diff options
| -rw-r--r-- | lib/aes.go | 24 |
1 files changed, 24 insertions, 0 deletions
@@ -3,6 +3,30 @@ package lib +func AddRoundKey(state, ks [][]byte) [][]byte { + if len(ks) != 4 { + return state + } + nb := 4 + + // Get tranpose of ks. + ks_t := make([][]byte, 4) + for i := 0; i < 4; i++ { + ks_t[i] = make([]byte, 4) + for j := 0; j < 4; j++ { + ks_t[i][j] = ks[j][i] + } + } + + // Round key transformation. + for c := 0; c < nb; c++ { + for r := 0; r < 4; r++ { + state[r][c] = state[r][c] ^ ks_t[r][c] + } + } + return state +} + // Makes and returns initial the state array from 16-byte input 'in'. func MkState(in []byte) [][]byte { if len(in) != 16 { |