/* $OpenBSD: chpass.c,v 1.37 2009/10/27 23:59:36 deraadt Exp $ */ /* $NetBSD: chpass.c,v 1.8 1996/05/15 21:50:43 jtc Exp $ */ /*- * Copyright (c) 1988, 1993, 1994 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "chpass.h" extern char *__progname; enum { NEWSH, LOADENTRY, EDITENTRY } op; uid_t uid; #ifdef YP int use_yp; int force_yp = 0; #endif void baduser(void); void kbintr(int); void usage(void); int main(int argc, char *argv[]) { struct passwd *pw = NULL, *opw = NULL, lpw; int i, ch, pfd, tfd, dfd; char *tz, *arg = NULL; sigset_t fullset; #ifdef YP use_yp = _yp_check(NULL); #endif /* We need to use the system timezone for date conversions. */ if ((tz = getenv("TZ")) != NULL) { unsetenv("TZ"); tzset(); setenv("TZ", tz, 1); } op = EDITENTRY; while ((ch = getopt(argc, argv, "a:s:ly")) != -1) switch(ch) { case 'a': op = LOADENTRY; arg = optarg; break; case 's': op = NEWSH; arg = optarg; break; #ifdef YP case 'l': use_yp = 0; break; case 'y': if (!use_yp) { warnx("YP not in use."); usage(); } force_yp = 1; break; #endif case '?': default: usage(); } argc -= optind; argv += optind; #ifdef YP if (op == LOADENTRY && use_yp) errx(1, "cannot load using YP, use -l to load local."); #endif uid = getuid(); if (op == EDITENTRY || op == NEWSH) switch(argc) { case 0: pw = getpwuid(uid); #ifdef YP if (pw && !force_yp) use_yp = 0; else if (use_yp) pw = ypgetpwuid(uid); #endif /* YP */ if (!pw) errx(1, "unknown user: uid %u", uid); break; case 1: pw = getpwnam(*argv); #ifdef YP if (pw && !force_yp) use_yp = 0; else if (use_yp) pw = ypgetpwnam(*argv); #endif /* YP */ if (!pw) errx(1, "unknown user: %s", *argv); if (uid && uid != pw->pw_uid) baduser(); break; default: usage(); } if (op == LOADENTRY) { if (argc != 0) errx(1, "option -a does not accept user argument"); if (uid) baduser(); pw = &lpw; if (!pw_scan(arg, pw, NULL)) exit(1); opw = getpwnam(pw->pw_name); } if (opw == NULL && (opw = pw_dup(pw)) == NULL) err(1, NULL); /* Edit the user passwd information if requested. */ if (op == EDITENTRY) { char tempname[] = _PATH_VARTMP "pw.XXXXXXXXXX"; int edit_status; if ((pw = pw_dup(pw)) == NULL) pw_error(NULL, 1, 1); dfd = mkstemp(tempname); if (dfd == -1 || fcntl(dfd, F_SETFD, 1) == -1) pw_error(tempname, 1, 1); display(tempname, dfd, pw); edit_status = edit(tempname, pw); close(dfd); unlink(tempname); switch (edit_status) { case EDIT_OK: break; case EDIT_NOCHANGE: pw_error(NULL, 0, 0); break; case EDIT_ERROR: default: pw_error(tempname, 1, 1); break; } } if (op == NEWSH) { /* protect p_shell -- it thinks NULL is /bin/sh */ if (!arg[0]) usage(); if (p_shell(arg, pw, NULL)) pw_error(NULL, 0, 1); } /* Drop user's real uid and block all signals to avoid a DoS. */ setuid(0); sigfillset(&fullset); sigdelset(&fullset, SIGINT); sigprocmask(SIG_BLOCK, &fullset, NULL); /* Get the passwd lock file and open the passwd file for reading. */ pw_init(); for (i = 1; (tfd = pw_lock(0)) == -1; i++) { if (i == 4) (void)fputs("Attempting lock password file, " "please wait or press ^C to abort", stderr); (void)signal(SIGINT, kbintr); if (i % 16 == 0) fputc('.', stderr); usleep(250000); (void)signal(SIGINT, SIG_IGN); } if (i >= 4) fputc('\n', stderr); pfd = open(_PATH_MASTERPASSWD, O_RDONLY, 0); if (pfd == -1 || fcntl(pfd, F_SETFD, 1) == -1) pw_error(_PATH_MASTERPASSWD, 1, 1); #ifdef YP if (use_yp) { if (pw_yp(pw, uid)) pw_error(NULL, 0, 1); else { pw_abort(); exit(0); } } else #endif /* YP */ { /* Copy the passwd file to the lock file, updating pw. */ pw_copy(pfd, tfd, pw, opw); /* If username changed we need to rebuild the entire db. */ arg = !strcmp(opw->pw_name, pw->pw_name) ? pw->pw_name : NULL; /* Now finish the passwd file update. */ if (pw_mkdb(arg, 0) == -1) pw_error(NULL, 0, 1); } exit(0); } void baduser(void) { errx(1, "%s", strerror(EACCES)); } /* ARGSUSED */ void kbintr(int signo) { struct iovec iv[5]; iv[0].iov_base = "\n"; iv[0].iov_len = 1; iv[1].iov_base = __progname; iv[1].iov_len = strlen(__progname); iv[2].iov_base = ": "; iv[2].iov_len = 2; iv[3].iov_base = _PATH_MASTERPASSWD; iv[3].iov_len = sizeof(_PATH_MASTERPASSWD) - 1; iv[4].iov_base = " unchanged\n"; iv[4].iov_len = 11; writev(STDERR_FILENO, iv, 5); _exit(1); } void usage(void) { #ifdef YP (void)fprintf(stderr, "usage: %s [-l%s] [-s newshell] [user]\n", __progname, use_yp ? "y" : ""); (void)fprintf(stderr, " %s [-l] -a list\n", __progname); #else (void)fprintf(stderr, "usage: %s [-s newshell] [user]\n", __progname); (void)fprintf(stderr, " %s -a list\n", __progname); #endif exit(1); }