1 /* $OpenBSD: sshkey.c,v 1.96 2019/11/25 00:51:37 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 case KEY_ED25519_SK_CERT: 827 #ifdef WITH_XMSS 828 case KEY_XMSS_CERT: 829 #endif /* WITH_XMSS */ 830 /* Use the existing blob */ 831 /* XXX modified flag? */ 832 if ((ret = sshbuf_putb(b, key->cert->certblob)) != 0) 833 return ret; 834 break; 835 #ifdef WITH_OPENSSL 836 case KEY_DSA: 837 if (key->dsa == NULL) 838 return SSH_ERR_INVALID_ARGUMENT; 839 DSA_get0_pqg(key->dsa, &dsa_p, &dsa_q, &dsa_g); 840 DSA_get0_key(key->dsa, &dsa_pub_key, NULL); 841 if ((ret = sshbuf_put_cstring(b, typename)) != 0 || 842 (ret = sshbuf_put_bignum2(b, dsa_p)) != 0 || 843 (ret = sshbuf_put_bignum2(b, dsa_q)) != 0 || 844 (ret = sshbuf_put_bignum2(b, dsa_g)) != 0 || 845 (ret = sshbuf_put_bignum2(b, dsa_pub_key)) != 0) 846 return ret; 847 break; 848 # ifdef OPENSSL_HAS_ECC 849 case KEY_ECDSA: 850 case KEY_ECDSA_SK: 851 if (key->ecdsa == NULL) 852 return SSH_ERR_INVALID_ARGUMENT; 853 if ((ret = sshbuf_put_cstring(b, typename)) != 0 || 854 (ret = sshbuf_put_cstring(b, 855 sshkey_curve_nid_to_name(key->ecdsa_nid))) != 0 || 856 (ret = sshbuf_put_eckey(b, key->ecdsa)) != 0) 857 return ret; 858 if (type == KEY_ECDSA_SK) { 859 if ((ret = sshbuf_put_cstring(b, 860 key->sk_application)) != 0) 861 return ret; 862 } 863 break; 864 # endif 865 case KEY_RSA: 866 if (key->rsa == NULL) 867 return SSH_ERR_INVALID_ARGUMENT; 868 RSA_get0_key(key->rsa, &rsa_n, &rsa_e, NULL); 869 if ((ret = sshbuf_put_cstring(b, typename)) != 0 || 870 (ret = sshbuf_put_bignum2(b, rsa_e)) != 0 || 871 (ret = sshbuf_put_bignum2(b, rsa_n)) != 0) 872 return ret; 873 break; 874 #endif /* WITH_OPENSSL */ 875 case KEY_ED25519: 876 case KEY_ED25519_SK: 877 if (key->ed25519_pk == NULL) 878 return SSH_ERR_INVALID_ARGUMENT; 879 if ((ret = sshbuf_put_cstring(b, typename)) != 0 || 880 (ret = sshbuf_put_string(b, 881 key->ed25519_pk, ED25519_PK_SZ)) != 0) 882 return ret; 883 if (type == KEY_ED25519_SK) { 884 if ((ret = sshbuf_put_cstring(b, 885 key->sk_application)) != 0) 886 return ret; 887 } 888 break; 889 #ifdef WITH_XMSS 890 case KEY_XMSS: 891 if (key->xmss_name == NULL || key->xmss_pk == NULL || 892 sshkey_xmss_pklen(key) == 0) 893 return SSH_ERR_INVALID_ARGUMENT; 894 if ((ret = sshbuf_put_cstring(b, typename)) != 0 || 895 (ret = sshbuf_put_cstring(b, key->xmss_name)) != 0 || 896 (ret = sshbuf_put_string(b, 897 key->xmss_pk, sshkey_xmss_pklen(key))) != 0 || 898 (ret = sshkey_xmss_serialize_pk_info(key, b, opts)) != 0) 899 return ret; 900 break; 901 #endif /* WITH_XMSS */ 902 default: 903 return SSH_ERR_KEY_TYPE_UNKNOWN; 904 } 905 return 0; 906 } 907 908 int 909 sshkey_putb(const struct sshkey *key, struct sshbuf *b) 910 { 911 return to_blob_buf(key, b, 0, SSHKEY_SERIALIZE_DEFAULT); 912 } 913 914 int 915 sshkey_puts_opts(const struct sshkey *key, struct sshbuf *b, 916 enum sshkey_serialize_rep opts) 917 { 918 struct sshbuf *tmp; 919 int r; 920 921 if ((tmp = sshbuf_new()) == NULL) 922 return SSH_ERR_ALLOC_FAIL; 923 r = to_blob_buf(key, tmp, 0, opts); 924 if (r == 0) 925 r = sshbuf_put_stringb(b, tmp); 926 sshbuf_free(tmp); 927 return r; 928 } 929 930 int 931 sshkey_puts(const struct sshkey *key, struct sshbuf *b) 932 { 933 return sshkey_puts_opts(key, b, SSHKEY_SERIALIZE_DEFAULT); 934 } 935 936 int 937 sshkey_putb_plain(const struct sshkey *key, struct sshbuf *b) 938 { 939 return to_blob_buf(key, b, 1, SSHKEY_SERIALIZE_DEFAULT); 940 } 941 942 static int 943 to_blob(const struct sshkey *key, u_char **blobp, size_t *lenp, int force_plain, 944 enum sshkey_serialize_rep opts) 945 { 946 int ret = SSH_ERR_INTERNAL_ERROR; 947 size_t len; 948 struct sshbuf *b = NULL; 949 950 if (lenp != NULL) 951 *lenp = 0; 952 if (blobp != NULL) 953 *blobp = NULL; 954 if ((b = sshbuf_new()) == NULL) 955 return SSH_ERR_ALLOC_FAIL; 956 if ((ret = to_blob_buf(key, b, force_plain, opts)) != 0) 957 goto out; 958 len = sshbuf_len(b); 959 if (lenp != NULL) 960 *lenp = len; 961 if (blobp != NULL) { 962 if ((*blobp = malloc(len)) == NULL) { 963 ret = SSH_ERR_ALLOC_FAIL; 964 goto out; 965 } 966 memcpy(*blobp, sshbuf_ptr(b), len); 967 } 968 ret = 0; 969 out: 970 sshbuf_free(b); 971 return ret; 972 } 973 974 int 975 sshkey_to_blob(const struct sshkey *key, u_char **blobp, size_t *lenp) 976 { 977 return to_blob(key, blobp, lenp, 0, SSHKEY_SERIALIZE_DEFAULT); 978 } 979 980 int 981 sshkey_plain_to_blob(const struct sshkey *key, u_char **blobp, size_t *lenp) 982 { 983 return to_blob(key, blobp, lenp, 1, SSHKEY_SERIALIZE_DEFAULT); 984 } 985 986 int 987 sshkey_fingerprint_raw(const struct sshkey *k, int dgst_alg, 988 u_char **retp, size_t *lenp) 989 { 990 u_char *blob = NULL, *ret = NULL; 991 size_t blob_len = 0; 992 int r = SSH_ERR_INTERNAL_ERROR; 993 994 if (retp != NULL) 995 *retp = NULL; 996 if (lenp != NULL) 997 *lenp = 0; 998 if (ssh_digest_bytes(dgst_alg) == 0) { 999 r = SSH_ERR_INVALID_ARGUMENT; 1000 goto out; 1001 } 1002 if ((r = to_blob(k, &blob, &blob_len, 1, SSHKEY_SERIALIZE_DEFAULT)) 1003 != 0) 1004 goto out; 1005 if ((ret = calloc(1, SSH_DIGEST_MAX_LENGTH)) == NULL) { 1006 r = SSH_ERR_ALLOC_FAIL; 1007 goto out; 1008 } 1009 if ((r = ssh_digest_memory(dgst_alg, blob, blob_len, 1010 ret, SSH_DIGEST_MAX_LENGTH)) != 0) 1011 goto out; 1012 /* success */ 1013 if (retp != NULL) { 1014 *retp = ret; 1015 ret = NULL; 1016 } 1017 if (lenp != NULL) 1018 *lenp = ssh_digest_bytes(dgst_alg); 1019 r = 0; 1020 out: 1021 free(ret); 1022 if (blob != NULL) { 1023 explicit_bzero(blob, blob_len); 1024 free(blob); 1025 } 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 explicit_bzero(dgst_raw, dgst_raw_len); 1284 free(dgst_raw); 1285 return NULL; 1286 } 1287 explicit_bzero(dgst_raw, dgst_raw_len); 1288 free(dgst_raw); 1289 return retval; 1290 } 1291 1292 static int 1293 peek_type_nid(const char *s, size_t l, int *nid) 1294 { 1295 const struct keytype *kt; 1296 1297 for (kt = keytypes; kt->type != -1; kt++) { 1298 if (kt->name == NULL || strlen(kt->name) != l) 1299 continue; 1300 if (memcmp(s, kt->name, l) == 0) { 1301 *nid = -1; 1302 if (key_type_is_ecdsa_variant(kt->type)) 1303 *nid = kt->nid; 1304 return kt->type; 1305 } 1306 } 1307 return KEY_UNSPEC; 1308 } 1309 1310 /* XXX this can now be made const char * */ 1311 int 1312 sshkey_read(struct sshkey *ret, char **cpp) 1313 { 1314 struct sshkey *k; 1315 char *cp, *blobcopy; 1316 size_t space; 1317 int r, type, curve_nid = -1; 1318 struct sshbuf *blob; 1319 1320 if (ret == NULL) 1321 return SSH_ERR_INVALID_ARGUMENT; 1322 1323 switch (ret->type) { 1324 case KEY_UNSPEC: 1325 case KEY_RSA: 1326 case KEY_DSA: 1327 case KEY_ECDSA: 1328 case KEY_ECDSA_SK: 1329 case KEY_ED25519: 1330 case KEY_ED25519_SK: 1331 case KEY_DSA_CERT: 1332 case KEY_ECDSA_CERT: 1333 case KEY_ECDSA_SK_CERT: 1334 case KEY_RSA_CERT: 1335 case KEY_ED25519_CERT: 1336 case KEY_ED25519_SK_CERT: 1337 #ifdef WITH_XMSS 1338 case KEY_XMSS: 1339 case KEY_XMSS_CERT: 