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using System;
using Org.BouncyCastle.Math.Raw;
using Org.BouncyCastle.Utilities.Encoders;
namespace Org.BouncyCastle.Math.EC.Custom.Sec
{
internal class SecT131R1Curve
: AbstractF2mCurve
{
private const int SECT131R1_DEFAULT_COORDS = COORD_LAMBDA_PROJECTIVE;
private const int SECT131R1_FE_LONGS = 3;
protected readonly SecT131R1Point m_infinity;
public SecT131R1Curve()
: base(131, 2, 3, 8)
{
this.m_infinity = new SecT131R1Point(this, null, null);
this.m_a = FromBigInteger(new BigInteger(1, Hex.Decode("07A11B09A76B562144418FF3FF8C2570B8")));
this.m_b = FromBigInteger(new BigInteger(1, Hex.Decode("0217C05610884B63B9C6C7291678F9D341")));
this.m_order = new BigInteger(1, Hex.Decode("0400000000000000023123953A9464B54D"));
this.m_cofactor = BigInteger.Two;
this.m_coord = SECT131R1_DEFAULT_COORDS;
}
protected override ECCurve CloneCurve()
{
return new SecT131R1Curve();
}
public override bool SupportsCoordinateSystem(int coord)
{
switch (coord)
{
case COORD_LAMBDA_PROJECTIVE:
return true;
default:
return false;
}
}
public override ECPoint Infinity
{
get { return m_infinity; }
}
public override int FieldSize
{
get { return 131; }
}
public override ECFieldElement FromBigInteger(BigInteger x)
{
return new SecT131FieldElement(x);
}
protected internal override ECPoint CreateRawPoint(ECFieldElement x, ECFieldElement y, bool withCompression)
{
return new SecT131R1Point(this, x, y, withCompression);
}
protected internal override ECPoint CreateRawPoint(ECFieldElement x, ECFieldElement y, ECFieldElement[] zs, bool withCompression)
{
return new SecT131R1Point(this, x, y, zs, withCompression);
}
public override bool IsKoblitz
{
get { return false; }
}
public virtual int M
{
get { return 131; }
}
public virtual bool IsTrinomial
{
get { return false; }
}
public virtual int K1
{
get { return 2; }
}
public virtual int K2
{
get { return 3; }
}
public virtual int K3
{
get { return 8; }
}
public override ECLookupTable CreateCacheSafeLookupTable(ECPoint[] points, int off, int len)
{
ulong[] table = new ulong[len * SECT131R1_FE_LONGS * 2];
{
int pos = 0;
for (int i = 0; i < len; ++i)
{
ECPoint p = points[off + i];
Nat192.Copy64(((SecT131FieldElement)p.RawXCoord).x, 0, table, pos); pos += SECT131R1_FE_LONGS;
Nat192.Copy64(((SecT131FieldElement)p.RawYCoord).x, 0, table, pos); pos += SECT131R1_FE_LONGS;
}
}
return new SecT131R1LookupTable(this, table, len);
}
private class SecT131R1LookupTable
: ECLookupTable
{
private readonly SecT131R1Curve m_outer;
private readonly ulong[] m_table;
private readonly int m_size;
internal SecT131R1LookupTable(SecT131R1Curve 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 = Nat192.Create64(), y = Nat192.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 < SECT131R1_FE_LONGS; ++j)
{
x[j] ^= m_table[pos + j] & MASK;
y[j] ^= m_table[pos + SECT131R1_FE_LONGS + j] & MASK;
}
pos += (SECT131R1_FE_LONGS * 2);
}
return m_outer.CreateRawPoint(new SecT131FieldElement(x), new SecT131FieldElement(y), false);
}
}
}
}
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