1 /* $OpenBSD: passwd.c,v 1.29 2001/11/14 19:50:23 deraadt Exp $ */ 2 3 /* 4 * Copyright (c) 1987, 1993, 1994, 1995 5 * The Regents of the University of California. 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. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #if defined(LIBC_SCCS) && !defined(lint) 37 static char rcsid[] = "$OpenBSD: passwd.c,v 1.29 2001/11/14 19:50:23 deraadt Exp $"; 38 #endif /* LIBC_SCCS and not lint */ 39 40 #include <sys/types.h> 41 #include <sys/stat.h> 42 #include <sys/time.h> 43 #include <sys/resource.h> 44 #include <sys/wait.h> 45 46 #include <fcntl.h> 47 #include <unistd.h> 48 #include <stdlib.h> 49 #include <stdio.h> 50 #include <string.h> 51 #include <ctype.h> 52 #include <pwd.h> 53 #include <err.h> 54 #include <errno.h> 55 #include <paths.h> 56 #include <signal.h> 57 #include <limits.h> 58 59 #include "util.h" 60 61 #define NUM_OPTIONS 2 /* Number of hardcoded defaults */ 62 63 static void pw_cont __P((int sig)); 64 65 static const char options[NUM_OPTIONS][2][80] = 66 { 67 {"localcipher", "blowfish,4"}, 68 {"ypcipher", "old"} 69 }; 70 71 static char pw_defdir[] = "/etc"; 72 static char *pw_dir = pw_defdir; 73 static char *pw_lck; 74 75 /* Removes head and/or tail spaces. */ 76 static void 77 trim_whitespace(line) 78 char *line; 79 { 80 char *p; 81 82 /* Remove leading spaces */ 83 p = line; 84 while (isspace(*p)) 85 p++; 86 (void) memmove(line, p, strlen(p) + 1); 87 88 /* Remove trailing spaces */ 89 p = line + strlen(line) - 1; 90 while (isspace(*p)) 91 p--; 92 *(p + 1) = '\0'; 93 } 94 95 96 /* Get one line, remove spaces from front and tail */ 97 static int 98 read_line(fp, line, max) 99 FILE *fp; 100 char *line; 101 int max; 102 { 103 char *p; 104 /* Read one line of config */ 105 if (fgets(line, max, fp) == 0) 106 return 0; 107 if (!(p = strchr(line, '\n'))) { 108 warnx("line too long"); 109 return 0; 110 } 111 *p = '\0'; 112 113 /* Remove comments */ 114 if ((p = strchr(line, '#'))) 115 *p = '\0'; 116 117 trim_whitespace(line); 118 return 1; 119 } 120 121 122 static const char * 123 pw_default(option) 124 char *option; 125 { 126 int i; 127 for (i = 0; i < NUM_OPTIONS; i++) 128 if (!strcmp(options[i][0], option)) 129 return options[i][1]; 130 return NULL; 131 } 132 133 char * 134 pw_file(nm) 135 const char *nm; 136 { 137 const char *p = strrchr(nm, '/'); 138 char *new_nm; 139 140 if (p) 141 p++; 142 else 143 p = nm; 144 new_nm = malloc(strlen(pw_dir) + strlen(p) + 2); 145 if (!new_nm) 146 return NULL; 147 sprintf(new_nm, "%s/%s", pw_dir, p); 148 return new_nm; 149 } 150 151 152 /* 153 * Retrieve password information from the /etc/passwd.conf file, 154 * at the moment this is only for choosing the cipher to use. 155 * It could easily be used for other authentication methods as 156 * well. 157 */ 158 void 159 pw_getconf(data, max, key, option) 160 char *data; 161 size_t max; 162 const char *key; 163 const char *option; 164 { 165 FILE *fp; 166 char line[LINE_MAX]; 167 static char result[LINE_MAX]; 168 char *p; 169 int got = 0; 170 int found = 0; 171 172 result[0] = '\0'; 173 174 p = pw_file(_PATH_PASSWDCONF); 175 if (!p || (fp = fopen(p, "r")) == NULL) { 176 if (p) 177 free(p); 178 if((p = (char *)pw_default(option))) { 179 