| /* |
| * copyright (c) 2007 Michael Niedermayer <michaelni@gmx.at> |
| * |
| * 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 "common.h" |
| #include "aes.h" |
| |
| typedef struct AVAES{ |
| // Note: round_key[16] is accessed in the init code, but this only |
| // overwrites state, which does not matter (see also r7471). |
| uint8_t round_key[15][4][4]; |
| uint8_t state[2][4][4]; |
| int rounds; |
| }AVAES; |
| |
| const int av_aes_size= sizeof(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]; |
| #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 |
| |
| static inline void addkey(uint64_t dst[2], const uint64_t src[2], const uint64_t round_key[2]){ |
| dst[0] = src[0] ^ round_key[0]; |
| dst[1] = src[1] ^ round_key[1]; |
| } |
| |
| static void subshift(uint8_t s0[2][16], int s, const uint8_t *box){ |
| uint8_t (*s1)[16]= s0[0] - s; |
| uint8_t (*s3)[16]= s0[0] + s; |
| 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]]; |
| 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]]; |
| 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]]; |
| 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]]; |
| } |
| |
| static inline int mix_core(uint32_t multbl[4][256], int a, int b, int c, int d){ |
| #if CONFIG_SMALL |
| #define ROT(x,s) ((x<<s)|(x>>(32-s))) |
| return multbl[0][a] ^ ROT(multbl[0][b], 8) ^ ROT(multbl[0][c], 16) ^ ROT(multbl[0][d], 24); |
| #else |
| return multbl[0][a] ^ multbl[1][b] ^ multbl[2][c] ^ multbl[3][d]; |
| #endif |
| } |
| |
| static inline void mix(uint8_t state[2][4][4], uint32_t multbl[4][256], int s1, int s3){ |
| ((uint32_t *)(state))[0] = mix_core(multbl, state[1][0][0], state[1][s1 ][1], state[1][2][2], state[1][s3 ][3]); |
| ((uint32_t *)(state))[1] = mix_core(multbl, state[1][1][0], state[1][s3-1][1], state[1][3][2], state[1][s1-1][3]); |
| ((uint32_t *)(state))[2] = mix_core(multbl, state[1][2][0], state[1][s3 ][1], state[1][0][2], state[1][s1 ][3]); |
| ((uint32_t *)(state))[3] = mix_core(multbl, state[1][3][0], state[1][s1-1][1], state[1][1][2], state[1][s3-1][3]); |
| } |
| |
| static inline void crypt(AVAES *a, int s, const uint8_t *sbox, const uint32_t *multbl){ |
| int r; |
| |
| for(r=a->rounds-1; r>0; r--){ |
| mix(a->state, multbl, 3-s, 1+s); |
| addkey(a->state[1], a->state[0], a->round_key[r]); |
| } |
| subshift(a->state[0][0], s, sbox); |
| } |
| |
| void av_aes_crypt(AVAES *a, uint8_t *dst, const uint8_t *src, int count, uint8_t *iv, int decrypt){ |
| while(count--){ |
| addkey(a->state[1], src, a->round_key[a->rounds]); |
| if(decrypt) { |
| crypt(a, 0, inv_sbox, dec_multbl); |
| if(iv){ |
| addkey(a->state[0], a->state[0], iv); |
| memcpy(iv, src, 16); |
| } |
| addkey(dst, a->state[0], a->round_key[0]); |
| }else{ |
| if(iv) addkey(a->state[1], a->state[1], iv); |
| crypt(a, 2, sbox, enc_multbl); |
| addkey(dst, a->state[0], a->round_key[0]); |
| if(iv) memcpy(iv, dst, 16); |
| } |
| src+=16; |
| dst+=16; |
| } |
| } |
| |
| static void init_multbl2(uint8_t tbl[1024], const int c[4], const uint8_t *log8, const uint8_t *alog8, const uint8_t *sbox){ |
| int i, j; |
