Add Xor methods to Nat classes

2 files changed, 171 insertions, 1 deletions

diff --git a/crypto/src/math/raw/Nat.cs b/crypto/src/math/raw/Nat.cs
index 71c794197..89b6881d3 100644
--- a/crypto/src/math/raw/Nat.cs
+++ b/crypto/src/math/raw/Nat.cs
@@ -2640,6 +2640,110 @@ namespace Org.BouncyCastle.Math.Raw
         }
 #endif
 
+        public static void Xor(int len, uint[] x, uint[] y, uint[] z)
+        {
+            for (int i = 0; i < len; ++i)
+            {
+                z[i] = x[i] ^ y[i];
+            }
+        }
+
+        public static void Xor(int len, uint[] x, int xOff, uint[] y, int yOff, uint[] z, int zOff)
+        {
+            for (int i = 0; i < len; ++i)
+            {
+                z[zOff + i] = x[xOff + i] ^ y[yOff + i];
+            }
+        }
+
+#if NETCOREAPP2_1_OR_GREATER || NETSTANDARD2_1_OR_GREATER
+        public static void Xor(int len, ReadOnlySpan<uint> x, ReadOnlySpan<uint> y, Span<uint> z)
+        {
+            for (int i = 0; i < len; ++i)
+            {
+                z[i] = x[i] ^ y[i];
+            }
+        }
+#endif
+
+        public static void Xor64(int len, ulong[] x, ulong[] y, ulong[] z)
+        {
+            for (int i = 0; i < len; ++i)
+            {
+                z[i] = x[i] ^ y[i];
+            }
+        }
+
+        public static void Xor64(int len, ulong[] x, int xOff, ulong[] y, int yOff, ulong[] z, int zOff)
+        {
+            for (int i = 0; i < len; ++i)
+            {
+                z[zOff + i] = x[xOff + i] ^ y[yOff + i];
+            }
+        }
+
+#if NETCOREAPP2_1_OR_GREATER || NETSTANDARD2_1_OR_GREATER
+        public static void Xor64(int len, ReadOnlySpan<ulong> x, ReadOnlySpan<ulong> y, Span<ulong> z)
+        {
+            for (int i = 0; i < len; ++i)
+            {
+                z[i] = x[i] ^ y[i];
+            }
+        }
+#endif
+
+        public static void XorTo(int len, uint[] x, uint[] z)
+        {
+            for (int i = 0; i < len; ++i)
+            {
+                z[i] ^= x[i];
+            }
+        }
+
+        public static void XorTo(int len, uint[] x, int xOff, uint[] z, int zOff)
+        {
+            for (int i = 0; i < len; ++i)
+            {
+                z[zOff + i] ^= x[xOff + i];
+            }
+        }
+
+#if NETCOREAPP2_1_OR_GREATER || NETSTANDARD2_1_OR_GREATER
+        public static void XorTo(int len, ReadOnlySpan<uint> x, Span<uint> z)
+        {
+            for (int i = 0; i < len; ++i)
+            {
+                z[i] ^= x[i];
+            }
+        }
+#endif
+
+        public static void XorTo64(int len, ulong[] x, ulong[] z)
+        {
+            for (int i = 0; i < len; ++i)
+            {
+                z[i] ^= x[i];
+            }
+        }
+
+        public static void XorTo64(int len, ulong[] x, int xOff, ulong[] z, int zOff)
+        {
+            for (int i = 0; i < len; ++i)
+            {
+                z[zOff + i] ^= x[xOff + i];
+            }
+        }
+
+#if NETCOREAPP2_1_OR_GREATER || NETSTANDARD2_1_OR_GREATER
+        public static void XorTo64(int len, ReadOnlySpan<ulong> x, Span<ulong> z)
+        {
+            for (int i = 0; i < len; ++i)
+            {
+                z[i] ^= x[i];
+            }
+        }
+#endif
+
         public static void Zero(int len, uint[] z)
         {
 #if NETCOREAPP2_1_OR_GREATER || NETSTANDARD2_1_OR_GREATER
diff --git a/crypto/src/math/raw/Nat512.cs b/crypto/src/math/raw/Nat512.cs
index a9ef2b3b6..6e8c593fd 100644
--- a/crypto/src/math/raw/Nat512.cs
+++ b/crypto/src/math/raw/Nat512.cs
@@ -1,5 +1,10 @@
 using System;
-using System.Diagnostics;
+#if NETCOREAPP3_0_OR_GREATER
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+using System.Runtime.Intrinsics;
+using System.Runtime.Intrinsics.X86;
+#endif
 
