Hashing Utilities

Utilities.Hash.php

<?php

	namespace Utilities;

	class Hash
	{

		const PASSWORD_STRENGTHENING = 50000;

		/**
		 * Allows for salt outside of this class
		 *
		 * @author  Gavin Staniforth <@gsphpdev>
		 * @param     String $string
		 * @param     String $salt
		 * @return  {hash: (128char), salt: (32char)}
		 */
		public static function hash($string, $salt=null)
		{
			if($salt === null){
				// Convert from null, to an empty string
				$salt = (string)$salt;

				// create a 128 char random salt
				for($i=0;$i<128;++$i){
					// use the ascii character set to create a random char, http://www.asciitable.com/
					$salt += chr(rand(33, 122));
				}

				// hash it up so ensure its 'always' 32 chars & A-Z0-9. so the field salt === varchar(32)
				$salt = md5($salt);
			}

			$hash = $string;

			for($i=0;$i<self::PASSWORD_STRENGTHENING;++$i){
				$hash = hash('sha512', $hash . $salt);
			}

			return (object)array(
				'hash' => $hash,
				'salt' => $salt
			);
		}

		/**
		 * Asserts a match
		 *
		 * @author  Gavin Staniforth <@gsphpdev>
		 * @param     String $string
		 * @param     String $hash
		 * @param     String $salt
		 * @return  boolean
		 */
		public static function assert($string, $hash, $salt)
		{
			$currentHash = $string;

			for($i=0;$i<self::PASSWORD_STRENGTHENING;++$i){
				$currentHash = hash('sha512', $currentHash . $salt);
			}

			return (bool)($currentHash === $hash);
		}

	}

	$x = Hash::hash('password');
	echo '<h1>Hashed Dump</h1><pre>' . print_r($x, true) . '</pre>';

	$b = Hash::assert('password', $x->hash, $x->salt);
	echo '<h1>Assert Dump</h1>' . var_dump($b);