package org.bouncycastle.math.ec.custom.sec;
import java.math.BigInteger;
import org.bouncycastle.math.raw.Nat;
import org.bouncycastle.math.raw.Nat192;
public class SecP192R1Field
{
private static final long M = 0xFFFFFFFFL;
// 2^192 - 2^64 - 1
static final int[] P = new int[]{ 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFE, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF };
static final int[] PExt = new int[]{ 0x00000001, 0x00000000, 0x00000002, 0x00000000, 0x00000001,
0x00000000, 0xFFFFFFFE, 0xFFFFFFFF, 0xFFFFFFFD, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF };
private static final int[] PExtInv = new int[]{ 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFD, 0xFFFFFFFF, 0xFFFFFFFE,
0xFFFFFFFF, 0x00000001, 0x00000000, 0x00000002 };
private static final int P5 = 0xFFFFFFFF;
private static final int PExt11 = 0xFFFFFFFF;
public static void add(int[] x, int[] y, int[] z)
{
int c = Nat192.add(x, y, z);
if (c != 0 || (z[5] == P5 && Nat192.gte(z, P)))
{
addPInvTo(z);
}
}
public static void addExt(int[] xx, int[] yy, int[] zz)
{
int c = Nat.add(12, xx, yy, zz);
if (c != 0 || (zz[11] == PExt11 && Nat.gte(12, zz, PExt)))
{
if (Nat.addTo(PExtInv.length, PExtInv, zz) != 0)
{
Nat.incAt(12, zz, PExtInv.length);
}
}
}
public static void addOne(int[] x, int[] z)
{
int c = Nat.inc(6, x, z);
if (c != 0 || (z[5] == P5 && Nat192.gte(z, P)))
{
addPInvTo(z);
}
}
public static int[] fromBigInteger(BigInteger x)
{
int[] z = Nat192.fromBigInteger(x);
if (z[5] == P5 && Nat192.gte(z, P))
{
Nat192.subFrom(P, z);
}
return z;
}
public static void half(int[] x, int[] z)
{
if ((x[0] & 1) == 0)
{
Nat.shiftDownBit(6, x, 0, z);
}
else
{
int c = Nat192.add(x, P, z);
Nat.shiftDownBit(6, z, c);
}
}
public static void multiply(int[] x, int[] y, int[] z)
{
int[] tt = Nat192.createExt();
Nat192.mul(x, y, tt);
reduce(tt, z);
}
public static void multiplyAddToExt(int[] x, int[] y, int[] zz)
{
int c = Nat192.mulAddTo(x, y, zz);
if (c != 0 || (zz[11] == PExt11 && Nat.gte(12, zz, PExt)))
{
if (Nat.addTo(PExtInv.length, PExtInv, zz) != 0)
{
Nat.incAt(12, zz, PExtInv.length);
}
}
}
public static void negate(int[] x, int[] z)
{
if (Nat192.isZero(x))
{
Nat192.zero(z);
}
else
{
Nat192.sub(P, x, z);
}
}
public static void reduce(int[] xx, int[] z)
{
long xx06 = xx[6] & M, xx07 = xx[7] & M, xx08 = xx[8] & M;
long xx09 = xx[9] & M, xx10 = xx[10] & M, xx11 = xx[11] & M;
long t0 = xx06 + xx10;
long t1 = xx07 + xx11;
long cc = 0;
cc += (xx[0] & M) + t0;
int z0 = (int)cc;
cc >>= 32;
cc += (xx[1] & M) + t1;
z[1] = (int)cc;
cc >>= 32;
t0 += xx08;
t1 += xx09;
cc += (xx[2] & M) + t0;
long z2 = cc & M;
cc >>= 32;
cc += (xx[3] & M) + t1;
z[3] = (int)cc;
cc >>= 32;
t0 -= xx06;
t1 -= xx07;
cc += (xx[4] & M) + t0;
z[4] = (int)cc;
cc >>= 32;
cc += (xx[5] & M) + t1;
z[5] = (int)cc;
cc >>= 32;
z2 += cc;
cc += (z0 & M);
z[0] = (int)cc;
cc >>= 32;
if (cc != 0)
{
cc += (z[1] & M);
z[1] = (int)cc;
z2 += cc >> 32;
}
z[2] = (int)z2;
cc = z2 >> 32;
// assert cc == 0 || cc == 1;
if ((cc != 0 && Nat.incAt(6, z, 3) != 0)
|| (z[5] == P5 && Nat192.gte(z, P)))
{
addPInvTo(z);
}
}
public static void reduce32(int x, int[] z)
{
long cc = 0;
if (x != 0)
{
long xx06 = x & M;
cc += (z[0] & M) + xx06;
z[0] = (int)cc;
cc >>= 32;
if (cc != 0)
{
cc += (z[1] & M);
z[1] = (int)cc;
cc >>= 32;
}
cc += (z[2] & M) + xx06;
z[2] = (int)cc;
cc >>= 32;
// assert cc == 0 || cc == 1;
}
if ((cc != 0 && Nat.incAt(6, z, 3) != 0)
|| (z[5] == P5 && Nat192.gte(z, P)))
{
addPInvTo(z);
}
}
public static void square(int[] x, int[] z)
{
int[] tt = Nat192.createExt();
Nat192.square(x, tt);
reduce(tt, z);
}
public static void squareN(int[] x, int n, int[] z)
{
// assert n > 0;
int[] tt = Nat192.createExt();
Nat192.square(x, tt);
reduce(tt, z);
while (--n > 0)
{
Nat192.square(z, tt);
reduce(tt, z);
}
}
public static void subtract(int[] x, int[] y, int[] z)
{
int c = Nat192.sub(x, y, z);
if (c != 0)
{
subPInvFrom(z);
}
}
public static void subtractExt(int[] xx, int[] yy, int[] zz)
{
int c = Nat.sub(12, xx, yy, zz);
if (c != 0)
{
if (Nat.subFrom(PExtInv.length, PExtInv, zz) != 0)
{
Nat.decAt(12, zz, PExtInv.length);
}
}
}
public static void twice(int[] x, int[] z)
{
int c = Nat.shiftUpBit(6, x, 0, z);
if (c != 0 || (z[5] == P5 && Nat192.gte(z, P)))
{
addPInvTo(z);
}
}
private static void addPInvTo(int[] z)
{
long c = (z[0] & M) + 1;
z[0] = (int)c;
c >>= 32;
if (c != 0)
{
c += (z[1] & M);
z[1] = (int)c;
c >>= 32;
}
c += (z[2] & M) + 1;
z[2] = (int)c;
c >>= 32;
if (c != 0)
{
Nat.incAt(6, z, 3);
}
}
private static void subPInvFrom(int[] z)
{
long c = (z[0] & M) - 1;
z[0] = (int)c;
c >>= 32;
if (c != 0)
{
c += (z[1] & M);
z[1] = (int)c;
c >>= 32;
}
c += (z[2] & M) - 1;
z[2] = (int)c;
c >>= 32;
if (c != 0)
{
Nat.decAt(6, z, 3);
}
}
}