strncpy(data, p, max - 1); 180 data[max - 1] = '\0'; 181 } else 182 data[0] = '\0'; 183 return; 184 } 185 free(p); 186 187 while (!found && (got || read_line(fp, line, LINE_MAX))) { 188 got = 0; 189 if (strncmp(key, line, strlen(key)) || 190 line[strlen(key)] != ':') 191 continue; 192 193 /* Now we found our specified key */ 194 while (read_line(fp, line, LINE_MAX)) { 195 char *p2; 196 /* Leaving key field */ 197 if (strchr(line, ':')) { 198 got = 1; 199 break; 200 } 201 p2 = line; 202 if (!(p = strsep(&p2, "=")) || p2 == NULL) 203 continue; 204 trim_whitespace(p); 205 if (!strncmp(p, option, strlen(option))) { 206 trim_whitespace(p2); 207 strcpy(result, p2); 208 found = 1; 209 break; 210 } 211 } 212 } 213 fclose(fp); 214 215 /* 216 * If we got no result and were looking for a default 217 * value, try hard coded defaults. 218 */ 219 220 if (!strlen(result) && !strcmp(key,"default") && 221 (p=(char *)pw_default(option))) 222 strncpy(data, p, max - 1); 223 else 224 strncpy(data, result, max - 1); 225 data[max - 1] = '\0'; 226 } 227 228 229 void 230 pw_setdir(dir) 231 const char *dir; 232 { 233 char *p; 234 235 if (strcmp (dir, pw_dir) == 0) 236 return; 237 if (pw_dir != pw_defdir) 238 free(pw_dir); 239 pw_dir = strdup(dir); 240 if (pw_lck) { 241 p = pw_file(pw_lck); 242 free(pw_lck); 243 pw_lck = p; 244 } 245 } 246 247 248 int 249 pw_lock(retries) 250 int retries; 251 { 252 int i, fd; 253 mode_t old_mode; 254 int save_errno; 255 256 if (!pw_lck) 257 return (-1); 258 /* Acquire the lock file. */ 259 old_mode = umask(0); 260 fd = open(pw_lck, O_WRONLY|O_CREAT|O_EXCL, 0600); 261 for (i = 0; i < retries && fd < 0 && errno == EEXIST; i++) { 262 sleep(1); 263 fd = open(pw_lck, O_WRONLY|O_CREAT|O_EXCL, 0600); 264 } 265 save_errno = errno; 266 if (fd != -1 && fcntl(fd, F_SETFD, 1) == -1) { 267 close(fd); 268 fd = -1; 269 } 270 (void) umask(old_mode); 271 errno = save_errno; 272 return (fd); 273 } 274 275 int 276 pw_mkdb(username, flags) 277 char *username; 278 int flags; 279 { 280 int pstat, ac; 281 pid_t pid; 282 char *av[8]; 283 struct stat sb; 284 285 if (pw_lck == NULL) 286 return(-1); 287 288 /* A zero length passwd file is never ok */ 289 if (stat(pw_lck, &sb) == 0 && sb.st_size == 0) { 290 warnx("%s is zero length", pw_lck); 291 return (-1); 292 } 293 294 ac = 0; 295 av[ac++] = "pwd_mkdb"; 296 av[ac++] = "-d"; 297 av[ac++] = pw_dir; 298 if (flags & _PASSWORD_SECUREONLY) 299 av[ac++] = "-s"; 300 else if (!(flags & _PASSWORD_OMITV7)) 301 av[ac++] = "-p"; 302 if (username) { 303 av[ac++] = "-u"; 304 av[ac++] = username; 305 } 306 av[ac++] = pw_lck; 307 av[ac] = NULL; 308 309 pid = vfork(); 310 if (pid == -1) 311 return (-1); 312 if (pid == 0) { 313 if (pw_lck) 314 execv(_PATH_PWD_MKDB, av); 315 _exit(1); 316 } 317 pid = waitpid(pid, &pstat, 0); 318 if (pid == -1 || !WIFEXITED(pstat) || WEXITSTATUS(pstat) != 0) 319 return (-1); 320 return (0); 321 } 322 323 int 324 pw_abort() 325 { 326 return (pw_lck ? unlink(pw_lck) : -1); 327 } 328 329 /* Everything below this point is intended for the convenience of programs 330 * which allow a user to interactively edit the passwd file. Errors in the 331 * routines below will cause the process to abort. */ 332 333 static pid_t editpid = -1; 334 335 