// www.thinkmiddleware.com
// JAAS/LDAP Authentication Tutorial
// TMCallbackHandler.java
// 22 Nov 2008
// Notes:
//
//Per license requriments, the original copy right notice is included
//below.
//
// Contact 01@thinkmiddleware.com with questions.
//
/*
 * @(#)SampleAcn.java
 *
 * Copyright 2001-2002 Sun Microsystems, Inc. All Rights Reserved.
 *
 * Redistribution and use in source and binary forms, with or
 * without modification, are permitted provided that the following
 * conditions are met:
 *
 * -Redistributions of source code must retain the above copyright
 * notice, this  list of conditions and the following disclaimer.
 *
 * -Redistribution in binary form must reproduct the above copyright
 * notice, this list of conditions and the following disclaimer in
 * the documentation and/or other materials provided with the
 * distribution.
 *
 * Neither the name of Sun Microsystems, Inc. or the names of
 * contributors may be used to endorse or promote products derived
 * from this software without specific prior written permission.
 *
 * This software is provided "AS IS," without a warranty of any
 * kind. ALL EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND
 * WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY
 * EXCLUDED. SUN AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY
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 */

package com.tm.jaas;

import java.io.*;
import java.util.*;
import javax.security.auth.login.*;
import javax.security.auth.*;
import javax.security.auth.callback.*;
import java.security.Principal;

public class TMCallbackHandler implements CallbackHandler 
{
    public void handle(Callback[] callbacks)
      throws IOException, UnsupportedCallbackException 
    {
	for (int i = 0; i < callbacks.length; i++) 
        {
	  if (callbacks[i] instanceof TextOutputCallback) {
		TextOutputCallback toc = (TextOutputCallback)callbacks[i];
		switch (toc.getMessageType()) {
		case TextOutputCallback.INFORMATION:
 		    System.out.println(toc.getMessage());
 		    break;
 		case TextOutputCallback.ERROR:
 		    System.out.println("ERROR: " + toc.getMessage());
 		    break;
 		case TextOutputCallback.WARNING:
 		    System.out.println("WARNING: " + toc.getMessage());
 		    break;
 		default:
 		    throw new IOException("Unsupported message type: " +
 					toc.getMessageType());
 		}
 
 	    } else if (callbacks[i] instanceof NameCallback) {
  
 		// prompt the user for a username
 		NameCallback nc = (NameCallback)callbacks[i];
 		System.out.println("Username: "); 
 		nc.setName((new BufferedReader
			(new InputStreamReader(System.in))).readLine());
 
 	    } else if (callbacks[i] instanceof PasswordCallback) {
  
 		// prompt the user for sensitive information
 		PasswordCallback pc = (PasswordCallback)callbacks[i];
		System.out.println("Password: ");
 		pc.setPassword(readPassword(System.in));
  
 	    } else {
 		throw new UnsupportedCallbackException
 			(callbacks[i], "Unrecognized Callback");
 	    }
	}
    }
   
    private char[] readPassword(InputStream in) throws IOException {
	
	char[] lineBuffer;
	char[] buf;
	int i;

	buf = lineBuffer = new char[128];

	int room = buf.length;
	int offset = 0;
	int c;

loop:	while (true) {
 	    switch (c = in.read()) {
 	    case -1:
 	    case '\n':
		break loop;

 	    case '\r':
 		int c2 = in.read();
 		if ((c2 != '\n') && (c2 != -1)) {
 		    if (!(in instanceof PushbackInputStream)) {
 			in = new PushbackInputStream(in);
 		    }
 		    ((PushbackInputStream)in).unread(c2);
 		} else
 		    break loop;

 	    default:
 		if (--room < 0) {
 		    buf = new char[offset + 128];
 		    room = buf.length - offset - 1;
 		    System.arraycopy(lineBuffer, 0, buf, 0, offset);
 		    Arrays.fill(lineBuffer, ' ');
 		    lineBuffer = buf;
 		}
 		buf[offset++] = (char) c;
 		break;
 	    }
 	}

 	if (offset == 0) {
 	    return null;
 	}

 	char[] ret = new char[offset];
 	System.arraycopy(buf, 0, ret, 0, offset);
 	Arrays.fill(buf, ' ');

 	return ret;
    }
}