From 1aa72a703c92a494d1abef27deaa15ae623e7818 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Mon, 15 Jan 2007 13:45:48 +0000 Subject: [PATCH] merge shift into mix 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 --- libavutil/aes.c | 48 ++++++++++++++++++++++++++++-------------------- 1 file changed, 28 insertions(+), 20 deletions(-) diff --git a/libavutil/aes.c b/libavutil/aes.c index f183efdbcc..4127df616c 100644 --- a/libavutil/aes.c +++ b/libavutil/aes.c @@ -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<>(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; iround_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++){