Added DPAPI implementation that works on mono

src/Microsoft.AspNet.Hosting/HostingServices.cs

@@ -37,11 +37,20 @@ namespace Microsoft.AspNet.Hosting
                 Lifecycle = LifecycleKind.Scoped
             };
 
-            // The default IDataProtectionProvider is a singleton.
-            // Note: DPAPI isn't usable in IIS where the user profile hasn't been loaded, but loading DPAPI
-            // is deferred until the first call to Protect / Unprotect. It's up to an IIS-based host to
-            // replace this service as part of application initialization.
-            yield return describer.Instance<IDataProtectionProvider>(DataProtectionProvider.CreateFromDpapi());
+            if (PlatformHelper.IsMono)
+            {
+#if NET45
+                yield return describer.Instance<IDataProtectionProvider>(DataProtectionProvider.CreateFromLegacyDpapi());
+#endif
+            }
+            else
+            {
+                // The default IDataProtectionProvider is a singleton.
+                // Note: DPAPI isn't usable in IIS where the user profile hasn't been loaded, but loading DPAPI
+                // is deferred until the first call to Protect / Unprotect. It's up to an IIS-based host to
+                // replace this service as part of application initialization.
+                yield return describer.Instance<IDataProtectionProvider>(DataProtectionProvider.CreateFromDpapi());
+            }
         }
     }
 }

src/Microsoft.AspNet.Hosting/Microsoft.AspNet.Hosting.kproj

@@ -29,6 +29,7 @@
     <Compile Include="HostingServices.cs" />
     <Compile Include="IHostingEngine.cs" />
     <Compile Include="PipelineInstance.cs" />
+    <Compile Include="PlatformHelper.cs" />
     <Compile Include="Program.cs" />
     <Compile Include="Server\IServerFactory.cs" />
     <Compile Include="Server\IServerManager.cs" />

src/Microsoft.AspNet.Hosting/PlatformHelper.cs

@@ -0,0 +1,17 @@
+using System;
+
+namespace Microsoft.AspNet.Hosting
+{
+    internal static class PlatformHelper
+    {
+        private static Lazy<bool> _isMono = new Lazy<bool>(() => Type.GetType("Mono.Runtime") != null);
+
+        public static bool IsMono
+        {
+            get
+            {
+                return _isMono.Value;
+            }
+        }
+    }
+}