How can I implement a custom challenge handler in Xamarin for iOS using IBM MobileFirst? - ios

Question

I'm trying to implement an adapter-based authentication using IBM MobileFirst Platform Foundation 6.3 and Xamarin in iOS.
I have followed the IBM documentation on how to setup a customSecurityTest, adding realms and equivalent loginModules within authenticationConfig.xml. I have then setup 2 adapter procedures:
authenticateUser with securityTest="wl_unprotected", and another
HelloFromServer with a securityTest="SingleStepAuthAdapter" that actually does a user authentication, and executing WL.Server.setActiveUser("SingleStepAuthRealm", userIdentity) to create the user identity.
I have then created an iOS app using Xamarin Studio. Tried to invoke HelloFromServer, which as expected runs my ChallengeHandler module BUT within the HandleChallenge method while trying to invoke the authenticateUser procedure on the server, it respond back with another authRequired=TRUE.
Anybody having the same problem?

Answer 1

You did not provide any useful implementation code that can be inspected for errors - add both the adapter authentication implementation as well as the client-side code of the challenge handler.
While I have no experience with Xamarin, it should be noted that in order to get started you could:
Use the same exact implementation as done in the Adapter-based authentication tutorial. That is, the implementation in the adapter files, project configuration and so on.
Follow through the native iOS implementation, also based on the tutorial
The MFP Studio project and the native iOS project can be downloaded from here.

Answer 2

If you are repeatedly getting back authRequired=true, it looks like you are not notifying the server of the success from your HandleChallenge function. You can refer to the CustomChallengeHandler.cs provided with the sample that is shipped with the component. This is coded to handle a form-based challenge. You can modify it to handle an realm for adapter-based authentication.
So, here are the changes you need to do
1) You should implement the GetAdapterAuthenticationParameters method in your ChallengeHandler class.
For example,
public AdapterAuthenticationInfo AdapterAuthenticationParameters = new AdapterAuthenticationInfo();
....
public override AdapterAuthenticationInfo GetAdapterAuthenticationParameters ()
{
return AdapterAuthenticationParameters;
}
2) In the HandleChallenge function of your ChallengeHandler class, set the isAuthRequired = true. For example,
if (challenge.ResponseJSON["authRequired"] == true)
{
WorklightProcedureInvocationData invocationData = new WorklightProcedureInvocationData("DemoAdapter",
"submitAuthentication" , new object[1]); // Add the parameters you want to pass to the adapter
AdapterAuthenticationParameters.InvocationData = invocationData;
AdapterAuthenticationParameters.RequestOptions = null;
isAdapterAuth = true;
}
else
{
isAdapterAuth = false;
authSuccess = true;
}