (!sshkey_type_is_valid_ca(ca->type)) 2187 return SSH_ERR_KEY_CERT_INVALID_SIGN_KEY; 2188 if ((impl = sshkey_impl_from_key(k)) == NULL) 2189 return SSH_ERR_INTERNAL_ERROR; 2190 2191 /* 2192 * If no alg specified as argument but a signature_type was set, 2193 * then prefer that. If both were specified, then they must match. 2194 */ 2195 if (alg == NULL) 2196 alg = k->cert->signature_type; 2197 else if (k->cert->signature_type != NULL && 2198 strcmp(alg, k->cert->signature_type) != 0) 2199 return SSH_ERR_INVALID_ARGUMENT; 2200 2201 /* 2202 * If no signing algorithm or signature_type was specified and we're 2203 * using a RSA key, then default to a good signature algorithm. 2204 */ 2205 if (alg == NULL && ca->type == KEY_RSA) 2206 alg = "rsa-sha2-512"; 2207 2208 if ((ret = sshkey_to_blob(ca, &ca_blob, &ca_len)) != 0) 2209 return SSH_ERR_KEY_CERT_INVALID_SIGN_KEY; 2210 2211 cert = k->cert->certblob; /* for readability */ 2212 sshbuf_reset(cert); 2213 if ((ret = sshbuf_put_cstring(cert, sshkey_ssh_name(k))) != 0) 2214 goto out; 2215 2216 /* -v01 certs put nonce first */ 2217 arc4random_buf(&nonce, sizeof(nonce)); 2218 if ((ret = sshbuf_put_string(cert, nonce, sizeof(nonce))) != 0) 2219 goto out; 2220 2221 /* Public key next */ 2222 if ((ret = impl->funcs->serialize_public(k, cert, 2223 SSHKEY_SERIALIZE_DEFAULT)) != 0) 2224 goto out; 2225 2226 /* Then remaining cert fields */ 2227 if ((ret = sshbuf_put_u64(cert, k->cert->serial)) != 0 || 2228 (ret = sshbuf_put_u32(cert, k->cert->type)) != 0 || 2229 (ret = sshbuf_put_cstring(cert, k->cert->key_id)) != 0) 2230 goto out; 2231 2232 if ((principals = sshbuf_new()) == NULL) { 2233 ret = SSH_ERR_ALLOC_FAIL; 2234 goto out; 2235 } 2236 for (i = 0; i < k->cert->nprincipals; i++) { 2237 if ((ret = sshbuf_put_cstring(principals, 2238 k->cert->principals[i])) != 0) 2239 goto out; 2240 } 2241 if ((ret = sshbuf_put_stringb(cert, principals)) != 0 || 2242 (ret = sshbuf_put_u64(cert, k->cert->valid_after)) != 0 || 2243 (ret = sshbuf_put_u64(cert, k->cert->valid_before)) != 0 || 2244 (ret = sshbuf_put_stringb(cert, k->cert->critical)) != 0 || 2245 (ret = sshbuf_put_stringb(cert, k->cert->extensions)) != 0 || 2246 (ret = sshbuf_put_string(cert, NULL, 0)) != 0 || /* Reserved */ 2247 (ret = sshbuf_put_string(cert, ca_blob, ca_len)) != 0) 2248 goto out; 2249 2250 /* Sign the whole mess */ 2251 if ((ret = signer(ca, &sig_blob, &sig_len, sshbuf_ptr(cert), 2252 sshbuf_len(cert), alg, sk_provider, sk_pin, 0, signer_ctx)) != 0) 2253 goto out; 2254 /* Check and update signature_type against what was actually used */ 2255 if ((ret = sshkey_get_sigtype(sig_blob, sig_len, &sigtype)) != 0) 2256 goto out; 2257 if (alg != NULL && strcmp(alg, sigtype) != 0) { 2258 ret = SSH_ERR_SIGN_ALG_UNSUPPORTED; 2259 goto out; 2260 } 2261 if (k->cert->signature_type == NULL) { 2262 k->cert->signature_type = sigtype; 2263 sigtype = NULL; 2264 } 2265 /* Append signature and we are done */ 2266 if ((ret = sshbuf_put_string(cert, sig_blob, sig_len)) != 0) 2267 goto out; 2268 ret = 0; 2269 out: 2270 if (ret != 0) 2271 sshbuf_reset(cert); 2272 free(sig_blob); 2273 free(ca_blob); 2274 free(sigtype); 2275 sshbuf_free(principals); 2276 return ret; 2277 } 2278 2279 static int 2280 default_key_sign(struct sshkey *key, u_char **sigp, size_t *lenp, 2281 const u_char *data, size_t datalen, 2282 const char *alg, const char *sk_provider, const char *sk_pin, 2283 u_int compat, void *ctx) 2284 { 2285 if (ctx != NULL) 2286 return SSH_ERR_INVALID_ARGUMENT; 2287 return sshkey_sign(key, sigp, lenp, data, datalen, alg, 2288 sk_provider, sk_pin, compat); 2289 } 2290 2291 int 2292 sshkey_certify(struct sshkey *k, struct sshkey *ca, const char *alg, 2293 const char *sk_provider, const char *sk_pin) 2294 { 2295 return sshkey_certify_custom(k, ca, alg, sk_provider, sk_pin, 2296 default_key_sign, NULL); 2297 } 2298 2299 int 2300 sshkey_cert_check_authority(const struct sshkey *k, 2301 int want_host, int require_principal, int wildcard_pattern, 2302 uint64_t verify_time, const char *name, const char **reason) 2303 { 2304 u_int i, principal_matches; 2305 2306 if (reason == NULL) 2307 return SSH_ERR_INVALID_ARGUMENT; 2308 if (!sshkey_is_cert(k)) { 2309 *reason = "Key is not a certificate"; 2310 return SSH_ERR_KEY_CERT_INVALID; 2311 } 2312 if (want_host) { 2313 if (k->cert->type != SSH2_CERT_TYPE_HOST) { 2314 *reason = "Certificate invalid: not a host certificate"; 2315 return SSH_ERR_KEY_CERT_INVALID; 2316 } 2317 } else { 2318 if (k->cert->type != SSH2_CERT_TYPE_USER) { 2319 *reason = "Certificate invalid: not a user certificate"; 2320 return SSH_ERR_KEY_CERT_INVALID; 2321 } 2322 } 2323 if (verify_time < k->cert->valid_after) { 2324 *reason = "Certificate invalid: not yet valid"; 2325 return SSH_ERR_KEY_CERT_INVALID; 2326 } 2327 if (verify_time >= k->cert->valid_before) { 2328 *reason = "Certificate invalid: expired"; 2329 return SSH_ERR_KEY_CERT_INVALID; 2330 } 2331 if (k->cert->nprincipals == 0) { 2332 if (require_principal) { 2333 *reason = "Certificate lacks principal list"; 2334 return SSH_ERR_KEY_CERT_INVALID; 2335 } 2336 } else if (name != NULL) { 2337 principal_matches = 0; 2338 for (i = 0; i < k->cert->nprincipals; i++) { 2339 if (wildcard_pattern) { 2340 if (match_pattern(k->cert->principals[i], 2341 name)) { 2342 principal_matches = 1; 2343 break; 2344 } 2345 } else if (strcmp(name, k->cert->principals[i]) == 0) { 2346 principal_matches = 1; 