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 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 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;

import java.security.spec.MGF1ParameterSpec;

/**

 * This class specifies the set of parameters used with OAEP Padding,

 * as defined in the

 *

 * Its ASN.1 definition in PKCS#1 standard is described below:

 * <pre>

 * RSAES-OAEP-params ::= SEQUENCE {

 * }

 * </pre>

 * where

 * <pre>

 * OAEP-PSSDigestAlgorithms    ALGORITHM-IDENTIFIER ::= {

 *   ...  -- Allows for future expansion --

 * }

 * PKCS1MGFAlgorithms    ALGORITHM-IDENTIFIER ::= {

 *   ...  -- Allows for future expansion --

 * }

 * PKCS1PSourceAlgorithms    ALGORITHM-IDENTIFIER ::= {

 *   ...  -- Allows for future expansion --

 * }

 * </pre>

 * <p>Note: the OAEPParameterSpec.DEFAULT uses the following:

 *     message digest  -- "SHA-1"

 *     mask generation function (mgf) -- "MGF1"

 *     parameters for mgf -- MGF1ParameterSpec.SHA1

 *     source of encoding input -- PSource.PSpecified.DEFAULT

 *

 * @see java.security.spec.MGF1ParameterSpec

 * @see PSource

 *

 * @author Valerie Peng

 *

 * @since 1.5

 */

public class OAEPParameterSpec implements AlgorithmParameterSpec {

    private String mdName = "SHA-1";

    private String mgfName = "MGF1";

    private AlgorithmParameterSpec mgfSpec = MGF1ParameterSpec.SHA1;

    private PSource pSrc = PSource.PSpecified.DEFAULT;

    /**

     * The OAEP parameter set with all default values.

     */

    public static final OAEPParameterSpec DEFAULT = new OAEPParameterSpec();

    /**

     * Constructs a parameter set for OAEP padding as defined in

     * the PKCS #1 standard using the default values.

     */

    private OAEPParameterSpec() {

    }

    /**

     * Constructs a parameter set for OAEP padding as defined in

     * the PKCS #1 standard using the specified message digest

     * algorithm <code>mdName</code>, mask generation function

     * algorithm <code>mgfName</code>, parameters for the mask

     * generation function <code>mgfSpec</code>, and source of

     * the encoding input P <code>pSrc</code>.

     *

     * @param mdName the algorithm name for the message digest.

     * @param mgfName the algorithm name for the mask generation

     * function.

     * @param mgfSpec the parameters for the mask generation function.

     * If null is specified, null will be returned by getMGFParameters().

     * @param pSrc the source of the encoding input P.

     * @exception NullPointerException if <code>mdName</code>,

     * <code>mgfName</code>, or <code>pSrc</code> is null.

     */

    public OAEPParameterSpec(String mdName, String mgfName,

                             AlgorithmParameterSpec mgfSpec,

                             PSource pSrc) {

        if (mdName == null) {

            throw new NullPointerException("digest algorithm is null");

        }

        if (mgfName == null) {

            throw new NullPointerException("mask generation function " +

                                           "algorithm is null");

        }

        if (pSrc == null) {

            throw new NullPointerException("source of the encoding input " +

                                           "is null");

        }

        this.mdName =  mdName;

        this.mgfName =  mgfName;

        this.mgfSpec =  mgfSpec;

        this.pSrc =  pSrc;

    }

    /**

     * Returns the message digest algorithm name.

     *

     * @return the message digest algorithm name.

     */

    public String getDigestAlgorithm() {

        return mdName;

    }

    /**

     * Returns the mask generation function algorithm name.

     *

     * @return the mask generation function algorithm name.

     */

    public String getMGFAlgorithm() {

        return mgfName;

    }

    /**

     * Returns the parameters for the mask generation function.

     *

     * @return the parameters for the mask generation function.

     */

    public AlgorithmParameterSpec getMGFParameters() {

        return mgfSpec;

    }

    /**

     * Returns the source of encoding input P.

     *

     * @return the source of encoding input P.

     */

    public PSource getPSource() {

        return pSrc;

    }

}