Read rho 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 93c5b7e..29908fb 100644
--- a/library/sha3.c
+++ b/library/sha3.c
@@ -35,8 +35,8 @@
0x8000000080008081, 0x8000000000008080, 0x0000000080000001, 0x8000000080008008,
};
-static const uint8_t rho[24] = {
- 63, 2, 36, 37, 28, 20, 58, 9, 44, 61, 54, 21, 39, 25, 23, 19, 49, 43, 56, 46, 62, 3, 8, 50
+static const uint32_t rho[6] = {
+ 0x3f022425, 0x1c143a09, 0x2c3d3615, 0x27191713, 0x312b382e, 0x3e030832
};
static const uint8_t pi[24] = {
@@ -83,8 +83,13 @@
s[4] ^= t; s[9] ^= t; s[14] ^= t; s[19] ^= t; s[24] ^= t;
/* Rho */
- for (i = 1; i < 25; i++) {
- s[i] = ROTR64(s[i], rho[i-1]);
+ for (i = 1; i < 25; i += 4) {
+ uint32_t r = rho[(i - 1) >> 2];
+ for (int j = i; j < i + 4; j++) {
+ uint8_t r8 = r >> 24;
+ r <<= 8;
+ s[j] = ROTR64(s[j], r8);
+ }
}
/* Pi */