<?php

/**
 * QuickSDK游戏同步加解密算法描述
 * @copyright quicksdk 2015
 * @author quicksdk 
 * @version quicksdk v 0.0.1 2014/9/2
 */
class quickAsy
{

	/**
	 * 解密方法
	 * $strEncode 密文
	 * $keys 解密密钥 为游戏接入时分配的 callback_key
	 */
	public static function decode($strEncode, $keys)
	{
		if (empty($strEncode)) {
			return $strEncode;
		}
		preg_match_all('(\d+)', $strEncode, $list);
		$list = $list[0];
		if (count($list) > 0) {
			$keys = self::getBytes($keys);
			for ($i = 0; $i < count($list); $i++) {
				$keyVar = $keys[$i % count($keys)];
				$data[$i] = $list[$i] - (0xff & $keyVar);
			}
			return self::toStr($data);
		} else {
			return $strEncode;
		}
	}

	/**
	 * 计算游戏同步签名
	 */
	public static function getSign($params, $callbackkey)
	{

		return md5($params['nt_data'] . $params['sign'] . $callbackkey);
	}
	
	/**
	 * 本地计算MD5签名PHP示例代码
	 * @param $callbackkey 后台分配的通信密钥
	 * @return 本地计算的md5签名值
	 */
	public static function getMd5Sign($callbackkey)
	{
		$params = $_POST;
		unset($params['sign']);
		ksort($params);
		$signKey = '';
		foreach ($params as $key => $val) {
			$signKey .= $key . '=' . $val . '&';
		}
		$signKey .= $callbackkey;
		return md5($signKey);
	}

	public static function getMd5Sign2($callbackkey, $needLinkSign = true, $signKeyName = "sign")
	{
		$params = $_POST;
		unset($params[$signKeyName]);
		ksort($params);
		$signKey = '';
		foreach ($params as $key => $val) {
			if ($signKey != '') {
				$signKey .= "&";
			}
			$signKey .= $key . '=' . $val;
		}
		if ($needLinkSign) {
			$signKey .= '&';
		}
		$signKey .= $callbackkey;
		return md5($signKey);
	}

	/**
	 * MD5签名替换
	 */
	static private function replaceMD5($md5)
	{

		strtolower($md5);
		$bytes = self::getBytes($md5);

		$len = count($bytes);

		if ($len >= 23) {
			$change = $bytes[1];
			$bytes[1] = $bytes[13];
			$bytes[13] = $change;

			$change2 = $bytes[5];
			$bytes[5] = $bytes[17];
			$bytes[17] = $change2;

			$change3 = $bytes[7];
			$bytes[7] = $bytes[23];
			$bytes[23] = $change3;
		} else {
			return $md5;
		}

		return self::toStr($bytes);
	}

	/**
	 * 转成字符数据
	 */
	private static function getBytes($string)
	{
		$bytes = array();
		for ($i = 0; $i < strlen($string); $i++) {
			$bytes[] = ord($string[$i]);
		}
		return $bytes;
	}

	/**
	 * 转化字符串
	 */
	private static function toStr($bytes)
	{
		$str = '';
		foreach ($bytes as $ch) {
			$str .= chr($ch);
		}
		return $str;
	}
}