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-rw-r--r--libbb/obscure.c368
1 files changed, 144 insertions, 224 deletions
diff --git a/libbb/obscure.c b/libbb/obscure.c
index 6244970de..a152456b2 100644
--- a/libbb/obscure.c
+++ b/libbb/obscure.c
@@ -1,259 +1,179 @@
/* vi: set sw=4 ts=4: */
/*
- * Copyright 1989 - 1994, Julianne Frances Haugh <jockgrrl@austin.rr.com>
- * Copyright 2006, Bernhard Fischer <busybox@busybox.net>
- * All rights reserved.
+ * Mini weak password checker implementation for busybox
*
- * 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.
+ * Copyright (C) 2006 Tito Ragusa <farmatito@tiscali.it>
*
- * 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.
+ * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
-/*
- * 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.
- */
+/* A good password:
+ 1) should contain at least six characters (man passwd);
+ 2) empty passwords are not permitted;
+ 3) should contain a mix of four different types of characters
+ upper case letters,
+ lower case letters,
+ numbers,
+ special characters such as !@#$%^&*,;".
+ This password types should not be permitted:
+ a) pure numbers: birthdates, social security number, license plate, phone numbers;
+ b) words and all letters only passwords (uppercase, lowercase or mixed)
+ as palindromes, consecutive or repetitive letters
+ or adjacent letters on your keyboard;
+ c) username, real name, company name or (e-mail?) address
+ in any form (as-is, reversed, capitalized, doubled, etc.).
+ (we can check only against username, gecos and hostname)
+ d) common and obvious letter-number replacements
+ (e.g. replace the letter O with number 0)
+ such as "M1cr0$0ft" or "P@ssw0rd" (CAVEAT: we cannot check for them
+ without the use of a dictionary).
+
+ For each missing type of characters an increase of password length is
+ requested.
+
+ If user is root we warn only.
+
+ CAVEAT: some older versions of crypt() truncates passwords to 8 chars,
+ so that aaaaaaaa1Q$ is equal to aaaaaaaa making it possible to fool
+ some of our checks. We don't test for this special case as newer versions
+ of crypt do not truncate passwords.
+*/
-#include <stdlib.h>
-#include <stdio.h>
-#include <string.h>
#include <ctype.h>
-#include "libbb.h"
-
-/*
- * can't be a palindrome - like `R A D A R' or `M A D A M'
- */
+#include <unistd.h>
+#include <string.h>
-static int palindrome(const char *newval)
-{
- int i, j;
+#include "libbb.h"
- i = strlen(newval);
- for (j = 0; j < i; j++)
- if (newval[i - j - 1] != newval[j])
- return 0;
+/* passwords should consist of 6 (to 8 characters) */
+#define MINLEN 6
- return 1;
-}
-/*
- * more than half of the characters are different ones.
- */
+static int string_checker_helper(const char *p1, const char *p2) __attribute__ ((__pure__));
-static int similiar(const char *old, const char *newval)
+static int string_checker_helper(const char *p1, const char *p2)
{
- int i, j;
-
- for (i = j = 0; newval[i] && old[i]; i++)
- if (strchr(newval, old[i]))
- j++;
-
- if (i >= j * 2)
- return 0;
-
- return 1;
+ /* as-is or capitalized */
+ if (strcasecmp(p1, p2) == 0
+ /* as sub-string */
+ || strcasestr(p2, p1) != NULL
+ /* invert in case haystack is shorter than needle */
+ || strcasestr(p1, p2) != NULL)
+ return 1;
+ return 0;
}
-/*
- * a nice mix of characters.
- */
-
-static int simple(const char *newval)
+static int string_checker(const char *p1, const char *p2)
{
-#define digits 1
-#define uppers 2
-#define lowers 4
-#define others 8
- int c, is_simple = 0;
int size;
- int i;
-
- for (i = 0; (c = *newval++) != 0; i++) {
- if (isdigit(c))
- is_simple |= digits;
- else if (isupper(c))
- is_simple |= uppers;
- else if (islower(c))
- is_simple |= lowers;
- else
- is_simple |= others;
+ /* check string */
+ int ret = string_checker_helper(p1, p2);
+ /* Make our own copy */
+ char *p = bb_xstrdup(p1);
+ /* reverse string */
+ size = strlen(p);
+
+ while (size--) {
+ *p = p1[size];
+ p++;
}
-
- /*
- * 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 (is_simple & digits)
- size--;
- if (is_simple & uppers)
- size--;
- if (is_simple & lowers)
- size--;
- if (is_simple & others)
- size--;
-
- if (size <= i)
- return 0;
-
- return 1;
-#undef digits
-#undef uppers
-#undef lowers
-#undef others
+ /* restore pointer */
+ p -= strlen(p1);
+ /* check reversed string */
+ ret |= string_checker_helper(p, p2);
+ /* clean up */
+ memset(p, 0, strlen(p1));
