java/internal/TtyAuthenticator.java

/*
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 *
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 *
 *   - Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
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 *   - Redistributions in binary form must reproduce the above copyright
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 *     documentation and/or other materials provided with the distribution.
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 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
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 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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 */

import java.io.*;
import java.net.*;
import javax.mail.*;
import javax.mail.PasswordAuthentication;
import javax.mail.Authenticator;

/**
 * A simple Authenticator that prompts for the user name and password on stdin.
 * Puts up a dialog something like:
 * <p> <pre>
 * Connecting to &lt;protocol&gt; mail service on host &lt;addr&gt;, port &lt;port&gt;.
 * &lt;prompt&gt;
 *
 * User Name: [defaultUserName]
 * Password:
 * </pre> <p>
 *
 * @author Bill Shannon
 */

public class TtyAuthenticator extends Authenticator {

    /**
     * @return The PasswordAuthentication collected from the
     *      user, or null if none is provided.
     */
    protected PasswordAuthentication getPasswordAuthentication() {
    BufferedReader in = new BufferedReader(
                new InputStreamReader((System.in)));
    StringBuffer sb = new StringBuffer();
    sb.append("Connecting to ");
    sb.append(getRequestingProtocol());
    sb.append(" mail service on host ");
    sb.append(getRequestingSite().getHostName());
    int port = getRequestingPort();
    if (port > 0) {
        sb.append(", port ");
        sb.append(port);
    }
    sb.append(".");
    System.out.println(sb.toString());
    String prompt = getRequestingPrompt();
    if (prompt != null)
        System.out.println(prompt);
    System.out.println();
    String userName = get(in, "User Name", getDefaultUserName());
    String password = getpw("Password");
    if (userName == null)
        return null;
    else
        return new PasswordAuthentication(userName, password);
    }

    private static final String get(BufferedReader in,
                String name, String value) {
    PrintStream p = System.out;

    p.print(name + ": ");
    if (value != null)
        p.print("[" + value + "] ");
    p.flush();

    try {
        String s = in.readLine();
        if (s.length() == 0)
        return value;
        else
        return s;
    } catch (IOException e) {
        return value;
    }
    }

    private static final String getpw(String name) {
    Console cons;
    char[] passwd;
    if ((cons = System.console()) != null &&
        (passwd = cons.readPassword("[%s] ", name)) != null)
        return new String(passwd);
    return "";
    }

    // main program, for debugging.
    // Usage: java TtyAuthenticator host port protocol prompt defaultUser
    public static void main(String argv[]) throws Exception {
    Session sess = Session.getInstance(System.getProperties(),
                    new TtyAuthenticator());
    PasswordAuthentication pw = sess.requestPasswordAuthentication(
        InetAddress.getByName(argv[0]),
        Integer.parseInt(argv[1]), argv[2], z(argv[3]), z(argv[4]));
    System.out.println("User: " + n(pw.getUserName()));
    System.out.println("Password: " + n(pw.getPassword()));
    }

    private static final String n(String s) {
    return s == null ? "<null>" : s;
    }

    private static final String z(String s) {
    return s.length() > 0 ? s : null;
    }
}