Add custom curves for secp192k1 and secp192r1 (P-192)

1 files changed, 156 insertions, 0 deletions

diff --git a/crypto/src/math/ec/custom/sec/SecP192K1Field.cs b/crypto/src/math/ec/custom/sec/SecP192K1Field.cs
new file mode 100644
index 000000000..30c107c86
--- /dev/null
+++ b/crypto/src/math/ec/custom/sec/SecP192K1Field.cs
@@ -0,0 +1,156 @@
+using System;
+using System.Diagnostics;
+
+namespace Org.BouncyCastle.Math.EC.Custom.Sec
+{
+    internal class SecP192K1Field
+    {
+        // 2^192 - 2^32 - 2^12 - 2^8 - 2^7 - 2^6 - 2^3 - 1
+        internal static readonly uint[] P = new uint[]{ 0xFFFFEE37, 0xFFFFFFFE, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF };
+        private const uint P5 = 0xFFFFFFFF;
+        private static readonly uint[] PExt = new uint[]{ 0x013C4FD1, 0x00002392, 0x00000001, 0x00000000, 0x00000000,
+            0x00000000, 0xFFFFDC6E, 0xFFFFFFFD, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF };
+        private const uint PExt11 = 0xFFFFFFFF;
+        private const ulong PInv = 0x00000001000011C9L;
+        private const uint PInvLow = 0x11C9;
+
+        public static void Add(uint[] x, uint[] y, uint[] z)
+        {
+            uint c = Nat192.Add(x, y, z);
+            if (c != 0 || (z[5] == P5 && Nat192.Gte(z, P)))
+            {
+                Nat192.AddDWord(PInv, z, 0);
+            }
+        }
+
+        public static void AddExt(uint[] xx, uint[] yy, uint[] zz)
+        {
+            uint c = Nat192.AddExt(xx, yy, zz);
+            if (c != 0 || (zz[11] == PExt11 && Nat192.GteExt(zz, PExt)))
+            {
+                Nat192.SubExt(zz, PExt, zz);
+            }
+        }
+
+        public static void AddOne(uint[] x, uint[] z)
+        {
+            Array.Copy(x, 0, z, 0, 6);
+            uint c = Nat192.Inc(z, 0);
+            if (c != 0 || (z[5] == P5 && Nat192.Gte(z, P)))
+            {
+                Nat192.AddDWord(PInv, z, 0);
+            }
+        }
+
+        public static uint[] FromBigInteger(BigInteger x)
+        {
+            uint[] z = Nat192.FromBigInteger(x);
+            if (z[5] == P5 && Nat192.Gte(z, P))
+            {
+                Nat192.AddDWord(PInv, z, 0);
+            }
+            return z;
+        }
+
+        public static void Half(uint[] x, uint[] z)
+        {
+            if ((x[0] & 1) == 0)
+            {
+                Nat192.ShiftDownBit(x, 0, z);
+            }
+            else
+            {
+                uint c = Nat192.Add(x, P, z);
+                Nat192.ShiftDownBit(z, c, z);
+            }
+        }
+
+        public static void Multiply(uint[] x, uint[] y, uint[] z)
+        {
+            uint[] tt = Nat192.CreateExt();
+            Nat192.Mul(x, y, tt);
+            Reduce(tt, z);
+        }
+
+        public static void Negate(uint[] x, uint[] z)
+        {
+            if (Nat192.IsZero(x))
+            {
+                Nat192.Zero(z);
+            }
+            else
+            {
+                Nat192.Sub(P, x, z);
+            }
+        }
+
+        public static void Reduce(uint[] tt, uint[] z)
+        {
+            long extra = -(long)tt[6];
+            extra += (long)Nat192.MulWordAddExt(PInvLow, tt, 6, tt, 0);
+            extra += (long)Nat192.AddToExt(tt, 6, tt, 1) << 32;
+            extra += (long)tt[6];
+
+            ulong c = Nat192.MulWordDwordAdd(PInvLow, (ulong)extra, tt, 0);
+            c += Nat192.AddDWord((ulong)extra, tt, 1);
+
+            Debug.Assert(c == 0 || c == 1);
+
+            if (c != 0 || (tt[5] == P5 && Nat192.Gte(tt, P)))
+            {
+                Nat192.AddDWord(PInv, tt, 0);
+            }
+
+            Array.Copy(tt, 0, z, 0, 6);
+        }
+
+        public static void Square(uint[] x, uint[] z)
+        {
+            uint[] tt = Nat192.CreateExt();
+            Nat192.Square(x, tt);
+            Reduce(tt, z);
+        }
+
+        public static void SquareN(uint[] x, int n, uint[] z)
+        {
+            Debug.Assert(n > 0);
+
+            uint[] tt = Nat192.CreateExt();
+            Nat192.Square(x, tt);
+            Reduce(tt, z);
+
+            while (--n > 0)
+            {
+                Nat192.Square(z, tt);
+                Reduce(tt, z);
+            }
+        }
+
+        public static void Subtract(uint[] x, uint[] y, uint[] z)
+        {
+            int c = Nat192.Sub(x, y, z);
+            if (c != 0)
+            {
+                Nat192.SubDWord(PInv, z);
+            }
+        }
+
+        public static void SubtractExt(uint[] xx, uint[] yy, uint[] zz)
+        {
+            int c = Nat192.SubExt(xx, yy, zz);
+            if (c != 0)
+            {
+                Nat192.AddExt(zz, PExt, zz);
+            }
+        }
+
+        public static void Twice(uint[] x, uint[] z)
+        {
+            uint c = Nat192.ShiftUpBit(x, 0, z);
+            if (c != 0 || (z[5] == P5 && Nat192.Gte(z, P)))
+            {
+                Nat192.AddDWord(PInv, z, 0);
+            }
+        }
+    }
+}