1 /* $OpenBSD: auth2.c,v 1.150 2018/09/13 02:08:33 djm Exp $ */ 2 /* 3 * Copyright (c) 2000 Markus Friedl. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24 */ 25 26 27 #include <sys/types.h> 28 #include <sys/stat.h> 29 #include <sys/uio.h> 30 31 #include <fcntl.h> 32 #include <limits.h> 33 #include <pwd.h> 34 #include <stdarg.h> 35 #include <string.h> 36 #include <unistd.h> 37 38 #include "atomicio.h" 39 #include "xmalloc.h" 40 #include "ssh2.h" 41 #include "packet.h" 42 #include "log.h" 43 #include "sshbuf.h" 44 #include "misc.h" 45 #include "servconf.h" 46 #include "compat.h" 47 #include "sshkey.h" 48 #include "hostfile.h" 49 #include "auth.h" 50 #include "dispatch.h" 51 #include "pathnames.h" 52 #ifdef GSSAPI 53 #include "ssh-gss.h" 54 #endif 55 #include "monitor_wrap.h" 56 #include "ssherr.h" 57 #include "digest.h" 58 59 /* import */ 60 extern ServerOptions options; 61 extern u_char *session_id2; 62 extern u_int session_id2_len; 63 64 /* methods */ 65 66 extern Authmethod method_none; 67 extern Authmethod method_pubkey; 68 extern Authmethod method_passwd; 69 extern Authmethod method_kbdint; 70 extern Authmethod method_hostbased; 71 #ifdef GSSAPI 72 extern Authmethod method_gssapi; 73 #endif 74 75 Authmethod *authmethods[] = { 76 &method_none, 77 &method_pubkey, 78 #ifdef GSSAPI 79 &method_gssapi, 80 #endif 81 &method_passwd, 82 &method_kbdint, 83 &method_hostbased, 84 NULL 85 }; 86 87 /* protocol */ 88 89 static int input_service_request(int, u_int32_t, struct ssh *); 90 static int input_userauth_request(int, u_int32_t, struct ssh *); 91 92 /* helper */ 93 static Authmethod *authmethod_lookup(Authctxt *, const char *); 94 static char *authmethods_get(Authctxt *authctxt); 95 96 #define MATCH_NONE 0 /* method or submethod mismatch */ 97 #define MATCH_METHOD 1 /* method matches (no submethod specified) */ 98 #define MATCH_BOTH 2 /* method and submethod match */ 99 #define MATCH_PARTIAL 3 /* method matches, submethod can't be checked */ 100 static int list_starts_with(const char *, const char *, const char *); 101 102 char * 103 auth2_read_banner(void) 104 { 105 struct stat st; 106 char *banner = NULL; 107 size_t len, n; 108 int fd; 109 110 if ((fd = open(options.banner, O_RDONLY)) == -1) 111 return (NULL); 112 if (fstat(fd, &st) == -1) { 113 close(fd); 114 return (NULL); 115 } 116 if (st.st_size <= 0 || st.st_size > 1*1024*1024) { 117 close(fd); 118 return (NULL); 119 } 120 121 len = (size_t)st.st_size; /* truncate */ 122 banner = xmalloc(len + 1); 123 n = atomicio(read, fd, banner, len); 124 close(fd); 125 126 if (n != len) { 127 free(banner); 128 return (NULL); 129 } 130 banner[n] = '\0'; 131 132 return (banner); 133 } 134 135 static void 136 userauth_banner(void) 137 { 138 char *banner = NULL; 139 140 if (options.banner == NULL) 141 return; 142 143 if ((banner = PRIVSEP(auth2_read_banner())) == NULL) 144 goto done; 145 146 packet_start(SSH2_MSG_USERAUTH_BANNER); 147 packet_put_cstring(banner); 148 packet_put_cstring(""); /* language, unused */ 149 packet_send(); 150 debug("userauth_banner: sent"); 151 done: 152 free(banner); 153 } 154 155 /* 156 * loop until authctxt->success == TRUE 157 */ 158 void 159 do_authentication2(Authctxt *authctxt) 160 { 161 struct ssh *ssh = active_state; /* XXX */ 162 ssh->authctxt = authctxt; /* XXX move to caller */ 163 ssh_dispatch_init(ssh, &dispatch_protocol_error); 164 ssh_dispatch_set(ssh, SSH2_MSG_SERVICE_REQUEST, &input_service_request); 165 ssh_dispatch_run_fatal(ssh, DISPATCH_BLOCK, &authctxt->success); 166 ssh->authctxt = NULL; 167 } 168 169 /*ARGSUSED*/ 170 