| for(i=0; i<1024; i++){ |
| int x= sbox[i>>2]; |
| if(x) tbl[i]= alog8[ log8[x] + log8[c[i&3]] ]; |
| } |
| #if !CONFIG_SMALL |
| for(j=256; j<1024; j++) |
| for(i=0; i<4; i++) |
| tbl[4*j+i]= tbl[4*j + ((i-1)&3) - 1024]; |
| #endif |
| } |
| |
| // 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) { |
| int i, j, t, rconpointer = 0; |
| uint8_t tk[8][4]; |
| int KC= key_bits>>5; |
| int rounds= KC + 6; |
| uint8_t log8[256]; |
| uint8_t alog8[512]; |
| |
| if(!enc_multbl[0][sizeof(enc_multbl)/sizeof(enc_multbl[0][0])-1]){ |
| 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; |
| } |
| init_multbl2(dec_multbl[0], (const int[4]){0xe, 0x9, 0xd, 0xb}, log8, alog8, inv_sbox); |
| init_multbl2(enc_multbl[0], (const int[4]){0x2, 0x1, 0x1, 0x3}, log8, alog8, sbox); |
| } |
| |
| if(key_bits!=128 && key_bits!=192 && key_bits!=256) |
| return -1; |
| |
| a->rounds= rounds; |
| |
| memcpy(tk, key, KC*4); |
| |
| for(t= 0; t < (rounds+1)*16;) { |
| memcpy(a->round_key[0][0]+t, tk, KC*4); |
| t+= KC*4; |
| |
| 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>>1) |
| 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++){ |
| uint8_t tmp[3][16]; |
| memcpy(tmp[2], a->round_key[i][0], 16); |
| subshift(tmp[1], 0, sbox); |
| mix(tmp, dec_multbl, 1, 3); |
| memcpy(a->round_key[i][0], tmp[0], 16); |
| } |
| }else{ |
| for(i=0; i<(rounds+1)>>1; i++){ |
| for(j=0; j<16; j++) |
| FFSWAP(int, a->round_key[i][0][j], a->round_key[rounds-i][0][j]); |
| } |
| } |
| |
| return 0; |
| } |
| |
| #ifdef TEST |
| #include "lfg.h" |
| #include "log.h" |
| |
| int main(void){ |
| int i,j; |
| AVAES ae, ad, b; |
| uint8_t rkey[2][16]= { |
| {0}, |
| {0x10, 0xa5, 0x88, 0x69, 0xd7, 0x4b, 0xe5, 0xa3, 0x74, 0xcf, 0x86, 0x7c, 0xfb, 0x47, 0x38, 0x59}}; |
| uint8_t pt[16], rpt[2][16]= { |
| {0x6a, 0x84, 0x86, 0x7c, 0xd7, 0x7e, 0x12, 0xad, 0x07, 0xea, 0x1b, 0xe8, 0x95, 0xc5, 0x3f, 0xa3}, |
| {0}}; |
| uint8_t rct[2][16]= { |
| {0x73, 0x22, 0x81, 0xc0, 0xa0, 0xaa, 0xb8, 0xf7, 0xa5, 0x4a, 0x0c, 0x67, 0xa0, 0xc4, 0x5e, 0xcf}, |
| {0x6d, 0x25, 0x1e, 0x69, 0x44, 0xb0, 0x51, 0xe0, 0x4e, 0xaa, 0x6f, 0xb4, 0xdb, 0xf7, 0x84, 0x65}}; |
| uint8_t temp[16]; |
| AVLFG prn; |
| |
| av_aes_init(&ae, "PI=3.141592654..", 128, 0); |
| av_aes_init(&ad, "PI=3.141592654..", 128, 1); |
| av_log_set_level(AV_LOG_DEBUG); |
| av_lfg_init(&prn, 1); |
| |
| for(i=0; i<2; i++){ |
| av_aes_init(&b, rkey[i], 128, 1); |
| av_aes_crypt(&b, temp, rct[i], 1, NULL, 1); |
| for(j=0; j<16; j++) |
| if(rpt[i][j] != temp[j]) |
| av_log(NULL, AV_LOG_ERROR, "%d %02X %02X\n", j, rpt[i][j], temp[j]); |
| } |
| |
| for(i=0; i<10000; i++){ |
| for(j=0; j<16; j++){ |
| pt[j] = av_lfg_get(&prn); |
| } |
| {START_TIMER |
| av_aes_crypt(&ae, temp, pt, 1, NULL, 0); |
| if(!(i&(i-1))) |
| av_log(NULL, AV_LOG_ERROR, "%02X %02X %02X %02X\n", temp[0], temp[5], temp[10], temp[15]); |
| av_aes_crypt(&ad, temp, temp, 1, NULL, 1); |
| STOP_TIMER("aes")} |
| for(j=0; j<16; j++){ |
| if(pt[j] != temp[j]){ |
| av_log(NULL, AV_LOG_ERROR, "%d %d %02X %02X\n", i,j, pt[j], temp[j]); |
| } |
| } |
| } |
| return 0; |
| } |
| #endif |
