http://www.jasypt.org: Java library which enables encryption in java apps with minimum effort. (The JASYPT team)
  • Daniel Fernandez 
/*
 * =============================================================================
 * 
 *   Copyright (c) 2019, 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.iv;



Common interface for all initialization vector (IV) generators which can be applied in
encryption operations.




Every implementation of this interface must be thread-safe.



Author:Hoki Torres
Since:1.9.3
/**
 * <p>
 * Common interface for all initialization vector (IV) generators which can be applied in
 * encryption operations.
 * </p>
 * <p>
 * <b>Every implementation of this interface must be thread-safe</b>.
 * </p>
 * 
 * @since 1.9.3
 * 
 * @author Hoki Torres
 * 
 */
public interface IvGenerator {

    

This method will be called for requesting the generation of a new
IV of the specified length.



Params:
  • lengthBytes – the requested length for the IV.
Returns:the generated IV.
/**
     * <p>
     * This method will be called for requesting the generation of a new
     * IV of the specified length.
     * </p>
     * 
     * @param lengthBytes the requested length for the IV.
     * @return the generated IV.
     */
    public byte[] generateIv(int lengthBytes);
    
    
    

Determines if the encrypted messages created with a
specific IV generator will include (prepended) the unencrypted
IV itself, so that it can be used for decryption
operations.




Generally, including the IV unencrypted in encryption results will
be mandatory for randomly generated IV, or for those generated in a
non-predictable manner.
Otherwise, decryption operations will always fail.
For fixed IV, inclusion will be optional (and in fact undesirable
if we want to hide the IV value).

    

Returns:whether the plain (unencrypted) IV has to be included in
        encryption results or not.
/**
     * <p>
     * Determines if the encrypted messages created with a
     * specific IV generator will include (prepended) the unencrypted
     * IV itself, so that it can be used for decryption
     * operations.
     * </p>
     * <p>
     * Generally, including the IV unencrypted in encryption results will
     * be mandatory for randomly generated IV, or for those generated in a
     * non-predictable manner.
     * Otherwise, decryption operations will always fail.
     * For fixed IV, inclusion will be optional (and in fact undesirable
     * if we want to hide the IV value).
     * </p>    
     * 
     * @return whether the plain (unencrypted) IV has to be included in
     *         encryption results or not.
     */
    public boolean includePlainIvInEncryptionResults();

    
}