1 /* $OpenBSD: auth.c,v 1.161 2024/05/17 00:30:23 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 #include "includes.h" 27 28 #include <sys/types.h> 29 #include <sys/stat.h> 30 #include <sys/socket.h> 31 #include <sys/wait.h> 32 33 #include <netinet/in.h> 34 35 #include <stdlib.h> 36 #include <errno.h> 37 #include <fcntl.h> 38 #ifdef HAVE_PATHS_H 39 # include <paths.h> 40 #endif 41 #include <pwd.h> 42 #ifdef HAVE_LOGIN_H 43 #include <login.h> 44 #endif 45 #ifdef USE_SHADOW 46 #include <shadow.h> 47 #endif 48 #include <stdarg.h> 49 #include <stdio.h> 50 #include <string.h> 51 #include <unistd.h> 52 #include <limits.h> 53 #include <netdb.h> 54 #include <time.h> 55 56 #include "xmalloc.h" 57 #include "match.h" 58 #include "groupaccess.h" 59 #include "log.h" 60 #include "sshbuf.h" 61 #include "misc.h" 62 #include "servconf.h" 63 #include "sshkey.h" 64 #include "hostfile.h" 65 #include "auth.h" 66 #include "auth-options.h" 67 #include "canohost.h" 68 #include "uidswap.h" 69 #include "packet.h" 70 #include "loginrec.h" 71 #ifdef GSSAPI 72 #include "ssh-gss.h" 73 #endif 74 #include "authfile.h" 75 #include "monitor_wrap.h" 76 #include "ssherr.h" 77 #include "channels.h" 78 79 /* import */ 80 extern ServerOptions options; 81 extern struct include_list includes; 82 extern struct sshbuf *loginmsg; 83 extern struct passwd *privsep_pw; 84 extern struct sshauthopt *auth_opts; 85 86 /* Debugging messages */ 87 static struct sshbuf *auth_debug; 88 89 /* 90 * Check if the user is allowed to log in via ssh. If user is listed 91 * in DenyUsers or one of user's groups is listed in DenyGroups, false 92 * will be returned. If AllowUsers isn't empty and user isn't listed 93 * there, or if AllowGroups isn't empty and one of user's groups isn't 94 * listed there, false will be returned. 95 * If the user's shell is not executable, false will be returned. 96 * Otherwise true is returned. 97 */ 98 int 99 allowed_user(struct ssh *ssh, struct passwd * pw) 100 { 101 struct stat st; 102 const char *hostname = NULL, *ipaddr = NULL; 103 u_int i; 104 int r; 105 106 /* Shouldn't be called if pw is NULL, but better safe than sorry... */ 107 if (!pw || !pw->pw_name) 108 return 0; 109 110 if (!options.use_pam && platform_locked_account(pw)) { 111 logit("User %.100s not allowed because account is locked", 112 pw->pw_name); 113 return 0; 114 } 115 116 /* 117 * Deny if shell does not exist or is not executable unless we 118 * are chrooting. 119 */ 120 if (options.chroot_directory == NULL || 121 strcasecmp(options.chroot_directory, "none") == 0) { 122 char *shell = xstrdup((pw->pw_shell[0] == '\0') ? 123 _PATH_BSHELL : pw->pw_shell); /* empty = /bin/sh */ 124 125 if (stat(shell, &st) == -1) { 126 logit("User %.100s not allowed because shell %.100s " 127 "does not exist", pw->pw_name, shell); 128 free(shell); 129 return 0; 130 } 131 if (S_ISREG(st.st_mode) == 0 || 132 (st.st_mode & (S_IXOTH|S_IXUSR|S_IXGRP)) == 0) { 133 logit("User %.100s not allowed because shell %.100s " 134 "is not executable", pw->pw_name, shell); 135 free(shell); 136 return 0; 137 } 138 