org.bouncycastle.math.ec.custom.sec.SecP384R1FieldElement Maven / Gradle / Ivy

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The Bouncy Castle Java APIs for CMS, PKCS, EAC, TSP, CMP, CRMF, OCSP, and certificate generation. This jar contains APIs for JDK 1.5 and up. The APIs can be used in conjunction with a JCE/JCA provider such as the one provided with the Bouncy Castle Cryptography APIs.
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package org.bouncycastle.math.ec.custom.sec;

import java.math.BigInteger;

import org.bouncycastle.math.ec.ECFieldElement;
import org.bouncycastle.math.raw.Nat;
import org.bouncycastle.util.Arrays;
import org.bouncycastle.util.encoders.Hex;

public class SecP384R1FieldElement extends ECFieldElement.AbstractFp
{
    public static final BigInteger Q = new BigInteger(1,
        Hex.decodeStrict("FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEFFFFFFFF0000000000000000FFFFFFFF"));

    protected int[] x;

    public SecP384R1FieldElement(BigInteger x)
    {
        if (x == null || x.signum() < 0 || x.compareTo(Q) >= 0)
        {
            throw new IllegalArgumentException("x value invalid for SecP384R1FieldElement");
        }

        this.x = SecP384R1Field.fromBigInteger(x);
    }

    public SecP384R1FieldElement()
    {
        this.x = Nat.create(12);
    }

    protected SecP384R1FieldElement(int[] x)
    {
        this.x = x;
    }

    public boolean isZero()
    {
        return Nat.isZero(12, x);
    }

    public boolean isOne()
    {
        return Nat.isOne(12, x);
    }

    public boolean testBitZero()
    {
        return Nat.getBit(x, 0) == 1;
    }

    public BigInteger toBigInteger()
    {
        return Nat.toBigInteger(12, x);
    }

    public String getFieldName()
    {
        return "SecP384R1Field";
    }

    public int getFieldSize()
    {
        return Q.bitLength();
    }

    public ECFieldElement add(ECFieldElement b)
    {
        int[] z = Nat.create(12);
        SecP384R1Field.add(x, ((SecP384R1FieldElement)b).x, z);
        return new SecP384R1FieldElement(z);
    }

    public ECFieldElement addOne()
    {
        int[] z = Nat.create(12);
        SecP384R1Field.addOne(x, z);
        return new SecP384R1FieldElement(z);
    }

    public ECFieldElement subtract(ECFieldElement b)
    {
        int[] z = Nat.create(12);
        SecP384R1Field.subtract(x, ((SecP384R1FieldElement)b).x, z);
        return new SecP384R1FieldElement(z);
    }

    public ECFieldElement multiply(ECFieldElement b)
    {
        int[] z = Nat.create(12);
        SecP384R1Field.multiply(x, ((SecP384R1FieldElement)b).x, z);
        return new SecP384R1FieldElement(z);
    }

    public ECFieldElement divide(ECFieldElement b)
    {
//        return multiply(b.invert());
        int[] z = Nat.create(12);
        SecP384R1Field.inv(((SecP384R1FieldElement)b).x, z);
        SecP384R1Field.multiply(z, x, z);
        return new SecP384R1FieldElement(z);
    }

    public ECFieldElement negate()
    {
        int[] z = Nat.create(12);
        SecP384R1Field.negate(x, z);
        return new SecP384R1FieldElement(z);
    }

    public ECFieldElement square()
    {
        int[] z = Nat.create(12);
        SecP384R1Field.square(x, z);
        return new SecP384R1FieldElement(z);
    }

    public ECFieldElement invert()
    {
//        return new SecP384R1FieldElement(toBigInteger().modInverse(Q));
        int[] z = Nat.create(12);
        SecP384R1Field.inv(x, z);
        return new SecP384R1FieldElement(z);
    }

    /**
     * return a sqrt root - the routine verifies that the calculation returns the right value - if
     * none exists it returns null.
     */
    public ECFieldElement sqrt()
    {
        // Raise this element to the exponent 2^382 - 2^126 - 2^94 + 2^30

        int[] x1 = this.x;
        if (Nat.isZero(12, x1) || Nat.isOne(12, x1))
        {
            return this;
        }

        int[] t1 = Nat.create(12);
        int[] t2 = Nat.create(12);
        int[] t3 = Nat.create(12);
        int[] t4 = Nat.create(12);

        SecP384R1Field.square(x1, t1);
        SecP384R1Field.multiply(t1, x1, t1);

        SecP384R1Field.squareN(t1, 2, t2);
        SecP384R1Field.multiply(t2, t1, t2);

        SecP384R1Field.square(t2, t2);
        SecP384R1Field.multiply(t2, x1, t2);

        SecP384R1Field.squareN(t2, 5, t3);
        SecP384R1Field.multiply(t3, t2, t3);

        SecP384R1Field.squareN(t3, 5, t4);
        SecP384R1Field.multiply(t4, t2, t4);

        SecP384R1Field.squareN(t4, 15, t2);
        SecP384R1Field.multiply(t2, t4, t2);

        SecP384R1Field.squareN(t2, 2, t3);
        SecP384R1Field.multiply(t1, t3, t1);

        SecP384R1Field.squareN(t3, 28, t3);
        SecP384R1Field.multiply(t2, t3, t2);

        SecP384R1Field.squareN(t2, 60, t3);
        SecP384R1Field.multiply(t3, t2, t3);

        int[] r = t2;

        SecP384R1Field.squareN(t3, 120, r);
        SecP384R1Field.multiply(r, t3, r);

        SecP384R1Field.squareN(r, 15, r);
        SecP384R1Field.multiply(r, t4, r);

        SecP384R1Field.squareN(r, 33, r);
        SecP384R1Field.multiply(r, t1, r);

        SecP384R1Field.squareN(r, 64, r);
        SecP384R1Field.multiply(r, x1, r);

        SecP384R1Field.squareN(r, 30, t1);
        SecP384R1Field.square(t1, t2);

        return Nat.eq(12, x1, t2) ? new SecP384R1FieldElement(t1) : null;
    }

    public boolean equals(Object other)
    {
        if (other == this)
        {
            return true;
        }

        if (!(other instanceof SecP384R1FieldElement))
        {
            return false;
        }

        SecP384R1FieldElement o = (SecP384R1FieldElement)other;
        return Nat.eq(12, x, o.x);
    }

    public int hashCode()
    {
        return Q.hashCode() ^ Arrays.hashCode(x, 0, 12);
    }
}