2347 break; 2348 } 2349 } 2350 if (!principal_matches) { 2351 *reason = "Certificate invalid: name is not a listed " 2352 "principal"; 2353 return SSH_ERR_KEY_CERT_INVALID; 2354 } 2355 } 2356 return 0; 2357 } 2358 2359 int 2360 sshkey_cert_check_authority_now(const struct sshkey *k, 2361 int want_host, int require_principal, int wildcard_pattern, 2362 const char *name, const char **reason) 2363 { 2364 time_t now; 2365 2366 if ((now = time(NULL)) < 0) { 2367 /* yikes - system clock before epoch! */ 2368 *reason = "Certificate invalid: not yet valid"; 2369 return SSH_ERR_KEY_CERT_INVALID; 2370 } 2371 return sshkey_cert_check_authority(k, want_host, require_principal, 2372 wildcard_pattern, (uint64_t)now, name, reason); 2373 } 2374 2375 int 2376 sshkey_cert_check_host(const struct sshkey *key, const char *host, 2377 int wildcard_principals, const char *ca_sign_algorithms, 2378 const char **reason) 2379 { 2380 int r; 2381 2382 if ((r = sshkey_cert_check_authority_now(key, 1, 0, wildcard_principals, 2383 host, reason)) != 0) 2384 return r; 2385 if (sshbuf_len(key->cert->critical) != 0) { 2386 *reason = "Certificate contains unsupported critical options"; 2387 return SSH_ERR_KEY_CERT_INVALID; 2388 } 2389 if (ca_sign_algorithms != NULL && 2390 (r = sshkey_check_cert_sigtype(key, ca_sign_algorithms)) != 0) { 2391 *reason = "Certificate signed with disallowed algorithm"; 2392 return SSH_ERR_KEY_CERT_INVALID; 2393 } 2394 return 0; 2395 } 2396 2397 size_t 2398 sshkey_format_cert_validity(const struct sshkey_cert *cert, char *s, size_t l) 2399 { 2400 char from[32], to[32], ret[128]; 2401 2402 *from = *to = '\0'; 2403 if (cert->valid_after == 0 && 2404 cert->valid_before == 0xffffffffffffffffULL) 2405 return strlcpy(s, "forever", l); 2406 2407 if (cert->valid_after != 0) 2408 format_absolute_time(cert->valid_after, from, sizeof(from)); 2409 if (cert->valid_before != 0xffffffffffffffffULL) 2410 format_absolute_time(cert->valid_before, to, sizeof(to)); 2411 2412 if (cert->valid_after == 0) 2413 snprintf(ret, sizeof(ret), "before %s", to); 2414 else if (cert->valid_before == 0xffffffffffffffffULL) 2415 snprintf(ret, sizeof(ret), "after %s", from); 2416 else 2417 snprintf(ret, sizeof(ret), "from %s to %s", from, to); 2418 2419 return strlcpy(s, ret, l); 2420 } 2421 2422 /* Common serialization for FIDO private keys */ 2423 int 2424 sshkey_serialize_private_sk(const struct sshkey *key, struct sshbuf *b) 2425 { 2426 int r; 2427 2428 if ((r = sshbuf_put_cstring(b, key->sk_application)) != 0 || 2429 (r = sshbuf_put_u8(b, key->sk_flags)) != 0 || 2430 (r = sshbuf_put_stringb(b, key->sk_key_handle)) != 0 || 2431 (r = sshbuf_put_stringb(b, key->sk_reserved)) != 0) 2432 return r; 2433 2434 return 0; 2435 } 2436 2437 int 2438 sshkey_private_serialize_opt(struct sshkey *key, struct sshbuf *buf, 2439 enum sshkey_serialize_rep opts) 2440 { 2441 int r = SSH_ERR_INTERNAL_ERROR; 2442 int was_shielded = sshkey_is_shielded(key); 2443 struct sshbuf *b = NULL; 2444 const struct sshkey_impl *impl; 2445 2446 if ((impl = sshkey_impl_from_key(key)) == NULL) 2447 return SSH_ERR_INTERNAL_ERROR; 2448 if ((r = sshkey_unshield_private(key)) != 0) 2449 return r; 2450 if ((b = sshbuf_new()) == NULL) 2451 return SSH_ERR_ALLOC_FAIL; 2452 if ((r = sshbuf_put_cstring(b, sshkey_ssh_name(key))) != 0) 2453 goto out; 2454 if (sshkey_is_cert(key)) { 2455 if (key->cert == NULL || 2456 sshbuf_len(key->cert->certblob) == 0) { 2457 r = SSH_ERR_INVALID_ARGUMENT; 2458 goto out; 2459 } 2460 if ((r = sshbuf_put_stringb(b, key->cert->certblob)) != 0) 2461 goto out; 2462 } 2463 if ((r = impl->funcs->serialize_private(key, b, opts)) != 0) 2464 goto out; 2465 2466 /* 2467 * success (but we still need to append the output to buf after 2468 * possibly re-shielding the private key) 2469 */ 2470 r = 0; 2471 out: 2472 if (was_shielded) 2473 r = sshkey_shield_private(key); 2474 if (r == 0) 2475 r = sshbuf_putb(buf, b); 2476 sshbuf_free(b); 2477 2478 return r; 2479 } 2480 2481 int 2482 sshkey_private_serialize(struct sshkey *key, struct sshbuf *b) 2483 { 2484 return sshkey_private_serialize_opt(key, b, 2485 SSHKEY_SERIALIZE_DEFAULT); 2486 } 2487 2488 /* Shared deserialization of FIDO private key components */ 2489 int 2490 sshkey_private_deserialize_sk(struct sshbuf *buf, struct sshkey *k) 2491 { 2492 int r; 2493 2494 if ((k->sk_key_handle = sshbuf_new()) == NULL || 2495 (k->sk_reserved = sshbuf_new()) == NULL) 2496 return SSH_ERR_ALLOC_FAIL; 2497 if ((r = sshbuf_get_cstring(buf, &k->sk_application, NULL)) != 0 || 2498 (r = sshbuf_get_u8(buf, &k->sk_flags)) != 0 || 2499 (r = sshbuf_get_stringb(buf, k->sk_key_handle)) != 0 || 2500 (r = sshbuf_get_stringb(buf, k->sk_reserved)) != 0) 2501 return r; 2502 2503 return 0; 2504 } 2505 2506 int 2507 sshkey_private_deserialize(struct sshbuf *buf, struct sshkey **kp) 2508 { 2509 const struct sshkey_impl *impl; 2510 char *tname = NULL; 2511 char *expect_sk_application = NULL; 2512 u_char *expect_ed25519_pk = NULL; 2513 struct sshkey *k = NULL; 2514 int type, r = SSH_ERR_INTERNAL_ERROR; 2515 2516 if (kp != NULL) 2517 *kp = NULL; 2518 if ((r = sshbuf_get_cstring(buf, &tname, NULL)) != 0) 2519 goto out; 2520 type = sshkey_type_from_name(tname); 2521 if (sshkey_type_is_cert(type)) { 2522 /* 2523 * Certificate key private keys begin with the certificate 2524 * itself. Make sure this matches the type of the enclosing 2525 * private key. 2526 */ 2527 if ((r = sshkey_froms(buf, &k)) != 0) 2528 goto out; 2529 if (k->type != type) { 2530 r = SSH_ERR_KEY_CERT_MISMATCH; 2531 goto out; 2532 } 2533 /* For ECDSA keys, the group must match too */ 2534 if (k->type == KEY_ECDSA && 2535 k->ecdsa_nid != sshkey_ecdsa_nid_from_name(tname)) { 2536 r = SSH_ERR_KEY_CERT_MISMATCH; 2537 goto out; 2538 } 2539 /* 2540 * Several fields are redundant between certificate and 2541 * private key body, we require these to match. 