/*

 * Copyright (c) 1997, 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

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package java.util;

import java.io.Serializable;

import java.io.IOException;

import java.security.*;

import java.util.Map;

import java.util.HashMap;

import java.util.Enumeration;

import java.util.Hashtable;

import java.util.Collections;

import java.io.ObjectStreamField;

import java.io.ObjectOutputStream;

import java.io.ObjectInputStream;

import java.io.IOException;

import sun.security.util.SecurityConstants;

/**

 * This class is for property permissions.

 *

 * <P>

 * The name is the name of the property ("java.home",

 * "os.name", etc). The naming

 * convention follows the  hierarchical property naming convention.

 * Also, an asterisk

 * may appear at the end of the name, following a ".", or by itself, to

 * signify a wildcard match. For example: "java.*" and "*" signify a wildcard

 * match, while "*java" and "a*b" do not.

 * <P>

 * The actions to be granted are passed to the constructor in a string containing

 * a list of one or more comma-separated keywords. The possible keywords are

 * "read" and "write". Their meaning is defined as follows:

 *

 * <DL>

 *    <DT> read

 *    <DD> read permission. Allows <code>System.getProperty</code> to

 *         be called.

 *    <DT> write

 *    <DD> write permission. Allows <code>System.setProperty</code> to

 *         be called.

 * </DL>

 * <P>

 * The actions string is converted to lowercase before processing.

 * <P>

 * Care should be taken before granting code permission to access

 * certain system properties.  For example, granting permission to

 * access the "java.home" system property gives potentially malevolent

 * code sensitive information about the system environment (the Java

 * installation directory).  Also, granting permission to access

 * the "user.name" and "user.home" system properties gives potentially

 * malevolent code sensitive information about the user environment

 * (the user's account name and home directory).

 *

 * @see java.security.BasicPermission

 * @see java.security.Permission

 * @see java.security.Permissions

 * @see java.security.PermissionCollection

 * @see java.lang.SecurityManager

 *

 *

 * @author Roland Schemers

 * @since 1.2

 *

 * @serial exclude

 */

public final class PropertyPermission extends BasicPermission {

    /**

     * Read action.

     */

    private final static int READ    = 0x1;

    /**

     * Write action.

     */

    private final static int WRITE   = 0x2;

    /**

     * All actions (read,write);

     */

    private final static int ALL     = READ|WRITE;

    /**

     * No actions.

     */

    private final static int NONE    = 0x0;

    /**

     * The actions mask.

     *

     */

    private transient int mask;

    /**

     * The actions string.

     *

     * @serial

     */

    private String actions; // Left null as long as possible, then

                            // created and re-used in the getAction function.

    /**

     * initialize a PropertyPermission object. Common to all constructors.

     * Also called during de-serialization.

     *

     * @param mask the actions mask to use.

     *

     */

    private void init(int mask) {

        if ((mask & ALL) != mask)

            throw new IllegalArgumentException("invalid actions mask");

        if (mask == NONE)

            throw new IllegalArgumentException("invalid actions mask");

        if (getName() == null)

            throw new NullPointerException("name can't be null");

        this.mask = mask;

    }

    /**

     * Creates a new PropertyPermission object with the specified name.

     * The name is the name of the system property, and

     * <i>actions</i> contains a comma-separated list of the

     * desired actions granted on the property. Possible actions are

     * "read" and "write".

     *

     * @param name the name of the PropertyPermission.

     * @param actions the actions string.

     *

     * @throws NullPointerException if <code>name</code> is <code>null</code>.

     * @throws IllegalArgumentException if <code>name</code> is empty or if

     * <code>actions</code> is invalid.

     */

    public PropertyPermission(String name, String actions) {

        super(name,actions);

        init(getMask(actions));

    }

    /**

     * Checks if this PropertyPermission object "implies" the specified

     * permission.

     * <P>

     * More specifically, this method returns true if:

     * <ul>

     * <li> <i>p</i> is an instanceof PropertyPermission,

     * <li> <i>p</i>'s actions are a subset of this

     * object's actions, and

     * <li> <i>p</i>'s name is implied by this object's

     *      name. For example, "java.*" implies "java.home".

     * </ul>

     * @param p the permission to check against.

     *

     * @return true if the specified permission is implied by this object,

     * false if not.

