Change to jonas API

Author: thalesfragoso

examples/ecb-demo/README.md

@@ -13,7 +13,7 @@ This demo uses the [rtt-target](https://crates.io/crates/rtt-target) crate for c
 If using `cargo-embed`, just run
 
 ```console
-$ cargo embed --release --features=52832
+$ cargo embed --release --features=52832 --target=thumbv7em-none-eabihf
 ```
 
-Replace `52832` with the correct feature for your microcontroller.
+Replace `52832` and `thumbv7em-none-eabihf` with the correct feature and target for your microcontroller.

examples/ecb-demo/src/main.rs

@@ -17,12 +17,12 @@ use {
         sync::atomic::{compiler_fence, Ordering},
     },
     cortex_m_rt::entry,
-    hal::{ecb::EcbData, Clocks, Ecb},
+    hal::{Clocks, Ecb},
     rtt_target::{rprint, rprintln, rtt_init_print},
 };
 
-const MSG: &[u8; 16] = b"Message to encry";
-const KEY: &[u8; 16] = b"aaaaaaaaaaaaaaaa";
+const MSG: [u8; 16] = *b"Message to encry";
+const KEY: [u8; 16] = *b"aaaaaaaaaaaaaaaa";
 const CIPHER_MSG: [u8; 16] = [
     0xFE, 0xF1, 0x63, 0x82, 0xB4, 0x54, 0x6B, 0xE4, 0xEB, 0x9A, 0x5C, 0x0E, 0xB6, 0x0E, 0x49, 0x2F,
 ];
@@ -34,26 +34,21 @@ fn main() -> ! {
     let _clocks = Clocks::new(p.CLOCK).enable_ext_hfosc();
     rtt_init_print!();
 
-    let data = EcbData::new(*KEY, None);
-    let mut ecb = Ecb::init(p.ECB, data);
-
-    let clear_text = ecb.clear_text();
-    *clear_text = *MSG;
-    rprintln!(
-        "Clear text: {}",
-        core::str::from_utf8(&clear_text[..]).unwrap(),
-    );
+    let mut ecb = Ecb::init(p.ECB);
 
     loop {
-        ecb.encrypt().unwrap();
-        let chiper_text = ecb.cipher_text();
-        for number in chiper_text.iter() {
+        rprintln!("Starting Encryption\n");
+        rprintln!("Clear text: {}", core::str::from_utf8(&MSG[..]).unwrap());
+
+        let cipher_text = ecb.crypt_block(MSG, KEY).unwrap();
+        rprint!("Cipher Text: ");
+        for number in cipher_text.iter() {
             rprint!("{:x} ", *number);
         }
-        assert_eq!(*chiper_text, CIPHER_MSG);
-        rprintln!("\n Encryption Done\n");
+        assert_eq!(cipher_text, CIPHER_MSG);
+        rprintln!("\r\n Encryption Done\n");
 
-        cortex_m::asm::delay(68_000_000);
+        cortex_m::asm::delay(136_000_000);
     }
 }
 

nrf-hal-common/src/ecb.rs

@@ -5,76 +5,73 @@
 use crate::target::ECB;
 use core::sync::atomic::{compiler_fence, Ordering};
 
-#[derive(Debug, Copy, Clone)]
 /// Error type to represent a sharing conflict during encryption
+#[derive(Debug, Copy, Clone)]
 pub struct EncryptionError {}
 
