1 /* $OpenBSD: sshkey.c,v 1.113 2021/01/15 04:31:25 dtucker 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 <string.h> 45 #include <resolv.h> 46 #include <time.h> 47 #ifdef HAVE_UTIL_H 48 #include <util.h> 49 #endif /* HAVE_UTIL_H */ 50 51 #include "ssh2.h" 52 #include "ssherr.h" 53 #include "misc.h" 54 #include "sshbuf.h" 55 #include "cipher.h" 56 #include "digest.h" 57 #define SSHKEY_INTERNAL 58 #include "sshkey.h" 59 #include "match.h" 60 #include "ssh-sk.h" 61 62 #ifdef WITH_XMSS 63 #include "sshkey-xmss.h" 64 #include "xmss_fast.h" 65 #endif 66 67 #include "openbsd-compat/openssl-compat.h" 68 69 /* openssh private key file format */ 70 #define MARK_BEGIN "-----BEGIN OPENSSH PRIVATE KEY-----\n" 71 #define MARK_END "-----END OPENSSH PRIVATE KEY-----\n" 72 #define MARK_BEGIN_LEN (sizeof(MARK_BEGIN) - 1) 73 #define MARK_END_LEN (sizeof(MARK_END) - 1) 74 #define KDFNAME "bcrypt" 75 #define AUTH_MAGIC "openssh-key-v1" 76 #define SALT_LEN 16 77 #define DEFAULT_CIPHERNAME "aes256-ctr" 78 #define DEFAULT_ROUNDS 16 79 80 /* Version identification string for SSH v1 identity files. */ 81 #define LEGACY_BEGIN "SSH PRIVATE KEY FILE FORMAT 1.1\n" 82 83 /* 84 * Constants relating to "shielding" support; protection of keys expected 85 * to remain in memory for long durations 86 */ 87 #define SSHKEY_SHIELD_PREKEY_LEN (16 * 1024) 88 #define SSHKEY_SHIELD_CIPHER "aes256-ctr" /* XXX want AES-EME* */ 89 #define SSHKEY_SHIELD_PREKEY_HASH SSH_DIGEST_SHA512 90 91 int sshkey_private_serialize_opt(struct sshkey *key, 92 struct sshbuf *buf, enum sshkey_serialize_rep); 93 static int sshkey_from_blob_internal(struct sshbuf *buf, 94 struct sshkey **keyp, int allow_cert); 95 96 /* Supported key types */ 97 struct keytype { 98 const char *name; 99 const char *shortname; 100 const char *sigalg; 101 int type; 102 int nid; 103 int cert; 104 int sigonly; 105 }; 106 static const struct keytype keytypes[] = { 107 { "ssh-ed25519", "ED25519", NULL, KEY_ED25519, 0, 0, 0 }, 108 { "ssh-ed25519-cert-v01@openssh.com", "ED25519-CERT", NULL, 109 KEY_ED25519_CERT, 0, 1, 0 }, 110 { "sk-ssh-ed25519@openssh.com", "ED25519-SK", NULL, 111 KEY_ED25519_SK, 0, 0, 0 }, 112 { "sk-ssh-ed25519-cert-v01@openssh.com", "ED25519-SK-CERT", NULL, 113 KEY_ED25519_SK_CERT, 0, 1, 0 }, 114 #ifdef WITH_XMSS 115 { "ssh-xmss@openssh.com", "XMSS", NULL, KEY_XMSS, 0, 0, 0 }, 116 { "ssh-xmss-cert-v01@openssh.com", "XMSS-CERT", NULL, 117 KEY_XMSS_CERT, 0, 1, 0 }, 118 #endif /* WITH_XMSS */ 119 #ifdef WITH_OPENSSL 120 { "ssh-rsa", "RSA", NULL, KEY_RSA, 0, 0, 0 }, 121 { "rsa-sha2-256", "RSA", NULL, KEY_RSA, 0, 0, 1 }, 122 { "rsa-sha2-512", "RSA", NULL, KEY_RSA, 0, 0, 1 }, 123 { "ssh-dss", "DSA", NULL, KEY_DSA, 0, 0, 0 }, 124 # ifdef OPENSSL_HAS_ECC 125 { "ecdsa-sha2-nistp256", "ECDSA", NULL, 126 KEY_ECDSA, NID_X9_62_prime256v1, 0, 0 }, 127 { "ecdsa-sha2-nistp384", "ECDSA", NULL, 128 KEY_ECDSA, NID_secp384r1, 0, 0 }, 129 # ifdef OPENSSL_HAS_NISTP521 130 { "ecdsa-sha2-nistp521", "ECDSA", NULL, 131 KEY_ECDSA, NID_secp521r1, 0, 0 }, 132 # endif /* OPENSSL_HAS_NISTP521 */ 133 { "sk-ecdsa-sha2-nistp256@openssh.com", "ECDSA-SK", NULL, 134 KEY_ECDSA_SK, NID_X9_62_prime256v1, 0, 0 }, 135 { "webauthn-sk-ecdsa-sha2-nistp256@openssh.com", "ECDSA-SK", NULL, 136 KEY_ECDSA_SK, NID_X9_62_prime256v1, 0, 1 }, 137 # endif /* OPENSSL_HAS_ECC */ 138 { "ssh-rsa-cert-v01@openssh.com", "RSA-CERT", NULL, 139 KEY_RSA_CERT, 0, 1, 0 }, 140 { "rsa-sha2-256-cert-v01@openssh.com", "RSA-CERT", 141 "rsa-sha2-256", KEY_RSA_CERT, 0, 1, 1 }, 142 { "rsa-sha2-512-cert-v01@openssh.com", "RSA-CERT", 143 "rsa-sha2-512", KEY_RSA_CERT, 0, 1, 1 }, 144 { "ssh-dss-cert-v01@openssh.com", "DSA-CERT", NULL, 145 KEY_DSA_CERT, 0, 1, 0 }, 146 # ifdef OPENSSL_HAS_ECC 147 { "ecdsa-sha2-nistp256-cert-v01@openssh.com", "ECDSA-CERT", NULL, 148 KEY_ECDSA_CERT, NID_X9_62_prime256v1, 1, 0 }, 149 { "ecdsa-sha2-nistp384-cert-v01@openssh.com", "ECDSA-CERT", NULL, 150 KEY_ECDSA_CERT, NID_secp384r1, 1, 0 }, 151 # ifdef OPENSSL_HAS_NISTP521 152 { "ecdsa-sha2-nistp521-cert-v01@openssh.com", "ECDSA-CERT", NULL, 153 KEY_ECDSA_CERT, NID_secp521r1, 1, 0 }, 154 # endif /* OPENSSL_HAS_NISTP521 */ 155 { "sk-ecdsa-sha2-nistp256-cert-v01@openssh.com", "ECDSA-SK-CERT", NULL, 156 KEY_ECDSA_SK_CERT, NID_X9_62_prime256v1, 1, 0 }, 157 # endif /* OPENSSL_HAS_ECC */ 158 #endif /* WITH_OPENSSL */ 159 { NULL, NULL, NULL, -1, -1, 0, 0 } 160 }; 161 162 const char * 163 sshkey_type(const struct sshkey *k) 164 { 165 const struct keytype *kt; 166 167 for (kt = keytypes; kt->type != -1; kt++) { 168 if (kt->type == k->type) 169 return kt->shortname; 170 } 171 return "unknown"; 172 } 173 174 static const char * 175 sshkey_ssh_name_from_type_nid(int type, int nid) 176 { 177 const struct keytype *kt; 178 179 for (kt = keytypes; kt->type != -1; kt++) { 180 if (kt->type == type && (kt->nid == 0 || kt->nid == nid)) 181 return kt->name; 182 } 183 return "ssh-unknown"; 184 } 185 186 int 187 sshkey_type_is_cert(int type) 188 { 189 const struct keytype *kt; 190 191 for (kt = keytypes; kt->type != -1; kt++) { 192 if (kt->type == type) 193 return kt->cert; 194 } 195 return 0; 196 } 197 198 const char * 199 sshkey_ssh_name(const struct sshkey *k) 200 { 201 return sshkey_ssh_name_from_type_nid(k->type, k->ecdsa_nid); 202 } 203 204 const char * 205 sshkey_ssh_name_plain(const struct sshkey *k) 206 { 207 return sshkey_ssh_name_from_type_nid(sshkey_type_plain(k->type), 208 k->ecdsa_nid); 209 } 210 211 int 212 sshkey_type_from_name(const char *name) 213 { 214 const struct keytype *kt; 215 216 for (kt = keytypes; kt->type != -1; kt++) { 217 /* Only allow shortname matches for plain key types */ 218 if ((kt->name != NULL && strcmp(name, kt->name) == 0) || 219 (!kt->cert && strcasecmp(kt->shortname, name) == 0)) 220 return kt->type; 221 } 222 return KEY_UNSPEC; 223 } 224 225 static int 226 key_type_is_ecdsa_variant(int type) 227 { 228 switch (type) { 229 case KEY_ECDSA: 230 case KEY_ECDSA_CERT: 231 case KEY_ECDSA_SK: 232 case KEY_ECDSA_SK_CERT: 233 return 1; 234 } 235 return 0; 236 } 237 238 int 239 sshkey_ecdsa_nid_from_name(const char *name) 240 { 241 const struct keytype *kt; 242 243 for (kt = keytypes; kt->type != -1; kt++) { 244 if (!key_type_is_ecdsa_variant(kt->type)) 245 continue; 246 if (kt->name != NULL && strcmp(name, kt->name) == 0) 247 return kt->nid; 248 } 249 return -1; 250 } 251 252 char * 253 sshkey_alg_list(int certs_only, int plain_only, int include_sigonly, char sep) 254 { 255 char *tmp, *ret = NULL; 256 size_t nlen, rlen = 0; 257 const struct keytype *kt; 258 259 for (kt = keytypes; kt->type != -1; kt++) { 260 if (kt->name == NULL) 261 continue; 262 if (!include_sigonly && kt->sigonly) 263 continue; 264 if ((certs_only && !kt->cert) || (plain_only && kt->cert)) 265 continue; 266 if (ret != NULL) 267 ret[rlen++] = sep; 268 nlen = strlen(kt->name); 269 if ((tmp = realloc(ret, rlen + nlen + 2)) == NULL) { 270 free(ret); 271 return NULL; 272 } 273 ret = tmp; 274 memcpy(ret + rlen, kt->name, nlen + 1); 275 rlen += nlen; 276 } 277 return ret; 278 } 279 280 int 281 sshkey_names_valid2(const char *names, int allow_wildcard) 282 { 283 char *s, *cp, *p; 284 const struct keytype *kt; 285 int type; 286 287 if (names == NULL || strcmp(names, "") == 0) 288 return 0; 289 if ((s = cp = strdup(names)) == NULL) 290 return 0; 291 for ((p = strsep(&cp, ",")); p && *p != '\0'; 292 (p = strsep(&cp, ","))) { 293 type = sshkey_type_from_name(p); 294 if (type == KEY_UNSPEC) { 295 if (allow_wildcard) { 296 /* 297 * Try matching key types against the string. 298 * If any has a positive or negative match then 299 * the component is accepted. 300 */ 301 for (kt = keytypes; kt->type != -1; kt++) { 302 if (match_pattern_list(kt->name, 303 p, 0) != 0) 304 break; 305 } 306 if (kt->type != -1) 307 continue; 308 } 309 free(s); 310 return 0; 311 } 312 } 313 free(s); 314 return 1; 315 } 316 317 u_int 318 sshkey_size(const struct sshkey *k) 319 { 320 #ifdef WITH_OPENSSL 321 const BIGNUM *rsa_n, *dsa_p; 322 #endif /* WITH_OPENSSL */ 323 324 switch (k->type) { 325 #ifdef WITH_OPENSSL 326 case KEY_RSA: 327 case KEY_RSA_CERT: 328 if (k->rsa == NULL) 329 return 0; 330 RSA_get0_key(k->rsa, &rsa_n, NULL, NULL); 331 return BN_num_bits(rsa_n); 332 case KEY_DSA: 333 case KEY_DSA_CERT: 334 if (k->dsa == NULL) 335 return 0; 336 DSA_get0_pqg(k->dsa, &dsa_p, NULL, NULL); 337 return BN_num_bits(dsa_p); 338 case KEY_ECDSA: 339 case KEY_ECDSA_CERT: 340 case KEY_ECDSA_SK: 341 case KEY_ECDSA_SK_CERT: 342 return sshkey_curve_nid_to_bits(k->ecdsa_nid); 343 #endif /* WITH_OPENSSL */ 344 case KEY_ED25519: 345 case KEY_ED25519_CERT: 346 case KEY_ED25519_SK: 347 case KEY_ED25519_SK_CERT: 348 case KEY_XMSS: 349 case KEY_XMSS_CERT: 350 return 256; /* XXX */ 351 } 352 return 0; 353 } 354 355 static int 356 sshkey_type_is_valid_ca(int type) 357 { 358 switch (type) { 359 case KEY_RSA: 360 case KEY_DSA: 361 case KEY_ECDSA: 362 case KEY_ECDSA_SK: 363 case KEY_ED25519: 364 case KEY_ED25519_SK: 365 case KEY_XMSS: 366 return 1; 367 default: 368 return 0; 369 } 370 } 371 372 int 373 sshkey_is_cert(const struct sshkey *k) 374 { 375 if (k == NULL) 376 return 0; 377 return sshkey_type_is_cert(k->type); 378 } 379 380 int 381 sshkey_is_sk(const struct sshkey *k) 382 { 383 if (k == NULL) 384 return 0; 385 switch (sshkey_type_plain(k->type)) { 386 case KEY_ECDSA_SK: 387 case KEY_ED25519_SK: 388 return 1; 389 default: 390 return 0; 391 } 392 } 393 394 /* Return the cert-less equivalent to a certified key type */ 395 int 396 sshkey_type_plain(int type) 397 { 398 switch (type) { 399 case KEY_RSA_CERT: 400 return KEY_RSA; 401 case KEY_DSA_CERT: 402 return KEY_DSA; 403 case KEY_ECDSA_CERT: 404 return KEY_ECDSA; 405 case KEY_ECDSA_SK_CERT: 406 return KEY_ECDSA_SK; 407 case KEY_ED25519_CERT: 408 return KEY_ED25519; 409 case KEY_ED25519_SK_CERT: 410 return KEY_ED25519_SK; 411 case KEY_XMSS_CERT: 412 return KEY_XMSS; 413 default: 414 return type; 415 } 416 } 417 418 #ifdef WITH_OPENSSL 419 /* XXX: these are really begging for a table-driven approach */ 420 int 421 sshkey_curve_name_to_nid(const char *name) 422 { 423 if (strcmp(name, "nistp256") == 0) 424 return NID_X9_62_prime256v1; 425 else if (strcmp(name, "nistp384") == 0) 426 return NID_secp384r1; 427 # ifdef OPENSSL_HAS_NISTP521 428 else if (strcmp(name, "nistp521") == 0) 429 return NID_secp521r1; 430 # endif /* OPENSSL_HAS_NISTP521 */ 431 else 432 return -1; 433 } 434 435 u_int 436 sshkey_curve_nid_to_bits(int