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- /*
- * copyright (c) 2007 Michael Niedermayer <michaelni@gmx.at> and 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 "common.h"
- #include "log.h"
- #include "aes.h"
-
- typedef struct AVAES{
- uint8_t round_key[15][4][4];
- uint8_t state[4][4];
- int rounds;
- }AVAES;
-
- static const uint8_t rcon[10] = {
- 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36
- };
-
- static uint8_t sbox[256];
- static uint8_t inv_sbox[256];
- #ifdef 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
-
- static inline void addkey(uint64_t state[2], uint64_t round_key[2]){
- state[0] ^= round_key[0];
- state[1] ^= round_key[1];
- }
-
- #define SUBSHIFT0(s, box) s[0]=box[s[ 0]]; s[ 4]=box[s[ 4]]; s[ 8]=box[s[ 8]]; s[12]=box[s[12]];
- #define SUBSHIFT1(s, box) t=s[0]; s[0]=box[s[ 4]]; s[ 4]=box[s[ 8]]; s[ 8]=box[s[12]]; s[12]=box[t];
- #define SUBSHIFT2(s, box) t=s[0]; s[0]=box[s[ 8]]; s[ 8]=box[ t]; t=s[ 4]; s[ 4]=box[s[12]]; s[12]=box[t];
- #define SUBSHIFT3(s, box) t=s[0]; s[0]=box[s[12]]; s[12]=box[s[ 8]]; s[ 8]=box[s[ 4]]; s[ 4]=box[t];
-
- #define SUBSHIFT1x(s) t=s[0]; s[0]=s[ 4]; s[ 4]=s[ 8]; s[ 8]=s[12]; s[12]=t;
- #define SUBSHIFT2x(s) t=s[0]; s[0]=s[ 8]; s[ 8]= t; t=s[ 4]; s[ 4]=s[12]; s[12]=t;
- #define SUBSHIFT3x(s) t=s[0]; s[0]=s[12]; s[12]=s[ 8]; s[ 8]=s[ 4]; s[ 4]=t;
-
- #define ROT(x,s) ((x<<s)|(x>>(32-s)))
-
- static inline void mix(uint8_t state[4][4], uint32_t multbl[4][256]){
- int i;
- for(i=0; i<4; i++)
- #ifdef CONFIG_SMALL
- ((uint32_t *)(state))[i] = multbl[0][state[i][0]] ^ ROT(multbl[0][state[i][1]], 8)
- ^ROT(multbl[0][state[i][2]],16) ^ ROT(multbl[0][state[i][3]],24);
-
- #else
- ((uint32_t *)(state))[i] = multbl[0][state[i][0]] ^ multbl[1][state[i][1]]
- ^multbl[2][state[i][2]] ^ multbl[3][state[i][3]];
- #endif
- }
-
- static inline void crypt(AVAES *a, int s, uint8_t *sbox, uint32_t *multbl){
- int t, r;
-
- for(r=a->rounds; r>1; r--){
- addkey(a->state, a->round_key[r]);
- SUBSHIFT3x((a->state[0]+1+s))
- SUBSHIFT2x((a->state[0]+2))
- SUBSHIFT1x((a->state[0]+3-s))
- mix(a->state, multbl);
- }
- addkey(a->state, a->round_key[1]);
- SUBSHIFT0((a->state[0]+0 ), sbox)
- SUBSHIFT3((a->state[0]+1+s), sbox)
- SUBSHIFT2((a->state[0]+2 ), sbox)
- SUBSHIFT1((a->state[0]+3-s), sbox)
- addkey(a->state, a->round_key[0]);
- }
-
- void av_aes_decrypt(AVAES *a){
- crypt(a, 0, inv_sbox, dec_multbl);
