SecP256R1FieldElement
using Org.BouncyCastle.Math.Raw;
using Org.BouncyCastle.Utilities;
using Org.BouncyCastle.Utilities.Encoders;
using System;
namespace Org.BouncyCastle.Math.EC.Custom.Sec
{
internal class SecP256R1FieldElement : AbstractFpFieldElement
{
public static readonly BigInteger Q = new BigInteger(1, Hex.DecodeStrict("FFFFFFFF00000001000000000000000000000000FFFFFFFFFFFFFFFFFFFFFFFF"));
protected internal readonly uint[] x;
public override bool IsZero => Nat256.IsZero(x);
public override bool IsOne => Nat256.IsOne(x);
public override string FieldName => "SecP256R1Field";
public override int FieldSize => Q.BitLength;
public SecP256R1FieldElement(BigInteger x)
{
if (x == null || x.SignValue < 0 || x.CompareTo(Q) >= 0)
throw new ArgumentException("value invalid for SecP256R1FieldElement", "x");
this.x = SecP256R1Field.FromBigInteger(x);
}
public SecP256R1FieldElement()
{
x = Nat256.Create();
}
protected internal SecP256R1FieldElement(uint[] x)
{
this.x = x;
}
public override bool TestBitZero()
{
return Nat256.GetBit(x, 0) == 1;
}
public override BigInteger ToBigInteger()
{
return Nat256.ToBigInteger(x);
}
public override ECFieldElement Add(ECFieldElement b)
{
uint[] z = Nat256.Create();
SecP256R1Field.Add(x, ((SecP256R1FieldElement)b).x, z);
return new SecP256R1FieldElement(z);
}
public override ECFieldElement AddOne()
{
uint[] z = Nat256.Create();
SecP256R1Field.AddOne(x, z);
return new SecP256R1FieldElement(z);
}
public override ECFieldElement Subtract(ECFieldElement b)
{
uint[] z = Nat256.Create();
SecP256R1Field.Subtract(x, ((SecP256R1FieldElement)b).x, z);
return new SecP256R1FieldElement(z);
}
public override ECFieldElement Multiply(ECFieldElement b)
{
uint[] z = Nat256.Create();
SecP256R1Field.Multiply(x, ((SecP256R1FieldElement)b).x, z);
return new SecP256R1FieldElement(z);
}
public override ECFieldElement Divide(ECFieldElement b)
{
uint[] z = Nat256.Create();
SecP256R1Field.Inv(((SecP256R1FieldElement)b).x, z);
SecP256R1Field.Multiply(z, x, z);
return new SecP256R1FieldElement(z);
}
public override ECFieldElement Negate()
{
uint[] z = Nat256.Create();
SecP256R1Field.Negate(x, z);
return new SecP256R1FieldElement(z);
}
public override ECFieldElement Square()
{
uint[] z = Nat256.Create();
SecP256R1Field.Square(x, z);
return new SecP256R1FieldElement(z);
}
public override ECFieldElement Invert()
{
uint[] z = Nat256.Create();
SecP256R1Field.Inv(x, z);
return new SecP256R1FieldElement(z);
}
public override ECFieldElement Sqrt()
{
uint[] y = x;
if (Nat256.IsZero(y) || Nat256.IsOne(y))
return this;
uint[] tt = Nat256.CreateExt();
uint[] array = Nat256.Create();
uint[] array2 = Nat256.Create();
SecP256R1Field.Square(y, array, tt);
SecP256R1Field.Multiply(array, y, array, tt);
SecP256R1Field.SquareN(array, 2, array2, tt);
SecP256R1Field.Multiply(array2, array, array2, tt);
SecP256R1Field.SquareN(array2, 4, array, tt);
SecP256R1Field.Multiply(array, array2, array, tt);
SecP256R1Field.SquareN(array, 8, array2, tt);
SecP256R1Field.Multiply(array2, array, array2, tt);
SecP256R1Field.SquareN(array2, 16, array, tt);
SecP256R1Field.Multiply(array, array2, array, tt);
SecP256R1Field.SquareN(array, 32, array, tt);
SecP256R1Field.Multiply(array, y, array, tt);
SecP256R1Field.SquareN(array, 96, array, tt);
SecP256R1Field.Multiply(array, y, array, tt);
SecP256R1Field.SquareN(array, 94, array, tt);
SecP256R1Field.Multiply(array, array, array2, tt);
if (!Nat256.Eq(y, array2))
return null;
return new SecP256R1FieldElement(array);
}
public override bool Equals(object obj)
{
return Equals(obj as SecP256R1FieldElement);
}
public override bool Equals(ECFieldElement other)
{
return Equals(other as SecP256R1FieldElement);
}
public virtual bool Equals(SecP256R1FieldElement other)
{
if (this == other)
return true;
if (other == null)
return false;
return Nat256.Eq(x, other.x);
}
public override int GetHashCode()
{
return Q.GetHashCode() ^ Arrays.GetHashCode(x, 0, 8);
}
}
}