nid) 437 { 438 switch (nid) { 439 case NID_X9_62_prime256v1: 440 return 256; 441 case NID_secp384r1: 442 return 384; 443 # ifdef OPENSSL_HAS_NISTP521 444 case NID_secp521r1: 445 return 521; 446 # endif /* OPENSSL_HAS_NISTP521 */ 447 default: 448 return 0; 449 } 450 } 451 452 int 453 sshkey_ecdsa_bits_to_nid(int bits) 454 { 455 switch (bits) { 456 case 256: 457 return NID_X9_62_prime256v1; 458 case 384: 459 return NID_secp384r1; 460 # ifdef OPENSSL_HAS_NISTP521 461 case 521: 462 return NID_secp521r1; 463 # endif /* OPENSSL_HAS_NISTP521 */ 464 default: 465 return -1; 466 } 467 } 468 469 const char * 470 sshkey_curve_nid_to_name(int nid) 471 { 472 switch (nid) { 473 case NID_X9_62_prime256v1: 474 return "nistp256"; 475 case NID_secp384r1: 476 return "nistp384"; 477 # ifdef OPENSSL_HAS_NISTP521 478 case NID_secp521r1: 479 return "nistp521"; 480 # endif /* OPENSSL_HAS_NISTP521 */ 481 default: 482 return NULL; 483 } 484 } 485 486 int 487 sshkey_ec_nid_to_hash_alg(int nid) 488 { 489 int kbits = sshkey_curve_nid_to_bits(nid); 490 491 if (kbits <= 0) 492 return -1; 493 494 /* RFC5656 section 6.2.1 */ 495 if (kbits <= 256) 496 return SSH_DIGEST_SHA256; 497 else if (kbits <= 384) 498 return SSH_DIGEST_SHA384; 499 else 500 return SSH_DIGEST_SHA512; 501 } 502 #endif /* WITH_OPENSSL */ 503 504 static void 505 cert_free(struct sshkey_cert *cert) 506 { 507 u_int i; 508 509 if (cert == NULL) 510 return; 511 sshbuf_free(cert->certblob); 512 sshbuf_free(cert->critical); 513 sshbuf_free(cert->extensions); 514 free(cert->key_id); 515 for (i = 0; i < cert->nprincipals; i++) 516 free(cert->principals[i]); 517 free(cert->principals); 518 sshkey_free(cert->signature_key); 519 free(cert->signature_type); 520 freezero(cert, sizeof(*cert)); 521 } 522 523 static struct sshkey_cert * 524 cert_new(void) 525 { 526 struct sshkey_cert *cert; 527 528 if ((cert = calloc(1, sizeof(*cert))) == NULL) 529 return NULL; 530 if ((cert->certblob = sshbuf_new()) == NULL || 531 (cert->critical = sshbuf_new()) == NULL || 532 (cert->extensions = sshbuf_new()) == NULL) { 533 cert_free(cert); 534 return NULL; 535 } 536 cert->key_id = NULL; 537 cert->principals = NULL; 538 cert->signature_key = NULL; 539 cert->signature_type = NULL; 540 return cert; 541 } 542 543 struct sshkey * 544 sshkey_new(int type) 545 { 546 struct sshkey *k; 547 #ifdef WITH_OPENSSL 548 RSA *rsa; 549 DSA *dsa; 550 #endif /* WITH_OPENSSL */ 551 552 if ((k = calloc(1, sizeof(*k))) == NULL) 553 return NULL; 554 k->type = type; 555 k->ecdsa = NULL; 556 k->ecdsa_nid = -1; 557 k->dsa = NULL; 558 k->rsa = NULL; 559 k->cert = NULL; 560 k->ed25519_sk = NULL; 561 k->ed25519_pk = NULL; 562 k->xmss_sk = NULL; 563 k->xmss_pk = NULL; 564 switch (k->type) { 565 #ifdef WITH_OPENSSL 566 case KEY_RSA: 567 case KEY_RSA_CERT: 568 if ((rsa = RSA_new()) == NULL) { 569 free(k); 570 return NULL; 571 } 572 k->rsa = rsa; 573 break; 574 case KEY_DSA: 575 case KEY_DSA_CERT: 576 if ((dsa = DSA_new()) == NULL) { 577 free(k); 578 return NULL; 579 } 580 k->dsa = dsa; 581 break; 582 case KEY_ECDSA: 583 case KEY_ECDSA_CERT: 584 case KEY_ECDSA_SK: 585 case KEY_ECDSA_SK_CERT: 586 /* Cannot do anything until we know the group */ 587 break; 588 #endif /* WITH_OPENSSL */ 589 case KEY_ED25519: 590 case KEY_ED25519_CERT: 591 case KEY_ED25519_SK: 592 case KEY_ED25519_SK_CERT: 593 case KEY_XMSS: 594 case KEY_XMSS_CERT: 595 /* no need to prealloc */ 596 break; 597 case KEY_UNSPEC: 598 break; 599 default: 600 free(k); 601 return NULL; 602 } 603 604 if (sshkey_is_cert(k)) { 605 if ((k->cert = cert_new()) == NULL) { 606 sshkey_free(k); 607 return NULL; 608 } 609 } 610 611 return k; 612 } 613 614 void 615 sshkey_free(struct sshkey *k) 616 { 617 if (k == NULL) 618 return; 619 switch (k->type) { 620 #ifdef WITH_OPENSSL 621 case KEY_RSA: 622 case KEY_RSA_CERT: 623 RSA_free(k->rsa); 624 k->rsa = NULL; 625 break; 626 case KEY_DSA: 627 case KEY_DSA_CERT: 628 DSA_free(k->dsa); 629 k->dsa = NULL; 630 break; 631 # ifdef OPENSSL_HAS_ECC 632 case KEY_ECDSA_SK: 633 case KEY_ECDSA_SK_CERT: 634 free(k->sk_application); 635 sshbuf_free(k->sk_key_handle); 636 sshbuf_free(k->sk_reserved); 637 /* FALLTHROUGH */ 638 case KEY_ECDSA: 639 case KEY_ECDSA_CERT: 640 EC_KEY_free(k->ecdsa); 641 k->ecdsa = NULL; 642 break; 643 # endif /* OPENSSL_HAS_ECC */ 644 #endif /* WITH_OPENSSL */ 645 case KEY_ED25519_SK: 646 case KEY_ED25519_SK_CERT: 647 free(k->sk_application); 648 sshbuf_free(k->sk_key_handle); 649 sshbuf_free(k->sk_reserved); 650 /* FALLTHROUGH */ 651 case KEY_ED25519: 652 case KEY_ED25519_CERT: 653 freezero(k->ed25519_pk, ED25519_PK_SZ); 654 k->ed25519_pk = NULL; 655 freezero(k->ed25519_sk, ED25519_SK_SZ); 656 k->ed25519_sk = NULL; 657 break; 658 #ifdef WITH_XMSS 659 case KEY_XMSS: 660 case KEY_XMSS_CERT: 661 freezero(k->xmss_pk, sshkey_xmss_pklen(k)); 662 k->xmss_pk = NULL; 663 freezero(k->xmss_sk, sshkey_xmss_sklen(k)); 664 k->xmss_sk = NULL; 665 sshkey_xmss_free_state(k); 666 free(k->xmss_name); 667 k->xmss_name = NULL; 668 free(k->xmss_filename); 669 k->xmss_filename = NULL; 670 break; 671 #endif /* WITH_XMSS */ 672 case KEY_UNSPEC: 673 break; 674 default: 675 break; 676 } 677 if (sshkey_is_cert(k)) 678 cert_free(k->cert); 679 freezero(k->shielded_private, k->shielded_len); 680 freezero(k->shield_prekey, k->shield_prekey_len); 681 freezero(k, sizeof(*k)); 682 } 683 684 static int 685 cert_compare(struct sshkey_cert *a, struct sshkey_cert *b) 686 { 687 if (a == NULL && b == NULL) 688 return 1; 689 if (a == NULL || b == NULL) 690 return 0; 691 if (sshbuf_len(a->certblob) != sshbuf_len(b->certblob)) 692 return 0; 693 if (timingsafe_bcmp(sshbuf_ptr(a->certblob), sshbuf_ptr(b->certblob), 694 sshbuf_len(a->certblob)) != 0) 695 return 0; 696 return 1; 697 } 698 699 /* 700 * Compare public portions of key only, allowing comparisons between 701 * certificates and plain keys too. 702 */ 703 int 704 sshkey_equal_public(const struct sshkey *a, const struct sshkey *b) 705 { 706 #if defined(WITH_OPENSSL) 707 const BIGNUM *rsa_e_a, *rsa_n_a; 708 const BIGNUM *rsa_e_b, *rsa_n_b; 709 const BIGNUM *dsa_p_a, *dsa_q_a, *dsa_g_a, *dsa_pub_key_a; 710 const BIGNUM *dsa_p_b, *dsa_q_b, *dsa_g_b, *dsa_pub_key_b; 711 #endif /* WITH_OPENSSL */ 712 713 if (a == NULL || b == NULL || 714 sshkey_type_plain(a->type) != sshkey_type_plain(b->type)) 715 return 0; 716 717 switch (a->type) { 718 #ifdef WITH_OPENSSL 719 case KEY_RSA_CERT: 720 case KEY_RSA: 721 if (a->rsa == NULL || b->rsa == NULL) 722 return 0; 723 RSA_get0_key(a->rsa, &rsa_n_a, &rsa_e_a, NULL); 724 RSA_get0_key(b->rsa, &rsa_n_b, &rsa_e_b, NULL); 725 return BN_cmp(rsa_e_a, rsa_e_b) == 0 && 726 BN_cmp(rsa_n_a, rsa_n_b) == 0; 727 case KEY_DSA_CERT: 728 case KEY_DSA: 729 if (a->dsa == NULL || b->dsa == NULL) 730 return 0; 731 DSA_get0_pqg(a->dsa, &dsa_p_a, &dsa_q_a, &dsa_g_a); 732 DSA_get0_pqg(b->dsa, &dsa_p_b, &dsa_q_b, &dsa_g_b); 733 DSA_get0_key(a->dsa, &dsa_pub_key_a, NULL); 734 DSA_get0_key(b->dsa, &dsa_pub_key_b, NULL); 735 return BN_cmp(dsa_p_a, dsa_p_b) == 0 && 736 BN_cmp(dsa_q_a, dsa_q_b) == 0 && 737 BN_cmp(dsa_g_a, dsa_g_b) == 0 && 738 BN_cmp(dsa_pub_key_a, dsa_pub_key_b) == 0; 739 # ifdef OPENSSL_HAS_ECC 740 case KEY_ECDSA_SK: 741 case KEY_ECDSA_SK_CERT: 742 if (a->sk_application == NULL || b->sk_application == NULL) 743 return 0; 744 if (strcmp(a->sk_application, b->sk_application) != 0) 745 return 0; 746 /* FALLTHROUGH */ 747 case KEY_ECDSA_CERT: 748 case KEY_ECDSA: 749 if (a->ecdsa == NULL || b->ecdsa == NULL || 750 EC_KEY_get0_public_key(a->ecdsa) == NULL || 751 EC_KEY_get0_public_key(b->ecdsa) == NULL) 752 return 0; 753 if (EC_GROUP_cmp(EC_KEY_get0_group(a->ecdsa), 754 EC_KEY_get0_group(b->ecdsa), NULL) != 0 || 755 EC_POINT_cmp(EC_KEY_get0_group(a->ecdsa), 756 EC_KEY_get0_public_key(a->ecdsa), 757 EC_KEY_get0_public_key(b->ecdsa), NULL) != 0) 758 return 0; 759 return 1; 760 # endif /* OPENSSL_HAS_ECC */ 761 #endif /* WITH_OPENSSL */ 762 case KEY_ED25519_SK: 763 case KEY_ED25519_SK_CERT: 764 if (a->sk_application == NULL || b->sk_application == NULL) 765 return 0; 766 if (strcmp(a->sk_application, b->sk_application) != 0) 767 return 0; 768 /* FALLTHROUGH */ 769 case KEY_ED25519: 770 case KEY_ED25519_CERT: 771 return a->ed25519_pk != NULL && b->ed25519_pk != NULL && 772 memcmp(a->ed25519_pk, b->ed25519_pk, ED25519_PK_SZ) == 0; 773 #ifdef WITH_XMSS 774 case KEY_XMSS: 775 case KEY_XMSS_CERT: 776 return a->xmss_pk != NULL && b->xmss_pk != NULL && 777 sshkey_xmss_pklen(a) == sshkey_xmss_pklen(b) && 778 memcmp(a->xmss_pk, b->xmss_pk, sshkey_xmss_pklen(a)) == 0; 779 #endif /* WITH_XMSS */ 780 default: 781 return 0; 782 } 783 /* NOTREACHED */ 784 } 785 786 int 787 sshkey_equal(const struct sshkey *a, const struct sshkey *b) 788 { 789 if (a == NULL || b == NULL || a->type != b->type) 790 return 0; 791 if (sshkey_is_cert(a)) { 792 if (!cert_compare(a->cert, b->cert)) 793 return 0; 794 } 795 return sshkey_equal_public(a, b); 796 } 797 798 static int 799 to_blob_buf(const struct sshkey *key, struct sshbuf *b, int force_plain, 800 enum sshkey_serialize_rep opts) 801 { 802 int type, ret = SSH_ERR_INTERNAL_ERROR; 803 const char *typename; 804 #ifdef WITH_OPENSSL 805 const BIGNUM *rsa_n, *rsa_e, *dsa_p, *dsa_q, *dsa_g, *dsa_pub_key; 806 #endif /* WITH_OPENSSL */ 807 808 if (key == NULL) 809 return SSH_ERR_INVALID_ARGUMENT; 810 811 if (sshkey_is_cert(key)) { 812 if (key->cert == NULL) 813 return SSH_ERR_EXPECTED_CERT; 814 if (sshbuf_len(key->cert->certblob) == 0) 815 return SSH_ERR_KEY_LACKS_CERTBLOB; 816 } 817 type = force_plain ? sshkey_type_plain(key->type) : key->type; 818 typename = sshkey_ssh_name_from_type_nid(type, key->ecdsa_nid); 819 820 switch (type) { 821 #ifdef WITH_OPENSSL 822 case KEY_DSA_CERT: 823 case KEY_ECDSA_CERT: 824 case KEY_ECDSA_SK_CERT: 825 case KEY_RSA_CERT: 826 #endif /* WITH_OPENSSL */ 827 case KEY_ED25519_CERT: 828 case KEY_ED25519_SK_CERT: 829 #ifdef WITH_XMSS 830 case KEY_XMSS_CERT: 831 #endif /* WITH_XMSS */ 832 /* Use the existing blob */ 833 /* XXX modified flag? */ 834 if ((ret = sshbuf_putb(b, key->cert->certblob)) != 0) 835 return ret; 836 break; 837 #ifdef WITH_OPENSSL 838 case KEY_DSA: 839 if (key->dsa == NULL) 840 return SSH_ERR_INVALID_ARGUMENT; 841 DSA_get0_pqg(key->dsa, &dsa_p, &dsa_q, &dsa_g); 842 DSA_get0_key(key->dsa, &dsa_pub_key, NULL); 843 if ((ret = sshbuf_put_cstring(b, typename)) != 0 || 844 (ret = sshbuf_put_bignum2(b, dsa_p)) != 0 || 845 (ret = sshbuf_put_bignum2(b, dsa_q)) != 