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/* GENERATED SOURCE. DO NOT MODIFY. */
package com.android.org.bouncycastle.math.ec.custom.sec;
import java.math.BigInteger;
import java.security.SecureRandom;
import com.android.org.bouncycastle.math.raw.Mod;
import com.android.org.bouncycastle.math.raw.Nat;
import com.android.org.bouncycastle.math.raw.Nat256;
import com.android.org.bouncycastle.util.Pack;
/**
* @hide This class is not part of the Android public SDK API
*/
public class SecP256K1Field
{
// 2^256 - 2^32 - 2^9 - 2^8 - 2^7 - 2^6 - 2^4 - 1
static final int[] P = new int[]{ 0xFFFFFC2F, 0xFFFFFFFE, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF,
0xFFFFFFFF, 0xFFFFFFFF };
private static final int[] PExt = new int[]{ 0x000E90A1, 0x000007A2, 0x00000001, 0x00000000, 0x00000000, 0x00000000,
0x00000000, 0x00000000, 0xFFFFF85E, 0xFFFFFFFD, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF,
0xFFFFFFFF };
private static final int[] PExtInv = new int[]{ 0xFFF16F5F, 0xFFFFF85D, 0xFFFFFFFE, 0xFFFFFFFF, 0xFFFFFFFF,
0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0x000007A1, 0x00000002 };
private static final int P7 = 0xFFFFFFFF;
private static final int PExt15 = 0xFFFFFFFF;
private static final int PInv33 = 0x3D1;
public static void add(int[] x, int[] y, int[] z)
{
int c = Nat256.add(x, y, z);
if (c != 0 || (z[7] == P7 && Nat256.gte(z, P)))
{
Nat.add33To(8, PInv33, z);
}
}
public static void addExt(int[] xx, int[] yy, int[] zz)
{
int c = Nat.add(16, xx, yy, zz);
if (c != 0 || (zz[15] == PExt15 && Nat.gte(16, zz, PExt)))
{
if (Nat.addTo(PExtInv.length, PExtInv, zz) != 0)
{
Nat.incAt(16, zz, PExtInv.length);
}
}
}
public static void addOne(int[] x, int[] z)
{
int c = Nat.inc(8, x, z);
if (c != 0 || (z[7] == P7 && Nat256.gte(z, P)))
{
Nat.add33To(8, PInv33, z);
}
}
public static int[] fromBigInteger(BigInteger x)
{
int[] z = Nat256.fromBigInteger(x);
if (z[7] == P7 && Nat256.gte(z, P))
{
Nat256.subFrom(P, z);
}
return z;
}
public static void half(int[] x, int[] z)
{
if ((x[0] & 1) == 0)
{
Nat.shiftDownBit(8, x, 0, z);
}
else
{
int c = Nat256.add(x, P, z);
Nat.shiftDownBit(8, z, c);
}
}
public static void inv(int[] x, int[] z)
{
Mod.checkedModOddInverse(P, x, z);
}
public static int isZero(int[] x)
{
int d = 0;
for (int i = 0; i < 8; ++i)
{
d |= x[i];
}
d = (d >>> 1) | (d & 1);
return (d - 1) >> 31;
}
public static void multiply(int[] x, int[] y, int[] z)
{
int[] tt = Nat256.createExt();
Nat256.mul(x, y, tt);
reduce(tt, z);
}
public static void multiplyAddToExt(int[] x, int[] y, int[] zz)
{
int c = Nat256.mulAddTo(x, y, zz);
if (c != 0 || (zz[15] == PExt15 && Nat.gte(16, zz, PExt)))
{
if (Nat.addTo(PExtInv.length, PExtInv, zz) != 0)
{
Nat.incAt(16, zz, PExtInv.length);
}
}
}
public static void negate(int[] x, int[] z)
{
if (0 != isZero(x))
{
Nat256.sub(P, P, z);
}
else
{
Nat256.sub(P, x, z);
}
}
public static void random(SecureRandom r, int[] z)
{
byte[] bb = new byte[8 * 4];
do
{
r.nextBytes(bb);
Pack.littleEndianToInt(bb, 0, z, 0, 8);
}
while (0 == Nat.lessThan(8, z, P));
}
public static void randomMult(SecureRandom r, int[] z)
{
do
{
random(r, z);
}
while (0 != isZero(z));
}
public static void reduce(int[] xx, int[] z)
{
long cc = Nat256.mul33Add(PInv33, xx, 8, xx, 0, z, 0);
int c = Nat256.mul33DWordAdd(PInv33, cc, z, 0);
// assert c == 0L || c == 1L;
if (c != 0 || (z[7] == P7 && Nat256.gte(z, P)))
{
Nat.add33To(8, PInv33, z);
}
}
public static void reduce32(int x, int[] z)
{
if ((x != 0 && Nat256.mul33WordAdd(PInv33, x, z, 0) != 0)
|| (z[7] == P7 && Nat256.gte(z, P)))
{
Nat.add33To(8, PInv33, z);
}
}
public static void square(int[] x, int[] z)
{
int[] tt = Nat256.createExt();
Nat256.square(x, tt);
reduce(tt, z);
}
public static void squareN(int[] x, int n, int[] z)
{
// assert n > 0;
int[] tt = Nat256.createExt();
Nat256.square(x, tt);
reduce(tt, z);
while (--n > 0)
{
Nat256.square(z, tt);
reduce(tt, z);
}
}
public static void subtract(int[] x, int[] y, int[] z)
{
int c = Nat256.sub(x, y, z);
if (c != 0)
{
Nat.sub33From(8, PInv33, z);
}
}
public static void subtractExt(int[] xx, int[] yy, int[] zz)
{
int c = Nat.sub(16, xx, yy, zz);
if (c != 0)
{
if (Nat.subFrom(PExtInv.length, PExtInv, zz) != 0)
{
Nat.decAt(16, zz, PExtInv.length);
}
}
}
public static void twice(int[] x, int[] z)
{
int c = Nat.shiftUpBit(8, x, 0, z);
if (c != 0 || (z[7] == P7 && Nat256.gte(z, P)))
{
Nat.add33To(8, PInv33, z);
}
}
}
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