SecurityUtil.java
/*
* 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.catalina.security;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.security.Principal;
import java.security.PrivilegedActionException;
import java.security.PrivilegedExceptionAction;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import javax.security.auth.Subject;
import javax.servlet.Filter;
import javax.servlet.Servlet;
import javax.servlet.ServletException;
import javax.servlet.UnavailableException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
import org.apache.catalina.Globals;
import org.apache.juli.logging.Log;
import org.apache.juli.logging.LogFactory;
import org.apache.tomcat.util.ExceptionUtils;
import org.apache.tomcat.util.res.StringManager;
/**
* This utility class associates a <code>Subject</code> to the current <code>AccessControlContext</code>. When a
* <code>SecurityManager</code> is used, the container will always associate the called thread with an
* AccessControlContext containing only the principal of the requested Servlet/Filter. This class uses reflection to
* invoke the methods.
*/
public final class SecurityUtil {
// Note that indexes overlap.
// A Servlet uses "init", "service", "event", "destroy".
// A Filter uses "doFilter", "doFilterEvent", "destroy".
private static final int INIT = 0;
private static final int SERVICE = 1;
private static final int DOFILTER = 1;
private static final int EVENT = 2;
private static final int DOFILTEREVENT = 2;
private static final int DESTROY = 3;
private static final String INIT_METHOD = "init";
private static final String DOFILTER_METHOD = "doFilter";
private static final String SERVICE_METHOD = "service";
private static final String EVENT_METHOD = "event";
private static final String DOFILTEREVENT_METHOD = "doFilterEvent";
private static final String DESTROY_METHOD = "destroy";
/**
* Cache every class for which we are creating methods.
*/
private static final Map<Class<?>,Method[]> classCache = new ConcurrentHashMap<>();
private static final Log log = LogFactory.getLog(SecurityUtil.class);
private static final boolean packageDefinitionEnabled =
(System.getProperty("package.definition") == null && System.getProperty("package.access") == null) ? false :
true;
/**
* The string resources for this package.
*/
private static final StringManager sm = StringManager.getManager(Constants.PACKAGE);
/**
* Perform work as a particular <code>Subject</code>. Here the work will be granted to a <code>null</code> subject.
*
* @param methodName the method to apply the security restriction
* @param targetObject the <code>Servlet</code> on which the method will be called.
*
* @throws Exception an execution error occurred
*/
public static void doAsPrivilege(final String methodName, final Servlet targetObject) throws Exception {
doAsPrivilege(methodName, targetObject, null, null, null);
}
/**
* Perform work as a particular <code>Subject</code>. Here the work will be granted to a <code>null</code> subject.
*
* @param methodName the method to apply the security restriction
* @param targetObject the <code>Servlet</code> on which the method will be called.
* @param targetType <code>Class</code> array used to instantiate a <code>Method</code> object.
* @param targetArguments <code>Object</code> array contains the runtime parameters instance.
*
* @throws Exception an execution error occurred
*/
public static void doAsPrivilege(final String methodName, final Servlet targetObject, final Class<?>[] targetType,
final Object[] targetArguments) throws Exception {
doAsPrivilege(methodName, targetObject, targetType, targetArguments, null);
}
/**
* Perform work as a particular <code>Subject</code>. Here the work will be granted to a <code>null</code> subject.
*
* @param methodName the method to apply the security restriction
* @param targetObject the <code>Servlet</code> on which the method will be called.
* @param targetParameterTypes <code>Class</code> array used to instantiate a <code>Method</code> object.
* @param targetArguments <code>Object</code> array contains the runtime parameters instance.
* @param principal the <code>Principal</code> to which the security privilege applies
*
* @throws Exception an execution error occurred
*/
public static void doAsPrivilege(final String methodName, final Servlet targetObject,
final Class<?>[] targetParameterTypes, final Object[] targetArguments, Principal principal)
throws Exception {
Method method = null;
Method[] methodsCache = classCache.get(Servlet.class);
if (methodsCache == null) {
method = createMethodAndCacheIt(null, Servlet.class, methodName, targetParameterTypes);
} else {
method = findMethod(methodsCache, methodName);
if (method == null) {
method = createMethodAndCacheIt(methodsCache, Servlet.class, methodName, targetParameterTypes);
}
}
execute(method, targetObject, targetArguments, principal);
}
/**
* Perform work as a particular <code>Subject</code>. Here the work will be granted to a <code>null</code> subject.
*
* @param methodName the method to apply the security restriction
* @param targetObject the <code>Filter</code> on which the method will be called.
*
* @throws Exception an execution error occurred
*/
public static void doAsPrivilege(final String methodName, final Filter targetObject) throws Exception {
doAsPrivilege(methodName, targetObject, null, null);
}
/**
* Perform work as a particular <code>Subject</code>. Here the work will be granted to a <code>null</code> subject.
*
* @param methodName the method to apply the security restriction
* @param targetObject the <code>Filter</code> on which the method will be called.
* @param targetType <code>Class</code> array used to instantiate a <code>Method</code> object.
* @param targetArguments <code>Object</code> array contains the runtime parameters instance.
*
* @throws Exception an execution error occurred
*/
public static void doAsPrivilege(final String methodName, final Filter targetObject, final Class<?>[] targetType,
final Object[] targetArguments) throws Exception {
doAsPrivilege(methodName, targetObject, targetType, targetArguments, null);
}
/**
* Perform work as a particular <code>Subject</code>. Here the work will be granted to a <code>null</code> subject.
*
* @param methodName the method to apply the security restriction
* @param targetObject the <code>Filter</code> on which the method will be called.
* @param targetParameterTypes <code>Class</code> array used to instantiate a <code>Method</code> object.
