Moved association creation logic from test assembly to library.

16 files changed, 476 insertions, 271 deletions

diff --git a/src/DotNetOpenAuth.Test/CoordinatorBase.cs b/src/DotNetOpenAuth.Test/CoordinatorBase.cs
index 9c16eac..4463dde 100644
--- a/src/DotNetOpenAuth.Test/CoordinatorBase.cs
+++ b/src/DotNetOpenAuth.Test/CoordinatorBase.cs
@@ -22,6 +22,10 @@ namespace DotNetOpenAuth.Test {
 			this.party2Action = party2Action;
 		}
 
+		protected internal Action<IProtocolMessage> IncomingMessageFilter { get; set; }
+
+		protected internal Action<IProtocolMessage> OutgoingMessageFilter { get; set; }
+
 		internal abstract void Run();
 
 		protected void RunCore(T1 party1Object, T2 party2Object) {
diff --git a/src/DotNetOpenAuth.Test/Mocks/CoordinatingChannel.cs b/src/DotNetOpenAuth.Test/Mocks/CoordinatingChannel.cs
index bba9285..bb094af 100644
--- a/src/DotNetOpenAuth.Test/Mocks/CoordinatingChannel.cs
+++ b/src/DotNetOpenAuth.Test/Mocks/CoordinatingChannel.cs
@@ -17,12 +17,16 @@ namespace DotNetOpenAuth.Test.Mocks {
 		private EventWaitHandle incomingMessageSignal = new AutoResetEvent(false);
 		private IProtocolMessage incomingMessage;
 		private Response incomingRawResponse;
+		private Action<IProtocolMessage> incomingMessageFilter;
+		private Action<IProtocolMessage> outgoingMessageFilter;
 
-		internal CoordinatingChannel(Channel wrappedChannel)
+		internal CoordinatingChannel(Channel wrappedChannel, Action<IProtocolMessage> incomingMessageFilter, Action<IProtocolMessage> outgoingMessageFilter)
 			: base(GetMessageTypeProvider(wrappedChannel), wrappedChannel.BindingElements.ToArray()) {
 			ErrorUtilities.VerifyArgumentNotNull(wrappedChannel, "wrappedChannel");
 
 			this.wrappedChannel = wrappedChannel;
+			this.incomingMessageFilter = incomingMessageFilter;
+			this.outgoingMessageFilter = outgoingMessageFilter;
 		}
 
 		/// <summary>
@@ -35,26 +39,32 @@ namespace DotNetOpenAuth.Test.Mocks {
 		}
 
 		protected override IProtocolMessage RequestInternal(IDirectedProtocolMessage request) {
+			this.ProcessMessageFilter(request, true);
 			HttpRequestInfo requestInfo = this.SpoofHttpMethod(request);
 			// Drop the outgoing message in the other channel's in-slot and let them know it's there.
 			this.RemoteChannel.incomingMessage = requestInfo.Message;
 			this.RemoteChannel.incomingMessageSignal.Set();
 			// Now wait for a response...
-			return this.AwaitIncomingMessage();
+			IProtocolMessage response = this.AwaitIncomingMessage();
+			this.ProcessMessageFilter(response, false);
+			return response;
 		}
 
 		protected override Response SendDirectMessageResponse(IProtocolMessage response) {
+			this.ProcessMessageFilter(response, true);
 			this.RemoteChannel.incomingMessage = CloneSerializedParts(response, null);
 			this.RemoteChannel.incomingMessageSignal.Set();
 			return null;
 		}
 
 		protected override Response SendIndirectMessage(IDirectedProtocolMessage message) {
+			this.ProcessMessageFilter(message, true);
 			// In this mock transport, direct and indirect messages are the same.
 			return this.SendDirectMessageResponse(message);
 		}
 
 		protected override IDirectedProtocolMessage ReadFromRequestInternal(HttpRequestInfo request) {
+			this.ProcessMessageFilter(request.Message, false);
 			return request.Message;
 		}
 
@@ -104,5 +114,17 @@ namespace DotNetOpenAuth.Test.Mocks {
 			this.incomingMessage = null;
 			return response;
 		}
+
+		private void ProcessMessageFilter(IProtocolMessage message, bool outgoing) {
+			if (outgoing) {
+				if (this.outgoingMessageFilter != null) {
+					this.outgoingMessageFilter(message);
+				}
+			} else {
+				if (this.incomingMessageFilter != null) {
+					this.incomingMessageFilter(message);
+				}
+			}
+		}
 	}
 }
diff --git a/src/DotNetOpenAuth.Test/OpenId/OpenIdCoordinator.cs b/src/DotNetOpenAuth.Test/OpenId/OpenIdCoordinator.cs
index 78fb921..6ec2f38 100644
--- a/src/DotNetOpenAuth.Test/OpenId/OpenIdCoordinator.cs
+++ b/src/DotNetOpenAuth.Test/OpenId/OpenIdCoordinator.cs
@@ -21,8 +21,8 @@ namespace DotNetOpenAuth.Test.OpenId {
 			OpenIdRelyingParty rp = new OpenIdRelyingParty();
 			OpenIdProvider op = new OpenIdProvider();
 
-			var rpCoordinatingChannel = new CoordinatingChannel(rp.Channel);
-			var opCoordinatingChannel = new CoordinatingChannel(op.Channel);
+			var rpCoordinatingChannel = new CoordinatingChannel(rp.Channel, this.IncomingMessageFilter, this.OutgoingMessageFilter);
+			var opCoordinatingChannel = new CoordinatingChannel(op.Channel, this.IncomingMessageFilter, this.OutgoingMessageFilter);
 			rpCoordinatingChannel.RemoteChannel = opCoordinatingChannel;
 			opCoordinatingChannel.RemoteChannel = rpCoordinatingChannel;
 