0 || 846 (ret = sshbuf_put_bignum2(b, dsa_g)) != 0 || 847 (ret = sshbuf_put_bignum2(b, dsa_pub_key)) != 0) 848 return ret; 849 break; 850 # ifdef OPENSSL_HAS_ECC 851 case KEY_ECDSA: 852 case KEY_ECDSA_SK: 853 if (key->ecdsa == NULL) 854 return SSH_ERR_INVALID_ARGUMENT; 855 if ((ret = sshbuf_put_cstring(b, typename)) != 0 || 856 (ret = sshbuf_put_cstring(b, 857 sshkey_curve_nid_to_name(key->ecdsa_nid))) != 0 || 858 (ret = sshbuf_put_eckey(b, key->ecdsa)) != 0) 859 return ret; 860 if (type == KEY_ECDSA_SK) { 861 if ((ret = sshbuf_put_cstring(b, 862 key->sk_application)) != 0) 863 return ret; 864 } 865 break; 866 # endif 867 case KEY_RSA: 868 if (key->rsa == NULL) 869 return SSH_ERR_INVALID_ARGUMENT; 870 RSA_get0_key(key->rsa, &rsa_n, &rsa_e, NULL); 871 if ((ret = sshbuf_put_cstring(b, typename)) != 0 || 872 (ret = sshbuf_put_bignum2(b, rsa_e)) != 0 || 873 (ret = sshbuf_put_bignum2(b, rsa_n)) != 0) 874 return ret; 875 break; 876 #endif /* WITH_OPENSSL */ 877 case KEY_ED25519: 878 case KEY_ED25519_SK: 879 if (key->ed25519_pk == NULL) 880 return SSH_ERR_INVALID_ARGUMENT; 881 if ((ret = sshbuf_put_cstring(b, typename)) != 0 || 882 (ret = sshbuf_put_string(b, 883 key->ed25519_pk, ED25519_PK_SZ)) != 0) 884 return ret; 885 if (type == KEY_ED25519_SK) { 886 if ((ret = sshbuf_put_cstring(b, 887 key->sk_application)) != 0) 888 return ret; 889 } 890 break; 891 #ifdef WITH_XMSS 892 case KEY_XMSS: 893 if (key->xmss_name == NULL || key->xmss_pk == NULL || 894 sshkey_xmss_pklen(key) == 0) 895 return SSH_ERR_INVALID_ARGUMENT; 896 if ((ret = sshbuf_put_cstring(b, typename)) != 0 || 897 (ret = sshbuf_put_cstring(b, key->xmss_name)) != 0 || 898 (ret = sshbuf_put_string(b, 899 key->xmss_pk, sshkey_xmss_pklen(key))) != 0 || 900 (ret = sshkey_xmss_serialize_pk_info(key, b, opts)) != 0) 901 return ret; 902 break; 903 #endif /* WITH_XMSS */ 904 default: 905 return SSH_ERR_KEY_TYPE_UNKNOWN; 906 } 907 return 0; 908 } 909 910 int 911 sshkey_putb(const struct sshkey *key, struct sshbuf *b) 912 { 913 return to_blob_buf(key, b, 0, SSHKEY_SERIALIZE_DEFAULT); 914 } 915 916 int 917 sshkey_puts_opts(const struct sshkey *key, struct sshbuf *b, 918 enum sshkey_serialize_rep opts) 919 { 920 struct sshbuf *tmp; 921 int r; 922 923 if ((tmp = sshbuf_new()) == NULL) 924 return SSH_ERR_ALLOC_FAIL; 925 r = to_blob_buf(key, tmp, 0, opts); 926 if (r == 0) 927 r = sshbuf_put_stringb(b, tmp); 928 sshbuf_free(tmp); 929 return r; 930 } 931 932 int 933 sshkey_puts(const struct sshkey *key, struct sshbuf *b) 934 { 935 return sshkey_puts_opts(key, b, SSHKEY_SERIALIZE_DEFAULT); 936 } 937 938 int 939 sshkey_putb_plain(const struct sshkey *key, struct sshbuf *b) 940 { 941 return to_blob_buf(key, b, 1, SSHKEY_SERIALIZE_DEFAULT); 942 } 943 944 static int 945 to_blob(const struct sshkey *key, u_char **blobp, size_t *lenp, int force_plain, 946 enum sshkey_serialize_rep opts) 947 { 948 int ret = SSH_ERR_INTERNAL_ERROR; 949 size_t len; 950 struct sshbuf *b = NULL; 951 952 if (lenp != NULL) 953 *lenp = 0; 954 if (blobp != NULL) 955 *blobp = NULL; 956 if ((b = sshbuf_new()) == NULL) 957 return SSH_ERR_ALLOC_FAIL; 958 if ((ret = to_blob_buf(key, b, force_plain, opts)) != 0) 959 goto out; 960 len = sshbuf_len(b); 961 if (lenp != NULL) 962 *lenp = len; 963 if (blobp != NULL) { 964 if ((*blobp = malloc(len)) == NULL) { 965 ret = SSH_ERR_ALLOC_FAIL; 966 goto out; 967 } 968 memcpy(*blobp, sshbuf_ptr(b), len); 969 } 970 ret = 0; 971 out: 972 sshbuf_free(b); 973 return ret; 974 } 975 976 int 977 sshkey_to_blob(const struct sshkey *key, u_char **blobp, size_t *lenp) 978 { 979 return to_blob(key, blobp, lenp, 0, SSHKEY_SERIALIZE_DEFAULT); 980 } 981 982 int 983 sshkey_plain_to_blob(const struct sshkey *key, u_char **blobp, size_t *lenp) 984 { 985 return to_blob(key, blobp, lenp, 1, SSHKEY_SERIALIZE_DEFAULT); 986 } 987 988 int 989 sshkey_fingerprint_raw(const struct sshkey *k, int dgst_alg, 990 u_char **retp, size_t *lenp) 991 { 992 u_char *blob = NULL, *ret = NULL; 993 size_t blob_len = 0; 994 int r = SSH_ERR_INTERNAL_ERROR; 995 996 if (retp != NULL) 997 *retp = NULL; 998 if (lenp != NULL) 999 *lenp = 0; 1000 if (ssh_digest_bytes(dgst_alg) == 0) { 1001 r = SSH_ERR_INVALID_ARGUMENT; 1002 goto out; 1003 } 1004 if ((r = to_blob(k, &blob, &blob_len, 1, SSHKEY_SERIALIZE_DEFAULT)) 1005 != 0) 1006 goto out; 1007 if ((ret = calloc(1, SSH_DIGEST_MAX_LENGTH)) == NULL) { 1008 r = SSH_ERR_ALLOC_FAIL; 1009 goto out; 1010 } 1011 if ((r = ssh_digest_memory(dgst_alg, blob, blob_len, 1012 ret, SSH_DIGEST_MAX_LENGTH)) != 0) 1013 goto out; 1014 /* success */ 1015 if (retp != NULL) { 1016 *retp = ret; 1017 ret = NULL; 1018 } 1019 if (lenp != NULL) 1020 *lenp = ssh_digest_bytes(dgst_alg); 1021 r = 0; 1022 out: 1023 free(ret); 1024 if (blob != NULL) 1025 freezero(blob, blob_len); 1026 return r; 1027 } 1028 1029 static char * 1030 fingerprint_b64(const char *alg, u_char *dgst_raw, size_t dgst_raw_len) 1031 { 1032 char *ret; 1033 size_t plen = strlen(alg) + 1; 1034 size_t rlen = ((dgst_raw_len + 2) / 3) * 4 + plen + 1; 1035 1036 if (dgst_raw_len > 65536 || (ret = calloc(1, rlen)) == NULL) 1037 return NULL; 1038 strlcpy(ret, alg, rlen); 1039 strlcat(ret, ":", rlen); 1040 if (dgst_raw_len == 0) 1041 return ret; 1042 if (b64_ntop(dgst_raw, dgst_raw_len, ret + plen, rlen - plen) == -1) { 1043 freezero(ret, rlen); 1044 return NULL; 1045 } 1046 /* Trim padding characters from end */ 1047 ret[strcspn(ret, "=")] = '\0'; 1048 return ret; 1049 } 1050 1051 static char * 1052 fingerprint_hex(const char *alg, u_char *dgst_raw, size_t dgst_raw_len) 1053 { 1054 char *retval, hex[5]; 1055 size_t i, rlen = dgst_raw_len * 3 + strlen(alg) + 2; 1056 1057 if (dgst_raw_len > 65536 || (retval = calloc(1, rlen)) == NULL) 1058 return NULL; 1059 strlcpy(retval, alg, rlen); 1060 strlcat(retval, ":", rlen); 1061 for (i = 0; i < dgst_raw_len; i++) { 1062 snprintf(hex, sizeof(hex), "%s%02x", 1063 i > 0 ? ":" : "", dgst_raw[i]); 1064 strlcat(retval, hex, rlen); 1065 } 1066 return retval; 1067 } 1068 1069 static char * 1070 fingerprint_bubblebabble(u_char *dgst_raw, size_t dgst_raw_len) 1071 { 1072 char vowels[] = { 'a', 'e', 'i', 'o', 'u', 'y' }; 1073 char consonants[] = { 'b', 'c', 'd', 'f', 'g', 'h', 'k', 'l', 'm', 1074 'n', 'p', 'r', 's', 't', 'v', 'z', 'x' }; 1075 u_int i, j = 0, rounds, seed = 1; 1076 char *retval; 1077 1078 rounds = (dgst_raw_len / 2) + 1; 1079 if ((retval = calloc(rounds, 6)) == NULL) 1080 return NULL; 1081 retval[j++] = 'x'; 1082 for (i = 0; i < rounds; i++) { 1083 u_int idx0, idx1, idx2, idx3, idx4; 1084 if ((i + 1 < rounds) || (dgst_raw_len % 2 != 0)) { 1085 idx0 = (((((u_int)(dgst_raw[2 * i])) >> 6) & 3) + 1086 seed) % 6; 1087 idx1 = (((u_int)(dgst_raw[2 * i])) >> 2) & 15; 1088 idx2 = ((((u_int)(dgst_raw[2 * i])) & 3) + 1089 (seed / 6)) % 6; 1090 retval[j++] = vowels[idx0]; 1091 retval[j++] = consonants[idx1]; 1092 retval[j++] = vowels[idx2]; 1093 if ((i + 1) < rounds) { 1094 idx3 = (((u_int)(dgst_raw[(2 * i) + 1])) >> 4) & 15; 1095 idx4 = (((u_int)(dgst_raw[(2 * i) + 1]))) & 15; 1096 retval[j++] = consonants[idx3]; 1097 retval[j++] = '-'; 1098 retval[j++] = consonants[idx4]; 1099 seed = ((seed * 5) + 1100 ((((u_int)(dgst_raw[2 * i])) * 7) + 1101 ((u_int)(dgst_raw[(2 * i) + 1])))) % 36; 1102 } 1103 } else { 1104 idx0 = seed % 6; 1105 idx1 = 16; 1106 idx2 = seed / 6; 1107 retval[j++] = vowels[idx0]; 1108 retval[j++] = consonants[idx1]; 1109 retval[j++] = vowels[idx2]; 1110 } 1111 } 1112 retval[j++] = 'x'; 1113 retval[j++] = '\0'; 1114 return retval; 1115 } 1116 1117 /* 1118 * Draw an ASCII-Art representing the fingerprint so human brain can 1119 * profit from its built-in pattern recognition ability. 1120 * This technique is called "random art" and can be found in some 1121 * scientific publications like this original paper: 1122 * 1123 * "Hash Visualization: a New Technique to improve Real-World Security", 1124 * Perrig A. and Song D., 1999, International Workshop on Cryptographic 1125 * Techniques and E-Commerce (CrypTEC '99) 1126 * sparrow.ece.cmu.edu/~adrian/projects/validation/validation.pdf 1127 * 1128 * The subject came up in a talk by Dan Kaminsky, too. 1129 * 1130 * If you see the picture is different, the key is different. 1131 * If the picture looks the same, you still know nothing. 1132 * 1133 * The algorithm used here is a worm crawling over a discrete plane, 1134 * leaving a trace (augmenting the field) everywhere it goes. 1135 * Movement is taken from dgst_raw 2bit-wise. Bumping into walls 1136 * makes the respective movement vector be ignored for this turn. 1137 * Graphs are not unambiguous, because circles in graphs can be 1138 * walked in either direction. 1139 */ 1140 1141 /* 1142 * Field sizes for the random art. Have to be odd, so the starting point 1143 * can be in the exact middle of the picture, and FLDBASE should be >=8 . 1144 * Else pictures would be too dense, and drawing the frame would 1145 * fail, too, because the key type would not fit in anymore. 1146 */ 1147 #define FLDBASE 8 1148 #define FLDSIZE_Y (FLDBASE + 1) 1149 #define FLDSIZE_X (FLDBASE * 2 + 1) 1150 static char * 1151 fingerprint_randomart(const char *alg, u_char *dgst_raw, size_t dgst_raw_len, 1152 const struct sshkey *k) 1153 { 1154 /* 1155 * Chars to be used after each other every time the worm 1156 * intersects with itself. Matter of taste. 1157 */ 1158 char *augmentation_string = " .o+=*BOX@%&#/^SE"; 1159 char *retval, *p, title[FLDSIZE_X], hash[FLDSIZE_X]; 1160 u_char field[FLDSIZE_X][FLDSIZE_Y]; 1161 size_t i, tlen, hlen; 1162 u_int b; 1163 int x, y, r; 1164 size_t len = strlen(augmentation_string) - 1; 1165 1166 if ((retval = calloc((FLDSIZE_X + 3), (FLDSIZE_Y + 2))) == NULL) 1167 return NULL; 1168 1169 /* initialize field */ 1170 memset(field, 0, FLDSIZE_X * FLDSIZE_Y * sizeof(char)); 1171 x = FLDSIZE_X / 2; 1172 y = FLDSIZE_Y / 2; 1173 1174 /* process raw key */ 1175 for (i = 0; i < dgst_raw_len; i++) { 1176 int input; 1177 /* each byte conveys four 2-bit move commands */ 1178 input = dgst_raw[i]; 1179 for (b = 0; b < 4; b++) { 1180 /* evaluate 2 bit, rest is shifted later */ 1181 x += (input & 0x1) ? 1 : -1; 1182 y += (input & 0x2) ? 