(*****************************************************************************) (* *) (* Open Source License *) (* Copyright (c) 2018 Dynamic Ledger Solutions, Inc. *) (* *) (* Permission is hereby granted, free of charge, to any person obtaining a *) (* copy of this software and associated documentation files (the "Software"),*) (* to deal in the Software without restriction, including without limitation *) (* the rights to use, copy, modify, merge, publish, distribute, sublicense, *) (* and/or sell copies of the Software, and to permit persons to whom the *) (* Software is furnished to do so, subject to the following conditions: *) (* *) (* The above copyright notice and this permission notice shall be included *) (* in all copies or substantial portions of the Software. *) (* *) (* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR*) (* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, *) (* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL *) (* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER*) (* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING *) (* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER *) (* DEALINGS IN THE SOFTWARE. *) (* *) (*****************************************************************************) open Client_keys include Tezos_stdlib.Logging.Make(struct let name = "client.signer.ledger" end) let scheme = "ledger" let title = "Built-in signer using Ledger Nano S." let description = "Valid URIs are of the form\n\ \ - ledger://[/]\n\ where is the Base58-encoded public key hash of the key \ at m/44'/1729' and is a BIP32 path anchored at \ m/44'/1729'. Ledger does not yet support non-hardened path so each \ node of the path must be hardened.\n\ Use `tezos-client list connected ledgers` to get the of \ all connected devices." let hard = Int32.logor 0x8000_0000l let unhard = Int32.logand 0x7fff_ffffl let is_hard n = Int32.logand 0x8000_0000l n <> 0l let tezos_root = [hard 44l ; hard 1729l] module Bip32_path = struct let node_of_string str = match Int32.of_string_opt str with | Some node -> Some node | None -> match Int32.of_string_opt String.(sub str 0 ((length str) - 1)) with | None -> None | Some node -> Some (hard node) let node_of_string_exn str = match node_of_string str with | None -> invalid_arg (Printf.sprintf "node_of_string_exn: got %S" str) | Some str -> str let pp_node ppf node = match is_hard node with | true -> Fmt.pf ppf "%ld'" (unhard node) | false -> Fmt.pf ppf "%ld" node let string_of_node = Fmt.to_to_string pp_node let path_of_string_exn s = match String.split_on_char '/' s with | [""] -> [] | nodes -> List.map node_of_string_exn nodes let path_of_string s = try Some (path_of_string_exn s) with _ -> None let pp_path = Fmt.(list ~sep:(const char '/') pp_node) let string_of_path = Fmt.to_to_string pp_path end (* Those are always valid on Ledger Nano S with latest firmware. *) let vendor_id = 0x2c97 let product_id = 0x0001 let pks : (pk_uri, Signature.Public_key.t) Hashtbl.t = Hashtbl.create 13 let pkhs : (pk_uri, Signature.Public_key_hash.t) Hashtbl.t = Hashtbl.create 13 let curve_of_pkh : Signature.public_key_hash -> Ledgerwallet_tezos.curve = function | Ed25519 _ -> Ledgerwallet_tezos.Ed25519 | Secp256k1 _ -> Secp256k1 | P256 _ -> Secp256r1 let secp256k1_ctx = Libsecp256k1.External.Context.create ~sign:false ~verify:false () type error += | LedgerError of Ledgerwallet.Transport.error let error_encoding = let open Data_encoding in conv (fun e -> Format.asprintf "%a" Ledgerwallet.Transport.pp_error e) (fun _ ->invalid_arg "Ledger error is not deserializable") (obj1 (req "ledger-error" string)) let () = register_error_kind `Permanent ~id: "signer.ledger" ~title: "Ledger error" ~description: "Error when communication to a Ledger Nano S device" ~pp:(fun ppf e -> Format.fprintf ppf "Ledger %a" Ledgerwallet.Transport.pp_error e) error_encoding (function LedgerError e -> Some e | _ -> None) (fun e -> LedgerError e) type id = | Animals of Ledger_names.t * Ledgerwallet_tezos.curve option | Pkh of Signature.Public_key_hash.t let pp_id ppf = function | Pkh pkh -> Signature.Public_key_hash.pp ppf pkh | Animals (cthd, curve) -> Format.fprintf ppf "%a%a" Ledger_names.pp cthd (fun fmt -> function | None -> Format.fprintf fmt "" | Some a -> Format.fprintf fmt "/%a" Ledgerwallet_tezos.pp_curve a) curve let parse_animals animals = match String.split '-' animals with | [c; t; h; d] -> Some { Ledger_names.c ; t ; h ; d } | _ -> None let id_of_uri uri = let host = Uri.host uri in match Option.apply host ~f:Signature.Public_key_hash.of_b58check_opt with | Some pkh -> return (Pkh pkh) | None -> match Option.apply host ~f:parse_animals, Option.apply (List.hd_opt (String.split '/' (Uri.path uri))) ~f:Ledgerwallet_tezos.curve_of_string with | Some animals, curve -> return (Animals (animals, curve)) | (ann, curr) -> failwith "No public key hash or animal names in %a (%a, %a)" Uri.pp_hum uri (fun fmt -> function | None -> Format.fprintf fmt "NONE" | Some a -> Format.fprintf fmt "%a" Ledger_names.pp a) ann (fun fmt -> function | None -> Format.fprintf fmt "NONE" | Some a -> Format.fprintf fmt "%a" Ledgerwallet_tezos.pp_curve a) curr let id_of_pk_uri (uri : pk_uri) = id_of_uri (uri :> Uri.t) let id_of_sk_uri (uri : sk_uri) = id_of_uri (uri :> Uri.t) let wrap_ledger_cmd f = let buf = Buffer.create 100 in let pp = Format.formatter_of_buffer buf in let res = f pp in debug "%s" (Buffer.contents buf) ; match res with | Error err -> fail (LedgerError err) | Ok v -> return v let get_public_key ?(authorize_baking=false) ?(prompt=false) ledger curve path = let path = tezos_root @ path in begin match authorize_baking with | false -> wrap_ledger_cmd begin fun pp -> Ledgerwallet_tezos.get_public_key ~prompt ~pp ledger curve path end | true -> wrap_ledger_cmd begin fun pp -> Ledgerwallet_tezos.authorize_baking ~pp ledger curve path end end >>|? fun pk -> let pk = Cstruct.to_bigarray pk in match curve with | Ledgerwallet_tezos.Ed25519 -> MBytes.set_int8 pk 0 0 ; (* hackish, but works. *) Data_encoding.Binary.of_bytes_exn Signature.Public_key.encoding pk | Secp256k1 -> let open Libsecp256k1.External in let buf = MBytes.create (Key.compressed_pk_bytes + 1) in let pk = Key.read_pk_exn secp256k1_ctx pk in MBytes.set_int8 buf 0 1 ; let _nb_written = Key.write secp256k1_ctx ~pos:1 buf pk in Data_encoding.Binary.of_bytes_exn Signature.Public_key.encoding buf | Secp256r1 -> let open Uecc in let pklen = compressed_size secp256r1 in let buf = MBytes.create (pklen + 1) in match pk_of_bytes secp256r1 pk with | None -> Pervasives.failwith "Impossible to read P256 public key from Ledger" | Some pk -> MBytes.set_int8 buf 0 2 ; let _nb_written = write_key ~compress:true (MBytes.sub buf 1 pklen) pk in Data_encoding.Binary.of_bytes_exn Signature.Public_key.encoding buf module Ledger = struct type t = { device_info : Hidapi.device_info ; version : Ledgerwallet_tezos.Version.t ; git_commit : string option ; of_curve : (Ledgerwallet_tezos.curve * (Signature.Public_key.t * Signature.Public_key_hash.t)) list ; of_pkh : (Signature.Public_key_hash.t * (Signature.Public_key.t * Ledgerwallet_tezos.curve)) list ; } let create ?git_commit ~device_info ~version ~of_curve ~of_pkh () = { device_info ; version ; git_commit ; of_curve ; of_pkh } let curves { Ledgerwallet_tezos.Version.major ; minor ; patch ; _ } = let open Ledgerwallet_tezos in if (major, minor, patch) <= (0, 1, 0) then [ Ed25519 ; Secp256k1 ] else [ Ed25519 ; Secp256k1 ; Secp256r1 ] let animals_of_pkh pkh = pkh |> Signature.Public_key_hash.to_string |> Ledger_names.crouching_tiger let find_ledgers ?id ?git_commit h device_info version = fold_left_s begin fun (ledger_found, of_curve, of_pkh) curve -> get_public_key h curve [] >>|? fun pk -> let cur_pkh = Signature.Public_key.hash pk in let cur_animals = animals_of_pkh cur_pkh in log_info "Found PK: %a" Signature.Public_key.pp pk ; log_info "Found PKH: %a" Signature.Public_key_hash.pp cur_pkh ; log_info "Found Animals: %a" Ledger_names.pp cur_animals ; ledger_found || (match id with | Some (Pkh pkh) when pkh = cur_pkh -> true | Some (Animals (animals, _)) when animals = cur_animals -> true | _ -> false), (curve, (pk, cur_pkh)) :: of_curve, (cur_pkh, (pk, curve)) :: of_pkh end (false, [], []) (curves version) >>=? fun (ledger_found, of_curve, of_pkh) -> match id with | None -> return_some (create ?git_commit ~device_info ~version ~of_curve ~of_pkh ()) | Some _ when ledger_found -> return_some (create ?git_commit ~device_info ~version ~of_curve ~of_pkh ()) | _ -> return None let of_hidapi ?id device_info h = let buf = Buffer.create 100 in let pp = Format.formatter_of_buffer buf in let version = Ledgerwallet_tezos.get_version ~pp h in debug "%s" (Buffer.contents buf) ; match version with | Error (AppError { status = Ledgerwallet.Transport.Status.Ins_not_supported ; _ }) | Error (AppError { status = Ledgerwallet_tezos.Version.Tezos_impossible_to_read_version ; _ }) -> (* version is < 0.1.1. Assume it is 0.0.1, Tezos app. *) let version = { Ledgerwallet_tezos.Version.app_class = Tezos ; major = 0 ; minor = 0 ; patch = 1 ; } in warn "Impossible to read Tezos version, assuming %a" Ledgerwallet_tezos.Version.pp version ; find_ledgers ?id h device_info version | Error e -> warn "WARNING:@ The device at [%s] is not a Tezos application@ \ %a" device_info.Hidapi.path Ledgerwallet.Transport.pp_error e ; return None | Ok ({ major; minor; patch; _ } as version) -> log_info "Found a %a application at [%s]" Ledgerwallet_tezos.Version.pp version device_info.path ; begin if (major, minor, patch) >= (1, 4, 0) then wrap_ledger_cmd (fun pp -> Ledgerwallet_tezos.get_git_commit ~pp h) >>=? fun c -> return_some c else return_none end >>=? fun git_commit -> find_ledgers ?id ?git_commit h device_info version end let find_ledgers ?id () = let ledgers = Hidapi.enumerate ~vendor_id ~product_id () in log_info "Found %d Ledger(s)" (List.length ledgers) ; filter_map_s begin fun device_info -> log_info "Processing Ledger at path [%s]" device_info.Hidapi.path ; (* HID interfaces get the number 0 (cf. https://github.com/LedgerHQ/ledger-nano-s/issues/48) *BUT* on MacOSX the Hidapi library does not report the interface-number so we look at the usage-page (which is even more unspecified but used by prominent Ledger users: https://github.com/LedgerHQ/ledgerjs/commit/333ade0d55dc9c59bcc4b451cf7c976e78629681). *) if (device_info.Hidapi.interface_number = 0) || (device_info.Hidapi.interface_number = -1 && device_info.Hidapi.usage_page = 0xffa0) then begin match Hidapi.