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esp-idf/components/mbedtls/port/esp32s3/aes.c

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crypto accelerator support on esp32s3 SHA: passing unit tests RSA: pass tests AES: tests passing
2020-08-19 02:39:12 -04:00
/**
* \brief AES block cipher, ESP32-S2 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 <stdio.h>
#include <string.h>
#include <sys/lock.h>
#include "mbedtls/aes.h"
#include "esp32s3/aes.h"
#include "soc/cpu.h"
#include "soc/dport_reg.h"
#include "soc/hwcrypto_reg.h"
#include "soc/periph_defs.h"
#include "esp32s3/rom/lldesc.h"
#include "esp32s3/rom/cache.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 "soc/soc_memory_layout.h"
#include "soc/gdma_reg.h"
#include "soc/gdma_struct.h"
#include "soc/extmem_reg.h"
#include "freertos/FreeRTOS.h"
#include "freertos/semphr.h"
#define AES_BLOCK_BYTES 16
#define IV_WORDS 4
#define DMA_PERIPH_AES 6 /* DMA peripheral indexes */
#define DMA_PERIPH_SHA 7
/* 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
#define ESP_PUT_BE64(a, val) \
do { \
*(uint64_t*)(a) = __builtin_bswap64( (uint64_t)(val) ); \
} while (0)
/* DMA AES working modes*/
typedef enum {
ESP_AES_BLOCK_MODE_ECB = 0,
ESP_AES_BLOCK_MODE_CBC,
ESP_AES_BLOCK_MODE_OFB,
ESP_AES_BLOCK_MODE_CTR,
ESP_AES_BLOCK_MODE_CFB8,
ESP_AES_BLOCK_MODE_CFB128,
} esp_aes_mode_t;
#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 _lock_t s_aes_lock;
static inline bool valid_key_length(const esp_aes_context *ctx)
{
return ctx->key_bytes == 128 / 8 || ctx->key_bytes == 256 / 8;
}
void esp_aes_acquire_hardware( void )
{
_lock_acquire(&s_aes_lock);
/* Enable AES hardware */
//periph_module_enable(PERIPH_AES_DMA_MODULE);
/* Enable AES hardware */
REG_SET_BIT(SYSTEM_PERIP_CLK_EN1_REG, SYSTEM_CRYPTO_AES_CLK_EN | SYSTEM_DMA_CLK_EN);
/* Clear reset on digital signature unit,
otherwise AES unit is held in reset also. */
REG_CLR_BIT(SYSTEM_PERIP_RST_EN1_REG,
SYSTEM_CRYPTO_AES_RST | SYSTEM_DMA_RST | SYSTEM_CRYPTO_DS_RST);
}
/* Function to disable AES and Crypto DMA clocks and release locks */
void esp_aes_release_hardware( void )
{
/* Disable AES hardware */
//periph_module_disable(PERIPH_AES_DMA_MODULE);
/* Disable AES hardware */
REG_SET_BIT(SYSTEM_PERIP_RST_EN1_REG, SYSTEM_CRYPTO_AES_RST | SYSTEM_DMA_RST);
/* Don't return other units to reset, as this pulls
reset on RSA & SHA units, respectively. */
REG_CLR_BIT(SYSTEM_PERIP_CLK_EN1_REG, SYSTEM_CRYPTO_AES_CLK_EN | SYSTEM_DMA_CLK_EN);
_lock_release(&s_aes_lock);
}
/* Function to init AES context to zero */
void esp_aes_init( esp_aes_context *ctx )
{
if ( ctx == NULL ) {
return;
}
bzero( ctx, sizeof( esp_aes_context ) );
}
/* Function to clear AES context */
void esp_aes_free( esp_aes_context *ctx )
{
if ( ctx == NULL ) {
return;
}
bzero( ctx, sizeof( esp_aes_context ) );
}
/*
* AES key schedule (same for encryption or decryption, as hardware handles schedule)
*
*/
int esp_aes_setkey( esp_aes_context *ctx, const unsigned char *key,
unsigned int keybits )
{
if (keybits == 192) {
return MBEDTLS_ERR_AES_FEATURE_UNAVAILABLE;
}
if (keybits != 128 && keybits != 256) {
return MBEDTLS_ERR_AES_INVALID_KEY_LENGTH;
}
ctx->key_bytes = keybits / 8;
memcpy(ctx->key, key, ctx->key_bytes);
ctx->key_in_hardware = 0;
return 0;
}
/*
* Helper function to copy key from esp_aes_context buffer
* to hardware key registers.
