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1   /*
2    * Copyright (C) 2018, Thomas Wolf <thomas.wolf@paranor.ch>
3    * and other copyright owners as documented in the project's IP log.
4    *
5    * This program and the accompanying materials are made available
6    * under the terms of the Eclipse Distribution License v1.0 which
7    * accompanies this distribution, is reproduced below, and is
8    * available at http://www.eclipse.org/org/documents/edl-v10.php
9    *
10   * All rights reserved.
11   *
12   * Redistribution and use in source and binary forms, with or
13   * without modification, are permitted provided that the following
14   * conditions are met:
15   *
16   * - Redistributions of source code must retain the above copyright
17   *   notice, this list of conditions and the following disclaimer.
18   *
19   * - Redistributions in binary form must reproduce the above
20   *   copyright notice, this list of conditions and the following
21   *   disclaimer in the documentation and/or other materials provided
22   *   with the distribution.
23   *
24   * - Neither the name of the Eclipse Foundation, Inc. nor the
25   *   names of its contributors may be used to endorse or promote
26   *   products derived from this software without specific prior
27   *   written permission.
28   *
29   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
30   * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
31   * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
32   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
33   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
34   * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
35   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
36   * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
37   * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
38   * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39   * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
40   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
41   * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
42   */
43  package org.eclipse.jgit.internal.transport.sshd;
44  
45  import static org.eclipse.jgit.internal.transport.ssh.OpenSshConfigFile.flag;
46  import static org.eclipse.jgit.internal.transport.ssh.OpenSshConfigFile.positive;
47  
48  import java.io.File;
49  import java.io.IOException;
50  import java.net.SocketAddress;
51  import java.util.Map;
52  import java.util.TreeMap;
53  
54  import org.apache.sshd.client.config.hosts.HostConfigEntry;
55  import org.apache.sshd.client.config.hosts.HostConfigEntryResolver;
56  import org.apache.sshd.common.AttributeRepository;
57  import org.apache.sshd.common.util.net.SshdSocketAddress;
58  import org.eclipse.jgit.annotations.NonNull;
59  import org.eclipse.jgit.internal.transport.ssh.OpenSshConfigFile;
60  import org.eclipse.jgit.internal.transport.ssh.OpenSshConfigFile.HostEntry;
61  import org.eclipse.jgit.transport.SshConstants;
62  
63  /**
64   * A {@link HostConfigEntryResolver} adapted specifically for JGit.
65   * <p>
66   * We use our own config file parser and entry resolution since the default
67   * {@link org.apache.sshd.client.config.hosts.ConfigFileHostEntryResolver
68   * ConfigFileHostEntryResolver} has a number of problems:
69   * </p>
70   * <ul>
71   * <li>It does case-insensitive pattern matching. Matching in OpenSsh is
72   * case-sensitive! Compare also bug 531118.</li>
73   * <li>It only merges values from the global items (before the first "Host"
74   * line) into the host entries. Otherwise it selects the most specific match.
75   * OpenSsh processes <em>all</em> entries in the order they appear in the file
76   * and whenever one matches, it updates values as appropriate.</li>
77   * <li>We have to ensure that ~ replacement uses the same HOME directory as
78   * JGit. Compare bug bug 526175.</li>
79   * </ul>
80   * Therefore, this re-uses the parsing and caching from
81   * {@link OpenSshConfigFile}.
82   *
83   */
84  public class JGitSshConfig implements HostConfigEntryResolver {
85  
86  	private final OpenSshConfigFile configFile;
87  
88  	private final String localUserName;
89  
90  	/**
91  	 * Creates a new {@link OpenSshConfigFile} that will read the config from
92  	 * file {@code config} use the given file {@code home} as "home" directory.
93  	 *
94  	 * @param home
95  	 *            user's home directory for the purpose of ~ replacement
96  	 * @param config
97  	 *            file to load; may be {@code null} if no ssh config file
98  	 *            handling is desired
99  	 * @param localUserName
100 	 *            user name of the current user on the local host OS
101 	 */
102 	public JGitSshConfig(@NonNull File home, File config,
103 			@NonNull String localUserName) {
104 		this.localUserName = localUserName;
105 		configFile = config == null ?  null : new OpenSshConfigFile(home, config, localUserName);
106 	}
107 
108 	@Override
109 	public HostConfigEntry resolveEffectiveHost(String host, int port,
110 			SocketAddress localAddress, String username,
111 			AttributeRepository attributes) throws IOException {
112 		HostEntry entry = configFile == null ? new HostEntry() : configFile.lookup(host, port, username);
113 		JGitHostConfigEntry config = new JGitHostConfigEntry();
114 		// Apache MINA conflates all keys, even multi-valued ones, in one map
115 		// and puts multiple values separated by commas in one string. See
116 		// the javadoc on HostConfigEntry.
117 		Map<String, String> allOptions = new TreeMap<>(
118 				String.CASE_INSENSITIVE_ORDER);
119 		allOptions.putAll(entry.getOptions());
120 		// And what if a value contains a comma??
121 		entry.getMultiValuedOptions().entrySet().stream()
122 				.forEach(e -> allOptions.put(e.getKey(),
123 						String.join(",", e.getValue()))); //$NON-NLS-1$
124 		config.setProperties(allOptions);
125 		// The following is an extension from JGitHostConfigEntry
126 		config.setMultiValuedOptions(entry.getMultiValuedOptions());
127 		// Also make sure the underlying properties are set
128 		String hostName = entry.getValue(SshConstants.HOST_NAME);
129 		if (hostName == null || hostName.isEmpty()) {
130 			hostName = host;
131 		}
132 		config.setHostName(hostName);
133 		config.setProperty(SshConstants.HOST_NAME, hostName);
134 		config.setHost(SshdSocketAddress.isIPv6Address(hostName) ? "" : hostName); //$NON-NLS-1$
135 		String user = username != null && !username.isEmpty() ? username
136 				: entry.getValue(SshConstants.USER);
137 		if (user == null || user.isEmpty()) {
138 			user = localUserName;
139 		}
140 		config.setUsername(user);
141 		config.setProperty(SshConstants.USER, user);
142 		int p = port >= 0 ? port : positive(entry.getValue(SshConstants.PORT));
143 		config.setPort(p >= 0 ? p : SshConstants.SSH_DEFAULT_PORT);
144 		config.setProperty(SshConstants.PORT,
145 				Integer.toString(config.getPort()));
146 		config.setIdentities(entry.getValues(SshConstants.IDENTITY_FILE));
147 		config.setIdentitiesOnly(
148 				flag(entry.getValue(SshConstants.IDENTITIES_ONLY)));
149 		return config;
150 	}
151 
152 }