- }
-
- void av_aes_encrypt(AVAES *a){
- crypt(a, 2, sbox, enc_multbl);
- }
-
- static init_multbl2(uint8_t tbl[1024], int c[4], uint8_t *log8, uint8_t *alog8, uint8_t *sbox){
- int i;
- for(i=0; i<1024; i++){
- int x= sbox[i/4];
- if(x) tbl[i]= alog8[ log8[x] + log8[c[i&3]] ];
- }
- }
-
-
- // this is based on the reference AES code by Paulo Barreto and Vincent Rijmen
- AVAES *av_aes_init(uint8_t *key, int key_bits, int decrypt) {
- AVAES *a;
- int i, j, t, rconpointer = 0;
- uint8_t tk[8][4];
- int KC= key_bits/32;
- int rounds= KC + 6;
- uint8_t log8[256];
- uint8_t alog8[512];
-
- if(!sbox[255]){
- j=1;
- for(i=0; i<255; i++){
- alog8[i]=
- alog8[i+255]= j;
- log8[j]= i;
- j^= j+j;
- if(j>255) j^= 0x11B;
- }
- for(i=0; i<256; i++){
- j= i ? alog8[255-log8[i]] : 0;
- j ^= (j<<1) ^ (j<<2) ^ (j<<3) ^ (j<<4);
- j = (j ^ (j>>8) ^ 99) & 255;
- inv_sbox[j]= i;
- sbox [i]= j;
- // av_log(NULL, AV_LOG_ERROR, "%d, ", log8[i]);
- }
- init_multbl2(dec_multbl[0], (int[4]){0xe, 0x9, 0xd, 0xb}, log8, alog8, inv_sbox);
- #ifndef CONFIG_SMALL
- init_multbl2(dec_multbl[1], (int[4]){0xb, 0xe, 0x9, 0xd}, log8, alog8, inv_sbox);
- init_multbl2(dec_multbl[2], (int[4]){0xd, 0xb, 0xe, 0x9}, log8, alog8, inv_sbox);
- init_multbl2(dec_multbl[3], (int[4]){0x9, 0xd, 0xb, 0xe}, log8, alog8, inv_sbox);
- #endif
- init_multbl2(enc_multbl[0], (int[4]){0x2, 0x1, 0x1, 0x3}, log8, alog8, sbox);
- #ifndef CONFIG_SMALL
- init_multbl2(enc_multbl[1], (int[4]){0x3, 0x2, 0x1, 0x1}, log8, alog8, sbox);
- init_multbl2(enc_multbl[2], (int[4]){0x1, 0x3, 0x2, 0x1}, log8, alog8, sbox);
- init_multbl2(enc_multbl[3], (int[4]){0x1, 0x1, 0x3, 0x2}, log8, alog8, sbox);
- #endif
- }
-
- if(key_bits!=128 && key_bits!=192 && key_bits!=256)
- return NULL;
-
- a= av_malloc(sizeof(AVAES));
- a->rounds= rounds;
-
- memcpy(tk, key, KC*4);
-
- for(t= 0; t < (rounds+1)*4;) {
- memcpy(a->round_key[0][t], tk, KC*4);
- t+= KC;
-
- for(i = 0; i < 4; i++)
- tk[0][i] ^= sbox[tk[KC-1][(i+1)&3]];
- tk[0][0] ^= rcon[rconpointer++];
-
- for(j = 1; j < KC; j++){
- if(KC != 8 || j != KC/2)
- for(i = 0; i < 4; i++) tk[j][i] ^= tk[j-1][i];
- else
- for(i = 0; i < 4; i++) tk[j][i] ^= sbox[tk[j-1][i]];
- }
- }
-
- if(decrypt){
- for(i=1; i<rounds; i++){
- for(j=0; j<16; j++)
- a->round_key[i][0][j]= sbox[a->round_key[i][0][j]];
- mix(a->round_key[i], dec_multbl);
- }
- }else{
- for(i=0; i<(rounds+1)/2; i++){
