su.c revision 1.61
1 /* $NetBSD: su.c,v 1.61 2005/01/08 18:12:35 christos Exp $ */ 2 3 /* 4 * Copyright (c) 1988 The Regents of the University of California. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 #ifndef lint 34 __COPYRIGHT( 35 "@(#) Copyright (c) 1988 The Regents of the University of California.\n\ 36 All rights reserved.\n"); 37 #endif /* not lint */ 38 39 #ifndef lint 40 #if 0 41 static char sccsid[] = "@(#)su.c 8.3 (Berkeley) 4/2/94";*/ 42 #else 43 __RCSID("$NetBSD: su.c,v 1.61 2005/01/08 18:12:35 christos Exp $"); 44 #endif 45 #endif /* not lint */ 46 47 #include <sys/param.h> 48 #include <sys/time.h> 49 #ifdef USE_PAM 50 #include <sys/wait.h> 51 #endif 52 #include <sys/resource.h> 53 #include <err.h> 54 #include <errno.h> 55 #include <grp.h> 56 #include <paths.h> 57 #include <pwd.h> 58 #include <stdio.h> 59 #ifdef SKEY 60 #include <skey.h> 61 #endif 62 #include <stdlib.h> 63 #include <string.h> 64 #include <syslog.h> 65 #include <time.h> 66 #include <tzfile.h> 67 #include <unistd.h> 68 69 #ifdef USE_PAM 70 #include <security/pam_appl.h> 71 #include <security/openpam.h> /* for openpam_ttyconv() */ 72 73 static pam_handle_t *pamh; 74 static struct pam_conv pamc; 75 76 #define fatal(x) do { \ 77 if (pam_err == PAM_SUCCESS) \ 78 pam_end(pamh, pam_err); \ 79 err x; \ 80 } while (/*CONSTCOND*/ 0) 81 #define fatalx(x) do { \ 82 if (pam_err == PAM_SUCCESS) \ 83 pam_end(pamh, pam_err); \ 84 errx x; \ 85 } while (/*CONSTCOND*/ 0) 86 87 #else 88 #define fatal(x) err x 89 #define fatalx(x) errx x 90 91 #endif 92 93 #ifdef LOGIN_CAP 94 #include <login_cap.h> 95 #endif 96 97 #ifdef KERBEROS 98 #include <des.h> 99 #include <krb.h> 100 #include <netdb.h> 101 102 static int kerberos __P((char *, char *, int)); 103 static int koktologin __P((char *, char *, char *)); 104 105 #endif 106 107 #ifdef KERBEROS5 108 #include <krb5.h> 109 110 static int kerberos5 __P((char *, char *, int)); 111 112 #endif 113 114 #if defined(KERBEROS) || defined(KERBEROS5) 115 116 #define ARGSTRX "-Kdflm" 117 118 int use_kerberos = 1; 119 120 #else 121 #define ARGSTRX "-dflm" 122 #endif 123 124 #ifndef SU_GROUP 125 #define SU_GROUP "wheel" 126 #endif 127 128 #ifdef LOGIN_CAP 129 #define ARGSTR ARGSTRX "c:" 130 #else 131 #define ARGSTR ARGSTRX 132 #endif 133 134 int main __P((int, char **)); 135 136 static int chshell __P((const char *)); 137 static char *ontty __P((void)); 138 static int check_ingroup __P((int, const char *, const char *, int)); 139 140 141 int 142 main(argc, argv) 143 int argc; 144 char **argv; 145 { 146 extern char **environ; 147 struct passwd *pwd; 148 char *p; 149 #ifdef BSD4_4 150 struct timeval tp; 151 #endif 152 uid_t ruid; 153 int asme, ch, asthem, fastlogin, prio, gohome; 154 enum { UNSET, YES, NO } iscsh = UNSET; 155 char *user, *shell, *avshell, *username, **np; 156 char *userpass, *class; 157 char shellbuf[MAXPATHLEN], avshellbuf[MAXPATHLEN]; 158 time_t pw_warntime = _PASSWORD_WARNDAYS * SECSPERDAY; 159 #ifdef LOGIN_CAP 160 login_cap_t *lc; 161 #endif 162 #ifdef USE_PAM 163 