.Net: Azure OpenAI Temporary Fix [401 Retry Bug] (#9465)

### Motivation and Context

- Fix #8929

dotnet/src/Connectors/Connectors.AzureOpenAI.UnitTests/Core/ClientCoreTests.cs

@@ -0,0 +1,89 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System;
+using System.ClientModel.Primitives;
+using System.Net.Http;
+using System.Threading;
+using System.Threading.Tasks;
+using Azure.AI.OpenAI;
+using Azure.Core;
+using Microsoft.SemanticKernel.ChatCompletion;
+using Microsoft.SemanticKernel.Connectors.AzureOpenAI;
+using SemanticKernel.Connectors.AzureOpenAI.Core;
+
+namespace SemanticKernel.Connectors.AzureOpenAI.UnitTests.Core;
+
+public sealed class ClientCoreTests : IDisposable
+{
+    private readonly MultipleHttpMessageHandlerStub _multiHttpMessageHandlerStub;
+    private readonly HttpClient _httpClient;
+
+    public ClientCoreTests()
+    {
+        this._multiHttpMessageHandlerStub = new MultipleHttpMessageHandlerStub();
+        this._httpClient = new HttpClient(this._multiHttpMessageHandlerStub);
+    }
+
+    public void Dispose()
+    {
+        this._httpClient.Dispose();
+        this._multiHttpMessageHandlerStub.Dispose();
+    }
+
+    [Fact]
+    public async Task AuthenticationHeaderShouldBeProvidedOnlyOnce()
+    {
+        // Arrange
+        using var firstResponse = new HttpResponseMessage(System.Net.HttpStatusCode.TooManyRequests);
+        using var secondResponse = new HttpResponseMessage(System.Net.HttpStatusCode.TooManyRequests);
+        using var thirdResponse = new HttpResponseMessage(System.Net.HttpStatusCode.TooManyRequests);
+
+        this._multiHttpMessageHandlerStub.ResponsesToReturn.AddRange([firstResponse, secondResponse, thirdResponse]);
+        var options = new AzureOpenAIClientOptions()
+        {
+            Transport = new HttpClientPipelineTransport(this._httpClient),
+            RetryPolicy = new ClientRetryPolicy(2),
+            NetworkTimeout = TimeSpan.FromSeconds(10),
+        };
+
+        // Bug fix workaround
+        options.AddPolicy(new SingleAuthorizationHeaderPolicy(), PipelinePosition.PerTry);
+
+        var azureClient = new AzureOpenAIClient(
+            endpoint: new Uri("http://any"),
+            credential: new TestJWTBearerTokenCredential(),
+            options: options);
+
+        var clientCore = new AzureClientCore("deployment-name", azureClient);
+
+        ChatHistory chatHistory = [];
+        chatHistory.AddUserMessage("User test");
+
+        // Act
+        var exception = await Record.ExceptionAsync(() => clientCore.GetChatMessageContentsAsync("model-id", chatHistory, null, null, CancellationToken.None));
+
+        // Assert
+        Assert.NotNull(exception);
+        Assert.Equal(3, this._multiHttpMessageHandlerStub.RequestHeaders.Count);
+
+        foreach (var requestHeaders in this._multiHttpMessageHandlerStub.RequestHeaders)
+        {
+            this._multiHttpMessageHandlerStub.RequestHeaders[2]!.TryGetValues("Authorization", out var authHeaders);
+            Assert.NotNull(authHeaders);
+            Assert.Single(authHeaders);
+        }
+    }
+
+    private sealed class TestJWTBearerTokenCredential : TokenCredential
+    {
+        public override AccessToken GetToken(TokenRequestContext requestContext, CancellationToken cancellationToken)
+        {
+            return new AccessToken("JWT", DateTimeOffset.Now.AddHours(1));
+        }
+
+        public override ValueTask<AccessToken> GetTokenAsync(TokenRequestContext requestContext, CancellationToken cancellationToken)
+        {
+            return ValueTask.FromResult(new AccessToken("JWT", DateTimeOffset.Now.AddHours(1)));
+        }
+    }
+}

dotnet/src/Connectors/Connectors.AzureOpenAI/Core/AzureClientCore.cs

@@ -15,6 +15,7 @@
 using Microsoft.SemanticKernel.Connectors.OpenAI;
 using Microsoft.SemanticKernel.Http;
 using OpenAI;
+using SemanticKernel.Connectors.AzureOpenAI.Core;
 
 namespace Microsoft.SemanticKernel.Connectors.AzureOpenAI;
 
@@ -146,6 +147,7 @@ internal static AzureOpenAIClientOptions GetAzureOpenAIClientOptions(HttpClient?
 
         options.UserAgentApplicationId = HttpHeaderConstant.Values.UserAgent;
         options.AddPolicy(CreateRequestHeaderPolicy(HttpHeaderConstant.Names.SemanticKernelVersion, HttpHeaderConstant.Values.GetAssemblyVersion(typeof(AzureClientCore))), PipelinePosition.PerCall);
+        options.AddPolicy(new SingleAuthorizationHeaderPolicy(), PipelinePosition.PerTry);
 
         if (httpClient is not null)
         {

dotnet/src/Connectors/Connectors.AzureOpenAI/Core/SingleAuthorizationHeaderPolicy.cs

@@ -0,0 +1,46 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System.ClientModel.Primitives;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+
+namespace SemanticKernel.Connectors.AzureOpenAI.Core;
+
+/// <summary>
+/// This class is used to remove duplicate Authorization headers from the request Azure OpenAI Bug.
+/// https://github.com/Azure/azure-sdk-for-net/issues/46109 (Remove when beta.2 is released)
+/// </summary>
+internal sealed class SingleAuthorizationHeaderPolicy : PipelinePolicy
+{
+    private const string AuthorizationHeaderName = "Authorization";
+
+    public override void Process(PipelineMessage message, IReadOnlyList<PipelinePolicy> pipeline, int currentIndex)
+    {
+        RemoveDuplicateHeaderValues(message.Request.Headers);
+
+        ProcessNext(message, pipeline, currentIndex);
+    }
+
+    public override async ValueTask ProcessAsync(PipelineMessage message, IReadOnlyList<PipelinePolicy> pipeline, int currentIndex)
+    {
+        RemoveDuplicateHeaderValues(message.Request.Headers);
+
+        await ProcessNextAsync(message, pipeline, currentIndex).ConfigureAwait(false);
+    }
+
+    private static void RemoveDuplicateHeaderValues(PipelineRequestHeaders headers)
+    {
+        if (headers.TryGetValues(AuthorizationHeaderName, out var headerValues)
+            && headerValues is not null
+#if NET 
+            && headerValues.TryGetNonEnumeratedCount(out var count) && count > 1
+#else
+            && headerValues.Count() > 1
+#endif
+            )
+        {
+            headers.Set(AuthorizationHeaderName, headerValues.First());
+        }
+    }
+}

dotnet/src/Connectors/Connectors.OpenAI/Connectors.OpenAI.csproj

@@ -28,6 +28,7 @@
 
   <ItemGroup>
     <InternalsVisibleTo Include="SemanticKernel.Connectors.OpenAI.UnitTests" />
+    <InternalsVisibleTo Include="SemanticKernel.Connectors.AzureOpenAI.UnitTests" />
     <InternalsVisibleTo Include="Microsoft.SemanticKernel.Connectors.AzureOpenAI" />
   </ItemGroup>