2542 */ 2543 expect_sk_application = k->sk_application; 2544 expect_ed25519_pk = k->ed25519_pk; 2545 k->sk_application = NULL; 2546 k->ed25519_pk = NULL; 2547 /* XXX xmss too or refactor */ 2548 } else { 2549 if ((k = sshkey_new(type)) == NULL) { 2550 r = SSH_ERR_ALLOC_FAIL; 2551 goto out; 2552 } 2553 } 2554 if ((impl = sshkey_impl_from_type(type)) == NULL) { 2555 r = SSH_ERR_INTERNAL_ERROR; 2556 goto out; 2557 } 2558 if ((r = impl->funcs->deserialize_private(tname, buf, k)) != 0) 2559 goto out; 2560 2561 /* XXX xmss too or refactor */ 2562 if ((expect_sk_application != NULL && (k->sk_application == NULL || 2563 strcmp(expect_sk_application, k->sk_application) != 0)) || 2564 (expect_ed25519_pk != NULL && (k->ed25519_pk == NULL || 2565 memcmp(expect_ed25519_pk, k->ed25519_pk, ED25519_PK_SZ) != 0))) { 2566 r = SSH_ERR_KEY_CERT_MISMATCH; 2567 goto out; 2568 } 2569 /* success */ 2570 r = 0; 2571 if (kp != NULL) { 2572 *kp = k; 2573 k = NULL; 2574 } 2575 out: 2576 free(tname); 2577 sshkey_free(k); 2578 free(expect_sk_application); 2579 free(expect_ed25519_pk); 2580 return r; 2581 } 2582 2583 #if defined(WITH_OPENSSL) && defined(OPENSSL_HAS_ECC) 2584 int 2585 sshkey_ec_validate_public(const EC_GROUP *group, const EC_POINT *public) 2586 { 2587 EC_POINT *nq = NULL; 2588 BIGNUM *order = NULL, *x = NULL, *y = NULL, *tmp = NULL; 2589 int ret = SSH_ERR_KEY_INVALID_EC_VALUE; 2590 2591 /* 2592 * NB. This assumes OpenSSL has already verified that the public 2593 * point lies on the curve. This is done by EC_POINT_oct2point() 2594 * implicitly calling EC_POINT_is_on_curve(). If this code is ever 2595 * reachable with public points not unmarshalled using 2596 * EC_POINT_oct2point then the caller will need to explicitly check. 2597 */ 2598 2599 /* 2600 * We shouldn't ever hit this case because bignum_get_ecpoint() 2601 * refuses to load GF2m points. 2602 */ 2603 if (EC_METHOD_get_field_type(EC_GROUP_method_of(group)) != 2604 NID_X9_62_prime_field) 2605 goto out; 2606 2607 /* Q != infinity */ 2608 if (EC_POINT_is_at_infinity(group, public)) 2609 goto out; 2610 2611 if ((x = BN_new()) == NULL || 2612 (y = BN_new()) == NULL || 2613 (order = BN_new()) == NULL || 2614 (tmp = BN_new()) == NULL) { 2615 ret = SSH_ERR_ALLOC_FAIL; 2616 goto out; 2617 } 2618 2619 /* log2(x) > log2(order)/2, log2(y) > log2(order)/2 */ 2620 if (EC_GROUP_get_order(group, order, NULL) != 1 || 2621 EC_POINT_get_affine_coordinates_GFp(group, public, 2622 x, y, NULL) != 1) { 2623 ret = SSH_ERR_LIBCRYPTO_ERROR; 2624 goto out; 2625 } 2626 if (BN_num_bits(x) <= BN_num_bits(order) / 2 || 2627 BN_num_bits(y) <= BN_num_bits(order) / 2) 2628 goto out; 2629 2630 /* nQ == infinity (n == order of subgroup) */ 2631 if ((nq = EC_POINT_new(group)) == NULL) { 2632 ret = SSH_ERR_ALLOC_FAIL; 2633 goto out; 2634 } 2635 if (EC_POINT_mul(group, nq, NULL, public, order, NULL) != 1) { 2636 ret = SSH_ERR_LIBCRYPTO_ERROR; 2637 goto out; 2638 } 2639 if (EC_POINT_is_at_infinity(group, nq) != 1) 2640 goto out; 2641 2642 /* x < order - 1, y < order - 1 */ 2643 if (!BN_sub(tmp, order, BN_value_one())) { 2644 ret = SSH_ERR_LIBCRYPTO_ERROR; 2645 goto out; 2646 } 2647 if (BN_cmp(x, tmp) >= 0 || BN_cmp(y, tmp) >= 0) 2648 goto out; 2649 ret = 0; 2650 out: 2651 BN_clear_free(x); 2652 BN_clear_free(y); 2653 BN_clear_free(order); 2654 BN_clear_free(tmp); 2655 EC_POINT_free(nq); 2656 return ret; 2657 } 2658 2659 int 2660 sshkey_ec_validate_private(const EC_KEY *key) 2661 { 2662 BIGNUM *order = NULL, *tmp = NULL; 2663 int ret = SSH_ERR_KEY_INVALID_EC_VALUE; 2664 2665 if ((order = BN_new()) == NULL || (tmp = BN_new()) == NULL) { 2666 ret = SSH_ERR_ALLOC_FAIL; 2667 goto out; 2668 } 2669 2670 /* log2(private) > log2(order)/2 */ 2671 if (EC_GROUP_get_order(EC_KEY_get0_group(key), order, NULL) != 1) { 2672 ret = SSH_ERR_LIBCRYPTO_ERROR; 2673 goto out; 2674 } 2675 if (BN_num_bits(EC_KEY_get0_private_key(key)) <= 2676 BN_num_bits(order) / 2) 2677 goto out; 2678 2679 /* private < order - 1 */ 2680 if (!BN_sub(tmp, order, BN_value_one())) { 2681 ret = SSH_ERR_LIBCRYPTO_ERROR; 2682 goto out; 2683 } 2684 if (BN_cmp(EC_KEY_get0_private_key(key), tmp) >= 0) 2685 goto out; 2686 ret = 0; 2687 out: 2688 BN_clear_free(order); 2689 BN_clear_free(tmp); 2690 return ret; 2691 } 2692 2693 void 2694 sshkey_dump_ec_point(const EC_GROUP *group, const EC_POINT *point) 2695 { 2696 BIGNUM *x = NULL, *y = NULL; 2697 2698 if (point == NULL) { 2699 fputs("point=(NULL)\n", stderr); 2700 return; 2701 } 2702 if ((x = BN_new()) == NULL || (y = BN_new()) == NULL) { 2703 fprintf(stderr, "%s: BN_new failed\n", __func__); 2704 goto out; 2705 } 2706 if (EC_METHOD_get_field_type(EC_GROUP_method_of(group)) != 2707 NID_X9_62_prime_field) { 2708 fprintf(stderr, "%s: group is not a prime field\n", __func__); 2709 goto out; 2710 } 2711 if (EC_POINT_get_affine_coordinates_GFp(group, point, 2712 x, y, NULL) != 1) { 2713 fprintf(stderr, "%s: EC_POINT_get_affine_coordinates_GFp\n", 2714 __func__); 2715 goto out; 