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	/*
	* Copyright (c) 1997, 2017, 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.
	*/

	package java.security;

	import java.util.ArrayList;
	import java.util.Collections;
	import java.util.Enumeration;
	import java.util.List;
	import java.util.Map;
	import java.util.WeakHashMap;
	import sun.misc.JavaSecurityAccess;
	import sun.misc.JavaSecurityProtectionDomainAccess;
	import static sun.misc.JavaSecurityProtectionDomainAccess.ProtectionDomainCache;
	import sun.misc.SharedSecrets;
	import sun.security.util.Debug;
	import sun.security.util.SecurityConstants;

	/**
	* The ProtectionDomain class encapsulates the characteristics of a domain,
	* which encloses a set of classes whose instances are granted a set
	* of permissions when being executed on behalf of a given set of Principals.
	* <p>
	* A static set of permissions can be bound to a ProtectionDomain when it is
	* constructed; such permissions are granted to the domain regardless of the
	* Policy in force. However, to support dynamic security policies, a
	* ProtectionDomain can also be constructed such that it is dynamically
	* mapped to a set of permissions by the current Policy whenever a permission
	* is checked.
	* <p>
	*
	* @author Li Gong
	* @author Roland Schemers
	* @author Gary Ellison
	*/

	public class ProtectionDomain {
	private static class JavaSecurityAccessImpl implements JavaSecurityAccess {

	private JavaSecurityAccessImpl() {
	}

	@Override
	public <T> T doIntersectionPrivilege(
	PrivilegedAction<T> action,
	final AccessControlContext stack,
	final AccessControlContext context) {
	if (action == null) {
	throw new NullPointerException();
	}

	return AccessController.doPrivileged(
	action,
	getCombinedACC(context, stack)
	);
	}

	@Override
	public <T> T doIntersectionPrivilege(
	PrivilegedAction<T> action,
	AccessControlContext context) {
	return doIntersectionPrivilege(action,
	AccessController.getContext(), context);
	}

	private static AccessControlContext getCombinedACC(AccessControlContext context, AccessControlContext stack) {
	AccessControlContext acc = new AccessControlContext(context, stack.getCombiner(), true);

	return new AccessControlContext(stack.getContext(), acc).optimize();
	}
	}

	static {
	// Set up JavaSecurityAccess in SharedSecrets
	SharedSecrets.setJavaSecurityAccess(new JavaSecurityAccessImpl());
	}

	/* CodeSource */
	private CodeSource codesource ;

	/* ClassLoader the protection domain was consed from */
	private ClassLoader classloader;

	/* Principals running-as within this protection domain */
	private Principal[] principals;

	/* the rights this protection domain is granted */
	private PermissionCollection permissions;

	/* if the permissions object has AllPermission */
	private boolean hasAllPerm = false;

	/* the PermissionCollection is static (pre 1.4 constructor)
	or dynamic (via a policy refresh) */
	private boolean staticPermissions;

	/*
	* An object used as a key when the ProtectionDomain is stored in a Map.
	*/
	final Key key = new Key();

	private static final Debug debug = Debug.getInstance("domain");

	/**
	* Creates a new ProtectionDomain with the given CodeSource and
	* Permissions. If the permissions object is not null, then
	* {@code setReadOnly())} will be called on the passed in
	* Permissions object. The only permissions granted to this domain
	* are the ones specified; the current Policy will not be consulted.
	*
	* @param codesource the codesource associated with this domain
	* @param permissions the permissions granted to this domain
	*/
	public ProtectionDomain(CodeSource codesource,
	PermissionCollection permissions) {
	this.codesource = codesource;
	if (permissions != null) {
	this.permissions = permissions;
	this.permissions.setReadOnly();
	if (permissions instanceof Permissions &&
	((Permissions)permissions).allPermission != null) {
	hasAllPerm = true;
	}
	}
	this.classloader = null;
	this.principals = new Principal[0];
	staticPermissions = true;
	}

