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https://github.com/sheumann/hush.git
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104 lines
2.7 KiB
C
104 lines
2.7 KiB
C
/* vi: set sw=4 ts=4: */
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/*
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* Mini su implementation for busybox
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*
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* Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
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*/
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#include "libbb.h"
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#include <syslog.h>
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#define SU_OPT_mp (3)
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#define SU_OPT_l (4)
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int su_main(int argc, char **argv);
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int su_main(int argc, char **argv)
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{
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unsigned flags;
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char *opt_shell = NULL;
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char *opt_command = NULL;
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const char *opt_username = "root";
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struct passwd *pw;
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uid_t cur_uid = getuid();
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const char *tty;
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char *old_user;
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flags = getopt32(argc, argv, "mplc:s:", &opt_command, &opt_shell);
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argc -= optind;
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argv += optind;
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if (argc && LONE_DASH(argv[0])) {
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flags |= SU_OPT_l;
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argc--;
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argv++;
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}
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/* get user if specified */
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if (argc) {
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opt_username = argv[0];
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// argc--;
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argv++;
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}
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if (ENABLE_FEATURE_SU_SYSLOG) {
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/* The utmp entry (via getlogin) is probably the best way to identify
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the user, especially if someone su's from a su-shell.
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But getlogin can fail -- usually due to lack of utmp entry.
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in this case resort to getpwuid. */
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old_user = xstrdup(USE_FEATURE_UTMP(getlogin() ? : ) (pw = getpwuid(cur_uid)) ? pw->pw_name : "");
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tty = ttyname(2) ? : "none";
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openlog(applet_name, 0, LOG_AUTH);
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}
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pw = getpwnam(opt_username);
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if (!pw)
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bb_error_msg_and_die("unknown id: %s", opt_username);
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/* Make sure pw->pw_shell is non-NULL. It may be NULL when NEW_USER
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is a username that is retrieved via NIS (YP), but that doesn't have
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a default shell listed. */
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if (!pw->pw_shell || !pw->pw_shell[0])
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pw->pw_shell = (char *)DEFAULT_SHELL;
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if ((cur_uid == 0) || correct_password(pw)) {
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if (ENABLE_FEATURE_SU_SYSLOG)
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syslog(LOG_NOTICE, "%c %s %s:%s",
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'+', tty, old_user, opt_username);
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} else {
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if (ENABLE_FEATURE_SU_SYSLOG)
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syslog(LOG_NOTICE, "%c %s %s:%s",
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'-', tty, old_user, opt_username);
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bb_error_msg_and_die("incorrect password");
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}
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if (ENABLE_FEATURE_CLEAN_UP && ENABLE_FEATURE_SU_SYSLOG) {
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closelog();
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free(old_user);
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}
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if (!opt_shell && (flags & SU_OPT_mp))
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opt_shell = getenv("SHELL");
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#if ENABLE_FEATURE_SU_CHECKS_SHELLS
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if (opt_shell && cur_uid && restricted_shell(pw->pw_shell)) {
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/* The user being su'd to has a nonstandard shell, and so is
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probably a uucp account or has restricted access. Don't
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compromise the account by allowing access with a standard
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shell. */
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bb_error_msg("using restricted shell");
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opt_shell = 0;
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}
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#endif
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if (!opt_shell)
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opt_shell = pw->pw_shell;
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change_identity(pw);
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setup_environment(opt_shell, flags & SU_OPT_l, !(flags & SU_OPT_mp), pw);
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USE_SELINUX(set_current_security_context(NULL);)
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/* Never returns */
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run_shell(opt_shell, flags & SU_OPT_l, opt_command, (const char**)argv);
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return EXIT_FAILURE;
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}
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