/*

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

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

 *

 * 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).

 *

 * 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,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 */

package sun.security.mscapi;

import java.util.UUID;

import java.security.*;

import java.security.spec.AlgorithmParameterSpec;

import java.security.spec.RSAKeyGenParameterSpec;

import sun.security.jca.JCAUtil;

import sun.security.rsa.RSAKeyFactory;

/**

 * RSA keypair generator.

 *

 * Standard algorithm, minimum key length is 512 bit, maximum is 16,384.

 * Generates a private key that is exportable.

 *

 * @since 1.6

 */

public final class RSAKeyPairGenerator extends KeyPairGeneratorSpi {

    // Supported by Microsoft Base, Strong and Enhanced Cryptographic Providers

    static final int KEY_SIZE_MIN = 512; // disallow MSCAPI min. of 384

    static final int KEY_SIZE_MAX = 16384;

    private static final int KEY_SIZE_DEFAULT = 1024;

    // size of the key to generate, KEY_SIZE_MIN <= keySize <= KEY_SIZE_MAX

    private int keySize;

    public RSAKeyPairGenerator() {

        // initialize to default in case the app does not call initialize()

        initialize(KEY_SIZE_DEFAULT, null);

    }

    // initialize the generator. See JCA doc

    // random is always ignored

    public void initialize(int keySize, SecureRandom random) {

        try {

            RSAKeyFactory.checkKeyLengths(keySize, null,

                KEY_SIZE_MIN, KEY_SIZE_MAX);

        } catch (InvalidKeyException e) {

            throw new InvalidParameterException(e.getMessage());

        }

        this.keySize = keySize;

    }

    // second initialize method. See JCA doc

    // random and exponent are always ignored

    public void initialize(AlgorithmParameterSpec params, SecureRandom random)

            throws InvalidAlgorithmParameterException {

        int tmpSize;

        if (params == null) {

            tmpSize = KEY_SIZE_DEFAULT;

        } else if (params instanceof RSAKeyGenParameterSpec) {

            if (((RSAKeyGenParameterSpec) params).getPublicExponent() != null) {

                throw new InvalidAlgorithmParameterException

                    ("Exponent parameter is not supported");

            }

            tmpSize = ((RSAKeyGenParameterSpec) params).getKeysize();

        } else {

            throw new InvalidAlgorithmParameterException

                ("Params must be an instance of RSAKeyGenParameterSpec");

        }

        try {

            RSAKeyFactory.checkKeyLengths(tmpSize, null,

                KEY_SIZE_MIN, KEY_SIZE_MAX);

        } catch (InvalidKeyException e) {

            throw new InvalidAlgorithmParameterException(

                "Invalid Key sizes", e);

        }

        this.keySize = tmpSize;

    }

    // generate the keypair. See JCA doc

    public KeyPair generateKeyPair() {

        // Generate each keypair in a unique key container

        RSAKeyPair keys =

            generateRSAKeyPair(keySize,

                "{" + UUID.randomUUID().toString() + "}");

        return new KeyPair(keys.getPublic(), keys.getPrivate());

    }

    private static native RSAKeyPair generateRSAKeyPair(int keySize,

        String keyContainerName);

}