Moved access token request scope parameter into a derived class so that it does not apply to the authorization code access token request.

Deleted the assertion access token request message which is no longer in the base spec.

10 files changed, 154 insertions, 98 deletions

diff --git a/src/DotNetOpenAuth/DotNetOpenAuth.csproj b/src/DotNetOpenAuth/DotNetOpenAuth.csproj
index 8123d7a..1cbdabe 100644
--- a/src/DotNetOpenAuth/DotNetOpenAuth.csproj
+++ b/src/DotNetOpenAuth/DotNetOpenAuth.csproj
@@ -385,7 +385,6 @@ http://opensource.org/licenses/ms-pl.html
     <Compile Include="OAuth2\IClientAuthorizationTracker.cs" />
     <Compile Include="OAuth2\IConsumerDescription.cs" />
     <Compile Include="OAuth2\Messages\AccessProtectedResourceRequest.cs" />
-    <Compile Include="OAuth2\Messages\AccessTokenAssertionRequest.cs" />
     <Compile Include="OAuth2\Messages\AccessTokenAuthorizationCodeRequest.cs" />
     <Compile Include="OAuth2\Messages\AccessTokenResourceOwnerPasswordCredentialsRequest.cs" />
     <Compile Include="OAuth2\Messages\AccessTokenRequestBase.cs" />
@@ -398,6 +397,7 @@ http://opensource.org/licenses/ms-pl.html
     <Compile Include="OAuth2\Messages\AccessTokenRefreshRequest.cs" />
     <Compile Include="OAuth2\Messages\EndUserAuthorizationResponseType.cs" />
     <Compile Include="OAuth2\Messages\IMessageWithClientState.cs" />
+    <Compile Include="OAuth2\Messages\ScopedAccessTokenRequest.cs" />
     <Compile Include="OAuth2\Messages\UnauthorizedResponse.cs" />
     <Compile Include="OAuth2\Messages\AccessTokenFailedResponse.cs" />
     <Compile Include="OAuth2\Messages\AccessTokenSuccessResponse.cs" />
diff --git a/src/DotNetOpenAuth/OAuth2/ChannelElements/AccessRequestBindingElement.cs b/src/DotNetOpenAuth/OAuth2/ChannelElements/AccessRequestBindingElement.cs
index af00409..cc4bfef 100644
--- a/src/DotNetOpenAuth/OAuth2/ChannelElements/AccessRequestBindingElement.cs
+++ b/src/DotNetOpenAuth/OAuth2/ChannelElements/AccessRequestBindingElement.cs
@@ -126,8 +126,11 @@ namespace DotNetOpenAuth.OAuth2.ChannelElements {
 					var client = this.AuthorizationServer.GetClientOrThrow(accessRequest.ClientIdentifier);
 					ErrorUtilities.VerifyProtocol(MessagingUtilities.EqualsConstantTime(client.Secret, accessRequest.ClientSecret), Protocol.incorrect_client_credentials);
 
-					// Make sure the scope the client is requesting does not exceed the scope in the grant.
-					ErrorUtilities.VerifyProtocol(accessRequest.Scope.IsSubsetOf(tokenRequest.AuthorizationDescription.Scope), OAuthStrings.AccessScopeExceedsGrantScope, accessRequest.Scope, tokenRequest.AuthorizationDescription.Scope);
+					var scopedAccessRequest = accessRequest as ScopedAccessTokenRequest;
+					if (scopedAccessRequest != null) {
+						// Make sure the scope the client is requesting does not exceed the scope in the grant.
