moved the secure random class from JMSSecurityExtraBundle to Symfony (closes #3595)

9 files changed, 401 insertions, 36 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index b1c8192..251666a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,7 @@ CHANGELOG
 2.1.0
 -----
 
+ * added secure random number generator
  * [BC BREAK] The signature of ExceptionListener has changed
  * changed the HttpUtils constructor signature to take a UrlGenerator and a UrlMatcher instead of a Router
  * EncoderFactoryInterface::getEncoder() can now also take a class name as an argument
diff --git a/Core/Encoder/BasePasswordEncoder.php b/Core/Encoder/BasePasswordEncoder.php
index ae1c7d4..e73bbbd 100644
--- a/Core/Encoder/BasePasswordEncoder.php
+++ b/Core/Encoder/BasePasswordEncoder.php
@@ -11,6 +11,8 @@
 
 namespace Symfony\Component\Security\Core\Encoder;
 
+use Symfony\Component\Security\Core\Util\String;
+
 /**
  * BasePasswordEncoder is the base class for all password encoders.
  *
@@ -77,15 +79,6 @@ abstract class BasePasswordEncoder implements PasswordEncoderInterface
      */
     protected function comparePasswords($password1, $password2)
     {
-        if (strlen($password1) !== strlen($password2)) {
-            return false;
-        }
-
-        $result = 0;
-        for ($i = 0; $i < strlen($password1); $i++) {
-            $result |= ord($password1[$i]) ^ ord($password2[$i]);
-        }
-
-        return 0 === $result;
+        return String::equals($password1, $password2);
     }
 }
diff --git a/Core/Util/Prng.php b/Core/Util/Prng.php
new file mode 100644
index 0000000..ab8baa7
--- /dev/null
+++ b/Core/Util/Prng.php
@@ -0,0 +1,104 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Security\Core\Util;
+
+use Symfony\Component\HttpKernel\Log\LoggerInterface;
+
+/**
+ * A secure random number generator implementation.
+ *
+ * @author Johannes M. Schmitt <schmittjoh@gmail.com>
+ */
+final class Prng
+{
+    private $logger;
+    private $useOpenSsl;
+    private $seed;
+    private $seedUpdated;
+    private $seedLastUpdatedAt;
+    private $seedProvider;
+
+    /**
+     * Constructor.
+     *
+     * Be aware that a guessable seed will severely compromise the PRNG
+     * algorithm that is employed.
+     *
+     * @param SeedProviderInterface $provider
+     * @param LoggerInterface       $logger
+     */
+    public function __construct(SeedProviderInterface $provider = null, LoggerInterface $logger = null)
+    {
+        $this->seedProvider = $provider;
+        $this->logger = $logger;
+
+        // determine whether to use OpenSSL
+        if (defined('PHP_WINDOWS_VERSION_BUILD') && version_compare(PHP_VERSION, '5.3.4', '<')) {
+            $this->useOpenSsl = false;
+        } elseif (!function_exists('openssl_random_pseudo_bytes')) {
+            if (null !== $this->logger) {
+                $this->logger->notice('It is recommended that you enable the "openssl" extension for random number generation.');
+            }
+            $this->useOpenSsl = false;
+        } else {
+            $this->useOpenSsl = true;
+        }
+    }
+
+    /**
+     * Generates the specified number of secure random bytes.
+     *
+     * @param integer $nbBytes
+     * @return string
+     */
+    public function nextBytes($nbBytes)
+    {
+        // try OpenSSL
+        if ($this->useOpenSsl) {
+            $bytes = openssl_random_pseudo_bytes($nbBytes, $strong);
+
+            if (false !== $bytes && true === $strong) {
+                return $bytes;
+            }
+
+            if (null !== $this->logger) {
+                $this->logger->info('OpenSSL did not produce a secure random number.');
+            }
+        }
+
+        // initialize seed
+        if (null === $this->seed) {
+            if (null === $this->seedProvider) {
+                throw new \RuntimeException('You need to specify a custom seed provider.');
+            }
+
+            list($this->seed, $this->seedLastUpdatedAt) = $this->seedProvider->loadSeed();
+        }
+
+        $bytes = '';
+        while (strlen($bytes) < $nbBytes) {
+            static $incr = 1;
+            $bytes .= hash('sha512', $incr++.$this->seed.uniqid(mt_rand(), true).$nbBytes, true);
+            $this->seed = base64_encode(hash('sha512', $this->seed.$bytes.$nbBytes, true));
+
+            if (!$this->seedUpdated && $this->seedLastUpdatedAt->getTimestamp() < time() - mt_rand(1, 10)) {
+                if (null !== $this->seedProvider) {
+                    $this->seedProvider->updateSeed($this->seed);
+                }
+
+                $this->seedUpdated = true;
+            }
+        }
+
+        return substr($bytes, 0, $nbBytes);
+    }
+}
diff --git a/Core/Util/SeedProviderInterface.php b/Core/Util/SeedProviderInterface.php
new file mode 100644
index 0000000..dd960b9
--- /dev/null
+++ b/Core/Util/SeedProviderInterface.php
@@ -0,0 +1,37 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Security\Core\Util;
+
+/**
+ * Seed Provider Interface.
+ *
+ * @author Johannes M. Schmitt <schmittjoh@gmail.com>
+ */
+interface SeedProviderInterface
+{
+    /**
+     * Loads the initial seed.
+     *
+     * Whatever is returned from this method, it should not be guessable.
+     *
+     * @return array of the format array(string, DateTime) where string is the
+     *               initial seed, and DateTime is the last time it was updated
+     */
+    function loadSeed();
+
+    /**
+     * Updates the seed.
+     *
+     * @param string $seed
+     */
+    function updateSeed($seed);
+}
diff --git a/Core/Util/String.php b/Core/Util/String.php
new file mode 100644
index 0000000..096878b
--- /dev/null
+++ b/Core/Util/String.php
@@ -0,0 +1,48 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Security\Core\Util;
+
+/**
+ * String utility functions.
+ *
+ * @author Fabien Potencier <fabien@symfony.com>
+ */
+final class String
+{
+    private final function __construct()
+    {
+    }
+
+    /**
+     * Compares two strings.
+     *
+     * This method implements a constant-time algorithm to compare strings.
+     *
+     * @param string $str1 The first string
+     * @param string $str2 The second string
+     *
+     * @return Boolean true if the two strings are the same, false otherwise
+     */
+    public static function equals($str1, $str2)
+    {
+        if (strlen($str1) !== $c = strlen($str2)) {
+            return false;
+        }
+
+        $result = 0;
+        for ($i = 0; $i < $c; $i++) {
+            $result |= ord($str1[$i]) ^ ord($str2[$i]);
+        }
+
+        return 0 === $result;
+    }
+}
diff --git a/Http/RememberMe/PersistentTokenBasedRememberMeServices.php b/Http/RememberMe/PersistentTokenBasedRememberMeServices.php
index 8944672..d36eb01 100644
--- a/Http/RememberMe/PersistentTokenBasedRememberMeServices.php
+++ b/Http/RememberMe/PersistentTokenBasedRememberMeServices.php
@@ -19,6 +19,7 @@ use Symfony\Component\Security\Core\Exception\AuthenticationException;
 use Symfony\Component\Security\Core\Exception\CookieTheftException;
 use Symfony\Component\Security\Core\Authentication\RememberMe\PersistentToken;
 use Symfony\Component\Security\Core\Authentication\Token\TokenInterface;
+use Symfony\Component\Security\Core\Util\Prng;
 