1340 #endif /* WITH_XMSS */ 1341 break; /* ok */ 1342 default: 1343 return SSH_ERR_INVALID_ARGUMENT; 1344 } 1345 1346 /* Decode type */ 1347 cp = *cpp; 1348 space = strcspn(cp, " \t"); 1349 if (space == strlen(cp)) 1350 return SSH_ERR_INVALID_FORMAT; 1351 if ((type = peek_type_nid(cp, space, &curve_nid)) == KEY_UNSPEC) 1352 return SSH_ERR_INVALID_FORMAT; 1353 1354 /* skip whitespace */ 1355 for (cp += space; *cp == ' ' || *cp == '\t'; cp++) 1356 ; 1357 if (*cp == '\0') 1358 return SSH_ERR_INVALID_FORMAT; 1359 if (ret->type != KEY_UNSPEC && ret->type != type) 1360 return SSH_ERR_KEY_TYPE_MISMATCH; 1361 if ((blob = sshbuf_new()) == NULL) 1362 return SSH_ERR_ALLOC_FAIL; 1363 1364 /* find end of keyblob and decode */ 1365 space = strcspn(cp, " \t"); 1366 if ((blobcopy = strndup(cp, space)) == NULL) { 1367 sshbuf_free(blob); 1368 return SSH_ERR_ALLOC_FAIL; 1369 } 1370 if ((r = sshbuf_b64tod(blob, blobcopy)) != 0) { 1371 free(blobcopy); 1372 sshbuf_free(blob); 1373 return r; 1374 } 1375 free(blobcopy); 1376 if ((r = sshkey_fromb(blob, &k)) != 0) { 1377 sshbuf_free(blob); 1378 return r; 1379 } 1380 sshbuf_free(blob); 1381 1382 /* skip whitespace and leave cp at start of comment */ 1383 for (cp += space; *cp == ' ' || *cp == '\t'; cp++) 1384 ; 1385 1386 /* ensure type of blob matches type at start of line */ 1387 if (k->type != type) { 1388 sshkey_free(k); 1389 return SSH_ERR_KEY_TYPE_MISMATCH; 1390 } 1391 if (key_type_is_ecdsa_variant(type) && curve_nid != k->ecdsa_nid) { 1392 sshkey_free(k); 1393 return SSH_ERR_EC_CURVE_MISMATCH; 1394 } 1395 1396 /* Fill in ret from parsed key */ 1397 ret->type = type; 1398 if (sshkey_is_cert(ret)) { 1399 if (!sshkey_is_cert(k)) { 1400 sshkey_free(k); 1401 return SSH_ERR_EXPECTED_CERT; 1402 } 1403 if (ret->cert != NULL) 1404 cert_free(ret->cert); 1405 ret->cert = k->cert; 1406 k->cert = NULL; 1407 } 1408 switch (sshkey_type_plain(ret->type)) { 1409 #ifdef WITH_OPENSSL 1410 case KEY_RSA: 1411 RSA_free(ret->rsa); 1412 ret->rsa = k->rsa; 1413 k->rsa = NULL; 1414 #ifdef DEBUG_PK 1415 RSA_print_fp(stderr, ret->rsa, 8); 1416 #endif 1417 break; 1418 case KEY_DSA: 1419 DSA_free(ret->dsa); 1420 ret->dsa = k->dsa; 1421 k->dsa = NULL; 1422 #ifdef DEBUG_PK 1423 DSA_print_fp(stderr, ret->dsa, 8); 1424 #endif 1425 break; 1426 # ifdef OPENSSL_HAS_ECC 1427 case KEY_ECDSA: 1428 EC_KEY_free(ret->ecdsa); 1429 ret->ecdsa = k->ecdsa; 1430 ret->ecdsa_nid = k->ecdsa_nid; 1431 k->ecdsa = NULL; 1432 k->ecdsa_nid = -1; 1433 #ifdef DEBUG_PK 1434 sshkey_dump_ec_key(ret->ecdsa); 1435 #endif 1436 break; 1437 case KEY_ECDSA_SK: 1438 EC_KEY_free(ret->ecdsa); 1439 ret->ecdsa = k->ecdsa; 1440 ret->ecdsa_nid = k->ecdsa_nid; 1441 ret->sk_application = k->sk_application; 1442 k->ecdsa = NULL; 1443 k->ecdsa_nid = -1; 1444 k->sk_application = NULL; 1445 #ifdef DEBUG_PK 1446 sshkey_dump_ec_key(ret->ecdsa); 1447 fprintf(stderr, "App: %s\n", ret->sk_application); 1448 #endif 1449 break; 1450 # endif /* OPENSSL_HAS_ECC */ 1451 #endif /* WITH_OPENSSL */ 1452 case KEY_ED25519: 1453 freezero(ret->ed25519_pk, ED25519_PK_SZ); 1454 ret->ed25519_pk = k->ed25519_pk; 1455 k->ed25519_pk = NULL; 1456 #ifdef DEBUG_PK 1457 /* XXX */ 1458 #endif 1459 break; 1460 case KEY_ED25519_SK: 1461 freezero(ret->ed25519_pk, ED25519_PK_SZ); 1462 ret->ed25519_pk = k->ed25519_pk; 1463 ret->sk_application = k->sk_application; 1464 k->ed25519_pk = NULL; 1465 k->sk_application = NULL; 1466 break; 1467 #ifdef WITH_XMSS 1468 case KEY_XMSS: 1469 free(ret->xmss_pk); 1470 ret->xmss_pk = k->xmss_pk; 1471 k->xmss_pk = NULL; 1472 free(ret->xmss_state); 1473 ret->xmss_state = k->xmss_state; 1474 k->xmss_state = NULL; 1475 free(ret->xmss_name); 1476 ret->xmss_name = k->xmss_name; 1477 k->xmss_name = NULL; 1478 free(ret->xmss_filename); 1479 ret->xmss_filename = k->xmss_filename; 1480 k->xmss_filename = NULL; 1481 #ifdef DEBUG_PK 1482 /* XXX */ 1483 #endif 1484 break; 1485 #endif /* WITH_XMSS */ 1486 default: 1487 sshkey_free(k); 1488 return SSH_ERR_INTERNAL_ERROR; 1489 } 1490 sshkey_free(k); 1491 1492 /* success */ 1493 *cpp = cp; 1494 return 0; 1495 } 1496 1497 1498 int 1499 sshkey_to_base64(const struct sshkey *key, char **b64p) 1500 { 1501 int r = SSH_ERR_INTERNAL_ERROR; 1502 struct sshbuf *b = NULL; 1503 char *uu = NULL; 1504 1505 if (b64p != NULL) 1506 *b64p = NULL; 1507 if ((b = sshbuf_new()) == NULL) 1508 return SSH_ERR_ALLOC_FAIL; 1509 if ((r = sshkey_putb(key, b)) != 0) 1510 goto out; 1511 if ((uu = sshbuf_dtob64_string(b, 0)) == NULL) { 1512 r = SSH_ERR_ALLOC_FAIL; 1513 goto out; 1514 } 1515 /* Success */ 1516 if (b64p != NULL) { 1517 *b64p = uu; 1518 uu = NULL; 1519 } 1520 r = 0; 1521 out: 1522 sshbuf_free(b); 1523 free(uu); 1524 return r; 1525 } 1526 1527 int 1528 sshkey_format_text(const struct sshkey *key, struct sshbuf *b) 1529 { 1530 int r = SSH_ERR_INTERNAL_ERROR; 1531 char *uu = NULL; 1532 1533 if ((r = sshkey_to_base64(key, &uu)) != 0) 1534 goto out; 1535 if ((r = sshbuf_putf(b, "%s %s", 1536 sshkey_ssh_name(key), uu)) != 0) 1537 goto out; 1538 r = 0; 1539 out: 1540 free(uu); 1541 return r; 1542 } 1543 1544 int 1545 sshkey_write(const struct sshkey *key, FILE *f) 1546 { 1547 struct sshbuf *b = NULL; 1548 int r = SSH_ERR_INTERNAL_ERROR; 1549 1550 if ((b = sshbuf_new()) == NULL) 1551 return SSH_ERR_ALLOC_FAIL; 1552 if ((r = sshkey_format_text(key, b)) != 0) 1553 goto out; 1554 if (fwrite(sshbuf_ptr(b), sshbuf_len(b), 1, f) != 1) { 1555 if (feof(f)) 1556 errno = EPIPE; 1557 r = SSH_ERR_SYSTEM_ERROR; 1558 goto out; 1559 } 1560 /* Success */ 1561 r = 0; 1562 out: 1563 sshbuf_free(b); 1564 return r; 1565 } 1566 1567 const char * 1568 sshkey_cert_type(const struct sshkey *k) 1569 { 1570 switch (k->cert->type) { 1571 case SSH2_CERT_TYPE_USER: 1572 return "user"; 1573 case SSH2_CERT_TYPE_HOST: 1574 return "host"; 1575 default: 1576 return "unknown"; 1577 } 1578 } 1579 1580 #ifdef WITH_OPENSSL 1581 static int 1582 rsa_generate_private_key(u_int bits, RSA **rsap) 1583 { 1584 RSA *private = NULL; 1585 BIGNUM *f4 = NULL; 1586 int ret = SSH_ERR_INTERNAL_ERROR; 1587 1588 if (rsap == NULL) 1589 return SSH_ERR_INVALID_ARGUMENT; 1590 if (bits < SSH_RSA_MINIMUM_MODULUS_SIZE || 1591 bits > SSHBUF_MAX_BIGNUM * 8) 1592 return SSH_ERR_KEY_LENGTH; 1593 *rsap = NULL; 1594 if ((private = RSA_new()) == NULL || (f4 = BN_new()) == NULL) { 1595 ret = SSH_ERR_ALLOC_FAIL; 1596 goto out; 1597 } 1598 if (!BN_set_word(f4, RSA_F4) || 1599 !RSA_generate_key_ex(private, bits, f4, NULL)) { 1600 ret = SSH_ERR_LIBCRYPTO_ERROR; 1601 goto out; 1602 } 1603 *rsap = private; 1604 private = NULL; 1605 ret = 0; 1606 out: 1607 RSA_free(private); 1608 BN_free(f4); 1609 return ret; 1610 } 1611 1612 static int 1613 dsa_generate_private_key(u_int bits, DSA **dsap) 1614 { 1615 DSA *private; 1616 int ret = SSH_ERR_INTERNAL_ERROR; 1617 1618 if (dsap == NULL) 1619 return SSH_ERR_INVALID_ARGUMENT; 1620 if (bits != 1024) 1621 return SSH_ERR_KEY_LENGTH; 