1 : -1; 1183 1184 /* assure we are still in bounds */ 1185 x = MAXIMUM(x, 0); 1186 y = MAXIMUM(y, 0); 1187 x = MINIMUM(x, FLDSIZE_X - 1); 1188 y = MINIMUM(y, FLDSIZE_Y - 1); 1189 1190 /* augment the field */ 1191 if (field[x][y] < len - 2) 1192 field[x][y]++; 1193 input = input >> 2; 1194 } 1195 } 1196 1197 /* mark starting point and end point*/ 1198 field[FLDSIZE_X / 2][FLDSIZE_Y / 2] = len - 1; 1199 field[x][y] = len; 1200 1201 /* assemble title */ 1202 r = snprintf(title, sizeof(title), "[%s %u]", 1203 sshkey_type(k), sshkey_size(k)); 1204 /* If [type size] won't fit, then try [type]; fits "[ED25519-CERT]" */ 1205 if (r < 0 || r > (int)sizeof(title)) 1206 r = snprintf(title, sizeof(title), "[%s]", sshkey_type(k)); 1207 tlen = (r <= 0) ? 0 : strlen(title); 1208 1209 /* assemble hash ID. */ 1210 r = snprintf(hash, sizeof(hash), "[%s]", alg); 1211 hlen = (r <= 0) ? 0 : strlen(hash); 1212 1213 /* output upper border */ 1214 p = retval; 1215 *p++ = '+'; 1216 for (i = 0; i < (FLDSIZE_X - tlen) / 2; i++) 1217 *p++ = '-'; 1218 memcpy(p, title, tlen); 1219 p += tlen; 1220 for (i += tlen; i < FLDSIZE_X; i++) 1221 *p++ = '-'; 1222 *p++ = '+'; 1223 *p++ = '\n'; 1224 1225 /* output content */ 1226 for (y = 0; y < FLDSIZE_Y; y++) { 1227 *p++ = '|'; 1228 for (x = 0; x < FLDSIZE_X; x++) 1229 *p++ = augmentation_string[MINIMUM(field[x][y], len)]; 1230 *p++ = '|'; 1231 *p++ = '\n'; 1232 } 1233 1234 /* output lower border */ 1235 *p++ = '+'; 1236 for (i = 0; i < (FLDSIZE_X - hlen) / 2; i++) 1237 *p++ = '-'; 1238 memcpy(p, hash, hlen); 1239 p += hlen; 1240 for (i += hlen; i < FLDSIZE_X; i++) 1241 *p++ = '-'; 1242 *p++ = '+'; 1243 1244 return retval; 1245 } 1246 1247 char * 1248 sshkey_fingerprint(const struct sshkey *k, int dgst_alg, 1249 enum sshkey_fp_rep dgst_rep) 1250 { 1251 char *retval = NULL; 1252 u_char *dgst_raw; 1253 size_t dgst_raw_len; 1254 1255 if (sshkey_fingerprint_raw(k, dgst_alg, &dgst_raw, &dgst_raw_len) != 0) 1256 return NULL; 1257 switch (dgst_rep) { 1258 case SSH_FP_DEFAULT: 1259 if (dgst_alg == SSH_DIGEST_MD5) { 1260 retval = fingerprint_hex(ssh_digest_alg_name(dgst_alg), 1261 dgst_raw, dgst_raw_len); 1262 } else { 1263 retval = fingerprint_b64(ssh_digest_alg_name(dgst_alg), 1264 dgst_raw, dgst_raw_len); 1265 } 1266 break; 1267 case SSH_FP_HEX: 1268 retval = fingerprint_hex(ssh_digest_alg_name(dgst_alg), 1269 dgst_raw, dgst_raw_len); 1270 break; 1271 case SSH_FP_BASE64: 1272 retval = fingerprint_b64(ssh_digest_alg_name(dgst_alg), 1273 dgst_raw, dgst_raw_len); 1274 break; 1275 case SSH_FP_BUBBLEBABBLE: 1276 retval = fingerprint_bubblebabble(dgst_raw, dgst_raw_len); 1277 break; 1278 case SSH_FP_RANDOMART: 1279 retval = fingerprint_randomart(ssh_digest_alg_name(dgst_alg), 1280 dgst_raw, dgst_raw_len, k); 1281 break; 1282 default: 1283 freezero(dgst_raw, dgst_raw_len); 1284 return NULL; 1285 } 1286 freezero(dgst_raw, dgst_raw_len); 1287 return retval; 1288 } 1289 1290 static int 1291 peek_type_nid(const char *s, size_t l, int *nid) 1292 { 1293 const struct keytype *kt; 1294 1295 for (kt = keytypes; kt->type != -1; kt++) { 1296 if (kt->name == NULL || strlen(kt->name) != l) 1297 continue; 1298 if (memcmp(s, kt->name, l) == 0) { 1299 *nid = -1; 1300 if (key_type_is_ecdsa_variant(kt->type)) 1301 *nid = kt->nid; 1302 return kt->type; 1303 } 1304 } 1305 return KEY_UNSPEC; 1306 } 1307 1308 /* XXX this can now be made const char * */ 1309 int 1310 sshkey_read(struct sshkey *ret, char **cpp) 1311 { 1312 struct sshkey *k; 1313 char *cp, *blobcopy; 1314 size_t space; 1315 int r, type, curve_nid = -1; 1316 struct sshbuf *blob; 1317 1318 if (ret == NULL) 1319 return SSH_ERR_INVALID_ARGUMENT; 1320 1321 switch (ret->type) { 1322 case KEY_UNSPEC: 1323 case KEY_RSA: 1324 case KEY_DSA: 1325 case KEY_ECDSA: 1326 case KEY_ECDSA_SK: 1327 case KEY_ED25519: 1328 case KEY_ED25519_SK: 1329 case KEY_DSA_CERT: 1330 case KEY_ECDSA_CERT: 1331 case KEY_ECDSA_SK_CERT: 1332 case KEY_RSA_CERT: 1333 case KEY_ED25519_CERT: 1334 case KEY_ED25519_SK_CERT: 1335 #ifdef WITH_XMSS 1336 case KEY_XMSS: 1337 case KEY_XMSS_CERT: 1338 #endif /* WITH_XMSS */ 1339 break; /* ok */ 1340 default: 1341 return SSH_ERR_INVALID_ARGUMENT; 1342 } 1343 1344 /* Decode type */ 1345 cp = *cpp; 1346 space = strcspn(cp, " \t"); 1347 if (space == strlen(cp)) 1348 return SSH_ERR_INVALID_FORMAT; 1349 if ((type = peek_type_nid(cp, space, &curve_nid)) == KEY_UNSPEC) 1350 return SSH_ERR_INVALID_FORMAT; 1351 1352 /* skip whitespace */ 1353 for (cp += space; *cp == ' ' || *cp == '\t'; cp++) 1354 ; 1355 if (*cp == '\0') 1356 return SSH_ERR_INVALID_FORMAT; 1357 if (ret->type != KEY_UNSPEC && ret->type != type) 1358 return SSH_ERR_KEY_TYPE_MISMATCH; 1359 if ((blob = sshbuf_new()) == NULL) 1360 return SSH_ERR_ALLOC_FAIL; 1361 1362 /* find end of keyblob and decode */ 1363 space = strcspn(cp, " \t"); 1364 if ((blobcopy = strndup(cp, space)) == NULL) { 1365 sshbuf_free(blob); 1366 return SSH_ERR_ALLOC_FAIL; 1367 } 1368 if ((r = sshbuf_b64tod(blob, blobcopy)) != 0) { 1369 free(blobcopy); 1370 sshbuf_free(blob); 1371 return r; 1372 } 1373 free(blobcopy); 1374 if ((r = sshkey_fromb(blob, &k)) != 0) { 1375 sshbuf_free(blob); 1376 return r; 1377 } 1378 sshbuf_free(blob); 1379 1380 /* skip whitespace and leave cp at start of comment */ 1381 for (cp += space; *cp == ' ' || *cp == '\t'; cp++) 1382 ; 1383 1384 /* ensure type of blob matches type at start of line */ 1385 if (k->type != type) { 1386 sshkey_free(k); 1387 return SSH_ERR_KEY_TYPE_MISMATCH; 1388 } 1389 if (key_type_is_ecdsa_variant(type) && curve_nid != k->ecdsa_nid) { 1390 sshkey_free(k); 1391 return SSH_ERR_EC_CURVE_MISMATCH; 1392 } 1393 1394 /* Fill in ret from parsed key */ 1395 ret->type = type; 1396 if (sshkey_is_cert(ret)) { 1397 if (!sshkey_is_cert(k)) { 1398 sshkey_free(k); 1399 return SSH_ERR_EXPECTED_CERT; 1400 } 1401 if (ret->cert != NULL) 1402 cert_free(ret->cert); 1403 ret->cert = k->cert; 1404 k->cert = NULL; 1405 } 1406 switch (sshkey_type_plain(ret->type)) { 1407 #ifdef WITH_OPENSSL 1408 case KEY_RSA: 1409 RSA_free(ret->rsa); 1410 ret->rsa = k->rsa; 1411 k->rsa = NULL; 1412 #ifdef DEBUG_PK 1413 RSA_print_fp(stderr, ret->rsa, 8); 1414 #endif 1415 break; 1416 case KEY_DSA: 1417 DSA_free(ret->dsa); 1418 ret->dsa = k->dsa; 1419 k->dsa = NULL; 1420 #ifdef DEBUG_PK 1421 DSA_print_fp(stderr, ret->dsa, 8); 1422 #endif 1423 break; 1424 # ifdef OPENSSL_HAS_ECC 1425 case KEY_ECDSA: 1426 EC_KEY_free(ret->ecdsa); 1427 ret->ecdsa = k->ecdsa; 1428 ret->ecdsa_nid = k->ecdsa_nid; 1429 k->ecdsa = NULL; 1430 k->ecdsa_nid = -1; 1431 #ifdef DEBUG_PK 1432 sshkey_dump_ec_key(ret->ecdsa); 1433 #endif 1434 break; 1435 case KEY_ECDSA_SK: 1436 EC_KEY_free(ret->ecdsa); 1437 ret->ecdsa = k->ecdsa; 1438 ret->ecdsa_nid = k->ecdsa_nid; 1439 ret->sk_application = k->sk_application; 1440 k->ecdsa = NULL; 1441 k->ecdsa_nid = -1; 1442 k->sk_application = NULL; 1443 #ifdef DEBUG_PK 1444 sshkey_dump_ec_key(ret->ecdsa); 1445 fprintf(stderr, "App: %s\n", ret->sk_application); 1446 #endif 1447 break; 1448 # endif /* OPENSSL_HAS_ECC */ 1449 #endif /* WITH_OPENSSL */ 1450 case KEY_ED25519: 1451 freezero(ret->ed25519_pk, ED25519_PK_SZ); 1452 ret->ed25519_pk = k->ed25519_pk; 1453 k->ed25519_pk = NULL; 1454 #ifdef DEBUG_PK 1455 /* XXX */ 1456 #endif 1457 break; 1458 case KEY_ED25519_SK: 1459 freezero(ret->ed25519_pk, ED25519_PK_SZ); 1460 ret->ed25519_pk = k->ed25519_pk; 1461 ret->sk_application = k->sk_application; 1462 k->ed25519_pk = NULL; 1463 k->sk_application = NULL; 1464 break; 1465 #ifdef WITH_XMSS 1466 case KEY_XMSS: 1467 free(ret->xmss_pk); 1468 ret->xmss_pk = k->xmss_pk; 1469 k->xmss_pk = NULL; 1470 free(ret->xmss_state); 1471 ret->xmss_state = k->xmss_state; 1472 k->xmss_state = NULL; 1473 free(ret->xmss_name); 1474 ret->xmss_name = k->xmss_name; 1475 k->xmss_name = NULL; 1476 free(ret->xmss_filename); 1477 ret->xmss_filename = k->xmss_filename; 1478 k->xmss_filename = NULL; 1479 #ifdef DEBUG_PK 1480 /* XXX */ 1481 #endif 1482 break; 1483 #endif /* WITH_XMSS */ 1484 default: 1485 sshkey_free(k); 1486 return SSH_ERR_INTERNAL_ERROR; 1487 } 1488 sshkey_free(k); 1489 1490 /* success */ 1491 *cpp = cp; 1492 return 0; 1493 } 1494 1495 1496 int 1497 sshkey_to_base64(const struct sshkey *key, char **b64p) 1498 { 1499 int r = SSH_ERR_INTERNAL_ERROR; 1500 struct sshbuf *b = NULL; 1501 char *uu = NULL; 1502 1503 if (b64p != NULL) 1504 *b64p = NULL; 1505 if ((b = sshbuf_new()) == NULL) 1506 return SSH_ERR_ALLOC_FAIL; 1507 if ((r = sshkey_putb(key, b)) != 0) 1508 goto out; 1509 if ((uu = sshbuf_dtob64_string(b, 0)) == NULL) { 1510 r = SSH_ERR_ALLOC_FAIL; 1511 goto out; 1512 } 1513 /* Success */ 1514 if (b64p != NULL) { 1515 *b64p = uu; 1516 uu = NULL; 1517 } 1518 r = 0; 1519 out: 1520 sshbuf_free(b); 1521 free(uu); 1522 return r; 1523 } 1524 1525 int 1526 sshkey_format_text(const struct sshkey *key, struct sshbuf *b) 1527 { 1528 int r = SSH_ERR_INTERNAL_ERROR; 1529 char *uu = NULL; 1530 1531 if ((r = sshkey_to_base64(key, &uu)) != 0) 1532 goto out; 1533 if ((r = sshbuf_putf(b, "%s %s", 1534 sshkey_ssh_name(key), uu)) != 0) 1535 goto out; 1536 r = 0; 1537 out: 1538 free(uu); 1539 return r; 1540 } 1541 1542 int 1543 sshkey_write(const struct sshkey *key, FILE *f) 1544 { 1545 struct sshbuf *b = NULL; 1546 int r = SSH_ERR_INTERNAL_ERROR; 1547 1548 if ((b = sshbuf_new()) == NULL) 1549 return SSH_ERR_ALLOC_FAIL; 1550 if ((r = sshkey_format_text(key, b)) != 0) 1551 goto out; 1552 if (fwrite(sshbuf_ptr(b), sshbuf_len(b), 1, f) != 1) { 1553 if (feof(f)) 1554 errno = EPIPE; 1555 r = SSH_ERR_SYSTEM_ERROR; 1556 goto out; 1557 } 1558 /* Success */ 1559 r = 0; 1560 out: 1561 sshbuf_free(b); 1562 return r; 1563 } 1564 1565 const char * 1566 sshkey_cert_type(const struct sshkey *k) 1567 { 1568 switch (k->cert->type) { 1569 case SSH2_CERT_TYPE_USER: 1570 return "user"; 1571 case SSH2_CERT_TYPE_HOST: 1572 return "host"; 1573 default: 1574 return "unknown"; 1575 } 1576 } 1577 1578 #ifdef WITH_OPENSSL 1579 static int 1580 rsa_generate_private_key(u_int bits, RSA **rsap) 1581 { 1582 RSA *private = NULL; 1583 BIGNUM *f4 = NULL; 1584 int ret = SSH_ERR_INTERNAL_ERROR; 1585 1586 if (rsap == NULL) 1587 return SSH_ERR_INVALID_ARGUMENT; 1588 if (bits < SSH_RSA_MINIMUM_MODULUS_SIZE || 1589 bits > SSHBUF_MAX_BIGNUM * 8) 1590 return SSH_ERR_KEY_LENGTH; 1591 *rsap = NULL; 1592 if ((private = RSA_new()) == NULL || (f4 = BN_new()) == NULL) { 1593 ret = SSH_ERR_ALLOC_FAIL; 1594 goto out; 1595 } 1596 if (!BN_set_word(f4, RSA_F4) || 1597 !RSA_generate_key_ex(private, bits, f4, NULL)) { 1598 ret = SSH_ERR_LIBCRYPTO_ERROR; 1599 goto out; 1600 } 1601 *rsap = private; 1602 private = NULL; 1603 ret = 0; 1604 out: 1605 RSA_free(private); 1606 BN_free(f4); 1607 return ret; 1608 } 1609 1610 static int 1611 dsa_generate_private_key(u_int bits, DSA **dsap) 1612 { 1613 DSA *private; 1614 int ret = SSH_ERR_INTERNAL_ERROR; 1615 1616 if (dsap == NULL) 1617 return SSH_ERR_INVALID_ARGUMENT; 1618 if (bits != 1024) 1619 return SSH_ERR_KEY_LENGTH; 1620 if ((private = DSA_new()) == NULL) { 1621 ret = SSH_ERR_ALLOC_FAIL; 1622 goto out; 1623 } 1624 *dsap = NULL; 1625 if (!DSA_generate_parameters_ex(private, bits, NULL, 0, NULL, 1626 NULL, NULL) || !DSA_generate_key(private)) { 1627 ret = SSH_ERR_LIBCRYPTO_ERROR; 1628 goto out; 1629 } 1630 *dsap = private; 1631 private = NULL; 1632 ret = 0; 1633 out: 1634 DSA_free(private); 1635 return ret; 1636 } 1637 1638 # ifdef OPENSSL_HAS_ECC 1639 int 1640 sshkey_ecdsa_key_to_nid(EC_KEY *k) 1641 { 1642 EC_GROUP *eg; 1643 int nids[] = { 1644 NID_X9_62_prime256v1, 1645 NID_secp384r1, 1646 # ifdef OPENSSL_HAS_NISTP521 1647 NID_secp521r1, 1648 # endif /* OPENSSL_HAS_NISTP521 */ 1649 -1 1650 }; 1651 int nid; 1652 u_int i; 1653 const EC_GROUP *g = EC_KEY_get0_group(k); 1654 1655 /* 1656 * The group may be stored in a ASN.1 encoded private key in one of two 1657 * ways: as a "named group", which is reconstituted by ASN.1 object ID 1658 * or explicit group parameters encoded into the key blob. Only the 1659 * "named group" case sets the group NID for us, but we can figure 1660 * it out for the other case by comparing against all the groups that 1661 * are supported. 