1 /* $OpenBSD: sshkey.c,v 1.93 2019/11/15 06:00:20 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 <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 # endif /* OPENSSL_HAS_ECC */ 136 { "ssh-rsa-cert-v01@openssh.com", "RSA-CERT", NULL, 137 KEY_RSA_CERT, 0, 1, 0 }, 138 { "rsa-sha2-256-cert-v01@openssh.com", "RSA-CERT", 139 "rsa-sha2-256", KEY_RSA_CERT, 0, 1, 1 }, 140 { "rsa-sha2-512-cert-v01@openssh.com", "RSA-CERT", 141 "rsa-sha2-512", KEY_RSA_CERT, 0, 1, 1 }, 142 { "ssh-dss-cert-v01@openssh.com", "DSA-CERT", NULL, 143 KEY_DSA_CERT, 0, 1, 0 }, 144 # ifdef OPENSSL_HAS_ECC 145 { "ecdsa-sha2-nistp256-cert-v01@openssh.com", "ECDSA-CERT", NULL, 146 KEY_ECDSA_CERT, NID_X9_62_prime256v1, 1, 0 }, 147 { "ecdsa-sha2-nistp384-cert-v01@openssh.com", "ECDSA-CERT", NULL, 148 KEY_ECDSA_CERT, NID_secp384r1, 1, 0 }, 149 # ifdef OPENSSL_HAS_NISTP521 150 { "ecdsa-sha2-nistp521-cert-v01@openssh.com", "ECDSA-CERT", NULL, 151 KEY_ECDSA_CERT, NID_secp521r1, 1, 0 }, 152 # endif /* OPENSSL_HAS_NISTP521 */ 153 { "sk-ecdsa-sha2-nistp256-cert-v01@openssh.com", "ECDSA-SK-CERT", NULL, 154 KEY_ECDSA_SK_CERT, NID_X9_62_prime256v1, 1, 0 }, 155 # endif /* OPENSSL_HAS_ECC */ 156 #endif /* WITH_OPENSSL */ 157 { NULL, NULL, NULL, -1, -1, 0, 0 } 158 }; 159 160 const char * 161 sshkey_type(const struct sshkey *k) 162 { 163 const struct keytype *kt; 164 165 for (kt = keytypes; kt->type != -1; kt++) { 166 if (kt->type == k->type) 167 return kt->shortname; 168 } 169 return "unknown"; 170 } 171 172 static const char * 173 sshkey_ssh_name_from_type_nid(int type, int nid) 174 { 175 const struct keytype *kt; 176 177 for (kt = keytypes; kt->type != -1; kt++) { 178 if (kt->type == type && (kt->nid == 0 || kt->nid == nid)) 179 return kt->name; 180 } 181 return "ssh-unknown"; 182 } 183 184 int 185 sshkey_type_is_cert(int type) 186 { 187 const struct keytype *kt; 188 189 for (kt = keytypes; kt->type != -1; kt++) { 190 if (kt->type == type) 191 return kt->cert; 192 } 193 return 0; 194 } 195 196 const char * 197 sshkey_ssh_name(const struct sshkey *k) 198 { 199 return sshkey_ssh_name_from_type_nid(k->type, k->ecdsa_nid); 200 } 201 202 const char * 203 sshkey_ssh_name_plain(const struct sshkey *k) 204 { 205 return sshkey_ssh_name_from_type_nid(sshkey_type_plain(k->type), 206 k->ecdsa_nid); 207 } 208 209 int 210 sshkey_type_from_name(const char *name) 211 { 212 const struct keytype *kt; 213 214 for (kt = keytypes; kt->type != -1; kt++) { 215 /* Only allow shortname matches for plain key types */ 216 if ((kt->name != NULL && strcmp(name, kt->name) == 0) || 217 (!kt->cert && strcasecmp(kt->shortname, name) == 0)) 218 return kt->type; 219 } 220 return KEY_UNSPEC; 221 } 222 223 static int 224 key_type_is_ecdsa_variant(int type) 225 { 226 switch (type) { 227 case KEY_ECDSA: 228 case KEY_ECDSA_CERT: 229 case KEY_ECDSA_SK: 230 case KEY_ECDSA_SK_CERT: 231 return 1; 232 } 233 return 0; 234 } 235 236 int 237 sshkey_ecdsa_nid_from_name(const char *name) 238 { 239 const struct keytype *kt; 240 241 for (kt = keytypes; kt->type != -1; kt++) { 242 if (!key_type_is_ecdsa_variant(kt->type)) 243 continue; 244 if (kt->name != NULL && strcmp(name, kt->name) == 0) 245 return kt->nid; 246 } 247 return -1; 248 } 249 250 char * 251 sshkey_alg_list(int certs_only, int plain_only, int include_sigonly, char sep) 252 { 253 char *tmp, *ret = NULL; 254 size_t nlen, rlen = 0; 255 const struct keytype *kt; 256 257 for (kt = keytypes; kt->type != -1; kt++) { 258 if (kt->name == NULL) 259 continue; 260 if (!include_sigonly && kt->sigonly) 261 continue; 262 if ((certs_only && !kt->cert) || (plain_only && kt->cert)) 263 continue; 264 if (ret != NULL) 265 ret[rlen++] = sep; 266 nlen = strlen(kt->name); 267 if ((tmp = realloc(ret, rlen + nlen + 2)) == NULL) { 268 free(ret); 269 return NULL; 270 } 271 ret = tmp; 272 memcpy(ret + rlen, kt->name, nlen + 1); 273 rlen += nlen; 274 } 275 return ret; 276 } 277 278 int 279 sshkey_names_valid2(const char *names, int allow_wildcard) 280 { 281 char *s, *cp, *p; 282 const struct keytype *kt; 283 int type; 284 285 if (names == NULL || strcmp(names, "") == 0) 286 return 0; 287 if ((s = cp = strdup(names)) == NULL) 288 return 0; 289 for ((p = strsep(&cp, ",")); p && *p != '\0'; 290 (p = strsep(&cp, ","))) { 291 type = sshkey_type_from_name(p); 292 if (type == KEY_UNSPEC) { 293 if (allow_wildcard) { 294 /* 295 * Try matching key types against the string. 296 * If any has a positive or negative match then 297 * the component is accepted. 298 */ 299 for (kt = keytypes; kt->type != -1; kt++) { 300 if (match_pattern_list(kt->name, 301 p, 0) != 0) 302 break; 303 } 304 if (kt->type != -1) 305 continue; 306 } 307 free(s); 308 return 0; 309 } 310 } 311 free(s); 312 return 1; 313 } 314 315 u_int 316 sshkey_size(const struct sshkey *k) 317 { 318 #ifdef WITH_OPENSSL 319 const BIGNUM *rsa_n, *dsa_p; 320 #endif /* WITH_OPENSSL */ 321 322 switch (k->type) { 323 #ifdef WITH_OPENSSL 324 case KEY_RSA: 325 case KEY_RSA_CERT: 326 if (k->rsa == NULL) 327 return 0; 328 RSA_get0_key(k->rsa, &rsa_n, NULL, NULL); 329 return BN_num_bits(rsa_n); 330 case KEY_DSA: 331 case KEY_DSA_CERT: 332 if (k->dsa == NULL) 333 return 0; 334 DSA_get0_pqg(k->dsa, &dsa_p, NULL, NULL); 335 return BN_num_bits(dsa_p); 336 case KEY_ECDSA: 337 case KEY_ECDSA_CERT: 338 case KEY_ECDSA_SK: 339 case KEY_ECDSA_SK_CERT: 340 return sshkey_curve_nid_to_bits(k->ecdsa_nid); 341 #endif /* WITH_OPENSSL */ 342 case KEY_ED25519: 343 case KEY_ED25519_CERT: 344 case KEY_ED25519_SK: 345 case KEY_ED25519_SK_CERT: 346 case KEY_XMSS: 347 case KEY_XMSS_CERT: 348 return 256; /* XXX */ 349 } 350 return 0; 351 } 352 353 static int 354 sshkey_type_is_valid_ca(int type) 355 { 356 switch (type) { 357 case KEY_RSA: 358 case KEY_DSA: 359 case KEY_ECDSA: 360 case KEY_ECDSA_SK: 361 case KEY_ED25519: 362 case KEY_ED25519_SK: 363 case KEY_XMSS: 364 return 1; 365 default: 366 return 0; 367 } 368 } 369 370 int 371 sshkey_is_cert(const struct sshkey *k) 372 { 373 if (k == NULL) 374 return 0; 375 return sshkey_type_is_cert(k->type); 376 } 377 378 int 379 sshkey_is_sk(const struct sshkey *k) 380 { 381 if (k == NULL) 382 return 0; 383 switch (sshkey_type_plain(k->type)) { 384 case KEY_ECDSA_SK: 385 case KEY_ED25519_SK: 386 return 1; 387 default: 388 return 0; 389 } 390 } 391 392 /* Return the cert-less equivalent to a certified key type */ 393 int 394 sshkey_type_plain(int type) 395 { 396 switch (type) { 397 case KEY_RSA_CERT: 398 return KEY_RSA; 399 case KEY_DSA_CERT: 400 return KEY_DSA; 401 case KEY_ECDSA_CERT: 402 return KEY_ECDSA; 403 case KEY_ECDSA_SK_CERT: 404 return KEY_ECDSA_SK; 405 case KEY_ED25519_CERT: 406 return KEY_ED25519; 407 case KEY_ED25519_SK_CERT: 408 return KEY_ED25519_SK; 409 case KEY_XMSS_CERT: 410 return KEY_XMSS; 411 default: 412 return type; 413 } 414 } 415 416 #ifdef WITH_OPENSSL 417 /* XXX: these are really begging for a table-driven approach */ 418 int 419 sshkey_curve_name_to_nid(const char *name) 420 { 421 if (strcmp(name, "nistp256") == 0) 422 return NID_X9_62_prime256v1; 423 else if (strcmp(name, "nistp384") == 0) 424 return NID_secp384r1; 425 # ifdef OPENSSL_HAS_NISTP521 426 else if (strcmp(name, "nistp521") == 0) 427 return NID_secp521r1; 428 # endif /* OPENSSL_HAS_NISTP521 */ 429 else 430 return -1; 431 } 432 433 u_int 434 sshkey_curve_nid_to_bits(int nid) 435 { 436 switch (nid) { 437 case NID_X9_62_prime256v1: 438 return 256; 439 case NID_secp384r1: 440 return 384; 441 # ifdef OPENSSL_HAS_NISTP521 442 case NID_secp521r1: 443 return 521; 444 # endif /* OPENSSL_HAS_NISTP521 */ 445 default: 446 return 0; 447 } 448 } 449 450 int 451 sshkey_ecdsa_bits_to_nid(int bits) 452 { 453 switch (bits) { 454 case 256: 455 return NID_X9_62_prime256v1; 456 case 384: 457 return NID_secp384r1; 458 # ifdef OPENSSL_HAS_NISTP521 459 case 521: 460 return NID_secp521r1; 461 # endif /* OPENSSL_HAS_NISTP521 */ 462 default: 463 return -1; 464 } 465 } 466 467 const char * 468 sshkey_curve_nid_to_name(int nid) 469 { 470 switch (nid) { 471 case NID_X9_62_prime256v1: 472 return "nistp256"; 473 case NID_secp384r1: 474 return "nistp384"; 475 # ifdef OPENSSL_HAS_NISTP521 476 case NID_secp521r1: 477 return "nistp521"; 478 # endif /* OPENSSL_HAS_NISTP521 */ 479 default: 480 return NULL; 481 } 482 } 483 484 int 485 sshkey_ec_nid_to_hash_alg(int nid) 486 { 487 int kbits = sshkey_curve_nid_to_bits(nid); 488 489 if (kbits <= 0) 490 return -1; 491 492 /* RFC5656 section 6.2.1 */ 493 if (kbits <= 256) 494 return SSH_DIGEST_SHA256; 495 else if (kbits <= 384) 496 return SSH_DIGEST_SHA384; 497 else 498 return SSH_DIGEST_SHA512; 499 } 500 #endif /* WITH_OPENSSL */ 501 502 static void 503 cert_free(struct sshkey_cert *cert) 504 { 505 u_int i; 506 507 if (cert == NULL) 508 return; 509 sshbuf_free(cert->certblob); 510 sshbuf_free(cert->critical); 511 sshbuf_free(cert->extensions); 512 free(cert->key_id); 513 for (i = 0; i < cert->nprincipals; i++) 514 free(cert->principals[i]); 515 free(cert->principals); 516 sshkey_free(cert->signature_key); 517 free(cert->signature_type); 518 freezero(cert, sizeof(*cert)); 519 } 520 521 static struct sshkey_cert * 522 cert_new(void) 523 { 524 struct sshkey_cert *cert; 525 526 if ((cert = calloc(1, sizeof(*cert))) == NULL) 527 return NULL; 528 if ((cert->certblob = sshbuf_new()) == NULL || 529 (cert->critical = sshbuf_new()) == NULL || 530 (cert->extensions = sshbuf_new()) == NULL) { 531 cert_free(cert); 532 return NULL; 533 } 534 cert->key_id = NULL; 535 cert->principals = NULL; 536 cert->signature_key = NULL; 537 cert->signature_type = NULL; 538 return cert; 539 } 540 541 struct sshkey * 542 sshkey_new(int type) 543 { 544 struct sshkey *k; 545 #ifdef WITH_OPENSSL 546 RSA *rsa; 547 DSA *dsa; 548 #endif /* WITH_OPENSSL */ 549 550 if ((k = calloc(1, sizeof(*k))) == NULL) 551 return NULL; 552 k->type = type; 553 k->ecdsa = NULL; 554 k->ecdsa_nid = -1; 555 k->dsa = NULL; 556 k->rsa = NULL; 557 k->cert = NULL; 558 k->ed25519_sk = NULL; 559 k->ed25519_pk = NULL; 560 k->xmss_sk = NULL; 561 k->xmss_pk = NULL; 562 switch (k->type) { 563 #ifdef WITH_OPENSSL 