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

993 wiersze
36 KiB
C
Czysty Wina Historia

/*
* SPDX-FileCopyrightText: 2024 Espressif Systems (Shanghai) CO LTD
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <string.h>
#include <sys/param.h>
#include "esp_attr.h"
#include "esp_cache.h"
#include "esp_check.h"
#include "esp_dma_utils.h"
#include "esp_err.h"
#include "esp_heap_caps.h"
#include "esp_intr_alloc.h"
#include "esp_log.h"
#include "esp_memory_utils.h"
#include "esp_private/esp_cache_private.h"
#include "esp_private/periph_ctrl.h"
#if CONFIG_PM_ENABLE
#include "esp_pm.h"
#endif
#include "hal/aes_hal.h"
#include "esp_aes_dma_priv.h"
#include "esp_aes_internal.h"
#include "esp_crypto_dma.h"
#include "freertos/FreeRTOS.h"
#include "freertos/semphr.h"
#include "mbedtls/aes.h"
#include "mbedtls/platform_util.h"
#if SOC_AES_SUPPORT_GCM
#include "aes/esp_aes_gcm.h"
#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
/* With buffers in PSRAM (worst condition) we still achieve a speed of 4 MB/s
thus a 2 second timeout value should be suffient for even very large buffers.
*/
#define AES_WAIT_INTR_TIMEOUT_MS 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 bool s_check_dma_capable(const void *p)
{
bool is_capable = false;
#if CONFIG_SPIRAM
is_capable |= esp_ptr_dma_ext_capable(p);
#endif
is_capable |= esp_ptr_dma_capable(p);
return is_capable;
}
#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();
}
}
void esp_aes_intr_alloc(void)
{
if (op_complete_sem == NULL) {
const int isr_flags = esp_intr_level_to_flags(CONFIG_MBEDTLS_AES_INTERRUPT_LEVEL);
esp_err_t ret = esp_intr_alloc(ETS_AES_INTR_SOURCE, isr_flags, esp_aes_complete_isr, NULL, NULL);
if (ret != ESP_OK) {
ESP_LOGE(TAG, "Failed to allocate AES interrupt %d", ret);
// This should be treated as fatal error as this API would mostly
// be invoked within mbedTLS interface. There is no way for the system
// to proceed if the AES interrupt allocation fails here.
abort();
}
static StaticSemaphore_t op_sem_buf;
op_complete_sem = xSemaphoreCreateBinaryStatic(&op_sem_buf);
// Static semaphore creation is unlikley to fail but still basic sanity
assert(op_complete_sem != NULL);
}
}
static esp_err_t esp_aes_isr_initialise( void )
{
aes_hal_interrupt_clear();
aes_hal_interrupt_enable(true);
/* 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
static inline void esp_aes_wait_dma_done(crypto_dma_desc_t *output)
{
/* Wait for DMA write operation to complete */
while (1) {
if ( esp_aes_dma_done(output) ) {
break;
}
}
}
/* Wait for AES hardware block operation to complete */
static int esp_aes_dma_wait_complete(bool use_intr, crypto_dma_desc_t *output_desc_tail)
{
#if defined (CONFIG_MBEDTLS_AES_USE_INTERRUPT)
if (use_intr) {
if (!xSemaphoreTake(op_complete_sem, AES_WAIT_INTR_TIMEOUT_MS / portTICK_PERIOD_MS)) {
/* indicates a fundamental problem with driver */
ESP_LOGE(TAG, "Timed out waiting for completion of AES Interrupt");
return -1;
}
#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_tail);
return 0;
}
/* 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
The function esp_aes_process_dma_ext_ram zeroises the output buffer in the case of memory allocation failure.
