Authenticate to Azure Function from within App

Question

I'm using Facebook Authentication for my Azure Function App, it works fine if I navigate to a function within the browser. I would like to invoke my functions from within an app but an unsure how to perform the authentication.

At current I am attempting to use the Facebook Client, this returns me an access_token that I am then forwarding to the ".auth/login/facebook/callback" function within my function app. Unfortunately that's as far as I can get, doing this via a GET returns HTML with JavaScript in, and doing it via a POST redirects back to Facebook.

What I really need is the cookie created by the azure function, AppServiceAuthSession, I believe I can then use this to call the functions.

Edit: I don't think i can just use the cookie, like I said above so I need to authenticate properly.

Nick.

Answer 1

I was able to get the tokens passed along to the function app while using the Facebook Javascript SDK (I wasn't having any luck with the C# one) -- maybe this will get you moving in the right direction.

The client:

1. Performs the login to Facebook, which returns an accessToken.
2. Client needs to exchange this accessToken for an 'App Service Token'. It does this by making a POST to https://{app}.azurewebsites.net/.auth/login/facebook with the content { "access_token" : "{token from Facebook}" }. This will return back an authenticationToken.
3. Use that authenticationToken in a header named x-zumo-auth. Make all requests to your function app using that header.

From within your function app, you should then have the current Principal set to that logged in user.