File: 007_modules_pam_unix

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Index: pam.debian/modules/pam_unix/pam_unix_passwd.c
===================================================================
--- pam.debian.orig/modules/pam_unix/pam_unix_passwd.c
+++ pam.debian/modules/pam_unix/pam_unix_passwd.c
@@ -102,6 +102,9 @@
 # endif				/* GNU libc 2.1 */
 #endif
 
+extern const char *obscure_msg(const char *, const char *, const struct passwd *,
+			       unsigned int);
+
 /*
    How it works:
    Gets in username (has to be done) from the calling program
@@ -521,6 +524,11 @@
 				return retval;
 			}
 		}
+		if (!remark && pass_old != NULL) { /* only check if we don't already have a failure */
+			struct passwd *pwd;
+			pwd = pam_modutil_getpwnam(pamh, user);
+			remark = (char *)obscure_msg(pass_old,pass_new,pwd,ctrl); /* do obscure checks */
+		}
 	}
 	if (remark) {
 		_make_remark(pamh, ctrl, PAM_ERROR_MSG, remark);
@@ -536,7 +544,7 @@
 	int retval;
 	int remember = -1;
 	int rounds = -1;
-	int pass_min_len = 0;
+	int pass_min_len = 6;
 
 	/* <DO NOT free() THESE> */
 	const char *user;
Index: pam.debian/modules/pam_unix/support.h
===================================================================
--- pam.debian.orig/modules/pam_unix/support.h
+++ pam.debian/modules/pam_unix/support.h
@@ -97,8 +97,9 @@
 					   password hash algorithms */
 #define UNIX_BLOWFISH_PASS       26	/* new password hashes will use blowfish */
 #define UNIX_MIN_PASS_LEN        27	/* min length for password */
+#define UNIX_OBSCURE_CHECKS      28	/* enable obscure checks on passwords */
 /* -------------- */
-#define UNIX_CTRLS_              28	/* number of ctrl arguments defined */
+#define UNIX_CTRLS_              29	/* number of ctrl arguments defined */
 
 #define UNIX_DES_CRYPT(ctrl)	(off(UNIX_MD5_PASS,ctrl)&&off(UNIX_BIGCRYPT,ctrl)&&off(UNIX_SHA256_PASS,ctrl)&&off(UNIX_SHA512_PASS,ctrl)&&off(UNIX_BLOWFISH_PASS,ctrl))
 
@@ -107,34 +108,35 @@
 /* symbol                  token name          ctrl mask             ctrl     *
  * ----------------------- ------------------- --------------------- -------- */
 
