1：获取

https://api.mch.weixin.qq.com/risk/getcertficates

获取到了

serial_no 和pem

与解密后是一本证书

-----BEGIN CERTIFICATE-----
MIID3DCCAsSgAwIBAgIUZPK3dQ2TBNA/Doe4YwWiLDDt+DowDQYJKoZIhvcNAQEL
BQAwXjELMAkGA1UEBhMCQ04xEzARBgNVBAoTClRlbnBheS5jb20xHTAbBgNVBAsT
FFRlbnBheS5jb20gQ0Eg****************************************
2开始对 要解密的内容加密
$data['id_card_name']=$this->controllerUnit->getEncrypt($data_micro['really_name']);
$data['id_card_number']=$this->controllerUnit->getEncrypt($data_micro['identity_id']);
$data['account_name']=$this->controllerUnit->getEncrypt($data_micro['bank_card_name']);
$data['account_number']=$this->controllerUnit->getEncrypt($data_micro['bank_card_id']);
$data['contact']=$this->controllerUnit->getEncrypt($data_micro['contract_name']);
$data['contact_phone']=$this->controllerUnit->getEncrypt($data_micro['contract_phone']);
$data['contact_email']=$this->controllerUnit->getEncrypt($data_micro['contract_email']);
2.1其中  getEncrypt（） 方法如下

public function getEncrypt($str){

    $encrypted = '';
    openssl_public_encrypt($str,$encrypted,$this->getcertficates);
    //base64编码
    $sign = base64_encode($encrypted);
    return $sign;
}

$this->getcertficates 就是 上面第一步解密后的证书
与解密后是一本证书
-----BEGIN CERTIFICATE-----
MIID3DCCAsSgAwIBAgIUZPK3dQ2TBNA/Doe4YwWiLDDt+DowDQYJKoZIhvcNAQEL
BQAwXjELMAkGA1UEBhMCQ04xEzARBgNVBA




3:发送post返回
<xml><return_code><![CDATA[FAIL]]></return_code>
<return_msg><![CDATA[解密敏感信息失败，请检查后再试]]></return_msg>
</xml>