1 /* 2 * Copyright (c) 2000 Markus Friedl. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 14 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 15 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 16 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 17 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 18 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 19 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 20 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 21 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 22 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 23 */ 24 25 #include "includes.h" 26 RCSID("$OpenBSD: auth2.c,v 1.85 2002/02/24 19:14:59 markus Exp $"); 27 RCSID("$FreeBSD$"); 28 29 #include <openssl/evp.h> 30 31 #include "ssh2.h" 32 #include "xmalloc.h" 33 #include "rsa.h" 34 #include "sshpty.h" 35 #include "packet.h" 36 #include "buffer.h" 37 #include "log.h" 38 #include "servconf.h" 39 #include "compat.h" 40 #include "channels.h" 41 #include "bufaux.h" 42 #include "auth.h" 43 #include "session.h" 44 #include "dispatch.h" 45 #include "key.h" 46 #include "cipher.h" 47 #include "kex.h" 48 #include "pathnames.h" 49 #include "uidswap.h" 50 #include "auth-options.h" 51 #include "misc.h" 52 #include "hostfile.h" 53 #include "canohost.h" 54 #include "match.h" 55 56 #ifdef HAVE_LOGIN_CAP 57 #include <login_cap.h> 58 #endif /* HAVE_LOGIN_CAP */ 59 60 /* import */ 61 extern ServerOptions options; 62 extern u_char *session_id2; 63 extern int session_id2_len; 64 65 static Authctxt *x_authctxt = NULL; 66 static int one = 1; 67 68 typedef struct Authmethod Authmethod; 69 struct Authmethod { 70 char *name; 71 int (*userauth)(Authctxt *authctxt); 72 int *enabled; 73 }; 74 75 /* protocol */ 76 77 static void input_service_request(int, u_int32_t, void *); 78 static void input_userauth_request(int, u_int32_t, void *); 79 80 /* helper */ 81 static Authmethod *authmethod_lookup(const char *); 82 static char *authmethods_get(void); 83 static int user_key_allowed(struct passwd *, Key *); 84 static int hostbased_key_allowed(struct passwd *, const char *, char *, Key *); 85 86 /* auth */ 87 static void userauth_banner(void); 88 static int userauth_none(Authctxt *); 89 static int userauth_passwd(Authctxt *); 90 static int userauth_pubkey(Authctxt *); 91 static int userauth_hostbased(Authctxt *); 92 static int userauth_kbdint(Authctxt *); 93 94 Authmethod authmethods[] = { 95 {"none", 96 userauth_none, 97 &one}, 98 {"publickey", 99 userauth_pubkey, 100 &options.pubkey_authentication}, 101 {"password", 102 userauth_passwd, 103 &options.password_authentication}, 104 {"keyboard-interactive", 105 userauth_kbdint, 106 &options.kbd_interactive_authentication}, 107 {"hostbased", 108 userauth_hostbased, 109 &options.hostbased_authentication}, 110 {NULL, NULL, NULL} 111 }; 112 113 /* 114 * loop until authctxt->success == TRUE 115 */ 116 117 void 118 do_authentication2(void) 119 { 120 Authctxt *authctxt = authctxt_new(); 121 122 x_authctxt = authctxt; /*XXX*/ 123 124 /* challenge-response is implemented via keyboard interactive */ 125 if (options.challenge_response_authentication) 126 options.kbd_interactive_authentication = 1; 