/*
---------------------------------------------------------------------------
Copyright (c) 1998-2010, Brian Gladman, Worcester, UK. All rights reserved.

The redistribution and use of this software (with or without changes)
is allowed without the payment of fees or royalties provided that:

  source code distributions include the above copyright notice, this
  list of conditions and the following disclaimer;

  binary distributions include the above copyright notice, this list
  of conditions and the following disclaimer in their documentation.

This software is provided 'as is' with no explicit or implied warranties
in respect of its operation, including, but not limited to, correctness
and fitness for purpose.
---------------------------------------------------------------------------
Issue Date: 20/12/2007
*/

#define DO_TABLES

#include "aes.h"
#include "aesopt.h"

#if defined(FIXED_TABLES)

#define sb_data(w) {\
    w(0x63), w(0x7c), w(0x77), w(0x7b), w(0xf2), w(0x6b), w(0x6f), w(0xc5),\
    w(0x30), w(0x01), w(0x67), w(0x2b), w(0xfe), w(0xd7), w(0xab), w(0x76),\
    w(0xca), w(0x82), w(0xc9), w(0x7d), w(0xfa), w(0x59), w(0x47), w(0xf0),\
    w(0xad), w(0xd4), w(0xa2), w(0xaf), w(0x9c), w(0xa4), w(0x72), w(0xc0),\
    w(0xb7), w(0xfd), w(0x93), w(0x26), w(0x36), w(0x3f), w(0xf7), w(0xcc),\
    w(0x34), w(0xa5), w(0xe5), w(0xf1), w(0x71), w(0xd8), w(0x31), w(0x15),\
    w(0x04), w(0xc7), w(0x23), w(0xc3), w(0x18), w(0x96), w(0x05), w(0x9a),\
    w(0x07), w(0x12), w(0x80), w(0xe2), w(0xeb), w(0x27), w(0xb2), w(0x75),\
    w(0x09), w(0x83), w(0x2c), w(0x1a), w(0x1b), w(0x6e), w(0x5a), w(0xa0),\
    w(0x52), w(0x3b), w(0xd6), w(0xb3), w(0x29), w(0xe3), w(0x2f), w(0x84),\
