Earlier check was for only input buffer but it is quite likely to have output buffer also from non-DMA memory range and hence requirement to reallocate and then copy data from AES engine.
1524 lines
42 KiB
C
1524 lines
42 KiB
C
/**
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* \brief AES block cipher, ESP32-S2 hardware accelerated version
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* Based on mbedTLS FIPS-197 compliant version.
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*
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* Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
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* Additions Copyright (C) 2016-2020, Espressif Systems (Shanghai) PTE Ltd
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* SPDX-License-Identifier: Apache-2.0
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*
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* Licensed under the Apache License, Version 2.0 (the "License"); you may
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* not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*
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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 <stdio.h>
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#include <string.h>
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#include <sys/lock.h>
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#include "mbedtls/aes.h"
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#include "esp32s2/aes.h"
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#include "esp32s2/gcm.h"
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#include "soc/cpu.h"
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#include "soc/dport_reg.h"
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#include "soc/hwcrypto_reg.h"
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#include "soc/crypto_dma_reg.h"
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#include "soc/periph_defs.h"
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#include "esp32s2/rom/lldesc.h"
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#include "esp32s2/rom/cache.h"
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#include "esp_intr_alloc.h"
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#include "driver/periph_ctrl.h"
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#include "esp_log.h"
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#include "soc/lldesc.h"
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#include "esp_heap_caps.h"
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#include "sys/param.h"
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#include "esp_pm.h"
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#include "esp_crypto_lock.h"
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#include "freertos/FreeRTOS.h"
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#include "freertos/semphr.h"
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#define AES_BLOCK_BYTES 16
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#define IV_WORDS 4
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/* Max size of each chunk to process when output buffer is in unaligned external ram
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must be a multiple of block size
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*/
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#define AES_MAX_CHUNK_WRITE_SIZE 1600
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/* Input over this length will yield and wait for interrupt instead of
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busy-waiting, 30000 bytes is approx 0.5 ms */
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#define AES_DMA_INTR_TRIG_LEN 2000
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#define ESP_PUT_BE64(a, val) \
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do { \
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*(uint64_t*)(a) = __builtin_bswap64( (uint64_t)(val) ); \
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} while (0)
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/* DMA AES working modes*/
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typedef enum {
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ESP_AES_BLOCK_MODE_ECB = 0,
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ESP_AES_BLOCK_MODE_CBC,
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ESP_AES_BLOCK_MODE_OFB,
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ESP_AES_BLOCK_MODE_CTR,
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ESP_AES_BLOCK_MODE_CFB8,
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ESP_AES_BLOCK_MODE_CFB128,
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ESP_AES_BLOCK_MODE_GCM,
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} esp_aes_mode_t;
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#if defined(CONFIG_MBEDTLS_AES_USE_INTERRUPT)
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static SemaphoreHandle_t op_complete_sem;
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#if defined(CONFIG_PM_ENABLE)
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static esp_pm_lock_handle_t s_pm_cpu_lock;
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static esp_pm_lock_handle_t s_pm_sleep_lock;
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#endif
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#endif
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static const char *TAG = "esp-aes";
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static inline bool valid_key_length(const esp_aes_context *ctx)
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{
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return ctx->key_bytes == 128 / 8 || ctx->key_bytes == 192 / 8 || ctx->key_bytes == 256 / 8;
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}
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void esp_aes_acquire_hardware( void )
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{
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/* Need to lock DMA since it is shared with SHA block */
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esp_crypto_dma_lock_acquire();
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/* Enable AES hardware */
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periph_module_enable(PERIPH_AES_DMA_MODULE);
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}
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/* Function to disable AES and Crypto DMA clocks and release locks */
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void esp_aes_release_hardware( void )
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{
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/* Disable AES hardware */
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periph_module_disable(PERIPH_AES_DMA_MODULE);
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esp_crypto_dma_lock_release();
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}
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/* Function to init AES context to zero */
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void esp_aes_init( 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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/* Function to clear AES context */
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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 (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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/*
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* Helper function to copy key from esp_aes_context buffer
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* to hardware key registers.
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*
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* Call only while holding esp_aes_acquire_hardware().
