Source file transport.ml

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
(*---------------------------------------------------------------------------
   Copyright (c) 2017 Vincent Bernardoff. All rights reserved.
   Distributed under the ISC license, see terms at the end of the file.
  ---------------------------------------------------------------------------*)

open Rresult
open Lwt_result
open Lwt_result.Infix
open Lwt.Syntax

let return_unit = Lwt.return_ok ()

type t = Hidapi of Hidapi_lwt.t | Proxy of Transport_proxy.t

type hidapi_path = Hidapi_lwt.device_info

type proxy_path = {addr : string option; port : int option}

type path = Hidapi_path of hidapi_path | Proxy_path of proxy_path

type transport_error =
  | HidapiError of Transport_hidapi.error
  | ProxyError of Transport_proxy.error

type error =
  | AppError of {status : Status.t; msg : string}
  | TransportError of transport_error

let app_error ~msg r = R.reword_error (fun status -> AppError {status; msg}) r

let pp_error ppf = function
  | AppError {status; msg} ->
      Format.fprintf ppf "Application level error (%s): %a" msg Status.pp status
  | TransportError (HidapiError e) -> Transport_hidapi.pp_error ppf e
  | TransportError (ProxyError e) -> Transport_proxy.pp_error ppf e

module Ids = struct
  let ( -- ) i j = List.init (j - i + 1) (fun x -> x + i)

  (* Those constants are provided by the vendor (e.g. check the udev
     rules they provide): *)
  let vendor_id = 0x2c97

  (* These come from the ledger's udev rules *)
  let nano_s_product_ids = [0x0001] @ (0x1000 -- 0x101f)

  let nano_x_product_ids = [0x0004] @ (0x4000 -- 0x401f)

  let nano_s_plus_product_ids = [0x0005] @ (0x5000 -- 0x501f)

  let stax_product_ids = [0x0006] @ (0x6000 -- 0x601f)

  let flex_product_ids = [0x0007] @ (0x7000 -- 0x701f)
end

let enumerate_hidapi () =
  let open Ids in
  let all_product_ids =
    nano_s_product_ids @ nano_x_product_ids @ nano_s_plus_product_ids @ stax_product_ids @ flex_product_ids
  in
  let open Hidapi_lwt in
  let+ infos = enumerate ~vendor_id () in
  List.filter_map
    (fun hid ->
      if List.exists (fun (v : int) -> v = hid.product_id) all_product_ids then
        Some (Hidapi_path hid)
      else None)
    infos

let enumerate_proxy () =
  let addr = Sys.getenv_opt "LEDGER_PROXY_ADDRESS" in
  let port =
    Option.bind (Sys.getenv_opt "LEDGER_PROXY_PORT") (fun s ->
        try Some (int_of_string s) with _ -> None)
  in
  match (addr, port) with None, None -> [] | _ -> [Proxy_path {addr; port}]

let enumerate () =
  let+ hidapi_infos = enumerate_hidapi () in
  enumerate_proxy () @ hidapi_infos

let open_id ~vendor_id ~product_id =
  let* o = Hidapi_lwt.open_id ~vendor_id ~product_id in
  Lwt.return (Option.map (fun o -> Hidapi o) o)

let open_path (path : path) =
  match path with
  | Hidapi_path device_info ->
      let* o = Hidapi_lwt.open_path device_info.Hidapi_lwt.path in
      Lwt.return (Option.map (fun o -> Hidapi o) o)
  | Proxy_path {addr; port} ->
      Lwt.return_some (Proxy (Transport_proxy.create ?name:addr ?port ()))

let close = function
  | Hidapi h -> Hidapi_lwt.close h
  | Proxy p -> Lwt.return (Transport_proxy.close p)

let with_connection f = function
  | Some h ->
      Lwt.catch
        (fun () ->
          let* out = f h in
          let* () = close h in
          Lwt.return_some out)
        (fun exn ->
          let* () = close h in
          Lwt.fail exn)
  | None -> Lwt.return_none

let with_connection_id ~vendor_id ~product_id f =
  let* device = open_id ~vendor_id ~product_id in
  with_connection f device

let with_connection_path path f =
  let* device = open_path path in
  with_connection f device

let write_apdu ?pp ?buf h apdu =
  match h with
  | Hidapi h ->
      let* result = Transport_hidapi.write_apdu ?pp ?buf h apdu in
      Lwt.return
        (R.reword_error (fun e -> TransportError (HidapiError e)) result)
  | Proxy p ->
      Lwt.return
        (R.reword_error
           (fun e -> TransportError (ProxyError e))
           (Transport_proxy.write_apdu ?pp p apdu))

let read ?pp ?buf h =
  match h with
  | Hidapi h ->
      map_error
        (fun e -> TransportError (HidapiError e))
        (Transport_hidapi.read ?pp ?buf h)
  | Proxy p ->
      Lwt.return
        (R.reword_error
           (fun e -> TransportError (ProxyError e))
           (Transport_proxy.read p))

let ping ?pp ?buf h =
  match h with
  | Hidapi h ->
      map_error
        (fun e -> TransportError (HidapiError e))
        (Transport_hidapi.ping ?pp ?buf h)
  | Proxy _ -> return_unit

let apdu ?pp ?(msg = "") ?buf h apdu =
  write_apdu ?pp ?buf h apdu >>= fun () ->
  read ?pp ?buf h >>= fun (status, payload) ->
  (match pp with
  | None -> ()
  | Some pp ->
      Format.fprintf
        pp
        "<- RESP [%a] %a@."
        Status.pp
        status
        Cstruct.hexdump_pp
        payload ;
      Format.pp_print_flush pp ()) ;
  match status with
  | Status.Ok -> return payload
  | status -> Lwt.return (app_error ~msg (R.error status))

let write_payload ?pp ?(msg = "write_payload") ?buf ?(mark_last = false) ~cmd
    ?p1 ?p2 h cs =
  let rec inner cs =
    let cs_len = Cstruct.length cs in
    let lc = min Apdu.max_data_length cs_len in
    let last = lc = cs_len in
    let p1 =
      match (last, mark_last, p1) with
      | true, true, None -> Some 0x80
      | true, true, Some p1 -> Some (0x80 lor p1)
      | _ -> p1
    in
    apdu
      ?pp
      ~msg
      ?buf
      h
      Apdu.(create ?p1 ?p2 ~lc ~data:(Cstruct.sub cs 0 lc) cmd)
    >>= fun response ->
    if last then return response else inner (Cstruct.shift cs lc)
  in
  if Cstruct.length cs = 0 then return cs else inner cs

(*---------------------------------------------------------------------------
   Copyright (c) 2017 Vincent Bernardoff

   Permission to use, copy, modify, and/or distribute this software for any
   purpose with or without fee is hereby granted, provided that the above
   copyright notice and this permission notice appear in all copies.

   THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
   MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
   ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
   WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
   ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
   OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  ---------------------------------------------------------------------------*)