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- /* vi: set sw=4 ts=4: */
- /*
- * Licensed under GPLv2 or later, see file LICENSE in this source tree.
- */
- //config:config PASSWD
- //config: bool "passwd (21 kb)"
- //config: default y
- //config: select FEATURE_SYSLOG
- //config: help
- //config: passwd changes passwords for user and group accounts. A normal user
- //config: may only change the password for his/her own account, the super user
- //config: may change the password for any account. The administrator of a group
- //config: may change the password for the group.
- //config:
- //config: Note that busybox binary must be setuid root for this applet to
- //config: work properly.
- //config:
- //config:config FEATURE_PASSWD_WEAK_CHECK
- //config: bool "Check new passwords for weakness"
- //config: default y
- //config: depends on PASSWD
- //config: help
- //config: With this option passwd will refuse new passwords which are "weak".
- //applet:/* Needs to be run by root or be suid root - needs to change /etc/{passwd,shadow}: */
- //applet:IF_PASSWD(APPLET(passwd, BB_DIR_USR_BIN, BB_SUID_REQUIRE))
- //kbuild:lib-$(CONFIG_PASSWD) += passwd.o
- //usage:#define passwd_trivial_usage
- //usage: "[-a ALG] [-dlu] [USER]"
- //usage:#define passwd_full_usage "\n\n"
- //usage: "Change USER's password (default: current user)"
- //usage: "\n"
- //usage: "\n -a ALG "CRYPT_METHODS_HELP_STR
- //usage: "\n -d Set password to ''"
- //usage: "\n -l Lock (disable) account"
- //usage: "\n -u Unlock (enable) account"
- #include "libbb.h"
- #include <syslog.h>
- static char* new_password(const struct passwd *pw, uid_t myuid, const char *algo)
- {
- char salt[MAX_PW_SALT_LEN];
- char *orig = NULL;
- char *newp = NULL;
- char *cp = NULL;
- char *ret = NULL; /* failure so far */
- if (myuid != 0 && pw->pw_passwd[0]) {
- char *encrypted;
- orig = bb_ask_noecho_stdin("Old password: "); /* returns malloced str */
- if (!orig)
- goto err_ret;
- encrypted = pw_encrypt(orig, pw->pw_passwd, 1); /* returns malloced str */
- if (strcmp(encrypted, pw->pw_passwd) != 0) {
- syslog(LOG_WARNING, "incorrect password for %s", pw->pw_name);
- pause_after_failed_login();
- puts("Incorrect password");
- goto err_ret;
- }
- if (ENABLE_FEATURE_CLEAN_UP)
- free(encrypted);
- }
- newp = bb_ask_noecho_stdin("New password: "); /* returns malloced str */
- if (!newp)
- goto err_ret;
- if (ENABLE_FEATURE_PASSWD_WEAK_CHECK
- && obscure(orig, newp, pw) /* NB: passing NULL orig is ok */
- && myuid != 0
- ) {
- goto err_ret; /* non-root is not allowed to have weak passwd */
- }
- cp = bb_ask_noecho_stdin("Retype password: ");
- if (!cp)
- goto err_ret;
- if (strcmp(cp, newp) != 0) {
- puts("Passwords don't match");
- goto err_ret;
- }
- crypt_make_pw_salt(salt, algo);
- /* pw_encrypt returns malloced str */
- ret = pw_encrypt(newp, salt, 1);
- /* whee, success! */
- err_ret:
- nuke_str(orig);
- if (ENABLE_FEATURE_CLEAN_UP) free(orig);
- nuke_str(newp);
- if (ENABLE_FEATURE_CLEAN_UP) free(newp);
- nuke_str(cp);
- if (ENABLE_FEATURE_CLEAN_UP) free(cp);
- return ret;
- }
- int passwd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
- int passwd_main(int argc UNUSED_PARAM, char **argv)
- {
- enum {
- OPT_algo = (1 << 0), /* -a - password algorithm */
- OPT_lock = (1 << 1), /* -l - lock account */
- OPT_unlock = (1 << 2), /* -u - unlock account */
- OPT_delete = (1 << 3), /* -d - delete password */
- OPT_lud = OPT_lock | OPT_unlock | OPT_delete,
- };
- unsigned opt;
- int rc;