564 case KEY_RSA: 565 case KEY_RSA_CERT: 566 if ((rsa = RSA_new()) == NULL) { 567 free(k); 568 return NULL; 569 } 570 k->rsa = rsa; 571 break; 572 case KEY_DSA: 573 case KEY_DSA_CERT: 574 if ((dsa = DSA_new()) == NULL) { 575 free(k); 576 return NULL; 577 } 578 k->dsa = dsa; 579 break; 580 case KEY_ECDSA: 581 case KEY_ECDSA_CERT: 582 case KEY_ECDSA_SK: 583 case KEY_ECDSA_SK_CERT: 584 /* Cannot do anything until we know the group */ 585 break; 586 #endif /* WITH_OPENSSL */ 587 case KEY_ED25519: 588 case KEY_ED25519_CERT: 589 case KEY_ED25519_SK: 590 case KEY_ED25519_SK_CERT: 591 case KEY_XMSS: 592 case KEY_XMSS_CERT: 593 /* no need to prealloc */ 594 break; 595 case KEY_UNSPEC: 596 break; 597 default: 598 free(k); 599 return NULL; 600 } 601 602 if (sshkey_is_cert(k)) { 603 if ((k->cert = cert_new()) == NULL) { 604 sshkey_free(k); 605 return NULL; 606 } 607 } 608 609 return k; 610 } 611 612 void 613 sshkey_free(struct sshkey *k) 614 { 615 if (k == NULL) 616 return; 617 switch (k->type) { 618 #ifdef WITH_OPENSSL 619 case KEY_RSA: 620 case KEY_RSA_CERT: 621 RSA_free(k->rsa); 622 k->rsa = NULL; 623 break; 624 case KEY_DSA: 625 case KEY_DSA_CERT: 626 DSA_free(k->dsa); 627 k->dsa = NULL; 628 break; 629 # ifdef OPENSSL_HAS_ECC 630 case KEY_ECDSA_SK: 631 case KEY_ECDSA_SK_CERT: 632 free(k->sk_application); 633 sshbuf_free(k->sk_key_handle); 634 sshbuf_free(k->sk_reserved); 635 /* FALLTHROUGH */ 636 case KEY_ECDSA: 637 case KEY_ECDSA_CERT: 638 EC_KEY_free(k->ecdsa); 639 k->ecdsa = NULL; 640 break; 641 # endif /* OPENSSL_HAS_ECC */ 642 #endif /* WITH_OPENSSL */ 643 case KEY_ED25519_SK: 644 case KEY_ED25519_SK_CERT: 645 free(k->sk_application); 646 sshbuf_free(k->sk_key_handle); 647 sshbuf_free(k->sk_reserved); 648 /* FALLTHROUGH */ 649 case KEY_ED25519: 650 case KEY_ED25519_CERT: 651 freezero(k->ed25519_pk, ED25519_PK_SZ); 652 k->ed25519_pk = NULL; 653 freezero(k->ed25519_sk, ED25519_SK_SZ); 654 k->ed25519_sk = NULL; 655 break; 656 #ifdef WITH_XMSS 657 case KEY_XMSS: 658 case KEY_XMSS_CERT: 659 freezero(k->xmss_pk, sshkey_xmss_pklen(k)); 660 k->xmss_pk = NULL; 661 freezero(k->xmss_sk, sshkey_xmss_sklen(k)); 662 k->xmss_sk = NULL; 663 sshkey_xmss_free_state(k); 664 free(k->xmss_name); 665 k->xmss_name = NULL; 666 free(k->xmss_filename); 667 k->xmss_filename = NULL; 668 break; 669 #endif /* WITH_XMSS */ 670 case KEY_UNSPEC: 671 break; 672 default: 673 break; 674 } 675 if (sshkey_is_cert(k)) 676 cert_free(k->cert); 677 freezero(k->shielded_private, k->shielded_len); 678 freezero(k->shield_prekey, k->shield_prekey_len); 679 freezero(k, sizeof(*k)); 680 } 681 682 static int 683 cert_compare(struct sshkey_cert *a, struct sshkey_cert *b) 684 { 685 if (a == NULL && b == NULL) 686 return 1; 687 if (a == NULL || b == NULL) 688 return 0; 689 if (sshbuf_len(a->certblob) != sshbuf_len(b->certblob)) 690 return 0; 691 if (timingsafe_bcmp(sshbuf_ptr(a->certblob), sshbuf_ptr(b->certblob), 692 sshbuf_len(a->certblob)) != 0) 693 return 0; 694 return 1; 695 } 696 697 /* 698 * Compare public portions of key only, allowing comparisons between 699 * certificates and plain keys too. 700 */ 701 int 702 sshkey_equal_public(const struct sshkey *a, const struct sshkey *b) 703 { 704 #if defined(WITH_OPENSSL) 705 const BIGNUM *rsa_e_a, *rsa_n_a; 706 const BIGNUM *rsa_e_b, *rsa_n_b; 707 const BIGNUM *dsa_p_a, *dsa_q_a, *dsa_g_a, *dsa_pub_key_a; 708 const BIGNUM *dsa_p_b, *dsa_q_b, *dsa_g_b, *dsa_pub_key_b; 709 #endif /* WITH_OPENSSL */ 710 711 if (a == NULL || b == NULL || 712 sshkey_type_plain(a->type) != sshkey_type_plain(b->type)) 713 return 0; 714 715 switch (a->type) { 716 #ifdef WITH_OPENSSL 717 case KEY_RSA_CERT: 718 case KEY_RSA: 719 if (a->rsa == NULL || b->rsa == NULL) 720 return 0; 721 RSA_get0_key(a->rsa, &rsa_n_a, &rsa_e_a, NULL); 722 RSA_get0_key(b->rsa, &rsa_n_b, &rsa_e_b, NULL); 723 return BN_cmp(rsa_e_a, rsa_e_b) == 0 && 724 BN_cmp(rsa_n_a, rsa_n_b) == 0; 725 case KEY_DSA_CERT: 726 case KEY_DSA: 727 if (a->dsa == NULL || b->dsa == NULL) 728 return 0; 729 DSA_get0_pqg(a->dsa, &dsa_p_a, &dsa_q_a, &dsa_g_a); 730 DSA_get0_pqg(b->dsa, &dsa_p_b, &dsa_q_b, &dsa_g_b); 731 DSA_get0_key(a->dsa, &dsa_pub_key_a, NULL); 732 DSA_get0_key(b->dsa, &dsa_pub_key_b, NULL); 733 return BN_cmp(dsa_p_a, dsa_p_b) == 0 && 734 BN_cmp(dsa_q_a, dsa_q_b) == 0 && 735 BN_cmp(dsa_g_a, dsa_g_b) == 0 && 736 BN_cmp(dsa_pub_key_a, dsa_pub_key_b) == 0; 737 # ifdef OPENSSL_HAS_ECC 738 case KEY_ECDSA_SK: 739 case KEY_ECDSA_SK_CERT: 740 if (a->sk_application == NULL || b->sk_application == NULL) 741 return 0; 742 if (strcmp(a->sk_application, b->sk_application) != 0) 743 return 0; 744 /* FALLTHROUGH */ 745 case KEY_ECDSA_CERT: 746 case KEY_ECDSA: 747 if (a->ecdsa == NULL || b->ecdsa == NULL || 748 EC_KEY_get0_public_key(a->ecdsa) == NULL || 749 EC_KEY_get0_public_key(b->ecdsa) == NULL) 750 return 0; 751 if (EC_GROUP_cmp(EC_KEY_get0_group(a->ecdsa), 752 EC_KEY_get0_group(b->ecdsa), NULL) != 0 || 753 EC_POINT_cmp(EC_KEY_get0_group(a->ecdsa), 754 EC_KEY_get0_public_key(a->ecdsa), 755 EC_KEY_get0_public_key(b->ecdsa), NULL) != 0) 756 return 0; 757 return 1; 758 # endif /* OPENSSL_HAS_ECC */ 759 #endif /* WITH_OPENSSL */ 760 case KEY_ED25519_SK: 761 case KEY_ED25519_SK_CERT: 762 if (a->sk_application == NULL || b->sk_application == NULL) 763 return 0; 764 if (strcmp(a->sk_application, b->sk_application) != 0) 765 return 0; 766 /* FALLTHROUGH */ 767 case KEY_ED25519: 768 case KEY_ED25519_CERT: 769 return a->ed25519_pk != NULL && b->ed25519_pk != NULL && 770 memcmp(a->ed25519_pk, b->ed25519_pk, ED25519_PK_SZ) == 0; 771 #ifdef WITH_XMSS 772 case KEY_XMSS: 773 case KEY_XMSS_CERT: 774 return a->xmss_pk != NULL && b->xmss_pk != NULL && 775 sshkey_xmss_pklen(a) == sshkey_xmss_pklen(b) && 776 memcmp(a->xmss_pk, b->xmss_pk, sshkey_xmss_pklen(a)) == 0; 777 #endif /* WITH_XMSS */ 778 default: 779 return 0; 780 } 781 /* NOTREACHED */ 782 } 783 784 int 785 sshkey_equal(const struct sshkey *a, const struct sshkey *b) 786 { 787 if (a == NULL || b == NULL || a->type != b->type) 788 return 0; 789 if (sshkey_is_cert(a)) { 790 if (!cert_compare(a->cert, b->cert)) 791 return 0; 792 } 793 return sshkey_equal_public(a, b); 794 } 795 796 static int 797 to_blob_buf(const struct sshkey *key, struct sshbuf *b, int force_plain, 798 enum sshkey_serialize_rep opts) 799 { 800 int type, ret = SSH_ERR_INTERNAL_ERROR; 801 const char *typename; 802 #ifdef WITH_OPENSSL 803 const BIGNUM *rsa_n, *rsa_e, *dsa_p, *dsa_q, *dsa_g, *dsa_pub_key; 804 #endif /* WITH_OPENSSL */ 805 806 if (key == NULL) 807 return SSH_ERR_INVALID_ARGUMENT; 808 809 if (sshkey_is_cert(key)) { 810 if (key->cert == NULL) 811 return SSH_ERR_EXPECTED_CERT; 812 if (sshbuf_len(key->cert->certblob) == 0) 813 return SSH_ERR_KEY_LACKS_CERTBLOB; 814 } 815 type = force_plain ? sshkey_type_plain(key->type) : key->type; 816 typename = sshkey_ssh_name_from_type_nid(type, key->ecdsa_nid); 817 818 switch (type) { 819 #ifdef WITH_OPENSSL 820 case KEY_DSA_CERT: 821 case KEY_ECDSA_CERT: 822 case KEY_ECDSA_SK_CERT: 823 case KEY_RSA_CERT: 824 #endif /* WITH_OPENSSL */ 825 case KEY_ED25519_CERT: 826 #ifdef WITH_XMSS 827 case KEY_XMSS_CERT: 828 #endif /* WITH_XMSS */ 829 /* Use the existing blob */ 830 /* XXX modified flag? */ 831 if ((ret = sshbuf_putb(b, key->cert->certblob)) != 0) 832 return ret; 833 break; 834 #ifdef WITH_OPENSSL 835 case KEY_DSA: 836 if (key->dsa == NULL) 837 return SSH_ERR_INVALID_ARGUMENT; 838 DSA_get0_pqg(key->dsa, &dsa_p, &dsa_q, &dsa_g); 839 DSA_get0_key(key->dsa, &dsa_pub_key, NULL); 840 if ((ret = sshbuf_put_cstring(b, typename)) != 0 || 841 (ret = sshbuf_put_bignum2(b, dsa_p)) != 0 || 842 (ret = sshbuf_put_bignum2(b, dsa_q)) != 0 || 843 (ret = sshbuf_put_bignum2(b, dsa_g)) != 0 || 844 (ret = sshbuf_put_bignum2(b, dsa_pub_key)) != 0) 845 return ret; 846 break; 847 # ifdef OPENSSL_HAS_ECC 848 case KEY_ECDSA: 849 case KEY_ECDSA_SK: 850 if (key->ecdsa == NULL) 851 return SSH_ERR_INVALID_ARGUMENT; 852 if ((ret = sshbuf_put_cstring(b, typename)) != 0 || 853 (ret = sshbuf_put_cstring(b, 854 sshkey_curve_nid_to_name(key->ecdsa_nid))) != 0 || 855 (ret = sshbuf_put_eckey(b, key->ecdsa)) != 0) 856 return ret; 857 if (type == KEY_ECDSA_SK) { 858 if ((ret = sshbuf_put_cstring(b, 859 key->sk_application)) != 0) 860 return ret; 861 } 862 break; 863 # endif 864 case KEY_RSA: 865 if (key->rsa == NULL) 866 return SSH_ERR_INVALID_ARGUMENT; 867 RSA_get0_key(key->rsa, &rsa_n, &rsa_e, NULL); 868 if ((ret = sshbuf_put_cstring(b, typename)) != 0 || 869 (ret = sshbuf_put_bignum2(b, rsa_e)) != 0 || 870 (ret = sshbuf_put_bignum2(b, rsa_n)) != 0) 871 return ret; 872 break; 873 #endif /* WITH_OPENSSL */ 874 case KEY_ED25519: 875 case KEY_ED25519_SK: 876 if (key->ed25519_pk == NULL) 877 return SSH_ERR_INVALID_ARGUMENT; 878 if ((ret = sshbuf_put_cstring(b, typename)) != 0 || 879 (ret = sshbuf_put_string(b, 880 key->ed25519_pk, ED25519_PK_SZ)) != 0) 881 return ret; 882 if (type == KEY_ED25519_SK) { 883 if ((ret = sshbuf_put_cstring(b, 884 key->sk_application)) != 0) 885 return ret; 886 } 887 break; 888 #ifdef WITH_XMSS 889 case KEY_XMSS: 890 if (key->xmss_name == NULL || key->xmss_pk == NULL || 891 sshkey_xmss_pklen(key) == 0) 892 return SSH_ERR_INVALID_ARGUMENT; 893 if ((ret = sshbuf_put_cstring(b, typename)) != 0 || 894 (ret = sshbuf_put_cstring(b, key->xmss_name)) != 0 || 895 (ret = sshbuf_put_string(b, 896 key->xmss_pk, sshkey_xmss_pklen(key))) != 0 || 897 (ret = sshkey_xmss_serialize_pk_info(key, b, opts)) != 0) 898 return ret; 899 break; 900 #endif /* WITH_XMSS */ 901 default: 902 return SSH_ERR_KEY_TYPE_UNKNOWN; 903 } 904 return 0; 905 } 906 907 int 908 sshkey_putb(const struct sshkey *key, struct sshbuf *b) 909 { 910 return to_blob_buf(key, b, 0, SSHKEY_SERIALIZE_DEFAULT); 911 } 912 913 int 914 sshkey_puts_opts(const struct sshkey *key, struct sshbuf *b, 915 enum sshkey_serialize_rep opts) 916 { 917 struct sshbuf *tmp; 918 int r; 919 920 if ((tmp = sshbuf_new()) == NULL) 921 return SSH_ERR_ALLOC_FAIL; 922 r = to_blob_buf(key, tmp, 0, opts); 923 if (r == 0) 924 r = sshbuf_put_stringb(b, tmp); 