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*/
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static void esp_aes_setkey_hardware( esp_aes_context *ctx, int crypt_mode)
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{
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const uint32_t MODE_DECRYPT_BIT = 4;
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unsigned mode_reg_base = (crypt_mode == ESP_AES_ENCRYPT) ? 0 : MODE_DECRYPT_BIT;
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ctx->key_in_hardware = 0;
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for (int i = 0; i < ctx->key_bytes / 4; ++i) {
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REG_WRITE(AES_KEY_BASE + i * 4, *(((uint32_t *)ctx->key) + i));
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ctx->key_in_hardware += 4;
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}
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REG_WRITE(AES_MODE_REG, mode_reg_base + ((ctx->key_bytes / 8) - 2));
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/* Fault injection check: all words of key data should have been written to hardware */
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if (ctx->key_in_hardware < 16
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|| ctx->key_in_hardware != ctx->key_bytes) {
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abort();
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}
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}
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/*
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* Sets the AES DMA block mode (ECB, CBC, CFB, OFB, GCM, CTR)
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* and intializes the required registers for that working mode
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*/
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static inline void esp_aes_mode_init(esp_aes_mode_t mode)
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{
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/* Set the algorithm mode CBC, CFB ... */
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REG_WRITE(AES_BLOCK_MODE_REG, mode);
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/* Presently hard-coding the INC function to 32 bit */
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if (mode == ESP_AES_BLOCK_MODE_CTR) {
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REG_WRITE(AES_INC_SEL_REG, 0);
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}
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}
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/*
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* Write IV to hardware iv registers
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*/
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static inline void esp_aes_set_iv(uint8_t *iv)
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{
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uint32_t *iv_words = (uint32_t*)iv;
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uint32_t *reg_addr_buf = (uint32_t *)(AES_IV_BASE);
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for (int i = 0; i<IV_WORDS; i++ ) {
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REG_WRITE(®_addr_buf[i], iv_words[i]);
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}
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}
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/*
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* Read IV from hardware iv registers
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*/
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static inline void esp_aes_get_iv(uint8_t *iv)
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{
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esp_dport_access_read_buffer((uint32_t*)iv, AES_IV_BASE, IV_WORDS);
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}
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#if defined (CONFIG_MBEDTLS_AES_USE_INTERRUPT)
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static IRAM_ATTR void esp_aes_complete_isr(void *arg)
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{
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BaseType_t higher_woken;
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REG_WRITE(AES_INT_CLR_REG, 1);
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xSemaphoreGiveFromISR(op_complete_sem, &higher_woken);
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if (higher_woken) {
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portYIELD_FROM_ISR();
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}
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}
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static esp_err_t esp_aes_isr_initialise( void )
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{
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REG_WRITE(AES_INT_CLR_REG, 1);
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REG_WRITE(AES_INT_ENA_REG, 1);
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if (op_complete_sem == NULL) {
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op_complete_sem = xSemaphoreCreateBinary();
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if (op_complete_sem == NULL) {
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ESP_LOGE(TAG, "Failed to create intr semaphore");
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return ESP_FAIL;
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}
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esp_intr_alloc(ETS_AES_INTR_SOURCE, 0, esp_aes_complete_isr, NULL, NULL);
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}
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/* AES is clocked proportionally to CPU clock, take power management lock */
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#ifdef CONFIG_PM_ENABLE
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if (s_pm_cpu_lock == NULL) {
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if (esp_pm_lock_create(ESP_PM_NO_LIGHT_SLEEP, 0, "aes_sleep", &s_pm_sleep_lock) != ESP_OK) {
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ESP_LOGE(TAG, "Failed to create PM sleep lock");