free(shell); 139 } 140 141 if (options.num_deny_users > 0 || options.num_allow_users > 0 || 142 options.num_deny_groups > 0 || options.num_allow_groups > 0) { 143 hostname = auth_get_canonical_hostname(ssh, options.use_dns); 144 ipaddr = ssh_remote_ipaddr(ssh); 145 } 146 147 /* Return false if user is listed in DenyUsers */ 148 if (options.num_deny_users > 0) { 149 for (i = 0; i < options.num_deny_users; i++) { 150 r = match_user(pw->pw_name, hostname, ipaddr, 151 options.deny_users[i]); 152 if (r < 0) { 153 fatal("Invalid DenyUsers pattern \"%.100s\"", 154 options.deny_users[i]); 155 } else if (r != 0) { 156 logit("User %.100s from %.100s not allowed " 157 "because listed in DenyUsers", 158 pw->pw_name, hostname); 159 return 0; 160 } 161 } 162 } 163 /* Return false if AllowUsers isn't empty and user isn't listed there */ 164 if (options.num_allow_users > 0) { 165 for (i = 0; i < options.num_allow_users; i++) { 166 r = match_user(pw->pw_name, hostname, ipaddr, 167 options.allow_users[i]); 168 if (r < 0) { 169 fatal("Invalid AllowUsers pattern \"%.100s\"", 170 options.allow_users[i]); 171 } else if (r == 1) 172 break; 173 } 174 /* i < options.num_allow_users iff we break for loop */ 175 if (i >= options.num_allow_users) { 176 logit("User %.100s from %.100s not allowed because " 177 "not listed in AllowUsers", pw->pw_name, hostname); 178 return 0; 179 } 180 } 181 if (options.num_deny_groups > 0 || options.num_allow_groups > 0) { 182 /* Get the user's group access list (primary and supplementary) */ 183 if (ga_init(pw->pw_name, pw->pw_gid) == 0) { 184 logit("User %.100s from %.100s not allowed because " 185 "not in any group", pw->pw_name, hostname); 186 return 0; 187 } 188 189 /* Return false if one of user's groups is listed in DenyGroups */ 190 if (options.num_deny_groups > 0) 191 if (ga_match(options.deny_groups, 192 options.num_deny_groups)) { 193 ga_free(); 194 logit("User %.100s from %.100s not allowed " 195 "because a group is listed in DenyGroups", 196 pw->pw_name, hostname); 197 return 0; 198 } 199 /* 200 * Return false if AllowGroups isn't empty and one of user's groups 201 * isn't listed there 202 */ 203 if (options.num_allow_groups > 0) 204 if (!ga_match(options.allow_groups, 205 options.num_allow_groups)) { 206 ga_free(); 207 logit("User %.100s from %.100s not allowed " 208 "because none of user's groups are listed " 209 "in AllowGroups", pw->pw_name, hostname); 210 return 0; 211 } 212 ga_free(); 213 } 214 215 #ifdef CUSTOM_SYS_AUTH_ALLOWED_USER 216 if (!sys_auth_allowed_user(pw, loginmsg)) 217 return 0; 218 #endif 219 220 /* We found no reason not to let this user try to log on... */ 221 return 1; 222 } 223 224 /* 225 * Formats any key left in authctxt->auth_method_key for inclusion in 226 * auth_log()'s message. Also includes authxtct->auth_method_info if present. 