1 /* $OpenBSD: hostfile.c,v 1.66 2015/05/04 06:10:48 djm Exp $ */ 2 /* 3 * Author: Tatu Ylonen <ylo@cs.hut.fi> 4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland 5 * All rights reserved 6 * Functions for manipulating the known hosts files. 7 * 8 * As far as I am concerned, the code I have written for this software 9 * can be used freely for any purpose. Any derived versions of this 10 * software must be clearly marked as such, and if the derived work is 11 * incompatible with the protocol description in the RFC file, it must be 12 * called by a name other than "ssh" or "Secure Shell". 13 * 14 * 15 * Copyright (c) 1999, 2000 Markus Friedl. All rights reserved. 16 * Copyright (c) 1999 Niels Provos. All rights reserved. 17 * 18 * Redistribution and use in source and binary forms, with or without 19 * modification, are permitted provided that the following conditions 20 * are met: 21 * 1. Redistributions of source code must retain the above copyright 22 * notice, this list of conditions and the following disclaimer. 23 * 2. Redistributions in binary form must reproduce the above copyright 24 * notice, this list of conditions and the following disclaimer in the 25 * documentation and/or other materials provided with the distribution. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 28 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 29 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 30 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 31 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 32 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 33 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 34 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 35 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 36 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 #include <sys/types.h> 40 #include <sys/stat.h> 41 42 #include <netinet/in.h> 43 44 #include <errno.h> 45 #include <resolv.h> 46 #include <stdio.h> 47 #include <stdlib.h> 48 #include <string.h> 49 #include <stdarg.h> 50 #include <unistd.h> 51 52 #include "xmalloc.h" 53 #include "match.h" 54 #include "sshkey.h" 55 #include "hostfile.h" 56 #include "log.h" 57 #include "misc.h" 58 #include "ssherr.h" 59 #include "digest.h" 60 #include "hmac.h" 61 62 struct hostkeys { 63 struct hostkey_entry *entries; 64 u_int num_entries; 65 }; 66 67 /* XXX hmac is too easy to dictionary attack; use bcrypt? */ 68 69 static int 70 extract_salt(const char *s, u_int l, u_char *salt, size_t salt_len) 71 { 72 char *p, *b64salt; 73 u_int b64len; 74 int ret; 75 76 if (l < sizeof(HASH_MAGIC) - 1) { 77 debug2("extract_salt: string too short"); 78 return (-1); 79 } 80 if (strncmp(s, HASH_MAGIC, sizeof(HASH_MAGIC) - 1) != 0) { 81 debug2("extract_salt: invalid magic identifier"); 82 return (-1); 83 } 84 s += sizeof(HASH_MAGIC) - 1; 85 l -= sizeof(HASH_MAGIC) - 1; 86 if ((p = memchr(s, HASH_DELIM, l)) == NULL) { 87 debug2("extract_salt: missing salt termination character"); 88 return (-1); 89 } 90 91 b64len = p - s; 92 /* Sanity check */ 93 if (b64len == 0 || b64len > 1024) { 94 debug2("extract_salt: bad encoded salt length %u", b64len); 95 return (-1); 96 } 97 b64salt = xmalloc(1 + b64len); 98 memcpy(b64salt, s, b64len); 99 b64salt[b64len] = '\0'; 100 101 ret = __b64_pton(b64salt, salt, salt_len); 102 free(b64salt); 103 if (ret == -1) { 104 debug2("extract_salt: salt decode error"); 105 return (-1); 106 } 107 if (ret != (int)ssh_hmac_bytes(SSH_DIGEST_SHA1)) { 108 debug2("extract_salt: expected salt len %zd, got %d", 109 ssh_hmac_bytes(SSH_DIGEST_SHA1), ret); 110 return (-1); 111 } 112 113 return (0); 114 } 115 116 char * 117 host_hash(const char *host, const char *name_from_hostfile, u_int src_len) 118 { 119 struct ssh_hmac_ctx *ctx; 120 u_char salt[256], result[256]; 121 char uu_salt[512], uu_result[512]; 122 static char encoded[1024]; 123 u_int i, len; 124 125 len = ssh_digest_bytes(SSH_DIGEST_SHA1); 126 127 if (name_from_hostfile == NULL) { 128 /* Create new salt */ 129 for (i = 0; i < len; i++) 130 salt[i] = arc4random(); 131 } else { 132 /* Extract salt from known host entry */ 133 if (extract_salt(name_from_hostfile, src_len, salt, 134 sizeof(salt)) == -1) 135 return (NULL); 136 } 137 138 if ((ctx = ssh_hmac_start(SSH_DIGEST_SHA1)) == NULL || 139 ssh_hmac_init(ctx, salt, len) < 0 || 140 ssh_hmac_update(ctx, host, strlen(host)) < 0 || 141 ssh_hmac_final(ctx, result, sizeof(result))) 142 fatal("%s: ssh_hmac failed", __func__); 143 ssh_hmac_free(ctx); 144 145 if (__b64_ntop(salt, len, uu_salt, sizeof(uu_salt)) == -1 || 146 __b64_ntop(result, len, uu_result, sizeof(uu_result)) == -1) 147 fatal("%s: __b64_ntop failed", __func__); 148 149 snprintf(encoded, sizeof(encoded), "%s%s%c%s", HASH_MAGIC, uu_salt, 150 HASH_DELIM, uu_result); 151 152 return (encoded); 153 } 154 155 /* 156 * Parses an RSA (number of bits, e, n) or DSA key from a string. Moves the 157 * pointer over the key. Skips any whitespace at the beginning and at end. 158 */ 159 160 int 161 hostfile_read_key(char **cpp, u_int *bitsp, struct sshkey *ret) 162 { 163 char *cp; 164 int r; 165 166 /* Skip leading whitespace. */ 167 for (cp = *cpp; *cp == ' ' || *cp == '\t'; cp++) 168 ; 169 170 if ((r = sshkey_read(ret, &cp)) != 0) 171 return 0; 172 173 /* Skip trailing whitespace. */ 174 for (; *cp == ' ' || *cp == '\t'; cp++) 175 ; 176 177 /* Return results. */ 178 *cpp = cp; 179 if (bitsp != NULL) 180 *bitsp = sshkey_size(ret); 181 return 1; 182 } 183 184 static HostkeyMarker 185 check_markers(char **cpp) 186 { 187 char marker[32], *sp, *cp = *cpp; 188 int ret = MRK_NONE; 189 190 while (*cp == '@') { 191 /* Only one marker is allowed */ 192 if (ret != MRK_NONE) 193 return MRK_ERROR; 194 /* Markers are terminated by whitespace */ 195 if ((sp = strchr(cp, ' ')) == NULL && 196 (sp = strchr(cp, '\t')) == NULL) 197 return MRK_ERROR; 198 /* Extract marker for comparison */ 199 if (sp <= cp + 1 || sp >= cp + sizeof(marker)) 200 return MRK_ERROR; 201 memcpy(marker, cp, sp - cp); 202 marker[sp - cp] = '\0'; 203 if (strcmp(marker, CA_MARKER) == 0) 204 ret = MRK_CA; 205 else if (strcmp(marker, REVOKE_MARKER) == 0) 206 ret = MRK_REVOKE; 207 else 208 return MRK_ERROR; 209 210 /* Skip past marker and any whitespace that follows it */ 211 cp = sp; 212 for (; *cp == ' ' || *cp == '\t'; cp++) 213 ; 214 } 215 *cpp = cp; 216 return ret; 217 } 218 219 struct hostkeys * 220 init_hostkeys(void) 221 { 222 struct hostkeys *ret = xcalloc(1, sizeof(*ret)); 223 224 ret->entries = NULL; 225 return ret; 226 } 227 228 struct load_callback_ctx { 229 const char *host; 230 u_long num_loaded; 231 struct hostkeys *hostkeys; 232 }; 233 234 static int 235 record_hostkey(struct hostkey_foreach_line *l, void *_ctx) 236 { 237 struct load_callback_ctx *ctx = (struct load_callback_ctx *)_ctx; 238 struct hostkeys *hostkeys = ctx->hostkeys; 239 struct hostkey_entry *tmp; 240 241 if (l->status == HKF_STATUS_INVALID) { 242 /* XXX make this verbose() in the future */ 243 debug("%s:%ld: parse error in hostkeys file", 244 l->path, l->linenum); 245 return 0; 246 } 247 248 debug3("%s: found %skey type %s in file %s:%lu", __func__, 249 l->marker == MRK_NONE ? "" : 250 (l->marker == MRK_CA ? "ca " : "revoked "), 251 sshkey_type(l->key), l->path, l->linenum); 252 if ((tmp = reallocarray(hostkeys->entries, 253 hostkeys->num_entries + 1, sizeof(*hostkeys->entries))) == NULL) 254 return SSH_ERR_ALLOC_FAIL; 255 hostkeys->entries = tmp; 256 hostkeys->entries[hostkeys->num_entries].host = xstrdup(ctx->host); 257 hostkeys->entries[hostkeys->num_entries].file = xstrdup(l->path); 258 hostkeys->entries[hostkeys->num_entries].line = l->linenum; 259 hostkeys->entries[hostkeys->num_entries].key = l->key; 260 l->key = NULL; /* steal it */ 261 hostkeys->entries[hostkeys->num_entries].marker = l->marker; 262 hostkeys->num_entries++; 263 ctx->num_loaded++; 264 265 return 0; 266 } 267 268 void 269 load_hostkeys(struct hostkeys *hostkeys, const char *host, const char *path) 270 { 271 int r; 272 struct load_callback_ctx ctx; 273 274 ctx.host = host; 275 ctx.num_loaded = 0; 276 ctx.hostkeys = hostkeys; 277 278 if ((r = hostkeys_foreach(path, record_hostkey, &ctx, host, NULL, 279 HKF_WANT_MATCH|HKF_WANT_PARSE_KEY)) != 0) { 280 if (r != SSH_ERR_SYSTEM_ERROR && errno != ENOENT) 281 debug("%s: hostkeys_foreach failed for %s: %s", 282 __func__, path, ssh_err(r)); 283 } 284 if (ctx.num_loaded != 0) 285 debug3("%s: loaded %lu keys from %s", __func__, 286 ctx.num_loaded, host); 287 } 288 289 void 290 free_hostkeys(struct hostkeys *hostkeys) 291 { 292 u_int i; 293 294 for (i = 0; i < hostkeys->num_entries; i++) { 295 free(hostkeys->entries[i].host); 296 free(hostkeys->entries[i].file); 297 sshkey_free(hostkeys->entries[i].key); 298 explicit_bzero(hostkeys->entries + i, sizeof(*hostkeys->entries)); 299 } 300 free(hostkeys->entries); 301 explicit_bzero(hostkeys, sizeof(*hostkeys)); 302 free(hostkeys); 303 } 304 305 static int 306 check_key_not_revoked(struct hostkeys *hostkeys, struct sshkey *k) 307 { 308 int is_cert = sshkey_is_cert(k); 309 u_int i; 310 311 for (i = 0; i < hostkeys->num_entries; i++) { 312 if (hostkeys->entries[i].marker != MRK_REVOKE) 313 continue; 314 if (sshkey_equal_public(k, hostkeys->entries[i].key)) 315 return -1; 316 if (is_cert && 317 sshkey_equal_public(k->cert->signature_key, 318 hostkeys->entries[i].key)) 319 return -1; 320 } 321 return 0; 322 } 323 324 /* 325 * Match keys against a specified key, or look one up by key type. 326 * 327 * If looking for a keytype (key == NULL) and one is found then return 328 * HOST_FOUND, otherwise HOST_NEW. 329 * 330 * If looking for a key (key != NULL): 331 * 1. If the key is a cert and a matching CA is found, return HOST_OK 332 * 2. If the key is not a cert and a matching key is found, return HOST_OK 333 * 3. If no key matches but a key with a different type is found, then 334 * return HOST_CHANGED 335 * 4. If no matching keys are found, then return HOST_NEW. 336 * 337 * Finally, check any found key is not revoked. 338 */ 339 static HostStatus 340 check_hostkeys_by_key_or_type(struct hostkeys *hostkeys, 341 struct sshkey *k, int keytype, const struct hostkey_entry **found) 342 { 343 u_int i; 344 HostStatus end_return = HOST_NEW; 345 int want_cert = sshkey_is_cert(k); 346 HostkeyMarker want_marker = want_cert ? MRK_CA : MRK_NONE; 347 int proto = (k ? k->type : keytype) == KEY_RSA1 ? 1 : 2; 348 349 if (found != NULL) 350 *found = NULL; 351 352 for (i = 0; i < hostkeys->num_entries; i++) { 353 if (proto == 1 && hostkeys->entries[i].key->type != KEY_RSA1) 354 continue; 355 if (proto == 2 && hostkeys->entries[i].key->type == KEY_RSA1) 356 continue; 357 if (hostkeys->entries[i].marker != want_marker) 358 continue; 359 if (k == NULL) { 360 if (hostkeys->entries[i].key->type != keytype) 361 continue; 362 end_return = HOST_FOUND; 363 if (found != NULL) 364 *found = hostkeys->entries + i; 365 k = hostkeys->entries[i].key; 366 break; 367 } 368 if (want_cert) { 369 if (sshkey_equal_public(k->cert->signature_key, 370 hostkeys->entries[i].key)) { 371 /* A matching CA exists */ 372 end_return = HOST_OK; 373 if (found != NULL) 374 *found = hostkeys->entries + i; 375 break; 376 } 377 } else { 378 if (sshkey_equal(k, hostkeys->entries[i].key)) { 379 end_return = HOST_OK; 380 if (found != NULL) 381 *found = hostkeys->entries + i; 382 break; 383 } 384 /* A non-maching key exists */ 385 end_return = HOST_CHANGED; 386 if (found != NULL) 387 *found = hostkeys->entries + i; 388 } 389 } 390 if (check_key_not_revoked(hostkeys, k) != 0) { 391 end_return = HOST_REVOKED; 392 if (found != NULL) 393 *found = NULL; 394 } 395 return end_return; 396 } 397 398 HostStatus 399 check_key_in_hostkeys(struct hostkeys *hostkeys, struct sshkey *key, 400 const struct hostkey_entry **found) 401 { 402 if (key == NULL) 403 fatal("no key to look up"); 404 return check_hostkeys_by_key_or_type(hostkeys, key, 0, found); 405 } 406 407 int 408 lookup_key_in_hostkeys_by_type(struct hostkeys *hostkeys, int keytype, 409 const struct hostkey_entry **found) 410 { 411 return (check_hostkeys_by_key_or_type(hostkeys, NULL, keytype, 