Merge #178 178: Add support for running HMAC operations r=alistair23 a=alistair23 This PR adds the HMAC driver and a HMAC example. Co-authored-by: Alistair Francis <alistair.francis@wdc.com>
diff --git a/examples/hmac.rs b/examples/hmac.rs new file mode 100644 index 0000000..97184f7 --- /dev/null +++ b/examples/hmac.rs
@@ -0,0 +1,55 @@ +#![no_std] + +use core::fmt::Write; +use libtock::hmac::{HmacDataBuffer, HmacDestBuffer, HmacKeyBuffer}; +use libtock::result::TockResult; +use libtock::syscalls; + +#[libtock::main] +async fn main() -> TockResult<()> { + let mut drivers = libtock::retrieve_drivers()?; + let mut console = drivers.console.create_console(); + writeln!(console, "Starting HMAC example")?; + let hmac_driver = drivers.hmac.init_driver()?; + + writeln!(console, "Loading in 0 key")?; + let mut key_buffer = HmacKeyBuffer::default(); + let _key_buffer = hmac_driver.init_key_buffer(&mut key_buffer)?; + writeln!(console, " done")?; + + writeln!(console, "Creating data buffer")?; + let mut data_buffer = HmacDataBuffer::default(); + let data: &[u8; 72] = + b"A language empowering everyone to build reliable and efficient software."; + + for (i, d) in data.iter().enumerate() { + data_buffer.buffer[i] = *d; + } + let _data_buffer = hmac_driver.init_data_buffer(&mut data_buffer)?; + writeln!(console, " done")?; + + writeln!(console, "Creating dest buffer")?; + let mut dest_buffer = HmacDestBuffer::default(); + let dest_buffer = hmac_driver.init_dest_buffer(&mut dest_buffer)?; + writeln!(console, " done")?; + + let mut temp_buffer = [0; libtock::hmac::DEST_BUFFER_SIZE]; + + writeln!(console, "Setting callback and running")?; + let mut callback = |_result, _digest| { + writeln!(console, "HMAC Complete, printing digest").unwrap(); + dest_buffer.read_bytes(&mut temp_buffer[..]); + + for buf in temp_buffer.iter().take(libtock::hmac::DEST_BUFFER_SIZE) { + write!(console, "{:x}", *buf).unwrap(); + } + }; + + let _subscription = hmac_driver.subscribe(&mut callback)?; + + hmac_driver.run()?; + + loop { + unsafe { syscalls::raw::yieldk() }; + } +}
diff --git a/src/drivers.rs b/src/drivers.rs index 185f6ea..bd7f45b 100644 --- a/src/drivers.rs +++ b/src/drivers.rs
@@ -2,6 +2,7 @@ use crate::buttons::ButtonsDriverFactory; use crate::console::ConsoleDriver; use crate::gpio::GpioDriverFactory; +use crate::hmac::HmacDriverFactory; use crate::leds::LedsDriverFactory; use crate::result::OtherError; use crate::result::TockError; @@ -23,6 +24,7 @@ pub leds: LedsDriverFactory, pub timer: DriverContext, pub gpio: GpioDriverFactory, + pub hmac: HmacDriverFactory, pub temperature: TemperatureDriverFactory, pub buttons: ButtonsDriverFactory, pub adc: AdcDriverFactory, @@ -71,6 +73,7 @@ active_timer: Cell::new(None), }, gpio: GpioDriverFactory, + hmac: HmacDriverFactory, temperature: TemperatureDriverFactory, rng: RngDriver, ambient_light_sensor: AmbientLightSensor,
diff --git a/src/hmac.rs b/src/hmac.rs new file mode 100644 index 0000000..e5475cc --- /dev/null +++ b/src/hmac.rs