1622 if ((private = DSA_new()) == NULL) { 1623 ret = SSH_ERR_ALLOC_FAIL; 1624 goto out; 1625 } 1626 *dsap = NULL; 1627 if (!DSA_generate_parameters_ex(private, bits, NULL, 0, NULL, 1628 NULL, NULL) || !DSA_generate_key(private)) { 1629 ret = SSH_ERR_LIBCRYPTO_ERROR; 1630 goto out; 1631 } 1632 *dsap = private; 1633 private = NULL; 1634 ret = 0; 1635 out: 1636 DSA_free(private); 1637 return ret; 1638 } 1639 1640 # ifdef OPENSSL_HAS_ECC 1641 int 1642 sshkey_ecdsa_key_to_nid(EC_KEY *k) 1643 { 1644 EC_GROUP *eg; 1645 int nids[] = { 1646 NID_X9_62_prime256v1, 1647 NID_secp384r1, 1648 # ifdef OPENSSL_HAS_NISTP521 1649 NID_secp521r1, 1650 # endif /* OPENSSL_HAS_NISTP521 */ 1651 -1 1652 }; 1653 int nid; 1654 u_int i; 1655 const EC_GROUP *g = EC_KEY_get0_group(k); 1656 1657 /* 1658 * The group may be stored in a ASN.1 encoded private key in one of two 1659 * ways: as a "named group", which is reconstituted by ASN.1 object ID 1660 * or explicit group parameters encoded into the key blob. Only the 1661 * "named group" case sets the group NID for us, but we can figure 1662 * it out for the other case by comparing against all the groups that 1663 * are supported. 1664 */ 1665 if ((nid = EC_GROUP_get_curve_name(g)) > 0) 1666 return nid; 1667 for (i = 0; nids[i] != -1; i++) { 1668 if ((eg = EC_GROUP_new_by_curve_name(nids[i])) == NULL) 1669 return -1; 1670 if (EC_GROUP_cmp(g, eg, NULL) == 0) 1671 break; 1672 EC_GROUP_free(eg); 1673 } 1674 if (nids[i] != -1) { 1675 /* Use the group with the NID attached */ 1676 EC_GROUP_set_asn1_flag(eg, OPENSSL_EC_NAMED_CURVE); 1677 if (EC_KEY_set_group(k, eg) != 1) { 1678 EC_GROUP_free(eg); 1679 return -1; 1680 } 1681 } 1682 return nids[i]; 1683 } 1684 1685 static int 1686 ecdsa_generate_private_key(u_int bits, int *nid, EC_KEY **ecdsap) 1687 { 1688 EC_KEY *private; 1689 int ret = SSH_ERR_INTERNAL_ERROR; 1690 1691 if (nid == NULL || ecdsap == NULL) 1692 return SSH_ERR_INVALID_ARGUMENT; 1693 if ((*nid = sshkey_ecdsa_bits_to_nid(bits)) == -1) 1694 return SSH_ERR_KEY_LENGTH; 1695 *ecdsap = NULL; 1696 if ((private = EC_KEY_new_by_curve_name(*nid)) == NULL) { 1697 ret = SSH_ERR_ALLOC_FAIL; 1698 goto out; 1699 } 1700 if (EC_KEY_generate_key(private) != 1) { 1701 ret = SSH_ERR_LIBCRYPTO_ERROR; 1702 goto out; 1703 } 1704 EC_KEY_set_asn1_flag(private, OPENSSL_EC_NAMED_CURVE); 1705 *ecdsap = private; 1706 private = NULL; 1707 ret = 0; 1708 out: 1709 EC_KEY_free(private); 1710 return ret; 1711 } 1712 # endif /* OPENSSL_HAS_ECC */ 1713 #endif /* WITH_OPENSSL */ 1714 1715 int 1716 sshkey_generate(int type, u_int bits, struct sshkey **keyp) 1717 { 1718 struct sshkey *k; 1719 int ret = SSH_ERR_INTERNAL_ERROR; 1720 1721 if (keyp == NULL) 1722 return SSH_ERR_INVALID_ARGUMENT; 1723 *keyp = NULL; 1724 if ((k = sshkey_new(KEY_UNSPEC)) == NULL) 1725 return SSH_ERR_ALLOC_FAIL; 1726 switch (type) { 1727 case KEY_ED25519: 1728 if ((k->ed25519_pk = malloc(ED25519_PK_SZ)) == NULL || 1729 (k->ed25519_sk = malloc(ED25519_SK_SZ)) == NULL) { 1730 ret = SSH_ERR_ALLOC_FAIL; 1731 break; 1732 } 1733 crypto_sign_ed25519_keypair(k->ed25519_pk, k->ed25519_sk); 1734 ret = 0; 1735 break; 1736 #ifdef WITH_XMSS 1737 case KEY_XMSS: 1738 ret = sshkey_xmss_generate_private_key(k, bits); 1739 break; 1740 #endif /* WITH_XMSS */ 1741 #ifdef WITH_OPENSSL 1742 case KEY_DSA: 1743 ret = dsa_generate_private_key(bits, &k->dsa); 1744 break; 1745 # ifdef OPENSSL_HAS_ECC 1746 case KEY_ECDSA: 1747 ret = ecdsa_generate_private_key(bits, &k->ecdsa_nid, 1748 &k->ecdsa); 1749 break; 1750 # endif /* OPENSSL_HAS_ECC */ 1751 case KEY_RSA: 1752 ret = rsa_generate_private_key(bits, &k->rsa); 1753 break; 1754 #endif /* WITH_OPENSSL */ 1755 default: 1756 ret = SSH_ERR_INVALID_ARGUMENT; 1757 } 1758 if (ret == 0) { 1759 k->type = type; 1760 *keyp = k; 1761 } else 1762 sshkey_free(k); 1763 return ret; 1764 } 1765 1766 int 1767 sshkey_cert_copy(const struct sshkey *from_key, struct sshkey *to_key) 1768 { 1769 u_int i; 1770 const struct sshkey_cert *from; 1771 struct sshkey_cert *to; 1772 int r = SSH_ERR_INTERNAL_ERROR; 1773 1774 if (to_key == NULL || (from = from_key->cert) == NULL) 1775 return SSH_ERR_INVALID_ARGUMENT; 1776 1777 if ((to = cert_new()) == NULL) 1778 return SSH_ERR_ALLOC_FAIL; 1779 1780 if ((r = sshbuf_putb(to->certblob, from->certblob)) != 0 || 1781 (r = sshbuf_putb(to->critical, from->critical)) != 0 || 1782 (r = sshbuf_putb(to->extensions, from->extensions)) != 0) 1783 goto out; 1784 1785 to->serial = from->serial; 1786 to->type = from->type; 1787 if (from->key_id == NULL) 1788 to->key_id = NULL; 1789 else if ((to->key_id = strdup(from->key_id)) == NULL) { 1790 r = SSH_ERR_ALLOC_FAIL; 1791 goto out; 1792 } 1793 to->valid_after = from->valid_after; 1794 to->valid_before = from->valid_before; 1795 if (from->signature_key == NULL) 1796 to->signature_key = NULL; 1797 else if ((r = sshkey_from_private(from->signature_key, 1798 &to->signature_key)) != 0) 1799 goto out; 1800 if (from->signature_type != NULL && 1801 (to->signature_type = strdup(from->signature_type)) == NULL) { 1802 r = SSH_ERR_ALLOC_FAIL; 1803 goto out; 1804 } 1805 if (from->nprincipals > SSHKEY_CERT_MAX_PRINCIPALS) { 1806 r = SSH_ERR_INVALID_ARGUMENT; 1807 goto out; 1808 } 1809 if (from->nprincipals > 0) { 1810 if ((to->principals = calloc(from->nprincipals, 1811 sizeof(*to->principals))) == NULL) { 1812 r = SSH_ERR_ALLOC_FAIL; 1813 goto out; 1814 } 1815 for (i = 0; i < from->nprincipals; i++) { 1816 to->principals[i] = strdup(from->principals[i]); 1817 if (to->principals[i] == NULL) { 1818 to->nprincipals = i; 1819 r = SSH_ERR_ALLOC_FAIL; 1820 goto out; 1821 } 1822 } 1823 } 1824 to->nprincipals = from->nprincipals; 1825 1826 /* success */ 1827 cert_free(to_key->cert); 1828 to_key->cert = to; 1829 to = NULL; 1830 r = 0; 1831 out: 1832 cert_free(to); 1833 return r; 1834 } 1835 1836 int 1837 sshkey_from_private(const struct sshkey *k, struct sshkey **pkp) 1838 { 1839 struct sshkey *n = NULL; 1840 int r = SSH_ERR_INTERNAL_ERROR; 1841 #ifdef WITH_OPENSSL 1842 const BIGNUM *rsa_n, *rsa_e; 1843 BIGNUM *rsa_n_dup = NULL, *rsa_e_dup = NULL; 1844 const BIGNUM *dsa_p, *dsa_q, *dsa_g, *dsa_pub_key; 1845 BIGNUM *dsa_p_dup = NULL, *dsa_q_dup = NULL, *dsa_g_dup = NULL; 1846 BIGNUM *dsa_pub_key_dup = NULL; 1847 #endif /* WITH_OPENSSL */ 1848 1849 *pkp = NULL; 1850 if ((n = sshkey_new(k->type)) == NULL) { 1851 r = SSH_ERR_ALLOC_FAIL; 1852 goto out; 1853 } 1854 switch (k->type) { 1855 #ifdef WITH_OPENSSL 1856 case KEY_DSA: 1857 case KEY_DSA_CERT: 1858 DSA_get0_pqg(k->dsa, &dsa_p, &dsa_q, &dsa_g); 1859 DSA_get0_key(k->dsa, &dsa_pub_key, NULL); 1860 if ((dsa_p_dup = BN_dup(dsa_p)) == NULL || 1861 (dsa_q_dup = BN_dup(dsa_q)) == NULL || 1862 (dsa_g_dup = BN_dup(dsa_g)) == NULL || 1863 (dsa_pub_key_dup = BN_dup(dsa_pub_key)) == NULL) { 1864 r = SSH_ERR_ALLOC_FAIL; 1865 goto out; 1866 } 1867 if (!DSA_set0_pqg(n->dsa, dsa_p_dup, dsa_q_dup, dsa_g_dup)) { 