From 9df0f3bd565dfbf8c97d02969a17504c688bf381 Mon Sep 17 00:00:00 2001
From: Robin Krahl <robin.krahl@ireas.org>
Date: Mon, 18 Feb 2019 21:36:31 +0000
Subject: Refactor command execution into commands module

This patch refactors the command execution.  A command is represented by
a struct implementing the Command trait.  The enum_cmd macro is used to
generate a mapping from the CommandId enum to a Command instance and to
execute the command.  The request and response data is manually
converted from and to raw byte slices.

As we do not have a standard library, we cannot create a Box<Command>
from a CommandId.  Instead, we directly delegate the execute method to
the corresponding Command.
---
 src/device.rs | 49 ++-----------------------------------------------
 1 file changed, 2 insertions(+), 47 deletions(-)

(limited to 'src/device.rs')

diff --git a/src/device.rs b/src/device.rs
index a6bf9bf..300ce56 100644
--- a/src/device.rs
+++ b/src/device.rs
@@ -4,13 +4,13 @@
 use usb_device::bus::{UsbBus, UsbBusAllocator};
 use usb_device::device::{UsbDevice, UsbDeviceBuilder, UsbVidPid};
 
+use crate::commands::{CommandId, COMMAND_LEN};
 use crate::hid::{HidDevice, Protocol, ReportType, Subclass};
 use crate::util::TryFrom;
 
 const VID_CLAY_LOGIC: u16 = 0x20a0;
 const PID_NITROKEY_PRO: u16 = 0x4108;
 
-const COMMAND_LEN: usize = 53;
 const REPORT_LEN: usize = 64;
 const REPORT_DESCRIPTOR: &[u8] = &[
     0x05, 0x01, 0x09, 0x06, 0xA1, 0x01, 0x05, 0x07, 0x19, 0xE0, 0x29, 0xE7, 0x15, 0x00, 0x25, 0x01,
@@ -47,14 +47,6 @@ enum_u8! {
     }
 }
 
-enum_u8! {
-    #[derive(Clone, Copy, Debug, PartialEq)]
-    pub enum CommandId {
-        GetStatus = 0,
-        ReadSlotName = 2,
-    }
-}
-
 pub struct Nitrokey {
     buf: [u8; REPORT_LEN],
 }
@@ -65,43 +57,6 @@ impl Nitrokey {
             buf: [0; REPORT_LEN],
         }
     }
-
-    fn execute_command(&self, command_id: CommandId, data: &[u8], buf: &mut [u8]) -> CommandStatus {
-        let data: &[u8] = match command_id {
-            CommandId::GetStatus => {
-                &[
-                    1, // firmware_version_st.minor
-                    0, // firmware_version_st.major
-                    0, // card_serial[0]
-                    0, // card_serial[1]
-                    0, // card_serial[2]
-                    0, // card_serial[3]
-                    0, // numlock
-                    0, // capslock
-                    0, // enable_user_password
-                    0, // delete_user_password
-                ]
-            }
-            CommandId::ReadSlotName => {
-                assert!(data.len() > 1);
-                let slot_number = data[0];
-                if slot_number != 0x20 {
-                    return CommandStatus::SlotNotProgrammed;
-                }
-
-                &[
-                    0x74, // t
-                    0x65, // e
-                    0x73, // s
-                    0x74, // t
-                    0x00, // NULL
-                ]
-            }
-        };
-        assert!(buf.len() >= data.len());
-        buf[..data.len()].copy_from_slice(data);
-        CommandStatus::Ok
-    }
 }
 
 impl HidDevice for Nitrokey {
@@ -131,7 +86,7 @@ impl HidDevice for Nitrokey {
         let device_status = DeviceStatus::Ok;
         let command_id = self.buf[0];
         let command_status = if let Ok(command_id) = CommandId::try_from(command_id) {
-            self.execute_command(command_id, &self.buf[1..60], &mut buf)
+            command_id.execute(&self.buf[1..60], &mut buf)
         } else {
             CommandStatus::UnknownCommand
         };
-- 
cgit v1.2.1