faster aes decryption

[avr-crypto-lib.git] / aes_dec.c

diff --git a/aes_dec.c b/aes_dec.c
index c2ee5f2a7dd94f44502ab7d3d5d2d63625ec9acc..48d6ab77cce588dcef42d415672d0618e5a5ae78 100644 (file)
--- a/aes_dec.c
+++ b/aes_dec.c
@@ -59,7 +59,7 @@ void aes_dec_round(aes_cipher_state_t* state, const aes_roundkey_t* k){
                t = tmp[4*i+3] ^ tmp[4*i+2];
                u = tmp[4*i+1] ^ tmp[4*i+0];
                v = t ^ u;
-               v ^= gf256mul(0x08, v, 0x1b);
+               v = gf256mul(0x09, v, 0x1b);
                w = v ^ gf256mul(0x04, tmp[4*i+2] ^ tmp[4*i+0], 0x1b);
                v = v ^ gf256mul(0x04, tmp[4*i+3] ^ tmp[4*i+1], 0x1b);
                state->s[4*i+3] = tmp[4*i+3] ^ v ^ gf256mul(0x02, tmp[4*i+0] ^ tmp[4*i+3], 0x1b);