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return ESP_FAIL;
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}
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if (esp_pm_lock_create(ESP_PM_CPU_FREQ_MAX, 0, "aes_cpu", &s_pm_cpu_lock) != ESP_OK) {
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ESP_LOGE(TAG, "Failed to create PM CPU lock");
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return ESP_FAIL;
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}
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}
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esp_pm_lock_acquire(s_pm_cpu_lock);
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esp_pm_lock_acquire(s_pm_sleep_lock);
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#endif
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return ESP_OK;
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}
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#endif // CONFIG_MBEDTLS_AES_USE_INTERRUPT
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/* Wait for AES hardware block operation to complete */
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static void esp_aes_dma_wait_complete(bool use_intr, lldesc_t *output_desc)
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{
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volatile uint32_t dma_done;
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#if defined (CONFIG_MBEDTLS_AES_USE_INTERRUPT)
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if (use_intr) {
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if (!xSemaphoreTake(op_complete_sem, 2000 / portTICK_PERIOD_MS)) {
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/* indicates a fundamental problem with driver */
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ESP_LOGE("AES", "Timed out waiting for completion of AES Interrupt");
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abort();
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}
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#ifdef CONFIG_PM_ENABLE
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esp_pm_lock_release(s_pm_cpu_lock);
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esp_pm_lock_release(s_pm_sleep_lock);
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#endif // CONFIG_PM_ENABLE
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}
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#endif
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/* Checking this if interrupt is used also, to avoid
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issues with AES fault injection
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*/
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while (REG_READ(AES_STATE_REG) != AES_STATE_DONE) {
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}
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/* Wait for DMA write operation to complete */
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while (1) {
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dma_done = REG_READ(CRYPTO_DMA_INT_RAW_REG);
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// Wait for ownership of buffer to be transferred back to CPU
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if ( ((dma_done & INT_RAW_IN_SUC_EOF) == INT_RAW_IN_SUC_EOF) && (output_desc->owner == 0) ) {
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break;
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}
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}
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}
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/* Init DMA related registers for AES operation */
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static void esp_aes_dma_init(lldesc_t *input, lldesc_t *output)
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{
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/* Enable DMA mode */
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REG_WRITE(AES_DMA_ENABLE_REG, 1);
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|
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/* Reset DMA */
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SET_PERI_REG_MASK(CRYPTO_DMA_CONF0_REG, CONF0_REG_AHBM_RST | CONF0_REG_IN_RST | CONF0_REG_OUT_RST | CONF0_REG_AHBM_FIFO_RST);
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CLEAR_PERI_REG_MASK(CRYPTO_DMA_CONF0_REG, CONF0_REG_AHBM_RST | CONF0_REG_IN_RST | CONF0_REG_OUT_RST | CONF0_REG_AHBM_FIFO_RST);
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|
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/* Set DMA for AES Use */
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REG_WRITE(CRYPTO_DMA_AES_SHA_SELECT_REG, 0);
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|
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/* Set descriptors */
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CLEAR_PERI_REG_MASK(CRYPTO_DMA_OUT_LINK_REG, OUT_LINK_REG_OUTLINK_ADDR);
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SET_PERI_REG_MASK(CRYPTO_DMA_OUT_LINK_REG, ((uint32_t)(input))&OUT_LINK_REG_OUTLINK_ADDR);
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CLEAR_PERI_REG_MASK(CRYPTO_DMA_IN_LINK_REG, IN_LINK_REG_INLINK_ADDR);
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SET_PERI_REG_MASK(CRYPTO_DMA_IN_LINK_REG, ((uint32_t)(output))&IN_LINK_REG_INLINK_ADDR);
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|
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/* Start transfer */
|
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SET_PERI_REG_MASK(CRYPTO_DMA_OUT_LINK_REG, OUT_LINK_REG_OUTLINK_START);
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SET_PERI_REG_MASK(CRYPTO_DMA_IN_LINK_REG, IN_LINK_REG_INLINK_START);
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}
|
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|
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static int esp_aes_process_dma(esp_aes_context *ctx, const unsigned char *input, unsigned char *output, size_t len, uint8_t *stream_out);
|
|
|
|
|
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/* Output buffers in external ram needs to be 16-byte aligned and DMA cant access input in the iCache mem range,
|
