[Ffmpeg-cvslog] r7487 - trunk/libavutil/aes.c
michael
subversion
Sun Jan 14 19:47:06 CET 2007
Author: michael
Date: Sun Jan 14 19:47:01 2007
New Revision: 7487
Modified:
trunk/libavutil/aes.c
Log:
merge inv_sbox into inv_mix
Modified: trunk/libavutil/aes.c
==============================================================================
--- trunk/libavutil/aes.c (original)
+++ trunk/libavutil/aes.c Sun Jan 14 19:47:01 2007
@@ -23,7 +23,8 @@
#include "aes.h"
typedef struct AVAES{
- uint8_t round_key[15][4][4];
+ uint8_t round_enc_key[15][4][4];
+ uint8_t round_dec_key[15][4][4];
uint8_t state[4][4];
int rounds;
}AVAES;
@@ -74,40 +75,38 @@
void av_aes_decrypt(AVAES *a){
int t, r;
- addkey(a->state, a->round_key[a->rounds]);
- for(r=a->rounds-1; r>=0; r--){
- if(r!=a->rounds-1)
- mix(a->state, dec_multbl);
- SUBSHIFT0((a->state[0]+0), inv_sbox)
- SUBSHIFT3((a->state[0]+1), inv_sbox)
- SUBSHIFT2((a->state[0]+2), inv_sbox)
- SUBSHIFT1((a->state[0]+3), inv_sbox)
- addkey(a->state, a->round_key[r]);
- }
+ addkey(a->state, a->round_enc_key[a->rounds]);
+ for(r=a->rounds-2; r>=0; r--){
+// SUBSHIFT0((a->state[0]+0), inv_sbox)
+ SUBSHIFT3x((a->state[0]+1), inv_sbox)
+ SUBSHIFT2x((a->state[0]+2), inv_sbox)
+ SUBSHIFT1x((a->state[0]+3), inv_sbox)
+ mix(a->state, dec_multbl);
+ addkey(a->state, a->round_dec_key[r+1]);
+ }
+ SUBSHIFT0((a->state[0]+0), inv_sbox)
+ SUBSHIFT3((a->state[0]+1), inv_sbox)
+ SUBSHIFT2((a->state[0]+2), inv_sbox)
+ SUBSHIFT1((a->state[0]+3), inv_sbox)
+ addkey(a->state, a->round_enc_key[0]);
}
void av_aes_encrypt(AVAES *a){
int r, t;
for(r=0; r<a->rounds-1; r++){
- addkey(a->state, a->round_key[r]);
+ addkey(a->state, a->round_enc_key[r]);
SUBSHIFT1x((a->state[0]+1), sbox)
SUBSHIFT2x((a->state[0]+2), sbox)
SUBSHIFT3x((a->state[0]+3), sbox)
mix(a->state, enc_multbl); //FIXME replace log8 by const / optimze mix as this can be simplified alot
}
- addkey(a->state, a->round_key[r]);
+ addkey(a->state, a->round_enc_key[r]);
SUBSHIFT0((a->state[0]+0), sbox)
SUBSHIFT1((a->state[0]+1), sbox)
SUBSHIFT2((a->state[0]+2), sbox)
SUBSHIFT3((a->state[0]+3), sbox)
- addkey(a->state, a->round_key[r+1]);
-}
-
-static init_multbl(uint8_t tbl[1024], int c[4], uint8_t *log8, uint8_t *alog8){
- int i;
- for(i=4; i<1024; i++)
- tbl[i]= alog8[ log8[i/4] + log8[c[i&3]] ];
+ addkey(a->state, a->round_enc_key[r+1]);
}
static init_multbl2(uint8_t tbl[1024], int c[4], uint8_t *log8, uint8_t *alog8, uint8_t *sbox){
@@ -147,11 +146,11 @@
sbox [i]= j;
// av_log(NULL, AV_LOG_ERROR, "%d, ", log8[i]);
}
- init_multbl(dec_multbl[0], (int[4]){0xe, 0x9, 0xd, 0xb}, log8, alog8);
+ init_multbl2(dec_multbl[0], (int[4]){0xe, 0x9, 0xd, 0xb}, log8, alog8, inv_sbox);
#ifndef CONFIG_SMALL
- init_multbl(dec_multbl[1], (int[4]){0xb, 0xe, 0x9, 0xd}, log8, alog8);
- init_multbl(dec_multbl[2], (int[4]){0xd, 0xb, 0xe, 0x9}, log8, alog8);
- init_multbl(dec_multbl[3], (int[4]){0x9, 0xd, 0xb, 0xe}, log8, alog8);
+ 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
@@ -170,7 +169,7 @@
memcpy(tk, key, KC*4);
for(t= 0; t < (rounds+1)*4;) {
- memcpy(a->round_key[0][t], tk, KC*4);
+ memcpy(a->round_enc_key[0][t], tk, KC*4);
t+= KC;
for(i = 0; i < 4; i++)
@@ -184,6 +183,12 @@
for(i = 0; i < 4; i++) tk[j][i] ^= sbox[tk[j-1][i]];
}
}
+
+ for(i=0; i<sizeof(a->round_enc_key); i++)
+ a->round_dec_key[0][0][i]= sbox[a->round_enc_key[0][0][i]];
+ for(i=1; i<rounds; i++)
+ mix(a->round_dec_key[i], dec_multbl);
+
return a;
}
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