org.jasypt/jasypt/1.9.3 : org/jasypt/encryption/pbe/StandardPBEByteEncryptor.java

StandardPBEByteEncryptor
http://www.jasypt.org: Java library which enables encryption in java apps with minimum effort. (The JASYPT team)
The Apache Software License, Version 2.0
Daniel Fernandez
/*
 * =============================================================================
 * 
 *   Copyright (c) 2007-2010, The JASYPT team (http://www.jasypt.org)
 * 
 *   Licensed under the Apache License, Version 2.0 (the "License");
 *   you may not use this file except in compliance with the License.
 *   You may obtain a copy of the License at
 * 
 *       http://www.apache.org/licenses/LICENSE-2.0
 * 
 *   Unless required by applicable law or agreed to in writing, software
 *   distributed under the License is distributed on an "AS IS" BASIS,
 *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *   See the License for the specific language governing permissions and
 *   limitations under the License.
 * 
 * =============================================================================
 */
package org.jasypt.encryption.pbe;

import java.lang.reflect.Constructor;
import java.security.InvalidKeyException;
import java.security.Provider;
import java.security.spec.AlgorithmParameterSpec;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.spec.PBEParameterSpec;

import org.jasypt.commons.CommonUtils;
import org.jasypt.encryption.pbe.config.PBECleanablePasswordConfig;
import org.jasypt.encryption.pbe.config.PBEConfig;
import org.jasypt.exceptions.AlreadyInitializedException;
import org.jasypt.exceptions.EncryptionInitializationException;
import org.jasypt.exceptions.EncryptionOperationNotPossibleException;
import org.jasypt.iv.IvGenerator;
import org.jasypt.iv.NoIvGenerator;
import org.jasypt.normalization.Normalizer;
import org.jasypt.salt.FixedSaltGenerator;
import org.jasypt.salt.RandomSaltGenerator;
import org.jasypt.salt.SaltGenerator;

 Standard implementation of the PBEByteEncryptor interface. This class lets the user specify the algorithm, provider and the initialization vector (IV) generator to be used for encryption, the password to use, the number of hashing iterations and the salt generator that will be applied for obtaining the encryption key. 

This class is thread-safe.



Configuration


The algorithm, provider, IV generator, password, key-obtention iterations
and salt generator can take values in any of these ways:

  Using its default values (except for password).
  Setting a PBEConfig 
      object which provides new 
      configuration values.
  Calling the corresponding setAlgorithm(...), 
      setProvider(...), setProviderName(...),
      setIvGenerator(...),
      setPassword(...), setKeyObtentionIterations(...) or
      setSaltGenerator(...) methods.

And the actual values to be used for initialization will be established
by applying the following priorities:

  First, the default values are considered (except for password).
  Then, if a PBEConfig 
      object has been set with
      setConfig(...), the non-null values returned by its
      getX() methods override the default values.
  Finally, if the corresponding setX(...) method has been called
      on the encryptor itself for any of the configuration parameters, the 
      values set by these calls override all of the above.




Initialization


Before it is ready to encrypt, an object of this class has to be
initialized. Initialization happens:

  When initialize() is called.
  When encrypt(...) or decrypt(...) are called for the
      first time, if initialize() has not been called before.

Once an encryptor has been initialized, trying to
change its configuration will
result in an AlreadyInitializedException being thrown.



Usage


An encryptor may be used for:

  Encrypting messages, by calling the encrypt(...) method.
  Decrypting messages, by calling the decrypt(...) method. 

If a random salt generator is used, two encryption results for 
the same message will always be different
(except in the case of random salt coincidence). This may enforce
security by difficulting brute force attacks on sets of data at a time
and forcing attackers to perform a brute force attack on each separate
piece of encrypted data.
The same applies when a random IV generator is used.

     
To learn more about the mechanisms involved in encryption, read
PKCS #5: Password-Based Cryptography Standard.

Author: Daniel Fernández
Since: 1.0/**
 * <p>
 * Standard implementation of the {@link PBEByteEncryptor} interface.
 * This class lets the user specify the algorithm, provider and
 * the initialization vector (IV) generator to be used for
 * encryption, the password to use,
 * the number of hashing iterations and the salt generator
 * that will be applied for obtaining the encryption key.
 * </p>
 * <p>
 * This class is <i>thread-safe</i>.
 * </p>
 * <p>
 * <br/><b><u>Configuration</u></b>
 * </p>
 * <p>
 * The algorithm, provider, IV generator, password, key-obtention iterations
 * and salt generator can take values in any of these ways:
 * <ul>
 *   <li>Using its default values (except for password).</li>
 *   <li>Setting a <tt>{@link org.jasypt.encryption.pbe.config.PBEConfig}</tt> 
 *       object which provides new 
 *       configuration values.</li>
 *   <li>Calling the corresponding <tt>setAlgorithm(...)</tt>, 
 *       <tt>setProvider(...)</tt>, <tt>setProviderName(...)</tt>,
 *       <tt>setIvGenerator(...)</tt>,
 *       <tt>setPassword(...)</tt>, <tt>setKeyObtentionIterations(...)</tt> or
 *       <tt>setSaltGenerator(...)</tt> methods.</li>
 * </ul>
 * And the actual values to be used for initialization will be established
 * by applying the following priorities:
 * <ol>
 *   <li>First, the default values are considered (except for password).</li>
 *   <li>Then, if a <tt>{@link org.jasypt.encryption.pbe.config.PBEConfig}</tt> 
 *       object has been set with
 *       <tt>setConfig(...)</tt>, the non-null values returned by its
 *       <tt>getX()</tt> methods override the default values.</li>
 *   <li>Finally, if the corresponding <tt>setX(...)</tt> method has been called
 *       on the encryptor itself for any of the configuration parameters, the 
 *       values set by these calls override all of the above.</li>
 * </ol>
 * </p>
 * 
 * <p>
 * <br/><b><u>Initialization</u></b>
 * </p>
 * <p>
 * Before it is ready to encrypt, an object of this class has to be
 * <i>initialized</i>. Initialization happens:
 * <ul>
 *   <li>When <tt>initialize()</tt> is called.</li>
 *   <li>When <tt>encrypt(...)</tt> or <tt>decrypt(...)</tt> are called for the
 *       first time, if <tt>initialize()</tt> has not been called before.</li>
 * </ul>
 * Once an encryptor has been initialized, trying to
 * change its configuration will
 * result in an <tt>AlreadyInitializedException</tt> being thrown.
 * </p>
 * 
 * <p>
 * <br/><b><u>Usage</u></b>
 * </p>
 * <p>
 * An encryptor may be used for:
 * <ul>
 *   <li><i>Encrypting messages</i>, by calling the <tt>encrypt(...)</tt> method.</li>
 *   <li><i>Decrypting messages</i>, by calling the <tt>decrypt(...)</tt> method.</li> 
 * </ul>
 * <b>If a random salt generator is used, two encryption results for 
 * the same message will always be different
 * (except in the case of random salt coincidence)</b>. This may enforce
 * security by difficulting brute force attacks on sets of data at a time
 * and forcing attackers to perform a brute force attack on each separate
 * piece of encrypted data.
 * The same applies when a random IV generator is used.
 * </p>
 * <p>     
 * To learn more about the mechanisms involved in encryption, read
 * <a href="http://www.rsasecurity.com/rsalabs/node.asp?id=2127" 
 * target="_blank">PKCS &#035;5: Password-Based Cryptography Standard</a>.
 * </p>
 * 
 * @since 1.0
 * 
 * @author Daniel Fern&aacute;ndez
 * 
 */
public final class StandardPBEByteEncryptor implements PBEByteCleanablePasswordEncryptor {