    w(0x53), w(0xd1), w(0x00), w(0xed), w(0x20), w(0xfc), w(0xb1), w(0x5b),\
    w(0x6a), w(0xcb), w(0xbe), w(0x39), w(0x4a), w(0x4c), w(0x58), w(0xcf),\
    w(0xd0), w(0xef), w(0xaa), w(0xfb), w(0x43), w(0x4d), w(0x33), w(0x85),\
    w(0x45), w(0xf9), w(0x02), w(0x7f), w(0x50), w(0x3c), w(0x9f), w(0xa8),\
    w(0x51), w(0xa3), w(0x40), w(0x8f), w(0x92), w(0x9d), w(0x38), w(0xf5),\
    w(0xbc), w(0xb6), w(0xda), w(0x21), w(0x10), w(0xff), w(0xf3), w(0xd2),\
    w(0xcd), w(0x0c), w(0x13), w(0xec), w(0x5f), w(0x97), w(0x44), w(0x17),\
    w(0xc4), w(0xa7), w(0x7e), w(0x3d), w(0x64), w(0x5d), w(0x19), w(0x73),\
    w(0x60), w(0x81), w(0x4f), w(0xdc), w(0x22), w(0x2a), w(0x90), w(0x88),\
    w(0x46), w(0xee), w(0xb8), w(0x14), w(0xde), w(0x5e), w(0x0b), w(0xdb),\
    w(0xe0), w(0x32), w(0x3a), w(0x0a), w(0x49), w(0x06), w(0x24), w(0x5c),\
    w(0xc2), w(0xd3), w(0xac), w(0x62), w(0x91), w(0x95), w(0xe4), w(0x79),\
    w(0xe7), w(0xc8), w(0x37), w(0x6d), w(0x8d), w(0xd5), w(0x4e), w(0xa9),\
    w(0x6c), w(0x56), w(0xf4), w(0xea), w(0x65), w(0x7a), w(0xae), w(0x08),\
    w(0xba), w(0x78), w(0x25), w(0x2e), w(0x1c), w(0xa6), w(0xb4), w(0xc6),\
    w(0xe8), w(0xdd), w(0x74), w(0x1f), w(0x4b), w(0xbd), w(0x8b), w(0x8a),\
    w(0x70), w(0x3e), w(0xb5), w(0x66), w(0x48), w(0x03), w(0xf6), w(0x0e),\
    w(0x61), w(0x35), w(0x57), w(0xb9), w(0x86), w(0xc1), w(0x1d), w(0x9e),\
    w(0xe1), w(0xf8), w(0x98), w(0x11), w(0x69), w(0xd9), w(0x8e), w(0x94),\
    w(0x9b), w(0x1e), w(0x87), w(0xe9), w(0xce), w(0x55), w(0x28), w(0xdf),\
    w(0x8c), w(0xa1), w(0x89), w(0x0d), w(0xbf), w(0xe6), w(0x42), w(0x68),\
    w(0x41), w(0x99), w(0x2d), w(0x0f), w(0xb0), w(0x54), w(0xbb), w(0x16) }

