SaslModule.cs

using System;
using System.Collections.Generic;
using System.Reflection;
using System.Threading.Tasks;
using Waher.Events;
using Waher.Runtime.Inventory;
 
namespace Waher.Networking.SASL
{
    public class SaslModule : IModule
    {
        private static IAuthenticationMechanism[] mechanisms = Array.Empty<IAuthenticationMechanism>();
 
        public async Task Start()
        {
            mechanisms = await GetMechanisms();
            Types.OnInvalidated += Types_OnInvalidated;
        }
 
        public Task Stop()
        {
            Types.OnInvalidated -= Types_OnInvalidated;
            mechanisms = Array.Empty<IAuthenticationMechanism>();
            return Task.CompletedTask;
        }
 
        public static IAuthenticationMechanism[] Mechanisms => mechanisms;
 
        private static async void Types_OnInvalidated(object Sender, EventArgs e)
        {
            try
            {
                mechanisms = await GetMechanisms();
            }
            catch (Exception ex)
            {
                Log.Exception(ex);
            }
        }
 
        private static async Task<IAuthenticationMechanism[]> GetMechanisms()
        {
            Dictionary<string, bool> MechanismsFound = new Dictionary<string, bool>();
            List<IAuthenticationMechanism> Result = new List<IAuthenticationMechanism>();
            ConstructorInfo CI;
            IAuthenticationMechanism Mechanism;
            Type[] MechanismTypes = Types.GetTypesImplementingInterface(typeof(IAuthenticationMechanism));
 
            foreach (Type T in MechanismTypes)
            {
                if (T.IsAbstract)
                    continue;
 
                CI = T.GetConstructor(Types.NoTypes);
                if (CI is null)
                    continue;
 
                try
                {
                    Mechanism = (IAuthenticationMechanism)CI.Invoke(Types.NoParameters);
 
                    if (MechanismsFound.ContainsKey(Mechanism.Name))
                        throw new Exception("Authentication mechanism collision." + T.FullName + ": " + Mechanism.Name);
 
                    await Mechanism.Initialize();
 
                    MechanismsFound[Mechanism.Name] = true;
                    Result.Add(Mechanism);
                }
                catch (Exception ex)
                {
                    Log.Exception(ex);
                }
            }
 
            Result.Sort((m1, m2) => m2.Weight - m1.Weight);
 
            return Result.ToArray();
        }
    }
}