    The default algorithm to be used if none specified: PBEWithMD5AndDES.
/**
     * The default algorithm to be used if none specified: PBEWithMD5AndDES.
     */
    public static final String DEFAULT_ALGORITHM = "PBEWithMD5AndDES";

    The default number of hashing iterations applied for obtaining the
encryption key from the specified password, set to 1000. 
/**
     * The default number of hashing iterations applied for obtaining the
     * encryption key from the specified password, set to 1000. 
     */
    public static final int DEFAULT_KEY_OBTENTION_ITERATIONS = 1000;

    The default salt size, only used if the chosen encryption algorithm
is not a block algorithm and thus block size cannot be used as salt size. 
/**
     * The default salt size, only used if the chosen encryption algorithm
     * is not a block algorithm and thus block size cannot be used as salt size. 
     */
    public static final int DEFAULT_SALT_SIZE_BYTES = 8;

    The default IV size, only used if the chosen encryption algorithm
is not a block algorithm and thus block size cannot be used as IV size.
/**
     * The default IV size, only used if the chosen encryption algorithm
     * is not a block algorithm and thus block size cannot be used as IV size.
     */
    public static final int DEFAULT_IV_SIZE_BYTES = 16;


    // Algorithm (and provider-related info) for Password Based Encoding.
    private String algorithm = DEFAULT_ALGORITHM;
    private String providerName = null;
    private Provider provider = null;
    
    // Password to be applied. This will NOT have a default value. If none
    // is set during configuration, an exception will be thrown.
    private char[] password = null;
    
    // Number of hashing iterations to be applied for obtaining the encryption
    // key from the specified password.
    private int keyObtentionIterations = DEFAULT_KEY_OBTENTION_ITERATIONS;
    
    // SaltGenerator to be used. Initialization of a salt generator is costly,
    // and so default value will be applied only in initialize(), if it finally
    // becomes necessary.
    private SaltGenerator saltGenerator = null;

    // Size in bytes of the salt to be used for obtaining the
    // encryption key. This size will depend on the PBE algorithm being used,
    // and it will be set to the size of the block for the specific
    // chosen algorithm (if the algorithm is not a block algorithm, the 
    // default value will be used).
    private int saltSizeBytes = DEFAULT_SALT_SIZE_BYTES;

    // IvGenerator to be used. Initialization of a IV generator is costly,
    // and so default value will be applied only in initialize(), if it finally
    // becomes necessary.
    private IvGenerator ivGenerator = null;

    // Size in bytes of the IV. This size will depend on the PBE algorithm
    // being used, and it will be set to the size of the block for the specific
    // chosen algorithm (if the algorithm is not a block algorithm, the
    // default value will be used).
    private int ivSizeBytes = DEFAULT_IV_SIZE_BYTES;


    // Config object set (optionally).
    private PBEConfig config = null;

    /*
     * Set of booleans which indicate whether the config or default values
     * have to be overriden because of the setX methods having been
     * called.
     */
    private boolean algorithmSet = false;
    private boolean passwordSet = false;
    private boolean iterationsSet = false;
    private boolean saltGeneratorSet = false;
    private boolean ivGeneratorSet = false;
    private boolean providerNameSet = false;
    private boolean providerSet = false;
    
    
    /*
     * Flag which indicates whether the encryptor has been initialized or not.
     * 
     * Once initialized, no further modifications to its configuration will
     * be allowed.
     */
    private boolean initialized = false;

    
    // Encryption key generated.
    private SecretKey key = null;
    
    // Ciphers to be used for encryption and decryption.
    private Cipher encryptCipher = null;
    private Cipher decryptCipher = null;
    

    // Flag which indicates whether the salt generator being used is a
    // FixedSaltGenerator implementation (in which case some optimizations can
    // be applied).
    private boolean optimizingDueFixedSalt = false;
    private byte[] fixedSaltInUse = null;

    
    
    
    Creates a new instance of StandardPBEByteEncryptor.
/**
     * Creates a new instance of <tt>StandardPBEByteEncryptor</tt>.
     */
    public StandardPBEByteEncryptor() {
        super();
    }

    
    
Sets a PBEConfig object 
for the encryptor. If this config
object is set, it will be asked values for:


  Algorithm
  Security Provider (or provider name)
  Password
  Hashing iterations for obtaining the encryption key
  Salt generator
  IV generator


The non-null values it returns will override the default ones, 
and will be overriden by any values specified with a setX
method.