*/
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) {
mbedtls_platform_zeroize(output, len);
ESP_LOGE(TAG, "Failed to allocate memory");
return -1;
}
}
if (realloc_output) {
output_buf = heap_caps_malloc(chunk_len, MALLOC_CAP_DMA);
if (output_buf == NULL) {
mbedtls_platform_zeroize(output, len);
ESP_LOGE(TAG, "Failed to allocate memory");
return -1;
}
} 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;
}
#if SOC_CACHE_INTERNAL_MEM_VIA_L1CACHE
#define ALIGN_UP(num, align) (((num) + ((align) - 1)) & ~((align) - 1))
#define ALIGN_DOWN(num, align) ((num) & ~((align) - 1))
#define AES_DMA_ALLOC_CAPS (MALLOC_CAP_DMA | MALLOC_CAP_8BIT)
static inline void *aes_dma_calloc(size_t num, size_t size, uint32_t caps, size_t *actual_size)
{
void *ptr = NULL;
esp_dma_calloc(num, size, caps, &ptr, actual_size);
return ptr;
}
static inline size_t get_cache_line_size(const void *addr)
{
esp_err_t ret = ESP_FAIL;
size_t cache_line_size = 0;
#if (CONFIG_SPIRAM && SOC_PSRAM_DMA_CAPABLE)
if (esp_ptr_external_ram(addr)) {
ret = esp_cache_get_alignment(ESP_CACHE_MALLOC_FLAG_PSRAM, &cache_line_size);
} else
#endif
{
ret = esp_cache_get_alignment(ESP_CACHE_MALLOC_FLAG_DMA, &cache_line_size);
}
if (ret != ESP_OK) {
return 0;
}
return cache_line_size;
}
static inline esp_err_t dma_desc_link(crypto_dma_desc_t *dmadesc, size_t crypto_dma_desc_num, size_t cache_line_size)
{
esp_err_t ret = ESP_OK;
for (int i = 0; i < crypto_dma_desc_num; i++) {
dmadesc[i].dw0.suc_eof = ((i == crypto_dma_desc_num - 1) ? 1 : 0);
dmadesc[i].next = ((i == crypto_dma_desc_num - 1) ? NULL : &dmadesc[i+1]);
#if SOC_CACHE_INTERNAL_MEM_VIA_L1CACHE
/* Write back both input buffers and output buffers to clear any cache dirty bit if set */
ret = esp_cache_msync(dmadesc[i].buffer, dmadesc[i].dw0.length, ESP_CACHE_MSYNC_FLAG_DIR_C2M | ESP_CACHE_MSYNC_FLAG_UNALIGNED);
if (ret != ESP_OK) {
return ret;
}
}
ret = esp_cache_msync(dmadesc, ALIGN_UP(crypto_dma_desc_num * sizeof(crypto_dma_desc_t), cache_line_size), ESP_CACHE_MSYNC_FLAG_DIR_C2M);
#else
}
#endif
return ret;
}
static inline void dma_desc_populate(crypto_dma_desc_t *dmadesc, const uint8_t *data, size_t len, int max_desc_size, size_t index)
{
int dmachunklen = 0;
while (len) {
dmachunklen = len;
if (dmachunklen > max_desc_size) {
dmachunklen = max_desc_size;
}
dmadesc[index].dw0.size = dmachunklen;
dmadesc[index].dw0.length = dmachunklen;
dmadesc[index].dw0.owner = DMA_DESCRIPTOR_BUFFER_OWNER_DMA;
dmadesc[index].buffer = (void *)data;
len -= dmachunklen;
data += dmachunklen;
index++;
}
}
/**
* @brief Function that allocates and populates a given number of DMA descriptors to form a DMA descriptor linked list
*
* @param buffer Data (can be unaligned) buffer that is to be operated upon in an AES operation (ciphertext or plaintext)
* @param len Length of the above data buffer
* @param start_alignment_buffer The buffer which the first DMA descriptor points to for processing start_alignment length of bytes from the above buffer
* @param end_alignment_buffer The buffer which the last DMA descriptor points to for processing end_alignment length of bytes from the above buffer
* @param alignment_buffer_size Size of an alignment buffer
* @param cache_line_size Size of cache line that is needed to align the buffers and DMA descriptors before cache sync
* @param[out] start_alignment The least number of bytes from the start of the buffer that are unaligned to the Cache requirements (L1 Cache alignments)
