Java example source code file (Config.java)
The Config.java Java example source code
/*
* Copyright (c) 2000, 2013, 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;
import java.io.File;
import java.io.FileInputStream;
import java.util.Hashtable;
import java.util.Vector;
import java.util.ArrayList;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.IOException;
import java.util.StringTokenizer;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.security.AccessController;
import java.security.PrivilegedExceptionAction;
import java.util.Arrays;
import java.util.List;
import java.util.Locale;
import sun.net.dns.ResolverConfiguration;
import sun.security.krb5.internal.crypto.EType;
import sun.security.krb5.internal.Krb5;
/**
* This class maintains key-value pairs of Kerberos configurable constants
* from configuration file or from user specified system properties.
*/
public class Config {
/*
* Only allow a single instance of Config.
*/
private static Config singleton = null;
/*
* Hashtable used to store configuration information.
*/
private Hashtable<String,Object> stanzaTable = new Hashtable<>();
private static boolean DEBUG = sun.security.krb5.internal.Krb5.DEBUG;
// these are used for hexdecimal calculation.
private static final int BASE16_0 = 1;
private static final int BASE16_1 = 16;
private static final int BASE16_2 = 16 * 16;
private static final int BASE16_3 = 16 * 16 * 16;
/**
* Specified by system properties. Must be both null or non-null.
*/
private final String defaultRealm;
private final String defaultKDC;
// used for native interface
private static native String getWindowsDirectory(boolean isSystem);
/**
* Gets an instance of Config class. One and only one instance (the
* singleton) is returned.
*
* @exception KrbException if error occurs when constructing a Config
* instance. Possible causes would be either of java.security.krb5.realm or
* java.security.krb5.kdc not specified, error reading configuration file.
*/
public static synchronized Config getInstance() throws KrbException {
if (singleton == null) {
singleton = new Config();
}
return singleton;
}
/**
* Refresh and reload the Configuration. This could involve,
* for example reading the Configuration file again or getting
* the java.security.krb5.* system properties again. This method
* also tries its best to update static fields in other classes
* that depend on the configuration.
*
* @exception KrbException if error occurs when constructing a Config
* instance. Possible causes would be either of java.security.krb5.realm or
* java.security.krb5.kdc not specified, error reading configuration file.
*/
public static synchronized void refresh() throws KrbException {
singleton = new Config();
KdcComm.initStatic();
EType.initStatic();
Checksum.initStatic();
}
private static boolean isMacosLionOrBetter() {
// split the "10.x.y" version number
String osname = getProperty("os.name");
if (!osname.contains("OS X")) {
return false;
}
String osVersion = getProperty("os.version");
String[] fragments = osVersion.split("\\.");
// sanity check the "10." part of the version
if (!fragments[0].equals("10")) return false;
if (fragments.length < 2) return false;
// check if Mac OS X 10.7(.y)
try {
int minorVers = Integer.parseInt(fragments[1]);
if (minorVers >= 7) return true;
} catch (NumberFormatException e) {
// was not an integer
}
return false;
}
/**
* Private constructor - can not be instantiated externally.
*/
private Config() throws KrbException {
/*
* If either one system property is specified, we throw exception.
*/
String tmp = getProperty("java.security.krb5.kdc");
if (tmp != null) {
// The user can specify a list of kdc hosts separated by ":"
defaultKDC = tmp.replace(':', ' ');
} else {
defaultKDC = null;
}
defaultRealm = getProperty("java.security.krb5.realm");
if ((defaultKDC == null && defaultRealm != null) ||
(defaultRealm == null && defaultKDC != null)) {
throw new KrbException
("System property java.security.krb5.kdc and " +
"java.security.krb5.realm both must be set or " +
"neither must be set.");
}
// Always read the Kerberos configuration file
try {
List<String> configFile;
String fileName = getJavaFileName();
if (fileName != null) {
configFile = loadConfigFile(fileName);
stanzaTable = parseStanzaTable(configFile);
if (DEBUG) {
System.out.println("Loaded from Java config");
}
} else {
boolean found = false;
if (isMacosLionOrBetter()) {
try {
stanzaTable = SCDynamicStoreConfig.getConfig();
if (DEBUG) {
System.out.println("Loaded from SCDynamicStoreConfig");
}
found = true;
} catch (IOException ioe) {
// OK. Will go on with file
}
}
if (!found) {
fileName = getNativeFileName();
configFile = loadConfigFile(fileName);
stanzaTable = parseStanzaTable(configFile);
if (DEBUG) {
System.out.println("Loaded from native config");
}
}
}
} catch (IOException ioe) {
// I/O error, mostly like krb5.conf missing.
// No problem. We'll use DNS or system property etc.
}
}
/**
* Gets the last-defined string value for the specified keys.
* @param keys the keys, as an array from section name, sub-section names
* (if any), to value name.
