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diff --git a/src/DotNetOpenAuth.OpenId/OpenId/Extensions/OpenIdExtensionFactoryAggregator.cs b/src/DotNetOpenAuth.OpenId/OpenId/Extensions/OpenIdExtensionFactoryAggregator.cs
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+++ b/src/DotNetOpenAuth.OpenId/OpenId/Extensions/OpenIdExtensionFactoryAggregator.cs
@@ -0,0 +1,81 @@
+//-----------------------------------------------------------------------
+// <copyright file="OpenIdExtensionFactoryAggregator.cs" company="Andrew Arnott">
+//     Copyright (c) Andrew Arnott. All rights reserved.
+// </copyright>
+//-----------------------------------------------------------------------
+
+namespace DotNetOpenAuth.OpenId.Extensions {
+	using System.Collections.Generic;
+	using System.Diagnostics.Contracts;
+	using DotNetOpenAuth.Messaging;
+	using DotNetOpenAuth.OpenId.ChannelElements;
+	using DotNetOpenAuth.OpenId.Messages;
+
+	/// <summary>
+	/// An OpenID extension factory that only delegates extension
+	/// instantiation requests to other factories.
+	/// </summary>
+	internal class OpenIdExtensionFactoryAggregator : IOpenIdExtensionFactory {
+		/// <summary>
+		/// The list of factories this factory delegates to.
+		/// </summary>
+		private List<IOpenIdExtensionFactory> factories = new List<IOpenIdExtensionFactory>(2);
+
+		/// <summary>
+		/// Initializes a new instance of the <see cref="OpenIdExtensionFactoryAggregator"/> class.
+		/// </summary>
+		internal OpenIdExtensionFactoryAggregator() {
+		}
+
+		/// <summary>
+		/// Gets the extension factories that this aggregating factory delegates to.
+		/// </summary>
+		/// <value>A list of factories.  May be empty, but never null.</value>
+		internal IList<IOpenIdExtensionFactory> Factories {
+			get { return this.factories; }
+		}
+
+		#region IOpenIdExtensionFactory Members
+
+		/// <summary>
+		/// Creates a new instance of some extension based on the received extension parameters.
+		/// </summary>
+		/// <param name="typeUri">The type URI of the extension.</param>
+		/// <param name="data">The parameters associated specifically with this extension.</param>
+		/// <param name="baseMessage">The OpenID message carrying this extension.</param>
+		/// <param name="isProviderRole">A value indicating whether this extension is being received at the OpenID Provider.</param>
+		/// <returns>
+		/// An instance of <see cref="IOpenIdMessageExtension"/> if the factory recognizes
+		/// the extension described in the input parameters; <c>null</c> otherwise.
+		/// </returns>
+		/// <remarks>
+		/// This factory method need only initialize properties in the instantiated extension object
+		/// that are not bound using <see cref="MessagePartAttribute"/>.
+		/// </remarks>
+		public IOpenIdMessageExtension Create(string typeUri, IDictionary<string, string> data, IProtocolMessageWithExtensions baseMessage, bool isProviderRole) {
+			foreach (var factory in this.factories) {
+				IOpenIdMessageExtension result = factory.Create(typeUri, data, baseMessage, isProviderRole);
+				if (result != null) {
+					return result;
+				}
+			}
+
+			return null;
+		}
+
+		#endregion
+
+		/// <summary>
+		/// Loads the default factory and additional ones given by the configuration.
+		/// </summary>
+		/// <returns>A new instance of <see cref="OpenIdExtensionFactoryAggregator"/>.</returns>
+		internal static OpenIdExtensionFactoryAggregator LoadFromConfiguration() {
+			Contract.Ensures(Contract.Result<OpenIdExtensionFactoryAggregator>() != null);
+			var factoriesElement = DotNetOpenAuth.Configuration.DotNetOpenAuthSection.Configuration.OpenId.ExtensionFactories;
+			var aggregator = new OpenIdExtensionFactoryAggregator();
+			aggregator.Factories.Add(new StandardOpenIdExtensionFactory());
+			aggregator.factories.AddRange(factoriesElement.CreateInstances(false));
+			return aggregator;
+		}
+	}
+}