2 * copyright (c) 2007 Michael Niedermayer <michaelni@gmx.at>
4 * This file is part of FFmpeg.
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 * some optimization ideas from aes128.c by Reimar Doeffinger
27 uint8_t round_key[15][4][4];
28 uint8_t state[2][4][4];
32 const int av_aes_size= sizeof(AVAES);
34 static const uint8_t rcon[10] = {
35 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36
38 static uint8_t sbox[256];
39 static uint8_t inv_sbox[256];
41 static uint32_t enc_multbl[1][256];
42 static uint32_t dec_multbl[1][256];
44 static uint32_t enc_multbl[4][256];
45 static uint32_t dec_multbl[4][256];
48 static inline void addkey(uint64_t dst[2], uint64_t src[2], uint64_t round_key[2]){
49 dst[0] = src[0] ^ round_key[0];
50 dst[1] = src[1] ^ round_key[1];
53 static void subshift(uint8_t s0[2][16], int s, uint8_t *box){
54 uint8_t (*s1)[16]= s0[0] - s;
55 uint8_t (*s3)[16]= s0[0] + s;
56 s0[0][0]=box[s0[1][ 0]]; s0[0][ 4]=box[s0[1][ 4]]; s0[0][ 8]=box[s0[1][ 8]]; s0[0][12]=box[s0[1][12]];
57 s1[0][3]=box[s1[1][ 7]]; s1[0][ 7]=box[s1[1][11]]; s1[0][11]=box[s1[1][15]]; s1[0][15]=box[s1[1][ 3]];
58 s0[0][2]=box[s0[1][10]]; s0[0][10]=box[s0[1][ 2]]; s0[0][ 6]=box[s0[1][14]]; s0[0][14]=box[s0[1][ 6]];
59 s3[0][1]=box[s3[1][13]]; s3[0][13]=box[s3[1][ 9]]; s3[0][ 9]=box[s3[1][ 5]]; s3[0][ 5]=box[s3[1][ 1]];
62 #define ROT(x,s) ((x<<s)|(x>>(32-s)))
64 static inline void mix(uint8_t state[4][4], uint32_t multbl[4][256]){
68 ((uint32_t *)(state))[i] = multbl[0][state[i][0]] ^ ROT(multbl[0][state[i][1]], 8)
69 ^ROT(multbl[0][state[i][2]],16) ^ ROT(multbl[0][state[i][3]],24);
71 ((uint32_t *)(state))[i] = multbl[0][state[i][0]] ^ multbl[1][state[i][1]]
72 ^multbl[2][state[i][2]] ^ multbl[3][state[i][3]];
77 static inline void mix(uint8_t state[2][4][4], uint32_t multbl[4][256], int s1, int s3){
78 ((uint32_t *)(state))[0] = multbl[0][state[1][0][0]] ^ multbl[1][state[1][s1 ][1]]
79 ^multbl[2][state[1][2][2]] ^ multbl[3][state[1][s3 ][3]];
80 ((uint32_t *)(state))[1] = multbl[0][state[1][1][0]] ^ multbl[1][state[1][s3-1][1]]
81 ^multbl[2][state[1][3][2]] ^ multbl[3][state[1][s1-1][3]];
82 ((uint32_t *)(state))[2] = multbl[0][state[1][2][0]] ^ multbl[1][state[1][s3 ][1]]
83 ^multbl[2][state[1][0][2]] ^ multbl[3][state[1][s1 ][3]];
84 ((uint32_t *)(state))[3] = multbl[0][state[1][3][0]] ^ multbl[1][state[1][s1-1][1]]
85 ^multbl[2][state[1][1][2]] ^ multbl[3][state[1][s3-1][3]];
88 static inline void crypt(AVAES *a, int s, uint8_t *sbox, uint32_t *multbl, uint8_t *dst, uint8_t *src){
91 addkey(a->state[1], src, a->round_key[a->rounds]);
92 for(r=a->rounds-1; r>0; r--){
93 mix(a->state, multbl, 3-s, 1+s);
94 addkey(a->state[1], a->state[0], a->round_key[r]);
96 subshift(a->state[0][0], s, sbox);
97 addkey(dst, a->state[0], a->round_key[0]);