-#[repr(C)]
-/// Type that represents the data structure used by the ECB module
-pub struct EcbData {
-    key: [u8; 16],
-    clear_text: [u8; 16],
-    chiper_text: [u8; 16],
-}
-
-impl EcbData {
-    /// Creates the data structures needed for ECB utilization
-    ///
-    /// If `clear_text` is `None` it will be initialized to zero
-    pub fn new(key: [u8; 16], clear_text: Option<[u8; 16]>) -> Self {
-        Self {
-            key,
-            clear_text: clear_text.unwrap_or_default(),
-            chiper_text: [0; 16],
-        }
-    }
-}
-
-/// HAL structure interface to use the capabilities of the ECB peripheral
+/// A safe, blocking wrapper around the AES-ECB peripheral.
+///
+/// It's really just blockwise AES and not an ECB stream cipher. Blocks can be
+/// encrypted by calling `crypt_block`.
 pub struct Ecb {
     regs: ECB,
-    data: EcbData,
 }
 
 impl Ecb {
-    /// Method for initialization
-    pub fn init(regs: ECB, data: EcbData) -> Self {
+    /// Takes ownership of the `ECB` peripheral, returning a safe wrapper.
+    pub fn init(regs: ECB) -> Self {
         // Disable all interrupts
         regs.intenclr
             .write(|w| w.endecb().clear().errorecb().clear());
 
         // NOTE(unsafe) 1 is a valid pattern to write to this register
         regs.tasks_stopecb.write(|w| unsafe { w.bits(1) });
-        Self { regs, data }
+        Self { regs }
     }
 
-    /// Gets a reference to the clear text memory
-    ///
-    /// This is the data that will be encrypted by the encrypt method
-    #[inline]
-    pub fn clear_text(&mut self) -> &mut [u8; 16] {
-        &mut self.data.clear_text
-    }
+    /// Destroys `self`, giving the `ECB` peripheral back.
+    pub fn into_inner(self) -> ECB {
+        // Clear all events
+        self.regs.events_endecb.reset();
+        self.regs.events_errorecb.reset();
 
-    /// Get a reference to the cipher text memory
-    ///
-    /// This will contain the encrypted data after a successful encryption
-    #[inline]
-    pub fn cipher_text(&mut self) -> &mut [u8; 16] {
-        &mut self.data.chiper_text
+        self.regs
     }
 
-    /// Encrypts the data in the `clear_text` field, the encrypted data will be located in the
-    /// cipher text field only if this method returns `Ok`
+    /// Blocking encryption.
     ///
-    /// In case of an error, this method will return `Err(EncryptionError)`, in this case, the data
-    /// in `cipher_text` is not valid
-    pub fn encrypt(&mut self) -> Result<(), EncryptionError> {
-        // Ecb data is repr(C) and has no padding
-        let data_ptr = &mut self.data as *mut _ as u32;
+    /// Encrypts a `block` with `key`.
+    ///
+    /// # Errors
+    ///
+    /// An error will be returned when the AES hardware raises an `ERRORECB`
+    /// event. This can happen when an operation is started that shares the AES
+    /// hardware resources with the AES ECB peripheral while an encryption
+    /// operation is running.
+    pub fn crypt_block(
+        &mut self,
+        block: [u8; 16],
+        key: [u8; 16],
+    ) -> Result<[u8; 16], EncryptionError> {
+        #[repr(C)]
+        struct EcbData {
+            key: [u8; 16],
+            clear_text: [u8; 16],
+            cipher_text: [u8; 16],
+        }
+
+        // We allocate the DMA'd buffer on the stack, which means that we must
+        // not panic or return before the AES operation is finished.
+        let mut buf = EcbData {
+            key,
+            clear_text: block,
+            cipher_text: [0; 16],
+        };
 
         // NOTE(unsafe) Any 32bits pattern is safe to write to this register
-        self.regs.ecbdataptr.write(|w| unsafe { w.bits(data_ptr) });
+        self.regs
+            .ecbdataptr
+            .write(|w| unsafe { w.bits(&mut buf as *mut _ as u32) });
 
         // Clear all events
         self.regs.events_endecb.reset();
@@ -96,6 +93,6 @@ impl Ecb {
             // It's ok to return here, the events will be cleared before the next encryption
             return Err(EncryptionError {});
         }
-        Ok(())
+        Ok(buf.cipher_text)
     }
 }