keith-turner commented on a change in pull request #300: ACCUMULO-4708 Limit RFile block size to 2GB URL: https://github.com/apache/accumulo/pull/300#discussion_r147172071
########## File path: core/src/main/java/org/apache/accumulo/core/security/crypto/RFileCipherOutputStream.java ########## @@ -0,0 +1,95 @@ +/* + * 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.accumulo.core.security.crypto; + +import java.io.IOException; +import java.io.OutputStream; + +import javax.crypto.Cipher; +import javax.crypto.CipherOutputStream; + +/** + * + * This class extends {@link CipherOutputStream} to include a way to track the number of bytes that have + * been encrypted by the stream. The write method also includes a mechanism to stop writing and + * throw an exception if exceeding a maximum number of bytes is attempted. + * + */ +public class RFileCipherOutputStream extends CipherOutputStream { + + // This is the maximum size encrypted stream that can be written. Attempting to write anything larger + // will cause an exception. Given that each block in an rfile is encrypted separately, and blocks + // should be written such that a block cannot ever reach 16GiB, this is believed to be a safe number. + // If this does cause an exception, it is an issue best addressed elsewhere. + private final long maxOutputSize = 1L << 34; //16GiB + + // the cipher engine to use to process stream data + private Cipher cipher; + + // the underlying output stream + private OutputStream output; + + // the buffer holding data ready to be written out + private byte[] obuffer; + + // The total number of bytes that have been written out + private long count = 0; + + /** + * + * Constructs a RFileCipherOutputStream + * + * @param os + * the OutputStream object + * @param c + * an initialized Cipher object + */ + public RFileCipherOutputStream(OutputStream os, Cipher c) { + super(os, c); + output = os; + cipher = c; + } + + /** + * Override of CipherOutputStream's write to count the number of bytes that have been encrypted. + * This method now throws an exception if an attempt to write bytes beyond a maximum is made. + * + * Writes <code>len</code> bytes from the specified byte array starting at offset <code>off</code> to this output stream. + * + * @param b + * the data. + * @param off + * the start offset in the data. + * @param len + * the number of bytes to write. + * @exception IOException + * if an I/O error occurs. + * @since JCE1.2 + */ + @Override + public void write(byte b[], int off, int len) throws IOException { + count += len; + if (count > maxOutputSize) { + throw new IOException("Attempt to write " + count + " bytes was made. A maximum of " + maxOutputSize + " is allowed for an encryption stream."); + } + obuffer = cipher.update(b, off, len); Review comment: can you call super.write here? ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services