127 128 dispatch_init(&dispatch_protocol_error); 129 dispatch_set(SSH2_MSG_SERVICE_REQUEST, &input_service_request); 130 dispatch_run(DISPATCH_BLOCK, &authctxt->success, authctxt); 131 do_authenticated(authctxt); 132 } 133 134 static void 135 input_service_request(int type, u_int32_t seq, void *ctxt) 136 { 137 Authctxt *authctxt = ctxt; 138 u_int len; 139 int accept = 0; 140 char *service = packet_get_string(&len); 141 packet_check_eom(); 142 143 if (authctxt == NULL) 144 fatal("input_service_request: no authctxt"); 145 146 if (strcmp(service, "ssh-userauth") == 0) { 147 if (!authctxt->success) { 148 accept = 1; 149 /* now we can handle user-auth requests */ 150 dispatch_set(SSH2_MSG_USERAUTH_REQUEST, &input_userauth_request); 151 } 152 } 153 /* XXX all other service requests are denied */ 154 155 if (accept) { 156 packet_start(SSH2_MSG_SERVICE_ACCEPT); 157 packet_put_cstring(service); 158 packet_send(); 159 packet_write_wait(); 160 } else { 161 debug("bad service request %s", service); 162 packet_disconnect("bad service request %s", service); 163 } 164 xfree(service); 165 } 166 167 static void 168 input_userauth_request(int type, u_int32_t seq, void *ctxt) 169 { 170 Authctxt *authctxt = ctxt; 171 Authmethod *m = NULL; 172 char *user, *service, *method, *style = NULL; 173 int authenticated = 0; 174 #ifdef HAVE_LOGIN_CAP 175 login_cap_t *lc; 176 #endif /* HAVE_LOGIN_CAP */ 177 #if defined(HAVE_LOGIN_CAP) || defined(LOGIN_ACCESS) 178 const char *from_host, *from_ip; 179 180 from_host = get_canonical_hostname(options.verify_reverse_mapping); 181 from_ip = get_remote_ipaddr(); 182 #endif /* HAVE_LOGIN_CAP || LOGIN_ACCESS */ 183 184 if (authctxt == NULL) 185 fatal("input_userauth_request: no authctxt"); 186 187 user = packet_get_string(NULL); 188 service = packet_get_string(NULL); 189 method = packet_get_string(NULL); 190 debug("userauth-request for user %s service %s method %s", user, service, method); 191 debug("attempt %d failures %d", authctxt->attempt, authctxt->failures); 192 193 if ((style = strchr(user, ':')) != NULL) 194 *style++ = 0; 195 196 if (authctxt->attempt++ == 0) { 197 /* setup auth context */ 198 struct passwd *pw = NULL; 199 pw = getpwnam(user); 200 if (pw && allowed_user(pw) && strcmp(service, "ssh-connection")==0) { 201 authctxt->pw = pwcopy(pw); 202 authctxt->valid = 1; 203 debug2("input_userauth_request: setting up authctxt for %s", user); 204 #ifdef USE_PAM 205 start_pam(pw); 206 #endif 207 } else { 208 log("input_userauth_request: illegal user %s", user); 209 authctxt->pw = NULL; 210 } 211 setproctitle("%s", pw ? user : "unknown"); 212 authctxt->user = xstrdup(user); 213 authctxt->service = xstrdup(service); 214 authctxt->style = style ? xstrdup(style) : NULL; 215 } else if (strcmp(user, authctxt->user) != 0 || 216 strcmp(service, authctxt->service) != 0) { 217 packet_disconnect("Change of username or service not allowed: " 218 "(%s,%s) -> (%s,%s)", 219 authctxt->user, authctxt->service, user, service); 220 } 221 222 #ifdef HAVE_LOGIN_CAP 223 if (authctxt->pw != NULL) { 224 lc = login_getpwclass(authctxt->pw); 225 if (lc == NULL) 226 lc = login_getclassbyname(NULL, authctxt->pw); 227 if (!auth_hostok(lc, from_host, from_ip)) { 