1868 r = SSH_ERR_LIBCRYPTO_ERROR; 1869 goto out; 1870 } 1871 dsa_p_dup = dsa_q_dup = dsa_g_dup = NULL; /* transferred */ 1872 if (!DSA_set0_key(n->dsa, dsa_pub_key_dup, NULL)) { 1873 r = SSH_ERR_LIBCRYPTO_ERROR; 1874 goto out; 1875 } 1876 dsa_pub_key_dup = NULL; /* transferred */ 1877 1878 break; 1879 # ifdef OPENSSL_HAS_ECC 1880 case KEY_ECDSA: 1881 case KEY_ECDSA_CERT: 1882 case KEY_ECDSA_SK: 1883 case KEY_ECDSA_SK_CERT: 1884 n->ecdsa_nid = k->ecdsa_nid; 1885 n->ecdsa = EC_KEY_new_by_curve_name(k->ecdsa_nid); 1886 if (n->ecdsa == NULL) { 1887 r = SSH_ERR_ALLOC_FAIL; 1888 goto out; 1889 } 1890 if (EC_KEY_set_public_key(n->ecdsa, 1891 EC_KEY_get0_public_key(k->ecdsa)) != 1) { 1892 r = SSH_ERR_LIBCRYPTO_ERROR; 1893 goto out; 1894 } 1895 if (k->type != KEY_ECDSA_SK && k->type != KEY_ECDSA_SK_CERT) 1896 break; 1897 /* Append security-key application string */ 1898 if ((n->sk_application = strdup(k->sk_application)) == NULL) 1899 goto out; 1900 break; 1901 # endif /* OPENSSL_HAS_ECC */ 1902 case KEY_RSA: 1903 case KEY_RSA_CERT: 1904 RSA_get0_key(k->rsa, &rsa_n, &rsa_e, NULL); 1905 if ((rsa_n_dup = BN_dup(rsa_n)) == NULL || 1906 (rsa_e_dup = BN_dup(rsa_e)) == NULL) { 1907 r = SSH_ERR_ALLOC_FAIL; 1908 goto out; 1909 } 1910 if (!RSA_set0_key(n->rsa, rsa_n_dup, rsa_e_dup, NULL)) { 1911 r = SSH_ERR_LIBCRYPTO_ERROR; 1912 goto out; 1913 } 1914 rsa_n_dup = rsa_e_dup = NULL; /* transferred */ 1915 break; 1916 #endif /* WITH_OPENSSL */ 1917 case KEY_ED25519: 1918 case KEY_ED25519_CERT: 1919 case KEY_ED25519_SK: 1920 case KEY_ED25519_SK_CERT: 1921 if (k->ed25519_pk != NULL) { 1922 if ((n->ed25519_pk = malloc(ED25519_PK_SZ)) == NULL) { 1923 r = SSH_ERR_ALLOC_FAIL; 1924 goto out; 1925 } 1926 memcpy(n->ed25519_pk, k->ed25519_pk, ED25519_PK_SZ); 1927 } 1928 if (k->type != KEY_ED25519_SK && 1929 k->type != KEY_ED25519_SK_CERT) 1930 break; 1931 /* Append security-key application string */ 1932 if ((n->sk_application = strdup(k->sk_application)) == NULL) 1933 goto out; 1934 break; 1935 #ifdef WITH_XMSS 1936 case KEY_XMSS: 1937 case KEY_XMSS_CERT: 1938 if ((r = sshkey_xmss_init(n, k->xmss_name)) != 0) 1939 goto out; 1940 if (k->xmss_pk != NULL) { 1941 u_int32_t left; 1942 size_t pklen = sshkey_xmss_pklen(k); 1943 if (pklen == 0 || sshkey_xmss_pklen(n) != pklen) { 1944 r = SSH_ERR_INTERNAL_ERROR; 1945 goto out; 1946 } 1947 if ((n->xmss_pk = malloc(pklen)) == NULL) { 1948 r = SSH_ERR_ALLOC_FAIL; 1949 goto out; 1950 } 1951 memcpy(n->xmss_pk, k->xmss_pk, pklen); 1952 /* simulate number of signatures left on pubkey */ 1953 left = sshkey_xmss_signatures_left(k); 1954 if (left) 1955 sshkey_xmss_enable_maxsign(n, left); 1956 } 1957 break; 1958 #endif /* WITH_XMSS */ 1959 default: 1960 r = SSH_ERR_KEY_TYPE_UNKNOWN; 1961 goto out; 1962 } 1963 if (sshkey_is_cert(k) && (r = sshkey_cert_copy(k, n)) != 0) 1964 goto out; 1965 /* success */ 1966 *pkp = n; 1967 n = NULL; 1968 r = 0; 1969 out: 1970 sshkey_free(n); 1971 #ifdef WITH_OPENSSL 1972 BN_clear_free(rsa_n_dup); 1973 BN_clear_free(rsa_e_dup); 1974 BN_clear_free(dsa_p_dup); 1975 BN_clear_free(dsa_q_dup); 1976 BN_clear_free(dsa_g_dup); 1977 BN_clear_free(dsa_pub_key_dup); 1978 #endif 1979 1980 return r; 1981 } 1982 1983 int 1984 sshkey_is_shielded(struct sshkey *k) 1985 { 1986 return k != NULL && k->shielded_private != NULL; 1987 } 1988 1989 int 1990 sshkey_shield_private(struct sshkey *k) 1991 { 1992 struct sshbuf *prvbuf = NULL; 1993 u_char *prekey = NULL, *enc = NULL, keyiv[SSH_DIGEST_MAX_LENGTH]; 1994 struct sshcipher_ctx *cctx = NULL; 1995 const struct sshcipher *cipher; 1996 size_t i, enclen = 0; 1997 struct sshkey *kswap = NULL, tmp; 1998 int r = SSH_ERR_INTERNAL_ERROR; 1999 2000 #ifdef DEBUG_PK 2001 fprintf(stderr, "%s: entering for %s\n", __func__, sshkey_ssh_name(k)); 2002 #endif 2003 if ((cipher = cipher_by_name(SSHKEY_SHIELD_CIPHER)) == NULL) { 2004 r = SSH_ERR_INVALID_ARGUMENT; 2005 goto out; 2006 } 2007 if (cipher_keylen(cipher) + cipher_ivlen(cipher) > 2008 ssh_digest_bytes(SSHKEY_SHIELD_PREKEY_HASH)) { 2009 r = SSH_ERR_INTERNAL_ERROR; 2010 goto out; 2011 } 2012 2013 /* Prepare a random pre-key, and from it an ephemeral key */ 2014 if ((prekey = malloc(SSHKEY_SHIELD_PREKEY_LEN)) == NULL) { 2015 r = SSH_ERR_ALLOC_FAIL; 2016 goto out; 2017 } 2018 arc4random_buf(prekey, SSHKEY_SHIELD_PREKEY_LEN); 2019 if ((r = ssh_digest_memory(SSHKEY_SHIELD_PREKEY_HASH, 2020 prekey, SSHKEY_SHIELD_PREKEY_LEN, 2021 keyiv, SSH_DIGEST_MAX_LENGTH)) != 0) 2022 goto out; 2023 #ifdef DEBUG_PK 2024 fprintf(stderr, "%s: key+iv\n", __func__); 2025 sshbuf_dump_data(keyiv, ssh_digest_bytes(SSHKEY_SHIELD_PREKEY_HASH), 2026 stderr); 2027 #endif 2028 if ((r = cipher_init(&cctx, cipher, keyiv, cipher_keylen(cipher), 2029 keyiv + cipher_keylen(cipher), cipher_ivlen(cipher), 1)) != 0) 2030 goto out; 2031 2032 /* Serialise and encrypt the private key using the ephemeral key */ 2033 if ((prvbuf = sshbuf_new()) == NULL) { 2034 r = SSH_ERR_ALLOC_FAIL; 2035 goto out; 2036 } 2037 if (sshkey_is_shielded(k) && (r = sshkey_unshield_private(k)) != 0) 2038 goto out; 2039 if ((r = sshkey_private_serialize_opt(k, prvbuf, 2040 SSHKEY_SERIALIZE_SHIELD)) != 0) 2041 goto out; 2042 /* pad to cipher blocksize */ 2043 i = 0; 2044 while (sshbuf_len(prvbuf) % cipher_blocksize(cipher)) { 2045 if ((r = sshbuf_put_u8(prvbuf, ++i & 0xff)) != 0) 2046 goto out; 2047 } 2048 #ifdef DEBUG_PK 2049 fprintf(stderr, "%s: serialised\n", __func__); 2050 sshbuf_dump(prvbuf, stderr); 2051 #endif 2052 /* encrypt */ 2053 enclen = sshbuf_len(prvbuf); 2054 if ((enc = malloc(enclen)) == NULL) { 2055 r = SSH_ERR_ALLOC_FAIL; 2056 goto out; 2057 } 2058 if ((r = cipher_crypt(cctx, 0, enc, 2059 sshbuf_ptr(prvbuf), sshbuf_len(prvbuf), 0, 0)) != 0) 2060 goto out; 2061 #ifdef DEBUG_PK 2062 fprintf(stderr, "%s: encrypted\n", __func__); 2063 sshbuf_dump_data(enc, enclen, stderr); 2064 #endif 2065 2066 /* Make a scrubbed, public-only copy of our private key argument */ 2067 if ((r = sshkey_from_private(k, &kswap)) != 0) 2068 goto out; 2069 2070 /* Swap the private key out (it will be destroyed below) */ 2071 tmp = *kswap; 2072 *kswap = *k; 2073 *k = tmp; 2074 2075 /* Insert the shielded key into our argument */ 2076 k->shielded_private = enc; 2077 k->shielded_len = enclen; 2078 k->shield_prekey = prekey; 2079 k->shield_prekey_len = SSHKEY_SHIELD_PREKEY_LEN; 2080 enc = prekey = NULL; /* transferred */ 2081 enclen = 0; 2082 2083 /* success */ 2084 r = 0; 2085 2086 out: 2087 /* XXX behaviour on error - invalidate original private key? */ 2088 cipher_free(cctx); 2089 explicit_bzero(keyiv, sizeof(keyiv)); 2090 explicit_bzero(&tmp, sizeof(tmp)); 2091 freezero(enc, enclen); 2092 freezero(prekey, SSHKEY_SHIELD_PREKEY_LEN); 2093 sshkey_free(kswap); 2094 sshbuf_free(prvbuf); 2095 return r; 2096 } 2097 2098 int 2099 sshkey_unshield_private(struct sshkey *k) 2100 { 2101 struct sshbuf *prvbuf = NULL; 2102 u_char pad, *cp, keyiv[SSH_DIGEST_MAX_LENGTH]; 