| /** |
| * 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 org.apache.hadoop.crypto.random; |
| |
| import java.io.Closeable; |
| import java.io.File; |
| import java.io.FileInputStream; |
| import java.io.IOException; |
| import java.util.Random; |
| |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.conf.Configurable; |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.io.IOUtils; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| import static org.apache.hadoop.fs.CommonConfigurationKeysPublic.HADOOP_SECURITY_SECURE_RANDOM_DEVICE_FILE_PATH_KEY; |
| import static org.apache.hadoop.fs.CommonConfigurationKeysPublic.HADOOP_SECURITY_SECURE_RANDOM_DEVICE_FILE_PATH_DEFAULT; |
| |
| /** |
| * A Random implementation that uses random bytes sourced from the |
| * operating system. |
| */ |
| @InterfaceAudience.Private |
| public class OsSecureRandom extends Random implements Closeable, Configurable { |
| public static final Logger LOG = |
| LoggerFactory.getLogger(OsSecureRandom.class); |
| |
| private static final long serialVersionUID = 6391500337172057900L; |
| |
| private transient Configuration conf; |
| |
| private final int RESERVOIR_LENGTH = 8192; |
| |
| private String randomDevPath; |
| |
| private transient FileInputStream stream; |
| |
| private final byte[] reservoir = new byte[RESERVOIR_LENGTH]; |
| |
| private int pos = reservoir.length; |
| |
| private void fillReservoir(int min) { |
| if (pos >= reservoir.length - min) { |
| try { |
| if (stream == null) { |
| stream = new FileInputStream(new File(randomDevPath)); |
| } |
| IOUtils.readFully(stream, reservoir, 0, reservoir.length); |
| } catch (IOException e) { |
| throw new RuntimeException("failed to fill reservoir", e); |
| } |
| pos = 0; |
| } |
| } |
| |
| public OsSecureRandom() { |
| } |
| |
| @Override |
| synchronized public void setConf(Configuration conf) { |
| this.conf = conf; |
| this.randomDevPath = conf.get( |
| HADOOP_SECURITY_SECURE_RANDOM_DEVICE_FILE_PATH_KEY, |
| HADOOP_SECURITY_SECURE_RANDOM_DEVICE_FILE_PATH_DEFAULT); |
| close(); |
| } |
| |
| @Override |
| synchronized public Configuration getConf() { |
| return conf; |
| } |
| |
| @Override |
| synchronized public void nextBytes(byte[] bytes) { |
| int off = 0; |
| int n = 0; |
| while (off < bytes.length) { |
| fillReservoir(0); |
| n = Math.min(bytes.length - off, reservoir.length - pos); |
| System.arraycopy(reservoir, pos, bytes, off, n); |
| off += n; |
| pos += n; |
| } |
| } |
| |
| @Override |
| synchronized protected int next(int nbits) { |
| fillReservoir(4); |
| int n = 0; |
| for (int i = 0; i < 4; i++) { |
| n = ((n << 8) | (reservoir[pos++] & 0xff)); |
| } |
| return n & (0xffffffff >> (32 - nbits)); |
| } |
| |
| @Override |
| synchronized public void close() { |
| if (stream != null) { |
| IOUtils.cleanupWithLogger(LOG, stream); |
| stream = null; |
| } |
| } |
| |
| @Override |
| protected void finalize() throws Throwable { |
| close(); |
| } |
| } |