我正在尝试实现3d安全。我有一个xml，其中包含3d安全所需的一些数据。类似：
<CardinalMPI>
<MsgType>cmpi_lookup</MsgType>
<Version>1.7</Version>
<ProcessorId>xxx</ProcessorId>
<MerchantId>xxxxxx</MerchantId>
<TransactionPwd>xxxxxxxxxxx</TransactionPwd>
<TransactionType>C</TransactionType>
<Amount>56999</Amount>
<CurrencyCode>xxxxx</CurrencyCode>
<OrderNumber>xxxx</OrderNumber>
<CardNumber>xxx</CardNumber>
<CardExpMonth>xxx</CardExpMonth>
<CardExpYear>xxx</CardExpYear>
</CardinalMPI>
那么我该如何请求http://msgtest.bankserv.co.za/maps/txns.asp使用上面的xml并得到他们的响应？我试过卷发、香皂等，但都错了。请帮我提供一些详细的答案。
我尝试了以下代码。如果这个代码不正确，请告诉我。
$writer = new XMLWriter();
$writer->openMemory();
$writer->startElement("CardinalMPI");
$writer->writeElement("MsgType","cmpi_lookup");
$writer->writeElement("Version","1.7");
$writer->writeElement("ProcessorId","xxxxx");
$writer->writeElement("MerchantId","xxxxxxx");
$writer->writeElement("TransactionPwd","xxxxx");
$writer->writeElement("TransactionType","C");
$writer->writeElement("Amount",$xxxx);
$writer->writeElement("CurrencyCode","xxxx");
$writer->writeElement("OrderNumber","xxxxxxxxxx");
$writer->writeElement("CardNumber","'xxxxxxxxx");
$writer->writeElement("CardExpMonth","xx");
$writer->writeElement("CardExpYear","xxxx");
$writer->endElement();
$writer->endElement();
$writer->endDocument();
$request = $writer->outputMemory(true);
$serviceArguments = array("validateRequest"=>"0","protocol"=>"v_xml","protocolVersion"=>"2.0","request"=> $request);
$client = new SoapClient("msgtest.bankserv.co.za/maps/txns.asp", array('local_cert'=> "certificate.pem"));
$result = $client->Execute($serviceArguments);
$xml=$result->ExecuteResult;
当我运行这个代码时，我会得到异常。
对于发布值，我们可以在php中使用CURL。在这里你可以使用：
$ch = curl_init();
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_setopt($ch, CURLOPT_RETURNTRANSFER,1);
curl_setopt($ch, CURLOPT_URL, "your url");
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, "yr_variable=".$your xml);
$result=curl_exec($ch);
curl_close($ch);