-/* UNIX__OLD_PASSWD */     {NULL,              _ALL_ON_,                  01, 0},
-/* UNIX__VERIFY_PASSWD */  {NULL,              _ALL_ON_,                  02, 0},
-/* UNIX__IAMROOT */        {NULL,              _ALL_ON_,                  04, 0},
-/* UNIX_AUDIT */           {"audit",           _ALL_ON_,                 010, 0},
-/* UNIX_USE_FIRST_PASS */  {"use_first_pass",  _ALL_ON_^(060),           020, 0},
-/* UNIX_TRY_FIRST_PASS */  {"try_first_pass",  _ALL_ON_^(060),           040, 0},
-/* UNIX_NOT_SET_PASS */    {"not_set_pass",    _ALL_ON_,                0100, 0},
-/* UNIX__PRELIM */         {NULL,              _ALL_ON_^(0600),         0200, 0},
-/* UNIX__UPDATE */         {NULL,              _ALL_ON_^(0600),         0400, 0},
-/* UNIX__NONULL */         {NULL,              _ALL_ON_,               01000, 0},
-/* UNIX__QUIET */          {NULL,              _ALL_ON_,               02000, 0},
-/* UNIX_USE_AUTHTOK */     {"use_authtok",     _ALL_ON_,               04000, 0},
-/* UNIX_SHADOW */          {"shadow",          _ALL_ON_,              010000, 0},
-/* UNIX_MD5_PASS */        {"md5",            _ALL_ON_^(0260420000),  020000, 1},
-/* UNIX__NULLOK */         {"nullok",          _ALL_ON_^(01000),           0, 0},
-/* UNIX_DEBUG */           {"debug",           _ALL_ON_,              040000, 0},
-/* UNIX_NODELAY */         {"nodelay",         _ALL_ON_,             0100000, 0},
-/* UNIX_NIS */             {"nis",             _ALL_ON_,             0200000, 0},
-/* UNIX_BIGCRYPT */        {"bigcrypt",       _ALL_ON_^(0260420000), 0400000, 1},
-/* UNIX_LIKE_AUTH */       {"likeauth",        _ALL_ON_,            01000000, 0},
-/* UNIX_REMEMBER_PASSWD */ {"remember=",       _ALL_ON_,            02000000, 0},
-/* UNIX_NOREAP */          {"noreap",          _ALL_ON_,            04000000, 0},
-/* UNIX_BROKEN_SHADOW */   {"broken_shadow",   _ALL_ON_,           010000000, 0},
-/* UNIX_SHA256_PASS */     {"sha256",       _ALL_ON_^(0260420000), 020000000, 1},
-/* UNIX_SHA512_PASS */     {"sha512",       _ALL_ON_^(0260420000), 040000000, 1},
-/* UNIX_ALGO_ROUNDS */     {"rounds=",         _ALL_ON_,          0100000000, 0},
-/* UNIX_BLOWFISH_PASS */   {"blowfish",    _ALL_ON_^(0260420000), 0200000000, 1},
-/* UNIX_MIN_PASS_LEN */    {"minlen=",		_ALL_ON_,         0400000000, 0},
+/* UNIX__OLD_PASSWD */     {NULL,              _ALL_ON_,                  0x1, 0},
+/* UNIX__VERIFY_PASSWD */  {NULL,              _ALL_ON_,                  0x2, 0},
+/* UNIX__IAMROOT */        {NULL,              _ALL_ON_,                  0x4, 0},
+/* UNIX_AUDIT */           {"audit",           _ALL_ON_,                  0x8, 0},
+/* UNIX_USE_FIRST_PASS */  {"use_first_pass",  _ALL_ON_^(0x30),          0x10, 0},
+/* UNIX_TRY_FIRST_PASS */  {"try_first_pass",  _ALL_ON_^(0x30),          0x20, 0},
+/* UNIX_NOT_SET_PASS */    {"not_set_pass",    _ALL_ON_,                 0x40, 0},
+/* UNIX__PRELIM */         {NULL,              _ALL_ON_^(0x180),         0x80, 0},
+/* UNIX__UPDATE */         {NULL,              _ALL_ON_^(0x180),        0x100, 0},
+/* UNIX__NONULL */         {NULL,              _ALL_ON_,                0x200, 0},
+/* UNIX__QUIET */          {NULL,              _ALL_ON_,                0x400, 0},
+/* UNIX_USE_AUTHTOK */     {"use_authtok",     _ALL_ON_,                0x800, 0},
+/* UNIX_SHADOW */          {"shadow",          _ALL_ON_,               0x1000, 0},
+/* UNIX_MD5_PASS */        {"md5",             _ALL_ON_^(0x2C22000),   0x2000, 1},
+/* UNIX__NULLOK */         {"nullok",          _ALL_ON_^(0x200),            0, 0},
+/* UNIX_DEBUG */           {"debug",           _ALL_ON_,               0x4000, 0},
+/* UNIX_NODELAY */         {"nodelay",         _ALL_ON_,               0x8000, 0},
+/* UNIX_NIS */             {"nis",             _ALL_ON_,              0x10000, 0},
+/* UNIX_BIGCRYPT */        {"bigcrypt",        _ALL_ON_^(0x2C22000),  0x20000, 1},
+/* UNIX_LIKE_AUTH */       {"likeauth",        _ALL_ON_,              0x40000, 0},
+/* UNIX_REMEMBER_PASSWD */ {"remember=",       _ALL_ON_,              0x80000, 0},
+/* UNIX_NOREAP */          {"noreap",          _ALL_ON_,             0x100000, 0},
+/* UNIX_BROKEN_SHADOW */   {"broken_shadow",   _ALL_ON_,             0x200000, 0},
+/* UNIX_SHA256_PASS */     {"sha256",          _ALL_ON_^(0x2C22000), 0x400000, 1},
+/* UNIX_SHA512_PASS */     {"sha512",          _ALL_ON_^(0x2C22000), 0x800000, 1},
+/* UNIX_ALGO_ROUNDS */     {"rounds=",         _ALL_ON_,            0x1000000, 0},
+/* UNIX_BLOWFISH_PASS */   {"blowfish",        _ALL_ON_^(0x2C22000),0x2000000, 1},
+/* UNIX_MIN_PASS_LEN */    {"minlen=",         _ALL_ON_,            0x4000000, 0},
+/* UNIX_OBSCURE_CHECKS */  {"obscure",         _ALL_ON_,            0x8000000, 0},
 };
 
