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Java example source code file (PBEWithMD5AndTripleDESCipher.java)

This example Java source code file (PBEWithMD5AndTripleDESCipher.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

algorithmparameters, algorithmparameterspec, badpaddingexception, crypto, desede, illegalblocksizeexception, invalidalgorithmparameterexception, invalidkeyexception, key, nosuchalgorithmexception, nosuchpaddingexception, pbes1core, pbewithmd5andtripledescipher, securerandom, security, shortbufferexception

The PBEWithMD5AndTripleDESCipher.java Java example source code

/*
 * Copyright (c) 1998, 2013, 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 com.sun.crypto.provider;

import java.io.UnsupportedEncodingException;
import java.security.*;
import java.security.spec.*;
import javax.crypto.*;
import javax.crypto.spec.*;

/**
 * This class implements a proprietary password-based encryption algorithm.
 * It is based on password-based encryption as defined by the PKCS #5
 * standard, except that is uses triple DES instead of DES.
 *
 * Here's how this algorithm works:
 *
 * 1. Create random salt and split it in two halves. If the two halves are
 *    identical, invert one of them.
 * 2. Concatenate password with each of the halves.
 * 3. Digest each concatenation with c iterations, where c is the
 *    iterationCount. Concatenate the output from each digest round with the
 *    password, and use the result as the input to the next digest operation.
 *    The digest algorithm is MD5.
 * 4. After c iterations, use the 2 resulting digests as follows:
 *    The 16 bytes of the first digest and the 1st 8 bytes of the 2nd digest
 *    form the triple DES key, and the last 8 bytes of the 2nd digest form the
 *    IV.
 *
 * @author Jan Luehe
 * @see javax.crypto.Cipher
 */
public final class PBEWithMD5AndTripleDESCipher extends CipherSpi {

    private PBES1Core core;

    /**
     * Creates an instance of this cipher, and initializes its mode (CBC) and
     * padding (PKCS5).
     *
     * @exception NoSuchAlgorithmException if the required cipher mode (CBC) is
     * unavailable
     * @exception NoSuchPaddingException if the required padding mechanism
     * (PKCS5Padding) is unavailable
     */
    public PBEWithMD5AndTripleDESCipher()
        throws NoSuchAlgorithmException, NoSuchPaddingException
    {
        // set the encapsulated cipher to do triple DES
        core = new PBES1Core("DESede");
    }

    /**
     * Sets the mode of this cipher. This algorithm can only be run in CBC
     * mode.
     *
     * @param mode the cipher mode
     *
     * @exception NoSuchAlgorithmException if the requested cipher mode is
     * invalid
     */
    protected void engineSetMode(String mode) throws NoSuchAlgorithmException {
        if ((mode != null) && (!mode.equalsIgnoreCase("CBC"))) {
            throw new NoSuchAlgorithmException("Invalid cipher mode: " + mode);
        }
    }

     /**
     * Sets the padding mechanism of this cipher. This algorithm only uses
     * PKCS #5 padding.
     *
     * @param padding the padding mechanism
     *
     * @exception NoSuchPaddingException if the requested padding mechanism
     * is invalid
     */
    protected void engineSetPadding(String paddingScheme)
        throws NoSuchPaddingException
    {
        if ((paddingScheme != null) &&
            (!paddingScheme.equalsIgnoreCase("PKCS5Padding"))) {
            throw new NoSuchPaddingException("Invalid padding scheme: " +
                                             paddingScheme);
        }
    }

    /**
     * Returns the block size (in bytes).
     *
     * @return the block size (in bytes)
     */
    protected int engineGetBlockSize() {
        return core.getBlockSize();
    }

    /**
     * Returns the length in bytes that an output buffer would need to be in
     * order to hold the result of the next <code>update or
     * <code>doFinal operation, given the input length
     * <code>inputLen (in bytes).
     *
     * <p>This call takes into account any unprocessed (buffered) data from a
     * previous <code>update call, and padding.
     *
     * <p>The actual output length of the next update or
     * <code>doFinal call may be smaller than the length returned by
     * this method.
     *
     * @param inputLen the input length (in bytes)
     *
     * @return the required output buffer size (in bytes)
     *
     */
    protected int engineGetOutputSize(int inputLen) {
        return core.getOutputSize(inputLen);
    }

    /**
     * Returns the initialization vector (IV) in a new buffer.
     *
     * <p> This is useful in the case where a random IV has been created
     * (see <a href = "#init">init),
     * or in the context of password-based encryption or
     * decryption, where the IV is derived from a user-supplied password.
     *
     * @return the initialization vector in a new buffer, or null if the
     * underlying algorithm does not use an IV, or if the IV has not yet
     * been set.
     */
    protected byte[] engineGetIV() {
        return core.getIV();
    }

