diff options
Diffstat (limited to 'libavutil/aes.c')
| -rw-r--r-- | libavutil/aes.c | 51 |
1 files changed, 31 insertions, 20 deletions
diff --git a/libavutil/aes.c b/libavutil/aes.c index 83c07696fd..7c92a2757f 100644 --- a/libavutil/aes.c +++ b/libavutil/aes.c @@ -54,6 +54,12 @@ static uint32_t enc_multbl[4][256]; static uint32_t dec_multbl[4][256]; #endif +#if HAVE_BIGENDIAN +# define ROT(x, s) ((x >> s) | (x << (32-s))) +#else +# define ROT(x, s) ((x << s) | (x >> (32-s))) +#endif + static inline void addkey(av_aes_block *dst, const av_aes_block *src, const av_aes_block *round_key) { @@ -86,7 +92,6 @@ static void subshift(av_aes_block s0[2], int s, const uint8_t *box) static inline int mix_core(uint32_t multbl[][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]; @@ -127,7 +132,7 @@ void av_aes_crypt(AVAES *a, uint8_t *dst_, const uint8_t *src_, crypt(a, 0, inv_sbox, dec_multbl); if (iv) { addkey(&a->state[0], &a->state[0], iv); - memcpy(iv, src, 16); + *iv = *src; } addkey(dst, &a->state[0], &a->round_key[0]); } else { @@ -136,29 +141,36 @@ void av_aes_crypt(AVAES *a, uint8_t *dst_, const uint8_t *src_, crypt(a, 2, sbox, enc_multbl); addkey(dst, &a->state[0], &a->round_key[0]); if (iv) - memcpy(iv, dst, 16); + *iv = *dst; } src++; dst++; } } -static void init_multbl2(uint8_t tbl[1024], const int c[4], +static void init_multbl2(uint32_t tbl[][256], 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]]]; - } + int i; + + for (i = 0; i < 256; i++) { + int x = sbox[i]; + if (x) { + int k, l, m, n; + x = log8[x]; + k = alog8[x + log8[c[0]]]; + l = alog8[x + log8[c[1]]]; + m = alog8[x + log8[c[2]]]; + n = alog8[x + log8[c[3]]]; + tbl[0][i] = AV_NE(MKBETAG(k,l,m,n), MKTAG(k,l,m,n)); #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]; + tbl[1][i] = ROT(tbl[0][i], 8); + tbl[2][i] = ROT(tbl[0][i], 16); + tbl[3][i] = ROT(tbl[0][i], 24); #endif + } + } } // this is based on the reference AES code by Paulo Barreto and Vincent Rijmen @@ -187,9 +199,9 @@ int av_aes_init(AVAES *a, const uint8_t *key, int key_bits, int decrypt) inv_sbox[j] = i; sbox[i] = j; } - init_multbl2(dec_multbl[0], (const int[4]) { 0xe, 0x9, 0xd, 0xb }, + init_multbl2(dec_multbl, (const int[4]) { 0xe, 0x9, 0xd, 0xb }, log8, alog8, inv_sbox); - init_multbl2(enc_multbl[0], (const int[4]) { 0x2, 0x1, 0x1, 0x3 }, + init_multbl2(enc_multbl, (const int[4]) { 0x2, 0x1, 0x1, 0x3 }, log8, alog8, sbox); } @@ -221,15 +233,14 @@ int av_aes_init(AVAES *a, const uint8_t *key, int key_bits, int decrypt) if (decrypt) { for (i = 1; i < rounds; i++) { av_aes_block tmp[3]; - memcpy(&tmp[2], &a->round_key[i], 16); + tmp[2] = a->round_key[i]; subshift(&tmp[1], 0, sbox); mix(tmp, dec_multbl, 1, 3); - memcpy(&a->round_key[i], &tmp[0], 16); + a->round_key[i] = tmp[0]; } } else { for (i = 0; i < (rounds + 1) >> 1; i++) { - for (j = 0; j < 16; j++) - FFSWAP(int, a->round_key[i].u8[j], a->round_key[rounds-i].u8[j]); + FFSWAP(av_aes_block, a->round_key[i], a->round_key[rounds-i]); } } |