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esp-idf/components/mbedtls/port/aes/dma/esp_aes.c

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/**
* \brief AES block cipher, ESP DMA hardware accelerated version
* Based on mbedTLS FIPS-197 compliant version.
*
* Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
* Additions Copyright (C) 2016-2020, Espressif Systems (Shanghai) PTE Ltd
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
/*
* The AES block cipher was designed by Vincent Rijmen and Joan Daemen.
*
* http://csrc.nist.gov/encryption/aes/rijndael/Rijndael.pdf
* http://csrc.nist.gov/publications/fips/fips197/fips-197.pdf
*/
#include <string.h>
#include "mbedtls/aes.h"
#include "esp_intr_alloc.h"
#include "driver/periph_ctrl.h"
#include "esp_log.h"
#include "soc/lldesc.h"
#include "esp_heap_caps.h"
#include "sys/param.h"
#include "esp_pm.h"
#include "esp_crypto_lock.h"
#include "hal/aes_hal.h"
#include "aes/esp_aes_internal.h"
#include "esp_aes_dma_priv.h"
#if CONFIG_IDF_TARGET_ESP32S2
#include "esp32s2/rom/cache.h"
#elif CONFIG_IDF_TARGET_ESP32S3
#include "esp32s3/rom/cache.h"
#endif
#include "freertos/FreeRTOS.h"
#include "freertos/semphr.h"
#if SOC_AES_SUPPORT_GCM
#include "aes/esp_aes_gcm.h"
#endif
#if SOC_AES_GDMA
#define AES_LOCK() esp_crypto_sha_aes_lock_acquire()
#define AES_RELEASE() esp_crypto_sha_aes_lock_release()
#elif SOC_AES_CRYPTO_DMA
#define AES_LOCK() esp_crypto_dma_lock_acquire()
#define AES_RELEASE() esp_crypto_dma_lock_release()
#endif
/* Max size of each chunk to process when output buffer is in unaligned external ram
must be a multiple of block size
*/
#define AES_MAX_CHUNK_WRITE_SIZE 1600
/* Input over this length will yield and wait for interrupt instead of
busy-waiting, 30000 bytes is approx 0.5 ms */
#define AES_DMA_INTR_TRIG_LEN 2000
#if defined(CONFIG_MBEDTLS_AES_USE_INTERRUPT)
static SemaphoreHandle_t op_complete_sem;
#if defined(CONFIG_PM_ENABLE)
static esp_pm_lock_handle_t s_pm_cpu_lock;
static esp_pm_lock_handle_t s_pm_sleep_lock;
#endif
#endif
static const char *TAG = "esp-aes";
static inline void esp_aes_wait_dma_done(lldesc_t *output)
{
/* Wait for DMA write operation to complete */
while (1) {
if ( esp_aes_dma_done(output) ) {
break;
}
}
}
/* Append a descriptor to the chain, set head if chain empty */
static inline void lldesc_append(lldesc_t **head, lldesc_t *item)
{
lldesc_t *it;
if (*head == NULL) {
*head = item;
return;
}
it = *head;
while (it->empty != 0) {
it = (lldesc_t *)it->empty;
}
it->eof = 0;
it->empty = (uint32_t)item;
}
void esp_aes_acquire_hardware( void )
{
/* Released by esp_aes_release_hardware()*/
AES_LOCK();
/* Enable AES and DMA hardware */
#if SOC_AES_CRYPTO_DMA
periph_module_enable(PERIPH_AES_DMA_MODULE);
#elif SOC_AES_GDMA
periph_module_enable(PERIPH_AES_MODULE);
#endif
}
/* Function to disable AES and Crypto DMA clocks and release locks */
void esp_aes_release_hardware( void )
{
/* Disable AES and DMA hardware */
#if SOC_AES_CRYPTO_DMA
periph_module_disable(PERIPH_AES_DMA_MODULE);
#elif SOC_AES_GDMA
periph_module_disable(PERIPH_AES_MODULE);
