Configure Authentication with Azure Functions on LocalHost

Question

I'd like to use Visual Studio 2017 to build Azure Function App with HttpTrigger. However, I can't find the way how I could add Azure Active Directory authentication to secure the end point.

Will it work if I just add jwt token to the http request and then call ClaimsPrincipal.Current.Claims inside the method? Is there any other solution?

Answer 1

AFAIK, the authentication for the external identity data provider only can config on the Azure portal. And if you host the Azure function on Azure, the answer is yes. However if you host the Azure function on local, there is no way we can config for the authentication using Azure Active Directory.

As a workaround, you need to get the token from headers and verify the token manually before run the function code. And if you want to support to config the authentication for host Azure function on local, you can submit the feedback from here .

Answer 2

You can use the Microsoft OpenID Connect and JWT libraries to validate the token and get claims based on a received access token. Here's an example: https://github.com/azure-samples/ms-identity-dotnet-webapi-azurefunctions/tree/master/

1. Create an app registration in AD
2. Issue a browser request to get an access code
3. Issue an HTTP POST request for an access token using the code and the secret via cURL
4. Send the access token as an Authorization Bearer header to the local function endpoint

I had issues using newer versions of Microsoft.IdentityModel.Protocols.OpenIdConnect with .NET 6.0 and Azure Functions 4 and had to fall back to version 6.10.2.