@@ -0,0 +1,123 @@ +use crate::callback::CallbackSubscription; +use crate::callback::Consumer; +use crate::result::TockResult; +use crate::syscalls; +use core::marker::PhantomData; +use libtock_core::shared_memory::SharedMemory; + +const DRIVER_NUMBER: usize = 0x40003; + +pub const KEY_BUFFER_SIZE: usize = 32; +pub const DATA_BUFFER_SIZE: usize = 256; +pub const DEST_BUFFER_SIZE: usize = 32; + +mod command_nr { + pub const SET_ALGORITHM: usize = 0; + pub const RUN: usize = 1; +} + +mod subscribe_nr { + pub const SUBSCRIBE_CALLBACK: usize = 0; +} + +mod allow_nr { + pub const KEY: usize = 0; + pub const DATA: usize = 1; + pub const DEST: usize = 2; +} + +#[non_exhaustive] +pub struct HmacDriverFactory; + +impl HmacDriverFactory { + pub fn init_driver(&mut self) -> TockResult<HmacDriver> { + let hmac = HmacDriver { + lifetime: PhantomData, + }; + Ok(hmac) + } +} + +struct HmacEventConsumer; + +impl<CB: FnMut(usize, usize)> Consumer<CB> for HmacEventConsumer { + fn consume(callback: &mut CB, result: usize, digest: usize, _: usize) { + callback(result, digest); + } +} + +pub struct HmacKeyBuffer { + buffer: [u8; KEY_BUFFER_SIZE], +} + +impl Default for HmacKeyBuffer { + fn default() -> Self { + HmacKeyBuffer { + buffer: [0; KEY_BUFFER_SIZE], + } + } +} + +pub struct HmacDataBuffer { + pub buffer: [u8; DATA_BUFFER_SIZE], +} + +impl Default for HmacDataBuffer { + fn default() -> Self { + HmacDataBuffer { + buffer: [0; DATA_BUFFER_SIZE], + } + } +} + +pub struct HmacDestBuffer { + buffer: [u8; DEST_BUFFER_SIZE], +} + +impl Default for HmacDestBuffer { + fn default() -> Self { + HmacDestBuffer { + buffer: [0; DEST_BUFFER_SIZE], + } + } +} + +pub struct HmacDriver<'a> { + lifetime: PhantomData<&'a ()>, +} + +impl<'a> HmacDriver<'a> { + pub fn init_key_buffer(&self, buffer: &'a mut HmacKeyBuffer) -> TockResult<SharedMemory> { + syscalls::allow(DRIVER_NUMBER, allow_nr::KEY, &mut buffer.buffer).map_err(Into::into) + } + + pub fn init_data_buffer(&self, buffer: &'a mut HmacDataBuffer) -> TockResult<SharedMemory> { + syscalls::allow(DRIVER_NUMBER, allow_nr::DATA, &mut buffer.buffer).map_err(Into::into) + } + + pub fn init_dest_buffer(&self, buffer: &'a mut HmacDestBuffer) -> TockResult<SharedMemory> { + syscalls::allow(DRIVER_NUMBER, allow_nr::DEST, &mut buffer.buffer).map_err(Into::into) + } + + pub fn subscribe<CB: FnMut(usize, usize) -> () + FnMut(usize, usize)>( + &self, + callback: &'a mut CB, + ) -> TockResult<CallbackSubscription> { + syscalls::subscribe::<HmacEventConsumer, _>( + DRIVER_NUMBER, + subscribe_nr::SUBSCRIBE_CALLBACK, + callback, + ) + .map_err(Into::into) + } + + pub fn set_algorithm(&self, hash: usize) -> TockResult<()> { + syscalls::command(DRIVER_NUMBER, command_nr::SET_ALGORITHM, hash, 0)?; + Ok(()) + } + + pub fn run(&self) -> TockResult<()> { + syscalls::command(DRIVER_NUMBER, command_nr::RUN, 0, 0)?; + Ok(()) + } +}
diff --git a/src/lib.rs b/src/lib.rs index 152e223..eb13b94 100644 --- a/src/lib.rs +++ b/src/lib.rs
@@ -11,6 +11,7 @@ pub mod executor; pub mod futures; pub mod gpio; +pub mod hmac; pub mod leds; pub mod result; pub mod rng;