FilenameEncryptionStrategy.java

/*
 * EncFS Java Library
 * Copyright (C) 2013 encfs-java authors
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published
 * by the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program 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 Lesser General Public License for more details.
 */
package org.mrpdaemon.sec.encfs;


/**
 * Common class for all filename encryption strategies.
 */
abstract class FilenameEncryptionStrategy {

    private final EncFSVolume volume;

    private final String volumePath;

    private final EncFSFilenameEncryptionAlgorithm algorithm;


    String getVolumePath() {
        return volumePath;
    }


    EncFSVolume getVolume() {
        return volume;
    }


    FilenameEncryptionStrategy(EncFSVolume volume, String volumePath,
            EncFSFilenameEncryptionAlgorithm algorithm) {
        this.volume = volume;
        this.volumePath = volumePath;
        this.algorithm = algorithm;
    }


    // Encryption implementation to be provided by subclass

    protected abstract String encryptImpl(String fileName)
            throws EncFSCorruptDataException;


    // Encrypt the given filename

    public String encrypt(String filename) throws EncFSCorruptDataException {
        if (volume.getConfig().getFilenameAlgorithm()!=algorithm) {
            throw new IllegalStateException(
                    "only accessable when algorithm is "+algorithm);
        }

        return encryptImpl(filename);
    }

}