User authentication through REST web service on a different domain - asp.net - asp.net

Question

I am looking to connect to a web service on a different domain in order to authenticate users. The Web Service itself is a RESTful service, written in Java. Data is passed to and from it in JSON.
I initially tried to connect using jQuery (see below)
function Login()
{
$.ajax({
url: "http://www.externaldomain.com/login/authenticate",
type: "POST",
dataType: "json",
contentType: "application/json",
data: "{'emailAddress':'bob#bob.com', 'password':'Password1'}",
success: LoadUsersSuccess,
error: LoadUsersError
});
}
function LoadUsersSuccess(){
alert(1);
}
function LoadUsersError(){
alert(2);
}
However, when checking on Firebug, this brought up a 405 Method Not Allowed error.
At this stage, as this is the first time I've really worked with web services, I really just wondered whether this was the best way to do things? Is it worth persevering with this method in order to find a solution, or am I best to maybe try and find a server-side answer to this issue? If so, does anyone have any examples they could post up?
Many thanks

Answer 1

Doing cross-domain web service calls in a browser is very tricky. Because it's a potential security vulnerability, browsers block these types of requests. However, there is a workaround called JSONP. If you use JSONP instead of plain JSON, you should be able to make the cross-domain request.

Answer 2

Right ok, to update where I am, I checked in firebug and on the external server and the reason why I'm getting a 405 error is because I'm doing a Get rather than a Post.
What I need to do is send the username and password, then receive a GUID back which will then be used for any future requests. I thought by having 'type:post' in the code would be enough but apparently not. Anyone know where I might be going wrong here? As I said, a novice to web services and nothing I have tried from looking online has had any effect. Many thanks

Answer 3

Ok, I got the problem solved, and I did it by going back to C# and doing it there instead of using jQuery or JSONP and I used Json.Net for handling the data received. Here is the code:
protected void uxLogin_Click(object sender, EventArgs e)
{
StringBuilder data = new StringBuilder();
data.Append("{");
data.Append("'emailAddress': '" + uxEmail.Text + "', ");
data.Append("'password': '" + uxPassword.Text + "'");
data.Append("}");
byte[] byteData = UTF8Encoding.UTF8.GetBytes(data.ToString());
string url = System.Configuration.ConfigurationManager.AppSettings["AuthenticationURL"].ToString();
string JSONCallback = string.Empty;
Uri address = new Uri(url);
// Create the web request
HttpWebRequest request = WebRequest.Create(address) as HttpWebRequest;
// Set type to POST
request.Method = "POST";
request.ContentType = "application/json";
// Create a byte array of the data we want to send
// Set the content length in the request headers
request.ContentLength = byteData.Length;
// Write data
using (Stream postStream = request.GetRequestStream())
{
postStream.Write(byteData, 0, byteData.Length);
}
// Get response
using (HttpWebResponse response = request.GetResponse() as HttpWebResponse)
{
// Get the response stream
StreamReader reader = new StreamReader(response.GetResponseStream());
// Console application output
JSONCallback = reader.ReadToEnd().ToString();
}
if (!String.IsNullOrEmpty(JSONCallback))
{
JObject jObject = JObject.Parse(JSONCallback);
if ((bool)jObject["loginResult"] == false)
{
string errorMessage = jObject["errorMessage"].ToString();
int errorCode = (int)jObject["errorCode"];
}
else
{
string idToken = jObject["idToken"].ToString();
Session["Userid"] = idToken;
Response.Redirect("~/MyDetails.aspx");
}
}
else
{
uxReturnData.Text = "The web service request was not successful - no data was returned";
}
}
Thanks anyway :)