925 sshbuf_free(tmp); 926 return r; 927 } 928 929 int 930 sshkey_puts(const struct sshkey *key, struct sshbuf *b) 931 { 932 return sshkey_puts_opts(key, b, SSHKEY_SERIALIZE_DEFAULT); 933 } 934 935 int 936 sshkey_putb_plain(const struct sshkey *key, struct sshbuf *b) 937 { 938 return to_blob_buf(key, b, 1, SSHKEY_SERIALIZE_DEFAULT); 939 } 940 941 static int 942 to_blob(const struct sshkey *key, u_char **blobp, size_t *lenp, int force_plain, 943 enum sshkey_serialize_rep opts) 944 { 945 int ret = SSH_ERR_INTERNAL_ERROR; 946 size_t len; 947 struct sshbuf *b = NULL; 948 949 if (lenp != NULL) 950 *lenp = 0; 951 if (blobp != NULL) 952 *blobp = NULL; 953 if ((b = sshbuf_new()) == NULL) 954 return SSH_ERR_ALLOC_FAIL; 955 if ((ret = to_blob_buf(key, b, force_plain, opts)) != 0) 956 goto out; 957 len = sshbuf_len(b); 958 if (lenp != NULL) 959 *lenp = len; 960 if (blobp != NULL) { 961 if ((*blobp = malloc(len)) == NULL) { 962 ret = SSH_ERR_ALLOC_FAIL; 963 goto out; 964 } 965 memcpy(*blobp, sshbuf_ptr(b), len); 966 } 967 ret = 0; 968 out: 969 sshbuf_free(b); 970 return ret; 971 } 972 973 int 974 sshkey_to_blob(const struct sshkey *key, u_char **blobp, size_t *lenp) 975 { 976 return to_blob(key, blobp, lenp, 0, SSHKEY_SERIALIZE_DEFAULT); 977 } 978 979 int 980 sshkey_plain_to_blob(const struct sshkey *key, u_char **blobp, size_t *lenp) 981 { 982 return to_blob(key, blobp, lenp, 1, SSHKEY_SERIALIZE_DEFAULT); 983 } 984 985 int 986 sshkey_fingerprint_raw(const struct sshkey *k, int dgst_alg, 987 u_char **retp, size_t *lenp) 988 { 989 u_char *blob = NULL, *ret = NULL; 990 size_t blob_len = 0; 991 int r = SSH_ERR_INTERNAL_ERROR; 992 993 if (retp != NULL) 994 *retp = NULL; 995 if (lenp != NULL) 996 *lenp = 0; 997 if (ssh_digest_bytes(dgst_alg) == 0) { 998 r = SSH_ERR_INVALID_ARGUMENT; 999 goto out; 1000 } 1001 if ((r = to_blob(k, &blob, &blob_len, 1, SSHKEY_SERIALIZE_DEFAULT)) 1002 != 0) 1003 goto out; 1004 if ((ret = calloc(1, SSH_DIGEST_MAX_LENGTH)) == NULL) { 1005 r = SSH_ERR_ALLOC_FAIL; 1006 goto out; 1007 } 1008 if ((r = ssh_digest_memory(dgst_alg, blob, blob_len, 1009 ret, SSH_DIGEST_MAX_LENGTH)) != 0) 1010 goto out; 1011 /* success */ 1012 if (retp != NULL) { 1013 *retp = ret; 1014 ret = NULL; 1015 } 1016 if (lenp != NULL) 1017 *lenp = ssh_digest_bytes(dgst_alg); 1018 r = 0; 1019 out: 1020 free(ret); 1021 if (blob != NULL) { 1022 explicit_bzero(blob, blob_len); 1023 free(blob); 1024 } 1025 return r; 1026 } 1027 1028 static char * 1029 fingerprint_b64(const char *alg, u_char *dgst_raw, size_t dgst_raw_len) 1030 { 1031 char *ret; 1032 size_t plen = strlen(alg) + 1; 1033 size_t rlen = ((dgst_raw_len + 2) / 3) * 4 + plen + 1; 1034 1035 if (dgst_raw_len > 65536 || (ret = calloc(1, rlen)) == NULL) 1036 return NULL; 1037 strlcpy(ret, alg, rlen); 1038 strlcat(ret, ":", rlen); 1039 if (dgst_raw_len == 0) 1040 return ret; 1041 if (b64_ntop(dgst_raw, dgst_raw_len, ret + plen, rlen - plen) == -1) { 1042 freezero(ret, rlen); 1043 return NULL; 1044 } 1045 /* Trim padding characters from end */ 1046 ret[strcspn(ret, "=")] = '\0'; 1047 return ret; 1048 } 1049 1050 static char * 1051 fingerprint_hex(const char *alg, u_char *dgst_raw, size_t dgst_raw_len) 1052 { 1053 char *retval, hex[5]; 1054 size_t i, rlen = dgst_raw_len * 3 + strlen(alg) + 2; 1055 1056 if (dgst_raw_len > 65536 || (retval = calloc(1, rlen)) == NULL) 1057 return NULL; 1058 strlcpy(retval, alg, rlen); 1059 strlcat(retval, ":", rlen); 1060 for (i = 0; i < dgst_raw_len; i++) { 1061 snprintf(hex, sizeof(hex), "%s%02x", 1062 i > 0 ? ":" : "", dgst_raw[i]); 1063 strlcat(retval, hex, rlen); 1064 } 1065 return retval; 1066 } 1067 1068 static char * 1069 fingerprint_bubblebabble(u_char *dgst_raw, size_t dgst_raw_len) 1070 { 1071 char vowels[] = { 'a', 'e', 'i', 'o', 'u', 'y' }; 1072 char consonants[] = { 'b', 'c', 'd', 'f', 'g', 'h', 'k', 'l', 'm', 1073 'n', 'p', 'r', 's', 't', 'v', 'z', 'x' }; 1074 u_int i, j = 0, rounds, seed = 1; 1075 char *retval; 1076 1077 rounds = (dgst_raw_len / 2) + 1; 1078 if ((retval = calloc(rounds, 6)) == NULL) 1079 return NULL; 1080 retval[j++] = 'x'; 1081 for (i = 0; i < rounds; i++) { 1082 u_int idx0, idx1, idx2, idx3, idx4; 1083 if ((i + 1 < rounds) || (dgst_raw_len % 2 != 0)) { 1084 idx0 = (((((u_int)(dgst_raw[2 * i])) >> 6) & 3) + 1085 seed) % 6; 1086 idx1 = (((u_int)(dgst_raw[2 * i])) >> 2) & 15; 1087 idx2 = ((((u_int)(dgst_raw[2 * i])) & 3) + 1088 (seed / 6)) % 6; 1089 retval[j++] = vowels[idx0]; 1090 retval[j++] = consonants[idx1]; 1091 retval[j++] = vowels[idx2]; 1092 if ((i + 1) < rounds) { 1093 idx3 = (((u_int)(dgst_raw[(2 * i) + 1])) >> 4) & 15; 1094 idx4 = (((u_int)(dgst_raw[(2 * i) + 1]))) & 15; 1095 retval[j++] = consonants[idx3]; 1096 retval[j++] = '-'; 1097 retval[j++] = consonants[idx4]; 1098 seed = ((seed * 5) + 1099 ((((u_int)(dgst_raw[2 * i])) * 7) + 1100 ((u_int)(dgst_raw[(2 * i) + 1])))) % 36; 1101 } 1102 } else { 1103 idx0 = seed % 6; 1104 idx1 = 16; 1105 idx2 = seed / 6; 1106 retval[j++] = vowels[idx0]; 1107 retval[j++] = consonants[idx1]; 1108 retval[j++] = vowels[idx2]; 1109 } 1110 } 1111 retval[j++] = 'x'; 1112 retval[j++] = '\0'; 1113 return retval; 1114 } 1115 1116 /* 1117 * Draw an ASCII-Art representing the fingerprint so human brain can 1118 * profit from its built-in pattern recognition ability. 1119 * This technique is called "random art" and can be found in some 1120 * scientific publications like this original paper: 1121 * 1122 * "Hash Visualization: a New Technique to improve Real-World Security", 1123 * Perrig A. and Song D., 1999, International Workshop on Cryptographic 1124 * Techniques and E-Commerce (CrypTEC '99) 1125 * sparrow.ece.cmu.edu/~adrian/projects/validation/validation.pdf 1126 * 1127 * The subject came up in a talk by Dan Kaminsky, too. 1128 * 1129 * If you see the picture is different, the key is different. 1130 * If the picture looks the same, you still know nothing. 1131 * 1132 * The algorithm used here is a worm crawling over a discrete plane, 1133 * leaving a trace (augmenting the field) everywhere it goes. 1134 * Movement is taken from dgst_raw 2bit-wise. Bumping into walls 1135 * makes the respective movement vector be ignored for this turn. 1136 * Graphs are not unambiguous, because circles in graphs can be 1137 * walked in either direction. 1138 */ 1139 1140 /* 1141 * Field sizes for the random art. Have to be odd, so the starting point 1142 * can be in the exact middle of the picture, and FLDBASE should be >=8 . 1143 * Else pictures would be too dense, and drawing the frame would 1144 * fail, too, because the key type would not fit in anymore. 1145 */ 1146 #define FLDBASE 8 1147 #define FLDSIZE_Y (FLDBASE + 1) 1148 #define FLDSIZE_X (FLDBASE * 2 + 1) 1149 static char * 1150 fingerprint_randomart(const char *alg, u_char *dgst_raw, size_t dgst_raw_len, 1151 const struct sshkey *k) 1152 { 1153 /* 1154 * Chars to be used after each other every time the worm 1155 * intersects with itself. Matter of taste. 1156 */ 1157 char *augmentation_string = " .o+=*BOX@%&#/^SE"; 1158 char *retval, *p, title[FLDSIZE_X], hash[FLDSIZE_X]; 1159 u_char field[FLDSIZE_X][FLDSIZE_Y]; 1160 size_t i, tlen, hlen; 1161 u_int b; 1162 int x, y, r; 1163 size_t len = strlen(augmentation_string) - 1; 1164 1165 if ((retval = calloc((FLDSIZE_X + 3), (FLDSIZE_Y + 2))) == NULL) 1166 return NULL; 1167 1168 /* initialize field */ 1169 memset(field, 0, FLDSIZE_X * FLDSIZE_Y * sizeof(char)); 1170 x = FLDSIZE_X / 2; 1171 y = FLDSIZE_Y / 2; 1172 1173 /* process raw key */ 1174 for (i = 0; i < dgst_raw_len; i++) { 1175 int input; 1176 /* each byte conveys four 2-bit move commands */ 1177 input = dgst_raw[i]; 1178 for (b = 0; b < 4; b++) { 1179 /* evaluate 2 bit, rest is shifted later */ 1180 x += (input & 0x1) ? 1 : -1; 1181 y += (input & 0x2) ? 1 : -1; 1182 1183 /* assure we are still in bounds */ 1184 x = MAXIMUM(x, 0); 1185 y = MAXIMUM(y, 0); 1186 x = MINIMUM(x, FLDSIZE_X - 1); 1187 y = MINIMUM(y, FLDSIZE_Y - 1); 1188 1189 /* augment the field */ 1190 if (field[x][y] < len - 2) 1191 field[x][y]++; 1192 input = input >> 2; 1193 } 1194 } 1195 1196 /* mark starting point and end point*/ 1197 field[FLDSIZE_X / 2][FLDSIZE_Y / 2] = len - 1; 1198 field[x][y] = len; 1199 1200 /* assemble title */ 1201 r = snprintf(title, sizeof(title), "[%s %u]", 1202 sshkey_type(k), sshkey_size(k)); 1203 /* If [type size] won't fit, then try [type]; fits "[ED25519-CERT]" */ 1204 if (r < 0 || r > (int)sizeof(title)) 1205 r = snprintf(title, sizeof(title), "[%s]", sshkey_type(k)); 1206 tlen = (r <= 0) ? 0 : strlen(title); 1207 1208 /* assemble hash ID. */ 1209 r = snprintf(hash, sizeof(hash), "[%s]", alg); 1210 hlen = (r <= 0) ? 