RSA签名方式（参考代码）

 $private_key = "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";
 $pemPriKey = chunk_split($private_key, 64, "\n");
 $pemPriKey = "-----BEGIN RSA PRIVATE KEY-----\n".$pemPriKey."-----END RSA PRIVATE KEY-----\n";


 $sign = $this->sign($sign,'base64',$pemPriKey);



 public function sign($data, $code = 'base64',$priKey){
 $ret = false;
 if (openssl_sign($data, $ret, $priKey)){
 $ret = $this->_encode($ret, $code);
 }  
 return $ret;
 }




    private function _encode($data, $code){  
        switch (strtolower($code)){  
            case 'base64':  
                $data = base64_encode(''.$data);  
                break;  
            case 'hex':  
                $data = bin2hex($data);  
                break;  
            case 'bin':  
            default:  
        }  
        return $data;  
    }