*
* Call only while holding esp_aes_acquire_hardware().
*/
static void esp_aes_setkey_hardware( esp_aes_context *ctx, int crypt_mode)
{
const uint32_t MODE_DECRYPT_BIT = 4;
unsigned mode_reg_base = (crypt_mode == ESP_AES_ENCRYPT) ? 0 : MODE_DECRYPT_BIT;
ctx->key_in_hardware = 0;
for (int i = 0; i < ctx->key_bytes / 4; ++i) {
REG_WRITE(AES_KEY_BASE + i * 4, *(((uint32_t *)ctx->key) + i));
ctx->key_in_hardware += 4;
}
REG_WRITE(AES_MODE_REG, mode_reg_base + ((ctx->key_bytes / 8) - 2));
/* Fault injection check: all words of key data should have been written to hardware */
if (ctx->key_in_hardware < 16
|| ctx->key_in_hardware != ctx->key_bytes) {
abort();
}
}
/*
* Sets the AES DMA block mode (ECB, CBC, CFB, OFB, GCM, CTR)
* and intializes the required registers for that working mode
*/
static inline void esp_aes_mode_init(esp_aes_mode_t mode)
{
/* Set the algorithm mode CBC, CFB ... */
REG_WRITE(AES_BLOCK_MODE_REG, mode);
/* Presently hard-coding the INC function to 32 bit */
if (mode == ESP_AES_BLOCK_MODE_CTR) {
REG_WRITE(AES_INC_SEL_REG, 0);
}
}
/*
* Write IV to hardware iv registers
*/
static inline void esp_aes_set_iv(uint8_t *iv)
{
uint32_t *iv_words = (uint32_t *)iv;
uint32_t *reg_addr_buf = (uint32_t *)(AES_IV_BASE);
for (int i = 0; i < IV_WORDS; i++ ) {
REG_WRITE(&reg_addr_buf[i], iv_words[i]);
}
}
/*
* Read IV from hardware iv registers
*/
static inline void esp_aes_get_iv(uint8_t *iv)
{
esp_dport_access_read_buffer((uint32_t *)iv, AES_IV_BASE, IV_WORDS);
}
#if defined (CONFIG_MBEDTLS_AES_USE_INTERRUPT)
static IRAM_ATTR void esp_aes_complete_isr(void *arg)
{
BaseType_t higher_woken;
REG_WRITE(AES_INT_CLR_REG, 1);
xSemaphoreGiveFromISR(op_complete_sem, &higher_woken);
if (higher_woken) {
portYIELD_FROM_ISR();
}
}
static esp_err_t esp_aes_isr_initialise( void )
{
REG_WRITE(AES_INT_CLR_REG, 1);
REG_WRITE(AES_INT_ENA_REG, 1);
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)
{
__attribute__((unused)) volatile uint32_t dma_done;
#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
*/
while (REG_READ(AES_STATE_REG) != AES_STATE_DONE) {
}
/* Wait for DMA write operation to complete */
while (1) {
dma_done = REG_READ(CRYPTO_DMA_INT_RAW_REG);
// Wait for ownership of buffer to be transferred back to CPU
if ( (output_desc->owner == 0) ) {
break;
}
}
}
/* Init DMA related registers for AES operation */
static void esp_aes_dma_init(lldesc_t *input, lldesc_t *output)
{
/* Enable DMA mode */
REG_WRITE(AES_DMA_ENABLE_REG, 1);
REG_CLR_BIT(SYSTEM_PERIP_CLK_EN1_REG, SYSTEM_DMA_CLK_EN);
REG_SET_BIT(SYSTEM_PERIP_CLK_EN1_REG, SYSTEM_DMA_CLK_EN);
REG_SET_BIT(SYSTEM_PERIP_RST_EN1_REG, SYSTEM_DMA_RST);
REG_CLR_BIT(SYSTEM_PERIP_RST_EN1_REG, SYSTEM_DMA_RST);
/* Initialize DMA registers - this is probably mostly one off initialization
Note: hardcoded to DMA channel 0
*/
/* Note: burst mode has alignment requirements that we have not checked here */
GDMA.conf0[0].outdscr_burst_en = 0;
GDMA.conf0[0].indscr_burst_en = 0;
GDMA.conf0[0].out_data_burst_en = 0;
GDMA.conf0[0].in_data_burst_en = 0;
GDMA.peri_sel[0].peri_out_sel = DMA_PERIPH_AES;
GDMA.peri_sel[0].peri_in_sel = DMA_PERIPH_AES;
/* Set descriptor addresses: NOTE BACKWARDS AS DMA IN/OUT is reverse of AES in/out */
GDMA.out_link[0].addr = (uint32_t)input;
GDMA.in_link[0].addr = (uint32_t)output;
GDMA.sram_size[0].in_size = 3; /* 40 bytes, also minimum size for EDMA */
GDMA.sram_size[0].out_size = 3;
GDMA.conf1[0].in_ext_mem_bk_size = 0; // 16 bytes