     */

    public boolean implies(Permission p) {

        if (!(p instanceof PropertyPermission))

            return false;

        PropertyPermission that = (PropertyPermission) p;

        // we get the effective mask. i.e., the "and" of this and that.

        // They must be equal to that.mask for implies to return true.

        return ((this.mask & that.mask) == that.mask) && super.implies(that);

    }

    /**

     * Checks two PropertyPermission objects for equality. Checks that <i>obj</i> is

     * a PropertyPermission, and has the same name and actions as this object.

     *

     * @param obj the object we are testing for equality with this object.

     * @return true if obj is a PropertyPermission, and has the same name and

     * actions as this PropertyPermission object.

     */

    public boolean equals(Object obj) {

        if (obj == this)

            return true;

        if (! (obj instanceof PropertyPermission))

            return false;

        PropertyPermission that = (PropertyPermission) obj;

        return (this.mask == that.mask) &&

            (this.getName().equals(that.getName()));

    }

    /**

     * Returns the hash code value for this object.

     * The hash code used is the hash code of this permissions name, that is,

     * <code>getName().hashCode()</code>, where <code>getName</code> is

     * from the Permission superclass.

     *

     * @return a hash code value for this object.

     */

    public int hashCode() {

        return this.getName().hashCode();

    }

    /**

     * Converts an actions String to an actions mask.

     *

     * @param actions the action string.

     * @return the actions mask.

     */

    private static int getMask(String actions) {

        int mask = NONE;

        if (actions == null) {

            return mask;

        }

        // Use object identity comparison against known-interned strings for

        // performance benefit (these values are used heavily within the JDK).

        if (actions == SecurityConstants.PROPERTY_READ_ACTION) {

            return READ;

        } if (actions == SecurityConstants.PROPERTY_WRITE_ACTION) {

            return WRITE;

        } else if (actions == SecurityConstants.PROPERTY_RW_ACTION) {

            return READ|WRITE;

        }

        char[] a = actions.toCharArray();

        int i = a.length - 1;

        if (i < 0)

            return mask;

        while (i != -1) {

            char c;

            // skip whitespace

            while ((i!=-1) && ((c = a[i]) == ' ' ||

                               c == '\r' ||

                               c == '\n' ||

                               c == '\f' ||

                               c == '\t'))

                i--;

            // check for the known strings

            int matchlen;

            if (i >= 3 && (a[i-3] == 'r' || a[i-3] == 'R') &&

                          (a[i-2] == 'e' || a[i-2] == 'E') &&

                          (a[i-1] == 'a' || a[i-1] == 'A') &&

                          (a[i] == 'd' || a[i] == 'D'))

            {

                matchlen = 4;

                mask |= READ;

            } else if (i >= 4 && (a[i-4] == 'w' || a[i-4] == 'W') &&

                                 (a[i-3] == 'r' || a[i-3] == 'R') &&

                                 (a[i-2] == 'i' || a[i-2] == 'I') &&

                                 (a[i-1] == 't' || a[i-1] == 'T') &&

                                 (a[i] == 'e' || a[i] == 'E'))

            {

                matchlen = 5;

                mask |= WRITE;

            } else {

                // parse error

                throw new IllegalArgumentException(

                        "invalid permission: " + actions);

            }

            // make sure we didn't just match the tail of a word

            // like "ackbarfaccept".  Also, skip to the comma.

            boolean seencomma = false;

            while (i >= matchlen && !seencomma) {

                switch(a[i-matchlen]) {

                case ',':

                    seencomma = true;

                    break;

                case ' ': case '\r': case '\n':

                case '\f': case '\t':

                    break;

                default:

                    throw new IllegalArgumentException(

                            "invalid permission: " + actions);

                }

                i--;

            }

            // point i at the location of the comma minus one (or -1).

            i -= matchlen;

        }

        return mask;

    }

    /**

     * Return the canonical string representation of the actions.

     * Always returns present actions in the following order:

     * read, write.

     *

     * @return the canonical string representation of the actions.

     */

    static String getActions(int mask) {

        StringBuilder sb = new StringBuilder();

        boolean comma = false;

        if ((mask & READ) == READ) {

            comma = true;

            sb.append("read");

        }

        if ((mask & WRITE) == WRITE) {

            if (comma) sb.append(',');

            else comma = true;

            sb.append("write");

        }

        return sb.toString();

    }

    /**

     * Returns the "canonical string representation" of the actions.

