From 9374ebe5299fb3bcd1cc86cf6f7c598976885454 Mon Sep 17 00:00:00 2001 From: Mahavir Jain Date: Mon, 30 Jan 2023 09:40:50 +0530 Subject: [PATCH] esp32h2: add support for AES peripheral Closes IDF-6280 --- components/hal/esp32h2/include/hal/aes_ll.h | 225 ++++++++++++++++++++ 1 file changed, 225 insertions(+) create mode 100644 components/hal/esp32h2/include/hal/aes_ll.h diff --git a/components/hal/esp32h2/include/hal/aes_ll.h b/components/hal/esp32h2/include/hal/aes_ll.h new file mode 100644 index 0000000000..792205edc0 --- /dev/null +++ b/components/hal/esp32h2/include/hal/aes_ll.h @@ -0,0 +1,225 @@ +/* + * SPDX-FileCopyrightText: 2023 Espressif Systems (Shanghai) CO LTD + * + * SPDX-License-Identifier: Apache-2.0 + */ + +#pragma once + +#include +#include +#include "soc/hwcrypto_reg.h" +#include "hal/aes_types.h" + +#ifdef __cplusplus +extern "C" { +#endif + +/** + * @brief State of AES accelerator, busy, idle or done + * + */ +typedef enum { + ESP_AES_STATE_IDLE = 0, /* AES accelerator is idle */ + ESP_AES_STATE_BUSY, /* Transform in progress */ + ESP_AES_STATE_DONE, /* Transform completed */ +} esp_aes_state_t; + + +/** + * @brief Write the encryption/decryption key to hardware + * + * @param key Key to be written to the AES hardware + * @param key_word_len Number of words in the key + * + * @return Number of bytes written to hardware, used for fault injection check + */ +static inline uint8_t aes_ll_write_key(const uint8_t *key, size_t key_word_len) +{ + /* This variable is used for fault injection checks, so marked volatile to avoid optimisation */ + volatile uint8_t key_in_hardware = 0; + /* Memcpy to avoid potential unaligned access */ + uint32_t key_word; + for (int i = 0; i < key_word_len; i++) { + memcpy(&key_word, key + 4 * i, 4); + REG_WRITE(AES_KEY_0_REG + i * 4, key_word); + key_in_hardware += 4; + } + return key_in_hardware; +} + +/** + * @brief Sets the mode + * + * @param mode ESP_AES_ENCRYPT = 1, or ESP_AES_DECRYPT = 0 + * @param key_bytes Number of bytes in the key + */ +static inline void aes_ll_set_mode(int mode, uint8_t key_bytes) +{ + const uint32_t MODE_DECRYPT_BIT = 4; + unsigned mode_reg_base = (mode == ESP_AES_ENCRYPT) ? 0 : MODE_DECRYPT_BIT; + + /* See TRM for the mapping between keylength and mode bit */ + REG_WRITE(AES_MODE_REG, mode_reg_base + ((key_bytes / 8) - 2)); +} + +/** + * @brief Writes message block to AES hardware + * + * @param input Block to be written + */ +static inline void aes_ll_write_block(const void *input) +{ + uint32_t input_word; + + for (int i = 0; i < AES_BLOCK_WORDS; i++) { + memcpy(&input_word, (uint8_t*)input + 4 * i, 4); + REG_WRITE(AES_TEXT_IN_0_REG + i * 4, input_word); + } +} + +/** + * @brief Read the AES block + * + * @param output the output of the transform, length = AES_BLOCK_BYTES + */ +static inline void aes_ll_read_block(void *output) +{ + uint32_t output_word; + const size_t REG_WIDTH = sizeof(uint32_t); + + for (size_t i = 0; i < AES_BLOCK_WORDS; i++) { + output_word = REG_READ(AES_TEXT_OUT_0_REG + (i * REG_WIDTH)); + /* Memcpy to avoid potential unaligned access */ + memcpy( (uint8_t*)output + i * 4, &output_word, sizeof(output_word)); + } +} + +/** + * @brief Starts block transform + * + */ +static inline void aes_ll_start_transform(void) +{ + REG_WRITE(AES_TRIGGER_REG, 1); +} + + +/** + * @brief Read state of AES accelerator + * + * @return esp_aes_state_t + */ +static inline esp_aes_state_t aes_ll_get_state(void) +{ + return REG_READ(AES_STATE_REG); +} + + +/** + * @brief Set mode of operation + * + * @note Only used for DMA transforms + * + * @param mode + */ +static inline void aes_ll_set_block_mode(esp_aes_mode_t mode) +{ + REG_WRITE(AES_BLOCK_MODE_REG, mode); +} + +/** + * @brief Set AES-CTR counter to INC32 + * + * @note Only affects AES-CTR mode + * + */ +static inline void aes_ll_set_inc(void) +{ + REG_WRITE(AES_INC_SEL_REG, 0); +} + +/** + * @brief Release the DMA + * + */ +static inline void aes_ll_dma_exit(void) +{ + REG_WRITE(AES_DMA_EXIT_REG, 0); +} + +/** + * @brief Sets the number of blocks to be transformed + * + * @note Only used for DMA transforms + * + * @param num_blocks Number of blocks to transform + */ +static inline void aes_ll_set_num_blocks(size_t num_blocks) +{ + REG_WRITE(AES_BLOCK_NUM_REG, num_blocks); +} + +/* + * Write IV to hardware iv registers + */ +static inline void aes_ll_set_iv(const uint8_t *iv) +{ + uint32_t *reg_addr_buf = (uint32_t *)(AES_IV_MEM); + uint32_t iv_word; + + for (int i = 0; i < IV_WORDS; i++ ) { + /* Memcpy to avoid potential unaligned access */ + memcpy(&iv_word, iv + 4 * i, sizeof(iv_word)); + REG_WRITE(®_addr_buf[i], iv_word); + } +} + +/* + * Read IV from hardware iv registers + */ +static inline void aes_ll_read_iv(uint8_t *iv) +{ + uint32_t iv_word; + const size_t REG_WIDTH = sizeof(uint32_t); + + for (size_t i = 0; i < IV_WORDS; i++) { + iv_word = REG_READ(AES_IV_MEM + (i * REG_WIDTH)); + /* Memcpy to avoid potential unaligned access */ + memcpy(iv + i * 4, &iv_word, sizeof(iv_word)); + } +} + +/** + * @brief Enable or disable DMA mode + * + * @param enable true to enable, false to disable. + */ +static inline void aes_ll_dma_enable(bool enable) +{ + REG_WRITE(AES_DMA_ENABLE_REG, enable); +} + +/** + * @brief Enable or disable transform completed interrupt + * + * @param enable true to enable, false to disable. + */ +static inline void aes_ll_interrupt_enable(bool enable) +{ + REG_WRITE(AES_INT_ENA_REG, enable); +} + +/** + * @brief Clears the interrupt + * + */ +static inline void aes_ll_interrupt_clear(void) +{ + REG_WRITE(AES_INT_CLEAR_REG, 1); +} + + +#ifdef __cplusplus +} +#endif