Decrement and shift in separate steps

jedisct1 · Oct 23, 2024 · 59607d5 · 59607d5
1 parent 409b3a7
commit 59607d5
Showing 1 changed file with 3 additions and 2 deletions.
diff --git a/src/libsodium/crypto_core/ed25519/ref10/ed25519_ref10.c b/src/libsodium/crypto_core/ed25519/ref10/ed25519_ref10.c
@@ -566,9 +566,10 @@ static unsigned char
 equal(signed char b, signed char c)
 {
     const unsigned char x  = (unsigned char) b ^ (unsigned char) c; /* 0: yes; 1..255: no */
-    const uint32_t      y  = (uint32_t) x; /* 0: yes; 1..255: no */
+    uint32_t      y  = (uint32_t) x; /* 0: yes; 1..255: no */
 
-    return (((y - 1) >> 29) ^ optblocker_u8) >> 2; /* 1: yes; 0: no */
+    y--;
+    return ((y >> 29) ^ optblocker_u8) >> 2; /* 1: yes; 0: no */
 }
 
 static unsigned char