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- /**
- *
- * \file
- *
- * \brief SAM Advanced Encryption Standard driver.
- *
- * This file defines a useful set of functions for the AES on SAM devices.
- *
- * Copyright (c) 2014-2016 Atmel Corporation. All rights reserved.
- *
- * \asf_license_start
- *
- * \page License
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are met:
- *
- * 1. Redistributions of source code must retain the above copyright notice,
- * this list of conditions and the following disclaimer.
- *
- * 2. Redistributions in binary form must reproduce the above copyright notice,
- * this list of conditions and the following disclaimer in the documentation
- * and/or other materials provided with the distribution.
- *
- * 3. The name of Atmel may not be used to endorse or promote products derived
- * from this software without specific prior written permission.
- *
- * 4. This software may only be redistributed and used in connection with an
- * Atmel microcontroller product.
- *
- * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
- * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
- * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
- * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
- * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
- * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
- * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
- * POSSIBILITY OF SUCH DAMAGE.
- *
- * \asf_license_stop
- *
- */
- /*
- * Support and FAQ: visit <a href="http://www.atmel.com/design-support/">Atmel Support</a>
- */
- #include <aes.h>
- #include <system.h>
- /**
- * \brief Initializes an AES configuration structure to defaults.
- *
- * Initializes the specified AES configuration structure to a set of
- * known default values.
- *
- * \note This function should be called to initialize <b>all</b> new instances of
- * AES configuration structures before they are further modified by the user
- * application.
- *
- * The default configuration is as follows:
- * - Data encryption
- * - 128-bit AES key size
- * - 128-bit cipher feedback size
- * - Manual start mode
- * - Electronic Codebook (ECB) mode
- * - All countermeasures are enabled
- * - XRO key is disabled
- * - Key generation is disabled
- * - Last output data mode is disabled
- *
- * \param[out] config Pointer to an AES configuration structure
- */
- void aes_get_config_defaults(
- struct aes_config *const config)
- {
- /* Sanity check arguments */
- Assert(config);
- config->encrypt_mode = AES_ENCRYPTION;
- config->key_size = AES_KEY_SIZE_128;
- config->start_mode = AES_MANUAL_START;
- config->opmode= AES_ECB_MODE;
- config->cfb_size = AES_CFB_SIZE_128;
- config->ctype = AES_COUNTERMEASURE_TYPE_ALL;
- config->enable_xor_key = false;
- config->enable_key_gen = false;
- config->lod = false;
- }
- /**
- * \brief Initialize the AES module.
- *
- * \param[out] module Pointer to the software instance struct
- * \param[in] hw Module hardware register base address pointer
- * \param[in] config Pointer to an AES configuration structure
- */
- void aes_init(
- struct aes_module *const module,
- Aes *const hw,
- struct aes_config *const config)
- {
- /* Sanity check arguments */
- Assert(hw);
- Assert(config);
- Assert(module);
- /* Enable clock for AES */
- system_apb_clock_set_mask(SYSTEM_CLOCK_APB_APBC, MCLK_APBCMASK_AES);
- /* Perform a software reset */
- hw->CTRLA.reg = AES_CTRLA_SWRST;
- /* Initialize the AES with new configurations */
- aes_set_config(module,hw, config);
- }
- /**
- * \brief Enable the AES module.
- *
- * \param[in,out] module Pointer to the software instance struct
- */
- void aes_enable(struct aes_module *const module)
- {
- Assert(module);
- Assert(module->hw);
- module->hw->CTRLA.reg |= AES_CTRLA_ENABLE;
- }
- /**
- * \brief Disable the AES module.
- * \param[in] module Pointer to the software instance struct
- */
- void aes_disable(struct aes_module *const module)
- {
- Assert(module);
- Assert(module->hw);
- /* Disbale interrupt */
- module->hw->INTENCLR.reg = AES_INTENCLR_MASK;
- /* Clear interrupt flag */
- module->hw->INTFLAG.reg = AES_INTFLAG_MASK;
- module->hw->CTRLA.reg &= (~AES_CTRLA_ENABLE);
- }
- /**
- * \brief Configure the AES module.
