passwd.c revision 1.21
1 /* $NetBSD: passwd.c,v 1.21 2000/07/06 13:09:47 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 1.21 2000/07/06 13:09:47 ad Exp $"); 39 #endif /* LIBC_SCCS and not lint */ 40 41 #include <sys/types.h> 42 #include <sys/stat.h> 43 #include <sys/time.h> 44 #include <sys/resource.h> 45 #include <sys/wait.h> 46 47 #include <assert.h> 48 #include <ctype.h> 49 #include <err.h> 50 #include <errno.h> 51 #include <fcntl.h> 52 #include <limits.h> 53 #include <paths.h> 54 #include <pwd.h> 55 #include <signal.h> 56 #include <stdio.h> 57 #include <stdlib.h> 58 #include <string.h> 59 #include <unistd.h> 60 #include <util.h> 61 62 static void pw_cont(int sig); 63 static int pw_equal(char *buf, struct passwd *old_pw); 64 65 int 66 pw_lock(int retries) 67 { 68 int i, fd; 69 mode_t old_mode; 70 int oerrno; 71 72 /* Acquire the lock file. */ 73 old_mode = umask(0); 74 fd = open(_PATH_MASTERPASSWD_LOCK, O_WRONLY|O_CREAT|O_EXCL, 0600); 75 for (i = 0; i < retries && fd < 0 && errno == EEXIST; i++) { 76 sleep(1); 77 fd = open(_PATH_MASTERPASSWD_LOCK, O_WRONLY|O_CREAT|O_EXCL, 78 0600); 79 } 80 oerrno = errno; 81 (void)umask(old_mode); 82 errno = oerrno; 83 return(fd); 84 } 85 86 int 87 pw_mkdb(void) 88 { 89 int pstat; 90 pid_t pid; 91 92 pid = vfork(); 93 if (pid == -1) 94 return (-1); 95 96 if (pid == 0) { 97 execl(_PATH_PWD_MKDB, "pwd_mkdb", "-p", 98 _PATH_MASTERPASSWD_LOCK, NULL); 99 _exit(1); 100 } 101 pid = waitpid(pid, &pstat, 0); 102 if (pid == -1 || !WIFEXITED(pstat) || WEXITSTATUS(pstat) != 0) 103 return(-1); 104 return(0); 105 } 106 107 int 108 pw_abort(void) 109 { 110 111 return(unlink(_PATH_MASTERPASSWD_LOCK)); 112 } 113 114 /* Everything below this point is intended for the convenience of programs 115 * which allow a user to interactively edit the passwd file. Errors in the 116 * routines below will cause the process to abort. */ 117 118 static pid_t editpid = -1; 119 120 static void 121 pw_cont(int sig) 122 { 123 124 if (editpid != -1) 125 kill(editpid, sig); 126 } 127 128 void 129 pw_init(void) 130 { 131 struct rlimit rlim; 132 133 /* Unlimited resource limits. */ 134 rlim.rlim_cur = rlim.rlim_max = RLIM_INFINITY; 135 (void)setrlimit(RLIMIT_CPU, &rlim); 136 (void)setrlimit(RLIMIT_FSIZE, &rlim); 137 (void)setrlimit(RLIMIT_STACK, &rlim); 138 (void)setrlimit(RLIMIT_DATA, &rlim); 139 (void)setrlimit(RLIMIT_RSS, &rlim); 140 141 /* Don't drop core (not really necessary, but GP's). */ 142 rlim.rlim_cur = rlim.rlim_max = 0; 143 (void)setrlimit(RLIMIT_CORE, &rlim); 144 145 /* Turn off signals. */ 146 (void)signal(SIGALRM, SIG_IGN); 147 (void)signal(SIGHUP, SIG_IGN); 148 (void)signal(SIGINT, SIG_IGN); 149 (void)signal(SIGPIPE, SIG_IGN); 150 (void)signal(SIGQUIT, SIG_IGN); 151 (void)signal(SIGTERM, SIG_IGN); 152 (void)signal(SIGCONT, pw_cont); 153 } 154 155 void 156 pw_edit(int notsetuid, const char *filename) 157 { 158 int pstat; 159 char *p, *editor; 160 char *argp[] = { "sh", "-c", NULL, NULL }; 161 162 #ifdef __GNUC__ 163 (void) &editor; 164 #endif 165 166 if (filename == NULL) 167 filename = _PATH_MASTERPASSWD_LOCK; 168 169 if ((editor = getenv("EDITOR")) == NULL) 170 editor = _PATH_VI; 171 172 p = malloc(strlen(editor) + 1 + strlen(filename) + 1); 173 if (p == NULL) 174 return; 175 176 