2716 } 2717 fputs("x=", stderr); 2718 BN_print_fp(stderr, x); 2719 fputs("\ny=", stderr); 2720 BN_print_fp(stderr, y); 2721 fputs("\n", stderr); 2722 out: 2723 BN_clear_free(x); 2724 BN_clear_free(y); 2725 } 2726 2727 void 2728 sshkey_dump_ec_key(const EC_KEY *key) 2729 { 2730 const BIGNUM *exponent; 2731 2732 sshkey_dump_ec_point(EC_KEY_get0_group(key), 2733 EC_KEY_get0_public_key(key)); 2734 fputs("exponent=", stderr); 2735 if ((exponent = EC_KEY_get0_private_key(key)) == NULL) 2736 fputs("(NULL)", stderr); 2737 else 2738 BN_print_fp(stderr, EC_KEY_get0_private_key(key)); 2739 fputs("\n", stderr); 2740 } 2741 #endif /* WITH_OPENSSL && OPENSSL_HAS_ECC */ 2742 2743 static int 2744 sshkey_private_to_blob2(struct sshkey *prv, struct sshbuf *blob, 2745 const char *passphrase, const char *comment, const char *ciphername, 2746 int rounds) 2747 { 2748 u_char *cp, *key = NULL, *pubkeyblob = NULL; 2749 u_char salt[SALT_LEN]; 2750 size_t i, pubkeylen, keylen, ivlen, blocksize, authlen; 2751 u_int check; 2752 int r = SSH_ERR_INTERNAL_ERROR; 2753 struct sshcipher_ctx *ciphercontext = NULL; 2754 const struct sshcipher *cipher; 2755 const char *kdfname = KDFNAME; 2756 struct sshbuf *encoded = NULL, *encrypted = NULL, *kdf = NULL; 2757 2758 if (rounds <= 0) 2759 rounds = DEFAULT_ROUNDS; 2760 if (passphrase == NULL || !strlen(passphrase)) { 2761 ciphername = "none"; 2762 kdfname = "none"; 2763 } else if (ciphername == NULL) 2764 ciphername = DEFAULT_CIPHERNAME; 2765 if ((cipher = cipher_by_name(ciphername)) == NULL) { 2766 r = SSH_ERR_INVALID_ARGUMENT; 2767 goto out; 2768 } 2769 2770 if ((kdf = sshbuf_new()) == NULL || 2771 (encoded = sshbuf_new()) == NULL || 2772 (encrypted = sshbuf_new()) == NULL) { 2773 r = SSH_ERR_ALLOC_FAIL; 2774 goto out; 2775 } 2776 blocksize = cipher_blocksize(cipher); 2777 keylen = cipher_keylen(cipher); 2778 ivlen = cipher_ivlen(cipher); 2779 authlen = cipher_authlen(cipher); 2780 if ((key = calloc(1, keylen + ivlen)) == NULL) { 2781 r = SSH_ERR_ALLOC_FAIL; 2782 goto out; 2783 } 2784 if (strcmp(kdfname, "bcrypt") == 0) { 2785 arc4random_buf(salt, SALT_LEN); 2786 if (bcrypt_pbkdf(passphrase, strlen(passphrase), 2787 salt, SALT_LEN, key, keylen + ivlen, rounds) < 0) { 2788 r = SSH_ERR_INVALID_ARGUMENT; 2789 goto out; 2790 } 2791 if ((r = sshbuf_put_string(kdf, salt, SALT_LEN)) != 0 || 2792 (r = sshbuf_put_u32(kdf, rounds)) != 0) 2793 goto out; 2794 } else if (strcmp(kdfname, "none") != 0) { 2795 /* Unsupported KDF type */ 2796 r = SSH_ERR_KEY_UNKNOWN_CIPHER; 2797 goto out; 2798 } 2799 if ((r = cipher_init(&ciphercontext, cipher, key, keylen, 2800 key + keylen, ivlen, 1)) != 0) 2801 goto out; 2802 2803 if ((r = sshbuf_put(encoded, AUTH_MAGIC, sizeof(AUTH_MAGIC))) != 0 || 2804 (r = sshbuf_put_cstring(encoded, ciphername)) != 0 || 2805 (r = sshbuf_put_cstring(encoded, kdfname)) != 0 || 2806 (r = sshbuf_put_stringb(encoded, kdf)) != 0 || 2807 (r = sshbuf_put_u32(encoded, 1)) != 0 || /* number of keys */ 2808 (r = sshkey_to_blob(prv, &pubkeyblob, &pubkeylen)) != 0 || 2809 (r = sshbuf_put_string(encoded, pubkeyblob, pubkeylen)) != 0) 2810 goto out; 2811 2812 /* set up the buffer that will be encrypted */ 2813 2814 /* Random check bytes */ 2815 check = arc4random(); 2816 if ((r = sshbuf_put_u32(encrypted, check)) != 0 || 2817 (r = sshbuf_put_u32(encrypted, check)) != 0) 2818 goto out; 2819 2820 /* append private key and comment*/ 2821 if ((r = sshkey_private_serialize_opt(prv, encrypted, 2822 SSHKEY_SERIALIZE_FULL)) != 0 || 2823 (r = sshbuf_put_cstring(encrypted, comment)) != 0) 2824 goto out; 2825 2826 /* padding */ 2827 i = 0; 2828 while (sshbuf_len(encrypted) % blocksize) { 2829 if ((r = sshbuf_put_u8(encrypted, ++i & 0xff)) != 0) 2830 goto out; 2831 } 2832 2833 /* length in destination buffer */ 2834 if ((r = sshbuf_put_u32(encoded, sshbuf_len(encrypted))) != 0) 2835 goto out; 2836 2837 /* encrypt */ 2838 if ((r = sshbuf_reserve(encoded, 2839 sshbuf_len(encrypted) + authlen, &cp)) != 0) 2840 goto out; 2841 if ((r = cipher_crypt(ciphercontext, 0, cp, 2842 sshbuf_ptr(encrypted), sshbuf_len(encrypted), 0, authlen)) != 0) 2843 goto out; 2844 2845 sshbuf_reset(blob); 2846 2847 /* assemble uuencoded key */ 2848 if ((r = sshbuf_put(blob, MARK_BEGIN, MARK_BEGIN_LEN)) != 0 || 2849 (r = sshbuf_dtob64(encoded, blob, 1)) != 0 || 2850 (r = sshbuf_put(blob, MARK_END, MARK_END_LEN)) != 0) 2851 goto out; 2852 2853 /* success */ 2854 r = 0; 2855 2856 out: 2857 sshbuf_free(kdf); 2858 sshbuf_free(encoded); 2859 sshbuf_free(encrypted); 2860 cipher_free(ciphercontext); 2861 explicit_bzero(salt, sizeof(salt)); 2862 if (key != NULL) 2863 freezero(key, keylen + ivlen); 2864 if (pubkeyblob != NULL) 2865 freezero(pubkeyblob, pubkeylen); 2866 return r; 2867 } 2868 2869 static int 2870 private2_uudecode(struct sshbuf *blob, struct sshbuf **decodedp) 2871 { 2872 const u_char *cp; 2873 size_t encoded_len; 2874 int r; 2875 u_char last; 2876 struct sshbuf *encoded = NULL, *decoded = NULL; 2877 2878 if (blob == NULL || decodedp == NULL) 2879 return SSH_ERR_INVALID_ARGUMENT; 2880 2881 *decodedp = NULL; 2882 2883 if ((encoded = sshbuf_new()) == NULL || 2884 (decoded = sshbuf_new()) == NULL) { 2885 r = SSH_ERR_ALLOC_FAIL; 2886 goto out; 2887 } 2888 2889 /* check preamble */ 2890 cp = sshbuf_ptr(blob); 2891 encoded_len = sshbuf_len(blob); 2892 if (encoded_len < (MARK_BEGIN_LEN + MARK_END_LEN) || 2893 memcmp(cp, MARK_BEGIN, MARK_BEGIN_LEN) != 0) { 