311 lines
11 KiB
Java
311 lines
11 KiB
Java
/* Policy.java --- Policy Manager Class
|
|
Copyright (C) 1999, 2003, 2004 Free Software Foundation, Inc.
|
|
|
|
This file is part of GNU Classpath.
|
|
|
|
GNU Classpath is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation; either version 2, or (at your option)
|
|
any later version.
|
|
|
|
GNU Classpath 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 for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with GNU Classpath; see the file COPYING. If not, write to the
|
|
Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
|
|
02110-1301 USA.
|
|
|
|
Linking this library statically or dynamically with other modules is
|
|
making a combined work based on this library. Thus, the terms and
|
|
conditions of the GNU General Public License cover the whole
|
|
combination.
|
|
|
|
As a special exception, the copyright holders of this library give you
|
|
permission to link this library with independent modules to produce an
|
|
executable, regardless of the license terms of these independent
|
|
modules, and to copy and distribute the resulting executable under
|
|
terms of your choice, provided that you also meet, for each linked
|
|
independent module, the terms and conditions of the license of that
|
|
module. An independent module is a module which is not derived from
|
|
or based on this library. If you modify this library, you may extend
|
|
this exception to your version of the library, but you are not
|
|
obligated to do so. If you do not wish to do so, delete this
|
|
exception statement from your version. */
|
|
|
|
package java.security;
|
|
|
|
import java.util.Collections;
|
|
import java.util.Enumeration;
|
|
import java.util.LinkedHashMap;
|
|
import java.util.Map;
|
|
|
|
/**
|
|
* <p>This is an abstract class for representing the system security policy for
|
|
* a Java application environment (specifying which permissions are available
|
|
* for code from various sources). That is, the security policy is represented
|
|
* by a <code>Policy</code> subclass providing an implementation of the abstract
|
|
* methods in this <code>Policy</code> class.</p>
|
|
*
|
|
* <p>There is only one <code>Policy</code> object in effect at any given time.
|
|
* </p>
|
|
*
|
|
* <p>The source location for the policy information utilized by the
|
|
* <code>Policy</code> object is up to the <code>Policy</code> implementation.
|
|
* The policy configuration may be stored, for example, as a flat ASCII file, as
|
|
* a serialized binary file of the <code>Policy</code> class, or as a database.
|
|
* </p>
|
|
*
|
|
* <p>The currently-installed <code>Policy</code> object can be obtained by
|
|
* calling the <code>getPolicy()</code> method, and it can be changed by a call
|
|
* to the <code>setPolicy()</code> method (by code with permission to reset the
|
|
* <code>Policy</code>).</p>
|
|
*
|
|
* <p>The <code>refresh()</code> method causes the policy object to refresh /
|
|
* reload its current configuration.</p>
|
|
*
|
|
* <p>This is implementation-dependent. For example, if the policy object stores
|
|
* its policy in configuration files, calling <code>refresh()</code> will cause
|
|
* it to re-read the configuration policy files. The refreshed policy may not
|
|
* have an effect on classes in a particular {@link ProtectionDomain}. This is
|
|
* dependent on the <code>Policy</code> provider's implementation of the
|
|
* <code>implies()</code> method and the {@link PermissionCollection} caching
|
|
* strategy.</p>
|
|
*
|
|
* <p>The default <code>Policy</code> implementation can be changed by setting
|
|
* the value of the <code>"policy.provider"</code> security property (in the
|
|
* Java security properties file) to the fully qualified name of the desired
|
|
* <code>Policy</code> implementation class. The Java security properties file
|
|
* is located in the file named <code><JAVA_HOME>/lib/security/java.security
|
|
* </code>, where <code><JAVA_HOME></code> refers to the directory where the
|
|
* SDK was installed.</p>
|
|
*
|
|
* <p><b>IMPLEMENTATION NOTE:</b> This implementation attempts to read the
|
|
* System property named <code>policy.provider</code> to find the concrete
|
|
* implementation of the <code>Policy</code>. If/when this fails, it falls back
|
|
* to a default implementation, which <b>allows everything</b>.
