/* $OpenBSD: chpass.c,v 1.47 2021/07/12 15:09:19 beck 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 "chpass.h" extern char *__progname; enum { NEWSH, LOADENTRY, EDITENTRY } op; uid_t uid; 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; /* 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:")) != -1) switch(ch) { case 'a': op = LOADENTRY; arg = optarg; break; case 's': op = NEWSH; arg = optarg; break; case '?': default: usage(); } argc -= optind; argv += optind; uid = getuid(); if (op == EDITENTRY || op == NEWSH) switch(argc) { case 0: pw = getpwuid_shadow(uid); if (!pw) errx(1, "unknown user: uid %u", uid); break; case 1: pw = getpwnam_shadow(*argv); 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_shadow(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 = mkostemp(tempname, O_CLOEXEC); if (dfd == -1) pw_error(tempname, 1, 1); display(tempname, dfd, pw); if (unveil(_PATH_BSHELL, "x") == -1) err(1, "unveil %s", _PATH_BSHELL); if (unveil(_PATH_SHELLS, "r") == -1) err(1, "unveil %s", _PATH_SHELLS); if (unveil(tempname, "rc") == -1) err(1, "unveil %s", tempname); if (pledge("stdio rpath wpath cpath id proc exec unveil", NULL) == -1) err(1, "pledge"); 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) { if (unveil(_PATH_SHELLS, "r") == -1) err(1, "unveil %s", _PATH_SHELLS); if (pledge("stdio rpath wpath cpath id proc exec unveil", NULL) == -1) err(1, "pledge"); /* 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); if (unveil(_PATH_MASTERPASSWD_LOCK, "rwc") == -1) err(1, "unveil %s", _PATH_MASTERPASSWD_LOCK); if (unveil(_PATH_MASTERPASSWD, "r") == -1) err(1, "unveil %s", _PATH_MASTERPASSWD); if (unveil(_PATH_PWD_MKDB, "x") == -1) err(1, "unveil %s", _PATH_PWD_MKDB); if (pledge("stdio rpath wpath cpath proc exec", NULL) == -1) err(1, "pledge"); /* 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 to 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|O_CLOEXEC, 0); if (pfd == -1) pw_error(_PATH_MASTERPASSWD, 1, 1); /* 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) { dprintf(STDERR_FILENO, "\n%s: %s unchanged\n", __progname, _PATH_MASTERPASSWD); _exit(1); } void usage(void) { (void)fprintf(stderr, "usage: %s [-s newshell] [user]\n", __progname); (void)fprintf(stderr, " %s -a list\n", __progname); exit(1); }