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	/*
	* Copyright (c) 1997, 2021, 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.io.IOException;
	import java.io.ObjectInputStream;
	import java.io.ObjectOutputStream;
	import java.io.ObjectStreamField;
	import java.util.Enumeration;
	import java.util.Hashtable;
	import java.util.concurrent.ConcurrentHashMap;

	/**
	* The BasicPermission class extends the Permission class, and
	* can be used as the base class for permissions that want to
	* follow the same naming convention as BasicPermission.
	* <P>
	* The name for a BasicPermission is the name of the given permission
	* (for example, "exit",
	* "setFactory", "print.queueJob", etc). The naming
	* convention follows the hierarchical property naming convention.
	* An asterisk may appear by itself, or if immediately preceded by a "."
	* may appear at the end of the name, to signify a wildcard match.
	* For example, "" and "java." signify a wildcard match, while "java", "ab",
	* and "java*" do not.
	* <P>
	* The action string (inherited from Permission) is unused.
	* Thus, BasicPermission is commonly used as the base class for
	* "named" permissions
	* (ones that contain a name but no actions list; you either have the
	* named permission or you don't.)
	* Subclasses may implement actions on top of BasicPermission,
	* if desired.
	*
	* @see java.security.Permission
	* @see java.security.Permissions
	* @see java.security.PermissionCollection
	* @see java.lang.SecurityManager
	*
	* @author Marianne Mueller
	* @author Roland Schemers
	* @since 1.2
	*/

	public abstract class BasicPermission extends Permission
	implements java.io.Serializable
	{

	@java.io.Serial
	private static final long serialVersionUID = 6279438298436773498L;

	// does this permission have a wildcard at the end?
	private transient boolean wildcard;

	// the name without the wildcard on the end
	private transient String path;

	// is this permission the old-style exitVM permission (pre JDK 1.6)?
	private transient boolean exitVM;

	/**
	* initialize a BasicPermission object. Common to all constructors.
	*/
	private void init(String name) {
	if (name == null)
	throw new NullPointerException("name can't be null");

	int len = name.length();

	if (len == 0) {
	throw new IllegalArgumentException("name can't be empty");
	}

	char last = name.charAt(len - 1);

	// Is wildcard or ends with ".*"?
	if (last == '*' && (len == 1 \|\| name.charAt(len - 2) == '.')) {
	wildcard = true;
	if (len == 1) {
	path = "";
	} else {
	path = name.substring(0, len - 1);
	}
	} else {
	if (name.equals("exitVM")) {
	wildcard = true;
	path = "exitVM.";
	exitVM = true;
	} else {
	path = name;
	}
	}
	}

	/**
	* Creates a new BasicPermission with the specified name.
	* Name is the symbolic name of the permission, such as
	* "setFactory",
	* "print.queueJob", or "topLevelWindow", etc.
	*
	* @param name the name of the BasicPermission.
	*
	* @throws NullPointerException if {@code name} is {@code null}.
	* @throws IllegalArgumentException if {@code name} is empty.
	*/
	public BasicPermission(String name) {
	super(name);
	init(name);
	}


	/**
	* Creates a new BasicPermission object with the specified name.
	* The name is the symbolic name of the BasicPermission, and the
	* actions String is currently unused.
	*
	* @param name the name of the BasicPermission.
	* @param actions ignored.
	*
	* @throws NullPointerException if {@code name} is {@code null}.
	* @throws IllegalArgumentException if {@code name} is empty.
	*/
	public BasicPermission(String name, String actions) {
	super(name);
	init(name);
	}

	/**
	* Checks if the specified permission is "implied" by
	* this object.
	* <P>
	* More specifically, this method returns true if:
	* <ul>
	* <li> {@code p}'s class is the same as this object's class, and
	* <li> {@code p}'s name equals or (in the case of wildcards)
	* is implied by this object's
	* name. For example, "a.b.*" implies "a.b.c".
	* </ul>
	*
	* @param p the permission to check against.
	*
	* @return true if the passed permission is equal to or
	* implied by this permission, false otherwise.
	*/
	@Override
	public boolean implies(Permission p) {
	if ((p == null) \|\| (p.getClass() != getClass()))
	return false;

	BasicPermission that = (BasicPermission) p;

	if (this.wildcard) {
	if (that.wildcard) {
	// one wildcard can imply another
	return that.path.startsWith(path);
	} else {
	// make sure ap.path is longer so a.b.* doesn't imply a.b
	return (that.path.length() > this.path.length()) &&
	that.path.startsWith(this.path);
	}
	} else {
	if (that.wildcard) {
	// a non-wildcard can't imply a wildcard
	return false;
	}
	else {
	return this.path.equals(that.path);
	}
	}
	}

	/**
	* Checks two BasicPermission objects for equality.
	* Checks that {@code obj}'s class is the same as this object's class
	* and has the same name as this object.
	*
	* @param obj the object we are testing for equality with this object.
	* @return true if {@code obj}'s class is the same as this object's class
	* and has the same name as this BasicPermission object, false otherwise.
	*/
	@Override
	public boolean equals(Object obj) {
	if (obj == this)
	return true;

	if ((obj == null) \|\| (obj.getClass() != getClass()))
	return false;