228 log("Denied connection for %.200s from %.200s [%.200s].", 229 authctxt->pw->pw_name, from_host, from_ip); 230 packet_disconnect("Sorry, you are not allowed to connect."); 231 } 232 if (!auth_timeok(lc, time(NULL))) { 233 log("LOGIN %.200s REFUSED (TIME) FROM %.200s", 234 authctxt->pw->pw_name, from_host); 235 packet_disconnect("Logins not available right now."); 236 } 237 login_close(lc); 238 lc = NULL; 239 } 240 #endif /* HAVE_LOGIN_CAP */ 241 #ifdef LOGIN_ACCESS 242 if (authctxt->pw != NULL && 243 !login_access(authctxt->pw->pw_name, from_host)) { 244 log("Denied connection for %.200s from %.200s [%.200s].", 245 authctxt->pw->pw_name, from_host, from_ip); 246 packet_disconnect("Sorry, you are not allowed to connect."); 247 } 248 #endif /* LOGIN_ACCESS */ 249 /* reset state */ 250 auth2_challenge_stop(authctxt); 251 authctxt->postponed = 0; 252 253 /* try to authenticate user */ 254 m = authmethod_lookup(method); 255 if (m != NULL) { 256 debug2("input_userauth_request: try method %s", method); 257 authenticated = m->userauth(authctxt); 258 } 259 #ifdef USE_PAM 260 if (authenticated && authctxt->user && !do_pam_account(authctxt->user, NULL)) 261 authenticated = 0; 262 #endif /* USE_PAM */ 263 userauth_finish(authctxt, authenticated, method); 264 265 xfree(service); 266 xfree(user); 267 xfree(method); 268 } 269 270 void 271 userauth_finish(Authctxt *authctxt, int authenticated, char *method) 272 { 273 char *methods; 274 275 if (!authctxt->valid && authenticated) 276 fatal("INTERNAL ERROR: authenticated invalid user %s", 277 authctxt->user); 278 279 /* Special handling for root */ 280 if (authenticated && authctxt->pw->pw_uid == 0 && 281 !auth_root_allowed(method)) 282 authenticated = 0; 283 284 /* Log before sending the reply */ 285 auth_log(authctxt, authenticated, method, " ssh2"); 286 287 if (authctxt->postponed) 288 return; 289 290 /* XXX todo: check if multiple auth methods are needed */ 291 if (authenticated == 1) { 292 /* turn off userauth */ 293 dispatch_set(SSH2_MSG_USERAUTH_REQUEST, &dispatch_protocol_ignore); 294 packet_start(SSH2_MSG_USERAUTH_SUCCESS); 295 packet_send(); 296 packet_write_wait(); 297 /* now we can break out */ 298 authctxt->success = 1; 299 } else { 300 if (authctxt->failures++ > AUTH_FAIL_MAX) 301 packet_disconnect(AUTH_FAIL_MSG, authctxt->user); 302 methods = authmethods_get(); 303 packet_start(SSH2_MSG_USERAUTH_FAILURE); 304 packet_put_cstring(methods); 305 packet_put_char(0); /* XXX partial success, unused */ 306 packet_send(); 307 packet_write_wait(); 308 xfree(methods); 309 } 310 } 311 312 static void 313 userauth_banner(void) 314 { 315 struct stat st; 316 char *banner = NULL; 317 off_t len, n; 318 int fd; 319 320 if (options.banner == NULL || (datafellows & SSH_BUG_BANNER)) 321 return; 322 if ((fd = open(options.banner, O_RDONLY)) < 0) 323 return; 324 if (fstat(fd, &st) < 0) 325 goto done; 326 len = st.st_size; 327 banner = xmalloc(len + 1); 328 if ((n = read(fd, banner, len)) < 0) 329 goto done; 330 banner[n] = '\0'; 331 packet_start(SSH2_MSG_USERAUTH_BANNER); 332 packet_put_cstring(banner); 333 packet_put_cstring(""); /* language, unused */ 334 packet_send(); 335 debug("userauth_banner: sent"); 336 done: 