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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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* published by the Free Software Foundation. Oracle designates this
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*
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
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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
*
* @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;
}
}