jdk/src/java.base/share/classes/sun/security/acl/AclImpl.java
changeset 29100 56267f38f743
parent 29099 766801b4d95d
child 29101 55f7a91aaa32
--- a/jdk/src/java.base/share/classes/sun/security/acl/AclImpl.java	Mon Feb 23 08:46:07 2015 -0800
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,408 +0,0 @@
-/*
- * Copyright (c) 1996, 2011, 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 sun.security.acl;
-
-import java.io.*;
-import java.util.*;
-import java.security.Principal;
-import java.security.acl.*;
-
-/**
- * An Access Control List (ACL) is encapsulated by this class.
- * @author      Satish Dharmaraj
- */
-public class AclImpl extends OwnerImpl implements Acl {
-    //
-    // Maintain four tables. one each for positive and negative
-    // ACLs. One each depending on whether the entity is a group
-    // or principal.
-    //
-    private Hashtable<Principal, AclEntry> allowedUsersTable =
-                                        new Hashtable<>(23);
-    private Hashtable<Principal, AclEntry> allowedGroupsTable =
-                                        new Hashtable<>(23);
-    private Hashtable<Principal, AclEntry> deniedUsersTable =
-                                        new Hashtable<>(23);
-    private Hashtable<Principal, AclEntry> deniedGroupsTable =
-                                        new Hashtable<>(23);
-    private String aclName = null;
-    private Vector<Permission> zeroSet = new Vector<>(1,1);
-
-
-    /**
-     * Constructor for creating an empty ACL.
-     */
-    public AclImpl(Principal owner, String name) {
-        super(owner);
-        try {
-            setName(owner, name);
-        } catch (Exception e) {}
-    }
-
-    /**
-     * Sets the name of the ACL.
-     * @param caller the principal who is invoking this method.
-     * @param name the name of the ACL.
-     * @exception NotOwnerException if the caller principal is
-     * not on the owners list of the Acl.
-     */
-    public void setName(Principal caller, String name)
-      throws NotOwnerException
-    {
-        if (!isOwner(caller))
-            throw new NotOwnerException();
-
-        aclName = name;
-    }
-
-    /**
-     * Returns the name of the ACL.
-     * @return the name of the ACL.
-     */
-    public String getName() {
-        return aclName;
-    }
-
-    /**
-     * Adds an ACL entry to this ACL. An entry associates a
-     * group or a principal with a set of permissions. Each
-     * user or group can have one positive ACL entry and one
-     * negative ACL entry. If there is one of the type (negative
-     * or positive) already in the table, a false value is returned.
-     * The caller principal must be a part of the owners list of
-     * the ACL in order to invoke this method.
-     * @param caller the principal who is invoking this method.
-     * @param entry the ACL entry that must be added to the ACL.
-     * @return true on success, false if the entry is already present.
-     * @exception NotOwnerException if the caller principal
-     * is not on the owners list of the Acl.
-     */
-    public synchronized boolean addEntry(Principal caller, AclEntry entry)
-      throws NotOwnerException
-    {
-        if (!isOwner(caller))
-            throw new NotOwnerException();
-
-        Hashtable<Principal, AclEntry> aclTable = findTable(entry);
-        Principal key = entry.getPrincipal();
-
-        if (aclTable.get(key) != null)
-            return false;
-
-        aclTable.put(key, entry);
-        return true;
-    }
-
-    /**
-     * Removes an ACL entry from this ACL.
-     * The caller principal must be a part of the owners list of the ACL
-     * in order to invoke this method.
-     * @param caller the principal who is invoking this method.
-     * @param entry the ACL entry that must be removed from the ACL.
-     * @return true on success, false if the entry is not part of the ACL.
-     * @exception NotOwnerException if the caller principal is not
-     * the owners list of the Acl.
-     */
-    public synchronized boolean removeEntry(Principal caller, AclEntry entry)
-      throws NotOwnerException
-    {
-        if (!isOwner(caller))
-            throw new NotOwnerException();
-
-        Hashtable<Principal, AclEntry> aclTable = findTable(entry);
-        Principal key = entry.getPrincipal();
-
-        AclEntry o = aclTable.remove(key);
-        return (o != null);
-    }
-
-    /**
-     * This method returns the set of allowed permissions for the
-     * specified principal. This set of allowed permissions is calculated
-     * as follows:
-     *
-     * If there is no entry for a group or a principal an empty permission
-     * set is assumed.
