From 1e127de5173e3b8fb62efc79f97651ca22694441 Mon Sep 17 00:00:00 2001
From: Robin Krahl <robin.krahl@ireas.org>
Date: Tue, 19 Feb 2019 22:09:04 +0000
Subject: Validate CRC of incoming data

The data sent with Set_Report requests contains a CRC which we so far
ignored.  This patch adds a Crc struct that uses the CRC peripheral to
calculate the CRC for some data and uses it to validate the CRC of the
received data.
---
 src/main.rs | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

(limited to 'src/main.rs')

diff --git a/src/main.rs b/src/main.rs
index caf7fdf..7e364ab 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -10,6 +10,7 @@ extern crate panic_halt;
 mod util;
 
 mod commands;
+mod crc;
 mod device;
 mod hid;
 
@@ -18,6 +19,7 @@ use hal::prelude::*;
 use stm32f103xx_usb::UsbBus;
 use usb_device::class::UsbClass;
 
+use crate::crc::Crc;
 use crate::device::Nitrokey;
 use crate::hid::HidClass;
 
@@ -25,6 +27,9 @@ use crate::hid::HidClass;
 fn main() -> ! {
     let p = hal::stm32::Peripherals::take().unwrap();
 
+    p.RCC.ahbenr.modify(|_, w| w.crcen().set_bit());
+    let crc = Crc::new(p.CRC);
+
     let mut flash = p.FLASH.constrain();
     let mut rcc = p.RCC.constrain();
 
@@ -40,7 +45,7 @@ fn main() -> ! {
     let mut gpioa = p.GPIOA.split(&mut rcc.apb2);
 
     let usb_bus = UsbBus::usb_with_reset(p.USB, &mut rcc.apb1, &clocks, &mut gpioa.crh, gpioa.pa12);
-    let mut usb_class = HidClass::new(Nitrokey::new(), &usb_bus);
+    let mut usb_class = HidClass::new(Nitrokey::new(crc), &usb_bus);
     let mut usb_dev = device::create_usb_device(&usb_bus);
     usb_dev.force_reset().expect("USB reset failed");
 
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