#endif
AES_RELEASE();
}
#if defined (CONFIG_MBEDTLS_AES_USE_INTERRUPT)
static IRAM_ATTR void esp_aes_complete_isr(void *arg)
{
BaseType_t higher_woken;
aes_hal_interrupt_clear();
xSemaphoreGiveFromISR(op_complete_sem, &higher_woken);
if (higher_woken) {
portYIELD_FROM_ISR();
}
}
static esp_err_t esp_aes_isr_initialise( void )
{
aes_hal_interrupt_clear();
aes_hal_interrupt_enable(true);
if (op_complete_sem == NULL) {
op_complete_sem = xSemaphoreCreateBinary();
if (op_complete_sem == NULL) {
ESP_LOGE(TAG, "Failed to create intr semaphore");
return ESP_FAIL;
}
esp_intr_alloc(ETS_AES_INTR_SOURCE, 0, esp_aes_complete_isr, NULL, NULL);
}
/* AES is clocked proportionally to CPU clock, take power management lock */
#ifdef CONFIG_PM_ENABLE
if (s_pm_cpu_lock == NULL) {
if (esp_pm_lock_create(ESP_PM_NO_LIGHT_SLEEP, 0, "aes_sleep", &s_pm_sleep_lock) != ESP_OK) {
ESP_LOGE(TAG, "Failed to create PM sleep lock");
return ESP_FAIL;
}
if (esp_pm_lock_create(ESP_PM_CPU_FREQ_MAX, 0, "aes_cpu", &s_pm_cpu_lock) != ESP_OK) {
ESP_LOGE(TAG, "Failed to create PM CPU lock");
return ESP_FAIL;
}
}
esp_pm_lock_acquire(s_pm_cpu_lock);
esp_pm_lock_acquire(s_pm_sleep_lock);
#endif
return ESP_OK;
}
#endif // CONFIG_MBEDTLS_AES_USE_INTERRUPT
/* Wait for AES hardware block operation to complete */
static void esp_aes_dma_wait_complete(bool use_intr, lldesc_t *output_desc)
{
#if defined (CONFIG_MBEDTLS_AES_USE_INTERRUPT)
if (use_intr) {
if (!xSemaphoreTake(op_complete_sem, 2000 / portTICK_PERIOD_MS)) {
/* indicates a fundamental problem with driver */
ESP_LOGE("AES", "Timed out waiting for completion of AES Interrupt");
abort();
}
#ifdef CONFIG_PM_ENABLE
esp_pm_lock_release(s_pm_cpu_lock);
esp_pm_lock_release(s_pm_sleep_lock);
#endif // CONFIG_PM_ENABLE
}
#endif
/* Checking this if interrupt is used also, to avoid
issues with AES fault injection
*/
aes_hal_wait_done();
esp_aes_wait_dma_done(output_desc);
}
static int esp_aes_process_dma(esp_aes_context *ctx, const unsigned char *input, unsigned char *output, size_t len, uint8_t *stream_out);
/* Output buffers in external ram needs to be 16-byte aligned and DMA cant access input in the iCache mem range,
reallocate them into internal memory and encrypt in chunks to avoid
having to malloc too big of a buffer
*/
static int esp_aes_process_dma_ext_ram(esp_aes_context *ctx, const unsigned char *input, unsigned char *output, size_t len, uint8_t *stream_out, bool realloc_input, bool realloc_output)
{
size_t chunk_len;
int ret = 0;
int offset = 0;
unsigned char *input_buf = NULL;
unsigned char *output_buf = NULL;
const unsigned char *dma_input;
chunk_len = MIN(AES_MAX_CHUNK_WRITE_SIZE, len);
if (realloc_input) {
input_buf = heap_caps_malloc(chunk_len, MALLOC_CAP_DMA);
if (input_buf == NULL) {
ESP_LOGE(TAG, "Failed to allocate memory");
ret = -1;
goto cleanup;
}
}
if (realloc_output) {
output_buf = heap_caps_malloc(chunk_len, MALLOC_CAP_DMA);
if (output_buf == NULL) {
ESP_LOGE(TAG, "Failed to allocate memory");
ret = -1;
goto cleanup;
}
} else {
output_buf = output;
}
while (len) {
chunk_len = MIN(AES_MAX_CHUNK_WRITE_SIZE, len);
