Fixes NullReferenceException thrown when the HttpContext.Current is null or its Session property is null.

Fixes Trac #189

3 files changed, 32 insertions, 3 deletions

diff --git a/src/DotNetOpenAuth/Messaging/MessagingStrings.Designer.cs b/src/DotNetOpenAuth/Messaging/MessagingStrings.Designer.cs
index 0bbac42..6f8c4f9 100644
--- a/src/DotNetOpenAuth/Messaging/MessagingStrings.Designer.cs
+++ b/src/DotNetOpenAuth/Messaging/MessagingStrings.Designer.cs
@@ -1,7 +1,7 @@
 //------------------------------------------------------------------------------
 // <auto-generated>
 //     This code was generated by a tool.
-//     Runtime Version:4.0.30104.0
+//     Runtime Version:4.0.30319.1
 //
 //     Changes to this file may cause incorrect behavior and will be lost if
 //     the code is regenerated.
@@ -394,6 +394,15 @@ namespace DotNetOpenAuth.Messaging {
         }
         
         /// <summary>
+        ///   Looks up a localized string similar to An HttpContext.Current.Session object is required..
+        /// </summary>
+        internal static string SessionRequired {
+            get {
+                return ResourceManager.GetString("SessionRequired", resourceCulture);
+            }
+        }
+        
+        /// <summary>
         ///   Looks up a localized string similar to Message signature was incorrect..
         /// </summary>
         internal static string SignatureInvalid {
diff --git a/src/DotNetOpenAuth/Messaging/MessagingStrings.resx b/src/DotNetOpenAuth/Messaging/MessagingStrings.resx
index 34385d4..bdf4f68 100644
--- a/src/DotNetOpenAuth/Messaging/MessagingStrings.resx
+++ b/src/DotNetOpenAuth/Messaging/MessagingStrings.resx
@@ -300,4 +300,7 @@
   <data name="BinaryDataRequiresMultipart" xml:space="preserve">
     <value>Unable to send all message data because some of it requires multi-part POST, but IMessageWithBinaryData.SendAsMultipart was false.</value>
   </data>
+  <data name="SessionRequired" xml:space="preserve">
+    <value>An HttpContext.Current.Session object is required.</value>
+  </data>
 </root>
\ No newline at end of file
diff --git a/src/DotNetOpenAuth/OpenId/Provider/ProviderEndpoint.cs b/src/DotNetOpenAuth/OpenId/Provider/ProviderEndpoint.cs
index 445978e..e792a81 100644
--- a/src/DotNetOpenAuth/OpenId/Provider/ProviderEndpoint.cs
+++ b/src/DotNetOpenAuth/OpenId/Provider/ProviderEndpoint.cs
@@ -98,11 +98,15 @@ namespace DotNetOpenAuth.OpenId.Provider {
 		/// </remarks>
 		public static IAuthenticationRequest PendingAuthenticationRequest {
 			get {
+				Contract.Requires<InvalidOperationException>(HttpContext.Current != null, MessagingStrings.HttpContextRequired);
+				Contract.Requires<InvalidOperationException>(HttpContext.Current.Session != null, MessagingStrings.SessionRequired);
 				Contract.Ensures(Contract.Result<IAuthenticationRequest>() == null || PendingRequest != null);
 				return HttpContext.Current.Session[PendingRequestKey] as IAuthenticationRequest;
 			}
 
 			set {
+				Contract.Requires<InvalidOperationException>(HttpContext.Current != null, MessagingStrings.HttpContextRequired);
+				Contract.Requires<InvalidOperationException>(HttpContext.Current.Session != null, MessagingStrings.SessionRequired);
 				HttpContext.Current.Session[PendingRequestKey] = value;
 			}
 		}
@@ -118,11 +122,15 @@ namespace DotNetOpenAuth.OpenId.Provider {
 		/// </remarks>
 		public static IAnonymousRequest PendingAnonymousRequest {
 			get {
+				Contract.Requires<InvalidOperationException>(HttpContext.Current != null, MessagingStrings.HttpContextRequired);
+				Contract.Requires<InvalidOperationException>(HttpContext.Current.Session != null, MessagingStrings.SessionRequired);
 				Contract.Ensures(Contract.Result<IAnonymousRequest>() == null || PendingRequest != null);
 				return HttpContext.Current.Session[PendingRequestKey] as IAnonymousRequest;
 			}
 
 			set {
+				Contract.Requires<InvalidOperationException>(HttpContext.Current != null, MessagingStrings.HttpContextRequired);
+				Contract.Requires<InvalidOperationException>(HttpContext.Current.Session != null, MessagingStrings.SessionRequired);
 				HttpContext.Current.Session[PendingRequestKey] = value;
 			}
 		}
@@ -137,8 +145,17 @@ namespace DotNetOpenAuth.OpenId.Provider {
 		/// before responding to the relying party's request.
 		/// </remarks>
 		public static IHostProcessedRequest PendingRequest {
-			get { return HttpContext.Current.Session[PendingRequestKey] as IHostProcessedRequest; }
-			set { HttpContext.Current.Session[PendingRequestKey] = value; }
+			get {
+				Contract.Requires<InvalidOperationException>(HttpContext.Current != null, MessagingStrings.HttpContextRequired);
+				Contract.Requires<InvalidOperationException>(HttpContext.Current.Session != null, MessagingStrings.SessionRequired);
+				return HttpContext.Current.Session[PendingRequestKey] as IHostProcessedRequest;
+			}
+
+			set {
+				Contract.Requires<InvalidOperationException>(HttpContext.Current != null, MessagingStrings.HttpContextRequired);
+				Contract.Requires<InvalidOperationException>(HttpContext.Current.Session != null, MessagingStrings.SessionRequired);
+				HttpContext.Current.Session[PendingRequestKey] = value;
+			}
 		}
 
 		/// <summary>