(open_path device_info.path) with | None -> return_none | Some h -> Lwt.finalize (fun () -> Ledger.of_hidapi ?id device_info h) (fun () -> Hidapi.close h ; Lwt.return_unit) end else return_none end ledgers let with_ledger id f = find_ledgers ~id () >>=? function | [] -> failwith "No Ledger found for %a" pp_id id | { device_info ; version ; of_curve ; of_pkh ; _ } :: _ -> match Hidapi.open_path device_info.path with | None -> failwith "Cannot open Ledger %a at path %s" pp_id id device_info.path | Some h -> Lwt.finalize (fun () -> f h version of_curve of_pkh) (fun () -> Hidapi.close h; Lwt.return_unit) let int32_of_path_element x = match Int32.of_string_opt x with | Some i -> Some i | None -> let len = String.length x in if len < 2 then None else Option.map ~f:hard (Int32.of_string_opt (String.sub x 0 (len - 1))) let int32_of_path_element_exn x = match int32_of_path_element x with | None -> invalid_arg "int32_of_path_element_exn" | Some p -> p let neuterize (sk : sk_uri) = return (make_pk_uri (sk :> Uri.t)) let path_of_sk_uri (uri : sk_uri) = match TzString.split_path (Uri.path (uri :> Uri.t)) with | [] -> [] | curve :: path when Ledgerwallet_tezos.curve_of_string curve <> None -> List.map int32_of_path_element_exn path | path -> List.map int32_of_path_element_exn path let path_of_pk_uri (uri : pk_uri) = match TzString.split_path (Uri.path (uri :> Uri.t)) with | [] -> [] | curve :: path when Ledgerwallet_tezos.curve_of_string curve <> None -> List.map int32_of_path_element_exn path | path -> List.map int32_of_path_element_exn path let unopt_curve annimal = function | Some curve -> return curve | None -> failwith "A curve specification is required for this operation,@ e.g.@ \ \"ledger://%a/{ed25519,...}\"" Ledger_names.pp annimal let public_key ?(interactive : Client_context.io_wallet option) (pk_uri : pk_uri) = let find_curve of_pkh = function | Pkh pkh -> protect (fun () -> return (snd (List.assoc pkh of_pkh))) | Animals (a, curve_opt) -> unopt_curve a curve_opt in match Hashtbl.find_opt pks pk_uri with | Some pk -> return pk | None -> id_of_pk_uri pk_uri >>=? fun id -> with_ledger id begin fun ledger _version _of_curve of_pkh -> find_curve of_pkh id >>=? fun curve -> let path = path_of_pk_uri pk_uri in begin match interactive with | Some cctxt -> get_public_key ~prompt:false ledger curve path >>=? fun pk -> let pkh = Signature.Public_key.hash pk in cctxt#message "Please validate@ (and write down)@ the public key hash\ @ displayed@ on the Ledger,@ it should be equal@ to `%a`:" Signature.Public_key_hash.pp pkh >>= fun () -> get_public_key ~prompt:true ledger curve path | None -> get_public_key ~prompt:false ledger curve path end >>=? fun pk -> let pkh = Signature.Public_key.hash pk in Hashtbl.replace pks pk_uri pk ; Hashtbl.replace pkhs pk_uri pkh ; return pk end >>= function | Error err -> failwith "%a" pp_print_error err | Ok v -> return v let public_key_hash ?interactive pk_uri = match Hashtbl.find_opt pkhs pk_uri with | Some pkh -> return (pkh, None) | None -> public_key ?interactive pk_uri >>=? fun pk -> return (Hashtbl.find pkhs pk_uri, Some pk) let curve_of_id = function | Pkh pkh -> return (curve_of_pkh pkh) | Animals (a, curve_opt) -> unopt_curve a curve_opt let sign ?watermark sk_uri msg = id_of_sk_uri sk_uri >>=? fun id -> with_ledger id begin fun ledger { major; minor; patch; _ } _of_curve _of_pkh -> let msg = Option.unopt_map watermark ~default:msg ~f:begin fun watermark -> MBytes.concat "" [Signature.bytes_of_watermark watermark ; msg] end in curve_of_id id >>=? fun curve -> let path = tezos_root @ path_of_sk_uri sk_uri in let msg_len = MBytes.length msg in wrap_ledger_cmd begin fun pp -> if msg_len > 1024 && (major, minor, patch) < (1, 1, 0) then Ledgerwallet_tezos.sign ~hash_on_ledger:false ~pp ledger curve path (Cstruct.of_bigarray (Blake2B.(to_bytes (hash_bytes [ msg ])))) else Ledgerwallet_tezos.sign ~pp ledger curve path (Cstruct.of_bigarray msg) end >>=? fun signature -> match curve with | Ed25519 -> let signature = Cstruct.to_bigarray signature in let signature = Ed25519.of_bytes_exn signature in return (Signature.of_ed25519 signature) | Secp256k1 -> (* Remove parity info *) Cstruct.