<?php
/**
 * @author      Jan Altensen (Stricted)
 * @copyright   2013-2014 Jan Altensen (Stricted)
 * @license     GNU Lesser General Public License <http://opensource.org/licenses/lgpl-license.php>
 */
class hash {
	/**
	 * raw output
	 * @var	string
	 */
	protected $raw = '';
	
	/**
	 * hash with hmac
	 * @var	string
	 */
	protected $hmac = '';
	
	/**
	 * hmac key
	 * @var	string
	 */
	protected $key = '';
	
	/**
	 * hash algorithm
	 * @var	string
	 */
	protected $algo = '';
	
	/**
	 * constructor to validate algorithm
	 *
	 * @param	string	$algo
	 * @param	string	$raw
	 * @param	string	$hmac
	 * @param	string	$key
	 */
	public function __construct ($algo, $raw = '', $hmac = '', $key = '') {
		$this->raw = $raw;
		$this->hmac = $hmac;
		$this->key = $key;
		
		if (in_array($algo, hash_algos())) {
			$this->algo = $algo;
		}
		else {
			die("algorithm ".$algo." not supported");
		}
	}
	
	/**
	 * hash given data with given algorithm
	 *
	 * @param	string	$data
	 * @return	string
	 */
	public function hash ($data) {
		if (!empty($this->hmac)) {
			return hash_hmac($this->algo, $data, $this->key, $this->raw);
		}
		else {
			return hash($this->algo, $data, $this->raw);
		}
	}
	
	/**
	 * hash given file with given algorithm
	 *
	 * @param	string	$file
	 * @return	string
	 */
	public function hash_file ($file) {
		if (!empty($this->hmac)) {
			return hash_hmac_file($this->algo, $file, $this->key, $this->raw);
		}
		else {
			return hash_file($this->algo, $file, $this->raw);
		}
	}
	
	/**
	 * compare the given data
	 *
	 * @param	string	$hash
	 * @param	string	$data
	 * @return	boolean
	 */
	public function compare ($hash, $data) {
		$newhash = $this->hash($data);
		
		if ($newhash == $hash) {
			return true;
		}
		
		return false;
	}
	
	/**
	 * compare the given file
	 *
	 * @param	string	$hash
	 * @param	string	$file
	 * @return	boolean
	 */
	public function compare_file ($hash, $file) {
		$newhash = $this->hash_file($file);
		
		if ($newhash == $hash) {
			return true;
		}
		
		return false;
	}
}
?>