SecP256R1Field
class SecP256R1Field
using Org.BouncyCastle.Crypto.Utilities;
using Org.BouncyCastle.Math.Raw;
using Org.BouncyCastle.Security;
namespace Org.BouncyCastle.Math.EC.Custom.Sec
{
internal class SecP256R1Field
{
internal static readonly uint[] P = new uint[8] {
uint.MaxValue,
uint.MaxValue,
uint.MaxValue,
0,
0,
0,
1,
uint.MaxValue
};
private static readonly uint[] PExt = new uint[16] {
1,
0,
0,
4294967294,
uint.MaxValue,
uint.MaxValue,
4294967294,
1,
4294967294,
1,
4294967294,
1,
1,
4294967294,
2,
4294967294
};
private const uint P7 = uint.MaxValue;
private const uint PExt15 = 4294967294;
public static void Add(uint[] x, uint[] y, uint[] z)
{
if (Nat256.Add(x, y, z) != 0 || (z[7] == uint.MaxValue && Nat256.Gte(z, P)))
AddPInvTo(z);
}
public static void AddExt(uint[] xx, uint[] yy, uint[] zz)
{
if (Nat.Add(16, xx, yy, zz) != 0 || (zz[15] >= 4294967294 && Nat.Gte(16, zz, PExt)))
Nat.SubFrom(16, PExt, zz);
}
public static void AddOne(uint[] x, uint[] z)
{
if (Nat.Inc(8, x, z) != 0 || (z[7] == uint.MaxValue && Nat256.Gte(z, P)))
AddPInvTo(z);
}
public static uint[] FromBigInteger(BigInteger x)
{
uint[] array = Nat.FromBigInteger(256, x);
if (array[7] == uint.MaxValue && Nat256.Gte(array, P))
Nat256.SubFrom(P, array, 0);
return array;
}
public static void Half(uint[] x, uint[] z)
{
if ((x[0] & 1) == 0)
Nat.ShiftDownBit(8, x, 0, z);
else {
uint c = Nat256.Add(x, P, z);
Nat.ShiftDownBit(8, z, c);
}
}
public static void Inv(uint[] x, uint[] z)
{
Mod.CheckedModOddInverse(P, x, z);
}
public static int IsZero(uint[] x)
{
uint num = 0;
for (int i = 0; i < 8; i++) {
num |= x[i];
}
num = ((num >> 1) | (num & 1));
return (int)(num - 1) >> 31;
}
public static void Multiply(uint[] x, uint[] y, uint[] z)
{
uint[] array = Nat256.CreateExt();
Nat256.Mul(x, y, array);
Reduce(array, z);
}
public static void Multiply(uint[] x, uint[] y, uint[] z, uint[] tt)
{
Nat256.Mul(x, y, tt);
Reduce(tt, z);
}
public static void MultiplyAddToExt(uint[] x, uint[] y, uint[] zz)
{
if (Nat256.MulAddTo(x, y, zz) != 0 || (zz[15] >= 4294967294 && Nat.Gte(16, zz, PExt)))
Nat.SubFrom(16, PExt, zz);
}
public static void Negate(uint[] x, uint[] z)
{
if (IsZero(x) != 0)
Nat256.Sub(P, P, z);
else
Nat256.Sub(P, x, z);
}
public static void Random(SecureRandom r, uint[] z)
{
byte[] array = new byte[32];
do {
r.NextBytes(array);
Pack.LE_To_UInt32(array, 0, z, 0, 8);
} while (Nat.LessThan(8, z, P) == 0);
}
public static void RandomMult(SecureRandom r, uint[] z)
{
do {
Random(r, z);
} while (IsZero(z) != 0);
}
public static void Reduce(uint[] xx, uint[] z)
{
long num = xx[8];
long num2 = xx[9];
long num3 = xx[10];
long num4 = xx[11];
long num5 = xx[12];
long num6 = xx[13];
long num7 = xx[14];
long num8 = xx[15];
num -= 6;
long num9 = num + num2;
long num10 = num2 + num3;
long num11 = num3 + num4 - num8;
long num12 = num4 + num5;
long num13 = num5 + num6;
long num14 = num6 + num7;
long num15 = num7 + num8;
long num16 = num14 - num9;
long num17 = 0;
num17 += xx[0] - num12 - num16;
z[0] = (uint)num17;
num17 >>= 32;