Params: config – the PBEConfig object to be used as the 
              source for configuration parameters./**
     * <p>
     * Sets a <tt>{@link org.jasypt.encryption.pbe.config.PBEConfig}</tt> object 
     * for the encryptor. If this config
     * object is set, it will be asked values for:
     * </p>
     * 
     * <ul>
     *   <li>Algorithm</li>
     *   <li>Security Provider (or provider name)</li>
     *   <li>Password</li>
     *   <li>Hashing iterations for obtaining the encryption key</li>
     *   <li>Salt generator</li>
     *   <li>IV generator</li>
     * </ul>
     * 
     * <p>
     * The non-null values it returns will override the default ones, 
     * <i>and will be overriden by any values specified with a <tt>setX</tt>
     * method</i>.
     * </p>
     * 
     * @param config the <tt>PBEConfig</tt> object to be used as the 
     *               source for configuration parameters.
     */
    public synchronized void setConfig(PBEConfig config) {
        CommonUtils.validateNotNull(config, "Config cannot be set null");
        if (isInitialized()) {
            throw new AlreadyInitializedException();
        }
        this.config = config;
    }

    
    
Sets the algorithm to be used for encryption, like 
PBEWithMD5AndDES.


This algorithm has to be supported by your JCE provider (if you specify
one, or the default JVM provider if you don't) and, if it is supported,
you can also specify mode and padding for 
it, like ALGORITHM/MODE/PADDING.

Params: algorithm – the name of the algorithm to be used./**
     * <p>
     * Sets the algorithm to be used for encryption, like 
     * <tt>PBEWithMD5AndDES</tt>.
     * </p>
     * <p>
     * This algorithm has to be supported by your JCE provider (if you specify
     * one, or the default JVM provider if you don't) and, if it is supported,
     * you can also specify <i>mode</i> and <i>padding</i> for 
     * it, like <tt>ALGORITHM/MODE/PADDING</tt>.
     * </p>
     * 
     * @param algorithm the name of the algorithm to be used.
     */
    public synchronized void setAlgorithm(String algorithm) {
        CommonUtils.validateNotEmpty(algorithm, "Algorithm cannot be set empty");
        if (isInitialized()) {
            throw new AlreadyInitializedException();
        }
        this.algorithm = algorithm;
        this.algorithmSet = true;
    }
    
    
    
Sets the password to be used.


There is no default value for password, so not setting this parameter either from a PBEConfig object or from a call to setPassword will result in an
EncryptionInitializationException being thrown during initialization.

Params: password – the password to be used./**
     * <p>
     * Sets the password to be used.
     * </p>
     * <p>
     * <b>There is no default value for password</b>, so not setting
     * this parameter either from a 
     * {@link org.jasypt.encryption.pbe.config.PBEConfig} object or from
     * a call to <tt>setPassword</tt> will result in an
     * EncryptionInitializationException being thrown during initialization.
     * </p>
     * 
     * @param password the password to be used.
     */
    public synchronized void setPassword(String password) {
        CommonUtils.validateNotEmpty(password, "Password cannot be set empty");
        if (isInitialized()) {
            throw new AlreadyInitializedException();
        }
        if (this.password != null) {
            // We clean the old password, if there is one.
            cleanPassword(this.password);
        }
        this.password = password.toCharArray();
        this.passwordSet = true;
    }
    
    
    
Sets the password to be used, as a char[].


This allows the password to be specified as a cleanable
char[] instead of a String, in extreme security conscious environments
in which no copy of the password as an immutable String should
be kept in memory.


Important: the array specified as a parameter WILL BE COPIED
in order to be stored as encryptor configuration. The caller of
this method will therefore be responsible for its cleaning (jasypt
will only clean the internally stored copy).


There is no default value for password, so not setting this parameter either from a PBEConfig object or from a call to setPassword will result in an
EncryptionInitializationException being thrown during initialization.

Params: password – the password to be used.
Since: 1.8/**
     * <p>
     * Sets the password to be used, as a char[].
     * </p>
     * <p>
     * This allows the password to be specified as a <i>cleanable</i>
     * char[] instead of a String, in extreme security conscious environments
     * in which no copy of the password as an immutable String should
     * be kept in memory.
     * </p>
     * <p>
     * <b>Important</b>: the array specified as a parameter WILL BE COPIED
     * in order to be stored as encryptor configuration. The caller of
     * this method will therefore be responsible for its cleaning (jasypt
     * will only clean the internally stored copy).
     * </p>
     * <p>
     * <b>There is no default value for password</b>, so not setting
     * this parameter either from a 
     * {@link org.jasypt.encryption.pbe.config.PBEConfig} object or from
     * a call to <tt>setPassword</tt> will result in an
     * EncryptionInitializationException being thrown during initialization.
     * </p>
     * 
     * @since 1.8
     * 
     * @param password the password to be used.
     */
    public synchronized void setPasswordCharArray(char[] password) {
        CommonUtils.validateNotNull(password, "Password cannot be set null");
        CommonUtils.validateIsTrue(password.length > 0, "Password cannot be set empty");
        if (isInitialized()) {
            throw new AlreadyInitializedException();
        }
        if (this.password != null) {
            // We clean the old password, if there is one.
            cleanPassword(this.password);
        }
        this.password = new char[password.length];
        System.arraycopy(password, 0, this.password, 0, password.length);
        this.passwordSet = true;
    }
    
    
    
Set the number of hashing iterations applied to obtain the
encryption key.


This mechanism is explained in 
PKCS #5: Password-Based Cryptography Standard.

Params: keyObtentionIterations – the number of iterations/**
     * <p>
     * Set the number of hashing iterations applied to obtain the
     * encryption key.
     * </p>
     * <p>
     * This mechanism is explained in 
     * <a href="http://www.rsasecurity.com/rsalabs/node.asp?id=2127" 
     * target="_blank">PKCS &#035;5: Password-Based Cryptography Standard</a>.
     * </p>
     * 
     * @param keyObtentionIterations the number of iterations
     */
    public synchronized void setKeyObtentionIterations(
            int keyObtentionIterations) {
        CommonUtils.validateIsTrue(keyObtentionIterations > 0, 
                "Number of iterations for key obtention must be " +
                "greater than zero");
        if (isInitialized()) {
            throw new AlreadyInitializedException();
        }
        this.keyObtentionIterations = keyObtentionIterations;
        this.iterationsSet = true;
    }

