Merge branch 'security/ZF2015-09'

Fix for ZF2015-09.

library/Zend/Captcha/Word.php

@@ -22,6 +22,9 @@
 /** @see Zend_Captcha_Base */
 require_once 'Zend/Captcha/Base.php';
 
+/** @see Zend_Crypt_Math */
+require_once 'Zend/Crypt/Math.php';
+
 /**
  * Word-based captcha adapter
  *
@@ -39,10 +42,10 @@ abstract class Zend_Captcha_Word extends Zend_Captcha_Base
     /**#@+
      * @var array Character sets
      */
-    static $V  = array("a", "e", "i", "o", "u", "y");
-    static $VN = array("a", "e", "i", "o", "u", "y","2","3","4","5","6","7","8","9");
-    static $C  = array("b","c","d","f","g","h","j","k","m","n","p","q","r","s","t","u","v","w","x","z");
-    static $CN = array("b","c","d","f","g","h","j","k","m","n","p","q","r","s","t","u","v","w","x","z","2","3","4","5","6","7","8","9");
+    static public $V  = array("a", "e", "i", "o", "u", "y");
+    static public $VN = array("a", "e", "i", "o", "u", "y","2","3","4","5","6","7","8","9");
+    static public $C  = array("b","c","d","f","g","h","j","k","m","n","p","q","r","s","t","u","v","w","x","z");
+    static public $CN = array("b","c","d","f","g","h","j","k","m","n","p","q","r","s","t","u","v","w","x","z","2","3","4","5","6","7","8","9");
     /**#@-*/
 
     /**
@@ -175,7 +178,7 @@ abstract class Zend_Captcha_Word extends Zend_Captcha_Base
      *
      * @return string
      */
-    public function getId ()
+    public function getId()
     {
         if (null === $this->_id) {
             $this->_setId($this->_generateRandomId());
@@ -189,7 +192,7 @@ abstract class Zend_Captcha_Word extends Zend_Captcha_Base
      * @param string $id
      * @return Zend_Captcha_Word
      */
-    protected function _setId ($id)
+    protected function _setId($id)
     {
         $this->_id = $id;
         return $this;
@@ -250,7 +253,7 @@ abstract class Zend_Captcha_Word extends Zend_Captcha_Base
         $this->_useNumbers = $_useNumbers;
         return $this;
     }
-    
+
     /**
      * Get session object
      *
@@ -280,7 +283,7 @@ abstract class Zend_Captcha_Word extends Zend_Captcha_Base
     public function setSession(Zend_Session_Namespace $session)
     {
         $this->_session = $session;
-        if($session) {
+        if ($session) {
             $this->_keepSession = true;
         }
         return $this;
@@ -326,10 +329,12 @@ abstract class Zend_Captcha_Word extends Zend_Captcha_Base
         $vowels     = $this->_useNumbers ? self::$VN : self::$V;
         $consonants = $this->_useNumbers ? self::$CN : self::$C;
 
+        $totIndexCon = count($consonants) - 1;
+        $totIndexVow = count($vowels) - 1;
         for ($i=0; $i < $wordLen; $i = $i + 2) {
             // generate word with mix of vowels and consonants
-            $consonant = $consonants[array_rand($consonants)];
-            $vowel     = $vowels[array_rand($vowels)];
+            $consonant = $consonants[Zend_Crypt_Math::randInteger(0, $totIndexCon, true)];
+            $vowel     = $vowels[Zend_Crypt_Math::randInteger(0, $totIndexVow, true)];
             $word     .= $consonant . $vowel;
         }
 
@@ -347,7 +352,7 @@ abstract class Zend_Captcha_Word extends Zend_Captcha_Base
      */
     public function generate()
     {
-        if(!$this->_keepSession) {
+        if (!$this->_keepSession) {
             $this->_session = null;
         }
         $id = $this->_generateRandomId();
@@ -359,7 +364,7 @@ abstract class Zend_Captcha_Word extends Zend_Captcha_Base
 
     protected function _generateRandomId()
     {
-        return md5(mt_rand(0, 1000) . microtime(true));
+        return md5(Zend_Crypt_Math::randBytes(32));
     }
 
     /**

library/Zend/Crypt/Math.php

@@ -57,21 +57,109 @@ class Zend_Crypt_Math extends Zend_Crypt_Math_BigInteger
         }
         $rand = '';
         $i2 = strlen($maximum) - 1;
-        for ($i = 1;$i < $i2;$i++) {
-            $rand .= mt_rand(0,9);
+        for ($i = 1; $i < $i2; $i++) {
+            $rand .= mt_rand(0, 9);
         }
-        $rand .= mt_rand(0,9);
+        $rand .= mt_rand(0, 9);
         return $rand;
     }
 