2894 r = SSH_ERR_INVALID_FORMAT; 2895 goto out; 2896 } 2897 cp += MARK_BEGIN_LEN; 2898 encoded_len -= MARK_BEGIN_LEN; 2899 2900 /* Look for end marker, removing whitespace as we go */ 2901 while (encoded_len > 0) { 2902 if (*cp != '\n' && *cp != '\r') { 2903 if ((r = sshbuf_put_u8(encoded, *cp)) != 0) 2904 goto out; 2905 } 2906 last = *cp; 2907 encoded_len--; 2908 cp++; 2909 if (last == '\n') { 2910 if (encoded_len >= MARK_END_LEN && 2911 memcmp(cp, MARK_END, MARK_END_LEN) == 0) { 2912 /* \0 terminate */ 2913 if ((r = sshbuf_put_u8(encoded, 0)) != 0) 2914 goto out; 2915 break; 2916 } 2917 } 2918 } 2919 if (encoded_len == 0) { 2920 r = SSH_ERR_INVALID_FORMAT; 2921 goto out; 2922 } 2923 2924 /* decode base64 */ 2925 if ((r = sshbuf_b64tod(decoded, (char *)sshbuf_ptr(encoded))) != 0) 2926 goto out; 2927 2928 /* check magic */ 2929 if (sshbuf_len(decoded) < sizeof(AUTH_MAGIC) || 2930 memcmp(sshbuf_ptr(decoded), AUTH_MAGIC, sizeof(AUTH_MAGIC))) { 2931 r = SSH_ERR_INVALID_FORMAT; 2932 goto out; 2933 } 2934 /* success */ 2935 *decodedp = decoded; 2936 decoded = NULL; 2937 r = 0; 2938 out: 2939 sshbuf_free(encoded); 2940 sshbuf_free(decoded); 2941 return r; 2942 } 2943 2944 static int 2945 private2_decrypt(struct sshbuf *decoded, const char *passphrase, 2946 struct sshbuf **decryptedp, struct sshkey **pubkeyp) 2947 { 2948 char *ciphername = NULL, *kdfname = NULL; 2949 const struct sshcipher *cipher = NULL; 2950 int r = SSH_ERR_INTERNAL_ERROR; 2951 size_t keylen = 0, ivlen = 0, authlen = 0, slen = 0; 2952 struct sshbuf *kdf = NULL, *decrypted = NULL; 2953 struct sshcipher_ctx *ciphercontext = NULL; 2954 struct sshkey *pubkey = NULL; 2955 u_char *key = NULL, *salt = NULL, *dp; 2956 u_int blocksize, rounds, nkeys, encrypted_len, check1, check2; 2957 2958 if (decoded == NULL || decryptedp == NULL || pubkeyp == NULL) 2959 return SSH_ERR_INVALID_ARGUMENT; 2960 2961 *decryptedp = NULL; 2962 *pubkeyp = NULL; 2963 2964 if ((decrypted = sshbuf_new()) == NULL) { 2965 r = SSH_ERR_ALLOC_FAIL; 2966 goto out; 2967 } 2968 2969 /* parse public portion of key */ 2970 if ((r = sshbuf_consume(decoded, sizeof(AUTH_MAGIC))) != 0 || 2971 (r = sshbuf_get_cstring(decoded, &ciphername, NULL)) != 0 || 2972 (r = sshbuf_get_cstring(decoded, &kdfname, NULL)) != 0 || 2973 (r = sshbuf_froms(decoded, &kdf)) != 0 || 2974 (r = sshbuf_get_u32(decoded, &nkeys)) != 0) 2975 goto out; 2976 2977 if (nkeys != 1) { 2978 /* XXX only one key supported at present */ 2979 r = SSH_ERR_INVALID_FORMAT; 2980 goto out; 2981 } 2982 2983 if ((r = sshkey_froms(decoded, &pubkey)) != 0 || 2984 (r = sshbuf_get_u32(decoded, &encrypted_len)) != 0) 2985 goto out; 2986 2987 if ((cipher = cipher_by_name(ciphername)) == NULL) { 2988 r = SSH_ERR_KEY_UNKNOWN_CIPHER; 2989 goto out; 2990 } 2991 if (strcmp(kdfname, "none") != 0 && strcmp(kdfname, "bcrypt") != 0) { 2992 r = SSH_ERR_KEY_UNKNOWN_CIPHER; 2993 goto out; 2994 } 2995 if (strcmp(kdfname, "none") == 0 && strcmp(ciphername, "none") != 0) { 2996 r = SSH_ERR_INVALID_FORMAT; 2997 goto out; 2998 } 2999 if ((passphrase == NULL || strlen(passphrase) == 0) && 3000 strcmp(kdfname, "none") != 0) { 3001 /* passphrase required */ 3002 r = SSH_ERR_KEY_WRONG_PASSPHRASE; 3003 goto out; 3004 } 3005 3006 /* check size of encrypted key blob */ 3007 blocksize = cipher_blocksize(cipher); 3008 if (encrypted_len < blocksize || (encrypted_len % blocksize) != 0) { 3009 r = SSH_ERR_INVALID_FORMAT; 3010 goto out; 3011 } 3012 3013 /* setup key */ 3014 keylen = cipher_keylen(cipher); 3015 ivlen = cipher_ivlen(cipher); 3016 authlen = cipher_authlen(cipher); 3017 if ((key = calloc(1, keylen + ivlen)) == NULL) { 3018 r = SSH_ERR_ALLOC_FAIL; 3019 goto out; 3020 } 3021 if (strcmp(kdfname, "bcrypt") == 0) { 3022 if ((r = sshbuf_get_string(kdf, &salt, &slen)) != 0 || 3023 (r = sshbuf_get_u32(kdf, &rounds)) != 0) 3024 goto out; 3025 if (bcrypt_pbkdf(passphrase, strlen(passphrase), salt, slen, 3026 key, keylen + ivlen, rounds) < 0) { 3027 r = SSH_ERR_INVALID_FORMAT; 3028 goto out; 3029 } 3030 } 3031 3032 /* check that an appropriate amount of auth data is present */ 3033 if (sshbuf_len(decoded) < authlen || 3034 sshbuf_len(decoded) - authlen < encrypted_len) { 3035 r = SSH_ERR_INVALID_FORMAT; 3036 goto out; 3037 } 3038 3039 /* decrypt private portion of key */ 3040 if ((r = sshbuf_reserve(decrypted, encrypted_len, &dp)) != 0 || 3041 (r = cipher_init(&ciphercontext, cipher, key, keylen, 3042 key + keylen, ivlen, 0)) != 0) 3043 goto out; 3044 if ((r = cipher_crypt(ciphercontext, 0, dp, sshbuf_ptr(decoded), 3045 encrypted_len, 0, authlen)) != 0) { 3046 /* an integrity error here indicates an incorrect passphrase */ 3047 if (r == SSH_ERR_MAC_INVALID) 3048 r = SSH_ERR_KEY_WRONG_PASSPHRASE; 3049 goto out; 3050 } 3051 if ((r = sshbuf_consume(decoded, encrypted_len + authlen)) != 0) 3052 goto out; 3053 /* there should be no trailing data */ 3054 if (sshbuf_len(decoded) != 0) { 3055 r = SSH_ERR_INVALID_FORMAT; 3056 goto out; 3057 } 3058 3059 /* check check bytes */ 3060 if ((r = sshbuf_get_u32(decrypted, &check1)) != 0 || 3061 (r = sshbuf_get_u32(decrypted, &check2)) != 0) 3062 goto out; 3063 if (check1 != check2) { 3064 r = SSH_ERR_KEY_WRONG_PASSPHRASE; 3065 goto out; 3066 } 3067 /* success */ 3068 *decryptedp = decrypted; 3069 decrypted = NULL; 3070 *pubkeyp = pubkey; 3071 pubkey = NULL; 3072 r = 0; 3073 out: 3074 cipher_free(ciphercontext); 3075 free(ciphername); 3076 free(kdfname); 