- /*
- * @(#)ECParameterSpec.java 1.3 03/12/19
- *
- * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
- * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
- */
- package java.security.spec;
-
- import java.math.BigInteger;
-
- /**
- * This immutable class specifies the set of domain parameters
- * used with elliptic curve cryptography (ECC).
- *
- * @see AlgorithmParameterSpec
- *
- * @author Valerie Peng
- * @version 1.3, 12/19/03
- *
- * @since 1.5
- */
- public class ECParameterSpec implements AlgorithmParameterSpec {
-
- private final EllipticCurve curve;
- private final ECPoint g;
- private final BigInteger n;
- private final int h;
-
- /**
- * Creates elliptic curve domain parameters based on the
- * specified values.
- * @param curve the elliptic curve which this parameter
- * defines.
- * @param g the generator which is also known as the base point.
- * @param n the order of the generator <code>g</code>.
- * @param h the cofactor.
- * @exception NullPointerException if <code>curve</code>,
- * <code>g</code>, or <code>n</code> is null.
- * @exception IllegalArgumentException if <code>n</code>
- * or <code>h</code> is not positive.
- */
- public ECParameterSpec(EllipticCurve curve, ECPoint g,
- BigInteger n, int h) {
- if (curve == null) {
- throw new NullPointerException("curve is null");
- }
- if (g == null) {
- throw new NullPointerException("g is null");
- }
- if (n == null) {
- throw new NullPointerException("n is null");
- }
- if (n.signum() != 1) {
- throw new IllegalArgumentException("n is not positive");
- }
- if (h <= 0) {
- throw new IllegalArgumentException("h is not positive");
- }
- this.curve = curve;
- this.g = g;
- this.n = n;
- this.h = h;
- }
-
- /**
- * Returns the elliptic curve that this parameter defines.
- * @return the elliptic curve that this parameter defines.
- */
- public EllipticCurve getCurve() {
- return curve;
- }
-
- /**
- * Returns the generator which is also known as the base point.
- * @return the generator which is also known as the base point.
- */
- public ECPoint getGenerator() {
- return g;
- }
-
- /**
- * Returns the order of the generator.
- * @return the order of the generator.
- */
- public BigInteger getOrder() {
- return n;
- }
-
- /**
- * Returns the cofactor.
- * @return the cofactor.
- */
- public int getCofactor() {
- return h;
- }
- }