SM2P256V1Curve
using Org.BouncyCastle.Math.Raw;
using Org.BouncyCastle.Security;
using Org.BouncyCastle.Utilities.Encoders;
namespace Org.BouncyCastle.Math.EC.Custom.GM
{
internal class SM2P256V1Curve : AbstractFpCurve
{
private class SM2P256V1LookupTable : AbstractECLookupTable
{
private readonly SM2P256V1Curve m_outer;
private readonly uint[] m_table;
private readonly int m_size;
public override int Size => m_size;
internal SM2P256V1LookupTable(SM2P256V1Curve 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 SM2P256V1FieldElement(x), new SM2P256V1FieldElement(y), SM2P256V1_AFFINE_ZS);
}
}
public static readonly BigInteger q = SM2P256V1FieldElement.Q;
private const int SM2P256V1_DEFAULT_COORDS = 2;
private const int SM2P256V1_FE_INTS = 8;
private static readonly ECFieldElement[] SM2P256V1_AFFINE_ZS = new ECFieldElement[1] {
new SM2P256V1FieldElement(BigInteger.One)
};
protected readonly SM2P256V1Point m_infinity;
public virtual BigInteger Q => q;
public override ECPoint Infinity => m_infinity;
public override int FieldSize => q.BitLength;
public SM2P256V1Curve()
: base(q, true)
{
m_infinity = new SM2P256V1Point(this, null, null);
m_a = FromBigInteger(new BigInteger(1, Hex.DecodeStrict("FFFFFFFEFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF00000000FFFFFFFFFFFFFFFC")));
m_b = FromBigInteger(new BigInteger(1, Hex.DecodeStrict("28E9FA9E9D9F5E344D5A9E4BCF6509A7F39789F515AB8F92DDBCBD414D940E93")));
m_order = new BigInteger(1, Hex.DecodeStrict("FFFFFFFEFFFFFFFFFFFFFFFFFFFFFFFF7203DF6B21C6052B53BBF40939D54123"));
m_cofactor = BigInteger.One;
m_coord = 2;
}
protected override ECCurve CloneCurve()
{
return new SM2P256V1Curve();
}
public override bool SupportsCoordinateSystem(int coord)
{
if (coord == 2)
return true;
return false;
}
public override ECFieldElement FromBigInteger(BigInteger x)
{
return new SM2P256V1FieldElement(x);
}
protected internal override ECPoint CreateRawPoint(ECFieldElement x, ECFieldElement y)
{
return new SM2P256V1Point(this, x, y);
}
protected internal override ECPoint CreateRawPoint(ECFieldElement x, ECFieldElement y, ECFieldElement[] zs)
{
return new SM2P256V1Point(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(((SM2P256V1FieldElement)obj.RawXCoord).x, 0, array, num);
num += 8;
Nat256.Copy(((SM2P256V1FieldElement)obj.RawYCoord).x, 0, array, num);
num += 8;
}
return new SM2P256V1LookupTable(this, array, len);
}
public override ECFieldElement RandomFieldElement(SecureRandom r)
{
uint[] array = Nat256.Create();
SM2P256V1Field.Random(r, array);
return new SM2P256V1FieldElement(array);
}
public override ECFieldElement RandomFieldElementMult(SecureRandom r)
{
uint[] array = Nat256.Create();
SM2P256V1Field.RandomMult(r, array);
return new SM2P256V1FieldElement(array);
}
}
}