remove now-unneeded memset

[oweals/busybox.git] / loginutils / sulogin.c

diff --git a/loginutils/sulogin.c b/loginutils/sulogin.c
index f633fbbf1b793543b2c38b2916741e978b4a5a94..6e3d3b0190922c08ca11c6a366f450246a540e7b 100644 (file)
--- a/loginutils/sulogin.c
+++ b/loginutils/sulogin.c
@@ -5,77 +5,51 @@
  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
  */
 
-#include <syslog.h>
-
 #include "libbb.h"
+#include <syslog.h>
 
-static const char forbid[] ALIGN1 =
-       "ENV" "\0"
-       "BASH_ENV" "\0"
-       "HOME" "\0"
-       "IFS" "\0"
-       "PATH" "\0"
-       "SHELL" "\0"
-       "LD_LIBRARY_PATH" "\0"
-       "LD_PRELOAD" "\0"
-       "LD_TRACE_LOADED_OBJECTS" "\0"
-       "LD_BIND_NOW" "\0"
-       "LD_AOUT_LIBRARY_PATH" "\0"
-       "LD_AOUT_PRELOAD" "\0"
-       "LD_NOWARN" "\0"
-       "LD_KEEPDIR" "\0";
-
-//static void catchalarm(int ATTRIBUTE_UNUSED junk)
+//static void catchalarm(int UNUSED_PARAM junk)
 //{
 //     exit(EXIT_FAILURE);
 //}
 
 
 int sulogin_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
-int sulogin_main(int argc, char **argv)
+int sulogin_main(int argc UNUSED_PARAM, char **argv)
 {
        char *cp;
        int timeout = 0;
-       char *timeout_arg;
-       const char *p;
        struct passwd *pwd;
        const char *shell;
 #if ENABLE_FEATURE_SHADOWPASSWDS
        /* Using _r function to avoid pulling in static buffers */
        char buffer[256];
        struct spwd spw;
-       struct spwd *result;
 #endif
 
        logmode = LOGMODE_BOTH;
        openlog(applet_name, 0, LOG_AUTH);
 
-       if (getopt32(argv, "t:", &timeout_arg)) {
-               timeout = xatoi_u(timeout_arg);
-       }
+       opt_complementary = "t+"; /* -t N */
+       getopt32(argv, "t:", &timeout);
+       argv += optind;
 
-       if (argv[optind]) {
+       if (argv[0]) {
                close(0);
                close(1);
-               dup(xopen(argv[optind], O_RDWR));
+               dup(xopen(argv[0], O_RDWR));
                close(2);
                dup(0);
        }
 
+       /* Malicious use like "sulogin /dev/sda"? */
        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 */
-       p = forbid;
-       do {
-               unsetenv(p);
-               p += strlen(p) + 1;
-       } while (*p);
-
-// bb_askpass() already handles this
-//     signal(SIGALRM, catchalarm);
+       /* Clear dangerous stuff, set PATH */
+       sanitize_env_if_suid();
 
        pwd = getpwuid(0);
        if (!pwd) {
@@ -83,15 +57,24 @@ int sulogin_main(int argc, char **argv)
        }
 
 #if ENABLE_FEATURE_SHADOWPASSWDS
-       if (getspnam_r(pwd->pw_name, &spw, buffer, sizeof(buffer), &result)) {
-               goto auth_error;
+       {
+               /* getspnam_r may return 0 yet set result to NULL.
+                * At least glibc 2.4 does this. Be extra paranoid here. */
+               struct spwd *result = NULL;
+               int r = getspnam_r(pwd->pw_name, &spw, buffer, sizeof(buffer), &result);
+               if (r || !result) {
+                       goto auth_error;
+               }
+               pwd->pw_passwd = result->sp_pwdp;
        }
-       pwd->pw_passwd = spw.sp_pwdp;
 #endif
 
        while (1) {
+               char *encrypted;
+               int r;
+
                /* cp points to a static buffer that is zeroed every time */
-               cp = bb_askpass(timeout,
+               cp = bb_ask(STDIN_FILENO, timeout,
                                "Give root password for system maintenance\n"
                                "(or type Control-D for normal startup):");
 
@@ -99,7 +82,10 @@ int sulogin_main(int argc, char **argv)
                        bb_info_msg("Normal startup");
                        return 0;
                }
-               if (strcmp(pw_encrypt(cp, pwd->pw_passwd), pwd->pw_passwd) == 0) {
+               encrypted = pw_encrypt(cp, pwd->pw_passwd, 1);
+               r = strcmp(encrypted, pwd->pw_passwd);
+               free(encrypted);
+               if (r == 0) {
                        break;
                }
                bb_do_delay(FAIL_DELAY);
@@ -110,7 +96,7 @@ int sulogin_main(int argc, char **argv)
 
        bb_info_msg("System Maintenance Mode");
 
-       USE_SELINUX(renew_current_security_context());
+       IF_SELINUX(renew_current_security_context());
 
        shell = getenv("SUSHELL");
        if (!shell)