使用私有X509密钥签署xml数据类型

I need to sign an xml data type with a private X509 key Here is the code I've used: $data->save("test.xml");

$data = new DOMDocument("1.0", "utf-8");
$xml_order = $data->createElement("order");
$xml_tag1 = $data->createElement("signature","000");
$xml_tag2 = $data->createElement("service","000");
$xml_tag3 = $data->createElement("url");
$xml_tag_confirm = $data->createElement("confirm","yes");

$attr = $data->appendChild( $xml_order);
$attr->appendChild($xml_tag1);
$attr->appendChild($xml_tag2);
$url = $attr->appendChild($xml_tag3);
$url->appendChild($xml_tag_confirm);
$attr->setAttribute("type","ama");
$attr->setAttribute("id", "passwordiguess");
$attr->setAttribute("date", date("YmdHis"));
$signature;
$pkeyid = openssl_pkey_get_private(file_get_contents('./private.key'));
$keyData = openssl_pkey_get_details($pkeyid);
openssl_sign($data, $signature, $pkeyid);
openssl_free_key($pkeyid);

The error that it returns is:

Warning: openssl_sign() expects parameter 1 to be string, object given in C:\xampp\htdocs\test\index.php on line 32

well the problem is you are passing a file as a parameter , instead of a string in openssl_sign function

You should convert you xml document to string, try adding this line

 $data = new DOMDocument("1.0", "utf-8");
 $xml_order = $data->createElement("order");
 $xml_tag1 = $data->createElement("signature","000");
 $xml_tag2 = $data->createElement("service","000");
 $xml_tag3 = $data->createElement("url");
 $xml_tag_confirm = $data->createElement("confirm","yes");

 $attr = $data->appendChild( $xml_order);
 $attr->appendChild($xml_tag1);
 $attr->appendChild($xml_tag2);
 $url = $attr->appendChild($xml_tag3);
 $url->appendChild($xml_tag_confirm);
 $attr->setAttribute("type","ama");
 $attr->setAttribute("id", "passwordiguess");
 $attr->setAttribute("date", date("YmdHis"));
 /* this would convert the xml document to string  */
 $output = $data->saveXML();
 $signature;
 $pkeyid = openssl_pkey_get_private(file_get_contents('./private.key'));
 $keyData = openssl_pkey_get_details($pkeyid);
 /* then pass the $output to  openssl_sign*/
 openssl_sign($output, $signature, $pkeyid);
 openssl_free_key($pkeyid);