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using System;
using Org.BouncyCastle.Math.EC.Multiplier;
using Org.BouncyCastle.Math.Raw;
using Org.BouncyCastle.Utilities.Encoders;
namespace Org.BouncyCastle.Math.EC.Custom.Sec
{
internal class SecT571K1Curve
: AbstractF2mCurve
{
private const int SECT571K1_DEFAULT_COORDS = COORD_LAMBDA_PROJECTIVE;
private const int SECT571K1_FE_LONGS = 9;
protected readonly SecT571K1Point m_infinity;
public SecT571K1Curve()
: base(571, 2, 5, 10)
{
this.m_infinity = new SecT571K1Point(this, null, null);
this.m_a = FromBigInteger(BigInteger.Zero);
this.m_b = FromBigInteger(BigInteger.One);
this.m_order = new BigInteger(1, Hex.Decode("020000000000000000000000000000000000000000000000000000000000000000000000131850E1F19A63E4B391A8DB917F4138B630D84BE5D639381E91DEB45CFE778F637C1001"));
this.m_cofactor = BigInteger.ValueOf(4);
this.m_coord = SECT571K1_DEFAULT_COORDS;
}
protected override ECCurve CloneCurve()
{
return new SecT571K1Curve();
}
public override bool SupportsCoordinateSystem(int coord)
{
switch (coord)
{
case COORD_LAMBDA_PROJECTIVE:
return true;
default:
return false;
}
}
protected override ECMultiplier CreateDefaultMultiplier()
{
return new WTauNafMultiplier();
}
public override ECPoint Infinity
{
get { return m_infinity; }
}
public override int FieldSize
{
get { return 571; }
}
public override ECFieldElement FromBigInteger(BigInteger x)
{
return new SecT571FieldElement(x);
}
protected internal override ECPoint CreateRawPoint(ECFieldElement x, ECFieldElement y, bool withCompression)
{
return new SecT571K1Point(this, x, y, withCompression);
}
protected internal override ECPoint CreateRawPoint(ECFieldElement x, ECFieldElement y, ECFieldElement[] zs, bool withCompression)
{
return new SecT571K1Point(this, x, y, zs, withCompression);
}
public override bool IsKoblitz
{
get { return true; }
}
public virtual int M
{
get { return 571; }
}
public virtual bool IsTrinomial
{
get { return false; }
}
public virtual int K1
{
get { return 2; }
}
public virtual int K2
{
get { return 5; }
}
public virtual int K3
{
get { return 10; }
}
public override ECLookupTable CreateCacheSafeLookupTable(ECPoint[] points, int off, int len)
{
ulong[] table = new ulong[len * SECT571K1_FE_LONGS * 2];
{
int pos = 0;
for (int i = 0; i < len; ++i)
{
ECPoint p = points[off + i];
Nat576.Copy64(((SecT571FieldElement)p.RawXCoord).x, 0, table, pos); pos += SECT571K1_FE_LONGS;
Nat576.Copy64(((SecT571FieldElement)p.RawYCoord).x, 0, table, pos); pos += SECT571K1_FE_LONGS;
}
}
return new SecT571K1LookupTable(this, table, len);
}
private class SecT571K1LookupTable
: ECLookupTable
{
private readonly SecT571K1Curve m_outer;
private readonly ulong[] m_table;
private readonly int m_size;
internal SecT571K1LookupTable(SecT571K1Curve outer, ulong[] table, int size)
{
this.m_outer = outer;
this.m_table = table;
this.m_size = size;
}
public virtual int Size
{
get { return m_size; }
}
public virtual ECPoint Lookup(int index)
{
ulong[] x = Nat576.Create64(), y = Nat576.Create64();
int pos = 0;
for (int i = 0; i < m_size; ++i)
{
ulong MASK = (ulong)(long)(((i ^ index) - 1) >> 31);
for (int j = 0; j < SECT571K1_FE_LONGS; ++j)
{
x[j] ^= m_table[pos + j] & MASK;
y[j] ^= m_table[pos + SECT571K1_FE_LONGS + j] & MASK;
}
pos += (SECT571K1_FE_LONGS * 2);
}
return m_outer.CreateRawPoint(new SecT571FieldElement(x), new SecT571FieldElement(y), false);
}
}
}
}
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