/**
* 检验消息的真实性，并且获取解密后的明文.
* <ol>
* <li>利用收到的密文生成安全签名，进行签名验证</li>
* <li>若验证通过，则提取xml中的加密消息</li>
* <li>对消息进行解密</li>
* </ol>
*
* @param string $msgSignature 签名串，对应URL参数的msg_signature
* @param string $nonce 随机串，对应URL参数的nonce
* @param string $timestamp 时间戳 对应URL参数的timestamp
* @param string $postXML 密文，对应POST请求的数据
*
* @return array
*/
public function decryptMsg($msgSignature, $nonce, $timestamp, $postXML)
{
//提取密文
$array = XML::parse($postXML);
if (empty($array)) {
echo 'Invalid xml.';
}
$encrypted = $array['Encrypt'];
//验证安全签名
$signature = $this->getSHA1($this->token, $timestamp, $nonce, $encrypted);
if ($signature !== $msgSignature) {
echo 'Invalid Signature.';
}
return XML::parse($this->decrypt($encrypted, $this->appId));
}
/**
* 初始化POST请求数据
*
* @return Bag
*/
protected function prepareInput()
{
if ($this->input instanceof Bag) {
return;
}
$input = array();
if ($_SERVER['REQUEST_METHOD'] == "POST") {
$xmlInput = file_get_contents('php://input');
$array = XML::parse($xmlInput);
if (isset($array['Encrypt'])) {
$this->encryptStr = $array['Encrypt'];
}
$input = $this->getCrypt()->decryptMsg($_REQUEST['msg_signature'], $_REQUEST['nonce'], $_REQUEST['timestamp'], $xmlInput);
}
$this->input = new Bag(array_merge($_REQUEST, (array) $input));
}