* @param[out] end_alignment The number of bytes at the end of the buffer aligned up to AES_BLOCK_BYTES that are unaligned to the Cache requirements (L1 Cache alignments)
* @param[out] dma_descs Pointer to the list of DMA descriptors that are needed to be populated
* @param[out] dma_desc_num Number of DMA descriptors that are needed to be allocated
*/
static esp_err_t generate_descriptor_list(const uint8_t *buffer, const size_t len, uint8_t **start_alignment_buffer, uint8_t **end_alignment_buffer, size_t alignment_buffer_size, size_t cache_line_size, size_t *start_alignment, size_t *end_alignment, crypto_dma_desc_t **dma_descs, size_t *dma_desc_num, bool is_output)
{
size_t unaligned_start_bytes = 0;
size_t aligned_block_bytes = 0;
size_t unaligned_end_bytes = 0;
size_t dma_descs_needed = 0;
uint8_t *start_alignment_stream_buffer = NULL;
uint8_t *end_alignment_stream_buffer = NULL;
crypto_dma_desc_t *dma_descriptors = NULL;
if (len == 0) {
goto ret;
}
/* Extra bytes that were needed to be processed for supplying the AES peripheral a padded multiple of 16 bytes input */
size_t extra_bytes = ALIGN_UP(len, AES_BLOCK_BYTES) - len;
size_t start_offset = ((intptr_t)buffer & (cache_line_size - 1));
if (start_offset) {
unaligned_start_bytes = cache_line_size - start_offset;
} else {
unaligned_start_bytes = 0;
}
if (unaligned_start_bytes < len) {
aligned_block_bytes = ALIGN_DOWN((len - unaligned_start_bytes), cache_line_size);
unaligned_end_bytes = len - unaligned_start_bytes - aligned_block_bytes + extra_bytes;
} else {
unaligned_start_bytes = len + extra_bytes;
unaligned_end_bytes = 0;
aligned_block_bytes = 0;
}
size_t max_desc_size = (is_output) ? DMA_DESCRIPTOR_BUFFER_MAX_SIZE_16B_ALIGNED : DMA_DESCRIPTOR_BUFFER_MAX_SIZE_4B_ALIGNED;
dma_descs_needed = (unaligned_start_bytes ? 1 : 0) + dma_desc_get_required_num(aligned_block_bytes, max_desc_size) + (unaligned_end_bytes ? 1 : 0);
/* Allocate memory for DMA descriptors of total size aligned up to a multiple of cache line size */
dma_descriptors = (crypto_dma_desc_t *) aes_dma_calloc(dma_descs_needed, sizeof(crypto_dma_desc_t), MALLOC_CAP_DMA, NULL);
if (dma_descriptors == NULL) {
ESP_LOGE(TAG, "Failed to allocate memory for the array of DMA descriptors");
return ESP_FAIL;
}
size_t populated_dma_descs = 0;
if (unaligned_start_bytes) {
start_alignment_stream_buffer = aes_dma_calloc(alignment_buffer_size, sizeof(uint8_t), AES_DMA_ALLOC_CAPS, NULL);
if (start_alignment_stream_buffer == NULL) {
ESP_LOGE(TAG, "Failed to allocate memory for start alignment buffer");
return ESP_FAIL;
}
memset(start_alignment_stream_buffer, 0, unaligned_start_bytes);
memcpy(start_alignment_stream_buffer, buffer, (unaligned_start_bytes > len) ? len : unaligned_start_bytes);
memset(start_alignment_stream_buffer + unaligned_start_bytes, 0, alignment_buffer_size - unaligned_start_bytes);
// add start alignment node to the DMA linked list
dma_desc_populate(dma_descriptors, start_alignment_stream_buffer, unaligned_start_bytes, DMA_DESCRIPTOR_BUFFER_MAX_SIZE_4B_ALIGNED, populated_dma_descs);
populated_dma_descs += (unaligned_start_bytes ? 1 : 0);
}
if (aligned_block_bytes) {
// add "aligned_dma_desc_num" nodes to DMA linked list
dma_desc_populate(dma_descriptors, buffer + unaligned_start_bytes, aligned_block_bytes, max_desc_size, populated_dma_descs);
populated_dma_descs += dma_desc_get_required_num(aligned_block_bytes, max_desc_size);
}
if (unaligned_end_bytes) {