    /**
     * Returns the parameters used with this cipher.
     *
     * <p>The returned parameters may be the same that were used to initialize
     * this cipher, or may contain the default set of parameters or a set of
     * randomly generated parameters used by the underlying cipher
     * implementation (provided that the underlying cipher implementation
     * uses a default set of parameters or creates new parameters if it needs
     * parameters but was not initialized with any).
     *
     * @return the parameters used with this cipher, or null if this cipher
     * does not use any parameters.
     */
    protected AlgorithmParameters engineGetParameters() {
        return core.getParameters();
    }

    /**
     * Initializes this cipher with a key and a source
     * of randomness.
     * The cipher is initialized for one of the following four operations:
     * encryption, decryption, key wrapping or key unwrapping, depending on
     * the value of <code>opmode.
     *
     * <p>If this cipher (including its underlying feedback or padding scheme)
     * requires any random bytes, it will get them from <code>random.
     *
     * @param opmode the operation mode of this cipher (this is one of
     * the following:
     * <code>ENCRYPT_MODE, DECRYPT_MODE),
     * <code>WRAP_MODE or UNWRAP_MODE)
     * @param key the encryption key
     * @param random the source of randomness
     *
     * @exception InvalidKeyException if the given key is inappropriate for
     * initializing this cipher
     */
    protected void engineInit(int opmode, Key key, SecureRandom random)
        throws InvalidKeyException {
        try {
            core.init(opmode, key, (AlgorithmParameterSpec) null, random);
        } catch (InvalidAlgorithmParameterException ie) {
            InvalidKeyException ike =
                new InvalidKeyException("requires PBE parameters");
            ike.initCause(ie);
            throw ike;
        }
    }

    /**
     * Initializes this cipher with a key, a set of
     * algorithm parameters, and a source of randomness.
     * The cipher is initialized for encryption or decryption, depending on
     * the value of <code>opmode.
     *
     * <p>If this cipher (including its underlying feedback or padding scheme)
     * requires any random bytes, it will get them from <code>random.
     *
     * @param opmode the operation mode of this cipher (this is either
     * <code>ENCRYPT_MODE or DECRYPT_MODE)
     * @param key the encryption key
     * @param params the algorithm parameters
     * @param random the source of randomness
     *
     * @exception InvalidKeyException if the given key is inappropriate for
     * initializing this cipher
     * @exception InvalidAlgorithmParameterException if the given algorithm
     * parameters are inappropriate for this cipher
     */
    protected void engineInit(int opmode, Key key,
                              AlgorithmParameterSpec params,
                              SecureRandom random)
        throws InvalidKeyException, InvalidAlgorithmParameterException {
        core.init(opmode, key, params, random);
    }

    protected void engineInit(int opmode, Key key,
                              AlgorithmParameters params,
                              SecureRandom random)
        throws InvalidKeyException, InvalidAlgorithmParameterException
    {
        core.init(opmode, key, params, random);
    }

    /**
     * Continues a multiple-part encryption or decryption operation
     * (depending on how this cipher was initialized), processing another data
     * part.
     *
     * <p>The first inputLen bytes in the input
     * buffer, starting at <code>inputOffset, are processed, and the
     * result is stored in a new buffer.
     *
     * @param input the input buffer
     * @param inputOffset the offset in <code>input where the input
     * starts
     * @param inputLen the input length
     *
     * @return the new buffer with the result
     *
     */
    protected byte[] engineUpdate(byte[] input, int inputOffset, int inputLen)
    {
        return core.update(input, inputOffset, inputLen);
    }

    /**
     * Continues a multiple-part encryption or decryption operation
     * (depending on how this cipher was initialized), processing another data
     * part.
     *
     * <p>The first inputLen bytes in the input
     * buffer, starting at <code>inputOffset, are processed, and the
     * result is stored in the <code>output buffer, starting at
     * <code>outputOffset.
     *
     * @param input the input buffer
     * @param inputOffset the offset in <code>input where the input
     * starts
     * @param inputLen the input length
     * @param output the buffer for the result
     * @param outputOffset the offset in <code>output where the result
     * is stored
     *
     * @return the number of bytes stored in <code>output
     *
     * @exception ShortBufferException if the given output buffer is too small
     * to hold the result
     */
    protected int engineUpdate(byte[] input, int inputOffset, int inputLen,
                               byte[] output, int outputOffset)
        throws ShortBufferException
    {
        return core.update(input, inputOffset, inputLen,
                           output, outputOffset);
    }