1662 */ 1663 if ((nid = EC_GROUP_get_curve_name(g)) > 0) 1664 return nid; 1665 for (i = 0; nids[i] != -1; i++) { 1666 if ((eg = EC_GROUP_new_by_curve_name(nids[i])) == NULL) 1667 return -1; 1668 if (EC_GROUP_cmp(g, eg, NULL) == 0) 1669 break; 1670 EC_GROUP_free(eg); 1671 } 1672 if (nids[i] != -1) { 1673 /* Use the group with the NID attached */ 1674 EC_GROUP_set_asn1_flag(eg, OPENSSL_EC_NAMED_CURVE); 1675 if (EC_KEY_set_group(k, eg) != 1) { 1676 EC_GROUP_free(eg); 1677 return -1; 1678 } 1679 } 1680 return nids[i]; 1681 } 1682 1683 static int 1684 ecdsa_generate_private_key(u_int bits, int *nid, EC_KEY **ecdsap) 1685 { 1686 EC_KEY *private; 1687 int ret = SSH_ERR_INTERNAL_ERROR; 1688 1689 if (nid == NULL || ecdsap == NULL) 1690 return SSH_ERR_INVALID_ARGUMENT; 1691 if ((*nid = sshkey_ecdsa_bits_to_nid(bits)) == -1) 1692 return SSH_ERR_KEY_LENGTH; 1693 *ecdsap = NULL; 1694 if ((private = EC_KEY_new_by_curve_name(*nid)) == NULL) { 1695 ret = SSH_ERR_ALLOC_FAIL; 1696 goto out; 1697 } 1698 if (EC_KEY_generate_key(private) != 1) { 1699 ret = SSH_ERR_LIBCRYPTO_ERROR; 1700 goto out; 1701 } 1702 EC_KEY_set_asn1_flag(private, OPENSSL_EC_NAMED_CURVE); 1703 *ecdsap = private; 1704 private = NULL; 1705 ret = 0; 1706 out: 1707 EC_KEY_free(private); 1708 return ret; 1709 } 1710 # endif /* OPENSSL_HAS_ECC */ 1711 #endif /* WITH_OPENSSL */ 1712 1713 int 1714 sshkey_generate(int type, u_int bits, struct sshkey **keyp) 1715 { 1716 struct sshkey *k; 1717 int ret = SSH_ERR_INTERNAL_ERROR; 1718 1719 if (keyp == NULL) 1720 return SSH_ERR_INVALID_ARGUMENT; 1721 *keyp = NULL; 1722 if ((k = sshkey_new(KEY_UNSPEC)) == NULL) 1723 return SSH_ERR_ALLOC_FAIL; 1724 switch (type) { 1725 case KEY_ED25519: 1726 if ((k->ed25519_pk = malloc(ED25519_PK_SZ)) == NULL || 1727 (k->ed25519_sk = malloc(ED25519_SK_SZ)) == NULL) { 1728 ret = SSH_ERR_ALLOC_FAIL; 1729 break; 1730 } 1731 crypto_sign_ed25519_keypair(k->ed25519_pk, k->ed25519_sk); 1732 ret = 0; 1733 break; 1734 #ifdef WITH_XMSS 1735 case KEY_XMSS: 1736 ret = sshkey_xmss_generate_private_key(k, bits); 1737 break; 1738 #endif /* WITH_XMSS */ 1739 #ifdef WITH_OPENSSL 1740 case KEY_DSA: 1741 ret = dsa_generate_private_key(bits, &k->dsa); 1742 break; 1743 # ifdef OPENSSL_HAS_ECC 1744 case KEY_ECDSA: 1745 ret = ecdsa_generate_private_key(bits, &k->ecdsa_nid, 1746 &k->ecdsa); 1747 break; 1748 # endif /* OPENSSL_HAS_ECC */ 1749 case KEY_RSA: 1750 ret = rsa_generate_private_key(bits, &k->rsa); 1751 break; 1752 #endif /* WITH_OPENSSL */ 1753 default: 1754 ret = SSH_ERR_INVALID_ARGUMENT; 1755 } 1756 if (ret == 0) { 1757 k->type = type; 1758 *keyp = k; 1759 } else 1760 sshkey_free(k); 1761 return ret; 1762 } 1763 1764 int 1765 sshkey_cert_copy(const struct sshkey *from_key, struct sshkey *to_key) 1766 { 1767 u_int i; 1768 const struct sshkey_cert *from; 1769 struct sshkey_cert *to; 1770 int r = SSH_ERR_INTERNAL_ERROR; 1771 1772 if (to_key == NULL || (from = from_key->cert) == NULL) 1773 return SSH_ERR_INVALID_ARGUMENT; 1774 1775 if ((to = cert_new()) == NULL) 1776 return SSH_ERR_ALLOC_FAIL; 1777 1778 if ((r = sshbuf_putb(to->certblob, from->certblob)) != 0 || 1779 (r = sshbuf_putb(to->critical, from->critical)) != 0 || 1780 (r = sshbuf_putb(to->extensions, from->extensions)) != 0) 1781 goto out; 1782 1783 to->serial = from->serial; 1784 to->type = from->type; 1785 if (from->key_id == NULL) 1786 to->key_id = NULL; 1787 else if ((to->key_id = strdup(from->key_id)) == NULL) { 1788 r = SSH_ERR_ALLOC_FAIL; 1789 goto out; 1790 } 1791 to->valid_after = from->valid_after; 1792 to->valid_before = from->valid_before; 1793 if (from->signature_key == NULL) 1794 to->signature_key = NULL; 1795 else if ((r = sshkey_from_private(from->signature_key, 1796 &to->signature_key)) != 0) 1797 goto out; 1798 if (from->signature_type != NULL && 1799 (to->signature_type = strdup(from->signature_type)) == NULL) { 1800 r = SSH_ERR_ALLOC_FAIL; 1801 goto out; 1802 } 1803 if (from->nprincipals > SSHKEY_CERT_MAX_PRINCIPALS) { 1804 r = SSH_ERR_INVALID_ARGUMENT; 1805 goto out; 1806 } 1807 if (from->nprincipals > 0) { 1808 if ((to->principals = calloc(from->nprincipals, 1809 sizeof(*to->principals))) == NULL) { 1810 r = SSH_ERR_ALLOC_FAIL; 1811 goto out; 1812 } 1813 for (i = 0; i < from->nprincipals; i++) { 1814 to->principals[i] = strdup(from->principals[i]); 1815 if (to->principals[i] == NULL) { 1816 to->nprincipals = i; 1817 r = SSH_ERR_ALLOC_FAIL; 1818 goto out; 1819 } 1820 } 1821 } 1822 to->nprincipals = from->nprincipals; 1823 1824 /* success */ 1825 cert_free(to_key->cert); 1826 to_key->cert = to; 1827 to = NULL; 1828 r = 0; 1829 out: 1830 cert_free(to); 1831 return r; 1832 } 1833 1834 int 1835 sshkey_from_private(const struct sshkey *k, struct sshkey **pkp) 1836 { 1837 struct sshkey *n = NULL; 1838 int r = SSH_ERR_INTERNAL_ERROR; 1839 #ifdef WITH_OPENSSL 1840 const BIGNUM *rsa_n, *rsa_e; 1841 BIGNUM *rsa_n_dup = NULL, *rsa_e_dup = NULL; 1842 const BIGNUM *dsa_p, *dsa_q, *dsa_g, *dsa_pub_key; 1843 BIGNUM *dsa_p_dup = NULL, *dsa_q_dup = NULL, *dsa_g_dup = NULL; 1844 BIGNUM *dsa_pub_key_dup = NULL; 1845 #endif /* WITH_OPENSSL */ 1846 1847 *pkp = NULL; 1848 if ((n = sshkey_new(k->type)) == NULL) { 1849 r = SSH_ERR_ALLOC_FAIL; 1850 goto out; 1851 } 1852 switch (k->type) { 1853 #ifdef WITH_OPENSSL 1854 case KEY_DSA: 1855 case KEY_DSA_CERT: 1856 DSA_get0_pqg(k->dsa, &dsa_p, &dsa_q, &dsa_g); 1857 DSA_get0_key(k->dsa, &dsa_pub_key, NULL); 1858 if ((dsa_p_dup = BN_dup(dsa_p)) == NULL || 1859 (dsa_q_dup = BN_dup(dsa_q)) == NULL || 1860 (dsa_g_dup = BN_dup(dsa_g)) == NULL || 1861 (dsa_pub_key_dup = BN_dup(dsa_pub_key)) == NULL) { 1862 r = SSH_ERR_ALLOC_FAIL; 1863 goto out; 1864 } 1865 if (!DSA_set0_pqg(n->dsa, dsa_p_dup, dsa_q_dup, dsa_g_dup)) { 1866 r = SSH_ERR_LIBCRYPTO_ERROR; 1867 goto out; 1868 } 1869 dsa_p_dup = dsa_q_dup = dsa_g_dup = NULL; /* transferred */ 1870 if (!DSA_set0_key(n->dsa, dsa_pub_key_dup, NULL)) { 1871 r = SSH_ERR_LIBCRYPTO_ERROR; 1872 goto out; 1873 } 1874 dsa_pub_key_dup = NULL; /* transferred */ 1875 1876 break; 1877 # ifdef OPENSSL_HAS_ECC 1878 case KEY_ECDSA: 1879 case KEY_ECDSA_CERT: 1880 case KEY_ECDSA_SK: 1881 case KEY_ECDSA_SK_CERT: 1882 n->ecdsa_nid = k->ecdsa_nid; 1883 n->ecdsa = EC_KEY_new_by_curve_name(k->ecdsa_nid); 1884 if (n->ecdsa == NULL) { 1885 r = SSH_ERR_ALLOC_FAIL; 1886 goto out; 1887 } 1888 if (EC_KEY_set_public_key(n->ecdsa, 1889 EC_KEY_get0_public_key(k->ecdsa)) != 1) { 1890 r = SSH_ERR_LIBCRYPTO_ERROR; 1891 goto out; 1892 } 1893 if (k->type != KEY_ECDSA_SK && k->type != KEY_ECDSA_SK_CERT) 1894 break; 1895 /* Append security-key application string */ 1896 if ((n->sk_application = strdup(k->sk_application)) == NULL) 1897 goto out; 1898 break; 1899 # endif /* OPENSSL_HAS_ECC */ 1900 case KEY_RSA: 1901 case KEY_RSA_CERT: 1902 RSA_get0_key(k->rsa, &rsa_n, &rsa_e, NULL); 1903 if ((rsa_n_dup = BN_dup(rsa_n)) == NULL || 1904 (rsa_e_dup = BN_dup(rsa_e)) == NULL) { 1905 r = SSH_ERR_ALLOC_FAIL; 1906 goto out; 1907 } 1908 if (!RSA_set0_key(n->rsa, rsa_n_dup, rsa_e_dup, NULL)) { 1909 r = SSH_ERR_LIBCRYPTO_ERROR; 1910 goto out; 1911 } 1912 rsa_n_dup = rsa_e_dup = NULL; /* transferred */ 1913 break; 1914 #endif /* WITH_OPENSSL */ 1915 case KEY_ED25519: 1916 case KEY_ED25519_CERT: 1917 case KEY_ED25519_SK: 1918 case KEY_ED25519_SK_CERT: 1919 if (k->ed25519_pk != NULL) { 1920 if ((n->ed25519_pk = malloc(ED25519_PK_SZ)) == NULL) { 1921 r = SSH_ERR_ALLOC_FAIL; 1922 goto out; 1923 } 1924 memcpy(n->ed25519_pk, k->ed25519_pk, ED25519_PK_SZ); 1925 } 1926 if (k->type != KEY_ED25519_SK && 1927 k->type != KEY_ED25519_SK_CERT) 1928 break; 1929 /* Append security-key application string */ 1930 if ((n->sk_application = strdup(k->sk_application)) == NULL) 1931 goto out; 1932 break; 1933 #ifdef WITH_XMSS 1934 case KEY_XMSS: 1935 case KEY_XMSS_CERT: 1936 if ((r = sshkey_xmss_init(n, k->xmss_name)) != 0) 1937 goto out; 1938 if (k->xmss_pk != NULL) { 1939 u_int32_t left; 1940 size_t pklen = sshkey_xmss_pklen(k); 1941 if (pklen == 0 || sshkey_xmss_pklen(n) != pklen) { 1942 r = SSH_ERR_INTERNAL_ERROR; 1943 goto out; 1944 } 1945 if ((n->xmss_pk = malloc(pklen)) == NULL) { 1946 r = SSH_ERR_ALLOC_FAIL; 1947 goto out; 1948 } 1949 memcpy(n->xmss_pk, k->xmss_pk, pklen); 1950 /* simulate number of signatures left on pubkey */ 1951 left = sshkey_xmss_signatures_left(k); 1952 if (left) 1953 sshkey_xmss_enable_maxsign(n, left); 1954 } 1955 break; 1956 #endif /* WITH_XMSS */ 1957 default: 1958 r = SSH_ERR_KEY_TYPE_UNKNOWN; 1959 goto out; 1960 } 1961 if (sshkey_is_cert(k) && (r = sshkey_cert_copy(k, n)) != 0) 1962 goto out; 1963 /* success */ 1964 *pkp = n; 1965 n = NULL; 1966 r = 0; 1967 out: 1968 sshkey_free(n); 1969 #ifdef WITH_OPENSSL 1970 BN_clear_free(rsa_n_dup); 1971 BN_clear_free(rsa_e_dup); 1972 BN_clear_free(dsa_p_dup); 1973 BN_clear_free(dsa_q_dup); 1974 BN_clear_free(dsa_g_dup); 1975 BN_clear_free(dsa_pub_key_dup); 1976 #endif 1977 1978 return r; 1979 } 1980 1981 int 1982 sshkey_is_shielded(struct sshkey *k) 1983 { 1984 