1 files changed, 75 insertions, 0 deletions
diff --git a/src/DotNetOpenAuth.OAuth2.AuthorizationServer/OAuth2/ChannelElements/ClientAuthenticationModuleBase.cs b/src/DotNetOpenAuth.OAuth2.AuthorizationServer/OAuth2/ChannelElements/ClientAuthenticationModuleBase.cs
new file mode 100644
index 0000000..262116d
--- /dev/null
+++ b/src/DotNetOpenAuth.OAuth2.AuthorizationServer/OAuth2/ChannelElements/ClientAuthenticationModuleBase.cs
@@ -0,0 +1,75 @@
+//-----------------------------------------------------------------------
+// <copyright file="ClientAuthenticationModuleBase.cs" company="Andrew Arnott">
+//     Copyright (c) Andrew Arnott. All rights reserved.
+// </copyright>
+//-----------------------------------------------------------------------
+
+namespace DotNetOpenAuth.OAuth2.ChannelElements {
+	using System;
+	using System.Collections.Generic;
+	using System.Linq;
+	using System.Text;
+	using System.Threading;
+	using System.Web;
+	using DotNetOpenAuth.Messaging;
+	using DotNetOpenAuth.OAuth2.Messages;
+
+	/// <summary>
+	/// A convenient base class for imlementations of the <see cref="IClientAuthenticationModule"/> interface.
+	/// </summary>
+	public abstract class ClientAuthenticationModuleBase : IClientAuthenticationModule {
+		/// <summary>
+		/// Initializes a new instance of the <see cref="ClientAuthenticationModuleBase"/> class.
+		/// </summary>
+		protected ClientAuthenticationModuleBase() {
+		}
+
+		/// <summary>
+		/// Attempts to extract client identification/authentication information from a message.
+		/// </summary>
+		/// <param name="requestMessage">The incoming message.</param>
+		/// <param name="clientIdentifier">Receives the client identifier, if one was found.</param>
+		/// <returns>The level of the extracted client information.</returns>
+		public abstract ClientAuthenticationResult TryAuthenticateClient(AuthenticatedClientRequestBase requestMessage, out string clientIdentifier);
+
+		/// <summary>
+		/// Attempts to extract client identification/authentication information from a message.
+		/// </summary>
+		/// <param name="requestMessage">The incoming message.  Always an instance of <see cref="AuthenticatedClientRequestBase"/></param>
+		/// <param name="clientIdentifier">Receives the client identifier, if one was found.</param>
+		/// <returns>The level of the extracted client information.</returns>
+		public ClientAuthenticationResult TryAuthenticateClient(IDirectedProtocolMessage requestMessage, out string clientIdentifier) {
+			return this.TryAuthenticateClient((AuthenticatedClientRequestBase)requestMessage, out clientIdentifier);
+		}
+
+		/// <summary>
+		/// Validates a client identifier and shared secret against the authoriation server's database.
+		/// </summary>
+		/// <param name="authorizationServerHost">The authorization server host; cannot be <c>null</c>.</param>
+		/// <param name="clientIdentifier">The alleged client identifier.</param>
+		/// <param name="clientSecret">The alleged client secret to be verified.</param>
+		/// <returns>An indication as to the outcome of the validation.</returns>
+		protected static ClientAuthenticationResult TryAuthenticateClient(IAuthorizationServerHost authorizationServerHost, string clientIdentifier, string clientSecret) {
+			Requires.NotNull(authorizationServerHost, "authorizationServerHost");
+
+			if (!string.IsNullOrEmpty(clientIdentifier)) {
+				var client = authorizationServerHost.GetClient(clientIdentifier);
+				if (client != null) {
+					if (!string.IsNullOrEmpty(clientSecret)) {
+						if (client.IsValidClientSecret(clientSecret)) {
+							return ClientAuthenticationResult.ClientAuthenticated;
+						} else { // invalid client secret
+							return ClientAuthenticationResult.ClientAuthenticationRejected;
+						}
+					} else { // no client secret provided
+						return ClientAuthenticationResult.ClientIdNotAuthenticated;
+					}
+				} else { // The client identifier is not recognized.
+					return ClientAuthenticationResult.ClientAuthenticationRejected;
+				}
+			} else { // no client id provided.
+				return ClientAuthenticationResult.NoAuthenticationRecognized;
+			}
+		}
+	}
+}