	BasicPermission bp = (BasicPermission) obj;

	return getName().equals(bp.getName());
	}


	/**
	* Returns the hash code value for this object.
	* The hash code used is the hash code of the name, that is,
	* {@code getName().hashCode()}, where {@code getName} is
	* from the Permission superclass.
	*
	* @return a hash code value for this object.
	*/
	@Override
	public int hashCode() {
	return this.getName().hashCode();
	}

	/**
	* Returns the canonical string representation of the actions,
	* which currently is the empty string "", since there are no actions for
	* a BasicPermission.
	*
	* @return the empty string "".
	*/
	@Override
	public String getActions() {
	return "";
	}

	/**
	* Returns a new PermissionCollection object for storing BasicPermission
	* objects.
	*
	* <p>BasicPermission objects must be stored in a manner that allows them
	* to be inserted in any order, but that also enables the
	* PermissionCollection {@code implies} method
	* to be implemented in an efficient (and consistent) manner.
	*
	* @return a new PermissionCollection object suitable for
	* storing BasicPermissions.
	*/
	@Override
	public PermissionCollection newPermissionCollection() {
	return new BasicPermissionCollection(this.getClass());
	}

	/**
	* readObject is called to restore the state of the BasicPermission from
	* a stream.
	*
	* @param s the {@code ObjectInputStream} from which data is read
	* @throws IOException if an I/O error occurs
	* @throws ClassNotFoundException if a serialized class cannot be loaded
	*/
	@java.io.Serial
	private void readObject(ObjectInputStream s)
	throws IOException, ClassNotFoundException
	{
	s.defaultReadObject();
	// init is called to initialize the rest of the values.
	init(getName());
	}

	/**
	* Returns the canonical name of this BasicPermission.
	* All internal invocations of getName should invoke this method, so
	* that the pre-JDK 1.6 "exitVM" and current "exitVM.*" permission are
	* equivalent in equals/hashCode methods.
	*
	* @return the canonical name of this BasicPermission.
	*/
	final String getCanonicalName() {
	return exitVM ? "exitVM.*" : getName();
	}
	}

	/**
	* A BasicPermissionCollection stores a collection
	* of BasicPermission permissions. BasicPermission objects
	* must be stored in a manner that allows them to be inserted in any
	* order, but enable the implies function to evaluate the implies
	* method in an efficient (and consistent) manner.
	*
	* A BasicPermissionCollection handles comparing a permission like "a.b.c.d.e"
	* with a Permission such as "a.b.", or "".
	*
	* @see java.security.Permission
	* @see java.security.Permissions
	*
	*
	* @author Roland Schemers
	*
	* @serial include
	*/

	final class BasicPermissionCollection
	extends PermissionCollection
	implements java.io.Serializable
	{

	@java.io.Serial
	private static final long serialVersionUID = 739301742472979399L;

	/**
	* Key is name, value is permission. All permission objects in
	* collection must be of the same type.
	* Not serialized; see serialization section at end of class.
	*/
	private transient ConcurrentHashMap<String, Permission> perms;

	/**
	* This is set to {@code true} if this BasicPermissionCollection
	* contains a BasicPermission with '*' as its permission name.
	*
	* @see #serialPersistentFields
	*/
	private boolean all_allowed;

	/**
	* The class to which all BasicPermissions in this
	* BasicPermissionCollection belong.
	*
	* @see #serialPersistentFields
	*/
	private Class<?> permClass;

	/**
	* Create an empty BasicPermissionCollection object.
	*
	*/
	public BasicPermissionCollection(Class<?> clazz) {
	perms = new ConcurrentHashMap<>(11);
	all_allowed = false;
	permClass = clazz;
	}

	/**
	* Adds a permission to the BasicPermissions. The key for the hash is
	* permission.path.
	*
	* @param permission the Permission object to add.
	*
	* @throws IllegalArgumentException if the permission is not a
	* BasicPermission, or if
	* the permission is not of the
	* same Class as the other
	* permissions in this collection.
	*
	* @throws SecurityException if this BasicPermissionCollection object
	* has been marked readonly
	*/
	@Override
	public void add(Permission permission) {
	if (!(permission instanceof BasicPermission basicPermission))
	throw new IllegalArgumentException("invalid permission: "+
	permission);
	if (isReadOnly())
	throw new SecurityException("attempt to add a Permission to a readonly PermissionCollection");

	// make sure we only add new BasicPermissions of the same class
	// Also check null for compatibility with deserialized form from
	// previous versions.
	if (permClass == null) {
	// adding first permission
	permClass = basicPermission.getClass();
	} else {
	if (basicPermission.getClass() != permClass)
	throw new IllegalArgumentException("invalid permission: " +
	permission);
	}

	String canonName = basicPermission.getCanonicalName();
	perms.put(canonName, permission);