/* If input needs realloc then copy it, else use the input with offset*/
if (realloc_input) {
memcpy(input_buf, input + offset, chunk_len);
dma_input = input_buf;
} else {
dma_input = input + offset;
}
if (esp_aes_process_dma(ctx, dma_input, output_buf, chunk_len, stream_out) != 0) {
ret = -1;
goto cleanup;
}
if (realloc_output) {
memcpy(output + offset, output_buf, chunk_len);
} else {
output_buf = output + offset + chunk_len;
}
len -= chunk_len;
offset += chunk_len;
}
cleanup:
if (realloc_input) {
free(input_buf);
}
if (realloc_output) {
free(output_buf);
}
return ret;
}
/* Encrypt/decrypt the input using DMA */
static int esp_aes_process_dma(esp_aes_context *ctx, const unsigned char *input, unsigned char *output, size_t len, uint8_t *stream_out)
{
lldesc_t stream_in_desc, stream_out_desc;
lldesc_t *in_desc_head = NULL, *out_desc_head = NULL;
lldesc_t *out_desc_tail = NULL; /* pointer to the final output descriptor */
lldesc_t *block_desc = NULL, *block_in_desc = NULL, *block_out_desc = NULL;
size_t lldesc_num;
uint8_t stream_in[16] = {};
unsigned stream_bytes = len % AES_BLOCK_BYTES; // bytes which aren't in a full block
unsigned block_bytes = len - stream_bytes; // bytes which are in a full block
unsigned char *non_icache_input = NULL;
unsigned blocks = (block_bytes / AES_BLOCK_BYTES) + ((stream_bytes > 0) ? 1 : 0);
bool use_intr = false;
bool input_needs_realloc = false;
bool output_needs_realloc = false;
int ret = 0;
assert(len > 0); // caller shouldn't ever have len set to zero
assert(stream_bytes == 0 || stream_out != NULL); // stream_out can be NULL if we're processing full block(s)
/* If no key is written to hardware yet, either the user hasn't called
mbedtls_aes_setkey_enc/mbedtls_aes_setkey_dec - meaning we also don't
know which mode to use - or a fault skipped the
key write to hardware. Treat this as a fatal error and zero the output block.
*/
if (ctx->key_in_hardware != ctx->key_bytes) {
bzero(output, len);
return MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH;
}
if (block_bytes > 0) {
/* Flush cache if input in external ram */
#if (CONFIG_SPIRAM_USE_CAPS_ALLOC || CONFIG_SPIRAM_USE_MALLOC)
if (esp_ptr_external_ram(input)) {
Cache_WriteBack_All();
}
if (esp_ptr_external_ram(output)) {
if (((intptr_t)(output) & 0xF) != 0) {
// Non aligned ext-mem buffer
output_needs_realloc = true;
}
}
#endif
/* DMA cannot access memory in the iCache range, copy input to internal ram */
if (!esp_ptr_dma_ext_capable(input) && !esp_ptr_dma_capable(input)) {
input_needs_realloc = true;
}
if (!esp_ptr_dma_ext_capable(output) && !esp_ptr_dma_capable(output)) {
output_needs_realloc = true;
}
/* If either input or output is unaccessible to the DMA then they need to be reallocated */
if (input_needs_realloc || output_needs_realloc) {
return esp_aes_process_dma_ext_ram(ctx, input, output, len, stream_out, input_needs_realloc, output_needs_realloc);
}
/* Set up dma descriptors for input and output */
lldesc_num = lldesc_get_required_num(block_bytes);
/* Allocate both in and out descriptors to save a malloc/free per function call */
