From 9b1eb22ac4a3db91563c16f24bbeb6bc1d55c742 Mon Sep 17 00:00:00 2001
From: swrup <swrup@protonmail.com>
Date: Fri, 28 Nov 2025 11:08:43 +0100
Subject: [PATCH]

---
 tools/dune       |  2 +-
 tools/offline.ml | 90 +++++++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 90 insertions(+), 2 deletions(-)

diff --git a/tools/dune b/tools/dune
index 3375a448..3366e550 100644
--- a/tools/dune
+++ b/tools/dune
@@ -2,4 +2,4 @@
  (public_name offline)
  (name offline)
  (modules offline)
- (libraries cmdliner bos fmt mirage-crypto ptime mte))
+ (libraries cmdliner bos fmt mirage-crypto ptime mte vif))
diff --git a/tools/offline.ml b/tools/offline.ml
index 5d06c89b..624665f9 100644
--- a/tools/offline.ml
+++ b/tools/offline.ml
@@ -1 +1,89 @@
-let () = Fmt.pr "hello~@."; ()
+(* TODO
+   - clean up cmdliner
+   - setup
+   - sign *)
+(* doc: https://docs.taler.net/manpages/taler-exchange-offline.1.html *)
+
+let download ~base_url ~output =
+  let open Bos in
+  let uri =
+    Uri.with_path (Uri.of_string base_url) "/management/keys/" |> Uri.to_string
+  in
+  let wget = Cmd.(v "wget" % "-O" % output % uri) in
+  OS.Cmd.run wget
+
+let sign ~input ~output ~master_key =
+  let open Syntax in
+  let open Bos.OS in
+  let open Crypto in
+  let input = Fpath.v input in
+  let _output = Fpath.v output in
+  let master_key = Fpath.v master_key in
+  let* input = File.read input |> unwrap_err_msg in
+  let* master_key = File.read master_key |> unwrap_err_msg in
+  let _master_key = EddsaPrivateKey.of_octets master_key in
+  let* _future_key_response = Api.decode Api.FutureKeysResponse.jsont input in
+  (* TODO *)
+  Ok ()
+
+(* CLI *)
+
+open Cmdliner
+open Cmdliner.Term.Syntax
+
+let download_cmd =
+  let doc = "Downloads /management/keys/" in
+  let man =
+    [ `S Manpage.s_description; `P "$(cmd) download /management/keys." ]
+  in
+  let output =
+    let doc = "File to save data to be signed." in
+    Arg.(
+      value & opt filepath "management_keys.json" & info [ "o"; "output" ] ~doc)
+  in
+  let base_url =
+    let doc = "Base url of the exchange." in
+    Arg.(value & opt string "http://localhost:3434/" & info [ "base-url" ] ~doc)
+  in
+  Cmd.make (Cmd.info "download" ~version:"%%VERSION%%" ~doc ~man)
+  @@
+  let+ output = output and+ base_url = base_url in
+  match download ~base_url ~output with
+  | Error (`Msg err) ->
+      Fmt.epr "Download failure: %s@." err;
+      exit 1
+  | Ok () -> ()
+
+let sign_cmd =
+  let doc = "Sign FutureKeysResponse." in
+  let input =
+    let doc = "File with FutureKeysResponse data." in
+    Arg.(
+      value & opt filepath "management_keys.json" & info [ "i"; "input" ] ~doc)
+  in
+  let output =
+    let doc = "File to save signature to." in
+    Arg.(
+      value
+      & opt filepath "signed_management_keys.json"
+      & info [ "o"; "output" ] ~doc)
+  in
+  let master_key =
+    let doc = "Master offline Eddsa private key file." in
+    Arg.(
+      value
+      & opt filepath "data/eddsa_master_offline"
+      & info [ "master-key" ] ~doc)
+  in
+  Cmd.make (Cmd.info "sign" ~version:"%%VERSION%%" ~doc)
+  @@
+  let+ input = input and+ output = output and+ master_key = master_key in
+  match sign ~input ~output ~master_key with
+  | Error (*`Msg*) err ->
+      Fmt.epr "Signature failure: %s@." err;
+      exit 1
+  | Ok () -> ()
+
+let main () = Cmd.eval download_cmd
+let _main () = Cmd.eval sign_cmd
+let () = if !Sys.interactive then () else exit (main ())