nl.open.jwtdependency.org.bouncycastle.math.field.FiniteFields Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of java-jwt-nodependencies Show documentation

This is a drop in replacement for the auth0 java-jwt library (see https://github.com/auth0/java-jwt). This jar makes sure there are no external dependencies (e.g. fasterXml, Apacha Commons) needed. This is useful when deploying to an application server (e.g. tomcat with Alfreso or Pega).

The newest version!

package org.bouncycastle.math.field;

import java.math.BigInteger;

public abstract class FiniteFields
{
    static final FiniteField GF_2 = new PrimeField(BigInteger.valueOf(2));
    static final FiniteField GF_3 = new PrimeField(BigInteger.valueOf(3));

    public static PolynomialExtensionField getBinaryExtensionField(int[] exponents)
    {
        if (exponents[0] != 0)
        {
            throw new IllegalArgumentException("Irreducible polynomials in GF(2) must have constant term");
        }
        for (int i = 1; i < exponents.length; ++i)
        {
            if (exponents[i] <= exponents[i - 1])
            {
                throw new IllegalArgumentException("Polynomial exponents must be montonically increasing");
            }
        }

        return new GenericPolynomialExtensionField(GF_2, new GF2Polynomial(exponents));
    }

//    public static PolynomialExtensionField getTernaryExtensionField(Term[] terms)
//    {
//        return new GenericPolynomialExtensionField(GF_3, new GF3Polynomial(terms));
//    }

    public static FiniteField getPrimeField(BigInteger characteristic)
    {
        int bitLength = characteristic.bitLength();
        if (characteristic.signum() <= 0 || bitLength < 2)
        {
            throw new IllegalArgumentException("'characteristic' must be >= 2");
        }

        if (bitLength < 3)
        {
            switch (characteristic.intValue())
            {
            case 2:
                return GF_2;
            case 3:
                return GF_3;
            }
        }

        return new PrimeField(characteristic);
    }
}