From 1deb0b8812b18994a070ef8c5b23890a05325779 Mon Sep 17 00:00:00 2001
From: Frank Denis <github@pureftpd.org>
Date: Wed, 23 Oct 2024 18:54:54 +0200
Subject: [PATCH] More optblocker usage

---
 src/libsodium/crypto_core/ed25519/ref10/ed25519_ref10.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/src/libsodium/crypto_core/ed25519/ref10/ed25519_ref10.c b/src/libsodium/crypto_core/ed25519/ref10/ed25519_ref10.c
index c522eb4629..66e8d89b94 100644
--- a/src/libsodium/crypto_core/ed25519/ref10/ed25519_ref10.c
+++ b/src/libsodium/crypto_core/ed25519/ref10/ed25519_ref10.c
@@ -321,6 +321,7 @@ slide_vartime(signed char *r, const unsigned char *a)
 }
 
 static volatile unsigned char optblocker_u8;
+static volatile uint64_t optblocker_u64;
 
 int
 ge25519_frombytes(ge25519_p3 *h, const unsigned char *s)
@@ -619,11 +620,9 @@ static unsigned char
 negative(signed char b)
 {
     /* 18446744073709551361..18446744073709551615: yes; 0..255: no */
-    uint64_t x = b;
+    const uint64_t x = (uint64_t) b;
 
-    x >>= 63; /* 1: yes; 0: no */
-
-    return x;
+    return ((x >> 61) ^ optblocker_u64) >> 2; /* 1: yes; 0: no */
 }
 
 static void