(set_uint8 signature 0 (get_uint8 signature 0 land 0xfe)) ; let signature = Cstruct.to_bigarray signature in let open Libsecp256k1.External in let signature = Sign.read_der_exn secp256k1_ctx signature in let bytes = Sign.to_bytes secp256k1_ctx signature in let signature = Secp256k1.of_bytes_exn bytes in return (Signature.of_secp256k1 signature) | Secp256r1 -> (* Remove parity info *) Cstruct.(set_uint8 signature 0 (get_uint8 signature 0 land 0xfe)) ; let signature = Cstruct.to_bigarray signature in let open Libsecp256k1.External in (* We use secp256r1 library to extract P256 DER signature. *) let signature = Sign.read_der_exn secp256k1_ctx signature in let buf = Sign.to_bytes secp256k1_ctx signature in let signature = P256.of_bytes_exn buf in return (Signature.of_p256 signature) end let commands = let open Clic in let group = { Clic.name = "ledger" ; title = "Commands for managing the connected Ledger Nano S devices" } in fun () -> [ Clic.command ~group ~desc: "List supported Ledger Nano S devices connected." no_options (fixed [ "list" ; "connected" ; "ledgers" ]) (fun () (cctxt : Client_context.io_wallet) -> find_ledgers () >>=? function | [] -> cctxt#message "No device found." >>= fun () -> cctxt#message "Make sure a Ledger Nano S is connected and in the Tezos Wallet app." >>= fun () -> return_unit | ledgers -> iter_s begin fun { Ledger.device_info = { Hidapi.path ; manufacturer_string ; product_string ; _ } ; of_curve ; version ; git_commit ; _ } -> let manufacturer = Option.unopt ~default:"(none)" manufacturer_string in let product = Option.unopt ~default:"(none)" product_string in cctxt#message "Found a %a (commit %s) application running on %s %s at [%s]." Ledgerwallet_tezos.Version.pp version (match git_commit with None -> "unknown" | Some c -> c) manufacturer product path >>= fun () -> let of_curve = List.rev of_curve in begin match List.hd_opt of_curve with | None -> failwith "No curve available, upgrade Ledger software" | Some (_, (_, pkh)) -> return (Ledger_names.crouching_tiger (Signature.Public_key_hash.to_string pkh)) end >>=? fun animals -> cctxt#message "@[@,To use keys at BIP32 path \ m/44'/1729'/0'/0' (default Tezos key path), use \ one of@, @[%a@]@]" (Format.pp_print_list (fun ppf (curve, _) -> Format.fprintf ppf "tezos-client import secret key \ ledger_%s \"ledger://%a/0'/0'\"" (Sys.getenv "USER") pp_id (Animals (animals, Some curve)))) of_curve >>= fun () -> return_unit end ledgers) ; Clic.command ~group ~desc: "Display version/public-key/address information for a Ledger URI" (args1 (switch ~doc:"Test signing operation" ~long:"test-sign" ())) (prefixes [ "show" ; "ledger" ] @@ Client_keys.sk_uri_param @@ stop) (fun test_sign sk_uri (cctxt : Client_context.io_wallet) -> neuterize sk_uri >>=? fun pk_uri -> id_of_pk_uri pk_uri >>=? fun id -> find_ledgers ~id () >>=? function | [] -> failwith "No ledger found for %a" pp_id id | { Ledger.device_info ; version ; _ } :: _ -> let manufacturer = Option.unopt ~default:"(none)" device_info.manufacturer_string in let product = Option.unopt ~default:"(none)" device_info.product_string in cctxt#message "Found a %a application running on a \ %s %s at [%s]." Ledgerwallet_tezos.Version.pp version manufacturer product device_info.path >>= fun () -> begin match id with | (Pkh _ | Animals (_, Some _)) -> (* → Can public keys. *) public_key pk_uri >>=? fun pk -> public_key_hash pk_uri >>=? fun (pkh, _) -> cctxt#message "@[Tezos address at this path/curve: %a@,\ Corresponding full public key: %a@]" Signature.Public_key_hash.pp pkh Signature.Public_key.pp pk >>= fun () -> begin match test_sign, version.app_class with | true, Tezos -> let pkh_bytes = Signature.Public_key_hash.to_bytes pkh in (* Signing requires validation on the