+						ErrorUtilities.VerifyProtocol(scopedAccessRequest.Scope.IsSubsetOf(tokenRequest.AuthorizationDescription.Scope), OAuthStrings.AccessScopeExceedsGrantScope, scopedAccessRequest.Scope, tokenRequest.AuthorizationDescription.Scope);
+					}
 				}
 
 				// Make sure the authorization this token represents hasn't already been revoked.
diff --git a/src/DotNetOpenAuth/OAuth2/ChannelElements/OAuth2ChannelBase.cs b/src/DotNetOpenAuth/OAuth2/ChannelElements/OAuth2ChannelBase.cs
index d53e7ef..a646f51 100644
--- a/src/DotNetOpenAuth/OAuth2/ChannelElements/OAuth2ChannelBase.cs
+++ b/src/DotNetOpenAuth/OAuth2/ChannelElements/OAuth2ChannelBase.cs
@@ -24,7 +24,6 @@ namespace DotNetOpenAuth.OAuth2.ChannelElements {
 			typeof(AccessTokenRefreshRequest),
 			typeof(AccessTokenAuthorizationCodeRequest),
 			typeof(AccessTokenResourceOwnerPasswordCredentialsRequest),
-			typeof(AccessTokenAssertionRequest),
 			typeof(AccessTokenClientCredentialsRequest),
 			typeof(AccessTokenSuccessResponse),
 			typeof(AccessTokenFailedResponse),
diff --git a/src/DotNetOpenAuth/OAuth2/Messages/AccessTokenAssertionRequest.cs b/src/DotNetOpenAuth/OAuth2/Messages/AccessTokenAssertionRequest.cs
deleted file mode 100644
index fa50f6b..0000000
--- a/src/DotNetOpenAuth/OAuth2/Messages/AccessTokenAssertionRequest.cs
+++ /dev/null
@@ -1,49 +0,0 @@
-//-----------------------------------------------------------------------
-// <copyright file="AccessTokenAssertionRequest.cs" company="Andrew Arnott">
-//     Copyright (c) Andrew Arnott. All rights reserved.
-// </copyright>
-//-----------------------------------------------------------------------
-
-namespace DotNetOpenAuth.OAuth2.Messages {
-	using System;
-	using System.Collections.Generic;
-	using System.Linq;
-	using System.Text;
-	using DotNetOpenAuth.Messaging;
-
-	/// <summary>
-	/// A request from a Client to an Authorization Server to exchange some assertion for an access token.
-	/// </summary>
-	internal class AccessTokenAssertionRequest : AccessTokenRequestBase {
-		/// <summary>
-		/// Initializes a new instance of the <see cref="AccessTokenAssertionRequest"/> class.
-		/// </summary>
-		/// <param name="tokenEndpoint">The Authorization Server's access token endpoint URL.</param>
-		/// <param name="version">The version.</param>
-		internal AccessTokenAssertionRequest(Uri tokenEndpoint, Version version)
-			: base(tokenEndpoint, version) {
-		}
-
-		/// <summary>
-		/// Gets or sets the format of the assertion as defined by the Authorization Server.
-		/// </summary>
-		/// <value>The assertion format.</value>
-		[MessagePart(Protocol.assertion_type, IsRequired = true)]
-		internal Uri AssertionType { get; set; }
-
-		/// <summary>
-		/// Gets or sets the assertion.
-		/// </summary>
-		/// <value>The assertion.</value>
-		[MessagePart(Protocol.assertion, IsRequired = true)]
-		internal string Assertion { get; set; }
-
-		/// <summary>
-		/// Gets the type of the grant.
-		/// </summary>
-		/// <value>The type of the grant.</value>
-		internal override GrantType GrantType {
-			get { return GrantType.Assertion; }
-		}
-	}
-}
diff --git a/src/DotNetOpenAuth/OAuth2/Messages/AccessTokenClientCredentialsRequest.cs b/src/DotNetOpenAuth/OAuth2/Messages/AccessTokenClientCredentialsRequest.cs
index ec6f36f..01e1633 100644
--- a/src/DotNetOpenAuth/OAuth2/Messages/AccessTokenClientCredentialsRequest.cs
+++ b/src/DotNetOpenAuth/OAuth2/Messages/AccessTokenClientCredentialsRequest.cs
@@ -19,7 +19,7 @@ namespace DotNetOpenAuth.OAuth2.Messages {
 	/// <remarks>
 	/// This is somewhat analogous to 2-legged OAuth.
