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The Bouncy Castle Crypto package is a Java implementation of cryptographic algorithms. This jar contains JCE provider and lightweight API for the Bouncy Castle Cryptography APIs for JDK 1.5 to JDK 1.7. Note: this package includes the IDEA and NTRU encryption algorithms.
package org.bouncycastle.math.ec.custom.sec;
import java.math.BigInteger;
import org.bouncycastle.math.raw.Nat;
import org.bouncycastle.math.raw.Nat224;
public class SecP224R1Field
{
private static final long M = 0xFFFFFFFFL;
// 2^224 - 2^96 + 1
static final int[] P = new int[]{ 0x00000001, 0x00000000, 0x00000000, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF };
static final int[] PExt = new int[]{ 0x00000001, 0x00000000, 0x00000000, 0xFFFFFFFE, 0xFFFFFFFF,
0xFFFFFFFF, 0x00000000, 0x00000002, 0x00000000, 0x00000000, 0xFFFFFFFE, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF };
private static final int[] PExtInv = new int[]{ 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0x00000001, 0x00000000,
0x00000000, 0xFFFFFFFF, 0xFFFFFFFD, 0xFFFFFFFF, 0xFFFFFFFF, 0x00000001 };
private static final int P6 = 0xFFFFFFFF;
private static final int PExt13 = 0xFFFFFFFF;
public static void add(int[] x, int[] y, int[] z)
{
int c = Nat224.add(x, y, z);
if (c != 0 || (z[6] == P6 && Nat224.gte(z, P)))
{
addPInvTo(z);
}
}
public static void addExt(int[] xx, int[] yy, int[] zz)
{
int c = Nat.add(14, xx, yy, zz);
if (c != 0 || (zz[13] == PExt13 && Nat.gte(14, zz, PExt)))
{
if (Nat.addTo(PExtInv.length, PExtInv, zz) != 0)
{
Nat.incAt(14, zz, PExtInv.length);
}
}
}
public static void addOne(int[] x, int[] z)
{
int c = Nat.inc(7, x, z);
if (c != 0 || (z[6] == P6 && Nat224.gte(z, P)))
{
addPInvTo(z);
}
}
public static int[] fromBigInteger(BigInteger x)
{
int[] z = Nat224.fromBigInteger(x);
if (z[6] == P6 && Nat224.gte(z, P))
{
Nat224.subFrom(P, z);
}
return z;
}
public static void half(int[] x, int[] z)
{
if ((x[0] & 1) == 0)
{
Nat.shiftDownBit(7, x, 0, z);
}
else
{
int c = Nat224.add(x, P, z);
Nat.shiftDownBit(7, z, c);
}
}
public static void multiply(int[] x, int[] y, int[] z)
{
int[] tt = Nat224.createExt();
Nat224.mul(x, y, tt);
reduce(tt, z);
}
public static void multiplyAddToExt(int[] x, int[] y, int[] zz)
{
int c = Nat224.mulAddTo(x, y, zz);
if (c != 0 || (zz[13] == PExt13 && Nat.gte(14, zz, PExt)))
{
if (Nat.addTo(PExtInv.length, PExtInv, zz) != 0)
{
Nat.incAt(14, zz, PExtInv.length);
}
}
}
public static void negate(int[] x, int[] z)
{
if (Nat224.isZero(x))
{
Nat224.zero(z);
}
else
{
Nat224.sub(P, x, z);
}
}
public static void reduce(int[] xx, int[] z)
{
long xx10 = xx[10] & M, xx11 = xx[11] & M, xx12 = xx[12] & M, xx13 = xx[13] & M;
final long n = 1;
long t0 = (xx[7] & M) + xx11 - n;
long t1 = (xx[8] & M) + xx12;
long t2 = (xx[9] & M) + xx13;
long cc = 0;
cc += (xx[0] & M) - t0;
long z0 = cc & M;
cc >>= 32;
cc += (xx[1] & M) - t1;
z[1] = (int)cc;
cc >>= 32;
cc += (xx[2] & M) - t2;
z[2] = (int)cc;
cc >>= 32;
cc += (xx[3] & M) + t0 - xx10;
long z3 = cc & M;
cc >>= 32;
cc += (xx[4] & M) + t1 - xx11;
z[4] = (int)cc;
cc >>= 32;
cc += (xx[5] & M) + t2 - xx12;
z[5] = (int)cc;
cc >>= 32;
cc += (xx[6] & M) + xx10 - xx13;
z[6] = (int)cc;
cc >>= 32;
cc += n;
// assert cc >= 0;
z3 += cc;
z0 -= cc;
z[0] = (int)z0;
cc = z0 >> 32;
if (cc != 0)
{
cc += (z[1] & M);
z[1] = (int)cc;
cc >>= 32;
cc += (z[2] & M);
z[2] = (int)cc;
z3 += cc >> 32;
}
z[3] = (int)z3;
cc = z3 >> 32;
// assert cc == 0 || cc == 1;
if ((cc != 0 && Nat.incAt(7, z, 4) != 0)
|| (z[6] == P6 && Nat224.gte(z, P)))
{
addPInvTo(z);
}
}
public static void reduce32(int x, int[] z)
{
long cc = 0;
if (x != 0)
{
long xx07 = x & M;
cc += (z[0] & M) - xx07;
z[0] = (int)cc;
cc >>= 32;
if (cc != 0)
{
cc += (z[1] & M);
z[1] = (int)cc;
cc >>= 32;
cc += (z[2] & M);
z[2] = (int)cc;
cc >>= 32;
}
cc += (z[3] & M) + xx07;
z[3] = (int)cc;
cc >>= 32;
// assert cc == 0 || cc == 1;
}
if ((cc != 0 && Nat.incAt(7, z, 4) != 0)
|| (z[6] == P6 && Nat224.gte(z, P)))
{
addPInvTo(z);
}
}
public static void square(int[] x, int[] z)
{
int[] tt = Nat224.createExt();
Nat224.square(x, tt);
reduce(tt, z);
}
public static void squareN(int[] x, int n, int[] z)
{
// assert n > 0;
int[] tt = Nat224.createExt();
Nat224.square(x, tt);
reduce(tt, z);
while (--n > 0)
{
Nat224.square(z, tt);
reduce(tt, z);
}
}
public static void subtract(int[] x, int[] y, int[] z)
{
int c = Nat224.sub(x, y, z);
if (c != 0)
{
subPInvFrom(z);
}
}
public static void subtractExt(int[] xx, int[] yy, int[] zz)
{
int c = Nat.sub(14, xx, yy, zz);
if (c != 0)
{
if (Nat.subFrom(PExtInv.length, PExtInv, zz) != 0)
{
Nat.decAt(14, zz, PExtInv.length);
}
}
}
public static void twice(int[] x, int[] z)
{
int c = Nat.shiftUpBit(7, x, 0, z);
if (c != 0 || (z[6] == P6 && Nat224.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);
z[2] = (int)c;
c >>= 32;
}
c += (z[3] & M) + 1;
z[3] = (int)c;
c >>= 32;
if (c != 0)
{
Nat.incAt(7, z, 4);
}
}
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);
z[2] = (int)c;
c >>= 32;
}
c += (z[3] & M) - 1;
z[3] = (int)c;
c >>= 32;
if (c != 0)
{
Nat.decAt(7, z, 4);
}
}
}
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