Custom Error Handling

WsFederation Middleware Error Handling

The WsFederation Middleware by default will map unhandled Exceptions to HttpStatus codes depending on the type of Exception thrown. If more control over this error handling process is required, then the IWsFederationMiddlewareExceptionHandler interface can be replaced to provide this functionality.

IWsFederationMiddlewareExceptionHandler

/// <summary>
/// Allows exceptions in the <see cref="IdentityServerWsFederationMiddleware"/> to be handled. 
/// </summary>
public interface IWsFederationMiddlewareExceptionHandler
{
    /// <summary>
    /// Handle the exception
    /// </summary>
    /// <param name="context">HttpContext of the request</param>
    /// <param name="wsFederationException">Exception thrown during the request</param>
    /// <returns>
    /// True if the exception was handled.
    /// False if the exception should be handled by the middleware.
    /// </returns>
    bool Handle(HttpContext context, Exception wsFederationException);
}

The Handle function exposes the HttpContext and the Exception that caused the failure. If the IWsFederationMiddlewareExceptionHandler wants to handle the error, then the HttpContext can be written to directly and a true result returned. This will tell the middleware to halt any further processing or error handling.