release/src/router/nettle/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., 51 Franklin Street, Fifth Floor, Boston,
  23  * MA 02111-1301, USA.
  24  */
  25
  26 #ifndef NETTLE_AES_INTERNAL_H_INCLUDED
  27 #define NETTLE_AES_INTERNAL_H_INCLUDED
  28
  29 #include "aes.h"
  30
  31 /* Name mangling */
  32 #define _aes_encrypt _nettle_aes_encrypt
  33 #define _aes_decrypt _nettle_aes_decrypt
  34 #define _aes_encrypt_table _nettle_aes_encrypt_table
  35
  36 /* Define to use only small tables. */
  37 #ifndef AES_SMALL
  38 # define AES_SMALL 0
  39 #endif
  40
  41 #if AES_SMALL
  42 # define AES_TABLE_SIZE 1
  43 #else
  44 # define AES_TABLE_SIZE 4
  45 #endif
  46
  47 struct aes_table
  48 {
  49   uint8_t sbox[0x100];
  50   uint32_t table[AES_TABLE_SIZE][0x100];
  51 };
  52
  53 void
  54 _aes_encrypt(const struct aes_ctx *ctx,
  55              const struct aes_table *T,
  56              unsigned length, uint8_t *dst,
  57              const uint8_t *src);
  58
  59 void
  60 _aes_decrypt(const struct aes_ctx *ctx,
  61              const struct aes_table *T,
  62              unsigned length, uint8_t *dst,
  63              const uint8_t *src);
  64
  65 /* Macros */
  66 /* Get the byte with index 0, 1, 2 and 3 */
  67 #define B0(x) ((x) & 0xff)
  68 #define B1(x) (((x) >> 8) & 0xff)
  69 #define B2(x) (((x) >> 16) & 0xff)
  70 #define B3(x) (((x) >> 24) & 0xff)
  71
  72 #define SUBBYTE(x, box) ((uint32_t)(box)[B0(x)]         \
  73                       | ((uint32_t)(box)[B1(x)] << 8)   \
  74                       | ((uint32_t)(box)[B2(x)] << 16)  \
  75                       | ((uint32_t)(box)[B3(x)] << 24))
  76
  77 #define AES_ROUND(T, w0, w1, w2, w3, k)         \
  78 ((  T->table[0][ B0(w0) ]                       \
  79   ^ T->table[1][ B1(w1) ]                       \
  80   ^ T->table[2][ B2(w2) ]                       \
  81   ^ T->table[3][ B3(w3) ]) ^ (k))
  82
  83 #define AES_FINAL_ROUND(T, w0, w1, w2, w3, k)           \
  84 ((   (uint32_t) T->sbox[ B0(w0) ]                       \
  85   | ((uint32_t) T->sbox[ B1(w1) ] << 8)                 \
  86   | ((uint32_t) T->sbox[ B2(w2) ] << 16)                \
  87   | ((uint32_t) T->sbox[ B3(w3) ] << 24)) ^ (k))
  88
  89 /* Globally visible so that the same sbox table can be used by aes_set_encrypt_key */
  90
  91 extern const struct aes_table _aes_encrypt_table;
  92 #define aes_sbox (_aes_encrypt_table.sbox)
  93
  94 #endif /* NETTLE_AES_INTERNAL_H_INCLUDED */