How to Integrate Azure Key Vault in ASP.NET Core for Secure Secret Management?

Storing sensitive settings such as database connection strings and third-party API credentials directly inside appsettings.json introduces significant security vulnerabilities. Azure Key Vault provides a centralized, secure cloud solution for managing application secrets.

Prerequisites and NuGet Packages

To integrate Azure Key Vault into your ASP.NET Core application, install the following packages:

• Azure.Identity: Provides seamless authentication via Microsoft Entra ID.
• Azure.Extensions.AspNetCore.Configuration.Secrets: Integrates Key Vault seamlessly into the ASP.NET Core configuration framework.

Configuring Key Vault in Program.cs

Utilize DefaultAzureCredential to support passwordless authentication across local development and production environments:

using Azure.Identity;

var builder = WebApplication.CreateBuilder(args);

if (!builder.Environment.IsDevelopment())
{
    var keyVaultUri = builder.Configuration["AzureKeyVault:VaultUri"];
    builder.Configuration.AddAzureKeyVault(
        new Uri(keyVaultUri),
        new DefaultAzureCredential()
    );
}

var app = builder.Build();

Accessing Secrets in Services

Once configured, secrets in Azure Key Vault automatically become part of standard ASP.NET Core IConfiguration injection.