3077 sshkey_free(pubkey); 3078 if (salt != NULL) { 3079 explicit_bzero(salt, slen); 3080 free(salt); 3081 } 3082 if (key != NULL) { 3083 explicit_bzero(key, keylen + ivlen); 3084 free(key); 3085 } 3086 sshbuf_free(kdf); 3087 sshbuf_free(decrypted); 3088 return r; 3089 } 3090 3091 static int 3092 sshkey_parse_private2(struct sshbuf *blob, int type, const char *passphrase, 3093 struct sshkey **keyp, char **commentp) 3094 { 3095 char *comment = NULL; 3096 int r = SSH_ERR_INTERNAL_ERROR; 3097 struct sshbuf *decoded = NULL, *decrypted = NULL; 3098 struct sshkey *k = NULL, *pubkey = NULL; 3099 3100 if (keyp != NULL) 3101 *keyp = NULL; 3102 if (commentp != NULL) 3103 *commentp = NULL; 3104 3105 /* Undo base64 encoding and decrypt the private section */ 3106 if ((r = private2_uudecode(blob, &decoded)) != 0 || 3107 (r = private2_decrypt(decoded, passphrase, 3108 &decrypted, &pubkey)) != 0) 3109 goto out; 3110 3111 if (type != KEY_UNSPEC && 3112 sshkey_type_plain(type) != sshkey_type_plain(pubkey->type)) { 3113 r = SSH_ERR_KEY_TYPE_MISMATCH; 3114 goto out; 3115 } 3116 3117 /* Load the private key and comment */ 3118 if ((r = sshkey_private_deserialize(decrypted, &k)) != 0 || 3119 (r = sshbuf_get_cstring(decrypted, &comment, NULL)) != 0) 3120 goto out; 3121 3122 /* Check deterministic padding after private section */ 3123 if ((r = private2_check_padding(decrypted)) != 0) 3124 goto out; 3125 3126 /* Check that the public key in the envelope matches the private key */ 3127 if (!sshkey_equal(pubkey, k)) { 3128 r = SSH_ERR_INVALID_FORMAT; 3129 goto out; 3130 } 3131 3132 /* success */ 3133 r = 0; 3134 if (keyp != NULL) { 3135 *keyp = k; 3136 k = NULL; 3137 } 3138 if (commentp != NULL) { 3139 *commentp = comment; 3140 comment = NULL; 3141 } 3142 out: 3143 free(comment); 3144 sshbuf_free(decoded); 3145 sshbuf_free(decrypted); 3146 sshkey_free(k); 3147 sshkey_free(pubkey); 3148 return r; 3149 } 3150 3151 static int 3152 sshkey_parse_private2_pubkey(struct sshbuf *blob, int type, 3153 struct sshkey **keyp) 3154 { 3155 int r = SSH_ERR_INTERNAL_ERROR; 3156 struct sshbuf *decoded = NULL; 3157 struct sshkey *pubkey = NULL; 3158 u_int nkeys = 0; 3159 3160 if (keyp != NULL) 3161 *keyp = NULL; 3162 3163 if ((r = private2_uudecode(blob, &decoded)) != 0) 3164 goto out; 3165 /* parse public key from unencrypted envelope */ 3166 if ((r = sshbuf_consume(decoded, sizeof(AUTH_MAGIC))) != 0 || 3167 (r = sshbuf_skip_string(decoded)) != 0 || /* cipher */ 3168 (r = sshbuf_skip_string(decoded)) != 0 || /* KDF alg */ 3169 (r = sshbuf_skip_string(decoded)) != 0 || /* KDF hint */ 3170 (r = sshbuf_get_u32(decoded, &nkeys)) != 0) 3171 goto out; 3172 3173 if (nkeys != 1) { 3174 /* XXX only one key supported at present */ 3175 r = SSH_ERR_INVALID_FORMAT; 3176 goto out; 3177 } 3178 3179 /* Parse the public key */ 3180 if ((r = sshkey_froms(decoded, &pubkey)) != 0) 3181 goto out; 3182 3183 if (type != KEY_UNSPEC && 3184 sshkey_type_plain(type) != sshkey_type_plain(pubkey->type)) { 3185 r = SSH_ERR_KEY_TYPE_MISMATCH; 3186 goto out; 3187 } 3188 3189 /* success */ 3190 r = 0; 3191 if (keyp != NULL) { 3192 *keyp = pubkey; 3193 pubkey = NULL; 3194 } 3195 out: 3196 sshbuf_free(decoded); 3197 sshkey_free(pubkey); 3198 return r; 3199 } 3200 3201 #ifdef WITH_OPENSSL 3202 /* convert SSH v2 key to PEM or PKCS#8 format */ 3203 static int 3204 sshkey_private_to_blob_pem_pkcs8(struct sshkey *key, struct sshbuf *buf, 3205 int format, const char *_passphrase, const char *comment) 3206 { 3207 int was_shielded = sshkey_is_shielded(key); 3208 int success, r; 3209 int blen, len = strlen(_passphrase); 3210 u_char *passphrase = (len > 0) ? (u_char *)_passphrase : NULL; 3211 const EVP_CIPHER *cipher = (len > 0) ? EVP_aes_128_cbc() : NULL; 3212 char *bptr; 3213 BIO *bio = NULL; 3214 struct sshbuf *blob; 3215 EVP_PKEY *pkey = NULL; 3216 3217 if (len > 0 && len <= 4) 3218 return SSH_ERR_PASSPHRASE_TOO_SHORT; 3219 if ((blob = sshbuf_new()) == NULL) 3220 return SSH_ERR_ALLOC_FAIL; 3221 if ((bio = BIO_new(BIO_s_mem())) == NULL) { 3222 r = SSH_ERR_ALLOC_FAIL; 3223 goto out; 3224 } 3225 if (format == SSHKEY_PRIVATE_PKCS8 && (pkey = EVP_PKEY_new()) == NULL) { 3226 r = SSH_ERR_ALLOC_FAIL; 3227 goto out; 3228 } 3229 if ((r = sshkey_unshield_private(key)) != 0) 3230 goto out; 3231 3232 switch (key->type) { 3233 case KEY_DSA: 3234 if (format == SSHKEY_PRIVATE_PEM) { 3235 success = PEM_write_bio_DSAPrivateKey(bio, key->dsa, 3236 cipher, passphrase, len, NULL, NULL); 3237 } else { 3238 success = EVP_PKEY_set1_DSA(pkey, key->dsa); 3239 } 3240 break; 3241 #ifdef OPENSSL_HAS_ECC 3242 case KEY_ECDSA: 3243 if (format == SSHKEY_PRIVATE_PEM) { 3244 success = PEM_write_bio_ECPrivateKey(bio, key->ecdsa, 3245 cipher, passphrase, len, NULL, NULL); 3246 } else { 3247 success = EVP_PKEY_set1_EC_KEY(pkey, key->ecdsa); 3248 } 3249 break; 3250 #endif 3251 case KEY_RSA: 3252 if (format == SSHKEY_PRIVATE_PEM) { 3253 success = PEM_write_bio_RSAPrivateKey(bio, key->rsa, 3254 cipher, passphrase, len, NULL, NULL); 3255 } else { 3256 success = EVP_PKEY_set1_RSA(pkey, key->rsa); 3257 } 3258 break; 3259 default: 3260 success = 0; 3261 break; 3262 } 3263 if (success == 0) { 3264 r = SSH_ERR_LIBCRYPTO_ERROR; 3265 goto out; 3266 } 3267 if (format == SSHKEY_PRIVATE_PKCS8) { 3268 if ((success = PEM_write_bio_PrivateKey(bio, pkey, cipher, 3269 passphrase, len, NULL, NULL)) == 0) { 3270 r = SSH_ERR_LIBCRYPTO_ERROR; 3271 goto out; 