sha3: code shrink

function                                             old     new   delta
KeccakF                                             1053    1078     +25
KeccakF_RoundConstants                               192      48    -144

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/libbb/hash_md5_sha.c b/libbb/hash_md5_sha.c
index a0eec77897be30437cc1ce466d3fa3fb92e60bf0..4cd2244a182f4158ef20d8d7a8e9e7a15cdb90b1 100644 (file)
--- a/libbb/hash_md5_sha.c
+++ b/libbb/hash_md5_sha.c
@@ -933,32 +933,40 @@ enum {
        cKeccakNumberOfRounds = 24,
 };
 
-static const uint64_t KeccakF_RoundConstants[cKeccakNumberOfRounds] = {
-       0x0000000000000001ULL,
-       0x0000000000008082ULL,
-       0x800000000000808aULL,
-       0x8000000080008000ULL,
-       0x000000000000808bULL,
-       0x0000000080000001ULL,
-       0x8000000080008081ULL,
-       0x8000000000008009ULL,
-       0x000000000000008aULL,
-       0x0000000000000088ULL,
-       0x0000000080008009ULL,
-       0x000000008000000aULL,
-       0x000000008000808bULL,
-       0x800000000000008bULL,
-       0x8000000000008089ULL,
-       0x8000000000008003ULL,
-       0x8000000000008002ULL,
-       0x8000000000000080ULL,
-       0x000000000000800aULL,
-       0x800000008000000aULL,
-       0x8000000080008081ULL,
-       0x8000000000008080ULL,
-       0x0000000080000001ULL,
-       0x8000000080008008ULL
+/* Elements should be 64-bit, but top half is always zero or 0x80000000.
+ * It is encoded as a separate word below.
+ * Same is true for 31th bits.
+ */
+static const uint16_t KeccakF_RoundConstants[cKeccakNumberOfRounds] = {
+       0x0001UL,
+       0x8082UL,
+       0x808aUL,
+       0x8000UL,
+       0x808bUL,
+       0x0001UL,
+       0x8081UL,
+       0x8009UL,
+       0x008aUL,
+       0x0088UL,
+       0x8009UL,
+       0x000aUL,
+       0x808bUL,
+       0x008bUL,
+       0x8089UL,
+       0x8003UL,
+       0x8002UL,
+       0x0080UL,
+       0x800aUL,
+       0x000aUL,
+       0x8081UL,
+       0x8080UL,
+       0x0001UL,
+       0x8008UL
 };
+/* 0th first - 0011 0011 0000 0111 1101 1101: */
+#define KeccakF_RoundConstantBit63 ((uint32_t)(0x3307dd00))
+/* 0th first - 0001 0110 0011 1000 0001 1011: */
+#define KeccakF_RoundConstantBit31 ((uint32_t)(0x16381b00))
 
 static const uint8_t KeccakF_RotationConstants[25] = {
        1, 3, 6, 10, 15, 21, 28, 36, 45, 55, 2, 14, 27, 41, 56, 8, 25, 43, 62,
@@ -1075,7 +1083,9 @@ static void KeccakF(uint64_t *state)
                }
 
                /* Iota */
-               state[0] ^= KeccakF_RoundConstants[round];
+               state[0] ^= KeccakF_RoundConstants[round]
+                       | (uint32_t)((KeccakF_RoundConstantBit31 << round) & 0x80000000)
+                       | (uint64_t)((KeccakF_RoundConstantBit63 << round) & 0x80000000) << 32;
        }
 
        if (BB_BIG_ENDIAN) {