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// I retain copyright in this code but I encourage its free use provided
// that I don't carry any responsibility for the results. I am especially
// happy to see it used in free and open source software. If you do use
// it I would appreciate an acknowledgement of its origin in the code or
// the product that results and I would also appreciate knowing a little
// about the use to which it is being put. I am grateful to Frank Yellin
// for some ideas that are used in this implementation.
//
// Dr B. R. Gladman <brg@gladman.uk.net> 6th April 2001.
//
// This is an implementation of the AES encryption algorithm (Rijndael)
// designed by Joan Daemen and Vincent Rijmen. This version is designed
// to provide both fixed and dynamic block and key lengths and can also
// run with either big or little endian internal byte order (see aes.h).
// It inputs block and key lengths in bytes with the legal values being
// 16, 24 and 32.
/*
* Modified by Jari Ruusu, May 1 2001
* - Fixed some compile warnings, code was ok but gcc warned anyway.
* - Changed basic types: byte -> unsigned char, word -> u_int32_t
* - Major name space cleanup: Names visible to outside now begin
* with "aes_" or "AES_". A lot of stuff moved from aes.h to aes.c
* - Removed C++ and DLL support as part of name space cleanup.
* - Eliminated unnecessary recomputation of tables. (actual bug fix)
* - Merged precomputed constant tables to aes.c file.
* - Removed data alignment restrictions for portability reasons.
* - Made block and key lengths accept bit count (128/192/256)
* as well byte count (16/24/32).
* - Removed all error checks. This change also eliminated the need
* to preinitialize the context struct to zero.
* - Removed some totally unused constants.
*/
#ifndef _AES_H
#define _AES_H
#if defined(__linux__) && defined(__KERNEL__)
# include <linux/types.h>
#else
# include <sys/types.h>
#endif
// CONFIGURATION OPTIONS (see also aes.c)
//
// Define AES_BLOCK_SIZE to set the cipher block size (16, 24 or 32) or
// leave this undefined for dynamically variable block size (this will
// result in much slower code).
// IMPORTANT NOTE: AES_BLOCK_SIZE is in BYTES (16, 24, 32 or undefined). If
// left undefined a slower version providing variable block length is compiled
#define AES_BLOCK_SIZE 16
// The number of key schedule words for different block and key lengths
// allowing for method of computation which requires the length to be a
// multiple of the key length
//
// Nk = 4 6 8
// -------------
// Nb = 4 | 60 60 64
// 6 | 96 90 96
// 8 | 120 120 120
#if !defined(AES_BLOCK_SIZE) || (AES_BLOCK_SIZE == 32)
#define AES_KS_LENGTH 120
#define AES_RC_LENGTH 29
#else
#define AES_KS_LENGTH 4 * AES_BLOCK_SIZE
#define AES_RC_LENGTH (9 * AES_BLOCK_SIZE) / 8 - 8
#endif
typedef struct
{
u_int32_t aes_Nkey; // the number of words in the key input block
u_int32_t aes_Nrnd; // the number of cipher rounds
u_int32_t aes_e_key[AES_KS_LENGTH]; // the encryption key schedule
u_int32_t aes_d_key[AES_KS_LENGTH]; // the decryption key schedule
#if !defined(AES_BLOCK_SIZE)
u_int32_t aes_Ncol; // the number of columns in the cipher state
#endif
} aes_context;
// THE CIPHER INTERFACE
#if !defined(AES_BLOCK_SIZE)
extern void aes_set_blk(aes_context *, const int);
#endif
extern void aes_set_key(aes_context *, const unsigned char [], const int, const int);
extern void aes_encrypt(const aes_context *, const unsigned char [], unsigned char []);
extern void aes_decrypt(const aes_context *, const unsigned char [], unsigned char []);
// The block length inputs to aes_set_block and aes_set_key are in numbers
// of bytes or bits. The calls to subroutines must be made in the above
// order but multiple calls can be made without repeating earlier calls
// if their parameters have not changed.
#endif // _AES_H
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