 	/// </remarks>
-	internal class AccessTokenClientCredentialsRequest : AccessTokenRequestBase {
+	internal class AccessTokenClientCredentialsRequest : ScopedAccessTokenRequest {
 		/// <summary>
 		/// Initializes a new instance of the <see cref="AccessTokenClientCredentialsRequest"/> class.
 		/// </summary>
diff --git a/src/DotNetOpenAuth/OAuth2/Messages/AccessTokenRefreshRequest.cs b/src/DotNetOpenAuth/OAuth2/Messages/AccessTokenRefreshRequest.cs
index c193392..66b2497 100644
--- a/src/DotNetOpenAuth/OAuth2/Messages/AccessTokenRefreshRequest.cs
+++ b/src/DotNetOpenAuth/OAuth2/Messages/AccessTokenRefreshRequest.cs
@@ -6,6 +6,7 @@
 
 namespace DotNetOpenAuth.OAuth2.Messages {
 	using System;
+	using System.Collections.Generic;
 	using DotNetOpenAuth.Messaging;
 	using DotNetOpenAuth.OAuth2.ChannelElements;
 
@@ -13,7 +14,7 @@ namespace DotNetOpenAuth.OAuth2.Messages {
 	/// A request from the client to the token endpoint for a new access token
 	/// in exchange for a refresh token that the client has previously obtained.
 	/// </summary>
-	internal class AccessTokenRefreshRequest : AccessTokenRequestBase, ITokenCarryingRequest {
+	internal class AccessTokenRefreshRequest : ScopedAccessTokenRequest, ITokenCarryingRequest {
 		/// <summary>
 		/// Initializes a new instance of the <see cref="AccessTokenRefreshRequest"/> class.
 		/// </summary>
diff --git a/src/DotNetOpenAuth/OAuth2/Messages/AccessTokenRequestBase.cs b/src/DotNetOpenAuth/OAuth2/Messages/AccessTokenRequestBase.cs
index 55387a6..a71dc70 100644
--- a/src/DotNetOpenAuth/OAuth2/Messages/AccessTokenRequestBase.cs
+++ b/src/DotNetOpenAuth/OAuth2/Messages/AccessTokenRequestBase.cs
@@ -25,7 +25,6 @@ namespace DotNetOpenAuth.OAuth2.Messages {
 		protected AccessTokenRequestBase(Uri tokenEndpoint, Version version)
 			: base(tokenEndpoint, version) {
 			this.HttpMethods = HttpDeliveryMethods.PostRequest;
-			this.Scope = new HashSet<string>(OAuthUtilities.ScopeStringComparer);
 		}
 
 		/// <summary>
@@ -36,13 +35,6 @@ namespace DotNetOpenAuth.OAuth2.Messages {
 		internal abstract GrantType GrantType { get; }
 
 		/// <summary>
-		/// Gets the set of scopes the Client would like the access token to provide access to.
-		/// </summary>
-		/// <value>A set of scopes.  Never null.</value>
-		[MessagePart(Protocol.scope, IsRequired = false, Encoder = typeof(ScopeEncoder))]
-		internal HashSet<string> Scope { get; private set; }
-
-		/// <summary>
 		/// Checks the message state for conformity to the protocol specification
 		/// and throws an exception if the message is invalid.
 		/// </summary>
diff --git a/src/DotNetOpenAuth/OAuth2/Messages/AccessTokenResourceOwnerPasswordCredentialsRequest.cs b/src/DotNetOpenAuth/OAuth2/Messages/AccessTokenResourceOwnerPasswordCredentialsRequest.cs
index ed22843..82febe9 100644
--- a/src/DotNetOpenAuth/OAuth2/Messages/AccessTokenResourceOwnerPasswordCredentialsRequest.cs
+++ b/src/DotNetOpenAuth/OAuth2/Messages/AccessTokenResourceOwnerPasswordCredentialsRequest.cs
@@ -15,7 +15,7 @@ namespace DotNetOpenAuth.OAuth2.Messages {
 	/// <summary>
 	/// A request from a Client to an Authorization Server to exchange the user's username and password for an access token.