num17 += xx[1] + num10 - num13 - num15;
z[1] = (uint)num17;
num17 >>= 32;
num17 += xx[2] + num11 - num14;
z[2] = (uint)num17;
num17 >>= 32;
num17 += xx[3] + (num12 << 1) + num16 - num15;
z[3] = (uint)num17;
num17 >>= 32;
num17 += xx[4] + (num13 << 1) + num7 - num10;
z[4] = (uint)num17;
num17 >>= 32;
num17 += xx[5] + (num14 << 1) - num11;
z[5] = (uint)num17;
num17 >>= 32;
num17 += xx[6] + (num15 << 1) + num16;
z[6] = (uint)num17;
num17 >>= 32;
num17 += xx[7] + (num8 << 1) + num - num11 - num13;
z[7] = (uint)num17;
num17 >>= 32;
num17 += 6;
Reduce32((uint)num17, z);
}
public static void Reduce32(uint x, uint[] z)
{
long num = 0;
if (x != 0) {
long num2 = x;
num += z[0] + num2;
z[0] = (uint)num;
num >>= 32;
if (num != 0) {
num += z[1];
z[1] = (uint)num;
num >>= 32;
num += z[2];
z[2] = (uint)num;
num >>= 32;
}
num += z[3] - num2;
z[3] = (uint)num;
num >>= 32;
if (num != 0) {
num += z[4];
z[4] = (uint)num;
num >>= 32;
num += z[5];
z[5] = (uint)num;
num >>= 32;
}
num += z[6] - num2;
z[6] = (uint)num;
num >>= 32;
num += z[7] + num2;
z[7] = (uint)num;
num >>= 32;
}
if (num != 0 || (z[7] == uint.MaxValue && Nat256.Gte(z, P)))
AddPInvTo(z);
}
public static void Square(uint[] x, uint[] z)
{
uint[] array = Nat256.CreateExt();
Nat256.Square(x, array);
Reduce(array, z);
}
public static void Square(uint[] x, uint[] z, uint[] tt)
{
Nat256.Square(x, tt);
Reduce(tt, z);
}
public static void SquareN(uint[] x, int n, uint[] z)
{
uint[] array = Nat256.CreateExt();
Nat256.Square(x, array);
Reduce(array, z);
while (--n > 0) {
Nat256.Square(z, array);
Reduce(array, z);
}
}
public static void SquareN(uint[] x, int n, uint[] z, uint[] tt)
{
Nat256.Square(x, tt);
Reduce(tt, z);
while (--n > 0) {
Nat256.Square(z, tt);
Reduce(tt, z);
}
}
public static void Subtract(uint[] x, uint[] y, uint[] z)
{
if (Nat256.Sub(x, y, z) != 0)
SubPInvFrom(z);
}
public static void SubtractExt(uint[] xx, uint[] yy, uint[] zz)
{
if (Nat.Sub(16, xx, yy, zz) != 0)
Nat.AddTo(16, PExt, zz);
}
public static void Twice(uint[] x, uint[] z)
{
if (Nat.ShiftUpBit(8, x, 0, z) != 0 || (z[7] == uint.MaxValue && Nat256.Gte(z, P)))
AddPInvTo(z);
}
private static void AddPInvTo(uint[] z)
{
long num = (long)z[0] + 1;
z[0] = (uint)num;
num >>= 32;
if (num != 0) {
num += z[1];
z[1] = (uint)num;
num >>= 32;
num += z[2];
z[2] = (uint)num;
num >>= 32;
}
num += (long)z[3] - 1;
z[3] = (uint)num;
num >>= 32;
if (num != 0) {
num += z[4];
z[4] = (uint)num;
num >>= 32;
num += z[5];
z[5] = (uint)num;
num >>= 32;
}
num += (long)z[6] - 1;
z[6] = (uint)num;
num >>= 32;
num += (long)z[7] + 1;
z[7] = (uint)num;
}
private static void SubPInvFrom(uint[] z)
{
long num = (long)z[0] - 1;
z[0] = (uint)num;
num >>= 32;
if (num != 0) {
num += z[1];
z[1] = (uint)num;
num >>= 32;
num += z[2];
z[2] = (uint)num;
num >>= 32;
}
num += (long)z[3] + 1;
z[3] = (uint)num;
num >>= 32;
if (num != 0) {
num += z[4];
z[4] = (uint)num;
num >>= 32;
num += z[5];
z[5] = (uint)num;
num >>= 32;
}
num += (long)z[6] + 1;
z[6] = (uint)num;
num >>= 32;
num += (long)z[7] - 1;
z[7] = (uint)num;
}
}
}