static int 171 input_service_request(int type, u_int32_t seq, struct ssh *ssh) 172 { 173 Authctxt *authctxt = ssh->authctxt; 174 u_int len; 175 int acceptit = 0; 176 char *service = packet_get_cstring(&len); 177 packet_check_eom(); 178 179 if (authctxt == NULL) 180 fatal("input_service_request: no authctxt"); 181 182 if (strcmp(service, "ssh-userauth") == 0) { 183 if (!authctxt->success) { 184 acceptit = 1; 185 /* now we can handle user-auth requests */ 186 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_REQUEST, &input_userauth_request); 187 } 188 } 189 /* XXX all other service requests are denied */ 190 191 if (acceptit) { 192 packet_start(SSH2_MSG_SERVICE_ACCEPT); 193 packet_put_cstring(service); 194 packet_send(); 195 packet_write_wait(); 196 } else { 197 debug("bad service request %s", service); 198 packet_disconnect("bad service request %s", service); 199 } 200 free(service); 201 return 0; 202 } 203 204 #define MIN_FAIL_DELAY_SECONDS 0.005 205 static double 206 user_specific_delay(const char *user) 207 { 208 char b[512]; 209 size_t len = ssh_digest_bytes(SSH_DIGEST_SHA512); 210 u_char *hash = xmalloc(len); 211 double delay; 212 213 (void)snprintf(b, sizeof b, "%llu%s", 214 (unsigned long long)options.timing_secret, user); 215 if (ssh_digest_memory(SSH_DIGEST_SHA512, b, strlen(b), hash, len) != 0) 216 fatal("%s: ssh_digest_memory", __func__); 217 /* 0-4.2 ms of delay */ 218 delay = (double)PEEK_U32(hash) / 1000 / 1000 / 1000 / 1000; 219 freezero(hash, len); 220 debug3("%s: user specific delay %0.3lfms", __func__, delay/1000); 221 return MIN_FAIL_DELAY_SECONDS + delay; 222 } 223 224 static void 225 ensure_minimum_time_since(double start, double seconds) 226 { 227 struct timespec ts; 228 double elapsed = monotime_double() - start, req = seconds, remain; 229 230 /* if we've already passed the requested time, scale up */ 231 while ((remain = seconds - elapsed) < 0.0) 232 seconds *= 2; 233 234 ts.tv_sec = remain; 235 ts.tv_nsec = (remain - ts.tv_sec) * 1000000000; 236 debug3("%s: elapsed %0.3lfms, delaying %0.3lfms (requested %0.3lfms)", 237 __func__, elapsed*1000, remain*1000, req*1000); 238 nanosleep(&ts, NULL); 239 } 240 241 /*ARGSUSED*/ 242 static int 243 input_userauth_request(int type, u_int32_t seq, struct ssh *ssh) 244 { 245 Authctxt *authctxt = ssh->authctxt; 246 Authmethod *m = NULL; 247 char *user, *service, *method, *style = NULL; 248 int authenticated = 0; 249 double tstart = monotime_double(); 250 251 if (authctxt == NULL) 252 fatal("input_userauth_request: no authctxt"); 253 254 user = packet_get_cstring(NULL); 255 service = packet_get_cstring(NULL); 256 method = packet_get_cstring(NULL); 257 debug("userauth-request for user %s service %s method %s", user, service, method); 258 debug("attempt %d failures %d", authctxt->attempt, authctxt->failures); 259 260 if ((style = strchr(user, ':')) != NULL) 261 *style++ = 0; 262 263 if (authctxt->attempt++ == 0) { 264 /* setup auth context */ 265 authctxt->pw = PRIVSEP(getpwnamallow(user)); 266 if (authctxt->pw && strcmp(service, "ssh-connection")==0) { 267 authctxt->valid = 1; 268 debug2("%s: setting up authctxt for %s", 269 __func__, user); 270 } else { 271 /* Invalid user, fake password information */ 272 authctxt->pw = fakepw(); 273 } 274 ssh_packet_set_log_preamble(ssh, "%suser %s", 275 authctxt->valid ? "authenticating " : "invalid ", user); 276 setproctitle("%s%s", authctxt->valid ? user : "unknown", 277 use_privsep ? " [net]" : ""); 278 authctxt->user = xstrdup(user); 279 authctxt->service = xstrdup(service); 280 authctxt->style = style ? xstrdup(style) : NULL; 281 if (use_privsep) 282 mm_inform_authserv(service, style); 283 userauth_banner(); 284 if (auth2_setup_methods_lists(authctxt) != 0) 285 packet_disconnect("no authentication methods enabled"); 286 } else if (strcmp(user, authctxt->user) != 0 || 287 strcmp(service, authctxt->service) != 0) { 288 packet_disconnect("Change of username or service not allowed: " 289 "(%s,%s) -> (%s,%s)", 290 authctxt->user, authctxt->service, user, service); 291 } 292 /* reset state */ 293 auth2_challenge_stop(ssh); 294 295 #ifdef GSSAPI 296 /* XXX move to auth2_gssapi_stop() */ 297 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL); 298 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, NULL); 299 #endif 300 301 auth2_authctxt_reset_info(authctxt); 302 authctxt->postponed = 0; 303 authctxt->server_caused_failure = 0; 304 305 /* try to authenticate user */ 306 m = authmethod_lookup(authctxt, method); 307 if (m != NULL && authctxt->failures < options.max_authtries) { 308 debug2("input_userauth_request: try method %s", method); 309 authenticated = m->userauth(ssh); 310 } 311 if (!authctxt->authenticated) 312 ensure_minimum_time_since(tstart, 313 user_specific_delay(authctxt->user)); 314 userauth_finish(ssh, authenticated, method, NULL); 315 316 free(service); 317 free(user); 318 free(method); 319 return 0; 320 } 321 322 void 323 userauth_finish(struct ssh *ssh, int authenticated, const char *method, 324 const char *submethod) 325 { 326 Authctxt *authctxt = ssh->authctxt; 327 char *methods; 328 int partial = 0; 329 330 if (!authctxt->valid && authenticated) 331 fatal("INTERNAL ERROR: authenticated invalid user %s", 332 authctxt->user); 333 if (authenticated && authctxt->postponed) 334 fatal("INTERNAL ERROR: authenticated and postponed"); 335 336 /* Special handling for root */ 337 if (authenticated && authctxt->pw->pw_uid == 0 && 338 !auth_root_allowed(ssh, method)) 339 authenticated = 0; 340 341 if (authenticated && options.num_auth_methods != 0) { 342 if (!auth2_update_methods_lists(authctxt, method, submethod)) { 343 authenticated = 0; 344 partial = 1; 345 } 346 } 347 348 /* Log before sending the reply */ 349 auth_log(authctxt, authenticated, partial, method, submethod); 350 351 /* Update information exposed to session */ 352 if (authenticated || partial) 353 auth2_update_session_info(authctxt, method, submethod); 354 355 if (authctxt->postponed) 356 return; 357 358 if (authenticated == 1) { 359 /* turn off userauth */ 360 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_REQUEST, &dispatch_protocol_ignore); 361 packet_start(SSH2_MSG_USERAUTH_SUCCESS); 362 packet_send(); 363 packet_write_wait(); 364 /* now we can break out */ 365 authctxt->success = 1; 366 ssh_packet_set_log_preamble(ssh, "user %s", authctxt->user); 367 } else { 368 /* Allow initial try of "none" auth without failure penalty */ 369 if (!partial && !authctxt->server_caused_failure && 370 (authctxt->attempt > 1 || strcmp(method, "none") != 0)) 371 authctxt->failures++; 372 if (authctxt->failures >= options.max_authtries) 373 auth_maxtries_exceeded(authctxt); 374 methods = authmethods_get(authctxt); 375 debug3("%s: failure partial=%d next methods=\"%s\"", __func__, 376 partial, methods); 377 packet_start(SSH2_MSG_USERAUTH_FAILURE); 378 packet_put_cstring(methods); 379 packet_put_char(partial); 380 packet_send(); 381 packet_write_wait(); 382 free(methods); 383 } 384 } 385 386 /* 387 * Checks whether method is allowed by at least one AuthenticationMethods 388 * methods list. Returns 1 if allowed, or no methods lists configured. 