end_alignment_stream_buffer = aes_dma_calloc(alignment_buffer_size, sizeof(uint8_t), AES_DMA_ALLOC_CAPS, NULL);
if (end_alignment_stream_buffer == NULL) {
ESP_LOGE(TAG, "Failed to allocate memory for end alignment buffer");
return ESP_FAIL;
}
memset(end_alignment_stream_buffer, 0, unaligned_end_bytes);
memcpy(end_alignment_stream_buffer, buffer + unaligned_start_bytes + aligned_block_bytes, unaligned_end_bytes - extra_bytes);
memset(end_alignment_stream_buffer + unaligned_end_bytes, 0, alignment_buffer_size - unaligned_end_bytes);
// add end alignment node to the DMA linked list
dma_desc_populate(dma_descriptors, end_alignment_stream_buffer, unaligned_end_bytes, DMA_DESCRIPTOR_BUFFER_MAX_SIZE_4B_ALIGNED, populated_dma_descs);
populated_dma_descs += (unaligned_end_bytes ? 1 : 0);
}
if (dma_desc_link(dma_descriptors, dma_descs_needed, cache_line_size) != ESP_OK) {
ESP_LOGE(TAG, "DMA descriptors cache sync C2M failed");
return ESP_FAIL;
}
ret:
if (start_alignment != NULL) {
*start_alignment = unaligned_start_bytes;
}
if (end_alignment != NULL) {
*end_alignment = unaligned_end_bytes;
}
if (dma_desc_num != NULL) {
*dma_desc_num = dma_descs_needed;
}
*dma_descs = dma_descriptors;
*start_alignment_buffer = start_alignment_stream_buffer;
*end_alignment_buffer = end_alignment_stream_buffer;
return ESP_OK;
}
int esp_aes_process_dma(esp_aes_context *ctx, const unsigned char *input, unsigned char *output, size_t len, uint8_t *stream_out)
{
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;
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) {
mbedtls_platform_zeroize(output, len);
return MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH;
}
/* DMA cannot access memory in the iCache range, copy input to internal ram */
if (!s_check_dma_capable(input)) {
input_needs_realloc = true;
}
if (!s_check_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);
}
size_t input_cache_line_size = get_cache_line_size(input);
size_t output_cache_line_size = get_cache_line_size(output);
if (input_cache_line_size == 0 || output_cache_line_size == 0) {
mbedtls_platform_zeroize(output, len);
ESP_LOGE(TAG, "Getting cache line size failed");
return -1;
}
size_t input_alignment_buffer_size = MAX(2 * input_cache_line_size, AES_BLOCK_BYTES);
crypto_dma_desc_t *input_desc = NULL;
uint8_t *input_start_stream_buffer = NULL;
uint8_t *input_end_stream_buffer = NULL;
if (generate_descriptor_list(input, len, &input_start_stream_buffer, &input_end_stream_buffer, input_alignment_buffer_size, input_cache_line_size, NULL, NULL, &input_desc, NULL, false) != ESP_OK) {
mbedtls_platform_zeroize(output, len);
ESP_LOGE(TAG, "Generating input DMA descriptors failed");
return -1;
}
size_t output_alignment_buffer_size = MAX(2 * output_cache_line_size, AES_BLOCK_BYTES);
crypto_dma_desc_t *output_desc = NULL;
uint8_t *output_start_stream_buffer = NULL;
uint8_t *output_end_stream_buffer = NULL;
size_t output_start_alignment = 0;
size_t output_end_alignment = 0;
size_t output_dma_desc_num = 0;
if (generate_descriptor_list(output, len, &output_start_stream_buffer, &output_end_stream_buffer, output_alignment_buffer_size, output_cache_line_size, &output_start_alignment, &output_end_alignment, &output_desc, &output_dma_desc_num, true) != ESP_OK) {
mbedtls_platform_zeroize(output, len);
ESP_LOGE(TAG, "Generating output DMA descriptors failed");
return -1;
}
crypto_dma_desc_t *out_desc_tail = &output_desc[output_dma_desc_num - 1];
