diff options
Diffstat (limited to 'crypto/src/math/ec/custom/sec/SecP160R2Field.cs')
| -rw-r--r-- | crypto/src/math/ec/custom/sec/SecP160R2Field.cs | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/crypto/src/math/ec/custom/sec/SecP160R2Field.cs b/crypto/src/math/ec/custom/sec/SecP160R2Field.cs new file mode 100644 index 000000000..1bef32eea --- /dev/null +++ b/crypto/src/math/ec/custom/sec/SecP160R2Field.cs @@ -0,0 +1,178 @@ +using System; +using System.Diagnostics; + +using Org.BouncyCastle.Math.Raw; + +namespace Org.BouncyCastle.Math.EC.Custom.Sec +{ + internal class SecP160R2Field + { + // 2^160 - 2^32 - 2^14 - 2^12 - 2^9 - 2^8 - 2^7 - 2^3 - 2^2 - 1 + internal static readonly uint[] P = new uint[]{ 0xFFFFAC73, 0xFFFFFFFE, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF }; + internal static readonly uint[] PExt = new uint[]{ 0x1B44BBA9, 0x0000A71A, 0x00000001, 0x00000000, 0x00000000, + 0xFFFF58E6, 0xFFFFFFFD, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF }; + private static readonly uint[] PExtInv = new uint[]{ 0xE4BB4457, 0xFFFF58E5, 0xFFFFFFFE, 0xFFFFFFFF, 0xFFFFFFFF, + 0x0000A719, 0x00000002 }; + private const uint P4 = 0xFFFFFFFF; + private const uint PExt9 = 0xFFFFFFFF; + private const uint PInv33 = 0x538D; + + public static void Add(uint[] x, uint[] y, uint[] z) + { + uint c = Nat160.Add(x, y, z); + if (c != 0 || (z[4] == P4 && Nat160.Gte(z, P))) + { + Nat.Add33To(5, PInv33, z); + } + } + + public static void AddExt(uint[] xx, uint[] yy, uint[] zz) + { + uint c = Nat.Add(10, xx, yy, zz); + if (c != 0 || (zz[9] == PExt9 && Nat.Gte(10, zz, PExt))) + { + if (Nat.AddTo(PExtInv.Length, PExtInv, zz) != 0) + { + Nat.IncAt(10, zz, PExtInv.Length); + } + } + } + + public static void AddOne(uint[] x, uint[] z) + { + uint c = Nat.Inc(5, x, z); + if (c != 0 || (z[4] == P4 && Nat160.Gte(z, P))) + { + Nat.Add33To(5, PInv33, z); + } + } + + public static uint[] FromBigInteger(BigInteger x) + { + uint[] z = Nat160.FromBigInteger(x); + if (z[4] == P4 && Nat160.Gte(z, P)) + { + Nat160.SubFrom(P, z); + } + return z; + } + + public static void Half(uint[] x, uint[] z) + { + if ((x[0] & 1) == 0) + { + Nat.ShiftDownBit(5, x, 0, z); + } + else + { + uint c = Nat160.Add(x, P, z); + Nat.ShiftDownBit(5, z, c); + } + } + + public static void Multiply(uint[] x, uint[] y, uint[] z) + { + uint[] tt = Nat160.CreateExt(); + Nat160.Mul(x, y, tt); + Reduce(tt, z); + } + + public static void MultiplyAddToExt(uint[] x, uint[] y, uint[] zz) + { + uint c = Nat160.MulAddTo(x, y, zz); + if (c != 0 || (zz[9] == PExt9 && Nat.Gte(10, zz, PExt))) + { + if (Nat.AddTo(PExtInv.Length, PExtInv, zz) != 0) + { + Nat.IncAt(10, zz, PExtInv.Length); + } + } + } + + public static void Negate(uint[] x, uint[] z) + { + if (Nat160.IsZero(x)) + { + Nat160.Zero(z); + } + else + { + Nat160.Sub(P, x, z); + } + } + + public static void Reduce(uint[] xx, uint[] z) + { + ulong cc = Nat160.Mul33Add(PInv33, xx, 5, xx, 0, z, 0); + uint c = Nat160.Mul33DWordAdd(PInv33, cc, z, 0); + + Debug.Assert(c == 0 || c == 1); + + if (c != 0 || (z[4] == P4 && Nat160.Gte(z, P))) + { + Nat.Add33To(5, PInv33, z); + } + } + + public static void Reduce32(uint x, uint[] z) + { + if ((x != 0 && Nat160.Mul33WordAdd(PInv33, x, z, 0) != 0) + || (z[4] == P4 && Nat160.Gte(z, P))) + { + Nat.Add33To(5, PInv33, z); + } + } + + public static void Square(uint[] x, uint[] z) + { + uint[] tt = Nat160.CreateExt(); + Nat160.Square(x, tt); + Reduce(tt, z); + } + + public static void SquareN(uint[] x, int n, uint[] z) + { + Debug.Assert(n > 0); + + uint[] tt = Nat160.CreateExt(); + Nat160.Square(x, tt); + Reduce(tt, z); + + while (--n > 0) + { + Nat160.Square(z, tt); + Reduce(tt, z); + } + } + + public static void Subtract(uint[] x, uint[] y, uint[] z) + { + int c = Nat160.Sub(x, y, z); + if (c != 0) + { + Nat.Sub33From(5, PInv33, z); + } + } + + public static void SubtractExt(uint[] xx, uint[] yy, uint[] zz) + { + int c = Nat.Sub(10, xx, yy, zz); + if (c != 0) + { + if (Nat.SubFrom(PExtInv.Length, PExtInv, zz) != 0) + { + Nat.DecAt(10, zz, PExtInv.Length); + } + } + } + + public static void Twice(uint[] x, uint[] z) + { + uint c = Nat.ShiftUpBit(5, x, 0, z); + if (c != 0 || (z[4] == P4 && Nat160.Gte(z, P))) + { + Nat.Add33To(5, PInv33, z); + } + } + } +} |