Make an HTTP POST authentication basic request using Javascript

Question

I want to use JavaScript to perform a POST request using the common "Authorization: Basic" method. The server hosts an OWIN C# App and on successful authentication it should give me a token in JSON format.

This is the wireshark equivalent of what I want to accomplish using plain Javascript:

    POST /connect/token HTTP/1.1
    Authorization: Basic c2lsaWNvbjpGNjIxRjQ3MC05NzMxLTRBMjUtODBFRi02N0E2RjdDNUY0Qjg=
    Content-Type: application/x-www-form-urlencoded
    Host: localhost:44333
    Content-Length: 40
    Expect: 100-continue
    Connection: Keep-Alive

    HTTP/1.1 100 Continue

    grant_type=client_credentials&scope=api1HTTP/1.1 200 OK
    Cache-Control: no-store, no-cache, max-age=0, private
    Pragma: no-cache
    Content-Length: 91
    Content-Type: application/json; charset=utf-8
    Server: Microsoft-HTTPAPI/2.0
    Date: Fri, 17 Jul 2015 08:52:23 GMT

    {"access_token":"c1cad8180e11deceb43bc1545c863695","expires_in":3600,"token_type":"Bearer"}

is it possible to do so? If so, how?

Solution

This is the javascript request:

var clientId = "MyApp";
var clientSecret = "MySecret";

// var authorizationBasic = $.base64.btoa(clientId + ':' + clientSecret);
var authorizationBasic = window.btoa(clientId + ':' + clientSecret);

var request = new XMLHttpRequest();
request.open('POST', oAuth.AuthorizationServer, true);
request.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded; charset=UTF-8');
request.setRequestHeader('Authorization', 'Basic ' + authorizationBasic);
request.setRequestHeader('Accept', 'application/json');
request.send("username=John&password=Smith&grant_type=password");

request.onreadystatechange = function () {
    if (request.readyState === 4) {
       alert(request.responseText);
    }
};

and this is the jQuery version:

var clientId = "MyApp";
var clientSecret = "MySecret";

// var authorizationBasic = $.base64.btoa(clientId + ':' + clientSecret);
var authorizationBasic = window.btoa(clientId + ':' + clientSecret);

$.ajax({
    type: 'POST',
    url: oAuth.AuthorizationServer,
    data: { username: 'John', password: 'Smith', grant_type: 'password' },
    dataType: "json",
    contentType: 'application/x-www-form-urlencoded; charset=utf-8',
    xhrFields: {
       withCredentials: true
    },
    // crossDomain: true,
    headers: {
       'Authorization': 'Basic ' + authorizationBasic
    },
    //beforeSend: function (xhr) {
    //},
    success: function (result) {
       var token = result;
    },
    //complete: function (jqXHR, textStatus) {
    //},
    error: function (req, status, error) {
    alert(error);
    }
});

In both situation I've encoded the clientId and the clientSecret in a string base64 using a jquery plugin. I am pretty sure you can find something similar in plain javascript.

This is a project where you have a Owin Web Api running in a console and a project where you can test your request in a web page using jQuery or the plain vanilla javascript. You might need to change the urls for the requests.