- Initial commit

Runtime/3rdParty/BouncyCastle/crypto/modes/gcm/Tables1kGcmExponentiator.cs

@@ -0,0 +1,63 @@
+#if !BESTHTTP_DISABLE_ALTERNATE_SSL && (!UNITY_WEBGL || UNITY_EDITOR)
+#pragma warning disable
+using System;
+using System.Collections.Generic;
+
+namespace Best.HTTP.SecureProtocol.Org.BouncyCastle.Crypto.Modes.Gcm
+{
+    public class Tables1kGcmExponentiator
+        : IGcmExponentiator
+    {
+        // A lookup table of the power-of-two powers of 'x'
+        // - lookupPowX2[i] = x^(2^i)
+        private IList<GcmUtilities.FieldElement> lookupPowX2;
+
+        public void Init(byte[] x)
+        {
+            GcmUtilities.FieldElement y;
+            GcmUtilities.AsFieldElement(x, out y);
+            if (lookupPowX2 != null && y.Equals(lookupPowX2[0]))
+                return;
+
+            lookupPowX2 = new List<GcmUtilities.FieldElement>(8);
+            lookupPowX2.Add(y);
+        }
+
+        public void ExponentiateX(long pow, byte[] output)
+        {
+            GcmUtilities.FieldElement y;
+            GcmUtilities.One(out y);
+            int bit = 0;
+            while (pow > 0)
+            {
+                if ((pow & 1L) != 0)
+                {
+                    EnsureAvailable(bit);
+                    GcmUtilities.FieldElement powX2 = (GcmUtilities.FieldElement)lookupPowX2[bit];
+                    GcmUtilities.Multiply(ref y, ref powX2);
+                }
+                ++bit;
+                pow >>= 1;
+            }
+
+            GcmUtilities.AsBytes(ref y, output);
+        }
+
+        private void EnsureAvailable(int bit)
+        {
+            int count = lookupPowX2.Count;
+            if (count <= bit)
+            {
+                GcmUtilities.FieldElement powX2 = (GcmUtilities.FieldElement)lookupPowX2[count - 1];
+                do
+                {
+                    GcmUtilities.Square(ref powX2);
+                    lookupPowX2.Add(powX2);
+                }
+                while (++count <= bit);
+            }
+        }
+    }
+}
+#pragma warning restore
+#endif