#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_OK) {
ESP_LOGE(TAG, "ESP-AES ISR initialisation failed");
ret = -1;
goto cleanup;
}
} else
#endif
{
aes_hal_interrupt_enable(false);
}
if (esp_aes_dma_start(input_desc, output_desc) != ESP_OK) {
ESP_LOGE(TAG, "esp_aes_dma_start failed, no DMA channel available");
ret = -1;
goto cleanup;
}
aes_hal_transform_dma_start(blocks);
if (esp_aes_dma_wait_complete(use_intr, out_desc_tail) < 0) {
ESP_LOGE(TAG, "esp_aes_dma_wait_complete failed");
ret = -1;
goto cleanup;
}
#if SOC_CACHE_INTERNAL_MEM_VIA_L1CACHE
if (esp_cache_msync(output_desc, ALIGN_UP(output_dma_desc_num * sizeof(crypto_dma_desc_t), output_cache_line_size), ESP_CACHE_MSYNC_FLAG_DIR_M2C) != ESP_OK) {
ESP_LOGE(TAG, "Output DMA descriptor cache sync M2C failed");
ret = -1;
goto cleanup;
}
for (int i = 0; i < output_dma_desc_num; i++) {
if (esp_cache_msync(output_desc[i].buffer, output_desc[i].dw0.length, ESP_CACHE_MSYNC_FLAG_DIR_M2C | ESP_CACHE_MSYNC_FLAG_UNALIGNED) != ESP_OK) {
ESP_LOGE(TAG, "Output DMA descriptor buffers cache sync M2C failed");
ret = -1;
goto cleanup;
}
}
#endif
aes_hal_transform_dma_finish();
/* Extra bytes that were needed to be processed for supplying the AES peripheral a padded multiple of 16 bytes input */
size_t extra_bytes = ALIGN_UP(len, AES_BLOCK_BYTES) - len;
if (output_start_alignment) {
memcpy(output, output_start_stream_buffer, (output_start_alignment > len) ? len : output_start_alignment);
}
if (output_end_alignment) {
memcpy(output + len - (output_end_alignment - extra_bytes), output_end_stream_buffer, output_end_alignment - extra_bytes);
}
if (stream_bytes > 0) {
if (output_end_alignment) {
if (output_end_alignment >= AES_BLOCK_BYTES) {
memcpy(stream_out, output_end_stream_buffer + output_end_alignment - AES_BLOCK_BYTES, AES_BLOCK_BYTES);
} else {
size_t to_copy_from_output = AES_BLOCK_BYTES - output_end_alignment;
memcpy(stream_out, output + len - to_copy_from_output, to_copy_from_output);
memcpy(stream_out + to_copy_from_output, output_end_stream_buffer, output_end_alignment);
}
}
else if (output_start_alignment >= len) {
memcpy(stream_out, output_start_stream_buffer + output_start_alignment - AES_BLOCK_BYTES, AES_BLOCK_BYTES);
}
}
cleanup:
if (ret != 0) {
mbedtls_platform_zeroize(output, len);
}
free(input_start_stream_buffer);
free(input_end_stream_buffer);
free(output_start_stream_buffer);
free(output_end_stream_buffer);
free(input_desc);
free(output_desc);
return ret;
}
#else /* SOC_CACHE_INTERNAL_MEM_VIA_L1CACHE */
/* These are static due to:
* * Must be in DMA capable memory, so stack is not a safe place to put them
* * To avoid having to malloc/free them for every DMA operation
*/
static DRAM_ATTR crypto_dma_desc_t s_stream_in_desc;
static DRAM_ATTR crypto_dma_desc_t s_stream_out_desc;
static DRAM_ATTR uint8_t s_stream_in[AES_BLOCK_BYTES];
static DRAM_ATTR uint8_t s_stream_out[AES_BLOCK_BYTES];
/** Append a descriptor to the chain, set head if chain empty
*
* @param[out] head Pointer to the first/head node of the DMA descriptor linked list
* @param item Pointer to the DMA descriptor node that has to be appended
*/
static inline void dma_desc_append(crypto_dma_desc_t **head, crypto_dma_desc_t *item)
{
crypto_dma_desc_t *it;
if (*head == NULL) {
*head = item;
return;
}
it = *head;
while (it->next != 0) {
it = (crypto_dma_desc_t *)it->next;
}
it->dw0.suc_eof = 0;
it->next = item;
}
/**
* Generate a linked list pointing to a (huge) buffer in an descriptor array.