char **pam_envlist, **pam_env; 164 char hostname[MAXHOSTNAMELEN]; 165 const char **usernamep; 166 char *tty; 167 int pam_err, status; 168 pid_t pid; 169 #ifdef notdef 170 extern int _openpam_debug; 171 _openpam_debug = 1; 172 #endif 173 #endif 174 175 asme = asthem = fastlogin = 0; 176 gohome = 1; 177 shell = class = NULL; 178 while ((ch = getopt(argc, argv, ARGSTR)) != -1) 179 switch((char)ch) { 180 #if defined(KERBEROS) || defined(KERBEROS5) 181 case 'K': 182 use_kerberos = 0; 183 break; 184 #endif 185 #ifdef LOGIN_CAP 186 case 'c': 187 class = optarg; 188 break; 189 #endif 190 case 'd': 191 asme = 0; 192 asthem = 1; 193 gohome = 0; 194 break; 195 case 'f': 196 fastlogin = 1; 197 break; 198 case '-': 199 case 'l': 200 asme = 0; 201 asthem = 1; 202 break; 203 case 'm': 204 asme = 1; 205 asthem = 0; 206 break; 207 case '?': 208 default: 209 (void)fprintf(stderr, 210 "usage: %s [%s] [login [shell arguments]]\n", 211 getprogname(), ARGSTR); 212 exit(1); 213 } 214 argv += optind; 215 216 /* Lower the priority so su runs faster */ 217 errno = 0; 218 prio = getpriority(PRIO_PROCESS, 0); 219 if (errno) 220 prio = 0; 221 if (prio > -2) 222 (void)setpriority(PRIO_PROCESS, 0, -2); 223 openlog("su", 0, LOG_AUTH); 224 225 /* get current login name and shell */ 226 ruid = getuid(); 227 username = getlogin(); 228 /* get target login information, default to root */ 229 user = *argv ? *argv : "root"; 230 231 #ifdef USE_PAM 232 pamc.conv = &openpam_ttyconv; 233 pam_start("su", user, &pamc, &pamh); 234 235 /* Fill in hostname, username and tty */ 236 if ((pam_err = pam_set_item(pamh, PAM_RUSER, username)) != PAM_SUCCESS) 237 goto pam_failed; 238 239 gethostname(hostname, sizeof(hostname)); 240 if ((pam_err = pam_set_item(pamh, PAM_RHOST, hostname)) != PAM_SUCCESS) 241 goto pam_failed; 242 243 tty = ttyname(STDERR_FILENO); 244 if ((pam_err = pam_set_item(pamh, PAM_TTY, tty)) != PAM_SUCCESS) 245 goto pam_failed; 246 247 /* authentication */ 248 if ((pam_err = pam_authenticate(pamh, 0)) != PAM_SUCCESS) 249 goto pam_failed; 250 251 if ((pam_err = pam_acct_mgmt(pamh, 0)) == PAM_NEW_AUTHTOK_REQD) 252 pam_err = pam_chauthtok(pamh, PAM_CHANGE_EXPIRED_AUTHTOK); 253 if (pam_err != PAM_SUCCESS) 254 goto pam_failed; 255 256 /* Get user credentials */ 257 if ((pam_err = pam_setcred(pamh, PAM_ESTABLISH_CRED)) != PAM_SUCCESS) 258 goto pam_failed; 259 260 /* Open the session */ 261 if ((pam_err = pam_open_session(pamh, 0)) != PAM_SUCCESS) 262 goto pam_failed; 263 264 /* New user name? */ 265 usernamep = (const char **)&username; 266 pam_err = pam_get_item(pamh, PAM_USER, (const void **)usernamep); 267 if (pam_err != PAM_SUCCESS) 268 goto pam_failed; 269 270 pam_failed: 271 if (pam_err != PAM_SUCCESS) { 272 warnx("PAM failed, fallback to plain old authentication"); 273 pam_end(pamh, pam_err); 274 username = getlogin(); 275 } 276 277 /* 278 * Now any failure should use fatal/fatalx instead of err/errx 279 * so that pam_end() is called on errors. 