Added API key authentication

NzbDrone.Api/Authentication/EnableStatelessAuthInNancy.cs

@@ -0,0 +1,50 @@
+using System.Linq;
+using Nancy;
+using Nancy.Bootstrapper;
+using NzbDrone.Common.EnvironmentInfo;
+using NzbDrone.Core.Configuration;
+
+namespace NzbDrone.Api.Authentication
+{
+    public interface IEnableStatelessAuthInNancy
+    {
+        void Register(IPipelines pipelines);
+    }
+
+    public class EnableStatelessAuthInNancy : IEnableStatelessAuthInNancy
+    {
+        private readonly IConfigFileProvider _configFileProvider;
+
+        public EnableStatelessAuthInNancy(IConfigFileProvider configFileProvider)
+        {
+            _configFileProvider = configFileProvider;
+        }
+
+        public void Register(IPipelines pipelines)
+        {
+            pipelines.BeforeRequest.AddItemToEndOfPipeline(ValidateApiKey);
+        }
+
+        public Response ValidateApiKey(NancyContext context)
+        {
+            Response response = null;
+            var apiKey = context.Request.Headers["ApiKey"].FirstOrDefault();
+
+            if (!RuntimeInfo.IsProduction &&
+                (context.Request.UserHostAddress.Equals("localhost") ||
+                context.Request.UserHostAddress.Equals("127.0.0.1") ||
+                context.Request.UserHostAddress.Equals("::1")))
+            {
+                return response;
+            }
+            
+            if (context.Request.Path.StartsWith("/api/") && 
+                (apiKey == null || !apiKey.Equals(_configFileProvider.ApiKey)))
+            {
+                response = new Response { StatusCode = HttpStatusCode.Unauthorized };
+            }
+
+            return response;
+        }
+    }
+}