aria: define P3 macro
This will allow to replace it with an optimised implementation later
@@ -91,6 +91,13 @@ static void mbedtls_zeroize( void *v, size_t n ) {
*/
#define ARIA_P2(x) (((x) >> 16) ^ ((x) << 16))
+/*
+ * modify byte order: ( A B C D ) -> ( D C B A ), i.e. change endianness
+ *
+ * This is submatrix P3 in [1] Appendix B.1
+ */
+#define ARIA_P3(x) ARIA_P2( ARIA_P1 ( x ) )
+
/*
* ARIA Affine Transform
* (a, b, c, d) = state in/out
@@ -336,14 +343,14 @@ static void aria_rot128(uint32_t r[4], const uint32_t a[4],
const uint8_t n2 = n1 ? 32 - n1 : 0; // reverse bit offset
j = (n / 32) % 4; // initial word offset
- t = ARIA_P2( ARIA_P1( b[j] ) ); // big endian
+ t = ARIA_P3( b[j] ); // big endian
for( i = 0; i < 4; i++ )
{
j = (j + 1) % 4; // get next word, big endian
- u = ARIA_P2( ARIA_P1( b[j] ) );
+ u = ARIA_P3( b[j] );
t <<= n1; // rotate
t |= u >> n2;
- t = ARIA_P2( ARIA_P1( t ) ); // back to little endian
+ t = ARIA_P3( t ); // back to little endian
r[i] = a[i] ^ t; // store
t = u; // move to next word
}