 #define UNIX_DEFAULTS  (unix_args[UNIX__NONULL].flag)
Index: pam.debian/modules/pam_unix/pam_unix.8.xml
===================================================================
--- pam.debian.orig/modules/pam_unix/pam_unix.8.xml
+++ pam.debian/modules/pam_unix/pam_unix.8.xml
@@ -337,8 +337,81 @@
         <listitem>
           <para>
             Set a minimum password length of <replaceable>n</replaceable>
-            characters. The max. for DES crypt based passwords are 8
-            characters.
+            characters.  The default value is 6.  The maximum for DES
+            crypt-based passwords is 8 characters.
+          </para>
+        </listitem>
+      </varlistentry>
+      <varlistentry>
+        <term>
+          <option>obscure</option>
+        </term>
+        <listitem>
+          <para>
+            Enable some extra checks on password strength.  These checks
+            are based on the "obscure" checks in the original shadow
+            package.  The behavior is similar to the pam_cracklib
+            module, but for non-dictionary-based checks.  The following
+            checks are implemented:
+            <variablelist>
+              <varlistentry>
+                <term>
+                  <option>Palindrome</option>
+                </term>
+                <listitem>
+                  <para>
+                    Verifies that the new password is not a palindrome
+                    of (i.e., the reverse of) the previous one.
+                  </para>
+                </listitem>
+              </varlistentry>
+              <varlistentry>
+                <term>
+                  <option>Case Change Only</option>
+                </term>
+                <listitem>
+                  <para>
+                    Verifies that the new password isn't the same as the
+                    old one with a change of case.
+                  </para>
+                </listitem>
+              </varlistentry>
+              <varlistentry>
+                <term>
+                  <option>Similar</option>
+                </term>
+                <listitem>
+                  <para>
+                    Verifies that the new password isn't too much like
+                    the previous one.
+                  </para>
+                </listitem>
+              </varlistentry>
+              <varlistentry>
+                <term>
+                  <option>Simple</option>
+                </term>
+                <listitem>
+                  <para>
+                    Is the new password too simple?  This is based on
+                    the length of the password and the number of
+                    different types of characters (alpha, numeric, etc.)
+                    used.
+                  </para>
+                </listitem>
+              </varlistentry>
+              <varlistentry>
+                <term>
+                  <option>Rotated</option>
+                </term>
+                <listitem>
+                  <para>
+                    Is the new password a rotated version of the old
+                    password?  (E.g., "billy" and "illyb")
+                  </para>
+                </listitem>
+              </varlistentry>
+            </variablelist>
           </para>
         </listitem>
       </varlistentry>
Index: pam.debian/modules/pam_unix/obscure.c
===================================================================
--- /dev/null
+++ pam.debian/modules/pam_unix/obscure.c
@@ -0,0 +1,198 @@
+/*
+ * 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 "config.h"
+
+#include <ctype.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <string.h>
+#include <stdlib.h>
+#include <pwd.h>
+#include <security/pam_modules.h>
+#include <security/_pam_macros.h>
+
+
+#include "support.h"
+
+/* can't be a palindrome - like `R A D A R' or `M A D A M' */
+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. */
+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. */
+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;
+
+	if (strcmp(new, old) == 0)
+		return _("Bad: new password must be different than the old one");
+
+	newmono = str_lower(strdup(new));
+	oldmono = str_lower(strdup(old));
+	wrapped = (char *)malloc(strlen(oldmono) * 2 + 1);
+	strcpy (wrapped, oldmono);
+	strcat (wrapped, oldmono);
+
+	if (palindrome(oldmono, newmono)) {
+		msg = _("Bad: new password cannot be a palindrome");
+	} else if (strcmp(oldmono, newmono) == 0) {
+		msg = _("Bad: new and old password must differ by more than just case");
+	} else if (similar(oldmono, newmono)) {
+		msg = _("Bad: new and old password are too similar");
+	} else if (simple(old, new)) {
+		msg = _("Bad: new password is too simple");
+	} else if (strstr(wrapped, newmono)) {
+		msg = _("Bad: new password is just a wrapped version of the old one");
+	}
+
+	_pam_delete(newmono);
+	_pam_delete(oldmono);
+	_pam_delete(wrapped);
+
+	return msg;
+}
+
+const char *obscure_msg(const char *old, const char *new,
+			       const struct passwd *pwdp, unsigned int ctrl) {
+	int oldlen, newlen;
+	char *new1, *old1;
+	const char *msg;
+
+	if (old == NULL)
+		return NULL; /* no check if old is NULL */
+
+	oldlen = strlen(old);
+	newlen = strlen(new);
+
+	/* Remaining checks are optional. */
+	if (off(UNIX_OBSCURE_CHECKS,ctrl))
+		return NULL;
+
+	if ((msg = password_check(old, new, pwdp)) != NULL)
+		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 (!UNIX_DES_CRYPT(ctrl))
+		return NULL;  /* unlimited password length */
+
+	if (oldlen <= 8 && newlen <= 8)
+		return NULL;
+
+	new1 = strndup(new,8);
+	old1 = strndup(old,8);
+
+	msg = password_check(old1, new1, pwdp);
+
+	_pam_delete(new1);
+	_pam_delete(old1);
+
+	return msg;
+}
Index: pam.debian/modules/pam_unix/Makefile.am
===================================================================
--- pam.debian.orig/modules/pam_unix/Makefile.am
+++ pam.debian/modules/pam_unix/Makefile.am
@@ -43,7 +43,7 @@
 