227 */ 228 static char * 229 format_method_key(Authctxt *authctxt) 230 { 231 const struct sshkey *key = authctxt->auth_method_key; 232 const char *methinfo = authctxt->auth_method_info; 233 char *fp, *cafp, *ret = NULL; 234 235 if (key == NULL) 236 return NULL; 237 238 if (sshkey_is_cert(key)) { 239 fp = sshkey_fingerprint(key, 240 options.fingerprint_hash, SSH_FP_DEFAULT); 241 cafp = sshkey_fingerprint(key->cert->signature_key, 242 options.fingerprint_hash, SSH_FP_DEFAULT); 243 xasprintf(&ret, "%s %s ID %s (serial %llu) CA %s %s%s%s", 244 sshkey_type(key), fp == NULL ? "(null)" : fp, 245 key->cert->key_id, 246 (unsigned long long)key->cert->serial, 247 sshkey_type(key->cert->signature_key), 248 cafp == NULL ? "(null)" : cafp, 249 methinfo == NULL ? "" : ", ", 250 methinfo == NULL ? "" : methinfo); 251 free(fp); 252 free(cafp); 253 } else { 254 fp = sshkey_fingerprint(key, options.fingerprint_hash, 255 SSH_FP_DEFAULT); 256 xasprintf(&ret, "%s %s%s%s", sshkey_type(key), 257 fp == NULL ? "(null)" : fp, 258 methinfo == NULL ? "" : ", ", 259 methinfo == NULL ? "" : methinfo); 260 free(fp); 261 } 262 return ret; 263 } 264 265 void 266 auth_log(struct ssh *ssh, int authenticated, int partial, 267 const char *method, const char *submethod) 268 { 269 Authctxt *authctxt = (Authctxt *)ssh->authctxt; 270 int level = SYSLOG_LEVEL_VERBOSE; 271 const char *authmsg; 272 char *extra = NULL; 273 274 if (!mm_is_monitor() && !authctxt->postponed) 275 return; 276 277 /* Raise logging level */ 278 if (authenticated == 1 || 279 !authctxt->valid || 280 authctxt->failures >= options.max_authtries / 2 || 281 strcmp(method, "password") == 0) 282 level = SYSLOG_LEVEL_INFO; 283 284 if (authctxt->postponed) 285 authmsg = "Postponed"; 286 else if (partial) 287 authmsg = "Partial"; 288 else 289 authmsg = authenticated ? "Accepted" : "Failed"; 290 291 if ((extra = format_method_key(authctxt)) == NULL) { 292 if (authctxt->auth_method_info != NULL) 293 extra = xstrdup(authctxt->auth_method_info); 294 } 295 296 do_log2(level, "%s %s%s%s for %s%.100s from %.200s port %d ssh2%s%s", 297 authmsg, 298 method, 299 submethod != NULL ? "/" : "", submethod == NULL ? "" : submethod, 300 authctxt->valid ? "" : "invalid user ", 301 authctxt->user, 302 ssh_remote_ipaddr(ssh), 303 ssh_remote_port(ssh), 304 extra != NULL ? ": " : "", 305 extra != NULL ? extra : ""); 306 307 free(extra); 308 309 #if defined(CUSTOM_FAILED_LOGIN) || defined(SSH_AUDIT_EVENTS) 310 if (authenticated == 0 && !(authctxt->postponed || partial)) { 311 /* Log failed login attempt */ 312 # ifdef CUSTOM_FAILED_LOGIN 313 if (strcmp(method, "password") == 0 || 314 strncmp(method, "keyboard-interactive", 20) == 0 || 315 strcmp(method, "challenge-response") == 0) 316 record_failed_login(ssh, authctxt->user, 317 auth_get_canonical_hostname(ssh, options.use_dns), "ssh"); 318 # endif 319 # ifdef SSH_AUDIT_EVENTS 320 audit_event(ssh, audit_classify_auth(method)); 321 # endif 322 } 323 #endif 324 #if defined(CUSTOM_FAILED_LOGIN) && defined(WITH_AIXAUTHENTICATE) 325 if (authenticated) 326 sys_auth_record_login(authctxt->user, 327 auth_get_canonical_hostname(ssh, options.use_dns), "ssh", 328 loginmsg); 329 #endif 330 } 331 332 void 333 auth_maxtries_exceeded(struct ssh *ssh) 334 { 335 Authctxt *authctxt = (Authctxt *)ssh->authctxt; 336 337 error("maximum authentication attempts exceeded for " 338 "%s%.100s from %.200s port %d ssh2", 339 authctxt->valid ? "" : "invalid user ", 340 authctxt->user, 341 ssh_remote_ipaddr(ssh), 342 ssh_remote_port(ssh)); 343 ssh_packet_disconnect(ssh, "Too many authentication failures"); 344 /* NOTREACHED */ 345 } 346 347 /* 348 * Check whether root logins are disallowed. 