class SimpleERP {    private $_config;    private $_domain;    private $_private_pem="./private.pem";    public function __construct() {           if(version_compare(PHP_VERSION,'5.5.9','<'))  die('require PHP > 5.5.9 !');        $this->_config = require 'config.php';    }    public function login() {        $user["tokenEnc"] = $this->_config['AUTH_TOKEN_ENC'];        $user['sign'] =$this->getSign($this->_config['AUTH_TOKEN_ENC']);        $urlData= http_build_query($user);                $url = $this->_config['WEB_URL'] . "system/user/loginByToken.do";        $header=array(            'user-agent:SIMPLE-HTTPCLIENT-RELEASED-RSA2',            'Content-Type:application/x-www-form-urlencoded;charset=utf-8'        );        $res = HttpService::postRequest($url, $urlData,$header);        var_dump($res);    }        private function getSign($data=""){        $private_key= file_get_contents($this->_private_pem);        $res= openssl_get_privatekey($private_key);        openssl_sign($data, $sign,$res,OPENSSL_ALGO_SHA256);        return  base64_encode($sign);    }}

1、php版本最好5.6  我用5.4版本同样的秘钥失败

2、加密的格式

3、加密好的签名进行base64转码获得字符串

4、url拼接http_build_query

5、header头部发送的设置