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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

 * particular file as subject to the "Classpath" exception as provided

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 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

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 * accompanied this code).

 *

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package java.security.spec;

import java.util.Objects;

/**

 * A class representing elliptic curve private keys as defined in RFC 7748,

 * including the curve and other algorithm parameters. The private key is

 * represented as an encoded scalar value. The decoding procedure defined in

 * the RFC includes an operation that forces certain bits of the key to either

 * 1 or 0. This operation is known as "pruning" or "clamping" the private key.

 * All arrays in this spec are unpruned, and implementations will need to prune

 * the array before using it in any numerical operations.

 *

 * @since 11

 */

public class XECPrivateKeySpec implements KeySpec {

    private final AlgorithmParameterSpec params;

    private final byte[] scalar;

    /**

     * Construct a private key spec using the supplied parameters and

     * encoded scalar value.

     *

     * @param params the algorithm parameters

     * @param scalar the unpruned encoded scalar value. This array is copied

     *               to protect against subsequent modification.

     *

     * @throws NullPointerException if {@code params} or {@code scalar}

     *                              is null.

     */

    public XECPrivateKeySpec(AlgorithmParameterSpec params, byte[] scalar) {

        Objects.requireNonNull(params, "params must not be null");

        Objects.requireNonNull(scalar, "scalar must not be null");

        this.params = params;

        this.scalar = scalar.clone();

    }

    /**

     * Get the algorithm parameters that define the curve and other settings.

     *

     * @return the algorithm parameters

     */

    public AlgorithmParameterSpec getParams() {

        return params;

    }

    /**

     * Get the scalar value encoded as an unpruned byte array. A new copy of

     * the array is returned each time this method is called.

     *

     * @return the unpruned encoded scalar value

     */

    public byte[] getScalar() {

        return scalar.clone();

    }

}