net.schmizz.sshj.transport.random.JCERandom Maven / Gradle / Ivy
/*
* Copyright 2010 Shikhar Bhushan
*
* 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.
*
* This file may incorporate work covered by the following copyright and
* permission notice:
*
* 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 net.schmizz.sshj.transport.random;
import java.security.SecureRandom;
/** A {@link Random} implementation using the built-in {@link SecureRandom} PRNG. */
public class JCERandom
implements Random {
/** Named factory for the JCE {@link Random} */
public static class Factory
implements net.schmizz.sshj.common.Factory.Named {
@Override
public Random create() {
return new JCERandom();
}
@Override
public String getName() {
return "default";
}
}
private byte[] tmp = new byte[16];
private SecureRandom random = null;
public JCERandom() {
random = new SecureRandom();
}
/**
* Fill the given byte-array with random bytes from this PRNG.
*
* @param foo the byte-array
* @param start the offset to start at
* @param len the number of bytes to fill
*/
@Override
public synchronized void fill(byte[] foo, int start, int len) {
if (start == 0 && len == foo.length)
random.nextBytes(foo);
else
synchronized (this) {
if (len > tmp.length)
tmp = new byte[len];
random.nextBytes(tmp);
System.arraycopy(tmp, 0, foo, start, len);
}
}
}