Static class containing utilities to decrypt strings encrypted with the SLX RW EL

SlxRwEl.cs

    /// <summary>
    /// Static class containing utilities to decrypt strings encrypted with the SLX RW EL
    /// </summary>
    public class SlxRwEl
    {
        /// <summary>
        /// Decode the specified data.
        /// </summary>
        /// <param name="data"></param>
        /// <param name="key"></param>
        /// <returns></returns>
        public static String Decrypt(String data, String key)
        {            
            return InvokeRwMethod<String>("RemoveKey", data, key);
        }


        /// <summary>
        /// Decrypt key-less data (only used for RWPASS)
        /// </summary>
        /// <param name="data"></param>
        /// <returns></returns>
        public static String Decrypt(String data)
        {
            return InvokeRwMethod<String>("Remove", data);
        }

        /// <summary>
        /// Encrypt specified data.
        /// </summary>
        /// <param name="data"></param>
        /// <param name="key"></param>
        /// <returns></returns>
        public static String Encrypt(String data, String key)
        {
            return InvokeRwMethod<String>("AddKey", data, key);
        }

        /// <summary>
        /// Invoke late-bound method.
        /// TODO: add caching.
        /// </summary>
        /// <typeparam name="T1"></typeparam>
        /// <param name="methodName"></param>
        /// <param name="args"></param>
        /// <returns></returns>
        private static T1 InvokeRwMethod<T1>(string methodName, params object[] args)
        {
            Type t = Type.GetTypeFromProgID("SLXRWEL.SLXRWEOBJ");
            if (t == null)
                throw new InvalidOperationException("SLXRWEL is not available.");
            object instance = Activator.CreateInstance(t);
            try
            {            
                return (T1)t.InvokeMember(methodName, BindingFlags.InvokeMethod, null, instance, args);                
            }
            finally
            {
                System.Runtime.InteropServices.Marshal.ReleaseComObject(instance);
            }
        }
    }