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Diffstat (limited to 'libjava/classpath/java/security/BasicPermission.java')
| -rw-r--r-- | libjava/classpath/java/security/BasicPermission.java | 308 |
1 files changed, 308 insertions, 0 deletions
diff --git a/libjava/classpath/java/security/BasicPermission.java b/libjava/classpath/java/security/BasicPermission.java new file mode 100644 index 00000000000..267a6e292ab --- /dev/null +++ b/libjava/classpath/java/security/BasicPermission.java @@ -0,0 +1,308 @@ +/* BasicPermission.java -- implements a simple named permission + Copyright (C) 1998, 1999, 2002, 2003, 2004, 2005 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.io.Serializable; +import java.util.Enumeration; +import java.util.Hashtable; + +/** + * This class implements a simple model for named permissions without an + * associated action list. That is, either the named permission is granted + * or it is not. + * + * <p>It also supports trailing wildcards to allow the easy granting of + * permissions in a hierarchical fashion. (For example, the name "org.gnu.*" + * might grant all permissions under the "org.gnu" permissions hierarchy). + * The only valid wildcard character is a '*' which matches anything. It + * must be the rightmost element in the permission name and must follow a + * '.' or else the Permission name must consist of only a '*'. Any other + * occurrence of a '*' is not valid. + * + * <p>This class ignores the action list. Subclasses can choose to implement + * actions on top of this class if desired. + * + * @author Aaron M. Renn (arenn@urbanophile.com) + * @author Eric Blake (ebb9@email.byu.edu) + * @see Permission + * @see Permissions + * @see PermissionCollection + * @see RuntimePermission + * @see SecurityPermission + * @see PropertyPermission + * @see AWTPermission + * @see NetPermission + * @see SecurityManager + * @since 1.1 + * @status updated to 1.4 + */ +public abstract class BasicPermission extends java.security.Permission + implements Serializable + // FIXME extends with fully qualified classname as workaround for gcj 3.3. +{ + /** + * Compatible with JDK 1.1+. + */ + private static final long serialVersionUID = 6279438298436773498L; + + /** + * Create a new instance with the specified permission name. If the + * name is empty an exception is thrown. + * + * @param name the name of this permission + * @throws NullPointerException if name is null + * @throws IllegalArgumentException if name is invalid + */ + public BasicPermission(String name) + { + super(name); + + // This routine used to check for illegal wildcards, but no such + // requirement exists in the specification and Sun's runtime + // doesn't appear to do it. + + if ("".equals(name)) + throw new IllegalArgumentException("Empty name"); + } + + /** + * Create a new instance with the specified permission name. If the name + * is empty, or contains an illegal wildcard character, an exception is + * thrown. The actions parameter is ignored. + * + * @param name the name of this permission + * @param actions ignored + * @throws NullPointerException if name is null + * @throws IllegalArgumentException if name is invalid + */ + public BasicPermission(String name, String actions) + { + this(name); + } + + /** + * This method tests to see if the specified permission is implied by this + * permission. This will be true if the following conditions are met:<ul> + * <li>The specified object is an instance of the same class as this + * object.</li> + * <li>The name of the specified permission is implied by this permission's + * name based on wildcard matching. For example, "a.*" implies "a.b".</li> + * </ul> + * + * @param perm the <code>Permission</code> object to test against + * @return true if the specified permission is implied + */ + public boolean implies(Permission perm) + { + if (! getClass().isInstance(perm)) + return false; + + String otherName = perm.getName(); + String name = getName(); + + if (name.equals(otherName)) + return true; + + int last = name.length() - 1; + return name.charAt(last) == '*' + && otherName.startsWith(name.substring(0, last)); + } + + /** + * This method tests to see if this object is equal to the specified + * <code>Object</code>. This will be true if and only if the specified + * object meets the following conditions:<ul> + * <li>It is an instance of the same class as this.</li> + * <li>It has the same name as this permission.</li> + * </ul> + * + * @param obj the <code>Object</code> to test for equality + * @return true if obj is semantically equal to this + */ + public boolean equals(Object obj) + { + return getClass().isInstance(obj) + && getName().equals(((BasicPermission) obj).getName()); + } + + /** + * This method returns a hash code for this permission object. The hash + * code returned is the value returned by calling the <code>hashCode</code> + * method on the <code>String</code> that is the name of this permission. + * + * @return a hash value for this object + */ + public int hashCode() + { + return getName().hashCode(); + } + + /** + * This method returns a list of the actions associated with this + * permission. This method always returns the empty string ("") since + * this class ignores actions. + * + * @return the action list + */ + public String getActions() + { + return ""; + } + + /** + * This method returns an instance of <code>PermissionCollection</code> + * suitable for storing <code>BasicPermission</code> objects. The + * collection returned can only store objects of the same type as this. + * Subclasses which use actions must override this method; but a class with + * no actions will work fine with this. + * + * @return a new empty <code>PermissionCollection</code> object + */ + public PermissionCollection newPermissionCollection() + { + return new BasicPermissionCollection(getClass()); + } + + /** + * Implements AllPermission.newPermissionCollection, and obeys serialization + * of JDK. + * + * @author Eric Blake (ebb9@email.byu.edu) + */ + private static final class BasicPermissionCollection extends PermissionCollection + { + /** + * Compatible with JDK 1.1+. + */ + private static final long serialVersionUID = 739301742472979399L; + + /** + * The permissions in the collection. + * + * @serial a hash mapping name to permissions, all of type permClass + */ + private final Hashtable permissions = new Hashtable(); + + /** + * If "*" is in the collection. + * + * @serial true if a permission named "*" is in the collection + */ + private boolean all_allowed; + + /** + * The runtime class which all entries in the table must belong to. + * + * @serial the limiting subclass of this collection + */ + private final Class permClass; + + /** + * Construct a collection over the given runtime class. + * + * @param c the class + */ + BasicPermissionCollection(Class c) + { + permClass = c; + } + + /** + * Add a Permission. It must be of the same type as the permission which + * created this collection. + * + * @param perm the permission to add + * @throws IllegalArgumentException if perm is not the correct type + * @throws SecurityException if the collection is read-only + */ + public void add(Permission perm) + { + if (isReadOnly()) + throw new SecurityException("readonly"); + if (! permClass.isInstance(perm)) + throw new IllegalArgumentException("Expecting instance of " + permClass); + BasicPermission bp = (BasicPermission) perm; + String name = bp.getName(); + if (name.equals("*")) + all_allowed = true; + permissions.put(name, bp); + } + + /** + * Returns true if this collection implies the given permission. + * + * @param permission the permission to check + * @return true if it is implied by this + */ + public boolean implies(Permission permission) + { + if (! permClass.isInstance(permission)) + return false; + if (all_allowed) + return true; + BasicPermission toImply = (BasicPermission) permission; + String name = toImply.getName(); + if (name.equals("*")) + return false; + int prefixLength = name.length(); + if (name.endsWith("*")) + prefixLength -= 2; + + while (true) + { + if (permissions.get(name) != null) + return true; + prefixLength = name.lastIndexOf('.', prefixLength); + if (prefixLength < 0) + return false; + name = name.substring(0, prefixLength + 1) + '*'; + } + } + + /** + * Enumerate over the collection. + * + * @return an enumeration of the collection contents + */ + public Enumeration elements() + { + return permissions.elements(); + } + } // class BasicPermissionCollection +} // class BasicPermission |