|
|
*
|
|
* @author Mark Benvenuto
|
|
* @see CodeSource
|
|
* @see PermissionCollection
|
|
* @see SecureClassLoader
|
|
* @since 1.2
|
|
*/
|
|
public abstract class Policy
|
|
{
|
|
private static Policy currentPolicy;
|
|
|
|
/** Map of ProtectionDomains to PermissionCollections for this instance. */
|
|
private Map pd2pc = null;
|
|
|
|
/** Constructs a new <code>Policy</code> object. */
|
|
public Policy()
|
|
{
|
|
}
|
|
|
|
/**
|
|
* Returns the installed <code>Policy</code> object. This value should not be
|
|
* cached, as it may be changed by a call to <code>setPolicy()</code>. This
|
|
* method first calls {@link SecurityManager#checkPermission(Permission)} with
|
|
* a <code>SecurityPermission("getPolicy")</code> permission to ensure it's ok
|
|
* to get the <code>Policy</code> object.
|
|
*
|
|
* @return the installed <code>Policy</code>.
|
|
* @throws SecurityException if a security manager exists and its
|
|
* <code>checkPermission()</code> method doesn't allow getting the
|
|
* <code>Policy</code> object.
|
|
* @see SecurityManager#checkPermission(Permission)
|
|
* @see #setPolicy(Policy)
|
|
*/
|
|
public static Policy getPolicy()
|
|
{
|
|
SecurityManager sm = System.getSecurityManager();
|
|
if (sm != null)
|
|
sm.checkPermission(new SecurityPermission("getPolicy"));
|
|
|
|
return getCurrentPolicy();
|
|
}
|
|
|
|
/**
|
|
* Sets the system-wide <code>Policy</code> object. This method first calls
|
|
* {@link SecurityManager#checkPermission(Permission)} with a
|
|
* <code>SecurityPermission("setPolicy")</code> permission to ensure it's ok
|
|
* to set the <code>Policy</code>.
|
|
*
|
|
* @param policy the new system <code>Policy</code> object.
|
|
* @throws SecurityException if a security manager exists and its
|
|
* <code>checkPermission()</code> method doesn't allow setting the
|
|
* <code>Policy</code>.
|
|
* @see SecurityManager#checkPermission(Permission)
|
|
* @see #getPolicy()
|
|
*/
|
|
public static void setPolicy(Policy policy)
|
|
{
|
|
SecurityManager sm = System.getSecurityManager();
|
|
if (sm != null)
|
|
sm.checkPermission(new SecurityPermission("setPolicy"));
|
|
|
|
setup(policy);
|
|
currentPolicy = policy;
|
|
}
|
|
|
|
private static void setup(final Policy policy)
|
|
{
|
|
if (policy.pd2pc == null)
|
|
policy.pd2pc = Collections.synchronizedMap(new LinkedHashMap());
|
|
|
|
ProtectionDomain pd = policy.getClass().getProtectionDomain();
|
|
if (pd.getCodeSource() != null)
|
|
{
|
|
PermissionCollection pc = null;
|
|
if (currentPolicy != null)
|
|
pc = currentPolicy.getPermissions(pd);
|
|
|
|
if (pc == null) // assume it has all
|
|
{
|
|
pc = new Permissions();
|
|
pc.add(new AllPermission());
|
|
}
|
|
|
|
policy.pd2pc.put(pd, pc); // add the mapping pd -> pc
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Ensures/forces loading of the configured policy provider, while bypassing
|
|
* the {@link SecurityManager} checks for <code>"getPolicy"</code> security
|
|
* permission. Needed by {@link ProtectionDomain}.
|
|
*/
|
|
static Policy getCurrentPolicy()
|
|
{
|
|
// FIXME: The class name of the Policy provider should really be sourced
|
|
// from the "java.security" configuration file. For now, just hard-code
|
|
// a stub implementation.
|
|
if (currentPolicy == null)
|
|
{
|
|
String pp = System.getProperty ("policy.provider");
|
|
if (pp != null)
|
|
try
|
|
{
|
|
currentPolicy = (Policy) Class.forName(pp).newInstance();
|
|
}
|
|
catch (Exception e)
|
|
{
|
|
// Ignored.
