/* * Copyright 1989 - 1994, Julianne Frances Haugh * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of Julianne F. Haugh nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY JULIE HAUGH AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL JULIE HAUGH OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include #include "rcsid.h" RCSID ("$Id: obscure.c,v 1.11 2003/05/05 21:44:15 kloczek Exp $") /* * This version of obscure.c contains modifications to support "cracklib" * by Alec Muffet (alec.muffett@uk.sun.com). You must obtain the Cracklib * library source code for this function to operate. */ #include #include #include "prototypes.h" #include "defines.h" #include "getdef.h" /* * can't be a palindrome - like `R A D A R' or `M A D A M' */ /*ARGSUSED*/ static int palindrome (const char *old, const char *new) { int i, j; i = strlen (new); for (j = 0; j < i; j++) if (new[i - j - 1] != new[j]) return 0; return 1; } /* * more than half of the characters are different ones. */ /*ARGSUSED*/ static int similar (const char *old, 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 0; for (i = j = 0; new[i] && old[i]; i++) if (strchr (new, old[i])) j++; if (i >= j * 2) return 0; return 1; } /* * a nice mix of characters. */ /*ARGSUSED*/ static int simple (const char *old, const char *new) { int digits = 0; int uppers = 0; int lowers = 0; int others = 0; int size; int i; for (i = 0; new[i]; i++) { if (isdigit (new[i])) digits++; else if (isupper (new[i])) uppers++; else if (islower (new[i])) lowers++; else others++; } /* * The scam is this - a password of only one character type * must be 8 letters long. Two types, 7, and so on. */ size = 9; if (digits) size--; if (uppers) size--; if (lowers) size--; if (others) size--; if (size <= i) return 0; return 1; } static char *str_lower (char *string) { char *cp; for (cp = string; *cp; cp++) *cp = tolower (*cp); return string; } static const char *password_check (const char *old, const char *new, const struct passwd *pwdp) { const char *msg = NULL; char *oldmono, *newmono, *wrapped; #ifdef HAVE_LIBCRACK char *dictpath; #ifdef HAVE_LIBCRACK_PW char *FascistCheckPw (); #else char *FascistCheck (); #endif #endif if (strcmp (new, old) == 0) return "no change"; newmono = str_lower (xstrdup (new)); oldmono = str_lower (xstrdup (old)); wrapped = xmalloc (strlen (oldmono) * 2 + 1); strcpy (wrapped, oldmono); strcat (wrapped, oldmono); if (palindrome (oldmono, newmono)) msg = "a palindrome"; if (!msg && strcmp (oldmono, newmono) == 0) msg = "case changes only"; if (!msg && similar (oldmono, newmono)) msg = "too similar"; if (!msg && simple (old, new)) msg = "too simple"; if (!msg && strstr (wrapped, newmono)) msg = "rotated"; #ifdef HAVE_LIBCRACK /* * Invoke Alec Muffett's cracklib routines. */ if (!msg && (dictpath = getdef_str ("CRACKLIB_DICTPATH"))) #ifdef HAVE_LIBCRACK_PW msg = FascistCheckPw (new, dictpath, pwdp); #else msg = FascistCheck (new, dictpath); #endif #endif strzero (newmono); strzero (oldmono); strzero (wrapped); free (newmono); free (oldmono); free (wrapped); return msg; } /*ARGSUSED*/ static const char *obscure_msg (const char *old, const char *new, const struct passwd *pwdp) { int maxlen, oldlen, newlen; char *new1, *old1; const char *msg; oldlen = strlen (old); newlen = strlen (new); if (newlen < 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 (msg) return msg; /* 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; /* unlimited password length */ maxlen = getdef_num ("PASS_MAX_LEN", 8); if (oldlen <= maxlen && newlen <= maxlen) return NULL; new1 = xstrdup (new); old1 = xstrdup (old); if (newlen > maxlen) new1[maxlen] = '\0'; if (oldlen > maxlen) old1[maxlen] = '\0'; msg = password_check (old1, new1, pwdp); memzero (new1, newlen); memzero (old1, oldlen); free (new1); free (old1); 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. */ int obscure (const char *old, const char *new, const struct passwd *pwdp) { const char *msg = obscure_msg (old, new, pwdp); if (msg) { printf (_("Bad password: %s. "), msg); return 0; } return 1; }