349 */ 350 int 351 auth_root_allowed(struct ssh *ssh, const char *method) 352 { 353 switch (options.permit_root_login) { 354 case PERMIT_YES: 355 return 1; 356 case PERMIT_NO_PASSWD: 357 if (strcmp(method, "publickey") == 0 || 358 strcmp(method, "hostbased") == 0 || 359 strcmp(method, "gssapi-with-mic") == 0) 360 return 1; 361 break; 362 case PERMIT_FORCED_ONLY: 363 if (auth_opts->force_command != NULL) { 364 logit("Root login accepted for forced command."); 365 return 1; 366 } 367 break; 368 } 369 logit("ROOT LOGIN REFUSED FROM %.200s port %d", 370 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh)); 371 return 0; 372 } 373 374 375 /* 376 * Given a template and a passwd structure, build a filename 377 * by substituting % tokenised options. Currently, %% becomes '%', 378 * %h becomes the home directory and %u the username. 379 * 380 * This returns a buffer allocated by xmalloc. 381 */ 382 char * 383 expand_authorized_keys(const char *filename, struct passwd *pw) 384 { 385 char *file, uidstr[32], ret[PATH_MAX]; 386 int i; 387 388 snprintf(uidstr, sizeof(uidstr), "%llu", 389 (unsigned long long)pw->pw_uid); 390 file = percent_expand(filename, "h", pw->pw_dir, 391 "u", pw->pw_name, "U", uidstr, (char *)NULL); 392 393 /* 394 * Ensure that filename starts anchored. If not, be backward 395 * compatible and prepend the '%h/' 396 */ 397 if (path_absolute(file)) 398 return (file); 399 400 i = snprintf(ret, sizeof(ret), "%s/%s", pw->pw_dir, file); 401 if (i < 0 || (size_t)i >= sizeof(ret)) 402 fatal("expand_authorized_keys: path too long"); 403 free(file); 404 return (xstrdup(ret)); 405 } 406 407 char * 408 authorized_principals_file(struct passwd *pw) 409 { 410 if (options.authorized_principals_file == NULL) 411 return NULL; 412 return expand_authorized_keys(options.authorized_principals_file, pw); 413 } 414 415 /* return ok if key exists in sysfile or userfile */ 416 HostStatus 417 check_key_in_hostfiles(struct passwd *pw, struct sshkey *key, const char *host, 418 const char *sysfile, const char *userfile) 419 { 420 char *user_hostfile; 421 struct stat st; 422 HostStatus host_status; 423 struct hostkeys *hostkeys; 424 const struct hostkey_entry *found; 425 426 hostkeys = init_hostkeys(); 427 load_hostkeys(hostkeys, host, sysfile, 0); 428 if (userfile != NULL) { 429 user_hostfile = tilde_expand_filename(userfile, pw->pw_uid); 430 if (options.strict_modes && 431 (stat(user_hostfile, &st) == 0) && 432 ((st.st_uid != 0 && st.st_uid != pw->pw_uid) || 433 (st.st_mode & 022) != 0)) { 434 logit("Authentication refused for %.100s: " 435 "bad owner or modes for %.200s", 436 pw->pw_name, user_hostfile); 437 auth_debug_add("Ignored %.200s: bad ownership or modes", 438 user_hostfile); 439 } else { 