busybox/loginutils/passwd.c

189 lines
4.9 KiB
C

/* vi: set sw=4 ts=4: */
/*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
#include "libbb.h"
#include <syslog.h>
static void nuke_str(char *str)
{
if (str) memset(str, 0, strlen(str));
}
static char* new_password(const struct passwd *pw, uid_t myuid, int algo)
{
char salt[sizeof("$N$XXXXXXXX")]; /* "$N$XXXXXXXX" or "XX" */
char *orig = (char*)"";
char *newp = NULL;
char *cipher = NULL;
char *cp = NULL;
char *ret = NULL; /* failure so far */
if (myuid && pw->pw_passwd[0]) {
orig = bb_askpass(0, "Old password:"); /* returns ptr to static */
if (!orig)
goto err_ret;
cipher = pw_encrypt(orig, pw->pw_passwd); /* returns ptr to static */
if (strcmp(cipher, pw->pw_passwd) != 0) {
syslog(LOG_WARNING, "incorrect password for '%s'",
pw->pw_name);
bb_do_delay(FAIL_DELAY);
puts("Incorrect password");
goto err_ret;
}
}
orig = xstrdup(orig); /* or else bb_askpass() will destroy it */
newp = bb_askpass(0, "New password:"); /* returns ptr to static */
if (!newp)
goto err_ret;
newp = xstrdup(newp); /* we are going to bb_askpass() again, so save it */
if (ENABLE_FEATURE_PASSWD_WEAK_CHECK
&& obscure(orig, newp, pw) && myuid)
goto err_ret; /* non-root is not allowed to have weak passwd */
cp = bb_askpass(0, "Retype password:");
if (!cp)
goto err_ret;
if (strcmp(cp, newp)) {
puts("Passwords don't match");
goto err_ret;
}
/*memset(salt, 0, sizeof(salt)); - why?*/
crypt_make_salt(salt, 1, 0); /* des */
if (algo) { /* MD5 */
strcpy(salt, "$1$");
crypt_make_salt(salt + 3, 4, 0);
}
ret = xstrdup(pw_encrypt(newp, salt)); /* returns ptr to static */
/* 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(cipher);
nuke_str(cp);
return ret;
}
int passwd_main(int argc, char **argv);
int passwd_main(int argc, char **argv)
{
enum {
OPT_algo = 0x1, /* -a - password algorithm */
OPT_lock = 0x2, /* -l - lock account */
OPT_unlock = 0x4, /* -u - unlock account */
OPT_delete = 0x8, /* -d - delete password */
OPT_lud = 0xe,
STATE_ALGO_md5 = 0x10,
/*STATE_ALGO_des = 0x20, not needed yet */
};
unsigned opt;
int rc;
const char *opt_a = "";
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;
struct spwd *result;
char buffer[256];
#endif
logmode = LOGMODE_BOTH;
openlog(applet_name, LOG_NOWAIT, LOG_AUTH);
opt = getopt32(argc, argv, "a:lud", &opt_a);
argc -= optind;
argv += optind;
if (strcasecmp(opt_a, "des") != 0) /* -a */
opt |= STATE_ALGO_md5;
//else
// opt |= STATE_ALGO_des;
myuid = getuid();
if ((opt & OPT_lud) && (!argc || myuid))
bb_show_usage();
myname = xstrdup(bb_getpwuid(NULL, myuid, -1));
name = argc ? argv[0] : myname;
pw = getpwnam(name);
if (!pw) bb_error_msg_and_die("unknown user %s", name);
if (myuid && pw->pw_uid != myuid) {
/* LOGMODE_BOTH */
bb_error_msg_and_die("%s can't change password for %s", myname, name);
}
filename = bb_path_passwd_file;
#if ENABLE_FEATURE_SHADOWPASSWDS
if (getspnam_r(pw->pw_name, &spw, buffer, sizeof(buffer), &result)) {
/* LOGMODE_BOTH */
bb_error_msg("no record of %s in %s, using %s",
name, bb_path_shadow_file,
bb_path_passwd_file);
} else {
filename = bb_path_shadow_file;
pw->pw_passwd = spw.sp_pwdp;
}
#endif
/* Decide what the new password will be */
newp = NULL;
c = pw->pw_passwd[0] - '!';
if (!(opt & OPT_lud)) {
if (myuid && !c) { /* passwd starts with '!' */
/* LOGMODE_BOTH */
bb_error_msg_and_die("cannot change "
"locked password for %s", name);
}
printf("Changing password for %s\n", name);
newp = new_password(pw, myuid, opt & STATE_ALGO_md5);
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 '!' */
newp = xstrdup(&pw->pw_passwd[1]);
} else if (opt & OPT_delete) {
newp = xstrdup("");
}
rlimit_fsize.rlim_cur = rlimit_fsize.rlim_max = 512L * 30000;
setrlimit(RLIMIT_FSIZE, &rlimit_fsize);
signal(SIGHUP, SIG_IGN);
signal(SIGINT, SIG_IGN);
signal(SIGQUIT, SIG_IGN);
umask(077);
xsetuid(0);
rc = update_passwd(filename, name, newp);
logmode = LOGMODE_BOTH;
if (rc < 0)
bb_error_msg_and_die("cannot update password file %s",
filename);
bb_info_msg("Password for %s changed by %s", name, myname);
if (ENABLE_FEATURE_CLEAN_UP) free(newp);
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;
}