block_desc = heap_caps_malloc(sizeof(lldesc_t) * lldesc_num * 2, MALLOC_CAP_DMA);
if (block_desc == NULL) {
ESP_LOGE(TAG, "Failed to allocate memory");
ret = -1;
goto cleanup;
}
block_in_desc = block_desc;
block_out_desc = block_desc + lldesc_num;
lldesc_setup_link(block_in_desc, input, block_bytes, 0);
lldesc_setup_link(block_out_desc, output, block_bytes, 0);
out_desc_tail = &block_out_desc[lldesc_num - 1];
}
/* Any leftover bytes which are appended as an additional DMA list */
if (stream_bytes > 0) {
memcpy(stream_in, input + block_bytes, stream_bytes);
lldesc_setup_link(&stream_in_desc, stream_in, AES_BLOCK_BYTES, 0);
lldesc_setup_link(&stream_out_desc, stream_out, AES_BLOCK_BYTES, 0);
if (block_bytes > 0) {
/* Link with block descriptors*/
block_in_desc[lldesc_num - 1].empty = (uint32_t)&stream_in_desc;
block_out_desc[lldesc_num - 1].empty = (uint32_t)&stream_out_desc;
}
out_desc_tail = &stream_out_desc;
}
// block buffers are sent to DMA first, unless there aren't any
in_desc_head = (block_bytes > 0) ? block_in_desc : &stream_in_desc;
out_desc_head = (block_bytes > 0) ? block_out_desc : &stream_out_desc;
#if defined (CONFIG_MBEDTLS_AES_USE_INTERRUPT)
/* Only use interrupt for long AES operations */
if (len > AES_DMA_INTR_TRIG_LEN) {
use_intr = true;
if (esp_aes_isr_initialise() == ESP_FAIL) {
ret = -1;
goto cleanup;
}
} else
#endif
{
aes_hal_interrupt_enable(false);
}
if (esp_aes_dma_start(in_desc_head, out_desc_head) != ESP_OK) {
ESP_LOGE(TAG, "esp_aes_dma_start failed, no DMA channel available");
ret = -1;
goto cleanup;
}
aes_hal_transform_dma_start(blocks);
esp_aes_dma_wait_complete(use_intr, out_desc_tail);
#if (CONFIG_SPIRAM_USE_CAPS_ALLOC || CONFIG_SPIRAM_USE_MALLOC)
if (block_bytes > 0) {
if (esp_ptr_external_ram(output)) {
Cache_Invalidate_DCache_All();
}
}
#endif
aes_hal_transform_dma_finish();
if (stream_bytes > 0) {
memcpy(output + block_bytes, stream_out, stream_bytes);
}
cleanup:
free(non_icache_input);
free(block_desc);
return ret;
}
#if SOC_AES_SUPPORT_GCM
/* Encrypt/decrypt with AES-GCM the input using DMA */
int esp_aes_process_dma_gcm(esp_aes_context *ctx, const unsigned char *input, unsigned char *output, size_t len, lldesc_t *aad_desc, size_t aad_len)
{
lldesc_t *in_desc_head = NULL, *out_desc_head = NULL, *len_desc = NULL;
lldesc_t stream_in_desc, stream_out_desc;
lldesc_t *block_desc = NULL, *block_in_desc = NULL, *block_out_desc = NULL;
size_t lldesc_num;
uint32_t len_buf[4] = {};
uint8_t stream_in[16] = {};
uint8_t stream_out[16] = {};
unsigned stream_bytes = len % AES_BLOCK_BYTES; // bytes which aren't in a full block
unsigned block_bytes = len - stream_bytes; // bytes which are in a full block
unsigned blocks = (block_bytes / AES_BLOCK_BYTES) + ((stream_bytes > 0) ? 1 : 0);
bool use_intr = false;
int ret = 0;
/* If no key is written to hardware yet, either the user hasn't called
mbedtls_aes_setkey_enc/mbedtls_aes_setkey_dec - meaning we also don't
know which mode to use - or a fault skipped the
key write to hardware. Treat this as a fatal error and zero the output block.