389 * 0 otherwise. 390 */ 391 int 392 auth2_method_allowed(Authctxt *authctxt, const char *method, 393 const char *submethod) 394 { 395 u_int i; 396 397 /* 398 * NB. authctxt->num_auth_methods might be zero as a result of 399 * auth2_setup_methods_lists(), so check the configuration. 400 */ 401 if (options.num_auth_methods == 0) 402 return 1; 403 for (i = 0; i < authctxt->num_auth_methods; i++) { 404 if (list_starts_with(authctxt->auth_methods[i], method, 405 submethod) != MATCH_NONE) 406 return 1; 407 } 408 return 0; 409 } 410 411 static char * 412 authmethods_get(Authctxt *authctxt) 413 { 414 struct sshbuf *b; 415 char *list; 416 int i, r; 417 418 if ((b = sshbuf_new()) == NULL) 419 fatal("%s: sshbuf_new failed", __func__); 420 for (i = 0; authmethods[i] != NULL; i++) { 421 if (strcmp(authmethods[i]->name, "none") == 0) 422 continue; 423 if (authmethods[i]->enabled == NULL || 424 *(authmethods[i]->enabled) == 0) 425 continue; 426 if (!auth2_method_allowed(authctxt, authmethods[i]->name, 427 NULL)) 428 continue; 429 if ((r = sshbuf_putf(b, "%s%s", sshbuf_len(b) ? "," : "", 430 authmethods[i]->name)) != 0) 431 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 432 } 433 if ((list = sshbuf_dup_string(b)) == NULL) 434 fatal("%s: sshbuf_dup_string failed", __func__); 435 sshbuf_free(b); 436 return list; 437 } 438 439 static Authmethod * 440 authmethod_lookup(Authctxt *authctxt, const char *name) 441 { 442 int i; 443 444 if (name != NULL) 445 for (i = 0; authmethods[i] != NULL; i++) 446 if (authmethods[i]->enabled != NULL && 447 *(authmethods[i]->enabled) != 0 && 448 strcmp(name, authmethods[i]->name) == 0 && 449 auth2_method_allowed(authctxt, 450 authmethods[i]->name, NULL)) 451 return authmethods[i]; 452 debug2("Unrecognized authentication method name: %s", 453 name ? name : "NULL"); 454 return NULL; 455 } 456 457 /* 458 * Check a comma-separated list of methods for validity. Is need_enable is 459 * non-zero, then also require that the methods are enabled. 460 * Returns 0 on success or -1 if the methods list is invalid. 461 */ 462 int 463 auth2_methods_valid(const char *_methods, int need_enable) 464 { 465 char *methods, *omethods, *method, *p; 466 u_int i, found; 467 int ret = -1; 468 469 if (*_methods == '\0') { 470 error("empty authentication method list"); 471 return -1; 472 } 473 omethods = methods = xstrdup(_methods); 474 while ((method = strsep(&methods, ",")) != NULL) { 475 for (found = i = 0; !found && authmethods[i] != NULL; i++) { 476 if ((p = strchr(method, ':')) != NULL) 477 *p = '\0'; 478 if (strcmp(method, authmethods[i]->name) != 0) 479 continue; 480 if (need_enable) { 481 if (authmethods[i]->enabled == NULL || 482 *(authmethods[i]->enabled) == 0) { 483 error("Disabled method \"%s\" in " 484 "AuthenticationMethods list \"%s\"", 485 method, _methods); 486 goto out; 487 } 488 } 489 found = 1; 490 break; 491 } 492 if (!found) { 493 error("Unknown authentication method \"%s\" in list", 494 method); 495 goto out; 496 } 497 } 498 ret = 0; 499 out: 500 free(omethods); 501 return ret; 502 } 503 504 /* 505 * Prune the AuthenticationMethods supplied in the configuration, removing 506 * any methods lists that include disabled methods. Note that this might 507 * leave authctxt->num_auth_methods == 0, even when multiple required auth 508 * has been requested. For this reason, all tests for whether multiple is 509 * enabled should consult options.num_auth_methods directly. 