	// No sync on all_allowed; staleness OK
	if (!all_allowed) {
	if (canonName.equals("*"))
	all_allowed = true;
	}
	}

	/**
	* Check and see if this set of permissions implies the permissions
	* expressed in "permission".
	*
	* @param permission the Permission object to compare
	*
	* @return true if "permission" is a proper subset of a permission in
	* the set, false if not.
	*/
	@Override
	public boolean implies(Permission permission) {
	if (!(permission instanceof BasicPermission basicPermission))
	return false;

	// random subclasses of BasicPermission do not imply each other
	if (basicPermission.getClass() != permClass)
	return false;

	// short circuit if the "*" Permission was added
	if (all_allowed)
	return true;

	// strategy:
	// Check for full match first. Then work our way up the
	// path looking for matches on a.b..*

	String path = basicPermission.getCanonicalName();
	//System.out.println("check "+path);

	Permission x = perms.get(path);

	if (x != null) {
	// we have a direct hit!
	return x.implies(permission);
	}

	// work our way up the tree...
	int last, offset;

	offset = path.length()-1;

	while ((last = path.lastIndexOf('.', offset)) != -1) {

	path = path.substring(0, last+1) + "*";
	//System.out.println("check "+path);

	x = perms.get(path);

	if (x != null) {
	return x.implies(permission);
	}
	offset = last -1;
	}

	// we don't have to check for "*" as it was already checked
	// at the top (all_allowed), so we just return false
	return false;
	}

	/**
	* Returns an enumeration of all the BasicPermission objects in the
	* container.
	*
	* @return an enumeration of all the BasicPermission objects.
	*/
	@Override
	public Enumeration<Permission> elements() {
	return perms.elements();
	}

	// Need to maintain serialization interoperability with earlier releases,
	// which had the serializable field:
	//
	// @serial the Hashtable is indexed by the BasicPermission name
	//
	// private Hashtable permissions;
	/**
	* @serialField permissions java.util.Hashtable
	* The BasicPermissions in this BasicPermissionCollection.
	* All BasicPermissions in the collection must belong to the same class.
	* The Hashtable is indexed by the BasicPermission name; the value
	* of the Hashtable entry is the permission.
	* @serialField all_allowed boolean
	* This is set to {@code true} if this BasicPermissionCollection
	* contains a BasicPermission with '*' as its permission name.
	* @serialField permClass java.lang.Class
	* The class to which all BasicPermissions in this
	* BasicPermissionCollection belongs.
	*/
	@java.io.Serial
	private static final ObjectStreamField[] serialPersistentFields = {
	new ObjectStreamField("permissions", Hashtable.class),
	new ObjectStreamField("all_allowed", Boolean.TYPE),
	new ObjectStreamField("permClass", Class.class),
	};

	/*
	* @serialData Default fields.
	*/

	/**
	* Writes the contents of the perms field out as a Hashtable for
	* serialization compatibility with earlier releases. all_allowed
	* and permClass unchanged.
	*
	* @param out the {@code ObjectOutputStream} to which data is written
	* @throws IOException if an I/O error occurs
	*/
	@java.io.Serial
	private void writeObject(ObjectOutputStream out) throws IOException {
	// Don't call out.defaultWriteObject()

	// Copy perms into a Hashtable
	Hashtable<String, Permission> permissions =
	new Hashtable<>(perms.size()*2);

	permissions.putAll(perms);

	// Write out serializable fields
	ObjectOutputStream.PutField pfields = out.putFields();
	pfields.put("all_allowed", all_allowed);
	pfields.put("permissions", permissions);
	pfields.put("permClass", permClass);
	out.writeFields();
	}

	/**
	* readObject is called to restore the state of the
	* BasicPermissionCollection from a stream.
	*
	* @param in the {@code ObjectInputStream} from which data is read
	* @throws IOException if an I/O error occurs
	* @throws ClassNotFoundException if a serialized class cannot be loaded
	*/
	@java.io.Serial
	private void readObject(java.io.ObjectInputStream in)
	throws IOException, ClassNotFoundException
	{
	// Don't call defaultReadObject()

	// Read in serialized fields
	ObjectInputStream.GetField gfields = in.readFields();

	// Get permissions
	// writeObject writes a Hashtable<String, Permission> for the
	// permissions key, so this cast is safe, unless the data is corrupt.
	@SuppressWarnings("unchecked")
	Hashtable<String, Permission> permissions =
	(Hashtable<String, Permission>)gfields.get("permissions", null);
	perms = new ConcurrentHashMap<>(permissions.size()*2);
	perms.putAll(permissions);

	// Get all_allowed
	all_allowed = gfields.get("all_allowed", false);

	// Get permClass
	permClass = (Class<?>) gfields.get("permClass", null);

	if (permClass == null) {
	// set permClass
	Enumeration<Permission> e = permissions.elements();
	if (e.hasMoreElements()) {
	Permission p = e.nextElement();
	permClass = p.getClass();
	}
	}
	}
	}

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