*/
if (ctx->key_in_hardware != ctx->key_bytes) {
bzero(output, len);
return MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH;
}
/* Set up dma descriptors for input and output */
lldesc_num = lldesc_get_required_num(block_bytes);
/* Allocate both in and out descriptors to save a malloc/free per function call, add 1 for length descriptor */
block_desc = heap_caps_calloc( (lldesc_num * 2) + 1, sizeof(lldesc_t), MALLOC_CAP_DMA);
if (block_desc == NULL) {
ESP_LOGE(TAG, "Failed to allocate memory");
ret = -1;
goto cleanup;
}
block_in_desc = block_desc;
len_desc = block_desc + lldesc_num;
block_out_desc = block_desc + lldesc_num + 1;
if (aad_desc != NULL) {
lldesc_append(&in_desc_head, aad_desc);
}
if (block_bytes > 0) {
lldesc_setup_link(block_in_desc, input, block_bytes, 0);
lldesc_setup_link(block_out_desc, output, block_bytes, 0);
lldesc_append(&in_desc_head, block_in_desc);
lldesc_append(&out_desc_head, block_out_desc);
}
/* Any leftover bytes which are appended as an additional DMA list */
if (stream_bytes > 0) {
memcpy(stream_in, input + block_bytes, stream_bytes);
lldesc_setup_link(&stream_in_desc, stream_in, AES_BLOCK_BYTES, 0);
lldesc_setup_link(&stream_out_desc, stream_out, AES_BLOCK_BYTES, 0);
lldesc_append(&in_desc_head, &stream_in_desc);
lldesc_append(&out_desc_head, &stream_out_desc);
}
len_buf[1] = __builtin_bswap32(aad_len * 8);
len_buf[3] = __builtin_bswap32(len * 8);
len_desc->length = sizeof(len_buf);
len_desc->size = sizeof(len_buf);
len_desc->owner = 1;
len_desc->eof = 1;
len_desc->buf = (uint8_t *)len_buf;
lldesc_append(&in_desc_head, len_desc);
#if defined (CONFIG_MBEDTLS_AES_USE_INTERRUPT)
/* Only use interrupt for long AES operations */
if (len > AES_DMA_INTR_TRIG_LEN) {
use_intr = true;
if (esp_aes_isr_initialise() == ESP_FAIL) {
ret = -1;
goto cleanup;
}
} else
#endif
{
aes_hal_interrupt_enable(false);
}
/* Start AES operation */
if (esp_aes_dma_start(in_desc_head, out_desc_head) != ESP_OK) {
ESP_LOGE(TAG, "esp_aes_dma_start failed, no DMA channel available");
ret = -1;
goto cleanup;
}
aes_hal_transform_dma_gcm_start(blocks);
esp_aes_dma_wait_complete(use_intr, out_desc_head);
aes_hal_transform_dma_finish();
if (stream_bytes > 0) {
memcpy(output + block_bytes, stream_out, stream_bytes);
}
cleanup:
free(block_desc);
return ret;
}
#endif //SOC_AES_SUPPORT_GCM
static int esp_aes_validate_input(esp_aes_context *ctx, const unsigned char *input,
unsigned char *output )
{
if (!ctx) {
ESP_LOGE(TAG, "No AES context supplied");
return -1;
}
if (!input) {
ESP_LOGE(TAG, "No input supplied");
return -1;
}
if (!output) {
ESP_LOGE(TAG, "No output supplied");
return -1;
}
return 0;
}
/*
* AES-ECB single block encryption
*/
int esp_internal_aes_encrypt(esp_aes_context *ctx,
const unsigned char input[16],
unsigned char output[16] )
{
int r;
if (esp_aes_validate_input(ctx, input, output)) {
return -1;
}
if (!valid_key_length(ctx)) {
return MBEDTLS_ERR_AES_INVALID_KEY_LENGTH;
}
esp_aes_acquire_hardware();
ctx->key_in_hardware = 0;