GDMA.conf1[0].out_ext_mem_bk_size = 0; // 16 bytes
/*
printf("DESC HEAD pointers IN/outlink %p OUT/inlink / %p\n", in_desc_head, out_desc_head);
printf("before starting in_desc_head owner %d out_desc_head owner %d INT_RAW 0x%08x\n",
in_desc_head->owner,
out_desc_head->owner,
DMA.int_raw.val);
*/
//REG_SET_BIT(EXTMEM_CACHE_MMU_OWNER_REG, 1<<23); //mark PSRAM DCache as belonging to DMA
GDMA.conf0[0].in_rst = 1;
GDMA.conf0[0].in_rst = 0;
GDMA.conf0[0].out_rst = 1;
GDMA.conf0[0].out_rst = 0;
/* Start transfer */
GDMA.out_link[0].start = 1;
GDMA.in_link[0].start = 1;
}
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, *out_desc_head;
lldesc_t *block_desc = NULL, *block_in_desc, *block_out_desc;
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_desc, input, block_bytes, 0);
lldesc_setup_link(block_desc + lldesc_num, output, block_bytes, 0);
}
/* 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;
}
}
// 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;
esp_aes_dma_init(in_desc_head, out_desc_head);
/* Write the number of blocks */
REG_WRITE(AES_BLOCK_NUM_REG, blocks);
#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
{
REG_WRITE(AES_INT_ENA_REG, 0);
}
/* Start AES operation */
REG_WRITE(AES_TRIGGER_REG, 1);
esp_aes_dma_wait_complete(use_intr, out_desc_head);
#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
REG_WRITE(AES_DMA_EXIT_REG, 0);
/* Disable DMA mode */
REG_WRITE(AES_DMA_ENABLE_REG, 0);
if (stream_bytes > 0) {
memcpy(output + block_bytes, stream_out, stream_bytes);
}
cleanup:
free(non_icache_input);
free(block_desc);
return ret;
}
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;
esp_aes_setkey_hardware(ctx, ESP_AES_ENCRYPT);
esp_aes_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;
esp_aes_setkey_hardware(ctx, ESP_AES_DECRYPT);
esp_aes_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;
esp_aes_setkey_hardware(ctx, mode);
esp_aes_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;
esp_aes_setkey_hardware(ctx, mode);
esp_aes_mode_init(ESP_AES_BLOCK_MODE_CBC);
esp_aes_set_iv(iv);
r = esp_aes_process_dma(ctx, input, output, length, NULL);
if (r != 0) {
esp_aes_release_hardware();
return r;
}
esp_aes_get_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;
esp_aes_setkey_hardware(ctx, mode);
esp_aes_mode_init(ESP_AES_BLOCK_MODE_CFB8);
esp_aes_set_iv(iv);
r = esp_aes_process_dma(ctx, input, output, block_bytes, NULL);
esp_aes_get_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;
esp_aes_setkey_hardware(ctx, MBEDTLS_AES_ENCRYPT);
esp_aes_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;
esp_aes_setkey_hardware(ctx, mode);
esp_aes_mode_init(ESP_AES_BLOCK_MODE_CFB128);
esp_aes_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
esp_aes_get_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;
esp_aes_setkey_hardware(ctx, ESP_AES_DECRYPT);
esp_aes_mode_init(ESP_AES_BLOCK_MODE_OFB);
esp_aes_set_iv(iv);
r = esp_aes_process_dma(ctx, input, output, length, iv);
if (r != 0) {
esp_aes_release_hardware();
return r;
}
esp_aes_get_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;
esp_aes_setkey_hardware(ctx, ESP_AES_DECRYPT);
esp_aes_mode_init(ESP_AES_BLOCK_MODE_CTR);
esp_aes_set_iv(nonce_counter);
r = esp_aes_process_dma(ctx, input, output, length, stream_block);
if (r != 0) {
esp_aes_release_hardware();
return r;
}
esp_aes_get_iv(nonce_counter);
esp_aes_release_hardware();
}
*nc_off = n + (length % AES_BLOCK_BYTES);
return r;
}
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