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//------------------------------------------------------------------------------
/// \unit
///
/// !Purpose
/// 
/// Firmware encryption using AES hardware acceleration
/// This code is based on the AES reference implementation published by Paulo
/// Barreto and Vincent Rijmen.
/// 
/// !Usage
/// 
/// -# aes_hard_init: Initialize AES hardware 
/// -# aes_hard_init_CBC: for the CBC mode
/// -# aes_hard_init_CTR: for the CTR mode
/// -# aes_hard_init_ECB: for the ECB mode
/// -# aes_hard_cleanup: Cleans up AES
/// -# aes_hard_decrypt: Decrypts a variable-length cipher text
//------------------------------------------------------------------------------

#ifndef BOOTLOADER_AES_HARDWARE_H
#define BOOTLOADER_AES_HARDWARE_H

//------------------------------------------------------------------------------
// Includes
//------------------------------------------------------------------------------
#include "config.h"

#if defined(USE_ENCRYPTION) && defined(ENCRYPTION_AES_HARD)

//------------------------------------------------------------------------------
// Check configuration
//------------------------------------------------------------------------------
#if (ENCRYPTION_KEY_LENGTH != 16) && (ENCRYPTION_KEY_LENGTH != 24) \
 && (ENCRYPTION_KEY_LENGTH != 32)
  #error Hardware AES acceleration only supports ENCRYPTION_KEY_LENGTH bits keys.
#endif

#if (ENCRYPTION_BLOCK_LENGTH !=  16)
  #error Hardware AES acceleration only supports ENCRYPTION_KEY_LENGTH bits blocks.
#endif

#if !defined(ENCRYPTION_ECB) && \
    !defined(ENCRYPTION_CBC) && \
    !defined(ENCRYPTION_CTR)
  #error Only ECB, CBC & CTR modes are supported.
#endif

//------------------------------------------------------------------------------
// Definitions
//------------------------------------------------------------------------------
#ifdef ONLY_ONE_ENCRYPTION
#define ENCRYPTION_INIT     aes_hard_init
#define ENCRYPTION_CLEANUP  aes_hard_cleanup
#define ENCRYPTION_DECRYPT  aes_hard_decrypt
#endif

//------------------------------------------------------------------------------
//         Exported functions
//------------------------------------------------------------------------------
extern void aes_hard_init(void);
#ifndef ONLY_ONE_ENCRYPTION
extern void aes_hard_init_CBC(void);
extern void aes_hard_init_CTR(void);
extern void aes_hard_init_ECB(void);
#endif
extern void aes_hard_cleanup(void);
extern int aes_hard_decrypt(const unsigned char *, unsigned char *, unsigned int);

#endif // defined(USE_ENCRYPTION) && defined(ENCRYPTION_AES_HARD)
#endif // BOOTLOADER_AES_HARDWARE_H