/*
* 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
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/*
* (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
*
*/
public class KeyTabInputStream extends KrbDataInputStream implements KeyTabConstants {
boolean DEBUG = Krb5.DEBUG;
static int index;
public KeyTabInputStream(InputStream is) {
super(is);
}
/**
* 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(nameParts, nameType);
service.setRealm(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;
}
}