* @return the value. When there are multiple values for the same key,
* returns the last one. {@code null} is returned if not all the keys are
* defined. For example, {@code get("libdefaults", "forwardable")} will
* return null if "forwardable" is not defined in [libdefaults], and
* {@code get("realms", "R", "kdc")} will return null if "R" is not
* defined in [realms] or "kdc" is not defined for "R".
* @throws IllegalArgumentException if any of the keys is illegal, either
* because a key not the last one is not a (sub)section name or the last
* key is still a section name. For example, {@code get("libdefaults")}
* throws this exception because [libdefaults] is a section name instead of
* a value name, and {@code get("libdefaults", "forwardable", "tail")}
* also throws this exception because "forwardable" is already a value name
* and has no sub-key at all (given "forwardable" is defined, otherwise,
* this method has no knowledge if it's a value name or a section name),
*/
public String get(String... keys) {
Vector<String> v = getString0(keys);
if (v == null) return null;
return v.lastElement();
}
/**
* Gets all values for the specified keys.
* @throws IllegalArgumentException if any of the keys is illegal
* (See {@link #get})
*/
public String getAll(String... keys) {
Vector<String> v = getString0(keys);
if (v == null) return null;
StringBuilder sb = new StringBuilder();
boolean first = true;
for (String s: v) {
if (first) {
sb.append(s);
first = false;
} else {
sb.append(' ').append(s);
}
}
return sb.toString();
}
/**
* Returns true if keys exists, can be either final string(s) or sub-stanza
* @throws IllegalArgumentException if any of the keys is illegal
* (See {@link #get})
*/
public boolean exists(String... keys) {
return get0(keys) != null;
}
// Returns final string value(s) for given keys.
@SuppressWarnings("unchecked")
private Vector<String> getString0(String... keys) {
try {
return (Vector<String>)get0(keys);
} catch (ClassCastException cce) {
throw new IllegalArgumentException(cce);
}
}
// Internal method. Returns the value for keys, which can be a sub-stanza
// or final string value(s).
// The only method (except for toString) that reads stanzaTable directly.
@SuppressWarnings("unchecked")
private Object get0(String... keys) {
Object current = stanzaTable;
try {
for (String key: keys) {
current = ((Hashtable<String,Object>)current).get(key);
if (current == null) return null;
}
return current;
} catch (ClassCastException cce) {
throw new IllegalArgumentException(cce);
}
}
/**
* Gets the int value for the specified keys.
* @param keys the keys
* @return the int value, Integer.MIN_VALUE is returned if it cannot be
* found or the value is not a legal integer.
* @throw IllegalArgumentException if any of the keys is illegal
* @see #get(java.lang.String[])
*/
public int getIntValue(String... keys) {
String result = get(keys);
int value = Integer.MIN_VALUE;
if (result != null) {
try {
value = parseIntValue(result);
} catch (NumberFormatException e) {
if (DEBUG) {
System.out.println("Exception in getting value of " +
Arrays.toString(keys) + " " +
e.getMessage());
System.out.println("Setting " + Arrays.toString(keys) +
" to minimum value");
}
value = Integer.MIN_VALUE;
}
}
return value;
}
/**
* Gets the boolean value for the specified keys.
* @param keys the keys
* @return the boolean value, false is returned if it cannot be
* found or the value is not "true" (case insensitive).
* @throw IllegalArgumentException if any of the keys is illegal
* @see #get(java.lang.String[])
*/
public boolean getBooleanValue(String... keys) {
String val = get(keys);
if (val != null && val.equalsIgnoreCase("true")) {
return true;
} else {
return false;
}
}
/**
* Parses a string to an integer. The convertible strings include the
* string representations of positive integers, negative integers, and
* hex decimal integers. Valid inputs are, e.g., -1234, +1234,
* 0x40000.
*
* @param input the String to be converted to an Integer.
* @return an numeric value represented by the string
* @exception NumberFormationException if the String does not contain a
* parsable integer.
*/
private int parseIntValue(String input) throws NumberFormatException {
int value = 0;
if (input.startsWith("+")) {
String temp = input.substring(1);
return Integer.parseInt(temp);
} else if (input.startsWith("0x")) {
String temp = input.substring(2);
char[] chars = temp.toCharArray();
if (chars.length > 8) {
throw new NumberFormatException();
} else {
for (int i = 0; i < chars.length; i++) {
int index = chars.length - i - 1;
switch (chars[i]) {
case '0':
value += 0;
break;
case '1':
value += 1 * getBase(index);
break;
case '2':
value += 2 * getBase(index);
break;
case '3':
value += 3 * getBase(index);
break;
case '4':
value += 4 * getBase(index);
break;
case '5':
value += 5 * getBase(index);
break;
case '6':
value += 6 * getBase(index);
break;
case '7':
value += 7 * getBase(index);
break;
case '8':
value += 8 * getBase(index);
break;
case '9':
value += 9 * getBase(index);
break;
case 'a':
case 'A':
value += 10 * getBase(index);
break;
case 'b':
case 'B':
value += 11 * getBase(index);
break;
case 'c':
case 'C':
value += 12 * getBase(index);
break;
case 'd':
case 'D':
value += 13 * getBase(index);
break;
case 'e':
case 'E':
value += 14 * getBase(index);
break;
case 'f':
case 'F':
value += 15 * getBase(index);
break;
default:
throw new NumberFormatException("Invalid numerical format");
}
}
}
if (value < 0) {
throw new NumberFormatException("Data overflow.");
}
} else {
value = Integer.parseInt(input);
}
return value;
}
private int getBase(int i) {
int result = 16;
switch (i) {
case 0:
result = BASE16_0;
break;
case 1:
result = BASE16_1;
break;
case 2:
result = BASE16_2;
break;
case 3:
result = BASE16_3;
break;
default:
for (int j = 1; j < i; j++) {
result *= 16;
}
}
return result;
}
/**
* Reads lines to the memory from the configuration file.
