1 /* $NetBSD: passwd.c,v 1.35 2003/08/07 16:44:59 agc 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. 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 #if defined(LIBC_SCCS) && !defined(lint) 34 __RCSID("$NetBSD: passwd.c,v 1.35 2003/08/07 16:44:59 agc Exp $"); 35 #endif /* LIBC_SCCS and not lint */ 36 37 #include <sys/types.h> 38 #include <sys/param.h> 39 #include <sys/stat.h> 40 #include <sys/time.h> 41 #include <sys/resource.h> 42 #include <sys/wait.h> 43 44 #include <assert.h> 45 #include <ctype.h> 46 #include <err.h> 47 #include <errno.h> 48 #include <fcntl.h> 49 #include <limits.h> 50 #include <paths.h> 51 #include <pwd.h> 52 #include <signal.h> 53 #include <stdio.h> 54 #include <stdlib.h> 55 #include <string.h> 56 #include <unistd.h> 57 #include <util.h> 58 59 static const char *pw_filename(const char *filename); 60 static void pw_cont(int sig); 61 static int pw_equal(char *buf, struct passwd *old_pw); 62 static const char *pw_default(const char *option); 63 static int read_line(FILE *fp, char *line, int max); 64 static void trim_whitespace(char *line); 65 66 static char pw_prefix[MAXPATHLEN]; 67 68 const char * 69 pw_getprefix(void) 70 { 71 72 return(pw_prefix); 73 } 74 75 int 76 pw_setprefix(const char *new_prefix) 77 { 78 size_t length; 79 80 _DIAGASSERT(new_prefix != NULL); 81 82 length = strlen(new_prefix); 83 if (length < sizeof(pw_prefix)) { 84 (void)strcpy(pw_prefix, new_prefix); 85 while (length > 0 && pw_prefix[length - 1] == '/') 86 pw_prefix[--length] = '\0'; 87 return(0); 88 } 89 errno = ENAMETOOLONG; 90 return(-1); 91 } 92 93 static const char * 94 pw_filename(const char *filename) 95 { 96 static char newfilename[MAXPATHLEN]; 97 98 _DIAGASSERT(filename != NULL); 99 100 if (pw_prefix[0] == '\0') 101 return filename; 102 103 if (strlen(pw_prefix) + strlen(filename) < sizeof(newfilename)) 104 return strcat(strcpy(newfilename, pw_prefix), filename); 105 106 errno = ENAMETOOLONG; 107 return(NULL); 108 } 109 110 int 111 pw_lock(int retries) 112 { 113 const char *filename; 114 int i, fd; 115 mode_t old_mode; 116 int oerrno; 117 118 /* Acquire the lock file. */ 119 filename = pw_filename(_PATH_MASTERPASSWD_LOCK); 120 if (filename == NULL) 121 return(-1); 122 old_mode = umask(0); 123 fd = open(filename, O_WRONLY|O_CREAT|O_EXCL, 0600); 124 for (i = 0; i < retries && fd < 0 && errno == EEXIST; i++) { 125 sleep(1); 126 fd = open(filename, O_WRONLY|O_CREAT|O_EXCL, 127 0600); 128 } 129 oerrno = errno; 130 (void)umask(old_mode); 131 errno = oerrno; 132 return(fd); 133 } 134 135 int 136 pw_mkdb(username, secureonly) 137 const char *username; 138 int secureonly; 139 { 140 const char *args[9]; 141 int pstat, i; 142 pid_t pid; 143 144 pid = vfork(); 145 if (pid == -1) 146 return (-1); 147 148 if (pid == 0) { 149 args[0] = "pwd_mkdb"; 150 args[1] = "-d"; 151 args[2] = pw_prefix; 152 args[3] = "-p"; 153 i = 4; 154 155 if (secureonly) 156 args[i++] = "-s"; 157 if (username != NULL) { 158 args[i++] = "-u"; 159 args[i++] = username; 160 } 161 162 args[i++] = pw_filename(_PATH_MASTERPASSWD_LOCK); 