/**
* \brief AES block cipher, ESP32 hardware accelerated version
* Based on mbedTLS FIPS-197 compliant version.
*
* Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
* Additions Copyright (C) 2016, 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.
*
*
*/
#ifndef ESP_AES_H
#define ESP_AES_H
#include "esp_types.h"
#include "rom/aes.h"
#ifdef __cplusplus
extern "C" {
#endif
/* padlock.c and aesni.c rely on these values! */
#define ESP_AES_ENCRYPT 1
#define ESP_AES_DECRYPT 0
#define ERR_ESP_AES_INVALID_KEY_LENGTH -0x0020 /**< Invalid key length. */
#define ERR_ESP_AES_INVALID_INPUT_LENGTH -0x0022 /**< Invalid data input length. */
/**
* \brief AES context structure
*
*/
typedef struct {
uint8_t key_bytes;
volatile uint8_t key_in_hardware; /* This variable is used for fault injection checks, so marked volatile to avoid optimisation */
uint8_t key[32];
} esp_aes_context;
/**
* \brief The AES XTS context-type definition.
*/
typedef struct
{
esp_aes_context crypt; /*!< The AES context to use for AES block
encryption or decryption. */
esp_aes_context tweak; /*!< The AES context used for tweak
computation. */
} esp_aes_xts_context;
/**
* \brief Lock access to AES hardware unit
*
* AES hardware unit can only be used by one
* consumer at a time.
*
* esp_aes_xxx API calls automatically manage locking & unlocking of
* hardware, this function is only needed if you want to call
* ets_aes_xxx functions directly.
*/
void esp_aes_acquire_hardware( void );
/**
* \brief Unlock access to AES hardware unit
*
* esp_aes_xxx API calls automatically manage locking & unlocking of
* hardware, this function is only needed if you want to call
* ets_aes_xxx functions directly.
*/
void esp_aes_release_hardware( void );
/**
* \brief Initialize AES context
*
* \param ctx AES context to be initialized
*/
void esp_aes_init( esp_aes_context *ctx );
/**
* \brief Clear AES context
*
* \param ctx AES context to be cleared
*/
void esp_aes_free( esp_aes_context *ctx );
/**
* \brief This function initializes the specified AES XTS context.
*
* It must be the first API called before using
* the context.
*
* \param ctx The AES XTS context to initialize.
*/
void esp_aes_xts_init( esp_aes_xts_context *ctx );
/**
* \brief This function releases and clears the specified AES XTS context.
*
* \param ctx The AES XTS context to clear.
*/
void esp_aes_xts_free( esp_aes_xts_context *ctx );
/**
* \brief AES set key schedule (encryption or decryption)
*
* \param ctx AES context to be initialized
* \param key encryption key
* \param keybits must be 128, 192 or 256
*
* \return 0 if successful, or ERR_AES_INVALID_KEY_LENGTH
*/
int esp_aes_setkey( esp_aes_context *ctx, const unsigned char *key, unsigned int keybits );
/**
* \brief AES-ECB block encryption/decryption
*
* \param ctx AES context
* \param mode AES_ENCRYPT or AES_DECRYPT
* \param input 16-byte input block
* \param output 16-byte output block
*
* \return 0 if successful
*/
int esp_aes_crypt_ecb( esp_aes_context *ctx, int mode, const unsigned char input[16], unsigned char output[16] );
/**
* \brief AES-CBC buffer encryption/decryption
* Length should be a multiple of the block
* size (16 bytes)
*
* \note Upon exit, the content of the IV is updated so that you can
* call the function same function again on the following
* block(s) of data and get the same result as if it was
* encrypted in one call. This allows a "streaming" usage.
* If on the other hand you need to retain the contents of the
* IV, you should either save it manually or use the cipher
* module instead.
*
* \param ctx AES context
* \param mode AES_ENCRYPT or AES_DECRYPT
* \param length length of the input data
* \param iv initialization vector (updated after use)
* \param input buffer holding the input data
* \param output buffer holding the output data
*
* \return 0 if successful, or ERR_AES_INVALID_INPUT_LENGTH
*/
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 );
/**
* \brief AES-CFB128 buffer encryption/decryption.
*
* Note: Due to the nature of CFB you should use the same key schedule for
* both encryption and decryption. So a context initialized with
* esp_aes_setkey_enc() for both AES_ENCRYPT and AES_DECRYPT.
*
* \note Upon exit, the content of the IV is updated so that you can
* call the function same function again on the following
* block(s) of data and get the same result as if it was
* encrypted in one call. This allows a "streaming" usage.
* If on the other hand you need to retain the contents of the
* IV, you should either save it manually or use the cipher
* module instead.