3272 } 3273 } 3274 if ((blen = BIO_get_mem_data(bio, &bptr)) <= 0) { 3275 r = SSH_ERR_INTERNAL_ERROR; 3276 goto out; 3277 } 3278 if ((r = sshbuf_put(blob, bptr, blen)) != 0) 3279 goto out; 3280 r = 0; 3281 out: 3282 if (was_shielded) 3283 r = sshkey_shield_private(key); 3284 if (r == 0) 3285 r = sshbuf_putb(buf, blob); 3286 3287 EVP_PKEY_free(pkey); 3288 sshbuf_free(blob); 3289 BIO_free(bio); 3290 return r; 3291 } 3292 #endif /* WITH_OPENSSL */ 3293 3294 /* Serialise "key" to buffer "blob" */ 3295 int 3296 sshkey_private_to_fileblob(struct sshkey *key, struct sshbuf *blob, 3297 const char *passphrase, const char *comment, 3298 int format, const char *openssh_format_cipher, int openssh_format_rounds) 3299 { 3300 switch (key->type) { 3301 #ifdef WITH_OPENSSL 3302 case KEY_DSA: 3303 case KEY_ECDSA: 3304 case KEY_RSA: 3305 break; /* see below */ 3306 #endif /* WITH_OPENSSL */ 3307 case KEY_ED25519: 3308 case KEY_ED25519_SK: 3309 #ifdef WITH_XMSS 3310 case KEY_XMSS: 3311 #endif /* WITH_XMSS */ 3312 #ifdef WITH_OPENSSL 3313 case KEY_ECDSA_SK: 3314 #endif /* WITH_OPENSSL */ 3315 return sshkey_private_to_blob2(key, blob, passphrase, 3316 comment, openssh_format_cipher, openssh_format_rounds); 3317 default: 3318 return SSH_ERR_KEY_TYPE_UNKNOWN; 3319 } 3320 3321 #ifdef WITH_OPENSSL 3322 switch (format) { 3323 case SSHKEY_PRIVATE_OPENSSH: 3324 return sshkey_private_to_blob2(key, blob, passphrase, 3325 comment, openssh_format_cipher, openssh_format_rounds); 3326 case SSHKEY_PRIVATE_PEM: 3327 case SSHKEY_PRIVATE_PKCS8: 3328 return sshkey_private_to_blob_pem_pkcs8(key, blob, 3329 format, passphrase, comment); 3330 default: 3331 return SSH_ERR_INVALID_ARGUMENT; 3332 } 3333 #endif /* WITH_OPENSSL */ 3334 } 3335 3336 #ifdef WITH_OPENSSL 3337 static int 3338 translate_libcrypto_error(unsigned long pem_err) 3339 { 3340 int pem_reason = ERR_GET_REASON(pem_err); 3341 3342 switch (ERR_GET_LIB(pem_err)) { 3343 case ERR_LIB_PEM: 3344 switch (pem_reason) { 3345 case PEM_R_BAD_PASSWORD_READ: 3346 #ifdef PEM_R_PROBLEMS_GETTING_PASSWORD 3347 case PEM_R_PROBLEMS_GETTING_PASSWORD: 3348 #endif 3349 #ifdef PEM_R_BAD_DECRYPT 3350 case PEM_R_BAD_DECRYPT: 3351 #endif 3352 return SSH_ERR_KEY_WRONG_PASSPHRASE; 3353 default: 3354 return SSH_ERR_INVALID_FORMAT; 3355 } 3356 case ERR_LIB_EVP: 3357 switch (pem_reason) { 3358 #ifdef EVP_R_BAD_DECRYPT 3359 case EVP_R_BAD_DECRYPT: 3360 return SSH_ERR_KEY_WRONG_PASSPHRASE; 3361 #endif 3362 #ifdef EVP_R_BN_DECODE_ERROR 3363 case EVP_R_BN_DECODE_ERROR: 3364 #endif 3365 case EVP_R_DECODE_ERROR: 3366 #ifdef EVP_R_PRIVATE_KEY_DECODE_ERROR 3367 case EVP_R_PRIVATE_KEY_DECODE_ERROR: 3368 #endif 3369 return SSH_ERR_INVALID_FORMAT; 3370 default: 3371 return SSH_ERR_LIBCRYPTO_ERROR; 3372 } 3373 case ERR_LIB_ASN1: 3374 return SSH_ERR_INVALID_FORMAT; 3375 } 3376 return SSH_ERR_LIBCRYPTO_ERROR; 3377 } 3378 3379 static void 3380 clear_libcrypto_errors(void) 3381 { 3382 while (ERR_get_error() != 0) 3383 ; 3384 } 3385 3386 /* 3387 * Translate OpenSSL error codes to determine whether 3388 * passphrase is required/incorrect. 3389 */ 3390 static int 3391 convert_libcrypto_error(void) 3392 { 3393 /* 3394 * Some password errors are reported at the beginning 3395 * of the error queue. 3396 */ 3397 if (translate_libcrypto_error(ERR_peek_error()) == 3398 SSH_ERR_KEY_WRONG_PASSPHRASE) 3399 return SSH_ERR_KEY_WRONG_PASSPHRASE; 3400 return translate_libcrypto_error(ERR_peek_last_error()); 3401 } 3402 3403 static int 3404 pem_passphrase_cb(char *buf, int size, int rwflag, void *u) 3405 { 3406 char *p = (char *)u; 3407 size_t len; 3408 3409 if (p == NULL || (len = strlen(p)) == 0) 3410 return -1; 3411 if (size < 0 || len > (size_t)size) 3412 return -1; 3413 memcpy(buf, p, len); 3414 return (int)len; 3415 } 3416 3417 static int 3418 sshkey_parse_private_pem_fileblob(struct sshbuf *blob, int type, 3419 const char *passphrase, struct sshkey **keyp) 3420 { 3421 EVP_PKEY *pk = NULL; 3422 struct sshkey *prv = NULL; 3423 BIO *bio = NULL; 3424 int r; 3425 3426 if (keyp != NULL) 3427 *keyp = NULL; 3428 3429 if ((bio = BIO_new(BIO_s_mem())) == NULL || sshbuf_len(blob) > INT_MAX) 3430 return SSH_ERR_ALLOC_FAIL; 3431 if (BIO_write(bio, sshbuf_ptr(blob), sshbuf_len(blob)) != 3432 (int)sshbuf_len(blob)) { 3433 r = SSH_ERR_ALLOC_FAIL; 3434 goto out; 3435 } 3436 3437 clear_libcrypto_errors(); 3438 if ((pk = PEM_read_bio_PrivateKey(bio, NULL, pem_passphrase_cb, 3439 (char *)passphrase)) == NULL) { 3440 /* 3441 * libcrypto may return various ASN.1 errors when attempting 3442 * to parse a key with an incorrect passphrase. 3443 * Treat all format errors as "incorrect passphrase" if a 3444 * passphrase was supplied. 