OpenID messages that are missing signed parameters now throws ProtocolException instead of KeyNotFoundException.

Fixes #45

3 files changed, 34 insertions, 2 deletions

diff --git a/src/DotNetOpenAuth.Core/Messaging/ErrorUtilities.cs b/src/DotNetOpenAuth.Core/Messaging/ErrorUtilities.cs
index c6a652b..129a03d 100644
--- a/src/DotNetOpenAuth.Core/Messaging/ErrorUtilities.cs
+++ b/src/DotNetOpenAuth.Core/Messaging/ErrorUtilities.cs
@@ -6,6 +6,7 @@
 
 namespace DotNetOpenAuth.Messaging {
 	using System;
+	using System.Collections.Generic;
 	using System.Diagnostics;
 	using System.Diagnostics.Contracts;
 	using System.Globalization;
@@ -361,5 +362,24 @@ namespace DotNetOpenAuth.Messaging {
 			Contract.Ensures(HttpContext.Current.Request != null);
 			ErrorUtilities.VerifyOperation(HttpContext.Current != null && HttpContext.Current.Request != null, MessagingStrings.HttpContextRequired);
 		}
+
+		/// <summary>
+		/// Obtains a value from the dictionary if possible, or throws a <see cref="ProtocolException"/> if it's missing.
+		/// </summary>
+		/// <typeparam name="TKey">The type of key in the dictionary.</typeparam>
+		/// <typeparam name="TValue">The type of value in the dictionary.</typeparam>
+		/// <param name="dictionary">The dictionary.</param>
+		/// <param name="key">The key to use to look up the value.</param>
+		/// <param name="message">The message to claim is invalid if the key cannot be found.</param>
+		/// <returns>The value for the given key.</returns>
+		[Pure]
+		internal static TValue GetValueOrThrow<TKey, TValue>(this IDictionary<TKey, TValue> dictionary, TKey key, IMessage message) {
+			Requires.NotNull(dictionary, "dictionary");
+			Requires.NotNull(message, "message");
+
+			TValue value;
+			VerifyProtocol(dictionary.TryGetValue(key, out value), MessagingStrings.ExpectedParameterWasMissing, key, message.GetType().Name);
+			return value;
+		}
 	}
 }
diff --git a/src/DotNetOpenAuth.Core/Messaging/MessagingStrings.Designer.cs b/src/DotNetOpenAuth.Core/Messaging/MessagingStrings.Designer.cs
index 11bd751..3ad2bdd 100644
--- a/src/DotNetOpenAuth.Core/Messaging/MessagingStrings.Designer.cs
+++ b/src/DotNetOpenAuth.Core/Messaging/MessagingStrings.Designer.cs
@@ -1,7 +1,7 @@
 //------------------------------------------------------------------------------
 // <auto-generated>
 //     This code was generated by a tool.
-//     Runtime Version:4.0.30319.1
+//     Runtime Version:4.0.30319.239
 //
 //     Changes to this file may cause incorrect behavior and will be lost if
 //     the code is regenerated.
@@ -187,6 +187,15 @@ namespace DotNetOpenAuth.Messaging {
         }
         
         /// <summary>
+        ///   Looks up a localized string similar to The message part {0} was expected in the {1} message but was not found..
+        /// </summary>
+        internal static string ExpectedParameterWasMissing {
+            get {
+                return ResourceManager.GetString("ExpectedParameterWasMissing", resourceCulture);
+            }
+        }
+        
+        /// <summary>
         ///   Looks up a localized string similar to The message expired at {0} and it is now {1}..
         /// </summary>
         internal static string ExpiredMessage {
diff --git a/src/DotNetOpenAuth.Core/Messaging/MessagingStrings.resx b/src/DotNetOpenAuth.Core/Messaging/MessagingStrings.resx
index bd10b76..5f3f79a 100644
--- a/src/DotNetOpenAuth.Core/Messaging/MessagingStrings.resx
+++ b/src/DotNetOpenAuth.Core/Messaging/MessagingStrings.resx
@@ -321,4 +321,7 @@
   <data name="ExtraParameterAddFailure" xml:space="preserve">
     <value>Failed to add extra parameter '{0}' with value '{1}'.</value>
   </data>
-</root>
+  <data name="ExpectedParameterWasMissing" xml:space="preserve">
+    <value>The message part {0} was expected in the {1} message but was not found.</value>
+  </data>
+</root>
\ No newline at end of file