0 : strlen(hash); 1211 1212 /* output upper border */ 1213 p = retval; 1214 *p++ = '+'; 1215 for (i = 0; i < (FLDSIZE_X - tlen) / 2; i++) 1216 *p++ = '-'; 1217 memcpy(p, title, tlen); 1218 p += tlen; 1219 for (i += tlen; i < FLDSIZE_X; i++) 1220 *p++ = '-'; 1221 *p++ = '+'; 1222 *p++ = '\n'; 1223 1224 /* output content */ 1225 for (y = 0; y < FLDSIZE_Y; y++) { 1226 *p++ = '|'; 1227 for (x = 0; x < FLDSIZE_X; x++) 1228 *p++ = augmentation_string[MINIMUM(field[x][y], len)]; 1229 *p++ = '|'; 1230 *p++ = '\n'; 1231 } 1232 1233 /* output lower border */ 1234 *p++ = '+'; 1235 for (i = 0; i < (FLDSIZE_X - hlen) / 2; i++) 1236 *p++ = '-'; 1237 memcpy(p, hash, hlen); 1238 p += hlen; 1239 for (i += hlen; i < FLDSIZE_X; i++) 1240 *p++ = '-'; 1241 *p++ = '+'; 1242 1243 return retval; 1244 } 1245 1246 char * 1247 sshkey_fingerprint(const struct sshkey *k, int dgst_alg, 1248 enum sshkey_fp_rep dgst_rep) 1249 { 1250 char *retval = NULL; 1251 u_char *dgst_raw; 1252 size_t dgst_raw_len; 1253 1254 if (sshkey_fingerprint_raw(k, dgst_alg, &dgst_raw, &dgst_raw_len) != 0) 1255 return NULL; 1256 switch (dgst_rep) { 1257 case SSH_FP_DEFAULT: 1258 if (dgst_alg == SSH_DIGEST_MD5) { 1259 retval = fingerprint_hex(ssh_digest_alg_name(dgst_alg), 1260 dgst_raw, dgst_raw_len); 1261 } else { 1262 retval = fingerprint_b64(ssh_digest_alg_name(dgst_alg), 1263 dgst_raw, dgst_raw_len); 1264 } 1265 break; 1266 case SSH_FP_HEX: 1267 retval = fingerprint_hex(ssh_digest_alg_name(dgst_alg), 1268 dgst_raw, dgst_raw_len); 1269 break; 1270 case SSH_FP_BASE64: 1271 retval = fingerprint_b64(ssh_digest_alg_name(dgst_alg), 1272 dgst_raw, dgst_raw_len); 1273 break; 1274 case SSH_FP_BUBBLEBABBLE: 1275 retval = fingerprint_bubblebabble(dgst_raw, dgst_raw_len); 1276 break; 1277 case SSH_FP_RANDOMART: 1278 retval = fingerprint_randomart(ssh_digest_alg_name(dgst_alg), 1279 dgst_raw, dgst_raw_len, k); 1280 break; 1281 default: 1282 explicit_bzero(dgst_raw, dgst_raw_len); 1283 free(dgst_raw); 1284 return NULL; 1285 } 1286 explicit_bzero(dgst_raw, dgst_raw_len); 1287 free(dgst_raw); 1288 return retval; 1289 } 1290 1291 static int 1292 peek_type_nid(const char *s, size_t l, int *nid) 1293 { 1294 const struct keytype *kt; 1295 1296 for (kt = keytypes; kt->type != -1; kt++) { 1297 if (kt->name == NULL || strlen(kt->name) != l) 1298 continue; 1299 if (memcmp(s, kt->name, l) == 0) { 1300 *nid = -1; 1301 if (key_type_is_ecdsa_variant(kt->type)) 1302 *nid = kt->nid; 1303 return kt->type; 1304 } 1305 } 1306 return KEY_UNSPEC; 1307 } 1308 1309 /* XXX this can now be made const char * */ 1310 int 1311 sshkey_read(struct sshkey *ret, char **cpp) 1312 { 1313 struct sshkey *k; 1314 char *cp, *blobcopy; 1315 size_t space; 1316 int r, type, curve_nid = -1; 1317 struct sshbuf *blob; 1318 1319 if (ret == NULL) 1320 return SSH_ERR_INVALID_ARGUMENT; 1321 1322 switch (ret->type) { 1323 case KEY_UNSPEC: 1324 case KEY_RSA: 1325 case KEY_DSA: 1326 case KEY_ECDSA: 1327 case KEY_ECDSA_SK: 1328 case KEY_ED25519: 1329 case KEY_ED25519_SK: 1330 case KEY_DSA_CERT: 1331 case KEY_ECDSA_CERT: 1332 case KEY_ECDSA_SK_CERT: 1333 case KEY_RSA_CERT: 1334 case KEY_ED25519_CERT: 1335 case KEY_ED25519_SK_CERT: 1336 #ifdef WITH_XMSS 1337 case KEY_XMSS: 1338 case KEY_XMSS_CERT: 1339 #endif /* WITH_XMSS */ 1340 break; /* ok */ 1341 default: 1342 return SSH_ERR_INVALID_ARGUMENT; 1343 } 1344 1345 /* Decode type */ 1346 cp = *cpp; 1347 space = strcspn(cp, " \t"); 1348 if (space == strlen(cp)) 1349 return SSH_ERR_INVALID_FORMAT; 1350 if ((type = peek_type_nid(cp, space, &curve_nid)) == KEY_UNSPEC) 1351 return SSH_ERR_INVALID_FORMAT; 1352 1353 /* skip whitespace */ 1354 for (cp += space; *cp == ' ' || *cp == '\t'; cp++) 1355 ; 1356 if (*cp == '\0') 1357 return SSH_ERR_INVALID_FORMAT; 1358 if (ret->type != KEY_UNSPEC && ret->type != type) 1359 return SSH_ERR_KEY_TYPE_MISMATCH; 1360 if ((blob = sshbuf_new()) == NULL) 1361 return SSH_ERR_ALLOC_FAIL; 1362 1363 /* find end of keyblob and decode */ 1364 space = strcspn(cp, " \t"); 1365 if ((blobcopy = strndup(cp, space)) == NULL) { 1366 sshbuf_free(blob); 1367 return SSH_ERR_ALLOC_FAIL; 1368 } 1369 if ((r = sshbuf_b64tod(blob, blobcopy)) != 0) { 1370 free(blobcopy); 1371 sshbuf_free(blob); 1372 return r; 1373 } 1374 free(blobcopy); 1375 if ((r = sshkey_fromb(blob, &k)) != 0) { 1376 sshbuf_free(blob); 1377 return r; 1378 } 1379 sshbuf_free(blob); 1380 1381 /* skip whitespace and leave cp at start of comment */ 1382 for (cp += space; *cp == ' ' || *cp == '\t'; cp++) 1383 ; 1384 1385 /* ensure type of blob matches type at start of line */ 1386 if (k->type != type) { 1387 sshkey_free(k); 1388 return SSH_ERR_KEY_TYPE_MISMATCH; 1389 } 1390 if (key_type_is_ecdsa_variant(type) && curve_nid != k->ecdsa_nid) { 1391 sshkey_free(k); 1392 return SSH_ERR_EC_CURVE_MISMATCH; 1393 } 1394 1395 /* Fill in ret from parsed key */ 1396 ret->type = type; 1397 if (sshkey_is_cert(ret)) { 1398 if (!sshkey_is_cert(k)) { 1399 sshkey_free(k); 1400 return SSH_ERR_EXPECTED_CERT; 1401 } 1402 if (ret->cert != NULL) 1403 cert_free(ret->cert); 1404 ret->cert = k->cert; 1405 k->cert = NULL; 1406 } 1407 switch (sshkey_type_plain(ret->type)) { 1408 #ifdef WITH_OPENSSL 1409 case KEY_RSA: 1410 RSA_free(ret->rsa); 1411 ret->rsa = k->rsa; 1412 k->rsa = NULL; 1413 #ifdef DEBUG_PK 1414 RSA_print_fp(stderr, ret->rsa, 8); 1415 #endif 1416 break; 1417 case KEY_DSA: 1418 DSA_free(ret->dsa); 1419 ret->dsa = k->dsa; 1420 k->dsa = NULL; 1421 #ifdef DEBUG_PK 1422 DSA_print_fp(stderr, ret->dsa, 8); 1423 #endif 1424 break; 1425 # ifdef OPENSSL_HAS_ECC 1426 case KEY_ECDSA: 1427 EC_KEY_free(ret->ecdsa); 1428 ret->ecdsa = k->ecdsa; 1429 ret->ecdsa_nid = k->ecdsa_nid; 1430 k->ecdsa = NULL; 1431 k->ecdsa_nid = -1; 1432 #ifdef DEBUG_PK 1433 sshkey_dump_ec_key(ret->ecdsa); 1434 #endif 1435 break; 1436 case KEY_ECDSA_SK: 1437 EC_KEY_free(ret->ecdsa); 1438 ret->ecdsa = k->ecdsa; 1439 ret->ecdsa_nid = k->ecdsa_nid; 1440 ret->sk_application = k->sk_application; 1441 k->ecdsa = NULL; 1442 k->ecdsa_nid = -1; 1443 k->sk_application = NULL; 1444 #ifdef DEBUG_PK 1445 sshkey_dump_ec_key(ret->ecdsa); 1446 fprintf(stderr, "App: %s\n", ret->sk_application); 1447 #endif 1448 break; 1449 # endif /* OPENSSL_HAS_ECC */ 1450 #endif /* WITH_OPENSSL */ 1451 case KEY_ED25519: 1452 freezero(ret->ed25519_pk, ED25519_PK_SZ); 1453 ret->ed25519_pk = k->ed25519_pk; 1454 k->ed25519_pk = NULL; 1455 #ifdef DEBUG_PK 1456 /* XXX */ 1457 #endif 1458 break; 1459 case KEY_ED25519_SK: 1460 freezero(ret->ed25519_pk, ED25519_PK_SZ); 1461 ret->ed25519_pk = k->ed25519_pk; 1462 ret->sk_application = k->sk_application; 1463 k->ed25519_pk = NULL; 1464 k->sk_application = NULL; 1465 break; 1466 #ifdef WITH_XMSS 1467 case KEY_XMSS: 1468 free(ret->xmss_pk); 1469 ret->xmss_pk = k->xmss_pk; 1470 k->xmss_pk = NULL; 1471 free(ret->xmss_state); 1472 ret->xmss_state = k->xmss_state; 1473 k->xmss_state = NULL; 1474 free(ret->xmss_name); 1475 ret->xmss_name = k->xmss_name; 1476 k->xmss_name = NULL; 1477 free(ret->xmss_filename); 1478 ret->xmss_filename = k->xmss_filename; 1479 k->xmss_filename = NULL; 1480 #ifdef DEBUG_PK 1481 /* XXX */ 1482 #endif 1483 break; 1484 #endif /* WITH_XMSS */ 1485 default: 1486 sshkey_free(k); 1487 return SSH_ERR_INTERNAL_ERROR; 1488 } 1489 sshkey_free(k); 1490 1491 /* success */ 1492 *cpp = cp; 1493 return 0; 1494 } 1495 1496 1497 int 1498 sshkey_to_base64(const struct sshkey *key, char **b64p) 1499 { 1500 int r = SSH_ERR_INTERNAL_ERROR; 1501 struct sshbuf *b = NULL; 1502 char *uu = NULL; 1503 1504 if (b64p != NULL) 1505 *b64p = NULL; 1506 if ((b = sshbuf_new()) == NULL) 1507 return SSH_ERR_ALLOC_FAIL; 1508 if ((r = sshkey_putb(key, b)) != 0) 1509 goto out; 1510 if ((uu = sshbuf_dtob64_string(b, 0)) == NULL) { 1511 r = SSH_ERR_ALLOC_FAIL; 1512 goto out; 1513 } 1514 /* Success */ 1515 if (b64p != NULL) { 1516 *b64p = uu; 1517 uu = NULL; 1518 } 1519 r = 0; 1520 out: 1521 sshbuf_free(b); 1522 free(uu); 1523 return r; 1524 } 1525 1526 int 1527 sshkey_format_text(const struct sshkey *key, struct sshbuf *b) 1528 { 1529 int r = SSH_ERR_INTERNAL_ERROR; 1530 char *uu = NULL; 1531 1532 if ((r = sshkey_to_base64(key, &uu)) != 0) 1533 goto out; 1534 if ((r = sshbuf_putf(b, "%s %s", 1535 sshkey_ssh_name(key), uu)) != 0) 1536 goto out; 1537 r = 0; 1538 out: 1539 free(uu); 1540 return r; 1541 } 1542 1543 int 1544 sshkey_write(const struct sshkey *key, FILE *f) 1545 { 1546 struct sshbuf *b = NULL; 1547 int r = SSH_ERR_INTERNAL_ERROR; 1548 1549 if ((b = sshbuf_new()) == NULL) 1550 return SSH_ERR_ALLOC_FAIL; 1551 if ((r = sshkey_format_text(key, b)) != 0) 1552 goto out; 1553 if (fwrite(sshbuf_ptr(b), sshbuf_len(b), 1, f) != 1) { 1554 if (feof(f)) 1555 errno = EPIPE; 1556 r = SSH_ERR_SYSTEM_ERROR; 1557 goto out; 1558 } 1559 /* Success */ 1560 r = 0; 1561 out: 1562 sshbuf_free(b); 1563 return r; 1564 } 1565 1566 const char * 1567 sshkey_cert_type(const struct sshkey *k) 1568 { 1569 switch (k->cert->type) { 1570 case SSH2_CERT_TYPE_USER: 1571 return "user"; 1572 case SSH2_CERT_TYPE_HOST: 1573 return "host"; 1574 default: 1575 return "unknown"; 1576 } 1577 } 1578 1579 #ifdef WITH_OPENSSL 1580 static int 1581 rsa_generate_private_key(u_int bits, RSA **rsap) 1582 { 1583 RSA *private = NULL; 1584 BIGNUM *f4 = NULL; 1585 int ret = SSH_ERR_INTERNAL_ERROR; 1586 1587 if (rsap == NULL) 1588 return SSH_ERR_INVALID_ARGUMENT; 1589 if (bits < SSH_RSA_MINIMUM_MODULUS_SIZE || 1590 bits > SSHBUF_MAX_BIGNUM * 8) 1591 return SSH_ERR_KEY_LENGTH; 1592 *rsap = NULL; 1593 if ((private = RSA_new()) == NULL || (f4 = BN_new()) == NULL) { 1594 ret = SSH_ERR_ALLOC_FAIL; 1595 goto out; 1596 } 1597 if (!BN_set_word(f4, RSA_F4) || 1598 !RSA_generate_key_ex(private, bits, f4, NULL)) { 1599 ret = SSH_ERR_LIBCRYPTO_ERROR; 1600 goto out; 1601 } 1602 *rsap = private; 1603 private = NULL; 1604 ret = 0; 1605 out: 1606 RSA_free(private); 1607 BN_free(f4); 1608 return ret; 1609 } 1610 1611 static int 1612 dsa_generate_private_key(u_int bits, DSA **dsap) 1613 { 1614 DSA *private; 1615 int ret = SSH_ERR_INTERNAL_ERROR; 1616 1617 if (dsap == NULL) 1618 return SSH_ERR_INVALID_ARGUMENT; 1619 if (bits != 1024) 1620 return SSH_ERR_KEY_LENGTH; 1621 if ((private = DSA_new()) == NULL) { 1622 ret = SSH_ERR_ALLOC_FAIL; 1623 goto out; 1624 } 1625 *dsap = NULL; 1626 if (!DSA_generate_parameters_ex(private, bits, NULL, 0, NULL, 1627 NULL, NULL) || !DSA_generate_key(private)) { 1628 ret = SSH_ERR_LIBCRYPTO_ERROR; 1629 goto out; 1630 } 1631 *dsap = private; 1632 private = NULL; 1633 ret = 0; 1634 out: 1635 DSA_free(private); 1636 return ret; 1637 } 1638 1639 # ifdef OPENSSL_HAS_ECC 1640 int 1641 sshkey_ecdsa_key_to_nid(EC_KEY *k) 1642 { 1643 EC_GROUP *eg; 1644 int nids[] = { 1645 NID_X9_62_prime256v1, 1646 NID_secp384r1, 1647 # ifdef OPENSSL_HAS_NISTP521 1648 NID_secp521r1, 1649 # endif /* OPENSSL_HAS_NISTP521 */ 1650 -1 1651 }; 1652 int nid; 1653 u_int i; 1654 const EC_GROUP *g = EC_KEY_get0_group(k); 1655 1656 /* 1657 * The group may be stored in a ASN.1 encoded private key in one of two 1658 * ways: as a "named group", which is reconstituted by ASN.1 object ID 1659 * or explicit group parameters encoded into the key blob. Only the 1660 * "named group" case sets the group NID for us, but we can figure 1661 * it out for the other case by comparing against all the groups that 1662 * are supported. 