440 temporarily_use_uid(pw); 441 load_hostkeys(hostkeys, host, user_hostfile, 0); 442 restore_uid(); 443 } 444 free(user_hostfile); 445 } 446 host_status = check_key_in_hostkeys(hostkeys, key, &found); 447 if (host_status == HOST_REVOKED) 448 error("WARNING: revoked key for %s attempted authentication", 449 host); 450 else if (host_status == HOST_OK) 451 debug_f("key for %s found at %s:%ld", 452 found->host, found->file, found->line); 453 else 454 debug_f("key for host %s not found", host); 455 456 free_hostkeys(hostkeys); 457 458 return host_status; 459 } 460 461 struct passwd * 462 getpwnamallow(struct ssh *ssh, const char *user) 463 { 464 #ifdef HAVE_LOGIN_CAP 465 extern login_cap_t *lc; 466 #ifdef BSD_AUTH 467 auth_session_t *as; 468 #endif 469 #endif 470 struct passwd *pw; 471 struct connection_info *ci; 472 u_int i; 473 474 ci = server_get_connection_info(ssh, 1, options.use_dns); 475 ci->user = user; 476 parse_server_match_config(&options, &includes, ci); 477 log_change_level(options.log_level); 478 log_verbose_reset(); 479 for (i = 0; i < options.num_log_verbose; i++) 480 log_verbose_add(options.log_verbose[i]); 481 server_process_permitopen(ssh); 482 483 #if defined(_AIX) && defined(HAVE_SETAUTHDB) 484 aix_setauthdb(user); 485 #endif 486 487 pw = getpwnam(user); 488 489 #if defined(_AIX) && defined(HAVE_SETAUTHDB) 490 aix_restoreauthdb(); 491 #endif 492 if (pw == NULL) { 493 logit("Invalid user %.100s from %.100s port %d", 494 user, ssh_remote_ipaddr(ssh), ssh_remote_port(ssh)); 495 #ifdef CUSTOM_FAILED_LOGIN 496 record_failed_login(ssh, user, 497 auth_get_canonical_hostname(ssh, options.use_dns), "ssh"); 498 #endif 499 #ifdef SSH_AUDIT_EVENTS 500 audit_event(ssh, SSH_INVALID_USER); 501 #endif /* SSH_AUDIT_EVENTS */ 502 return (NULL); 503 } 504 if (!allowed_user(ssh, pw)) 505 return (NULL); 506 #ifdef HAVE_LOGIN_CAP 507 if ((lc = login_getpwclass(pw)) == NULL) { 508 debug("unable to get login class: %s", user); 509 return (NULL); 510 } 511 #ifdef BSD_AUTH 512 if ((as = auth_open()) == NULL || auth_setpwd(as, pw) != 0 || 513 auth_approval(as, lc, pw->pw_name, "ssh") <= 0) { 514 debug("Approval failure for %s", user); 515 pw = NULL; 516 } 517 if (as != NULL) 518 auth_close(as); 519 #endif 520 #endif 521 if (pw != NULL) 522 return (pwcopy(pw)); 523 return (NULL); 524 } 525 526 /* Returns 1 if key is revoked by revoked_keys_file, 0 otherwise */ 527 int 528 auth_key_is_revoked(struct sshkey *key) 529 { 530 char *fp = NULL; 531 int r; 532 533 if (options.revoked_keys_file == NULL) 534 return 0; 535 if ((fp = sshkey_fingerprint(key, options.fingerprint_hash, 536 SSH_FP_DEFAULT)) == NULL) { 537 r = SSH_ERR_ALLOC_FAIL; 538 error_fr(r, "fingerprint key"); 539 goto out; 540 } 541 542 r = sshkey_check_revoked(key, options.revoked_keys_file); 543 switch (r) { 544 case 0: 545 break; /* not revoked */ 546 case SSH_ERR_KEY_REVOKED: 547 error("Authentication key %s %s revoked by file %s", 548 sshkey_type(key), fp, options.revoked_keys_file); 549 goto out; 550 default: 551 error_r(r, "Error checking authentication key %s %s in " 552 "revoked keys file %s", sshkey_type(key), fp, 553 options.revoked_keys_file); 554 goto out; 555 } 556 557 /* Success */ 558 r = 0; 559 560 out: 561 free(fp); 562 return r == 0 ? 