163 args[i] = NULL; 164 execv(_PATH_PWD_MKDB, (char * const *)args); 165 _exit(1); 166 } 167 pid = waitpid(pid, &pstat, 0); 168 if (pid == -1 || !WIFEXITED(pstat) || WEXITSTATUS(pstat) != 0) 169 return(-1); 170 return(0); 171 } 172 173 int 174 pw_abort(void) 175 { 176 const char *filename; 177 178 filename = pw_filename(_PATH_MASTERPASSWD_LOCK); 179 return((filename == NULL) ? -1 : unlink(filename)); 180 } 181 182 /* Everything below this point is intended for the convenience of programs 183 * which allow a user to interactively edit the passwd file. Errors in the 184 * routines below will cause the process to abort. */ 185 186 static pid_t editpid = -1; 187 188 static void 189 pw_cont(int sig) 190 { 191 192 if (editpid != -1) 193 kill(editpid, sig); 194 } 195 196 void 197 pw_init(void) 198 { 199 struct rlimit rlim; 200 201 /* Unlimited resource limits. */ 202 rlim.rlim_cur = rlim.rlim_max = RLIM_INFINITY; 203 (void)setrlimit(RLIMIT_CPU, &rlim); 204 (void)setrlimit(RLIMIT_FSIZE, &rlim); 205 (void)setrlimit(RLIMIT_STACK, &rlim); 206 (void)setrlimit(RLIMIT_DATA, &rlim); 207 (void)setrlimit(RLIMIT_RSS, &rlim); 208 209 /* Don't drop core (not really necessary, but GP's). */ 210 rlim.rlim_cur = rlim.rlim_max = 0; 211 (void)setrlimit(RLIMIT_CORE, &rlim); 212 213 /* Turn off signals. */ 214 (void)signal(SIGALRM, SIG_IGN); 215 (void)signal(SIGHUP, SIG_IGN); 216 (void)signal(SIGINT, SIG_IGN); 217 (void)signal(SIGPIPE, SIG_IGN); 218 (void)signal(SIGQUIT, SIG_IGN); 219 (void)signal(SIGTERM, SIG_IGN); 220 (void)signal(SIGCONT, pw_cont); 221 } 222 223 void 224 pw_edit(int notsetuid, const char *filename) 225 { 226 int pstat; 227 char *p, *editor; 228 char *argp[] = { "sh", "-c", NULL, NULL }; 229 230 #ifdef __GNUC__ 231 (void) &editor; 232 #endif 233 234 if (filename == NULL) 235 filename = _PATH_MASTERPASSWD_LOCK; 236 237 filename = pw_filename(filename); 238 if (filename == NULL) 239 return; 240 241 if ((editor = getenv("EDITOR")) == NULL) 242 editor = _PATH_VI; 243 244 p = malloc(strlen(editor) + 1 + strlen(filename) + 1); 245 if (p == NULL) 246 return; 247 248 sprintf(p, "%s %s", editor, filename); 249 argp[2] = p; 250 251 switch(editpid = vfork()) { 252 case -1: 253 free(p); 254 return; 255 case 0: 256 if (notsetuid) { 257 setgid(getgid()); 258 setuid(getuid()); 259 } 260 execvp(_PATH_BSHELL, argp); 261 _exit(1); 262 } 263 264 free(p); 265 266 for (;;) { 267 editpid = waitpid(editpid, (int *)&pstat, WUNTRACED); 268 if (editpid == -1) 269 pw_error(editor, 1, 1); 270 else if (WIFSTOPPED(pstat)) 271 raise(WSTOPSIG(pstat)); 272 else if (WIFEXITED(pstat) && WEXITSTATUS(pstat) == 0) 273 break; 274 else 275 pw_error(editor, 1, 1); 276 } 277 editpid = -1; 278 } 279 280 void 281 pw_prompt(void) 282 { 283 int c; 284 285 (void)printf("re-edit the password file? [y]: "); 286 (void)fflush(stdout); 287 c = getchar(); 288 if (c != EOF && c != '\n') 289 while (getchar() != '\n'); 290 if (c == 'n') 291 pw_error(NULL, 0, 0); 292 } 293 294 /* for use in pw_copy(). Compare a pw entry to a pw struct. */ 295 static