ctx->key_in_hardware = aes_hal_setkey(ctx->key, ctx->key_bytes, ESP_AES_ENCRYPT);
aes_hal_mode_init(ESP_AES_BLOCK_MODE_ECB);
r = esp_aes_process_dma(ctx, input, output, AES_BLOCK_BYTES, NULL);
esp_aes_release_hardware();
return r;
}
void esp_aes_encrypt(esp_aes_context *ctx,
const unsigned char input[16],
unsigned char output[16] )
{
esp_internal_aes_encrypt(ctx, input, output);
}
/*
* AES-ECB single block decryption
*/
int esp_internal_aes_decrypt(esp_aes_context *ctx,
const unsigned char input[16],
unsigned char output[16] )
{
int r;
if (esp_aes_validate_input(ctx, input, output)) {
return -1;
}
if (!valid_key_length(ctx)) {
return MBEDTLS_ERR_AES_INVALID_KEY_LENGTH;
}
esp_aes_acquire_hardware();
ctx->key_in_hardware = 0;
ctx->key_in_hardware = aes_hal_setkey(ctx->key, ctx->key_bytes, ESP_AES_DECRYPT);
aes_hal_mode_init(ESP_AES_BLOCK_MODE_ECB);
r = esp_aes_process_dma(ctx, input, output, AES_BLOCK_BYTES, NULL);
esp_aes_release_hardware();
return r;
}
void esp_aes_decrypt(esp_aes_context *ctx,
const unsigned char input[16],
unsigned char output[16] )
{
esp_internal_aes_decrypt(ctx, input, output);
}
/*
* AES-ECB block encryption/decryption
*/
int esp_aes_crypt_ecb(esp_aes_context *ctx,
int mode,
const unsigned char input[16],
unsigned char output[16] )
{
int r;
if (esp_aes_validate_input(ctx, input, output)) {
return -1;
}
if (!valid_key_length(ctx)) {
return MBEDTLS_ERR_AES_INVALID_KEY_LENGTH;
}
esp_aes_acquire_hardware();
ctx->key_in_hardware = 0;
ctx->key_in_hardware = aes_hal_setkey(ctx->key, ctx->key_bytes, mode);
aes_hal_mode_init(ESP_AES_BLOCK_MODE_ECB);
r = esp_aes_process_dma(ctx, input, output, AES_BLOCK_BYTES, NULL);
esp_aes_release_hardware();
return r;
}
/*
* AES-CBC buffer encryption/decryption
*/
int esp_aes_crypt_cbc(esp_aes_context *ctx,
int mode,
size_t length,
unsigned char iv[16],
const unsigned char *input,
unsigned char *output )
{
int r = 0;
if (esp_aes_validate_input(ctx, input, output)) {
return -1;
}
if (!iv) {
ESP_LOGE(TAG, "No IV supplied");
return -1;
}
/* For CBC input length should be multiple of
* AES BLOCK BYTES
* */
if ( (length % AES_BLOCK_BYTES) || (length == 0) ) {
return ERR_ESP_AES_INVALID_INPUT_LENGTH;
}
if (!valid_key_length(ctx)) {
return MBEDTLS_ERR_AES_INVALID_KEY_LENGTH;
}
esp_aes_acquire_hardware();
ctx->key_in_hardware = 0;
ctx->key_in_hardware = aes_hal_setkey(ctx->key, ctx->key_bytes, mode);
aes_hal_mode_init(ESP_AES_BLOCK_MODE_CBC);
aes_hal_set_iv(iv);
r = esp_aes_process_dma(ctx, input, output, length, NULL);
if (r != 0) {
esp_aes_release_hardware();
return r;
}
aes_hal_read_iv(iv);
esp_aes_release_hardware();
return r;
}
/*
* AES-CFB8 buffer encryption/decryption
*/
int esp_aes_crypt_cfb8(esp_aes_context *ctx,
int mode,
size_t length,
unsigned char iv[16],
const unsigned char *input,
unsigned char *output )
{
unsigned char c;
unsigned char ov[17];
int r = 0;
size_t block_bytes = length - (length % AES_BLOCK_BYTES);
if (esp_aes_validate_input(ctx, input, output)) {
