Add libsodium as a random number source

lib/RandomLib/Source/Sodium.php

@@ -0,0 +1,82 @@
+<?php
+/**
+ * The libsodium Random Number Source
+ *
+ * This uses the libsodium secure generator to generate high strength numbers
+ *
+ * PHP version 5.3
+ *
+ * @category   PHPCryptLib
+ * @package    Random
+ * @subpackage Source
+ * @author     Anthony Ferrara <ircmaxell@ircmaxell.com>
+ * @author     Ben Ramsey <ben@benramsey.com>
+ * @copyright  2011 The Authors
+ * @license    http://www.opensource.org/licenses/mit-license.html  MIT License
+ * @version    Build @@version@@
+ * @link       https://paragonie.com/book/pecl-libsodium
+ * @link       http://pecl.php.net/package/libsodium
+ */
+
+namespace RandomLib\Source;
+
+use SecurityLib\Strength;
+
+/**
+ * The libsodium Random Number Source
+ *
+ * This uses the libsodium secure generator to generate high strength numbers
+ *
+ * @category   PHPCryptLib
+ * @package    Random
+ * @subpackage Source
+ * @author     Anthony Ferrara <ircmaxell@ircmaxell.com>
+ * @author     Ben Ramsey <ben@benramsey.com>
+ */
+class Sodium implements \RandomLib\Source {
+
+    /**
+     * A property that may be forcibly set to `false` in the constructor, for
+     * the purpose of testing this source
+     *
+     * @var bool
+     */
+    private $hasLibsodium = false;
+
+    /**
+     * Constructs a libsodium Random Number Source
+     *
+     * @param bool $useLibsodium May be set to `false` to disable libsodium for
+     *                           testing purposes
+     */
+    public function __construct($useLibsodium = true) {
+        if ($useLibsodium && extension_loaded('libsodium')) {
+            $this->hasLibsodium = true;
+        }
+    }
+
+    /**
+     * Return an instance of Strength indicating the strength of the source
+     *
+     * @return Strength An instance of one of the strength classes
+     */
+    public static function getStrength() {
+        return new Strength(Strength::HIGH);
+    }
+
+    /**
+     * Generate a random string of the specified size
+     *
+     * @param int $size The size of the requested random string
+     *
+     * @return string A string of the requested size
+     */
+    public function generate($size) {
+        if (!$this->hasLibsodium || $size < 1) {
+            return str_repeat(chr(0), $size);
+        }
+
+        return \Sodium\randombytes_buf($size);
+    }
+
+}

test/Unit/RandomLib/Source/SodiumTest.php

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+<?php
+
+namespace RandomLib\Source;
+
+use SecurityLib\Strength;
+
+
+class SodiumTest extends \PHPUnit_Framework_TestCase {
+
+    public static function provideGenerate() {
+        $data = array();
+        for ($i = 1; $i < 100; $i += 5) {
+            $not = str_repeat(chr(0), $i);
+            $data[] = array($i, $not);
+        }
+        return $data;
+    }
+
+    /**
+     */
+    public function testGetStrength() {
+        $strength = new Strength(Strength::HIGH);
+        $actual = Sodium::getStrength();
+        $this->assertEquals($actual, $strength);
+    }
+
+    /**
+     * @dataProvider provideGenerate
+     */
+    public function testGenerate($length, $not) {
+        if (!extension_loaded('libsodium')) {
+            $this->markTestSkipped('The libsodium extension is not loaded');
+        }
+
+        $rand = new Sodium;
+        $stub = $rand->generate($length);
+        $this->assertEquals($length, strlen($stub));
+        $this->assertNotEquals($not, $stub);
+    }
+
+    /**
+     * @dataProvider provideGenerate
+     */
+    public function testGenerateWithoutLibsodium($length, $not) {
+        $rand = new Sodium(false);
+        $stub = $rand->generate($length);
+        $this->assertEquals($length, strlen($stub));
+        $this->assertEquals($not, $stub);
+    }
+
+    public function testGenerateWithZeroLength() {
+        if (!extension_loaded('libsodium')) {
+            $this->markTestSkipped('The libsodium extension is not loaded');
+        }
+
+        $rand = new Sodium;
+        $stub = $rand->generate(0);
+        $this->assertEquals(0, strlen($stub));
+        $this->assertEquals('', $stub);
+    }
+
+    public function testGenerateWithZeroLengthWithoutLibsodium() {
+        $rand = new Sodium(false);
+        $stub = $rand->generate(0);
+        $this->assertEquals(0, strlen($stub));
+        $this->assertEquals('', $stub);
+    }
+}