	/**
	* Creates a new ProtectionDomain qualified by the given CodeSource,
	* Permissions, ClassLoader and array of Principals. If the
	* permissions object is not null, then {@code setReadOnly()}
	* will be called on the passed in Permissions object.
	* The permissions granted to this domain are dynamic; they include
	* both the static permissions passed to this constructor, and any
	* permissions granted to this domain by the current Policy at the
	* time a permission is checked.
	* <p>
	* This constructor is typically used by
	* {@link SecureClassLoader ClassLoaders}
	* and {@link DomainCombiner DomainCombiners} which delegate to
	* {@code Policy} to actively associate the permissions granted to
	* this domain. This constructor affords the
	* Policy provider the opportunity to augment the supplied
	* PermissionCollection to reflect policy changes.
	* <p>
	*
	* @param codesource the CodeSource associated with this domain
	* @param permissions the permissions granted to this domain
	* @param classloader the ClassLoader associated with this domain
	* @param principals the array of Principals associated with this
	* domain. The contents of the array are copied to protect against
	* subsequent modification.
	* @see Policy#refresh
	* @see Policy#getPermissions(ProtectionDomain)
	* @since 1.4
	*/
	public ProtectionDomain(CodeSource codesource,
	PermissionCollection permissions,
	ClassLoader classloader,
	Principal[] principals) {
	this.codesource = codesource;
	if (permissions != null) {
	this.permissions = permissions;
	this.permissions.setReadOnly();
	if (permissions instanceof Permissions &&
	((Permissions)permissions).allPermission != null) {
	hasAllPerm = true;
	}
	}
	this.classloader = classloader;
	this.principals = (principals != null ? principals.clone():
	new Principal[0]);
	staticPermissions = false;
	}

	/**
	* Returns the CodeSource of this domain.
	* @return the CodeSource of this domain which may be null.
	* @since 1.2
	*/
	public final CodeSource getCodeSource() {
	return this.codesource;
	}


	/**
	* Returns the ClassLoader of this domain.
	* @return the ClassLoader of this domain which may be null.
	*
	* @since 1.4
	*/
	public final ClassLoader getClassLoader() {
	return this.classloader;
	}


	/**
	* Returns an array of principals for this domain.
	* @return a non-null array of principals for this domain.
	* Returns a new array each time this method is called.
	*
	* @since 1.4
	*/
	public final Principal[] getPrincipals() {
	return this.principals.clone();
	}

	/**
	* Returns the static permissions granted to this domain.
	*
	* @return the static set of permissions for this domain which may be null.
	* @see Policy#refresh
	* @see Policy#getPermissions(ProtectionDomain)
	*/
	public final PermissionCollection getPermissions() {
	return permissions;
	}

	/**
	* Check and see if this ProtectionDomain implies the permissions
	* expressed in the Permission object.
	* <p>
	* The set of permissions evaluated is a function of whether the
	* ProtectionDomain was constructed with a static set of permissions
	* or it was bound to a dynamically mapped set of permissions.
	* <p>
	* If the ProtectionDomain was constructed to a
	* {@link #ProtectionDomain(CodeSource, PermissionCollection)
	* statically bound} PermissionCollection then the permission will
	* only be checked against the PermissionCollection supplied at
	* construction.
	* <p>
	* However, if the ProtectionDomain was constructed with
	* the constructor variant which supports
	* {@link #ProtectionDomain(CodeSource, PermissionCollection,
	* ClassLoader, java.security.Principal[]) dynamically binding}
	* permissions, then the permission will be checked against the
	* combination of the PermissionCollection supplied at construction and
	* the current Policy binding.
	* <p>
	*
	* @param permission the Permission object to check.
	*
	* @return true if "permission" is implicit to this ProtectionDomain.
	*/
	public boolean implies(Permission permission) {

	if (hasAllPerm) {
	// internal permission collection already has AllPermission -
	// no need to go to policy
	return true;
	}

	if (!staticPermissions &&
	Policy.getPolicyNoCheck().implies(this, permission))
	return true;
	if (permissions != null)
	return permissions.implies(permission);

	return false;
	}

	// called by the VM -- do not remove
	boolean impliesCreateAccessControlContext() {
	return implies(SecurityConstants.CREATE_ACC_PERMISSION);
	}

	/**
	* Convert a ProtectionDomain to a String.
	*/
	@Override public String toString() {
	String pals = "<no principals>";
	if (principals != null && principals.length > 0) {
	StringBuilder palBuf = new StringBuilder("(principals ");

	for (int i = 0; i < principals.length; i++) {
	palBuf.append(principals[i].getClass().getName() +
	" \"" + principals[i].getName() +
	"\"");
	if (i < principals.length-1)
	palBuf.append(",\n");
	else
	palBuf.append(")\n");
	}
	pals = palBuf.toString();
	}

	// Check if policy is set; we don't want to load
	// the policy prematurely here
	PermissionCollection pc = Policy.isSet() && seeAllp() ?
	mergePermissions():
	getPermissions();

	return "ProtectionDomain "+
	" "+codesource+"\n"+
	" "+classloader+"\n"+
	" "+pals+"\n"+
	" "+pc+"\n";
	}

