Read pi table in 4-byte chunks
Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
diff --git a/library/sha3.c b/library/sha3.c
index 29908fb..9b22cfa 100644
--- a/library/sha3.c
+++ b/library/sha3.c
@@ -39,9 +39,8 @@
0x3f022425, 0x1c143a09, 0x2c3d3615, 0x27191713, 0x312b382e, 0x3e030832
};
-static const uint8_t pi[24] = {
- 10, 7, 11, 17, 18, 3, 5, 16, 8, 21, 24, 4,
- 15, 23, 19, 13, 12, 2, 20, 14, 22, 9, 6, 1,
+static const uint32_t pi[6] = {
+ 0x0a070b11, 0x12030510, 0x08151804, 0x0f17130d, 0x0c02140e, 0x16090601
};
#define ROTR64(x, y) (((x) << (64U - (y))) | ((x) >> (y))) // 64-bit rotate right
@@ -94,8 +93,13 @@
/* Pi */
t = s[1];
- for (i = 0; i < 24; i++) {
- SWAP(s[pi[i]], t);
+ for (i = 0; i < 24; i += 4) {
+ uint32_t p = pi[i >> 2];
+ for (unsigned j = 0; j < 4; j++) {
+ uint8_t p8 = (uint8_t) (p >> 24);
+ p <<= 8;
+ SWAP(s[p8], t);
+ }
}
/* Chi */