+ free(p);
+ return ret;
}
-static char *str_lower(char *string)
-{
- char *cp;
-
- for (cp = string; *cp; cp++)
- *cp = tolower(*cp);
- return string;
-}
+#define LOWERCASE 1
+#define UPPERCASE 2
+#define NUMBERS 4
+#define SPECIAL 8
-static const char *
-password_check(const char *old, const char *newval, const struct passwd *pwdp)
+static const char *obscure_msg(const char *old_p, const char *new_p, const struct passwd *pw)
{
- const char *msg;
- char *newmono, *wrapped;
- int lenwrap;
-
- if (strcmp(newval, old) == 0)
- return "no change";
- if (simple(newval))
- return "too simple";
-
- msg = NULL;
- newmono = str_lower(bb_xstrdup(newval));
- lenwrap = strlen(old);
- wrapped = (char *) xmalloc(lenwrap * 2 + 1);
- str_lower(strcpy(wrapped, old));
-
- if (palindrome(newmono))
- msg = "a palindrome";
-
- else if (strcmp(wrapped, newmono) == 0)
- msg = "case changes only";
-
- else if (similiar(wrapped, newmono))
- msg = "too similiar";
-
- else if ( strstr(newval, pwdp->pw_name) )
- msg = "username in password";
-
- else {
- safe_strncpy(wrapped + lenwrap, wrapped, lenwrap + 1);
- if (strstr(wrapped, newmono))
- msg = "rotated";
+ int i;
+ int c;
+ int length;
+ int mixed = 0;
+ /* Add 1 for each type of characters to the minlen of password */
+ int size = MINLEN + 8;
+ const char *p;
+ char hostname[255];
+
+ /* size */
+ if (!new_p || (length = strlen(new_p)) < MINLEN)
+ return("too short");
+
+ /* no username as-is, as sub-string, reversed, capitalized, doubled */
+ if (string_checker(new_p, pw->pw_name)) {
+ return "similar to username";
+ }
+ /* no gecos as-is, as sub-string, reversed, capitalized, doubled */
+ if (string_checker(new_p, pw->pw_gecos)) {
+ return "similar to gecos";
+ }
+ /* hostname as-is, as sub-string, reversed, capitalized, doubled */
+ if (gethostname(hostname, 255) == 0) {
+ hostname[254] = '\0';
+ if (string_checker(new_p, hostname)) {
+ return "similar to hostname";
+ }
}
- memset(newmono, 0, strlen(newmono));
- memset(wrapped, 0, lenwrap * 2);
- free(newmono);
- free(wrapped);
-
- return msg;
-}
-
-static const char *
-obscure_msg(const char *old, const char *newval, const struct passwd *pwdp)
-{
- int maxlen, oldlen, newlen;
- char *new1, *old1;
- const char *msg;
-
- oldlen = strlen(old);
- newlen = strlen(newval);
-
-#if 0 /* why not check the password when set for the first time? --marekm */
- if (old[0] == '\0')
- /* return (1); */
- return NULL;
-#endif
-
- if (newlen < 5)
- return "too short";
-
- /*
- * Remaining checks are optional.
- */
- /* Not for us -- Sean
- *if (!getdef_bool("OBSCURE_CHECKS_ENAB"))
- * return NULL;
- */
- msg = password_check(old, newval, 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 */
-
- maxlen = 8;
- if (oldlen <= maxlen && newlen <= maxlen)
- return NULL;
-
- new1 = (char *) bb_xstrdup(newval);
- old1 = (char *) bb_xstrdup(old);
- if (newlen > maxlen)
- new1[maxlen] = '\0';
- if (oldlen > maxlen)
- old1[maxlen] = '\0';
-
- msg = password_check(old1, new1, pwdp);
-
- memset(new1, 0, newlen);
- memset(old1, 0, oldlen);
- free(new1);
- free(old1);
-
- return msg;
+ /* Should / Must contain a mix of: */
+ for (i = 0; i < length; i++) {
+ if (islower(new_p[i])) { /* a-z */
+ mixed |= LOWERCASE;
+ } else if (isupper(new_p[i])) { /* A-Z */
+ mixed |= UPPERCASE;
+ } else if (isdigit(new_p[i])) { /* 0-9 */
+ mixed |= NUMBERS;
+ } else { /* special characters */
+ mixed |= SPECIAL;
+ }
+ /* More than 50% similar characters ? */
+ c = 0;
+ p = new_p;
+ while (1) {
+ if ((p = strchr(p, new_p[i])) == NULL) {
+ break;
+ }
+ c++;
+ if (!++p) {
+ break; /* move past the matched char if possible */
+ }
+ }
+
+ if (c >= (length / 2)) {
+ return "too many similar characters";
+ }
+ }
+ for(i=0;i<4;i++)
+ if (mixed & (1<<i)) size -= 2;
+ if (length < size)
+ return "too weak";
+
+ if (old_p && old_p[0] != '\0') {
+ /* check vs. old password */
+ if (string_checker(new_p, old_p)) {
+ return "similar to old password";
+ }
+ }
+ return NULL;
}
-/*
- * 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 *newval, const struct passwd *pwdp)
{
- const char *msg = obscure_msg(old, newval, pwdp);
+ const char *msg;
- /* if (msg) { */
- if (msg != NULL) {
+ if ((msg = obscure_msg(old, newval, pwdp))) {
printf("Bad password: %s.\n", msg);
- /* return 0; */
- return 1;
+ /* If user is root warn only */
+ return (getuid())? 1 : 0;
}
- /* return 1; */
return 0;
}
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