sprintf(p, "%s %s", editor, filename); 177 argp[2] = p; 178 179 switch(editpid = vfork()) { 180 case -1: 181 free(p); 182 return; 183 case 0: 184 if (notsetuid) { 185 setgid(getgid()); 186 setuid(getuid()); 187 } 188 execvp(_PATH_BSHELL, argp); 189 _exit(1); 190 } 191 192 free(p); 193 194 for (;;) { 195 editpid = waitpid(editpid, (int *)&pstat, WUNTRACED); 196 if (editpid == -1) 197 pw_error(editor, 1, 1); 198 else if (WIFSTOPPED(pstat)) 199 raise(WSTOPSIG(pstat)); 200 else if (WIFEXITED(pstat) && WEXITSTATUS(pstat) == 0) 201 break; 202 else 203 pw_error(editor, 1, 1); 204 } 205 editpid = -1; 206 } 207 208 void 209 pw_prompt(void) 210 { 211 int c; 212 213 (void)printf("re-edit the password file? [y]: "); 214 (void)fflush(stdout); 215 c = getchar(); 216 if (c != EOF && c != '\n') 217 while (getchar() != '\n'); 218 if (c == 'n') 219 pw_error(NULL, 0, 0); 220 } 221 222 /* for use in pw_copy(). Compare a pw entry to a pw struct. */ 223 static int 224 pw_equal(char *buf, struct passwd *pw) 225 { 226 struct passwd buf_pw; 227 int len; 228 229 _DIAGASSERT(buf != NULL); 230 _DIAGASSERT(pw != NULL); 231 232 len = strlen (buf); 233 if (buf[len-1] == '\n') 234 buf[len-1] = '\0'; 235 if (!pw_scan(buf, &buf_pw, NULL)) 236 return 0; 237 return !strcmp(pw->pw_name, buf_pw.pw_name) 238 && pw->pw_uid == buf_pw.pw_uid 239 && pw->pw_gid == buf_pw.pw_gid 240 && !strcmp(pw->pw_class, buf_pw.pw_class) 241 && (long)pw->pw_change == (long)buf_pw.pw_change 242 && (long)pw->pw_expire == (long)buf_pw.pw_expire 243 && !strcmp(pw->pw_gecos, buf_pw.pw_gecos) 244 && !strcmp(pw->pw_dir, buf_pw.pw_dir) 245 && !strcmp(pw->pw_shell, buf_pw.pw_shell); 246 } 247 248 void 249 pw_copy(int ffd, int tfd, struct passwd *pw, struct passwd *old_pw) 250 { 251 FILE *from, *to; 252 int done; 253 char *p, buf[8192]; 254 255 _DIAGASSERT(pw != NULL); 256 /* old_pw may be NULL */ 257 258 if (!(from = fdopen(ffd, "r"))) 259 pw_error(_PATH_MASTERPASSWD, 1, 1); 260 if (!(to = fdopen(tfd, "w"))) 261 pw_error(_PATH_MASTERPASSWD_LOCK, 1, 1); 262 263 for (done = 0; fgets(buf, sizeof(buf), from);) { 264 if (!strchr(buf, '\n')) { 265 warnx("%s: line too long", _PATH_MASTERPASSWD); 266 pw_error(NULL, 0, 1); 267 } 268 if (done) { 269 (void)fprintf(to, "%s", buf); 270 if (ferror(to)) 271 goto err; 272 continue; 273 } 274 if (!(p = strchr(buf, ':'))) { 275 warnx("%s: corrupted entry", _PATH_MASTERPASSWD); 276 pw_error(NULL, 0, 1); 277 } 278 *p = '\0'; 279 if (strcmp(buf, pw->pw_name)) { 280 *p = ':'; 281 (void)fprintf(to, "%s", buf); 282 if (ferror(to)) 283 goto err; 284 continue; 285 } 286 *p = ':'; 287 if (old_pw && !pw_equal(buf, old_pw)) { 288 warnx("%s: entry inconsistent", 289 _PATH_MASTERPASSWD); 290 pw_error(NULL, 0, 1); 291 } 292 (void)fprintf(to, "%s:%s:%d:%d:%s:%ld:%ld:%s:%s:%s\n", 293 pw->pw_name, pw->pw_passwd, pw->pw_uid, pw->pw_gid, 294 pw->pw_class, (long)pw->pw_change, (long)pw->pw_expire, 295 pw->pw_gecos, pw->pw_dir, pw->pw_shell); 296 done = 1; 297 if (ferror(to)) 298 goto err; 299 } 300 /* Only append a new entry if real uid is root! */ 301 if (!done) { 302 if (getuid() == 0) 303 (void)fprintf(to, "%s:%s:%d:%d:%s:%ld:%ld:%s:%s:%s\n", 304 pw->pw_name, pw->pw_passwd, pw->pw_uid, pw->pw_gid, 305 pw->pw_class, (long)pw->pw_change, 306 (long)pw->pw_expire, pw->pw_gecos, pw->pw_dir, 