static void 336 pw_cont(sig) 337 int sig; 338 { 339 int save_errno = errno; 340 341 if (editpid != -1) 342 kill(editpid, sig); 343 errno = save_errno; 344 } 345 346 void 347 pw_init() 348 { 349 struct rlimit rlim; 350 351 /* Unlimited resource limits. */ 352 rlim.rlim_cur = rlim.rlim_max = RLIM_INFINITY; 353 (void)setrlimit(RLIMIT_CPU, &rlim); 354 (void)setrlimit(RLIMIT_FSIZE, &rlim); 355 (void)setrlimit(RLIMIT_STACK, &rlim); 356 (void)setrlimit(RLIMIT_DATA, &rlim); 357 (void)setrlimit(RLIMIT_RSS, &rlim); 358 359 /* Don't drop core (not really necessary, but GP's). */ 360 rlim.rlim_cur = rlim.rlim_max = 0; 361 (void)setrlimit(RLIMIT_CORE, &rlim); 362 363 /* Turn off signals. */ 364 (void)signal(SIGALRM, SIG_IGN); 365 (void)signal(SIGHUP, SIG_IGN); 366 (void)signal(SIGINT, SIG_IGN); 367 (void)signal(SIGPIPE, SIG_IGN); 368 (void)signal(SIGQUIT, SIG_IGN); 369 (void)signal(SIGTERM, SIG_IGN); 370 (void)signal(SIGCONT, pw_cont); 371 372 if (!pw_lck) 373 pw_lck = pw_file(_PATH_MASTERPASSWD_LOCK); 374 } 375 376 void 377 pw_edit(notsetuid, filename) 378 int notsetuid; 379 const char *filename; 380 { 381 int pstat; 382 char *p, *editor; 383 char *argp[] = {"sh", "-c", NULL, NULL}; 384 385 #ifdef __GNUC__ 386 (void)&editor; 387 #endif 388 if (!filename) { 389 filename = pw_lck; 390 if (!filename) 391 return; 392 } 393 394 if ((editor = getenv("EDITOR")) == NULL) 395 editor = _PATH_VI; 396 397 p = malloc(strlen(editor) + 1 + strlen(filename) + 1); 398 if (p == NULL) 399 return; 400 sprintf(p, "%s %s", editor, filename); 401 argp[2] = p; 402 403 switch (editpid = vfork()) { 404 case -1: /* error */ 405 free(p); 406 return; 407 case 0: /* child */ 408 if (notsetuid) { 409 setgid(getgid()); 410 setuid(getuid()); 411 } 412 execv(_PATH_BSHELL, argp); 413 _exit(127); 414 } 415 416 free(p); 417 for (;;) { 418 editpid = waitpid(editpid, (int *)&pstat, WUNTRACED); 419 if (editpid == -1) 420 pw_error(editor, 1, 1); 421 else if (WIFSTOPPED(pstat)) 422 raise(WSTOPSIG(pstat)); 423 else if (WIFEXITED(pstat) && WEXITSTATUS(pstat) == 0) 424 break; 425 else 426 pw_error(editor, 1, 1); 427 } 428 editpid = -1; 429 } 430 431 void 432 pw_prompt() 433 { 434 int first, c; 435 436 (void)printf("re-edit the password file? [y]: "); 437 (void)fflush(stdout); 438 first = c = getchar(); 439 while (c != '\n' && c != EOF) 440 c = getchar(); 441 if (first == 'n') 442 pw_error(NULL, 0, 0); 443 } 444 445 void 446 pw_copy(ffd, tfd, pw) 447 int ffd, tfd; 448 struct passwd *pw; 449 { 450 FILE *from, *to; 451 int done; 452 char *p, buf[8192]; 453 char *master = pw_file(_PATH_MASTERPASSWD); 454 455 if (!master) 456 pw_error(NULL, 0, 1); 457 if (!(from = fdopen(ffd, "r"))) 458 pw_error(master, 1, 1); 459 if (!(to = fdopen(tfd, "w"))) 460 pw_error(pw_lck ? pw_lck : NULL, pw_lck ? 1 : 0, 1); 461 462 for (done = 0; fgets(buf, sizeof(buf), from);) { 463 if (!strchr(buf, '\n')) { 464 warnx("%s: line too long", master); 465 pw_error(NULL, 0, 1); 466 } 467 if (done) { 468 (void)fprintf(to, "%s", buf); 469 if (ferror(to)) 470 goto err; 471 continue; 472 } 473 if (!