Java example source code file (MacData.java)

This example Java source code file (MacData.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

algorithmid, algorithmparameters, derinputstream, deroutputstream, dervalue, illegalargumentexception, ioexception, macdata, nosuchalgorithmexception, nullpointerexception, parsingexception, security, string

The MacData.java Java example source code

/*
 * Copyright (c) 1999, 2007, 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
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package sun.security.pkcs12;

import java.io.*;
import java.security.*;

import sun.security.util.DerInputStream;
import sun.security.util.DerOutputStream;
import sun.security.util.DerValue;
import sun.security.x509.AlgorithmId;
import sun.security.pkcs.ParsingException;


/**
 * A MacData type, as defined in PKCS#12.
 *
 * @author Sharon Liu
 */

class MacData {

    private String digestAlgorithmName;
    private AlgorithmParameters digestAlgorithmParams;
    private byte[] digest;
    private byte[] macSalt;
    private int iterations;

    // the ASN.1 encoded contents of this class
    private byte[] encoded = null;

    /**
     * Parses a PKCS#12 MAC data.
     */
    MacData(DerInputStream derin)
        throws IOException, ParsingException
    {
        DerValue[] macData = derin.getSequence(2);

        // Parse the digest info
        DerInputStream digestIn = new DerInputStream(macData[0].toByteArray());
        DerValue[] digestInfo = digestIn.getSequence(2);

        // Parse the DigestAlgorithmIdentifier.
        AlgorithmId digestAlgorithmId = AlgorithmId.parse(digestInfo[0]);
        this.digestAlgorithmName = digestAlgorithmId.getName();
        this.digestAlgorithmParams = digestAlgorithmId.getParameters();
        // Get the digest.
        this.digest = digestInfo[1].getOctetString();

        // Get the salt.
        this.macSalt = macData[1].getOctetString();

        // Iterations is optional. The default value is 1.
        if (macData.length > 2) {
            this.iterations = macData[2].getInteger();
        } else {
            this.iterations = 1;
        }
    }

    MacData(String algName, byte[] digest, byte[] salt, int iterations)
        throws NoSuchAlgorithmException
    {
        if (algName == null)
           throw new NullPointerException("the algName parameter " +
                                               "must be non-null");

        AlgorithmId algid = AlgorithmId.get(algName);
        this.digestAlgorithmName = algid.getName();
        this.digestAlgorithmParams = algid.getParameters();

        if (digest == null) {
            throw new NullPointerException("the digest " +
                                           "parameter must be non-null");
        } else if (digest.length == 0) {
            throw new IllegalArgumentException("the digest " +
                                                "parameter must not be empty");
        } else {
            this.digest = digest.clone();
        }

        this.macSalt = salt;
        this.iterations = iterations;

        // delay the generation of ASN.1 encoding until
        // getEncoded() is called
        this.encoded = null;

    }

    MacData(AlgorithmParameters algParams, byte[] digest,
        byte[] salt, int iterations) throws NoSuchAlgorithmException
    {
        if (algParams == null)
           throw new NullPointerException("the algParams parameter " +
                                               "must be non-null");

        AlgorithmId algid = AlgorithmId.get(algParams);
        this.digestAlgorithmName = algid.getName();
        this.digestAlgorithmParams = algid.getParameters();

        if (digest == null) {
            throw new NullPointerException("the digest " +
                                           "parameter must be non-null");
        } else if (digest.length == 0) {
            throw new IllegalArgumentException("the digest " +
                                                "parameter must not be empty");
        } else {
            this.digest = digest.clone();
        }

        this.macSalt = salt;
        this.iterations = iterations;

        // delay the generation of ASN.1 encoding until
        // getEncoded() is called
        this.encoded = null;

    }

    String getDigestAlgName() {
        return digestAlgorithmName;
    }

    byte[] getSalt() {
        return macSalt;
    }

    int getIterations() {
        return iterations;
    }

    byte[] getDigest() {
        return digest;
    }

    /**
     * Returns the ASN.1 encoding of this object.
     * @return the ASN.1 encoding.
     * @exception IOException if error occurs when constructing its
     * ASN.1 encoding.
     */
    public byte[] getEncoded() throws NoSuchAlgorithmException, IOException
    {
        if (this.encoded != null)
            return this.encoded.clone();

        DerOutputStream out = new DerOutputStream();
        DerOutputStream tmp = new DerOutputStream();

        DerOutputStream tmp2 = new DerOutputStream();
        // encode encryption algorithm
        AlgorithmId algid = AlgorithmId.get(digestAlgorithmName);
        algid.encode(tmp2);

        // encode digest data
        tmp2.putOctetString(digest);

        tmp.write(DerValue.tag_Sequence, tmp2);

        // encode salt
        tmp.putOctetString(macSalt);

        // encode iterations
        tmp.putInteger(iterations);

        // wrap everything into a SEQUENCE
        out.write(DerValue.tag_Sequence, tmp);
        this.encoded = out.toByteArray();

        return this.encoded.clone();
    }

}