* @param targetParameterValues <code>Object</code> array contains the runtime parameters instance.
* @param principal the <code>Principal</code> to which the security privilege applies
*
* @throws Exception an execution error occurred
*/
public static void doAsPrivilege(final String methodName, final Filter targetObject,
final Class<?>[] targetParameterTypes, final Object[] targetParameterValues, Principal principal)
throws Exception {
Method method = null;
Method[] methodsCache = classCache.get(Filter.class);
if (methodsCache == null) {
method = createMethodAndCacheIt(null, Filter.class, methodName, targetParameterTypes);
} else {
method = findMethod(methodsCache, methodName);
if (method == null) {
method = createMethodAndCacheIt(methodsCache, Filter.class, methodName, targetParameterTypes);
}
}
execute(method, targetObject, targetParameterValues, principal);
}
/**
* Perform work as a particular <code>Subject</code>. Here the work will be granted to a <code>null</code> subject.
*
* @param method the method to apply the security restriction
* @param targetObject the <code>Servlet</code> on which the method will be called.
* @param targetArguments <code>Object</code> array contains the runtime parameters instance.
* @param principal the <code>Principal</code> to which the security privilege applies
*
* @throws Exception an execution error occurred
*/
private static void execute(final Method method, final Object targetObject, final Object[] targetArguments,
Principal principal) throws Exception {
try {
Subject subject = null;
PrivilegedExceptionAction<Void> pea = new PrivilegedExceptionAction<Void>() {
@Override
public Void run() throws Exception {
method.invoke(targetObject, targetArguments);
return null;
}
};
// The first argument is always the request object
if (targetArguments != null && targetArguments[0] instanceof HttpServletRequest) {
HttpServletRequest request = (HttpServletRequest) targetArguments[0];
boolean hasSubject = false;
HttpSession session = request.getSession(false);
if (session != null) {
subject = (Subject) session.getAttribute(Globals.SUBJECT_ATTR);
hasSubject = (subject != null);
}
if (subject == null) {
subject = new Subject();
if (principal != null) {
subject.getPrincipals().add(principal);
}
}
if (session != null && !hasSubject) {
session.setAttribute(Globals.SUBJECT_ATTR, subject);
}
}
Subject.doAsPrivileged(subject, pea, null);
} catch (PrivilegedActionException pe) {
Throwable e;
if (pe.getException() instanceof InvocationTargetException) {
e = pe.getException().getCause();
ExceptionUtils.handleThrowable(e);
} else {
e = pe;
}
if (log.isDebugEnabled()) {
log.debug(sm.getString("SecurityUtil.doAsPrivilege"), e);
}
if (e instanceof UnavailableException) {
throw (UnavailableException) e;
} else if (e instanceof ServletException) {
throw (ServletException) e;
} else if (e instanceof IOException) {
throw (IOException) e;
} else if (e instanceof RuntimeException) {
throw (RuntimeException) e;
} else {
throw new ServletException(e.getMessage(), e);
}
}
}
/**
* Find a method stored within the cache.
*
* @param methodsCache the cache used to store method instance
* @param methodName the method to apply the security restriction
*
* @return the method instance, null if not yet created.
*/
private static Method findMethod(Method[] methodsCache, String methodName) {
if (methodName.equals(INIT_METHOD)) {
return methodsCache[INIT];
} else if (methodName.equals(DESTROY_METHOD)) {
return methodsCache[DESTROY];
} else if (methodName.equals(SERVICE_METHOD)) {
return methodsCache[SERVICE];
} else if (methodName.equals(DOFILTER_METHOD)) {
return methodsCache[DOFILTER];
} else if (methodName.equals(EVENT_METHOD)) {
return methodsCache[EVENT];
} else if (methodName.equals(DOFILTEREVENT_METHOD)) {
return methodsCache[DOFILTEREVENT];
}
return null;
}
/**
* Create the method and cache it for further re-use.
*
* @param methodsCache the cache used to store method instance
* @param targetType the class on which the method will be called.
* @param methodName the method to apply the security restriction
* @param parameterTypes <code>Class</code> array used to instantiate a <code>Method</code> object.
*
* @return the method instance.
*
* @throws Exception an execution error occurred
*/
private static Method createMethodAndCacheIt(Method[] methodsCache, Class<?> targetType, String methodName,
Class<?>[] parameterTypes) throws Exception {
if (methodsCache == null) {
methodsCache = new Method[4];
}
Method method = targetType.getMethod(methodName, parameterTypes);
if (methodName.equals(INIT_METHOD)) {
methodsCache[INIT] = method;
} else if (methodName.equals(DESTROY_METHOD)) {
methodsCache[DESTROY] = method;
} else if (methodName.equals(SERVICE_METHOD)) {
methodsCache[SERVICE] = method;
} else if (methodName.equals(DOFILTER_METHOD)) {
methodsCache[DOFILTER] = method;
} else if (methodName.equals(EVENT_METHOD)) {
methodsCache[EVENT] = method;
} else if (methodName.equals(DOFILTEREVENT_METHOD)) {
methodsCache[DOFILTEREVENT] = method;
}
classCache.put(targetType, methodsCache);
return method;
}
/**
* Remove the object from the cache.
*
* @param cachedObject The object to remove
*/
public static void remove(Object cachedObject) {
classCache.remove(cachedObject);
}
/**
* Return the <code>SecurityManager</code> only if Security is enabled AND package protection mechanism is enabled.
*
* @return <code>true</code> if package level protection is enabled
*/
public static boolean isPackageProtectionEnabled() {
if (packageDefinitionEnabled && Globals.IS_SECURITY_ENABLED) {
return true;
}
return false;
}
}