diff --git a/src/DotNetOpenAuth.Test/OpenId/ScenarioTests.cs b/src/DotNetOpenAuth.Test/OpenId/ScenarioTests.cs
index f3d78e8..ddcae42 100644
--- a/src/DotNetOpenAuth.Test/OpenId/ScenarioTests.cs
+++ b/src/DotNetOpenAuth.Test/OpenId/ScenarioTests.cs
@@ -21,14 +21,11 @@ namespace DotNetOpenAuth.Test.OpenId {
 		[TestMethod]
 		public void AssociateDiffieHellmanMessages() {
 			Association rpAssociation = null, opAssociation = null;
+			AssociateDiffieHellmanResponse associateResponse = null;
 			OpenIdCoordinator coordinator = new OpenIdCoordinator(
 				rp => {
-					var associateRequest = new AssociateDiffieHellmanRequest(new Uri("http://host"));
-					associateRequest.AssociationType = Protocol.Args.SignatureAlgorithm.HMAC_SHA1;
-					associateRequest.SessionType = Protocol.Args.SessionType.DH_SHA1;
-					associateRequest.InitializeRequest();
-					var associateResponse = rp.Channel.Request<AssociateDiffieHellmanResponse>(associateRequest);
-					rpAssociation = associateResponse.CreateAssociation(associateRequest);
+					var op = new ProviderEndpointDescription(new Uri("http://host"), Protocol);
+					rpAssociation = rp.GetAssociation(op);
 					Assert.IsNotNull(rpAssociation);
 					Assert.IsFalse(MessagingUtilities.AreEquivalent(associateResponse.EncodedMacKey, rpAssociation.SecretKey), "Key should have been encrypted.");
 				},
@@ -39,6 +36,13 @@ namespace DotNetOpenAuth.Test.OpenId {
 					opAssociation = response.CreateAssociation(associateRequest);
 					op.Channel.Send(response);
 				});
+			coordinator.IncomingMessageFilter = (message) => {
+				var associateResponseMessage = message as AssociateDiffieHellmanResponse;
+				if (associateResponseMessage != null) {
+					// capture this message so we can analyze it later
+					associateResponse = associateResponseMessage;
+				}
+			};
 			coordinator.Run();
 			Assert.AreEqual(opAssociation.Handle, rpAssociation.Handle);
 			Assert.IsTrue(Math.Abs(opAssociation.SecondsTillExpiration - rpAssociation.SecondsTillExpiration) < 60);
diff --git a/src/DotNetOpenAuth/DotNetOpenAuth.csproj b/src/DotNetOpenAuth/DotNetOpenAuth.csproj
index 5c74ae3..8e94b2d 100644
--- a/src/DotNetOpenAuth/DotNetOpenAuth.csproj
+++ b/src/DotNetOpenAuth/DotNetOpenAuth.csproj
@@ -1,242 +1,244 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="3.5" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <ProductVersion>9.0.30729</ProductVersion>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>{3191B653-F76D-4C1A-9A5A-347BC3AAAAB7}</ProjectGuid>
-    <OutputType>Library</OutputType>
-    <AppDesignerFolder>Properties</AppDesignerFolder>
-    <RootNamespace>DotNetOpenAuth</RootNamespace>
-    <AssemblyName>DotNetOpenAuth</AssemblyName>
-    <TargetFrameworkVersion>v3.5</TargetFrameworkVersion>
-    <FileAlignment>512</FileAlignment>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <OutputPath>..\..\bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <ErrorReport>prompt</ErrorReport>
-    <WarningLevel>4</WarningLevel>
-    <AllowUnsafeBlocks>false</AllowUnsafeBlocks>
-    <DocumentationFile>..\..\bin\Debug\DotNetOpenAuth.xml</DocumentationFile>
-    <RunCodeAnalysis>false</RunCodeAnalysis>
-    <CodeAnalysisRules>-Microsoft.Design#CA1054;-Microsoft.Design#CA1056;-Microsoft.Design#CA1055</CodeAnalysisRules>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <OutputPath>..\..\bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <ErrorReport>prompt</ErrorReport>
-    <WarningLevel>4</WarningLevel>
-    <AllowUnsafeBlocks>false</AllowUnsafeBlocks>
-    <DocumentationFile>..\..\bin\debug\DotNetOpenAuth.xml</DocumentationFile>
-    <RunCodeAnalysis>true</RunCodeAnalysis>
-    <CodeAnalysisRules>-Microsoft.Design#CA1054;-Microsoft.Design#CA1056;-Microsoft.Design#CA1055</CodeAnalysisRules>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Sign)' == 'true' ">
-    <SignAssembly>true</SignAssembly>
-    <AssemblyOriginatorKeyFile>..\official-build-key.pfx</AssemblyOriginatorKeyFile>
-    <DefineConstants>$(DefineConstants);StrongNameSigned</DefineConstants>
-  </PropertyGroup>
-  <ItemGroup>
-    <Reference Include="log4net, Version=1.2.10.0, Culture=neutral, PublicKeyToken=1b44e1d426115821, processorArchitecture=MSIL">
-      <SpecificVersion>False</SpecificVersion>
-      <HintPath>..\..\lib\log4net.dll</HintPath>
-    </Reference>
-    <Reference Include="System" />
-    <Reference Include="System.configuration" />
-    <Reference Include="System.Core">
-      <RequiredTargetFramework>3.5</RequiredTargetFramework>
-    </Reference>
-    <Reference Include="System.Data" />
-    <Reference Include="System.ServiceModel">
-      <RequiredTargetFramework>3.0</RequiredTargetFramework>
-    </Reference>
-    <Reference Include="System.Web" />
-    <Reference Include="System.XML" />
-    <Reference Include="System.Xml.Linq">
-      <RequiredTargetFramework>3.5</RequiredTargetFramework>
-    </Reference>
-  </ItemGroup>
-  <ItemGroup>
-    <Compile Include="Configuration\ProviderSection.cs" />
-    <Compile Include="Configuration\ProviderSecuritySettingsElement.cs" />
-    <Compile Include="Configuration\RelyingPartySection.cs" />
-    <Compile Include="Configuration\RelyingPartySecuritySettingsElement.cs" />
-    <Compile Include="Configuration\TypeConfigurationElement.cs" />
-    <Compile Include="Configuration\UntrustedWebRequestSection.cs" />
-    <Compile Include="Configuration\HostNameOrRegexCollection.cs" />
-    <Compile Include="Configuration\HostNameElement.cs" />
-    <Compile Include="Messaging\EmptyDictionary.cs" />
-    <Compile Include="Messaging\EmptyEnumerator.cs" />
-    <Compile Include="Messaging\EmptyList.cs" />
-    <Compile Include="Messaging\ErrorUtilities.cs" />
-    <Compile Include="Messaging\Reflection\IMessagePartEncoder.cs" />
-    <Compile Include="OAuth\ChannelElements\OAuthConsumerMessageTypeProvider.cs" />
-    <Compile Include="OAuth\ChannelElements\ITokenGenerator.cs" />
-    <Compile Include="OAuth\ChannelElements\ITokenManager.cs" />
-    <Compile Include="OAuth\ChannelElements\OAuthHttpMethodBindingElement.cs" />
-    <Compile Include="OAuth\ChannelElements\PlaintextSigningBindingElement.cs" />