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reallocate them into internal memory and encrypt in chunks to avoid
|
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having to malloc too big of a buffer
|
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*/
|
|
|
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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)
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{
|
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size_t chunk_len;
|
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int ret = 0;
|
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int offset = 0;
|
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unsigned char *input_buf = NULL;
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unsigned char *output_buf = NULL;
|
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const unsigned char *dma_input;
|
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chunk_len = MIN(AES_MAX_CHUNK_WRITE_SIZE, len);
|
|
|
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if (realloc_input) {
|
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input_buf = heap_caps_malloc(chunk_len, MALLOC_CAP_DMA);
|
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|
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if (input_buf == NULL) {
|
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ESP_LOGE(TAG, "Failed to allocate memory");
|
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ret = -1;
|
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goto cleanup;
|
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}
|
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}
|
|
|
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if (realloc_output) {
|
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output_buf = heap_caps_malloc(chunk_len, MALLOC_CAP_DMA);
|
|
|
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if (output_buf == NULL) {
|
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ESP_LOGE(TAG, "Failed to allocate memory");
|
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ret = -1;
|
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goto cleanup;
|
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}
|
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} else {
|
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output_buf = output;
|
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}
|
|
|
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while (len) {
|
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chunk_len = MIN(AES_MAX_CHUNK_WRITE_SIZE, len);
|
|
|
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/* If input needs realloc then copy it, else use the input with offset*/
|
|
if (realloc_input) {
|
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memcpy(input_buf, input + offset, chunk_len);
|
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dma_input = input_buf;
|
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} else {
|
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dma_input = input + offset;
|
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}
|
|
|
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if (esp_aes_process_dma(ctx, dma_input, output_buf, chunk_len, stream_out) != 0) {
|
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ret = -1;
|
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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;
|
|
}
|
|
|
|
static void esp_gcm_ghash(esp_gcm_context *ctx, const unsigned char *x, size_t x_len, uint8_t *z);
|
|
|
|
/*
|
|
* Calculates the Initial Counter Block, J0
|
|
* and copies to to the esp_gcm_context
|
|
*/
|
|
static void esp_gcm_derive_J0(esp_gcm_context *ctx)
|
|
{
|
|
uint8_t len_buf[16];
|
|
|
|
memset(ctx->J0, 0, AES_BLOCK_BYTES);
|
|
memset(len_buf, 0, AES_BLOCK_BYTES);
|
|
|
|
/* If IV is 96 bits J0 = ( IV || 0^31 || 1 ) */
|
|
if (ctx->iv_len == 12) {
|
|
memcpy(ctx->J0, ctx->iv, ctx->iv_len);
|
|
ctx->J0[AES_BLOCK_BYTES - 1] |= 1;
|
|
} else {
|
|
/* For IV != 96 bit, J0 = GHASH(IV || 0[s+64] || [len(IV)]64) */
|
|
/* First calculate GHASH on IV */
|
|
esp_gcm_ghash(ctx, ctx->iv, ctx->iv_len, ctx->J0);
|
|
/* Next create 128 bit block which is equal to
|
|
64 bit 0 + iv length truncated to 64 bits */
|
|
ESP_PUT_BE64(len_buf + 8, ctx->iv_len * 8);
|
|
/* Calculate GHASH on last block */
|
|
esp_gcm_ghash(ctx, len_buf, 16, ctx->J0);
|
|
|
|
|
|
}
|
|
}
|
|
|
|
|
|
/*
|
|
* Increment J0 as per GCM spec, by applying the Standard Incrementing
|
|
Function INC_32 to it.
|
|
* j is the counter which needs to be incremented which is
|
|
* copied to ctx->J0 after incrementing
|
|
*/
|
|
static void increment32_j0(esp_gcm_context *ctx, uint8_t *j)
|
|
{
|
|
uint8_t j_len = AES_BLOCK_BYTES;
|
|
memcpy(j, ctx->J0, AES_BLOCK_BYTES);
|
|
if (j) {
|
|
for (uint32_t i = j_len; i > (j_len - 4); i--) {
|
|
if (++j[i - 1] != 0) {
|
|
break;
|
|
}
|
|
}
|
|
memcpy(ctx->J0, j, AES_BLOCK_BYTES);
|
|
}
|
|
}
|
|
|
|
/* Function to xor two data blocks */
|
|
static void xor_data(uint8_t *d, const uint8_t *s)
|
|
{
|
|
uint32_t *dst = (uint32_t *) d;
|
|
uint32_t *src = (uint32_t *) s;
|
|
*dst++ ^= *src++;
|
|
*dst++ ^= *src++;
|
|
*dst++ ^= *src++;
|
|
*dst++ ^= *src++;
|
|
}
|
|
|
|
|
|
/*
|
|
* 32-bit integer manipulation macros (big endian)
|
|
*/
|
|
#ifndef GET_UINT32_BE
|
|
#define GET_UINT32_BE(n,b,i) \
|
|
{ \
|
|
(n) = ( (uint32_t) (b)[(i) ] << 24 ) \
|
|
| ( (uint32_t) (b)[(i) + 1] << 16 ) \
|
|
| ( (uint32_t) (b)[(i) + 2] << 8 ) \
|
|
| ( (uint32_t) (b)[(i) + 3] ); \
|
|
}
|
|
#endif
|
|
|
|
#ifndef PUT_UINT32_BE
|
|
#define PUT_UINT32_BE(n,b,i) \
|
|
{ \
|
|
(b)[(i) ] = (unsigned char) ( (n) >> 24 ); \
|
|
(b)[(i) + 1] = (unsigned char) ( (n) >> 16 ); \
|
|
(b)[(i) + 2] = (unsigned char) ( (n) >> 8 ); \
|
|
(b)[(i) + 3] = (unsigned char) ( (n) ); \
|
|
}
|
|
#endif
|
|
|
|
/* Based on MbedTLS's implemenation
|
|
*
|
|
* Precompute small multiples of H, that is set
|
|
* HH[i] || HL[i] = H times i,
|
|
* where i is seen as a field element as in [MGV], ie high-order bits
|
|
* correspond to low powers of P. The result is stored in the same way, that
|
|
* is the high-order bit of HH corresponds to P^0 and the low-order bit of HL
|
|
* corresponds to P^127.