#define isb_data(w) {\
    w(0x52), w(0x09), w(0x6a), w(0xd5), w(0x30), w(0x36), w(0xa5), w(0x38),\
    w(0xbf), w(0x40), w(0xa3), w(0x9e), w(0x81), w(0xf3), w(0xd7), w(0xfb),\
    w(0x7c), w(0xe3), w(0x39), w(0x82), w(0x9b), w(0x2f), w(0xff), w(0x87),\
    w(0x34), w(0x8e), w(0x43), w(0x44), w(0xc4), w(0xde), w(0xe9), w(0xcb),\
    w(0x54), w(0x7b), w(0x94), w(0x32), w(0xa6), w(0xc2), w(0x23), w(0x3d),\
    w(0xee), w(0x4c), w(0x95), w(0x0b), w(0x42), w(0xfa), w(0xc3), w(0x4e),\
    w(0x08), w(0x2e), w(0xa1), w(0x66), w(0x28), w(0xd9), w(0x24), w(0xb2),\
    w(0x76), w(0x5b), w(0xa2), w(0x49), w(0x6d), w(0x8b), w(0xd1), w(0x25),\
    w(0x72), w(0xf8), w(0xf6), w(0x64), w(0x86), w(0x68), w(0x98), w(0x16),\
    w(0xd4), w(0xa4), w(0x5c), w(0xcc), w(0x5d), w(0x65), w(0xb6), w(0x92),\
    w(0x6c), w(0x70), w(0x48), w(0x50), w(0xfd), w(0xed), w(0xb9), w(0xda),\
    w(0x5e), w(0x15), w(0x46), w(0x57), w(0xa7), w(0x8d), w(0x9d), w(0x84),\
    w(0x90), w(0xd8), w(0xab), w(0x00), w(0x8c), w(0xbc), w(0xd3), w(0x0a),\
    w(0xf7), w(0xe4), w(0x58), w(0x05), w(0xb8), w(0xb3), w(0x45), w(0x06),\
    w(0xd0), w(0x2c), w(0x1e), w(0x8f), w(0xca), w(0x3f), w(0x0f), w(0x02),\
    w(0xc1), w(0xaf), w(0xbd), w(0x03), w(0x01), w(0x13), w(0x8a), w(0x6b),\
    w(0x3a), w(0x91), w(0x11), w(0x41), w(0x4f), w(0x67), w(0xdc), w(0xea),\
    w(0x97), w(0xf2), w(0xcf), w(0xce), w(0xf0), w(0xb4), w(0xe6), w(0x73),\
    w(0x96), w(0xac), w(0x74), w(0x22), w(0xe7), w(0xad), w(0x35), w(0x85),\
    w(0xe2), w(0xf9), w(0x37), w(0xe8), w(0x1c), w(0x75), w(0xdf), w(0x6e),\
    w(0x47), w(0xf1), w(0x1a), w(0x71), w(0x1d), w(0x29), w(0xc5), w(0x89),\
    w(0x6f), w(0xb7), w(0x62), w(0x0e), w(0xaa), w(0x18), w(0xbe), w(0x1b),\
    w(0xfc), w(0x56), w(0x3e), w(0x4b), w(0xc6), w(0xd2), w(0x79), w(0x20),\
    w(0x9a), w(0xdb), w(0xc0), w(0xfe), w(0x78), w(0xcd), w(0x5a), w(0xf4),\
    w(0x1f), w(0xdd), w(0xa8), w(0x33), w(0x88), w(0x07), w(0xc7), w(0x31),\
    w(0xb1), w(0x12), w(0x10), w(0x59), w(0x27), w(0x80), w(0xec), w(0x5f),\
    w(0x60), w(0x51), w(0x7f), w(0xa9), w(0x19), w(0xb5), w(0x4a), w(0x0d),\
    w(0x2d), w(0xe5), w(0x7a), w(0x9f), w(0x93), w(0xc9), w(0x9c), w(0xef),\
    w(0xa0), w(0xe0), w(0x3b), w(0x4d), w(0xae), w(0x2a), w(0xf5), w(0xb0),\
    w(0xc8), w(0xeb), w(0xbb), w(0x3c), w(0x83), w(0x53), w(0x99), w(0x61),\
    w(0x17), w(0x2b), w(0x04), w(0x7e), w(0xba), w(0x77), w(0xd6), w(0x26),\
    w(0xe1), w(0x69), w(0x14), w(0x63), w(0x55), w(0x21), w(0x0c), w(0x7d) }