 	/// </summary>
-	internal class AccessTokenResourceOwnerPasswordCredentialsRequest : AccessTokenRequestBase {
+	internal class AccessTokenResourceOwnerPasswordCredentialsRequest : ScopedAccessTokenRequest {
 		/// <summary>
 		/// Initializes a new instance of the <see cref="AccessTokenResourceOwnerPasswordCredentialsRequest"/> class.
 		/// </summary>
diff --git a/src/DotNetOpenAuth/OAuth2/Messages/OAuth 2 Messages.cd b/src/DotNetOpenAuth/OAuth2/Messages/OAuth 2 Messages.cd
index a9c7703..caacdff 100644
--- a/src/DotNetOpenAuth/OAuth2/Messages/OAuth 2 Messages.cd
+++ b/src/DotNetOpenAuth/OAuth2/Messages/OAuth 2 Messages.cd
@@ -1,22 +1,22 @@
 <?xml version="1.0" encoding="utf-8"?>
 <ClassDiagram MajorVersion="1" MinorVersion="1">
   <Class Name="DotNetOpenAuth.OAuth2.Messages.MessageBase" Collapsed="true">
-    <Position X="0.5" Y="4" Width="1.5" />
+    <Position X="0.5" Y="0.5" Width="1.5" />
     <TypeIdentifier>
       <HashCode>IAAMACQAQAAAgAkAAAAIAAYACgAAIAAAIACAACAAAIA=</HashCode>
       <FileName>OAuth2\Messages\MessageBase.cs</FileName>
     </TypeIdentifier>
     <Lollipop Position="0.2" />
   </Class>
-  <Class Name="DotNetOpenAuth.OAuth2.Messages.AccessTokenAssertionRequest" Collapsed="true">
-    <Position X="11" Y="5.5" Width="2.25" />
-    <TypeIdentifier>
-      <HashCode>AAAIAAAAAAAAAAAAAgAAAAAQAAAAAAAAAAAAAAAAAAA=</HashCode>
-      <FileName>OAuth2\Messages\AccessTokenAssertionRequest.cs</FileName>
-    </TypeIdentifier>
-  </Class>
   <Class Name="DotNetOpenAuth.OAuth2.Messages.AccessTokenAuthorizationCodeRequest" Collapsed="true">
-    <Position X="11" Y="6.5" Width="3" />
+    <Position X="6.75" Y="6.75" Width="3" />
+    <InheritanceLine Type="DotNetOpenAuth.OAuth2.Messages.AccessTokenRequestBase" FixedFromPoint="true" FixedToPoint="true">
+      <Path>
+        <Point X="6.5" Y="6.441" />
+        <Point X="6.5" Y="7.062" />
+        <Point X="6.75" Y="7.062" />
+      </Path>
+    </InheritanceLine>
     <TypeIdentifier>
       <HashCode>CCAAAAAAAAACAAAAAAAAAAAQAAAAAAAAAAAAAAAAQAA=</HashCode>
       <FileName>OAuth2\Messages\AccessTokenAuthorizationCodeRequest.cs</FileName>
@@ -24,14 +24,28 @@
     <Lollipop Position="0.2" />
   </Class>
   <Class Name="DotNetOpenAuth.OAuth2.Messages.AccessTokenClientCredentialsRequest" Collapsed="true">
-    <Position X="11" Y="3.75" Width="2.75" />
+    <Position X="8.5" Y="8.75" Width="2.75" />
+    <InheritanceLine Type="DotNetOpenAuth.OAuth2.Messages.ScopedAccessTokenRequest" FixedToPoint="true">
+      <Path>
+        <Point X="7.875" Y="8.441" />
+        <Point X="7.875" Y="9.062" />
+        <Point X="8.5" Y="9.062" />
+      </Path>
+    </InheritanceLine>
     <TypeIdentifier>
       <HashCode>AAAAAAAAAAAAAAAAAAAAAAAQAAAAAAAAAAAAAAAAAAA=</HashCode>
