Hashing Class

class PassHash {
 
	// blowfish
	private static $algo = '$2a';
        /*
          The Blowfish algorithm may not be implemented in all systems,
          even though it is quite popular by now. You may check your
          system with this code:
 
          if (CRYPT_BLOWFISH == 1) {
 	    echo "Yes";
          } else {
	    echo "No";
          }
 
        */
 
 
	// cost parameter
	private static $cost = '$10';
 
	// mainly for internal use
	public static function unique_salt() {
		return substr(sha1(mt_rand()),0,22);
	}
 
	// this will be used to generate a hash
	public static function hash($password) {
 
		return crypt($password,
					self::$algo .
					self::$cost .
					'$' . self::unique_salt());
 
	}
 
	// this will be used to compare a password against a hash
	public static function check_password($hash, $password) {
 
		$full_salt = substr($hash, 0, 29);
 
		$new_hash = crypt($password, $full_salt);
 
		return ($hash == $new_hash);
 
	}
 
}