(p = strchr(buf, ':'))) { 474 warnx("%s: corrupted entry", master); 475 pw_error(NULL, 0, 1); 476 } 477 *p = '\0'; 478 if (strcmp(buf, pw->pw_name)) { 479 *p = ':'; 480 (void)fprintf(to, "%s", buf); 481 if (ferror(to)) 482 goto err; 483 continue; 484 } 485 (void)fprintf(to, "%s:%s:%d:%d:%s:%d:%d:%s:%s:%s\n", 486 pw->pw_name, pw->pw_passwd, pw->pw_uid, pw->pw_gid, 487 pw->pw_class, pw->pw_change, pw->pw_expire, pw->pw_gecos, 488 pw->pw_dir, pw->pw_shell); 489 done = 1; 490 if (ferror(to)) 491 goto err; 492 } 493 if (!done) 494 (void)fprintf(to, "%s:%s:%d:%d:%s:%d:%d:%s:%s:%s\n", 495 pw->pw_name, pw->pw_passwd, pw->pw_uid, pw->pw_gid, 496 pw->pw_class, pw->pw_change, pw->pw_expire, pw->pw_gecos, 497 pw->pw_dir, pw->pw_shell); 498 499 if (ferror(to)) 500 err: 501 pw_error(NULL, 0, 1); 502 free(master); 503 (void)fclose(to); 504 } 505 506 int 507 pw_scan(bp, pw, flags) 508 char *bp; 509 struct passwd *pw; 510 int *flags; 511 { 512 u_long id; 513 int root; 514 char *p, *sh, *p2; 515 516 if (flags != (int *)NULL) 517 *flags = 0; 518 519 if (!(pw->pw_name = strsep(&bp, ":"))) /* login */ 520 goto fmt; 521 root = !strcmp(pw->pw_name, "root"); 522 523 if (!(pw->pw_passwd = strsep(&bp, ":"))) /* passwd */ 524 goto fmt; 525 526 if (!(p = strsep(&bp, ":"))) /* uid */ 527 goto fmt; 528 id = strtoul(p, &p2, 10); 529 if (root && id) { 530 warnx("root uid should be 0"); 531 return (0); 532 } 533 if (*p2 != '\0') { 534 warnx("illegal uid field"); 535 return (0); 536 } 537 if (id > UID_MAX) { 538 /* errno is set to ERANGE by strtoul(3) */ 539 warnx("uid greater than %u", UID_MAX-1); 540 return (0); 541 } 542 pw->pw_uid = (uid_t)id; 543 if ((*p == '\0') && (flags != (int *)NULL)) 544 *flags |= _PASSWORD_NOUID; 545 546 if (!(p = strsep(&bp, ":"))) /* gid */ 547 goto fmt; 548 id = strtoul(p, &p2, 10); 549 if (*p2 != '\0') { 550 warnx("illegal gid field"); 551 return (0); 552 } 553 if (id > UID_MAX) { 554 /* errno is set to ERANGE by strtoul(3) */ 555 warnx("gid greater than %u", UID_MAX-1); 556 return (0); 557 } 558 pw->pw_gid = (gid_t)id; 559 if ((*p == '\0') && (flags != (int *)NULL)) 560 *flags |= _PASSWORD_NOGID; 561 562 pw->pw_class = strsep(&bp, ":"); /* class */ 563 if (!(p = strsep(&bp, ":"))) /* change */ 564 goto fmt; 565 pw->pw_change = atol(p); 566 if ((*p == '\0') && (flags != (int *)NULL)) 567 *flags |= _PASSWORD_NOCHG; 568 if (!(p = strsep(&bp, ":"))) /* expire */ 569 goto fmt; 570 pw->pw_expire = atol(p); 571 if ((*p == '\0') && (flags != (int *)NULL)) 572 *flags |= _PASSWORD_NOEXP; 573 pw->pw_gecos = strsep(&bp, ":"); /* gecos */ 574 pw->pw_dir = strsep(&bp, ":"); /* directory */ 575 if (!(pw->pw_shell = strsep(&bp, ":"))) /* shell */ 576 goto fmt; 577 578 p = pw->pw_shell; 579 if (root && *p) { /* empty == /bin/sh */ 580 for (setusershell();;) { 581 if (!(sh = getusershell())) { 582 warnx("warning, unknown root shell"); 583 break; 584 } 585 if (!strcmp(p, sh)) 586 break; 587 } 588 endusershell(); 589 } 590 591 if ((p = strsep(&bp, ":"))) { /* too many */ 592 fmt: warnx("corrupted entry"); 593 return (0); 594 } 595 596 return (1); 597 } 598 599 void 600 pw_error(name, err, eval) 601 const char *name; 602 int err, eval; 603 { 604 char *master = pw_file(_PATH_MASTERPASSWD); 605 606 if (err) { 607 if (name) 608 warn("%s", name); 609 else 610 warn(NULL); 611 } 612 if (master) 613 warnx("%s: unchanged", master); 614 pw_abort(); 615 exit(eval); 616 } 617