org.bouncycastle.math.ec.custom.sec.SecP160R1Field Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of bcprov-ext-jdk15on Show documentation
Show all versions of bcprov-ext-jdk15on Show documentation
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 1.8. Note: this package includes the NTRU encryption algorithms.
package org.bouncycastle.math.ec.custom.sec;
import java.math.BigInteger;
import java.security.SecureRandom;
import org.bouncycastle.math.raw.Mod;
import org.bouncycastle.math.raw.Nat;
import org.bouncycastle.math.raw.Nat160;
import org.bouncycastle.util.Pack;
public class SecP160R1Field
{
private static final long M = 0xFFFFFFFFL;
// 2^160 - 2^31 - 1
static final int[] P = new int[]{ 0x7FFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF };
private static final int[] PExt = new int[]{ 0x00000001, 0x40000001, 0x00000000, 0x00000000, 0x00000000, 0xFFFFFFFE,
0xFFFFFFFE, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF };
private static final int[] PExtInv = new int[]{ 0xFFFFFFFF, 0xBFFFFFFE, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF,
0x00000001, 0x00000001 };
private static final int P4 = 0xFFFFFFFF;
private static final int PExt9 = 0xFFFFFFFF;
private static final int PInv = 0x80000001;
public static void add(int[] x, int[] y, int[] z)
{
int c = Nat160.add(x, y, z);
if (c != 0 || (z[4] == P4 && Nat160.gte(z, P)))
{
Nat.addWordTo(5, PInv, z);
}
}
public static void addExt(int[] xx, int[] yy, int[] zz)
{
int c = Nat.add(10, xx, yy, zz);
if (c != 0 || (zz[9] == PExt9 && Nat.gte(10, zz, PExt)))
{
if (Nat.addTo(PExtInv.length, PExtInv, zz) != 0)
{
Nat.incAt(10, zz, PExtInv.length);
}
}
}
public static void addOne(int[] x, int[] z)
{
int c = Nat.inc(5, x, z);
if (c != 0 || (z[4] == P4 && Nat160.gte(z, P)))
{
Nat.addWordTo(5, PInv, z);
}
}
public static int[] fromBigInteger(BigInteger x)
{
int[] z = Nat160.fromBigInteger(x);
if (z[4] == P4 && Nat160.gte(z, P))
{
Nat160.subFrom(P, z);
}
return z;
}
public static void half(int[] x, int[] z)
{
if ((x[0] & 1) == 0)
{
Nat.shiftDownBit(5, x, 0, z);
}
else
{
int c = Nat160.add(x, P, z);
Nat.shiftDownBit(5, 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 < 5; ++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 = Nat160.createExt();
Nat160.mul(x, y, tt);
reduce(tt, z);
}
public static void multiplyAddToExt(int[] x, int[] y, int[] zz)
{
int c = Nat160.mulAddTo(x, y, zz);
if (c != 0 || (zz[9] == PExt9 && Nat.gte(10, zz, PExt)))
{
if (Nat.addTo(PExtInv.length, PExtInv, zz) != 0)
{
Nat.incAt(10, zz, PExtInv.length);
}
}
}
public static void negate(int[] x, int[] z)
{
if (0 != isZero(x))
{
Nat160.sub(P, P, z);
}
else
{
Nat160.sub(P, x, z);
}
}
public static void random(SecureRandom r, int[] z)
{
byte[] bb = new byte[5 * 4];
do
{
r.nextBytes(bb);
Pack.littleEndianToInt(bb, 0, z, 0, 5);
}
while (0 == Nat.lessThan(5, 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 x5 = xx[5] & M, x6 = xx[6] & M, x7 = xx[7] & M, x8 = xx[8] & M, x9 = xx[9] & M;
long c = 0;
c += (xx[0] & M) + x5 + (x5 << 31);
z[0] = (int)c; c >>>= 32;
c += (xx[1] & M) + x6 + (x6 << 31);
z[1] = (int)c; c >>>= 32;
c += (xx[2] & M) + x7 + (x7 << 31);
z[2] = (int)c; c >>>= 32;
c += (xx[3] & M) + x8 + (x8 << 31);
z[3] = (int)c; c >>>= 32;
c += (xx[4] & M) + x9 + (x9 << 31);
z[4] = (int)c; c >>>= 32;
// assert c >>> 32 == 0;
reduce32((int)c, z);
}
public static void reduce32(int x, int[] z)
{
if ((x != 0 && Nat160.mulWordsAdd(PInv, x, z, 0) != 0)
|| (z[4] == P4 && Nat160.gte(z, P)))
{
Nat.addWordTo(5, PInv, z);
}
}
public static void square(int[] x, int[] z)
{
int[] tt = Nat160.createExt();
Nat160.square(x, tt);
reduce(tt, z);
}
public static void squareN(int[] x, int n, int[] z)
{
// assert n > 0;
int[] tt = Nat160.createExt();
Nat160.square(x, tt);
reduce(tt, z);
while (--n > 0)
{
Nat160.square(z, tt);
reduce(tt, z);
}
}
public static void subtract(int[] x, int[] y, int[] z)
{
int c = Nat160.sub(x, y, z);
if (c != 0)
{
Nat.subWordFrom(5, PInv, z);
}
}
public static void subtractExt(int[] xx, int[] yy, int[] zz)
{
int c = Nat.sub(10, xx, yy, zz);
if (c != 0)
{
if (Nat.subFrom(PExtInv.length, PExtInv, zz) != 0)
{
Nat.decAt(10, zz, PExtInv.length);
}
}
}
public static void twice(int[] x, int[] z)
{
int c = Nat.shiftUpBit(5, x, 0, z);
if (c != 0 || (z[4] == P4 && Nat160.gte(z, P)))
{
Nat.addWordTo(5, PInv, z);
}
}
}