Changed the compile-time switch for DH support into a runtime check f…

…or the supporting assembling.

Fixes #87

src/DotNetOpenAuth.OpenId.Provider/DotNetOpenAuth.OpenId.Provider.csproj

@@ -31,7 +31,7 @@
     <Compile Include="OpenId\Provider\Extensions\UI\UIRequestTools.cs" />
     <Compile Include="OpenId\Provider\HmacShaAssociationProvider.cs" />
     <Compile Include="OpenId\Messages\AssociateDiffieHellmanProviderRequest.cs" />
-    <Compile Include="OpenId\Messages\AssociateDiffieHellmanProviderResponse.cs" Condition=" '$(ExcludeDiffieHellman)' != 'true' " />
+    <Compile Include="OpenId\Messages\AssociateDiffieHellmanProviderResponse.cs" />
     <Compile Include="OpenId\Messages\IAssociateRequestProvider.cs" />
     <Compile Include="OpenId\Messages\AssociateRequestProviderTools.cs" />
     <Compile Include="OpenId\Messages\IAssociateSuccessfulResponseProvider.cs" />
@@ -67,7 +67,7 @@
       <Project>{3896A32A-E876-4C23-B9B8-78E17D134CD3}</Project>
       <Name>DotNetOpenAuth.OpenId</Name>
     </ProjectReference>
-    <ProjectReference Include="..\Org.Mentalis.Security.Cryptography\Org.Mentalis.Security.Cryptography.csproj" Condition=" '$(ExcludeDiffieHellman)' != 'true' ">
+    <ProjectReference Include="..\Org.Mentalis.Security.Cryptography\Org.Mentalis.Security.Cryptography.csproj" >
       <Project>{26DC877F-5987-48DD-9DDB-E62F2DE0E150}</Project>
       <Name>Org.Mentalis.Security.Cryptography</Name>
     </ProjectReference>

src/DotNetOpenAuth.OpenId.Provider/OpenId/Messages/AssociateDiffieHellmanProviderRequest.cs

@@ -31,13 +31,9 @@ internal AssociateDiffieHellmanProviderRequest(Version version, Uri providerEndp
 		/// The appropriate association response message.
 		/// </returns>
 		public IProtocolMessage CreateResponseCore() {
-#if !ExcludeDiffieHellman
 			var response = new AssociateDiffieHellmanProviderResponse(this.Version, this);
 			response.AssociationType = this.AssociationType;
 			return response;
-#else
-			throw new NotSupportedException();
-#endif
 		}
 	}
 }

src/DotNetOpenAuth.OpenId.RelyingParty/DotNetOpenAuth.OpenId.RelyingParty.csproj

@@ -34,7 +34,7 @@
     <Compile Include="OpenId\Interop\AuthenticationResponseShim.cs" />
     <Compile Include="OpenId\Interop\ClaimsResponseShim.cs" />
     <Compile Include="OpenId\Interop\OpenIdRelyingPartyShim.cs" />
-    <Compile Include="OpenId\Messages\AssociateDiffieHellmanRelyingPartyResponse.cs" Condition=" '$(ExcludeDiffieHellman)' != 'true' " />
+    <Compile Include="OpenId\Messages\AssociateDiffieHellmanRelyingPartyResponse.cs" />
     <Compile Include="OpenId\Messages\AssociateRequestRelyingParty.cs" />
     <Compile Include="OpenId\Messages\IAssociateSuccessfulResponseRelyingPartyContract.cs" />
     <Compile Include="OpenId\Messages\IAssociateSuccessfulResponseRelyingParty.cs" />
@@ -71,7 +71,7 @@
       <Project>{3896A32A-E876-4C23-B9B8-78E17D134CD3}</Project>
       <Name>DotNetOpenAuth.OpenId</Name>
     </ProjectReference>
-    <ProjectReference Include="..\Org.Mentalis.Security.Cryptography\Org.Mentalis.Security.Cryptography.csproj" Condition=" '$(ExcludeDiffieHellman)' != 'true' ">
+    <ProjectReference Include="..\Org.Mentalis.Security.Cryptography\Org.Mentalis.Security.Cryptography.csproj">
       <Project>{26DC877F-5987-48DD-9DDB-E62F2DE0E150}</Project>
       <Name>Org.Mentalis.Security.Cryptography</Name>
     </ProjectReference>

src/DotNetOpenAuth.OpenId.RelyingParty/OpenId/ChannelElements/OpenIdRelyingPartyMessageFactory.cs