1663 */ 1664 if ((nid = EC_GROUP_get_curve_name(g)) > 0) 1665 return nid; 1666 for (i = 0; nids[i] != -1; i++) { 1667 if ((eg = EC_GROUP_new_by_curve_name(nids[i])) == NULL) 1668 return -1; 1669 if (EC_GROUP_cmp(g, eg, NULL) == 0) 1670 break; 1671 EC_GROUP_free(eg); 1672 } 1673 if (nids[i] != -1) { 1674 /* Use the group with the NID attached */ 1675 EC_GROUP_set_asn1_flag(eg, OPENSSL_EC_NAMED_CURVE); 1676 if (EC_KEY_set_group(k, eg) != 1) { 1677 EC_GROUP_free(eg); 1678 return -1; 1679 } 1680 } 1681 return nids[i]; 1682 } 1683 1684 static int 1685 ecdsa_generate_private_key(u_int bits, int *nid, EC_KEY **ecdsap) 1686 { 1687 EC_KEY *private; 1688 int ret = SSH_ERR_INTERNAL_ERROR; 1689 1690 if (nid == NULL || ecdsap == NULL) 1691 return SSH_ERR_INVALID_ARGUMENT; 1692 if ((*nid = sshkey_ecdsa_bits_to_nid(bits)) == -1) 1693 return SSH_ERR_KEY_LENGTH; 1694 *ecdsap = NULL; 1695 if ((private = EC_KEY_new_by_curve_name(*nid)) == NULL) { 1696 ret = SSH_ERR_ALLOC_FAIL; 1697 goto out; 1698 } 1699 if (EC_KEY_generate_key(private) != 1) { 1700 ret = SSH_ERR_LIBCRYPTO_ERROR; 1701 goto out; 1702 } 1703 EC_KEY_set_asn1_flag(private, OPENSSL_EC_NAMED_CURVE); 1704 *ecdsap = private; 1705 private = NULL; 1706 ret = 0; 1707 out: 1708 EC_KEY_free(private); 1709 return ret; 1710 } 1711 # endif /* OPENSSL_HAS_ECC */ 1712 #endif /* WITH_OPENSSL */ 1713 1714 int 1715 sshkey_generate(int type, u_int bits, struct sshkey **keyp) 1716 { 1717 struct sshkey *k; 1718 int ret = SSH_ERR_INTERNAL_ERROR; 1719 1720 if (keyp == NULL) 1721 return SSH_ERR_INVALID_ARGUMENT; 1722 *keyp = NULL; 1723 if ((k = sshkey_new(KEY_UNSPEC)) == NULL) 1724 return SSH_ERR_ALLOC_FAIL; 1725 switch (type) { 1726 case KEY_ED25519: 1727 if ((k->ed25519_pk = malloc(ED25519_PK_SZ)) == NULL || 1728 (k->ed25519_sk = malloc(ED25519_SK_SZ)) == NULL) { 1729 ret = SSH_ERR_ALLOC_FAIL; 1730 break; 1731 } 1732 crypto_sign_ed25519_keypair(k->ed25519_pk, k->ed25519_sk); 1733 ret = 0; 1734 break; 1735 #ifdef WITH_XMSS 1736 case KEY_XMSS: 1737 ret = sshkey_xmss_generate_private_key(k, bits); 1738 break; 1739 #endif /* WITH_XMSS */ 1740 #ifdef WITH_OPENSSL 1741 case KEY_DSA: 1742 ret = dsa_generate_private_key(bits, &k->dsa); 1743 break; 1744 # ifdef OPENSSL_HAS_ECC 1745 case KEY_ECDSA: 1746 ret = ecdsa_generate_private_key(bits, &k->ecdsa_nid, 1747 &k->ecdsa); 1748 break; 1749 # endif /* OPENSSL_HAS_ECC */ 1750 case KEY_RSA: 1751 ret = rsa_generate_private_key(bits, &k->rsa); 1752 break; 1753 #endif /* WITH_OPENSSL */ 1754 default: 1755 ret = SSH_ERR_INVALID_ARGUMENT; 1756 } 1757 if (ret == 0) { 1758 k->type = type; 1759 *keyp = k; 1760 } else 1761 sshkey_free(k); 1762 return ret; 1763 } 1764 1765 int 1766 sshkey_cert_copy(const struct sshkey *from_key, struct sshkey *to_key) 1767 { 1768 u_int i; 1769 const struct sshkey_cert *from; 1770 struct sshkey_cert *to; 1771 int r = SSH_ERR_INTERNAL_ERROR; 1772 1773 if (to_key == NULL || (from = from_key->cert) == NULL) 1774 return SSH_ERR_INVALID_ARGUMENT; 1775 1776 if ((to = cert_new()) == NULL) 1777 return SSH_ERR_ALLOC_FAIL; 1778 1779 if ((r = sshbuf_putb(to->certblob, from->certblob)) != 0 || 1780 (r = sshbuf_putb(to->critical, from->critical)) != 0 || 1781 (r = sshbuf_putb(to->extensions, from->extensions)) != 0) 1782 goto out; 1783 1784 to->serial = from->serial; 1785 to->type = from->type; 1786 if (from->key_id == NULL) 1787 to->key_id = NULL; 1788 else if ((to->key_id = strdup(from->key_id)) == NULL) { 1789 r = SSH_ERR_ALLOC_FAIL; 1790 goto out; 1791 } 1792 to->valid_after = from->valid_after; 1793 to->valid_before = from->valid_before; 1794 if (from->signature_key == NULL) 1795 to->signature_key = NULL; 1796 else if ((r = sshkey_from_private(from->signature_key, 1797 &to->signature_key)) != 0) 1798 goto out; 1799 if (from->signature_type != NULL && 1800 (to->signature_type = strdup(from->signature_type)) == NULL) { 1801 r = SSH_ERR_ALLOC_FAIL; 1802 goto out; 1803 } 1804 if (from->nprincipals > SSHKEY_CERT_MAX_PRINCIPALS) { 1805 r = SSH_ERR_INVALID_ARGUMENT; 1806 goto out; 1807 } 1808 if (from->nprincipals > 0) { 1809 if ((to->principals = calloc(from->nprincipals, 1810 sizeof(*to->principals))) == NULL) { 1811 r = SSH_ERR_ALLOC_FAIL; 1812 goto out; 1813 } 1814 for (i = 0; i < from->nprincipals; i++) { 1815 to->principals[i] = strdup(from->principals[i]); 1816 if (to->principals[i] == NULL) { 1817 to->nprincipals = i; 1818 r = SSH_ERR_ALLOC_FAIL; 1819 goto out; 1820 } 1821 } 1822 } 1823 to->nprincipals = from->nprincipals; 1824 1825 /* success */ 1826 cert_free(to_key->cert); 1827 to_key->cert = to; 1828 to = NULL; 1829 r = 0; 1830 out: 1831 cert_free(to); 1832 return r; 1833 } 1834 1835 int 1836 sshkey_from_private(const struct sshkey *k, struct sshkey **pkp) 1837 { 1838 struct sshkey *n = NULL; 1839 int r = SSH_ERR_INTERNAL_ERROR; 1840 #ifdef WITH_OPENSSL 1841 const BIGNUM *rsa_n, *rsa_e; 1842 BIGNUM *rsa_n_dup = NULL, *rsa_e_dup = NULL; 1843 const BIGNUM *dsa_p, *dsa_q, *dsa_g, *dsa_pub_key; 1844 BIGNUM *dsa_p_dup = NULL, *dsa_q_dup = NULL, *dsa_g_dup = NULL; 1845 BIGNUM *dsa_pub_key_dup = NULL; 1846 #endif /* WITH_OPENSSL */ 1847 1848 *pkp = NULL; 1849 if ((n = sshkey_new(k->type)) == NULL) { 1850 r = SSH_ERR_ALLOC_FAIL; 1851 goto out; 1852 } 1853 switch (k->type) { 1854 #ifdef WITH_OPENSSL 1855 case KEY_DSA: 1856 case KEY_DSA_CERT: 1857 DSA_get0_pqg(k->dsa, &dsa_p, &dsa_q, &dsa_g); 1858 DSA_get0_key(k->dsa, &dsa_pub_key, NULL); 1859 if ((dsa_p_dup = BN_dup(dsa_p)) == NULL || 1860 (dsa_q_dup = BN_dup(dsa_q)) == NULL || 1861 (dsa_g_dup = BN_dup(dsa_g)) == NULL || 1862 (dsa_pub_key_dup = BN_dup(dsa_pub_key)) == NULL) { 1863 r = SSH_ERR_ALLOC_FAIL; 1864 goto out; 1865 } 1866 if (!DSA_set0_pqg(n->dsa, dsa_p_dup, dsa_q_dup, dsa_g_dup)) { 1867 r = SSH_ERR_LIBCRYPTO_ERROR; 1868 goto out; 1869 } 1870 dsa_p_dup = dsa_q_dup = dsa_g_dup = NULL; /* transferred */ 1871 if (!DSA_set0_key(n->dsa, dsa_pub_key_dup, NULL)) { 1872 r = SSH_ERR_LIBCRYPTO_ERROR; 1873 goto out; 1874 } 1875 dsa_pub_key_dup = NULL; /* transferred */ 1876 1877 break; 1878 # ifdef OPENSSL_HAS_ECC 1879 case KEY_ECDSA: 1880 case KEY_ECDSA_CERT: 1881 case KEY_ECDSA_SK: 1882 case KEY_ECDSA_SK_CERT: 1883 n->ecdsa_nid = k->ecdsa_nid; 1884 n->ecdsa = EC_KEY_new_by_curve_name(k->ecdsa_nid); 1885 if (n->ecdsa == NULL) { 1886 r = SSH_ERR_ALLOC_FAIL; 1887 goto out; 1888 } 1889 if (EC_KEY_set_public_key(n->ecdsa, 1890 EC_KEY_get0_public_key(k->ecdsa)) != 1) { 1891 r = SSH_ERR_LIBCRYPTO_ERROR; 1892 goto out; 1893 } 1894 if (k->type != KEY_ECDSA_SK && k->type != KEY_ECDSA_SK_CERT) 1895 break; 1896 /* Append security-key application string */ 1897 if ((n->sk_application = strdup(k->sk_application)) == NULL) 1898 goto out; 1899 break; 1900 # endif /* OPENSSL_HAS_ECC */ 1901 case KEY_RSA: 1902 case KEY_RSA_CERT: 1903 RSA_get0_key(k->rsa, &rsa_n, &rsa_e, NULL); 1904 if ((rsa_n_dup = BN_dup(rsa_n)) == NULL || 1905 (rsa_e_dup = BN_dup(rsa_e)) == NULL) { 1906 r = SSH_ERR_ALLOC_FAIL; 1907 goto out; 1908 } 1909 if (!RSA_set0_key(n->rsa, rsa_n_dup, rsa_e_dup, NULL)) { 1910 r = SSH_ERR_LIBCRYPTO_ERROR; 1911 goto out; 1912 } 1913 rsa_n_dup = rsa_e_dup = NULL; /* transferred */ 1914 break; 1915 #endif /* WITH_OPENSSL */ 1916 case KEY_ED25519: 1917 case KEY_ED25519_CERT: 1918 case KEY_ED25519_SK: 1919 case KEY_ED25519_SK_CERT: 1920 if (k->ed25519_pk != NULL) { 1921 if ((n->ed25519_pk = malloc(ED25519_PK_SZ)) == NULL) { 1922 r = SSH_ERR_ALLOC_FAIL; 1923 goto out; 1924 } 1925 memcpy(n->ed25519_pk, k->ed25519_pk, ED25519_PK_SZ); 1926 } 1927 if (k->type != KEY_ED25519_SK && 1928 k->type != KEY_ED25519_SK_CERT) 1929 break; 1930 /* Append security-key application string */ 1931 if ((n->sk_application = strdup(k->sk_application)) == NULL) 1932 goto out; 1933 break; 1934 #ifdef WITH_XMSS 1935 case KEY_XMSS: 1936 case KEY_XMSS_CERT: 1937 if ((r = sshkey_xmss_init(n, k->xmss_name)) != 0) 1938 goto out; 1939 if (k->xmss_pk != NULL) { 1940 u_int32_t left; 1941 size_t pklen = sshkey_xmss_pklen(k); 1942 if (pklen == 0 || sshkey_xmss_pklen(n) != pklen) { 1943 r = SSH_ERR_INTERNAL_ERROR; 1944 goto out; 1945 } 1946 if ((n->xmss_pk = malloc(pklen)) == NULL) { 1947 r = SSH_ERR_ALLOC_FAIL; 1948 goto out; 1949 } 1950 memcpy(n->xmss_pk, k->xmss_pk, pklen); 1951 /* simulate number of signatures left on pubkey */ 1952 left = sshkey_xmss_signatures_left(k); 1953 if (left) 1954 sshkey_xmss_enable_maxsign(n, left); 1955 } 1956 break; 1957 #endif /* WITH_XMSS */ 1958 default: 1959 r = SSH_ERR_KEY_TYPE_UNKNOWN; 1960 goto out; 1961 } 1962 if (sshkey_is_cert(k) && (r = sshkey_cert_copy(k, n)) != 0) 1963 goto out; 1964 /* success */ 1965 *pkp = n; 1966 n = NULL; 1967 r = 0; 1968 out: 1969 sshkey_free(n); 1970 #ifdef WITH_OPENSSL 1971 BN_clear_free(rsa_n_dup); 1972 BN_clear_free(rsa_e_dup); 1973 BN_clear_free(dsa_p_dup); 1974 BN_clear_free(dsa_q_dup); 1975 BN_clear_free(dsa_g_dup); 1976 BN_clear_free(dsa_pub_key_dup); 1977 #endif 1978 1979 return r; 1980 } 1981 1982 int 1983 sshkey_is_shielded(struct sshkey *k) 1984 { 1985 return k != NULL && k->shielded_private != NULL; 1986 } 1987 1988 int 1989 sshkey_shield_private(struct sshkey *k) 1990 { 1991 struct sshbuf *prvbuf = NULL; 1992 u_char *prekey = NULL, *enc = NULL, keyiv[SSH_DIGEST_MAX_LENGTH]; 1993 struct sshcipher_ctx *cctx = NULL; 1994 const struct sshcipher *cipher; 1995 size_t i, enclen = 0; 1996 struct sshkey *kswap = NULL, tmp; 1997 int r = SSH_ERR_INTERNAL_ERROR; 1998 1999 #ifdef DEBUG_PK 2000 fprintf(stderr, "%s: entering for %s\n", __func__, sshkey_ssh_name(k)); 2001 #endif 2002 if ((cipher = cipher_by_name(SSHKEY_SHIELD_CIPHER)) == NULL) { 2003 r = SSH_ERR_INVALID_ARGUMENT; 2004 goto out; 2005 } 2006 if (cipher_keylen(cipher) + cipher_ivlen(cipher) > 2007 ssh_digest_bytes(SSHKEY_SHIELD_PREKEY_HASH)) { 2008 r = SSH_ERR_INTERNAL_ERROR; 2009 goto out; 2010 } 2011 2012 /* Prepare a random pre-key, and from it an ephemeral key */ 2013 if ((prekey = malloc(SSHKEY_SHIELD_PREKEY_LEN)) == NULL) { 2014 r = SSH_ERR_ALLOC_FAIL; 2015 goto out; 2016 } 2017 arc4random_buf(prekey, SSHKEY_SHIELD_PREKEY_LEN); 2018 if ((r = ssh_digest_memory(SSHKEY_SHIELD_PREKEY_HASH, 2019 prekey, SSHKEY_SHIELD_PREKEY_LEN, 2020 keyiv, SSH_DIGEST_MAX_LENGTH)) != 