/** 退款通知解密* @Author WangZhaoBo* @param $str 微信同步的加密串req_info* @param $key 商户key*/
public function refund_decrypt($str) {$key = md5($this->appSecret);$str = base64_decode($str);$str = mcrypt_decrypt(MCRYPT_RIJNDAEL_128, $key, $str, MCRYPT_MODE_ECB);$block = mcrypt_get_block_size('rijndael_128', 'ecb');$pad = ord($str[($len = strlen($str)) - 1]);$len = strlen($str);$pad = ord($str[$len - 1]);return substr($str, 0, strlen($str) - $pad);
}

/***     作用：生成256签名*/public function get256Sign($Obj,$key = null){foreach ($Obj as $k => $v){$Parameters[$k] = $v;}//签名步骤一：按字典序排序参数
        ksort($Parameters);$String = $this->formatBizQueryParaMap($Parameters, false);//echo '【string1refund_decrypt】'.$String.'</br>';//签名步骤二：在string后加入KEYif(is_null($key)){$key =  WxPayConf_pub::$KEY;$String = $String."&key=".WxPayConf_pub::$KEY;}else{$String = $String."&key=".$key;}echo $String;//签名步骤三：MD5加密//$String = md5($String);$String = hash_hmac("sha256", $str, $key);//echo "【string3】 ".$String."</br>";//签名步骤四：所有字符转为大写$result_ = strtoupper($String);//echo "【result】 ".$result_."</br>";return $result_;}

//region 证书解密start public function decodePem(){$ciphertext = '加密后的证书内容';$nonce = '加密证书的随机串,加密证书的随机串';$associated_data = '加密证书的随机串,固定值： certificate';$key = '你的APIv3密钥';$check_sodium_mod = extension_loaded('sodium');if($check_sodium_mod === false){echo '没有安装sodium模块';die;}$check_aes256gcm = sodium_crypto_aead_aes256gcm_is_available();if($check_aes256gcm === false){echo '当前不支持aes256gcm';die;}$pem = sodium_crypto_aead_aes256gcm_decrypt(base64_decode($ciphertext),$associated_data,$nonce,$key);var_dump($pem); //这是解密出来的证书内容,复制出来保存就行了
    }//endregion 证书解密end 

ParagonIE_Sodium_Compat::crypto_aead_aes256gcm_decrypt($ciphertext,$associated_data,$nonce,$key);