aboutsummaryrefslogtreecommitdiffstats
path: root/trunk/infrastructure/rhino1_7R1/src/org/mozilla/javascript/SecureCaller.java
blob: bc8ed86181767e490a2c5384884b857de3c151a4 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Rhino code, released May 6, 1999.
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1997-1999
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
 * Alternatively, the contents of this file may be used under the terms of
 * the GNU General Public License Version 2 or later (the "GPL"), in which
 * case the provisions of the GPL are applicable instead of those above. If
 * you wish to allow use of your version of this file only under the terms of
 * the GPL and not to allow others to use your version of this file under the
 * MPL, indicate your decision by deleting the provisions above and replacing
 * them with the notice and other provisions required by the GPL. If you do
 * not delete the provisions above, a recipient may use your version of this
 * file under either the MPL or the GPL.
 *
 * ***** END LICENSE BLOCK ***** */

package org.mozilla.javascript;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.lang.ref.SoftReference;
import java.lang.reflect.UndeclaredThrowableException;
import java.net.URL;
import java.security.AccessController;
import java.security.CodeSource;
import java.security.PrivilegedAction;
import java.security.PrivilegedActionException;
import java.security.PrivilegedExceptionAction;
import java.security.SecureClassLoader;
import java.util.Map;
import java.util.WeakHashMap;

/**
 * @author Attila Szegedi
 */
public abstract class SecureCaller
{
    private static final byte[] secureCallerImplBytecode = loadBytecode();
    
    // We're storing a CodeSource -> (ClassLoader -> SecureRenderer), since we
    // need to have one renderer per class loader. We're using weak hash maps
    // and soft references all the way, since we don't want to interfere with
    // cleanup of either CodeSource or ClassLoader objects.
    private static final Map callers = new WeakHashMap();
    
    public abstract Object call(Callable callable, Context cx, 
            Scriptable scope, Scriptable thisObj, Object[] args);
    
    /**
     * Call the specified callable using a protection domain belonging to the 
     * specified code source. 
     */
    static Object callSecurely(final CodeSource codeSource, Callable callable, 
            Context cx, Scriptable scope, Scriptable thisObj, Object[] args)
    {
        final Thread thread = Thread.currentThread();
        // Run in doPrivileged as we might be checked for "getClassLoader" 
        // runtime permission
        final ClassLoader classLoader = (ClassLoader)AccessController.doPrivileged(
            new PrivilegedAction() {
                public Object run() {
                    return thread.getContextClassLoader();
                }
            });
        Map classLoaderMap;
        synchronized(callers)
        {
            classLoaderMap = (Map)callers.get(codeSource);
            if(classLoaderMap == null)
            {
                classLoaderMap = new WeakHashMap();
                callers.put(codeSource, classLoaderMap);
            }
        }
        SecureCaller caller;
        synchronized(classLoaderMap)
        {
            SoftReference ref = (SoftReference)classLoaderMap.get(classLoader);
            if(ref != null)
            {
                caller = (SecureCaller)ref.get();
            }
            else
            {
                caller = null;
            }
            if(caller == null)
            {
                try
                {
                    // Run in doPrivileged as we'll be checked for 
                    // "createClassLoader" runtime permission
                    caller = (SecureCaller)AccessController.doPrivileged(
                            new PrivilegedExceptionAction()
                    {
                        public Object run() throws Exception
                        {
                            ClassLoader effectiveClassLoader;
                            Class thisClass = getClass();
                            if(classLoader.loadClass(thisClass.getName()) != thisClass) {
                                effectiveClassLoader = thisClass.getClassLoader();
                            } else {
                                effectiveClassLoader = classLoader;
                            }  
                            SecureClassLoaderImpl secCl = 
                                new SecureClassLoaderImpl(effectiveClassLoader);
                            Class c = secCl.defineAndLinkClass(
                                    SecureCaller.class.getName() + "Impl", 
                                    secureCallerImplBytecode, codeSource);
                            return c.newInstance();
                        }
                    });
                    classLoaderMap.put(classLoader, new SoftReference(caller));
                }
                catch(PrivilegedActionException ex)
                {
                    throw new UndeclaredThrowableException(ex.getCause());
                }
            }
        }
        return caller.call(callable, cx, scope, thisObj, args);
    }
    
    private static class SecureClassLoaderImpl extends SecureClassLoader
    {
        SecureClassLoaderImpl(ClassLoader parent)
        {
            super(parent);
        }
        
        Class defineAndLinkClass(String name, byte[] bytes, CodeSource cs)
        {
            Class cl = defineClass(name, bytes, 0, bytes.length, cs);
            resolveClass(cl);
            return cl;
        }
    }
    
    private static byte[] loadBytecode()
    {
        return (byte[])AccessController.doPrivileged(new PrivilegedAction()
        {
            public Object run()
            {
                return loadBytecodePrivileged();
            }
        });
    }
    
    private static byte[] loadBytecodePrivileged()
    {
        URL url = SecureCaller.class.getResource("SecureCallerImpl.clazz");
        try
        {
            InputStream in = url.openStream();
            try
            {
                ByteArrayOutputStream bout = new ByteArrayOutputStream();
                for(;;)
                {
                    int r = in.read();
                    if(r == -1)
                    {
                        return bout.toByteArray();
                    }
                    bout.write(r);
                }
            }
            finally
            {
                in.close();
            }
        }
        catch(IOException e)
        {
            throw new UndeclaredThrowableException(e);
        }
    }
}