|
|
}
|
|
|
|
if (currentPolicy == null)
|
|
currentPolicy = new gnu.java.security.provider.DefaultPolicy();
|
|
}
|
|
return currentPolicy;
|
|
}
|
|
|
|
/**
|
|
* Tests if <code>currentPolicy</code> is not <code>null</code>,
|
|
* thus allowing clients to not force loading of any policy
|
|
* provider; needed by {@link ProtectionDomain}.
|
|
*/
|
|
static boolean isLoaded()
|
|
{
|
|
return currentPolicy != null;
|
|
}
|
|
|
|
/**
|
|
* Evaluates the global policy and returns a {@link PermissionCollection}
|
|
* object specifying the set of permissions allowed for code from the
|
|
* specified code source.
|
|
*
|
|
* @param codesource the {@link CodeSource} associated with the caller. This
|
|
* encapsulates the original location of the code (where the code came from)
|
|
* and the public key(s) of its signer.
|
|
* @return the set of permissions allowed for code from codesource according
|
|
* to the policy. The returned set of permissions must be a new mutable
|
|
* instance and it must support heterogeneous {@link Permission} types.
|
|
*/
|
|
public abstract PermissionCollection getPermissions(CodeSource codesource);
|
|
|
|
/**
|
|
* Evaluates the global policy and returns a {@link PermissionCollection}
|
|
* object specifying the set of permissions allowed given the characteristics
|
|
* of the protection domain.
|
|
*
|
|
* @param domain the {@link ProtectionDomain} associated with the caller.
|
|
* @return the set of permissions allowed for the domain according to the
|
|
* policy. The returned set of permissions must be a new mutable instance and
|
|
* it must support heterogeneous {@link Permission} types.
|
|
* @since 1.4
|
|
* @see ProtectionDomain
|
|
* @see SecureClassLoader
|
|
*/
|
|
public PermissionCollection getPermissions(ProtectionDomain domain)
|
|
{
|
|
if (domain == null)
|
|
return new Permissions();
|
|
|
|
if (pd2pc == null)
|
|
setup(this);
|
|
|
|
PermissionCollection result = (PermissionCollection) pd2pc.get(domain);
|
|
if (result != null)
|
|
{
|
|
Permissions realResult = new Permissions();
|
|
for (Enumeration e = result.elements(); e.hasMoreElements(); )
|
|
realResult.add((Permission) e.nextElement());
|
|
|
|
return realResult;
|
|
}
|
|
|
|
result = getPermissions(domain.getCodeSource());
|
|
if (result == null)
|
|
result = new Permissions();
|
|
|
|
PermissionCollection pc = domain.getPermissions();
|
|
if (pc != null)
|
|
for (Enumeration e = pc.elements(); e.hasMoreElements(); )
|
|
result.add((Permission) e.nextElement());
|
|
|
|
return result;
|
|
}
|
|
|
|
/**
|
|
* Evaluates the global policy for the permissions granted to the {@link
|
|
* ProtectionDomain} and tests whether the <code>permission</code> is granted.
|
|
*
|
|
* @param domain the {@link ProtectionDomain} to test.
|
|
* @param permission the {@link Permission} object to be tested for
|
|
* implication.
|
|
* @return <code>true</code> if <code>permission</code> is a proper subset of
|
|
* a permission granted to this {@link ProtectionDomain}.
|
|
* @since 1.4
|
|
* @see ProtectionDomain
|
|
*/
|
|
public boolean implies(ProtectionDomain domain, Permission permission)
|
|
{
|
|
if (pd2pc == null)
|
|
setup(this);
|
|
|
|
PermissionCollection pc = (PermissionCollection) pd2pc.get(domain);
|
|
if (pc != null)
|
|
return pc.implies(permission);
|
|
|
|
boolean result = false;
|
|
pc = getPermissions(domain);
|
|
if (pc != null)
|
|
{
|
|
result = pc.implies(permission);
|
|
pd2pc.put(domain, pc);
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
/**
|
|
* Refreshes/reloads the policy configuration. The behavior of this method
|
|
* depends on the implementation. For example, calling refresh on a file-based
|
|
* policy will cause the file to be re-read.
|
|
*/
|
|
public abstract void refresh();
|
|
}
|