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/***************************************************************************
    TWOFISH2.C  -- Optimized C API calls for TWOFISH AES submission

    Submitters:
        Bruce Schneier, Counterpane Systems
        Doug Whiting,   Hi/fn
        John Kelsey,    Counterpane Systems
        Chris Hall,     Counterpane Systems
        David Wagner,   UC Berkeley

    Code Author:        Doug Whiting,   Hi/fn

    Version  1.00       April 1998

    Copyright 1998, Hi/fn and Counterpane Systems.  All rights reserved.

    Notes:
        *   Optimized version
        *   Tab size is set to 4 characters in this file

***************************************************************************/
#include    "aes.h"
#include    "table.h"

#include    <memory.h>
/*#include    <assert.h>*/

#if   defined(min_key)  && !defined(MIN_KEY)
#define MIN_KEY     1           /* toupper() */
#elif defined(part_key) && !defined(PART_KEY)
#define PART_KEY    1
#elif defined(zero_key) && !defined(ZERO_KEY)
#define ZERO_KEY    1
#endif


#ifdef USE_ASM
extern  int useAsm;             /* ok to use ASM code? */

typedef int cdecl CipherProc
   (cipherInstance *cipher, keyInstance *key,BYTE *input,int inputLen,BYTE *outBuffer);
typedef int cdecl KeySetupProc(keyInstance *key);

extern CipherProc   *blockEncrypt_86;   /* ptr to ASM functions */
extern CipherProc   *blockDecrypt_86;
extern KeySetupProc *reKey_86;
extern DWORD        cdecl TwofishAsmCodeSize(void);
#endif

/*
+*****************************************************************************
*           Constants/Macros/Tables
-****************************************************************************/

#define     CONST                   /* help syntax from C++, NOP here */

static CONST       fullSbox MDStab;        /* not actually const.  Initialized ONE time */
static int         needToBuildMDS=1;       /* is MDStab initialized yet? */

#define     BIG_TAB     0

#if BIG_TAB
static BYTE        bigTab[4][256][256];    /* pre-computed S-box */
#endif

/* number of rounds for various key sizes:  128, 192, 256 */
/* (ignored for now in optimized code!) */
static CONST int   numRounds[4]= {0,ROUNDS_128,ROUNDS_192,ROUNDS_256};

#if REENTRANT
#define     _sBox_   key->sBox8x32
#else
static      fullSbox _sBox_;        /* permuted MDStab based on keys */
#endif
#define _sBox8_(N) (((BYTE *) _sBox_) + (N)*256)

/*------- see what level of S-box precomputation we need to do -----*/
#if   defined(ZERO_KEY)
#define MOD_STRING  "(Zero S-box keying)"
#define Fe32_128(x,R)   \
    (   MDStab[0][p8(01)[p8(02)[_b(x,R  )]^b0(SKEY[1])]^b0(SKEY[0])] ^  \
        MDStab[1][p8(11)[p8(12)[_b(x,R+1)]^b1(SKEY[1])]^b1(SKEY[0])] ^  \
        MDStab[2][p8(21)[p8(22)[_b(x,R+2)]^b2(SKEY[1])]^b2(SKEY[0])] ^  \
        MDStab[3][p8(31)[p8(32)[_b(x,R+3)]^b3(SKEY[1])]^b3(SKEY[0])] )
#define Fe32_192(x,R)   \
    (   MDStab[0][p8(01)[p8(02)[p8(03)[_b(x,R  )]^b0(SKEY[2])]^b0(SKEY[1])]^b0(SKEY[0])] ^ \
        MDStab[1][p8(11)[p8(12)[p8(13)[_b(x,R+1)]^b1(SKEY[2])]^b1(SKEY[1])]^b1(SKEY[0])] ^ \
        MDStab[2][p8(21)[p8(22)[p8(23)[_b(x,R+2)]^b2(SKEY[2])]^b2(SKEY[1])]^b2(SKEY[0])] ^ \
        MDStab[3][p8(31)[p8(32)[p8(33)[_b(x,R+3)]^b3(SKEY[2])]^b3(SKEY[1])]^b3(SKEY[0])] )
#define Fe32_256(x,R)   \
    (   MDStab[0][p8(01)[p8(02)[p8(03)[p8(04)[_b(x,R  )]^b0(SKEY[3])]^b0(SKEY[2])]^b0(SKEY[1])]^b0(SKEY[0])] ^ \
        MDStab[1][p8(11)[p8(12)[p8(13)[p8(14)[_b(x,R+1)]^b1(SKEY[3])]^b1(SKEY[2])]^b1(SKEY[1])]^b1(SKEY[0])] ^ \
        MDStab[2][p8(21)[p8(22)[p8(23)[p8(24)[_b(x,R+2)]^b2(SKEY[3])]^b2(SKEY[2])]^b2(SKEY[1])]^b2(SKEY[0])] ^ \
        MDStab[3][p8(31)[p8(32)[p8(33)[p8(34)[_b(x,R+3)]^b3(SKEY[3])]^b3(SKEY[2])]^b3(SKEY[1])]^b3(SKEY[0])] )

#define GetSboxKey  DWORD SKEY[4];  /* local copy */ \
                    memcpy(SKEY,key->sboxKeys,sizeof(SKEY));
/*----------------------------------------------------------------*/
#elif defined(MIN_KEY)
#define MOD_STRING  "(Minimal keying)"
#define Fe32_(x,R)(MDStab[0][p8(01)[_sBox8_(0)[_b(x,R  )]] ^ b0(SKEY0)] ^ \
                   MDStab[1][p8(11)[_sBox8_(1)[_b(x,R+1)]] ^ b1(SKEY0)] ^ \
                   MDStab[2][p8(21)[_sBox8_(2)[_b(x,R+2)]] ^ b2(SKEY0)] ^ \
                   MDStab[3][p8(31)[_sBox8_(3)[_b(x,R+3)]] ^ b3(SKEY0)])
#define sbSet(N,i,J,v) { _sBox8_(N)[i+J] = v; }
#define GetSboxKey  DWORD SKEY0 = key->sboxKeys[0]      /* local copy */
/*----------------------------------------------------------------*/
#elif defined(PART_KEY)
#define MOD_STRING  "(Partial keying)"
#define Fe32_(x,R)(MDStab[0][_sBox8_(0)[_b(x,R  )]] ^ \
                   MDStab[1][_sBox8_(1)[_b(x,R+1)]] ^ \
                   MDStab[2][_sBox8_(2)[_b(x,R+2)]] ^ \