-    <Compile Include="OAuth\ChannelElements\HmacSha1SigningBindingElement.cs" />
-    <Compile Include="OAuth\ChannelElements\SigningBindingElementChain.cs" />
-    <Compile Include="OAuth\ChannelElements\StandardTokenGenerator.cs" />
-    <Compile Include="OAuth\ChannelElements\TokenType.cs" />
-    <Compile Include="OAuth\ConsumerBase.cs" />
-    <Compile Include="OAuth\DesktopConsumer.cs" />
-    <Compile Include="GlobalSuppressions.cs" />
-    <Compile Include="OAuth\Messages\ITokenSecretContainingMessage.cs" />
-    <Compile Include="Messaging\ChannelEventArgs.cs" />
-    <Compile Include="Messaging\ITamperProtectionChannelBindingElement.cs" />
-    <Compile Include="OAuth\OAuthStrings.Designer.cs">
-      <AutoGen>True</AutoGen>
-      <DesignTime>True</DesignTime>
-      <DependentUpon>OAuthStrings.resx</DependentUpon>
-    </Compile>
-    <Compile Include="OAuth\ServiceProviderDescription.cs" />
-    <Compile Include="OAuth\Messages\ITokenContainingMessage.cs" />
-    <Compile Include="OAuth\Messages\SignedMessageBase.cs" />
-    <Compile Include="Messaging\Bindings\NonceMemoryStore.cs" />
-    <Compile Include="OAuth\ChannelElements\SigningBindingElementBase.cs" />
-    <Compile Include="OAuth\WebConsumer.cs" />
-    <Compile Include="Messaging\IWebRequestHandler.cs" />
-    <Compile Include="OAuth\ChannelElements\ITamperResistantOAuthMessage.cs" />
-    <Compile Include="OAuth\Messages\MessageBase.cs" />
-    <Compile Include="OAuth\Messages\AuthorizedTokenRequest.cs" />
-    <Compile Include="Messaging\Bindings\INonceStore.cs" />
-    <Compile Include="Messaging\Bindings\StandardReplayProtectionBindingElement.cs" />
-    <Compile Include="Messaging\MessagePartAttribute.cs" />
-    <Compile Include="Messaging\MessageProtections.cs" />
-    <Compile Include="Messaging\IChannelBindingElement.cs" />
-    <Compile Include="Messaging\Bindings\ReplayedMessageException.cs" />
-    <Compile Include="Messaging\Bindings\ExpiredMessageException.cs" />
-    <Compile Include="Messaging\Bindings\InvalidSignatureException.cs" />
-    <Compile Include="Messaging\Bindings\IReplayProtectedProtocolMessage.cs" />
-    <Compile Include="Messaging\Bindings\IExpiringProtocolMessage.cs" />
-    <Compile Include="OAuth\Messages\AccessProtectedResourceRequest.cs" />
-    <Compile Include="OAuth\Messages\AuthorizedTokenResponse.cs" />
-    <Compile Include="OAuth\Messages\UserAuthorizationResponse.cs" />
-    <Compile Include="OAuth\Messages\UserAuthorizationRequest.cs" />
-    <Compile Include="OAuth\Messages\UnauthorizedTokenResponse.cs" />
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-    <Compile Include="Messaging\HttpRequestInfo.cs" />
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-    <Compile Include="Logger.cs" />
-    <Compile Include="Loggers\ILog.cs" />
-    <Compile Include="Loggers\Log4NetLogger.cs" />
-    <Compile Include="Loggers\NoOpLogger.cs" />
-    <Compile Include="Loggers\TraceLogger.cs" />
-    <Compile Include="Messaging\HttpDeliveryMethods.cs" />
-    <Compile Include="Messaging\MessageTransport.cs" />
-    <Compile Include="OAuth\ChannelElements\OAuthServiceProviderMessageTypeProvider.cs" />
-    <Compile Include="Messaging\ProtocolException.cs" />
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-    <Compile Include="OpenId\AssociationMemoryStore.cs" />
-    <Compile Include="OpenId\Associations.cs" />
-    <Compile Include="OpenId\ChannelElements\ITamperResistantOpenIdMessage.cs" />
-    <Compile Include="OpenId\ChannelElements\SigningBindingElement.cs" />
-    <Compile Include="OpenId\ChannelElements\KeyValueFormEncoding.cs" />
-    <Compile Include="OpenId\ChannelElements\OpenIdChannel.cs" />
-    <Compile Include="OpenId\ChannelElements\OpenIdMessageTypeProvider.cs" />
-    <Compile Include="OpenId\Configuration.cs" />
-    <Compile Include="OpenId\DiffieHellmanUtilities.cs" />
-    <Compile Include="OpenId\DiffieHellman\DHKeyGeneration.cs" />
-    <Compile Include="OpenId\DiffieHellman\DHParameters.cs" />
-    <Compile Include="OpenId\DiffieHellman\DiffieHellman.cs" />
-    <Compile Include="OpenId\DiffieHellman\DiffieHellmanManaged.cs" />
-    <Compile Include="OpenId\DiffieHellman\mono\BigInteger.cs" />
-    <Compile Include="OpenId\DiffieHellman\mono\ConfidenceFactor.cs" />
-    <Compile Include="OpenId\DiffieHellman\mono\NextPrimeFinder.cs" />
-    <Compile Include="OpenId\DiffieHellman\mono\PrimalityTests.cs" />
-    <Compile Include="OpenId\DiffieHellman\mono\PrimeGeneratorBase.cs" />
-    <Compile Include="OpenId\DiffieHellman\mono\SequentialSearchPrimeGeneratorBase.cs" />
-    <Compile Include="OpenId\HmacShaAssociation.cs" />
-    <Compile Include="OpenId\IAssociationStore.cs" />
-    <Compile Include="OpenId\Messages\AssociateUnencryptedRequest.cs" />
-    <Compile Include="OpenId\OpenIdProvider.cs" />
-    <Compile Include="OpenId\Messages\AssociateDiffieHellmanRequest.cs" />
-    <Compile Include="OpenId\Messages\AssociateDiffieHellmanResponse.cs" />
-    <Compile Include="OpenId\Messages\AssociateRequest.cs" />
-    <Compile Include="OpenId\Messages\AssociateSuccessfulResponse.cs" />
-    <Compile Include="OpenId\Messages\AssociateUnencryptedResponse.cs" />
-    <Compile Include="OpenId\Messages\AssociateUnsuccessfulResponse.cs" />
-    <Compile Include="OpenId\Messages\IndirectErrorResponse.cs" />
-    <Compile Include="OpenId\Messages\DirectErrorResponse.cs" />
-    <Compile Include="OpenId\Messages\RequestBase.cs" />
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-    <Compile Include="OpenId\Provider\ProviderSecuritySettings.cs" />
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-    <Compile Include="Messaging\MessageReceivingEndpoint.cs" />
-    <Compile Include="Util.cs" />
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-    </EmbeddedResource>
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-      <Generator>ResXFileCodeGenerator</Generator>
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-    </EmbeddedResource>
-  </ItemGroup>
-  <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
-  <Import Project="..\..\tools\DotNetOpenAuth.Versioning.targets" />
+<?xml version="1.0" encoding="utf-8"?>