2103 struct sshcipher_ctx *cctx = NULL; 2104 const struct sshcipher *cipher; 2105 size_t i; 2106 struct sshkey *kswap = NULL, tmp; 2107 int r = SSH_ERR_INTERNAL_ERROR; 2108 2109 #ifdef DEBUG_PK 2110 fprintf(stderr, "%s: entering for %s\n", __func__, sshkey_ssh_name(k)); 2111 #endif 2112 if (!sshkey_is_shielded(k)) 2113 return 0; /* nothing to do */ 2114 2115 if ((cipher = cipher_by_name(SSHKEY_SHIELD_CIPHER)) == NULL) { 2116 r = SSH_ERR_INVALID_ARGUMENT; 2117 goto out; 2118 } 2119 if (cipher_keylen(cipher) + cipher_ivlen(cipher) > 2120 ssh_digest_bytes(SSHKEY_SHIELD_PREKEY_HASH)) { 2121 r = SSH_ERR_INTERNAL_ERROR; 2122 goto out; 2123 } 2124 /* check size of shielded key blob */ 2125 if (k->shielded_len < cipher_blocksize(cipher) || 2126 (k->shielded_len % cipher_blocksize(cipher)) != 0) { 2127 r = SSH_ERR_INVALID_FORMAT; 2128 goto out; 2129 } 2130 2131 /* Calculate the ephemeral key from the prekey */ 2132 if ((r = ssh_digest_memory(SSHKEY_SHIELD_PREKEY_HASH, 2133 k->shield_prekey, k->shield_prekey_len, 2134 keyiv, SSH_DIGEST_MAX_LENGTH)) != 0) 2135 goto out; 2136 if ((r = cipher_init(&cctx, cipher, keyiv, cipher_keylen(cipher), 2137 keyiv + cipher_keylen(cipher), cipher_ivlen(cipher), 0)) != 0) 2138 goto out; 2139 #ifdef DEBUG_PK 2140 fprintf(stderr, "%s: key+iv\n", __func__); 2141 sshbuf_dump_data(keyiv, ssh_digest_bytes(SSHKEY_SHIELD_PREKEY_HASH), 2142 stderr); 2143 #endif 2144 2145 /* Decrypt and parse the shielded private key using the ephemeral key */ 2146 if ((prvbuf = sshbuf_new()) == NULL) { 2147 r = SSH_ERR_ALLOC_FAIL; 2148 goto out; 2149 } 2150 if ((r = sshbuf_reserve(prvbuf, k->shielded_len, &cp)) != 0) 2151 goto out; 2152 /* decrypt */ 2153 #ifdef DEBUG_PK 2154 fprintf(stderr, "%s: encrypted\n", __func__); 2155 sshbuf_dump_data(k->shielded_private, k->shielded_len, stderr); 2156 #endif 2157 if ((r = cipher_crypt(cctx, 0, cp, 2158 k->shielded_private, k->shielded_len, 0, 0)) != 0) 2159 goto out; 2160 #ifdef DEBUG_PK 2161 fprintf(stderr, "%s: serialised\n", __func__); 2162 sshbuf_dump(prvbuf, stderr); 2163 #endif 2164 /* Parse private key */ 2165 if ((r = sshkey_private_deserialize(prvbuf, &kswap)) != 0) 2166 goto out; 2167 /* Check deterministic padding */ 2168 i = 0; 2169 while (sshbuf_len(prvbuf)) { 2170 if ((r = sshbuf_get_u8(prvbuf, &pad)) != 0) 2171 goto out; 2172 if (pad != (++i & 0xff)) { 2173 r = SSH_ERR_INVALID_FORMAT; 2174 goto out; 2175 } 2176 } 2177 2178 /* Swap the parsed key back into place */ 2179 tmp = *kswap; 2180 *kswap = *k; 2181 *k = tmp; 2182 2183 /* success */ 2184 r = 0; 2185 2186 out: 2187 cipher_free(cctx); 2188 explicit_bzero(keyiv, sizeof(keyiv)); 2189 explicit_bzero(&tmp, sizeof(tmp)); 2190 sshkey_free(kswap); 2191 sshbuf_free(prvbuf); 2192 return r; 2193 } 2194 2195 static int 2196 cert_parse(struct sshbuf *b, struct sshkey *key, struct sshbuf *certbuf) 2197 { 2198 struct sshbuf *principals = NULL, *crit = NULL; 2199 struct sshbuf *exts = NULL, *ca = NULL; 2200 u_char *sig = NULL; 2201 size_t signed_len = 0, slen = 0, kidlen = 0; 2202 int ret = SSH_ERR_INTERNAL_ERROR; 2203 2204 /* Copy the entire key blob for verification and later serialisation */ 2205 if ((ret = sshbuf_putb(key->cert->certblob, certbuf)) != 0) 2206 return ret; 2207 2208 /* Parse body of certificate up to signature */ 2209 if ((ret = sshbuf_get_u64(b, &key->cert->serial)) != 0 || 2210 (ret = sshbuf_get_u32(b, &key->cert->type)) != 0 || 2211 (ret = sshbuf_get_cstring(b, &key->cert->key_id, &kidlen)) != 0 || 2212 (ret = sshbuf_froms(b, &principals)) != 0 || 2213 (ret = sshbuf_get_u64(b, &key->cert->valid_after)) != 0 || 2214 (ret = sshbuf_get_u64(b, &key->cert->valid_before)) != 0 || 2215 (ret = sshbuf_froms(b, &crit)) != 0 || 2216 (ret = sshbuf_froms(b, &exts)) != 0 || 2217 (ret = sshbuf_get_string_direct(b, NULL, NULL)) != 0 || 2218 (ret = sshbuf_froms(b, &ca)) != 0) { 2219 /* XXX debug print error for ret */ 2220 ret = SSH_ERR_INVALID_FORMAT; 2221 goto out; 2222 } 2223 2224 /* Signature is left in the buffer so we can calculate this length */ 2225 signed_len = sshbuf_len(key->cert->certblob) - sshbuf_len(b); 2226 2227 if ((ret = sshbuf_get_string(b, &sig, &slen)) != 0) { 2228 ret = SSH_ERR_INVALID_FORMAT; 2229 goto out; 2230 } 2231 2232 if (key->cert->type != SSH2_CERT_TYPE_USER && 2233 key->cert->type != SSH2_CERT_TYPE_HOST) { 2234 ret = SSH_ERR_KEY_CERT_UNKNOWN_TYPE; 2235 goto out; 2236 } 2237 2238 /* Parse principals section */ 2239 while (sshbuf_len(principals) > 0) { 2240 char *principal = NULL; 2241 char **oprincipals = NULL; 2242 2243 if (key->cert->nprincipals >= SSHKEY_CERT_MAX_PRINCIPALS) { 2244 ret = SSH_ERR_INVALID_FORMAT; 2245 goto out; 2246 } 2247 if ((ret = sshbuf_get_cstring(principals, &principal, 2248 NULL)) != 0) { 2249 ret = SSH_ERR_INVALID_FORMAT; 2250 goto out; 2251 } 2252 oprincipals = key->cert->principals; 2253 key->cert->principals = recallocarray(key->cert->principals, 2254 key->cert->nprincipals, key->cert->nprincipals + 1, 2255 sizeof(*key->cert->principals)); 2256 if (key->cert->principals == NULL) { 2257 free(principal); 2258 key->cert->principals = oprincipals; 2259 ret = SSH_ERR_ALLOC_FAIL; 2260 goto out; 2261 } 2262 key->cert->principals[key->cert->nprincipals++] = principal; 2263 } 2264 2265 /* 2266 * Stash a copies of the critical options and extensions sections 2267 * for later use. 2268 */ 2269 if ((ret = sshbuf_putb(key->cert->critical, crit)) != 0 || 2270 (exts != NULL && 2271 (ret = sshbuf_putb(key->cert->extensions, exts)) != 0)) 2272 goto out; 2273 2274 /* 2275 * Validate critical options and extensions sections format. 2276 */ 2277 while (sshbuf_len(crit) != 0) { 2278 if ((ret = sshbuf_get_string_direct(crit, NULL, NULL)) != 0 || 2279 (ret = sshbuf_get_string_direct(crit, NULL, NULL)) != 0) { 2280 sshbuf_reset(key->cert->critical); 2281 ret = SSH_ERR_INVALID_FORMAT; 2282 goto out; 2283 } 2284 } 2285 while (exts != NULL && sshbuf_len(exts) != 0) { 2286 if ((ret = sshbuf_get_string_direct(exts, NULL, NULL)) != 0 || 2287 (ret = sshbuf_get_string_direct(exts, NULL, NULL)) != 0) { 2288 sshbuf_reset(key->cert->extensions); 2289 ret = SSH_ERR_INVALID_FORMAT; 2290 goto out; 2291 } 2292 } 2293 2294 /* Parse CA key and check signature */ 2295 if (sshkey_from_blob_internal(ca, &key->cert->signature_key, 0) != 0) { 2296 ret = SSH_ERR_KEY_CERT_INVALID_SIGN_KEY; 2297 goto out; 2298 } 2299 if (!sshkey_type_is_valid_ca(key->cert->signature_key->type)) { 2300 ret = SSH_ERR_KEY_CERT_INVALID_SIGN_KEY; 2301 goto out; 2302 } 2303 if ((ret = sshkey_verify(key->cert->signature_key, sig, slen, 2304 sshbuf_ptr(key->cert->certblob), signed_len, NULL, 0, NULL)) != 0) 2305 goto out; 2306 if ((ret = sshkey_get_sigtype(sig, slen, 2307 &key->cert->signature_type)) != 0) 2308 goto out; 2309 2310 /* Success */ 2311 ret = 0; 2312 out: 2313 sshbuf_free(ca); 2314 sshbuf_free(crit); 2315 sshbuf_free(exts); 2316 sshbuf_free(principals); 