/*
* 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 sun.security.krb5.internal.Krb5;
import sun.security.util.*;
import java.io.IOException;
import java.util.*;
import sun.security.krb5.internal.util.KerberosString;
/**
* Implements the ASN.1 Realm type.
*
* <xmp>
* Realm ::= GeneralString
* </xmp>
* This class is immutable.
*/
public class Realm implements Cloneable {
private final String realm; // not null nor empty
public Realm(String name) throws RealmException {
realm = parseRealm(name);
}
public static Realm getDefault() throws RealmException {
try {
return new Realm(Config.getInstance().getDefaultRealm());
} catch (RealmException re) {
throw re;
} catch (KrbException ke) {
throw new RealmException(ke);
}
}
// Immutable class, no need to clone
public Object clone() {
return this;
}
public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (!(obj instanceof Realm)) {
return false;
}
Realm that = (Realm)obj;
return this.realm.equals(that.realm);
}
public int hashCode() {
return realm.hashCode();
}
/**
* Constructs a Realm object.
* @param encoding a Der-encoded data.
* @exception Asn1Exception if an error occurs while decoding an ASN1 encoded data.
* @exception IOException if an I/O error occurs while reading encoded data.
* @exception RealmException if an error occurs while parsing a Realm object.
*/
public Realm(DerValue encoding)
throws Asn1Exception, RealmException, IOException {
if (encoding == null) {
throw new IllegalArgumentException("encoding can not be null");
}
realm = new KerberosString(encoding).toString();
if (realm == null || realm.length() == 0)
throw new RealmException(Krb5.REALM_NULL);
if (!isValidRealmString(realm))
throw new RealmException(Krb5.REALM_ILLCHAR);
}
public String toString() {
return realm;
}
// Extract realm from a string like dummy@REALM
public static String parseRealmAtSeparator(String name)
throws RealmException {
if (name == null) {
throw new IllegalArgumentException
("null input name is not allowed");
}
String temp = new String(name);
String result = null;
int i = 0;
while (i < temp.length()) {
if (temp.charAt(i) == PrincipalName.NAME_REALM_SEPARATOR) {
if (i == 0 || temp.charAt(i - 1) != '\\') {
if (i + 1 < temp.length()) {
result = temp.substring(i + 1, temp.length());
} else {
throw new IllegalArgumentException
("empty realm part not allowed");
}
break;
}
}
i++;
}
if (result != null) {
if (result.length() == 0)
throw new RealmException(Krb5.REALM_NULL);
if (!isValidRealmString(result))
throw new RealmException(Krb5.REALM_ILLCHAR);
}
return result;
}
public static String parseRealmComponent(String name) {
if (name == null) {
throw new IllegalArgumentException
("null input name is not allowed");
}
String temp = new String(name);
String result = null;
int i = 0;
while (i < temp.length()) {
if (temp.charAt(i) == PrincipalName.REALM_COMPONENT_SEPARATOR) {
if (i == 0 || temp.charAt(i - 1) != '\\') {
if (i + 1 < temp.length())
result = temp.substring(i + 1, temp.length());
break;
}
}
i++;
}
return result;
}
protected static String parseRealm(String name) throws RealmException {
String result = parseRealmAtSeparator(name);
if (result == null)
result = name;
if (result == null || result.length() == 0)
throw new RealmException(Krb5.REALM_NULL);
if (!isValidRealmString(result))
throw new RealmException(Krb5.REALM_ILLCHAR);
return result;
}
// This is protected because the definition of a realm
// string is fixed
protected static boolean isValidRealmString(String name) {
if (name == null)
return false;
if (name.length() == 0)
return false;
for (int i = 0; i < name.length(); i++) {
if (name.charAt(i) == '/' ||
name.charAt(i) == ':' ||
name.charAt(i) == '\0') {
return false;
}
}
return true;
}
/**
* Encodes a Realm object.
* @return the byte array of encoded KrbCredInfo object.
* @exception Asn1Exception if an error occurs while decoding an ASN1 encoded data.
* @exception IOException if an I/O error occurs while reading encoded data.
*
*/
public byte[] asn1Encode() throws Asn1Exception, IOException {
DerOutputStream out = new DerOutputStream();
out.putDerValue(new KerberosString(this.realm).toDerValue());
return out.toByteArray();
}
/**
* Parse (unmarshal) a realm from a DER input stream. This form
* parsing might be used when expanding a value which is part of
* a constructed sequence and uses explicitly tagged type.
*
* @exception Asn1Exception on error.
* @param data the Der input stream value, which contains one or more marshaled value.
* @param explicitTag tag number.
* @param optional indicate if this data field is optional
* @return an instance of Realm.
*
*/
public static Realm parse(DerInputStream data, byte explicitTag, boolean optional)
throws Asn1Exception, IOException, RealmException {
if ((optional) && (((byte)data.peekByte() & (byte)0x1F) != explicitTag)) {
return null;
}
DerValue der = data.getDerValue();
if (explicitTag != (der.getTag() & (byte)0x1F)) {
throw new Asn1Exception(Krb5.ASN1_BAD_ID);
} else {
DerValue subDer = der.getData().getDerValue();
return new Realm(subDer);
}
}
/**
* Returns an array of realms that may be traversed to obtain
* a TGT from the initiating realm cRealm to the target realm
* sRealm.
* <br>
* This method would read [capaths] to create a path, or generate a
* hierarchical path if [capaths] does not contain a sub-stanza for cRealm
* or the sub-stanza does not contain a tag for sRealm.