- *
- * \param[out] module Pointer to the software instance struct
- * \param[in] hw Module hardware register base address pointer
- * \param[in] config Pointer to an AES configuration structure
- */
- void aes_set_config(
- struct aes_module *const module,
- Aes *const hw,
- struct aes_config *const config)
- {
- uint32_t ul_mode = 0;
- /* Validate arguments. */
- Assert(hw);
- Assert(config);
- Assert(module);
- module->opmode = config->opmode;
- module->hw = hw;
- module->key_size = config->key_size;
- module->cfb_size = config->cfb_size;
- ul_mode |= (config->encrypt_mode << AES_CTRLA_CIPHER_Pos)
- | (config->start_mode << AES_CTRLA_STARTMODE_Pos)
- | (config->key_size << AES_CTRLA_KEYSIZE_Pos)
- | (config->opmode << AES_CTRLA_AESMODE_Pos)
- | (config->cfb_size << AES_CTRLA_CFBS_Pos)
- | (AES_CTRLA_CTYPE(config->ctype))
- | (config->enable_xor_key << AES_CTRLA_XORKEY_Pos)
- | (config->enable_key_gen << AES_CTRLA_KEYGEN_Pos)
- | (config->lod << AES_CTRLA_LOD_Pos);
- if (hw->CTRLA.reg & AES_CTRLA_ENABLE) {
- aes_disable(module);
- hw->CTRLA.reg = ul_mode;
- aes_enable(module);
- } else {
- hw->CTRLA.reg = ul_mode;
- }
- }
- /**
- * \brief Write the 128/192/256-bit cryptographic key.
- *
- * \param[in] module Pointer to the software instance struct
- * \param[in] key Pointer to 4/6/8 contiguous 32-bit words
- *
- * \note The key size depends on the current AES configuration.
- */
- void aes_write_key(
- struct aes_module *const module,
- const uint32_t *key)
- {
- uint32_t i, key_length = 0;
- /* Validate arguments. */
- Assert(module);
- Assert(module->hw);
- Assert(key);
- switch (module->key_size) {
- case AES_KEY_SIZE_128:
- key_length = 4;
- break;
- case AES_KEY_SIZE_192:
- key_length = 6;
- break;
- case AES_KEY_SIZE_256:
- key_length = 8;
- break;
- default:
- break;
- }
- for (i = 0; i < key_length; i++) {
- module->hw->KEYWORD[i].reg = *key;
- key++;
- }
- }
- /**
- * \brief Write the initialization vector (for the CBC, CFB, OFB, CTR, and GCM
- * cipher modes).
- *
- * \param[in] module Pointer to the software instance struct
- * \param[in] vector Pointer to four contiguous 32-bit words
- */
- void aes_write_init_vector(
- struct aes_module *const module,
- const uint32_t *vector)
- {
- uint32_t i;
- /* Validate arguments. */
- Assert(module);
- Assert(module->hw);
- Assert(module->opmode != AES_ECB_MODE);
- for (i = 0; i < 4; i++) {
- module->hw->INTVECTV[i].reg = *vector;
- vector++;
- }
- }
- /**
- * \brief Write the input data (four consecutive 32-bit words).
- *
- * \param[in] module Pointer to the software instance struct
- * \param[in] input_data_buffer Pointer to an input data buffer
- */
- void aes_write_input_data(
- struct aes_module *const module,
- const uint32_t *input_data_buffer)
- {
- uint32_t i;
- /* Validate arguments. */
- Assert(module);
- Assert(module->hw);;
- Assert(input_data_buffer);
- module->hw->DATABUFPTR.reg = 0;
- if (module->opmode == AES_CFB_MODE
- && module->cfb_size == AES_CFB_SIZE_64){
- for (i = 0; i < 2; i++) {
- module->hw->INDATA.reg = *input_data_buffer;
- input_data_buffer++;
- }
- } else if (module->opmode == AES_CFB_MODE
- && (module->cfb_size == AES_CFB_SIZE_32 || module->cfb_size == AES_CFB_SIZE_16)){
- module->hw->INDATA.reg = *input_data_buffer;
- } else {
- for (i = 0; i < 4; i++) {
- module->hw->INDATA.reg = *input_data_buffer;
- input_data_buffer++;
- }
- }
- }
- /**
- * \brief Read the output data.
- *
- * \note The data buffer that holds the processed data must be large enough to hold
- * four consecutive 32-bit words.
- *
- * \param[in] module Pointer to the software instance struct
- * \param[in] output_data_buffer Pointer to an output buffer
- */
- void aes_read_output_data(
- struct aes_module *const module,
- uint32_t *output_data_buffer)
- {
- uint32_t i;
- /* Validate arguments. */
- Assert(module);
- Assert(module->hw);
- Assert(output_data_buffer);
- module->hw->DATABUFPTR.reg = 0;
- if (module->opmode == AES_CFB_MODE
- && module->cfb_size == AES_CFB_SIZE_64){
- for (i = 0; i < 2; i++) {
- *output_data_buffer = module->hw->INDATA.reg;
- output_data_buffer++;
- }
- } else if (module->opmode == AES_CFB_MODE
- && (module->cfb_size == AES_CFB_SIZE_32 || module->cfb_size == AES_CFB_SIZE_16)){
- *output_data_buffer = module->hw->INDATA.reg;
- } else {
- for (i = 0; i < 4; i++) {
- *output_data_buffer = module->hw->INDATA.reg;
- output_data_buffer++;
- }
- }
- }
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