return k != NULL && k->shielded_private != NULL; 1985 } 1986 1987 int 1988 sshkey_shield_private(struct sshkey *k) 1989 { 1990 struct sshbuf *prvbuf = NULL; 1991 u_char *prekey = NULL, *enc = NULL, keyiv[SSH_DIGEST_MAX_LENGTH]; 1992 struct sshcipher_ctx *cctx = NULL; 1993 const struct sshcipher *cipher; 1994 size_t i, enclen = 0; 1995 struct sshkey *kswap = NULL, tmp; 1996 int r = SSH_ERR_INTERNAL_ERROR; 1997 1998 #ifdef DEBUG_PK 1999 fprintf(stderr, "%s: entering for %s\n", __func__, sshkey_ssh_name(k)); 2000 #endif 2001 if ((cipher = cipher_by_name(SSHKEY_SHIELD_CIPHER)) == NULL) { 2002 r = SSH_ERR_INVALID_ARGUMENT; 2003 goto out; 2004 } 2005 if (cipher_keylen(cipher) + cipher_ivlen(cipher) > 2006 ssh_digest_bytes(SSHKEY_SHIELD_PREKEY_HASH)) { 2007 r = SSH_ERR_INTERNAL_ERROR; 2008 goto out; 2009 } 2010 2011 /* Prepare a random pre-key, and from it an ephemeral key */ 2012 if ((prekey = malloc(SSHKEY_SHIELD_PREKEY_LEN)) == NULL) { 2013 r = SSH_ERR_ALLOC_FAIL; 2014 goto out; 2015 } 2016 arc4random_buf(prekey, SSHKEY_SHIELD_PREKEY_LEN); 2017 if ((r = ssh_digest_memory(SSHKEY_SHIELD_PREKEY_HASH, 2018 prekey, SSHKEY_SHIELD_PREKEY_LEN, 2019 keyiv, SSH_DIGEST_MAX_LENGTH)) != 0) 2020 goto out; 2021 #ifdef DEBUG_PK 2022 fprintf(stderr, "%s: key+iv\n", __func__); 2023 sshbuf_dump_data(keyiv, ssh_digest_bytes(SSHKEY_SHIELD_PREKEY_HASH), 2024 stderr); 2025 #endif 2026 if ((r = cipher_init(&cctx, cipher, keyiv, cipher_keylen(cipher), 2027 keyiv + cipher_keylen(cipher), cipher_ivlen(cipher), 1)) != 0) 2028 goto out; 2029 2030 /* Serialise and encrypt the private key using the ephemeral key */ 2031 if ((prvbuf = sshbuf_new()) == NULL) { 2032 r = SSH_ERR_ALLOC_FAIL; 2033 goto out; 2034 } 2035 if (sshkey_is_shielded(k) && (r = sshkey_unshield_private(k)) != 0) 2036 goto out; 2037 if ((r = sshkey_private_serialize_opt(k, prvbuf, 2038 SSHKEY_SERIALIZE_SHIELD)) != 0) 2039 goto out; 2040 /* pad to cipher blocksize */ 2041 i = 0; 2042 while (sshbuf_len(prvbuf) % cipher_blocksize(cipher)) { 2043 if ((r = sshbuf_put_u8(prvbuf, ++i & 0xff)) != 0) 2044 goto out; 2045 } 2046 #ifdef DEBUG_PK 2047 fprintf(stderr, "%s: serialised\n", __func__); 2048 sshbuf_dump(prvbuf, stderr); 2049 #endif 2050 /* encrypt */ 2051 enclen = sshbuf_len(prvbuf); 2052 if ((enc = malloc(enclen)) == NULL) { 2053 r = SSH_ERR_ALLOC_FAIL; 2054 goto out; 2055 } 2056 if ((r = cipher_crypt(cctx, 0, enc, 2057 sshbuf_ptr(prvbuf), sshbuf_len(prvbuf), 0, 0)) != 0) 2058 goto out; 2059 #ifdef DEBUG_PK 2060 fprintf(stderr, "%s: encrypted\n", __func__); 2061 sshbuf_dump_data(enc, enclen, stderr); 2062 #endif 2063 2064 /* Make a scrubbed, public-only copy of our private key argument */ 2065 if ((r = sshkey_from_private(k, &kswap)) != 0) 2066 goto out; 2067 2068 /* Swap the private key out (it will be destroyed below) */ 2069 tmp = *kswap; 2070 *kswap = *k; 2071 *k = tmp; 2072 2073 /* Insert the shielded key into our argument */ 2074 k->shielded_private = enc; 2075 k->shielded_len = enclen; 2076 k->shield_prekey = prekey; 2077 k->shield_prekey_len = SSHKEY_SHIELD_PREKEY_LEN; 2078 enc = prekey = NULL; /* transferred */ 2079 enclen = 0; 2080 2081 /* preserve key fields that are required for correct operation */ 2082 k->sk_flags = kswap->sk_flags; 2083 2084 /* success */ 2085 r = 0; 2086 2087 out: 2088 /* XXX behaviour on error - invalidate original private key? */ 2089 cipher_free(cctx); 2090 explicit_bzero(keyiv, sizeof(keyiv)); 2091 explicit_bzero(&tmp, sizeof(tmp)); 2092 freezero(enc, enclen); 2093 freezero(prekey, SSHKEY_SHIELD_PREKEY_LEN); 2094 sshkey_free(kswap); 2095 sshbuf_free(prvbuf); 2096 return r; 2097 } 2098 2099 int 2100 sshkey_unshield_private(struct sshkey *k) 2101 { 2102 struct sshbuf *prvbuf = NULL; 2103 u_char pad, *cp, keyiv[SSH_DIGEST_MAX_LENGTH]; 2104 struct sshcipher_ctx *cctx = NULL; 2105 const struct sshcipher *cipher; 2106 size_t i; 2107 struct sshkey *kswap = NULL, tmp; 2108 int r = SSH_ERR_INTERNAL_ERROR; 2109 2110 #ifdef DEBUG_PK 2111 fprintf(stderr, "%s: entering for %s\n", __func__, sshkey_ssh_name(k)); 2112 #endif 2113 if (!sshkey_is_shielded(k)) 2114 return 0; /* nothing to do */ 2115 2116 if ((cipher = cipher_by_name(SSHKEY_SHIELD_CIPHER)) == NULL) { 2117 r = SSH_ERR_INVALID_ARGUMENT; 2118 goto out; 2119 } 2120 if (cipher_keylen(cipher) + cipher_ivlen(cipher) > 2121 ssh_digest_bytes(SSHKEY_SHIELD_PREKEY_HASH)) { 2122 r = SSH_ERR_INTERNAL_ERROR; 2123 goto out; 2124 } 2125 /* check size of shielded key blob */ 2126 if (k->shielded_len < cipher_blocksize(cipher) || 2127 (k->shielded_len % cipher_blocksize(cipher)) != 0) { 2128 r = SSH_ERR_INVALID_FORMAT; 2129 goto out; 2130 } 2131 2132 /* Calculate the ephemeral key from the prekey */ 2133 if ((r = ssh_digest_memory(SSHKEY_SHIELD_PREKEY_HASH, 2134 k->shield_prekey, k->shield_prekey_len, 2135 keyiv, SSH_DIGEST_MAX_LENGTH)) != 0) 2136 goto out; 2137 if ((r = cipher_init(&cctx, cipher, keyiv, cipher_keylen(cipher), 2138 keyiv + cipher_keylen(cipher), cipher_ivlen(cipher), 0)) != 0) 2139 goto out; 2140 #ifdef DEBUG_PK 2141 fprintf(stderr, "%s: key+iv\n", __func__); 2142 sshbuf_dump_data(keyiv, ssh_digest_bytes(SSHKEY_SHIELD_PREKEY_HASH), 2143 stderr); 2144 #endif 2145 2146 /* Decrypt and parse the shielded private key using the ephemeral key */ 2147 if ((prvbuf = sshbuf_new()) == NULL) { 2148 r = SSH_ERR_ALLOC_FAIL; 2149 goto out; 2150 } 2151 if ((r = sshbuf_reserve(prvbuf, k->shielded_len, &cp)) != 0) 2152 goto out; 2153 /* decrypt */ 2154 #ifdef DEBUG_PK 2155 fprintf(stderr, "%s: encrypted\n", __func__); 2156 sshbuf_dump_data(k->shielded_private, k->shielded_len, stderr); 2157 #endif 2158 if ((r = cipher_crypt(cctx, 0, cp, 2159 k->shielded_private, k->shielded_len, 0, 0)) != 0) 2160 goto out; 2161 #ifdef DEBUG_PK 2162 fprintf(stderr, "%s: serialised\n", __func__); 2163 sshbuf_dump(prvbuf, stderr); 2164 #endif 2165 /* Parse private key */ 2166 if ((r = sshkey_private_deserialize(prvbuf, &kswap)) != 0) 2167 goto out; 2168 /* Check deterministic padding */ 2169 i = 0; 2170 while (sshbuf_len(prvbuf)) { 2171 if ((r = sshbuf_get_u8(prvbuf, &pad)) != 0) 2172 goto out; 2173 if (pad != (++i & 0xff)) { 2174 r = SSH_ERR_INVALID_FORMAT; 2175 goto out; 2176 } 2177 } 2178 2179 /* Swap the parsed key back into place */ 2180 tmp = *kswap; 2181 *kswap = *k; 2182 *k = tmp; 2183 2184 /* success */ 2185 r = 0; 2186 2187 out: 2188 cipher_free(cctx); 2189 explicit_bzero(keyiv, sizeof(keyiv)); 2190 explicit_bzero(&tmp, sizeof(tmp)); 2191 sshkey_free(kswap); 2192 sshbuf_free(prvbuf); 2193 return r; 2194 } 2195 2196 static int 2197 cert_parse(struct sshbuf *b, struct sshkey *key, struct sshbuf *certbuf) 2198 { 2199 struct sshbuf *principals = NULL, *crit = NULL; 2200 struct sshbuf *exts = NULL, *ca = NULL; 2201 u_char *sig = NULL; 2202 size_t signed_len = 0, slen = 0, kidlen = 0; 2203 int ret = SSH_ERR_INTERNAL_ERROR; 2204 2205 /* Copy the entire key blob for verification and later serialisation */ 2206 if ((ret = sshbuf_putb(key->cert->certblob, certbuf)) != 0) 2207 return ret; 2208 2209 /* Parse body of certificate up to signature */ 2210 if ((ret = sshbuf_get_u64(b, &key->cert->serial)) != 0 || 2211 (ret = sshbuf_get_u32(b, &key->cert->type)) != 0 || 2212 (ret = sshbuf_get_cstring(b, &key->cert->key_id, &kidlen)) != 0 || 2213 (ret = sshbuf_froms(b, &principals)) != 0 || 2214 (ret = sshbuf_get_u64(b, &key->cert->valid_after)) != 0 || 2215 (ret = sshbuf_get_u64(b, &key->cert->valid_before)) != 0 || 2216 (ret = sshbuf_froms(b, &crit)) != 0 || 2217 (ret = sshbuf_froms(b, &exts)) != 0 || 2218 (ret = sshbuf_get_string_direct(b, NULL, NULL)) != 0 || 2219 (ret = sshbuf_froms(b, &ca)) != 0) { 2220 /* XXX debug print error for ret */ 2221 ret = SSH_ERR_INVALID_FORMAT; 2222 goto out; 2223 } 2224 2225 /* Signature is left in the buffer so we can calculate this length */ 2226 signed_len = sshbuf_len(key->cert->certblob) - sshbuf_len(b); 2227 2228 if ((ret = sshbuf_get_string(b, &sig, &slen)) != 0) { 2229 ret = SSH_ERR_INVALID_FORMAT; 2230 goto out; 2231 } 2232 2233 if (key->cert->type != SSH2_CERT_TYPE_USER && 2234 key->cert->type != SSH2_CERT_TYPE_HOST) { 2235 ret = SSH_ERR_KEY_CERT_UNKNOWN_TYPE; 2236 goto out; 2237 } 2238 2239 /* Parse principals section */ 2240 while (sshbuf_len(principals) > 0) { 2241 char *principal = NULL; 2242 char **oprincipals = NULL; 2243 2244 if (key->cert->nprincipals >= SSHKEY_CERT_MAX_PRINCIPALS) { 2245 ret = SSH_ERR_INVALID_FORMAT; 2246 goto out; 2247 } 2248 if ((ret = sshbuf_get_cstring(principals, &principal, 2249 NULL)) != 0) { 2250 ret = SSH_ERR_INVALID_FORMAT; 2251 goto out; 2252 } 2253 oprincipals = key->cert->principals; 2254 key->cert->principals = recallocarray(key->cert->principals, 2255 key->cert->nprincipals, key->cert->nprincipals + 1, 2256 sizeof(*key->cert->principals)); 2257 if (key->cert->principals == NULL) { 2258 free(principal); 2259 key->cert->principals = oprincipals; 2260 ret = SSH_ERR_ALLOC_FAIL; 2261 goto out; 2262 } 2263 key->cert->principals[key->cert->nprincipals++] = principal; 2264 } 2265 2266 /* 2267 * Stash a copies of the critical options and extensions sections 2268 * for later use. 2269 */ 2270 if ((ret = sshbuf_putb(key->cert->critical, crit)) != 0 || 2271 (exts != NULL && 2272 (ret = sshbuf_putb(key->cert->extensions, exts)) != 0)) 2273 goto out; 2274 2275 /* 2276 * Validate critical options and extensions sections format. 