*
* \param ctx AES context
* \param mode AES_ENCRYPT or AES_DECRYPT
* \param length length of the input data
* \param iv_off offset in IV (updated after use)
* \param iv initialization vector (updated after use)
* \param input buffer holding the input data
* \param output buffer holding the output data
*
* \return 0 if successful
*/
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 );
/**
* \brief AES-CFB8 buffer encryption/decryption.
*
* Note: Due to the nature of CFB you should use the same key schedule for
* both encryption and decryption. So a context initialized with
* esp_aes_setkey_enc() for both AES_ENCRYPT and AES_DECRYPT.
*
* \note Upon exit, the content of the IV is updated so that you can
* call the function same function again on the following
* block(s) of data and get the same result as if it was
* encrypted in one call. This allows a "streaming" usage.
* If on the other hand you need to retain the contents of the
* IV, you should either save it manually or use the cipher
* module instead.
*
* \param ctx AES context
* \param mode AES_ENCRYPT or AES_DECRYPT
* \param length length of the input data
* \param iv initialization vector (updated after use)
* \param input buffer holding the input data
* \param output buffer holding the output data
*
* \return 0 if successful
*/
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 );
/**
* \brief AES-CTR buffer encryption/decryption
*
* Warning: You have to keep the maximum use of your counter in mind!
*
* Note: Due to the nature of CTR you should use the same key schedule for
* both encryption and decryption. So a context initialized with
* esp_aes_setkey_enc() for both AES_ENCRYPT and AES_DECRYPT.
*
* \param ctx AES context
* \param length The length of the data
* \param nc_off The offset in the current stream_block (for resuming
* within current cipher stream). The offset pointer to
* should be 0 at the start of a stream.
* \param nonce_counter The 128-bit nonce and counter.
* \param stream_block The saved stream-block for resuming. Is overwritten
* by the function.
* \param input The input data stream
* \param output The output data stream
*
* \return 0 if successful
*/
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 );
/**
* \brief This function prepares an XTS context for encryption and
* sets the encryption key.
*
* \param ctx The AES XTS context to which the key should be bound.
* \param key The encryption key. This is comprised of the XTS key1
* concatenated with the XTS key2.
* \param keybits The size of \p key passed in bits. Valid options are:
* <ul><li>256 bits (each of key1 and key2 is a 128-bit key)</li>
* <li>512 bits (each of key1 and key2 is a 256-bit key)</li></ul>
*
* \return \c 0 on success.
* \return #MBEDTLS_ERR_AES_INVALID_KEY_LENGTH on failure.
*/
int esp_aes_xts_setkey_enc( esp_aes_xts_context *ctx,
const unsigned char *key,
unsigned int keybits );
/**
* \brief This function prepares an XTS context for decryption and
* sets the decryption key.
*
* \param ctx The AES XTS context to which the key should be bound.
* \param key The decryption key. This is comprised of the XTS key1
* concatenated with the XTS key2.
* \param keybits The size of \p key passed in bits. Valid options are:
* <ul><li>256 bits (each of key1 and key2 is a 128-bit key)</li>
* <li>512 bits (each of key1 and key2 is a 256-bit key)</li></ul>
*
* \return \c 0 on success.
* \return #MBEDTLS_ERR_AES_INVALID_KEY_LENGTH on failure.
*/
int esp_aes_xts_setkey_dec( esp_aes_xts_context *ctx,
const unsigned char *key,
unsigned int keybits );
/**
* \brief Internal AES block encryption function
* (Only exposed to allow overriding it,
* see AES_ENCRYPT_ALT)
*
* \param ctx AES context
* \param input Plaintext block
* \param output Output (ciphertext) block
*/
int esp_internal_aes_encrypt( esp_aes_context *ctx, const unsigned char input[16], unsigned char output[16] );
/** Deprecated, see esp_aes_internal_encrypt */
void esp_aes_encrypt( esp_aes_context *ctx, const unsigned char input[16], unsigned char output[16] ) __attribute__((deprecated));
/**
* \brief Internal AES block decryption function
* (Only exposed to allow overriding it,
* see AES_DECRYPT_ALT)
*
* \param ctx AES context
* \param input Ciphertext block
* \param output Output (plaintext) block
*/
int esp_internal_aes_decrypt( esp_aes_context *ctx, const unsigned char input[16], unsigned char output[16] );
/** Deprecated, see esp_aes_internal_decrypt */
void esp_aes_decrypt( esp_aes_context *ctx, const unsigned char input[16], unsigned char output[16] ) __attribute__((deprecated));
#ifdef __cplusplus
}
#endif
#endif /* aes.h */