|
|
*/
|
|
static int gcm_gen_table( esp_gcm_context *ctx )
|
|
{
|
|
int i, j;
|
|
uint64_t hi, lo;
|
|
uint64_t vl, vh;
|
|
unsigned char *h;
|
|
|
|
h = ctx->H;
|
|
|
|
/* pack h as two 64-bits ints, big-endian */
|
|
GET_UINT32_BE( hi, h, 0 );
|
|
GET_UINT32_BE( lo, h, 4 );
|
|
vh = (uint64_t) hi << 32 | lo;
|
|
|
|
GET_UINT32_BE( hi, h, 8 );
|
|
GET_UINT32_BE( lo, h, 12 );
|
|
vl = (uint64_t) hi << 32 | lo;
|
|
|
|
/* 8 = 1000 corresponds to 1 in GF(2^128) */
|
|
ctx->HL[8] = vl;
|
|
ctx->HH[8] = vh;
|
|
|
|
/* 0 corresponds to 0 in GF(2^128) */
|
|
ctx->HH[0] = 0;
|
|
ctx->HL[0] = 0;
|
|
|
|
for( i = 4; i > 0; i >>= 1 )
|
|
{
|
|
uint32_t T = ( vl & 1 ) * 0xe1000000U;
|
|
vl = ( vh << 63 ) | ( vl >> 1 );
|
|
vh = ( vh >> 1 ) ^ ( (uint64_t) T << 32);
|
|
|
|
ctx->HL[i] = vl;
|
|
ctx->HH[i] = vh;
|
|
}
|
|
|
|
for( i = 2; i <= 8; i *= 2 )
|
|
{
|
|
uint64_t *HiL = ctx->HL + i, *HiH = ctx->HH + i;
|
|
vh = *HiH;
|
|
vl = *HiL;
|
|
for( j = 1; j < i; j++ )
|
|
{
|
|
HiH[j] = vh ^ ctx->HH[j];
|
|
HiL[j] = vl ^ ctx->HL[j];
|
|
}
|
|
}
|
|
|
|
return( 0 );
|
|
}
|
|
/*
|
|
* Shoup's method for multiplication use this table with
|
|
* last4[x] = x times P^128
|
|
* where x and last4[x] are seen as elements of GF(2^128) as in [MGV]
|
|
*/
|
|
static const uint64_t last4[16] =
|
|
{
|
|
0x0000, 0x1c20, 0x3840, 0x2460,
|
|
0x7080, 0x6ca0, 0x48c0, 0x54e0,
|
|
0xe100, 0xfd20, 0xd940, 0xc560,
|
|
0x9180, 0x8da0, 0xa9c0, 0xb5e0
|
|
};
|
|
/* Based on MbedTLS's implemenation
|
|
*
|
|
* Sets output to x times H using the precomputed tables.
|
|
* x and output are seen as elements of GF(2^128) as in [MGV].