337 if (banner) 338 xfree(banner); 339 close(fd); 340 return; 341 } 342 343 static int 344 userauth_none(Authctxt *authctxt) 345 { 346 /* disable method "none", only allowed one time */ 347 Authmethod *m = authmethod_lookup("none"); 348 if (m != NULL) 349 m->enabled = NULL; 350 packet_check_eom(); 351 userauth_banner(); 352 #ifdef USE_PAM 353 return authctxt->valid ? auth_pam_password(authctxt, "") : 0; 354 #else /* !USE_PAM */ 355 return authctxt->valid ? auth_password(authctxt, "") : 0; 356 #endif /* USE_PAM */ 357 } 358 359 static int 360 userauth_passwd(Authctxt *authctxt) 361 { 362 char *password; 363 int authenticated = 0; 364 int change; 365 u_int len; 366 change = packet_get_char(); 367 if (change) 368 log("password change not supported"); 369 password = packet_get_string(&len); 370 packet_check_eom(); 371 if (authctxt->valid && 372 #ifdef USE_PAM 373 auth_password(authctxt, password) == 1) 374 #else 375 auth_password(authctxt, password) == 1) 376 #endif 377 authenticated = 1; 378 memset(password, 0, len); 379 xfree(password); 380 return authenticated; 381 } 382 383 static int 384 userauth_kbdint(Authctxt *authctxt) 385 { 386 int authenticated = 0; 387 char *lang, *devs; 388 389 lang = packet_get_string(NULL); 390 devs = packet_get_string(NULL); 391 packet_check_eom(); 392 393 debug("keyboard-interactive devs %s", devs); 394 395 if (options.challenge_response_authentication) 396 authenticated = auth2_challenge(authctxt, devs); 397 398 xfree(devs); 399 xfree(lang); 400 return authenticated; 401 } 402 403 static int 404 userauth_pubkey(Authctxt *authctxt) 405 { 406 Buffer b; 407 Key *key = NULL; 408 char *pkalg; 409 u_char *pkblob, *sig; 410 u_int alen, blen, slen; 411 int have_sig, pktype; 412 int authenticated = 0; 413 414 if (!authctxt->valid) { 415 debug2("userauth_pubkey: disabled because of invalid user"); 416 return 0; 417 } 418 have_sig = packet_get_char(); 419 if (datafellows & SSH_BUG_PKAUTH) { 420 debug2("userauth_pubkey: SSH_BUG_PKAUTH"); 421 /* no explicit pkalg given */ 422 pkblob = packet_get_string(&blen); 423 buffer_init(&b); 424 buffer_append(&b, pkblob, blen); 425 /* so we have to extract the pkalg from the pkblob */ 426 pkalg = buffer_get_string(&b, &alen); 427 buffer_free(&b); 428 } else { 429 pkalg = packet_get_string(&alen); 430 pkblob = packet_get_string(&blen); 431 } 432 pktype = key_type_from_name(pkalg); 433 if (pktype == KEY_UNSPEC) { 434 /* this is perfectly legal */ 435 log("userauth_pubkey: unsupported public key algorithm: %s", 436 pkalg); 437 goto done; 438 } 439 key = key_from_blob(pkblob, blen); 440 if (key == NULL) { 441 error("userauth_pubkey: cannot decode key: %s", pkalg); 442 goto done; 443 } 444 if (key->type != pktype) { 445 error("userauth_pubkey: type mismatch for decoded key " 446 "(received %d, expected %d)", key->type, pktype); 447 goto done; 448 } 449 if (have_sig) { 450 sig = packet_get_string(&slen); 451 packet_check_eom(); 452 buffer_init(&b); 453 if (datafellows & SSH_OLD_SESSIONID) { 454 buffer_append(&b, session_id2, session_id2_len); 455 } else { 456 buffer_put_string(&b, session_id2, session_id2_len); 457 } 458 /* reconstruct packet */ 459 buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); 460 buffer_put_cstring(&b, authctxt->user); 461 buffer_put_cstring(&b, 462 datafellows & SSH_BUG_PKSERVICE ? 