Authentication handler

src/Microsoft.Graph.Core/Extensions/RequestExtensions.cs

@@ -0,0 +1,30 @@
+// ------------------------------------------------------------------------------
+//  Copyright (c) Microsoft Corporation.  All Rights Reserved.  Licensed under the MIT License.  See License in the project root for license information.
+// ------------------------------------------------------------------------------
+
+namespace Microsoft.Graph
+{
+    using System.Net.Http;
+    /// <summary>
+    /// Contains extension methods for <see cref="HttpRequestMessage"/>
+    /// </summary>
+    internal static class RequestExtensions
+    {
+        /// <summary>
+        /// Checks the HTTP request's content to determine if it's buffered or streamed content.
+        /// </summary>
+        /// <param name="httpRequestMessage">The <see cref="HttpRequestMessage"/>needs to be sent.</param>
+        /// <returns></returns>
+        internal static bool IsBuffered(this HttpRequestMessage httpRequestMessage)
+        {
+            HttpContent requestContent = httpRequestMessage.Content;
+
+            if ((httpRequestMessage.Method == HttpMethod.Put || httpRequestMessage.Method == HttpMethod.Post || httpRequestMessage.Method.Method.Equals("PATCH"))
+                && requestContent != null && (requestContent.Headers.ContentLength == null || (int)requestContent.Headers.ContentLength == -1))
+            {
+                return false;
+            }
+            return true;
+        }
+    }
+}

src/Microsoft.Graph.Core/Requests/AuthenticationHandler.cs

@@ -0,0 +1,120 @@
+// ------------------------------------------------------------------------------
+//  Copyright (c) Microsoft Corporation.  All Rights Reserved.  Licensed under the MIT License.  See License in the project root for license information.
+// ------------------------------------------------------------------------------
+
+namespace Microsoft.Graph
+{
+    using System.Net.Http;
+    using System.Threading;
+    using System.Threading.Tasks;
+    using System.Net;
+    /// <summary>
+    /// A <see cref="DelegatingHandler"/> implementation using standard .NET libraries.
+    /// </summary>
+    public class AuthenticationHandler: DelegatingHandler
+    {
+        /// <summary>
+        /// MaxRetry property for 401's
+        /// </summary>
+        public int MaxRetry { get; set; } = 1;
+
+        /// <summary>
+        /// AuthenticationProvider property
+        /// </summary>
+        public IAuthenticationProvider AuthenticationProvider { get; set; }
+
+        /// <summary>
+        /// Construct a new <see cref="AuthenticationHandler"/>
+        /// </summary>
+        public AuthenticationHandler()
+        {
+
+        }
+
+        /// <summary>
+        /// Construct a new <see cref="AuthenticationHandler"/>
+        /// <param name="authenticationProvider">An authentication provider to pass to <see cref="AuthenticationHandler"/> for authenticating requests.</param>
+        /// </summary>
+        public AuthenticationHandler(IAuthenticationProvider authenticationProvider)
+        {
+            AuthenticationProvider = authenticationProvider;
+        }
+
+        /// <summary>
+        /// Construct a new <see cref="AuthenticationHandler"/>
+        /// </summary>
+        /// <param name="authenticationProvider">An authentication provider to pass to <see cref="AuthenticationHandler"/> for authenticating requests.</param>
+        /// <param name="innerHandler">A HTTP message handler to pass to the <see cref="AuthenticationHandler"/> for sending requests.</param>
+        public AuthenticationHandler(IAuthenticationProvider authenticationProvider, HttpMessageHandler innerHandler)
+        {
+            InnerHandler = innerHandler;
+            AuthenticationProvider = authenticationProvider;
+        }
+
+        /// <summary>
+        /// Checks HTTP response message status code if it's unauthorized (401) or not
+        /// </summary>
+        /// <param name="httpResponseMessage">The <see cref="HttpResponseMessage"/>to send.</param>
+        /// <returns></returns>
+        private bool IsUnauthorized(HttpResponseMessage httpResponseMessage)
+        {
+            return httpResponseMessage.StatusCode == HttpStatusCode.Unauthorized;
+        }
+
+        /// <summary>
+        /// Retry sending HTTP request
+        /// </summary>
+        /// <param name="httpResponseMessage">The <see cref="HttpResponseMessage"/>to send.</param>
+        /// <param name="cancellationToken">The <see cref="CancellationToken"/>to send.</param>
+        /// <returns></returns>
+        private async Task<HttpResponseMessage> SendRetryAsync(HttpResponseMessage httpResponseMessage, CancellationToken cancellationToken)
+        {
+            int retryAttempt = 0;
+            while (retryAttempt < MaxRetry)
+            {
+                var originalRequest = httpResponseMessage.RequestMessage;
+
+                // Authenticate request using AuthenticationProvider
+                await AuthenticationProvider.AuthenticateRequestAsync(originalRequest);
+                httpResponseMessage = await base.SendAsync(originalRequest, cancellationToken);
+
+                retryAttempt++;
+
+                if (!IsUnauthorized(httpResponseMessage) || !originalRequest.IsBuffered())
+                {
+                    // Re-issue the request to get a new access token
+                    return httpResponseMessage;
+                }
+            }
+
+            return httpResponseMessage;
+        }
+
+        /// <summary>
+        /// Sends a HTTP request and retries the request when the response is unauthorized.
+        /// This can happen when a token from the cache expires between graph getting the request and the backend receiving the request
+        /// </summary>
+        /// <param name="httpRequestMessage">The <see cref="HttpRequestMessage"/> to send.</param>
+        /// <param name="cancellationToken">The <see cref="CancellationToken"/> for the request.</param>
+        /// <returns></returns>
+        protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage httpRequestMessage, CancellationToken cancellationToken)
+        {
+            // Authenticate request using AuthenticationProvider
+            if (AuthenticationProvider != null)
+            {
+                await AuthenticationProvider.AuthenticateRequestAsync(httpRequestMessage);
+            }
+
+            HttpResponseMessage response = await base.SendAsync(httpRequestMessage, cancellationToken);
+
+            // Chcek if response is a 401 & is not a streamed body (is buffered)
+            if (IsUnauthorized(response) && httpRequestMessage.IsBuffered() && (AuthenticationProvider != null))
+            {
+                // re-issue the request to get a new access token
+                response = await SendRetryAsync(response, cancellationToken);
+            }
+
+            return response;
+        }
+    }
+}