|
|
*/
|
|
static void gcm_mult( esp_gcm_context *ctx, const unsigned char x[16],
|
|
unsigned char output[16] )
|
|
{
|
|
int i = 0;
|
|
unsigned char lo, hi, rem;
|
|
uint64_t zh, zl;
|
|
|
|
lo = x[15] & 0xf;
|
|
|
|
zh = ctx->HH[lo];
|
|
zl = ctx->HL[lo];
|
|
|
|
for( i = 15; i >= 0; i-- )
|
|
{
|
|
lo = x[i] & 0xf;
|
|
hi = x[i] >> 4;
|
|
|
|
if( i != 15 )
|
|
{
|
|
rem = (unsigned char) zl & 0xf;
|
|
zl = ( zh << 60 ) | ( zl >> 4 );
|
|
zh = ( zh >> 4 );
|
|
zh ^= (uint64_t) last4[rem] << 48;
|
|
zh ^= ctx->HH[lo];
|
|
zl ^= ctx->HL[lo];
|
|
|
|
}
|
|
|
|
rem = (unsigned char) zl & 0xf;
|
|
zl = ( zh << 60 ) | ( zl >> 4 );
|
|
zh = ( zh >> 4 );
|
|
zh ^= (uint64_t) last4[rem] << 48;
|
|
zh ^= ctx->HH[hi];
|
|
zl ^= ctx->HL[hi];
|
|
}
|
|
|
|
PUT_UINT32_BE( zh >> 32, output, 0 );
|
|
PUT_UINT32_BE( zh, output, 4 );
|
|
PUT_UINT32_BE( zl >> 32, output, 8 );
|
|
PUT_UINT32_BE( zl, output, 12 );
|
|
}
|
|
|
|
|
|
|
|
/* Update the key value in gcm context */
|
|
int esp_aes_gcm_setkey( esp_gcm_context *ctx,
|
|
mbedtls_cipher_id_t cipher,
|
|
const unsigned char *key,
|
|
unsigned int keybits )
|
|
{
|
|
if (keybits != 128 && keybits != 192 && keybits != 256) {
|
|
return MBEDTLS_ERR_AES_INVALID_KEY_LENGTH;
|
|
}
|
|
|
|
ctx->aes_ctx.key_bytes = keybits / 8;
|
|
|
|
memcpy(ctx->aes_ctx.key, key, ctx->aes_ctx.key_bytes);
|
|
|
|
return ( 0 );
|
|
}
|
|
|
|
|
|
/* AES-GCM GHASH calculation z = GHASH(x) using h0 hash key
|
|
*/
|
|
static void esp_gcm_ghash(esp_gcm_context *ctx, const unsigned char *x, size_t x_len, uint8_t *z)
|
|
{
|
|
|
|
uint8_t tmp[AES_BLOCK_BYTES];
|
|
|
|
memset(tmp, 0, AES_BLOCK_BYTES);
|
|
/* GHASH(X) is calculated on input string which is multiple of 128 bits
|
|
* If input string bit length is not multiple of 128 bits it needs to
|
|
* be padded by 0
|
|
*
|
|
* Steps:
|
|
* 1. Let X1, X2, ... , Xm-1, Xm denote the unique sequence of blocks such
|
|
* that X = X1 || X2 || ... || Xm-1 || Xm.
|
|
* 2. Let Y0 be the “zero block,” 0128.
|
|
* 3. Fori=1,...,m,letYi =(Yi-1 ^ Xi)•H.
|
|
* 4. Return Ym
|
|
*/
|
|
|
|
/* If input bit string is >= 128 bits, process full 128 bit blocks */
|
|
while (x_len >= AES_BLOCK_BYTES) {
|
|
|
|
xor_data(z, x);
|
|
gcm_mult(ctx, z, z);
|
|
|
|
x += AES_BLOCK_BYTES;
|
|
x_len -= AES_BLOCK_BYTES;
|
|
}
|
|
|
|
/* If input bit string is not multiple of 128 create last 128 bit
|
|
* block by padding necessary 0s
|
|
*/
|
|
if (x_len) {
|
|
memcpy(tmp, x, x_len);
|
|
xor_data(z, tmp);
|
|
gcm_mult(ctx, z, z);
|
|
}
|
|
}
|
|
|
|
|
|
/* Function to init AES GCM context to zero */
|
|
void esp_aes_gcm_init( esp_gcm_context *ctx)
|
|
{
|
|
if (ctx == NULL) {
|
|
return;
|
|
}
|
|
|
|
bzero(ctx, sizeof(esp_gcm_context));
|
|
|
|
ctx->gcm_state = ESP_AES_GCM_STATE_INIT;
|
|
}
|
|
|
|
/* Function to clear AES-GCM context */
|
|
void esp_aes_gcm_free( esp_gcm_context *ctx)
|
|
{
|
|
if (ctx == NULL) {
|
|
return;
|
|
}
|
|
bzero(ctx, sizeof(esp_gcm_context));
|
|
}
|
|
|
|
/* Setup AES-GCM */
|
|
int esp_aes_gcm_starts( esp_gcm_context *ctx,
|