#define mm_data(w) {\
    w(0x00), w(0x01), w(0x02), w(0x03), w(0x04), w(0x05), w(0x06), w(0x07),\
    w(0x08), w(0x09), w(0x0a), w(0x0b), w(0x0c), w(0x0d), w(0x0e), w(0x0f),\
    w(0x10), w(0x11), w(0x12), w(0x13), w(0x14), w(0x15), w(0x16), w(0x17),\
    w(0x18), w(0x19), w(0x1a), w(0x1b), w(0x1c), w(0x1d), w(0x1e), w(0x1f),\
    w(0x20), w(0x21), w(0x22), w(0x23), w(0x24), w(0x25), w(0x26), w(0x27),\
    w(0x28), w(0x29), w(0x2a), w(0x2b), w(0x2c), w(0x2d), w(0x2e), w(0x2f),\
    w(0x30), w(0x31), w(0x32), w(0x33), w(0x34), w(0x35), w(0x36), w(0x37),\
    w(0x38), w(0x39), w(0x3a), w(0x3b), w(0x3c), w(0x3d), w(0x3e), w(0x3f),\
    w(0x40), w(0x41), w(0x42), w(0x43), w(0x44), w(0x45), w(0x46), w(0x47),\
    w(0x48), w(0x49), w(0x4a), w(0x4b), w(0x4c), w(0x4d), w(0x4e), w(0x4f),\
    w(0x50), w(0x51), w(0x52), w(0x53), w(0x54), w(0x55), w(0x56), w(0x57),\
    w(0x58), w(0x59), w(0x5a), w(0x5b), w(0x5c), w(0x5d), w(0x5e), w(0x5f),\
    w(0x60), w(0x61), w(0x62), w(0x63), w(0x64), w(0x65), w(0x66), w(0x67),\
    w(0x68), w(0x69), w(0x6a), w(0x6b), w(0x6c), w(0x6d), w(0x6e), w(0x6f),\
    w(0x70), w(0x71), w(0x72), w(0x73), w(0x74), w(0x75), w(0x76), w(0x77),\
    w(0x78), w(0x79), w(0x7a), w(0x7b), w(0x7c), w(0x7d), w(0x7e), w(0x7f),\
    w(0x80), w(0x81), w(0x82), w(0x83), w(0x84), w(0x85), w(0x86), w(0x87),\
    w(0x88), w(0x89), w(0x8a), w(0x8b), w(0x8c), w(0x8d), w(0x8e), w(0x8f),\
    w(0x90), w(0x91), w(0x92), w(0x93), w(0x94), w(0x95), w(0x96), w(0x97),\
    w(0x98), w(0x99), w(0x9a), w(0x9b), w(0x9c), w(0x9d), w(0x9e), w(0x9f),\
    w(0xa0), w(0xa1), w(0xa2), w(0xa3), w(0xa4), w(0xa5), w(0xa6), w(0xa7),\
    w(0xa8), w(0xa9), w(0xaa), w(0xab), w(0xac), w(0xad), w(0xae), w(0xaf),\
    w(0xb0), w(0xb1), w(0xb2), w(0xb3), w(0xb4), w(0xb5), w(0xb6), w(0xb7),\
    w(0xb8), w(0xb9), w(0xba), w(0xbb), w(0xbc), w(0xbd), w(0xbe), w(0xbf),\
    w(0xc0), w(0xc1), w(0xc2), w(0xc3), w(0xc4), w(0xc5), w(0xc6), w(0xc7),\
    w(0xc8), w(0xc9), w(0xca), w(0xcb), w(0xcc), w(0xcd), w(0xce), w(0xcf),\
    w(0xd0), w(0xd1), w(0xd2), w(0xd3), w(0xd4), w(0xd5), w(0xd6), w(0xd7),\
    w(0xd8), w(0xd9), w(0xda), w(0xdb), w(0xdc), w(0xdd), w(0xde), w(0xdf),\
    w(0xe0), w(0xe1), w(0xe2), w(0xe3), w(0xe4), w(0xe5), w(0xe6), w(0xe7),\
    w(0xe8), w(0xe9), w(0xea), w(0xeb), w(0xec), w(0xed), w(0xee), w(0xef),\
    w(0xf0), w(0xf1), w(0xf2), w(0xf3), w(0xf4), w(0xf5), w(0xf6), w(0xf7),\
    w(0xf8), w(0xf9), w(0xfa), w(0xfb), w(0xfc), w(0xfd), w(0xfe), w(0xff) }