int 296 pw_equal(char *buf, struct passwd *pw) 297 { 298 struct passwd buf_pw; 299 int len; 300 301 _DIAGASSERT(buf != NULL); 302 _DIAGASSERT(pw != NULL); 303 304 len = strlen (buf); 305 if (buf[len-1] == '\n') 306 buf[len-1] = '\0'; 307 if (!pw_scan(buf, &buf_pw, NULL)) 308 return 0; 309 return !strcmp(pw->pw_name, buf_pw.pw_name) 310 && pw->pw_uid == buf_pw.pw_uid 311 && pw->pw_gid == buf_pw.pw_gid 312 && !strcmp(pw->pw_class, buf_pw.pw_class) 313 && (long)pw->pw_change == (long)buf_pw.pw_change 314 && (long)pw->pw_expire == (long)buf_pw.pw_expire 315 && !strcmp(pw->pw_gecos, buf_pw.pw_gecos) 316 && !strcmp(pw->pw_dir, buf_pw.pw_dir) 317 && !strcmp(pw->pw_shell, buf_pw.pw_shell); 318 } 319 320 void 321 pw_copy(int ffd, int tfd, struct passwd *pw, struct passwd *old_pw) 322 { 323 const char *filename; 324 char mpwd[MAXPATHLEN], mpwdl[MAXPATHLEN], *p, buf[8192]; 325 FILE *from, *to; 326 int done; 327 328 _DIAGASSERT(pw != NULL); 329 /* old_pw may be NULL */ 330 331 if ((filename = pw_filename(_PATH_MASTERPASSWD)) == NULL) 332 pw_error(pw_prefix, 1,1); 333 (void)strcpy(mpwd, filename); 334 if ((filename = pw_filename(_PATH_MASTERPASSWD_LOCK)) == NULL) 335 pw_error(pw_prefix, 1,1); 336 (void)strcpy(mpwdl, filename); 337 338 if (!(from = fdopen(ffd, "r"))) 339 pw_error(mpwd, 1, 1); 340 if (!(to = fdopen(tfd, "w"))) 341 pw_error(mpwdl, 1, 1); 342 343 for (done = 0; fgets(buf, sizeof(buf), from);) { 344 if (!strchr(buf, '\n')) { 345 warnx("%s: line too long", mpwd); 346 pw_error(NULL, 0, 1); 347 } 348 if (done) { 349 (void)fprintf(to, "%s", buf); 350 if (ferror(to)) 351 goto err; 352 continue; 353 } 354 if (!(p = strchr(buf, ':'))) { 355 warnx("%s: corrupted entry", mpwd); 356 pw_error(NULL, 0, 1); 357 } 358 *p = '\0'; 359 if (strcmp(buf, pw->pw_name)) { 360 *p = ':'; 361 (void)fprintf(to, "%s", buf); 362 if (ferror(to)) 363 goto err; 364 continue; 365 } 366 *p = ':'; 367 if (old_pw && !pw_equal(buf, old_pw)) { 368 warnx("%s: entry inconsistent", mpwd); 369 pw_error(NULL, 0, 1); 370 } 371 (void)fprintf(to, "%s:%s:%d:%d:%s:%ld:%ld:%s:%s:%s\n", 372 pw->pw_name, pw->pw_passwd, pw->pw_uid, pw->pw_gid, 373 pw->pw_class, (long)pw->pw_change, (long)pw->pw_expire, 374 pw->pw_gecos, pw->pw_dir, pw->pw_shell); 375 done = 1; 376 if (ferror(to)) 377 goto err; 378 } 379 /* Only append a new entry if real uid is root! */ 380 if (!done) { 381 if (getuid() == 0) 382 (void)fprintf(to, "%s:%s:%d:%d:%s:%ld:%ld:%s:%s:%s\n", 383 pw->pw_name, pw->pw_passwd, pw->pw_uid, pw->pw_gid, 384 pw->pw_class, (long)pw->pw_change, 385 (long)pw->pw_expire, pw->pw_gecos, pw->pw_dir, 386 pw->pw_shell); 387 else 388 warnx("%s: changes not made, no such entry", mpwd); 389 } 390 391 if (ferror(to)) 392 err: pw_error(NULL, 1, 1); 393 (void)fclose(to); 394 } 395 396 void 397 pw_error(const char *name, int error, int eval) 398 { 399 400 if (error) { 401 if (name) 402 warn("%s", name); 403 else 404 warn(NULL); 405 } 406 407 warnx("%s%s: unchanged", pw_prefix, _PATH_MASTERPASSWD); 408 pw_abort(); 409 exit(eval); 410 } 411 412 /* Removes head and/or