multisig_all.ml

open SCaml;;

type amount    = tz;;
type dest      = unit contract;;
type threshold = nat;;
type keys      = key list;;

type action =
  | Transfer    of amount * dest
  | Change_keys of threshold * keys
  | Deposit of unit;;

type payload = {
    counter : nat;
    action  : action
};;

type parameter ={
    payload : payload;
    sigs    : signature option list
};;

type storage = {
    counter   : nat;
    threshold : nat;
    keys      : key list
};;




let [@entry] main (prm : parameter) (str : storage) =
  if not (str.counter = prm.payload.counter) then failwith "invalid count";

  let m = Obj.pack (Global.get_chain_id (), Global.get_source (), prm.payload) in
  let check k s = match s with
    | Some s -> Crypto.check_signature k s m
    | None   -> false in

  let exist  = List.fold_left (||) false in
  let forall = List.fold_left (&&) true in
  let g acc x = if exist x then List.rev_append acc [x] else acc in
  let filter = List.fold_left g [] in
  let ss = prm.sigs in
  let f k    = List.map (check k) ss in
  let bss    = List.map f str.keys in
  let bs     = filter  bss in
  let b      = List.length bs in
  if (b < str.threshold) then failwith "invalid signature";



 let str' = {str with counter = str.counter +^ Nat 1} in

  match prm.payload.action  with
  | Transfer (n, c) ->
     let op = Operation.transfer_tokens () n c
     in ([op], str')
  | Change_keys (n,ks) ->
     if (n > List.length ks) then failwith "invalid threshold";
     let str'' = {str' with threshold = n} in
     let str''' = {str'' with keys = ks} in
     ([], str''')
  | Deposit _ ->
     ([],str')