#define rc_data(w) {\
    w(0x01), w(0x02), w(0x04), w(0x08), w(0x10),w(0x20), w(0x40), w(0x80),\
    w(0x1b), w(0x36) }

#define h0(x)   (x)

#define w0(p)   bytes2word(p, 0, 0, 0)
#define w1(p)   bytes2word(0, p, 0, 0)
#define w2(p)   bytes2word(0, 0, p, 0)
#define w3(p)   bytes2word(0, 0, 0, p)

#define u0(p)   bytes2word(f2(p), p, p, f3(p))
#define u1(p)   bytes2word(f3(p), f2(p), p, p)
#define u2(p)   bytes2word(p, f3(p), f2(p), p)
#define u3(p)   bytes2word(p, p, f3(p), f2(p))

#define v0(p)   bytes2word(fe(p), f9(p), fd(p), fb(p))
#define v1(p)   bytes2word(fb(p), fe(p), f9(p), fd(p))
#define v2(p)   bytes2word(fd(p), fb(p), fe(p), f9(p))
#define v3(p)   bytes2word(f9(p), fd(p), fb(p), fe(p))

#endif

#if defined(FIXED_TABLES) || !defined(FF_TABLES)

#define f2(x)   ((x<<1) ^ (((x>>7) & 1) * WPOLY))
#define f4(x)   ((x<<2) ^ (((x>>6) & 1) * WPOLY) ^ (((x>>6) & 2) * WPOLY))
#define f8(x)   ((x<<3) ^ (((x>>5) & 1) * WPOLY) ^ (((x>>5) & 2) * WPOLY) \
                        ^ (((x>>5) & 4) * WPOLY))
#define f3(x)   (f2(x) ^ x)
#define f9(x)   (f8(x) ^ x)
#define fb(x)   (f8(x) ^ f2(x) ^ x)
#define fd(x)   (f8(x) ^ f4(x) ^ x)
#define fe(x)   (f8(x) ^ f4(x) ^ f2(x))

#else

#define f2(x) ((x) ? pow[log[x] + 0x19] : 0)
#define f3(x) ((x) ? pow[log[x] + 0x01] : 0)
#define f9(x) ((x) ? pow[log[x] + 0xc7] : 0)
#define fb(x) ((x) ? pow[log[x] + 0x68] : 0)
#define fd(x) ((x) ? pow[log[x] + 0xee] : 0)
#define fe(x) ((x) ? pow[log[x] + 0xdf] : 0)

#endif

#include "aestab.h"

#if defined(__cplusplus)
extern "C"
{
#endif

#if defined(FIXED_TABLES)

/* implemented in case of wrong call for fixed tables */

AES_RETURN aes_init(void)
{
    return EXIT_SUCCESS;
}

#else   /*  Generate the tables for the dynamic table option */

#if defined(FF_TABLES)

#define gf_inv(x)   ((x) ? pow[ 255 - log[x]] : 0)

#else 

/*  It will generally be sensible to use tables to compute finite
    field multiplies and inverses but where memory is scarse this
    code might sometimes be better. But it only has effect during
    initialisation so its pretty unimportant in overall terms.
*/

/*  return 2 ^ (n - 1) where n is the bit number of the highest bit
    set in x with x in the range 1 < x < 0x00000200.   This form is
    used so that locals within fi can be bytes rather than words
*/

static uint_8t hibit(const uint_32t x)
{   uint_8t r = (uint_8t)((x >> 1) | (x >> 2));

    r |= (r >> 2);
    r |= (r >> 4);
    return (r + 1) >> 1;
}

/* return the inverse of the finite field element x */

static uint_8t gf_inv(const uint_8t x)
{   uint_8t p1 = x, p2 = BPOLY, n1 = hibit(x), n2 = 0x80, v1 = 1, v2 = 0;

    if(x < 2) 
        return x;

    for( ; ; )
    {
        if(n1)
            while(n2 >= n1)             /* divide polynomial p2 by p1    */
            {
                n2 /= n1;               /* shift smaller polynomial left */ 
                p2 ^= (p1 * n2) & 0xff; /* and remove from larger one    */
                v2 ^= v1 * n2;          /* shift accumulated value and   */ 
                n2 = hibit(p2);         /* add into result               */
            }
        else
            return v1;

        if(n2)                          /* repeat with values swapped    */ 
            while(n1 >= n2)
            {
                n1 /= n2; 
                p1 ^= p2 * n1; 
                v1 ^= v2 * n1; 
                n1 = hibit(p1);
            }
        else
            return v2;
    }
}

#endif

/* The forward and inverse affine transformations used in the S-box */
uint_8t fwd_affine(const uint_8t x)
{   uint_32t w = x;
    w ^= (w << 1) ^ (w << 2) ^ (w << 3) ^ (w << 4);
    return 0x63 ^ ((w ^ (w >> 8)) & 0xff);
}

uint_8t inv_affine(const uint_8t x)
{   uint_32t w = x;
    w = (w << 1) ^ (w << 3) ^ (w << 6);
    return 0x05 ^ ((w ^ (w >> 8)) & 0xff);
}

static int init = 0;

AES_RETURN aes_init(void)
{   uint_32t  i, w;

