--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/java/security/acl/Acl.java Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,241 @@
+/*
+ * Copyright 1996-2004 Sun Microsystems, Inc. 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. Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+package java.security.acl;
+
+import java.util.Enumeration;
+import java.security.Principal;
+
+/**
+ * Interface representing an Access Control List (ACL). An Access
+ * Control List is a data structure used to guard access to
+ * resources.<p>
+ *
+ * An ACL can be thought of as a data structure with multiple ACL
+ * entries. Each ACL entry, of interface type AclEntry, contains a
+ * set of permissions associated with a particular principal. (A
+ * principal represents an entity such as an individual user or a
+ * group). Additionally, each ACL entry is specified as being either
+ * positive or negative. If positive, the permissions are to be
+ * granted to the associated principal. If negative, the permissions
+ * are to be denied.<p>
+ *
+ * The ACL Entries in each ACL observe the following rules:<p>
+ *
+ * <ul> <li>Each principal can have at most one positive ACL entry and
+ * one negative entry; that is, multiple positive or negative ACL
+ * entries are not allowed for any principal. Each entry specifies
+ * the set of permissions that are to be granted (if positive) or
+ * denied (if negative). <p>
+ *
+ * <li>If there is no entry for a particular principal, then the
+ * principal is considered to have a null (empty) permission set.<p>
+ *
+ * <li>If there is a positive entry that grants a principal a
+ * particular permission, and a negative entry that denies the
+ * principal the same permission, the result is as though the
+ * permission was never granted or denied. <p>
+ *
+ * <li>Individual permissions always override permissions of the
+ * group(s) to which the individual belongs. That is, individual
+ * negative permissions (specific denial of permissions) override the
+ * groups' positive permissions. And individual positive permissions
+ * override the groups' negative permissions.<p>
+ *
+ * </ul>
+ *
+ * The <code> java.security.acl </code> package provides the
+ * interfaces to the ACL and related data structures (ACL entries,
+ * groups, permissions, etc.), and the <code> sun.security.acl </code>
+ * classes provide a default implementation of the interfaces. For
+ * example, <code> java.security.acl.Acl </code> provides the
+ * interface to an ACL and the <code> sun.security.acl.AclImpl </code>
+ * class provides the default implementation of the interface.<p>
+ *
+ * The <code> java.security.acl.Acl </code> interface extends the
+ * <code> java.security.acl.Owner </code> interface. The Owner
+ * interface is used to maintain a list of owners for each ACL. Only
+ * owners are allowed to modify an ACL. For example, only an owner can
+ * call the ACL's <code>addEntry</code> method to add a new ACL entry
+ * to the ACL.
+ *
+ * @see java.security.acl.AclEntry
+ * @see java.security.acl.Owner
+ * @see java.security.acl.Acl#getPermissions
+ *
+ * @author Satish Dharmaraj
+ */
+
+public interface Acl extends Owner {
+
+ /**
+ * Sets the name of this ACL.
+ *
+ * @param caller the principal invoking this method. It must be an
+ * owner of this ACL.
+ *
+ * @param name the name to be given to this ACL.
+ *
+ * @exception NotOwnerException if the caller principal
+ * is not an owner of this ACL.
+ *
+ * @see #getName
+ */
+ public void setName(Principal caller, String name)
+ throws NotOwnerException;
+
+ /**
+ * Returns the name of this ACL.
+ *
+ * @return the name of this ACL.
+ *
+ * @see #setName
+ */
+ public String getName();
+
+ /**
+ * Adds an ACL entry to this ACL. An entry associates a principal
+ * (e.g., an individual or a group) with a set of
+ * permissions. Each principal can have at most one positive ACL
+ * entry (specifying permissions to be granted to the principal)
+ * and one negative ACL entry (specifying permissions to be
+ * denied). If there is already an ACL entry of the same type
+ * (negative or positive) already in the ACL, false is returned.
