1 files changed, 201 insertions, 0 deletions
diff --git a/src/DotNetOpenAuth.OAuth.ServiceProvider/OAuth/ChannelElements/TokenHandlingBindingElement.cs b/src/DotNetOpenAuth.OAuth.ServiceProvider/OAuth/ChannelElements/TokenHandlingBindingElement.cs
new file mode 100644
index 0000000..596336a
--- /dev/null
+++ b/src/DotNetOpenAuth.OAuth.ServiceProvider/OAuth/ChannelElements/TokenHandlingBindingElement.cs
@@ -0,0 +1,201 @@
+//-----------------------------------------------------------------------
+// <copyright file="TokenHandlingBindingElement.cs" company="Andrew Arnott">
+//     Copyright (c) Andrew Arnott. All rights reserved.
+// </copyright>
+//-----------------------------------------------------------------------
+
+namespace DotNetOpenAuth.OAuth.ChannelElements {
+	using System;
+	using System.Collections.Generic;
+	using System.Diagnostics.CodeAnalysis;
+	using System.Diagnostics.Contracts;
+	using System.Linq;
+	using System.Text;
+	using DotNetOpenAuth.Configuration;
+	using DotNetOpenAuth.Messaging;
+	using DotNetOpenAuth.OAuth.Messages;
+
+	/// <summary>
+	/// A binding element for Service Providers to manage the 
+	/// callbacks and verification codes on applicable messages.
+	/// </summary>
+	internal class TokenHandlingBindingElement : IChannelBindingElement {
+		/// <summary>
+		/// The token manager offered by the service provider.
+		/// </summary>
+		private IServiceProviderTokenManager tokenManager;
+
+		/// <summary>
+		/// The security settings for this service provider.
+		/// </summary>
+		private ServiceProviderSecuritySettings securitySettings;
+
+		/// <summary>
+		/// Initializes a new instance of the <see cref="TokenHandlingBindingElement"/> class.
+		/// </summary>
+		/// <param name="tokenManager">The token manager.</param>
+		/// <param name="securitySettings">The security settings.</param>
+		[SuppressMessage("Microsoft.Globalization", "CA1303:Do not pass literals as localized parameters", MessageId = "System.Diagnostics.Contracts.__ContractsRuntime.Requires<System.ArgumentNullException>(System.Boolean,System.String,System.String)", Justification = "Code contract"), SuppressMessage("Microsoft.Naming", "CA2204:Literals should be spelled correctly", MessageId = "securitySettings", Justification = "Code contracts")]
+		internal TokenHandlingBindingElement(IServiceProviderTokenManager tokenManager, ServiceProviderSecuritySettings securitySettings) {
+			Requires.NotNull(tokenManager, "tokenManager");
+			Requires.NotNull(securitySettings, "securitySettings");
+
+			this.tokenManager = tokenManager;
+			this.securitySettings = securitySettings;
+		}
+
+		#region IChannelBindingElement Members
+
+		/// <summary>
+		/// Gets or sets the channel that this binding element belongs to.
+		/// </summary>
+		/// <remarks>
+		/// This property is set by the channel when it is first constructed.
+		/// </remarks>
+		public Channel Channel { get; set; }
+
+		/// <summary>
+		/// Gets the protection commonly offered (if any) by this binding element.
+		/// </summary>
+		/// <remarks>
+		/// This value is used to assist in sorting binding elements in the channel stack.
+		/// </remarks>
+		public MessageProtections Protection {
+			get { return MessageProtections.None; }
+		}
+
+		/// <summary>
+		/// Prepares a message for sending based on the rules of this channel binding element.
+		/// </summary>
+		/// <param name="message">The message to prepare for sending.</param>
+		/// <returns>
+		/// The protections (if any) that this binding element applied to the message.
+		/// Null if this binding element did not even apply to this binding element.
+		/// </returns>
+		/// <remarks>
+		/// Implementations that provide message protection must honor the
+		/// <see cref="MessagePartAttribute.RequiredProtection"/> properties where applicable.
+		/// </remarks>
+		public MessageProtections? ProcessOutgoingMessage(IProtocolMessage message) {
+			var userAuthResponse = message as UserAuthorizationResponse;
+			if (userAuthResponse != null && userAuthResponse.Version >= Protocol.V10a.Version) {
+				var requestToken = this.tokenManager.GetRequestToken(userAuthResponse.RequestToken);
+				requestToken.VerificationCode = userAuthResponse.VerificationCode;
+				this.tokenManager.UpdateToken(requestToken);
+				return MessageProtections.None;
+			}
+
+			// Hook to store the token and secret on its way down to the Consumer.
+			var grantRequestTokenResponse = message as UnauthorizedTokenResponse;
+			if (grantRequestTokenResponse != null) {
+				this.tokenManager.StoreNewRequestToken(grantRequestTokenResponse.RequestMessage, grantRequestTokenResponse);
+
+				// The host may have already set these properties, but just to make sure...
