STIL Soap helper library

Styrelsen for IT og Læring (STIL) exposes their services via SOAP. The protocol used requires that the SOAP requests are signed with a certificate, and that the underlying HTTP connection is secured with mTLS (a client certificate).

This poses a problem for clients on Microsofts .NET platform, as signed SOAP messages are not supported on the newer .NET (Core) platform, only in the older .NET Framework platform.

This library can help you create strongly-typed and signed SOAP XML requests compatible with STIL in a way that is compatible with the newer .NET platform.

This does not use the WCF framework, but only relies only on HttpClient.

To use this library you need to have a certificate for signing the message that STIL will accept (typically an OCES certificate) and a certificate for securing the HTTP call (mTLS). The same certificate may be suitable for both uses, but that depends on your setup.

Out of the box the library also comes with some pre-built requests and responses. In the initial version, those would be the ones the authors needed in their initial application launch. These prebuilt requests and corresponding responses are exposed by the StilVeuServiceClient.

If you need to integrate with some of the other services exposed at integrationsplatformen.dk that are not currently supported, we encourage you to make a pull request to add the missing functionality. Use the implementation of StilVeuServiceClient as a guide to what to do.

If you decide you want to completely implement your own client instead, you can take a look in the Util\SoapHelper folder. The code in this location is what does the heavy lifting to go from a DTO request object to a SOAP request that STIL will accept.

How to use

Using the prebuilt client

If you happen to only require the already data implemented by StilVeuServiceClient, you can simply instantiate this class (or add it from dependency injection (see Extensions\ServiceCollectionExtensions.cs)) with a suitable certificate that STIL knows about and you should be good to go. See the DTOs folder for the currently supported operations.

If the operation you need it not one of the ones implemented, you'll need to use a raw HTTP POST operation to STIL instead, see the example below.

Using a raw request

In this example we'll assume you want to use the same certificate for signing the SOAP as well as securing the http connection. First attach the client certificate to a http client:

HttpClient GetHttpClientWithCertificateForSTIL(string certificateThumbprint)
{
  // Load from Cert Store or KeyVauly, etc.
  var certificate = GetCertificateFromThumbprint(certificateThumbprint);
  var handler = new HttpClientHandler()
  {
    ClientCertificates = { certificate }
  };
  
  // Alternatively: create a reusable one instead of new'ing up one
  var httpClientForStil = new HttpClient(handler);
  
  return httpClientForStil;
}

Then you build your DTO request and use the SignedStilSoapMessage to construct the XML SOAP message:

T request = BuildStronglyTypedRequest();

var certThumbprint = GetClientCertThumbprintFromConfig();
var clientCert = GetCertificate(certThumbprint);
var stilRequest = SignedStilSoapMessage<T>(request);

var signedRequest = stilRequest.GetSignedXml(clientCert);

Do not reformat the XML after this, as you will invalidate the signature!

Just use the signed SOAP XML as content to the HttpClient and send it to STIL:

var httpClient = GetHttpClientWithCertificateForSTIL(certThumbprint);
var content = new StringContent(signedRequest, Encoding.UTF8, "application/soap+xml");

// SOAP uses POST messages. 
var httpRequest = new HttpRequestMessage(HttpMethod.Post, "https://....");
httpRequest.Content = content;

var response = await client.SendAsync(httpRequest, HttpCompletionOption.ResponseHeadersRead);
var reply = await response.Content.ReadAsStringAsync();

The reply will now contain the SOAP response XML from STIL. You can then pick out the Body element, which will contain the actual response object. If you have the need you can also handle Faults as well.

Example using the IVEUServiceClient

The IVEUServiceClient contains a small number of service methods specific for integrationsplatformen's VEU (voksen efteruddannelse) endpoints, but you are welcome to extend this.

Setup using the service collection extension

program.cs

// uses default local certificate store, but you can optionally provide your own certificate handler
builder.Services.AddStilVeuServiceClient(builder.Configuration);

appsettings.json

"Stil": {
   "BaseUrl": "https://et.integrationsplatformen.dk",
   "SigningCertificateThumbprint": "<thumbprint for x509 certificate>"
 }

somefile.cs

// Create a request for the HentTilmeldingerVeuInteressenter method
HentTilmeldingerRequest request = new HentTilmeldingerRequest
{
    // ... set the properties of the request
};

// Call the HentTilmeldingerVeuInteressenter method and get the response
var response = await stilServiceClient.VEU.HentTilmeldingerVeuInteressenter(request);

// Use the response data
Console.WriteLine($"Number of tilmeldinger: {result.Message.hentTilmeldingerResponse.Resultat.Resultat.PersonListe.Length}");