| /* |
| * Copyright (c) 2000, 2007, 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; |
| |
| import sun.security.krb5.Confounder; |
| |
| public class LocalSeqNumber implements SeqNumber { |
| private int lastSeqNumber; |
| |
| public LocalSeqNumber() { |
| randInit(); |
| } |
| |
| public LocalSeqNumber(int start) { |
| init(start); |
| } |
| |
| public LocalSeqNumber(Integer start) { |
| init(start.intValue()); |
| } |
| |
| public synchronized void randInit() { |
| /* |
| * Sequence numbers fall in the range 0 through 2^32 - 1 and wrap |
| * to zero following the value 2^32 - 1. |
| * Previous implementations used signed sequence numbers. |
| * Workaround implementation incompatibilities by not generating |
| * initial sequence numbers greater than 2^30, as done |
| * in MIT distribution. |
| */ |
| // get the random confounder |
| byte[] data = Confounder.bytes(4); |
| data[0] = (byte)(data[0] & 0x3f); |
| int result = ((data[3] & 0xff) | |
| ((data[2] & 0xff) << 8) | |
| ((data[1] & 0xff) << 16) | |
| ((data[0] & 0xff) << 24)); |
| if (result == 0) { |
| result = 1; |
| } |
| lastSeqNumber = result; |
| } |
| |
| public synchronized void init(int start) { |
| lastSeqNumber = start; |
| } |
| |
| public synchronized int current() { |
| return lastSeqNumber; |
| } |
| |
| public synchronized int next() { |
| return lastSeqNumber + 1; |
| } |
| |
| public synchronized int step() { |
| return ++lastSeqNumber; |
| } |
| |
| } |