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      1 /*
      2  *  Licensed to the Apache Software Foundation (ASF) under one or more
      3  *  contributor license agreements.  See the NOTICE file distributed with
      4  *  this work for additional information regarding copyright ownership.
      5  *  The ASF licenses this file to You under the Apache License, Version 2.0
      6  *  (the "License"); you may not use this file except in compliance with
      7  *  the License.  You may obtain a copy of the License at
      8  *
      9  *     http://www.apache.org/licenses/LICENSE-2.0
     10  *
     11  *  Unless required by applicable law or agreed to in writing, software
     12  *  distributed under the License is distributed on an "AS IS" BASIS,
     13  *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     14  *  See the License for the specific language governing permissions and
     15  *  limitations under the License.
     16  */
     17 
     18 /**
     19 * @author Alexey V. Varlamov
     20 * @version $Revision$
     21 */
     22 
     23 package org.apache.harmony.security;
     24 
     25 import java.net.URL;
     26 import java.security.CodeSigner;
     27 import java.security.CodeSource;
     28 import java.security.Permission;
     29 import java.security.Principal;
     30 import java.util.Collection;
     31 import java.util.Collections;
     32 import org.apache.harmony.security.fortress.PolicyUtils;
     33 
     34 /**
     35  * This class represents an elementary block of a security policy. It associates
     36  * a CodeSource of an executable code, Principals allowed to execute the code,
     37  * and a set of granted Permissions.
     38  *
     39  * @see org.apache.harmony.security.fortress.DefaultPolicy
     40  */
     41 public class PolicyEntry {
     42 
     43     // Store CodeSource
     44     private final CodeSource cs;
     45 
     46     // Array of principals
     47     private final Principal[] principals;
     48 
     49     // Permissions collection
     50     private final Collection<Permission> permissions;
     51 
     52     /**
     53      * Constructor with initialization parameters. Passed collections are not
     54      * referenced directly, but copied.
     55      */
     56     public PolicyEntry(CodeSource cs, Collection<? extends Principal> prs,
     57             Collection<? extends Permission> permissions) {
     58         this.cs = (cs != null) ? normalizeCodeSource(cs) : null;
     59         this.principals = (prs == null || prs.isEmpty()) ? null
     60                 : (Principal[]) prs.toArray(new Principal[prs.size()]);
     61         this.permissions = (permissions == null || permissions.isEmpty()) ? null
     62                 : Collections.unmodifiableCollection(permissions);
     63     }
     64 
     65     /**
     66      * Checks if passed CodeSource matches this PolicyEntry. Null CodeSource of
     67      * PolicyEntry implies any CodeSource; non-null CodeSource forwards to its
     68      * imply() method.
     69      */
     70     public boolean impliesCodeSource(CodeSource codeSource) {
     71         if (cs == null) {
     72             return true;
     73         }
     74 
     75         if (codeSource == null) {
     76             return false;
     77         }
     78         return cs.implies(normalizeCodeSource(codeSource));
     79     }
     80 
     81     private CodeSource normalizeCodeSource(CodeSource codeSource) {
     82         URL codeSourceURL = PolicyUtils.normalizeURL(codeSource.getLocation());
     83         CodeSource result = codeSource;
     84 
     85         if (codeSourceURL != codeSource.getLocation()) {
     86             // URL was normalized - recreate codeSource with new URL
     87             CodeSigner[] signers = codeSource.getCodeSigners();
     88             if (signers == null) {
     89                 result = new CodeSource(codeSourceURL, codeSource
     90                         .getCertificates());
     91             } else {
     92                 result = new CodeSource(codeSourceURL, signers);
     93             }
     94         }
     95         return result;
     96     }
     97 
     98     /**
     99      * Checks if specified Principals match this PolicyEntry. Null or empty set
    100      * of Principals of PolicyEntry implies any Principals; otherwise specified
    101      * array must contain all Principals of this PolicyEntry.
    102      */
    103     public boolean impliesPrincipals(Principal[] prs) {
    104         return PolicyUtils.matchSubset(principals, prs);
    105     }
    106 
    107     /**
    108      * Returns unmodifiable collection of permissions defined by this
    109      * PolicyEntry, may be <code>null</code>.
    110      */
    111     public Collection<Permission> getPermissions() {
    112         return permissions;
    113     }
    114 
    115     /**
    116      * Returns true if this PolicyEntry defines no Permissions, false otherwise.
    117      */
    118     public boolean isVoid() {
    119         return permissions == null || permissions.size() == 0;
    120     }
    121 }
    122