0 : 1; 563 } 564 565 void 566 auth_debug_add(const char *fmt,...) 567 { 568 char buf[1024]; 569 va_list args; 570 int r; 571 572 va_start(args, fmt); 573 vsnprintf(buf, sizeof(buf), fmt, args); 574 va_end(args); 575 debug3("%s", buf); 576 if (auth_debug != NULL) 577 if ((r = sshbuf_put_cstring(auth_debug, buf)) != 0) 578 fatal_fr(r, "sshbuf_put_cstring"); 579 } 580 581 void 582 auth_debug_send(struct ssh *ssh) 583 { 584 char *msg; 585 int r; 586 587 if (auth_debug == NULL) 588 return; 589 while (sshbuf_len(auth_debug) != 0) { 590 if ((r = sshbuf_get_cstring(auth_debug, &msg, NULL)) != 0) 591 fatal_fr(r, "sshbuf_get_cstring"); 592 ssh_packet_send_debug(ssh, "%s", msg); 593 free(msg); 594 } 595 } 596 597 void 598 auth_debug_reset(void) 599 { 600 if (auth_debug != NULL) 601 sshbuf_reset(auth_debug); 602 else if ((auth_debug = sshbuf_new()) == NULL) 603 fatal_f("sshbuf_new failed"); 604 } 605 606 struct passwd * 607 fakepw(void) 608 { 609 static int done = 0; 610 static struct passwd fake; 611 const char hashchars[] = "./ABCDEFGHIJKLMNOPQRSTUVWXYZ" 612 "abcdefghijklmnopqrstuvwxyz0123456789"; /* from bcrypt.c */ 613 char *cp; 614 615 if (done) 616 return (&fake); 617 618 memset(&fake, 0, sizeof(fake)); 619 fake.pw_name = "NOUSER"; 620 fake.pw_passwd = xstrdup("$2a$10$" 621 "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"); 622 for (cp = fake.pw_passwd + 7; *cp != '\0'; cp++) 623 *cp = hashchars[arc4random_uniform(sizeof(hashchars) - 1)]; 624 #ifdef HAVE_STRUCT_PASSWD_PW_GECOS 625 fake.pw_gecos = "NOUSER"; 626 #endif 627 fake.pw_uid = privsep_pw == NULL ? (uid_t)-1 : privsep_pw->pw_uid; 628 fake.pw_gid = privsep_pw == NULL ? (gid_t)-1 : privsep_pw->pw_gid; 629 #ifdef HAVE_STRUCT_PASSWD_PW_CLASS 630 fake.pw_class = ""; 631 #endif 632 fake.pw_dir = "/nonexist"; 633 fake.pw_shell = "/nonexist"; 634 done = 1; 635 636 return (&fake); 637 } 638 639 /* 640 * Return the canonical name of the host in the other side of the current 641 * connection. The host name is cached, so it is efficient to call this 642 * several times. 643 */ 644 645 const char * 646 auth_get_canonical_hostname(struct ssh *ssh, int use_dns) 647 { 648 static char *dnsname; 649 650 if (!use_dns) 651 return ssh_remote_ipaddr(ssh); 652 if (dnsname != NULL) 653 return dnsname; 654 dnsname = ssh_remote_hostname(ssh); 655 return dnsname; 656 } 657 658 /* These functions link key/cert options to the auth framework */ 659 660 /* Log sshauthopt options locally and (optionally) for remote transmission */ 661 void 662 auth_log_authopts(const char *loc, const struct sshauthopt *opts, int do_remote) 663 { 664 int do_env = options.permit_user_env && opts->nenv > 0; 665 int do_permitopen = opts->npermitopen > 0 && 666 (options.allow_tcp_forwarding & FORWARD_LOCAL) != 0; 667 int do_permitlisten = opts->npermitlisten > 0 && 668 (options.allow_tcp_forwarding & FORWARD_REMOTE) != 0; 669 size_t i; 670 char