javax.crypto.spec.PBEKeySpec Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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 javax.crypto.spec;
import java.security.spec.KeySpec;
import java.util.Arrays;
import libcore.util.EmptyArray;
/**
* The key specification for a password based encryption key.
*
* Password based encryption is described in PKCS #5.
*/
public class PBEKeySpec implements KeySpec {
private char[] password;
private final byte[] salt;
private final int iterationCount;
private final int keyLength;
/**
* Creates a new PBEKeySpec with the specified password.
*
* @param password
* the password.
*/
public PBEKeySpec(char[] password) {
if (password == null) {
this.password = EmptyArray.CHAR;
} else {
this.password = new char[password.length];
System.arraycopy(password, 0, this.password, 0, password.length);
}
salt = null;
iterationCount = 0;
keyLength = 0;
}
/**
* Creates a new PBEKeySpec with the specified password, salt,
* iteration count and the desired length of the derived key.
*
* @param password
* the password.
* @param salt
* the salt.
* @param iterationCount
* the iteration count.
* @param keyLength
* the desired key length of the derived key,
* @throws NullPointerException
* if the salt is null.
* @throws IllegalArgumentException
* if the salt is empty, iteration count is zero or negative or
* the key length is zero or negative.
*/
public PBEKeySpec(char[] password, byte[] salt, int iterationCount,
int keyLength) {
if (salt == null) {
throw new NullPointerException("salt == null");
}
if (salt.length == 0) {
throw new IllegalArgumentException("salt.length == 0");
}
if (iterationCount <= 0) {
throw new IllegalArgumentException("iterationCount <= 0");
}
if (keyLength <= 0) {
throw new IllegalArgumentException("keyLength <= 0");
}
if (password == null) {
this.password = EmptyArray.CHAR;
} else {
this.password = new char[password.length];
System.arraycopy(password, 0, this.password, 0, password.length);
}
this.salt = new byte[salt.length];
System.arraycopy(salt, 0, this.salt, 0, salt.length);
this.iterationCount = iterationCount;
this.keyLength = keyLength;
}
/**
* Creates a new PBEKeySpec with the specified password, salt
* and iteration count.
*
* @param password
* the password.
* @param salt
* the salt.
* @param iterationCount
* the iteration count.
* @throws NullPointerException
* if salt is null.
* @throws IllegalArgumentException
* if the salt is empty or iteration count is zero or negative.
*/
public PBEKeySpec(char[] password, byte[] salt, int iterationCount) {
if (salt == null) {
throw new NullPointerException("salt == null");
}
if (salt.length == 0) {
throw new IllegalArgumentException("salt.length == 0");
}
if (iterationCount <= 0) {
throw new IllegalArgumentException("iterationCount <= 0");
}
if (password == null) {
this.password = EmptyArray.CHAR;
} else {
this.password = new char[password.length];
System.arraycopy(password, 0, this.password, 0, password.length);
}
this.salt = new byte[salt.length];
System.arraycopy(salt, 0, this.salt, 0, salt.length);
this.iterationCount = iterationCount;
this.keyLength = 0;
}
/**
* Clears the password by overwriting it.
*/
public final void clearPassword() {
Arrays.fill(password, '?');
password = null;
}
/**
* Returns a copy of the password of this key specification.
*
* @return a copy of the password of this key specification.
* @throws IllegalStateException
* if the password has been cleared before.
*/
public final char[] getPassword() {
if (password == null) {
throw new IllegalStateException("The password has been cleared");
}
char[] result = new char[password.length];
System.arraycopy(password, 0, result, 0, password.length);
return result;
}
/**
* Returns a copy of the salt of this key specification.
*
* @return a copy of the salt of this key specification or null if none is
* specified.
*/
public final byte[] getSalt() {
if (salt == null) {
return null;
}
byte[] result = new byte[salt.length];
System.arraycopy(salt, 0, result, 0, salt.length);
return result;
}
/**
* Returns the iteration count of this key specification.
*
* @return the iteration count of this key specification.
*/
public final int getIterationCount() {
return iterationCount;
}
/**
* Returns the desired key length of the derived key.
*
* @return the desired key length of the derived key.
*/
public final int getKeyLength() {
return keyLength;
}
}