+<Project ToolsVersion="3.5" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">

+  <PropertyGroup>

+    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>

+    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>

+    <ProductVersion>9.0.30729</ProductVersion>

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+    <ProjectGuid>{3191B653-F76D-4C1A-9A5A-347BC3AAAAB7}</ProjectGuid>

+    <OutputType>Library</OutputType>

+    <AppDesignerFolder>Properties</AppDesignerFolder>

+    <RootNamespace>DotNetOpenAuth</RootNamespace>

+    <AssemblyName>DotNetOpenAuth</AssemblyName>

+    <TargetFrameworkVersion>v3.5</TargetFrameworkVersion>

+    <FileAlignment>512</FileAlignment>

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+    <ErrorReport>prompt</ErrorReport>

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+    <CodeAnalysisRules>-Microsoft.Design#CA1054;-Microsoft.Design#CA1056;-Microsoft.Design#CA1055</CodeAnalysisRules>

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+    <DebugType>pdbonly</DebugType>

+    <Optimize>true</Optimize>

+    <OutputPath>..\..\bin\Release\</OutputPath>

+    <DefineConstants>TRACE</DefineConstants>

+    <ErrorReport>prompt</ErrorReport>

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+    <SignAssembly>true</SignAssembly>

+    <AssemblyOriginatorKeyFile>..\official-build-key.pfx</AssemblyOriginatorKeyFile>

+    <DefineConstants>$(DefineConstants);StrongNameSigned</DefineConstants>

+  </PropertyGroup>

+  <ItemGroup>

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+    <Reference Include="System" />

+    <Reference Include="System.configuration" />

+    <Reference Include="System.Core">

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+    </Reference>

+    <Reference Include="System.Data" />

+    <Reference Include="System.ServiceModel">

+      <RequiredTargetFramework>3.0</RequiredTargetFramework>

+    </Reference>

+    <Reference Include="System.Web" />

+    <Reference Include="System.XML" />

+    <Reference Include="System.Xml.Linq">

+      <RequiredTargetFramework>3.5</RequiredTargetFramework>

+    </Reference>

+  </ItemGroup>

+  <ItemGroup>

+    <Compile Include="Configuration\ProviderSection.cs" />

+    <Compile Include="Configuration\ProviderSecuritySettingsElement.cs" />

+    <Compile Include="Configuration\RelyingPartySection.cs" />

+    <Compile Include="Configuration\RelyingPartySecuritySettingsElement.cs" />

+    <Compile Include="Configuration\TypeConfigurationElement.cs" />

+    <Compile Include="Configuration\UntrustedWebRequestSection.cs" />

+    <Compile Include="Configuration\HostNameOrRegexCollection.cs" />

+    <Compile Include="Configuration\HostNameElement.cs" />

+    <Compile Include="Messaging\EmptyDictionary.cs" />

+    <Compile Include="Messaging\EmptyEnumerator.cs" />

+    <Compile Include="Messaging\EmptyList.cs" />

+    <Compile Include="Messaging\ErrorUtilities.cs" />

+    <Compile Include="Messaging\Reflection\IMessagePartEncoder.cs" />

+    <Compile Include="OAuth\ChannelElements\OAuthConsumerMessageTypeProvider.cs" />

+    <Compile Include="OAuth\ChannelElements\ITokenGenerator.cs" />

+    <Compile Include="OAuth\ChannelElements\ITokenManager.cs" />

+    <Compile Include="OAuth\ChannelElements\OAuthHttpMethodBindingElement.cs" />

+    <Compile Include="OAuth\ChannelElements\PlaintextSigningBindingElement.cs" />

+    <Compile Include="OAuth\ChannelElements\HmacSha1SigningBindingElement.cs" />

+    <Compile Include="OAuth\ChannelElements\SigningBindingElementChain.cs" />

+    <Compile Include="OAuth\ChannelElements\StandardTokenGenerator.cs" />

+    <Compile Include="OAuth\ChannelElements\TokenType.cs" />

+    <Compile Include="OAuth\ConsumerBase.cs" />

+    <Compile Include="OAuth\DesktopConsumer.cs" />

+    <Compile Include="GlobalSuppressions.cs" />

+    <Compile Include="OAuth\Messages\ITokenSecretContainingMessage.cs" />

+    <Compile Include="Messaging\ChannelEventArgs.cs" />

+    <Compile Include="Messaging\ITamperProtectionChannelBindingElement.cs" />

+    <Compile Include="OAuth\OAuthStrings.Designer.cs">

+      <AutoGen>True</AutoGen>

+      <DesignTime>True</DesignTime>

+      <DependentUpon>OAuthStrings.resx</DependentUpon>

+    </Compile>

+    <Compile Include="OAuth\ServiceProviderDescription.cs" />

+    <Compile Include="OAuth\Messages\ITokenContainingMessage.cs" />

+    <Compile Include="OAuth\Messages\SignedMessageBase.cs" />

+    <Compile Include="Messaging\Bindings\NonceMemoryStore.cs" />

+    <Compile Include="OAuth\ChannelElements\SigningBindingElementBase.cs" />

+    <Compile Include="OAuth\WebConsumer.cs" />

+    <Compile Include="Messaging\IWebRequestHandler.cs" />

+    <Compile Include="OAuth\ChannelElements\ITamperResistantOAuthMessage.cs" />

+    <Compile Include="OAuth\Messages\MessageBase.cs" />

+    <Compile Include="OAuth\Messages\AuthorizedTokenRequest.cs" />

+    <Compile Include="Messaging\Bindings\INonceStore.cs" />

+    <Compile Include="Messaging\Bindings\StandardReplayProtectionBindingElement.cs" />

+    <Compile Include="Messaging\MessagePartAttribute.cs" />

+    <Compile Include="Messaging\MessageProtections.cs" />

+    <Compile Include="Messaging\IChannelBindingElement.cs" />

+    <Compile Include="Messaging\Bindings\ReplayedMessageException.cs" />

+    <Compile Include="Messaging\Bindings\ExpiredMessageException.cs" />

+    <Compile Include="Messaging\Bindings\InvalidSignatureException.cs" />

+    <Compile Include="Messaging\Bindings\IReplayProtectedProtocolMessage.cs" />

+    <Compile Include="Messaging\Bindings\IExpiringProtocolMessage.cs" />

+    <Compile Include="OAuth\Messages\AccessProtectedResourceRequest.cs" />

+    <Compile Include="OAuth\Messages\AuthorizedTokenResponse.cs" />

+    <Compile Include="OAuth\Messages\UserAuthorizationResponse.cs" />

+    <Compile Include="OAuth\Messages\UserAuthorizationRequest.cs" />

+    <Compile Include="OAuth\Messages\UnauthorizedTokenResponse.cs" />

+    <Compile Include="Messaging\Channel.cs" />

+    <Compile Include="Messaging\HttpRequestInfo.cs" />

+    <Compile Include="Messaging\IDirectedProtocolMessage.cs" />

+    <Compile Include="Messaging\IMessageTypeProvider.cs" />

+    <Compile Include="Messaging\ITamperResistantProtocolMessage.cs" />

+    <Compile Include="Messaging\MessageSerializer.cs" />

+    <Compile Include="Messaging\MessagingStrings.Designer.cs">

+      <AutoGen>True</AutoGen>

+      <DesignTime>True</DesignTime>

+      <DependentUpon>MessagingStrings.resx</DependentUpon>

+    </Compile>

+    <Compile Include="Messaging\MessagingUtilities.cs" />

+    <Compile Include="Messaging\Bindings\StandardExpirationBindingElement.cs" />

