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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 java.util.concurrent.CancellationException;
46  
47  import org.apache.sshd.client.ClientAuthenticationManager;
48  import org.apache.sshd.client.auth.keyboard.UserInteraction;
49  import org.apache.sshd.client.auth.password.UserAuthPassword;
50  import org.apache.sshd.client.session.ClientSession;
51  
52  /**
53   * A password authentication handler that uses the {@link JGitUserInteraction}
54   * to ask the user for the password. It also respects the
55   * {@code NumberOfPasswordPrompts} ssh config.
56   */
57  public class JGitPasswordAuthentication extends UserAuthPassword {
58  
59  	private int maxAttempts;
60  
61  	private int attempts;
62  
63  	@Override
64  	public void init(ClientSession session, String service) throws Exception {
65  		super.init(session, service);
66  		maxAttempts = Math.max(1,
67  				session.getIntProperty(
68  						ClientAuthenticationManager.PASSWORD_PROMPTS,
69  						ClientAuthenticationManager.DEFAULT_PASSWORD_PROMPTS));
70  		attempts = 0;
71  	}
72  
73  	@Override
74  	protected boolean sendAuthDataRequest(ClientSession session, String service)
75  			throws Exception {
76  		if (++attempts > maxAttempts) {
77  			return false;
78  		}
79  		UserInteraction interaction = session.getUserInteraction();
80  		if (!interaction.isInteractionAllowed(session)) {
81  			return false;
82  		}
83  		String password = getPassword(session, interaction);
84  		if (password == null) {
85  			throw new CancellationException();
86  		}
87  		// sendPassword takes a buffer as first argument, but actually doesn't
88  		// use it and creates its own buffer...
89  		sendPassword(null, session, password, password);
90  		return true;
91  	}
92  
93  	private String getPassword(ClientSession session,
94  			UserInteraction interaction) {
95  		String[] results = interaction.interactive(session, null, null, "", //$NON-NLS-1$
96  				new String[] { SshdText.get().passwordPrompt },
97  				new boolean[] { false });
98  		return (results == null || results.length == 0) ? null : results[0];
99  	}
100 }