From 3fc5f0e61be2f9f6169d88b143e8c196d5e63b5e Mon Sep 17 00:00:00 2001
From: Peter Dettman <peter.dettman@bouncycastle.org>
Date: Mon, 29 Jul 2019 22:15:23 +0700
Subject: Fix field reduction for custom secp128r1 curve

- see https://github.com/bcgit/bc-java/issues/566
---
 crypto/src/math/ec/custom/sec/SecP128R1Field.cs | 5 +++++
 1 file changed, 5 insertions(+)

(limited to 'crypto/src/math/ec/custom')

diff --git a/crypto/src/math/ec/custom/sec/SecP128R1Field.cs b/crypto/src/math/ec/custom/sec/SecP128R1Field.cs
index d1ac009b3..cf91c7e5d 100644
--- a/crypto/src/math/ec/custom/sec/SecP128R1Field.cs
+++ b/crypto/src/math/ec/custom/sec/SecP128R1Field.cs
@@ -134,6 +134,11 @@ namespace Org.BouncyCastle.Math.EC.Custom.Sec
 
                 x = (uint)c;
             }
+
+            if (z[3] >= P3 && Nat128.Gte(z, P))
+            {
+                AddPInvTo(z);
+            }
         }
 
         public static void Square(uint[] x, uint[] z)
-- 
cgit 1.5.1