Add token auth sample for batch synthesis (#2744)

* Fix legacy voice

* Enhance Batch Synthesis Client to support token-based authentication and update README with authentication options

samples/batch-synthesis/csharp/BatchSynthesisSample/BatchSynthesisClient.cs

@@ -6,27 +6,33 @@
 using System.Text;
 using System.Text.Json;
 using System.Text.Json.Serialization;
+using System.Net.Http.Headers;
 
 public class BatchSynthesisClient
 {
     private const string OcpApimSubscriptionKey = "Ocp-Apim-Subscription-Key";
 
     private readonly string hostName;
     private readonly string baseUri;
-    private readonly string subscriptionKey;
     private readonly string apiVersion;
 
     private readonly HttpClient client;
 
-    public BatchSynthesisClient(string hostName, string key, string apiVersion)
+    public BatchSynthesisClient(string hostName, string credential, string apiVersion, bool isToken = false)
     {
         this.hostName = hostName;
-        this.subscriptionKey = key;
         this.baseUri = $"{this.hostName}/texttospeech/batchsyntheses";
         this.apiVersion = apiVersion;
 
         this.client = new HttpClient();
-        client.DefaultRequestHeaders.Add(OcpApimSubscriptionKey, this.subscriptionKey);
+        if (isToken)
+        {
+            client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", credential);
+        }
+        else
+        {
+            client.DefaultRequestHeaders.Add(OcpApimSubscriptionKey, credential);
+        }
     }
 
     public async Task<IEnumerable<BatchSynthesis>> GetAllSynthesesAsync()

samples/batch-synthesis/csharp/BatchSynthesisSample/BatchSynthesisSample.csproj

@@ -7,6 +7,7 @@
   <ItemGroup>
     <PackageReference Include="Microsoft.AspNet.WebApi.Client" version="5.2.7" PrivateAssets="All" />
     <PackageReference Include="Newtonsoft.Json" version="13.0.1" PrivateAssets="All" />
+    <PackageReference Include="Azure.Identity" Version="1.13.2" />
   </ItemGroup>
   <ItemGroup>
     <Content Include="..\..\Gatsby-chapter1.txt">

samples/batch-synthesis/csharp/BatchSynthesisSample/Program.cs

@@ -3,19 +3,35 @@
 // Licensed under the MIT license. See LICENSE.md file in the project root for full license information.
 //
 
-// Your Speech resource key and region
-// This example requires environment variables named "SPEECH_KEY" and "SPEECH_REGION"
-string speechRegion = Environment.GetEnvironmentVariable("SPEECH_REGION") 
-    ?? throw new ArgumentException("Please set SPEECH_REGION environment variable.");
+using Azure.Core;
+using Azure.Identity;
 
-string speechKey = Environment.GetEnvironmentVariable("SPEECH_KEY") 
-    ?? throw new ArgumentException("Please set the SPEECH_KEY environment variable to set speech resource key.");
+// The endpoint (and key) could be gotten from the Keys and Endpoint page in the Speech service resource.
+// The endpoint would be like: https://<region>.api.cognitive.microsoft.com or https://<custom_domain>.cognitiveservices.azure.com
+// If you want to use token authentication, custom domain is required.
+var host = Environment.GetEnvironmentVariable("SPEECH_ENDPOINT");
+BatchSynthesisClient synthesisClient;
+var apiVersion = "2024-04-01";
+if (!string.IsNullOrEmpty(host))
+{
+    // Use Azure Identity SDK to acquire token
+    var credential = new DefaultAzureCredential();
+    var tokenRequestContext = new TokenRequestContext(new[] { "https://cognitiveservices.azure.com/.default" });
+    var accessToken = (await credential.GetTokenAsync(tokenRequestContext)).Token;
 
-string apiVersion = "2024-04-01";
-var host = $"https://{speechRegion}.api.cognitive.microsoft.com";
-var sampleScript = await File.ReadAllTextAsync("../../Gatsby-chapter1.txt").ConfigureAwait(false);
+    // Use access token for authentication
+    synthesisClient = new BatchSynthesisClient(host, accessToken, apiVersion, isToken: true);
+}
+else
+{
+    string speechRegion = Environment.GetEnvironmentVariable("SPEECH_REGION") ?? throw new ArgumentException("Please set either the SPEECH_REGION or SPEECH_ENDPOINT environment variable.");
+    string speechKey = Environment.GetEnvironmentVariable("SPEECH_KEY") ?? throw new ArgumentException("Please set either the SPEECH_KEY and SPEECH_REGION environment variables, or the SPEECH_ENDPOINT environment variable for authentication.");
+
+    host = $"https://{speechRegion}.api.cognitive.microsoft.com";
+    synthesisClient = new BatchSynthesisClient(host, speechKey, apiVersion);
+}
 
-var synthesisClient = new BatchSynthesisClient(host, speechKey, apiVersion);
+var sampleScript = await File.ReadAllTextAsync("../../Gatsby-chapter1.txt").ConfigureAwait(false);
 
 // Get all synthesis jobs.
 var synthesisJobs = await synthesisClient.GetAllSynthesesAsync().ConfigureAwait(false);

samples/batch-synthesis/csharp/BatchSynthesisSample/README.md

@@ -1,13 +1,18 @@
 # C# Example to use the Speech Services Batch Synthesis API
 
-To successfully run this example you require:
+To successfully run this example, you must use one of the following authentication methods:
 
-- A Speech Service subscription key
-- The region information matching your subscription key
+Option 1: Token-based authentication (Recommended)
+
+- Set the Speech endpoint (set `SPEECH_ENDPOINT`)
+  - Ensure your Microsoft Entra account is assigned the "Cognitive Services Speech Contributor" or "Cognitive Services User" role.
+
+Option 2: Key-based authentication
+
+- Set the Speech Service subscription key (set `SPEECH_KEY`)
+- Set the region matching your subscription key (set `SPEECH_REGION`)
 
 Optionally:
 
 - The relationship between custom voice names and deployment ID, if you want to use custom voices
 - The URI of a writable Azure blob container, if you want to store the audio files in your own Azure storage
-
-Set the environment variables `SPEECH_KEY` and `SPEECH_REGION` before running the program.