|
int mode,
|
|
const unsigned char *iv,
|
|
size_t iv_len,
|
|
const unsigned char *aad,
|
|
size_t aad_len )
|
|
{
|
|
/* IV and AD are limited to 2^64 bits, so 2^61 bytes */
|
|
/* IV is not allowed to be zero length */
|
|
if ( iv_len == 0 ||
|
|
( (uint64_t) iv_len ) >> 61 != 0 ||
|
|
( (uint64_t) aad_len ) >> 61 != 0 ) {
|
|
return ( MBEDTLS_ERR_GCM_BAD_INPUT );
|
|
}
|
|
|
|
if (!ctx) {
|
|
ESP_LOGE(TAG, "No AES context supplied");
|
|
return -1;
|
|
}
|
|
|
|
if (!iv) {
|
|
ESP_LOGE(TAG, "No IV supplied");
|
|
return -1;
|
|
}
|
|
|
|
if ( (aad_len > 0) && !aad) {
|
|
ESP_LOGE(TAG, "No aad supplied");
|
|
return -1;
|
|
}
|
|
|
|
/* Initialize AES-GCM context */
|
|
memset(ctx->ghash, 0, sizeof(ctx->ghash));
|
|
ctx->data_len = 0;
|
|
|
|
ctx->iv = iv;
|
|
ctx->iv_len = iv_len;
|
|
ctx->aad = aad;
|
|
ctx->aad_len = aad_len;
|
|
ctx->mode = mode;
|
|
|
|
/* H and the lookup table are only generated once per ctx */
|
|
if (ctx->gcm_state == ESP_AES_GCM_STATE_INIT) {
|
|
/* Lock the AES engine to calculate ghash key H in hardware */
|
|
esp_aes_acquire_hardware();
|
|
esp_aes_setkey_hardware( &ctx->aes_ctx, mode);
|
|
esp_aes_mode_init(ESP_AES_BLOCK_MODE_GCM);
|
|
/* Enable DMA mode */
|
|
REG_WRITE(AES_DMA_ENABLE_REG, 1);
|
|
REG_WRITE(AES_TRIGGER_REG, 1);
|
|
while (REG_READ(AES_STATE_REG) != AES_STATE_IDLE);
|
|
|
|
memcpy(ctx->H, (uint8_t *)AES_H_BASE, AES_BLOCK_BYTES);
|
|
|
|
esp_aes_release_hardware();
|
|
|
|
gcm_gen_table(ctx);
|
|
}
|
|
|
|
ctx->gcm_state = ESP_AES_GCM_STATE_START;
|
|
|
|
/* Once H is obtained we need to derive J0 (Initial Counter Block) */
|
|
esp_gcm_derive_J0(ctx);
|
|
|
|
/* The initial counter block keeps updating during the esp_gcm_update call
|
|
* however to calculate final authentication tag T we need original J0
|
|
* so we make a copy here
|
|
*/
|
|
memcpy(ctx->ori_j0, ctx->J0, 16);
|
|
|
|
esp_gcm_ghash(ctx, ctx->aad, ctx->aad_len, ctx->ghash);
|
|
|
|
return ( 0 );
|
|
}
|
|
|
|
/* Perform AES-GCM operation */
|
|
int esp_aes_gcm_update( esp_gcm_context *ctx,
|
|
size_t length,
|
|
const unsigned char *input,
|
|
unsigned char *output )
|
|
{
|
|
size_t nc_off = 0;
|
|
uint8_t nonce_counter[AES_BLOCK_BYTES] = {0};
|
|
uint8_t stream[AES_BLOCK_BYTES] = {0};
|
|
|
|
if (!ctx) {
|
|
ESP_LOGE(TAG, "No GCM context supplied");
|
|
return -1;
|
|
}
|
|
if (!input) {
|
|
ESP_LOGE(TAG, "No input supplied");
|
|
return -1;
|
|
}
|
|
if (!output) {
|
|
ESP_LOGE(TAG, "No output supplied");
|
|
return -1;
|
|
}
|
|
|
|
if ( output > input && (size_t) ( output - input ) < length ) {
|
|
return ( MBEDTLS_ERR_GCM_BAD_INPUT );
|
|
}
|
|
/* If this is the first time esp_gcm_update is getting called
|
|
* calculate GHASH on aad and preincrement the ICB
|
|
*/
|
|
if (ctx->gcm_state == ESP_AES_GCM_STATE_START) {
|
|
/* Jo needs to be incremented first time, later the CTR
|
|
* operation will auto update it
|
|
*/
|
|
increment32_j0(ctx, nonce_counter);
|
|
ctx->gcm_state = ESP_AES_GCM_STATE_UPDATE;
|
|
} else if (ctx->gcm_state == ESP_AES_GCM_STATE_UPDATE) {
|
