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using System;
using Org.BouncyCastle.Math.Raw;
using Org.BouncyCastle.Utilities;
using Org.BouncyCastle.Utilities.Encoders;
namespace Org.BouncyCastle.Math.EC.Custom.Sec
{
internal class SecP521R1FieldElement
: AbstractFpFieldElement
{
public static readonly BigInteger Q = new BigInteger(1,
Hex.DecodeStrict("01FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF"));
protected internal readonly uint[] x;
public SecP521R1FieldElement(BigInteger x)
{
if (x == null || x.SignValue < 0 || x.CompareTo(Q) >= 0)
throw new ArgumentException("value invalid for SecP521R1FieldElement", "x");
this.x = SecP521R1Field.FromBigInteger(x);
}
public SecP521R1FieldElement()
{
this.x = Nat.Create(17);
}
protected internal SecP521R1FieldElement(uint[] x)
{
this.x = x;
}
public override bool IsZero
{
get { return Nat.IsZero(17, x); }
}
public override bool IsOne
{
get { return Nat.IsOne(17, x); }
}
public override bool TestBitZero()
{
return Nat.GetBit(x, 0) == 1;
}
public override BigInteger ToBigInteger()
{
return Nat.ToBigInteger(17, x);
}
public override string FieldName
{
get { return "SecP521R1Field"; }
}
public override int FieldSize
{
get { return Q.BitLength; }
}
public override ECFieldElement Add(ECFieldElement b)
{
uint[] z = Nat.Create(17);
SecP521R1Field.Add(x, ((SecP521R1FieldElement)b).x, z);
return new SecP521R1FieldElement(z);
}
public override ECFieldElement AddOne()
{
uint[] z = Nat.Create(17);
SecP521R1Field.AddOne(x, z);
return new SecP521R1FieldElement(z);
}
public override ECFieldElement Subtract(ECFieldElement b)
{
uint[] z = Nat.Create(17);
SecP521R1Field.Subtract(x, ((SecP521R1FieldElement)b).x, z);
return new SecP521R1FieldElement(z);
}
public override ECFieldElement Multiply(ECFieldElement b)
{
uint[] z = Nat.Create(17);
SecP521R1Field.Multiply(x, ((SecP521R1FieldElement)b).x, z);
return new SecP521R1FieldElement(z);
}
public override ECFieldElement Divide(ECFieldElement b)
{
//return Multiply(b.Invert());
uint[] z = Nat.Create(17);
SecP521R1Field.Inv(((SecP521R1FieldElement)b).x, z);
SecP521R1Field.Multiply(z, x, z);
return new SecP521R1FieldElement(z);
}
public override ECFieldElement Negate()
{
uint[] z = Nat.Create(17);
SecP521R1Field.Negate(x, z);
return new SecP521R1FieldElement(z);
}
public override ECFieldElement Square()
{
uint[] z = Nat.Create(17);
SecP521R1Field.Square(x, z);
return new SecP521R1FieldElement(z);
}
public override ECFieldElement Invert()
{
uint[] z = Nat.Create(17);
SecP521R1Field.Inv(x, z);
return new SecP521R1FieldElement(z);
}
/**
* return a sqrt root - the routine verifies that the calculation returns the right value - if
* none exists it returns null.
*/
public override ECFieldElement Sqrt()
{
// Raise this element to the exponent 2^519
uint[] x1 = this.x;
if (Nat.IsZero(17, x1) || Nat.IsOne(17, x1))
return this;
uint[] tt0 = Nat.Create(33);
uint[] t1 = Nat.Create(17);
uint[] t2 = Nat.Create(17);
SecP521R1Field.SquareN(x1, 519, t1, tt0);
SecP521R1Field.Square(t1, t2, tt0);
return Nat.Eq(17, x1, t2) ? new SecP521R1FieldElement(t1) : null;
}
public override bool Equals(object obj)
{
return Equals(obj as SecP521R1FieldElement);
}
public override bool Equals(ECFieldElement other)
{
return Equals(other as SecP521R1FieldElement);
}
public virtual bool Equals(SecP521R1FieldElement other)
{
if (this == other)
return true;
if (null == other)
return false;
return Nat.Eq(17, x, other.x);
}
public override int GetHashCode()
{
return Q.GetHashCode() ^ Arrays.GetHashCode(x, 0, 17);
}
}
}
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