crypto/aes-internal.h

   1 /* aes-internal.h
   2  *
   3  * The aes/rijndael block cipher.
   4  */
   5
   6 /* nettle, low-level cryptographics library
   7  *
   8  * Copyright (C) 2001 Niels Möller
   9  *
  10  * The nettle library is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU Lesser General Public License as published by
  12  * the Free Software Foundation; either version 2.1 of the License, or (at your
  13  * option) any later version.
  14  *
  15  * The nettle library is distributed in the hope that it will be useful, but
  16  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  17  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
  18  * License for more details.
  19  *
  20  * You should have received a copy of the GNU Lesser General Public License
  21  * along with the nettle library; see the file COPYING.LIB.  If not, write to
  22  * the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  23  * MA 02111-1307, USA.
  24  */
  25
  26 #ifndef NETTLE_AES_INTERNAL_H_INCLUDED
  27 #define NETTLE_AES_INTERNAL_H_INCLUDED
  28
  29 #include "aes.h"
  30
  31 /* Define to use only small tables. */
  32 #ifndef AES_SMALL
  33 # define AES_SMALL 0
  34 #endif
  35
  36 #if AES_SMALL
  37 # define AES_TABLE_SIZE 1
  38 #else
  39 # define AES_TABLE_SIZE 4
  40 #endif
  41
  42 /* Name mangling */
  43 #define _aes_crypt _nettle_aes_crypt
  44
  45 /* Assembler code using the table should get link errors if linked
  46  * against a small table. */
  47 #if AES_SMALL
  48 # define _aes_encrypt_table _nettle_aes_encrypt_table_small
  49 # define _aes_decrypt_table _nettle_aes_decrypt_table_small
  50 #else
  51 # define _aes_encrypt_table _nettle_aes_encrypt_table
  52 # define _aes_decrypt_table _nettle_aes_decrypt_table
  53 #endif
  54
  55 struct aes_table
  56 {
  57   uint8_t sbox[0x100];
  58   unsigned idx[3][4];
  59
  60   /* Variant of the idx array suitable for the sparc
  61    * assembler code.
  62    *
  63    * sparc_idx[0][i] = idx[0][i] * 4 + 2
  64    * sparc_idx[1][i] = idx[2][i] * 4
  65    */
  66
  67   unsigned sparc_idx [2][4];
  68
  69   uint32_t table[AES_TABLE_SIZE][0x100];
  70 };
  71
  72 void
  73 _aes_crypt(const struct aes_ctx *ctx,
  74            const struct aes_table *T,
  75            unsigned length, uint8_t *dst,
  76            const uint8_t *src);
  77
  78 /* Macros */
  79 #define ROTBYTE(x) (((x) >> 8) | (((x) & 0xff) << 24))
  80 #define ROTRBYTE(x) (((x) << 8) | (((x) >> 24) & 0xff))
  81 #define SUBBYTE(x, box) (((box)[((x) & 0xff)]) | \
  82                         ((box)[(((x) >> 8) & 0xff)] << 8) | \
  83                         ((box)[(((x) >> 16) & 0xff)] << 16) | \
  84                         ((box)[(((x) >> 24) & 0xff)] << 24))
  85
  86 /* Internal tables */
  87 extern const struct aes_table _aes_encrypt_table;
  88 extern const struct aes_table _aes_decrypt_table;
  89
  90 #define aes_sbox (_aes_encrypt_table.sbox)
  91
  92 #endif /* NETTLE_AES_INTERNAL_H_INCLUDED */