1 files changed, 117 insertions, 1 deletions
diff --git a/samples/DotNetOpenAuth.ApplicationBlock/TwitterConsumer.cs b/samples/DotNetOpenAuth.ApplicationBlock/TwitterConsumer.cs
index 29973c2..2e160f4 100644
--- a/samples/DotNetOpenAuth.ApplicationBlock/TwitterConsumer.cs
+++ b/samples/DotNetOpenAuth.ApplicationBlock/TwitterConsumer.cs
@@ -7,10 +7,13 @@
 namespace DotNetOpenAuth.ApplicationBlock {
 	using System;
 	using System.Collections.Generic;
+	using System.Configuration;
 	using System.IO;
 	using System.Net;
+	using System.Web;
 	using System.Xml;
 	using System.Xml.Linq;
+	using System.Xml.XPath;
 	using DotNetOpenAuth.Messaging;
 	using DotNetOpenAuth.OAuth;
 	using DotNetOpenAuth.OAuth.ChannelElements;
@@ -20,7 +23,8 @@ namespace DotNetOpenAuth.ApplicationBlock {
 	/// </summary>
 	public static class TwitterConsumer {
 		/// <summary>
-		/// The description of Twitter's OAuth protocol URIs.
+		/// The description of Twitter's OAuth protocol URIs for use with actually reading/writing
+		/// a user's private Twitter data.
 		/// </summary>
 		public static readonly ServiceProviderDescription ServiceDescription = new ServiceProviderDescription {
 			RequestTokenEndpoint = new MessageReceivingEndpoint("http://twitter.com/oauth/request_token", HttpDeliveryMethods.GetRequest | HttpDeliveryMethods.AuthorizationHeaderRequest),
@@ -30,6 +34,16 @@ namespace DotNetOpenAuth.ApplicationBlock {
 		};
 
 		/// <summary>
+		/// The description of Twitter's OAuth protocol URIs for use with their "Sign in with Twitter" feature.
+		/// </summary>
+		public static readonly ServiceProviderDescription SignInWithTwitterServiceDescription = new ServiceProviderDescription {
+			RequestTokenEndpoint = new MessageReceivingEndpoint("http://twitter.com/oauth/request_token", HttpDeliveryMethods.GetRequest | HttpDeliveryMethods.AuthorizationHeaderRequest),
+			UserAuthorizationEndpoint = new MessageReceivingEndpoint("http://twitter.com/oauth/authenticate", HttpDeliveryMethods.GetRequest | HttpDeliveryMethods.AuthorizationHeaderRequest),
+			AccessTokenEndpoint = new MessageReceivingEndpoint("http://twitter.com/oauth/access_token", HttpDeliveryMethods.GetRequest | HttpDeliveryMethods.AuthorizationHeaderRequest),
+			TamperProtectionElements = new ITamperProtectionChannelBindingElement[] { new HmacSha1SigningBindingElement() },
+		};
+
+		/// <summary>
 		/// The URI to get a user's favorites.
 		/// </summary>
 		private static readonly MessageReceivingEndpoint GetFavoritesEndpoint = new MessageReceivingEndpoint("http://twitter.com/favorites.xml", HttpDeliveryMethods.GetRequest);
@@ -43,6 +57,45 @@ namespace DotNetOpenAuth.ApplicationBlock {
 
 		private static readonly MessageReceivingEndpoint UpdateProfileImageEndpoint = new MessageReceivingEndpoint("http://twitter.com/account/update_profile_image.xml", HttpDeliveryMethods.PostRequest | HttpDeliveryMethods.AuthorizationHeaderRequest);
 
+		private static readonly MessageReceivingEndpoint VerifyCredentialsEndpoint = new MessageReceivingEndpoint("http://api.twitter.com/1/account/verify_credentials.xml", HttpDeliveryMethods.GetRequest | HttpDeliveryMethods.AuthorizationHeaderRequest);
+
+		private static InMemoryTokenManager ShortTermUserSessionTokenManager {
+			get {
+				var store = HttpContext.Current.Session;
+				var tokenManager = (InMemoryTokenManager)store["TwitterShortTermUserSessionTokenManager"];
+				if (tokenManager == null) {
+					string consumerKey = ConfigurationManager.AppSettings["twitterConsumerKey"];
+					string consumerSecret = ConfigurationManager.AppSettings["twitterConsumerSecret"];
+					if (IsTwitterConsumerConfigured) {
+						tokenManager = new InMemoryTokenManager(consumerKey, consumerSecret);
+						store["TwitterShortTermUserSessionTokenManager"] = tokenManager;
+					} else {
+						throw new InvalidOperationException("No Twitter OAuth consumer key and secret could be found in web.config AppSettings.");
+					}
+				}
+
+				return tokenManager;
+			}
+		}
+
+		private static WebConsumer signInConsumer;
+
+		private static object signInConsumerInitLock = new object();
+
+		private static WebConsumer TwitterSignIn {
+			get {
+				if (signInConsumer == null) {
+					lock (signInConsumerInitLock) {
+						if (signInConsumer == null) {
+							signInConsumer = new WebConsumer(SignInWithTwitterServiceDescription, ShortTermUserSessionTokenManager);
+						}
+					}
+				}
+
+				return signInConsumer;
+			}
+		}
+
 		/// <summary>
 		/// Initializes static members of the <see cref="TwitterConsumer"/> class.
 		/// </summary>
@@ -51,6 +104,13 @@ namespace DotNetOpenAuth.ApplicationBlock {
 			ServicePointManager.FindServicePoint(GetFavoritesEndpoint.Location).Expect100Continue = false;
 		}
 
