de.schlichtherle.key.PromptingAesKeyProvider Maven / Gradle / Ivy
/*
* Copyright (C) 2006-2010 Schlichtherle IT Services
*
* 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 de.schlichtherle.key;
/**
* An implementation of {@link AesKeyProvider} which prompts the user for
* a key and allows to select the cipher key strength when creating a new
* AES encrypted resource or replacing the entire contents of an already
* existing AES encrypted resource.
*
* This class is thread safe.
*
* @author Christian Schlichtherle
* @version $Id: PromptingAesKeyProvider.java,v 1.3 2010/08/16 10:55:46 christian_schlichtherle Exp $
* @since TrueZIP 6.0
*/
public class PromptingAesKeyProvider
extends PromptingKeyProvider
implements AesKeyProvider {
private int keyStrength = KEY_STRENGTH_256;
public int getKeyStrength() {
assert keyStrength == KEY_STRENGTH_128
|| keyStrength == KEY_STRENGTH_192
|| keyStrength == KEY_STRENGTH_256;
return keyStrength;
}
public void setKeyStrength(int keyStrength) {
if (keyStrength != KEY_STRENGTH_128
&& keyStrength != KEY_STRENGTH_192
&& keyStrength != KEY_STRENGTH_256)
throw new IllegalArgumentException();
this.keyStrength = keyStrength;
}
protected String getUIClassID() {
return "PromptingAesKeyProvider";
}
/**
* Resets the key strength to 256 bits.
*/
protected void onReset() {
keyStrength = KEY_STRENGTH_256;
}
/**
* Returns the current key strength.
*/
public String toString() {
return "" + (128 + keyStrength * 64);
}
}