galois_mul2 conditional-free implementation

This commit is contained in:
Simon Duquennoy 2015-08-03 15:13:00 +02:00
parent 195ada6668
commit bfba83ed16

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@ -71,12 +71,8 @@ static uint8_t round_keys[11][AES_128_KEY_LENGTH];
static uint8_t static uint8_t
galois_mul2(uint8_t value) galois_mul2(uint8_t value)
{ {
if(value >> 7) { uint8_t xor_val = (value >> 7) * 0x1b;
value = value << 1; return ((value << 1) ^ xor_val);
return value ^ 0x1b;
} else {
return value << 1;
}
} }
/*---------------------------------------------------------------------------*/ /*---------------------------------------------------------------------------*/
static void static void