AES accelerator implementation

esp-hal-common/build.rs

@@ -42,6 +42,7 @@ fn main() {
     //   - 'uart2'
     //   - 'usb_otg'
     //   - 'usb_serial_jtag'
+    //   - 'aes'
     //
     // New symbols can be added as needed, but please be sure to update both this
     // comment and the required vectors below.
@@ -60,6 +61,7 @@ fn main() {
             "timg0",
             "timg1",
             "uart2",
+            "aes",
         ]
     } else if esp32c2 {
         vec![
@@ -83,6 +85,7 @@ fn main() {
             "timg0",
             "timg1",
             "usb_serial_jtag",
+            "aes",
         ]
     } else if esp32s2 {
         vec![
@@ -99,6 +102,7 @@ fn main() {
             "timg0",
             "timg1",
             "usb_otg",
+            "aes",
         ]
     } else if esp32s3 {
         vec![
@@ -117,6 +121,7 @@ fn main() {
             "uart2",
             "usb_otg",
             "usb_serial_jtag",
+            "aes",
         ]
     } else {
         unreachable!(); // We've already confirmed exactly one chip was selected

esp-hal-common/src/aes/esp32.rs

@@ -0,0 +1,84 @@
+use crate::{
+    aes::{Aes, Aes128, Aes192, Aes256, AesFlavour, Endianness, ALIGN_SIZE},
+    system::{Peripheral as PeripheralEnable, PeripheralClockControl},
+};
+
+impl<'d> Aes<'d> {
+    pub(super) fn init(&mut self, peripheral_clock_control: &mut PeripheralClockControl) {
+        peripheral_clock_control.enable(PeripheralEnable::Aes);
+        self.write_endianness(
+            Endianness::BigEndian,
+            Endianness::BigEndian,
+            Endianness::BigEndian,
+            Endianness::BigEndian,
+            Endianness::BigEndian,
+            Endianness::BigEndian,
+        );
+    }
+
+    pub(super) fn write_key(&mut self, key: &[u8]) {
+        debug_assert!(key.len() <= self.aes.key_.len() * ALIGN_SIZE);
+        debug_assert_eq!(key.len() % ALIGN_SIZE, 0);
+        Self::write_to_regset(key, self.aes.key_.len(), &mut self.aes.key_[0]);
+    }
+
+    pub(super) fn write_block(&mut self, block: &[u8]) {
+        debug_assert_eq!(block.len(), self.aes.text_.len() * ALIGN_SIZE);
+        Self::write_to_regset(block, self.aes.text_.len(), &mut self.aes.text_[0]);
+    }
+
+    pub(super) fn write_mode(&mut self, mode: u32) {
+        Self::write_to_register(&mut self.aes.mode, mode);
+    }
+
+    /// Configures how the state matrix would be laid out
+    pub fn write_endianness(
+        &mut self,
+        input_text_word_endianess: Endianness,
+        input_text_byte_endianess: Endianness,
+        output_text_word_endianess: Endianness,
+        output_text_byte_endianess: Endianness,
+        key_word_endianess: Endianness,
+        key_byte_endianess: Endianness,
+    ) {
+        let mut to_write = 0_u32;
+        to_write |= key_byte_endianess as u32;
+        to_write |= (key_word_endianess as u32) << 1;
+        to_write |= (input_text_byte_endianess as u32) << 2;
+        to_write |= (input_text_word_endianess as u32) << 3;
+        to_write |= (output_text_byte_endianess as u32) << 4;
+        to_write |= (output_text_word_endianess as u32) << 5;
+        Self::write_to_register(&mut self.aes.endian, to_write);
+    }
+
+    pub(super) fn write_start(&mut self) {
+        self.aes.start.write(|w| w.start().set_bit())
+    }
+
+    pub(super) fn read_idle(&mut self) -> bool {
+        self.aes.idle.read().idle().bit_is_set()
+    }
+
+    pub(super) fn read_block(&self, block: &mut [u8]) {
+        debug_assert_eq!(block.len(), self.aes.text_.len() * ALIGN_SIZE);
+        Self::read_from_regset(block, self.aes.text_.len(), &self.aes.text_[0]);
+    }
+}
+
+impl AesFlavour for Aes128 {
+    type KeyType<'b> = &'b [u8; 16];
+    const ENCRYPT_MODE: u32 = 0;
+    const DECRYPT_MODE: u32 = 4;
+}
+
+impl AesFlavour for Aes192 {
+    type KeyType<'b> = &'b [u8; 24];
+    const ENCRYPT_MODE: u32 = 1;
+    const DECRYPT_MODE: u32 = 5;
+}
+
+impl AesFlavour for Aes256 {
+    type KeyType<'b> = &'b [u8; 32];
+    const ENCRYPT_MODE: u32 = 2;
+    const DECRYPT_MODE: u32 = 6;
+}

