1 files changed, 28 insertions, 27 deletions
diff --git a/crypto/src/math/ec/ECCurve.cs b/crypto/src/math/ec/ECCurve.cs
index 73b70f6de..3999ba4f0 100644
--- a/crypto/src/math/ec/ECCurve.cs
+++ b/crypto/src/math/ec/ECCurve.cs
@@ -90,6 +90,8 @@ namespace Org.BouncyCastle.Math.EC
         protected ECEndomorphism m_endomorphism = null;
         protected ECMultiplier m_multiplier = null;
 
+        private IDictionary<string, PreCompInfo> m_preCompTable = null;
+
         protected ECCurve(IFiniteField field)
         {
             this.m_field = field;
@@ -160,6 +162,32 @@ namespace Org.BouncyCastle.Math.EC
             }
         }
 
+        internal virtual PreCompInfo Precompute(string name, IPreCompCallback callback)
+        {
+            IDictionary<string, PreCompInfo> table;
+            lock (this)
+            {
+                table = m_preCompTable;
+                if (null == table)
+                {
+                    m_preCompTable = table = new Dictionary<string, PreCompInfo>();
+                }
+            }
+
+            lock (table)
+            {
+                PreCompInfo existing = table.TryGetValue(name, out var preCompInfo) ? preCompInfo : null;
+                PreCompInfo result = callback.Precompute(existing);
+
+                if (result != existing)
+                {
+                    table[name] = result;
+                }
+
+                return result;
+            }
+        }
+
         /**
          * Compute a <code>PreCompInfo</code> for a point on this curve, under a given name. Used by
          * <code>ECMultiplier</code>s to save the precomputation for this <code>ECPoint</code> for use
@@ -929,13 +957,6 @@ namespace Org.BouncyCastle.Math.EC
             return new LongArray(x).ModInverse(m, ks).ToBigInteger();
         }
 
-        /**
-         * The auxiliary values <code>s<sub>0</sub></code> and
-         * <code>s<sub>1</sub></code> used for partial modular reduction for
-         * Koblitz curves.
-         */
-        private BigInteger[] si = null;
-
         private static IFiniteField BuildField(int m, int k1, int k2, int k3)
         {
             int[] exponents = (k2 | k3) == 0
@@ -1102,26 +1123,6 @@ namespace Org.BouncyCastle.Math.EC
         }
 
         /**
-         * @return the auxiliary values <code>s<sub>0</sub></code> and
-         * <code>s<sub>1</sub></code> used for partial modular reduction for
-         * Koblitz curves.
-         */
-        internal virtual BigInteger[] GetSi()
-        {
-            if (si == null)
-            {
-                lock (this)
-                {
-                    if (si == null)
-                    {
-                        si = Tnaf.GetSi(this);
-                    }
-                }
-            }
-            return si;
-        }
-
-        /**
          * Returns true if this is a Koblitz curve (ABC curve).
          * @return true if this is a Koblitz curve (ABC curve), false otherwise
          */