2277 */ 2278 while (sshbuf_len(crit) != 0) { 2279 if ((ret = sshbuf_get_string_direct(crit, NULL, NULL)) != 0 || 2280 (ret = sshbuf_get_string_direct(crit, NULL, NULL)) != 0) { 2281 sshbuf_reset(key->cert->critical); 2282 ret = SSH_ERR_INVALID_FORMAT; 2283 goto out; 2284 } 2285 } 2286 while (exts != NULL && sshbuf_len(exts) != 0) { 2287 if ((ret = sshbuf_get_string_direct(exts, NULL, NULL)) != 0 || 2288 (ret = sshbuf_get_string_direct(exts, NULL, NULL)) != 0) { 2289 sshbuf_reset(key->cert->extensions); 2290 ret = SSH_ERR_INVALID_FORMAT; 2291 goto out; 2292 } 2293 } 2294 2295 /* Parse CA key and check signature */ 2296 if (sshkey_from_blob_internal(ca, &key->cert->signature_key, 0) != 0) { 2297 ret = SSH_ERR_KEY_CERT_INVALID_SIGN_KEY; 2298 goto out; 2299 } 2300 if (!sshkey_type_is_valid_ca(key->cert->signature_key->type)) { 2301 ret = SSH_ERR_KEY_CERT_INVALID_SIGN_KEY; 2302 goto out; 2303 } 2304 if ((ret = sshkey_verify(key->cert->signature_key, sig, slen, 2305 sshbuf_ptr(key->cert->certblob), signed_len, NULL, 0, NULL)) != 0) 2306 goto out; 2307 if ((ret = sshkey_get_sigtype(sig, slen, 2308 &key->cert->signature_type)) != 0) 2309 goto out; 2310 2311 /* Success */ 2312 ret = 0; 2313 out: 2314 sshbuf_free(ca); 2315 sshbuf_free(crit); 2316 sshbuf_free(exts); 2317 sshbuf_free(principals); 2318 free(sig); 2319 return ret; 2320 } 2321 2322 #ifdef WITH_OPENSSL 2323 static int 2324 check_rsa_length(const RSA *rsa) 2325 { 2326 const BIGNUM *rsa_n; 2327 2328 RSA_get0_key(rsa, &rsa_n, NULL, NULL); 2329 if (BN_num_bits(rsa_n) < SSH_RSA_MINIMUM_MODULUS_SIZE) 2330 return SSH_ERR_KEY_LENGTH; 2331 return 0; 2332 } 2333 #endif 2334 2335 static int 2336 sshkey_from_blob_internal(struct sshbuf *b, struct sshkey **keyp, 2337 int allow_cert) 2338 { 2339 int type, ret = SSH_ERR_INTERNAL_ERROR; 2340 char *ktype = NULL, *curve = NULL, *xmss_name = NULL; 2341 struct sshkey *key = NULL; 2342 size_t len; 2343 u_char *pk = NULL; 2344 struct sshbuf *copy; 2345 #if defined(WITH_OPENSSL) 2346 BIGNUM *rsa_n = NULL, *rsa_e = NULL; 2347 BIGNUM *dsa_p = NULL, *dsa_q = NULL, *dsa_g = NULL, *dsa_pub_key = NULL; 2348 # if defined(OPENSSL_HAS_ECC) 2349 EC_POINT *q = NULL; 2350 # endif /* OPENSSL_HAS_ECC */ 2351 #endif /* WITH_OPENSSL */ 2352 2353 #ifdef DEBUG_PK /* XXX */ 2354 sshbuf_dump(b, stderr); 2355 #endif 2356 if (keyp != NULL) 2357 *keyp = NULL; 2358 if ((copy = sshbuf_fromb(b)) == NULL) { 2359 ret = SSH_ERR_ALLOC_FAIL; 2360 goto out; 2361 } 2362 if (sshbuf_get_cstring(b, &ktype, NULL) != 0) { 2363 ret = SSH_ERR_INVALID_FORMAT; 2364 goto out; 2365 } 2366 2367 type = sshkey_type_from_name(ktype); 2368 if (!allow_cert && sshkey_type_is_cert(type)) { 2369 ret = SSH_ERR_KEY_CERT_INVALID_SIGN_KEY; 2370 goto out; 2371 } 2372 switch (type) { 2373 #ifdef WITH_OPENSSL 2374 case KEY_RSA_CERT: 2375 /* Skip nonce */ 2376 if (sshbuf_get_string_direct(b, NULL, NULL) != 0) { 2377 ret = SSH_ERR_INVALID_FORMAT; 2378 goto out; 2379 } 2380 /* FALLTHROUGH */ 2381 case KEY_RSA: 2382 if ((key = sshkey_new(type)) == NULL) { 2383 ret = SSH_ERR_ALLOC_FAIL; 2384 goto out; 2385 } 2386 if (sshbuf_get_bignum2(b, &rsa_e) != 0 || 2387 sshbuf_get_bignum2(b, &rsa_n) != 0) { 2388 ret = SSH_ERR_INVALID_FORMAT; 2389 goto out; 2390 } 2391 if (!RSA_set0_key(key->rsa, rsa_n, rsa_e, NULL)) { 2392 ret = SSH_ERR_LIBCRYPTO_ERROR; 2393 goto out; 2394 } 2395 rsa_n = rsa_e = NULL; /* transferred */ 2396 if ((ret = check_rsa_length(key->rsa)) != 0) 2397 goto out; 2398 #ifdef DEBUG_PK 2399 RSA_print_fp(stderr, key->rsa, 8); 2400 #endif 2401 break; 2402 case KEY_DSA_CERT: 2403 /* Skip nonce */ 2404 if (sshbuf_get_string_direct(b, NULL, NULL) != 0) { 2405 ret = SSH_ERR_INVALID_FORMAT; 2406 goto out; 2407 } 2408 /* FALLTHROUGH */ 2409 case KEY_DSA: 2410 if ((key = sshkey_new(type)) == NULL) { 2411 ret = SSH_ERR_ALLOC_FAIL; 2412 goto out; 2413 } 2414 if (sshbuf_get_bignum2(b, &dsa_p) != 0 || 2415 sshbuf_get_bignum2(b, &dsa_q) != 0 || 2416 sshbuf_get_bignum2(b, &dsa_g) != 0 || 2417 sshbuf_get_bignum2(b, &dsa_pub_key) != 0) { 2418 ret = SSH_ERR_INVALID_FORMAT; 2419 goto out; 2420 } 2421 if (!DSA_set0_pqg(key->dsa, dsa_p, dsa_q, dsa_g)) { 2422 ret = SSH_ERR_LIBCRYPTO_ERROR; 2423 goto out; 2424 } 2425 dsa_p = dsa_q = dsa_g = NULL; /* transferred */ 2426 if (!DSA_set0_key(key->dsa, dsa_pub_key, NULL)) { 2427 ret = SSH_ERR_LIBCRYPTO_ERROR; 2428 goto out; 2429 } 2430 dsa_pub_key = NULL; /* transferred */ 2431 #ifdef DEBUG_PK 2432 DSA_print_fp(stderr, key->dsa, 8); 2433 #endif 2434 break; 2435 # ifdef OPENSSL_HAS_ECC 2436 case KEY_ECDSA_CERT: 2437 case KEY_ECDSA_SK_CERT: 2438 /* Skip nonce */ 2439 if (sshbuf_get_string_direct(b, NULL, NULL) != 0) { 2440 ret = SSH_ERR_INVALID_FORMAT; 2441 goto out; 2442 } 2443 /* FALLTHROUGH */ 2444 case KEY_ECDSA: 2445 case KEY_ECDSA_SK: 2446 if ((key = sshkey_new(type)) == NULL) { 2447 ret = SSH_ERR_ALLOC_FAIL; 2448 goto out; 2449 } 2450 key->ecdsa_nid = sshkey_ecdsa_nid_from_name(ktype); 2451 if (sshbuf_get_cstring(b, &curve, NULL) != 0) { 2452 ret = SSH_ERR_INVALID_FORMAT; 2453 goto out; 2454 } 2455 if (key->ecdsa_nid != sshkey_curve_name_to_nid(curve)) { 2456 ret = SSH_ERR_EC_CURVE_MISMATCH; 2457 goto out; 2458 } 2459 EC_KEY_free(key->ecdsa); 2460 if ((key->ecdsa = EC_KEY_new_by_curve_name(key->ecdsa_nid)) 2461 == NULL) { 2462 ret = SSH_ERR_EC_CURVE_INVALID; 2463 goto out; 2464 } 2465 if ((q = EC_POINT_new(EC_KEY_get0_group(key->ecdsa))) == NULL) { 2466 ret = SSH_ERR_ALLOC_FAIL; 2467 goto out; 2468 } 2469 if (sshbuf_get_ec(b, q, EC_KEY_get0_group(key->ecdsa)) != 0) { 2470 ret = SSH_ERR_INVALID_FORMAT; 2471 goto out; 2472 } 2473 if (sshkey_ec_validate_public(EC_KEY_get0_group(key->ecdsa), 2474 q) != 0) { 2475 ret = SSH_ERR_KEY_INVALID_EC_VALUE; 2476 goto out; 2477 } 2478 if (EC_KEY_set_public_key(key->ecdsa, q) != 1) { 2479 /* XXX assume it is a allocation error */ 2480 ret = SSH_ERR_ALLOC_FAIL; 2481 goto out; 2482 } 2483 #ifdef DEBUG_PK 2484 sshkey_dump_ec_point(EC_KEY_get0_group(key->ecdsa), q); 2485 #endif 2486 if (type == KEY_ECDSA_SK || type == KEY_ECDSA_SK_CERT) { 2487 /* Parse additional security-key application string */ 2488 if (sshbuf_get_cstring(b, &key->sk_application, 2489 NULL) != 0) { 2490 ret = SSH_ERR_INVALID_FORMAT; 2491 goto out; 2492 } 2493 #ifdef DEBUG_PK 2494 fprintf(stderr, "App: %s\n", key->sk_application); 2495 #endif 2496 } 2497 break; 2498 # endif /* OPENSSL_HAS_ECC */ 2499 #endif /* WITH_OPENSSL */ 2500 case KEY_ED25519_CERT: 2501 case KEY_ED25519_SK_CERT: 2502 /* Skip nonce */ 2503 if (sshbuf_get_string_direct(b, NULL, NULL) != 0) { 2504 ret = SSH_ERR_INVALID_FORMAT; 2505 goto out; 2506 } 2507 /* FALLTHROUGH */ 2508 case KEY_ED25519: 2509 case KEY_ED25519_SK: 2510 if ((ret = sshbuf_get_string(b, &pk, &len)) != 0) 2511 goto out; 2512 if (len != ED25519_PK_SZ) { 2513 ret = SSH_ERR_INVALID_FORMAT; 2514 goto out; 2515 } 2516 if ((key = sshkey_new(type)) == NULL) { 2517 ret = SSH_ERR_ALLOC_FAIL; 2518 goto out; 2519 } 2520 if (type == KEY_ED25519_SK || type == KEY_ED25519_SK_CERT) { 2521 /* Parse additional security-key application string */ 2522 if (sshbuf_get_cstring(b, &key->sk_application, 2523 NULL) != 0) { 2524 ret = SSH_ERR_INVALID_FORMAT; 2525 goto out; 2526 } 2527 #ifdef DEBUG_PK 2528 fprintf(stderr, "App: %s\n", key->sk_application); 2529 #endif 2530 } 2531 key->ed25519_pk = pk; 2532 pk = NULL; 2533 break; 2534 #ifdef WITH_XMSS 2535 case KEY_XMSS_CERT: 2536 /* Skip nonce */ 2537 if (sshbuf_get_string_direct(b, NULL, NULL) != 0) { 2538 ret = SSH_ERR_INVALID_FORMAT; 2539 goto out; 2540 } 2541 /* FALLTHROUGH */ 2542 case KEY_XMSS: 2543 if ((ret = sshbuf_get_cstring(b, &xmss_name, NULL)) != 0) 2544 goto out; 2545 if ((key = sshkey_new(type)) == NULL) { 2546 ret = SSH_ERR_ALLOC_FAIL; 2547 goto out; 2548 } 2549 if ((ret = sshkey_xmss_init(key, xmss_name)) != 0) 2550 goto out; 2551 if ((ret = sshbuf_get_string(b, &pk, &len)) != 0) 2552 goto out; 2553 if (len == 0 || len != sshkey_xmss_pklen(key)) { 2554 ret = SSH_ERR_INVALID_FORMAT; 2555 goto out; 2556 } 2557 key->xmss_pk = pk; 2558 pk = NULL; 2559 if (type != KEY_XMSS_CERT && 2560 (ret = sshkey_xmss_deserialize_pk_info(key, b)) != 0) 2561 goto out; 2562 break; 2563 #endif /* WITH_XMSS */ 2564 case KEY_UNSPEC: 2565 default: 2566 ret = SSH_ERR_KEY_TYPE_UNKNOWN; 2567 goto out; 2568 } 2569 2570 /* Parse certificate potion */ 2571 if (sshkey_is_cert(key) && (ret = cert_parse(b, key, copy)) != 0) 2572 goto out; 2573 2574 if (key != NULL && sshbuf_len(b) != 0) { 2575 ret = SSH_ERR_INVALID_FORMAT; 2576 goto out; 2577 } 2578 ret = 0; 2579 if (keyp != NULL) { 2580 *keyp = key; 2581 key = NULL; 2582 } 2583 out: 2584 sshbuf_free(copy); 2585 sshkey_free(key); 2586 free(xmss_name); 2587 free(ktype); 2588 free(curve); 2589 free(pk); 2590 #if defined(WITH_OPENSSL) 2591 BN_clear_free(rsa_n); 2592 BN_clear_free(rsa_e); 2593 BN_clear_free(dsa_p); 2594 BN_clear_free(dsa_q); 2595 BN_clear_free(dsa_g); 2596 BN_clear_free(dsa_pub_key); 2597 # if defined(OPENSSL_HAS_ECC) 2598 EC_POINT_free(q); 2599 # endif /* OPENSSL_HAS_ECC */ 2600 #endif /* WITH_OPENSSL */ 2601 return ret; 2602 } 2603 2604 int 2605 sshkey_from_blob(const u_char *blob, size_t blen, struct sshkey **keyp) 2606 { 2607 struct sshbuf *b; 2608 int r; 2609 2610 if ((b = sshbuf_from(blob, blen)) == NULL) 2611 return SSH_ERR_ALLOC_FAIL; 2612 r = sshkey_from_blob_internal(b, keyp, 1); 2613 sshbuf_free(b); 2614 return r; 2615 } 2616 2617 int 2618 sshkey_fromb(struct sshbuf *b, struct sshkey **keyp) 2619 { 2620 return sshkey_from_blob_internal(b, keyp, 1); 2621 } 2622 2623 int 2624 sshkey_froms(struct sshbuf *buf, struct sshkey **keyp) 2625 { 2626 struct sshbuf *b; 2627 int r; 2628 2629 if ((r = sshbuf_froms(buf, &b)) != 0) 2630 return r; 2631 r = sshkey_from_blob_internal(b, keyp, 1); 2632 sshbuf_free(b); 2633 return r; 2634 } 2635 2636 int 2637 sshkey_get_sigtype(const u_char *sig, size_t siglen, char **sigtypep) 2638 { 2639 int r; 2640 struct sshbuf *b = NULL; 2641 char *sigtype = NULL; 2642 2643 if (sigtypep != NULL) 2644 *sigtypep = NULL; 2645 if ((b = sshbuf_from(sig, siglen)) == NULL) 2646 return SSH_ERR_ALLOC_FAIL; 2647 if ((r = sshbuf_get_cstring(b, &sigtype, NULL)) != 0) 2648 goto out; 2649 /* success */ 2650 if (sigtypep != NULL) { 2651 *sigtypep = sigtype; 2652 sigtype = NULL; 2653 } 2654 r = 0; 2655 out: 2656 free(sigtype); 2657 sshbuf_free(b); 2658 return r; 2659 } 2660 2661 /* 2662 * 2663 * Checks whether a certificate's signature type is allowed. 2664 * Returns 0 (success) if the certificate signature type appears in the 2665 * "allowed" pattern-list, or the key is not a certificate to begin with. 2666 * Otherwise returns a ssherr.h code. 2667 */ 2668 int 2669 sshkey_check_cert_sigtype(const struct sshkey *key, const char *allowed) 2670 { 2671 if (key == NULL || allowed == NULL) 2672 return SSH_ERR_INVALID_ARGUMENT; 2673 if (!sshkey_type_is_cert(key->type)) 2674 return 0; 2675 if (key->cert == NULL || key->cert->signature_type == NULL) 2676 return SSH_ERR_INVALID_ARGUMENT; 2677 if (match_pattern_list(key->cert->signature_type, allowed, 0) != 1) 2678 return SSH_ERR_SIGN_ALG_UNSUPPORTED; 2679 return 0; 2680 } 2681 2682 /* 2683 * Returns the expected signature algorithm for a given public key algorithm. 2684 */ 2685 const char * 2686 sshkey_sigalg_by_name(const char *name) 2687 { 2688 const struct keytype *kt; 2689 2690 for (kt = keytypes; kt->type != -1; kt++) { 2691 if (strcmp(kt->name, name) != 0) 2692 continue; 2693 if (kt->sigalg != NULL) 2694 return kt->sigalg; 2695 if (!kt->cert) 2696 return kt->name; 2697 return sshkey_ssh_name_from_type_nid( 2698 sshkey_type_plain(kt->type), kt->nid); 2699 } 2700 return NULL; 2701 } 2702 2703 /* 2704 * Verifies that the signature algorithm appearing inside the signature blob 2705 * matches that which was requested. 