device/fido/u2f_command_type.h

// Copyright 2017 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef DEVICE_FIDO_U2F_COMMAND_TYPE_H_
#define DEVICE_FIDO_U2F_COMMAND_TYPE_H_

#include <stdint.h>

namespace device {

// The type of a command that can be sent either to or from a U2F authenticator,
// i.e. a request or a response.
//
// Each request sent to a device results in a response of *the same* type sent
// back, unless there was an error in which case a CMD_ERROR is returned.
enum class U2fCommandType : uint8_t {
  UNDEFINED = 0x00,

  // Sends arbitrary data to the device which echoes the same data back.
  CMD_PING = 0x81,

  // Authenticator sends this in response to requests that it could not process
  // within a time limit. The client should take action appropriate to the
  // message reason (e.g., notify the user to perform a test-of-user-presence),
  // and wait for the next message.
  CMD_KEEPALIVE = 0x82,

  // Encapsulates a U2F protocol raw message.
  CMD_MSG = 0x83,

  // Requests a unique channel from a USB/HID device.
  CMD_INIT = 0x86,

  // Instructs a USB/HID authenticator to show the user that it is active.
  CMD_WINK = 0x88,

  // Used as a response in case an error occurs during a request.
  CMD_ERROR = 0xBF,
};

}  // namespace device

#endif  // DEVICE_FIDO_U2F_COMMAND_TYPE_H_