463 "ssh-userauth" : 464 authctxt->service); 465 if (datafellows & SSH_BUG_PKAUTH) { 466 buffer_put_char(&b, have_sig); 467 } else { 468 buffer_put_cstring(&b, "publickey"); 469 buffer_put_char(&b, have_sig); 470 buffer_put_cstring(&b, pkalg); 471 } 472 buffer_put_string(&b, pkblob, blen); 473 #ifdef DEBUG_PK 474 buffer_dump(&b); 475 #endif 476 /* test for correct signature */ 477 if (user_key_allowed(authctxt->pw, key) && 478 key_verify(key, sig, slen, buffer_ptr(&b), buffer_len(&b)) == 1) 479 authenticated = 1; 480 buffer_clear(&b); 481 xfree(sig); 482 } else { 483 debug("test whether pkalg/pkblob are acceptable"); 484 packet_check_eom(); 485 486 /* XXX fake reply and always send PK_OK ? */ 487 /* 488 * XXX this allows testing whether a user is allowed 489 * to login: if you happen to have a valid pubkey this 490 * message is sent. the message is NEVER sent at all 491 * if a user is not allowed to login. is this an 492 * issue? -markus 493 */ 494 if (user_key_allowed(authctxt->pw, key)) { 495 packet_start(SSH2_MSG_USERAUTH_PK_OK); 496 packet_put_string(pkalg, alen); 497 packet_put_string(pkblob, blen); 498 packet_send(); 499 packet_write_wait(); 500 authctxt->postponed = 1; 501 } 502 } 503 if (authenticated != 1) 504 auth_clear_options(); 505 done: 506 debug2("userauth_pubkey: authenticated %d pkalg %s", authenticated, pkalg); 507 if (key != NULL) 508 key_free(key); 509 xfree(pkalg); 510 xfree(pkblob); 511 return authenticated; 512 } 513 514 static int 515 userauth_hostbased(Authctxt *authctxt) 516 { 517 Buffer b; 518 Key *key = NULL; 519 char *pkalg, *cuser, *chost, *service; 520 u_char *pkblob, *sig; 521 u_int alen, blen, slen; 522 int pktype; 523 int authenticated = 0; 524 525 if (!authctxt->valid) { 526 debug2("userauth_hostbased: disabled because of invalid user"); 527 return 0; 528 } 529 pkalg = packet_get_string(&alen); 530 pkblob = packet_get_string(&blen); 531 chost = packet_get_string(NULL); 532 cuser = packet_get_string(NULL); 533 sig = packet_get_string(&slen); 534 535 debug("userauth_hostbased: cuser %s chost %s pkalg %s slen %d", 536 cuser, chost, pkalg, slen); 537 #ifdef DEBUG_PK 538 debug("signature:"); 539 buffer_init(&b); 540 buffer_append(&b, sig, slen); 541 buffer_dump(&b); 542 buffer_free(&b); 543 #endif 544 pktype = key_type_from_name(pkalg); 545 if (pktype == KEY_UNSPEC) { 546 /* this is perfectly legal */ 547 log("userauth_hostbased: unsupported " 548 "public key algorithm: %s", pkalg); 549 goto done; 550 } 551 key = key_from_blob(pkblob, blen); 552 if (key == NULL) { 553 error("userauth_hostbased: cannot decode key: %s", pkalg); 554 goto done; 555 } 556 if (key->type != pktype) { 557 error("userauth_hostbased: type mismatch for decoded key " 558 "(received %d, expected %d)", key->type, pktype); 559 goto done; 560 } 561 service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" : 562 authctxt->service; 563 buffer_init(&b); 564 buffer_put_string(&b, session_id2, session_id2_len); 565 /* reconstruct packet */ 566 buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); 567 buffer_put_cstring(&b, authctxt->user); 