msg[1024], buf[64]; 671 672 snprintf(buf, sizeof(buf), "%d", opts->force_tun_device); 673 /* Try to keep this alphabetically sorted */ 674 snprintf(msg, sizeof(msg), "key options:%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s", 675 opts->permit_agent_forwarding_flag ? " agent-forwarding" : "", 676 opts->force_command == NULL ? "" : " command", 677 do_env ? " environment" : "", 678 opts->valid_before == 0 ? "" : "expires", 679 opts->no_require_user_presence ? " no-touch-required" : "", 680 do_permitopen ? " permitopen" : "", 681 do_permitlisten ? " permitlisten" : "", 682 opts->permit_port_forwarding_flag ? " port-forwarding" : "", 683 opts->cert_principals == NULL ? "" : " principals", 684 opts->permit_pty_flag ? " pty" : "", 685 opts->require_verify ? " uv" : "", 686 opts->force_tun_device == -1 ? "" : " tun=", 687 opts->force_tun_device == -1 ? "" : buf, 688 opts->permit_user_rc ? " user-rc" : "", 689 opts->permit_x11_forwarding_flag ? " x11-forwarding" : ""); 690 691 debug("%s: %s", loc, msg); 692 if (do_remote) 693 auth_debug_add("%s: %s", loc, msg); 694 695 if (options.permit_user_env) { 696 for (i = 0; i < opts->nenv; i++) { 697 debug("%s: environment: %s", loc, opts->env[i]); 698 if (do_remote) { 699 auth_debug_add("%s: environment: %s", 700 loc, opts->env[i]); 701 } 702 } 703 } 704 705 /* Go into a little more details for the local logs. */ 706 if (opts->valid_before != 0) { 707 format_absolute_time(opts->valid_before, buf, sizeof(buf)); 708 debug("%s: expires at %s", loc, buf); 709 } 710 if (opts->cert_principals != NULL) { 711 debug("%s: authorized principals: \"%s\"", 712 loc, opts->cert_principals); 713 } 714 if (opts->force_command != NULL) 715 debug("%s: forced command: \"%s\"", loc, opts->force_command); 716 if (do_permitopen) { 717 for (i = 0; i < opts->npermitopen; i++) { 718 debug("%s: permitted open: %s", 719 loc, opts->permitopen[i]); 720 } 721 } 722 if (do_permitlisten) { 723 for (i = 0; i < opts->npermitlisten; i++) { 724 debug("%s: permitted listen: %s", 725 loc, opts->permitlisten[i]); 726 } 727 } 728 } 729 730 /* Activate a new set of key/cert options; merging with what is there. */ 731 int 732 auth_activate_options(struct ssh *ssh, struct sshauthopt *opts) 733 { 734 struct sshauthopt *old = auth_opts; 735 const char *emsg = NULL; 736 737 debug_f("setting new authentication options"); 738 if ((auth_opts = sshauthopt_merge(old, opts, &emsg)) == NULL) { 739 error("Inconsistent authentication options: %s", emsg); 740 return -1; 741 } 742 return 0; 743 } 744 745 /* Disable forwarding, etc for the session */ 746 void 747 auth_restrict_session(struct ssh *ssh) 748 { 749 struct sshauthopt *restricted; 750 751 debug_f("restricting session"); 752 753 /* A blank sshauthopt defaults to permitting nothing */ 754 if ((restricted = sshauthopt_new()) == NULL) 755 fatal_f("sshauthopt_new failed"); 756 restricted->permit_pty_flag = 1; 757 restricted->restricted = 1; 758 759 if (auth_activate_options(ssh, restricted) != 0) 760 fatal_f("failed to restrict session"); 761 sshauthopt_free(restricted); 762 } 763