SecP256R1Curve
using Org.BouncyCastle.Math.Raw;
using Org.BouncyCastle.Security;
using Org.BouncyCastle.Utilities.Encoders;
namespace Org.BouncyCastle.Math.EC.Custom.Sec
{
internal class SecP256R1Curve : AbstractFpCurve
{
private class SecP256R1LookupTable : AbstractECLookupTable
{
private readonly SecP256R1Curve m_outer;
private readonly uint[] m_table;
private readonly int m_size;
public override int Size => m_size;
internal SecP256R1LookupTable(SecP256R1Curve outer, uint[] table, int size)
{
m_outer = outer;
m_table = table;
m_size = size;
}
public override ECPoint Lookup(int index)
{
uint[] array = Nat256.Create();
uint[] array2 = Nat256.Create();
int num = 0;
for (int i = 0; i < m_size; i++) {
uint num2 = (uint)((i ^ index) - 1 >> 31);
for (int j = 0; j < 8; j++) {
array[j] ^= (m_table[num + j] & num2);
array2[j] ^= (m_table[num + 8 + j] & num2);
}
num += 16;
}
return CreatePoint(array, array2);
}
public override ECPoint LookupVar(int index)
{
uint[] array = Nat256.Create();
uint[] array2 = Nat256.Create();
int num = index * 8 * 2;
for (int i = 0; i < 8; i++) {
array[i] = m_table[num + i];
array2[i] = m_table[num + 8 + i];
}
return CreatePoint(array, array2);
}
private ECPoint CreatePoint(uint[] x, uint[] y)
{
return m_outer.CreateRawPoint(new SecP256R1FieldElement(x), new SecP256R1FieldElement(y), SECP256R1_AFFINE_ZS);
}
}
public static readonly BigInteger q = SecP256R1FieldElement.Q;
private const int SECP256R1_DEFAULT_COORDS = 2;
private const int SECP256R1_FE_INTS = 8;
private static readonly ECFieldElement[] SECP256R1_AFFINE_ZS = new ECFieldElement[1] {
new SecP256R1FieldElement(BigInteger.One)
};
protected readonly SecP256R1Point m_infinity;
public virtual BigInteger Q => q;
public override ECPoint Infinity => m_infinity;
public override int FieldSize => q.BitLength;
public SecP256R1Curve()
: base(q, true)
{
m_infinity = new SecP256R1Point(this, null, null);
m_a = FromBigInteger(new BigInteger(1, Hex.DecodeStrict("FFFFFFFF00000001000000000000000000000000FFFFFFFFFFFFFFFFFFFFFFFC")));
m_b = FromBigInteger(new BigInteger(1, Hex.DecodeStrict("5AC635D8AA3A93E7B3EBBD55769886BC651D06B0CC53B0F63BCE3C3E27D2604B")));
m_order = new BigInteger(1, Hex.DecodeStrict("FFFFFFFF00000000FFFFFFFFFFFFFFFFBCE6FAADA7179E84F3B9CAC2FC632551"));
m_cofactor = BigInteger.One;
m_coord = 2;
}
protected override ECCurve CloneCurve()
{
return new SecP256R1Curve();
}
public override bool SupportsCoordinateSystem(int coord)
{
if (coord == 2)
return true;
return false;
}
public override ECFieldElement FromBigInteger(BigInteger x)
{
return new SecP256R1FieldElement(x);
}
protected internal override ECPoint CreateRawPoint(ECFieldElement x, ECFieldElement y)
{
return new SecP256R1Point(this, x, y);
}
protected internal override ECPoint CreateRawPoint(ECFieldElement x, ECFieldElement y, ECFieldElement[] zs)
{
return new SecP256R1Point(this, x, y, zs);
}
public override ECLookupTable CreateCacheSafeLookupTable(ECPoint[] points, int off, int len)
{
uint[] array = new uint[len * 8 * 2];
int num = 0;
for (int i = 0; i < len; i++) {
ECPoint obj = points[off + i];
Nat256.Copy(((SecP256R1FieldElement)obj.RawXCoord).x, 0, array, num);
num += 8;
Nat256.Copy(((SecP256R1FieldElement)obj.RawYCoord).x, 0, array, num);
num += 8;
}
return new SecP256R1LookupTable(this, array, len);
}
public override ECFieldElement RandomFieldElement(SecureRandom r)
{
uint[] array = Nat256.Create();
SecP256R1Field.Random(r, array);
return new SecP256R1FieldElement(array);
}
public override ECFieldElement RandomFieldElementMult(SecureRandom r)
{
uint[] array = Nat256.Create();
SecP256R1Field.RandomMult(r, array);
return new SecP256R1FieldElement(array);
}
}
}