tail spaces. */ 413 static void 414 trim_whitespace(char *line) 415 { 416 char *p; 417 418 _DIAGASSERT(line != NULL); 419 420 /* Remove leading spaces */ 421 p = line; 422 while (isspace((unsigned char) *p)) 423 p++; 424 memmove(line, p, strlen(p) + 1); 425 426 /* Remove trailing spaces */ 427 p = line + strlen(line) - 1; 428 while (isspace((unsigned char) *p)) 429 p--; 430 *(p + 1) = '\0'; 431 } 432 433 434 /* Get one line, remove spaces from front and tail */ 435 static int 436 read_line(FILE *fp, char *line, int max) 437 { 438 char *p; 439 440 _DIAGASSERT(fp != NULL); 441 _DIAGASSERT(line != NULL); 442 443 /* Read one line of config */ 444 if (fgets(line, max, fp) == NULL) 445 return (0); 446 447 if ((p = strchr(line, '\n')) == NULL) { 448 warnx("line too long"); 449 return (0); 450 } 451 *p = '\0'; 452 453 /* Remove comments */ 454 if ((p = strchr(line, '#')) != NULL) 455 *p = '\0'; 456 457 trim_whitespace(line); 458 return (1); 459 } 460 461 static const char * 462 pw_default(const char *option) 463 { 464 static const char *options[][2] = { 465 { "localcipher", "old" }, 466 { "ypcipher", "old" }, 467 }; 468 int i; 469 470 _DIAGASSERT(option != NULL); 471 for (i = 0; i < sizeof(options) / sizeof(options[0]); i++) 472 if (strcmp(options[i][0], option) == 0) 473 return (options[i][1]); 474 475 return (NULL); 476 } 477 478 /* 479 * Retrieve password information from the /etc/passwd.conf file, at the 480 * moment this is only for choosing the cipher to use. It could easily be 481 * used for other authentication methods as well. 482 */ 483 void 484 pw_getconf(char *data, size_t max, const char *key, const char *option) 485 { 486 FILE *fp; 487 char line[LINE_MAX], *p, *p2; 488 static char result[LINE_MAX]; 489 int got, found; 490 const char *cp; 491 492 _DIAGASSERT(data != NULL); 493 _DIAGASSERT(key != NULL); 494 _DIAGASSERT(option != NULL); 495 496 got = 0; 497 found = 0; 498 result[0] = '\0'; 499 500 if ((fp = fopen(_PATH_PASSWD_CONF, "r")) == NULL) { 501 if ((cp = pw_default(option)) != NULL) 502 strlcpy(data, cp, max); 503 else 504 data[0] = '\0'; 505 return; 506 } 507 508 while (!found && (got || read_line(fp, line, LINE_MAX))) { 509 got = 0; 510 511 if (strncmp(key, line, strlen(key)) != 0 || 512 line[strlen(key)] != ':') 513 continue; 514 515 /* Now we found our specified key */ 516 while (read_line(fp, line, LINE_MAX)) { 517 /* Leaving key field */ 518 if (line[0] != '\0' && strchr(line + 1, ':') != NULL) { 519 got = 1; 520 break; 521 } 522 p2 = line; 523 if ((p = strsep(&p2, "=")) == NULL || p2 == NULL) 524 continue; 525 trim_whitespace(p); 526 527 if (!strncmp(p, option, strlen(option))) { 528 trim_whitespace(p2); 529 strcpy(result, p2); 530 found = 1; 531 break; 532 } 533 } 534 } 535 fclose(fp); 536 537 /* 538 * If we got no result and were looking for a default 539 * value, try hard coded defaults. 540 */ 541 542 if (strlen(result) == 0 && strcmp(key, "default") == 0 && 543 (cp = pw_default(option)) != NULL) 544 strlcpy(data, cp, max); 545 else 546 strlcpy(data, result, max); 547 } 548