 /**
  * Concrete implementation of the RememberMeServicesInterface which needs
@@ -30,6 +31,12 @@ use Symfony\Component\Security\Core\Authentication\Token\TokenInterface;
 class PersistentTokenBasedRememberMeServices extends AbstractRememberMeServices
 {
     private $tokenProvider;
+    private $prng;
+
+    public function setPrng(Prng $prng)
+    {
+        $this->prng = $prng;
+    }
 
     /**
      * Sets the token provider
@@ -79,7 +86,7 @@ class PersistentTokenBasedRememberMeServices extends AbstractRememberMeServices
         }
 
         $series = $persistentToken->getSeries();
-        $tokenValue = $this->generateRandomValue();
+        $tokenValue = $this->prng->nextBytes(64);
         $this->tokenProvider->updateToken($series, $tokenValue, new \DateTime());
         $request->attributes->set(self::COOKIE_ATTR_NAME,
             new Cookie(
@@ -101,8 +108,8 @@ class PersistentTokenBasedRememberMeServices extends AbstractRememberMeServices
      */
     protected function onLoginSuccess(Request $request, Response $response, TokenInterface $token)
     {
-        $series = $this->generateRandomValue();
-        $tokenValue = $this->generateRandomValue();
+        $series = $this->prng->nextBytes(64);
+        $tokenValue = $this->prng->nextBytes(64);
 