@@ -95,12 +95,12 @@ internal class OpenIdRelyingPartyMessageFactory : IMessageFactory {
 					// This is a special recognized error case that we create a special message for.
 					message = new AssociateUnsuccessfulResponse(protocol.Version, associateRequest);
 				} else if (message == null) {
-#if !ExcludeDiffieHellman
-					var associateDiffieHellmanRequest = request as AssociateDiffieHellmanRequest;
-					if (associateDiffieHellmanRequest != null) {
-						message = new AssociateDiffieHellmanRelyingPartyResponse(protocol.Version, associateDiffieHellmanRequest);
+					if (OpenIdUtilities.IsDiffieHellmanPresent) {
+						var associateDiffieHellmanRequest = request as AssociateDiffieHellmanRequest;
+						if (associateDiffieHellmanRequest != null) {
+							message = new AssociateDiffieHellmanRelyingPartyResponse(protocol.Version, associateDiffieHellmanRequest);
+						}
 					}
-#endif
 
 					var associateUnencryptedRequest = request as AssociateUnencryptedRequest;
 					if (associateUnencryptedRequest != null) {

src/DotNetOpenAuth.OpenId.RelyingParty/OpenId/Messages/AssociateRequestRelyingParty.cs

@@ -68,15 +68,15 @@ internal static class AssociateRequestRelyingParty {
 				associateRequest.AssociationType = associationType;
 				return associateRequest;
 			} else {
-#if !ExcludeDiffieHellman
-				var associateRequest = new AssociateDiffieHellmanRequest(provider.Version, provider.Uri);
-				associateRequest.AssociationType = associationType;
-				associateRequest.SessionType = sessionType;
-				associateRequest.InitializeRequest();
-				return associateRequest;
-#else
-				return null;
-#endif
+				if (OpenIdUtilities.IsDiffieHellmanPresent) {
+					var associateRequest = new AssociateDiffieHellmanRequest(provider.Version, provider.Uri);
+					associateRequest.AssociationType = associationType;
+					associateRequest.SessionType = sessionType;
+					associateRequest.InitializeRequest();
+					return associateRequest;
+				} else {
+					return null;
+				}
 			}
 		}
 	}

src/DotNetOpenAuth.OpenId/DotNetOpenAuth.OpenId.csproj

@@ -123,11 +123,11 @@
     <Compile Include="OpenId\ProviderEndpointDescription.cs" />
     <Compile Include="OpenId\Realm.cs" />
     <Compile Include="OpenId\RelyingPartyEndpointDescription.cs" />
-    <Compile Include="OpenId\DiffieHellmanUtilities.cs" Condition=" '$(ExcludeDiffieHellman)' != 'true' " />
+    <Compile Include="OpenId\DiffieHellmanUtilities.cs" />
     <Compile Include="OpenId\HmacShaAssociation.cs" />
     <Compile Include="OpenId\Messages\AssociateUnencryptedRequest.cs" />
     <Compile Include="OpenId\Messages\AssociateDiffieHellmanRequest.cs" />
-    <Compile Include="OpenId\Messages\AssociateDiffieHellmanResponse.cs" Condition=" '$(ExcludeDiffieHellman)' != 'true' " />
+    <Compile Include="OpenId\Messages\AssociateDiffieHellmanResponse.cs" />
     <Compile Include="OpenId\Messages\AssociateRequest.cs" />
     <Compile Include="OpenId\Messages\AssociateSuccessfulResponse.cs" />
     <Compile Include="OpenId\Messages\AssociateUnencryptedResponse.cs" />
@@ -180,7 +180,7 @@
       <Project>{60426312-6AE5-4835-8667-37EDEA670222}</Project>
       <Name>DotNetOpenAuth.Core</Name>
     </ProjectReference>
-    <ProjectReference Include="..\Org.Mentalis.Security.Cryptography\Org.Mentalis.Security.Cryptography.csproj" Condition=" '$(ExcludeDiffieHellman)' != 'true' ">
+    <ProjectReference Include="..\Org.Mentalis.Security.Cryptography\Org.Mentalis.Security.Cryptography.csproj">
       <Project>{26DC877F-5987-48DD-9DDB-E62F2DE0E150}</Project>
       <Name>Org.Mentalis.Security.Cryptography</Name>
     </ProjectReference>