src/Microsoft.Graph.Core/Requests/RetryHandler.cs

@@ -11,6 +11,7 @@ namespace Microsoft.Graph
     using System.Net.Http;
     using System.Net;
     using System.Net.Http.Headers;
+
     /// <summary>
     /// An <see cref="DelegatingHandler"/> implementation using standard .NET libraries.
     /// </summary>
@@ -54,7 +55,7 @@ protected async override Task<HttpResponseMessage> SendAsync(HttpRequestMessage
 
             var response = await base.SendAsync(httpRequest, cancellationToken);
 
-            if (IsRetry(response) && IsBuffered(httpRequest))
+            if (IsRetry(response) && httpRequest.IsBuffered())
             {
                 response = await SendRetryAsync(response, cancellationToken);
             }
@@ -94,7 +95,7 @@ public async Task<HttpResponseMessage> SendRetryAsync(HttpResponseMessage respon
                 // Call base.SendAsync to send the request
                 response = await base.SendAsync(request, cancellationToken);
 
-                if (!IsRetry(response) || !IsBuffered(request))
+                if (!IsRetry(response) || !request.IsBuffered())
                 {
                     return response;
                 }
@@ -126,23 +127,6 @@ public bool IsRetry(HttpResponseMessage response)
             return false;
         }
 
-        /// <summary>
-        /// Check the HTTP request's content to determine whether it can be retried or not.
-        /// </summary>
-        /// <param name="request">The <see cref="HttpRequestMessage"/>needs to be sent.</param>
-        /// <returns></returns>
-        private bool IsBuffered(HttpRequestMessage request)
-        {
-            HttpContent content = request.Content;
-
-            if ((request.Method == HttpMethod.Put || request.Method == HttpMethod.Post || request.Method.Method.Equals("PATCH")) 
-                && content != null && (content.Headers.ContentLength == null || (int)content.Headers.ContentLength == -1))
-            {
-                return false;
-            }
-            return true;
-
-        }
 