*
* Configuration file contains information about the default realm,
* ticket parameters, location of the KDC and the admin server for
* known realms, etc. The file is divided into sections. Each section
* contains one or more name/value pairs with one pair per line. A
* typical file would be:
* <pre>
* [libdefaults]
* default_realm = EXAMPLE.COM
* default_tgs_enctypes = des-cbc-md5
* default_tkt_enctypes = des-cbc-md5
* [realms]
* EXAMPLE.COM = {
* kdc = kerberos.example.com
* kdc = kerberos-1.example.com
* admin_server = kerberos.example.com
* }
* SAMPLE_COM = {
* kdc = orange.sample.com
* admin_server = orange.sample.com
* }
* [domain_realm]
* blue.sample.com = TEST.SAMPLE.COM
* .backup.com = EXAMPLE.COM
* </pre>
* @return an ordered list of strings representing the config file after
* some initial processing, including:<ol>
* <li> Comment lines and empty lines are removed
* <li> "{" not at the end of a line is appended to the previous line
* <li> The content of a section is also placed between "{" and "}".
* <li> Lines are trimmed
* @throws IOException if there is an I/O error
* @throws KrbException if there is a file format error
*/
private List<String> loadConfigFile(final String fileName)
throws IOException, KrbException {
try {
List<String> v = new ArrayList<>();
try (BufferedReader br = new BufferedReader(new InputStreamReader(
AccessController.doPrivileged(
new PrivilegedExceptionAction<FileInputStream> () {
public FileInputStream run() throws IOException {
return new FileInputStream(fileName);
}
})))) {
String line;
String previous = null;
while ((line = br.readLine()) != null) {
line = line.trim();
if (line.startsWith("#") || line.isEmpty()) {
// ignore comments and blank line
// Comments start with #.
continue;
}
// In practice, a subsection might look like:
// [realms]
// EXAMPLE.COM =
// {
// kdc = kerberos.example.com
// ...
// }
// Before parsed into stanza table, it needs to be
// converted into a canonicalized style (no indent):
// realms = {
// EXAMPLE.COM = {
// kdc = kerberos.example.com
// ...
// }
// }
//
if (line.startsWith("[")) {
if (!line.endsWith("]")) {
throw new KrbException("Illegal config content:"
+ line);
}
if (previous != null) {
v.add(previous);
v.add("}");
}
String title = line.substring(
1, line.length()-1).trim();
if (title.isEmpty()) {
throw new KrbException("Illegal config content:"
+ line);
}
previous = title + " = {";
} else if (line.startsWith("{")) {
if (previous == null) {
throw new KrbException(
"Config file should not start with \"{\"");
}
previous += " {";
if (line.length() > 1) {
// { and content on the same line
v.add(previous);
previous = line.substring(1).trim();
}
} else {
if (previous == null) {
throw new KrbException(
"Config file must starts with a section");
}
v.add(previous);
previous = line;
}
}
if (previous != null) {
v.add(previous);
v.add("}");
}
}
return v;
} catch (java.security.PrivilegedActionException pe) {
throw (IOException)pe.getException();
}
}
/**
* Parses stanza names and values from configuration file to
* stanzaTable (Hashtable). Hashtable key would be stanza names,
* (libdefaults, realms, domain_realms, etc), and the hashtable value
* would be another hashtable which contains the key-value pairs under
* a stanza name. The value of this sub-hashtable can be another hashtable
* containing another sub-sub-section or a vector of strings for
* final values (even if there is only one value defined).
* <p>
* For duplicates section names, the latter overwrites the former. For
* duplicate value names, the values are in a vector in its appearing order.
* </ol>
* Please note that this behavior is Java traditional. and it is
* not the same as the MIT krb5 behavior, where:<ol>
* <li>Duplicated root sections will be merged
* <li>For duplicated sub-sections, the former overwrites the latter
* <li>Duplicate keys for values are always saved in a vector
* </ol>
* @param v the strings in the file, never null, might be empty
* @throws KrbException if there is a file format error
*/
@SuppressWarnings("unchecked")
private Hashtable<String,Object> parseStanzaTable(List
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