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107 lines
3.3 KiB
C
107 lines
3.3 KiB
C
/*
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* AES block cipher, ESP hardware accelerated version, common
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* Based on mbedTLS FIPS-197 compliant version.
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*
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* SPDX-FileCopyrightText: The Mbed TLS Contributors
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*
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* SPDX-License-Identifier: Apache-2.0
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*
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* SPDX-FileContributor: 2016-2025 Espressif Systems (Shanghai) CO LTD
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*/
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/*
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* The AES block cipher was designed by Vincent Rijmen and Joan Daemen.
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*
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* http://csrc.nist.gov/encryption/aes/rijndael/Rijndael.pdf
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* http://csrc.nist.gov/publications/fips/fips197/fips-197.pdf
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*/
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#include "sdkconfig.h"
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#include "aes/esp_aes_internal.h"
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#include "mbedtls/aes.h"
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#include "hal/aes_hal.h"
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#include "hal/aes_types.h"
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#include "soc/soc_caps.h"
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#include "mbedtls/error.h"
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#include <string.h>
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#include "mbedtls/platform.h"
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#if SOC_AES_SUPPORT_DMA
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#include "esp_aes_dma_priv.h"
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#endif
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bool valid_key_length(const esp_aes_context *ctx)
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{
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bool valid_len = (ctx->key_bytes == AES_128_KEY_BYTES) || (ctx->key_bytes == AES_256_KEY_BYTES);
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#if SOC_AES_SUPPORT_AES_192
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valid_len |= ctx->key_bytes == AES_192_KEY_BYTES;
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#endif
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return valid_len;
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}
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void esp_aes_init(esp_aes_context *ctx)
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{
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bzero(ctx, sizeof(esp_aes_context));
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#if SOC_AES_SUPPORT_DMA && CONFIG_MBEDTLS_AES_USE_INTERRUPT
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esp_aes_intr_alloc();
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#endif
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}
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void esp_aes_free( esp_aes_context *ctx )
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{
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if ( ctx == NULL ) {
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return;
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}
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bzero( ctx, sizeof( esp_aes_context ) );
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}
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/*
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* AES key schedule (same for encryption or decryption, as hardware handles schedule)
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*
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*/
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int esp_aes_setkey( esp_aes_context *ctx, const unsigned char *key,
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unsigned int keybits )
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{
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#if !SOC_AES_SUPPORT_AES_192
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if (keybits == 192) {
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return MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED;
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}
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#endif
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if (keybits != 128 && keybits != 192 && keybits != 256) {
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return MBEDTLS_ERR_AES_INVALID_KEY_LENGTH;
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}
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ctx->key_bytes = keybits / 8;
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memcpy(ctx->key, key, ctx->key_bytes);
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ctx->key_in_hardware = 0;
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return 0;
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}
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#ifdef CONFIG_MBEDTLS_AES_USE_PSEUDO_ROUND_FUNC
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/* The total number of pseudo-rounds randomly inserted in an AES operation are controlled by
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* configuring the AES_PSEUDO_BASE, AES_PSEUDO_INC parameters.
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* Users can also set the frequency of random key updates by configuring the AES_PSEUDO_RNG_CNT.
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* Here, we would be using some pre-decided values for these parameters corresponding to the security needed.
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* For more information regarding these parameters please refer the TRM.
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*/
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#define AES_PSEUDO_ROUNDS_BASE_LOW 4
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#define AES_PSEUDO_ROUNDS_BASE_MEDIUM 7
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#define AES_PSEUDO_ROUNDS_BASE_HIGH 15
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#define AES_PSEUDO_ROUNDS_INC 3
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#define AES_PSEUDO_ROUNDS_RNG_CNT 7
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void esp_aes_enable_pseudo_rounds(esp_aes_psuedo_rounds_state_t state)
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{
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if (state == ESP_AES_PSEUDO_ROUNDS_DISABLE) {
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aes_hal_enable_pseudo_rounds(false, 0, 0, 0);
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} else if (state == ESP_AES_PSEUDO_ROUNDS_LOW) {
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aes_hal_enable_pseudo_rounds(true, AES_PSEUDO_ROUNDS_BASE_LOW, AES_PSEUDO_ROUNDS_INC, AES_PSEUDO_ROUNDS_RNG_CNT);
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} else if (state == ESP_AES_PSEUDO_ROUNDS_MEDIUM) {
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aes_hal_enable_pseudo_rounds(true, AES_PSEUDO_ROUNDS_BASE_MEDIUM, AES_PSEUDO_ROUNDS_INC, AES_PSEUDO_ROUNDS_RNG_CNT);
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} else {
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aes_hal_enable_pseudo_rounds(true, AES_PSEUDO_ROUNDS_BASE_HIGH, AES_PSEUDO_ROUNDS_INC, AES_PSEUDO_ROUNDS_RNG_CNT);
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}
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}
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#endif /* CONFIG_MBEDTLS_AES_USE_PSEUDO_ROUND_FUNC */
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