 pam_unix_la_SOURCES = bigcrypt.c pam_unix_acct.c \
 	pam_unix_auth.c pam_unix_passwd.c pam_unix_sess.c support.c \
-	passverify.c yppasswd_xdr.c md5_good.c md5_broken.c
+	passverify.c yppasswd_xdr.c md5_good.c md5_broken.c obscure.c
 if STATIC_MODULES
 pam_unix_la_SOURCES += pam_unix_static.c
 endif
Index: pam.debian/modules/pam_unix/pam_unix.8
===================================================================
--- pam.debian.orig/modules/pam_unix/pam_unix.8
+++ pam.debian/modules/pam_unix/pam_unix.8
@@ -183,7 +183,38 @@
 .RS 4
 Set a minimum password length of
 \fIn\fR
-characters\&. The max\&. for DES crypt based passwords are 8 characters\&.
+characters\&. The default value is 6\&. The maximum for DES crypt\-based passwords is 8 characters\&.
+.RE
+.PP
+\fBobscure\fR
+.RS 4
+Enable some extra checks on password strength\&. These checks are based on the "obscure" checks in the original shadow package\&. The behavior is similar to the pam_cracklib module, but for non\-dictionary\-based checks\&. The following checks are implemented:
+.PP
+\fBPalindrome\fR
+.RS 4
+Verifies that the new password is not a palindrome of (i\&.e\&., the reverse of) the previous one\&.
+.RE
+.PP
+\fBCase Change Only\fR
+.RS 4
+Verifies that the new password isn\*(Aqt the same as the old one with a change of case\&.
+.RE
+.PP
+\fBSimilar\fR
+.RS 4
+Verifies that the new password isn\*(Aqt too much like the previous one\&.
+.RE
+.PP
+\fBSimple\fR
+.RS 4
+Is the new password too simple? This is based on the length of the password and the number of different types of characters (alpha, numeric, etc\&.) used\&.
+.RE
+.PP
+\fBRotated\fR
+.RS 4
+Is the new password a rotated version of the old password? (E\&.g\&., "billy" and "illyb")
+.RE
+.sp
 .RE
 .PP
 Invalid arguments are logged with