+		public static bool IsTwitterConsumerConfigured {
+			get {
+				return !string.IsNullOrEmpty(ConfigurationManager.AppSettings["twitterConsumerKey"]) &&
+					!string.IsNullOrEmpty(ConfigurationManager.AppSettings["twitterConsumerSecret"]);
+			}
+		}
+
 		public static XDocument GetUpdates(ConsumerBase twitter, string accessToken) {
 			IncomingWebResponse response = twitter.PrepareAuthorizedRequestAndSend(GetFriendTimelineStatusEndpoint, accessToken);
 			return XDocument.Load(XmlReader.Create(response.GetResponseReader()));
@@ -87,5 +147,61 @@ namespace DotNetOpenAuth.ApplicationBlock {
 			string responseString = response.GetResponseReader().ReadToEnd();
 			return XDocument.Parse(responseString);
 		}
+
+		public static XDocument VerifyCredentials(ConsumerBase twitter, string accessToken) {
+			IncomingWebResponse response = twitter.PrepareAuthorizedRequestAndSend(VerifyCredentialsEndpoint, accessToken);
+			return XDocument.Load(XmlReader.Create(response.GetResponseReader()));
+		}
+
+		public static string GetUsername(ConsumerBase twitter, string accessToken) {
+			XDocument xml = VerifyCredentials(twitter, accessToken);
+			XPathNavigator nav = xml.CreateNavigator();
+			return nav.SelectSingleNode("/user/screen_name").Value;
+		}
+
+		/// <summary>
+		/// Prepares a redirect that will send the user to Twitter to sign in.
+		/// </summary>
+		/// <param name="forceNewLogin">if set to <c>true</c> the user will be required to re-enter their Twitter credentials even if already logged in to Twitter.</param>
+		/// <returns>The redirect message.</returns>
+		/// <remarks>
+		/// Call <see cref="OutgoingWebResponse.Send"/> or
+		/// <c>return StartSignInWithTwitter().<see cref="MessagingUtilities.AsActionResult">AsActionResult()</see></c>
+		/// to actually perform the redirect.
+		/// </remarks>
+		public static OutgoingWebResponse StartSignInWithTwitter(bool forceNewLogin) {
+			var redirectParameters = new Dictionary<string, string>();
+			if (forceNewLogin) {
+				redirectParameters["force_login"] = "true";
+			}
+			Uri callback = MessagingUtilities.GetRequestUrlFromContext().StripQueryArgumentsWithPrefix("oauth_");
+			var request = TwitterSignIn.PrepareRequestUserAuthorization(callback, null, redirectParameters);
+			return TwitterSignIn.Channel.PrepareResponse(request);
+		}
+
+		/// <summary>
+		/// Checks the incoming web request to see if it carries a Twitter authentication response,
+		/// and provides the user's Twitter screen name and unique id if available.
+		/// </summary>
+		/// <param name="screenName">The user's Twitter screen name.</param>
+		/// <param name="userId">The user's Twitter unique user ID.</param>
+		/// <returns>
+		/// A value indicating whether Twitter authentication was successful;
+		/// otherwise <c>false</c> to indicate that no Twitter response was present.
+		/// </returns>
+		public static bool TryFinishSignInWithTwitter(out string screenName, out int userId) {
+			screenName = null;
+			userId = 0;
+			var response = TwitterSignIn.ProcessUserAuthorization();
+			if (response == null) {
+				return false;
+			}
+
+			XDocument xml = VerifyCredentials(TwitterSignIn, response.AccessToken);
+			XPathNavigator nav = xml.CreateNavigator();
+			screenName = nav.SelectSingleNode("/user/screen_name").Value;
+			userId = int.Parse(nav.SelectSingleNode("/user/id").Value);
+			return true;
+		}
 	}
 }