return -1;
}
if (!iv) {
ESP_LOGE(TAG, "No IV supplied");
return -1;
}
if (!valid_key_length(ctx)) {
return MBEDTLS_ERR_AES_INVALID_KEY_LENGTH;
}
/* The DMA engine will only output correct IV if it runs
full blocks of input in CFB8 mode
*/
esp_aes_acquire_hardware();
if (block_bytes > 0) {
ctx->key_in_hardware = 0;
ctx->key_in_hardware = aes_hal_setkey(ctx->key, ctx->key_bytes, mode);
aes_hal_mode_init(ESP_AES_BLOCK_MODE_CFB8);
aes_hal_set_iv(iv);
r = esp_aes_process_dma(ctx, input, output, block_bytes, NULL);
aes_hal_read_iv(iv);
if (r != 0) {
esp_aes_release_hardware();
return r;
}
length -= block_bytes;
input += block_bytes;
output += block_bytes;
}
// Process remaining bytes block-at-a-time in ECB mode
if (length > 0) {
ctx->key_in_hardware = 0;
ctx->key_in_hardware = aes_hal_setkey(ctx->key, ctx->key_bytes, MBEDTLS_AES_ENCRYPT);
aes_hal_mode_init(ESP_AES_BLOCK_MODE_ECB);
while ( length-- ) {
memcpy( ov, iv, 16 );
r = esp_aes_process_dma(ctx, iv, iv, AES_BLOCK_BYTES, NULL);
if (r != 0) {
esp_aes_release_hardware();
return r;
}
if ( mode == MBEDTLS_AES_DECRYPT ) {
ov[16] = *input;
}
c = *output++ = ( iv[0] ^ *input++ );
if ( mode == MBEDTLS_AES_ENCRYPT ) {
ov[16] = c;
}
memcpy( iv, ov + 1, 16 );
}
}
esp_aes_release_hardware();
return r;
}
/*
* AES-CFB128 buffer encryption/decryption
*/
int esp_aes_crypt_cfb128(esp_aes_context *ctx,
int mode,
size_t length,
size_t *iv_off,
unsigned char iv[16],
const unsigned char *input,
unsigned char *output )
{
uint8_t c;
int r = 0;
size_t stream_bytes = 0;
size_t n;
if (esp_aes_validate_input(ctx, input, output)) {
return -1;
}
if (!iv) {
ESP_LOGE(TAG, "No IV supplied");
return -1;
}
if (!iv_off) {
ESP_LOGE(TAG, "No IV offset supplied");
return -1;
}
if (!valid_key_length(ctx)) {
return MBEDTLS_ERR_AES_INVALID_KEY_LENGTH;
}
n = *iv_off;
/* First process the *iv_off bytes
* which are pending from the previous call to this API
*/
while (n > 0 && length > 0) {
if (mode == MBEDTLS_AES_ENCRYPT) {
iv[n] = *output++ = *input++ ^ iv[n];
} else {
c = *input++;
*output++ = c ^ iv[n];
iv[n] = c;
}
n = (n + 1) % AES_BLOCK_BYTES;
length--;
}
if (length > 0) {
stream_bytes = length % AES_BLOCK_BYTES;
esp_aes_acquire_hardware();
ctx->key_in_hardware = 0;
ctx->key_in_hardware = aes_hal_setkey(ctx->key, ctx->key_bytes, mode);
aes_hal_mode_init(ESP_AES_BLOCK_MODE_CFB128);
aes_hal_set_iv(iv);
r = esp_aes_process_dma(ctx, input, output, length, iv);
if (r != 0) {
esp_aes_release_hardware();
return r;
}
if (stream_bytes == 0) {
// if we didn't need the partial 'stream block' then the new IV is in the IV register
aes_hal_read_iv(iv);
} else {
// if we did process a final partial block the new IV is already processed via DMA (and has some bytes of output in it),
// In decrypt mode any partial bytes are output plaintext (iv ^ c) and need to be swapped back to ciphertext (as the next
// block uses ciphertext as its IV input)
//
// Note: It may be more efficient to not process the partial block via DMA in this case.
