/*
 * Copyright (c) 2000, 2010, 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.ktab;

import sun.security.krb5.internal.*;
import sun.security.krb5.PrincipalName;
import sun.security.krb5.Realm;
import sun.security.krb5.RealmException;
import sun.security.krb5.internal.util.KrbDataInputStream;
import java.io.IOException;
import java.io.InputStream;

This class implements a buffered input stream. It is used for parsing key table data to memory.
Author:Yanni Zhang
/** * This class implements a buffered input stream. It is used for parsing key table * data to memory. * * @author Yanni Zhang * */
public class KeyTabInputStream extends KrbDataInputStream implements KeyTabConstants { boolean DEBUG = Krb5.DEBUG; int index; public KeyTabInputStream(InputStream is) { super(is); }
Reads the number of bytes this entry data occupy.
/** * Reads the number of bytes this entry data occupy. */
int readEntryLength() throws IOException { return read(4); } KeyTabEntry readEntry(int entryLen, int ktVersion) throws IOException, RealmException { index = entryLen; if (index == 0) { //in native implementation, when the last entry is deleted, a byte 0 is left. return null; } if (index < 0) { //in native implementation, when one of the entries is deleted, the entry length turns to be negative, and skip(Math.abs(index)); //the fields are left with 0 bytes return null; } int principalNum = read(2); //the number of service names. index -= 2; if (ktVersion == KRB5_KT_VNO_1) { //V1 includes realm in the count. principalNum -= 1; } Realm realm = new Realm(readName()); String[] nameParts = new String[principalNum]; for (int i = 0; i < principalNum; i++) { nameParts[i] = readName(); } int nameType = read(4); index -= 4; PrincipalName service = new PrincipalName(nameType, nameParts, realm); KerberosTime timeStamp = readTimeStamp(); int keyVersion = read() & 0xff; index -= 1; int keyType = read(2); index -= 2; int keyLength = read(2); index -= 2; byte[] keyblock = readKey(keyLength); index -= keyLength; // There might be a 32 bit kvno here. // If index is zero, assume that the 8 bit key version number was // right, otherwise trust the new nonzero value. if (index >= 4) { int extKvno = read(4); if (extKvno != 0) { keyVersion = extKvno; } index -= 4; } // if index is negative, the keytab format must be wrong. if (index < 0) { throw new RealmException("Keytab is corrupted"); } // ignore the left bytes. skip(index); return new KeyTabEntry(service, realm, timeStamp, keyVersion, keyType, keyblock); } byte[] readKey(int length) throws IOException { byte[] bytes = new byte[length]; read(bytes, 0, length); return bytes; } KerberosTime readTimeStamp() throws IOException { index -= 4; return new KerberosTime((long)read(4) * 1000); } String readName() throws IOException { String name; int length = read(2); //length of the realm name or service name index -= 2; byte[] bytes = new byte[length]; read(bytes, 0, length); index -= length; name = new String(bytes); if (DEBUG) { System.out.println(">>> KeyTabInputStream, readName(): " + name); } return name; } }