       <FileName>OAuth2\Messages\AccessTokenClientCredentialsRequest.cs</FileName>
     </TypeIdentifier>
   </Class>
   <Class Name="DotNetOpenAuth.OAuth2.Messages.AccessTokenFailedResponse" Collapsed="true">
-    <Position X="3.25" Y="1.75" Width="2.25" />
+    <Position X="3.25" Y="8.5" Width="2.25" />
+    <InheritanceLine Type="DotNetOpenAuth.OAuth2.Messages.MessageBase" FixedToPoint="true">
+      <Path>
+        <Point X="1.25" Y="1.062" />
+        <Point X="1.25" Y="8.812" />
+        <Point X="3.25" Y="8.812" />
+      </Path>
+    </InheritanceLine>
     <TypeIdentifier>
       <HashCode>AAAAAIAAAAAAAQAAAABAAAQAAAAAAAEQAAAAAAAAAAA=</HashCode>
       <FileName>OAuth2\Messages\AccessTokenFailedResponse.cs</FileName>
@@ -39,34 +53,48 @@
     <Lollipop Position="0.2" />
   </Class>
   <Class Name="DotNetOpenAuth.OAuth2.Messages.AccessTokenRefreshRequest" Collapsed="true">
-    <Position X="11" Y="4.75" Width="2.25" />
+    <Position X="8.5" Y="9.75" Width="2.25" />
+    <InheritanceLine Type="DotNetOpenAuth.OAuth2.Messages.ScopedAccessTokenRequest" FixedToPoint="true">
+      <Path>
+        <Point X="7.875" Y="8.441" />
+        <Point X="7.875" Y="10.125" />
+        <Point X="8.5" Y="10.125" />
+      </Path>
+    </InheritanceLine>
     <TypeIdentifier>
-      <HashCode>CCAAAAAAQAACAAAAAAAAAAAQAAAAAAAAAAAAAAAAAAA=</HashCode>
+      <HashCode>CCAAAAAAQAACACAAAAAAAAAQAAAAAAAAAAAAAAAAAAA=</HashCode>
       <FileName>OAuth2\Messages\AccessTokenRefreshRequest.cs</FileName>
     </TypeIdentifier>
     <Lollipop Position="0.2" />
   </Class>
   <Class Name="DotNetOpenAuth.OAuth2.Messages.AccessTokenRequestBase" Collapsed="true">
-    <Position X="7.75" Y="7.25" Width="2" />
+    <Position X="5.75" Y="5.75" Width="2" />
+    <InheritanceLine Type="DotNetOpenAuth.OAuth2.Messages.AuthenticatedClientRequestBase" FixedFromPoint="true">
+      <Path>
+        <Point X="4.375" Y="5.941" />
+        <Point X="4.375" Y="6.096" />
+        <Point X="5.75" Y="6.096" />
+      </Path>
+    </InheritanceLine>
     <TypeIdentifier>
-      <HashCode>AAAAAAAAQAAAACAAAAAAAAAQAAAAAAAAAAAAAAAAAAA=</HashCode>
+      <HashCode>AAAAAAAAQAAAAAAAAAAAAAAQAAAAAAAAAAAAAAAAAAA=</HashCode>
       <FileName>OAuth2\Messages\AccessTokenRequestBase.cs</FileName>
     </TypeIdentifier>
   </Class>
   <Class Name="DotNetOpenAuth.OAuth2.Messages.AccessTokenResourceOwnerPasswordCredentialsRequest" Collapsed="true">
-    <Position X="11" Y="7.25" Width="4" />
+    <Position X="8.5" Y="10.5" Width="4" />
     <TypeIdentifier>
-      <HashCode>AAAAAAAAAAAAAAAAAAAAAAAQAAAAAAACAQAAAAAAAAA=</HashCode>
+      <HashCode>AAAAAAAAAAAAACAAAAAAAAAQAAAAAAACAQAAAAAAAAA=</HashCode>
       <FileName>OAuth2\Messages\AccessTokenResourceOwnerPasswordCredentialsRequest.cs</FileName>
     </TypeIdentifier>
