Math.Raw support for custom binary curves

- Also migrate the 'raw' stuff into Math.Raw following Java build

1 files changed, 46 insertions, 0 deletions

diff --git a/crypto/src/math/raw/Nat512.cs b/crypto/src/math/raw/Nat512.cs
new file mode 100644
index 000000000..a9ef2b3b6
--- /dev/null
+++ b/crypto/src/math/raw/Nat512.cs
@@ -0,0 +1,46 @@
+using System;
+using System.Diagnostics;
+
+namespace Org.BouncyCastle.Math.Raw
+{
+    internal abstract class Nat512
+    {
+        public static void Mul(uint[] x, uint[] y, uint[] zz)
+        {
+            Nat256.Mul(x, y, zz);
+            Nat256.Mul(x, 8, y, 8, zz, 16);
+
+            uint c24 = Nat256.AddToEachOther(zz, 8, zz, 16);
+            uint c16 = c24 + Nat256.AddTo(zz, 0, zz, 8, 0);
+            c24 += Nat256.AddTo(zz, 24, zz, 16, c16);
+
+            uint[] dx = Nat256.Create(), dy = Nat256.Create();
+            bool neg = Nat256.Diff(x, 8, x, 0, dx, 0) != Nat256.Diff(y, 8, y, 0, dy, 0);
+
+            uint[] tt = Nat256.CreateExt();
+            Nat256.Mul(dx, dy, tt);
+
+            c24 += neg ? Nat.AddTo(16, tt, 0, zz, 8) : (uint)Nat.SubFrom(16, tt, 0, zz, 8);
+            Nat.AddWordAt(32, c24, zz, 24); 
+        }
+
+        public static void Square(uint[] x, uint[] zz)
+        {
+            Nat256.Square(x, zz);
+            Nat256.Square(x, 8, zz, 16);
+
+            uint c24 = Nat256.AddToEachOther(zz, 8, zz, 16);
+            uint c16 = c24 + Nat256.AddTo(zz, 0, zz, 8, 0);
+            c24 += Nat256.AddTo(zz, 24, zz, 16, c16);
+
+            uint[] dx = Nat256.Create();
+            Nat256.Diff(x, 8, x, 0, dx, 0);
+
+            uint[] m = Nat256.CreateExt();
+            Nat256.Square(dx, m);
+
+            c24 += (uint)Nat.SubFrom(16, m, 0, zz, 8);
+            Nat.AddWordAt(32, c24, zz, 24); 
+        }
+    }
+}