307 pw->pw_shell); 308 else 309 warnx("%s: changes not made, no such entry", 310 _PATH_MASTERPASSWD); 311 } 312 313 if (ferror(to)) 314 err: pw_error(NULL, 1, 1); 315 (void)fclose(to); 316 } 317 318 void 319 pw_error(const char *name, int err, int eval) 320 { 321 322 if (err) 323 warn(name); 324 325 warnx("%s: unchanged", _PATH_MASTERPASSWD); 326 pw_abort(); 327 exit(eval); 328 } 329 330 /* Removes head and/or tail spaces. */ 331 static void 332 trim_whitespace(char *line) 333 { 334 char *p; 335 336 /* Remove leading spaces */ 337 p = line; 338 while (isspace(*p)) 339 p++; 340 memmove(line, p, strlen(p) + 1); 341 342 /* Remove trailing spaces */ 343 p = line + strlen(line) - 1; 344 while (isspace(*p)) 345 p--; 346 *(p + 1) = '\0'; 347 } 348 349 350 /* Get one line, remove spaces from front and tail */ 351 static int 352 read_line(FILE *fp, char *line, int max) 353 { 354 char *p; 355 356 /* Read one line of config */ 357 if (fgets(line, max, fp) == NULL) 358 return (0); 359 360 if ((p = strchr(line, '\n')) == NULL) { 361 warnx("line too long"); 362 return (0); 363 } 364 *p = '\0'; 365 366 /* Remove comments */ 367 if ((p = strchr(line, '#')) != NULL) 368 *p = '\0'; 369 370 trim_whitespace(line); 371 return (1); 372 } 373 374 static const char * 375 pw_default(const char *option) 376 { 377 static const char *options[][2] = { 378 { "localcipher", "old" }, 379 { "ypcipher", "old" }, 380 }; 381 int i; 382 383 for (i = 0; i < sizeof(options) / sizeof(options[0]); i++) 384 if (strcmp(options[i][0], option) == 0) 385 return (options[i][1]); 386 387 return (NULL); 388 } 389 390 /* 391 * Retrieve password information from the /etc/passwd.conf file, at the 392 * moment this is only for choosing the cipher to use. It could easily be 393 * used for other authentication methods as well. 394 */ 395 void 396 pw_getconf(char *data, size_t max, const char *key, const char *option) 397 { 398 FILE *fp; 399 char line[LINE_MAX], *p, *p2; 400 static char result[LINE_MAX]; 401 int got, found; 402 const char *cp; 403 404 got = 0; 405 found = 0; 406 result[0] = '\0'; 407 408 if ((fp = fopen(_PATH_PASSWDCONF, "r")) == NULL) { 409 if ((cp = pw_default(option)) != NULL) 410 strlcpy(data, p, max); 411 else 412 data[0] = '\0'; 413 return; 414 } 415 416 while (!found && (got || read_line(fp, line, LINE_MAX))) { 417 got = 0; 418 419 if (strncmp(key, line, strlen(key)) != 0 || 420 line[strlen(key)] != ':') 421 continue; 422 423 /* Now we found our specified key */ 424 while (read_line(fp, line, LINE_MAX)) { 425 /* Leaving key field */ 426 if (line[0] != '\0' && strchr(line + 1, ':') != NULL) { 427 got = 1; 428 break; 429 } 430 p2 = line; 431 if ((p = strsep(&p2, "=")) == NULL || p2 == NULL) 432 continue; 433 trim_whitespace(p); 434 435 if (!strncmp(p, option, strlen(option))) { 436 trim_whitespace(p2); 437 strcpy(result, p2); 438 found = 1; 439 break; 440 } 441 } 442 } 443 fclose(fp); 444 445 /* 446 * If we got no result and were looking for a default 447 * value, try hard coded defaults. 448 */ 449 450 if (strlen(result) == 0 && strcmp(key, "default") == 0 && 451 (cp = pw_default(option)) != NULL) 452 strlcpy(data, p, max); 453 else 454 strlcpy(data, result, max); 455 } 456
Indexes created Tue Sep 23 14:10:03 GMT 2025