Add example and fix some bugs

Cargo.toml

@@ -15,6 +15,7 @@ members = [
   "examples/spi-demo",
   "examples/twi-ssd1306",
   "examples/ecb-demo",
+  "examples/ccm-demo",
 ]
 
 [profile.dev]

examples/ccm-demo/Cargo.toml

@@ -0,0 +1,29 @@
+[package]
+name = "ccm-demo"
+version = "0.0.1"
+edition = "2018"
+authors = [ "Thales Fragoso <[email protected]>"]
+
+[dependencies]
+cortex-m = "0.6.2"
+cortex-m-rt = "0.6.12"
+rtt-target = {version = "0.2.0", features = ["cortex-m"] }
+rand_core = "0.5.1"
+
+nrf52810-hal = { path = "../../nrf52810-hal", features = ["rt"], optional = true }
+nrf52832-hal = { path = "../../nrf52832-hal", features = ["rt"], optional = true }
+nrf52840-hal = { path = "../../nrf52840-hal", features = ["rt"], optional = true }
+nrf52833-hal = { path = "../../nrf52833-hal", features = ["rt"], optional = true }
+nrf51-hal = { path = "../../nrf51-hal", features = ["rt"], optional = true}
+
+[[bin]]
+name = "ccm-demo"
+doc = false
+test = false
+
+[features]
+51 = ["nrf51-hal"]
+52810 = ["nrf52810-hal"]
+52832 = ["nrf52832-hal"]
+52840 = ["nrf52840-hal"]
+52833 = ["nrf52833-hal"]

examples/ccm-demo/Embed.toml

@@ -0,0 +1,46 @@
+[probe]
+# The index of the probe in the connected probe list.
+# probe_index = 0
+# The protocol to be used for communicating with the target.
+protocol = "Swd"
+# The speed in kHz of the data link to the target.
+# speed = 1337
+
+[flashing]
+# Whether or not the target should be flashed.
+enabled = true
+# Whether or not the target should be halted after flashing.
+halt_afterwards = false
+# Whether or not bytes erased but not rewritten with data from the ELF
+# should be restored with their contents before erasing.
+restore_unwritten_bytes = false
+# The path where an SVG of the assembled flash layout should be written to.
+# flash_layout_output_path = "out.svg"
+
+[general]
+# The chip name of the chip to be debugged.
+chip = "nRF52832"
+# A list of chip descriptions to be loaded during runtime.
+chip_descriptions = []
+# The default log level to be used.
+log_level = "Warn"
+
+[rtt]
+# Whether or not an RTTUI should be opened after flashing.
+# This is exclusive and cannot be used with GDB at the moment.
+enabled = true
+# A list of channel associations to be displayed. If left empty, all channels are displayed.
+channels = [
+    # { up = 0, down = 0, name = "name" }
+]
+# The duration in ms for which the logger should retry to attach to RTT.
+timeout = 3000
+# Whether timestamps in the RTTUI are enabled
+show_timestamps = true
+
+[gdb]
+# Whether or not a GDB server should be opened after flashing.
+# This is exclusive and cannot be used with RTT at the moment.
+enabled = false
+# The connection string in host:port format wher the GDB server will open a socket.
+# gdb_connection_string

examples/ccm-demo/README.md

@@ -0,0 +1,19 @@
+# AES-CCM demo
+
+Choose the microcontroller with one of the following features:
+- 51
+- 52810
+- 52832
+- 52840
+
+Also, if using `cargo-embed`, change the `chip` and `protocol` fields in [Embed.toml](Embed.toml).
+
+This demo uses the [rtt-target](https://crates.io/crates/rtt-target) crate for communication.
+
+If using `cargo-embed`, just run
+
+```console
+$ cargo embed --release --features=52832 --target=thumbv7em-none-eabihf
+```
+
+Replace `52832` and `thumbv7em-none-eabihf` with the correct feature and target for your microcontroller.