2706 */ 2707 int 2708 sshkey_check_sigtype(const u_char *sig, size_t siglen, 2709 const char *requested_alg) 2710 { 2711 const char *expected_alg; 2712 char *sigtype = NULL; 2713 int r; 2714 2715 if (requested_alg == NULL) 2716 return 0; 2717 if ((expected_alg = sshkey_sigalg_by_name(requested_alg)) == NULL) 2718 return SSH_ERR_INVALID_ARGUMENT; 2719 if ((r = sshkey_get_sigtype(sig, siglen, &sigtype)) != 0) 2720 return r; 2721 r = strcmp(expected_alg, sigtype) == 0; 2722 free(sigtype); 2723 return r ? 0 : SSH_ERR_SIGN_ALG_UNSUPPORTED; 2724 } 2725 2726 int 2727 sshkey_sign(struct sshkey *key, 2728 u_char **sigp, size_t *lenp, 2729 const u_char *data, size_t datalen, 2730 const char *alg, const char *sk_provider, const char *sk_pin, u_int compat) 2731 { 2732 int was_shielded = sshkey_is_shielded(key); 2733 int r2, r = SSH_ERR_INTERNAL_ERROR; 2734 2735 if (sigp != NULL) 2736 *sigp = NULL; 2737 if (lenp != NULL) 2738 *lenp = 0; 2739 if (datalen > SSH_KEY_MAX_SIGN_DATA_SIZE) 2740 return SSH_ERR_INVALID_ARGUMENT; 2741 if ((r = sshkey_unshield_private(key)) != 0) 2742 return r; 2743 switch (key->type) { 2744 #ifdef WITH_OPENSSL 2745 case KEY_DSA_CERT: 2746 case KEY_DSA: 2747 r = ssh_dss_sign(key, sigp, lenp, data, datalen, compat); 2748 break; 2749 # ifdef OPENSSL_HAS_ECC 2750 case KEY_ECDSA_CERT: 2751 case KEY_ECDSA: 2752 r = ssh_ecdsa_sign(key, sigp, lenp, data, datalen, compat); 2753 break; 2754 # endif /* OPENSSL_HAS_ECC */ 2755 case KEY_RSA_CERT: 2756 case KEY_RSA: 2757 r = ssh_rsa_sign(key, sigp, lenp, data, datalen, alg); 2758 break; 2759 #endif /* WITH_OPENSSL */ 2760 case KEY_ED25519: 2761 case KEY_ED25519_CERT: 2762 r = ssh_ed25519_sign(key, sigp, lenp, data, datalen, compat); 2763 break; 2764 case KEY_ED25519_SK: 2765 case KEY_ED25519_SK_CERT: 2766 case KEY_ECDSA_SK_CERT: 2767 case KEY_ECDSA_SK: 2768 r = sshsk_sign(sk_provider, key, sigp, lenp, data, 2769 datalen, compat, sk_pin); 2770 break; 2771 #ifdef WITH_XMSS 2772 case KEY_XMSS: 2773 case KEY_XMSS_CERT: 2774 r = ssh_xmss_sign(key, sigp, lenp, data, datalen, compat); 2775 break; 2776 #endif /* WITH_XMSS */ 2777 default: 2778 r = SSH_ERR_KEY_TYPE_UNKNOWN; 2779 break; 2780 } 2781 if (was_shielded && (r2 = sshkey_shield_private(key)) != 0) 2782 return r2; 2783 return r; 2784 } 2785 2786 /* 2787 * ssh_key_verify returns 0 for a correct signature and < 0 on error. 2788 * If "alg" specified, then the signature must use that algorithm. 2789 */ 2790 int 2791 sshkey_verify(const struct sshkey *key, 2792 const u_char *sig, size_t siglen, 2793 const u_char *data, size_t dlen, const char *alg, u_int compat, 2794 struct sshkey_sig_details **detailsp) 2795 { 2796 if (detailsp != NULL) 2797 *detailsp = NULL; 2798 if (siglen == 0 || dlen > SSH_KEY_MAX_SIGN_DATA_SIZE) 2799 return SSH_ERR_INVALID_ARGUMENT; 2800 switch (key->type) { 2801 #ifdef WITH_OPENSSL 2802 case KEY_DSA_CERT: 2803 case KEY_DSA: 2804 return ssh_dss_verify(key, sig, siglen, data, dlen, compat); 2805 # ifdef OPENSSL_HAS_ECC 2806 case KEY_ECDSA_CERT: 2807 case KEY_ECDSA: 2808 return ssh_ecdsa_verify(key, sig, siglen, data, dlen, compat); 2809 case KEY_ECDSA_SK_CERT: 2810 case KEY_ECDSA_SK: 2811 return ssh_ecdsa_sk_verify(key, sig, siglen, data, dlen, 2812 compat, detailsp); 2813 # endif /* OPENSSL_HAS_ECC */ 2814 case KEY_RSA_CERT: 2815 case KEY_RSA: 2816 return ssh_rsa_verify(key, sig, siglen, data, dlen, alg); 2817 #endif /* WITH_OPENSSL */ 2818 case KEY_ED25519: 2819 case KEY_ED25519_CERT: 2820 return ssh_ed25519_verify(key, sig, siglen, data, dlen, compat); 2821 case KEY_ED25519_SK: 2822 case KEY_ED25519_SK_CERT: 2823 return ssh_ed25519_sk_verify(key, sig, siglen, data, dlen, 2824 compat, detailsp); 2825 #ifdef WITH_XMSS 2826 case KEY_XMSS: 2827 case KEY_XMSS_CERT: 2828 return ssh_xmss_verify(key, sig, siglen, data, dlen, compat); 2829 #endif /* WITH_XMSS */ 2830 default: 2831 return SSH_ERR_KEY_TYPE_UNKNOWN; 2832 } 2833 } 2834 2835 /* Convert a plain key to their _CERT equivalent */ 2836 int 2837 sshkey_to_certified(struct sshkey *k) 2838 { 2839 int newtype; 2840 2841 switch (k->type) { 2842 #ifdef WITH_OPENSSL 2843 case KEY_RSA: 2844 newtype = KEY_RSA_CERT; 2845 break; 2846 case KEY_DSA: 2847 newtype = KEY_DSA_CERT; 2848 break; 2849 case KEY_ECDSA: 2850 newtype = KEY_ECDSA_CERT; 2851 break; 2852 case KEY_ECDSA_SK: 2853 newtype = KEY_ECDSA_SK_CERT; 2854 break; 2855 #endif /* WITH_OPENSSL */ 2856 case KEY_ED25519_SK: 2857 newtype = KEY_ED25519_SK_CERT; 2858 break; 2859 case KEY_ED25519: 2860 newtype = KEY_ED25519_CERT; 2861 break; 2862 #ifdef WITH_XMSS 2863 case KEY_XMSS: 2864 newtype = KEY_XMSS_CERT; 2865 break; 2866 #endif /* WITH_XMSS */ 2867 default: 2868 return SSH_ERR_INVALID_ARGUMENT; 2869 } 2870 if ((k->cert = cert_new()) == NULL) 2871 return SSH_ERR_ALLOC_FAIL; 2872 k->type = newtype; 2873 return 0; 2874 } 2875 2876 /* Convert a certificate to its raw key equivalent */ 2877 int 2878 sshkey_drop_cert(struct sshkey *k) 2879 { 2880 if (!sshkey_type_is_cert(k->type)) 2881 return SSH_ERR_KEY_TYPE_UNKNOWN; 2882 cert_free(k->cert); 2883 k->cert = NULL; 2884 k->type = sshkey_type_plain(k->type); 2885 return 0; 2886 } 2887 2888 /* Sign a certified key, (re-)generating the signed certblob. */ 2889 int 2890 sshkey_certify_custom(struct sshkey *k, struct sshkey *ca, const char *alg, 2891 const char *sk_provider, const char *sk_pin, 2892 sshkey_certify_signer *signer, void *signer_ctx) 2893 { 2894 struct sshbuf *principals = NULL; 2895 u_char *ca_blob = NULL, *sig_blob = NULL, nonce[32]; 2896 size_t i, ca_len, sig_len; 2897 int ret = SSH_ERR_INTERNAL_ERROR; 2898 struct sshbuf *cert = NULL; 2899 char *sigtype = NULL; 2900 #ifdef WITH_OPENSSL 2901 const BIGNUM *rsa_n, *rsa_e, *dsa_p, *dsa_q, *dsa_g, *dsa_pub_key; 2902 #endif /* WITH_OPENSSL */ 2903 2904 if (k == NULL || k->cert == NULL || 2905 k->cert->certblob == NULL || ca == NULL) 2906 return SSH_ERR_INVALID_ARGUMENT; 2907 if (!sshkey_is_cert(k)) 2908 return SSH_ERR_KEY_TYPE_UNKNOWN; 2909 if (!sshkey_type_is_valid_ca(ca->type)) 2910 return SSH_ERR_KEY_CERT_INVALID_SIGN_KEY; 2911 2912 /* 2913 * If no alg specified as argument but a signature_type was set, 2914 * then prefer that. If both were specified, then they must match. 2915 */ 2916 if (alg == NULL) 2917 alg = k->cert->signature_type; 2918 else if (k->cert->signature_type != NULL && 2919 strcmp(alg, k->cert->signature_type) != 0) 2920 return SSH_ERR_INVALID_ARGUMENT; 2921 2922 /* 2923 * If no signing algorithm or signature_type was specified and we're 2924 * using a RSA key, then default to a good signature algorithm. 2925 */ 2926 if (alg == NULL && ca->type == KEY_RSA) 2927 alg = "rsa-sha2-512"; 2928 2929 if ((ret = sshkey_to_blob(ca, &ca_blob, &ca_len)) != 0) 2930 return SSH_ERR_KEY_CERT_INVALID_SIGN_KEY; 2931 2932 cert = k->cert->certblob; /* for readability */ 2933 sshbuf_reset(cert); 2934 if ((ret = sshbuf_put_cstring(cert, sshkey_ssh_name(k))) != 0) 2935 goto out; 2936 2937 /* -v01 certs put nonce first */ 2938 arc4random_buf(&nonce, sizeof(nonce)); 2939 if ((ret = sshbuf_put_string(cert, nonce, sizeof(nonce))) != 0) 2940 goto out; 2941 2942 /* XXX this substantially duplicates to_blob(); refactor */ 2943 switch (k->type) { 2944 #ifdef WITH_OPENSSL 2945 case KEY_DSA_CERT: 2946 DSA_get0_pqg(k->dsa, &dsa_p, &dsa_q, &dsa_g); 2947 DSA_get0_key(k->dsa, &dsa_pub_key, NULL); 2948 if ((ret = sshbuf_put_bignum2(cert, dsa_p)) != 0 || 2949 (ret = sshbuf_put_bignum2(cert, dsa_q)) != 0 || 2950 (ret = sshbuf_put_bignum2(cert, dsa_g)) != 0 || 2951 (ret = sshbuf_put_bignum2(cert, dsa_pub_key)) != 0) 2952 goto out; 2953 break; 2954 # ifdef OPENSSL_HAS_ECC 2955 case KEY_ECDSA_CERT: 2956 case KEY_ECDSA_SK_CERT: 2957 if ((ret = sshbuf_put_cstring(cert, 2958 sshkey_curve_nid_to_name(k->ecdsa_nid))) != 0 || 2959 (ret = sshbuf_put_ec(cert, 2960 EC_KEY_get0_public_key(k->ecdsa), 2961 EC_KEY_get0_group(k->ecdsa))) != 0) 2962 goto out; 2963 if (k->type == KEY_ECDSA_SK_CERT) { 2964 if ((ret = sshbuf_put_cstring(cert, 2965 k->sk_application)) != 0) 2966 goto out; 2967 } 2968 break; 2969 # endif /* OPENSSL_HAS_ECC */ 2970 case KEY_RSA_CERT: 2971 RSA_get0_key(k->rsa, &rsa_n, &rsa_e, NULL); 2972 if ((ret = sshbuf_put_bignum2(cert, rsa_e)) != 0 || 2973 (ret = sshbuf_put_bignum2(cert, rsa_n)) != 0) 2974 goto out; 2975 break; 2976 #endif /* WITH_OPENSSL */ 2977 case KEY_ED25519_CERT: 2978 case KEY_ED25519_SK_CERT: 2979 if ((ret = sshbuf_put_string(cert, 2980 k->ed25519_pk, ED25519_PK_SZ)) != 0) 2981 goto out; 2982 if (k->type == KEY_ED25519_SK_CERT) { 2983 if ((ret = sshbuf_put_cstring(cert, 2984 k->sk_application)) != 0) 2985 goto out; 2986 } 2987 break; 2988 #ifdef WITH_XMSS 2989 case KEY_XMSS_CERT: 2990 if (k->xmss_name == NULL) { 2991 ret = SSH_ERR_INVALID_ARGUMENT; 2992 goto out; 2993 } 2994 if ((ret = sshbuf_put_cstring(cert, k->xmss_name)) || 2995 (ret = sshbuf_put_string(cert, 2996 k->xmss_pk, sshkey_xmss_pklen(k))) != 0) 2997 goto out; 2998 break; 2999 #endif /* WITH_XMSS */ 3000 default: 3001 ret = SSH_ERR_INVALID_ARGUMENT; 3002 goto out; 3003 } 3004 3005 if ((ret = sshbuf_put_u64(cert, k->cert->serial)) != 0 || 3006 (ret = sshbuf_put_u32(cert, k->cert->type)) != 0 || 3007 (ret = sshbuf_put_cstring(cert, k->cert->key_id)) != 0) 3008 goto out; 3009 3010 if ((principals = sshbuf_new()) == NULL) { 3011 ret = SSH_ERR_ALLOC_FAIL; 3012 goto out; 3013 } 3014 for (i = 0; i < k->cert->nprincipals; i++) { 3015 if ((ret = sshbuf_put_cstring(principals, 3016 k->cert->principals[i])) != 0) 3017 goto out; 3018 } 3019 if ((ret = sshbuf_put_stringb(cert, principals)) != 0 || 3020 (ret = sshbuf_put_u64(cert, k->cert->valid_after)) != 0 || 3021 (ret = sshbuf_put_u64(cert, k->cert->valid_before)) != 0 || 3022 (ret = sshbuf_put_stringb(cert, k->cert->critical)) != 0 || 3023 (ret = sshbuf_put_stringb(cert, k->cert->extensions)) != 0 || 3024 (ret = sshbuf_put_string(cert, NULL, 0)) != 0 || /* Reserved */ 3025 (ret = sshbuf_put_string(cert, ca_blob, ca_len)) != 0) 3026 goto out; 3027 3028 /* Sign the whole mess */ 3029 if ((ret = signer(ca, &sig_blob, &sig_len, sshbuf_ptr(cert), 3030 sshbuf_len(cert), alg, sk_provider, sk_pin, 0, signer_ctx)) != 0) 3031 goto out; 3032