	/**
	* Return true (merge policy permissions) in the following cases:
	*
	* . SecurityManager is null
	*
	* . SecurityManager is not null,
	* debug is not null,
	* SecurityManager impelmentation is in bootclasspath,
	* Policy implementation is in bootclasspath
	* (the bootclasspath restrictions avoid recursion)
	*
	* . SecurityManager is not null,
	* debug is null,
	* caller has Policy.getPolicy permission
	*/
	private static boolean seeAllp() {
	SecurityManager sm = System.getSecurityManager();

	if (sm == null) {
	return true;
	} else {
	if (debug != null) {
	if (sm.getClass().getClassLoader() == null &&
	Policy.getPolicyNoCheck().getClass().getClassLoader()
	== null) {
	return true;
	}
	} else {
	try {
	sm.checkPermission(SecurityConstants.GET_POLICY_PERMISSION);
	return true;
	} catch (SecurityException se) {
	// fall thru and return false
	}
	}
	}

	return false;
	}

	private PermissionCollection mergePermissions() {
	if (staticPermissions)
	return permissions;

	PermissionCollection perms =
	java.security.AccessController.doPrivileged
	(new java.security.PrivilegedAction<PermissionCollection>() {
	public PermissionCollection run() {
	Policy p = Policy.getPolicyNoCheck();
	return p.getPermissions(ProtectionDomain.this);
	}
	});

	Permissions mergedPerms = new Permissions();
	int swag = 32;
	int vcap = 8;
	Enumeration<Permission> e;
	List<Permission> pdVector = new ArrayList<>(vcap);
	List<Permission> plVector = new ArrayList<>(swag);

	//
	// Build a vector of domain permissions for subsequent merge
	if (permissions != null) {
	synchronized (permissions) {
	e = permissions.elements();
	while (e.hasMoreElements()) {
	pdVector.add(e.nextElement());
	}
	}
	}

	//
	// Build a vector of Policy permissions for subsequent merge
	if (perms != null) {
	synchronized (perms) {
	e = perms.elements();
	while (e.hasMoreElements()) {
	plVector.add(e.nextElement());
	vcap++;
	}
	}
	}

	if (perms != null && permissions != null) {
	//
	// Weed out the duplicates from the policy. Unless a refresh
	// has occurred since the pd was consed this should result in
	// an empty vector.
	synchronized (permissions) {
	e = permissions.elements(); // domain vs policy
	while (e.hasMoreElements()) {
	Permission pdp = e.nextElement();
	Class<?> pdpClass = pdp.getClass();
	String pdpActions = pdp.getActions();
	String pdpName = pdp.getName();
	for (int i = 0; i < plVector.size(); i++) {
	Permission pp = plVector.get(i);
	if (pdpClass.isInstance(pp)) {
	// The equals() method on some permissions
	// have some side effects so this manual
	// comparison is sufficient.
	if (pdpName.equals(pp.getName()) &&
	pdpActions.equals(pp.getActions())) {
	plVector.remove(i);
	break;
	}
	}
	}
	}
	}
	}

	if (perms !=null) {
	// the order of adding to merged perms and permissions
	// needs to preserve the bugfix 4301064

	for (int i = plVector.size()-1; i >= 0; i--) {
	mergedPerms.add(plVector.get(i));
	}
	}
	if (permissions != null) {
	for (int i = pdVector.size()-1; i >= 0; i--) {
	mergedPerms.add(pdVector.get(i));
	}
	}

	return mergedPerms;
	}

	/**
	* Used for storing ProtectionDomains as keys in a Map.
	*/
	final class Key {}

	static {
	SharedSecrets.setJavaSecurityProtectionDomainAccess(
	new JavaSecurityProtectionDomainAccess() {
	@Override
	public ProtectionDomainCache getProtectionDomainCache() {
	return new ProtectionDomainCache() {
	private final Map<Key, PermissionCollection> map =
	Collections.synchronizedMap
	(new WeakHashMap<Key, PermissionCollection>());
	public void put(ProtectionDomain pd,
	PermissionCollection pc) {
	map.put((pd == null ? null : pd.key), pc);
	}
	public PermissionCollection get(ProtectionDomain pd) {
	return pd == null ? map.get(null) : map.get(pd.key);
	}
	};
	}

	@Override
	public boolean getStaticPermissionsField(ProtectionDomain pd) {
	return pd.staticPermissions;
	}
	});
	}
	}

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