    
     Sets the salt generator to be used. If no salt generator is specified, an instance of RandomSaltGenerator will be used. 
Params: saltGenerator – the salt generator to be used./**
     * <p>
     * Sets the salt generator to be used. If no salt generator is specified,
     * an instance of {@link org.jasypt.salt.RandomSaltGenerator} will be used. 
     * </p>
     * 
     * @param saltGenerator the salt generator to be used.
     */
    public synchronized void setSaltGenerator(SaltGenerator saltGenerator) {
        CommonUtils.validateNotNull(saltGenerator, "Salt generator cannot be set null");
        if (isInitialized()) {
            throw new AlreadyInitializedException();
        }
        this.saltGenerator = saltGenerator;
        this.saltGeneratorSet = true;
    }

     Sets the IV generator to be used. If no IV generator is specified, an instance of NoIvGenerator will be used. 
Params: ivGenerator – the IV generator to be used./**
     * <p>
     * Sets the IV generator to be used. If no IV generator is specified,
     * an instance of {@link org.jasypt.iv.NoIvGenerator} will be used.
     * </p>
     *
     * @param ivGenerator the IV generator to be used.
     */
    public synchronized void setIvGenerator(IvGenerator ivGenerator) { ;
        if (isInitialized()) {
            throw new AlreadyInitializedException();
        }
        this.ivGenerator = ivGenerator;
        this.ivGeneratorSet = true;
    }
    
    
    
Sets the name of the security provider to be asked for the
encryption algorithm. This security provider has to be registered 
beforehand at the JVM security framework. 

 The provider can also be set with the setProvider(Provider) method, in which case it will not be necessary neither registering the provider beforehand, nor calling this setProviderName(String) method to specify a provider name. 
 Note that a call to setProvider(Provider) overrides any value set by this method. 

If no provider name / provider is explicitly set, the default JVM
provider will be used.

Params: providerName – the name of the security provider to be asked
                    for the encryption algorithm.
Since: 1.3/**
     * <p>
     * Sets the name of the security provider to be asked for the
     * encryption algorithm. This security provider has to be registered 
     * beforehand at the JVM security framework. 
     * </p>
     * <p>
     * The provider can also be set with the {@link #setProvider(Provider)}
     * method, in which case it will not be necessary neither registering
     * the provider beforehand,
     * nor calling this {@link #setProviderName(String)} method to specify
     * a provider name.
     * </p>
     * <p>
     * Note that a call to {@link #setProvider(Provider)} overrides any value 
     * set by this method.
     * </p>
     * <p>
     * If no provider name / provider is explicitly set, the default JVM
     * provider will be used.
     * </p>
     * 
     * @since 1.3
     * 
     * @param providerName the name of the security provider to be asked
     *                     for the encryption algorithm.
     */
    public synchronized void setProviderName(String providerName) {
        CommonUtils.validateNotNull(providerName, "Provider name cannot be set null");
        if (isInitialized()) {
            throw new AlreadyInitializedException();
        }
        this.providerName = providerName;
        this.providerNameSet = true;
    }
    
    
    
Sets the security provider to be asked for the encryption algorithm.
The provider does not have to be registered at the security 
infrastructure beforehand, and its being used here will not result in
its being registered.

 If this method is called, calling setProviderName(String) becomes unnecessary. 

If no provider name / provider is explicitly set, the default JVM
provider will be used.

Params: provider – the provider to be asked for the chosen algorithm
Since: 1.3/**
     * <p>
     * Sets the security provider to be asked for the encryption algorithm.
     * The provider does not have to be registered at the security 
     * infrastructure beforehand, and its being used here will not result in
     * its being registered.
     * </p>
     * <p>
     * If this method is called, calling {@link #setProviderName(String)}
     * becomes unnecessary.
     * </p>
     * <p>
     * If no provider name / provider is explicitly set, the default JVM
     * provider will be used.
     * </p>
     * 
     * @since 1.3
     * 
     * @param provider the provider to be asked for the chosen algorithm
     */
    public synchronized void setProvider(Provider provider) {
        CommonUtils.validateNotNull(provider, "Provider cannot be set null");
        if (isInitialized()) {
            throw new AlreadyInitializedException();
        }
        this.provider = provider;
        this.providerSet = true;
    }


    
    


    
    
    
    
    /*
     * Clone this encryptor 'size' times and initialize it.
     * This encryptor will be at position 0 itself.
     * Clones will NOT be initialized.
     */
    synchronized StandardPBEByteEncryptor[] cloneAndInitializeEncryptor(final int size) {

        if (isInitialized()) {
            throw new EncryptionInitializationException(
                    "Cannot clone encryptor if it has been already initialized");
        }

        // If there is a config object, this forces the password configured value 
        // (if any) into the this.password property.
        resolveConfigurationPassword();
        
        final char[] copiedPassword = new char[this.password.length];
        System.arraycopy(this.password, 0, copiedPassword, 0, this.password.length);

        // Initialize the encryptor - note that this will clean the 
        // password (that's why copied it before)
        initialize();

        final StandardPBEByteEncryptor[] clones = new StandardPBEByteEncryptor[size];

        clones[0] = this;
        
        for (int i = 1; i < size; i++) {
            
            final StandardPBEByteEncryptor clone = new StandardPBEByteEncryptor();
            clone.setPasswordCharArray(copiedPassword);
            if (CommonUtils.isNotEmpty(this.algorithm)) {
                clone.setAlgorithm(this.algorithm);
            }
            clone.setKeyObtentionIterations(this.keyObtentionIterations);
            if (this.provider != null) {
                clone.setProvider(this.provider);
            }
            if (this.providerName != null) {
                clone.setProviderName(this.providerName);
            }
            if (this.saltGenerator != null) {
                clone.setSaltGenerator(this.saltGenerator);
            }
            if (this.ivGenerator != null) {
                clone.setIvGenerator(this.ivGenerator);
            }
            
            clones[i] = clone;
            
        }
        
        cleanPassword(copiedPassword);
        
        return clones;
        
    }
    
    
    
    
    
  Returns true if the encryptor has already been initialized, false if
  not.
 
  Initialization happens:


  When initialize is called.
  When encrypt or decrypt are called for the
      first time, if initialize has not been called before.