    /**
     * Encrypts or decrypts data in a single-part operation,
     * or finishes a multiple-part operation.
     * The data is encrypted or decrypted, depending on how this cipher was
     * initialized.
     *
     * <p>The first inputLen bytes in the input
     * buffer, starting at <code>inputOffset, and any input bytes that
     * may have been buffered during a previous <code>update operation,
     * are processed, with padding (if requested) being applied.
     * The result is stored in a new buffer.
     *
     * <p>The cipher is reset to its initial state (uninitialized) after this
     * call.
     *
     * @param input the input buffer
     * @param inputOffset the offset in <code>input where the input
     * starts
     * @param inputLen the input length
     *
     * @return the new buffer with the result
     *
     * @exception IllegalBlockSizeException if this cipher is a block cipher,
     * no padding has been requested (only in encryption mode), and the total
     * input length of the data processed by this cipher is not a multiple of
     * block size
     * @exception BadPaddingException if decrypting and padding is chosen,
     * but the last input data does not have proper padding bytes.
     */
    protected byte[] engineDoFinal(byte[] input, int inputOffset, int inputLen)
        throws IllegalBlockSizeException, BadPaddingException
    {
        return core.doFinal(input, inputOffset, inputLen);
    }

    /**
     * Encrypts or decrypts data in a single-part operation,
     * or finishes a multiple-part operation.
     * The data is encrypted or decrypted, depending on how this cipher was
     * initialized.
     *
     * <p>The first inputLen bytes in the input
     * buffer, starting at <code>inputOffset, and any input bytes that
     * may have been buffered during a previous <code>update operation,
     * are processed, with padding (if requested) being applied.
     * The result is stored in the <code>output buffer, starting at
     * <code>outputOffset.
     *
     * <p>The cipher is reset to its initial state (uninitialized) after this
     * call.
     *
     * @param input the input buffer
     * @param inputOffset the offset in <code>input where the input
     * starts
     * @param inputLen the input length
     * @param output the buffer for the result
     * @param outputOffset the offset in <code>output where the result
     * is stored
     *
     * @return the number of bytes stored in <code>output
     *
     * @exception IllegalBlockSizeException if this cipher is a block cipher,
     * no padding has been requested (only in encryption mode), and the total
     * input length of the data processed by this cipher is not a multiple of
     * block size
     * @exception ShortBufferException if the given output buffer is too small
     * to hold the result
     * @exception BadPaddingException if decrypting and padding is chosen,
     * but the last input data does not have proper padding bytes.
     */
    protected int engineDoFinal(byte[] input, int inputOffset, int inputLen,
                                byte[] output, int outputOffset)
        throws ShortBufferException, IllegalBlockSizeException,
               BadPaddingException
    {
        return core.doFinal(input, inputOffset, inputLen,
                            output, outputOffset);
    }

    /**
     *  Returns the key size of the given key object.
     *
     * @param key the key object.
     *
     * @return the key size of the given key object.
     *
     * @exception InvalidKeyException if <code>key is invalid.
     */
    protected int engineGetKeySize(Key key) throws InvalidKeyException {
        return 168;
    }

    /**
     * Wrap a key.
     *
     * @param key the key to be wrapped.
     *
     * @return the wrapped key.
     *
     * @exception IllegalBlockSizeException if this cipher is a block
     * cipher, no padding has been requested, and the length of the
     * encoding of the key to be wrapped is not a
     * multiple of the block size.
     *
     * @exception InvalidKeyException if it is impossible or unsafe to
     * wrap the key with this cipher (e.g., a hardware protected key is
     * being passed to a software only cipher).
     */
    protected byte[] engineWrap(Key key)
        throws IllegalBlockSizeException, InvalidKeyException {
        return core.wrap(key);
    }

    /**
     * Unwrap a previously wrapped key.
     *
     * @param wrappedKey the key to be unwrapped.
     *
     * @param wrappedKeyAlgorithm the algorithm the wrapped key is for.
     *
     * @param wrappedKeyType the type of the wrapped key.
     * This is one of <code>Cipher.SECRET_KEY,
     * <code>Cipher.PRIVATE_KEY, or Cipher.PUBLIC_KEY.
     *
     * @return the unwrapped key.
     *
     * @exception NoSuchAlgorithmException if no installed providers
     * can create keys of type <code>wrappedKeyType for the
     * <code>wrappedKeyAlgorithm.
     *
     * @exception InvalidKeyException if <code>wrappedKey does not
     * represent a wrapped key of type <code>wrappedKeyType for
     * the <code>wrappedKeyAlgorithm.
     */
    protected Key engineUnwrap(byte[] wrappedKey,
                                     String wrappedKeyAlgorithm,
                                     int wrappedKeyType)
        throws InvalidKeyException, NoSuchAlgorithmException {
        return core.unwrap(wrappedKey, wrappedKeyAlgorithm,
                           wrappedKeyType);
    }
}

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