/** * \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 "esp32s2beta/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 * * \note buf is able to hold 32 extra bytes, which can be used: * - for alignment purposes if VIA padlock is used, and/or * - to simplify key expansion in the 256-bit case by * generating an extra round key */ 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 */ /** * \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 performs an AES-OFB (Output Feedback Mode) * encryption or decryption operation. * * \param ctx The AES context to use for encryption or decryption. * It must be initialized and bound to a key. * \param length The length of the input data. * \param iv_off The offset in IV (updated after use). * It must point to a valid \c size_t. * \param iv The initialization vector (updated after use). * It must be a readable and writeable buffer of \c 16 Bytes. * \param input The buffer holding the input data. * It must be readable and of size \p length Bytes. * \param output The buffer holding the output data. * It must be writeable and of size \p length Bytes. * * \return \c 0 on success. */ 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 ); /** * \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: * * * \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 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_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)); /** AES-XTS buffer encryption/decryption */ int esp_aes_crypt_xts( esp_aes_xts_context *ctx, int mode, size_t length, const unsigned char data_unit[16], const unsigned char *input, unsigned char *output ); #ifdef __cplusplus } #endif #endif /* aes.h */