  Once an encryptor has been initialized, trying to
  change its configuration will
  result in an AlreadyInitializedException being thrown.

Returns: true if the encryptor has already been initialized, false if
        not./**
     * <p>
     *   Returns true if the encryptor has already been initialized, false if
     *   not.<br/> 
     *   Initialization happens:
     * </p>
     * <ul>
     *   <li>When <tt>initialize</tt> is called.</li>
     *   <li>When <tt>encrypt</tt> or <tt>decrypt</tt> are called for the
     *       first time, if <tt>initialize</tt> has not been called before.</li>
     * </ul>
     * <p>
     *   Once an encryptor has been initialized, trying to
     *   change its configuration will
     *   result in an <tt>AlreadyInitializedException</tt> being thrown.
     * </p>
     * 
     * @return true if the encryptor has already been initialized, false if
     *         not.
     */
    public boolean isInitialized() {
        return this.initialized;
    }

    
    
Initialize the encryptor.


This operation will consist in determining the actual configuration 
values to be used, and then initializing the encryptor with them.


These values are decided by applying the following priorities:


  First, the default values are considered (except for password).
  
  Then, if a 
      PBEConfig 
      object has been set with
      setConfig, the non-null values returned by its
      getX methods override the default values.
  Finally, if the corresponding setX method has been called
      on the encryptor itself for any of the configuration parameters, 
      the values set by these calls override all of the above.


  Once an encryptor has been initialized, trying to
  change its configuration will
  result in an AlreadyInitializedException being thrown.

Throws: EncryptionInitializationException – if initialization could not
        be correctly done (for example, no password has been set)./**
     * <p>
     * Initialize the encryptor.
     * </p>
     * <p>
     * This operation will consist in determining the actual configuration 
     * values to be used, and then initializing the encryptor with them.
     * <br/>
     * These values are decided by applying the following priorities:
     * </p>
     * <ol>
     *   <li>First, the default values are considered (except for password).
     *   </li>
     *   <li>Then, if a 
     *       <tt>{@link org.jasypt.encryption.pbe.config.PBEConfig}</tt> 
     *       object has been set with
     *       <tt>setConfig</tt>, the non-null values returned by its
     *       <tt>getX</tt> methods override the default values.</li>
     *   <li>Finally, if the corresponding <tt>setX</tt> method has been called
     *       on the encryptor itself for any of the configuration parameters, 
     *       the values set by these calls override all of the above.</li>
     * </ol>
     * <p>
     *   Once an encryptor has been initialized, trying to
     *   change its configuration will
     *   result in an <tt>AlreadyInitializedException</tt> being thrown.
     * </p>
     * 
     * @throws EncryptionInitializationException if initialization could not
     *         be correctly done (for example, no password has been set).
     */
    public synchronized void initialize() {
        
        // Double-check to avoid synchronization issues
        if (!this.initialized) {
            
            /*
             * If a PBEConfig object has been set, we need to 
             * consider the values it returns (if, for each value, the
             * corresponding "setX" method has not been called).
             */
            if (this.config != null) {

                resolveConfigurationPassword();
                
                final String configAlgorithm = this.config.getAlgorithm();
                if (configAlgorithm != null) {
                    CommonUtils.validateNotEmpty(configAlgorithm, 
                            "Algorithm cannot be set empty");
                }
                
                final Integer configKeyObtentionIterations = 
                    this.config.getKeyObtentionIterations();
                if (configKeyObtentionIterations != null) {
                    CommonUtils.validateIsTrue(configKeyObtentionIterations.intValue() > 0, 
                            "Number of iterations for key obtention must be " +
                            "greater than zero");
                }
                
                final SaltGenerator configSaltGenerator = this.config.getSaltGenerator();

                final IvGenerator configIvGenerator = this.config.getIvGenerator();
                
                final String configProviderName = this.config.getProviderName();
                if (configProviderName != null) {
                    CommonUtils.validateNotEmpty(configProviderName,
                            "Provider name cannot be empty");
                }
                
                final Provider configProvider = this.config.getProvider();
                
                this.algorithm = 
                    ((this.algorithmSet) || (configAlgorithm == null))?
                            this.algorithm : configAlgorithm;
                this.keyObtentionIterations = 
                    ((this.iterationsSet) || 
                     (configKeyObtentionIterations == null))?
                            this.keyObtentionIterations : 
                            configKeyObtentionIterations.intValue();
                this.saltGenerator = 
                    ((this.saltGeneratorSet) || (configSaltGenerator == null))?
                            this.saltGenerator : configSaltGenerator;
                this.ivGenerator =
                        ((this.ivGeneratorSet) || (configIvGenerator == null))?
                                this.ivGenerator : configIvGenerator;
                this.providerName = 
                    ((this.providerNameSet) || (configProviderName == null))?
                            this.providerName : configProviderName;
                this.provider = 
                    ((this.providerSet) || (configProvider == null))?
                            this.provider : configProvider;
                
            }
            
            /*
             * If the encryptor was not set a salt generator in any way,
             * it is time to apply its default value.
             */
            if (this.saltGenerator == null) {
                this.saltGenerator = new RandomSaltGenerator();
            }

            /*
             * Default value is a no-op IV generator to maintain backwards compatibility
             */
            if (this.ivGenerator == null) {
                this.ivGenerator = new NoIvGenerator();
            }
            
            try {
            
                // Password cannot be null.
                if (this.password == null) {
                    throw new EncryptionInitializationException(
                            "Password not set for Password Based Encryptor");
                }
                
                // Normalize password to NFC form
                final char[] normalizedPassword = Normalizer.normalizeToNfc(this.password);
                
                /*
                 * Encryption and decryption Ciphers are created the usual way.
                 */
                final PBEKeySpec pbeKeySpec = new PBEKeySpec(normalizedPassword);
                
                // We don't need the char[] passwords anymore -> clean!
                cleanPassword(this.password);
                cleanPassword(normalizedPassword);
                
                
                if (this.provider != null) {
                    
                    final SecretKeyFactory factory =
                        SecretKeyFactory.getInstance(
                                this.algorithm, 
                                this.provider);
                    
                    this.key = factory.generateSecret(pbeKeySpec);
                    
                    this.encryptCipher = 
                        Cipher.getInstance(this.algorithm, this.provider);
                    this.decryptCipher = 
                        Cipher.getInstance(this.algorithm, this.provider);
                    
