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 package org.apache.logging.log4j.core.net.ssl;
18
19 import java.io.IOException;
20 import java.nio.ByteBuffer;
21 import java.nio.CharBuffer;
22 import java.nio.charset.Charset;
23 import java.nio.file.Files;
24 import java.nio.file.NoSuchFileException;
25 import java.nio.file.Path;
26 import java.nio.file.Paths;
27 import java.util.Arrays;
28
29 /**
30 * PasswordProvider that reads password from a file.
31 * <p>
32 * This is a relatively secure way to handle passwords:
33 * <ul>
34 * <li>Managing file access privileges can be delegated to the operating system.</li>
35 * <li>The password file can be in a separate location from the logging configuration.
36 * This gives flexibility to have different passwords in different environments while
37 * using the same logging configuration. It also allows for separation of responsibilities:
38 * developers don't need to know the password that is used in the production environment.</li>
39 * <li>There is only a small window of opportunity for attackers to obtain the password from a memory
40 * dump: the password data is only resident in memory from the moment the caller calls the
41 * {@link #getPassword()} method and the password file is read until the moment that the caller
42 * completes authentication and overwrites the password char[] array.</li>
43 * </ul>
44 * </p><p>
45 * Less secure implementations are {@link MemoryPasswordProvider} and {@link EnvironmentPasswordProvider}.
46 * </p>
47 */
48 class FilePasswordProvider implements PasswordProvider {
49 private final Path passwordPath;
50
51 /**
52 * Constructs a new FilePasswordProvider with the specified path.
53 * @param passwordFile the path to the password file
54 * @throws NoSuchFileException if the password file does not exist when this FilePasswordProvider is constructed
55 */
56 public FilePasswordProvider(final String passwordFile) throws NoSuchFileException {
57 this.passwordPath = Paths.get(passwordFile);
58 if (!Files.exists(passwordPath)) {
59 throw new NoSuchFileException("PasswordFile '" + passwordFile + "' does not exist");
60 }
61 }
62
63 @Override
64 public char[] getPassword() {
65 byte[] bytes = null;
66 try {
67 bytes = Files.readAllBytes(passwordPath);
68 final ByteBuffer bb = ByteBuffer.wrap(bytes);
69 final CharBuffer decoded = Charset.defaultCharset().decode(bb);
70 final char[] result = new char[decoded.limit()];
71 decoded.get(result, 0, result.length);
72 decoded.rewind();
73 decoded.put(new char[result.length]); // erase decoded CharBuffer
74 return result;
75 } catch (final IOException e) {
76 throw new IllegalStateException("Could not read password from " + passwordPath + ": " + e, e);
77 } finally {
78 if (bytes != null) {
79 Arrays.fill(bytes, (byte) 0x0);
80 }
81 }
82 }
83 }