/* 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 <fcntl.h>
-#include <signal.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
+#include "libbb.h"
#include <syslog.h>
-#include <unistd.h>
-#include <utmp.h>
-#include <sys/resource.h>
-#include <sys/stat.h>
-#include <sys/types.h>
-#include <ctype.h>
-#include <time.h>
-
-#include "busybox.h"
-
-
-#define SULOGIN_PROMPT "\nGive root password for system maintenance\n" \
- "(or type Control-D for normal startup):"
-
-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);
-}
+//static void catchalarm(int UNUSED_PARAM junk)
+//{
+// exit(EXIT_FAILURE);
+//}
-int sulogin_main(int argc, char **argv)
+
+int sulogin_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int sulogin_main(int argc UNUSED_PARAM, char **argv)
{
char *cp;
- char *device = NULL;
- const char *name = "root";
int timeout = 0;
-
-#define pass bb_common_bufsiz1
-
- struct passwd pwent;
struct passwd *pwd;
- const char * const *p;
+ const char *shell;
#if ENABLE_FEATURE_SHADOWPASSWDS
- struct spwd *spwd = NULL;
+ /* Using _r function to avoid pulling in static buffers */
+ char buffer[256];
+ struct spwd spw;
#endif
- openlog("sulogin", LOG_PID | LOG_NOWAIT, LOG_AUTH);
logmode = LOGMODE_BOTH;
- if (argc > 1) {
- if (strncmp(argv[1], "-t", 2) == 0) {
- if (argv[1][2] == '\0') { /* -t NN */
- if (argc > 2) {
- timeout = atoi(argv[2]);
- if (argc > 3) {
- device = argv[3];
- }
- }
- } else { /* -tNNN */
- timeout = atoi(&argv[1][2]);
- if (argc > 2) {
- device = argv[2];
- }
- }
- } else {
- device = argv[1];
- }
- if (device) {
- close(0);
- close(1);
- close(2);
- if (open(device, O_RDWR) == 0) {
- dup(0);
- dup(0);
- } else {
- /* Well, it will go only to syslog :) */
- bb_perror_msg_and_die("Cannot open %s", device);
- }
- }
+ openlog(applet_name, 0, LOG_AUTH);
+
+ opt_complementary = "t+"; /* -t N */
+ getopt32(argv, "t:", &timeout);
+ argv += optind;
+
+ if (argv[0]) {
+ close(0);
+ close(1);
+ dup(xopen(argv[0], O_RDWR));
+ close(2);
+ dup(0);
}
+
+ /* Malicious use like "sulogin /dev/sda"? */
if (!isatty(0) || !isatty(1) || !isatty(2)) {
- exit(EXIT_FAILURE);
- }
- if (access(bb_path_passwd_file, 0) == -1) {
- bb_error_msg_and_die("No password file");
+ 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);
+ /* Clear dangerous stuff, set PATH */
+ sanitize_env_if_suid();
- signal(SIGALRM, catchalarm);
- if (!(pwd = getpwnam(name))) {
- bb_error_msg_and_die("No password entry for `root'");
+ pwd = getpwuid(0);
+ if (!pwd) {
+ goto auth_error;
}
- pwent = *pwd;
+
#if ENABLE_FEATURE_SHADOWPASSWDS
- spwd = NULL;
- if (pwd && ((strcmp(pwd->pw_passwd, "x") == 0)
- || (strcmp(pwd->pw_passwd, "*") == 0))) {
- endspent();
- spwd = getspnam(name);
- if (spwd) {
- pwent.pw_passwd = spwd->sp_pwdp;
+ {
+ /* 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;
}
#endif
+
while (1) {
- cp = bb_askpass(timeout, SULOGIN_PROMPT);
+ char *encrypted;
+ int r;
+
+ /* cp points to a static buffer that is zeroed every time */
+ cp = bb_ask(STDIN_FILENO, timeout,
+ "Give root password for system maintenance\n"
+ "(or type Control-D for normal startup):");
+
if (!cp || !*cp) {
- puts("\n"); /* Why only on error path? */
- fflush(stdout);
- /* Why only to syslog? */
- syslog(LOG_INFO, "Normal startup");
- exit(EXIT_SUCCESS);
- } else {
- safe_strncpy(pass, cp, sizeof(pass));
- memset(cp, 0, strlen(cp));
+ bb_info_msg("Normal startup");
+ return 0;
}
- if (strcmp(pw_encrypt(pass, pwent.pw_passwd), pwent.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);
- bb_error_msg("Incorrect root password");
+ bb_error_msg("login incorrect");
}
- memset(pass, 0, strlen(pass));
- signal(SIGALRM, SIG_DFL);
- bb_info_msg("Entering System Maintenance Mode");
+ memset(cp, 0, strlen(cp));
+// signal(SIGALRM, SIG_DFL);
-#if ENABLE_SELINUX
- renew_current_security_context();
-#endif
+ bb_info_msg("System Maintenance Mode");
- run_shell(pwent.pw_shell, 1, 0, 0);
+ IF_SELINUX(renew_current_security_context());
+
+ shell = getenv("SUSHELL");
+ if (!shell)
+ shell = getenv("sushell");
+ if (!shell) {
+ shell = "/bin/sh";
+ if (pwd->pw_shell[0])
+ shell = pwd->pw_shell;
+ }
+ /* Exec login shell with no additional parameters. Never returns. */
+ run_shell(shell, 1, NULL, NULL);
- return 0;
+ auth_error:
+ bb_error_msg_and_die("no password entry for root");
}
projects / oweals / busybox.git / blobdiff