 namespace Org.BouncyCastle.Math.Raw
 {
@@ -42,5 +47,66 @@ namespace Org.BouncyCastle.Math.Raw
             c24 += (uint)Nat.SubFrom(16, m, 0, zz, 8);
             Nat.AddWordAt(32, c24, zz, 24); 
         }
+
+        public static void Xor(uint[] x, int xOff, uint[] y, int yOff, uint[] z, int zOff)
+        {
+#if NETCOREAPP3_0_OR_GREATER
+            if (Avx2.IsSupported && Unsafe.SizeOf<Vector256<byte>>() == 32)
+            {
+                var X = MemoryMarshal.Cast<uint, byte>(x.AsSpan(xOff, 16));
+                var Y = MemoryMarshal.Cast<uint, byte>(y.AsSpan(yOff, 16));
+                var Z = MemoryMarshal.Cast<uint, byte>(z.AsSpan(zOff, 16));
+
+                var X0 = MemoryMarshal.Read<Vector256<byte>>(X[0x00..0x20]);
+                var X1 = MemoryMarshal.Read<Vector256<byte>>(X[0x20..0x40]);
+
+                var Y0 = MemoryMarshal.Read<Vector256<byte>>(Y[0x00..0x20]);
+                var Y1 = MemoryMarshal.Read<Vector256<byte>>(Y[0x20..0x40]);
+
+                var Z0 = Avx2.Xor(X0, Y0);
+                var Z1 = Avx2.Xor(X1, Y1);
+
+                MemoryMarshal.Write(Z[0x00..0x20], ref Z0);
+                MemoryMarshal.Write(Z[0x20..0x40], ref Z1);
+                return;
+            }
+
+            if (Sse2.IsSupported && Unsafe.SizeOf<Vector128<byte>>() == 16)
+            {
+                var X = MemoryMarshal.Cast<uint, byte>(x.AsSpan(xOff, 16));
+                var Y = MemoryMarshal.Cast<uint, byte>(y.AsSpan(yOff, 16));
+                var Z = MemoryMarshal.Cast<uint, byte>(z.AsSpan(zOff, 16));
+
+                var X0 = MemoryMarshal.Read<Vector128<byte>>(X[0x00..0x10]);
+                var X1 = MemoryMarshal.Read<Vector128<byte>>(X[0x10..0x20]);
+                var X2 = MemoryMarshal.Read<Vector128<byte>>(X[0x20..0x30]);
+                var X3 = MemoryMarshal.Read<Vector128<byte>>(X[0x30..0x40]);
+
+                var Y0 = MemoryMarshal.Read<Vector128<byte>>(Y[0x00..0x10]);
+                var Y1 = MemoryMarshal.Read<Vector128<byte>>(Y[0x10..0x20]);
+                var Y2 = MemoryMarshal.Read<Vector128<byte>>(Y[0x20..0x30]);
+                var Y3 = MemoryMarshal.Read<Vector128<byte>>(Y[0x30..0x40]);
+
+                var Z0 = Sse2.Xor(X0, Y0);
+                var Z1 = Sse2.Xor(X1, Y1);
+                var Z2 = Sse2.Xor(X2, Y2);
+                var Z3 = Sse2.Xor(X3, Y3);
+
+                MemoryMarshal.Write(Z[0x00..0x10], ref Z0);
+                MemoryMarshal.Write(Z[0x10..0x20], ref Z1);
+                MemoryMarshal.Write(Z[0x20..0x30], ref Z2);
+                MemoryMarshal.Write(Z[0x30..0x40], ref Z3);
+                return;
+            }
+#endif
+
+            for (int i = 0; i < 16; i += 4)
+            {
+                z[zOff + i + 0] = x[xOff + i + 0] ^ y[yOff + i + 0];
+                z[zOff + i + 1] = x[xOff + i + 1] ^ y[yOff + i + 1];
+                z[zOff + i + 2] = x[xOff + i + 2] ^ y[yOff + i + 2];
+                z[zOff + i + 3] = x[xOff + i + 3] ^ y[yOff + i + 3];
+            }
+        }
     }
 }