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merge shift into mix

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this need -fno-strict-aliasing to work (needs to be fixed of course)

Originally committed as revision 7534 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Michael Niedermayer 2007-01-15 13:45:48 +00:00
parent 1f83576b48
commit 1aa72a703c
1 changed files with 28 additions and 20 deletions
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48
libavutil/aes.c
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@ -50,17 +50,16 @@ static inline void addkey(uint64_t state[2], uint64_t round_key[2]){
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;
static void subshift(uint8_t s0[4], uint8_t s1[4], uint8_t s2[4], uint8_t s3[4], uint8_t *box){
int t;
s0[0]=box[s0[ 0]]; s0[ 4]=box[s0[ 4]]; s0[ 8]=box[s0[ 8]]; s0[12]=box[s0[12]];
t=s1[0]; s1[0]=box[s1[ 4]]; s1[ 4]=box[s1[ 8]]; s1[ 8]=box[s1[12]]; s1[12]=box[t];
t=s2[0]; s2[0]=box[s2[ 8]]; s2[ 8]=box[ t]; t=s2[ 4]; s2[ 4]=box[s2[12]]; s2[12]=box[t];
t=s3[0]; s3[0]=box[s3[12]]; s3[12]=box[s3[ 8]]; s3[ 8]=box[s3[ 4]]; s3[ 4]=box[t];
}
#define ROT(x,s) ((x<<s)|(x>>(32-s)))
#if 0
static inline void mix(uint8_t state[4][4], uint32_t multbl[4][256]){
int i;
for(i=0; i<4; i++)
@ -72,22 +71,32 @@ static inline void mix(uint8_t state[4][4], uint32_t multbl[4][256]){
^multbl[2][state[i][2]] ^ multbl[3][state[i][3]];
#endif
}
#endif
static inline void mix2(uint8_t state[4][4], uint32_t multbl[4][256], int s1, int s3){
int a = multbl[0][state[0][0]] ^ multbl[1][state[s1 ][1]]
^multbl[2][state[2][2]] ^ multbl[3][state[s3 ][3]];
int b = multbl[0][state[1][0]] ^ multbl[1][state[s3-1][1]]
^multbl[2][state[3][2]] ^ multbl[3][state[s1-1][3]];
int c = multbl[0][state[2][0]] ^ multbl[1][state[s3 ][1]]
^multbl[2][state[0][2]] ^ multbl[3][state[s1 ][3]];
int d = multbl[0][state[3][0]] ^ multbl[1][state[s1-1][1]]
^multbl[2][state[1][2]] ^ multbl[3][state[s3-1][3]];
((uint32_t *)(state))[0]=a;
((uint32_t *)(state))[1]=b;
((uint32_t *)(state))[2]=c;
((uint32_t *)(state))[3]=d;
}
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);
mix2(a->state, multbl, 3-s, 1+s);
}
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)
subshift(a->state[0], a->state[0]+3-s, a->state[0]+2, a->state[0]+1+s, sbox);
addkey(a->state, a->round_key[0]);
}
@ -166,9 +175,8 @@ int av_aes_init(AVAES *a, uint8_t *key, int key_bits, int decrypt) {
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);
subshift(a->round_key[i][0], a->round_key[i][0]+3, a->round_key[i][0]+2, a->round_key[i][0]+1, sbox);
mix2(a->round_key[i], dec_multbl, 1, 3);
}
}else{
for(i=0; i<(rounds+1)>>1; i++){