*
* The caller should ensure there is enough size to hold the array, by calling
* `dma_desc_get_required_num` with the same or less than the max_desc_size argument.
*
* @param[out] dmadesc Output of a descriptor array, the head should be fed to the DMA.
* @param data Buffer for the descriptors to point to.
* @param len Size (or length for TX) of the buffer
* @param max_desc_size Maximum length of each descriptor
* @param isrx The RX DMA may require the buffer to be word-aligned, set to true for a RX link, otherwise false.
*/
static inline void dma_desc_setup_link(crypto_dma_desc_t* dmadesc, const uint8_t *data, int len, int max_desc_size, bool isrx)
{
int i = 0;
while (len) {
int dmachunklen = len;
if (dmachunklen > max_desc_size) {
dmachunklen = max_desc_size;
}
if (isrx) {
//Receive needs DMA length rounded to next 32-bit boundary
dmadesc[i].dw0.size = (dmachunklen + 3) & (~3);
dmadesc[i].dw0.length = (dmachunklen + 3) & (~3);
} else {
dmadesc[i].dw0.size = dmachunklen;
dmadesc[i].dw0.length = dmachunklen;
}
dmadesc[i].buffer = (void *)data;
dmadesc[i].dw0.suc_eof = 0;
dmadesc[i].dw0.owner = DMA_DESCRIPTOR_BUFFER_OWNER_DMA;
dmadesc[i].next = &dmadesc[i + 1];
len -= dmachunklen;
data += dmachunklen;
i++;
}
dmadesc[i - 1].dw0.suc_eof = 1; //Mark last DMA desc as end of stream.
dmadesc[i - 1].next = NULL;
}
/* Encrypt/decrypt the input using DMA
* The function esp_aes_process_dma zeroises the output buffer in the case of following conditions:
* 1. If key is not written in the hardware
* 2. Memory allocation failures
* 3. If AES interrupt is enabled and ISR initialisation fails
* 4. Failure in any of the AES operations
*/
int esp_aes_process_dma(esp_aes_context *ctx, const unsigned char *input, unsigned char *output, size_t len, uint8_t *stream_out)
{
crypto_dma_desc_t *in_desc_head = NULL, *out_desc_head = NULL;
crypto_dma_desc_t *out_desc_tail = NULL; /* pointer to the final output descriptor */
crypto_dma_desc_t *block_desc = NULL, *block_in_desc = NULL, *block_out_desc = NULL;
size_t crypto_dma_desc_num = 0;
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;
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) {
mbedtls_platform_zeroize(output, len);
return MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH;
}
if (block_bytes > 0) {
/* Flush cache if input in external ram */
#if (CONFIG_SPIRAM && SOC_PSRAM_DMA_CAPABLE)
if (esp_ptr_external_ram(input)) {
if (esp_cache_msync((void *)input, len, ESP_CACHE_MSYNC_FLAG_DIR_C2M | ESP_CACHE_MSYNC_FLAG_UNALIGNED) != ESP_OK) {
mbedtls_platform_zeroize(output, len);
ESP_LOGE(TAG, "Cache sync failed for the input in external RAM");
return -1;
}
}
if (esp_ptr_external_ram(output)) {
size_t dcache_line_size;
ret = esp_cache_get_alignment(ESP_CACHE_MALLOC_FLAG_PSRAM, &dcache_line_size);
if (ret != ESP_OK) {
return ret;
}
if ((((intptr_t)(output) & (dcache_line_size - 1)) != 0) || (block_bytes % dcache_line_size != 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 (!s_check_dma_capable(input)) {
input_needs_realloc = true;
}
if (!s_check_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 considering the 16 byte alignment requirement for EDMA */
crypto_dma_desc_num = dma_desc_get_required_num(block_bytes, DMA_DESCRIPTOR_BUFFER_MAX_SIZE_16B_ALIGNED);
/* Allocate both in and out descriptors to save a malloc/free per function call */
block_desc = heap_caps_aligned_calloc(8, crypto_dma_desc_num * 2, sizeof(crypto_dma_desc_t), MALLOC_CAP_DMA);
if (block_desc == NULL) {
mbedtls_platform_zeroize(output, len);
ESP_LOGE(TAG, "Failed to allocate memory");
return -1;
}
block_in_desc = block_desc;
block_out_desc = block_desc + crypto_dma_desc_num;
// the size field has 12 bits, but 0 not for 4096.
