1 /* $NetBSD: passwd.c,v 1.34 2002/04/17 11:14:28 ad 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 #include <sys/cdefs.h> 37 #if defined(LIBC_SCCS) && !defined(lint) 38 __RCSID("$NetBSD: passwd.c,v 1.34 2002/04/17 11:14:28 ad Exp $"); 39 #endif /* LIBC_SCCS and not lint */ 40 41 #include <sys/types.h> 42 #include <sys/param.h> 43 #include <sys/stat.h> 44 #include <sys/time.h> 45 #include <sys/resource.h> 46 #include <sys/wait.h> 47 48 #include <assert.h> 49 #include <ctype.h> 50 #include <err.h> 51 #include <errno.h> 52 #include <fcntl.h> 53 #include <limits.h> 54 #include <paths.h> 55 #include <pwd.h> 56 #include <signal.h> 57 #include <stdio.h> 58 #include <stdlib.h> 59 #include <string.h> 60 #include <unistd.h> 61 #include <util.h> 62 63 static const char *pw_filename(const char *filename); 64 static void pw_cont(int sig); 65 static int pw_equal(char *buf, struct passwd *old_pw); 66 static const char *pw_default(const char *option); 67 static int read_line(FILE *fp, char *line, int max); 68 static void trim_whitespace(char *line); 69 70 static char pw_prefix[MAXPATHLEN]; 71 72 const char * 73 pw_getprefix(void) 74 { 75 76 return(pw_prefix); 77 } 78 79 int 80 pw_setprefix(const char *new_prefix) 81 { 82 size_t length; 83 84 _DIAGASSERT(new_prefix != NULL); 85 86 length = strlen(new_prefix); 87 if (length < sizeof(pw_prefix)) { 88 (void)strcpy(pw_prefix, new_prefix); 89 while (length > 0 && pw_prefix[length - 1] == '/') 90 pw_prefix[--length] = '\0'; 91 return(0); 92 } 93 errno = ENAMETOOLONG; 94 return(-1); 95 } 96 97 static const char * 98 pw_filename(const char *filename) 99 { 100 static char newfilename[MAXPATHLEN]; 101 102 _DIAGASSERT(filename != NULL); 103 104 if (pw_prefix[0] == '\0') 105 return filename; 106 107 if (strlen(pw_prefix) + strlen(filename) < sizeof(newfilename)) 108 return strcat(strcpy(newfilename, pw_prefix), filename); 109 110 errno = ENAMETOOLONG; 111 return(NULL); 112 } 113 114 int 115 pw_lock(int retries) 116 { 117 const char *filename; 118 int i, fd; 119 mode_t old_mode; 120 int oerrno; 121 122 /* Acquire the lock file. */ 123 filename = pw_filename(_PATH_MASTERPASSWD_LOCK); 124 if (filename == NULL) 125 return(-1); 126 old_mode = umask(0); 127 fd = open(filename, O_WRONLY|O_CREAT|O_EXCL, 0600); 128 for (i = 0; i < retries && fd < 0 && errno == EEXIST; i++) { 129 sleep(1); 130 fd = open(filename, O_WRONLY|O_CREAT|O_EXCL, 131 0600); 132 } 133 oerrno = errno; 134 (void)umask(old_mode); 135 errno = oerrno; 136 return(fd); 137 } 138 139 int 140 pw_mkdb(username, secureonly) 141 const char *username; 142 int secureonly; 143 { 144 const char *args[9]; 145 int pstat, i; 146 pid_t pid; 147 148 pid = vfork(); 149 if (pid == -1) 150 return (-1); 151 152 if (pid == 0) { 153 args[0] = "pwd_mkdb"; 154 args[1] = "-d"; 155 args[2] = pw_prefix; 156 args[3] = "-p"; 157 i = 4; 158 159 if (secureonly) 160 args[i++] = "-s"; 161 if (username != NULL) { 162 args[i++] = "-u"; 163 args[i++] = username; 164 } 165 166 args[i++] = pw_filename(_PATH_MASTERPASSWD_LOCK); 167 