tools/offline_impl.ml

@@ -411,11 +411,7 @@ let disable_wire ~output ~master_key ~payto_uri =
 let drain ~output ~master_key ~debit_account_section ~credit_payto_uri ~wtid
     ~date ~amount =
   let* key = read_master_key_file master_key in
-  let* () =
-    match String.length wtid = 32 with
-    | false -> Error "invalid wtid: must be 32 bytes"
-    | true -> Ok ()
-  in
+  let* wtid = Api.Bytes32.of_octets wtid in
   let master_sig =
     let open Signatures.MasterDrainProfit in
     signf (EddsaSignature.sign ~key)