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authorPeter Dettman <peter.dettman@bouncycastle.org>2015-03-24 22:57:22 +0700
committerPeter Dettman <peter.dettman@bouncycastle.org>2015-03-24 22:57:22 +0700
commit63ef85d468f05593c251a6e370d36d717dc08362 (patch)
tree5eb93ca3797905b9ca8c3cfa967f62e9d5a064b3 /crypto/src/math/ec/custom/sec/SecT239Field.cs
parentAdd GetHashCode methods for ulong[] (diff)
downloadBouncyCastle.NET-ed25519-63ef85d468f05593c251a6e370d36d717dc08362.tar.xz
Add custom implementations of SEC binary curves
Diffstat (limited to 'crypto/src/math/ec/custom/sec/SecT239Field.cs')
-rw-r--r--crypto/src/math/ec/custom/sec/SecT239Field.cs249
1 files changed, 249 insertions, 0 deletions
diff --git a/crypto/src/math/ec/custom/sec/SecT239Field.cs b/crypto/src/math/ec/custom/sec/SecT239Field.cs
new file mode 100644
index 000000000..1e0824af9
--- /dev/null
+++ b/crypto/src/math/ec/custom/sec/SecT239Field.cs
@@ -0,0 +1,249 @@
+using System;
+using System.Diagnostics;
+
+using Org.BouncyCastle.Math.Raw;
+
+namespace Org.BouncyCastle.Math.EC.Custom.Sec
+{
+    internal class SecT239Field
+    {
+        private const ulong M47 = ulong.MaxValue >> 17;
+        private const ulong M60 = ulong.MaxValue >> 4;
+
+        public static void Add(ulong[] x, ulong[] y, ulong[] z)
+        {
+            z[0] = x[0] ^ y[0];
+            z[1] = x[1] ^ y[1];
+            z[2] = x[2] ^ y[2];
+            z[3] = x[3] ^ y[3];
+        }
+
+        public static void AddExt(ulong[] xx, ulong[] yy, ulong[] zz)
+        {
+            zz[0] = xx[0] ^ yy[0];
+            zz[1] = xx[1] ^ yy[1];
+            zz[2] = xx[2] ^ yy[2];
+            zz[3] = xx[3] ^ yy[3];
+            zz[4] = xx[4] ^ yy[4];
+            zz[5] = xx[5] ^ yy[5];
+            zz[6] = xx[6] ^ yy[6];
+            zz[7] = xx[7] ^ yy[7];
+        }
+
+        public static void AddOne(ulong[] x, ulong[] z)
+        {
+            z[0] = x[0] ^ 1UL;
+            z[1] = x[1];
+            z[2] = x[2];
+            z[3] = x[3];
+        }
+
+        public static ulong[] FromBigInteger(BigInteger x)
+        {
+            ulong[] z = Nat256.FromBigInteger64(x);
+            Reduce17(z, 0);
+            return z;
+        }
+
+        public static void Multiply(ulong[] x, ulong[] y, ulong[] z)
+        {
+            ulong[] tt = Nat256.CreateExt64();
+            ImplMultiply(x, y, tt);
+            Reduce(tt, z);
+        }
+
+        public static void MultiplyAddToExt(ulong[] x, ulong[] y, ulong[] zz)
+        {
+            ulong[] tt = Nat256.CreateExt64();
+            ImplMultiply(x, y, tt);
+            AddExt(zz, tt, zz);
+        }
+
+        public static void Reduce(ulong[] xx, ulong[] z)
+        {
+            ulong x0 = xx[0], x1 = xx[1], x2 = xx[2], x3 = xx[3];
+            ulong x4 = xx[4], x5 = xx[5], x6 = xx[6], x7 = xx[7];
+
+            x3 ^= (x7 << 17);
+            x4 ^= (x7 >> 47);
+            x5 ^= (x7 << 47);
+            x6 ^= (x7 >> 17);
+
+            x2 ^= (x6 << 17);
+            x3 ^= (x6 >> 47);
+            x4 ^= (x6 << 47);
+            x5 ^= (x6 >> 17);
+
+            x1 ^= (x5 << 17);
+            x2 ^= (x5 >> 47);
+            x3 ^= (x5 << 47);
+            x4 ^= (x5 >> 17);
+
+            x0 ^= (x4 << 17);
+            x1 ^= (x4 >> 47);
+            x2 ^= (x4 << 47);
+            x3 ^= (x4 >> 17);
+
+            ulong t = x3 >> 47;
+            z[0]    = x0 ^ t;
+            z[1]    = x1;
+            z[2]    = x2 ^ (t << 30);
+            z[3]    = x3 & M47;
+        }
+
+        public static void Reduce17(ulong[] z, int zOff)
+        {
+            ulong z3     = z[zOff + 3], t = z3 >> 47;
+            z[zOff    ] ^= t;
+            z[zOff + 2] ^= (t << 30);
+            z[zOff + 3]  = z3 & M47;
+        }
+
+        public static void Square(ulong[] x, ulong[] z)
+        {
+            ulong[] tt = Nat256.CreateExt64();
+            ImplSquare(x, tt);
+            Reduce(tt, z);
+        }
+
+        public static void SquareAddToExt(ulong[] x, ulong[] zz)
+        {
+            ulong[] tt = Nat256.CreateExt64();
+            ImplSquare(x, tt);
+            AddExt(zz, tt, zz);
+        }
+
+        public static void SquareN(ulong[] x, int n, ulong[] z)