     /**
+     * Return a random strings of $length bytes
+     *
+     * @param  integer $length
+     * @param  boolean $strong
+     * @return string
+     */
+    public static function randBytes($length, $strong = false)
+    {
+        $length = (int) $length;
+        if ($length <= 0) {
+            return false;
+        }
+        if (function_exists('openssl_random_pseudo_bytes')) {
+            $bytes = openssl_random_pseudo_bytes($length, $usable);
+            if ($strong === $usable) {
+                return $bytes;
+            }
+        }
+        if (function_exists('mcrypt_create_iv')) {
+            $bytes = mcrypt_create_iv($length, MCRYPT_DEV_URANDOM);
+            if ($bytes !== false && strlen($bytes) === $length) {
+                return $bytes;
+            }
+        }
+        if (file_exists('/dev/urandom') && is_readable('/dev/urandom')) {
+            $frandom = fopen('/dev/urandom', 'r');
+            if ($frandom !== false) {
+                return fread($frandom, $length);
+            }
+        }
+        if (true === $strong) {
+            require_once 'Zend/Crypt/Exception.php';
+            throw new Zend_Crypt_Exception(
+                'This PHP environment doesn\'t support secure random number generation. ' .
+                'Please consider installing the OpenSSL and/or Mcrypt extensions'
+            );
+        }
+        $rand = '';
+        for ($i = 0; $i < $length; $i++) {
+            $rand .= chr(mt_rand(0, 255));
+        }
+        return $rand;
+    }
+
+    /**
+     * Return a random integer between $min and $max
+     *
+     * @param  integer $min
+     * @param  integer $max
+     * @param  boolean $strong
+     * @return integer
+     */
+    public static function randInteger($min, $max, $strong = false)
+    {
+        if ($min > $max) {
+            require_once 'Zend/Crypt/Exception.php';
+            throw new Zend_Crypt_Exception(
+                'The min parameter must be lower than max parameter'
+            );
+        }
+        $range = $max - $min;
+        if ($range == 0) {
+            return $max;
+        } elseif ($range > PHP_INT_MAX || is_float($range)) {
+            require_once 'Zend/Crypt/Exception.php';
+            throw new Zend_Crypt_Exception(
+                'The supplied range is too great to generate'
+            );
+        }
+        // calculate number of bits required to store range on this machine
+        $r = $range;
+        $bits = 0;
+        while ($r) {
+            $bits++;
+            $r >>= 1;
+        }
+        $bits   = (int) max($bits, 1);
+        $bytes  = (int) max(ceil($bits / 8), 1);
+        $filter = (int) ((1 << $bits) - 1);
+        do {
+            $rnd  = hexdec(bin2hex(self::randBytes($bytes, $strong)));
+            $rnd &= $filter;
+        } while ($rnd > $range);
+        return ($min + $rnd);
+    }
+
+    /**
      * Get the big endian two's complement of a given big integer in
      * binary notation
      *
      * @param string $long
      * @return string
      */
-    public function btwoc($long) {
+    public function btwoc($long)
+    {
         if (ord($long[0]) > 127) {
             return "\x00" . $long;
         }
@@ -84,7 +172,8 @@ class Zend_Crypt_Math extends Zend_Crypt_Math_BigInteger
      * @param string $binary
      * @return string
      */
-    public function fromBinary($binary) {
+    public function fromBinary($binary)
+    {
         return $this->_math->binaryToInteger($binary);
     }
 
@@ -98,5 +187,4 @@ class Zend_Crypt_Math extends Zend_Crypt_Math_BigInteger
     {
         return $this->_math->integerToBinary($integer);
     }
-
 }

tests/Zend/Crypt/MathTest.php

@@ -21,7 +21,7 @@
  */
 
 require_once 'Zend/Crypt/Math.php';
-
+require_once 'Zend/Crypt/Exception.php';
 
 /**
  * @category   Zend
@@ -36,8 +36,7 @@ class Zend_Crypt_MathTest extends PHPUnit_Framework_TestCase
 
     public function testRand()
     {
-        if (!extension_loaded('bcmath'))
-        {
+        if (!extension_loaded('bcmath')) {
             $this->markTestSkipped('Extension bcmath not loaded');
         }
 
@@ -59,4 +58,74 @@ class Zend_Crypt_MathTest extends PHPUnit_Framework_TestCase
         $this->assertTrue(bccomp($result, $lower) !== '-1');
     }
 
+    public function testRandBytes()
+    {
+        for ($length = 1; $length < 4096; $length++) {
+            $rand = Zend_Crypt_Math::randBytes($length);
+            $this->assertTrue(false !== $rand);
+            $this->assertEquals($length, strlen($rand));
+        }
+    }
+
+    public function testRandInteger()
+    {
+        for ($i = 0; $i < 1024; $i++) {
+            $min = rand(1, PHP_INT_MAX/2);
+            $max = $min + rand(1, PHP_INT_MAX/2 - 1);
+            $rand = Zend_Crypt_Math::randInteger($min, $max);
+            $this->assertGreaterThanOrEqual($min, $rand);
+            $this->assertLessThanOrEqual($max, $rand);
+        }
+    }
+
+    public static function provideRandInt()
+    {
+        return [
+            [2, 1, 10000, 100, 0.9, 1.1, false],
+            [2, 1, 10000, 100, 0.8, 1.2, true]
+        ];
+    }
+
+    /**
+     * A Monte Carlo test that generates $cycles numbers from 0 to $tot
+     * and test if the numbers are above or below the line y=x with a
+     * frequency range of [$min, $max]
+     *
+     * @dataProvider provideRandInt
+     */
+    public function testMontecarloRandInteger($num, $valid, $cycles, $tot, $min, $max, $strong)
+    {
+        try {
+            $test = Zend_Crypt_Math::randBytes(1, $strong);
+        } catch (Zend_Crypt_Exception $e) {
+            $this->markTestSkipped($e->getMessage());
+        }
+
+        $i     = 0;
+        $count = 0;
+        do {
+            $up   = 0;
+            $down = 0;
+            for ($i = 0; $i < $cycles; $i++) {
+                $x = Zend_Crypt_Math::randInteger(0, $tot, $strong);
+                $y = Zend_Crypt_Math::randInteger(0, $tot, $strong);
+                if ($x > $y) {
+                    $up++;
+                } elseif ($x < $y) {
+                    $down++;
+                }
+            }
+            $this->assertGreaterThan(0, $up);
+            $this->assertGreaterThan(0, $down);
+            $ratio = $up / $down;
+            if ($ratio > $min && $ratio < $max) {
+                $count++;
+            }
+            $i++;
+        } while ($i < $num && $count < $valid);
+
+        if ($count < $valid) {
+            $this->fail('The random number generator failed the Monte Carlo test');
+        }
+    }
 }