+    <Compile Include="Messaging\Reflection\ValueMapping.cs" />

+    <Compile Include="Messaging\Reflection\MessageDescription.cs" />

+    <Compile Include="Messaging\Reflection\MessageDictionary.cs" />

+    <Compile Include="Messaging\Reflection\MessagePart.cs" />

+    <Compile Include="Messaging\UnprotectedMessageException.cs" />

+    <Compile Include="OAuth\ChannelElements\OAuthChannel.cs" />

+    <Compile Include="Messaging\Response.cs" />

+    <Compile Include="Messaging\IProtocolMessage.cs" />

+    <Compile Include="Logger.cs" />

+    <Compile Include="Loggers\ILog.cs" />

+    <Compile Include="Loggers\Log4NetLogger.cs" />

+    <Compile Include="Loggers\NoOpLogger.cs" />

+    <Compile Include="Loggers\TraceLogger.cs" />

+    <Compile Include="Messaging\HttpDeliveryMethods.cs" />

+    <Compile Include="Messaging\MessageTransport.cs" />

+    <Compile Include="OAuth\ChannelElements\OAuthServiceProviderMessageTypeProvider.cs" />

+    <Compile Include="Messaging\ProtocolException.cs" />

+    <Compile Include="OpenId\Association.cs" />

+    <Compile Include="OpenId\AssociationMemoryStore.cs" />

+    <Compile Include="OpenId\Associations.cs" />

+    <Compile Include="OpenId\ChannelElements\ITamperResistantOpenIdMessage.cs" />

+    <Compile Include="OpenId\ChannelElements\SigningBindingElement.cs" />

+    <Compile Include="OpenId\ChannelElements\KeyValueFormEncoding.cs" />

+    <Compile Include="OpenId\ChannelElements\OpenIdChannel.cs" />

+    <Compile Include="OpenId\ChannelElements\OpenIdMessageTypeProvider.cs" />

+    <Compile Include="OpenId\Configuration.cs" />

+    <Compile Include="OpenId\RelyingPartyDescription.cs" />

+    <Compile Include="OpenId\DiffieHellmanUtilities.cs" />

+    <Compile Include="OpenId\DiffieHellman\DHKeyGeneration.cs" />

+    <Compile Include="OpenId\DiffieHellman\DHParameters.cs" />

+    <Compile Include="OpenId\DiffieHellman\DiffieHellman.cs" />

+    <Compile Include="OpenId\DiffieHellman\DiffieHellmanManaged.cs" />

+    <Compile Include="OpenId\DiffieHellman\mono\BigInteger.cs" />

+    <Compile Include="OpenId\DiffieHellman\mono\ConfidenceFactor.cs" />

+    <Compile Include="OpenId\DiffieHellman\mono\NextPrimeFinder.cs" />

+    <Compile Include="OpenId\DiffieHellman\mono\PrimalityTests.cs" />

+    <Compile Include="OpenId\DiffieHellman\mono\PrimeGeneratorBase.cs" />

+    <Compile Include="OpenId\DiffieHellman\mono\SequentialSearchPrimeGeneratorBase.cs" />