280 */ 281 #endif 282 if (username == NULL || (pwd = getpwnam(username)) == NULL || 283 pwd->pw_uid != ruid) 284 pwd = getpwuid(ruid); 285 if (pwd == NULL) 286 fatalx((1, "who are you?")); 287 288 username = strdup(pwd->pw_name); 289 userpass = strdup(pwd->pw_passwd); 290 if (username == NULL || userpass == NULL) 291 fatal((1, "strdup")); 292 293 #ifdef USE_PAM 294 /* Get PAM environment */ 295 if ((pam_err == PAM_SUCCESS) && 296 ((pam_envlist = pam_getenvlist(pamh)) != NULL)) { 297 for (pam_env = pam_envlist; *pam_env != NULL; ++pam_env) { 298 putenv(*pam_env); 299 free(*pam_env); 300 } 301 free(pam_envlist); 302 } 303 #endif 304 305 if (asme) { 306 if (pwd->pw_shell && *pwd->pw_shell) { 307 strlcpy(shellbuf, pwd->pw_shell, sizeof(shellbuf)); 308 shell = shellbuf; 309 } else { 310 shell = _PATH_BSHELL; 311 iscsh = NO; 312 } 313 } 314 np = *argv ? argv : argv-1; 315 316 if ((pwd = getpwnam(user)) == NULL) 317 fatalx((1, "unknown login %s", user)); 318 319 #ifdef LOGIN_CAP 320 /* force the usage of specified class */ 321 if (class) { 322 if (ruid) 323 fatalx((1, "Only root may use -c")); 324 325 pwd->pw_class = class; 326 } 327 lc = login_getclass(pwd->pw_class); 328 329 pw_warntime = login_getcaptime(lc, "password-warn", 330 _PASSWORD_WARNDAYS * SECSPERDAY, 331 _PASSWORD_WARNDAYS * SECSPERDAY); 332 #endif 333 334 if (ruid 335 #ifdef USE_PAM 336 && (pam_err != PAM_SUCCESS) 337 #endif 338 #ifdef KERBEROS5 339 && (!use_kerberos || kerberos5(username, user, pwd->pw_uid)) 340 #endif 341 #ifdef KERBEROS 342 && (!use_kerberos || kerberos(username, user, pwd->pw_uid)) 343 #endif 344 ) { 345 char *pass = pwd->pw_passwd; 346 int ok = pwd->pw_uid != 0; 347 348 #ifdef SU_ROOTAUTH 349 /* 350 * Allow those in group rootauth to su to root, by supplying 351 * their own password. 352 */ 353 if (!ok) { 354 if ((ok = check_ingroup(-1, SU_ROOTAUTH, username, 0))) { 355 pass = userpass; 356 user = username; 357 } 358 } 359 #endif 360 /* 361 * Only allow those in group SU_GROUP to su to root, 362 * but only if that group has any members. 363 * If SU_GROUP has no members, allow anyone to su root 364 */ 365 if (!ok) { 366 ok = check_ingroup(-1, SU_GROUP, username, 1); 367 } 368 if (!ok) 369 fatalx((1, 370 "you are not listed in the correct secondary group (%s) to su %s.", 371 SU_GROUP, user)); 372 /* if target requires a password, verify it */ 373 if (*pass) { 374 p = getpass("Password:"); 375 #ifdef SKEY 376 if (strcasecmp(p, "s/key") == 0) { 377 if (skey_haskey(user)) { 378 fatalx((1, 379 "Sorry, you have no s/key.")); 380 } else { 381 if (skey_authenticate(user)) { 382 goto badlogin; 383 } 384 } 385 386 } else 387 #endif 388 if (strcmp(pass, crypt(p, pass))) { 389 #ifdef SKEY 390 badlogin: 391 #endif 392 fprintf(stderr, "Sorry\n"); 393 syslog(LOG_WARNING, 394 "BAD SU %s to %s%s", username, 395 pwd->pw_name, ontty()); 396 exit(1); 397 } 398 } 399 } 400 401 if (asme) { 402 /* if asme and non-standard target shell, must be root */ 403 if (!chshell(pwd->pw_shell) && ruid) 404 fatalx((1,"permission denied (shell).")); 405 } else if (pwd->pw_shell && *pwd->pw_shell) { 406 shell = pwd->pw_shell; 407 iscsh = UNSET; 408 } else { 409 shell = _PATH_BSHELL; 410 iscsh = NO; 411 } 412 413 if ((p = strrchr(shell, '/')) != NULL) 414 avshell = p+1; 415 else 416 avshell = shell; 417 418 /* if we're forking a csh, we want to slightly muck the args */ 419 if (iscsh == UNSET) 420 iscsh = strstr(avshell, "csh") ? YES : NO; 421 422 #ifdef USE_PAM 423 /* 424 * If PAM is in use, we must release PAM resources and close 425 * the session after su child exits. That requires a fork now, 426 * before we drop the root privs (needed for PAM) 427 */ 428 if (pam_err == PAM_SUCCESS) { 429 switch(pid = fork()) { 430 case -1: 431 fatal((1, "fork")); 432 break; 433 case 0: /* child */ 434 break; 435 default: /* parent */ 436 waitpid(pid, &status, 0); 437 pam_err = pam_close_session(pamh, 0); 438 pam_end(pamh, pam_err); 439 440 exit(WEXITSTATUS(status)); 441 break; 442 } 443 } 444 445 /* 446 * Everything here happens in the child, it should not 447 * do any PAM operation anymore (don't use fatal/fatalx) 448 */ 449 #endif 450 /* set permissions */ 451 #ifdef LOGIN_CAP 452 if (setusercontext(lc, pwd, pwd->pw_uid, 453 (asthem ? (LOGIN_SETPRIORITY | LOGIN_SETUMASK) : 0) | 454 LOGIN_SETRESOURCES | LOGIN_SETGROUP | LOGIN_SETUSER)) 455 err(1, "setting user context"); 456 #else 457 if (setgid(pwd->pw_gid) < 0) 458 err(1, "setgid"); 459 if (initgroups(user, pwd->pw_gid)) 460 errx(1, "initgroups failed"); 461 if (setuid(pwd->pw_uid) < 0) 462 err(1, "setuid"); 463 #endif 464 465 if (!asme) { 466 if (asthem) { 467 p = getenv("TERM"); 468 /* Create an empty environment */ 469 if ((environ = malloc(sizeof(char *))) == NULL) 470 err(1, NULL); 471 environ[0] = NULL; 472 #ifdef LOGIN_CAP 473 if (setusercontext(lc, pwd, pwd->pw_uid, LOGIN_SETPATH)) 474 err(1, "setting user context"); 475 #else 476 (void)setenv("PATH", _PATH_DEFPATH, 1); 477 #endif 478 if (p) 479 (void)setenv("TERM", p, 1); 480 if (gohome && chdir(pwd->pw_dir) < 0) 481 errx(1, "no directory"); 482 } 483 484 if (asthem || pwd->pw_uid) 485 (void)setenv("USER", pwd->pw_name, 1); 486 (void)setenv("HOME", pwd->pw_dir, 1); 487 (void)setenv("SHELL", shell, 1); 488 } 489 (void)setenv("SU_FROM", username, 1); 490 491 if (iscsh == YES) { 492 if (fastlogin) 493 *np-- = "-f"; 494 if (asme) 495 *np-- = "-m"; 496 } else { 497 if (fastlogin) 498 unsetenv("ENV"); 499 } 500 501 if (asthem) { 502 avshellbuf[0] = '-'; 503 (void)strlcpy(avshellbuf+1, avshell, sizeof(avshellbuf) - 1); 504 avshell = avshellbuf; 505 } else if (iscsh == YES) { 506 /* csh strips the first character... */ 507 avshellbuf[0] = '_'; 508 (void)strlcpy(avshellbuf+1, avshell, sizeof(avshellbuf) - 1); 509 avshell = avshellbuf; 510 } 511 *np = avshell; 512 513 #ifdef BSD4_4 514 if (pwd->pw_change || pwd->pw_expire) 515 (void)gettimeofday(&tp, (struct timezone *)NULL); 516 if (pwd->pw_change) { 517 if (tp.tv_sec >= pwd->pw_change) { 518 (void)printf("%s -- %s's password has expired.