| /* GENERATED SOURCE. DO NOT MODIFY. */ |
| package com.android.org.bouncycastle.math.ec.custom.sec; |
| |
| import java.math.BigInteger; |
| |
| import com.android.org.bouncycastle.math.raw.Nat; |
| import com.android.org.bouncycastle.math.raw.Nat256; |
| |
| /** |
| * @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 }; |
| 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 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 (Nat256.isZero(x)) |
| { |
| Nat256.zero(z); |
| } |
| else |
| { |
| Nat256.sub(P, x, 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); |
| } |
| } |
| } |