0) 2021 goto out; 2022 #ifdef DEBUG_PK 2023 fprintf(stderr, "%s: key+iv\n", __func__); 2024 sshbuf_dump_data(keyiv, ssh_digest_bytes(SSHKEY_SHIELD_PREKEY_HASH), 2025 stderr); 2026 #endif 2027 if ((r = cipher_init(&cctx, cipher, keyiv, cipher_keylen(cipher), 2028 keyiv + cipher_keylen(cipher), cipher_ivlen(cipher), 1)) != 0) 2029 goto out; 2030 2031 /* Serialise and encrypt the private key using the ephemeral key */ 2032 if ((prvbuf = sshbuf_new()) == NULL) { 2033 r = SSH_ERR_ALLOC_FAIL; 2034 goto out; 2035 } 2036 if (sshkey_is_shielded(k) && (r = sshkey_unshield_private(k)) != 0) 2037 goto out; 2038 if ((r = sshkey_private_serialize_opt(k, prvbuf, 2039 SSHKEY_SERIALIZE_SHIELD)) != 0) 2040 goto out; 2041 /* pad to cipher blocksize */ 2042 i = 0; 2043 while (sshbuf_len(prvbuf) % cipher_blocksize(cipher)) { 2044 if ((r = sshbuf_put_u8(prvbuf, ++i & 0xff)) != 0) 2045 goto out; 2046 } 2047 #ifdef DEBUG_PK 2048 fprintf(stderr, "%s: serialised\n", __func__); 2049 sshbuf_dump(prvbuf, stderr); 2050 #endif 2051 /* encrypt */ 2052 enclen = sshbuf_len(prvbuf); 2053 if ((enc = malloc(enclen)) == NULL) { 2054 r = SSH_ERR_ALLOC_FAIL; 2055 goto out; 2056 } 2057 if ((r = cipher_crypt(cctx, 0, enc, 2058 sshbuf_ptr(prvbuf), sshbuf_len(prvbuf), 0, 0)) != 0) 2059 goto out; 2060 #ifdef DEBUG_PK 2061 fprintf(stderr, "%s: encrypted\n", __func__); 2062 sshbuf_dump_data(enc, enclen, stderr); 2063 #endif 2064 2065 /* Make a scrubbed, public-only copy of our private key argument */ 2066 if ((r = sshkey_from_private(k, &kswap)) != 0) 2067 goto out; 2068 2069 /* Swap the private key out (it will be destroyed below) */ 2070 tmp = *kswap; 2071 *kswap = *k; 2072 *k = tmp; 2073 2074 /* Insert the shielded key into our argument */ 2075 k->shielded_private = enc; 2076 k->shielded_len = enclen; 2077 k->shield_prekey = prekey; 2078 k->shield_prekey_len = SSHKEY_SHIELD_PREKEY_LEN; 2079 enc = prekey = NULL; /* transferred */ 2080 enclen = 0; 2081 2082 /* success */ 2083 r = 0; 2084 2085 out: 2086 /* XXX behaviour on error - invalidate original private key? */ 2087 cipher_free(cctx); 2088 explicit_bzero(keyiv, sizeof(keyiv)); 2089 explicit_bzero(&tmp, sizeof(tmp)); 2090 freezero(enc, enclen); 2091 freezero(prekey, SSHKEY_SHIELD_PREKEY_LEN); 2092 sshkey_free(kswap); 2093 sshbuf_free(prvbuf); 2094 return r; 2095 } 2096 2097 int 2098 sshkey_unshield_private(struct sshkey *k) 2099 { 2100 struct sshbuf *prvbuf = NULL; 2101 u_char pad, *cp, keyiv[SSH_DIGEST_MAX_LENGTH]; 2102 struct sshcipher_ctx *cctx = NULL; 2103 const struct sshcipher *cipher; 2104 size_t i; 2105 struct sshkey *kswap = NULL, tmp; 2106 int r = SSH_ERR_INTERNAL_ERROR; 2107 2108 #ifdef DEBUG_PK 2109 fprintf(stderr, "%s: entering for %s\n", __func__, sshkey_ssh_name(k)); 2110 #endif 2111 if (!sshkey_is_shielded(k)) 2112 return 0; /* nothing to do */ 2113 2114 if ((cipher = cipher_by_name(SSHKEY_SHIELD_CIPHER)) == NULL) { 2115 r = SSH_ERR_INVALID_ARGUMENT; 2116 goto out; 2117 } 2118 if (cipher_keylen(cipher) + cipher_ivlen(cipher) > 2119 ssh_digest_bytes(SSHKEY_SHIELD_PREKEY_HASH)) { 2120 r = SSH_ERR_INTERNAL_ERROR; 2121 goto out; 2122 } 2123 /* check size of shielded key blob */ 2124 if (k->shielded_len < cipher_blocksize(cipher) || 2125 (k->shielded_len % cipher_blocksize(cipher)) != 0) { 2126 r = SSH_ERR_INVALID_FORMAT; 2127 goto out; 2128 } 2129 2130 /* Calculate the ephemeral key from the prekey */ 2131 if ((r = ssh_digest_memory(SSHKEY_SHIELD_PREKEY_HASH, 2132 k->shield_prekey, k->shield_prekey_len, 2133 keyiv, SSH_DIGEST_MAX_LENGTH)) != 0) 2134 goto out; 2135 if ((r = cipher_init(&cctx, cipher, keyiv, cipher_keylen(cipher), 2136 keyiv + cipher_keylen(cipher), cipher_ivlen(cipher), 0)) != 0) 2137 goto out; 2138 #ifdef DEBUG_PK 2139 fprintf(stderr, "%s: key+iv\n", __func__); 2140 sshbuf_dump_data(keyiv, ssh_digest_bytes(SSHKEY_SHIELD_PREKEY_HASH), 2141 stderr); 2142 #endif 2143 2144 /* Decrypt and parse the shielded private key using the ephemeral key */ 2145 if ((prvbuf = sshbuf_new()) == NULL) { 2146 r = SSH_ERR_ALLOC_FAIL; 2147 goto out; 2148 } 2149 if ((r = sshbuf_reserve(prvbuf, k->shielded_len, &cp)) != 0) 2150 goto out; 2151 /* decrypt */ 2152 #ifdef DEBUG_PK 2153 fprintf(stderr, "%s: encrypted\n", __func__); 2154 sshbuf_dump_data(k->shielded_private, k->shielded_len, stderr); 2155 #endif 2156 if ((r = cipher_crypt(cctx, 0, cp, 2157 k->shielded_private, k->shielded_len, 0, 0)) != 0) 2158 goto out; 2159 #ifdef DEBUG_PK 2160 fprintf(stderr, "%s: serialised\n", __func__); 2161 sshbuf_dump(prvbuf, stderr); 2162 #endif 2163 /* Parse private key */ 2164 if ((r = sshkey_private_deserialize(prvbuf, &kswap)) != 0) 2165 goto out; 2166 /* Check deterministic padding */ 2167 i = 0; 2168 while (sshbuf_len(prvbuf)) { 2169 if ((r = sshbuf_get_u8(prvbuf, &pad)) != 0) 2170 goto out; 2171 if (pad != (++i & 0xff)) { 2172 r = SSH_ERR_INVALID_FORMAT; 2173 goto out; 2174 } 2175 } 2176 2177 /* Swap the parsed key back into place */ 2178 tmp = *kswap; 2179 *kswap = *k; 2180 *k = tmp; 2181 2182 /* success */ 2183 r = 0; 2184 2185 out: 2186 cipher_free(cctx); 2187 explicit_bzero(keyiv, sizeof(keyiv)); 2188 explicit_bzero(&tmp, sizeof(tmp)); 2189 sshkey_free(kswap); 2190 sshbuf_free(prvbuf); 2191 return r; 2192 } 2193 2194 static int 2195 cert_parse(struct sshbuf *b, struct sshkey *key, struct sshbuf *certbuf) 2196 { 2197 struct sshbuf *principals = NULL, *crit = NULL; 2198 struct sshbuf *exts = NULL, *ca = NULL; 2199 u_char *sig = NULL; 2200 size_t signed_len = 0, slen = 0, kidlen = 0; 2201 int ret = SSH_ERR_INTERNAL_ERROR; 2202 2203 /* Copy the entire key blob for verification and later serialisation */ 2204 if ((ret = sshbuf_putb(key->cert->certblob, certbuf)) != 0) 2205 return ret; 2206 2207 /* Parse body of certificate up to signature */ 2208 if ((ret = sshbuf_get_u64(b, &key->cert->serial)) != 0 || 2209 (ret = sshbuf_get_u32(b, &key->cert->type)) != 0 || 2210 (ret = sshbuf_get_cstring(b, &key->cert->key_id, &kidlen)) != 0 || 2211 (ret = sshbuf_froms(b, &principals)) != 0 || 2212 (ret = sshbuf_get_u64(b, &key->cert->valid_after)) != 0 || 2213 (ret = sshbuf_get_u64(b, &key->cert->valid_before)) != 0 || 2214 (ret = sshbuf_froms(b, &crit)) != 0 || 2215 (ret = sshbuf_froms(b, &exts)) != 0 || 2216 (ret = sshbuf_get_string_direct(b, NULL, NULL)) != 0 || 2217 (ret = sshbuf_froms(b, &ca)) != 0) { 2218 /* XXX debug print error for ret */ 2219 ret = SSH_ERR_INVALID_FORMAT; 2220 goto out; 2221 } 2222 2223 /* Signature is left in the buffer so we can calculate this length */ 2224 signed_len = sshbuf_len(key->cert->certblob) - sshbuf_len(b); 2225 2226 if ((ret = sshbuf_get_string(b, &sig, &slen)) != 0) { 2227 ret = SSH_ERR_INVALID_FORMAT; 2228 goto out; 2229 } 2230 2231 if (key->cert->type != SSH2_CERT_TYPE_USER && 2232 key->cert->type != SSH2_CERT_TYPE_HOST) { 2233 ret = SSH_ERR_KEY_CERT_UNKNOWN_TYPE; 2234 goto out; 2235 } 2236 2237 /* Parse principals section */ 2238 while (sshbuf_len(principals) > 0) { 2239 char *principal = NULL; 2240 char **oprincipals = NULL; 2241 2242 if (key->cert->nprincipals >= SSHKEY_CERT_MAX_PRINCIPALS) { 2243 ret = SSH_ERR_INVALID_FORMAT; 2244 goto out; 2245 } 2246 if ((ret = sshbuf_get_cstring(principals, &principal, 2247 NULL)) != 0) { 2248 ret = SSH_ERR_INVALID_FORMAT; 2249 goto out; 2250 } 2251 oprincipals = key->cert->principals; 2252 key->cert->principals = recallocarray(key->cert->principals, 2253 key->cert->nprincipals, key->cert->nprincipals + 1, 2254 sizeof(*key->cert->principals)); 2255 if (key->cert->principals == NULL) { 2256 free(principal); 2257 key->cert->principals = oprincipals; 2258 ret = SSH_ERR_ALLOC_FAIL; 2259 goto out; 2260 } 2261 key->cert->principals[key->cert->nprincipals++] = principal; 2262 } 2263 2264 /* 2265 * Stash a copies of the critical options and extensions sections 2266 * for later use. 2267 */ 2268 if ((ret = sshbuf_putb(key->cert->critical, crit)) != 0 || 2269 (exts != NULL && 2270 (ret = sshbuf_putb(key->cert->extensions, exts)) != 0)) 2271 goto out; 2272 2273 /* 2274 * Validate critical options and extensions sections format. 2275 */ 2276 while (sshbuf_len(crit) != 0) { 2277 if ((ret = sshbuf_get_string_direct(crit, NULL, NULL)) != 0 || 2278 (ret = sshbuf_get_string_direct(crit, NULL, NULL)) != 0) { 2279 sshbuf_reset(key->cert->critical); 2280 ret = SSH_ERR_INVALID_FORMAT; 2281 goto out; 2282 } 2283 } 2284 while (exts != NULL && sshbuf_len(exts) != 0) { 2285 if ((ret = sshbuf_get_string_direct(exts, NULL, NULL)) != 0 || 2286 (ret = sshbuf_get_string_direct(exts, NULL, NULL)) != 0) { 2287 sshbuf_reset(key->cert->extensions); 2288 ret = SSH_ERR_INVALID_FORMAT; 2289 goto out; 2290 } 2291 } 2292 2293 /* Parse CA key and check signature */ 2294 if (sshkey_from_blob_internal(ca, &key->cert->signature_key, 0) != 0) { 2295 ret = SSH_ERR_KEY_CERT_INVALID_SIGN_KEY; 2296 goto out; 2297 } 2298 if (!sshkey_type_is_valid_ca(key->cert->signature_key->type)) { 2299 ret = SSH_ERR_KEY_CERT_INVALID_SIGN_KEY; 2300 goto out; 2301 } 2302 if ((ret = sshkey_verify(key->cert->signature_key, sig, slen, 2303 sshbuf_ptr(key->cert->certblob), signed_len, NULL, 0)) != 0) 2304 goto out; 2305 if ((ret = sshkey_get_sigtype(sig, slen, 2306 &key->cert->signature_type)) != 0) 2307 goto out; 2308 2309 /* Success */ 2310 ret = 0; 2311 out: 2312 sshbuf_free(ca); 2313 sshbuf_free(crit); 2314 sshbuf_free(exts); 2315 sshbuf_free(principals); 2316 free(sig); 2317 return ret; 2318 } 2319 2320 #ifdef WITH_OPENSSL 2321 static int 2322 check_rsa_length(const RSA *rsa) 2323 { 2324 const BIGNUM *rsa_n; 2325 2326 RSA_get0_key(rsa, &rsa_n, NULL, NULL); 2327 if (BN_num_bits(rsa_n) < SSH_RSA_MINIMUM_MODULUS_SIZE) 2328 return SSH_ERR_KEY_LENGTH; 2329 return 0; 2330 } 2331 #endif 2332 2333 static int 2334 sshkey_from_blob_internal(struct sshbuf *b, struct sshkey **keyp, 2335 int allow_cert) 2336 { 2337 int type, ret = SSH_ERR_INTERNAL_ERROR; 2338 char *ktype = NULL, *curve = NULL, *xmss_name = NULL; 2339 struct sshkey *key = NULL; 2340 size_t len; 2341 u_char *pk = NULL; 2342 struct sshbuf *copy; 2343 #if