+ *
+ * @param caller the principal invoking this method. It must be an
+ * owner of this ACL.
+ *
+ * @param entry the ACL entry to be added to this ACL.
+ *
+ * @return true on success, false if an entry of the same type
+ * (positive or negative) for the same principal is already
+ * present in this ACL.
+ *
+ * @exception NotOwnerException if the caller principal
+ * is not an owner of this ACL.
+ */
+ public boolean addEntry(Principal caller, AclEntry entry)
+ throws NotOwnerException;
+
+ /**
+ * Removes an ACL entry from this ACL.
+ *
+ * @param caller the principal invoking this method. It must be an
+ * owner of this ACL.
+ *
+ * @param entry the ACL entry to be removed from this ACL.
+ *
+ * @return true on success, false if the entry is not part of this ACL.
+ *
+ * @exception NotOwnerException if the caller principal is not
+ * an owner of this Acl.
+ */
+ public boolean removeEntry(Principal caller, AclEntry entry)
+ throws NotOwnerException;
+
+ /**
+ * Returns an enumeration for the set of allowed permissions for the
+ * specified principal (representing an entity such as an individual or
+ * a group). This set of allowed permissions is calculated as
+ * follows:<p>
+ *
+ * <ul>
+ *
+ * <li>If there is no entry in this Access Control List for the
+ * specified principal, an empty permission set is returned.<p>
+ *
+ * <li>Otherwise, the principal's group permission sets are determined.
+ * (A principal can belong to one or more groups, where a group is a
+ * group of principals, represented by the Group interface.)
+ * The group positive permission set is the union of all
+ * the positive permissions of each group that the principal belongs to.
+ * The group negative permission set is the union of all
+ * the negative permissions of each group that the principal belongs to.
+ * If there is a specific permission that occurs in both
+ * the positive permission set and the negative permission set,
+ * it is removed from both.<p>
+ *
+ * The individual positive and negative permission sets are also
+ * determined. The positive permission set contains the permissions
+ * specified in the positive ACL entry (if any) for the principal.
+ * Similarly, the negative permission set contains the permissions
+ * specified in the negative ACL entry (if any) for the principal.
+ * The individual positive (or negative) permission set is considered
+ * to be null if there is not a positive (negative) ACL entry for the
+ * principal in this ACL.<p>
+ *
+ * The set of permissions granted to the principal is then calculated
+ * using the simple rule that individual permissions always override
+ * the group permissions. That is, the principal's individual negative
+ * permission set (specific denial of permissions) overrides the group
+ * positive permission set, and the principal's individual positive
+ * permission set overrides the group negative permission set.
+ *
+ * </ul>
+ *
+ * @param user the principal whose permission set is to be returned.
+ *
+ * @return the permission set specifying the permissions the principal
+ * is allowed.
+ */
+ public Enumeration<Permission> getPermissions(Principal user);
+
+ /**
+ * Returns an enumeration of the entries in this ACL. Each element in
+ * the enumeration is of type AclEntry.
+ *
+ * @return an enumeration of the entries in this ACL.
+ */
+ public Enumeration<AclEntry> entries();
+
+ /**
+ * Checks whether or not the specified principal has the specified
+ * permission. If it does, true is returned, otherwise false is returned.
+ *
+ * More specifically, this method checks whether the passed permission
+ * is a member of the allowed permission set of the specified principal.
+ * The allowed permission set is determined by the same algorithm as is
+ * used by the <code>getPermissions</code> method.
+ *
+ * @param principal the principal, assumed to be a valid authenticated
+ * Principal.
+ *
+ * @param permission the permission to be checked for.
+ *
+ * @return true if the principal has the specified permission, false
+ * otherwise.
+ *
+ * @see #getPermissions
+ */
+ public boolean checkPermission(Principal principal, Permission permission);
+
+ /**
+ * Returns a string representation of the
+ * ACL contents.
+ *
+ * @return a string representation of the ACL contents.
+ */
+ public String toString();
+}