/*
* @(#)PropertyPermission.java 1.35 06/04/21
*
* Copyright 2006 Sun Microsystems, Inc. All rights reserved.
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*/
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.*" or "*" is valid,
* "*java" or "a*b" is not valid.
* <P>
* <P>
* The actions to be granted are passed to the constructor in a string containing
* a list of zero or more comma-separated keywords. The possible keywords are
* "read" and "write". Their meaning is defined as follows:
* <P>
* <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
*
* @version 1.35 06/04/21
*
* @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:<p>
* <ul>
* <li> <i>p</i> is an instanceof PropertyPermission,<p>
* <li> <i>p</i>'s actions are a subset of this
* object's actions, and <p>
* <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.
* <P>
* @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 action the action string.
* @return the actions mask.
*/
private static int getMask(String actions) {
int mask = NONE;
if (actions == null) {
return mask;
}
// Check against use of constants (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;
/*FALLTHROUGH*/
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.
* <p>
*
* @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
*
* @version 1.35, 04/21/06
*
* @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 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 PropertyPermissions 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 = (PropertyPermission) 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, permission);
}
}
if (!all_allowed) {
if (propName.equals("*"))
all_allowed = true;
}
}
/**
* Check and see if this set of permissions implies the permissions
* expressed in "permission".
*
* @param p 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 = (PropertyPermission) perms.get("*");
}
if (x != null) {
effective |= x.getMask();
if ((effective & desired) == desired)
return true;
}
}
// strategy:
// Check for full match first. Then work our way up the
// name looking for matches on a.b.*
String name = pp.getName();
//System.out.println("check "+name);
synchronized (this) {
x = (PropertyPermission) perms.get(name);
}
if (x != null) {
// we have a direct hit!
effective |= x.getMask();
if ((effective & desired) == desired)
return true;
}
// work our way up the tree...
int last, offset;
offset = name.length()-1;
while ((last = name.lastIndexOf(".", offset)) != -1) {
name = name.substring(0, last+1) + "*";
//System.out.println("check "+name);
synchronized (this) {
x = (PropertyPermission) perms.get(name);
}
if (x != null) {
effective |= x.getMask();
if ((effective & desired) == desired)
return true;
}
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 PropertyPermission objects in the
* container.
*
* @return an enumeration of all the PropertyPermission objects.
*/
public Enumeration elements() {
// Convert Iterator of Map values into an Enumeration
synchronized (this) {
return Collections.enumeration(perms.values());
}
}
private static final long serialVersionUID = 7015263904581634791L;
// Need to maintain serialization interoperability with earlier releases,
// which had the serializable field:
//
// Table of permissions.
//
// @serial
//
// private Hashtable permissions;
/**
* @serialField permissions java.util.Hashtable
* A table of the PropertyPermissions.
* @serialField all_allowed boolean
* boolean saying if "*" is in the collection.
*/
private static final ObjectStreamField[] serialPersistentFields = {
new ObjectStreamField("permissions", Hashtable.class),
new ObjectStreamField("all_allowed", Boolean.TYPE),
};
/**
* @serialData Default fields.
*/
/*
* Writes the contents of the perms field out as a Hashtable for
* serialization compatibility with earlier releases. all_allowed
* unchanged.
*/
private void writeObject(ObjectOutputStream out) throws IOException {
// Don't call out.defaultWriteObject()
// Copy perms into a Hashtable
Hashtable permissions = new Hashtable(perms.size()*2);
synchronized (this) {
permissions.putAll(perms);
}
// Write out serializable fields
ObjectOutputStream.PutField pfields = out.putFields();
pfields.put("all_allowed", all_allowed);
pfields.put("permissions", permissions);
out.writeFields();
}
/*
* Reads in a Hashtable of PropertyPermissions and saves them in the
* perms field. Reads in all_allowed.
*/
private void readObject(ObjectInputStream in) throws IOException,
ClassNotFoundException {
// Don't call defaultReadObject()
// Read in serialized fields
ObjectInputStream.GetField gfields = in.readFields();
// Get all_allowed
all_allowed = gfields.get("all_allowed", false);
// Get permissions
Hashtable permissions = (Hashtable)gfields.get("permissions", null);
perms = new HashMap(permissions.size()*2);
perms.putAll(permissions);
}
}
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