args[i] = NULL; 168 execv(_PATH_PWD_MKDB, (char * const *)args); 169 _exit(1); 170 } 171 pid = waitpid(pid, &pstat, 0); 172 if (pid == -1 || !WIFEXITED(pstat) || WEXITSTATUS(pstat) != 0) 173 return(-1); 174 return(0); 175 } 176 177 int 178 pw_abort(void) 179 { 180 const char *filename; 181 182 filename = pw_filename(_PATH_MASTERPASSWD_LOCK); 183 return((filename == NULL) ? -1 : unlink(filename)); 184 } 185 186 /* Everything below this point is intended for the convenience of programs 187 * which allow a user to interactively edit the passwd file. Errors in the 188 * routines below will cause the process to abort. */ 189 190 static pid_t editpid = -1; 191 192 static void 193 pw_cont(int sig) 194 { 195 196 if (editpid != -1) 197 kill(editpid, sig); 198 } 199 200 void 201 pw_init(void) 202 { 203 struct rlimit rlim; 204 205 /* Unlimited resource limits. */ 206 rlim.rlim_cur = rlim.rlim_max = RLIM_INFINITY; 207 (void)setrlimit(RLIMIT_CPU, &rlim); 208 (void)setrlimit(RLIMIT_FSIZE, &rlim); 209 (void)setrlimit(RLIMIT_STACK, &rlim); 210 (void)setrlimit(RLIMIT_DATA, &rlim); 211 (void)setrlimit(RLIMIT_RSS, &rlim); 212 213 /* Don't drop core (not really necessary, but GP's). */ 214 rlim.rlim_cur = rlim.rlim_max = 0; 215 (void)setrlimit(RLIMIT_CORE, &rlim); 216 217 /* Turn off signals. */ 218 (void)signal(SIGALRM, SIG_IGN); 219 (void)signal(SIGHUP, SIG_IGN); 220 (void)signal(SIGINT, SIG_IGN); 221 (void)signal(SIGPIPE, SIG_IGN); 222 (void)signal(SIGQUIT, SIG_IGN); 223 (void)signal(SIGTERM, SIG_IGN); 224 (void)signal(SIGCONT, pw_cont); 225 } 226 227 void 228 pw_edit(int notsetuid, const char *filename) 229 { 230 int pstat; 231 char *p, *editor; 232 char *argp[] = { "sh", "-c", NULL, NULL }; 233 234 #ifdef __GNUC__ 235 (void) &editor; 236 #endif 237 238 if (filename == NULL) 239 filename = _PATH_MASTERPASSWD_LOCK; 240 241 filename = pw_filename(filename); 242 if (filename == NULL) 243 return; 244 245 if ((editor = getenv("EDITOR")) == NULL) 246 editor = _PATH_VI; 247 248 p = malloc(strlen(editor) + 1 + strlen(filename) + 1); 249 if (p == NULL) 250 return; 251 252 sprintf(p, "%s %s", editor, filename); 253 argp[2] = p; 254 255 switch(editpid = vfork()) { 256 case -1: 257 free(p); 258 return; 259 case 0: 260 if (notsetuid) { 261 setgid(getgid()); 262 setuid(getuid()); 263 } 264 execvp(_PATH_BSHELL, argp); 265 _exit(1); 266 } 267 268 free(p); 269 270 for (;;) { 271 editpid = waitpid(editpid, (int *)&pstat, WUNTRACED); 272 if (editpid == -1) 273 pw_error(editor, 1, 1); 274 else if (WIFSTOPPED(pstat)) 275 raise(WSTOPSIG(pstat)); 276 else if (WIFEXITED(pstat) && WEXITSTATUS(pstat) == 0) 277 break; 278 else 279 pw_error(editor, 1, 1); 280 } 281 editpid = -1; 282 } 283 284 void 285 pw_prompt(void) 286 { 287 int c; 288 289 (void)printf("re-edit the password file? [y]: "); 290 (void)fflush(stdout); 291 c = getchar(); 292 if (c != EOF && c != '\n') 293 while (getchar() != '\n'); 294 if (c == 'n') 295 pw_error(NULL, 0, 0); 296 } 297 298 /* for use in pw_copy(). Compare a pw entry to a pw struct. */ 299 static int 300 pw_equal(char *buf, struct passwd *pw) 301 { 302 struct passwd buf_pw; 303 int len; 304 305 _DIAGASSERT(buf != NULL); 306 _DIAGASSERT(pw != NULL); 307 308 len = strlen (buf); 309 if (buf[len-1] == '\n') 310 buf[len-1] = '\0'; 311 if (!pw_scan(buf, &buf_pw, NULL)) 312 return 0; 313 return !strcmp(pw->pw_name, buf_pw.pw_name) 314 && pw->pw_uid == buf_pw.pw_uid 315 && pw->pw_gid == buf_pw.pw_gid 316 && !strcmp(pw->pw_class, buf_pw.pw_class) 317 && (long)pw->pw_change == (long)buf_pw.pw_change 318 && (long)pw->pw_expire == (long)buf_pw.pw_expire 319 && !strcmp(pw->pw_gecos, buf_pw.pw_gecos) 320 && !strcmp(pw->pw_dir, buf_pw.pw_dir) 321 && !strcmp(pw->pw_shell, buf_pw.pw_shell); 322 } 323 324 void 325 pw_copy(int ffd, int tfd, struct passwd *pw, struct passwd *old_pw) 326 { 327 const char *filename; 328 char mpwd[MAXPATHLEN], mpwdl[MAXPATHLEN], *p, buf[8192]; 329 FILE *from, *to; 330 int done; 331 332 _DIAGASSERT(pw != NULL); 333 /* old_pw may be NULL */ 334 335 if ((filename = pw_filename(_PATH_MASTERPASSWD)) == NULL) 336 pw_error(pw_prefix, 1,1); 337 (void)strcpy(mpwd, filename); 338 if ((filename = pw_filename(_PATH_MASTERPASSWD_LOCK)) == NULL) 339 pw_error(pw_prefix, 1,1); 340 (void)strcpy(mpwdl, filename); 341 342 if (!(from = fdopen(ffd, "r"))) 343 pw_error(mpwd, 1, 1); 344 if (!(to = fdopen(tfd, "w"))) 345 pw_error(mpwdl, 1, 1); 346 347 for (done = 0; fgets(buf, sizeof(buf), from);) { 348 if (!strchr(buf, '\n')) { 349 warnx("%s: line too long", mpwd); 350 pw_error(NULL, 0, 1); 351 } 352 if (done) { 353 (void)fprintf(to, "%s", buf); 354 if (ferror(to)) 355 goto err; 356 continue; 357 } 358 if (!(p = strchr(buf, ':'))) { 359 warnx("%s: corrupted entry", mpwd); 360 pw_error(NULL, 0, 1); 361 } 362 *p = '\0'; 363 if (strcmp(buf, pw->pw_name)) { 364 *p = ':'; 365 (void)fprintf(to, "%s", buf); 366 if (ferror(to)) 367 goto err; 368 continue; 369 } 370 *p = ':'; 371 if (old_pw && !pw_equal(buf, old_pw)) { 372 warnx("%s: entry inconsistent", mpwd); 373 pw_error(NULL, 0, 1); 374 } 375 (void)fprintf(to, "%s:%s:%d:%d:%s:%ld:%ld:%s:%s:%s\n", 376 pw->pw_name, pw->pw_passwd, pw->pw_uid, pw->pw_gid, 377 pw->pw_class, (long)pw->pw_change, (long)pw->pw_expire, 378 pw->pw_gecos, pw->pw_dir, pw->pw_shell); 379 done = 1; 380 if (ferror(to)) 381 goto err; 382 } 383 /* Only append a new entry if real uid is root! */ 384 if (!done) { 385 if (getuid() == 0) 386 (void)fprintf(to, "%s:%s:%d:%d:%s:%ld:%ld:%s:%s:%s\n", 387 pw->pw_name, pw->pw_passwd, pw->pw_uid, pw->pw_gid, 388 pw->pw_class, (long)pw->pw_change, 389 (long)pw->pw_expire, pw->pw_gecos, pw->pw_dir, 390 pw->pw_shell); 391 else 392 warnx("%s: changes not made, no such entry", mpwd); 393 } 394 395 if (ferror(to)) 396 err: pw_error(NULL, 1, 1); 397 (void)fclose(to); 398 } 399 400 void 401 pw_error(const char *name, int error, int eval) 402 { 403 404 if (error) { 405 if (name) 406 warn("%s", name); 407 else 408 warn(NULL); 409 } 410 411 warnx("%s%s: unchanged", pw_prefix, _PATH_MASTERPASSWD); 412 pw_abort(); 413 exit(eval); 414 } 415 416 /* Removes head and/or tail