/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hadoop.security.authentication.util;
import static org.apache.hadoop.util.PlatformName.IBM_JAVA;
import java.io.File;
import java.io.IOException;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Locale;
import java.util.Set;
import java.util.regex.Pattern;
import org.apache.directory.server.kerberos.shared.keytab.Keytab;
import org.apache.directory.server.kerberos.shared.keytab.KeytabEntry;
import org.ietf.jgss.GSSException;
import org.ietf.jgss.Oid;
public class KerberosUtil {
/* Return the Kerberos login module name */
public static String getKrb5LoginModuleName() {
return System.getProperty("java.vendor").contains("IBM")
? "com.ibm.security.auth.module.Krb5LoginModule"
: "com.sun.security.auth.module.Krb5LoginModule";
}
public static Oid getOidInstance(String oidName)
throws ClassNotFoundException, GSSException, NoSuchFieldException,
IllegalAccessException {
Class<?> oidClass;
if (IBM_JAVA) {
if ("NT_GSS_KRB5_PRINCIPAL".equals(oidName)) {
// IBM JDK GSSUtil class does not have field for krb5 principal oid
return new Oid("1.2.840.113554.1.2.2.1");
}
oidClass = Class.forName("com.ibm.security.jgss.GSSUtil");
} else {
oidClass = Class.forName("sun.security.jgss.GSSUtil");
}
Field oidField = oidClass.getDeclaredField(oidName);
return (Oid)oidField.get(oidClass);
}
public static String getDefaultRealm()
throws ClassNotFoundException, NoSuchMethodException,
IllegalArgumentException, IllegalAccessException,
InvocationTargetException {
Object kerbConf;
Class<?> classRef;
Method getInstanceMethod;
Method getDefaultRealmMethod;
if (System.getProperty("java.vendor").contains("IBM")) {
classRef = Class.forName("com.ibm.security.krb5.internal.Config");
} else {
classRef = Class.forName("sun.security.krb5.Config");
}
getInstanceMethod = classRef.getMethod("getInstance", new Class[0]);
kerbConf = getInstanceMethod.invoke(classRef, new Object[0]);
getDefaultRealmMethod = classRef.getDeclaredMethod("getDefaultRealm",
new Class[0]);
return (String)getDefaultRealmMethod.invoke(kerbConf, new Object[0]);
}
/* Return fqdn of the current host */
static String getLocalHostName() throws UnknownHostException {
return InetAddress.getLocalHost().getCanonicalHostName();
}
/**
* Create Kerberos principal for a given service and hostname. It converts
* hostname to lower case. If hostname is null or "0.0.0.0", it uses
* dynamically looked-up fqdn of the current host instead.
*
* @param service
* Service for which you want to generate the principal.
* @param hostname
* Fully-qualified domain name.
* @return Converted Kerberos principal name.
* @throws UnknownHostException
* If no IP address for the local host could be found.
*/
public static final String getServicePrincipal(String service, String hostname)
throws UnknownHostException {
String fqdn = hostname;
if (null == fqdn || fqdn.equals("") || fqdn.equals("0.0.0.0")) {
fqdn = getLocalHostName();
}
// convert hostname to lowercase as kerberos does not work with hostnames
// with uppercase characters.
return service + "/" + fqdn.toLowerCase(Locale.US);
}
/**
* Get all the unique principals present in the keytabfile.
*
* @param keytabFileName
* Name of the keytab file to be read.
* @return list of unique principals in the keytab.
* @throws IOException
* If keytab entries cannot be read from the file.
*/
static final String[] getPrincipalNames(String keytabFileName) throws IOException {
Keytab keytab = Keytab.read(new File(keytabFileName));
Set<String> principals = new HashSet<String>();
List<KeytabEntry> entries = keytab.getEntries();
for (KeytabEntry entry: entries){
principals.add(entry.getPrincipalName().replace("\\", "/"));
}
return principals.toArray(new String[0]);
}
/**
* Get all the unique principals from keytabfile which matches a pattern.
*
* @param keytab
* Name of the keytab file to be read.
* @param pattern
* pattern to be matched.
* @return list of unique principals which matches the pattern.
* @throws IOException
*/
public static final String[] getPrincipalNames(String keytab,
Pattern pattern) throws IOException {
String[] principals = getPrincipalNames(keytab);
if (principals.length != 0) {
List<String> matchingPrincipals = new ArrayList<String>();
for (String principal : principals) {
if (pattern.matcher(principal).matches()) {
matchingPrincipals.add(principal);
}
}
principals = matchingPrincipals.toArray(new String[0]);
}
return principals;
}
}