XMLHttpRequest在NodeJs中返回状态为0的响应“未定义”

如何解决XMLHttpRequest在NodeJs中返回状态为0的响应“未定义”

我正在向EJBCA Web服务发送请求。请在下面查看我的代码。我收到undefined作为回应，正在打印的状态为0。

let XMLHttpRequest = require('xmlhttprequest').XMLHttpRequest;
process.env['NODE_TLS_REJECT_UNAUTHORIZED'] = 0;
const fs = require('fs');

let xmlhttp = new XMLHttpRequest();

xmlhttp.open('POST','https://104.211.18.242/ejbca/ejbcaws/ejbcaws',true,'ejbcaadmin','iBOTControls@123');

var strRequest = `
    <x:Envelope
    xmlns:x="http://schemas.xmlsoap.org/soap/envelope/"
    xmlns:ws="http://ws.protocol.core.ejbca.org/">
    <x:Header/>
    <x:Body>
        <ws:getAvailableCAs></ws:getAvailableCAs>
    </x:Body>
    </x:Envelope>
    `;

xmlhttp.setRequestHeader('Content-Type','text/xml; charset=utf-8');
xmlhttp.setRequestHeader('Access-Control-Allow-Origin','*');
xmlhttp.setRequestHeader('Access-Control-Allow-Methods','GET,POST,PATCH,PUT,DELETE,OPTIONS');
xmlhttp.setRequestHeader('Access-Control-Allow-Headers','Origin,X-Requested-With,Content-Type,Accept,x-client-key,x-client-token,x-client-secret,Authorization');


//send the SOAP request
xmlhttp.send(strRequest);

//Callback function for response
xmlhttp.onreadystatechange = function () {
    console.log(xmlhttp.response) // returns undefined
    console.log(xmlhttp.status) // prints 0
    fs.writeFileSync('./response.txt',xmlhttp.responseXML)
}

向此Web服务发送请求需要https客户端身份验证。通过浏览器发送请求时，我必须选择一个证书，然后收到200条响应。由于我没有将证书附加在node.js中，因此会失败吗？