         /// <summary>
         /// Update Retry-Attempt header in the HTTP request

tests/Microsoft.Graph.Core.Test/Extensions/RequestExtensionsTests.cs

@@ -0,0 +1,68 @@
+// ------------------------------------------------------------------------------
+//  Copyright (c) Microsoft Corporation.  All Rights Reserved.  Licensed under the MIT License.  See License in the project root for license information.
+// ------------------------------------------------------------------------------
+
+namespace Microsoft.Graph.Core.Test.Extensions
+{
+    using Microsoft.VisualStudio.TestTools.UnitTesting;
+    using System.Net.Http;
+
+    [TestClass]
+    public class RequestExtensionsTests
+    {
+        [TestMethod]
+        public void IsBuffered_Get()
+        {
+            HttpRequestMessage httpRequest = new HttpRequestMessage(HttpMethod.Get, "http://example.com");
+            var response = httpRequest.IsBuffered();
+
+            Assert.IsTrue(response, "Unexpected content type");
+        }
+        [TestMethod]
+        public void IsBuffered_PostWithNoContent()
+        {
+            HttpRequestMessage httpRequest = new HttpRequestMessage(HttpMethod.Post, "http://example.com");
+            var response = httpRequest.IsBuffered();
+
+            Assert.IsTrue(response, "Unexpected content type");
+        }
+        [TestMethod]
+        public void IsBuffered_PostWithBufferStringContent()
+        {
+            byte[] data = new byte[] { 1, 2, 3, 4, 5 };
+            HttpRequestMessage httpRequest = new HttpRequestMessage(HttpMethod.Post, "http://example.com");
+            httpRequest.Content = new ByteArrayContent(data);
+            var response = httpRequest.IsBuffered();
+
+            Assert.IsTrue(response, "Unexpected content type");
+        }
+
+        [TestMethod]
+        public void IsBuffered_PutWithStreamStringContent()
+        {
+            var stringContent = new StringContent("Hello World");
+            var byteArrayContent = new ByteArrayContent(new byte[] { 1, 2, 3, 4, 5 });
+            var mutliformDataContent = new MultipartFormDataContent();
+            mutliformDataContent.Add(stringContent);
+            mutliformDataContent.Add(byteArrayContent);
+
+            HttpRequestMessage httpRequest = new HttpRequestMessage(HttpMethod.Put, "http://example.com");
+            httpRequest.Content = mutliformDataContent;
+            httpRequest.Content.Headers.ContentLength = -1;
+            var response = httpRequest.IsBuffered();
+
+            Assert.IsFalse(response, "Unexpected content type");
+        }
+
+        [TestMethod]
+        public void IsBuffered_PatchWithStreamStringContent()
+        {
+            HttpRequestMessage httpRequest = new HttpRequestMessage(new HttpMethod("PATCH"), "http://example.com");
+            httpRequest.Content = new StringContent("Hello World");
+            httpRequest.Content.Headers.ContentLength = null;
+            var response = httpRequest.IsBuffered();
+
+            Assert.IsFalse(response, "Unexpected content type");
+        }
+    }
+}

tests/Microsoft.Graph.Core.Test/Microsoft.Graph.Core.Test.csproj

@@ -79,12 +79,14 @@
     <Compile Include="Authentication\DelegateAuthenticationProviderTests.cs" />
     <Compile Include="Exceptions\ErrorTests.cs" />
     <Compile Include="Exceptions\ServiceExceptionTests.cs" />
+    <Compile Include="Extensions\RequestExtensionsTests.cs" />
     <Compile Include="Helpers\ExtractSelectHelperTest.cs" />
     <Compile Include="Helpers\StringHelperTests.cs" />
     <Compile Include="Helpers\UrlHelperTests.cs" />
     <Compile Include="Mocks\MockProgress.cs" />
     <Compile Include="Mocks\MockRedirectHandler.cs" />
     <Compile Include="Requests\AsyncMonitorTests.cs" />
+    <Compile Include="Requests\AuthenticationHandlerTests.cs" />
     <Compile Include="Requests\BaseRequestBuilderTests.cs" />
     <Compile Include="Requests\GraphClientFactoryTests.cs" />
     <Compile Include="Requests\RedirectHandlerTests.cs" />

tests/Microsoft.Graph.Core.Test/Mocks/MockAuthenticationProvider.cs

@@ -16,7 +16,9 @@ public MockAuthenticationProvider()
         {
             this.SetupAllProperties();
 
-            this.Setup(provider => provider.AuthenticateRequestAsync(It.IsAny<HttpRequestMessage>())).Returns(Task.FromResult(0));
+            this.Setup(
+                provider => provider.AuthenticateRequestAsync(It.IsAny<HttpRequestMessage>()))
+                .Returns(Task.FromResult(0));
         }
     }
 }