- for(j=0; j<16; j++)
- FFSWAP(int, a->round_key[i][0][j], a->round_key[rounds-i][0][j]);
- }
- }
-
- return a;
- }
-
- #ifdef TEST
-
- int main(){
- int i,j,k;
- AVAES *ae= av_aes_init("PI=3.141592654..", 128, 0);
- AVAES *ad= av_aes_init("PI=3.141592654..", 128, 1);
- uint8_t zero[16]= {0};
- uint8_t pt[16]= {0x6a, 0x84, 0x86, 0x7c, 0xd7, 0x7e, 0x12, 0xad, 0x07, 0xea, 0x1b, 0xe8, 0x95, 0xc5, 0x3f, 0xa3};
- uint8_t ct[16]= {0x73, 0x22, 0x81, 0xc0, 0xa0, 0xaa, 0xb8, 0xf7, 0xa5, 0x4a, 0x0c, 0x67, 0xa0, 0xc4, 0x5e, 0xcf};
- AVAES *b= av_aes_init(zero, 128, 1);
-
- /* uint8_t key[16]= {0x42, 0x78, 0xb8, 0x40, 0xfb, 0x44, 0xaa, 0xa7, 0x57, 0xc1, 0xbf, 0x04, 0xac, 0xbe, 0x1a, 0x3e};
- uint8_t IV[16] = {0x57, 0xf0, 0x2a, 0x5c, 0x53, 0x39, 0xda, 0xeb, 0x0a, 0x29, 0x08, 0xa0, 0x6a, 0xc6, 0x39, 0x3f};
- uint8_t pt[16] = {0x3c, 0x88, 0x8b, 0xbb, 0xb1, 0xa8, 0xeb, 0x9f, 0x3e, 0x9b, 0x87, 0xac, 0xaa, 0xd9, 0x86, 0xc4};
- // 66e2f7071c83083b8a557971918850e5
- uint8_t ct[16] = {0x47, 0x9c, 0x89, 0xec, 0x14, 0xbc, 0x98, 0x99, 0x4e, 0x62, 0xb2, 0xc7, 0x05, 0xb5, 0x0, 0x14e};
- // 175bd7832e7e60a1e92aac568a861eb7*/
- uint8_t ckey[16]= {0x10, 0xa5, 0x88, 0x69, 0xd7, 0x4b, 0xe5, 0xa3, 0x74, 0xcf, 0x86, 0x7c, 0xfb, 0x47, 0x38, 0x59};
- uint8_t cct[16] = {0x6d, 0x25, 0x1e, 0x69, 0x44, 0xb0, 0x51, 0xe0, 0x4e, 0xaa, 0x6f, 0xb4, 0xdb, 0xf7, 0x84, 0x65};
- AVAES *c= av_aes_init(ckey, 128, 1);
-
- av_log_level= AV_LOG_DEBUG;
-
- memcpy(b->state, ct, 16);
- av_aes_decrypt(b);
- for(j=0; j<16; j++)
- if(pt[j] != b->state[0][j]){
- av_log(NULL, AV_LOG_ERROR, "%d %02X %02X\n", j, pt[j], b->state[0][j]);
- }
-
- memcpy(c->state, cct, 16);
- av_aes_decrypt(c);
- for(j=0; j<16; j++)
- if(zero[j] != c->state[0][j]){
- av_log(NULL, AV_LOG_ERROR, "%d %02X %02X\n", j, zero[j], c->state[0][j]);
- }
-
- for(i=0; i<10000; i++){
- for(j=0; j<16; j++){
- pt[j]= random();
- }
- memcpy(ae->state, pt, 16);
- {START_TIMER
- av_aes_encrypt(ae);
- if(!(i&(i-1)))
- av_log(NULL, AV_LOG_ERROR, "%02X %02X %02X %02X\n", ae->state[0][0], ae->state[1][1], ae->state[2][2], ae->state[3][3]);
- memcpy(ad->state, ae->state, 16);
- av_aes_decrypt(ad);
- STOP_TIMER("aes")}
- for(j=0; j<16; j++){
- if(pt[j] != ad->state[0][j]){
- av_log(NULL, AV_LOG_ERROR, "%d %d %02X %02X\n", i,j, pt[j], ad->state[0][j]);
- }
- }
- }
- return 0;
- }
- #endif
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