\n", 519 (ruid ? "Sorry" : "Note"), user); 520 if (ruid != 0) 521 exit(1); 522 } else if (pwd->pw_change - tp.tv_sec < pw_warntime) 523 (void)printf("Warning: %s's password expires on %s", 524 user, ctime(&pwd->pw_change)); 525 } 526 if (pwd->pw_expire) { 527 if (tp.tv_sec >= pwd->pw_expire) { 528 (void)printf("%s -- %s's account has expired.\n", 529 (ruid ? "Sorry" : "Note"), user); 530 if (ruid != 0) 531 exit(1); 532 } else if (pwd->pw_expire - tp.tv_sec < 533 _PASSWORD_WARNDAYS * SECSPERDAY) 534 (void)printf("Warning: %s's account expires on %s", 535 user, ctime(&pwd->pw_expire)); 536 } 537 #endif 538 if (ruid != 0) 539 syslog(LOG_NOTICE, "%s to %s%s", 540 username, pwd->pw_name, ontty()); 541 542 /* Raise our priority back to what we had before */ 543 (void)setpriority(PRIO_PROCESS, 0, prio); 544 545 execv(shell, np); 546 err(1, "%s", shell); 547 /* NOTREACHED */ 548 } 549 550 static int 551 chshell(sh) 552 const char *sh; 553 { 554 const char *cp; 555 556 setusershell(); 557 while ((cp = getusershell()) != NULL) 558 if (!strcmp(cp, sh)) 559 return (1); 560 return (0); 561 } 562 563 static char * 564 ontty() 565 { 566 char *p; 567 static char buf[MAXPATHLEN + 4]; 568 569 buf[0] = 0; 570 if ((p = ttyname(STDERR_FILENO)) != NULL) 571 (void)snprintf(buf, sizeof buf, " on %s", p); 572 return (buf); 573 } 574 575 #ifdef KERBEROS5 576 static int 577 kerberos5(username, user, uid) 578 char *username, *user; 579 int uid; 580 { 581 krb5_error_code ret; 582 krb5_context context; 583 krb5_principal princ = NULL; 584 krb5_ccache ccache, ccache2; 585 char *cc_name; 586 const char *filename; 587 588 ret = krb5_init_context(&context); 589 if (ret) 590 return (1); 591 592 if (strcmp (user, "root") == 0) 593 ret = krb5_make_principal(context, &princ, 594 NULL, username, "root", NULL); 595 else 596 ret = krb5_make_principal(context, &princ, 597 NULL, user, NULL); 598 if (ret) 599 goto fail; 600 if (!krb5_kuserok(context, princ, user) && !uid) { 601 warnx ("kerberos5: not in %s's ACL.", user); 602 goto fail; 603 } 604 ret = krb5_cc_gen_new(context, &krb5_mcc_ops, &ccache); 605 if (ret) 606 goto fail; 607 ret = krb5_verify_user_lrealm(context, princ, ccache, NULL, TRUE, 608 NULL); 609 if (ret) { 610 krb5_cc_destroy(context, ccache); 611 switch (ret) { 612 case KRB5_LIBOS_PWDINTR : 613 break; 614 case KRB5KRB_AP_ERR_BAD_INTEGRITY: 615 case KRB5KRB_AP_ERR_MODIFIED: 616 krb5_warnx(context, "Password incorrect"); 617 break; 618 default : 619 krb5_warn(context, ret, "krb5_verify_user"); 620 break; 621 } 622 goto fail; 623 } 624 ret = krb5_cc_gen_new(context, &krb5_fcc_ops, &ccache2); 625 if (ret) { 626 krb5_cc_destroy(context, ccache); 627 goto fail; 628 } 629 ret = krb5_cc_copy_cache(context, ccache, ccache2); 630 if (ret) { 631 krb5_cc_destroy(context, ccache); 632 krb5_cc_destroy(context, ccache2); 633 goto fail; 634 } 635 636 filename = krb5_cc_get_name(context, ccache2); 637 asprintf(&cc_name, "%s:%s", krb5_cc_get_type(context, ccache2), 638 filename); 639 if (chown (filename, uid, -1) < 0) { 640 warn("chown %s", filename); 641 free(cc_name); 642 krb5_cc_destroy(context, ccache); 643 krb5_cc_destroy(context, ccache2); 