/*
 ---------------------------------------------------------------------------
 Copyright (c) 1998-2006, Brian Gladman, Worcester, UK. All rights reserved.

 LICENSE TERMS

 The free distribution and use of this software in both source and binary
 form is allowed (with or without changes) provided that:

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

   2. distributions in binary form include the above copyright
      notice, this list of conditions and the following disclaimer
      in the documentation and/or other associated materials;

   3. the copyright holder's name is not used to endorse products
      built using this software without specific written permission.

 ALTERNATIVELY, provided that this notice is retained in full, this product
 may be distributed under the terms of the GNU General Public License (GPL),
 in which case the provisions of the GPL apply INSTEAD OF those given above.

 DISCLAIMER

 This software is provided 'as is' with no explicit or implied warranties
 in respect of its properties, including, but not limited to, correctness
 and/or fitness for purpose.
 ---------------------------------------------------------------------------
 Issue 09/09/2006
*/

#include "aesopt.h"
#include "aestab.h"

#ifdef USE_VIA_ACE_IF_PRESENT
#  include "aes_via_ace.h"
#endif

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

/* Initialise the key schedule from the user supplied key. The key
   length can be specified in bytes, with legal values of 16, 24
   and 32, or in bits, with legal values of 128, 192 and 256. These
   values correspond with Nk values of 4, 6 and 8 respectively.

   The following macros implement a single cycle in the key
   schedule generation process. The number of cycles needed
   for each cx->n_col and nk value is:

    nk =             4  5  6  7  8
    ------------------------------
    cx->n_col = 4   10  9  8  7  7
    cx->n_col = 5   14 11 10  9  9
    cx->n_col = 6   19 15 12 11 11
    cx->n_col = 7   21 19 16 13 14
    cx->n_col = 8   29 23 19 17 14
*/

#if (FUNCS_IN_C & ENC_KEYING_IN_C)

#if defined(AES_128) || defined(AES_VAR)

#define ke4(k,i) \
{   k[4*(i)+4] = ss[0] ^= ls_box(ss[3],3) ^ t_use(r,c)[i]; \
    k[4*(i)+5] = ss[1] ^= ss[0]; \
    k[4*(i)+6] = ss[2] ^= ss[1]; \
    k[4*(i)+7] = ss[3] ^= ss[2]; \
}

AES_RETURN aes_encrypt_key128(const unsigned char *key, aes_encrypt_ctx cx[1])
{   uint_32t    ss[4];

    cx->ks[0] = ss[0] = word_in(key, 0);
    cx->ks[1] = ss[1] = word_in(key, 1);
    cx->ks[2] = ss[2] = word_in(key, 2);
    cx->ks[3] = ss[3] = word_in(key, 3);

#if ENC_UNROLL == NONE
    {   uint_32t i;
        for(i = 0; i < 9; ++i)
            ke4(cx->ks, i);
    }
#else
    ke4(cx->ks, 0);  ke4(cx->ks, 1);
    ke4(cx->ks, 2);  ke4(cx->ks, 3);
    ke4(cx->ks, 4);  ke4(cx->ks, 5);
    ke4(cx->ks, 6);  ke4(cx->ks, 7);
    ke4(cx->ks, 8);
#endif
    ke4(cx->ks, 9);
    cx->inf.l = 0;
    cx->inf.b[0] = 10 * 16;

#ifdef USE_VIA_ACE_IF_PRESENT
    if(VIA_ACE_AVAILABLE)
        cx->inf.b[1] = 0xff;
#endif

#if defined( AES_ERR_CHK )
    return EXIT_SUCCESS;
#endif
}

#endif

#if defined(AES_192) || defined(AES_VAR)

#define kef6(k,i) \
{   k[6*(i)+ 6] = ss[0] ^= ls_box(ss[5],3) ^ t_use(r,c)[i]; \
    k[6*(i)+ 7] = ss[1] ^= ss[0]; \
    k[6*(i)+ 8] = ss[2] ^= ss[1]; \
    k[6*(i)+ 9] = ss[3] ^= ss[2]; \
}

#define ke6(k,i) \
{   kef6(k,i); \
    k[6*(i)+10] = ss[4] ^= ss[3]; \
    k[6*(i)+11] = ss[5] ^= ss[4]; \
}

AES_RETURN aes_encrypt_key192(const unsigned char *key, aes_encrypt_ctx cx[1])
{   uint_32t    ss[6];

    cx->ks[0] = ss[0] = word_in(key, 0);
    cx->ks[1] = ss[1] = word_in(key, 1);
    cx->ks[2] = ss[2] = word_in(key, 2);
    cx->ks[3] = ss[3] = word_in(key, 3);
    cx->ks[4] = ss[4] = word_in(key, 4);
    cx->ks[5] = ss[5] = word_in(key, 5);

#if ENC_UNROLL == NONE
    {   uint_32t i;
        for(i = 0; i < 7; ++i)
            ke6(cx->ks, i);
    }
#else
    ke6(cx->ks, 0);  ke6(cx->ks, 1);
    ke6(cx->ks, 2);  ke6(cx->ks, 3);
    ke6(cx->ks, 4);  ke6(cx->ks, 5);
    ke6(cx->ks, 6);
#endif
    kef6(cx->ks, 7);
    cx->inf.l = 0;
    cx->inf.b[0] = 12 * 16;

#ifdef USE_VIA_ACE_IF_PRESENT
    if(VIA_ACE_AVAILABLE)
        cx->inf.b[1] = 0xff;
#endif

#if defined( AES_ERR_CHK )
    return EXIT_SUCCESS;
#endif
}

#endif

#if defined(AES_256) || defined(AES_VAR)