   </Class>
   <Class Name="DotNetOpenAuth.OAuth2.Messages.AccessTokenSuccessResponse" Collapsed="true">
-    <Position X="3.25" Y="2.75" Width="2.25" />
+    <Position X="3.25" Y="7.5" Width="2.25" />
     <InheritanceLine Type="DotNetOpenAuth.OAuth2.Messages.MessageBase" FixedToPoint="true">
       <Path>
-        <Point X="1.25" Y="4" />
-        <Point X="1.25" Y="3.125" />
-        <Point X="3.25" Y="3.125" />
+        <Point X="1.25" Y="1.062" />
+        <Point X="1.25" Y="7.812" />
+        <Point X="3.25" Y="7.812" />
       </Path>
     </InheritanceLine>
     <TypeIdentifier>
@@ -76,14 +104,21 @@
     <Lollipop Position="0.2" />
   </Class>
   <Class Name="DotNetOpenAuth.OAuth2.Messages.AuthenticatedClientRequestBase" Collapsed="true">
-    <Position X="3.25" Y="7.25" Width="2.25" />
+    <Position X="3.25" Y="5.25" Width="2.25" />
     <TypeIdentifier>
       <HashCode>AAAAAAAAAAAAAAAAAAAAAAAAAAwAAAAAAAAAAAAAAAA=</HashCode>
       <FileName>OAuth2\Messages\AuthenticatedClientRequestBase.cs</FileName>
     </TypeIdentifier>
   </Class>
   <Class Name="DotNetOpenAuth.OAuth2.Messages.EndUserAuthorizationFailedResponse" Collapsed="true">
-    <Position X="3.25" Y="6.5" Width="2.75" />
+    <Position X="3.25" Y="4.5" Width="2.75" />
+    <InheritanceLine Type="DotNetOpenAuth.OAuth2.Messages.MessageBase" FixedToPoint="true">
+      <Path>
+        <Point X="1.25" Y="1.062" />
+        <Point X="1.25" Y="4.875" />
+        <Point X="3.25" Y="4.875" />
+      </Path>
+    </InheritanceLine>
     <TypeIdentifier>
       <HashCode>AAAAAIAAAAAAAQAAAAAAAAgAAAAAAAEAAAAAAAAAAAA=</HashCode>
       <FileName>OAuth2\Messages\EndUserAuthorizationFailedResponse.cs</FileName>
@@ -91,14 +126,21 @@
     <Lollipop Position="0.2" />
   </Class>
   <Class Name="DotNetOpenAuth.OAuth2.Messages.EndUserAuthorizationRequest" Collapsed="true">
-    <Position X="3.25" Y="5.5" Width="2.25" />
+    <Position X="3.25" Y="0.5" Width="2.25" />
     <TypeIdentifier>
       <HashCode>AAAAAAAAQAAAACAAAAAAAACAAAQAAAQAAAAAAAAAQAA=</HashCode>
       <FileName>OAuth2\Messages\EndUserAuthorizationRequest.cs</FileName>
     </TypeIdentifier>
   </Class>
   <Class Name="DotNetOpenAuth.OAuth2.Messages.EndUserAuthorizationSuccessAccessTokenResponse" Collapsed="true">
-    <Position X="6.75" Y="4.25" Width="3.75" />
+    <Position X="6.25" Y="3.75" Width="3.75" />
+    <InheritanceLine Type="DotNetOpenAuth.OAuth2.Messages.EndUserAuthorizationSuccessResponseBase" FixedToPoint="true">
+      <Path>
+        <Point X="4.625" Y="2.191" />
+        <Point X="4.625" Y="4.062" />
+        <Point X="6.25" Y="4.062" />
+      </Path>
+    </InheritanceLine>
     <TypeIdentifier>
       <HashCode>CCAAAAAAAAACAAAAAAAAAAACEAAAAAAAAAAAAAAAAgA=</HashCode>
