passwd.c revision 1.29
1 /* $NetBSD: passwd.c,v 1.29 2001/01/03 15:41:19 lukem 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 1.29 2001/01/03 15:41:19 lukem 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(void) 141 { 142 int pstat; 143 pid_t pid; 144 145 pid = vfork(); 146 if (pid == -1) 147 return (-1); 148 149 if (pid == 0) { 150 execl(_PATH_PWD_MKDB, "pwd_mkdb", "-d", pw_prefix, 151 "-p", pw_filename(_PATH_MASTERPASSWD_LOCK), NULL); 152 _exit(1); 153 } 154 pid = waitpid(pid, &pstat, 0); 155 if (pid == -1 || !WIFEXITED(pstat) || WEXITSTATUS(pstat) != 0) 156 return(-1); 157 return(0); 158 } 159 160 int 161 pw_abort(void) 162 { 163 const char *filename; 164 165 filename = pw_filename(_PATH_MASTERPASSWD_LOCK); 166 return((filename == NULL) ? -1 : unlink(filename)); 167 } 168 169 /* Everything below this point is intended for the convenience of programs 170 * which allow a user to interactively edit the passwd file. Errors in the 171 * routines below will cause the process to abort. */ 172 173 static pid_t editpid = -1; 174 175 static void 176 pw_cont(int sig) 177 { 178 179 if (editpid != -1) 180 kill(editpid, sig); 181 } 182 183 void 184 pw_init(void) 185 { 186 struct rlimit rlim; 187 188 /* Unlimited resource limits. */ 189 rlim.rlim_cur = rlim.rlim_max = RLIM_INFINITY; 190 (void)setrlimit(RLIMIT_CPU, &rlim); 191 (void)setrlimit(RLIMIT_FSIZE, &rlim); 192 (void)setrlimit(RLIMIT_STACK, &rlim); 193 (void)setrlimit(RLIMIT_DATA, &rlim); 194 (void)setrlimit(RLIMIT_RSS, &rlim); 195 196 /* Don't drop core (not really necessary, but GP's). */ 197 rlim.rlim_cur = rlim.rlim_max = 0; 198 (void)setrlimit(RLIMIT_CORE, &rlim); 199 200 /* Turn off signals. */ 201 (void)signal(SIGALRM, SIG_IGN); 202 (void)signal(SIGHUP, SIG_IGN); 203 (void)signal(SIGINT, SIG_IGN); 204 (void)signal(SIGPIPE, SIG_IGN); 205 (void)signal(SIGQUIT, SIG_IGN); 206 (void)signal(SIGTERM, SIG_IGN); 207 (void)signal(SIGCONT, pw_cont); 208 } 209 210 void 211 pw_edit(int notsetuid, const char *filename) 212 { 213 int pstat; 214 char *p, *editor; 215 char *argp[] = { "sh", "-c", NULL, NULL }; 216 217 #ifdef __GNUC__ 218 (void) &editor; 219 #endif 220 221 if (filename == NULL) 222 filename = _PATH_MASTERPASSWD_LOCK; 223 224 filename = pw_filename(filename); 225 if (filename == NULL) 226 return; 227 228 if ((editor = getenv("EDITOR")) == NULL) 229 editor = _PATH_VI; 230 231 p = malloc(strlen(editor) + 1 + strlen(filename) + 1); 232 if (p == NULL) 233 return; 234 235 sprintf(p, "%s %s", editor, filename); 236 argp[2] = p; 237 238 switch(editpid = vfork()) { 239 case -1: 240 free(p); 241 return; 242 case 0: 243 if (notsetuid) { 244 setgid(getgid()); 245 setuid(getuid()); 246 } 247 execvp(_PATH_BSHELL, argp); 248 _exit(1); 249 } 250 251 free(p); 252 253 for (;;) { 254 editpid = waitpid(editpid, (int *)&pstat, WUNTRACED); 255 if (editpid == -1) 256 pw_error(editor, 1, 1); 257 else if (WIFSTOPPED(pstat)) 258 raise(WSTOPSIG(pstat)); 259 else if (WIFEXITED(pstat) && WEXITSTATUS(pstat) == 0) 260 break; 261 else 262 pw_error(editor, 1, 1); 263 } 264 editpid = -1; 265 } 266 267 void 268 pw_prompt(void) 269 { 270 int c; 271 272 (void)printf("re-edit the password file? [y]: "); 273 (void)fflush(stdout); 274 c = getchar(); 275 if (c != EOF && c != '\n') 276 while (getchar() != '\n'); 277 if (c == 'n') 278 pw_error(NULL, 0, 0); 279 } 280 281 /* for use in pw_copy(). Compare a pw entry to a pw struct. */ 282 static int 283 pw_equal(char *buf, struct passwd *pw) 284 { 285 struct passwd buf_pw; 286 int len; 287 288 _DIAGASSERT(buf != NULL); 289 _DIAGASSERT(pw != NULL); 290 291 len = strlen (buf); 292 if (buf[len-1] == '\n') 293 buf[len-1] = '\0'; 294 if (!pw_scan(buf, &buf_pw, NULL)) 295 return 0; 296 return !strcmp(pw->pw_name, buf_pw.pw_name) 297 && pw->pw_uid == buf_pw.pw_uid 298 && pw->pw_gid == buf_pw.pw_gid 299 && !strcmp(pw->pw_class, buf_pw.pw_class) 300 && (long)pw->pw_change == (long)buf_pw.pw_change 301 && (long)pw->pw_expire == (long)buf_pw.pw_expire 302 && !strcmp(pw->pw_gecos, buf_pw.pw_gecos) 303 && !strcmp(pw->pw_dir, buf_pw.pw_dir) 304 && !strcmp(pw->pw_shell, buf_pw.pw_shell); 305 } 306 307 void 308 pw_copy(int ffd, int tfd, struct passwd *pw, struct passwd *old_pw) 309 { 310 const char *filename; 311 char mpwd[MAXPATHLEN], mpwdl[MAXPATHLEN], *p, buf[8192]; 312 FILE *from, *to; 313 int done; 314 315 _DIAGASSERT(pw != NULL); 316 /* old_pw may be NULL */ 317 318 if ((filename = pw_filename(_PATH_MASTERPASSWD)) == NULL) 319 pw_error(pw_prefix, 1,1); 320 (void)strcpy(mpwd, filename); 321 if ((filename = pw_filename(_PATH_MASTERPASSWD_LOCK)) == NULL) 322 pw_error(pw_prefix, 1,1); 323 (void)strcpy(mpwdl, filename); 324 325 if (!(from = fdopen(ffd, "r"))) 326 pw_error(mpwd, 1, 1); 327 if (!(to = fdopen(tfd, "w"))) 328 pw_error(mpwdl, 1, 1); 329 330 for (done = 0; fgets(buf, sizeof(buf), from);) { 331 if (!strchr(buf, '\n')) { 332 warnx("%s: line too long", mpwd); 333 pw_error(NULL, 0, 1); 334 } 335 if (done) { 336 (void)fprintf(to, "%s", buf); 337 if (ferror(to)) 338 goto err; 339 continue; 340 } 341 if (!(p = strchr(buf, ':'))) { 342 warnx("%s: corrupted entry", mpwd); 343 pw_error(NULL, 0, 1); 344 } 345 *p = '\0'; 346 if (strcmp(buf, pw->pw_name)) { 347 *p = ':'; 348 (void)fprintf(to, "%s", buf); 349 if (ferror(to)) 350 goto err; 351 continue; 352 } 353 *p = ':'; 354 if (old_pw && !pw_equal(buf, old_pw)) { 355 warnx("%s: entry inconsistent", mpwd); 356 pw_error(NULL, 0, 1); 357 } 358 (void)fprintf(to, "%s:%s:%d:%d:%s:%ld:%ld:%s:%s:%s\n", 359 pw->pw_name, pw->pw_passwd, pw->pw_uid, pw->pw_gid, 360 pw->pw_class, (long)pw->pw_change, (long)pw->pw_expire, 361 pw->pw_gecos, pw->pw_dir, pw->pw_shell); 362 done = 1; 363 if (ferror(to)) 364 goto err; 365 } 366 /* Only append a new entry if real uid is root! */ 367 if (!done) { 368 if (getuid() == 0) 369 (void)fprintf(to, "%s:%s:%d:%d:%s:%ld:%ld:%s:%s:%s\n", 370 pw->pw_name, pw->pw_passwd, pw->pw_uid, pw->pw_gid, 371 pw->pw_class, (long)pw->pw_change, 372 (long)pw->pw_expire, pw->pw_gecos, pw->pw_dir, 373 pw->pw_shell); 374 else 375 warnx("%s: changes not made, no such entry", mpwd); 376 } 377 378 if (ferror(to)) 379 err: pw_error(NULL, 1, 1); 380 (void)fclose(to); 381 } 382 383 void 384 pw_error(const char *name, int err, int eval) 385 { 386 387 if (err) { 388 if (name) 389 warn("%s", name); 390 else 391 warn(NULL); 392 } 393 394 warnx("%s%s: unchanged", pw_prefix, _PATH_MASTERPASSWD); 395 pw_abort(); 396 exit(eval); 397 } 398 399 /* Removes head and/or tail spaces. */ 400 static void 401 trim_whitespace(char *line) 402 { 403 char *p; 404 405 _DIAGASSERT(line != NULL); 406 407 /* Remove leading spaces */ 408 p = line; 409 while (isspace((unsigned char) *p)) 410 p++; 411 memmove(line, p, strlen(p) + 1); 412 413 /* Remove trailing spaces */ 414 p = line + strlen(line) - 1; 415 while (isspace((unsigned char) *p)) 416 p--; 417 *(p + 1) = '\0'; 418 } 419 420 421 /* Get one line, remove spaces from front and tail */ 422 static int 423 read_line(FILE *fp, char *line, int max) 424 { 425 char *p; 426 427 _DIAGASSERT(fp != NULL); 428 _DIAGASSERT(line != NULL); 429 430 /* Read one line of config */ 431 if (fgets(line, max, fp) == NULL) 432 return (0); 433 434 if ((p = strchr(line, '\n')) == NULL) { 435 warnx("line too long"); 436 return (0); 437 } 438 *p = '\0'; 439 440 /* Remove comments */ 441 if ((p = strchr(line, '#')) != NULL) 442 *p = '\0'; 443 444 trim_whitespace(line); 445 return (1); 446 } 447 448 static const char * 449 pw_default(const char *option) 450 { 451 static const char *options[][2] = { 452 { "localcipher", "old" }, 453 { "ypcipher", "old" }, 454 }; 455 int i; 456 457 _DIAGASSERT(option != NULL); 458 for (i = 0; i < sizeof(options) / sizeof(options[0]); i++) 459 if (strcmp(options[i][0], option) == 0) 460 return (options[i][1]); 461 462 return (NULL); 463 } 464 465 /* 466 * Retrieve password information from the /etc/passwd.conf file, at the 467 * moment this is only for choosing the cipher to use. It could easily be 468 * used for other authentication methods as well. 469 */ 470 void 471 pw_getconf(char *data, size_t max, const char *key, const char *option) 472 { 473 FILE *fp; 474 char line[LINE_MAX], *p, *p2; 475 static char result[LINE_MAX]; 476 int got, found; 477 const char *cp; 478 479 _DIAGASSERT(data != NULL); 480 _DIAGASSERT(key != NULL); 481 _DIAGASSERT(option != NULL); 482 483 got = 0; 484 found = 0; 485 result[0] = '\0'; 486 487 if ((fp = fopen(_PATH_PASSWDCONF, "r")) == NULL) { 488 if ((cp = pw_default(option)) != NULL) 489 strlcpy(data, cp, max); 490 else 491 data[0] = '\0'; 492 return; 493 } 494 495 while (!found && (got || read_line(fp, line, LINE_MAX))) { 496 got = 0; 497 498 if (strncmp(key, line, strlen(key)) != 0 || 499 line[strlen(key)] != ':') 500 continue; 501 502 /* Now we found our specified key */ 503 while (read_line(fp, line, LINE_MAX)) { 504 /* Leaving key field */ 505 if (line[0] != '\0' && strchr(line + 1, ':') != NULL) { 506 got = 1; 507 break; 508 } 509 p2 = line; 510 if ((p = strsep(&p2, "=")) == NULL || p2 == NULL) 511 continue; 512 trim_whitespace(p); 513 514 if (!strncmp(p, option, strlen(option))) { 515 trim_whitespace(p2); 516 strcpy(result, p2); 517 found = 1; 518 break; 519 } 520 } 521 } 522 fclose(fp); 523 524 /* 525 * If we got no result and were looking for a default 526 * value, try hard coded defaults. 527 */ 528 529 if (strlen(result) == 0 && strcmp(key, "default") == 0 && 530 (cp = pw_default(option)) != NULL) 531 strlcpy(data, cp, max); 532 else 533 strlcpy(data, result, max); 534 } 535
Indexes created Wed Sep 24 22:09:59 GMT 2025