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/* passwd.c - Program to update user password.
*
* Copyright 2012 Ashwini Kumar <ak.ashwini@gmail.com>
* Modified 2012 Jason Kyungwan Han <asura321@gmail.com>
*
* http://refspecs.linuxfoundation.org/LSB_4.1.0/LSB-Core-generic/LSB-Core-generic/passwd.html
USE_PASSWD(NEWTOY(passwd, ">1a:dlu", TOYFLAG_STAYROOT|TOYFLAG_USR|TOYFLAG_BIN))
config PASSWD
bool "passwd"
default y
depends on TOYBOX_SHADOW
help
usage: passwd [-a ALGO] [-dlu] <account name>
update user's authentication tokens. Default : current user
-a ALGO Encryption method (des, md5, sha256, sha512) default: des
-d Set password to ''
-l Lock (disable) account
-u Unlock (enable) account
config PASSWD_SAD
bool "Add sad password checking heuristics"
default n
depends on PASSWD
help
Password changes are checked to make sure they're at least 6 chars long,
don't include the entire username (but not a subset of it), or the entire
previous password (but changing password1, password2, password3 is fine).
This heuristic accepts "aaaaaa" and "123456".
*/
#define FOR_passwd
#include "toys.h"
GLOBALS(
char *a;
)
// Sad advisory heuristic, won't find password1 password2 password3...
static void weak_check(char *new, char *old, char *user)
{
char *msg = 0;
if (strlen(new) < 6) msg = "too short";
if (*new) {
if (strnstr(new, user) || strnstr(user, new)) msg = "user";
if (*old && (strnstr(new, old) || strnstr(old, new))) msg = "old";
}
if (msg) xprintf("BAD PASSWORD: %s\n",msg);
}
void passwd_main(void)
{
uid_t myuid;
struct passwd *pw = 0;
struct spwd *sp;
char *pass, *name, *encrypted = 0, salt[MAX_SALT_LEN];
int ret = -1;
// If we're root or not -lud, load specified user. Exit if not allowed.
if (!(myuid = getuid()) || !(toys.optflags&(FLAG_l|FLAG_u|FLAG_d))) {
if (*toys.optargs) pw = xgetpwnam(*toys.optargs);
else pw = xgetpwuid(myuid);
}
if (!pw || (myuid && (myuid != pw->pw_uid))) error_exit("Not root");
// Get password from /etc/passwd or /etc/shadow
// TODO: why still support non-shadow passwords...?
name = pw->pw_name;
if (*(pass = pw->pw_passwd)=='x' && (sp = getspnam(name))) pass = sp->sp_pwdp;
if (toys.optflags & FLAG_l) {
if (*pass=='!') error_exit("already locked");
printf("Locking '%s'\n", name);
encrypted = xmprintf("!%s", pass);
} else if (toys.optflags & FLAG_u) {
if (*pass!='!') error_exit("already unlocked");
printf("Unlocking '%s'\n", name);
encrypted = pass+1;
} else if (toys.optflags & FLAG_d) {
printf("Deleting password for '%s'\n", name);
encrypted = "";
} else {
if (get_salt(salt, TT.a ? TT.a : "des")<0) error_exit("bad -a '%s'", TT.a);
printf("Changing password for %s\n", name);
if (myuid) {
if (*pass=='!') error_exit("'%s' locked", name);
if (read_password(toybuf+2048, 2048, "Old password:")) return;
pass = crypt(toybuf+2048, pw->pw_passwd);
if (!pass || strcmp(pass, pw->pw_passwd)) error_exit("No");
}
if (read_password(toybuf, 2048, "New password:")) return;
if (CFG_PASSWD_SAD) weak_check(toybuf, toybuf+2048, name);
if (read_password(toybuf+2048, 2048, "Retype password:")) return;
if (strcmp(toybuf, toybuf+2048)) error_exit("Passwords do not match.");
encrypted = crypt(toybuf, salt);
}
// Update the passwd
ret = update_password(*pw->pw_passwd=='x' ? "/etc/shadow" : "/etc/passwd",
name, encrypted);
if (ret) error_msg("Failure");
else fprintf(stderr, "Success\n");
if (CFG_TOYBOX_FREE && (toys.optflags & FLAG_l)) free(encrypted);
}
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