       <FileName>OAuth2\Messages\EndUserAuthorizationSuccessAccessTokenResponse.cs</FileName>
@@ -106,13 +148,12 @@
     <Lollipop Position="0.2" />
   </Class>
   <Class Name="DotNetOpenAuth.OAuth2.Messages.EndUserAuthorizationSuccessAuthCodeResponse" Collapsed="true">
-    <Position X="6.75" Y="3" Width="3.5" />
-    <InheritanceLine Type="DotNetOpenAuth.OAuth2.Messages.EndUserAuthorizationSuccessResponseBase" FixedFromPoint="true">
+    <Position X="6.25" Y="2.5" Width="3.5" />
+    <InheritanceLine Type="DotNetOpenAuth.OAuth2.Messages.EndUserAuthorizationSuccessResponseBase" FixedToPoint="true">
       <Path>
-        <Point X="6" Y="4.062" />
-        <Point X="6.375" Y="4.062" />
-        <Point X="6.375" Y="3.346" />
-        <Point X="6.75" Y="3.346" />
+        <Point X="4.625" Y="2.191" />
+        <Point X="4.625" Y="2.875" />
+        <Point X="6.25" Y="2.875" />
       </Path>
     </InheritanceLine>
     <TypeIdentifier>
@@ -122,7 +163,14 @@
     <Lollipop Position="0.2" />
   </Class>
   <Class Name="DotNetOpenAuth.OAuth2.Messages.EndUserAuthorizationSuccessResponseBase" Collapsed="true">
-    <Position X="3.25" Y="3.75" Width="2.75" />
+    <Position X="3.25" Y="1.5" Width="2.75" />
+    <InheritanceLine Type="DotNetOpenAuth.OAuth2.Messages.MessageBase" FixedToPoint="true">
+      <Path>
+        <Point X="1.25" Y="1.062" />
+        <Point X="1.25" Y="1.75" />
+        <Point X="3.25" Y="1.75" />
+      </Path>
+    </InheritanceLine>
     <TypeIdentifier>
       <HashCode>AAACAAAAAAAAACAAAAAAAAgAAAAAAAAAAEAAAAAAAAA=</HashCode>
       <FileName>OAuth2\Messages\EndUserAuthorizationSuccessResponseBase.cs</FileName>
@@ -130,7 +178,14 @@
     <Lollipop Position="0.2" />
   </Class>
   <Class Name="DotNetOpenAuth.OAuth2.Messages.AccessProtectedResourceRequest" Collapsed="true">
-    <Position X="3.25" Y="4.75" Width="2.5" />
+    <Position X="3.25" Y="9.75" Width="2.5" />
+    <InheritanceLine Type="DotNetOpenAuth.OAuth2.Messages.MessageBase" FixedToPoint="true">
+      <Path>
+        <Point X="1.25" Y="1.062" />
+        <Point X="1.25" Y="10" />
+        <Point X="3.25" Y="10" />
+      </Path>
+    </InheritanceLine>
     <TypeIdentifier>
       <HashCode>CCAAAAAAQAACAAAAAAACAAAAEAAAAAAAAAEAAAQACAE=</HashCode>
       <FileName>OAuth2\Messages\AccessProtectedResourceRequest.cs</FileName>
@@ -138,13 +193,34 @@
     <Lollipop Position="0.2" />
   </Class>
   <Class Name="DotNetOpenAuth.OAuth2.Messages.UnauthorizedResponse" Collapsed="true">
-    <Position X="3.25" Y="0.75" Width="2" />
+    <Position X="3.25" Y="10.75" Width="2" />
+    <InheritanceLine Type="DotNetOpenAuth.OAuth2.Messages.MessageBase" FixedToPoint="true">
+      <Path>
+        <Point X="1.25" Y="1.062" />
+        <Point X="1.25" Y="11.125" />
+        <Point X="3.25" Y="11.125" />
+      </Path>
