Sharepoint 2013 REST api from desktop application - Authentication - authentication

Question

I am trying to consume SharePoint 2013 REST services from a Desktop application ( cross-platform, cross-os ). Application is basically a HTML page in application view.
Is there a simple way I can authenticate my calls using HTTP methods ?

Answer 1

Yes, you can get authenticated and receive a digest via a REST call.
string url = "http://Your.SP.Site";
HttpClient client = new HttpClient(new HttpClientHandler() { UseDefaultCredentials = true });
client.BaseAddress = new System.Uri(url);
string cmd = "_api/contextinfo";
client.DefaultRequestHeaders.Add("Accept", "application/json;odata=verbose");
client.DefaultRequestHeaders.Add("ContentType", "application/json");
client.DefaultRequestHeaders.Add("ContentLength", "0");
StringContent httpContent = new StringContent("");
var response = client.PostAsync(cmd, httpContent).Result;
if (response.IsSuccessStatusCode)
{
string content = response.Content.ReadAsStringAsync().Result;
JsonObject val = JsonValue.Parse(content).GetObject();
JsonObject d = val.GetNamedObject("d");
JsonObject wi = d.GetNamedObject("GetContextWebInformation");
retVal = wi.GetNamedString("FormDigestValue");
}
The above example shows how to retrieve the digest in C# with the HttpClient. This string needs to be passed as a header to all of the other rest calls you make to carry forward the authentication. You can create a credential by passing in a username and password if needed.
I have more examples here:
https://arcandotnet.wordpress.com/2015/04/01/sharepoint-2013-rest-services-using-c-and-the-httpclient-for-windows-store-apps/
You can do these calls in JavaScript as well and Microsoft has a lot of documentation on that. There is also .NET library, Microsoft.SharePoint.Client.DLL (CSOM) that simplifies this type of coding but you must have the library installed on the client.