+    <Compile Include="OpenId\HmacShaAssociation.cs" />

+    <Compile Include="OpenId\IAssociationStore.cs" />

+    <Compile Include="OpenId\Messages\AssociateUnencryptedRequest.cs" />

+    <Compile Include="OpenId\OpenIdProvider.cs" />

+    <Compile Include="OpenId\Messages\AssociateDiffieHellmanRequest.cs" />

+    <Compile Include="OpenId\Messages\AssociateDiffieHellmanResponse.cs" />

+    <Compile Include="OpenId\Messages\AssociateRequest.cs" />

+    <Compile Include="OpenId\Messages\AssociateSuccessfulResponse.cs" />

+    <Compile Include="OpenId\Messages\AssociateUnencryptedResponse.cs" />

+    <Compile Include="OpenId\Messages\AssociateUnsuccessfulResponse.cs" />

+    <Compile Include="OpenId\Messages\IndirectErrorResponse.cs" />

+    <Compile Include="OpenId\Messages\DirectErrorResponse.cs" />

+    <Compile Include="OpenId\Messages\RequestBase.cs" />

+    <Compile Include="OpenId\Messages\DirectResponseBase.cs" />

+    <Compile Include="OpenId\OpenIdRelyingParty.cs" />

+    <Compile Include="OpenId\OpenIdStrings.Designer.cs">

+      <DependentUpon>OpenIdStrings.resx</DependentUpon>

+      <DesignTime>True</DesignTime>

+      <AutoGen>True</AutoGen>

+    </Compile>

+    <Compile Include="OpenId\Protocol.cs" />

+    <Compile Include="OpenId\ProviderDescription.cs" />

+    <Compile Include="OpenId\Provider\ProviderSecuritySettings.cs" />

+    <Compile Include="OpenId\RelyingParty\RelyingPartySecuritySettings.cs" />

+    <Compile Include="OpenId\SecuritySettings.cs" />

+    <Compile Include="Properties\AssemblyInfo.cs" />

+    <Compile Include="OAuth\Messages\UnauthorizedTokenRequest.cs" />

+    <Compile Include="OAuth\ChannelElements\RsaSha1SigningBindingElement.cs" />

+    <Compile Include="Messaging\StandardWebRequestHandler.cs" />

+    <Compile Include="Messaging\MessageReceivingEndpoint.cs" />

+    <Compile Include="Util.cs" />

+    <Compile Include="OAuth\Protocol.cs" />

+    <Compile Include="OAuth\ServiceProvider.cs" />

+    <Compile Include="Strings.Designer.cs">

+      <AutoGen>True</AutoGen>

+      <DesignTime>True</DesignTime>

+      <DependentUpon>Strings.resx</DependentUpon>

+    </Compile>

+    <Compile Include="UriUtil.cs" />

+  </ItemGroup>

+  <ItemGroup>

+    <None Include="ClassDiagram.cd" />

+    <None Include="OAuth\Messages\OAuth Messages.cd" />

+    <None Include="Messaging\Bindings\Bindings.cd" />

+    <None Include="Messaging\Exceptions.cd" />

+    <None Include="Messaging\Messaging.cd" />

+  </ItemGroup>

+  <ItemGroup>

+    <EmbeddedResource Include="Messaging\MessagingStrings.resx">

+      <Generator>ResXFileCodeGenerator</Generator>

+      <LastGenOutput>MessagingStrings.Designer.cs</LastGenOutput>

+    </EmbeddedResource>

+    <EmbeddedResource Include="OAuth\OAuthStrings.resx">

+      <Generator>ResXFileCodeGenerator</Generator>

+      <LastGenOutput>OAuthStrings.Designer.cs</LastGenOutput>

+    </EmbeddedResource>

+    <EmbeddedResource Include="OpenId\OpenIdStrings.resx">

+      <Generator>ResXFileCodeGenerator</Generator>

+      <LastGenOutput>OpenIdStrings.Designer.cs</LastGenOutput>

+    </EmbeddedResource>

+    <EmbeddedResource Include="Strings.resx">

+      <Generator>ResXFileCodeGenerator</Generator>

+      <LastGenOutput>Strings.Designer.cs</LastGenOutput>

+      <SubType>Designer</SubType>

+    </EmbeddedResource>

+  </ItemGroup>

+  <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />

+  <Import Project="..\..\tools\DotNetOpenAuth.Versioning.targets" />

 </Project>
\ No newline at end of file
diff --git a/src/DotNetOpenAuth/Messaging/Channel.cs b/src/DotNetOpenAuth/Messaging/Channel.cs
index 6fbd909..73dddb1 100644
--- a/src/DotNetOpenAuth/Messaging/Channel.cs
+++ b/src/DotNetOpenAuth/Messaging/Channel.cs
@@ -280,23 +280,10 @@ namespace DotNetOpenAuth.Messaging {
 		public TRESPONSE Request<TRESPONSE>(IDirectedProtocolMessage request)
 			where TRESPONSE : class, IProtocolMessage {
 			IProtocolMessage response = this.Request(request);
-			if (response == null) {
-				throw new ProtocolException(
-					string.Format(
-						CultureInfo.CurrentCulture,
-						MessagingStrings.ExpectedMessageNotReceived,
-						typeof(TRESPONSE)));
-			}
+			ErrorUtilities.Verify(response != null, MessagingStrings.ExpectedMessageNotReceived, typeof(TRESPONSE));
 
 			var expectedResponse = response as TRESPONSE;
-			if (expectedResponse == null) {
-				throw new ProtocolException(
-					string.Format(
-						CultureInfo.CurrentCulture,
-						MessagingStrings.UnexpectedMessageReceived,
-						typeof(TRESPONSE),
-						response.GetType()));
-			}
+			ErrorUtilities.Verify(expectedResponse != null, MessagingStrings.UnexpectedMessageReceived, typeof(TRESPONSE), response.GetType());
 
 			return expectedResponse;
 		}
@@ -305,7 +292,8 @@ namespace DotNetOpenAuth.Messaging {
 		/// Sends a direct message to a remote party and waits for the response.
 		/// </summary>
 		/// <param name="request">The message to send.</param>
-		/// <returns>The remote party's response.</returns>
+		/// <returns>The remote party's response.  Guaranteed to never be null.</returns>
+		/// <exception cref="ProtocolException">Thrown if the response does not include a protocol message.</exception>
 		public IProtocolMessage Request(IDirectedProtocolMessage request) {
 			if (request == null) {
 				throw new ArgumentNullException("request");
@@ -314,6 +302,7 @@ namespace DotNetOpenAuth.Messaging {
 			this.PrepareMessageForSending(request);
 			Logger.DebugFormat("Sending request: {0}", request);
 			var responseMessage = this.RequestInternal(request);
+			ErrorUtilities.Verify(responseMessage != null, MessagingStrings.ExpectedMessageNotReceived, typeof(IProtocolMessage).Name);
 
 			Logger.DebugFormat("Received message response: {0}", responseMessage);
 			this.VerifyMessageAfterReceiving(responseMessage);
diff --git a/src/DotNetOpenAuth/Messaging/ErrorUtilities.cs b/src/DotNetOpenAuth/Messaging/ErrorUtilities.cs
index 8464066..fb62c76 100644
--- a/src/DotNetOpenAuth/Messaging/ErrorUtilities.cs
+++ b/src/DotNetOpenAuth/Messaging/ErrorUtilities.cs
@@ -52,6 +52,18 @@ namespace DotNetOpenAuth.Messaging {
 		}
 
 		/// <summary>
+		/// Verifies something about the argument supplied to a method.
+		/// </summary>
+		/// <param name="condition">The condition that must evaluate to true to avoid an exception.</param>
+		/// <param name="message">The message to use in the exception if the condition is false.</param>
+		/// <param name="args">The string formatting arguments, if any.</param>
+		internal static void VerifyArgument(bool condition, string message, params string[] args) {
+			if (!condition) {
+				throw new ArgumentException(string.Format(CultureInfo.CurrentCulture, message, args));
+			}
+		}
+
+		/// <summary>
 		/// Verifies that some given value is not null.
 		/// </summary>
 		/// <param name="value">The value to check.</param>
diff --git a/src/DotNetOpenAuth/Messaging/MessagingStrings.Designer.cs b/src/DotNetOpenAuth/Messaging/MessagingStrings.Designer.cs
index eb6e4f8..dcd8f4e 100644
--- a/src/DotNetOpenAuth/Messaging/MessagingStrings.Designer.cs
+++ b/src/DotNetOpenAuth/Messaging/MessagingStrings.Designer.cs
@@ -142,7 +142,7 @@ namespace DotNetOpenAuth.Messaging {
         }
         
         /// <summary>
-        ///   Looks up a localized string similar to Expected message {0} but received no recognizable message..
+        ///   Looks up a localized string similar to Expected {0} message but received no recognizable message..
         /// </summary>
         internal static string ExpectedMessageNotReceived {
             get {
@@ -421,6 +421,15 @@ namespace DotNetOpenAuth.Messaging {
         }
         