2317 free(sig); 2318 return ret; 2319 } 2320 2321 #ifdef WITH_OPENSSL 2322 static int 2323 check_rsa_length(const RSA *rsa) 2324 { 2325 const BIGNUM *rsa_n; 2326 2327 RSA_get0_key(rsa, &rsa_n, NULL, NULL); 2328 if (BN_num_bits(rsa_n) < SSH_RSA_MINIMUM_MODULUS_SIZE) 2329 return SSH_ERR_KEY_LENGTH; 2330 return 0; 2331 } 2332 #endif 2333 2334 static int 2335 sshkey_from_blob_internal(struct sshbuf *b, struct sshkey **keyp, 2336 int allow_cert) 2337 { 2338 int type, ret = SSH_ERR_INTERNAL_ERROR; 2339 char *ktype = NULL, *curve = NULL, *xmss_name = NULL; 2340 struct sshkey *key = NULL; 2341 size_t len; 2342 u_char *pk = NULL; 2343 struct sshbuf *copy; 2344 #if defined(WITH_OPENSSL) 2345 BIGNUM *rsa_n = NULL, *rsa_e = NULL; 2346 BIGNUM *dsa_p = NULL, *dsa_q = NULL, *dsa_g = NULL, *dsa_pub_key = NULL; 2347 # if defined(OPENSSL_HAS_ECC) 2348 EC_POINT *q = NULL; 2349 # endif /* OPENSSL_HAS_ECC */ 2350 #endif /* WITH_OPENSSL */ 2351 2352 #ifdef DEBUG_PK /* XXX */ 2353 sshbuf_dump(b, stderr); 2354 #endif 2355 if (keyp != NULL) 2356 *keyp = NULL; 2357 if ((copy = sshbuf_fromb(b)) == NULL) { 2358 ret = SSH_ERR_ALLOC_FAIL; 2359 goto out; 2360 } 2361 if (sshbuf_get_cstring(b, &ktype, NULL) != 0) { 2362 ret = SSH_ERR_INVALID_FORMAT; 2363 goto out; 2364 } 2365 2366 type = sshkey_type_from_name(ktype); 2367 if (!allow_cert && sshkey_type_is_cert(type)) { 2368 ret = SSH_ERR_KEY_CERT_INVALID_SIGN_KEY; 2369 goto out; 2370 } 2371 switch (type) { 2372 #ifdef WITH_OPENSSL 2373 case KEY_RSA_CERT: 2374 /* Skip nonce */ 2375 if (sshbuf_get_string_direct(b, NULL, NULL) != 0) { 2376 ret = SSH_ERR_INVALID_FORMAT; 2377 goto out; 2378 } 2379 /* FALLTHROUGH */ 2380 case KEY_RSA: 2381 if ((key = sshkey_new(type)) == NULL) { 2382 ret = SSH_ERR_ALLOC_FAIL; 2383 goto out; 2384 } 2385 if (sshbuf_get_bignum2(b, &rsa_e) != 0 || 2386 sshbuf_get_bignum2(b, &rsa_n) != 0) { 2387 ret = SSH_ERR_INVALID_FORMAT; 2388 goto out; 2389 } 2390 if (!RSA_set0_key(key->rsa, rsa_n, rsa_e, NULL)) { 2391 ret = SSH_ERR_LIBCRYPTO_ERROR; 2392 goto out; 2393 } 2394 rsa_n = rsa_e = NULL; /* transferred */ 2395 if ((ret = check_rsa_length(key->rsa)) != 0) 2396 goto out; 2397 #ifdef DEBUG_PK 2398 RSA_print_fp(stderr, key->rsa, 8); 2399 #endif 2400 break; 2401 case KEY_DSA_CERT: 2402 /* Skip nonce */ 2403 if (sshbuf_get_string_direct(b, NULL, NULL) != 0) { 2404 ret = SSH_ERR_INVALID_FORMAT; 2405 goto out; 2406 } 2407 /* FALLTHROUGH */ 2408 case KEY_DSA: 2409 if ((key = sshkey_new(type)) == NULL) { 2410 ret = SSH_ERR_ALLOC_FAIL; 2411 goto out; 2412 } 2413 if (sshbuf_get_bignum2(b, &dsa_p) != 0 || 2414 sshbuf_get_bignum2(b, &dsa_q) != 0 || 2415 sshbuf_get_bignum2(b, &dsa_g) != 0 || 2416 sshbuf_get_bignum2(b, &dsa_pub_key) != 0) { 2417 ret = SSH_ERR_INVALID_FORMAT; 2418 goto out; 2419 } 2420 if (!DSA_set0_pqg(key->dsa, dsa_p, dsa_q, dsa_g)) { 2421 ret = SSH_ERR_LIBCRYPTO_ERROR; 2422 goto out; 2423 } 2424 dsa_p = dsa_q = dsa_g = NULL; /* transferred */ 2425 if (!DSA_set0_key(key->dsa, dsa_pub_key, NULL)) { 2426 ret = SSH_ERR_LIBCRYPTO_ERROR; 2427 goto out; 2428 } 2429 dsa_pub_key = NULL; /* transferred */ 2430 #ifdef DEBUG_PK 2431 DSA_print_fp(stderr, key->dsa, 8); 2432 #endif 2433 break; 2434 # ifdef OPENSSL_HAS_ECC 2435 case KEY_ECDSA_CERT: 2436 case KEY_ECDSA_SK_CERT: 2437 /* Skip nonce */ 2438 if (sshbuf_get_string_direct(b, NULL, NULL) != 0) { 2439 ret = SSH_ERR_INVALID_FORMAT; 2440 goto out; 2441 } 2442 /* FALLTHROUGH */ 2443 case KEY_ECDSA: 2444 case KEY_ECDSA_SK: 2445 if ((key = sshkey_new(type)) == NULL) { 2446 ret = SSH_ERR_ALLOC_FAIL; 2447 goto out; 2448 } 2449 key->ecdsa_nid = sshkey_ecdsa_nid_from_name(ktype); 2450 if (sshbuf_get_cstring(b, &curve, NULL) != 0) { 2451 ret = SSH_ERR_INVALID_FORMAT; 2452 goto out; 2453 } 2454 if (key->ecdsa_nid != sshkey_curve_name_to_nid(curve)) { 2455 ret = SSH_ERR_EC_CURVE_MISMATCH; 2456 goto out; 2457 } 2458 EC_KEY_free(key->ecdsa); 2459 if ((key->ecdsa = EC_KEY_new_by_curve_name(key->ecdsa_nid)) 2460 == NULL) { 2461 ret = SSH_ERR_EC_CURVE_INVALID; 2462 goto out; 2463 } 2464 if ((q = EC_POINT_new(EC_KEY_get0_group(key->ecdsa))) == NULL) { 2465 ret = SSH_ERR_ALLOC_FAIL; 2466 goto out; 2467 } 2468 if (sshbuf_get_ec(b, q, EC_KEY_get0_group(key->ecdsa)) != 0) { 2469 ret = SSH_ERR_INVALID_FORMAT; 2470 goto out; 2471 } 2472 if (sshkey_ec_validate_public(EC_KEY_get0_group(key->ecdsa), 2473 q) != 0) { 2474 ret = SSH_ERR_KEY_INVALID_EC_VALUE; 2475 goto out; 2476 } 2477 if (EC_KEY_set_public_key(key->ecdsa, q) != 1) { 2478 /* XXX assume it is a allocation error */ 2479 ret = SSH_ERR_ALLOC_FAIL; 2480 goto out; 2481 } 2482 #ifdef DEBUG_PK 2483 sshkey_dump_ec_point(EC_KEY_get0_group(key->ecdsa), q); 2484 #endif 2485 if (type == KEY_ECDSA_SK || type == KEY_ECDSA_SK_CERT) { 2486 /* Parse additional security-key application string */ 2487 if (sshbuf_get_cstring(b, &key->sk_application, 2488 NULL) != 0) { 2489 ret = SSH_ERR_INVALID_FORMAT; 2490 goto out; 2491 } 2492 #ifdef DEBUG_PK 2493 fprintf(stderr, "App: %s\n", key->sk_application); 2494 #endif 2495 } 2496 break; 2497 # endif /* OPENSSL_HAS_ECC */ 2498 #endif /* WITH_OPENSSL */ 2499 case KEY_ED25519_CERT: 2500 case KEY_ED25519_SK_CERT: 2501 /* Skip nonce */ 2502 if (sshbuf_get_string_direct(b, NULL, NULL) != 0) { 2503 ret = SSH_ERR_INVALID_FORMAT; 2504 goto out; 2505 } 2506 /* FALLTHROUGH */ 2507 case KEY_ED25519: 2508 case KEY_ED25519_SK: 2509 if ((ret = sshbuf_get_string(b, &pk, &len)) != 0) 2510 goto out; 2511 if (len != ED25519_PK_SZ) { 2512 ret = SSH_ERR_INVALID_FORMAT; 2513 goto out; 2514 } 2515 if ((key = sshkey_new(type)) == NULL) { 2516 ret = SSH_ERR_ALLOC_FAIL; 2517 goto out; 2518 } 2519 if (type == KEY_ED25519_SK || type == KEY_ED25519_SK_CERT) { 2520 /* Parse additional security-key application string */ 2521 if (sshbuf_get_cstring(b, &key->sk_application, 2522 NULL) != 0) { 2523 ret = SSH_ERR_INVALID_FORMAT; 2524 goto out; 2525 } 2526 #ifdef DEBUG_PK 2527 fprintf(stderr, "App: %s\n", key->sk_application); 2528 #endif 2529 } 2530 key->ed25519_pk = pk; 2531 pk = NULL; 2532 break; 2533 #ifdef WITH_XMSS 2534 case KEY_XMSS_CERT: 2535 /* Skip nonce */ 2536 if (sshbuf_get_string_direct(b, NULL, NULL) != 0) { 2537 ret = SSH_ERR_INVALID_FORMAT; 2538 goto out; 2539 } 2540 /* FALLTHROUGH */ 2541 case KEY_XMSS: 2542 if ((ret = sshbuf_get_cstring(b, &xmss_name, NULL)) != 0) 2543 goto out; 2544 if ((key = sshkey_new(type)) == NULL) { 2545 ret = SSH_ERR_ALLOC_FAIL; 2546 goto out; 2547 } 2548 if ((ret = sshkey_xmss_init(key, xmss_name)) != 0) 2549 goto out; 2550 if ((ret = sshbuf_get_string(b, &pk, &len)) != 0) 2551 goto out; 2552 if (len == 0 || len != sshkey_xmss_pklen(key)) { 2553 ret = SSH_ERR_INVALID_FORMAT; 2554 goto out; 2555 } 2556 key->xmss_pk = pk; 2557 pk = NULL; 2558 if (type != KEY_XMSS_CERT && 2559 (ret = sshkey_xmss_deserialize_pk_info(key, b)) != 0) 2560 goto out; 2561 break; 2562 #endif /* WITH_XMSS */ 2563 case