/* Aes.h -- AES encryption / decryption
2008-08-05
Igor Pavlov
Public domain */

#ifndef __AES_H
#define __AES_H

#include "Types.h"

#define AES_BLOCK_SIZE 16

typedef struct
{
  unsigned numRounds2; /* = numRounds / 2 */
  UInt32 rkey[(14 + 1) * 4];
} CAes;

/* Call AesGenTables one time before other AES functions */
void AesGenTables(void);

/* keySize = 16 or 24 or 32 (bytes) */
void Aes_SetKeyEncode(CAes *p, const Byte *key, unsigned keySize);
void Aes_SetKeyDecode(CAes *p, const Byte *key, unsigned keySize);

/* Aes_Encode32 and Aes_Decode32 functions work with little-endian words.
  src and dest are pointers to 4 UInt32 words.
  arc and dest can point to same block */
void Aes_Encode32(const CAes *p, UInt32 *dest, const UInt32 *src);
void Aes_Decode32(const CAes *p, UInt32 *dest, const UInt32 *src);

typedef struct
{
  UInt32 prev[4];
  CAes aes;
} CAesCbc;

void AesCbc_Init(CAesCbc *p, const Byte *iv); /* iv size is AES_BLOCK_SIZE */

/* AesCbc_Encode and AesCbc_Decode:
  if (res <= size): Filter have converted res bytes
  if (res > size):  Filter have not converted anything. And it needs at
                    least res = AES_BLOCK_SIZE bytes to convert one block */

SizeT AesCbc_Encode(CAesCbc *p, Byte *data, SizeT size);
SizeT AesCbc_Decode(CAesCbc *p, Byte *data, SizeT size);

#endif