         /// <summary>
+        ///   Looks up a localized string similar to Unexpected message type received..
+        /// </summary>
+        internal static string UnexpectedMessageReceivedOfMany {
+            get {
+                return ResourceManager.GetString("UnexpectedMessageReceivedOfMany", resourceCulture);
+            }
+        }
+        
+        /// <summary>
         ///   Looks up a localized string similar to The type {0} or a derived type was expected, but {1} was given..
         /// </summary>
         internal static string UnexpectedType {
diff --git a/src/DotNetOpenAuth/Messaging/MessagingStrings.resx b/src/DotNetOpenAuth/Messaging/MessagingStrings.resx
index 406e0ff..aa0d9d0 100644
--- a/src/DotNetOpenAuth/Messaging/MessagingStrings.resx
+++ b/src/DotNetOpenAuth/Messaging/MessagingStrings.resx
@@ -145,7 +145,7 @@
     <value>This exception was not constructed with a root request message that caused it.</value>
   </data>
   <data name="ExpectedMessageNotReceived" xml:space="preserve">
-    <value>Expected message {0} but received no recognizable message.</value>
+    <value>Expected {0} message but received no recognizable message.</value>
   </data>
   <data name="ExpiredMessage" xml:space="preserve">
     <value>The message expired at {0} and it is now {1}.</value>
@@ -237,6 +237,9 @@
   <data name="UnexpectedMessageReceived" xml:space="preserve">
     <value>Expected message {0} but received {1} instead.</value>
   </data>
+  <data name="UnexpectedMessageReceivedOfMany" xml:space="preserve">
+    <value>Unexpected message type received.</value>
+  </data>
   <data name="UnexpectedType" xml:space="preserve">
     <value>The type {0} or a derived type was expected, but {1} was given.</value>
   </data>
diff --git a/src/DotNetOpenAuth/OpenId/Messages/AssociateDiffieHellmanResponse.cs b/src/DotNetOpenAuth/OpenId/Messages/AssociateDiffieHellmanResponse.cs
index 7c3a07d..39b7516 100644
--- a/src/DotNetOpenAuth/OpenId/Messages/AssociateDiffieHellmanResponse.cs
+++ b/src/DotNetOpenAuth/OpenId/Messages/AssociateDiffieHellmanResponse.cs
@@ -33,7 +33,25 @@ namespace DotNetOpenAuth.OpenId.Messages {
 		internal byte[] EncodedMacKey { get; set; }
 
 		/// <summary>
-		/// Called to create the Association based on a provided request previously given by the Relying Party.
+		/// Called to create the Association based on a request previously given by the Relying Party.
+		/// </summary>
+		/// <param name="request">The prior request for an association.</param>
+		/// <returns>The created association.</returns>
+		/// <remarks>
+		/// 	<para>The response message is updated to include the details of the created association by this method,
+		/// but the resulting association is <i>not</i> added to the association store and must be done by the caller.</para>
+		/// 	<para>This method is called by both the Provider and the Relying Party, but actually performs
+		/// quite different operations in either scenario.</para>
+		/// </remarks>
+		protected internal override Association CreateAssociation(AssociateRequest request) {
+			ErrorUtilities.VerifyArgumentNotNull(request, "request");
+			ErrorUtilities.VerifyArgument(request is AssociateDiffieHellmanRequest, "request");
+
+			return this.CreateAssociation((AssociateDiffieHellmanRequest)request);
+		}
+
+		/// <summary>
+		/// Called to create the Association based on a request previously given by the Relying Party.
 		/// </summary>
 		/// <param name="request">The request for an association.</param>
 		/// <returns>The created association.</returns>
@@ -43,7 +61,7 @@ namespace DotNetOpenAuth.OpenId.Messages {
 		/// <para>This method is called by both the Provider and the Relying Party, but actually performs
 		/// quite different operations in either scenario.</para>
 		/// </remarks>
-		internal Association CreateAssociation(AssociateDiffieHellmanRequest request) {
+		private Association CreateAssociation(AssociateDiffieHellmanRequest request) {
 			// If the encoded mac key is already set, then this is an incoming message at the Relying Party.
 			if (this.EncodedMacKey == null) {
 				return this.CreateAssociationAtProvider(request);
diff --git a/src/DotNetOpenAuth/OpenId/Messages/AssociateRequest.cs b/src/DotNetOpenAuth/OpenId/Messages/AssociateRequest.cs
index c5adb7e..9e4c533 100644
--- a/src/DotNetOpenAuth/OpenId/Messages/AssociateRequest.cs
+++ b/src/DotNetOpenAuth/OpenId/Messages/AssociateRequest.cs
@@ -60,5 +60,27 @@ namespace DotNetOpenAuth.OpenId.Messages {
 				OpenIdStrings.NoEncryptionSessionRequiresHttps,
 				this);
 		}
+
+		/// <summary>
+		/// Creates an association request message that is appropriate for a given Provider.
+		/// </summary>
+		/// <param name="provider">The provider to create an association with.</param>
+		/// <returns>The message to send to the Provider to request an association.</returns>
+		internal static AssociateRequest Create(ProviderEndpointDescription provider) {
+			AssociateRequest associateRequest;
+			if (provider.Endpoint.IsTransportSecure()) {
+				associateRequest = new AssociateUnencryptedRequest(provider.Endpoint);
+			} else {
+				// TODO: apply security policies and our knowledge of the provider's OpenID version
+				// to select the right association here.
+				var diffieHellmanAssociateRequest = new AssociateDiffieHellmanRequest(provider.Endpoint);
+				diffieHellmanAssociateRequest.AssociationType = provider.Protocol.Args.SignatureAlgorithm.HMAC_SHA1;
+				diffieHellmanAssociateRequest.SessionType = provider.Protocol.Args.SessionType.DH_SHA1;
+				diffieHellmanAssociateRequest.InitializeRequest();
+				associateRequest = diffieHellmanAssociateRequest;
+			}
+
+			return associateRequest;
+		}
 	}
 }
diff --git a/src/DotNetOpenAuth/OpenId/Messages/AssociateSuccessfulResponse.cs b/src/DotNetOpenAuth/OpenId/Messages/AssociateSuccessfulResponse.cs
index 5968171..8c6d39d 100644
--- a/src/DotNetOpenAuth/OpenId/Messages/AssociateSuccessfulResponse.cs
+++ b/src/DotNetOpenAuth/OpenId/Messages/AssociateSuccessfulResponse.cs
@@ -50,5 +50,18 @@ namespace DotNetOpenAuth.OpenId.Messages {
 		/// <value>An integer, represented in base 10 ASCII. </value>
 		[MessagePart("expires_in", IsRequired = true)]
 		internal long ExpiresIn { get; set; }
+
+		/// <summary>
+		/// Called to create the Association based on a request previously given by the Relying Party.
+		/// </summary>
+		/// <param name="request">The prior request for an association.</param>
+		/// <returns>The created association.</returns>
+		/// <remarks>
+		/// <para>The response message is updated to include the details of the created association by this method, 
+		/// but the resulting association is <i>not</i> added to the association store and must be done by the caller.</para>
+		/// <para>This method is called by both the Provider and the Relying Party, but actually performs
+		/// quite different operations in either scenario.</para>
+		/// </remarks>
+		protected internal abstract Association CreateAssociation(AssociateRequest request);
 	}
 }
diff --git a/src/DotNetOpenAuth/OpenId/Messages/AssociateUnencryptedResponse.cs b/src/DotNetOpenAuth/OpenId/Messages/AssociateUnencryptedResponse.cs
index 4d0a341..3790963 100644
--- a/src/DotNetOpenAuth/OpenId/Messages/AssociateUnencryptedResponse.cs
+++ b/src/DotNetOpenAuth/OpenId/Messages/AssociateUnencryptedResponse.cs
@@ -5,6 +5,7 @@
 //-----------------------------------------------------------------------
 
 namespace DotNetOpenAuth.OpenId.Messages {
+	using System;
 	using DotNetOpenAuth.Messaging;
 	using DotNetOpenAuth.Messaging.Reflection;
 