3445 */ 3446 if (passphrase != NULL && *passphrase != '\0') 3447 r = SSH_ERR_KEY_WRONG_PASSPHRASE; 3448 else 3449 r = convert_libcrypto_error(); 3450 goto out; 3451 } 3452 if (EVP_PKEY_base_id(pk) == EVP_PKEY_RSA && 3453 (type == KEY_UNSPEC || type == KEY_RSA)) { 3454 if ((prv = sshkey_new(KEY_UNSPEC)) == NULL) { 3455 r = SSH_ERR_ALLOC_FAIL; 3456 goto out; 3457 } 3458 prv->rsa = EVP_PKEY_get1_RSA(pk); 3459 prv->type = KEY_RSA; 3460 #ifdef DEBUG_PK 3461 RSA_print_fp(stderr, prv->rsa, 8); 3462 #endif 3463 if (RSA_blinding_on(prv->rsa, NULL) != 1) { 3464 r = SSH_ERR_LIBCRYPTO_ERROR; 3465 goto out; 3466 } 3467 if ((r = sshkey_check_rsa_length(prv, 0)) != 0) 3468 goto out; 3469 } else if (EVP_PKEY_base_id(pk) == EVP_PKEY_DSA && 3470 (type == KEY_UNSPEC || type == KEY_DSA)) { 3471 if ((prv = sshkey_new(KEY_UNSPEC)) == NULL) { 3472 r = SSH_ERR_ALLOC_FAIL; 3473 goto out; 3474 } 3475 prv->dsa = EVP_PKEY_get1_DSA(pk); 3476 prv->type = KEY_DSA; 3477 #ifdef DEBUG_PK 3478 DSA_print_fp(stderr, prv->dsa, 8); 3479 #endif 3480 #ifdef OPENSSL_HAS_ECC 3481 } else if (EVP_PKEY_base_id(pk) == EVP_PKEY_EC && 3482 (type == KEY_UNSPEC || type == KEY_ECDSA)) { 3483 if ((prv = sshkey_new(KEY_UNSPEC)) == NULL) { 3484 r = SSH_ERR_ALLOC_FAIL; 3485 goto out; 3486 } 3487 prv->ecdsa = EVP_PKEY_get1_EC_KEY(pk); 3488 prv->type = KEY_ECDSA; 3489 prv->ecdsa_nid = sshkey_ecdsa_key_to_nid(prv->ecdsa); 3490 if (prv->ecdsa_nid == -1 || 3491 sshkey_curve_nid_to_name(prv->ecdsa_nid) == NULL || 3492 sshkey_ec_validate_public(EC_KEY_get0_group(prv->ecdsa), 3493 EC_KEY_get0_public_key(prv->ecdsa)) != 0 || 3494 sshkey_ec_validate_private(prv->ecdsa) != 0) { 3495 r = SSH_ERR_INVALID_FORMAT; 3496 goto out; 3497 } 3498 # ifdef DEBUG_PK 3499 if (prv != NULL && prv->ecdsa != NULL) 3500 sshkey_dump_ec_key(prv->ecdsa); 3501 # endif 3502 #endif /* OPENSSL_HAS_ECC */ 3503 } else { 3504 r = SSH_ERR_INVALID_FORMAT; 3505 goto out; 3506 } 3507 r = 0; 3508 if (keyp != NULL) { 3509 *keyp = prv; 3510 prv = NULL; 3511 } 3512 out: 3513 BIO_free(bio); 3514 EVP_PKEY_free(pk); 3515 sshkey_free(prv); 3516 return r; 3517 } 3518 #endif /* WITH_OPENSSL */ 3519 3520 int 3521 sshkey_parse_private_fileblob_type(struct sshbuf *blob, int type, 3522 const char *passphrase, struct sshkey **keyp, char **commentp) 3523 { 3524 int r = SSH_ERR_INTERNAL_ERROR; 3525 3526 if (keyp != NULL) 3527 *keyp = NULL; 3528 if (commentp != NULL) 3529 *commentp = NULL; 3530 3531 switch (type) { 3532 case KEY_ED25519: 3533 case KEY_XMSS: 3534 /* No fallback for new-format-only keys */ 3535 return sshkey_parse_private2(blob, type, passphrase, 3536 keyp, commentp); 3537 default: 3538 r = sshkey_parse_private2(blob, type, passphrase, keyp, 3539 commentp); 3540 /* Only fallback to PEM parser if a format error occurred. */ 3541 if (r != SSH_ERR_INVALID_FORMAT) 3542 return r; 3543 #ifdef WITH_OPENSSL 3544 return sshkey_parse_private_pem_fileblob(blob, type, 3545 passphrase, keyp); 3546 #else 3547 return SSH_ERR_INVALID_FORMAT; 3548 #endif /* WITH_OPENSSL */ 3549 } 3550 } 3551 3552 int 3553 sshkey_parse_private_fileblob(struct sshbuf *buffer, const char *passphrase, 3554 struct sshkey **keyp, char **commentp) 3555 { 3556 if (keyp != NULL) 3557 *keyp = NULL; 3558 if (commentp != NULL) 3559 *commentp = NULL; 3560 3561 return sshkey_parse_private_fileblob_type(buffer, KEY_UNSPEC, 3562 passphrase, keyp, commentp); 3563 } 3564 3565 void 3566 sshkey_sig_details_free(struct sshkey_sig_details *details) 3567 { 3568 freezero(details, sizeof(*details)); 3569 } 3570 3571 int 3572 sshkey_parse_pubkey_from_private_fileblob_type(struct sshbuf *blob, int type, 3573 struct sshkey **pubkeyp) 3574 { 3575 int r = SSH_ERR_INTERNAL_ERROR; 3576 3577 if (pubkeyp != NULL) 3578 *pubkeyp = NULL; 3579 /* only new-format private keys bundle a public key inside */ 3580 if ((r = sshkey_parse_private2_pubkey(blob, type, pubkeyp)) != 0) 3581 return r; 3582 return 0; 3583 } 3584 3585 #ifdef WITH_XMSS 3586 /* 3587 * serialize the key with the current state and forward the state 3588 * maxsign times. 3589 */ 3590 int 3591 sshkey_private_serialize_maxsign(struct sshkey *k, struct sshbuf *b, 3592 u_int32_t maxsign, int printerror) 3593 { 3594 int r, rupdate; 3595 3596 if (maxsign == 0 || 3597 sshkey_type_plain(k->type) != KEY_XMSS) 3598 return sshkey_private_serialize_opt(k, b, 3599 SSHKEY_SERIALIZE_DEFAULT); 3600 if ((r = sshkey_xmss_get_state(k, printerror)) != 0 || 3601 (r = sshkey_private_serialize_opt(k, b, 3602 SSHKEY_SERIALIZE_STATE)) != 0 || 3603 (r = sshkey_xmss_forward_state(k, maxsign)) != 0) 3604 goto out; 3605 r = 0; 3606 out: 3607 if ((rupdate = sshkey_xmss_update_state(k, printerror)) != 0) { 3608 if (r == 0) 3609 r = rupdate; 3610 } 3611 return r; 3612 } 3613 3614 u_int32_t 3615 sshkey_signatures_left(const struct sshkey *k) 3616 { 3617 if (sshkey_type_plain(k->type) == KEY_XMSS) 3618 return sshkey_xmss_signatures_left(k); 3619 return 0; 3620 } 3621 3622 int 3623 sshkey_enable_maxsign(struct sshkey *k, u_int32_t maxsign) 3624 { 3625 if (sshkey_type_plain(k->type) != KEY_XMSS) 3626 return SSH_ERR_INVALID_ARGUMENT; 3627 return sshkey_xmss_enable_maxsign(k, maxsign); 3628 } 3629 3630 int 3631 sshkey_set_filename(struct sshkey *k, const char *filename) 3632 { 3633 if (k == NULL) 3634 return SSH_ERR_INVALID_ARGUMENT; 3635 if (sshkey_type_plain(k->type) != KEY_XMSS) 3636 return 0; 3637 if (filename == NULL) 3638 return SSH_ERR_INVALID_ARGUMENT; 3639 if ((k->xmss_filename = strdup(filename)) == NULL) 3640 return SSH_ERR_ALLOC_FAIL; 3641 return 0; 3642 } 3643 #else 3644 int 3645 sshkey_private_serialize_maxsign(struct sshkey *k, struct sshbuf *b, 3646 u_int32_t maxsign, int printerror) 3647 { 3648 return sshkey_private_serialize_opt(k, b, SSHKEY_SERIALIZE_DEFAULT); 3649 } 3650 3651 u_int32_t 3652 sshkey_signatures_left(const struct sshkey *k) 3653 { 3654 return 0; 3655 } 3656 3657 int 3658 sshkey_enable_maxsign(struct sshkey *k, u_int32_t maxsign) 3659 { 3660 return SSH_ERR_INVALID_ARGUMENT; 3661 } 3662 3663 int 3664 sshkey_set_filename(struct sshkey *k, const char *filename) 3665 { 3666 if (k == NULL) 3667 return SSH_ERR_INVALID_ARGUMENT; 3668 return 0; 3669 } 3670 #endif /* WITH_XMSS */ 3671