esp-hal-common/src/aes/esp32c3.rs

@@ -0,0 +1,58 @@
+use crate::{
+    aes::{Aes, Aes128, Aes256, AesFlavour, ALIGN_SIZE},
+    system::{Peripheral as PeripheralEnable, PeripheralClockControl},
+};
+
+impl<'d> Aes<'d> {
+    pub(super) fn init(&mut self, peripheral_clock_control: &mut PeripheralClockControl) {
+        peripheral_clock_control.enable(PeripheralEnable::Aes);
+        self.write_dma(false);
+    }
+
+    fn write_dma(&mut self, enable_dma: bool) {
+        match enable_dma {
+            true => self.aes.dma_enable.write(|w| w.dma_enable().set_bit()),
+            false => self.aes.dma_enable.write(|w| w.dma_enable().clear_bit()),
+        }
+    }
+
+    pub(super) fn write_key(&mut self, key: &[u8]) {
+        debug_assert!(key.len() <= 8 * ALIGN_SIZE);
+        debug_assert_eq!(key.len() % ALIGN_SIZE, 0);
+        Self::write_to_regset(key, 8, &mut self.aes.key_0);
+    }
+
+    pub(super) fn write_block(&mut self, block: &[u8]) {
+        debug_assert_eq!(block.len(), 4 * ALIGN_SIZE);
+        Self::write_to_regset(block, 4, &mut self.aes.text_in_0);
+    }
+
+    pub(super) fn write_mode(&mut self, mode: u32) {
+        Self::write_to_register(&mut self.aes.mode, mode);
+    }
+
+    pub(super) fn write_start(&mut self) {
+        self.aes.trigger.write(|w| w.trigger().set_bit())
+    }
+
+    pub(super) fn read_idle(&mut self) -> bool {
+        self.aes.state.read().state().bits() == 0
+    }
+
+    pub(super) fn read_block(&self, block: &mut [u8]) {
+        debug_assert_eq!(block.len(), 4 * ALIGN_SIZE);
+        Self::read_from_regset(block, 4, &self.aes.text_out_0);
+    }
+}
+
+impl AesFlavour for Aes128 {
+    type KeyType<'b> = &'b [u8; 16];
+    const ENCRYPT_MODE: u32 = 0;
+    const DECRYPT_MODE: u32 = 4;
+}
+
+impl AesFlavour for Aes256 {
+    type KeyType<'b> = &'b [u8; 32];
+    const ENCRYPT_MODE: u32 = 2;
+    const DECRYPT_MODE: u32 = 6;
+}