510 */ 511 int 512 auth2_setup_methods_lists(Authctxt *authctxt) 513 { 514 u_int i; 515 516 if (options.num_auth_methods == 0) 517 return 0; 518 debug3("%s: checking methods", __func__); 519 authctxt->auth_methods = xcalloc(options.num_auth_methods, 520 sizeof(*authctxt->auth_methods)); 521 authctxt->num_auth_methods = 0; 522 for (i = 0; i < options.num_auth_methods; i++) { 523 if (auth2_methods_valid(options.auth_methods[i], 1) != 0) { 524 logit("Authentication methods list \"%s\" contains " 525 "disabled method, skipping", 526 options.auth_methods[i]); 527 continue; 528 } 529 debug("authentication methods list %d: %s", 530 authctxt->num_auth_methods, options.auth_methods[i]); 531 authctxt->auth_methods[authctxt->num_auth_methods++] = 532 xstrdup(options.auth_methods[i]); 533 } 534 if (authctxt->num_auth_methods == 0) { 535 error("No AuthenticationMethods left after eliminating " 536 "disabled methods"); 537 return -1; 538 } 539 return 0; 540 } 541 542 static int 543 list_starts_with(const char *methods, const char *method, 544 const char *submethod) 545 { 546 size_t l = strlen(method); 547 int match; 548 const char *p; 549 550 if (strncmp(methods, method, l) != 0) 551 return MATCH_NONE; 552 p = methods + l; 553 match = MATCH_METHOD; 554 if (*p == ':') { 555 if (!submethod) 556 return MATCH_PARTIAL; 557 l = strlen(submethod); 558 p += 1; 559 if (strncmp(submethod, p, l)) 560 return MATCH_NONE; 561 p += l; 562 match = MATCH_BOTH; 563 } 564 if (*p != ',' && *p != '\0') 565 return MATCH_NONE; 566 return match; 567 } 568 569 /* 570 * Remove method from the start of a comma-separated list of methods. 571 * Returns 0 if the list of methods did not start with that method or 1 572 * if it did. 573 */ 574 static int 575 remove_method(char **methods, const char *method, const char *submethod) 576 { 577 char *omethods = *methods, *p; 578 size_t l = strlen(method); 579 int match; 580 581 match = list_starts_with(omethods, method, submethod); 582 if (match != MATCH_METHOD && match != MATCH_BOTH) 583 return 0; 584 p = omethods + l; 585 if (submethod && match == MATCH_BOTH) 586 p += 1 + strlen(submethod); /* include colon */ 587 if (*p == ',') 588 p++; 589 *methods = xstrdup(p); 590 free(omethods); 591 return 1; 592 } 593 594 /* 595 * Called after successful authentication. Will remove the successful method 596 * from the start of each list in which it occurs. If it was the last method 597 * in any list, then authentication is deemed successful. 598 * Returns 1 if the method completed any authentication list or 0 otherwise. 599 */ 600 int 601 auth2_update_methods_lists(Authctxt *authctxt, const char *method, 602 const char *submethod) 603 { 604 u_int i, found = 0; 605 606 debug3("%s: updating methods list after \"%s\"", __func__, method); 607 for (i = 0; i < authctxt->num_auth_methods; i++) { 608 if (!remove_method(&(authctxt->auth_methods[i]), method, 609 submethod)) 610 continue; 611 found = 1; 612 if (*authctxt->auth_methods[i] == '\0') { 613 debug2("authentication methods list %d complete", i); 614 return 1; 615 } 616 debug3("authentication methods list %d remaining: \"%s\"", 617 i, authctxt->auth_methods[i]); 618 } 619 /* This should not happen, but would be bad if it did */ 620 if (!found) 621 fatal("%s: method not in AuthenticationMethods", __func__); 622 return 0; 623 } 624 625 /* Reset method-specific information */ 626 void auth2_authctxt_reset_info(Authctxt *authctxt) 627 { 628 sshkey_free(authctxt->auth_method_key); 629 free(authctxt->auth_method_info); 630 authctxt->auth_method_key = NULL; 631 authctxt->auth_method_info = NULL; 632 } 633 634 /* Record auth method-specific information for logs */ 635 void 636 auth2_record_info(Authctxt *authctxt, const char *fmt, ...) 