// to avoid possible problem when the size is not word-aligned, we only use 4096-4 per desc.
// Maximum size of data in the buffer that a DMA descriptor can hold.
dma_desc_setup_link(block_in_desc, input, block_bytes, DMA_DESCRIPTOR_BUFFER_MAX_SIZE_4B_ALIGNED, 0);
//Limit max inlink descriptor length to be 16 byte aligned, require for EDMA
dma_desc_setup_link(block_out_desc, output, block_bytes, DMA_DESCRIPTOR_BUFFER_MAX_SIZE_16B_ALIGNED, 0);
/* Setup in/out start descriptors */
dma_desc_append(&in_desc_head, block_in_desc);
dma_desc_append(&out_desc_head, block_out_desc);
out_desc_tail = &block_out_desc[crypto_dma_desc_num - 1];
}
/* Any leftover bytes which are appended as an additional DMA list */
if (stream_bytes > 0) {
memset(&s_stream_in_desc, 0, sizeof(crypto_dma_desc_t));
memset(&s_stream_out_desc, 0, sizeof(crypto_dma_desc_t));
memset(s_stream_in, 0, AES_BLOCK_BYTES);
memset(s_stream_out, 0, AES_BLOCK_BYTES);
memcpy(s_stream_in, input + block_bytes, stream_bytes);
dma_desc_setup_link(&s_stream_in_desc, s_stream_in, AES_BLOCK_BYTES, DMA_DESCRIPTOR_BUFFER_MAX_SIZE_4B_ALIGNED, 0);
dma_desc_setup_link(&s_stream_out_desc, s_stream_out, AES_BLOCK_BYTES, DMA_DESCRIPTOR_BUFFER_MAX_SIZE_4B_ALIGNED, 0);
/* Link with block descriptors */
dma_desc_append(&in_desc_head, &s_stream_in_desc);
dma_desc_append(&out_desc_head, &s_stream_out_desc);
out_desc_tail = &s_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_OK) {
ESP_LOGE(TAG, "ESP-AES ISR initialisation failed");
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);
if (esp_aes_dma_wait_complete(use_intr, out_desc_tail) < 0) {
ESP_LOGE(TAG, "esp_aes_dma_wait_complete failed");
ret = -1;
goto cleanup;
}
#if (CONFIG_SPIRAM && SOC_PSRAM_DMA_CAPABLE)
if (block_bytes > 0) {
if (esp_ptr_external_ram(output)) {
if(esp_cache_msync((void*)output, block_bytes, ESP_CACHE_MSYNC_FLAG_DIR_M2C | ESP_CACHE_MSYNC_FLAG_UNALIGNED) != ESP_OK) {
mbedtls_platform_zeroize(output, len);
ESP_LOGE(TAG, "Cache sync failed for the output in external RAM");
return -1;
}
}
}
#endif
aes_hal_transform_dma_finish();
if (stream_bytes > 0) {
memcpy(output + block_bytes, s_stream_out, stream_bytes);
memcpy(stream_out, s_stream_out, AES_BLOCK_BYTES);
}
cleanup:
if (ret != 0) {
mbedtls_platform_zeroize(output, len);
}
free(block_desc);
return ret;
}
#endif /* SOC_CACHE_INTERNAL_MEM_VIA_L1CACHE */
#if CONFIG_MBEDTLS_HARDWARE_GCM
/* Encrypt/decrypt with AES-GCM the input using DMA
* The function esp_aes_process_dma_gcm zeroises the output buffer in the case of following conditions:
* 1. If key is not written in the hardware
* 2. Memory allocation failures
* 3. If AES interrupt is enabled and ISR initialisation fails
* 4. Failure in any of the AES operations
*/
int esp_aes_process_dma_gcm(esp_aes_context *ctx, const unsigned char *input, unsigned char *output, size_t len, crypto_dma_desc_t *aad_desc, size_t aad_len)
