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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

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

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 * 2 along with this work; if not, write to the Free Software Foundation,

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package javax.crypto.spec;

import java.math.BigInteger;

import java.security.spec.AlgorithmParameterSpec;

/**

 * This class specifies the set of parameters used with the Diffie-Hellman

 * algorithm, as specified in PKCS #3: <i>Diffie-Hellman Key-Agreement

 * Standard</i>.

 *

 * <p>A central authority generates parameters and gives them to the two

 * entities seeking to generate a secret key. The parameters are a prime

 * <code>p</code>, a base <code>g</code>, and optionally the length

 * in bits of the private value, <code>l</code>.

 *

 * <p>It is possible that more than one instance of parameters may be

 * generated by a given central authority, and that there may be more than

 * one central authority. Indeed, each individual may be its own central

 * authority, with different entities having different parameters.

 *

 * <p>Note that this class does not perform any validation on specified

 * parameters. Thus, the specified values are returned directly even

 * if they are null.

 *

 * @author Jan Luehe

 *

 * @see javax.crypto.KeyAgreement

 * @since 1.4

 */

public class DHParameterSpec implements AlgorithmParameterSpec {

    // The prime modulus

    private BigInteger p;

    // The base generator

    private BigInteger g;

    // The size in bits of the random exponent (private value) (optional)

    private int l;

    /**

     * Constructs a parameter set for Diffie-Hellman, using a prime modulus

     * <code>p</code> and a base generator <code>g</code>.

     *

     * @param p the prime modulus

     * @param g the base generator

     */

    public DHParameterSpec(BigInteger p, BigInteger g) {

        this.p = p;

        this.g = g;

        this.l = 0;

    }

    /**

     * Constructs a parameter set for Diffie-Hellman, using a prime modulus

     * <code>p</code>, a base generator <code>g</code>,

     * and the size in bits, <code>l</code>, of the random exponent

     * (private value).

     *

     * @param p the prime modulus

     * @param g the base generator

     * @param l the size in bits of the random exponent (private value)

     */

    public DHParameterSpec(BigInteger p, BigInteger g, int l) {

        this.p = p;

        this.g = g;

        this.l = l;

    }

    /**

     * Returns the prime modulus <code>p</code>.

     *

     * @return the prime modulus <code>p</code>

     */

    public BigInteger getP() {

        return this.p;

    }

    /**

     * Returns the base generator <code>g</code>.

     *

     * @return the base generator <code>g</code>

     */

    public BigInteger getG() {

        return this.g;

    }

    /**

     * Returns the size in bits, <code>l</code>, of the random exponent

     * (private value).

     *

     * @return the size in bits, <code>l</code>, of the random exponent

     * (private value), or 0 if this size has not been set

     */

    public int getL() {

        return this.l;

    }

}