chromium/third_party/ffmpeg/libavutil/aes.c

/*
 * copyright (c) 2007 Michael Niedermayer <[email protected]>
 *
 * some optimization ideas from aes128.c by Reimar Doeffinger
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include <string.h>

#include "config.h"
#include "aes.h"
#include "aes_internal.h"
#include "error.h"
#include "intreadwrite.h"
#include "macros.h"
#include "mem.h"

const int av_aes_size= …;

struct AVAES *av_aes_alloc(void)
{ … }

static const uint8_t rcon[10] = …;

static uint8_t     sbox[256];
static uint8_t inv_sbox[256];
#if CONFIG_SMALL
static uint32_t enc_multbl[1][256];
static uint32_t dec_multbl[1][256];
#else
static uint32_t enc_multbl[4][256];
static uint32_t dec_multbl[4][256];
#endif

#if HAVE_BIGENDIAN
#define ROT …
#else
#define ROT(x, s) …
#endif

static inline void addkey(av_aes_block *dst, const av_aes_block *src,
                          const av_aes_block *round_key)
{ … }

static inline void addkey_s(av_aes_block *dst, const uint8_t *src,
                            const av_aes_block *round_key)
{ … }

static inline void addkey_d(uint8_t *dst, const av_aes_block *src,
                            const av_aes_block *round_key)
{ … }

static void subshift(av_aes_block s0[2], int s, const uint8_t *box)
{ … }

static inline int mix_core(uint32_t multbl[][256], int a, int b, int c, int d)
{ … }

static inline void mix(av_aes_block state[2], uint32_t multbl[][256], int s1, int s3)
{ … }

static inline void aes_crypt(AVAES *a, int s, const uint8_t *sbox,
                         uint32_t multbl[][256])
{ … }

static void aes_encrypt(AVAES *a, uint8_t *dst, const uint8_t *src,
                        int count, uint8_t *iv, int rounds)
{ … }

static void aes_decrypt(AVAES *a, uint8_t *dst, const uint8_t *src,
                        int count, uint8_t *iv, int rounds)
{ … }

void av_aes_crypt(AVAES *a, uint8_t *dst, const uint8_t *src,
                  int count, uint8_t *iv, int decrypt)
{ … }

static void init_multbl2(uint32_t tbl[][256], const int c[4],
                         const uint8_t *log8, const uint8_t *alog8,
                         const uint8_t *sbox)
{ … }

// this is based on the reference AES code by Paulo Barreto and Vincent Rijmen
int av_aes_init(AVAES *a, const uint8_t *key, int key_bits, int decrypt)
{ … }