src/DotNetOpenAuth.OpenId/OpenId/HmacShaAssociation.cs

@@ -140,11 +140,13 @@ private HmacShaAssociation(HmacSha typeIdentity, string handle, byte[] secret, T
 					hashSizeInBits < securityRequirements.MinimumHashBitLength) {
 					continue;
 				}
-#if !ExcludeDiffieHellman
-				sessionType = DiffieHellmanUtilities.GetNameForSize(protocol, hashSizeInBits);
-#else
-				sessionType = requireMatchingDHSessionType ? null : protocol.Args.SessionType.NoEncryption;
-#endif
+
+				if (OpenIdUtilities.IsDiffieHellmanPresent) {
+					sessionType = DiffieHellmanUtilities.GetNameForSize(protocol, hashSizeInBits);
+				} else {
+					sessionType = requireMatchingDHSessionType ? null : protocol.Args.SessionType.NoEncryption;
+				}
+
 				if (requireMatchingDHSessionType && sessionType == null) {
 					continue;
 				}
@@ -178,14 +180,14 @@ private HmacShaAssociation(HmacSha typeIdentity, string handle, byte[] secret, T
 				return true;
 			}
 
-#if !ExcludeDiffieHellman
-			// When there _is_ a DH session, it must match in hash length with the association type.
-			int associationSecretLengthInBytes = GetSecretLength(protocol, associationType);
-			int sessionHashLengthInBytes = DiffieHellmanUtilities.Lookup(protocol, sessionType).HashSize / 8;
-			return associationSecretLengthInBytes == sessionHashLengthInBytes;
-#else
-			return false;
-#endif
+			if (OpenIdUtilities.IsDiffieHellmanPresent) {
+				// When there _is_ a DH session, it must match in hash length with the association type.
+				int associationSecretLengthInBytes = GetSecretLength(protocol, associationType);
+				int sessionHashLengthInBytes = DiffieHellmanUtilities.Lookup(protocol, sessionType).HashSize / 8;
+				return associationSecretLengthInBytes == sessionHashLengthInBytes;
+			} else {
+				return false;
+			}
 		}
 
 		/// <summary>

src/DotNetOpenAuth.OpenId/OpenId/Messages/AssociateDiffieHellmanRequest.cs

@@ -12,9 +12,7 @@ namespace DotNetOpenAuth.OpenId.Messages {
 	using System.Text;
 	using DotNetOpenAuth.Messaging;
 	using DotNetOpenAuth.Messaging.Reflection;
-#if !ExcludeDiffieHellman
 	using Org.Mentalis.Security.Cryptography;
-#endif
 
 	/// <summary>
 	/// An OpenID direct request from Relying Party to Provider to initiate an association that uses Diffie-Hellman encryption.
@@ -78,31 +76,25 @@ internal AssociateDiffieHellmanRequest(Version version, Uri providerEndpoint)
 		[MessagePart("openid.dh_consumer_public", IsRequired = true, AllowEmpty = false)]
 		internal byte[] DiffieHellmanConsumerPublic { get; set; }
 
-#if !ExcludeDiffieHellman
 		/// <summary>
 		/// Gets the Diffie-Hellman algorithm.
 		/// </summary>
 		/// <remarks>
 		/// This property is initialized with a call to <see cref="InitializeRequest"/>.
 		/// </remarks>
 		internal DiffieHellman Algorithm { get; private set; }
-#endif
 
