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

 *

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

 * 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).

 *

 * 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.

 *

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package com.sun.crypto.provider;

import javax.crypto.SecretKey;

import javax.crypto.SecretKeyFactorySpi;

import javax.crypto.spec.DESedeKeySpec;

import java.security.InvalidKeyException;

import java.security.spec.KeySpec;

import java.security.spec.InvalidKeySpecException;

import javax.crypto.spec.SecretKeySpec;

/**

 * This class implements the DES-EDE key factory of the Sun provider.

 *

 * @author Jan Luehe

 *

 */

public final class DESedeKeyFactory extends SecretKeyFactorySpi {

    /**

     * Empty constructor

     */

    public DESedeKeyFactory() {

    }

    /**

     * Generates a <code>SecretKey</code> object from the provided key

     * specification (key material).

     *

     * @param keySpec the specification (key material) of the secret key

     *

     * @return the secret key

     *

     * @exception InvalidKeySpecException if the given key specification

     * is inappropriate for this key factory to produce a public key.

     */

    protected SecretKey engineGenerateSecret(KeySpec keySpec)

        throws InvalidKeySpecException {

        try {

            if (keySpec instanceof DESedeKeySpec) {

                return new DESedeKey(((DESedeKeySpec)keySpec).getKey());

            }

            if (keySpec instanceof SecretKeySpec) {

                return new DESedeKey(((SecretKeySpec)keySpec).getEncoded());

            }

            throw new InvalidKeySpecException

                ("Inappropriate key specification");

        } catch (InvalidKeyException e) {

            throw new InvalidKeySpecException(e.getMessage());

        }

    }

    /**

     * Returns a specification (key material) of the given key

     * in the requested format.

     *

     * @param key the key

     *

     * @param keySpec the requested format in which the key material shall be

     * returned

     *

     * @return the underlying key specification (key material) in the

     * requested format

     *

     * @exception InvalidKeySpecException if the requested key specification is

     * inappropriate for the given key, or the given key cannot be processed

     * (e.g., the given key has an unrecognized algorithm or format).

     */

    protected KeySpec engineGetKeySpec(SecretKey key, Class<?> keySpec)

        throws InvalidKeySpecException {

        try {

            if ((key instanceof SecretKey)

                && (key.getAlgorithm().equalsIgnoreCase("DESede"))

                && (key.getFormat().equalsIgnoreCase("RAW"))) {

                // Check if requested key spec is amongst the valid ones

                if (DESedeKeySpec.class.isAssignableFrom(keySpec)) {

                    return new DESedeKeySpec(key.getEncoded());

                } else {

                    throw new InvalidKeySpecException

                        ("Inappropriate key specification");

                }

            } else {

                throw new InvalidKeySpecException

                    ("Inappropriate key format/algorithm");

            }

        } catch (InvalidKeyException e) {

            throw new InvalidKeySpecException("Secret key has wrong size");

        }

    }

    /**

     * Translates a <code>SecretKey</code> object, whose provider may be

     * unknown or potentially untrusted, into a corresponding

     * <code>SecretKey</code> object of this key factory.

     *

     * @param key the key whose provider is unknown or untrusted

     *

     * @return the translated key

     *

     * @exception InvalidKeyException if the given key cannot be processed by

     * this key factory.

     */

    protected SecretKey engineTranslateKey(SecretKey key)

        throws InvalidKeyException {

        try {

            if ((key != null)

                && (key.getAlgorithm().equalsIgnoreCase("DESede"))

                && (key.getFormat().equalsIgnoreCase("RAW"))) {

                // Check if key originates from this factory

                if (key instanceof com.sun.crypto.provider.DESedeKey) {

                    return key;

                }

                // Convert key to spec

                DESedeKeySpec desEdeKeySpec

                    = (DESedeKeySpec)engineGetKeySpec(key,

                                                      DESedeKeySpec.class);

                // Create key from spec, and return it

                return engineGenerateSecret(desEdeKeySpec);

            } else {

                throw new InvalidKeyException

                    ("Inappropriate key format/algorithm");

            }

        } catch (InvalidKeySpecException e) {

            throw new InvalidKeyException("Cannot translate key");

        }

    }

}