let _denom_signature ~key ~key_pub
    Api.FutureDenom.
      {
        section_name= _;
        value;
        stamp_start;
        stamp_expire_withdraw;
        stamp_expire_deposit;
        stamp_expire_legal;
        denom_pub;
        fee_withdraw;
        fee_deposit;
        fee_refresh;
        fee_refund= _;
        (* TODO check sigs *)
        denom_secmod_sig= _;
      } =
  let pub_octets =
    let denom_pub =
      match denom_pub with
      | Rsa v -> v
      | CS _ -> Fmt.failwith "CS key types are not supported."
    in
    let pub = denom_pub.Api.RsaDenominationKey.rsa_pub in
    Crypto.RsaPublicKey.to_octets pub
  in
  let h_denom_pub = Api.HashCode.hash pub_octets in
  let master_sig =
    let open Bin_type in
    let open Bin_signature.DenominationKeyValidityPS in
    {
      master= key_pub;
      start= stamp_start;
      expire_withdraw= stamp_expire_withdraw;
      expire_spend= stamp_expire_deposit;
      expire_legal= stamp_expire_legal;
      value;
      fee_withdraw;
      fee_deposit;
      fee_refresh;
      denom_hash= DenominationHash.hash pub_octets;
    }
    |> Bin.to_string bin
    |> Crypto.EddsaSignature.sign ~key
  in
  Api.DenomSignature.{ h_denom_pub; master_sig }

let sign_future_keys ~master_key:_ _future_key_response =
  (*
  let open Syntax in
  let open Crypto in
*)
  (* TODO sign *)
  assert false