if (mode == MBEDTLS_AES_DECRYPT) {
memcpy(iv, input + length - stream_bytes, stream_bytes);
}
}
esp_aes_release_hardware();
}
*iv_off = n + stream_bytes;
return r;
}
/*
* AES-OFB (Output Feedback Mode) buffer encryption/decryption
*/
int esp_aes_crypt_ofb(esp_aes_context *ctx,
size_t length,
size_t *iv_off,
unsigned char iv[16],
const unsigned char *input,
unsigned char *output )
{
int r = 0;
size_t n;
size_t stream_bytes = 0;
if (esp_aes_validate_input(ctx, input, output)) {
return -1;
}
if (!iv) {
ESP_LOGE(TAG, "No IV supplied");
return -1;
}
if (!iv_off) {
ESP_LOGE(TAG, "No IV offset supplied");
return -1;
}
n = *iv_off;
/* If there is an offset then use the output of the previous AES block
(the updated IV) to calculate the new output */
while (n > 0 && length > 0) {
*output++ = (*input++ ^ iv[n]);
n = (n + 1) & 0xF;
length--;
}
if (length > 0) {
stream_bytes = (length % AES_BLOCK_BYTES);
esp_aes_acquire_hardware();
ctx->key_in_hardware = 0;
ctx->key_in_hardware = aes_hal_setkey(ctx->key, ctx->key_bytes, ESP_AES_DECRYPT);
aes_hal_mode_init(ESP_AES_BLOCK_MODE_OFB);
aes_hal_set_iv(iv);
r = esp_aes_process_dma(ctx, input, output, length, iv);
if (r != 0) {
esp_aes_release_hardware();
return r;
}
aes_hal_read_iv(iv);
esp_aes_release_hardware();
}
*iv_off = n + stream_bytes;
return r;
}
/*
* AES-CTR buffer encryption/decryption
*/
int esp_aes_crypt_ctr(esp_aes_context *ctx,
size_t length,
size_t *nc_off,
unsigned char nonce_counter[16],
unsigned char stream_block[16],
const unsigned char *input,
unsigned char *output )
{
int r = 0;
size_t n;
if (esp_aes_validate_input(ctx, input, output)) {
return -1;
}
if (!nonce_counter) {
ESP_LOGE(TAG, "No nonce supplied");
return -1;
}
if (!nc_off) {
ESP_LOGE(TAG, "No nonce offset supplied");
return -1;
}
n = *nc_off;
if (!valid_key_length(ctx)) {
return MBEDTLS_ERR_AES_INVALID_KEY_LENGTH;
}
/* Process any unprocessed bytes left in stream block from
last operation */
while (n > 0 && length > 0) {
*output++ = (unsigned char)(*input++ ^ stream_block[n]);
n = (n + 1) & 0xF;
length--;
}
if (length > 0) {
esp_aes_acquire_hardware();
ctx->key_in_hardware = 0;
ctx->key_in_hardware = aes_hal_setkey(ctx->key, ctx->key_bytes, ESP_AES_DECRYPT);
aes_hal_mode_init(ESP_AES_BLOCK_MODE_CTR);
aes_hal_set_iv(nonce_counter);
r = esp_aes_process_dma(ctx, input, output, length, stream_block);
if (r != 0) {
esp_aes_release_hardware();
return r;
}
aes_hal_read_iv(nonce_counter);
esp_aes_release_hardware();
}
*nc_off = n + (length % AES_BLOCK_BYTES);
return r;
}
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