libxcrypt/libxcrypt-4.4.33-SHA512_Maj_optimization.patch

55 lines
1.9 KiB
Diff

From 59823543d095ad0fe4a063d819c52953249c9ba0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Esser?= <besser82@fedoraproject.org>
Date: Wed, 7 Dec 2022 07:04:51 +0100
Subject: [PATCH] alg-sha512.c: SHA-2 Maj() optimization proposed by Wei Dai.
This patch has already been applied to 'lib/alg-sha256.c'
in commit bb1721800932268a537c804a4b7655af8c62d5e8.
---
lib/alg-sha512.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/lib/alg-sha512.c b/lib/alg-sha512.c
index c30f8a0..4e9965d 100644
--- a/lib/alg-sha512.c
+++ b/lib/alg-sha512.c
@@ -1,6 +1,7 @@
/*-
* Copyright 2005 Colin Percival
* Copyright (c) 2015 Allan Jude <allanjude@FreeBSD.org>
+ * Copyright 2021, 2022 Alexander Peslyak
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
@@ -78,7 +79,11 @@ static const uint64_t K[80] = {
/* Elementary functions used by SHA512 */
#define Ch(x, y, z) ((x & (y ^ z)) ^ z)
-#define Maj(x, y, z) ((x & (y | z)) | (y & z))
+#if 1 /* Explicit caching/reuse of common subexpression between rounds */
+#define Maj(x, y, z) (y ^ ((x_xor_y = x ^ y) & y_xor_z))
+#else /* Let the compiler cache/reuse or not */
+#define Maj(x, y, z) (y ^ ((x ^ y) & (y ^ z)))
+#endif
#define SHR(x, n) (x >> n)
#define ROTR(x, n) ((x >> n) | (x << (64 - n)))
#define S0(x) (ROTR(x, 28) ^ ROTR(x, 34) ^ ROTR(x, 39))
@@ -90,7 +95,8 @@ static const uint64_t K[80] = {
#define RND(a, b, c, d, e, f, g, h, k) \
h += S1(e) + Ch(e, f, g) + k; \
d += h; \
- h += S0(a) + Maj(a, b, c);
+ h += S0(a) + Maj(a, b, c); \
+ y_xor_z = x_xor_y;
/* Adjusted round function for rotating state */
#define RNDr(S, W, i, ii) \
@@ -123,6 +129,7 @@ SHA512_Transform(uint64_t * state, const unsigned char block[SHA512_BLOCK_LENGTH
/* 3. Mix. */
for (i = 0; i < 80; i += 16) {
+ uint64_t x_xor_y, y_xor_z = S[(65 - i) % 8] ^ S[(66 - i) % 8];
RNDr(S, W, 0, i);
RNDr(S, W, 1, i);
RNDr(S, W, 2, i);