644 goto fail; 645 } 646 647 setenv("KRB5CCNAME", cc_name, 1); 648 free(cc_name); 649 krb5_cc_close(context, ccache2); 650 krb5_cc_destroy(context, ccache); 651 return (0); 652 653 fail: 654 if (princ != NULL) 655 krb5_free_principal (context, princ); 656 krb5_free_context (context); 657 return (1); 658 } 659 #endif 660 661 #ifdef KERBEROS 662 static int 663 kerberos(username, user, uid) 664 char *username, *user; 665 int uid; 666 { 667 KTEXT_ST ticket; 668 AUTH_DAT authdata; 669 struct hostent *hp; 670 int kerno; 671 u_long faddr; 672 char lrealm[REALM_SZ], krbtkfile[MAXPATHLEN]; 673 char hostname[MAXHOSTNAMELEN + 1], savehost[MAXHOSTNAMELEN + 1]; 674 675 if (krb_get_lrealm(lrealm, 1) != KSUCCESS) 676 return (1); 677 if (koktologin(username, lrealm, user) && !uid) { 678 warnx("kerberos: not in %s's ACL.", user); 679 return (1); 680 } 681 (void)snprintf(krbtkfile, sizeof krbtkfile, "%s_%s_%d", TKT_ROOT, 682 user, getuid()); 683 684 (void)setenv("KRBTKFILE", krbtkfile, 1); 685 (void)krb_set_tkt_string(krbtkfile); 686 /* 687 * Set real as well as effective ID to 0 for the moment, 688 * to make the kerberos library do the right thing. 689 */ 690 if (setuid(0) < 0) { 691 warn("setuid"); 692 return (1); 693 } 694 695 /* 696 * Little trick here -- if we are su'ing to root, 697 * we need to get a ticket for "xxx.root", where xxx represents 698 * the name of the person su'ing. Otherwise (non-root case), 699 * we need to get a ticket for "yyy.", where yyy represents 700 * the name of the person being su'd to, and the instance is null 701 * 702 * We should have a way to set the ticket lifetime, 703 * with a system default for root. 704 */ 705 { 706 char prompt[128]; 707 char passw[256]; 708 709 (void)snprintf (prompt, sizeof(prompt), 710 "%s's Password: ", 711 krb_unparse_name_long ((uid == 0 ? username : user), 712 (uid == 0 ? "root" : ""), 713 lrealm)); 714 if (des_read_pw_string (passw, sizeof (passw), prompt, 0)) { 715 memset (passw, 0, sizeof (passw)); 716 return (1); 717 } 718 if (strlen(passw) == 0) 719 return (1); /* Empty passwords are not allowed */ 720 721 kerno = krb_get_pw_in_tkt((uid == 0 ? username : user), 722 (uid == 0 ? "root" : ""), lrealm, 723 KRB_TICKET_GRANTING_TICKET, 724 lrealm, 725 DEFAULT_TKT_LIFE, 726 passw); 727 memset (passw, 0, strlen (passw)); 728 } 729 730 if (kerno != KSUCCESS) { 731 if (kerno == KDC_PR_UNKNOWN) { 732 warnx("kerberos: principal unknown: %s.%s@%s", 733 (uid == 0 ? username : user), 734 (uid == 0 ? "root" : ""), lrealm); 735 return (1); 736 } 737 warnx("kerberos: unable to su: %s", krb_err_txt[kerno]); 738 syslog(LOG_WARNING, 739 "BAD Kerberos SU: %s to %s%s: %s", 740 username, user, ontty(), krb_err_txt[kerno]); 741 return (1); 742 } 743 744 if (chown(krbtkfile, uid, -1) < 0) { 745 warn("chown"); 746 (void)unlink(krbtkfile); 747 return (1); 748 } 749 750 (void)setpriority(PRIO_PROCESS, 0, -2); 751 752 if (gethostname(hostname, sizeof(hostname)) == -1) { 753 warn("gethostname"); 754 dest_tkt(); 755 return (1); 756 } 757 hostname[sizeof(hostname) - 1] = '\0'; 758 759 (void)strlcpy(savehost, krb_get_phost(hostname), sizeof(savehost)); 760 savehost[sizeof(savehost) - 1] = '\0'; 761 762 kerno = krb_mk_req(&ticket, "rcmd", savehost, lrealm, 33); 763 764 if (kerno == KDC_PR_UNKNOWN) { 765 warnx("Warning: TGT not verified."); 766 syslog(LOG_WARNING, 767 "%s to %s%s, TGT not verified (%s); %s.