diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/ref/cipher.c | 40 |
1 files changed, 14 insertions, 26 deletions
diff --git a/src/ref/cipher.c b/src/ref/cipher.c index 5f26cc9..5822575 100644 --- a/src/ref/cipher.c +++ b/src/ref/cipher.c @@ -83,44 +83,32 @@ static void _compute_round_tweakeys( } +static uint8_t _Fj(uint8_t Xj, uint8_t RTKj) +{ + return S[Xj] ^ RTK[j]; +} + static void _nonlinear_layer(uint8_t X[BLOCK_BYTES], const uint8_t RTK[ROUND_TWEAKEY_BYTES]) { - uint8_t F[ROUND_TWEAKEY_BYTES]; - for (size_t j=0; j<ROUND_TWEAKEY_BYTES; j++) + for (size_t j=0; j<8; j++) { - F[j] = X[j] ^ RTK[j]; + X[15-j] ^= _Fj(X[j], RTK[j]); } +} - for (size_t j=0; j<ROUND_TWEAKEY_BYTES; j++) +static void _linear_layer(uint8_t X[BLOCK_BYTES]) +{ + for (size_t j=1; j<8; j++) { - F[j] = S[F[j]]; + X[15] ^= X[j]; } - for (size_t j=0; j<8; j++) + for (size_t j=9; j<15; j++) { - size_t dest_j = 15-j; - X[dest_j] ^= F[j]; + X[j] ^= X[7]; } } -static void _linear_layer(uint8_t X[BLOCK_BYTES]) -{ - X[15] ^= X[1]; - X[15] ^= X[2]; - X[15] ^= X[3]; - X[15] ^= X[4]; - X[15] ^= X[5]; - X[15] ^= X[6]; - X[15] ^= X[7]; - - X[14] ^= X[7]; - X[13] ^= X[7]; - X[12] ^= X[7]; - X[11] ^= X[7]; - X[10] ^= X[7]; - X[9] ^= X[7]; -} - static void _permutation_layer(uint8_t X[BLOCK_BYTES], permutation p) { if (p == PERMUTATION_NONE) |