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/**
* \file aes.h
*
* \brief AES block cipher
*
* Copyright (C) 2006-2014, ARM Limited, All Rights Reserved
*
* This file is part of mbed TLS (https://tls.mbed.org)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef MBEDTLS_AES_H
#define MBEDTLS_AES_H
#if !defined(MBEDTLS_CONFIG_FILE)
#include "config.h"
#else
#include MBEDTLS_CONFIG_FILE
#endif
#include <stddef.h>
#include <stdint.h>
/* padlock.c and aesni.c rely on these values! */
#define MBEDTLS_AES_ENCRYPT 1
#define MBEDTLS_AES_DECRYPT 0
#define MBEDTLS_ERR_AES_INVALID_KEY_LENGTH -0x0020 /**< Invalid key length. */
#define MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH -0x0022 /**< Invalid data input length. */
#if !defined(MBEDTLS_AES_ALT)
// Regular implementation
//
#ifdef __cplusplus
extern "C" {
#endif
/**
* \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
{
int nr; /*!< number of rounds */
uint32_t *rk; /*!< AES round keys */
uint32_t buf[68]; /*!< unaligned data */
}
mbedtls_aes_context;
/**
* \brief Initialize AES context
*
* \param ctx AES context to be initialized
*/
void mbedtls_aes_init( mbedtls_aes_context *ctx );
/**
* \brief Clear AES context
*
* \param ctx AES context to be cleared
*/
void mbedtls_aes_free( mbedtls_aes_context *ctx );
/**
* \brief AES key schedule (encryption)
*
* \param ctx AES context to be initialized
* \param key encryption key
* \param keybits must be 128, 192 or 256
*
* \return 0 if successful, or MBEDTLS_ERR_AES_INVALID_KEY_LENGTH
*/
int mbedtls_aes_setkey_enc( mbedtls_aes_context *ctx, const unsigned char *key,
unsigned int keybits );
/**
* \brief AES key schedule (decryption)
*
* \param ctx AES context to be initialized
* \param key decryption key
* \param keybits must be 128, 192 or 256
*
* \return 0 if successful, or MBEDTLS_ERR_AES_INVALID_KEY_LENGTH
*/
int mbedtls_aes_setkey_dec( mbedtls_aes_context *ctx, const unsigned char *key,
unsigned int keybits );
/**
* \brief AES-ECB block encryption/decryption
*
* \param ctx AES context
* \param mode MBEDTLS_AES_ENCRYPT or MBEDTLS_AES_DECRYPT
* \param input 16-byte input block
* \param output 16-byte output block
*
* \return 0 if successful
*/
int mbedtls_aes_crypt_ecb( mbedtls_aes_context *ctx,
int mode,
const unsigned char input[16],
unsigned char output[16] );
#if defined(MBEDTLS_CIPHER_MODE_CBC)
/**
* \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 MBEDTLS_AES_ENCRYPT or MBEDTLS_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 MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH
*/
int mbedtls_aes_crypt_cbc( mbedtls_aes_context *ctx,
int mode,
size_t length,
unsigned char iv[16],
const unsigned char *input,
unsigned char *output );
#endif /* MBEDTLS_CIPHER_MODE_CBC */
#if defined(MBEDTLS_CIPHER_MODE_CFB)
/**
* \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
* mbedtls_aes_setkey_enc() for both MBEDTLS_AES_ENCRYPT and MBEDTLS_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 MBEDTLS_AES_ENCRYPT or MBEDTLS_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 mbedtls_aes_crypt_cfb128( mbedtls_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
* mbedtls_aes_setkey_enc() for both MBEDTLS_AES_ENCRYPT and MBEDTLS_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 MBEDTLS_AES_ENCRYPT or MBEDTLS_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 mbedtls_aes_crypt_cfb8( mbedtls_aes_context *ctx,
int mode,
size_t length,
unsigned char iv[16],
const unsigned char *input,
unsigned char *output );
#endif /*MBEDTLS_CIPHER_MODE_CFB */
#if defined(MBEDTLS_CIPHER_MODE_CTR)
/**
* \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
* mbedtls_aes_setkey_enc() for both MBEDTLS_AES_ENCRYPT and MBEDTLS_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 mbedtls_aes_crypt_ctr( mbedtls_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 );
#endif /* MBEDTLS_CIPHER_MODE_CTR */
/**
* \brief Internal AES block encryption function
* (Only exposed to allow overriding it,
* see MBEDTLS_AES_ENCRYPT_ALT)
*
* \param ctx AES context
* \param input Plaintext block
* \param output Output (ciphertext) block
*/
void mbedtls_aes_encrypt( mbedtls_aes_context *ctx,
const unsigned char input[16],
unsigned char output[16] );
/**
* \brief Internal AES block decryption function
* (Only exposed to allow overriding it,
* see MBEDTLS_AES_DECRYPT_ALT)
*
* \param ctx AES context
* \param input Ciphertext block
* \param output Output (plaintext) block
*/
void mbedtls_aes_decrypt( mbedtls_aes_context *ctx,
const unsigned char input[16],
unsigned char output[16] );
#ifdef __cplusplus
}
#endif
#else /* MBEDTLS_AES_ALT */
#include "aes_alt.h"
#endif /* MBEDTLS_AES_ALT */
#ifdef __cplusplus
extern "C" {
#endif
/**
* \brief Checkup routine
*
* \return 0 if successful, or 1 if the test failed
*/
int mbedtls_aes_self_test( int verbose );
#ifdef __cplusplus
}
#endif
#endif /* aes.h */