#define kef8(k,i) \
{   k[8*(i)+ 8] = ss[0] ^= ls_box(ss[7],3) ^ t_use(r,c)[i]; \
    k[8*(i)+ 9] = ss[1] ^= ss[0]; \
    k[8*(i)+10] = ss[2] ^= ss[1]; \
    k[8*(i)+11] = ss[3] ^= ss[2]; \
}

#define ke8(k,i) \
{   kef8(k,i); \
    k[8*(i)+12] = ss[4] ^= ls_box(ss[3],0); \
    k[8*(i)+13] = ss[5] ^= ss[4]; \
    k[8*(i)+14] = ss[6] ^= ss[5]; \
    k[8*(i)+15] = ss[7] ^= ss[6]; \
}

AES_RETURN aes_encrypt_key256(const unsigned char *key, aes_encrypt_ctx cx[1])
{   uint_32t    ss[8];

    cx->ks[0] = ss[0] = word_in(key, 0);
    cx->ks[1] = ss[1] = word_in(key, 1);
    cx->ks[2] = ss[2] = word_in(key, 2);
    cx->ks[3] = ss[3] = word_in(key, 3);
    cx->ks[4] = ss[4] = word_in(key, 4);
    cx->ks[5] = ss[5] = word_in(key, 5);
    cx->ks[6] = ss[6] = word_in(key, 6);
    cx->ks[7] = ss[7] = word_in(key, 7);

#if ENC_UNROLL == NONE
    {   uint_32t i;
        for(i = 0; i < 6; ++i)
            ke8(cx->ks,  i);
    }
#else
    ke8(cx->ks, 0); ke8(cx->ks, 1);
    ke8(cx->ks, 2); ke8(cx->ks, 3);
    ke8(cx->ks, 4); ke8(cx->ks, 5);
#endif
    kef8(cx->ks, 6);
    cx->inf.l = 0;
    cx->inf.b[0] = 14 * 16;

#ifdef USE_VIA_ACE_IF_PRESENT
    if(VIA_ACE_AVAILABLE)
        cx->inf.b[1] = 0xff;
#endif

#if defined( AES_ERR_CHK )
    return EXIT_SUCCESS;
#endif
}

#endif

#if defined(AES_VAR)

AES_RETURN aes_encrypt_key(const unsigned char *key, int key_len, aes_encrypt_ctx cx[1])
{
    switch(key_len)
    {
#if defined( AES_ERR_CHK )
    case 16: case 128: return aes_encrypt_key128(key, cx);
    case 24: case 192: return aes_encrypt_key192(key, cx);
    case 32: case 256: return aes_encrypt_key256(key, cx);
    default: return EXIT_FAILURE;
#else
    case 16: case 128: aes_encrypt_key128(key, cx); return;
    case 24: case 192: aes_encrypt_key192(key, cx); return;
    case 32: case 256: aes_encrypt_key256(key, cx); return;
#endif
    }
}

#endif

#endif

#if (FUNCS_IN_C & DEC_KEYING_IN_C)

/* this is used to store the decryption round keys  */
/* in forward or reverse order                      */

#ifdef AES_REV_DKS
#define v(n,i)  ((n) - (i) + 2 * ((i) & 3))
#else
#define v(n,i)  (i)
#endif

#if DEC_ROUND == NO_TABLES
#define ff(x)   (x)
#else
#define ff(x)   inv_mcol(x)
#if defined( dec_imvars )
#define d_vars  dec_imvars
#endif
#endif

#if defined(AES_128) || defined(AES_VAR)

#define k4e(k,i) \
{   k[v(40,(4*(i))+4)] = ss[0] ^= ls_box(ss[3],3) ^ t_use(r,c)[i]; \
    k[v(40,(4*(i))+5)] = ss[1] ^= ss[0]; \
    k[v(40,(4*(i))+6)] = ss[2] ^= ss[1]; \
    k[v(40,(4*(i))+7)] = ss[3] ^= ss[2]; \
}

#if 1

#define kdf4(k,i) \
{   ss[0] = ss[0] ^ ss[2] ^ ss[1] ^ ss[3]; \
    ss[1] = ss[1] ^ ss[3]; \
    ss[2] = ss[2] ^ ss[3]; \
    ss[4] = ls_box(ss[(i+3) % 4], 3) ^ t_use(r,c)[i]; \
    ss[i % 4] ^= ss[4]; \
    ss[4] ^= k[v(40,(4*(i)))];   k[v(40,(4*(i))+4)] = ff(ss[4]); \
    ss[4] ^= k[v(40,(4*(i))+1)]; k[v(40,(4*(i))+5)] = ff(ss[4]); \
    ss[4] ^= k[v(40,(4*(i))+2)]; k[v(40,(4*(i))+6)] = ff(ss[4]); \
    ss[4] ^= k[v(40,(4*(i))+3)]; k[v(40,(4*(i))+7)] = ff(ss[4]); \
}

#define kd4(k,i) \
{   ss[4] = ls_box(ss[(i+3) % 4], 3) ^ t_use(r,c)[i]; \
    ss[i % 4] ^= ss[4]; ss[4] = ff(ss[4]); \
    k[v(40,(4*(i))+4)] = ss[4] ^= k[v(40,(4*(i)))]; \
    k[v(40,(4*(i))+5)] = ss[4] ^= k[v(40,(4*(i))+1)]; \
    k[v(40,(4*(i))+6)] = ss[4] ^= k[v(40,(4*(i))+2)]; \
    k[v(40,(4*(i))+7)] = ss[4] ^= k[v(40,(4*(i))+3)]; \
}