| /* |
| * Copyright (c) 2000, 2005, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| /* |
| * |
| * (C) Copyright IBM Corp. 1999 All Rights Reserved. |
| * Copyright 1997 The Open Group Research Institute. All rights reserved. |
| */ |
| |
| package sun.security.krb5.internal.util; |
| |
| import java.io.BufferedInputStream; |
| import java.io.InputStream; |
| import java.io.IOException; |
| |
| /** |
| * This class implements a buffered input stream. It provides methods to read a chunck |
| * of data from underlying data stream. |
| * |
| * @author Yanni Zhang |
| * |
| */ |
| public class KrbDataInputStream extends BufferedInputStream{ |
| private boolean bigEndian = true; |
| |
| public void setNativeByteOrder() { |
| if (java.nio.ByteOrder.nativeOrder(). |
| equals(java.nio.ByteOrder.BIG_ENDIAN)) { |
| bigEndian = true; |
| } else { |
| bigEndian = false; |
| } |
| } |
| public KrbDataInputStream(InputStream is){ |
| super(is); |
| } |
| |
| /** |
| * Reads a length value which is represented in 4 bytes from |
| * this input stream. The value must be positive. |
| * @return the length value represented by this byte array. |
| * @throws IOException if there are not enough bytes or it represents |
| * a negative value |
| */ |
| final public int readLength4() throws IOException { |
| int len = read(4); |
| if (len < 0) { |
| throw new IOException("Invalid encoding"); |
| } |
| return len; |
| } |
| |
| /** |
| * Reads up to the specific number of bytes from this input stream. |
| * @param num the number of bytes to be read. |
| * @return the int value of this byte array. |
| * @throws IOException if there are not enough bytes |
| */ |
| public int read(int num) throws IOException { |
| byte[] bytes = new byte[num]; |
| if (read(bytes, 0, num) != num) { |
| throw new IOException("Premature end of stream reached"); |
| } |
| int result = 0; |
| for (int i = 0; i < num; i++) { |
| if (bigEndian) { |
| result |= (bytes[i] & 0xff) << (num - i - 1) * 8; |
| } else { |
| result |= (bytes[i] & 0xff) << i * 8; |
| } |
| } |
| return result; |
| } |
| |
| public int readVersion() throws IOException { |
| // always read in big-endian mode |
| int result = (read() & 0xff) << 8; |
| return result | (read() & 0xff); |
| } |
| } |