This is a (non-standards-compliant) OAuth2 server that prompts a user for FurAffinity "a" and "b" cookie values, and returns them to the server as an access token that FAExport can use as the FA_COOKIE header value. The server runs on Azure Functions and is completely stateless.
You can deploy it to your own Azure account if you'd like. Just set a client
ID and client secret for OAuth by adding an application setting in the
Configuration section, with ClientSecret_{id} as the name and {secret}
as the value. {id} should be an integer, and {secret} should be a random
256-bit key, encoded in base 64. For example:
"ClientSecret_100": "ZJY677q34+PWuW4myNmSCblfVHhTPwFqx6xZNLWqyQs="
To create a random base-64-encoded 256-bit key in Visual Studio, you can enter this into F# Interactive:
let r = new System.Random() in [0 .. 31] |> Seq.map (fun _ -> r.Next(0, 255) |> byte) |> Array.ofSeq |> System.Convert.ToBase64String;;