/*

 * Copyright (c) 1998, 2012, Oracle and/or its affiliates. All rights reserved.

 * 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

 * 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.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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package com.sun.crypto.provider;

import java.io.*;

import java.math.BigInteger;

import java.security.AlgorithmParametersSpi;

import java.security.spec.AlgorithmParameterSpec;

import java.security.spec.InvalidParameterSpecException;

import javax.crypto.spec.PBEParameterSpec;

import sun.misc.HexDumpEncoder;

import sun.security.util.*;

/**

 * This class implements the parameter set used with password-based

 * encryption, which is defined in PKCS#5 as follows:

 *

 * <pre>

 * PBEParameter ::=  SEQUENCE {

 *     salt   OCTET STRING SIZE(8),

 *     iterationCount   INTEGER }

 * </pre>

 *

 * @author Jan Luehe

 *

 */

public final class PBEParameters extends AlgorithmParametersSpi {

    // the salt

    private byte[] salt = null;

    // the iteration count

    private int iCount = 0;

    // the cipher parameter

    private AlgorithmParameterSpec cipherParam = null;

    protected void engineInit(AlgorithmParameterSpec paramSpec)

        throws InvalidParameterSpecException

   {

       if (!(paramSpec instanceof PBEParameterSpec)) {

           throw new InvalidParameterSpecException

               ("Inappropriate parameter specification");

       }

       this.salt = ((PBEParameterSpec)paramSpec).getSalt().clone();

       this.iCount = ((PBEParameterSpec)paramSpec).getIterationCount();

       this.cipherParam = ((PBEParameterSpec)paramSpec).getParameterSpec();

    }

    protected void engineInit(byte[] encoded)

        throws IOException

    {

        try {

            DerValue val = new DerValue(encoded);

            if (val.tag != DerValue.tag_Sequence) {

                throw new IOException("PBE parameter parsing error: "

                                      + "not a sequence");

            }

            val.data.reset();

            this.salt = val.data.getOctetString();

            this.iCount = val.data.getInteger();

            if (val.data.available() != 0) {

                throw new IOException

                    ("PBE parameter parsing error: extra data");

            }

        } catch (NumberFormatException e) {

            throw new IOException("iteration count too big");

        }

    }

    protected void engineInit(byte[] encoded, String decodingMethod)

        throws IOException

    {

        engineInit(encoded);

    }

    protected <T extends AlgorithmParameterSpec>

            T engineGetParameterSpec(Class<T> paramSpec)

        throws InvalidParameterSpecException

    {

        if (PBEParameterSpec.class.isAssignableFrom(paramSpec)) {

            return paramSpec.cast(

                new PBEParameterSpec(this.salt, this.iCount, this.cipherParam));

        } else {

            throw new InvalidParameterSpecException

                ("Inappropriate parameter specification");

        }

    }

    protected byte[] engineGetEncoded() throws IOException {

        DerOutputStream out = new DerOutputStream();

        DerOutputStream bytes = new DerOutputStream();

        bytes.putOctetString(this.salt);

        bytes.putInteger(this.iCount);

        out.write(DerValue.tag_Sequence, bytes);

        return out.toByteArray();

    }

    protected byte[] engineGetEncoded(String encodingMethod)

        throws IOException

    {

        return engineGetEncoded();

    }

    /*

     * Returns a formatted string describing the parameters.

     */

    protected String engineToString() {

        String LINE_SEP = System.getProperty("line.separator");

        String saltString = LINE_SEP + "    salt:" + LINE_SEP + "[";

        HexDumpEncoder encoder = new HexDumpEncoder();

        saltString += encoder.encodeBuffer(salt);

        saltString += "]";

        return saltString + LINE_SEP + "    iterationCount:"

            + LINE_SEP + Debug.toHexString(BigInteger.valueOf(iCount))

            + LINE_SEP;

    }

}