                } else if (this.providerName != null) {
                    
                    final SecretKeyFactory factory =
                        SecretKeyFactory.getInstance(
                                this.algorithm, 
                                this.providerName);
                    
                    this.key = factory.generateSecret(pbeKeySpec);
                    
                    this.encryptCipher = 
                        Cipher.getInstance(this.algorithm, this.providerName);
                    this.decryptCipher = 
                        Cipher.getInstance(this.algorithm, this.providerName);
                    
                } else {
                    
                    final SecretKeyFactory factory =
                        SecretKeyFactory.getInstance(this.algorithm);
                    
                    this.key = factory.generateSecret(pbeKeySpec);
                    
                    this.encryptCipher = Cipher.getInstance(this.algorithm);
                    this.decryptCipher = Cipher.getInstance(this.algorithm);
                    
                }

            } catch (EncryptionInitializationException e) {
                throw e;
            } catch (Throwable t) {
                throw new EncryptionInitializationException(t);
            }
            

            // The salt size and the IV size for the chosen algorithm are set to be equal
            // to the algorithm's block size (if it is a block algorithm).
            final int algorithmBlockSize = this.encryptCipher.getBlockSize();
            if (algorithmBlockSize > 0) {
                this.saltSizeBytes = algorithmBlockSize;
                this.ivSizeBytes = algorithmBlockSize;
            }
            
            
            this.optimizingDueFixedSalt = (this.saltGenerator instanceof FixedSaltGenerator)
                                            && (this.ivGenerator instanceof NoIvGenerator);
            
            if (this.optimizingDueFixedSalt) {
                
                // Create salt
                this.fixedSaltInUse = 
                    this.saltGenerator.generateSalt(this.saltSizeBytes);

                /*
                 * Initialize the Cipher objects themselves. Due to the fact that
                 * we will be using a fixed salt, this can be done just once, which
                 * means a better performance at the encrypt/decrypt methods. 
                 */
                
                final PBEParameterSpec parameterSpec = 
                    new PBEParameterSpec(this.fixedSaltInUse, this.keyObtentionIterations);

                try {
                    
                    this.encryptCipher.init(
                            Cipher.ENCRYPT_MODE, this.key, parameterSpec);
                    this.decryptCipher.init(
                            Cipher.DECRYPT_MODE, this.key, parameterSpec);
                    
                } catch (final Exception e) {
                    // If encryption fails, it is more secure not to return any 
                    // information about the cause in nested exceptions. Simply fail.
                    throw new EncryptionOperationNotPossibleException();
                }
                
                
            }
            
            
            this.initialized = true;
            
        }
        
    }


    
    private synchronized void resolveConfigurationPassword() {
        
        // Double-check to avoid synchronization issues
        if (!this.initialized) {
            
            if (this.config != null && !this.passwordSet) {
                
                // Get the configured password. If the config object implements
                // CleanablePassword, we get password directly as a char array
                // in order to avoid unnecessary creation of immutable Strings
                // containing such password.
                char[] configPassword = null;
                if (this.config instanceof PBECleanablePasswordConfig) {
                    configPassword = ((PBECleanablePasswordConfig)this.config).getPasswordCharArray();
                } else {
                    final String configPwd = this.config.getPassword();
                    if (configPwd != null) {
                        configPassword = configPwd.toCharArray();
                    }
                }

                if (configPassword != null) {
                    CommonUtils.validateIsTrue(configPassword.length > 0, 
                            "Password cannot be set empty");
                }

                if (configPassword != null) {
                    this.password = new char[configPassword.length];
                    System.arraycopy(configPassword, 0, this.password, 0, configPassword.length);
                    this.passwordSet = true;
                    cleanPassword(configPassword);
                }
                
                // Finally, clean the password at the configuration object
                if (this.config instanceof PBECleanablePasswordConfig) {
                    ((PBECleanablePasswordConfig)this.config).cleanPassword();
                }
                
                
            }
            
        }
        
    }

        
    
    private static void cleanPassword(final char[] password) {
        if (password != null) {
            synchronized (password) {
                final int pwdLength = password.length;
                for (int i = 0; i < pwdLength; i++) {
                    password[i] = (char)0;
                }
            }
        }
    }
    
    

    
Encrypts a message using the specified configuration.


The mechanisms applied to perform the encryption operation are described
in PKCS #5: Password-Based Cryptography Standard.


This encryptor uses a salt and IV for each encryption
operation. Sizes of the salt and IV depends on the algorithm
being used. The salt and the IV, if generated by a random generator,
they are also appended unencrypted at the beginning
of the results so that a decryption operation can be performed.


If a random salt generator is used, two encryption results for 
the same message will always be different
(except in the case of random salt coincidence). This may enforce
security by difficulting brute force attacks on sets of data at a time
and forcing attackers to perform a brute force attack on each separate
piece of encrypted data.
The same is applied if a random IV generator is used.

Params: message – the byte array message to be encrypted
Throws: EncryptionOperationNotPossibleException – if the encryption 
        operation fails, ommitting any further information about the
        cause for security reasons.
EncryptionInitializationException – if initialization could not
        be correctly done (for example, no password has been set).
Returns: the result of encryption/**
     * <p>
     * Encrypts a message using the specified configuration.
     * </p>
     * <p>
     * The mechanisms applied to perform the encryption operation are described
     * in <a href="http://www.rsasecurity.com/rsalabs/node.asp?id=2127" 
     * target="_blank">PKCS &#035;5: Password-Based Cryptography Standard</a>.
     * </p>
     * <p>
     * This encryptor uses a salt and IV for each encryption
     * operation. Sizes of the salt and IV depends on the algorithm
     * being used. The salt and the IV, if generated by a random generator,
     * they are also appended unencrypted at the beginning
     * of the results so that a decryption operation can be performed.
     * </p>
     * <p>
     * <b>If a random salt generator is used, two encryption results for 
     * the same message will always be different
     * (except in the case of random salt coincidence)</b>. This may enforce
     * security by difficulting brute force attacks on sets of data at a time
     * and forcing attackers to perform a brute force attack on each separate
     * piece of encrypted data.
     * The same is applied if a random IV generator is used.
     * </p>
     * 
     * @param message the byte array message to be encrypted
     * @return the result of encryption 
     * @throws EncryptionOperationNotPossibleException if the encryption 
     *         operation fails, ommitting any further information about the
     *         cause for security reasons.
     * @throws EncryptionInitializationException if initialization could not
     *         be correctly done (for example, no password has been set).
     */
    public byte[] encrypt(final byte[] message) 
            throws EncryptionOperationNotPossibleException {
        