KEY_UNSPEC: 2564 default: 2565 ret = SSH_ERR_KEY_TYPE_UNKNOWN; 2566 goto out; 2567 } 2568 2569 /* Parse certificate potion */ 2570 if (sshkey_is_cert(key) && (ret = cert_parse(b, key, copy)) != 0) 2571 goto out; 2572 2573 if (key != NULL && sshbuf_len(b) != 0) { 2574 ret = SSH_ERR_INVALID_FORMAT; 2575 goto out; 2576 } 2577 ret = 0; 2578 if (keyp != NULL) { 2579 *keyp = key; 2580 key = NULL; 2581 } 2582 out: 2583 sshbuf_free(copy); 2584 sshkey_free(key); 2585 free(xmss_name); 2586 free(ktype); 2587 free(curve); 2588 free(pk); 2589 #if defined(WITH_OPENSSL) 2590 BN_clear_free(rsa_n); 2591 BN_clear_free(rsa_e); 2592 BN_clear_free(dsa_p); 2593 BN_clear_free(dsa_q); 2594 BN_clear_free(dsa_g); 2595 BN_clear_free(dsa_pub_key); 2596 # if defined(OPENSSL_HAS_ECC) 2597 EC_POINT_free(q); 2598 # endif /* OPENSSL_HAS_ECC */ 2599 #endif /* WITH_OPENSSL */ 2600 return ret; 2601 } 2602 2603 int 2604 sshkey_from_blob(const u_char *blob, size_t blen, struct sshkey **keyp) 2605 { 2606 struct sshbuf *b; 2607 int r; 2608 2609 if ((b = sshbuf_from(blob, blen)) == NULL) 2610 return SSH_ERR_ALLOC_FAIL; 2611 r = sshkey_from_blob_internal(b, keyp, 1); 2612 sshbuf_free(b); 2613 return r; 2614 } 2615 2616 int 2617 sshkey_fromb(struct sshbuf *b, struct sshkey **keyp) 2618 { 2619 return sshkey_from_blob_internal(b, keyp, 1); 2620 } 2621 2622 int 2623 sshkey_froms(struct sshbuf *buf, struct sshkey **keyp) 2624 { 2625 struct sshbuf *b; 2626 int r; 2627 2628 if ((r = sshbuf_froms(buf, &b)) != 0) 2629 return r; 2630 r = sshkey_from_blob_internal(b, keyp, 1); 2631 sshbuf_free(b); 2632 return r; 2633 } 2634 2635 int 2636 sshkey_get_sigtype(const u_char *sig, size_t siglen, char **sigtypep) 2637 { 2638 int r; 2639 struct sshbuf *b = NULL; 2640 char *sigtype = NULL; 2641 2642 if (sigtypep != NULL) 2643 *sigtypep = NULL; 2644 if ((b = sshbuf_from(sig, siglen)) == NULL) 2645 return SSH_ERR_ALLOC_FAIL; 2646 if ((r = sshbuf_get_cstring(b, &sigtype, NULL)) != 0) 2647 goto out; 2648 /* success */ 2649 if (sigtypep != NULL) { 2650 *sigtypep = sigtype; 2651 sigtype = NULL; 2652 } 2653 r = 0; 2654 out: 2655 free(sigtype); 2656 sshbuf_free(b); 2657 return r; 2658 } 2659 2660 /* 2661 * 2662 * Checks whether a certificate's signature type is allowed. 2663 * Returns 0 (success) if the certificate signature type appears in the 2664 * "allowed" pattern-list, or the key is not a certificate to begin with. 2665 * Otherwise returns a ssherr.h code. 2666 */ 2667 int 2668 sshkey_check_cert_sigtype(const struct sshkey *key, const char *allowed) 2669 { 2670 if (key == NULL || allowed == NULL) 2671 return SSH_ERR_INVALID_ARGUMENT; 2672 if (!sshkey_type_is_cert(key->type)) 2673 return 0; 2674 if (key->cert == NULL || key->cert->signature_type == NULL) 2675 return SSH_ERR_INVALID_ARGUMENT; 2676 if (match_pattern_list(key->cert->signature_type, allowed, 0) != 1) 2677 return SSH_ERR_SIGN_ALG_UNSUPPORTED; 2678 return 0; 2679 } 2680 2681 /* 2682 * Returns the expected signature algorithm for a given public key algorithm. 2683 */ 2684 const char * 2685 sshkey_sigalg_by_name(const char *name) 2686 { 2687 const struct keytype *kt; 2688 2689 for (kt = keytypes; kt->type != -1; kt++) { 2690 if (strcmp(kt->name, name) != 0) 2691 continue; 2692 if (kt->sigalg != NULL) 2693 return kt->sigalg; 2694 if (!kt->cert) 2695 return kt->name; 2696 return sshkey_ssh_name_from_type_nid( 2697 sshkey_type_plain(kt->type), kt->nid); 2698 } 2699 return NULL; 2700 } 2701 2702 /* 2703 * Verifies that the signature algorithm appearing inside the signature blob 2704 * matches that which was requested. 2705 */ 2706 int 2707 sshkey_check_sigtype(const u_char *sig, size_t siglen, 2708 const char *requested_alg) 2709 { 2710 const char *expected_alg; 2711 char *sigtype = NULL; 2712 int r; 2713 2714 if (requested_alg == NULL) 2715 return 0; 2716 if ((expected_alg = sshkey_sigalg_by_name(requested_alg)) == NULL) 2717 return SSH_ERR_INVALID_ARGUMENT; 2718 if ((r = sshkey_get_sigtype(sig, siglen, &sigtype)) != 0) 2719 return r; 2720 r = strcmp(expected_alg, sigtype) == 0; 2721 free(sigtype); 2722 return r ? 0 : SSH_ERR_SIGN_ALG_UNSUPPORTED; 2723 } 2724 2725 int 2726 sshkey_sign(struct sshkey *key, 2727 u_char **sigp, size_t *lenp, 2728 const u_char *data, size_t datalen, 2729 const char *alg, const char *sk_provider, u_int compat) 2730 { 2731 int was_shielded = sshkey_is_shielded(key); 2732 int r2, r = SSH_ERR_INTERNAL_ERROR; 2733 2734 if (sigp != NULL) 2735 *sigp = NULL; 2736 if (lenp != NULL) 2737 *lenp = 0; 2738 if (datalen > SSH_KEY_MAX_SIGN_DATA_SIZE) 2739 return SSH_ERR_INVALID_ARGUMENT; 2740 if ((r = sshkey_unshield_private(key)) != 0) 2741 return r; 2742 switch (key->type) { 2743 #ifdef WITH_OPENSSL 2744 case KEY_DSA_CERT: 2745 case KEY_DSA: 2746 r = ssh_dss_sign(key, sigp, lenp, data, datalen, compat); 2747 break; 2748 # ifdef OPENSSL_HAS_ECC 2749 case KEY_ECDSA_CERT: 2750 case KEY_ECDSA: 2751 r = ssh_ecdsa_sign(key, sigp, lenp, data, datalen, compat); 2752 break; 2753 # ifdef ENABLE_SK 2754 case KEY_ECDSA_SK_CERT: 2755 case KEY_ECDSA_SK: 2756 r = sshsk_sign(sk_provider, key, sigp, lenp, data, datalen, 2757 compat); 2758 break; 2759 # endif /* ENABLE_SK */ 2760 # endif /* OPENSSL_HAS_ECC */ 2761 case KEY_RSA_CERT: 2762 case KEY_RSA: 2763 r = ssh_rsa_sign(key, sigp, lenp, data, datalen, alg); 2764 break; 2765 #endif /* WITH_OPENSSL */ 2766 case KEY_ED25519: 2767 case KEY_ED25519_CERT: 2768 r = ssh_ed25519_sign(key, sigp, lenp, data, datalen, compat); 2769 break; 2770 #ifdef ENABLE_SK 2771 case KEY_ED25519_SK: 2772 case KEY_ED25519_SK_CERT: 2773 r = sshsk_sign(sk_provider, key, sigp, lenp, data, datalen, 2774 compat); 2775 break; 2776 #endif /* ENABLE_SK */ 2777 #ifdef WITH_XMSS 2778 case KEY_XMSS: 2779 case KEY_XMSS_CERT: 2780 r = ssh_xmss_sign(key, sigp, lenp, data, datalen, compat); 2781 break; 2782 #endif /* WITH_XMSS */ 2783 default: 2784 r = SSH_ERR_KEY_TYPE_UNKNOWN; 2785 break; 2786 } 2787 if (was_shielded && (r2 = sshkey_shield_private(key)) != 0) 2788 return r2; 2789 return r; 2790 } 2791 2792 /* 2793 * ssh_key_verify returns 0 for a correct signature and < 0 on error. 2794 * If "alg" specified, then the signature must use that algorithm. 