defined(WITH_OPENSSL) 2344 BIGNUM *rsa_n = NULL, *rsa_e = NULL; 2345 BIGNUM *dsa_p = NULL, *dsa_q = NULL, *dsa_g = NULL, *dsa_pub_key = NULL; 2346 # if defined(OPENSSL_HAS_ECC) 2347 EC_POINT *q = NULL; 2348 # endif /* OPENSSL_HAS_ECC */ 2349 #endif /* WITH_OPENSSL */ 2350 2351 #ifdef DEBUG_PK /* XXX */ 2352 sshbuf_dump(b, stderr); 2353 #endif 2354 if (keyp != NULL) 2355 *keyp = NULL; 2356 if ((copy = sshbuf_fromb(b)) == NULL) { 2357 ret = SSH_ERR_ALLOC_FAIL; 2358 goto out; 2359 } 2360 if (sshbuf_get_cstring(b, &ktype, NULL) != 0) { 2361 ret = SSH_ERR_INVALID_FORMAT; 2362 goto out; 2363 } 2364 2365 type = sshkey_type_from_name(ktype); 2366 if (!allow_cert && sshkey_type_is_cert(type)) { 2367 ret = SSH_ERR_KEY_CERT_INVALID_SIGN_KEY; 2368 goto out; 2369 } 2370 switch (type) { 2371 #ifdef WITH_OPENSSL 2372 case KEY_RSA_CERT: 2373 /* Skip nonce */ 2374 if (sshbuf_get_string_direct(b, NULL, NULL) != 0) { 2375 ret = SSH_ERR_INVALID_FORMAT; 2376 goto out; 2377 } 2378 /* FALLTHROUGH */ 2379 case KEY_RSA: 2380 if ((key = sshkey_new(type)) == NULL) { 2381 ret = SSH_ERR_ALLOC_FAIL; 2382 goto out; 2383 } 2384 if (sshbuf_get_bignum2(b, &rsa_e) != 0 || 2385 sshbuf_get_bignum2(b, &rsa_n) != 0) { 2386 ret = SSH_ERR_INVALID_FORMAT; 2387 goto out; 2388 } 2389 if (!RSA_set0_key(key->rsa, rsa_n, rsa_e, NULL)) { 2390 ret = SSH_ERR_LIBCRYPTO_ERROR; 2391 goto out; 2392 } 2393 rsa_n = rsa_e = NULL; /* transferred */ 2394 if ((ret = check_rsa_length(key->rsa)) != 0) 2395 goto out; 2396 #ifdef DEBUG_PK 2397 RSA_print_fp(stderr, key->rsa, 8); 2398 #endif 2399 break; 2400 case KEY_DSA_CERT: 2401 /* Skip nonce */ 2402 if (sshbuf_get_string_direct(b, NULL, NULL) != 0) { 2403 ret = SSH_ERR_INVALID_FORMAT; 2404 goto out; 2405 } 2406 /* FALLTHROUGH */ 2407 case KEY_DSA: 2408 if ((key = sshkey_new(type)) == NULL) { 2409 ret = SSH_ERR_ALLOC_FAIL; 2410 goto out; 2411 } 2412 if (sshbuf_get_bignum2(b, &dsa_p) != 0 || 2413 sshbuf_get_bignum2(b, &dsa_q) != 0 || 2414 sshbuf_get_bignum2(b, &dsa_g) != 0 || 2415 sshbuf_get_bignum2(b, &dsa_pub_key) != 0) { 2416 ret = SSH_ERR_INVALID_FORMAT; 2417 goto out; 2418 } 2419 if (!DSA_set0_pqg(key->dsa, dsa_p, dsa_q, dsa_g)) { 2420 ret = SSH_ERR_LIBCRYPTO_ERROR; 2421 goto out; 2422 } 2423 dsa_p = dsa_q = dsa_g = NULL; /* transferred */ 2424 if (!DSA_set0_key(key->dsa, dsa_pub_key, NULL)) { 2425 ret = SSH_ERR_LIBCRYPTO_ERROR; 2426 goto out; 2427 } 2428 dsa_pub_key = NULL; /* transferred */ 2429 #ifdef DEBUG_PK 2430 DSA_print_fp(stderr, key->dsa, 8); 2431 #endif 2432 break; 2433 case KEY_ECDSA_CERT: 2434 case KEY_ECDSA_SK_CERT: 2435 /* Skip nonce */ 2436 if (sshbuf_get_string_direct(b, NULL, NULL) != 0) { 2437 ret = SSH_ERR_INVALID_FORMAT; 2438 goto out; 2439 } 2440 /* FALLTHROUGH */ 2441 # ifdef OPENSSL_HAS_ECC 2442 case KEY_ECDSA: 2443 case KEY_ECDSA_SK: 2444 if ((key = sshkey_new(type)) == NULL) { 2445 ret = SSH_ERR_ALLOC_FAIL; 2446 goto out; 2447 } 2448 key->ecdsa_nid = sshkey_ecdsa_nid_from_name(ktype); 2449 if (sshbuf_get_cstring(b, &curve, NULL) != 0) { 2450 ret = SSH_ERR_INVALID_FORMAT; 2451 goto out; 2452 } 2453 if (key->ecdsa_nid != sshkey_curve_name_to_nid(curve)) { 2454 ret = SSH_ERR_EC_CURVE_MISMATCH; 2455 goto out; 2456 } 2457 EC_KEY_free(key->ecdsa); 2458 if ((key->ecdsa = EC_KEY_new_by_curve_name(key->ecdsa_nid)) 2459 == NULL) { 2460 ret = SSH_ERR_EC_CURVE_INVALID; 2461 goto out; 2462 } 2463 if ((q = EC_POINT_new(EC_KEY_get0_group(key->ecdsa))) == NULL) { 2464 ret = SSH_ERR_ALLOC_FAIL; 2465 goto out; 2466 } 2467 if (sshbuf_get_ec(b, q, EC_KEY_get0_group(key->ecdsa)) != 0) { 2468 ret = SSH_ERR_INVALID_FORMAT; 2469 goto out; 2470 } 2471 if (sshkey_ec_validate_public(EC_KEY_get0_group(key->ecdsa), 2472 q) != 0) { 2473 ret = SSH_ERR_KEY_INVALID_EC_VALUE; 2474 goto out; 2475 } 2476 if (EC_KEY_set_public_key(key->ecdsa, q) != 1) { 2477 /* XXX assume it is a allocation error */ 2478 ret = SSH_ERR_ALLOC_FAIL; 2479 goto out; 2480 } 2481 #ifdef DEBUG_PK 2482 sshkey_dump_ec_point(EC_KEY_get0_group(key->ecdsa), q); 2483 #endif 2484 if (type == KEY_ECDSA_SK || type == KEY_ECDSA_SK_CERT) { 2485 /* Parse additional security-key application string */ 2486 if (sshbuf_get_cstring(b, &key->sk_application, 2487 NULL) != 0) { 2488 ret = SSH_ERR_INVALID_FORMAT; 2489 goto out; 2490 } 2491 #ifdef DEBUG_PK 2492 fprintf(stderr, "App: %s\n", key->sk_application); 2493 #endif 2494 } 2495 break; 2496 # endif /* OPENSSL_HAS_ECC */ 2497 #endif /* WITH_OPENSSL */ 2498 case KEY_ED25519_CERT: 2499 case KEY_ED25519_SK_CERT: 2500 /* Skip nonce */ 2501 if (sshbuf_get_string_direct(b, NULL, NULL) != 0) { 2502 ret = SSH_ERR_INVALID_FORMAT; 2503 goto out; 2504 } 2505 /* FALLTHROUGH */ 2506 case KEY_ED25519: 2507 case KEY_ED25519_SK: 2508 if ((ret = sshbuf_get_string(b, &pk, &len)) != 0) 2509 goto out; 2510 if (len != ED25519_PK_SZ) { 2511 ret = SSH_ERR_INVALID_FORMAT; 2512 goto out; 2513 } 2514 if ((key = sshkey_new(type)) == NULL) { 2515 ret = SSH_ERR_ALLOC_FAIL; 2516 goto out; 2517 } 2518 if (type == KEY_ED25519_SK || type == KEY_ED25519_SK_CERT) { 2519 /* Parse additional security-key application string */ 2520 if (sshbuf_get_cstring(b, &key->sk_application, 2521 NULL) != 0) { 2522 ret = SSH_ERR_INVALID_FORMAT; 2523 goto out; 2524 } 2525 #ifdef DEBUG_PK 2526 fprintf(stderr, "App: %s\n", key->sk_application); 2527 #endif 2528 } 2529 key->ed25519_pk = pk; 2530 pk = NULL; 2531 break; 2532 #ifdef WITH_XMSS 2533 case KEY_XMSS_CERT: 2534 /* Skip nonce */ 2535 if (sshbuf_get_string_direct(b, NULL, NULL) != 0) { 2536 ret = SSH_ERR_INVALID_FORMAT; 2537 goto out; 2538 } 2539 /* FALLTHROUGH */ 2540 case KEY_XMSS: 2541 if ((ret = sshbuf_get_cstring(b, &xmss_name, NULL)) != 0) 2542 goto out; 2543 if ((key = sshkey_new(type)) == NULL) { 2544 ret = SSH_ERR_ALLOC_FAIL; 2545 goto out; 2546 } 2547 if ((ret = sshkey_xmss_init(key, xmss_name)) != 0) 2548 goto out; 2549 if ((ret = sshbuf_get_string(b, &pk, &len)) != 0) 2550 goto out; 2551 if (len == 0 || len != sshkey_xmss_pklen(key)) { 2552 ret = SSH_ERR_INVALID_FORMAT; 2553 goto out; 2554 } 2555 key->xmss_pk = pk; 2556 pk = NULL; 2557 if (type != KEY_XMSS_CERT && 2558 (ret = sshkey_xmss_deserialize_pk_info(key, b)) != 0) 2559 goto out; 2560 break; 2561 #endif /* WITH_XMSS */ 2562 case KEY_UNSPEC: 2563 default: 2564 ret = SSH_ERR_KEY_TYPE_UNKNOWN; 2565 goto out; 2566 } 2567 2568 /* Parse certificate potion */ 2569 if (sshkey_is_cert(key) && (ret = cert_parse(b, key, copy)) != 0) 2570 goto out; 2571 2572 if (key != NULL && sshbuf_len(b) != 0) { 2573 ret = SSH_ERR_INVALID_FORMAT; 2574 goto out; 2575 } 2576 ret = 0; 2577 if (keyp != NULL) { 2578 *keyp = key; 2579 key = NULL; 2580 } 2581 out: 2582 sshbuf_free(copy); 2583 sshkey_free(key); 2584 free(xmss_name); 2585 free(ktype); 2586 free(curve); 2587 free(pk); 2588 #if defined(WITH_OPENSSL) 2589 BN_clear_free(rsa_n); 2590 BN_clear_free(rsa_e); 2591 BN_clear_free(dsa_p); 2592 BN_clear_free(dsa_q); 2593 BN_clear_free(dsa_g); 2594 BN_clear_free(dsa_pub_key); 2595 # if defined(OPENSSL_HAS_ECC) 2596 EC_POINT_free(q); 2597 # endif /* OPENSSL_HAS_ECC */ 2598 #endif /* WITH_OPENSSL */ 2599 return ret; 2600 } 2601 2602 int 2603 sshkey_from_blob(const u_char *blob, size_t blen, struct sshkey **keyp) 2604 { 2605 struct sshbuf *b; 2606 int r; 2607 2608 if ((b = sshbuf_from(blob, blen)) == NULL) 2609 return SSH_ERR_ALLOC_FAIL; 2610 r = sshkey_from_blob_internal(b, keyp, 1); 2611 sshbuf_free(b); 2612 return r; 2613 } 2614 2615 int 2616 sshkey_fromb(struct sshbuf *b, struct sshkey **keyp) 2617 { 2618 return sshkey_from_blob_internal(b, keyp, 1); 2619 } 2620 2621 int 2622 sshkey_froms(struct sshbuf *buf, struct sshkey **keyp) 2623 { 2624 struct sshbuf *b; 2625 int r; 2626 2627 if ((r = sshbuf_froms(buf, &b)) != 0) 2628 return r; 2629 r = sshkey_from_blob_internal(b, keyp, 1); 2630 sshbuf_free(b); 2631 return r; 2632 } 2633 2634 int 2635 sshkey_get_sigtype(const u_char *sig, size_t siglen, char **sigtypep) 2636 { 2637 int r; 2638 struct sshbuf *b = NULL; 2639 char *sigtype = NULL; 2640 2641 if (sigtypep != NULL) 2642 *sigtypep = NULL; 2643 if ((b = sshbuf_from(sig, siglen)) == NULL) 2644 return SSH_ERR_ALLOC_FAIL; 2645 if ((r = sshbuf_get_cstring(b, &sigtype, NULL)) != 0) 2646 goto out; 2647 /* success */ 2648 if (sigtypep != NULL) { 2649 *sigtypep = sigtype; 2650 sigtype = NULL; 2651 } 2652 r = 0; 2653 out: 2654 free(sigtype); 2655 sshbuf_free(b); 2656 return r; 2657 } 2658 2659 /* 2660 * 2661 * Checks whether a certificate's signature type is allowed. 2662 * Returns 0 (success) if the certificate signature type appears in the 2663 * "allowed" pattern-list, or the key is not a certificate to begin with. 2664 * Otherwise returns a ssherr.h code. 2665 */ 2666 int 2667 sshkey_check_cert_sigtype(const struct sshkey *key, const char *allowed) 2668 { 2669 if (key == NULL || allowed == NULL) 2670 return SSH_ERR_INVALID_ARGUMENT; 2671 if (!sshkey_type_is_cert(key->type)) 2672 return 0; 2673 if (key->cert == NULL || key->cert->signature_type == NULL) 2674 return SSH_ERR_INVALID_ARGUMENT; 2675 if (match_pattern_list(key->cert->signature_type, allowed, 0) != 1) 2676 return SSH_ERR_SIGN_ALG_UNSUPPORTED; 2677 return 0; 2678 } 2679 2680 /* 2681 * Returns the expected signature algorithm for a given public key algorithm. 2682 */ 2683 const char * 2684 sshkey_sigalg_by_name(const char *name) 2685 { 2686 const struct keytype *kt; 2687 2688 for (kt = keytypes; kt->type != -1; kt++) { 2689 if (strcmp(kt->name, name) != 0) 2690 continue; 2691 if (kt->sigalg != NULL) 2692 return kt->sigalg; 2693 if (!kt->cert) 2694 return kt->name; 2695 return sshkey_ssh_name_from_type_nid( 2696 sshkey_type_plain(kt->type), kt->nid); 2697 } 2698 return NULL; 2699 } 2700 2701 /* 2702 * Verifies that the signature algorithm appearing inside the signature blob 2703 * matches that which was requested. 2704 */ 2705 int 2706 sshkey_check_sigtype(const u_char *sig, size_t siglen, 2707 const char *requested_alg) 2708 { 2709 const char *expected_alg; 2710 char *sigtype = NULL; 2711 int r; 2712 2713 if (requested_alg == NULL) 2714 return 0; 2715 if ((expected_alg = sshkey_sigalg_by_name(requested_alg)) == NULL) 2716 return SSH_ERR_INVALID_ARGUMENT; 2717 if ((r = sshkey_get_sigtype(sig, siglen, &sigtype)) != 0) 2718 return r; 2719 r = strcmp(expected_alg, sigtype) == 0; 2720 free(sigtype); 2721 return r ? 