637 { 638 va_list ap; 639 int i; 640 641 free(authctxt->auth_method_info); 642 authctxt->auth_method_info = NULL; 643 644 va_start(ap, fmt); 645 i = vasprintf(&authctxt->auth_method_info, fmt, ap); 646 va_end(ap); 647 648 if (i < 0 || authctxt->auth_method_info == NULL) 649 fatal("%s: vasprintf failed", __func__); 650 } 651 652 /* 653 * Records a public key used in authentication. This is used for logging 654 * and to ensure that the same key is not subsequently accepted again for 655 * multiple authentication. 656 */ 657 void 658 auth2_record_key(Authctxt *authctxt, int authenticated, 659 const struct sshkey *key) 660 { 661 struct sshkey **tmp, *dup; 662 int r; 663 664 if ((r = sshkey_from_private(key, &dup)) != 0) 665 fatal("%s: copy key: %s", __func__, ssh_err(r)); 666 sshkey_free(authctxt->auth_method_key); 667 authctxt->auth_method_key = dup; 668 669 if (!authenticated) 670 return; 671 672 /* If authenticated, make sure we don't accept this key again */ 673 if ((r = sshkey_from_private(key, &dup)) != 0) 674 fatal("%s: copy key: %s", __func__, ssh_err(r)); 675 if (authctxt->nprev_keys >= INT_MAX || 676 (tmp = recallocarray(authctxt->prev_keys, authctxt->nprev_keys, 677 authctxt->nprev_keys + 1, sizeof(*authctxt->prev_keys))) == NULL) 678 fatal("%s: reallocarray failed", __func__); 679 authctxt->prev_keys = tmp; 680 authctxt->prev_keys[authctxt->nprev_keys] = dup; 681 authctxt->nprev_keys++; 682 683 } 684 685 /* Checks whether a key has already been previously used for authentication */ 686 int 687 auth2_key_already_used(Authctxt *authctxt, const struct sshkey *key) 688 { 689 u_int i; 690 char *fp; 691 692 for (i = 0; i < authctxt->nprev_keys; i++) { 693 if (sshkey_equal_public(key, authctxt->prev_keys[i])) { 694 fp = sshkey_fingerprint(authctxt->prev_keys[i], 695 options.fingerprint_hash, SSH_FP_DEFAULT); 696 debug3("%s: key already used: %s %s", __func__, 697 sshkey_type(authctxt->prev_keys[i]), 698 fp == NULL ? "UNKNOWN" : fp); 699 free(fp); 700 return 1; 701 } 702 } 703 return 0; 704 } 705 706 /* 707 * Updates authctxt->session_info with details of authentication. Should be 708 * whenever an authentication method succeeds. 709 */ 710 void 711 auth2_update_session_info(Authctxt *authctxt, const char *method, 712 const char *submethod) 713 { 714 int r; 715 716 if (authctxt->session_info == NULL) { 717 if ((authctxt->session_info = sshbuf_new()) == NULL) 718 fatal("%s: sshbuf_new", __func__); 719 } 720 721 /* Append method[/submethod] */ 722 if ((r = sshbuf_putf(authctxt->session_info, "%s%s%s", 723 method, submethod == NULL ? "" : "/", 724 submethod == NULL ? "" : submethod)) != 0) 725 fatal("%s: append method: %s", __func__, ssh_err(r)); 726 727 /* Append key if present */ 728 if (authctxt->auth_method_key != NULL) { 729 if ((r = sshbuf_put_u8(authctxt->session_info, ' ')) != 0 || 730 (r = sshkey_format_text(authctxt->auth_method_key, 731 authctxt->session_info)) != 0) 732 fatal("%s: append key: %s", __func__, ssh_err(r)); 733 } 734 735 if (authctxt->auth_method_info != NULL) { 736 /* Ensure no ambiguity here */ 737 if (strchr(authctxt->auth_method_info, '\n') != NULL) 738 fatal("%s: auth_method_info contains \\n", __func__); 739 if ((r = sshbuf_put_u8(authctxt->session_info, ' ')) != 0 || 740 (r = sshbuf_putf(authctxt->session_info, "%s", 741 authctxt->auth_method_info)) != 0) { 742 fatal("%s: append method info: %s", 743 __func__, ssh_err(r)); 744 } 745 } 746 if ((r = sshbuf_put_u8(authctxt->session_info, '\n')) != 0) 747 fatal("%s: append: %s", __func__, ssh_err(r)); 748 } 749 750