|
memcpy(nonce_counter, ctx->J0, AES_BLOCK_BYTES);
|
|
}
|
|
|
|
/* Perform intermediate GHASH on "encrypted" data during decryption */
|
|
if (ctx->mode == ESP_AES_DECRYPT) {
|
|
esp_gcm_ghash(ctx, input, length, ctx->ghash);
|
|
}
|
|
|
|
/* Output = GCTR(J0, Input): Encrypt/Decrypt the input */
|
|
esp_aes_crypt_ctr(&ctx->aes_ctx, length, &nc_off, nonce_counter, stream, input, output);
|
|
|
|
/* ICB gets auto incremented after GCTR operation here so update the context */
|
|
memcpy(ctx->J0, nonce_counter, AES_BLOCK_BYTES);
|
|
|
|
/* Keep updating the length counter for final tag calculation */
|
|
ctx->data_len += length;
|
|
|
|
/* Perform intermediate GHASH on "encrypted" data during encryption*/
|
|
if (ctx->mode == ESP_AES_ENCRYPT) {
|
|
esp_gcm_ghash(ctx, output, length, ctx->ghash);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Function to read the tag value */
|
|
int esp_aes_gcm_finish( esp_gcm_context *ctx,
|
|
unsigned char *tag,
|
|
size_t tag_len )
|
|
{
|
|
size_t nc_off = 0;
|
|
uint8_t len_block[AES_BLOCK_BYTES] = {0};
|
|
|
|
if ( tag_len > 16 || tag_len < 4 ) {
|
|
return ( MBEDTLS_ERR_GCM_BAD_INPUT );
|
|
}
|
|
|
|
/* Calculate final GHASH on aad_len, data length */
|
|
ESP_PUT_BE64(len_block, ctx->aad_len * 8);
|
|
ESP_PUT_BE64(len_block + 8, ctx->data_len * 8);
|
|
esp_gcm_ghash(ctx, len_block, AES_BLOCK_BYTES, ctx->ghash);
|
|
|
|
/* Tag T = GCTR(J0, ) where T is truncated to tag_len */
|
|
esp_aes_crypt_ctr(&ctx->aes_ctx, tag_len, &nc_off, ctx->ori_j0, 0, ctx->ghash, tag);
|
|
|
|
return 0;
|
|
}
|
|
|
|
int esp_aes_gcm_crypt_and_tag( esp_gcm_context *ctx,
|
|
int mode,
|
|
size_t length,
|
|
const unsigned char *iv,
|
|
size_t iv_len,
|
|
const unsigned char *add,
|
|
size_t add_len,
|
|
const unsigned char *input,
|
|
unsigned char *output,
|
|
size_t tag_len,
|
|
unsigned char *tag )
|
|
{
|
|
int ret;
|
|
|
|
|
|
if ( ( ret = esp_aes_gcm_starts( ctx, mode, iv, iv_len, add, add_len ) ) != 0 ) {
|
|
return ( ret );
|
|
}
|
|
|
|
if ( ( ret = esp_aes_gcm_update( ctx, length, input, output ) ) != 0 ) {
|
|
return ( ret );
|
|
}
|
|
|
|
if ( ( ret = esp_aes_gcm_finish( ctx, tag, tag_len ) ) != 0 ) {
|
|
return ( ret );
|
|
}
|
|
|
|
return ( 0 );
|
|
}
|
|
|
|
int esp_aes_gcm_auth_decrypt( esp_gcm_context *ctx,
|
|
size_t length,
|
|
const unsigned char *iv,
|
|
size_t iv_len,
|
|
const unsigned char *add,
|
|
size_t add_len,
|
|
const unsigned char *tag,
|
|
size_t tag_len,
|
|
const unsigned char *input,
|
|
unsigned char *output )
|
|
{
|
|
int ret;
|
|
unsigned char check_tag[16];
|
|
size_t i;
|
|
int diff;
|
|
|
|
if ( ( ret = esp_aes_gcm_crypt_and_tag( ctx, ESP_AES_DECRYPT, length,
|
|
iv, iv_len, add, add_len,
|
|
input, output, tag_len, check_tag ) ) != 0 ) {
|
|
return ( ret );
|
|
}
|
|
|
|
/* Check tag in "constant-time" */
|
|
for ( diff = 0, i = 0; i < tag_len; i++ ) {
|
|
diff |= tag[i] ^ check_tag[i];
|
|
}
|
|
|
|
if ( diff != 0 ) {
|
|
bzero( output, length );
|
|
return ( MBEDTLS_ERR_GCM_AUTH_FAILED );
|
|
}
|
|
|
|
return ( 0 );
|
|
}
|