@@ -27,5 +28,21 @@ namespace DotNetOpenAuth.OpenId.Messages {
 		/// </summary>
 		[MessagePart("mac_key", IsRequired = true, AllowEmpty = false)]
 		internal byte[] MacKey { get; set; }
+
+		/// <summary>
+		/// Called to create the Association based on a request previously given by the Relying Party.
+		/// </summary>
+		/// <param name="request">The prior request for an association.</param>
+		/// <returns>The created association.</returns>
+		/// <remarks>
+		/// 	<para>The response message is updated to include the details of the created association by this method,
+		/// but the resulting association is <i>not</i> added to the association store and must be done by the caller.</para>
+		/// 	<para>This method is called by both the Provider and the Relying Party, but actually performs
+		/// quite different operations in either scenario.</para>
+		/// </remarks>
+		protected internal override Association CreateAssociation(AssociateRequest request) {
+			////return HmacShaAssociation.Create(Protocol, this.AssociationType, AssociationRelyingPartyType.
+			throw new NotImplementedException();
+		}
 	}
 }
diff --git a/src/DotNetOpenAuth/OpenId/OpenIdRelyingParty.cs b/src/DotNetOpenAuth/OpenId/OpenIdRelyingParty.cs
index f25bcaa..f5e2d9c 100644
--- a/src/DotNetOpenAuth/OpenId/OpenIdRelyingParty.cs
+++ b/src/DotNetOpenAuth/OpenId/OpenIdRelyingParty.cs
@@ -11,6 +11,7 @@ namespace DotNetOpenAuth.OpenId {
 	using System.Text;
 	using DotNetOpenAuth.Messaging;
 	using DotNetOpenAuth.OpenId.ChannelElements;
+	using DotNetOpenAuth.OpenId.Messages;
 
 	/// <summary>
 	/// Provides the programmatic facilities to act as an OpenId consumer.
@@ -27,5 +28,28 @@ namespace DotNetOpenAuth.OpenId {
 		/// Gets the channel to use for sending/receiving messages.
 		/// </summary>
 		public Channel Channel { get; internal set; }
+
+		/// <summary>
+		/// Gets an association between this Relying Party and a given Provider.
+		/// A new association is created if necessary and possible.
+		/// </summary>
+		/// <param name="provider">The provider to create an association with.</param>
+		/// <returns>The association if one exists and/or could be created.  Null otherwise.</returns>
+		internal Association GetAssociation(ProviderEndpointDescription provider) {
+			ErrorUtilities.VerifyArgumentNotNull(provider, "provider");
+
+			var associateRequest = AssociateRequest.Create(provider);
+			var associateResponse = this.Channel.Request(associateRequest);
+			var associateSuccessfulResponse = associateResponse as AssociateSuccessfulResponse;
+			var associateUnsuccessfulResponse = associateResponse as AssociateUnsuccessfulResponse;
+			if (associateSuccessfulResponse != null) {
+				return associateSuccessfulResponse.CreateAssociation(associateRequest);
+			} else if (associateUnsuccessfulResponse != null) {
+				// TODO: code here
+				throw new NotImplementedException();
+			} else {
+				throw new ProtocolException(MessagingStrings.UnexpectedMessageReceivedOfMany);
+			}
+		}
 	}
 }
diff --git a/src/DotNetOpenAuth/OpenId/ProviderDescription.cs b/src/DotNetOpenAuth/OpenId/ProviderDescription.cs
new file mode 100644
index 0000000..99faad1
--- /dev/null
+++ b/src/DotNetOpenAuth/OpenId/ProviderDescription.cs
@@ -0,0 +1,48 @@
+//-----------------------------------------------------------------------
+// <copyright file="ProviderDescription.cs" company="Andrew Arnott">
+//     Copyright (c) Andrew Arnott. All rights reserved.
+// </copyright>
+//-----------------------------------------------------------------------
+
+namespace DotNetOpenAuth.OpenId {
+	using System;
+	using System.Collections.Generic;
+	using System.Linq;
+	using System.Text;
+	using DotNetOpenAuth.Messaging;
+
+	/// <summary>
+	/// Describes some OpenID Provider endpoint and its capabilities.
+	/// </summary>
+	/// <remarks>
+	/// This is an immutable type.
+	/// </remarks>
+	internal class ProviderEndpointDescription {
+		/// <summary>
+		/// Initializes a new instance of the <see cref="ProviderEndpointDescription"/> class.
+		/// </summary>
+		/// <param name="providerEndpoint">The OpenID Provider endpoint URL.</param>
+		/// <param name="version">The OpenID version supported by this particular endpoint.</param>
+		internal ProviderEndpointDescription(Uri providerEndpoint, Protocol version) {
+			ErrorUtilities.VerifyArgumentNotNull(providerEndpoint, "providerEndpoint");
+			ErrorUtilities.VerifyArgumentNotNull(version, "version");
+
+			this.Endpoint = providerEndpoint;
+			this.Protocol = version;
+		}
+
+		/// <summary>
+		/// Gets the URL that the OpenID Provider listens for incoming OpenID messages on.
+		/// </summary>
+		internal Uri Endpoint { get; private set; }
+
+		/// <summary>
+		/// Gets the OpenID protocol version this endpoint supports.
+		/// </summary>
+		/// <remarks>
+		/// If an endpoint supports multiple versions, each version must be represented
+		/// by its own <see cref="ProviderEndpointDescription"/> object.
+		/// </remarks>
+		internal Protocol Protocol { get; private set; }
+	}
+}
diff --git a/src/DotNetOpenAuth/OpenId/RelyingPartyDescription.cs b/src/DotNetOpenAuth/OpenId/RelyingPartyDescription.cs
new file mode 100644
index 0000000..263daac
--- /dev/null
+++ b/src/DotNetOpenAuth/OpenId/RelyingPartyDescription.cs
@@ -0,0 +1,18 @@
+//-----------------------------------------------------------------------
+// <copyright file="RelyingPartyDescription.cs" company="Andrew Arnott">
+//     Copyright (c) Andrew Arnott. All rights reserved.
+// </copyright>
+//-----------------------------------------------------------------------
+
+namespace DotNetOpenAuth.OpenId {
+	using System;
+	using System.Collections.Generic;
+	using System.Linq;
+	using System.Text;
+
+	/// <summary>
+	/// A description of some OpenID Relying Party endpoint.
+	/// </summary>
+	internal class RelyingPartyEndpointDescription {
+	}
+}