2 files changed, 18 insertions, 4 deletions
diff --git a/crypto/src/math/ec/rfc7748/X25519Field.cs b/crypto/src/math/ec/rfc7748/X25519Field.cs
index fd5599657..b5938e2e7 100644
--- a/crypto/src/math/ec/rfc7748/X25519Field.cs
+++ b/crypto/src/math/ec/rfc7748/X25519Field.cs
@@ -179,14 +179,21 @@ namespace Org.BouncyCastle.Math.EC.Rfc7748
Mul(t, x2, z);
}
- public static bool IsZeroVar(int[] x)
+ public static int IsZero(int[] x)
{
int d = 0;
for (int i = 0; i < Size; ++i)
{
d |= x[i];
}
- return d == 0;
+ d |= d >> 16;
+ d &= 0xFFFF;
+ return (d - 1) >> 31;
+ }
+
+ public static bool IsZeroVar(int[] x)
+ {
+ return 0 != IsZero(x);
}
public static void Mul(int[] x, int y, int[] z)
diff --git a/crypto/src/math/ec/rfc7748/X448Field.cs b/crypto/src/math/ec/rfc7748/X448Field.cs
index 5a682714d..7cda6ebcc 100644
--- a/crypto/src/math/ec/rfc7748/X448Field.cs
+++ b/crypto/src/math/ec/rfc7748/X448Field.cs
@@ -195,14 +195,21 @@ namespace Org.BouncyCastle.Math.EC.Rfc7748
Mul(t, x, z);
}
- public static bool IsZeroVar(uint[] x)
+ public static int IsZero(uint[] x)
{
uint d = 0;
for (int i = 0; i < Size; ++i)
{
d |= x[i];
}
- return d == 0U;
+ d |= d >> 16;
+ d &= 0xFFFF;
+ return ((int)d - 1) >> 31;
+ }
+
+ public static bool IsZeroVar(uint[] x)
+ {
+ return 0U != IsZero(x);
}
public static void Mul(uint[] x, uint y, uint[] z)
|
