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authorDenys Vlasenko <vda.linux@googlemail.com>2013-01-15 00:12:26 (GMT)
committer Denys Vlasenko <vda.linux@googlemail.com>2013-01-15 00:12:26 (GMT)
commit30a8652fbf16884490cee4a624f039a9ab587269 (patch)
treecf6235392344386a06849e04fd5deb4f364f0a71
parent60cb48ca50fcff24aa6c3927f51e4a508fa118f4 (diff)
downloadbusybox-30a8652fbf16884490cee4a624f039a9ab587269.tar.gz
busybox-30a8652fbf16884490cee4a624f039a9ab587269.tar.bz2
sha3: make size/speed optimization decision configurable
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
-rw-r--r--libbb/Config.src10
-rw-r--r--libbb/hash_md5_sha.c77
2 files changed, 68 insertions, 19 deletions
diff --git a/libbb/Config.src b/libbb/Config.src
index ee1b66a..19021fe 100644
--- a/libbb/Config.src
+++ b/libbb/Config.src
@@ -28,6 +28,16 @@ config MD5_SMALL
2 3.0 5088
3 (smallest) 5.1 4912
+config SHA3_SMALL
+ int "SHA3: Trade bytes for speed (0:fast, 1:slow)"
+ default 1
+ range 0 1
+ help
+ Trade binary size versus speed for the sha3sum algorithm.
+ SHA3_SMALL=0 compared to SHA3_SMALL=1 (approximate):
+ 64-bit x86: +270 bytes of code, 45% faster
+ 32-bit x86: +450 bytes of code, 75% faster
+
config FEATURE_FAST_TOP
bool "Faster /proc scanning code (+100 bytes)"
default y
diff --git a/libbb/hash_md5_sha.c b/libbb/hash_md5_sha.c
index 06a2400..643cf20 100644
--- a/libbb/hash_md5_sha.c
+++ b/libbb/hash_md5_sha.c
@@ -918,6 +918,16 @@ void FAST_FUNC sha512_end(sha512_ctx_t *ctx, void *resbuf)
* Busybox modifications (C) Lauri Kasanen, under the GPLv2.
*/
+#if CONFIG_SHA3_SMALL < 0
+# define SHA3_SMALL 0
+#elif CONFIG_SHA3_SMALL > 1
+# define SHA3_SMALL 1
+#else
+# define SHA3_SMALL CONFIG_SHA3_SMALL
+#endif
+
+#define ARCH_IS_64BIT (sizeof(long) >= sizeof(uint64_t))
+
enum {
cKeccakR_SizeInBytes = 576 / 8,
cKeccakNumberOfRounds = 24,
@@ -967,8 +977,6 @@ static const uint8_t KeccakF_Mod5[10] = {
static void KeccakF(uint64_t *state)
{
uint8_t x, y;
- uint64_t temp;
- uint64_t BC[5];
int round;
if (BB_BIG_ENDIAN) {
@@ -979,30 +987,61 @@ static void KeccakF(uint64_t *state)
for (round = 0; round < cKeccakNumberOfRounds; ++round) {
/* Theta */
- for (x = 0; x < 5; ++x) {
- BC[x] = state[x] ^ state[5 + x] ^ state[10 + x] ^
- state[15 + x] ^ state[20 + x];
- }
- for (x = 0; x < 5; ++x) {
- temp = BC[KeccakF_Mod5[x + 4]] ^
- rotl64(BC[KeccakF_Mod5[x + 1]], 1);
-
- for (y = 0; y <= 20; y += 5) {
- state[y + x] ^= temp;
+ {
+ uint64_t BC[5];
+ for (x = 0; x < 5; ++x) {
+ BC[x] = state[x] ^ state[5 + x] ^ state[10 + x] ^
+ state[15 + x] ^ state[20 + x];
+ }
+ for (x = 0; x < 5; ++x) {
+ uint64_t temp = BC[KeccakF_Mod5[x + 4]] ^
+ rotl64(BC[KeccakF_Mod5[x + 1]], 1);
+ if (SHA3_SMALL && !ARCH_IS_64BIT) {
+ for (y = 0; y <= 20; y += 5)
+ state[y + x] ^= temp;
+ } else {
+ /* on 64-bit arch, this is actually smaller too */
+ state[0 + x] ^= temp;
+ state[5 + x] ^= temp;
+ state[10 + x] ^= temp;
+ state[15 + x] ^= temp;
+ state[20 + x] ^= temp;
+ }
}
}
/* Rho Pi */
- temp = state[1];
- for (x = 0; x < 24; ++x) {
- BC[0] = state[KeccakF_PiLane[x]];
- state[KeccakF_PiLane[x]] =
- rotl64(temp, KeccakF_RotationConstants[x]);
- temp = BC[0];
+ if (SHA3_SMALL) {
+ uint64_t t1 = state[1];
+ for (x = 0; x < 24; ++x) {
+ uint64_t t0 = state[KeccakF_PiLane[x]];
+ state[KeccakF_PiLane[x]] = rotl64(t1, KeccakF_RotationConstants[x]);
+ t1 = t0;
+ }
+ } else {
+ /* Especially large benefit for 32-bit arch:
+ * 64-bit rotations by non-constant usually are SLOW on those.
+ * We resort to unrolling here.
+ * This optimizes out KeccakF_PiLane[] and KeccakF_RotationConstants[],
+ * but generates 300-500 more bytes of code.
+ */
+ uint64_t t0;
+ uint64_t t1 = state[1];
+#define RhoPi_twice(x) \
+ t0 = state[KeccakF_PiLane[x ]]; state[KeccakF_PiLane[x ]] = rotl64(t1, KeccakF_RotationConstants[x ]); \
+ t1 = state[KeccakF_PiLane[x+1]]; state[KeccakF_PiLane[x+1]] = rotl64(t0, KeccakF_RotationConstants[x+1]);
+ RhoPi_twice(0); RhoPi_twice(2);
+ RhoPi_twice(4); RhoPi_twice(6);
+ RhoPi_twice(8); RhoPi_twice(10);
+ RhoPi_twice(12); RhoPi_twice(14);
+ RhoPi_twice(16); RhoPi_twice(18);
+ RhoPi_twice(20); RhoPi_twice(22);
+#undef RhoPi_twice
}
/* Chi */
- for (y = 0; y < 25; y += 5) {
+ for (y = 0; y <= 20; y += 5) {
+ uint64_t BC[5];
BC[0] = state[y + 0];
BC[1] = state[y + 1];
BC[2] = state[y + 2];