412 found) == HOST_FOUND); 413 } 414 415 static int 416 write_host_entry(FILE *f, const char *host, const char *ip, 417 const struct sshkey *key, int store_hash) 418 { 419 int r, success = 0; 420 char *hashed_host = NULL; 421 422 if (store_hash) { 423 if ((hashed_host = host_hash(host, NULL, 0)) == NULL) { 424 error("%s: host_hash failed", __func__); 425 return 0; 426 } 427 fprintf(f, "%s ", hashed_host); 428 } else if (ip != NULL) 429 fprintf(f, "%s,%s ", host, ip); 430 else 431 fprintf(f, "%s ", host); 432 433 if ((r = sshkey_write(key, f)) == 0) 434 success = 1; 435 else 436 error("%s: sshkey_write failed: %s", __func__, ssh_err(r)); 437 fputc('\n', f); 438 return success; 439 } 440 441 /* 442 * Appends an entry to the host file. Returns false if the entry could not 443 * be appended. 444 */ 445 int 446 add_host_to_hostfile(const char *filename, const char *host, 447 const struct sshkey *key, int store_hash) 448 { 449 FILE *f; 450 int success; 451 452 if (key == NULL) 453 return 1; /* XXX ? */ 454 f = fopen(filename, "a"); 455 if (!f) 456 return 0; 457 success = write_host_entry(f, host, NULL, key, store_hash); 458 fclose(f); 459 return success; 460 } 461 462 struct host_delete_ctx { 463 FILE *out; 464 int quiet; 465 const char *host; 466 int *skip_keys; /* XXX split for host/ip? might want to ensure both */ 467 struct sshkey * const *keys; 468 size_t nkeys; 469 int modified; 470 }; 471 472 static int 473 host_delete(struct hostkey_foreach_line *l, void *_ctx) 474 { 475 struct host_delete_ctx *ctx = (struct host_delete_ctx *)_ctx; 476 int loglevel = ctx->quiet ? SYSLOG_LEVEL_DEBUG1 : SYSLOG_LEVEL_VERBOSE; 477 size_t i; 478 479 if (l->status == HKF_STATUS_MATCHED) { 480 if (l->marker != MRK_NONE) { 481 /* Don't remove CA and revocation lines */ 482 fprintf(ctx->out, "%s\n", l->line); 483 return 0; 484 } 485 486 /* XXX might need a knob for this later */ 487 /* Don't remove RSA1 keys */ 488 if (l->key->type == KEY_RSA1) { 489 fprintf(ctx->out, "%s\n", l->line); 490 return 0; 491 } 492 493 /* 494 * If this line contains one of the keys that we will be 495 * adding later, then don't change it and mark the key for 496 * skipping. 497 */ 498 for (i = 0; i < ctx->nkeys; i++) { 499 if (sshkey_equal(ctx->keys[i], l->key)) { 500 ctx->skip_keys[i] = 1; 501 fprintf(ctx->out, "%s\n", l->line); 502 debug3("%s: %s key already at %s:%ld", __func__, 503 sshkey_type(l->key), l->path, l->linenum); 504 return 0; 505 } 506 } 507 508 /* 509 * Hostname matches and has no CA/revoke marker, delete it 510 * by *not* writing the line to ctx->out. 511 */ 512 do_log2(loglevel, "%s%s%s:%ld: Removed %s key for host %s", 513 ctx->quiet ? __func__ : "", ctx->quiet ? ": " : "", 514 l->path, l->linenum, sshkey_type(l->key), ctx->host); 515 ctx->modified = 1; 516 return 0; 517 } 518 /* Retain non-matching hosts and invalid lines when deleting */ 519 if (l->status == HKF_STATUS_INVALID) { 520 do_log2(loglevel, "%s%s%s:%ld: invalid known_hosts entry", 521 ctx->quiet ? __func__ : "", ctx->quiet ? ": " : "", 522 l->path, l->linenum); 523 } 524 fprintf(ctx->out, "%s\n", l->line); 525 return 0; 526 } 527 528 int 529 hostfile_replace_entries(const char *filename, const char *host, const char *ip, 530 struct sshkey **keys, size_t nkeys, int store_hash, int quiet, int hash_alg) 531 { 532 int r, fd, oerrno = 0; 533 int loglevel = quiet ? SYSLOG_LEVEL_DEBUG1 : SYSLOG_LEVEL_VERBOSE; 534 struct host_delete_ctx ctx; 535 char *fp, *temp = NULL, *back = NULL; 536 mode_t omask; 537 size_t i; 538 539 omask = umask(077); 540 541 memset(&ctx, 0, sizeof(ctx)); 542 ctx.host = host; 543 ctx.quiet = quiet; 544 if ((ctx.skip_keys = calloc(nkeys, sizeof(*ctx.skip_keys))) == NULL) 545 return SSH_ERR_ALLOC_FAIL; 546 ctx.keys = keys; 547 ctx.nkeys = nkeys; 548 ctx.modified = 0; 549 550 /* 551 * Prepare temporary file for in-place deletion. 552 */ 553 if ((r = asprintf(&temp, "%s.XXXXXXXXXXX", filename)) < 0 || 554 (r = asprintf(&back, "%s.old", filename)) < 0) { 555 r = SSH_ERR_ALLOC_FAIL; 556 goto fail; 557 } 558 559 if ((fd = mkstemp(temp)) == -1) { 560 oerrno = errno; 561 error("%s: mkstemp: %s", __func__, strerror(oerrno)); 562 r = SSH_ERR_SYSTEM_ERROR; 563 goto fail; 564 } 565 if ((ctx.out = fdopen(fd, "w")) == NULL) { 566 oerrno = errno; 567 close(fd); 568 error("%s: fdopen: %s", __func__, strerror(oerrno)); 569 r = SSH_ERR_SYSTEM_ERROR; 570 goto fail; 571 } 572 573 /* Remove all entries for the specified host from the file */ 574 if ((r = hostkeys_foreach(filename, host_delete, &ctx, host, ip, 575 HKF_WANT_PARSE_KEY)) != 0) { 576 error("%s: hostkeys_foreach failed: %s", __func__, ssh_err(r)); 577 goto fail; 578 } 579 580 /* Add the requested keys */ 581 for (i = 0; i < nkeys; i++) { 582 if (ctx.skip_keys[i]) 583 continue; 584 if ((fp = sshkey_fingerprint(keys[i], hash_alg, 585 SSH_FP_DEFAULT)) == NULL) { 586 r = SSH_ERR_ALLOC_FAIL; 587 goto fail; 588 } 589 do_log2(loglevel, "%s%sAdding new key for %s to %s: %s %s", 590 quiet ? __func__ : "", quiet ? ": " : "", host, filename, 591 sshkey_ssh_name(keys[i]), fp); 592 free(fp); 593 if (!write_host_entry(ctx.out, host, ip, keys[i], store_hash)) { 594 r = SSH_ERR_INTERNAL_ERROR; 595 goto fail; 596 } 597 ctx.modified = 1; 598 } 599 fclose(ctx.out); 600 ctx.out = NULL; 601 602 if (ctx.modified) { 603 /* Backup the original file and replace it with the temporary */ 604 if (unlink(back) == -1 && errno != ENOENT) { 605 oerrno = errno; 606 error("%s: unlink %.100s: %s", __func__, 607 back, strerror(errno)); 608 r = SSH_ERR_SYSTEM_ERROR; 609 goto fail; 610 } 611 if (link(filename, back) == -1) { 612 oerrno = errno; 613 error("%s: link %.100s to %.100s: %s", __func__, 614 filename, back, strerror(errno)); 615 r = SSH_ERR_SYSTEM_ERROR; 616 goto fail; 617 } 618 if (rename(temp, filename) == -1) { 619 oerrno = errno; 620 error("%s: rename \"%s\" to \"%s\": %s", __func__, 621 temp, filename, strerror(errno)); 622 r = SSH_ERR_SYSTEM_ERROR; 623 goto fail; 624 } 625 } else { 626 /* No changes made; just delete the temporary file */ 627 if (unlink(temp) != 0) 628 error("%s: unlink \"%s\": %s", __func__, 629 temp, strerror(errno)); 630 } 631 632 /* success */ 633 r = 0; 634 fail: 635 if (temp != NULL && r != 0) 636 unlink(temp); 637 free(temp); 638 free(back); 639 if (ctx.out != NULL) 640 fclose(ctx.out); 641 free(ctx.skip_keys); 642 umask(omask); 643 if (r == SSH_ERR_SYSTEM_ERROR) 644 errno = oerrno; 645 return r; 646 } 647 648 static int 649 match_maybe_hashed(const char *host, const char *names, int *was_hashed) 650 { 651 int hashed = *names == HASH_DELIM; 652 const char *hashed_host; 653 size_t nlen = strlen(names); 654 655 if (was_hashed != NULL) 656 *was_hashed = hashed; 657 if (hashed) { 658 if ((hashed_host = host_hash(host, names, nlen)) == NULL) 659 return -1; 660 return nlen == strlen(hashed_host) && 661 strncmp(hashed_host, names, nlen) == 0; 662 } 663 return match_hostname(host, names) == 1; 664 } 665 666 int 667 hostkeys_foreach(const char *path, hostkeys_foreach_fn *callback, void *ctx, 668 const char *host, const char *ip, u_int options) 669 { 670 FILE *f; 671 char line[8192], oline[8192], ktype[128]; 672 u_long linenum = 0; 673 char *cp, *cp2; 674 u_int kbits; 675 int hashed; 676 int s, r = 0; 677 struct hostkey_foreach_line lineinfo; 678 size_t l; 679 680 memset(&lineinfo, 0, sizeof(lineinfo)); 681 if (host == NULL && (options & HKF_WANT_MATCH) != 0) 682 return SSH_ERR_INVALID_ARGUMENT; 683 if ((f = fopen(path, "r")) == NULL) 684 return SSH_ERR_SYSTEM_ERROR; 685 686 debug3("%s: reading file \"%s\"", __func__, path); 687 while (read_keyfile_line(f, path, line, sizeof(line), &linenum) == 0) { 688 line[strcspn(line, "\n")] = '\0'; 689 strlcpy(oline, line, sizeof(oline)); 690 691 sshkey_free(lineinfo.key); 692 memset(&lineinfo, 0, sizeof(lineinfo)); 693 lineinfo.path = path; 694 lineinfo.linenum = linenum; 695 lineinfo.line = oline; 696 lineinfo.marker = MRK_NONE; 697 lineinfo.status = HKF_STATUS_OK; 698 lineinfo.keytype = KEY_UNSPEC; 699 700 /* Skip any leading whitespace, comments and empty lines. */ 701 for (cp = line; *cp == ' ' || *cp == '\t'; cp++) 702 ; 703 if (!*cp || *cp == '#' || *cp == '\n') { 704 if ((options & HKF_WANT_MATCH) == 0) { 705 lineinfo.status = HKF_STATUS_COMMENT; 706 if ((r = callback(&lineinfo, ctx)) != 0) 707 break; 708 } 709 continue; 710 } 711 712 if ((lineinfo.marker = check_markers(&cp)) == MRK_ERROR) { 713 verbose("%s: invalid marker at %s:%lu", 714 __func__, path, linenum); 715 if ((options & HKF_WANT_MATCH) == 0) 716 goto bad; 717 continue; 718 } 719 720 /* Find the end of the host name portion. */ 721 for (cp2 = cp; *cp2 && *cp2 != ' ' && *cp2 != '\t'; cp2++) 722 ; 723 lineinfo.hosts = cp; 724 *cp2++ = '\0'; 725 726 /* Check if the host name matches. */ 727 if (host != NULL) { 728 if ((s = match_maybe_hashed(host, lineinfo.hosts, 729 &hashed)) == -1) { 730 debug2("%s: %s:%ld: bad host hash \"%.32s\"", 731 __func__, path, linenum, lineinfo.hosts); 732 goto bad; 733 } 734 if (s == 1) { 735 lineinfo.status = HKF_STATUS_MATCHED; 736 lineinfo.match |= HKF_MATCH_HOST | 737 (hashed ? HKF_MATCH_HOST_HASHED : 0); 738 } 739 /* Try matching IP address if supplied */ 740 if (ip != NULL) { 741 if ((s = match_maybe_hashed(ip, lineinfo.hosts, 742 &hashed)) == -1) { 743 debug2("%s: %s:%ld: bad ip hash " 744 "\"%.32s\"", __func__, path, 745 linenum, lineinfo.hosts); 746 goto bad; 747 } 748 if (s == 1) { 749 lineinfo.status = HKF_STATUS_MATCHED; 750 lineinfo.match |= HKF_MATCH_IP | 751 (hashed ? HKF_MATCH_IP_HASHED : 0); 752 } 753 } 754 /* 755 * Skip this line if host matching requested and 756 * neither host nor address matched. 757 */ 758 if ((options & HKF_WANT_MATCH) != 0 && 759 lineinfo.status != HKF_STATUS_MATCHED) 760 continue; 761 } 762 763 /* Got a match. Skip host name and any following whitespace */ 764 for (; *cp2 == ' ' || *cp2 == '\t'; cp2++) 765 ; 766 if (*cp2 == '\0' || *cp2 == '#') { 767 debug2("%s:%ld: truncated before key type", 768 path, linenum); 769 goto bad; 770 } 771 lineinfo.rawkey = cp = cp2; 772 773 if ((options & HKF_WANT_PARSE_KEY) != 0) { 774 /* 775 * Extract the key from the line. This will skip 776 * any leading whitespace. Ignore badly formatted 777 * lines. 778 */ 779 if ((lineinfo.key = sshkey_new(KEY_UNSPEC)) == NULL) { 780 error("%s: sshkey_new failed", __func__); 781 r = SSH_ERR_ALLOC_FAIL; 782 break; 783 } 784 if (!hostfile_read_key(&cp, &kbits, lineinfo.key)) { 785 #ifdef WITH_SSH1 786 sshkey_free(lineinfo.key); 787 lineinfo.key = sshkey_new(KEY_RSA1); 788 if (lineinfo.key == NULL) { 789 error("%s: sshkey_new fail", __func__); 790 r = SSH_ERR_ALLOC_FAIL; 791 break; 792 } 793 if (!hostfile_read_key(&cp, &kbits, 794 lineinfo.key)) 795 goto bad; 796 #else 797 goto bad; 798 #endif 799 } 800 lineinfo.keytype = lineinfo.key->type; 801 lineinfo.comment = cp; 802 } else { 803 /* Extract and parse key type */ 804 l = strcspn(lineinfo.rawkey, " \t"); 805 if (l <= 1 || l >= sizeof(ktype) || 806 lineinfo.rawkey[l] == '\0') 807 goto bad; 808 memcpy(ktype, lineinfo.rawkey, l); 809 ktype[l] = '\0'; 810 lineinfo.keytype = sshkey_type_from_name(ktype); 811 812 /* 813 * Assume RSA1 if the first component is a short 814 * decimal number. 815 */ 816 if (lineinfo.keytype == KEY_UNSPEC && l < 8 && 817 strspn(ktype, "0123456789") == l) 818 lineinfo.keytype = KEY_RSA1; 819 820 /* 821 * Check that something other than whitespace follows 822 * the key type. This won't catch all corruption, but 823 * it does catch trivial truncation. 824 */ 825 cp2 += l; /* Skip past key type */ 826 for (; *cp2 == ' ' || *cp2 == '\t'; cp2++) 827 ; 828 if (*cp2 == '\0' || *cp2 == '#') { 829 debug2("%s:%ld: truncated after key type", 830 path, linenum); 831 lineinfo.keytype = KEY_UNSPEC; 832 } 833 if (lineinfo.keytype == KEY_UNSPEC) { 834 bad: 835 sshkey_free(lineinfo.key); 836 lineinfo.key = NULL; 837 lineinfo.status = HKF_STATUS_INVALID; 838 if ((r = callback(&lineinfo, ctx)) != 0) 839 break; 840 continue; 841 } 842 } 843 if ((r = callback(&lineinfo, ctx)) != 0) 844 break; 845 } 846 sshkey_free(lineinfo.key); 847 fclose(f); 848 return r; 849 } 850