#if defined(FF_TABLES)

    uint_8t  pow[512], log[256];

    if(init)
        return EXIT_SUCCESS;
    /*  log and power tables for GF(2^8) finite field with
        WPOLY as modular polynomial - the simplest primitive
        root is 0x03, used here to generate the tables
    */

    i = 0; w = 1;
    do
    {
        pow[i] = (uint_8t)w;
        pow[i + 255] = (uint_8t)w;
        log[w] = (uint_8t)i++;
        w ^=  (w << 1) ^ (w & 0x80 ? WPOLY : 0);
    }
    while (w != 1);

#else
    if(init)
        return EXIT_SUCCESS;
#endif

    for(i = 0, w = 1; i < RC_LENGTH; ++i)
    {
        t_set(r,c)[i] = bytes2word(w, 0, 0, 0);
        w = f2(w);
    }

    for(i = 0; i < 256; ++i)
    {   uint_8t    b;

        b = fwd_affine(gf_inv((uint_8t)i));
        w = bytes2word(f2(b), b, b, f3(b));

#if defined( SBX_SET )
        t_set(s,box)[i] = b;
#endif

#if defined( FT1_SET )                 /* tables for a normal encryption round */
        t_set(f,n)[i] = w;
#endif
#if defined( FT4_SET )
        t_set(f,n)[0][i] = w;
        t_set(f,n)[1][i] = upr(w,1);
        t_set(f,n)[2][i] = upr(w,2);
        t_set(f,n)[3][i] = upr(w,3);
#endif
        w = bytes2word(b, 0, 0, 0);

#if defined( FL1_SET )            /* tables for last encryption round (may also   */
        t_set(f,l)[i] = w;        /* be used in the key schedule)                 */
#endif
#if defined( FL4_SET )
        t_set(f,l)[0][i] = w;
        t_set(f,l)[1][i] = upr(w,1);
        t_set(f,l)[2][i] = upr(w,2);
        t_set(f,l)[3][i] = upr(w,3);
#endif

#if defined( LS1_SET )			/* table for key schedule if t_set(f,l) above is*/
        t_set(l,s)[i] = w;      /* not of the required form                     */
#endif
#if defined( LS4_SET )
        t_set(l,s)[0][i] = w;
        t_set(l,s)[1][i] = upr(w,1);
        t_set(l,s)[2][i] = upr(w,2);
        t_set(l,s)[3][i] = upr(w,3);
#endif

        b = gf_inv(inv_affine((uint_8t)i));
        w = bytes2word(fe(b), f9(b), fd(b), fb(b));

#if defined( IM1_SET )			/* tables for the inverse mix column operation  */
        t_set(i,m)[b] = w;
#endif
#if defined( IM4_SET )
        t_set(i,m)[0][b] = w;
        t_set(i,m)[1][b] = upr(w,1);
        t_set(i,m)[2][b] = upr(w,2);
        t_set(i,m)[3][b] = upr(w,3);
#endif

#if defined( ISB_SET )
        t_set(i,box)[i] = b;
#endif
#if defined( IT1_SET )			/* tables for a normal decryption round */
        t_set(i,n)[i] = w;
#endif
#if defined( IT4_SET )
        t_set(i,n)[0][i] = w;
        t_set(i,n)[1][i] = upr(w,1);
        t_set(i,n)[2][i] = upr(w,2);
        t_set(i,n)[3][i] = upr(w,3);
#endif
        w = bytes2word(b, 0, 0, 0);
#if defined( IL1_SET )			/* tables for last decryption round */
        t_set(i,l)[i] = w;
#endif
#if defined( IL4_SET )
        t_set(i,l)[0][i] = w;
        t_set(i,l)[1][i] = upr(w,1);
        t_set(i,l)[2][i] = upr(w,2);
        t_set(i,l)[3][i] = upr(w,3);
#endif
    }
    init = 1;
    return EXIT_SUCCESS;
}

#endif

#if defined(__cplusplus)
}
#endif