I am having trouble understanding how to convert a...

# http4k

[Arnab]

I am having trouble understanding how to convert an access token and csrf to a user object. Here is what I have so far:

fun contextFn(request: Request): Principal {
  val cookie = request.header("Cookie")
  val map =
    cookie?.split(";")?.associate {
      val (first, second) = it.split("=").map { s -> s.replace("\"", "") }
      first.trim() to second.trim()
    }
      ?: emptyMap()
  // TODO: take the GoogleCsrf and GoogleAccessToken and create a principal based on that
  val accessToken = map["GoogleAccessToken"]
  val csrf = map["GoogleCsrf"]
  return GoogleUser(UUID.randomUUID())
}

Is there something that I should read up on or what am I missing?

[dave]

First up - you can use request.cookie("name") to get a parsed cookie.

[dave]

What's the context here - are you doing oauth?

[Arnab]

Yes, I am doing oauth with google as the provider, and I would like to use the cookie that is set in the browser to set a context for my graphql endpoint 🙂

[Arnab]

If no cookie is set, then obviously there is nothing to do, and I want to set the principal as a AnonymousUser or something to that accord

[dave]

Have you looked at the example ? https://github.com/http4k/examples/tree/master/oauth

Are you currently trying to implement the OauthPersistence?

[Arnab]

I suspect I am asking the wrong question, or at least I am asking it in the wrong place. The core of what I’m trying to do is to take that access token, decode it and convert it into a User object of sorts and use that as a context for my GraphQL endpoint. I suspect I might need to use this maybe:
https://developers.google.com/identity/sign-in/web/backend-auth

[dave]

Aha - ok. Sorry. What you want is probably a request context. So you have a filter which will decode the cookie for use in a handler later in the chain? https://www.http4k.org/guide/howto/attach_context_to_a_request/

[Arnab]

I don’t think I actually need that tbh. This is how I have thought so far:

fun contextFn(request: Request): Principal {
  val accessToken = request.cookie("GoogleAccessToken")
  val csrf = request.cookie("GoogleCsrf")

  // TODO decode the access token
  return GoogleUser(UUID.randomUUID())
}

fun DataFetchingEnvironment.getPrincipal(): Principal? =
  graphQlContext.get<Principal>("principal")

and the contextFn is supplied like so:

"/graphql" bind graphQL(BaseHandler, ::contextFn, baseExceptionHandler)

So when I am in a query handler, I just need to do this:

fun hello(env: DataFetchingEnvironment) = "Hello ${env.getPrincipal() ?: "anonymous user"}"

[dave]

That looks like it will work. But you're right - if want help with a Google java API specifically then that's not something I can help with. 🙃

[dave]

The access token itself will just be an encoded JWT. But you will alao want to verify that it's legit