0 : SSH_ERR_SIGN_ALG_UNSUPPORTED; 2722 } 2723 2724 int 2725 sshkey_sign(struct sshkey *key, 2726 u_char **sigp, size_t *lenp, 2727 const u_char *data, size_t datalen, 2728 const char *alg, const char *sk_provider, u_int compat) 2729 { 2730 int was_shielded = sshkey_is_shielded(key); 2731 int r2, r = SSH_ERR_INTERNAL_ERROR; 2732 2733 if (sigp != NULL) 2734 *sigp = NULL; 2735 if (lenp != NULL) 2736 *lenp = 0; 2737 if (datalen > SSH_KEY_MAX_SIGN_DATA_SIZE) 2738 return SSH_ERR_INVALID_ARGUMENT; 2739 if ((r = sshkey_unshield_private(key)) != 0) 2740 return r; 2741 switch (key->type) { 2742 #ifdef WITH_OPENSSL 2743 case KEY_DSA_CERT: 2744 case KEY_DSA: 2745 r = ssh_dss_sign(key, sigp, lenp, data, datalen, compat); 2746 break; 2747 # ifdef OPENSSL_HAS_ECC 2748 case KEY_ECDSA_CERT: 2749 case KEY_ECDSA: 2750 r = ssh_ecdsa_sign(key, sigp, lenp, data, datalen, compat); 2751 break; 2752 # ifdef ENABLE_SK 2753 case KEY_ECDSA_SK_CERT: 2754 case KEY_ECDSA_SK: 2755 r = sshsk_sign(sk_provider, key, sigp, lenp, data, datalen, 2756 compat); 2757 break; 2758 # endif /* ENABLE_SK */ 2759 # endif /* OPENSSL_HAS_ECC */ 2760 case KEY_RSA_CERT: 2761 case KEY_RSA: 2762 r = ssh_rsa_sign(key, sigp, lenp, data, datalen, alg); 2763 break; 2764 #endif /* WITH_OPENSSL */ 2765 case KEY_ED25519: 2766 case KEY_ED25519_CERT: 2767 r = ssh_ed25519_sign(key, sigp, lenp, data, datalen, compat); 2768 break; 2769 #ifdef ENABLE_SK 2770 case KEY_ED25519_SK: 2771 case KEY_ED25519_SK_CERT: 2772 r = sshsk_sign(sk_provider, key, sigp, lenp, data, datalen, 2773 compat); 2774 break; 2775 #endif /* ENABLE_SK */ 2776 #ifdef WITH_XMSS 2777 case KEY_XMSS: 2778 case KEY_XMSS_CERT: 2779 r = ssh_xmss_sign(key, sigp, lenp, data, datalen, compat); 2780 break; 2781 #endif /* WITH_XMSS */ 2782 default: 2783 r = SSH_ERR_KEY_TYPE_UNKNOWN; 2784 break; 2785 } 2786 if (was_shielded && (r2 = sshkey_shield_private(key)) != 0) 2787 return r2; 2788 return r; 2789 } 2790 2791 /* 2792 * ssh_key_verify returns 0 for a correct signature and < 0 on error. 2793 * If "alg" specified, then the signature must use that algorithm. 2794 */ 2795 int 2796 sshkey_verify(const struct sshkey *key, 2797 const u_char *sig, size_t siglen, 2798 const u_char *data, size_t dlen, const char *alg, u_int compat) 2799 { 2800 if (siglen == 0 || dlen > SSH_KEY_MAX_SIGN_DATA_SIZE) 2801 return SSH_ERR_INVALID_ARGUMENT; 2802 switch (key->type) { 2803 #ifdef WITH_OPENSSL 2804 case KEY_DSA_CERT: 2805 case KEY_DSA: 2806 return ssh_dss_verify(key, sig, siglen, data, dlen, compat); 2807 # ifdef OPENSSL_HAS_ECC 2808 case KEY_ECDSA_CERT: 2809 case KEY_ECDSA: 2810 return ssh_ecdsa_verify(key, sig, siglen, data, dlen, compat); 2811 # ifdef ENABLE_SK 2812 case KEY_ECDSA_SK_CERT: 2813 case KEY_ECDSA_SK: 2814 return ssh_ecdsa_sk_verify(key, sig, siglen, data, dlen, 2815 compat); 2816 # endif /* ENABLE_SK */ 2817 # endif /* OPENSSL_HAS_ECC */ 2818 case KEY_RSA_CERT: 2819 case KEY_RSA: 2820 return ssh_rsa_verify(key, sig, siglen, data, dlen, alg); 2821 #endif /* WITH_OPENSSL */ 2822 case KEY_ED25519: 2823 case KEY_ED25519_CERT: 2824 return ssh_ed25519_verify(key, sig, siglen, data, dlen, compat); 2825 case KEY_ED25519_SK: 2826 case KEY_ED25519_SK_CERT: 2827 return ssh_ed25519_sk_verify(key, sig, siglen, data, dlen, 2828 compat); 2829 #ifdef WITH_XMSS 2830 case KEY_XMSS: 2831 case KEY_XMSS_CERT: 2832 return ssh_xmss_verify(key, sig, siglen, data, dlen, compat); 2833 #endif /* WITH_XMSS */ 2834 default: 2835 return SSH_ERR_KEY_TYPE_UNKNOWN; 2836 } 2837 } 2838 2839 /* Convert a plain key to their _CERT equivalent */ 2840 int 2841 sshkey_to_certified(struct sshkey *k) 2842 { 2843 int newtype; 2844 2845 switch (k->type) { 2846 #ifdef WITH_OPENSSL 2847 case KEY_RSA: 2848 newtype = KEY_RSA_CERT; 2849 break; 2850 case KEY_DSA: 2851 newtype = KEY_DSA_CERT; 2852 break; 2853 case KEY_ECDSA: 2854 newtype = KEY_ECDSA_CERT; 2855 break; 2856 case KEY_ECDSA_SK: 2857 newtype = KEY_ECDSA_SK_CERT; 2858 break; 2859 #endif /* WITH_OPENSSL */ 2860 case KEY_ED25519_SK: 2861 newtype = KEY_ED25519_SK_CERT; 2862 break; 2863 case KEY_ED25519: 2864 newtype = KEY_ED25519_CERT; 2865 break; 2866 #ifdef WITH_XMSS 2867 case KEY_XMSS: 2868 newtype = KEY_XMSS_CERT; 2869 break; 2870 #endif /* WITH_XMSS */ 2871 default: 2872 return SSH_ERR_INVALID_ARGUMENT; 2873 } 2874 if ((k->cert = cert_new()) == NULL) 2875 return SSH_ERR_ALLOC_FAIL; 2876 k->type = newtype; 2877 return 0; 2878 } 2879 2880 /* Convert a certificate to its raw key equivalent */ 2881 int 2882 sshkey_drop_cert(struct sshkey *k) 2883 { 2884 if (!sshkey_type_is_cert(k->type)) 2885 return SSH_ERR_KEY_TYPE_UNKNOWN; 2886 cert_free(k->cert); 2887 k->cert = NULL; 2888 k->type = sshkey_type_plain(k->type); 2889 return 0; 2890 } 2891 2892 /* Sign a certified key, (re-)generating the signed certblob. */ 2893 int 2894 sshkey_certify_custom(struct sshkey *k, struct sshkey *ca, const char *alg, 2895 const char *sk_provider, sshkey_certify_signer *signer, void *signer_ctx) 2896 { 2897 struct sshbuf *principals = NULL; 2898 u_char *ca_blob = NULL, *sig_blob = NULL, nonce[32]; 2899 size_t i, ca_len, sig_len; 2900 int ret = SSH_ERR_INTERNAL_ERROR; 2901 struct sshbuf *cert = NULL; 2902 char *sigtype = NULL; 2903 #ifdef WITH_OPENSSL 2904 const BIGNUM *rsa_n, *rsa_e, *dsa_p, *dsa_q, *dsa_g, *dsa_pub_key; 2905 #endif /* WITH_OPENSSL */ 2906 2907 if (k == NULL || k->cert == NULL || 2908 k->cert->certblob == NULL || ca == NULL) 2909 return SSH_ERR_INVALID_ARGUMENT; 2910 if (!sshkey_is_cert(k)) 2911 return SSH_ERR_KEY_TYPE_UNKNOWN; 2912 if (!sshkey_type_is_valid_ca(ca->type)) 2913 return SSH_ERR_KEY_CERT_INVALID_SIGN_KEY; 2914 2915 /* 2916 * If no alg specified as argument but a signature_type was set, 2917 * then prefer that. If both were specified, then they must match. 2918 */ 2919 if (alg == NULL) 2920 alg = k->cert->signature_type; 2921 else if (k->cert->signature_type != NULL && 2922 strcmp(alg, k->cert->signature_type) != 0) 2923 return SSH_ERR_INVALID_ARGUMENT; 2924 2925 /* 2926 * If no signing algorithm or signature_type was specified and we're 2927 * using a RSA key, then default to a good signature algorithm. 2928 */ 2929 if (alg == NULL && ca->type == KEY_RSA) 2930 alg = "rsa-sha2-512"; 2931 2932 if ((ret = sshkey_to_blob(ca, &ca_blob, &ca_len)) != 0) 2933 return SSH_ERR_KEY_CERT_INVALID_SIGN_KEY; 2934 2935 cert = k->cert->certblob; /* for readability */ 2936 sshbuf_reset(cert); 2937 if ((ret = sshbuf_put_cstring(cert, sshkey_ssh_name(k))) != 0) 2938 goto out; 2939 2940 /* -v01 certs put nonce first */ 2941 arc4random_buf(&nonce, sizeof(nonce)); 2942 if ((ret = sshbuf_put_string(cert, nonce, sizeof(nonce))) != 0) 2943 goto out; 2944 2945 /* XXX this substantially duplicates to_blob(); refactor */ 2946 switch (k->type) { 2947 #ifdef WITH_OPENSSL 2948 case KEY_DSA_CERT: 2949 DSA_get0_pqg(k->dsa, &dsa_p, &dsa_q, &dsa_g); 2950 DSA_get0_key(k->dsa, &dsa_pub_key, NULL); 2951 if ((ret = sshbuf_put_bignum2(cert, dsa_p)) != 0 || 2952 (ret = sshbuf_put_bignum2(cert, dsa_q)) != 0 || 2953 (ret = sshbuf_put_bignum2(cert, dsa_g)) != 0 || 2954 (ret = sshbuf_put_bignum2(cert, dsa_pub_key)) != 0) 2955 goto out; 2956 break; 2957 # ifdef OPENSSL_HAS_ECC 2958 case KEY_ECDSA_CERT: 2959 case KEY_ECDSA_SK_CERT: 2960 if ((ret = sshbuf_put_cstring(cert, 2961 sshkey_curve_nid_to_name(k->ecdsa_nid))) != 0 || 2962 (ret = sshbuf_put_ec(cert, 2963 EC_KEY_get0_public_key(k->ecdsa), 2964 EC_KEY_get0_group(k->ecdsa))) != 0) 2965 goto out; 2966 if (k->type == KEY_ECDSA_SK_CERT) { 2967 if ((ret = sshbuf_put_cstring(cert, 2968 k->sk_application)) != 0) 2969 goto out; 2970 } 2971 break; 2972 # endif /* OPENSSL_HAS_ECC */ 2973 case KEY_RSA_CERT: 2974 RSA_get0_key(k->rsa, &rsa_n, &rsa_e, NULL); 2975 if ((ret = sshbuf_put_bignum2(cert, rsa_e)) != 0 || 2976 (ret = sshbuf_put_bignum2(cert, rsa_n)) != 0) 2977 goto out; 2978 break; 2979 #endif /* WITH_OPENSSL */ 2980 case KEY_ED25519_CERT: 2981 if ((ret = sshbuf_put_string(cert, 2982 k->ed25519_pk, ED25519_PK_SZ)) != 0) 2983 goto out; 2984 break; 2985 #ifdef WITH_XMSS 2986 case KEY_XMSS_CERT: 2987 if (k->xmss_name == NULL) { 2988 ret = SSH_ERR_INVALID_ARGUMENT; 2989 goto out; 2990 } 2991 if ((ret = sshbuf_put_cstring(cert, k->xmss_name)) || 2992 (ret = sshbuf_put_string(cert, 2993 k->xmss_pk, sshkey_xmss_pklen(k))) != 0) 2994 goto out; 2995 break; 2996 #endif /* WITH_XMSS */ 2997 default: 2998 ret = SSH_ERR_INVALID_ARGUMENT; 2999 goto out; 3000 } 3001 3002 if ((ret = sshbuf_put_u64(cert, k->cert->serial)) != 0 || 3003 (ret = sshbuf_put_u32(cert, k->cert->type)) != 0 || 3004 (ret = sshbuf_put_cstring(cert, k->cert->key_id)) != 0) 3005 goto out; 3006 3007 if ((principals = sshbuf_new()) == NULL) { 3008 ret = SSH_ERR_ALLOC_FAIL; 3009 goto out; 3010 } 3011 for (i = 0; i < k->cert->nprincipals; i++) { 3012 if ((ret = sshbuf_put_cstring(principals, 3013 k->cert->principals[i])) != 0) 3014 goto out; 3015 } 3016 if ((ret = sshbuf_put_stringb(cert, principals)) != 0 || 3017 (ret = sshbuf_put_u64(cert, k->cert->valid_after)) != 0 || 3018 (ret = sshbuf_put_u64(cert, k->cert->valid_before)) != 0 || 3019 (ret = sshbuf_put_stringb(cert, k->cert->critical)) != 0 || 3020 (ret = sshbuf_put_stringb(cert, k->cert->extensions)) != 0 || 3021 (ret = sshbuf_put_string(cert, NULL, 0)) != 0 || /* Reserved */ 3022 (ret = sshbuf_put_string(cert, ca_blob, ca_len)) != 0) 3023 goto out; 3024 3025 /* Sign the whole mess */ 3026 if ((ret = signer(ca, &sig_blob, &sig_len, sshbuf_ptr(cert), 3027 sshbuf_len(cert), alg, sk_provider, 0, signer_ctx)) != 0) 3028 goto out; 3029 /* Check and update signature_type against what was actually used */ 3030 if ((ret = sshkey_get_sigtype(sig_blob, sig_len, &sigtype)) != 0) 3031 goto out; 3032 if (alg != NULL && strcmp(alg, sigtype) != 0) { 3033 ret = SSH_ERR_SIGN_ALG_UNSUPPORTED;