-     *
-     * The group positive permission set is the union of all
-     * the positive permissions of each group that the individual belongs to.
-     * The group negative permission set is the union of all
-     * the negative permissions of each group that the individual belongs to.
-     * If there is a specific permission that occurs in both
-     * the postive permission set and the negative permission set,
-     * it is removed from both. The group positive and negatoive permission
-     * sets are calculated.
-     *
-     * The individial positive permission set and the individual negative
-     * permission set is then calculated. Again abscence of an entry means
-     * the empty set.
-     *
-     * The set of permissions granted to the principal is then calculated using
-     * the simple rule: Individual permissions always override the Group permissions.
-     * Specifically, individual negative permission set (specific
-     * denial of permissions) overrides the group positive permission set.
-     * And the individual positive permission set override the group negative
-     * permission set.
-     *
-     * @param user the principal for which the ACL entry is returned.
-     * @return The resulting permission set that the principal is allowed.
-     */
-    public synchronized Enumeration<Permission> getPermissions(Principal user) {
-
-        Enumeration<Permission> individualPositive;
-        Enumeration<Permission> individualNegative;
-        Enumeration<Permission> groupPositive;
-        Enumeration<Permission> groupNegative;
-
-        //
-        // canonicalize the sets. That is remove common permissions from
-        // positive and negative sets.
-        //
-        groupPositive =
-            subtract(getGroupPositive(user), getGroupNegative(user));
-        groupNegative  =
-            subtract(getGroupNegative(user), getGroupPositive(user));
-        individualPositive =
-            subtract(getIndividualPositive(user), getIndividualNegative(user));
-        individualNegative =
-            subtract(getIndividualNegative(user), getIndividualPositive(user));
-
-        //
-        // net positive permissions is individual positive permissions
-        // plus (group positive - individual negative).
-        //
-        Enumeration<Permission> temp1 =
-            subtract(groupPositive, individualNegative);
-        Enumeration<Permission> netPositive =
-            union(individualPositive, temp1);
-
-        // recalculate the enumeration since we lost it in performing the
-        // subtraction
-        //
-        individualPositive =
-            subtract(getIndividualPositive(user), getIndividualNegative(user));
-        individualNegative =
-            subtract(getIndividualNegative(user), getIndividualPositive(user));
-
-        //
-        // net negative permissions is individual negative permissions
-        // plus (group negative - individual positive).
-        //
-        temp1 = subtract(groupNegative, individualPositive);
-        Enumeration<Permission> netNegative = union(individualNegative, temp1);
-
-        return subtract(netPositive, netNegative);
-    }
-
-    /**
-     * This method checks whether or not the specified principal
-     * has the required permission. If permission is denied
-     * permission false is returned, a true value is returned otherwise.
-     * This method does not authenticate the principal. It presumes that
-     * the principal is a valid authenticated principal.
-     * @param principal the name of the authenticated principal
-     * @param permission the permission that the principal must have.
-     * @return true of the principal has the permission desired, false
-     * otherwise.
-     */
-    public boolean checkPermission(Principal principal, Permission permission)
-    {
-        Enumeration<Permission> permSet = getPermissions(principal);
-        while (permSet.hasMoreElements()) {
-            Permission p = permSet.nextElement();
-            if (p.equals(permission))
-              return true;
-        }
-        return false;
-    }
-
-    /**
-     * returns an enumeration of the entries in this ACL.
-     */
-    public synchronized Enumeration<AclEntry> entries() {
-        return new AclEnumerator(this,
-                                 allowedUsersTable, allowedGroupsTable,
-                                 deniedUsersTable, deniedGroupsTable);
-    }
-
-    /**
-     * return a stringified version of the
-     * ACL.
-     */
-    public String toString() {
-        StringBuilder sb = new StringBuilder();
-        Enumeration<AclEntry> entries = entries();
-        while (entries.hasMoreElements()) {
-            AclEntry entry = entries.nextElement();
-            sb.append(entry.toString().trim());
-            sb.append("\n");
-        }
-
-        return sb.toString();
-    }
-
-    //
-    // Find the table that this entry belongs to. There are 4
-    // tables that are maintained. One each for postive and
-    // negative ACLs and one each for groups and users.
-    // This method figures out which
-    // table is the one that this AclEntry belongs to.