{
crypto_dma_desc_t *in_desc_head = NULL, *out_desc_head = NULL, *len_desc = NULL;
crypto_dma_desc_t *out_desc_tail = NULL; /* pointer to the final output descriptor */
crypto_dma_desc_t stream_in_desc, stream_out_desc;
crypto_dma_desc_t *block_desc = NULL, *block_in_desc = NULL, *block_out_desc = NULL;
size_t crypto_dma_desc_num = 0;
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) {
mbedtls_platform_zeroize(output, len);
return MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH;
}
/* Set up dma descriptors for input and output */
crypto_dma_desc_num = dma_desc_get_required_num(block_bytes, DMA_DESCRIPTOR_BUFFER_MAX_SIZE_4B_ALIGNED);
/* Allocate both in and out descriptors to save a malloc/free per function call, add 1 for length descriptor */
block_desc = heap_caps_calloc((crypto_dma_desc_num * 2) + 1, sizeof(crypto_dma_desc_t), MALLOC_CAP_DMA);
if (block_desc == NULL) {
mbedtls_platform_zeroize(output, len);
ESP_LOGE(TAG, "Failed to allocate memory");
return -1;
}
block_in_desc = block_desc;
len_desc = block_desc + crypto_dma_desc_num;
block_out_desc = block_desc + crypto_dma_desc_num + 1;
if (aad_desc != NULL) {
dma_desc_append(&in_desc_head, aad_desc);
}
if (block_bytes > 0) {
dma_desc_setup_link(block_in_desc, input, block_bytes, DMA_DESCRIPTOR_BUFFER_MAX_SIZE_4B_ALIGNED, 0);
dma_desc_setup_link(block_out_desc, output, block_bytes, DMA_DESCRIPTOR_BUFFER_MAX_SIZE_4B_ALIGNED, 0);
dma_desc_append(&in_desc_head, block_in_desc);
dma_desc_append(&out_desc_head, block_out_desc);
out_desc_tail = &block_out_desc[crypto_dma_desc_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);
dma_desc_setup_link(&stream_in_desc, stream_in, AES_BLOCK_BYTES, DMA_DESCRIPTOR_BUFFER_MAX_SIZE_4B_ALIGNED, 0);
dma_desc_setup_link(&stream_out_desc, stream_out, AES_BLOCK_BYTES, DMA_DESCRIPTOR_BUFFER_MAX_SIZE_4B_ALIGNED, 0);
dma_desc_append(&in_desc_head, &stream_in_desc);
dma_desc_append(&out_desc_head, &stream_out_desc);
out_desc_tail = &stream_out_desc;
}
len_buf[1] = __builtin_bswap32(aad_len * 8);
len_buf[3] = __builtin_bswap32(len * 8);
len_desc->dw0.length = sizeof(len_buf);
len_desc->dw0.size = sizeof(len_buf);
len_desc->dw0.owner = 1;
len_desc->dw0.suc_eof = 1;
len_desc->buffer = (uint8_t *)len_buf;
dma_desc_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_OK) {
ESP_LOGE(TAG, "ESP-AES ISR initialisation failed");
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);
if (esp_aes_dma_wait_complete(use_intr, out_desc_tail) < 0) {
ESP_LOGE(TAG, "esp_aes_dma_wait_complete failed");
ret = -1;
goto cleanup;
}
aes_hal_transform_dma_finish();
if (stream_bytes > 0) {
memcpy(output + block_bytes, stream_out, stream_bytes);
}
cleanup:
if (ret != 0) {
mbedtls_platform_zeroize(output, len);
}
free(block_desc);
return ret;
}
#endif //CONFIG_MBEDTLS_HARDWARE_GCM
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