spaces. */ 417 static void 418 trim_whitespace(char *line) 419 { 420 char *p; 421 422 _DIAGASSERT(line != NULL); 423 424 /* Remove leading spaces */ 425 p = line; 426 while (isspace((unsigned char) *p)) 427 p++; 428 memmove(line, p, strlen(p) + 1); 429 430 /* Remove trailing spaces */ 431 p = line + strlen(line) - 1; 432 while (isspace((unsigned char) *p)) 433 p--; 434 *(p + 1) = '\0'; 435 } 436 437 438 /* Get one line, remove spaces from front and tail */ 439 static int 440 read_line(FILE *fp, char *line, int max) 441 { 442 char *p; 443 444 _DIAGASSERT(fp != NULL); 445 _DIAGASSERT(line != NULL); 446 447 /* Read one line of config */ 448 if (fgets(line, max, fp) == NULL) 449 return (0); 450 451 if ((p = strchr(line, '\n')) == NULL) { 452 warnx("line too long"); 453 return (0); 454 } 455 *p = '\0'; 456 457 /* Remove comments */ 458 if ((p = strchr(line, '#')) != NULL) 459 *p = '\0'; 460 461 trim_whitespace(line); 462 return (1); 463 } 464 465 static const char * 466 pw_default(const char *option) 467 { 468 static const char *options[][2] = { 469 { "localcipher", "old" }, 470 { "ypcipher", "old" }, 471 }; 472 int i; 473 474 _DIAGASSERT(option != NULL); 475 for (i = 0; i < sizeof(options) / sizeof(options[0]); i++) 476 if (strcmp(options[i][0], option) == 0) 477 return (options[i][1]); 478 479 return (NULL); 480 } 481 482 /* 483 * Retrieve password information from the /etc/passwd.conf file, at the 484 * moment this is only for choosing the cipher to use. It could easily be 485 * used for other authentication methods as well. 486 */ 487 void 488 pw_getconf(char *data, size_t max, const char *key, const char *option) 489 { 490 FILE *fp; 491 char line[LINE_MAX], *p, *p2; 492 static char result[LINE_MAX]; 493 int got, found; 494 const char *cp; 495 496 _DIAGASSERT(data != NULL); 497 _DIAGASSERT(key != NULL); 498 _DIAGASSERT(option != NULL); 499 500 got = 0; 501 found = 0; 502 result[0] = '\0'; 503 504 if ((fp = fopen(_PATH_PASSWD_CONF, "r")) == NULL) { 505 if ((cp = pw_default(option)) != NULL) 506 strlcpy(data, cp, max); 507 else 508 data[0] = '\0'; 509 return; 510 } 511 512 while (!found && (got || read_line(fp, line, LINE_MAX))) { 513 got = 0; 514 515 if (strncmp(key, line, strlen(key)) != 0 || 516 line[strlen(key)] != ':') 517 continue; 518 519 /* Now we found our specified key */ 520 while (read_line(fp, line, LINE_MAX)) { 521 /* Leaving key field */ 522 if (line[0] != '\0' && strchr(line + 1, ':') != NULL) { 523 got = 1; 524 break; 525 } 526 p2 = line; 527 if ((p = strsep(&p2, "=")) == NULL || p2 == NULL) 528 continue; 529 trim_whitespace(p); 530 531 if (!strncmp(p, option, strlen(option))) { 532 trim_whitespace(p2); 533 strcpy(result, p2); 534 found = 1; 535 break; 536 } 537 } 538 } 539 fclose(fp); 540 541 /* 542 * If we got no result and were looking for a default 543 * value, try hard coded defaults. 544 */ 545 546 if (strlen(result) == 0 && strcmp(key, "default") == 0 && 547 (cp = pw_default(option)) != NULL) 548 strlcpy(data, cp, max); 549 else 550 strlcpy(data, result, max); 551 } 552