        if (message == null) {
            return null;
        }
        
        // Check initialization
        if (!isInitialized()) {
            initialize();
        }
        
        try {

            final byte[] salt;
            byte[] iv = null;
            byte[] encryptedMessage;
            if (this.optimizingDueFixedSalt) {

                salt = this.fixedSaltInUse;
                
                synchronized (this.encryptCipher) {
                    encryptedMessage = this.encryptCipher.doFinal(message);
                }
                
            } else {
            
                // Create salt
                salt = this.saltGenerator.generateSalt(this.saltSizeBytes);

                // Create IV
                iv = this.ivGenerator.generateIv(this.ivSizeBytes);


                /*
                 * Perform encryption using the Cipher
                 */
                final PBEParameterSpec parameterSpec = buildPBEParameterSpec(salt, iv);
    
                synchronized (this.encryptCipher) {
                    this.encryptCipher.init(
                            Cipher.ENCRYPT_MODE, this.key, parameterSpec);
                    encryptedMessage = this.encryptCipher.doFinal(message);
                }
                
            }

            // We build an array containing both the unencrypted IV
            // and the result of the encryption. This is done only
            // if the IV generator we are using specifies to do so.
            if (this.ivGenerator.includePlainIvInEncryptionResults()) {

                // Insert plain IV before the encryption result
                encryptedMessage = CommonUtils.appendArrays(iv, encryptedMessage);

            }
            
            // Finally we build an array containing both the unencrypted salt
            // and the result of the encryption. This is done only
            // if the salt generator we are using specifies to do so.
            if (this.saltGenerator.includePlainSaltInEncryptionResults()) {
                
                // Insert unhashed salt before the encryption result
                encryptedMessage = CommonUtils.appendArrays(salt, encryptedMessage);
                
            }

            
            return encryptedMessage;
            
        } catch (final InvalidKeyException e) {
            // The problem could be not having the unlimited strength policies
            // installed, so better give a usefull error message.
            handleInvalidKeyException(e);
            throw new EncryptionOperationNotPossibleException();
        } catch (final Exception e) {
            // If encryption fails, it is more secure not to return any 
            // information about the cause in nested exceptions. Simply fail.
            throw new EncryptionOperationNotPossibleException();
        }
        
    }


    
Decrypts a message using the specified configuration.


The mechanisms applied to perform the decryption operation are described
in PKCS #5: Password-Based Cryptography Standard.


If a random salt generator is used, this decryption operation will
expect to find an unencrypted salt at the 
beginning of the encrypted input, so that the decryption operation can be
correctly performed (there is no other way of knowing it).


If a random IV generator is used, this decryption operation will
expect to find an unencrypted IV at the
beginning of the encrypted input, so that the decryption operation can be
correctly performed (there is no other way of knowing it).

Params: encryptedMessage – the byte array message to be decrypted
Throws: EncryptionOperationNotPossibleException – if the decryption 
        operation fails, ommitting any further information about the
        cause for security reasons.
EncryptionInitializationException – if initialization could not
        be correctly done (for example, no password has been set).
Returns: the result of decryption/**
     * <p>
     * Decrypts a message using the specified configuration.
     * </p>
     * <p>
     * The mechanisms applied to perform the decryption operation are described
     * in <a href="http://www.rsasecurity.com/rsalabs/node.asp?id=2127" 
     * target="_blank">PKCS &#035;5: Password-Based Cryptography Standard</a>.
     * </p>
     * <p>
     * If a random salt generator is used, this decryption operation will
     * expect to find an unencrypted salt at the 
     * beginning of the encrypted input, so that the decryption operation can be
     * correctly performed (there is no other way of knowing it).
     * </p>
     * <p>
     * If a random IV generator is used, this decryption operation will
     * expect to find an unencrypted IV at the
     * beginning of the encrypted input, so that the decryption operation can be
     * correctly performed (there is no other way of knowing it).
     * </p>
     *
     * @param encryptedMessage the byte array message to be decrypted
     * @return the result of decryption 
     * @throws EncryptionOperationNotPossibleException if the decryption 
     *         operation fails, ommitting any further information about the
     *         cause for security reasons.
     * @throws EncryptionInitializationException if initialization could not
     *         be correctly done (for example, no password has been set).
     */
    public byte[] decrypt(final byte[] encryptedMessage) 
            throws EncryptionOperationNotPossibleException {
        
        if (encryptedMessage == null) {
            return null;
        }
        
        // Check initialization
        if (!isInitialized()) {
            initialize();
        }


        if (this.saltGenerator.includePlainSaltInEncryptionResults()
                && this.ivGenerator.includePlainIvInEncryptionResults()) {
            // Check that the received message is bigger than the salt + IV
            if (encryptedMessage.length <= this.saltSizeBytes + this.ivSizeBytes) {
                throw new EncryptionOperationNotPossibleException();
            }
        } else if (this.saltGenerator.includePlainSaltInEncryptionResults()) {
            // Check that the received message is bigger than the salt
            if (encryptedMessage.length <= this.saltSizeBytes) {
                throw new EncryptionOperationNotPossibleException();
            }
        } else if (this.ivGenerator.includePlainIvInEncryptionResults()) {
            // Check that the received message is bigger than the IV
            if (encryptedMessage.length <= this.ivSizeBytes) {
                throw new EncryptionOperationNotPossibleException();
            }
        }


        try {

            // If we are using a salt generator which specifies the salt
            // to be included into the encrypted message itself, get it from 
            // there. If not, the salt is supposed to be fixed and thus the
            // salt generator can be safely asked for it again.
            byte[] salt = null; 
            byte[] encryptedMessageKernel = null; 
            if (this.saltGenerator.includePlainSaltInEncryptionResults()) {
                
                final int saltStart = 0;
                final int saltSize = 
                    (this.saltSizeBytes < encryptedMessage.length? this.saltSizeBytes : encryptedMessage.length);
                final int encMesKernelStart =
                    (this.saltSizeBytes < encryptedMessage.length? this.saltSizeBytes : encryptedMessage.length);
                final int encMesKernelSize = 
                    (this.saltSizeBytes < encryptedMessage.length? (encryptedMessage.length - this.saltSizeBytes) : 0);
                
                salt = new byte[saltSize];
                encryptedMessageKernel = new byte[encMesKernelSize];
                
