passwordfile.java

linux下建立JAVA虚拟机的源码KAFFE

/* PasswordFile.java -- 
   Copyright (C) 2003, 2006 Free Software Foundation, Inc.

This file is a part of GNU Classpath.

GNU Classpath is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or (at
your option) any later version.

GNU Classpath is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU Classpath; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301
USA

Linking this library statically or dynamically with other modules is
making a combined work based on this library.  Thus, the terms and
conditions of the GNU General Public License cover the whole
combination.

As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent
modules, and to copy and distribute the resulting executable under
terms of your choice, provided that you also meet, for each linked
independent module, the terms and conditions of the license of that
module.  An independent module is a module which is not derived from
or based on this library.  If you modify this library, you may extend
this exception to your version of the library, but you are not
obligated to do so.  If you do not wish to do so, delete this
exception statement from your version.  */


package gnu.javax.crypto.sasl.crammd5;

import gnu.javax.crypto.sasl.NoSuchUserException;
import gnu.javax.crypto.sasl.UserAlreadyExistsException;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.HashMap;
import java.util.Iterator;
import java.util.NoSuchElementException;
import java.util.StringTokenizer;

/**
 * The CRAM-MD5 password file representation.
 */
public class PasswordFile
{

  // Constants and variables
  // -------------------------------------------------------------------------

  private static String DEFAULT_FILE;
  static
    {
      DEFAULT_FILE = System.getProperty(CramMD5Registry.PASSWORD_FILE,
                                        CramMD5Registry.DEFAULT_PASSWORD_FILE);
    }

  private HashMap entries;

  private File passwdFile;

  private long lastmod;

  // Constructor(s)
  // -------------------------------------------------------------------------

  public PasswordFile() throws IOException
  {
    this(DEFAULT_FILE);
  }

  public PasswordFile(final File pwFile) throws IOException
  {
    this(pwFile.getAbsolutePath());
  }

  public PasswordFile(final String fileName) throws IOException
  {
    passwdFile = new File(fileName);
    update();
  }

  // Class methods
  // -------------------------------------------------------------------------

  // Instance methods
  // -------------------------------------------------------------------------

  public synchronized void add(final String user, final String passwd,
                               final String[] attributes) throws IOException
  {
    checkCurrent(); // check if the entry exists
    if (entries.containsKey(user))
      {
        throw new UserAlreadyExistsException(user);
      }
    if (attributes.length != 5)
      {
        throw new IllegalArgumentException("Wrong number of attributes");
      }

    final String[] fields = new String[7]; // create the new entry
    fields[0] = user;
    fields[1] = passwd;
    System.arraycopy(attributes, 0, fields, 2, 5);
    entries.put(user, fields);
    savePasswd();
  }

  public synchronized void changePasswd(final String user, final String passwd)
      throws IOException
  {
    checkCurrent();
    if (!entries.containsKey(user))
      { // check if the entry exists
        throw new NoSuchUserException(user);
      }

    final String[] fields = (String[]) entries.get(user); // get the existing entry
    fields[1] = passwd; // modify the password field
    entries.remove(user); // delete the existing entry
    entries.put(user, fields); // add the new entry

    savePasswd();
  }

  public synchronized String[] lookup(final String user) throws IOException
  {
    checkCurrent();
    if (!entries.containsKey(user))
      {
        throw new NoSuchUserException(user);
      }
    return (String[]) entries.get(user);
  }

  public synchronized boolean contains(final String s) throws IOException
  {
    checkCurrent();

    return entries.containsKey(s);
  }

  private synchronized void update() throws IOException
  {
    lastmod = passwdFile.lastModified();
    readPasswd(new FileInputStream(passwdFile));
  }

  private void checkCurrent() throws IOException
  {
    if (passwdFile.lastModified() > lastmod)
      {
        update();
      }
  }

  private synchronized void readPasswd(final InputStream in) throws IOException
  {
    final BufferedReader din = new BufferedReader(new InputStreamReader(in));
    String line;
    entries = new HashMap();
    while ((line = din.readLine()) != null)
      {
        final String[] fields = new String[7];
        final StringTokenizer st = new StringTokenizer(line, ":", true);
        try
          {
            fields[0] = st.nextToken(); // username
            st.nextToken();

            fields[1] = st.nextToken(); // passwd
            if (fields[1].equals(":"))
              {
                fields[1] = "";
              }
            else
              {
                st.nextToken();
              }

            fields[2] = st.nextToken(); // uid
            if (fields[2].equals(":"))
              {
                fields[2] = "";
              }
            else
              {
                st.nextToken();
              }

            fields[3] = st.nextToken(); // gid
            if (fields[3].equals(":"))
              {
                fields[3] = "";
              }
            else
              {
                st.nextToken();
              }

            fields[4] = st.nextToken(); // gecos
            if (fields[4].equals(":"))
              {
                fields[4] = "";
              }
            else
              {
                st.nextToken();
              }

            fields[5] = st.nextToken(); // dir
            if (fields[5].equals(":"))
              {
                fields[5] = "";
              }
            else
              {
                st.nextToken();
              }

            fields[6] = st.nextToken(); // shell
            if (fields[6].equals(":"))
              {
                fields[6] = "";
              }
          }
        catch (NoSuchElementException x)
          {
            continue;
          }

        entries.put(fields[0], fields);
      }
  }

  private synchronized void savePasswd() throws IOException
  {
    if (passwdFile != null)
      {
        final FileOutputStream fos = new FileOutputStream(passwdFile);
        PrintWriter pw = null;
        try
          {
            pw = new PrintWriter(fos);
            String key;
            String[] fields;
            StringBuffer sb;
            int i;
            for (Iterator it = entries.keySet().iterator(); it.hasNext();)
              {
                key = (String) it.next();
                fields = (String[]) entries.get(key);
                sb = new StringBuffer(fields[0]);
                for (i = 1; i < fields.length; i++)
                  {
                    sb.append(":").append(fields[i]);
                  }
                pw.println(sb.toString());
              }
          }
        finally
          {
            if (pw != null)
              {
                try
                  {
                    pw.flush();
                  }
                finally
                  {
                    pw.close();
                  }
              }
            try
              {
                fos.close();
              }
            catch (IOException ignored)
              {
              }
            lastmod = passwdFile.lastModified();
          }
      }
  }
}