- const char *opt_a = CONFIG_FEATURE_DEFAULT_PASSWD_ALGO;
- const char *filename;
- char *myname;
- char *name;
- char *newp;
- struct passwd *pw;
- uid_t myuid;
- struct rlimit rlimit_fsize;
- char c;
- #if ENABLE_FEATURE_SHADOWPASSWDS
- /* Using _r function to avoid pulling in static buffers */
- struct spwd spw;
- char buffer[256];
- #endif
- logmode = LOGMODE_BOTH;
- openlog(applet_name, 0, LOG_AUTH);
- opt = getopt32(argv, "a:lud", &opt_a);
- //argc -= optind;
- argv += optind;
- myuid = getuid();
- /* -l, -u, -d require root priv and username argument */
- if ((opt & OPT_lud) && (myuid != 0 || !argv[0]))
- bb_show_usage();
- /* Will complain and die if username not found */
- myname = xstrdup(xuid2uname(myuid));
- name = argv[0] ? argv[0] : myname;
- pw = xgetpwnam(name);
- if (myuid != 0 && pw->pw_uid != myuid) {
- /* LOGMODE_BOTH */
- bb_error_msg_and_die("%s can't change password for %s", myname, name);
- }
- #if ENABLE_FEATURE_SHADOWPASSWDS
- {
- /* 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;
- errno = 0;
- if (getspnam_r(pw->pw_name, &spw, buffer, sizeof(buffer), &result) != 0
- || !result /* no error, but no record found either */
- || strcmp(result->sp_namp, pw->pw_name) != 0 /* paranoia */
- ) {
- if (errno != ENOENT) {
- /* LOGMODE_BOTH */
- bb_perror_msg("no record of %s in %s, using %s",
- name, bb_path_shadow_file,
- bb_path_passwd_file);
- }
- /* else: /etc/shadow does not exist,
- * apparently we are on a shadow-less system,
- * no surprise there */
- } else {
- pw->pw_passwd = result->sp_pwdp;
- }
- }
- #endif
- /* Decide what the new password will be */
- newp = NULL;
- c = pw->pw_passwd[0] - '!';
- if (!(opt & OPT_lud)) {
- if (myuid != 0 && !c) { /* passwd starts with '!' */
- /* LOGMODE_BOTH */
- bb_error_msg_and_die("can't change "
- "locked password for %s", name);
- }
- printf("Changing password for %s\n", name);
- newp = new_password(pw, myuid, opt_a);
- if (!newp) {
- logmode = LOGMODE_STDIO;
- bb_error_msg_and_die("password for %s is unchanged", name);
- }
- } else if (opt & OPT_lock) {
- if (!c)
- goto skip; /* passwd starts with '!' */
- newp = xasprintf("!%s", pw->pw_passwd);
- } else if (opt & OPT_unlock) {
- if (c)
- goto skip; /* not '!' */
- /* pw->pw_passwd points to static storage,
- * strdup'ing to avoid nasty surprizes */
- newp = xstrdup(&pw->pw_passwd[1]);
- } else if (opt & OPT_delete) {
- newp = (char*)"";
- }
- rlimit_fsize.rlim_cur = rlimit_fsize.rlim_max = 512L * 30000;
- setrlimit(RLIMIT_FSIZE, &rlimit_fsize);
- bb_signals(0
- + (1 << SIGHUP)
- + (1 << SIGINT)
- + (1 << SIGQUIT)
- , SIG_IGN);
- umask(077);
- xsetuid(0);
- #if ENABLE_FEATURE_SHADOWPASSWDS
- filename = bb_path_shadow_file;
- rc = update_passwd(bb_path_shadow_file, name, newp, NULL);
- if (rc > 0)
- /* password in /etc/shadow was updated */
- newp = (char*) "x";
- if (rc >= 0)
- /* 0 = /etc/shadow missing (not an error), >0 = passwd changed in /etc/shadow */
- #endif
- {
- filename = bb_path_passwd_file;
- rc = update_passwd(bb_path_passwd_file, name, newp, NULL);
- }
- /* LOGMODE_BOTH */
- if (rc < 0)
- bb_error_msg_and_die("can't update password file %s", filename);
- bb_info_msg("password for %s changed by %s", name, myname);
- /*if (ENABLE_FEATURE_CLEAN_UP) free(newp); - can't, it may be non-malloced */
- skip:
- if (!newp) {
- bb_error_msg_and_die("password for %s is already %slocked",
- name, (opt & OPT_unlock) ? "un" : "");
- }
- if (ENABLE_FEATURE_CLEAN_UP)
- free(myname);
- return 0;
- }
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