                System.arraycopy(encryptedMessage, saltStart, salt, 0, saltSize);
                System.arraycopy(encryptedMessage, encMesKernelStart, encryptedMessageKernel, 0, encMesKernelSize);
                
            } else if (!this.optimizingDueFixedSalt){
                
                salt = this.saltGenerator.generateSalt(this.saltSizeBytes);
                encryptedMessageKernel = encryptedMessage;
                
            } else {
                // this.optimizingDueFixedSalt == true
                
                salt = this.fixedSaltInUse;
                encryptedMessageKernel = encryptedMessage;
                
            }

            byte[] iv = null;
            byte[] finalEncryptedMessageKernel = null;
            if (this.ivGenerator.includePlainIvInEncryptionResults()) {

                final int ivStart = 0;
                final int ivSize =
                        (this.ivSizeBytes < encryptedMessageKernel.length? this.ivSizeBytes : encryptedMessageKernel.length);
                final int encMesKernelStart =
                        (this.ivSizeBytes < encryptedMessageKernel.length? this.ivSizeBytes : encryptedMessageKernel.length);
                final int encMesKernelSize =
                        (this.ivSizeBytes < encryptedMessageKernel.length? (encryptedMessageKernel.length - this.ivSizeBytes) : 0);

                iv = new byte[ivSize];
                finalEncryptedMessageKernel = new byte[encMesKernelSize];

                System.arraycopy(encryptedMessageKernel, ivStart, iv, 0, ivSize);
                System.arraycopy(encryptedMessageKernel, encMesKernelStart, finalEncryptedMessageKernel, 0, encMesKernelSize);

            } else {
                iv = ivGenerator.generateIv(ivSizeBytes);
                finalEncryptedMessageKernel = encryptedMessageKernel;

            }
            

            final byte[] decryptedMessage;
            if (this.optimizingDueFixedSalt) {
                
                /*
                 * Fixed salt is being used, therefore no initialization supposedly needed
                 */
                synchronized (this.decryptCipher) {
                    decryptedMessage = 
                        this.decryptCipher.doFinal(finalEncryptedMessageKernel);
                }

            } else {
                
                /*
                 * Perform decryption using the Cipher
                 */
                final PBEParameterSpec parameterSpec = buildPBEParameterSpec(salt, iv);
                     
                synchronized (this.decryptCipher) {
                    this.decryptCipher.init(
                            Cipher.DECRYPT_MODE, this.key, parameterSpec);
                    decryptedMessage = 
                        this.decryptCipher.doFinal(finalEncryptedMessageKernel);
                }

            }
            
            // Return the results
            return decryptedMessage;
            
        } catch (final InvalidKeyException e) {
            // The problem could be not having the unlimited strength policies
            // installed, so better give a usefull error message.
            handleInvalidKeyException(e);
            throw new EncryptionOperationNotPossibleException();
        } catch (final Exception e) {
            // If decryption fails, it is more secure not to return any 
            // information about the cause in nested exceptions. Simply fail.
            throw new EncryptionOperationNotPossibleException();
        }
        
    }    


    private PBEParameterSpec buildPBEParameterSpec(final byte[] salt, final byte[] iv) {

        PBEParameterSpec parameterSpec;

        try {
            Class[] parameters = {byte[].class, int.class, AlgorithmParameterSpec.class};
            Constructor<PBEParameterSpec> java8Constructor = PBEParameterSpec.class.getConstructor(parameters);

            Object[] parameterValues = {salt, this.keyObtentionIterations, new IvParameterSpec(iv)};

            parameterSpec = java8Constructor.newInstance(parameterValues);

        } catch (Exception e) {
            parameterSpec = new PBEParameterSpec(salt, this.keyObtentionIterations);
        }

        return parameterSpec;

    }

    /*
     * Method used to provide an useful error message in the case that the
     * user tried to use a strong PBE algorithm like TripleDES and he/she
     * has not installed the Unlimited Strength Policy files (the default
     * message for this is simply "invalid key size", which does not provide
     * enough clues for the user to know what is really going on).
     */
    private void handleInvalidKeyException(final InvalidKeyException e) {

        if ((e.getMessage() != null) && 
                ((e.getMessage().toUpperCase().indexOf("KEY SIZE") != -1))) {
            
            throw new EncryptionOperationNotPossibleException(
                    "Encryption raised an exception. A possible cause is " +
                    "you are using strong encryption algorithms and " +
                    "you have not installed the Java Cryptography " + 
                    "Extension (JCE) Unlimited Strength Jurisdiction " +
                    "Policy Files in this Java Virtual Machine");
            
        }
        
    }
    
}
Params:	providerName – the name of the security provider to be asked for the encryption algorithm.
Since:	1.3
Params:	provider – the provider to be asked for the chosen algorithm
Since:	1.3
Params:	message – the byte array message to be encrypted
Throws:	EncryptionOperationNotPossibleException – if the encryption operation fails, ommitting any further information about the cause for security reasons. EncryptionInitializationException – if initialization could not be correctly done (for example, no password has been set).
Returns:	the result of encryption
Params:	encryptedMessage – the byte array message to be decrypted
Throws:	EncryptionOperationNotPossibleException – if the decryption operation fails, ommitting any further information about the cause for security reasons. EncryptionInitializationException – if initialization could not be correctly done (for example, no password has been set).
Returns:	the result of decryption
/

org.jasypt/ jasypt/ 1.9.3/ org/jasypt/encryption/pbe/StandardPBEByteEncryptor.java