examples/ccm-demo/src/main.rs

@@ -0,0 +1,146 @@
+#![no_std]
+#![no_main]
+
+// Import the right HAL/PAC crate, depending on the target chip
+#[cfg(feature = "51")]
+pub use nrf51_hal as hal;
+#[cfg(feature = "52810")]
+pub use nrf52810_hal as hal;
+#[cfg(feature = "52832")]
+pub use nrf52832_hal as hal;
+#[cfg(feature = "52833")]
+pub use nrf52833_hal as hal;
+#[cfg(feature = "52840")]
+pub use nrf52840_hal as hal;
+
+use {
+    core::{
+        panic::PanicInfo,
+        sync::atomic::{compiler_fence, Ordering},
+    },
+    cortex_m_rt::entry,
+    hal::{
+        ccm::{CcmData, DataRate},
+        rng::Rng,
+        Ccm, Clocks,
+    },
+    rand_core::RngCore,
+    rtt_target::{rprintln, rtt_init_print},
+};
+
+mod stopwatch;
+use stopwatch::StopWatch;
+
+const MSG: [u8; 251] = *b"Lorem ipsum dolor sit amet, consectetur adipiscing elit. Duis justo
+libero, commodo eget tincidunt quis, elementum at ipsum. Praesent pharetra imperdiet eros, at
+vestibulum diam mattis ac. Nunc viverra cursus justo, sollicitudin placerat justo lectus.";
+
+const KEY: [u8; 16] = *b"aaaaaaaaaaaaaaaa";
+const HEADER_SIZE: usize = 3;
+const MIC_SIZE: usize = 4;
+const LENGTH_INDEX: usize = 1;
+
+#[entry]
+fn main() -> ! {
+    let p = hal::pac::Peripherals::take().unwrap();
+
+    let _clocks = Clocks::new(p.CLOCK).enable_ext_hfosc();
+    rtt_init_print!();
+
+    let mut rng = Rng::new(p.RNG);
+    let mut iv = [0u8; 8];
+    rng.fill_bytes(&mut iv);
+
+    let mut ccm_data_enc = CcmData::new(KEY, iv);
+    let mut ccm_data_dec = CcmData::new(KEY, iv);
+    let mut ccm = Ccm::init(p.CCM, p.AAR, DataRate::_1Mbit);
+
+    let mut clear_buffer = [0u8; 254];
+    let mut cipher_buffer = [0u8; 258];
+    let mut strach_area = [0u8; 271];
+
+    (&mut clear_buffer[HEADER_SIZE..]).copy_from_slice(&MSG[..]);
+
+    let mut stop_watch = StopWatch::new(p.TIMER0);
+
+    let payload_lengths: [usize; 5] = [251, 128, 64, 32, 16];
+
+    for &length in payload_lengths.iter() {
+        // Adjust payload length
+        clear_buffer[LENGTH_INDEX] = length as u8;
+
+        rprintln!("Starting Encryption of {} bytes", length);
+        stop_watch.start();
+
+        ccm.encrypt_packet(
+            &mut ccm_data_enc,
+            &clear_buffer[..],
+            &mut cipher_buffer[..],
+            &mut strach_area[..],
+        )
+        .unwrap();
+
+        let now = stop_watch.now();
+        stop_watch.stop();
+
+        assert_eq!(cipher_buffer[LENGTH_INDEX], (length + MIC_SIZE) as u8);
+
+        rprintln!("Encryption Took: {} us", now);
+
+        //rprint!("Cipher Packet: ");
+        //for number in cipher_buffer.iter().take(length + MIC_SIZE + HEADER_SIZE) {
+        //    rprint!("{:x} ", *number);
+        //}
+
+        // Since we're both encrypting and decrypting, we need to decrement the counter to have the
+        // same counter that encrypted the message. `encrypt_packet` and `decrypt_packet`
+        // automatically increments the counter when the operation succeeds.
+        //ccm_data.decrement_counter();
+
+        // Clears the buffer, so we can inspect the decrypted text
+        clear_buffer = [0u8; 254];
+
+        rprintln!("\r\nStarting Decryption of {} bytes", length + MIC_SIZE);
+        stop_watch.start();
+
+        ccm.decrypt_packet(
+            &mut ccm_data_dec,
+            &mut clear_buffer[..],
+            &cipher_buffer[..],
+            &mut strach_area[..],
+        )
+        .unwrap();
+
+        let now = stop_watch.now();
+        stop_watch.stop();
+
+        rprintln!("Decryption Took: {} us\n\n", now);
+
+        assert_eq!(clear_buffer[LENGTH_INDEX], length as u8);
+        assert_eq!(
+            &clear_buffer[HEADER_SIZE..length + HEADER_SIZE],
+            &MSG[..length]
+        );
+
+        //let msg = core::str::from_utf8(&clear_buffer[HEADER_SIZE..length]).unwrap();
+        //rprintln!("Clear text: {}\n", msg);
+
+        // Clears the cipher text for next round
+        cipher_buffer = [0u8; 258];
+    }
+
+    rprintln!("Done");
+
+    loop {
+        compiler_fence(Ordering::SeqCst);
+    }
+}
+
+#[inline(never)]
+#[panic_handler]
+fn panic(info: &PanicInfo) -> ! {
+    rprintln!("{}", info);
+    loop {
+        compiler_fence(Ordering::SeqCst);
+    }
+}