     * That is, this method always returns present actions in the following order:

     * read, write. For example, if this PropertyPermission object

     * allows both write and read actions, a call to <code>getActions</code>

     * will return the string "read,write".

     *

     * @return the canonical string representation of the actions.

     */

    public String getActions() {

        if (actions == null)

            actions = getActions(this.mask);

        return actions;

    }

    /**

     * Return the current action mask.

     * Used by the PropertyPermissionCollection

     *

     * @return the actions mask.

     */

    int getMask() {

        return mask;

    }

    /**

     * Returns a new PermissionCollection object for storing

     * PropertyPermission objects.

     *

     * @return a new PermissionCollection object suitable for storing

     * PropertyPermissions.

     */

    public PermissionCollection newPermissionCollection() {

        return new PropertyPermissionCollection();

    }

    private static final long serialVersionUID = 885438825399942851L;

    /**

     * WriteObject is called to save the state of the PropertyPermission

     * to a stream. The actions are serialized, and the superclass

     * takes care of the name.

     */

    private synchronized void writeObject(java.io.ObjectOutputStream s)

        throws IOException

    {

        // Write out the actions. The superclass takes care of the name

        // call getActions to make sure actions field is initialized

        if (actions == null)

            getActions();

        s.defaultWriteObject();

    }

    /**

     * readObject is called to restore the state of the PropertyPermission from

     * a stream.

     */

    private synchronized void readObject(java.io.ObjectInputStream s)

         throws IOException, ClassNotFoundException

    {

        // Read in the action, then initialize the rest

        s.defaultReadObject();

        init(getMask(actions));

    }

}

/**

 * A PropertyPermissionCollection stores a set of PropertyPermission

 * permissions.

 *

 * @see java.security.Permission

 * @see java.security.Permissions

 * @see java.security.PermissionCollection

 *

 *

 * @author Roland Schemers

 *

 * @serial include

 */

final class PropertyPermissionCollection extends PermissionCollection

    implements Serializable

{

    /**

     * Key is property name; value is PropertyPermission.

     * Not serialized; see serialization section at end of class.

     */

    private transient Map<String, PropertyPermission> perms;

    /**

     * Boolean saying if "*" is in the collection.

     *

     * @see #serialPersistentFields

     */

    // No sync access; OK for this to be stale.

    private boolean all_allowed;

    /**

     * Create an empty PropertyPermissionCollection object.

     */

    public PropertyPermissionCollection() {

        perms = new HashMap<>(32);     // Capacity for default policy

        all_allowed = false;

    }

    /**

     * Adds a permission to the PropertyPermissions. The key for the hash is

     * the name.

     *

     * @param permission the Permission object to add.

     *

     * @exception IllegalArgumentException - if the permission is not a

     *                                       PropertyPermission

     *

     * @exception SecurityException - if this PropertyPermissionCollection

     *                                object has been marked readonly

     */

    public void add(Permission permission) {

        if (! (permission instanceof PropertyPermission))

            throw new IllegalArgumentException("invalid permission: "+

                                               permission);

        if (isReadOnly())

            throw new SecurityException(

                "attempt to add a Permission to a readonly PermissionCollection");

        PropertyPermission pp = (PropertyPermission) permission;

        String propName = pp.getName();

        synchronized (this) {

            PropertyPermission existing = perms.get(propName);

            if (existing != null) {

                int oldMask = existing.getMask();

                int newMask = pp.getMask();

                if (oldMask != newMask) {

                    int effective = oldMask | newMask;

                    String actions = PropertyPermission.getActions(effective);

                    perms.put(propName, new PropertyPermission(propName, actions));

                }

            } else {

                perms.put(propName, pp);

            }

        }

        if (!all_allowed) {

            if (propName.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.

     */

    public boolean implies(Permission permission) {

        if (! (permission instanceof PropertyPermission))

                return false;

        PropertyPermission pp = (PropertyPermission) permission;

        PropertyPermission x;

        int desired = pp.getMask();

        int effective = 0;

        // short circuit if the "*" Permission was added

        if (all_allowed) {

            synchronized (this) {

                x = perms.get("*");

            }

            if (x != null) {

                effective |= x.getMask();

                if ((effective & desired) == desired)

                    return true;