+				var requestToken = this.tokenManager.GetRequestToken(grantRequestTokenResponse.RequestToken);
+				requestToken.ConsumerVersion = grantRequestTokenResponse.Version;
+				if (grantRequestTokenResponse.RequestMessage.Callback != null) {
+					requestToken.Callback = grantRequestTokenResponse.RequestMessage.Callback;
+				}
+				this.tokenManager.UpdateToken(requestToken);
+
+				return MessageProtections.None;
+			}
+
+			return null;
+		}
+
+		/// <summary>
+		/// Performs any transformation on an incoming message that may be necessary and/or
+		/// validates an incoming message based on the rules of this channel binding element.
+		/// </summary>
+		/// <param name="message">The incoming message to process.</param>
+		/// <returns>
+		/// The protections (if any) that this binding element applied to the message.
+		/// Null if this binding element did not even apply to this binding element.
+		/// </returns>
+		/// <exception cref="ProtocolException">
+		/// Thrown when the binding element rules indicate that this message is invalid and should
+		/// NOT be processed.
+		/// </exception>
+		/// <remarks>
+		/// Implementations that provide message protection must honor the
+		/// <see cref="MessagePartAttribute.RequiredProtection"/> properties where applicable.
+		/// </remarks>
+		public MessageProtections? ProcessIncomingMessage(IProtocolMessage message) {
+			var authorizedTokenRequest = message as AuthorizedTokenRequest;
+			if (authorizedTokenRequest != null) {
+				if (authorizedTokenRequest.Version >= Protocol.V10a.Version) {
+					string expectedVerifier = this.tokenManager.GetRequestToken(authorizedTokenRequest.RequestToken).VerificationCode;
+					ErrorUtilities.VerifyProtocol(string.Equals(authorizedTokenRequest.VerificationCode, expectedVerifier, StringComparison.Ordinal), OAuthStrings.IncorrectVerifier);
+					return MessageProtections.None;
+				}
+
+				this.VerifyThrowTokenTimeToLive(authorizedTokenRequest);
+			}
+
+			var userAuthorizationRequest = message as UserAuthorizationRequest;
+			if (userAuthorizationRequest != null) {
+				this.VerifyThrowTokenTimeToLive(userAuthorizationRequest);
+			}
+
+			var accessResourceRequest = message as AccessProtectedResourceRequest;
+			if (accessResourceRequest != null) {
+				this.VerifyThrowTokenNotExpired(accessResourceRequest);
+			}
+
+			return null;
+		}
+
+		#endregion
+
+		/// <summary>
+		/// Ensures that access tokens have not yet expired.
+		/// </summary>
+		/// <param name="message">The incoming message carrying the access token.</param>
+		private void VerifyThrowTokenNotExpired(AccessProtectedResourceRequest message) {
+			Requires.NotNull(message, "message");
+
+			try {
+				IServiceProviderAccessToken token = this.tokenManager.GetAccessToken(message.AccessToken);
+				if (token.ExpirationDate.HasValue && DateTime.Now >= token.ExpirationDate.Value.ToLocalTimeSafe()) {
+					Logger.OAuth.ErrorFormat(
+						"OAuth access token {0} rejected because it expired at {1}, and it is now {2}.",
+						token.Token,
+						token.ExpirationDate.Value,
+						DateTime.Now);
+					ErrorUtilities.ThrowProtocol(OAuthStrings.TokenNotFound);
+				}
+			} catch (KeyNotFoundException ex) {
+				throw ErrorUtilities.Wrap(ex, OAuthStrings.TokenNotFound);
+			}
+		}
+
+		/// <summary>
+		/// Ensures that short-lived request tokens included in incoming messages have not expired.
+		/// </summary>
+		/// <param name="message">The incoming message.</param>
+		/// <exception cref="ProtocolException">Thrown when the token in the message has expired.</exception>
+		private void VerifyThrowTokenTimeToLive(ITokenContainingMessage message) {
+			ErrorUtilities.VerifyInternal(!(message is AccessProtectedResourceRequest), "We shouldn't be verifying TTL on access tokens.");
+			if (message == null || string.IsNullOrEmpty(message.Token)) {
+				return;
+			}
+
+			try {
+				IServiceProviderRequestToken token = this.tokenManager.GetRequestToken(message.Token);
+				TimeSpan ttl = this.securitySettings.MaximumRequestTokenTimeToLive;
+				if (DateTime.Now >= token.CreatedOn.ToLocalTimeSafe() + ttl) {
+					Logger.OAuth.ErrorFormat(
+						"OAuth request token {0} rejected because it was originally issued at {1}, expired at {2}, and it is now {3}.",
+						token.Token,
+						token.CreatedOn,
+						token.CreatedOn + ttl,
+						DateTime.Now);
+					ErrorUtilities.ThrowProtocol(OAuthStrings.TokenNotFound);
+				}
+			} catch (KeyNotFoundException ex) {
+				throw ErrorUtilities.Wrap(ex, OAuthStrings.TokenNotFound);
+			}
+		}
+	}
+}