Integrate Azure Key Vault With ASP.NET

Integrating Azure Key Vault with an ASP.NET application allows you to securely access sensitive information such as secrets, keys, and certificates without hardcoding them in the application. Here's a step-by-step guide:

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Step 1: Set up Azure Key Vault

1. Create an Azure Key Vault:

   • Log in to the Azure Portal.
   • Navigate to Key Vaults and click Create.
   • Provide a name, select your subscription, resource group, and region, and click Review + Create.

2. Add Secrets to the Key Vault:

   • Open your Key Vault in the Azure portal.
   • Go to the Secrets section and click Generate/Import.
   • Add your secrets (e.g., DatabaseConnectionString, APIKey).

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Step 2: Set up Azure Active Directory (Azure AD) Authentication

1. Register your ASP.NET application:

   • Go to Azure Active Directory in the Azure portal.
   • Select App registrations > New registration.
   • Provide a name, set the account type, and click Register.

2. Grant your application access to the Key Vault:

   • In your Key Vault, go to Access policies > Add Access Policy.
   • Grant the necessary permissions (e.g., Get, List for Secrets) to your registered app.
   • Select the app by name and click Save.

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Step 3: Configure Your ASP.NET Project

1. Install NuGet Packages: Open the Package Manager Console or NuGet Manager and install the following packages:

   Install-Package Azure.Identity
   Install-Package Azure.Security.KeyVault.Secrets

2. Update Configuration Settings: Add the Key Vault name and Azure AD client details to appsettings.json:

   {
     "AzureKeyVault": {
       "VaultUri": "https://<YourKeyVaultName>.vault.azure.net/",
       "TenantId": "<Your-Tenant-ID>",
       "ClientId": "<Your-Client-ID>",
       "ClientSecret": "<Your-Client-Secret>"
     }
   }

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Step 4: Access Key Vault in ASP.NET Code

1. Configure Key Vault in Program.cs or Startup.cs: Add the Key Vault configuration to your application:

   using Azure.Identity;
   using Azure.Security.KeyVault.Secrets;
   
   public class Startup
   {
       public void ConfigureServices(IServiceCollection services)
       {
           var configuration = new ConfigurationBuilder()
               .AddJsonFile("appsettings.json")
               .Build();
   
           var keyVaultUri = configuration["AzureKeyVault:VaultUri"];
           var secretClient = new SecretClient(new Uri(keyVaultUri), new DefaultAzureCredential());
   
           // Retrieve a secret (example)
           var secret = secretClient.GetSecret("DatabaseConnectionString");
           Console.WriteLine($"Secret Value: {secret.Value.Value}");
   
           // Add services as needed
           services.AddControllersWithViews();
       }
   
       public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
       {
           if (env.IsDevelopment())
           {
               app.UseDeveloperExceptionPage();
           }
           else
           {
               app.UseExceptionHandler("/Home/Error");
               app.UseHsts();
           }
   
           app.UseHttpsRedirection();
           app.UseStaticFiles();
           app.UseRouting();
           app.UseAuthorization();
           app.UseEndpoints(endpoints => { endpoints.MapControllerRoute("default", "{controller=Home}/{action=Index}/{id?}"); });
       }
   }

2. Access Secrets in Your Application: You can now retrieve secrets from the Key Vault wherever needed in your application.

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Step 5: Use Managed Identity (Optional)

For better security, consider using Managed Identity:

1. Enable Managed Identity for your Azure App Service or Virtual Machine hosting the ASP.NET app.
2. Grant Access in the Key Vault's Access Policies.
3. Replace the client credentials in the code with:

   var secretClient = new SecretClient(new Uri(keyVaultUri), new DefaultAzureCredential());
   

This approach eliminates the need for storing credentials in your application.

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Testing

1. Deploy your app and ensure it runs correctly.
2. Test fetching secrets to verify the integration.