568 buffer_put_cstring(&b, service); 569 buffer_put_cstring(&b, "hostbased"); 570 buffer_put_string(&b, pkalg, alen); 571 buffer_put_string(&b, pkblob, blen); 572 buffer_put_cstring(&b, chost); 573 buffer_put_cstring(&b, cuser); 574 #ifdef DEBUG_PK 575 buffer_dump(&b); 576 #endif 577 /* test for allowed key and correct signature */ 578 if (hostbased_key_allowed(authctxt->pw, cuser, chost, key) && 579 key_verify(key, sig, slen, buffer_ptr(&b), buffer_len(&b)) == 1) 580 authenticated = 1; 581 582 buffer_clear(&b); 583 done: 584 debug2("userauth_hostbased: authenticated %d", authenticated); 585 if (key != NULL) 586 key_free(key); 587 xfree(pkalg); 588 xfree(pkblob); 589 xfree(cuser); 590 xfree(chost); 591 xfree(sig); 592 return authenticated; 593 } 594 595 /* get current user */ 596 597 struct passwd* 598 auth_get_user(void) 599 { 600 return (x_authctxt != NULL && x_authctxt->valid) ? x_authctxt->pw : NULL; 601 } 602 603 #define DELIM "," 604 605 static char * 606 authmethods_get(void) 607 { 608 Authmethod *method = NULL; 609 Buffer b; 610 char *list; 611 612 buffer_init(&b); 613 for (method = authmethods; method->name != NULL; method++) { 614 if (strcmp(method->name, "none") == 0) 615 continue; 616 if (method->enabled != NULL && *(method->enabled) != 0) { 617 if (buffer_len(&b) > 0) 618 buffer_append(&b, ",", 1); 619 buffer_append(&b, method->name, strlen(method->name)); 620 } 621 } 622 buffer_append(&b, "\0", 1); 623 list = xstrdup(buffer_ptr(&b)); 624 buffer_free(&b); 625 return list; 626 } 627 628 static Authmethod * 629 authmethod_lookup(const char *name) 630 { 631 Authmethod *method = NULL; 632 if (name != NULL) 633 for (method = authmethods; method->name != NULL; method++) 634 if (method->enabled != NULL && 635 *(method->enabled) != 0 && 636 strcmp(name, method->name) == 0) 637 return method; 638 debug2("Unrecognized authentication method name: %s", name ? name : "NULL"); 639 return NULL; 640 } 641 642 /* return 1 if user allows given key */ 643 static int 644 user_key_allowed2(struct passwd *pw, Key *key, char *file) 645 { 646 char line[8192]; 647 int found_key = 0; 648 FILE *f; 649 u_long linenum = 0; 650 struct stat st; 651 Key *found; 652 char *fp; 653 654 if (pw == NULL) 655 return 0; 656 657 /* Temporarily use the user's uid. */ 658 temporarily_use_uid(pw); 659 660 debug("trying public key file %s", file); 661 662 /* Fail quietly if file does not exist */ 663 if (stat(file, &st) < 0) { 664 /* Restore the privileged uid. */ 665 restore_uid(); 666 return 0; 667 } 668 /* Open the file containing the authorized keys. */ 669 f = fopen(file, "r"); 670 if (!f) { 671 /* Restore the privileged uid. */ 672 restore_uid(); 673 return 0; 674 } 675 if (options.strict_modes && 676 secure_filename(f, file, pw, line, sizeof(line)) != 0) { 677 fclose(f); 678 log("Authentication refused: %s", line); 679 restore_uid(); 680 return 0; 681 } 682 683 found_key = 0; 684 found = key_new(key->type); 685 686 while (fgets(line, sizeof(line), f)) { 687 char *cp, *options = NULL; 688 linenum++; 689 /* Skip leading whitespace, empty and comment lines. */ 690 for (cp = line; *cp == ' ' || *cp == '\t'; cp++) 691 ; 692 if (!