100 static void aes_decrypt(AVAES *a, uint8_t *dst, uint8_t *src){
101 crypt(a, 0, inv_sbox, dec_multbl, dst, src);
104 static void aes_encrypt(AVAES *a, uint8_t *dst, uint8_t *src){
105 crypt(a, 2, sbox, enc_multbl, dst, src);
108 static void init_multbl2(uint8_t tbl[1024], int c[4], uint8_t *log8, uint8_t *alog8, uint8_t *sbox){
110 for(i=0; i<1024; i++){
112 if(x) tbl[i]= alog8[ log8[x] + log8[c[i&3]] ];
115 for(j=256; j<1024; j++)
117 tbl[4*j+i]= tbl[4*j + ((i-1)&3) - 1024];
121 // this is based on the reference AES code by Paulo Barreto and Vincent Rijmen
122 int av_aes_init(AVAES *a, uint8_t *key, int key_bits, int decrypt) {
123 int i, j, t, rconpointer = 0;
130 if(!enc_multbl[4][1023]){
132 for(i=0; i<255; i++){
139 for(i=0; i<256; i++){
140 j= i ? alog8[255-log8[i]] : 0;
141 j ^= (j<<1) ^ (j<<2) ^ (j<<3) ^ (j<<4);
142 j = (j ^ (j>>8) ^ 99) & 255;
146 init_multbl2(dec_multbl[0], (int[4]){0xe, 0x9, 0xd, 0xb}, log8, alog8, inv_sbox);
147 init_multbl2(enc_multbl[0], (int[4]){0x2, 0x1, 0x1, 0x3}, log8, alog8, sbox);
150 if(key_bits!=128 && key_bits!=192 && key_bits!=256)
155 memcpy(tk, key, KC*4);
157 for(t= 0; t < (rounds+1)*4;) {
158 memcpy(a->round_key[0][t], tk, KC*4);
161 for(i = 0; i < 4; i++)
162 tk[0][i] ^= sbox[tk[KC-1][(i+1)&3]];
163 tk[0][0] ^= rcon[rconpointer++];
165 for(j = 1; j < KC; j++){
166 if(KC != 8 || j != KC>>1)
167 for(i = 0; i < 4; i++) tk[j][i] ^= tk[j-1][i];
169 for(i = 0; i < 4; i++) tk[j][i] ^= sbox[tk[j-1][i]];
174 for(i=1; i<rounds; i++){
176 memcpy(tmp[2], a->round_key[i][0], 16);
177 subshift(tmp[1], 0, sbox);
178 mix(tmp, dec_multbl, 1, 3);
179 memcpy(a->round_key[i][0], tmp[0], 16);
182 for(i=0; i<(rounds+1)>>1; i++){
184 FFSWAP(int, a->round_key[i][0][j], a->round_key[rounds-i][0][j]);
197 uint8_t rkey[2][16]= {
199 {0x10, 0xa5, 0x88, 0x69, 0xd7, 0x4b, 0xe5, 0xa3, 0x74, 0xcf, 0x86, 0x7c, 0xfb, 0x47, 0x38, 0x59}};
200 uint8_t pt[16], rpt[2][16]= {
201 {0x6a, 0x84, 0x86, 0x7c, 0xd7, 0x7e, 0x12, 0xad, 0x07, 0xea, 0x1b, 0xe8, 0x95, 0xc5, 0x3f, 0xa3},
203 uint8_t rct[2][16]= {
204 {0x73, 0x22, 0x81, 0xc0, 0xa0, 0xaa, 0xb8, 0xf7, 0xa5, 0x4a, 0x0c, 0x67, 0xa0, 0xc4, 0x5e, 0xcf},
205 {0x6d, 0x25, 0x1e, 0x69, 0x44, 0xb0, 0x51, 0xe0, 0x4e, 0xaa, 0x6f, 0xb4, 0xdb, 0xf7, 0x84, 0x65}};
208 av_aes_init(&ae, "PI=3.141592654..", 128, 0);
209 av_aes_init(&ad, "PI=3.141592654..", 128, 1);
210 av_log_level= AV_LOG_DEBUG;
213 av_aes_init(&b, rkey[i], 128, 1);
214 aes_decrypt(&b, temp, rct[i]);
216 if(rpt[i][j] != temp[j])
217 av_log(NULL, AV_LOG_ERROR, "%d %02X %02X\n", j, rpt[i][j], temp[j]);
220 for(i=0; i<10000; i++){
225 aes_encrypt(&ae, temp, pt);
227 av_log(NULL, AV_LOG_ERROR, "%02X %02X %02X %02X\n", temp[0], temp[5], temp[10], temp[15]);
228 aes_decrypt(&ad, temp, temp);
231 if(pt[j] != temp[j]){
232 av_log(NULL, AV_LOG_ERROR, "%d %d %02X %02X\n", i,j, pt[j], temp[j]);