martinchik / aspnetsaml

Very simple SAML 2.0 consumer module for ASP.NET/C#

AspNetSaml

Very simple SAML 2.0 "consumer" implementation in C# (i.e. allows adding SAML single-sign-on to your ASP.NET app, but not to provide auth services to other apps).

Consists of one short C# file you can throw into your project and start using it. Originally forked from OneLogin's .NET SAML library, but we had to fix a lot of stuff...

Usage

1. To redirect the user to the saml provider:

//specify the SAML provider url here, aka "Endpoint"
var samlEndpoint = "http://saml-provider-that-we-use.com/login/";

var request = new AuthRequest(
	"http://www.myapp.com", //put your app's "unique ID" here
	"http://www.myapp.com/SamlConsume" //assertion Consumer Url - the URL where provider will redirect authenticated users BACK
	);
	
string url = request.GetRedirectUrl(samlEndpoint);

//then redirect your user to the above "url" var
//for example, like this:
Response.Redirect(url);

2. After the user has been authenticated and redirected back to your app - you need to validate the SAML response (assertion) you have recieved from the provider.

Here's an example of how you do it in ASP.NET MVC

//ASP.NET MVC action method... But you can easily modify the code for Web-forms etc.
public ActionResult SamlConsume()
{
	//specify the certificate that your SAML provider has given to you
	string samlCertificate = @"-----BEGIN CERTIFICATE-----
BLAHBLAHBLAHBLAHBLAHBLAHBLAHBLAHBLAHBLAHBLAHBLAH123543==
-----END CERTIFICATE-----";

	Saml.Response samlResponse = new Response(samlCertificate);
	samlResponse.LoadXmlFromBase64(Request.Form["SAMLResponse"]); //SAML providers usually POST the data into this var

	if (samlResponse.IsValid())
	{
		//WOOHOO!!! user is logged in
		//YAY!
		
		//Some more optional stuff for you
		//lets extract username/firstname etc
		string username, email, firstname, lastname;
		try
		{
			username = samlResponse.GetNameID();
			email = samlResponse.GetEmail();
			firstname = samlResponse.GetFirstName();
			lastname = samlResponse.GetLastName();
		}
		catch(Exception ex)
		{
			//insert error handling code
			//no, really, please do
			return null;
		}
		
		//user has been authenticated, put your code here, like set a cookie or something...
		//or call FormsAuthentication.SetAuthCookie() or something
	}
}

(NEW!) Nuget

I've published this to Nuget.

Install-Package AspNetSaml

This will simply add the cs-file to the root of your project.

A version of this library has been used for years in production in our helpdesk app.