 		/// <summary>
 		/// Called by the Relying Party to initialize the Diffie-Hellman algorithm and consumer public key properties.
 		/// </summary>
 		internal void InitializeRequest() {
-#if !ExcludeDiffieHellman
 			if (this.DiffieHellmanModulus == null || this.DiffieHellmanGen == null) {
 				throw new InvalidOperationException(string.Format(CultureInfo.CurrentCulture, OpenIdStrings.DiffieHellmanRequiredPropertiesNotSet, string.Join(", ", new string[] { "DiffieHellmanModulus", "DiffieHellmanGen" })));
 			}
 
 			this.Algorithm = new DiffieHellmanManaged(this.DiffieHellmanModulus ?? DefaultMod, this.DiffieHellmanGen ?? DefaultGen, DefaultX);
 			byte[] consumerPublicKeyExchange = this.Algorithm.CreateKeyExchange();
 			this.DiffieHellmanConsumerPublic = DiffieHellmanUtilities.EnsurePositive(consumerPublicKeyExchange);
-#else
-			throw new NotSupportedException();
-#endif
 		}
 	}
 }

src/DotNetOpenAuth.OpenId/OpenId/OpenIdUtilities.cs

@@ -10,6 +10,7 @@ namespace DotNetOpenAuth.OpenId {
 	using System.Diagnostics.CodeAnalysis;
 	using System.Diagnostics.Contracts;
 	using System.Globalization;
+	using System.IO;
 	using System.Linq;
 	using System.Text;
 	using System.Text.RegularExpressions;
@@ -19,6 +20,7 @@ namespace DotNetOpenAuth.OpenId {
 	using DotNetOpenAuth.OpenId.ChannelElements;
 	using DotNetOpenAuth.OpenId.Extensions;
 	using DotNetOpenAuth.OpenId.Messages;
+	using Org.Mentalis.Security.Cryptography;
 
 	/// <summary>
 	/// A set of utilities especially useful to OpenID.
@@ -29,6 +31,31 @@ public static class OpenIdUtilities {
 		/// </summary>
 		internal const string CustomParameterPrefix = "dnoa.";
 
+		private static bool? diffieHellmanPresent;
+
+		internal static bool IsDiffieHellmanPresent {
+			get {
+				if (!diffieHellmanPresent.HasValue) {
+					try {
+						LoadDiffieHellmanTypes();
+						diffieHellmanPresent = true;
+					} catch (FileNotFoundException) {
+						diffieHellmanPresent = false;
+					} catch (TypeLoadException) {
+						diffieHellmanPresent = false;
+					}
+
+					if (diffieHellmanPresent.Value) {
+						Logger.OpenId.Info("Diffie-Hellman supporting assemblies found and loaded.");
+					} else {
+						Logger.OpenId.Warn("Diffie-Hellman supporting assemblies failed to load.  Only associations with HTTPS OpenID Providers will be supported.");
+					}
+				}
+
+				return diffieHellmanPresent.Value;
+			}
+		}
+
 		/// <summary>
 		/// Creates a random association handle.
 		/// </summary>
@@ -169,5 +196,9 @@ public static class OpenIdUtilities {
 			ErrorUtilities.VerifyOperation(aggregator != null, OpenIdStrings.UnsupportedChannelConfiguration);
 			return aggregator.Factories;
 		}
+
+		private static void LoadDiffieHellmanTypes() {
+			var dhAssemblyType = typeof(DiffieHellmanManaged);
+		}
 	}
 }

tools/DotNetOpenAuth.targets

@@ -18,7 +18,6 @@
 		<CodeContractsInstallDir>$(ProjectRoot)tools\Contracts\</CodeContractsInstallDir>
 		<DefineConstants Condition=" '$(SignAssembly)' == 'true' ">$(DefineConstants);StrongNameSigned</DefineConstants>
 		<DefineConstants Condition=" '$(ClrVersion)' == '4' ">$(DefineConstants);CLR4</DefineConstants>
-		<DefineConstants Condition=" '$(ExcludeDiffieHellman)' == 'true' ">$(DefineConstants);ExcludeDiffieHellman</DefineConstants>
 		<AssemblySearchPaths>$(ProjectRoot)lib;$(AssemblySearchPaths)</AssemblySearchPaths>
 		<AssemblySearchPaths Condition="Exists('$(ProjectRoot)lib\net-$(TargetFrameworkVersion)')">$(ProjectRoot)lib\net-$(TargetFrameworkVersion);$(AssemblySearchPaths)</AssemblySearchPaths>
 	</PropertyGroup>