+    </InheritanceLine>
     <TypeIdentifier>
       <HashCode>AUABAAAAAAAAACAAAAAAAAQIAAAAAAAQAAAAAAAAABA=</HashCode>
       <FileName>OAuth2\Messages\UnauthorizedResponse.cs</FileName>
     </TypeIdentifier>
     <Lollipop Position="0.2" />
   </Class>
+  <Class Name="DotNetOpenAuth.OAuth2.Messages.ScopedAccessTokenRequest" Collapsed="true">
+    <Position X="6.75" Y="7.75" Width="2.25" />
+    <InheritanceLine Type="DotNetOpenAuth.OAuth2.Messages.AccessTokenRequestBase" FixedFromPoint="true" FixedToPoint="true">
+      <Path>
+        <Point X="6.5" Y="6.441" />
+        <Point X="6.5" Y="8.125" />
+        <Point X="6.75" Y="8.125" />
+      </Path>
+    </InheritanceLine>
+    <TypeIdentifier>
+      <HashCode>AAAAAAAAAAAAACAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=</HashCode>
+      <FileName>OAuth2\Messages\ScopedAccessTokenRequest.cs</FileName>
+    </TypeIdentifier>
+  </Class>
   <Interface Name="DotNetOpenAuth.OAuth2.Messages.IMessageWithClientState">
     <Position X="11.5" Y="0.5" Width="2" />
     <TypeIdentifier>
diff --git a/src/DotNetOpenAuth/OAuth2/Messages/ScopedAccessTokenRequest.cs b/src/DotNetOpenAuth/OAuth2/Messages/ScopedAccessTokenRequest.cs
new file mode 100644
index 0000000..0e0329b
--- /dev/null
+++ b/src/DotNetOpenAuth/OAuth2/Messages/ScopedAccessTokenRequest.cs
@@ -0,0 +1,34 @@
+//-----------------------------------------------------------------------
+// <copyright file="ScopedAccessTokenRequest.cs" company="Andrew Arnott">
+//     Copyright (c) Andrew Arnott. All rights reserved.
+// </copyright>
+//-----------------------------------------------------------------------
+
+namespace DotNetOpenAuth.OAuth2.Messages {
+	using System;
+	using System.Collections.Generic;
+	using DotNetOpenAuth.Messaging;
+	using DotNetOpenAuth.OAuth2.ChannelElements;
+
+	/// <summary>
+	/// An access token request that includes a scope parameter.
+	/// </summary>
+	internal abstract class ScopedAccessTokenRequest : AccessTokenRequestBase {
+		/// <summary>
+		/// Initializes a new instance of the <see cref="ScopedAccessTokenRequest"/> class.
+		/// </summary>
+		/// <param name="tokenEndpoint">The Authorization Server's access token endpoint URL.</param>
+		/// <param name="version">The version.</param>
+		internal ScopedAccessTokenRequest(Uri tokenEndpoint, Version version)
+			: base(tokenEndpoint, version) {
+			this.Scope = new HashSet<string>(OAuthUtilities.ScopeStringComparer);
+		}
+
+		/// <summary>
+		/// Gets the set of scopes the Client would like the access token to provide access to.
+		/// </summary>
+		/// <value>A set of scopes.  Never null.</value>
+		[MessagePart(Protocol.scope, IsRequired = false, Encoder = typeof(ScopeEncoder))]
+		internal HashSet<string> Scope { get; private set; }
+	}
+}