ITfoxtec Identity SAML 2.0

Code

The code shown is only a selection of the example code in GitHub.

The ITfoxtec Identity Saml2 package is integrated into a ASP.NET MVC Core Relying Party (RP) application by configuration in Startup and adding an Auth Controller with the following four methods. The binding shown can be changed as needed depending on the requirements.

It is furthermore possible to set some optional parameters on the Saml2AuthnRequest and Saml2LogoutRequest. On the Saml2AuthnRequest e.g. ForceAuthn is supported, which will force the user to enter login credentials even though an SSO context already exists on the Security Token Service (STS) / Identity Provider (IdP).

Add configuration to the ConfigureServices method in Startup

Configuration using IdP metadata.

services.Configure<Saml2Configuration>(Configuration.GetSection("Saml2"));
services.Configure<Saml2Configuration>(saml2Configuration =>
{
    saml2Configuration.SigningCertificate = CertificateUtil.Load(AppEnvironment.MapToPhysicalFilePath(
        Configuration["Saml2:SigningCertificateFile"]), Configuration["Saml2:SigningCertificatePassword"]);
    saml2Configuration.AllowedAudienceUris.Add(saml2Configuration.Issuer);

    var entityDescriptor = new EntityDescriptor();
    entityDescriptor.ReadIdPSsoDescriptorFromUrl(new Uri(Configuration["Saml2:IdPMetadata"]));
    if (entityDescriptor.IdPSsoDescriptor != null)
    {
        saml2Configuration.SingleSignOnDestination = entityDescriptor.IdPSsoDescriptor.SingleSignOnServices.First().Location;
        saml2Configuration.SingleLogoutDestination = entityDescriptor.IdPSsoDescriptor.SingleLogoutServices.First().Location;
        saml2Configuration.SignatureValidationCertificates.AddRange(entityDescriptor.IdPSsoDescriptor.SigningCertificates);
    }
    else
    {
        throw new Exception("IdPSsoDescriptor not loaded from metadata.");
    }
});
services.AddSaml2();   

Configuration without metadata.

services.Configure<Saml2Configuration>(Configuration.GetSection("Saml2"));
services.Configure<Saml2Configuration>(saml2Configuration =>
{
    saml2Configuration.SigningCertificate = CertificateUtil.Load(AppEnvironment.MapToPhysicalFilePath(
        Configuration["Saml2:SigningCertificateFile"]), Configuration["Saml2:SigningCertificatePassword"]);
    saml2Configuration.AllowedAudienceUris.Add(saml2Configuration.Issuer);

    saml2Configuration.SignatureValidationCertificates.Add(CertificateUtil.Load(AppEnvironment.MapToPhysicalFilePath(
        Configuration["Saml2:SignatureValidationCertificateFile"])));
});
services.AddSaml2();   

Login method in the Auth Controller

[Route("Login")]
public IActionResult Login(string returnUrl = null)
{
    var binding = new Saml2RedirectBinding();
    binding.SetRelayStateQuery(new Dictionary<string, string> 
        { { relayStateReturnUrl, returnUrl ?? Url.Content("~/") } });

    return binding.Bind(new Saml2AuthnRequest(config)).ToActionResult();
}

AssertionConsumerService method in the Auth Controller

After successfully or failing login the ACS method receiver the response.

[Route("AssertionConsumerService")]
public async Task<IActionResult> AssertionConsumerService()
{       
    var httpRequest = Request.ToGenericHttpRequest(validate: true);
    var saml2AuthnResponse = new Saml2AuthnResponse(config);

    httpRequest.Binding.Unbind(httpRequest, saml2AuthnResponse);
    await saml2AuthnResponse.CreateSession(HttpContext, 
        ClaimsTransform: (claimsPrincipal) => ClaimsTransform.Transform(claimsPrincipal));

    var returnUrl = httpRequest.Binding.GetRelayStateQuery()[relayStateReturnUrl];
    return Redirect(string.IsNullOrWhiteSpace(returnUrl) ? Url.Content("~/") : returnUrl);
}

Logout method in the Auth Controller

[HttpPost("Logout")]
[ValidateAntiForgeryToken]
public async Task<IActionResult> Logout()
{
    if (!User.Identity.IsAuthenticated)
    {
        return Redirect(Url.Content("~/"));
    }

    var binding = new Saml2PostBinding();
    var saml2LogoutRequest = await new Saml2LogoutRequest(config, User).DeleteSession(HttpContext);
    return binding.Bind(saml2LogoutRequest).ToActionResult();
}

LoggedOut method in the Auth Controller

After successfully or failing logout the logged out method receive the response.

[Route("LoggedOut")]
public IActionResult LoggedOut()
{
    var httpRequest = Request.ToGenericHttpRequest(validate: true);
    httpRequest.Binding.Unbind(httpRequest, new Saml2LogoutResponse(config));

    return Redirect(Url.Content("~/"));
}

SingleLogout method in the Auth Controller

Receives a Single Logout request and send a response.

[Route("SingleLogout")]
public async Task<IActionResult> SingleLogout()
{
    Saml2StatusCodes status;
    var httpRequest = Request.ToGenericHttpRequest(validate: true);
    var logoutRequest = new Saml2LogoutRequest(config, User);
    try
    {
        httpRequest.Binding.Unbind(httpRequest, logoutRequest);
        status = Saml2StatusCodes.Success;
        await logoutRequest.DeleteSession(HttpContext);
    }
    catch (Exception exc)
    {
        // log exception
        Debug.WriteLine("SingleLogout error: " + exc.ToString());
        status = Saml2StatusCodes.RequestDenied;
    }

    var responseBinding = new Saml2PostBinding();
    responseBinding.RelayState = httpRequest.Binding.RelayState;
    var saml2LogoutResponse = new Saml2LogoutResponse(config)
    {
        InResponseToAsString = logoutRequest.IdAsString,
        Status = status,
    };
    return responseBinding.Bind(saml2LogoutResponse).ToActionResult();
}