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>>5; 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; } init_multbl2(dec_multbl[0], (int[4]){0xe, 0x9, 0xd, 0xb}, log8, alog8, inv_sbox); init_multbl2(enc_multbl[0], (int[4]){0x2, 0x1, 0x1, 0x3}, log8, alog8, sbox); } 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>>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++){ 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)>>1; i++){ for(j=0; j<16; j++) FFSWAP(int, a->round_key[i][0][j], a->round_key[rounds-i][0][j]); } } return a; }
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>>5; 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; } init_multbl2(dec_multbl[0], (int[4]){0xe, 0x9, 0xd, 0xb}, log8, alog8, inv_sbox); init_multbl2(enc_multbl[0], (int[4]){0x2, 0x1, 0x1, 0x3}, log8, alog8, sbox); } 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>>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++){ 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)>>1; i++){ for(j=0; j<16; j++) FFSWAP(int, a->round_key[i][0][j], a->round_key[rounds-i][0][j]); } } return a; }