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/* vi: set sw=4 ts=4: */
/*
* Mini sulogin implementation for busybox
*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
#include <syslog.h>
#include "busybox.h"
static const char * const forbid[] = {
"ENV",
"BASH_ENV",
"HOME",
"IFS",
"PATH",
"SHELL",
"LD_LIBRARY_PATH",
"LD_PRELOAD",
"LD_TRACE_LOADED_OBJECTS",
"LD_BIND_NOW",
"LD_AOUT_LIBRARY_PATH",
"LD_AOUT_PRELOAD",
"LD_NOWARN",
"LD_KEEPDIR",
(char *) 0
};
static void catchalarm(int ATTRIBUTE_UNUSED junk)
{
exit(EXIT_FAILURE);
}
int sulogin_main(int argc, char **argv)
{
char *cp;
int timeout = 0;
char *timeout_arg;
const char * const *p;
struct passwd *pwd;
struct spwd *spwd;
logmode = LOGMODE_BOTH;
openlog(bb_applet_name, 0, LOG_AUTH);
if (bb_getopt_ulflags (argc, argv, "t:", &timeout_arg)) {
if (safe_strtoi(timeout_arg, &timeout)) {
timeout = 0;
}
}
if (argv[optind]) {
close(0);
close(1);
close(2);
dup(xopen(argv[optind], O_RDWR));
dup(0);
}
if (!isatty(0) || !isatty(1) || !isatty(2)) {
logmode = LOGMODE_SYSLOG;
bb_error_msg_and_die("not a tty");
}
/* Clear out anything dangerous from the environment */
for (p = forbid; *p; p++)
unsetenv(*p);
signal(SIGALRM, catchalarm);
if (!(pwd = getpwuid(0))) {
goto auth_error;
}
if (ENABLE_FEATURE_SHADOWPASSWDS) {
if (!(spwd = getspnam(pwd->pw_name))) {
goto auth_error;
}
pwd->pw_passwd = spwd->sp_pwdp;
}
while (1) {
/* cp points to a static buffer that is zeroed every time */
cp = bb_askpass(timeout,
"Give root password for system maintenance\n"
"(or type Control-D for normal startup):");
if (!cp || !*cp) {
bb_info_msg("Normal startup");
return 0;
}
if (strcmp(pw_encrypt(cp, pwd->pw_passwd), pwd->pw_passwd) == 0) {
break;
}
bb_do_delay(FAIL_DELAY);
bb_error_msg("login incorrect");
}
memset(cp, 0, strlen(cp));
signal(SIGALRM, SIG_DFL);
bb_info_msg("System Maintenance Mode");
USE_SELINUX(renew_current_security_context());
run_shell(pwd->pw_shell, 1, 0, 0);
/* never returns */
auth_error:
bb_error_msg_and_die("no password entry for `root'");
}
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