aria: move conditional outside of loop
@@ -291,7 +291,7 @@ static void aria_fe_xor(uint32_t r[4],
r[3] = d ^ x[3];
}
-// Big endian 128-bit rotation: d = a ^ (b <<< n), used only in key setup.
+// Big endian 128-bit rotation: r = a ^ (b <<< n), used only in key setup.
// This is relatively slow since our implementation is geared towards
// little-endian targets and stores state in that order.
@@ -301,17 +301,16 @@ static void aria_rot128(uint32_t r[4], const uint32_t a[4],
uint8_t i, j;
uint32_t t, u;
- const uint8_t n1 = n & 0x1F; // bit offset
- const uint8_t n2 = 32 - n1; // reverse bit offset
+ const uint8_t n1 = n % 32; // bit offset
+ const uint8_t n2 = n1 ? 32 - n1 : 0; // reverse bit offset
- j = (n >> 5) & 3; // initial word offset
+ j = (n / 32) % 4; // initial word offset
t = ARIA_FLIP1( ARIA_FLIP2( b[j] ) ); // big endian
for( i = 0; i < 4; i++ )
{
- j = (j + 1) & 3; // get next word, big endian
+ j = (j + 1) % 4; // get next word, big endian
u = ARIA_FLIP1( ARIA_FLIP2( b[j] ) );
t <<= n1; // rotate
- if (n2 < 32) // rotate 32 bits = 0 bits..
t |= u >> n2;
t = ARIA_FLIP1( ARIA_FLIP2( t ) ); // back to little endian
r[i] = a[i] ^ t; // store
