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/*
* SPDX-FileCopyrightText: 1989 - 1994, Julianne Frances Haugh
* SPDX-FileCopyrightText: 1996 - 1999, Marek Michałkiewicz
* SPDX-FileCopyrightText: 2003 - 2005, Tomasz Kłoczko
* SPDX-FileCopyrightText: 2007 - 2010, Nicolas François
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <config.h>
#ident "$Id$"
#include <ctype.h>
#include <stdio.h>
#include "attr.h"
#include "prototypes.h"
#include "defines.h"
#include "getdef.h"
#include "string/memset/memzero.h"
#include "string/sprintf/xasprintf.h"
#include "string/strcmp/streq.h"
#include "string/strdup/xstrdup.h"
#if WITH_LIBBSD == 0
#include "freezero.h"
#endif /* WITH_LIBBSD */
/*
* can't be a palindrome - like `R A D A R' or `M A D A M'
*/
static bool palindrome (MAYBE_UNUSED const char *old, const char *new)
{
size_t i, j;
i = strlen (new);
for (j = 0; j < i; j++) {
if (new[i - j - 1] != new[j]) {
return false;
}
}
return true;
}
/*
* more than half of the characters are different ones.
*/
static bool similar (/*@notnull@*/const char *old, /*@notnull@*/const char *new)
{
int i, j;
/*
* XXX - sometimes this fails when changing from a simple password
* to a really long one (MD5). For now, I just return success if
* the new password is long enough. Please feel free to suggest
* something better... --marekm
*/
if (strlen (new) >= 8) {
return false;
}
for (i = j = 0; ('\0' != new[i]) && ('\0' != old[i]); i++) {
if (strchr (new, old[i]) != NULL) {
j++;
}
}
if (i >= j * 2) {
return false;
}
return true;
}
static char *str_lower (/*@returned@*/char *string)
{
char *cp;
for (cp = string; !streq(cp, ""); cp++) {
*cp = tolower (*cp);
}
return string;
}
static /*@observer@*//*@null@*/const char *password_check (
/*@notnull@*/const char *old,
/*@notnull@*/const char *new,
/*@notnull@*/MAYBE_UNUSED const struct passwd *pwdp)
{
const char *msg = NULL;
char *oldmono, *newmono, *wrapped;
if (streq(new, old)) {
return _("no change");
}
newmono = str_lower (xstrdup (new));
oldmono = str_lower (xstrdup (old));
xasprintf(&wrapped, "%s%s", oldmono, oldmono);
if (palindrome (oldmono, newmono)) {
msg = _("a palindrome");
} else if (streq(oldmono, newmono)) {
msg = _("case changes only");
} else if (similar (oldmono, newmono)) {
msg = _("too similar");
} else if (strstr (wrapped, newmono) != NULL) {
msg = _("rotated");
}
free(strzero(newmono));
free(strzero(oldmono));
free(strzero(wrapped));
return msg;
}
static /*@observer@*//*@null@*/const char *obscure_msg (
/*@notnull@*/const char *old,
/*@notnull@*/const char *new,
/*@notnull@*/const struct passwd *pwdp)
{
size_t maxlen, oldlen, newlen;
char *new1, *old1;
const char *msg;
const char *result;
oldlen = strlen (old);
newlen = strlen (new);
if (newlen < (size_t) getdef_num ("PASS_MIN_LEN", 0)) {
return _("too short");
}
/*
* Remaining checks are optional.
*/
if (!getdef_bool ("OBSCURE_CHECKS_ENAB")) {
return NULL;
}
msg = password_check (old, new, pwdp);
if (NULL != msg) {
return msg;
}
result = getdef_str ("ENCRYPT_METHOD");
if (NULL == result) {
/* The traditional crypt() truncates passwords to 8 chars. It is
possible to circumvent the above checks by choosing an easy
8-char password and adding some random characters to it...
Example: "password$%^&*123". So check it again, this time
truncated to the maximum length. Idea from npasswd. --marekm */
if (getdef_bool ("MD5_CRYPT_ENAB")) {
return NULL;
}
} else {
if ( streq(result, "MD5")
#ifdef USE_SHA_CRYPT
|| streq(result, "SHA256")
|| streq(result, "SHA512")
#endif
#ifdef USE_BCRYPT
|| streq(result, "BCRYPT")
#endif
#ifdef USE_YESCRYPT
|| streq(result, "YESCRYPT")
#endif
) {
return NULL;
}
}
maxlen = getdef_num ("PASS_MAX_LEN", 8);
if ( (oldlen <= maxlen)
&& (newlen <= maxlen)) {
return NULL;
}
new1 = xstrdup (new);
old1 = xstrdup (old);
if (newlen > maxlen)
stpcpy(&new1[maxlen], "");
if (oldlen > maxlen)
stpcpy(&old1[maxlen], "");
msg = password_check (old1, new1, pwdp);
freezero (new1, newlen);
freezero (old1, oldlen);
return msg;
}
/*
* Obscure - see if password is obscure enough.
*
* The programmer is encouraged to add as much complexity to this
* routine as desired. Included are some of my favorite ways to
* check passwords.
*/
bool obscure (const char *old, const char *new, const struct passwd *pwdp)
{
const char *msg = obscure_msg (old, new, pwdp);
if (NULL != msg) {
printf (_("Bad password: %s. "), msg);
return false;
}
return true;
}
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