1 /* $OpenBSD: chpass.c,v 1.36 2008/07/08 21:30:15 sobrado Exp $ */ 2 /* $NetBSD: chpass.c,v 1.8 1996/05/15 21:50:43 jtc Exp $ */ 3 4 /*- 5 * Copyright (c) 1988, 1993, 1994 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 #ifndef lint 34 static char copyright[] = 35 "@(#) Copyright (c) 1988, 1993, 1994\n\ 36 The Regents of the University of California. All rights reserved.\n"; 37 #endif /* not lint */ 38 39 #ifndef lint 40 #if 0 41 static char sccsid[] = "@(#)chpass.c 8.4 (Berkeley) 4/2/94"; 42 #else 43 static char rcsid[] = "$OpenBSD: chpass.c,v 1.36 2008/07/08 21:30:15 sobrado Exp $"; 44 #endif 45 #endif /* not lint */ 46 47 #include <sys/param.h> 48 #include <sys/resource.h> 49 #include <sys/stat.h> 50 #include <sys/time.h> 51 #include <sys/uio.h> 52 53 #include <err.h> 54 #include <errno.h> 55 #include <fcntl.h> 56 #include <paths.h> 57 #include <pwd.h> 58 #include <signal.h> 59 #include <stdio.h> 60 #include <stdlib.h> 61 #include <string.h> 62 #include <unistd.h> 63 #include <util.h> 64 65 #include "chpass.h" 66 67 extern char *__progname; 68 69 enum { NEWSH, LOADENTRY, EDITENTRY } op; 70 uid_t uid; 71 #ifdef YP 72 int use_yp; 73 int force_yp = 0; 74 #endif 75 76 void baduser(void); 77 void kbintr(int); 78 void usage(void); 79 80 int 81 main(int argc, char *argv[]) 82 { 83 struct passwd *pw = NULL, *opw = NULL, lpw; 84 int i, ch, pfd, tfd, dfd; 85 char *tz, *arg = NULL; 86 sigset_t fullset; 87 88 #ifdef YP 89 use_yp = _yp_check(NULL); 90 #endif 91 /* We need to use the system timezone for date conversions. */ 92 if ((tz = getenv("TZ")) != NULL) { 93 unsetenv("TZ"); 94 tzset(); 95 setenv("TZ", tz, 1); 96 } 97 98 op = EDITENTRY; 99 while ((ch = getopt(argc, argv, "a:s:ly")) != -1) 100 switch(ch) { 101 case 'a': 102 op = LOADENTRY; 103 arg = optarg; 104 break; 105 case 's': 106 op = NEWSH; 107 arg = optarg; 108 break; 109 #ifdef YP 110 case 'l': 111 use_yp = 0; 112 break; 113 case 'y': 114 if (!use_yp) { 115 warnx("YP not in use."); 116 usage(); 117 } 118 force_yp = 1; 119 break; 120 #endif 121 case '?': 122 default: 123 usage(); 124 } 125 argc -= optind; 126 argv += optind; 127 128 #ifdef YP 129 if (op == LOADENTRY && use_yp) 130 errx(1, "cannot load using YP, use -l to load local."); 131 #endif 132 uid = getuid(); 133 134 if (op == EDITENTRY || op == NEWSH) 135 switch(argc) { 136 case 0: 137 pw = getpwuid(uid); 138 #ifdef YP 139 if (pw && !force_yp) 140 use_yp = 0; 141 else if (use_yp) 142 pw = ypgetpwuid(uid); 143 #endif /* YP */ 144 if (!pw) 145 errx(1, "unknown user: uid %u", uid); 146 break; 147 case 1: 148 pw = getpwnam(*argv); 149 #ifdef YP 150 if (pw && !force_yp) 151 use_yp = 0; 152 else if (use_yp) 153 pw = ypgetpwnam(*argv); 154 #endif /* YP */ 155 if (!pw) 156 errx(1, "unknown user: %s", *argv); 157 if (uid && uid != pw->pw_uid) 158 baduser(); 159 break; 160 default: 161 usage(); 162 } 163 164 if (op == LOADENTRY) { 165 if (argc != 0) 166 errx(1, "option -a does not accept user argument"); 167 if (uid) 168 baduser(); 169 pw = &lpw; 170 if (!pw_scan(arg, pw, NULL)) 171 exit(1); 172 opw = getpwnam(pw->pw_name); 173 } 174 if (opw == NULL && (opw = pw_dup(pw)) == NULL) 175 err(1, NULL); 176 177 /* Edit the user passwd information if requested. */ 178 if (op == EDITENTRY) { 179 char tempname[] = _PATH_VARTMP "pw.XXXXXXXXXX"; 180 int edit_status; 181 182 if ((pw = pw_dup(pw)) == NULL) 183 pw_error(NULL, 1, 1); 184 dfd = mkstemp(tempname); 185 if (dfd == -1 || fcntl(dfd, F_SETFD, 1) == -1) 186 pw_error(tempname, 1, 1); 187 display(tempname, dfd, pw); 188 edit_status = edit(tempname, pw); 189 close(dfd); 190 unlink(tempname); 191 192 switch (edit_status) { 193 case EDIT_OK: 194 break; 195 case EDIT_NOCHANGE: 196 pw_error(NULL, 0, 0); 197 break; 198 case EDIT_ERROR: 199 default: 200 pw_error(tempname, 1, 1); 201 break; 202 } 203 } 204 205 if (op == NEWSH) { 206 /* protect p_shell -- it thinks NULL is /bin/sh */ 207 if (!arg[0]) 208 usage(); 209 if (p_shell(arg, pw, NULL)) 210 pw_error(NULL, 0, 1); 211 } 212 213 /* Drop user's real uid and block all signals to avoid a DoS. */ 214 setuid(0); 215 sigfillset(&fullset); 216 sigdelset(&fullset, SIGINT); 217 sigprocmask(SIG_BLOCK, &fullset, NULL); 218 219 /* Get the passwd lock file and open the passwd file for reading. */ 220 pw_init(); 221 for (i = 1; (tfd = pw_lock(0)) == -1; i++) { 222 if (i == 4) 223 (void)fputs("Attempting lock password file, " 224 "please wait or press ^C to abort", stderr); 225 (void)signal(SIGINT, kbintr); 226 if (i % 16 == 0) 227 fputc('.', stderr); 228 usleep(250000); 229 (void)signal(SIGINT, SIG_IGN); 230 } 231 if (i >= 4) 232 fputc('\n', stderr); 233 pfd = open(_PATH_MASTERPASSWD, O_RDONLY, 0); 234 if (pfd == -1 || fcntl(pfd, F_SETFD, 1) == -1) 235 pw_error(_PATH_MASTERPASSWD, 1, 1); 236 237 #ifdef YP 238 if (use_yp) { 239 if (pw_yp(pw, uid)) 240 pw_error(NULL, 0, 1); 241 else { 242 pw_abort(); 243 exit(0); 244 } 245 } else 246 #endif /* YP */ 247 { 248 /* Copy the passwd file to the lock file, updating pw. */ 249 pw_copy(pfd, tfd, pw, opw); 250 251 /* If username changed we need to rebuild the entire db. */ 252 arg = !strcmp(opw->pw_name, pw->pw_name) ? pw->pw_name : NULL; 253 254 /* Now finish the passwd file update. */ 255 if (pw_mkdb(arg, 0) == -1) 256 pw_error(NULL, 0, 1); 257 } 258 259 exit(0); 260 } 261 262 void 263 baduser(void) 264 { 265 266 errx(1, "%s", strerror(EACCES)); 267 } 268 269 /* ARGSUSED */ 270 void 271 kbintr(int signo) 272 { 273 struct iovec iv[5]; 274 275 iv[0].iov_base = "\n"; 276 iv[0].iov_len = 1; 277 iv[1].iov_base = __progname; 278 iv[1].iov_len = strlen(__progname); 279 iv[2].iov_base = ": "; 280 iv[2].iov_len = 2; 281 iv[3].iov_base = _PATH_MASTERPASSWD; 282 iv[3].iov_len = sizeof(_PATH_MASTERPASSWD) - 1; 283 iv[4].iov_base = " unchanged\n"; 284 iv[4].iov_len = 11; 285 writev(STDERR_FILENO, iv, 5); 286 287 _exit(1); 288 } 289 290 void 291 usage(void) 292 { 293 294 #ifdef YP 295 (void)fprintf(stderr, 296 "usage: %s [-l%s] [-s newshell] [user]\n", 297 __progname, use_yp ? "y" : ""); 298 (void)fprintf(stderr, 299 " %s [-l] -a list\n", __progname); 300 #else 301 (void)fprintf(stderr, "usage: %s [-s newshell] [user]\n", __progname); 302 (void)fprintf(stderr, " %s -a list\n", __progname); 303 #endif 304 exit(1); 305 } 306