esp-hal-common/src/aes/esp32s2.rs

@@ -0,0 +1,92 @@
+use crate::{
+    aes::{Aes, Aes128, Aes192, Aes256, AesFlavour, Endianness, ALIGN_SIZE},
+    system::{Peripheral as PeripheralEnable, PeripheralClockControl},
+};
+
+impl<'d> Aes<'d> {
+    pub(super) fn init(&mut self, peripheral_clock_control: &mut PeripheralClockControl) {
+        peripheral_clock_control.enable(PeripheralEnable::Aes);
+        self.write_dma(false);
+        self.write_endianness(
+            Endianness::BigEndian,
+            Endianness::BigEndian,
+            Endianness::BigEndian,
+            Endianness::BigEndian,
+            Endianness::BigEndian,
+            Endianness::BigEndian,
+        );
+    }
+
+    fn write_dma(&mut self, enable_dma: bool) {
+        match enable_dma {
+            true => self.aes.dma_enable.write(|w| w.dma_enable().set_bit()),
+            false => self.aes.dma_enable.write(|w| w.dma_enable().clear_bit()),
+        }
+    }
+
+    pub(super) fn write_key(&mut self, key: &[u8]) {
+        debug_assert!(key.len() <= self.aes.key_.len() * ALIGN_SIZE);
+        debug_assert_eq!(key.len() % ALIGN_SIZE, 0);
+        Self::write_to_regset(key, self.aes.key_.len(), &mut self.aes.key_[0]);
+    }
+
+    pub(super) fn write_block(&mut self, block: &[u8]) {
+        debug_assert_eq!(block.len(), self.aes.text_in_.len() * ALIGN_SIZE);
+        Self::write_to_regset(block, self.aes.text_in_.len(), &mut self.aes.text_in_[0]);
+    }
+
+    pub(super) fn write_mode(&mut self, mode: u32) {
+        Self::write_to_register(&mut self.aes.mode, mode);
+    }
+
+    /// Configures how the state matrix would be laid out.
+    pub fn write_endianness(
+        &mut self,
+        input_text_word_endianess: Endianness,
+        input_text_byte_endianess: Endianness,
+        output_text_word_endianess: Endianness,
+        output_text_byte_endianess: Endianness,
+        key_word_endianess: Endianness,
+        key_byte_endianess: Endianness,
+    ) {
+        let mut to_write = 0_u32;
+        to_write |= key_byte_endianess as u32;
+        to_write |= (key_word_endianess as u32) << 1;
+        to_write |= (input_text_byte_endianess as u32) << 2;
+        to_write |= (input_text_word_endianess as u32) << 3;
+        to_write |= (output_text_byte_endianess as u32) << 4;
+        to_write |= (output_text_word_endianess as u32) << 5;
+        Self::write_to_register(&mut self.aes.endian, to_write);
+    }
+
+    pub(super) fn write_start(&mut self) {
+        self.aes.trigger.write(|w| w.trigger().set_bit())
+    }
+
+    pub(super) fn read_idle(&mut self) -> bool {
+        self.aes.state.read().state().bits() == 0
+    }
+
+    pub(super) fn read_block(&self, block: &mut [u8]) {
+        debug_assert_eq!(block.len(), self.aes.text_out_.len() * ALIGN_SIZE);
+        Self::read_from_regset(block, self.aes.text_out_.len(), &self.aes.text_out_[0]);
+    }
+}
+
+impl AesFlavour for Aes128 {
+    type KeyType<'b> = &'b [u8; 16];
+    const ENCRYPT_MODE: u32 = 0;
+    const DECRYPT_MODE: u32 = 4;
+}
+
+impl AesFlavour for Aes192 {
+    type KeyType<'b> = &'b [u8; 24];
+    const ENCRYPT_MODE: u32 = 1;
+    const DECRYPT_MODE: u32 = 5;
+}
+
+impl AesFlavour for Aes256 {
+    type KeyType<'b> = &'b [u8; 32];
+    const ENCRYPT_MODE: u32 = 2;
+    const DECRYPT_MODE: u32 = 6;
+}

esp-hal-common/src/aes/esp32s3.rs

@@ -0,0 +1,58 @@
+use crate::{
+    aes::{Aes, Aes128, Aes256, AesFlavour, ALIGN_SIZE},
+    system::{Peripheral as PeripheralEnable, PeripheralClockControl},
+};
+
+impl<'d> Aes<'d> {
+    pub(super) fn init(&mut self, peripheral_clock_control: &mut PeripheralClockControl) {
+        peripheral_clock_control.enable(PeripheralEnable::Aes);
+        self.write_dma(false);
+    }
+
+    fn write_dma(&mut self, enable_dma: bool) {
+        match enable_dma {
+            true => self.aes.dma_enable.write(|w| w.dma_enable().set_bit()),
+            false => self.aes.dma_enable.write(|w| w.dma_enable().clear_bit()),
+        }
+    }
+
+    pub(super) fn write_key(&mut self, key: &[u8]) {
+        debug_assert!(key.len() <= self.aes.key_.len() * ALIGN_SIZE);
+        debug_assert_eq!(key.len() % ALIGN_SIZE, 0);
+        Self::write_to_regset(key, self.aes.key_.len(), &mut self.aes.key_[0]);
+    }
+
+    pub(super) fn write_block(&mut self, block: &[u8]) {
+        debug_assert_eq!(block.len(), self.aes.text_in_.len() * ALIGN_SIZE);
+        Self::write_to_regset(block, self.aes.text_in_.len(), &mut self.aes.text_in_[0]);
+    }
+
+    pub(super) fn write_mode(&mut self, mode: u32) {
+        Self::write_to_register(&mut self.aes.mode, mode);
+    }
+
+    pub(super) fn write_start(&mut self) {
+        self.aes.trigger.write(|w| w.trigger().set_bit())
+    }
+
+    pub(super) fn read_idle(&mut self) -> bool {
+        self.aes.state.read().state().bits() == 0
+    }
+
+    pub(super) fn read_block(&self, block: &mut [u8]) {
+        debug_assert_eq!(block.len(), self.aes.text_out_.len() * ALIGN_SIZE);
+        Self::read_from_regset(block, self.aes.text_out_.len(), &self.aes.text_out_[0]);
+    }
+}
+
+impl AesFlavour for Aes128 {
+    type KeyType<'b> = &'b [u8; 16];
+    const ENCRYPT_MODE: u32 = 0;
+    const DECRYPT_MODE: u32 = 4;
+}
+
+impl AesFlavour for Aes256 {
+    type KeyType<'b> = &'b [u8; 32];
+    const ENCRYPT_MODE: u32 = 2;
+    const DECRYPT_MODE: u32 = 6;
+}