+        {
+            Debug.Assert(n > 0);
+
+            ulong[] tt = Nat256.CreateExt64();
+            ImplSquare(x, tt);
+            Reduce(tt, z);
+
+            while (--n > 0)
+            {
+                ImplSquare(z, tt);
+                Reduce(tt, z);
+            }
+        }
+
+        protected static void ImplCompactExt(ulong[] zz)
+        {
+            ulong z0 = zz[0], z1 = zz[1], z2 = zz[2], z3 = zz[3], z4 = zz[4], z5 = zz[5], z6 = zz[6], z7 = zz[7];
+            zz[0] =  z0        ^ (z1 << 60);
+            zz[1] = (z1 >>  4) ^ (z2 << 56);
+            zz[2] = (z2 >>  8) ^ (z3 << 52);
+            zz[3] = (z3 >> 12) ^ (z4 << 48);
+            zz[4] = (z4 >> 16) ^ (z5 << 44);
+            zz[5] = (z5 >> 20) ^ (z6 << 40);
+            zz[6] = (z6 >> 24) ^ (z7 << 36);
+            zz[7] = (z7 >> 28);
+        }
+
+        protected static void ImplExpand(ulong[] x, ulong[] z)
+        {
+            ulong x0 = x[0], x1 = x[1], x2 = x[2], x3 = x[3];
+            z[0] = x0 & M60;
+            z[1] = ((x0 >> 60) ^ (x1 <<  4)) & M60;
+            z[2] = ((x1 >> 56) ^ (x2 <<  8)) & M60;
+            z[3] = ((x2 >> 52) ^ (x3 << 12));
+        }
+
+        protected static void ImplMultiply(ulong[] x, ulong[] y, ulong[] zz)
+        {
+            /*
+             * "Two-level seven-way recursion" as described in "Batch binary Edwards", Daniel J. Bernstein.
+             */
+
+            ulong[] f = new ulong[4], g = new ulong[4];
+            ImplExpand(x, f);
+            ImplExpand(y, g);
+
+            ImplMulwAcc(f[0], g[0], zz, 0);
+            ImplMulwAcc(f[1], g[1], zz, 1);
+            ImplMulwAcc(f[2], g[2], zz, 2);
+            ImplMulwAcc(f[3], g[3], zz, 3);
+
+            // U *= (1 - t^n)
+            for (int i = 5; i > 0; --i)
+            {
+                zz[i] ^= zz[i - 1];
+            }
+
+            ImplMulwAcc(f[0] ^ f[1], g[0] ^ g[1], zz, 1);
+            ImplMulwAcc(f[2] ^ f[3], g[2] ^ g[3], zz, 3);
+
+            // V *= (1 - t^2n)
+            for (int i = 7; i > 1; --i)
+            {
+                zz[i] ^= zz[i - 2];
+            }
+
+            // Double-length recursion
+            {
+                ulong c0 = f[0] ^ f[2], c1 = f[1] ^ f[3];
+                ulong d0 = g[0] ^ g[2], d1 = g[1] ^ g[3];
+                ImplMulwAcc(c0 ^ c1, d0 ^ d1, zz, 3);
+                ulong[] t = new ulong[3];
+                ImplMulwAcc(c0, d0, t, 0);
+                ImplMulwAcc(c1, d1, t, 1);
+                ulong t0 = t[0], t1 = t[1], t2 = t[2];
+                zz[2] ^= t0;
+                zz[3] ^= t0 ^ t1;
+                zz[4] ^= t2 ^ t1;
+                zz[5] ^= t2;
+            }
+
+            ImplCompactExt(zz);
+        }
+
+        protected static void ImplMulwAcc(ulong x, ulong y, ulong[] z, int zOff)
+        {
+            Debug.Assert(x >> 60 == 0);
+            Debug.Assert(y >> 60 == 0);
+
+            ulong[] u = new ulong[8];
+    //      u[0] = 0;
+            u[1] = y;
+            u[2] = u[1] << 1;
+            u[3] = u[2] ^  y;
+            u[4] = u[2] << 1;
+            u[5] = u[4] ^  y;
+            u[6] = u[3] << 1;
+            u[7] = u[6] ^  y;
+
+            uint j = (uint)x;
+            ulong g, h = 0, l = u[j & 7]
+                              ^ (u[(j >> 3) & 7] << 3);
+            int k = 54;
+            do
+            {
+                j = (uint)(x >> k);
+                g  = u[j & 7]
+                   ^ u[(j >> 3) & 7] << 3;
+                l ^= (g <<  k);
+                h ^= (g >> -k);
+            }
+            while ((k -= 6) > 0);
+
+            h ^= ((x & 0x0820820820820820L) & (ulong)(((long)y << 4) >> 63)) >> 5;
+
+            Debug.Assert(h >> 55 == 0);
+
+            z[zOff    ] ^= l & M60;
+            z[zOff + 1] ^= (l >> 60) ^ (h << 4);
+        }
+
+        protected static void ImplSquare(ulong[] x, ulong[] zz)
+        {
+            Interleave.Expand64To128(x[0], zz, 0);
+            Interleave.Expand64To128(x[1], zz, 2);
+            Interleave.Expand64To128(x[2], zz, 4);
+
+            ulong x3 = x[3];
+            zz[6] = Interleave.Expand32to64((uint)x3);
+            zz[7] = Interleave.Expand16to32((uint)(x3 >> 32));
+        }
+    }
+}