(* TODO

   https://docs.taler.net/taler-exchange-manual.html#offline-signing-setup-key-maintenance-and-tear-down


   The exchange HTTP service must be running before you can complete the following offline signing procedure. Note that when an exchange is running without offline keys its not fully operational. To make the exchange HTTP service fully operational, the following steps involving the offline signing machine must be completed:

  1) The public keys of various online keys used by the exchange service are exported via a management HTTP API.

  2) The offline signing system validates this request and signs it.
     Additionally, the offline signing system signs policy messages to configure the exchange’s bank
     accounts and associated fees.

  3) The messages generated by the offline signing system are uploaded via the management API
     of the exchange HTTP service.
*)

(*
   - generate (pub&priv) key for online signing key
   - generate (pub&priv) key for denomination(s)
   - implement `GET /management/keys`
   - implement `POST /management/keys`
   - offline tool do: GET -> sign -> POST
   - now we should have a server with valid keys signed by the master offline key *)