examples/ccm-demo/src/stopwatch.rs

@@ -0,0 +1,50 @@
+use super::hal::pac::TIMER0;
+
+pub struct StopWatch {
+    regs: TIMER0,
+}
+
+impl StopWatch {
+    pub fn new(regs: TIMER0) -> Self {
+        // NOTE(unsafe) 1 is a valid pattern to write to this register
+        regs.tasks_stop.write(|w| unsafe { w.bits(1) });
+
+        regs.bitmode.write(|w| w.bitmode()._32bit());
+
+        // 16 Mhz / 2**4 = 1 Mhz = µs resolution
+        // NOTE(unsafe) 4 is a valid pattern to write to this register
+        regs.prescaler.write(|w| unsafe { w.prescaler().bits(4) });
+        // NOTE(unsafe) 1 is a valid pattern to write to this register
+        regs.tasks_clear.write(|w| unsafe { w.bits(1) });
+
+        Self { regs }
+    }
+
+    #[inline(always)]
+    pub fn start(&mut self) {
+        // NOTE(unsafe) 1 is a valid pattern to write to this register
+        self.regs.tasks_start.write(|w| unsafe { w.bits(1) });
+    }
+
+    #[inline(always)]
+    pub fn now(&self) -> u32 {
+        // NOTE(unsafe) 1 is a valid pattern to write to this register
+        self.regs.tasks_capture[0].write(|w| unsafe { w.bits(1) });
+        self.regs.cc[0].read().bits()
+    }
+
+    //#[inline(always)]
+    //pub fn pause(&mut self) {
+    //    // NOTE(unsafe) 1 is a valid pattern to write to this register
+    //    self.regs.tasks_stop.write(|w| unsafe { w.bits(1) });
+    //}
+
+    #[inline(always)]
+    pub fn stop(&mut self) {
+        // NOTE(unsafe) 1 is a valid pattern to write to this register
+        self.regs.tasks_stop.write(|w| unsafe { w.bits(1) });
+
+        // NOTE(unsafe) 1 is a valid pattern to write to this register
+        self.regs.tasks_clear.write(|w| unsafe { w.bits(1) });
+    }
+}

nrf-hal-common/src/ccm.rs

@@ -101,6 +101,7 @@ pub enum CcmError {
 ///
 /// The NONCE vector (as specified by the Bluetooth Core Specification) will be generated by
 /// hardware based on this information.
+#[derive(Debug, PartialEq)]
 #[repr(C)]
 pub struct CcmData {
     key: [u8; 16],
@@ -188,7 +189,8 @@ impl Ccm {
     ///
     /// The generated MIC will be appended to after the payload in the `cipher_packet`. The slices
     /// passed to this method must have the correct size, for more information refer to the module
-    /// level documentation.
+    /// level documentation. The counter in `ccm_data` will be incremented if the operation
+    /// succeeds.
     pub fn encrypt_packet(
         &mut self,
         ccm_data: &mut CcmData,
@@ -223,7 +225,7 @@ impl Ccm {
             return Err(CcmError::InsufficientScratchArea);
         }
 
-        let length_variant = if payload_len > MAXIMUM_LENGTH_5BITS {
+        let length_variant = if payload_len <= MAXIMUM_LENGTH_5BITS {
             LENGTH_A::DEFAULT
         } else {
             #[cfg(any(feature = "52840", feature = "52833"))]
@@ -260,6 +262,7 @@ impl Ccm {
         // Clear events
         self.regs.events_endcrypt.reset();
         self.regs.events_error.reset();
+        self.regs.events_endksgen.reset();
 
         // "Preceding reads and writes cannot be moved past subsequent writes."
         compiler_fence(Ordering::Release);
@@ -289,7 +292,7 @@ impl Ccm {
     ///
     /// This method will return an error if the MIC verification fails. The slices passed to this
     /// method must have the correct size, for more information refer to the module level
-    /// documentation.
+    /// documentation. The counter in `ccm_data` will be incremented if the operation succeeds.
     pub fn decrypt_packet(
         &mut self,
         ccm_data: &mut CcmData,
@@ -329,7 +332,7 @@ impl Ccm {
             return Err(CcmError::InsufficientScratchArea);
         }
 
-        let length_variant = if payload_len > MAXIMUM_LENGTH_5BITS {
+        let length_variant = if payload_len <= MAXIMUM_LENGTH_5BITS {
             LENGTH_A::DEFAULT
         } else {
             #[cfg(any(feature = "52840", feature = "52833"))]
@@ -366,11 +369,12 @@ impl Ccm {
         // Clear events
         self.regs.events_endcrypt.reset();
         self.regs.events_error.reset();
+        self.regs.events_endksgen.reset();
 
         // "Preceding reads and writes cannot be moved past subsequent writes."
         compiler_fence(Ordering::Release);
 
-        // Start key generation, encryption will start automatically because of the enabled short
+        // Start key generation, decryption will start automatically because of the enabled short
         // in init
         // NOTE(unsafe) 1 is a valid pattern to write to this register
         self.regs.tasks_ksgen.write(|w| unsafe { w.bits(1) });

nrf51-hal/src/lib.rs

@@ -10,6 +10,7 @@ pub mod prelude {
 }
 
 pub use crate::adc::Adc;
+pub use crate::ccm::Ccm;
 pub use crate::clocks::Clocks;
 pub use crate::ecb::Ecb;
 pub use crate::rtc::Rtc;

nrf52810-hal/src/lib.rs

@@ -11,6 +11,7 @@ pub mod prelude {
     pub use crate::time::U32Ext;
 }
 
+pub use crate::ccm::Ccm;
 pub use crate::clocks::Clocks;
 pub use crate::delay::Delay;
 pub use crate::ecb::Ecb;

nrf52832-hal/src/lib.rs

@@ -9,6 +9,7 @@ pub mod prelude {
     pub use nrf_hal_common::prelude::*;
 }
 
+pub use crate::ccm::Ccm;
 pub use crate::clocks::Clocks;
 pub use crate::delay::Delay;
 pub use crate::ecb::Ecb;