-    //
-    private Hashtable<Principal, AclEntry> findTable(AclEntry entry) {
-        Hashtable<Principal, AclEntry> aclTable = null;
-
-        Principal p = entry.getPrincipal();
-        if (p instanceof Group) {
-            if (entry.isNegative())
-                aclTable = deniedGroupsTable;
-            else
-                aclTable = allowedGroupsTable;
-        } else {
-            if (entry.isNegative())
-                aclTable = deniedUsersTable;
-            else
-                aclTable = allowedUsersTable;
-        }
-        return aclTable;
-    }
-
-    //
-    // returns the set e1 U e2.
-    //
-    private static Enumeration<Permission> union(Enumeration<Permission> e1,
-                Enumeration<Permission> e2) {
-        Vector<Permission> v = new Vector<>(20, 20);
-
-        while (e1.hasMoreElements())
-            v.addElement(e1.nextElement());
-
-        while (e2.hasMoreElements()) {
-            Permission o = e2.nextElement();
-            if (!v.contains(o))
-                v.addElement(o);
-        }
-
-        return v.elements();
-    }
-
-    //
-    // returns the set e1 - e2.
-    //
-    private Enumeration<Permission> subtract(Enumeration<Permission> e1,
-                Enumeration<Permission> e2) {
-        Vector<Permission> v = new Vector<>(20, 20);
-
-        while (e1.hasMoreElements())
-            v.addElement(e1.nextElement());
-
-        while (e2.hasMoreElements()) {
-            Permission o = e2.nextElement();
-            if (v.contains(o))
-                v.removeElement(o);
-        }
-
-        return v.elements();
-    }
-
-    private Enumeration<Permission> getGroupPositive(Principal user) {
-        Enumeration<Permission> groupPositive = zeroSet.elements();
-        Enumeration<Principal> e = allowedGroupsTable.keys();
-        while (e.hasMoreElements()) {
-            Group g = (Group)e.nextElement();
-            if (g.isMember(user)) {
-                AclEntry ae = allowedGroupsTable.get(g);
-                groupPositive = union(ae.permissions(), groupPositive);
-            }
-        }
-        return groupPositive;
-    }
-
-    private Enumeration<Permission> getGroupNegative(Principal user) {
-        Enumeration<Permission> groupNegative = zeroSet.elements();
-        Enumeration<Principal> e = deniedGroupsTable.keys();
-        while (e.hasMoreElements()) {
-            Group g = (Group)e.nextElement();
-            if (g.isMember(user)) {
-                AclEntry ae = deniedGroupsTable.get(g);
-                groupNegative = union(ae.permissions(), groupNegative);
-            }
-        }
-        return groupNegative;
-    }
-
-    private Enumeration<Permission> getIndividualPositive(Principal user) {
-        Enumeration<Permission> individualPositive = zeroSet.elements();
-        AclEntry ae = allowedUsersTable.get(user);
-        if (ae != null)
-            individualPositive = ae.permissions();
-        return individualPositive;
-    }
-
-    private Enumeration<Permission> getIndividualNegative(Principal user) {
-        Enumeration<Permission> individualNegative = zeroSet.elements();
-        AclEntry ae  = deniedUsersTable.get(user);
-        if (ae != null)
-            individualNegative = ae.permissions();
-        return individualNegative;
-    }
-}
-
-final class AclEnumerator implements Enumeration<AclEntry> {
-    Acl acl;
-    Enumeration<AclEntry> u1, u2, g1, g2;
-
-    AclEnumerator(Acl acl, Hashtable<?,AclEntry> u1, Hashtable<?,AclEntry> g1,
-                  Hashtable<?,AclEntry> u2, Hashtable<?,AclEntry> g2) {
-        this.acl = acl;
-        this.u1 = u1.elements();
-        this.u2 = u2.elements();
-        this.g1 = g1.elements();
-        this.g2 = g2.elements();
-    }
-
-    public boolean hasMoreElements() {
-        return (u1.hasMoreElements() ||
-                u2.hasMoreElements() ||
-                g1.hasMoreElements() ||
-                g2.hasMoreElements());
-    }
-
-    public AclEntry nextElement()
-    {
-        AclEntry o;
-        synchronized (acl) {
-            if (u1.hasMoreElements())
-                return u1.nextElement();
-            if (u2.hasMoreElements())
-                return u2.nextElement();
-            if (g1.hasMoreElements())
-                return g1.nextElement();
-            if (g2.hasMoreElements())
-                return g2.nextElement();
-        }
-        throw new NoSuchElementException("Acl Enumerator");
-    }
-}