scilla_version 0

import PairUtils

library Ecdsa

let one_msg = 
  fun (msg : Message) => 
    let nil_msg = Nil {Message} in
    Cons {Message} msg nil_msg

let fst_f = @fst (ByStr32) (ByStr33)
let snd_f = @snd (ByStr32) (ByStr33)

contract Ecdsa
()

field pub_key : Option (ByStr33) = None {ByStr33}

transition verify(msg : ByStr, sig : ByStr64)
  pubk_o <- pub_key;
  match pubk_o with
  | Some pubk =>
    sig = builtin ecdsa_verify pubk msg sig;
    match sig with
    | True =>
      m = { _tag : ""; _recipient : _sender; _amount : Uint128 0; status : "verification successful" };
      mone = one_msg m;
      send mone
    | False =>
      m = { _tag : ""; _recipient : _sender; _amount : Uint128 0; status : "verification failed" };
      mone = one_msg m;
      send mone
    end
  | None =>
    (* We don't have a key-pair. *)
    m = { _tag : ""; _recipient : _sender; _amount : Uint128 0; status : "no key error" };
    mone = one_msg m;
    send mone
  end
end