2795 */ 2796 int 2797 sshkey_verify(const struct sshkey *key, 2798 const u_char *sig, size_t siglen, 2799 const u_char *data, size_t dlen, const char *alg, u_int compat, 2800 struct sshkey_sig_details **detailsp) 2801 { 2802 if (detailsp != NULL) 2803 *detailsp = NULL; 2804 if (siglen == 0 || dlen > SSH_KEY_MAX_SIGN_DATA_SIZE) 2805 return SSH_ERR_INVALID_ARGUMENT; 2806 switch (key->type) { 2807 #ifdef WITH_OPENSSL 2808 case KEY_DSA_CERT: 2809 case KEY_DSA: 2810 return ssh_dss_verify(key, sig, siglen, data, dlen, compat); 2811 # ifdef OPENSSL_HAS_ECC 2812 case KEY_ECDSA_CERT: 2813 case KEY_ECDSA: 2814 return ssh_ecdsa_verify(key, sig, siglen, data, dlen, compat); 2815 # ifdef ENABLE_SK 2816 case KEY_ECDSA_SK_CERT: 2817 case KEY_ECDSA_SK: 2818 return ssh_ecdsa_sk_verify(key, sig, siglen, data, dlen, 2819 compat, detailsp); 2820 # endif /* ENABLE_SK */ 2821 # endif /* OPENSSL_HAS_ECC */ 2822 case KEY_RSA_CERT: 2823 case KEY_RSA: 2824 return ssh_rsa_verify(key, sig, siglen, data, dlen, alg); 2825 #endif /* WITH_OPENSSL */ 2826 case KEY_ED25519: 2827 case KEY_ED25519_CERT: 2828 return ssh_ed25519_verify(key, sig, siglen, data, dlen, compat); 2829 case KEY_ED25519_SK: 2830 case KEY_ED25519_SK_CERT: 2831 return ssh_ed25519_sk_verify(key, sig, siglen, data, dlen, 2832 compat, detailsp); 2833 #ifdef WITH_XMSS 2834 case KEY_XMSS: 2835 case KEY_XMSS_CERT: 2836 return ssh_xmss_verify(key, sig, siglen, data, dlen, compat); 2837 #endif /* WITH_XMSS */ 2838 default: 2839 return SSH_ERR_KEY_TYPE_UNKNOWN; 2840 } 2841 } 2842 2843 /* Convert a plain key to their _CERT equivalent */ 2844 int 2845 sshkey_to_certified(struct sshkey *k) 2846 { 2847 int newtype; 2848 2849 switch (k->type) { 2850 #ifdef WITH_OPENSSL 2851 case KEY_RSA: 2852 newtype = KEY_RSA_CERT; 2853 break; 2854 case KEY_DSA: 2855 newtype = KEY_DSA_CERT; 2856 break; 2857 case KEY_ECDSA: 2858 newtype = KEY_ECDSA_CERT; 2859 break; 2860 case KEY_ECDSA_SK: 2861 newtype = KEY_ECDSA_SK_CERT; 2862 break; 2863 #endif /* WITH_OPENSSL */ 2864 case KEY_ED25519_SK: 2865 newtype = KEY_ED25519_SK_CERT; 2866 break; 2867 case KEY_ED25519: 2868 newtype = KEY_ED25519_CERT; 2869 break; 2870 #ifdef WITH_XMSS 2871 case KEY_XMSS: 2872 newtype = KEY_XMSS_CERT; 2873 break; 2874 #endif /* WITH_XMSS */ 2875 default: 2876 return SSH_ERR_INVALID_ARGUMENT; 2877 } 2878 if ((k->cert = cert_new()) == NULL) 2879 return SSH_ERR_ALLOC_FAIL; 2880 k->type = newtype; 2881 return 0; 2882 } 2883 2884 /* Convert a certificate to its raw key equivalent */ 2885 int 2886 sshkey_drop_cert(struct sshkey *k) 2887 { 2888 if (!sshkey_type_is_cert(k->type)) 2889 return SSH_ERR_KEY_TYPE_UNKNOWN; 2890 cert_free(k->cert); 2891 k->cert = NULL; 2892 k->type = sshkey_type_plain(k->type); 2893 return 0; 2894 } 2895 2896 /* Sign a certified key, (re-)generating the signed certblob. */ 2897 int 2898 sshkey_certify_custom(struct sshkey *k, struct sshkey *ca, const char *alg, 2899 const char *sk_provider, sshkey_certify_signer *signer, void *signer_ctx) 2900 { 2901 struct sshbuf *principals = NULL; 2902 u_char *ca_blob = NULL, *sig_blob = NULL, nonce[32]; 2903 size_t i, ca_len, sig_len; 2904 int ret = SSH_ERR_INTERNAL_ERROR; 2905 struct sshbuf *cert = NULL; 2906 char *sigtype = NULL; 2907 #ifdef WITH_OPENSSL 2908 const BIGNUM *rsa_n, *rsa_e, *dsa_p, *dsa_q, *dsa_g, *dsa_pub_key; 2909 #endif /* WITH_OPENSSL */ 2910 2911 if (k == NULL || k->cert == NULL || 2912 k->cert->certblob == NULL || ca == NULL) 2913 return SSH_ERR_INVALID_ARGUMENT; 2914 if (!sshkey_is_cert(k)) 2915 return SSH_ERR_KEY_TYPE_UNKNOWN; 2916 if (!sshkey_type_is_valid_ca(ca->type)) 2917 return SSH_ERR_KEY_CERT_INVALID_SIGN_KEY; 2918 2919 /* 2920 * If no alg specified as argument but a signature_type was set, 2921 * then prefer that. If both were specified, then they must match. 2922 */ 2923 if (alg == NULL) 2924 alg = k->cert->signature_type; 2925 else if (k->cert->signature_type != NULL && 2926 strcmp(alg, k->cert->signature_type) != 0) 2927 return SSH_ERR_INVALID_ARGUMENT; 2928 2929 /* 2930 * If no signing algorithm or signature_type was specified and we're 2931 * using a RSA key, then default to a good signature algorithm. 2932 */ 2933 if (alg == NULL && ca->type == KEY_RSA) 2934 alg = "rsa-sha2-512"; 2935 2936 if ((ret = sshkey_to_blob(ca, &ca_blob, &ca_len)) != 0) 2937 return SSH_ERR_KEY_CERT_INVALID_SIGN_KEY; 2938 2939 cert = k->cert->certblob; /* for readability */ 2940 sshbuf_reset(cert); 2941 if ((ret = sshbuf_put_cstring(cert, sshkey_ssh_name(k))) != 0) 2942 goto out; 2943 2944 /* -v01 certs put nonce first */ 2945 arc4random_buf(&nonce, sizeof(nonce)); 2946 if ((ret = sshbuf_put_string(cert, nonce, sizeof(nonce))) != 0) 2947 goto out; 2948 2949 /* XXX this substantially duplicates to_blob(); refactor */ 2950 switch (k->type) { 2951 #ifdef WITH_OPENSSL 2952 case KEY_DSA_CERT: 2953 DSA_get0_pqg(k->dsa, &dsa_p, &dsa_q, &dsa_g); 2954 DSA_get0_key(k->dsa, &dsa_pub_key, NULL); 2955 if ((ret = sshbuf_put_bignum2(cert, dsa_p)) != 0 || 2956 (ret = sshbuf_put_bignum2(cert, dsa_q)) != 0 || 2957 (ret = sshbuf_put_bignum2(cert, dsa_g)) != 0 || 2958 (ret = sshbuf_put_bignum2(cert, dsa_pub_key)) != 0) 2959 goto out; 2960 break; 2961 # ifdef OPENSSL_HAS_ECC 2962 case KEY_ECDSA_CERT: 2963 case KEY_ECDSA_SK_CERT: 2964 if ((ret = sshbuf_put_cstring(cert, 2965 sshkey_curve_nid_to_name(k->ecdsa_nid))) != 0 || 2966 (ret = sshbuf_put_ec(cert, 2967 EC_KEY_get0_public_key(k->ecdsa), 2968 EC_KEY_get0_group(k->ecdsa))) != 0) 2969 goto out; 2970 if (k->type == KEY_ECDSA_SK_CERT) { 2971 if ((ret = sshbuf_put_cstring(cert, 2972 k->sk_application)) != 0) 2973 goto out; 2974 } 2975 break; 2976 # endif /* OPENSSL_HAS_ECC */ 2977 case KEY_RSA_CERT: 2978 RSA_get0_key(k->rsa, &rsa_n, &rsa_e, NULL); 2979 if ((ret = sshbuf_put_bignum2(cert, rsa_e)) != 0 || 2980 (ret = sshbuf_put_bignum2(cert, rsa_n)) != 0) 2981 goto out; 2982 break; 2983 #endif /* WITH_OPENSSL */ 2984 case KEY_ED25519_CERT: 2985 case KEY_ED25519_SK_CERT: 2986 if ((ret = sshbuf_put_string(cert, 2987 k->ed25519_pk, ED25519_PK_SZ)) != 0) 2988 goto out; 2989 if (k->type == KEY_ED25519_SK_CERT) { 2990 if ((ret = sshbuf_put_cstring(cert, 2991 k->sk_application)) != 0) 2992 goto out; 2993 } 2994 break; 2995 #ifdef WITH_XMSS 2996 case KEY_XMSS_CERT: 2997 if (k->xmss_name == NULL) { 2998 ret = SSH_ERR_INVALID_ARGUMENT; 2999 goto out; 3000 } 3001 if ((ret = sshbuf_put_cstring(cert, k->xmss_name)) || 3002 (ret = sshbuf_put_string(cert, 3003 k->xmss_pk, sshkey_xmss_pklen(k))) != 0) 3004 goto out; 3005 break; 3006 #endif /* WITH_XMSS */ 3007 default: 3008 ret = SSH_ERR_INVALID_ARGUMENT; 3009 goto out; 3010 } 3011 3012 if ((ret = sshbuf_put_u64(cert, k->cert->serial)) != 0 || 3013 (ret = sshbuf_put_u32(cert, k->cert->type)) != 0 || 3014 (ret = sshbuf_put_cstring(cert, k->cert->key_id)) != 0) 3015 goto out; 3016 3017 if ((principals = sshbuf_new()) == NULL) { 3018 ret = SSH_ERR_ALLOC_FAIL; 3019 goto out; 3020 } 3021 for (i = 0; i < k->cert->nprincipals; i++) { 3022 if ((ret = sshbuf_put_cstring(principals, 3023 k->cert->principals[i])) != 0) 3024 goto out; 3025 } 3026 if ((ret = sshbuf_put_stringb(cert, principals)) != 0 || 3027 (ret = sshbuf_put_u64(cert, k->cert->valid_after)) != 0 || 3028 (ret = sshbuf_put_u64(cert, k->cert->valid_before)) != 0 || 3029 (ret = sshbuf_put_stringb(cert, k->cert->critical)) != 0 || 3030 (ret = sshbuf_put_stringb(cert, k->cert->extensions)) != 0 || 3031 (ret = sshbuf_put_string(cert, NULL, 0)) != 0 || /* Reserved */ 3032 (ret = sshbuf_put_string(cert, ca_blob, ca_len)) != 0) 3033 goto out; 3034 3035 /* Sign the whole mess */ 3036 if ((ret = signer(ca, &sig_blob, &