device. *) cctxt#message "Attempting a signature, please \ validate on the ledger." >>= fun () -> sign ~watermark:Generic_operation sk_uri pkh_bytes >>=? fun signature -> begin match Signature.check ~watermark:Generic_operation pk signature pkh_bytes with | false -> failwith "Fatal: Ledger cannot sign with %a" Signature.Public_key_hash.pp pkh | true -> cctxt#message "Tezos Wallet successfully signed." >>= fun () -> return_unit end | true, TezBake -> failwith "Option --test-sign only works \ for the Tezos Wallet app." | false, _ -> return_unit end | Animals (_, None) when test_sign -> failwith "Option --test-sign only works \ for the Tezos Wallet app with a \ curve/path specification." | Animals (_, None) -> cctxt#message "No curve was provided, \ there is no Tezos-address/public-key \ to show/test." >>= fun () -> return_unit end ) ; Clic.command ~group ~desc: "Query the path of the authorized key" no_options (prefixes [ "get" ; "ledger" ; "authorized" ; "path" ; "for" ] @@ Public_key.alias_param @@ stop) (fun () (name, (pk_uri, _)) (cctxt : Client_context.io_wallet) -> id_of_pk_uri pk_uri >>=? fun root_id -> with_ledger root_id begin fun h _version _of_curve _to_curve -> wrap_ledger_cmd begin fun pp -> Ledgerwallet_tezos.get_authorized_key ~pp h end >>=? function | [] -> cctxt#message "@[No baking key authorized for %s@]" name >>= fun () -> return_unit | path -> cctxt#message "@[Authorized baking path: %a@]" Bip32_path.pp_path path >>= fun () -> return_unit end) ; Clic.command ~group ~desc: "Authorize a Ledger to bake for a key" no_options (prefixes [ "authorize" ; "ledger" ; "to" ; "bake" ; "for" ] @@ Public_key.alias_param @@ stop) (fun () (_, (pk_uri, _)) (cctxt : Client_context.io_wallet) -> id_of_pk_uri pk_uri >>=? fun root_id -> with_ledger root_id begin fun h _version _of_curve _of_pkh -> let path = path_of_pk_uri pk_uri in curve_of_id root_id >>=? fun curve -> get_public_key ~authorize_baking:true h curve path >>=? fun pk -> let pkh = Signature.Public_key.hash pk in cctxt#message "@[Authorized baking for address: %a@,\ Corresponding full public key: %a@]" Signature.Public_key_hash.pp pkh Signature.Public_key.pp pk >>= fun () -> return_unit end) ; Clic.command ~group ~desc: "Get high water mark of a Ledger" no_options (prefixes [ "get" ; "ledger" ; "high" ; "watermark" ; "for" ] @@ Client_keys.sk_uri_param @@ stop) (fun () sk_uri (cctxt : Client_context.io_wallet) -> id_of_sk_uri sk_uri >>=? fun id -> with_ledger id begin fun h version _ _ -> match version.app_class with | Tezos -> failwith "Fatal: this operation is only valid with TezBake" | TezBake -> wrap_ledger_cmd begin fun pp -> Ledgerwallet_tezos.get_high_watermark ~pp h end >>=? fun hwm -> cctxt#message "@[%a has high water mark: %ld@]" pp_id id hwm >>= fun () -> return_unit end ) ; Clic.command ~group ~desc: "Set high water mark of a Ledger" no_options (prefixes [ "set" ; "ledger" ; "high" ; "watermark" ; "for" ] @@ Client_keys.sk_uri_param @@ (prefix "to") @@ (param ~name: "high watermark" ~desc: "High watermark" (parameter (fun _ctx s -> try return (Int32.of_string s) with _ -> failwith "%s is not an int32 value" s))) @@ stop) (fun () sk_uri hwm (cctxt : Client_context.io_wallet) -> id_of_sk_uri sk_uri >>=? fun id -> with_ledger id begin fun h version _ _ -> match version.app_class with | Tezos -> failwith "Fatal: this operation is only valid with TezBake" | TezBake -> wrap_ledger_cmd begin fun pp -> Ledgerwallet_tezos.set_high_watermark ~pp h hwm end >>=? fun () -> wrap_ledger_cmd begin fun pp -> Ledgerwallet_tezos.get_high_watermark ~pp h end >>=? fun new_hwm -> cctxt#message "@[%a has now high water mark: %ld@]" pp_id id new_hwm >>= fun () -> return_unit end ) ; ]