*cp || *cp == '\n' || *cp == '#') 693 continue; 694 695 if (key_read(found, &cp) != 1) { 696 /* no key? check if there are options for this key */ 697 int quoted = 0; 698 debug2("user_key_allowed: check options: '%s'", cp); 699 options = cp; 700 for (; *cp && (quoted || (*cp != ' ' && *cp != '\t')); cp++) { 701 if (*cp == '\\' && cp[1] == '"') 702 cp++; /* Skip both */ 703 else if (*cp == '"') 704 quoted = !quoted; 705 } 706 /* Skip remaining whitespace. */ 707 for (; *cp == ' ' || *cp == '\t'; cp++) 708 ; 709 if (key_read(found, &cp) != 1) { 710 debug2("user_key_allowed: advance: '%s'", cp); 711 /* still no key? advance to next line*/ 712 continue; 713 } 714 } 715 if (key_equal(found, key) && 716 auth_parse_options(pw, options, file, linenum) == 1) { 717 found_key = 1; 718 debug("matching key found: file %s, line %lu", 719 file, linenum); 720 fp = key_fingerprint(found, SSH_FP_MD5, SSH_FP_HEX); 721 verbose("Found matching %s key: %s", 722 key_type(found), fp); 723 xfree(fp); 724 break; 725 } 726 } 727 restore_uid(); 728 fclose(f); 729 key_free(found); 730 if (!found_key) 731 debug2("key not found"); 732 return found_key; 733 } 734 735 /* check whether given key is in .ssh/authorized_keys* */ 736 static int 737 user_key_allowed(struct passwd *pw, Key *key) 738 { 739 int success; 740 char *file; 741 742 file = authorized_keys_file(pw); 743 success = user_key_allowed2(pw, key, file); 744 xfree(file); 745 if (success) 746 return success; 747 748 /* try suffix "2" for backward compat, too */ 749 file = authorized_keys_file2(pw); 750 success = user_key_allowed2(pw, key, file); 751 xfree(file); 752 return success; 753 } 754 755 /* return 1 if given hostkey is allowed */ 756 static int 757 hostbased_key_allowed(struct passwd *pw, const char *cuser, char *chost, 758 Key *key) 759 { 760 const char *resolvedname, *ipaddr, *lookup; 761 HostStatus host_status; 762 int len; 763 764 resolvedname = get_canonical_hostname(options.verify_reverse_mapping); 765 ipaddr = get_remote_ipaddr(); 766 767 debug2("userauth_hostbased: chost %s resolvedname %s ipaddr %s", 768 chost, resolvedname, ipaddr); 769 770 if (options.hostbased_uses_name_from_packet_only) { 771 if (auth_rhosts2(pw, cuser, chost, chost) == 0) 772 return 0; 773 lookup = chost; 774 } else { 775 if (((len = strlen(chost)) > 0) && chost[len - 1] == '.') { 776 debug2("stripping trailing dot from chost %s", chost); 777 chost[len - 1] = '\0'; 778 } 779 if (strcasecmp(resolvedname, chost) != 0) 780 log("userauth_hostbased mismatch: " 781 "client sends %s, but we resolve %s to %s", 782 chost, ipaddr, resolvedname); 783 if (auth_rhosts2(pw, cuser, resolvedname, ipaddr) == 0) 784 return 0; 785 lookup = resolvedname; 786 } 787 debug2("userauth_hostbased: access allowed by auth_rhosts2"); 788 789 host_status = check_key_in_hostfiles(pw, key, lookup, 790 _PATH_SSH_SYSTEM_HOSTFILE, 791 options.ignore_user_known_hosts ? NULL : _PATH_SSH_USER_HOSTFILE); 792 793 /* backward compat if no key has been found. */ 794 if (host_status == HOST_NEW) 795 host_status = check_key_in_hostfiles(pw, key, lookup, 796 _PATH_SSH_SYSTEM_HOSTFILE2, 797 options.ignore_user_known_hosts ? NULL : 798 _PATH_SSH_USER_HOSTFILE2); 799 800 return (host_status == HOST_OK); 801 } 802