* <br>
* The returned list would never be null, and it always contains
* cRealm as the head entry. sRealm is not included as the tail.
*
* @param cRealm the initiating realm, not null
* @param sRealm the target realm, not null, not equals to cRealm
* @returns array of realms including at least cRealm as the first
* element
*/
public static String[] getRealmsList(String cRealm, String sRealm) {
try {
// Try [capaths]
return parseCapaths(cRealm, sRealm);
} catch (KrbException ke) {
// Now assume the realms are organized hierarchically.
return parseHierarchy(cRealm, sRealm);
}
}
/**
* Parses the [capaths] stanza of the configuration file for a
* list of realms to traverse to obtain credentials from the
* initiating realm cRealm to the target realm sRealm.
*
* For a given client realm C there is a tag C in [capaths] whose
* subtag S has a value which is a (possibly partial) path from C
* to S. When the path is partial, it contains only the tail of the
* full path. Values of other subtags will be used to build the full
* path. The value "." means a direct path from C to S. If realm S
* does not appear as a subtag, there is no path defined here.
*
* The implementation ignores all values which equals to C or S, or
* a "." in multiple values, or any duplicated realm names.
*
* When a path value has more than two realms, they can be specified
* with multiple key-value pairs each having a single value, but the
* order must not change.
*
* For example:
*
* [capaths]
* TIVOLI.COM = {
* IBM.COM = IBM_LDAPCENTRAL.COM MOONLITE.ORG
* IBM_LDAPCENTRAL.COM = LDAPCENTRAL.NET
* LDAPCENTRAL.NET = .
* }
*
* TIVOLI.COM has a direct path to LDAPCENTRAL.NET, which has a direct
* path to IBM_LDAPCENTRAL.COM. It also has a partial path to IBM.COM
* being "IBM_LDAPCENTRAL.COM MOONLITE.ORG". Merging these info together,
* a full path from TIVOLI.COM to IBM.COM will be
*
* TIVOLI.COM -> LDAPCENTRAL.NET -> IBM_LDAPCENTRAL.COM
* -> IBM_LDAPCENTRAL.COM -> MOONLITE.ORG
*
* Please note the sRealm IBM.COM does not appear in the path.
*
* @param cRealm the initiating realm
* @param sRealm the target realm, not the same as cRealm
* @returns array of realms including at least cRealm as the first
* element
* @throws KrbException if the config does not contain a sub-stanza
* for cRealm in [capaths] or the sub-stanza does not contain
* sRealm as a tag
*/
private static String[] parseCapaths(String cRealm, String sRealm)
throws KrbException {
// This line could throw a KrbException
Config cfg = Config.getInstance();
if (!cfg.exists("capaths", cRealm, sRealm)) {
throw new KrbException("No conf");
}
LinkedList<String> path = new LinkedList<>();
String head = sRealm;
while (true) {
String value = cfg.getAll("capaths", cRealm, head);
if (value == null) {
break;
}
String[] more = value.split("\\s+");
boolean changed = false;
for (int i=more.length-1; i>=0; i--) {
if (path.contains(more[i])
|| more[i].equals(".")
|| more[i].equals(cRealm)
|| more[i].equals(sRealm)
|| more[i].equals(head)) {
// Ignore invalid values
continue;
}
changed = true;
path.addFirst(more[i]);
}
if (!changed) break;
head = path.getFirst();
}
path.addFirst(cRealm);
return path.toArray(new String[path.size()]);
}
/**
* Build a list of realm that can be traversed
* to obtain credentials from the initiating realm cRealm
* for a service in the target realm sRealm.
* @param cRealm the initiating realm
* @param sRealm the target realm, not the same as cRealm
* @returns array of realms including cRealm as the first element
*/
private static String[] parseHierarchy(String cRealm, String sRealm) {
String[] cComponents = cRealm.split("\\.");
String[] sComponents = sRealm.split("\\.");
int cPos = cComponents.length;
int sPos = sComponents.length;
boolean hasCommon = false;
for (sPos--, cPos--; sPos >=0 && cPos >= 0 &&
sComponents[sPos].equals(cComponents[cPos]);
sPos--, cPos--) {
hasCommon = true;
}
// For those with common components:
// length pos
// SITES1.SALES.EXAMPLE.COM 4 1
// EVERYWHERE.EXAMPLE.COM 3 0
// For those without common components:
// length pos
// DEVEL.EXAMPLE.COM 3 2
// PROD.EXAMPLE.ORG 3 2
LinkedList<String> path = new LinkedList<>();
// Un-common ones for client side
for (int i=0; i<=cPos; i++) {
path.addLast(subStringFrom(cComponents, i));
}
// Common one
if (hasCommon) {
path.addLast(subStringFrom(cComponents, cPos+1));
}
// Un-common ones for server side
for (int i=sPos; i>=0; i--) {
path.addLast(subStringFrom(sComponents, i));
}
// Remove sRealm from path. Note that it might be added at last loop
// or as a common component, if sRealm is a parent of cRealm
path.removeLast();
return path.toArray(new String[path.size()]);
}
/**
* Creates a realm name using components from the given position.
* For example, subStringFrom({"A", "B", "C"}, 1) is "B.C".
*/
private static String subStringFrom(String[] components, int from) {
StringBuilder sb = new StringBuilder();
for (int i=from; i<components.length; i++) {
if (sb.length() != 0) sb.append('.');
sb.append(components[i]);
}
return sb.toString();
}
}