Ledger: implement git-commit APDU

src/lib_signer_backends/ledger.ml

@@ -139,14 +139,15 @@ 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 ~device_info ~version ~of_curve ~of_pkh =
-    { device_info ; version ; of_curve ; of_pkh }
+  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
@@ -156,7 +157,7 @@ module Ledger = struct
       [ Ed25519 ; Secp256k1 ; Secp256r1 ]
 
   let of_hidapi ?pkh device_info h =
-    let find_ledgers version =
+    let find_ledgers ?git_commit version =
       fold_left_s begin fun (pkh_found, of_curve, of_pkh) curve ->
         get_public_key h curve [] >>|? fun pk ->
         let cur_pkh = Signature.Public_key.hash pk in
@@ -167,9 +168,12 @@ module Ledger = struct
       end (false, [], []) (curves version)
       >>=? fun (pkh_found, of_curve, of_pkh) ->
       match pkh with
-      | None -> return (Some (create ~device_info ~version ~of_curve ~of_pkh))
+      | None ->
+          return (Some (create ?git_commit ~device_info ~version
+                          ~of_curve ~of_pkh ()))
       | Some _ when pkh_found ->
-          return (Some (create ~device_info ~version ~of_curve ~of_pkh))
+          return (Some (create ?git_commit ~device_info ~version
+                          ~of_curve ~of_pkh ()))
       | _ -> return None
     in
     let buf = Buffer.create 100 in
@@ -194,7 +198,15 @@ module Ledger = struct
           device_info.Hidapi.path
           Ledgerwallet.Transport.pp_error e ;
         return None
-    | Ok version -> find_ledgers version
+    | Ok ({ major; minor; patch; _ } as version) ->
+        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 ?git_commit version
 end
 
 let find_ledgers ?pkh () =
@@ -352,11 +364,12 @@ let commands =
                iter_s begin fun { Ledger.device_info = { Hidapi.path ;
                                                          manufacturer_string ;
                                                          product_string ; _ } ;
-                                  of_curve ; version ; _ } ->
+                                  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 application running on %s %s at [%s]."
+                 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
                  cctxt#message

vendors/ocaml-ledger-wallet/src/ledgerwallet_tezos.ml

@@ -55,6 +55,7 @@ end
 
 type ins =
   | Version
+  | Git_commit
   | Authorize_baking
   | Get_public_key
   | Prompt_public_key
@@ -72,6 +73,7 @@ let int_of_ins = function
   | Sign_unsafe -> 0x05
   | Reset_high_watermark -> 0x06
   | Query_high_watermark -> 0x08
+  | Git_commit -> 0x09
 
 type curve =
   | Ed25519
@@ -91,6 +93,11 @@ let get_version ?pp ?buf h =
   Transport.apdu ~msg:"get_version" ?pp ?buf h apdu >>=
   Version.read
 
+let get_git_commit ?pp ?buf h =
+  let apdu = Apdu.create (wrap_ins Git_commit) in
+  Transport.apdu ~msg:"get_git_commit" ?pp ?buf h apdu >>|
+  Cstruct.to_string
+
 let write_path cs path =
   ListLabels.fold_left path ~init:cs ~f:begin fun cs i ->
     Cstruct.BE.set_uint32 cs 0 i ;

vendors/ocaml-ledger-wallet/src/ledgerwallet_tezos.mli

@@ -32,6 +32,12 @@ val get_version :
 (** [get_version ?pp ?buf ledger] is the version information of the
     Ledger app running at [ledger]. *)
 
+val get_git_commit :
+  ?pp:Format.formatter -> ?buf:Cstruct.t ->
+  Hidapi.t -> (string, Transport.error) result
+(** [get_git_commit ?pp ?buf ledger] is the git commit information of
+   the Ledger app running at [ledger]. *)
+
 val get_public_key :
   ?prompt:bool ->
   ?pp:Format.formatter ->