         $this->tokenProvider->createNewToken(
             new PersistentToken(
@@ -126,26 +133,4 @@ class PersistentTokenBasedRememberMeServices extends AbstractRememberMeServices
             )
         );
     }
-
-    /**
-     * Generates a cryptographically strong random value
-     *
-     * @return string
-     */
-    protected function generateRandomValue()
-    {
-        if (function_exists('openssl_random_pseudo_bytes')) {
-            $bytes = openssl_random_pseudo_bytes(64, $strong);
-
-            if (true === $strong && false !== $bytes) {
-                return base64_encode($bytes);
-            }
-        }
-
-        if (null !== $this->logger) {
-            $this->logger->warn('Could not produce a cryptographically strong random value. Please install/update the OpenSSL extension.');
-        }
-
-        return base64_encode(hash('sha512', uniqid(mt_rand(), true), true));
-    }
 }
diff --git a/Tests/Core/Util/PrngTest.php b/Tests/Core/Util/PrngTest.php
new file mode 100755
index 0000000..7c9b2e2
--- /dev/null
+++ b/Tests/Core/Util/PrngTest.php
@@ -0,0 +1,179 @@
+<?php
+
+namespace Symfony\Component\Security\Tests\Core\Util;
+
+use Symfony\Component\Security\Core\Util\NullSeedProvider;
+use Symfony\Component\Security\Core\Util\PrngSchema;
+use Symfony\Component\Security\Core\Util\Prng;
+
+class PrngTest extends \PHPUnit_Framework_TestCase
+{
+    /**
+     * T1: Monobit test
+     *
+     * @dataProvider getPrngs
+     */
+    public function testMonobit($prng)
+    {
+        $nbOnBits = substr_count($this->getBitSequence($prng, 20000), '1');
+        $this->assertTrue($nbOnBits > 9654 && $nbOnBits < 10346, 'Monobit test failed, number of turned on bits: '.$nbOnBits);
+    }
+
+    /**
+     * T2: Chi-square test with 15 degrees of freedom (chi-Quadrat-Anpassungstest)
+     *
+     * @dataProvider getPrngs
+     */
+    public function testPoker($prng)
+    {
+        $b = $this->getBitSequence($prng, 20000);
+        $c = array();
+        for ($i=0;$i<=15;$i++) {
+            $c[$i] = 0;
+        }
+
+        for ($j=1; $j<=5000; $j++) {
+            $k = 4 * $j - 1;
+            $c[8 * $b[$k - 3] + 4 * $b[$k - 2] + 2 * $b[$k - 1] + $b[$k]] += 1;
+        }
+
+        $f = 0;
+        for ($i=0; $i<= 15; $i++) {
+            $f += $c[$i] * $c[$i];
+        }
+
+        $Y = 16/5000 * $f - 5000;
+
+        $this->assertTrue($Y > 1.03 && $Y < 57.4, 'Poker test failed, Y = '.$Y);
+    }
+
+    /**
+     * Run test
+     *
+     * @dataProvider getPrngs
+     */
+    public function testRun($prng)
+    {
+        $b = $this->getBitSequence($prng, 20000);
+
+        $runs = array();
+        for ($i=1; $i<=6; $i++) {
+            $runs[$i] = 0;
+        }
+
+        $addRun = function($run) use (&$runs) {
+            if ($run > 6) {
+                $run = 6;
+            }
+
+            $runs[$run] += 1;
+        };
+
+        $currentRun = 0;
+        $lastBit = null;
+        for ($i=0; $i<20000; $i++) {
+            if ($lastBit === $b[$i]) {
+                $currentRun += 1;
+            } else {
+                if ($currentRun > 0) {
+                    $addRun($currentRun);
+                }
+
+                $lastBit = $b[$i];
+                $currentRun = 0;
+            }
+        }
+        if ($currentRun > 0) {
+            $addRun($currentRun);
+        }
+
+        $this->assertTrue($runs[1] > 2267 && $runs[1] < 2733, 'Runs of length 1 outside of defined interval: '.$runs[1]);
+        $this->assertTrue($runs[2] > 1079 && $runs[2] < 1421, 'Runs of length 2 outside of defined interval: '.$runs[2]);
+        $this->assertTrue($runs[3] > 502 && $runs[3] < 748, 'Runs of length 3 outside of defined interval: '.$runs[3]);
+        $this->assertTrue($runs[4] > 233 && $runs[4] < 402, 'Runs of length 4 outside of defined interval: '.$runs[4]);
+        $this->assertTrue($runs[5] > 90 && $runs[5] < 223, 'Runs of length 5 outside of defined interval: '.$runs[5]);
+        $this->assertTrue($runs[6] > 90 && $runs[6] < 233, 'Runs of length 6 outside of defined interval: '.$runs[6]);
