Authentication Methods for REST API

Function Key (without Easy Auth)

• X-Functions-Key: Functions Host Key

Azure AD Authentication

1. Expose an API

• Configuted env in https://github.com/shibayan/terraform-azurerm-keyvault-acmebot

2. Create a Service Principal
3. Add Key Vault Acmebot permissions to Service Principal

Sample code

using System.Net.Http.Headers;

using Microsoft.Identity.Client;

var app = ConfidentialClientApplicationBuilder.Create("<client id>")
    .WithClientSecret("<client secret>")
    .WithTenantId("<tenant id>")
    .Build();

var token = await app.AcquireTokenForClient(new[] { "<application uri>/.default" }).ExecuteAsync();

var httpClient = new HttpClient();

httpClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", token.AccessToken);

var response = await httpClient.GetStringAsync("https://***.azurewebsites.net/api/certificates");

Console.WriteLine(response);