%s not registered?", 768 username, user, ontty(), krb_err_txt[kerno], 769 "rcmd", savehost); 770 } else if (kerno != KSUCCESS) { 771 warnx("Unable to use TGT: %s", krb_err_txt[kerno]); 772 syslog(LOG_WARNING, "failed su: %s to %s%s: %s", 773 username, user, ontty(), krb_err_txt[kerno]); 774 dest_tkt(); 775 return (1); 776 } else { 777 if (!(hp = gethostbyname(hostname))) { 778 warnx("can't get addr of %s", hostname); 779 dest_tkt(); 780 return (1); 781 } 782 memmove((char *)&faddr, (char *)hp->h_addr, sizeof(faddr)); 783 784 if ((kerno = krb_rd_req(&ticket, "rcmd", savehost, faddr, 785 &authdata, "")) != KSUCCESS) { 786 warnx("kerberos: unable to verify rcmd ticket: %s", 787 krb_err_txt[kerno]); 788 syslog(LOG_WARNING, 789 "failed su: %s to %s%s: %s", username, 790 user, ontty(), krb_err_txt[kerno]); 791 dest_tkt(); 792 return (1); 793 } 794 } 795 return (0); 796 } 797 798 static int 799 koktologin(name, realm, toname) 800 char *name, *realm, *toname; 801 { 802 return krb_kuserok(name, 803 strcmp (toname, "root") == 0 ? "root" : "", 804 realm, 805 toname); 806 } 807 #endif 808 809 static int 810 check_ingroup (gid, gname, user, ifempty) 811 int gid; 812 const char *gname; 813 const char *user; 814 int ifempty; 815 { 816 struct group *gr; 817 char **g; 818 #ifdef SU_INDIRECT_GROUP 819 char **gr_mem; 820 int n = 0; 821 int i = 0; 822 #endif 823 int ok = 0; 824 825 if (gname == NULL) 826 gr = getgrgid((gid_t) gid); 827 else 828 gr = getgrnam(gname); 829 830 /* 831 * XXX we are relying on the fact that we only set ifempty when 832 * calling to check for SU_GROUP and that is the only time a 833 * missing group is acceptable. 834 */ 835 if (gr == NULL) 836 return ifempty; 837 if (!*gr->gr_mem) /* empty */ 838 return ifempty; 839 840 /* 841 * Ok, first see if user is in gr_mem 842 */ 843 for (g = gr->gr_mem; *g; ++g) { 844 if (strcmp(*g, user) == 0) 845 return 1; /* ok */ 846 #ifdef SU_INDIRECT_GROUP 847 ++n; /* count them */ 848 #endif 849 } 850 #ifdef SU_INDIRECT_GROUP 851 /* 852 * No. 853 * Now we need to duplicate the gr_mem list, and recurse for 854 * each member to see if it is a group, and if so whether user is 855 * in it. 856 */ 857 gr_mem = malloc((n + 1) * sizeof (char *)); 858 for (g = gr->gr_mem, i = 0; *g; ++g) { 859 gr_mem[i] = strdup(*g); 860 if (!gr_mem[i]) 861 err(1, "strdup"); 862 i++; 863 } 864 gr_mem[i++] = NULL; 865 866 for (g = gr_mem; ok == 0 && *g; ++g) { 867 /* 868 * If we get this far we don't accept empty/missing groups. 869 */ 870 ok = check_ingroup(-1, *g, user, 0); 871 } 872 for (g = gr_mem; *g; ++g) { 873 free(*g); 874 } 875 free(gr_mem); 876 #endif 877 return ok; 878 } 879
Indexes created Mon Oct 27 20:09:55 GMT 2025