+    }
+
+    /**
+     * Long-run test
+     *
+     * @dataProvider getPrngs
+     */
+    public function testLongRun($prng)
+    {
+        $b = $this->getBitSequence($prng, 20000);
+
+        $longestRun = 0;
+        $currentRun = $lastBit = null;
+        for ($i=0;$i<20000;$i++) {
+            if ($lastBit === $b[$i]) {
+                $currentRun += 1;
+            } else {
+                if ($currentRun > $longestRun) {
+                    $longestRun = $currentRun;
+                }
+                $lastBit = $b[$i];
+                $currentRun = 0;
+            }
+        }
+        if ($currentRun > $longestRun) {
+            $longestRun = $currentRun;
+        }
+
+        $this->assertTrue($longestRun < 34, 'Failed longest run test: '.$longestRun);
+    }
+
+    /**
+     * Serial Correlation (Autokorrelationstest)
+     *
+     * @dataProvider getPrngs
+     */
+    public function testSerialCorrelation($prng)
+    {
+        $shift = rand(1, 5000);
+        $b = $this->getBitSequence($prng, 20000);
+
+        $Z = 0;
+        for ($i=0; $i<5000; $i++) {
+            $Z += $b[$i] === $b[$i+$shift] ? 1 : 0;
+        }
+
+        $this->assertTrue($Z > 2326 && $Z < 2674, 'Failed serial correlation test: '.$Z);
+    }
+
+    public function getPrngs()
+    {
+        $prngs = array();
+
+        // openssl with fallback
+        $prng = new Prng(new NullSeedProvider());
+        $prngs[] = array($prng);
+
+        // no-openssl with custom seed provider
+        $prng = new Prng(new NullSeedProvider());
+        $this->disableOpenSsl($prng);
+        $prngs[] = array($prng);
+
+        return $prngs;
+    }
+
+    protected function disableOpenSsl($prng)
+    {
+        $ref = new \ReflectionProperty($prng, 'useOpenSsl');
+        $ref->setAccessible(true);
+        $ref->setValue($prng, false);
+    }
+
+    private function getBitSequence($prng, $length)
+    {
+        $bitSequence = '';
+        for ($i=0;$i<$length; $i+=40) {
+            $value = unpack('H*', $prng->nextBytes(5));
+            $value = str_pad(base_convert($value[1], 16, 2), 40, '0', STR_PAD_LEFT);
+            $bitSequence .= $value;
+        }
+
+        return substr($bitSequence, 0, $length);
+    }
+}
diff --git a/Tests/Core/Util/StringTest.php b/Tests/Core/Util/StringTest.php
new file mode 100755
index 0000000..fe4eae4
--- /dev/null
+++ b/Tests/Core/Util/StringTest.php
@@ -0,0 +1,14 @@
+<?php
+
+namespace Symfony\Component\Security\Tests\Core\Util;
+
+use Symfony\Component\Security\Core\Util\String;
+
+class StringTest extends \PHPUnit_Framework_TestCase
+{
+    public function testEquals()
+    {
+        $this->assertTrue(String::equals('password', 'password'));
+        $this->assertFalse(String::equals('password', 'foo'));
+    }
+}
diff --git a/Tests/Http/RememberMe/PersistentTokenBasedRememberMeServicesTest.php b/Tests/Http/RememberMe/PersistentTokenBasedRememberMeServicesTest.php
index 3b3691d..846ee9b 100644
--- a/Tests/Http/RememberMe/PersistentTokenBasedRememberMeServicesTest.php
+++ b/Tests/Http/RememberMe/PersistentTokenBasedRememberMeServicesTest.php
@@ -22,6 +22,7 @@ use Symfony\Component\HttpFoundation\ResponseHeaderBag;
 use Symfony\Component\Security\Http\RememberMe\PersistentTokenBasedRememberMeServices;
 use Symfony\Component\Security\Core\Exception\TokenNotFoundException;
 use Symfony\Component\Security\Core\Exception\CookieTheftException;
+use Symfony\Component\Security\Core\Util\Prng;
 
 class PersistentTokenBasedRememberMeServicesTest extends \PHPUnit_Framework_TestCase
 {
@@ -318,7 +319,10 @@ class PersistentTokenBasedRememberMeServicesTest extends \PHPUnit_Framework_Test
             $userProvider = $this->getProvider();
         }
 
-        return new PersistentTokenBasedRememberMeServices(array($userProvider), 'fookey', 'fookey', $options, $logger);
+        $r = new PersistentTokenBasedRememberMeServices(array($userProvider), 'fookey', 'fookey', $options, $logger);
+        $r->setPrng(new Prng());
+
+        return $r;
     }
 
     protected function getProvider()