/* * 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 1.9 1999/03/07 19:14:40 marekm 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 0 /* why not check the password when set for the first time? --marekm */ if (old[0] == '\0') return NULL; #endif 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; }