httpauth.java

使用工具jublider开发的一个聊天室实现基本功能,

package freecs.util;

import java.util.NoSuchElementException;
import java.util.StringTokenizer;

public class HttpAuth {

/**
 *  class for parsing http auth username/password combinations
 *  static decode and static encode from library by kevin kelley
 *  (copyright notice see below)
 */	

	public String username;
	public String password;
	
	public static HttpAuth parse(String auth) {

        if ((auth == null) || "".equals(auth)) {
            return null;
        }

        StringTokenizer tok;

        if (auth.startsWith("Basic ")) {
        	String decoded = new String(decode((auth.substring(6)).toCharArray()));
            tok = new StringTokenizer(decoded ,":");
        } else {
        	String decoded = new String(decode(auth.toCharArray()));
            tok = new StringTokenizer(decoded, ":");
        }

        HttpAuth reval = new HttpAuth();
        try {
            reval.username = tok.nextToken();
        } catch (NoSuchElementException e) {
            reval.username = null;
        }

        try {
            reval.password = tok.nextToken();
        } catch (NoSuchElementException e) {
            reval.password = null;
        }
        return reval;
        
    }
	
	
	
	
	
	
	//////////////////////license & copyright header/////////////////////////
//  //
//Base64 - encode/decode data using the Base64 encoding scheme     //
//  //
//Copyright (c) 1998 by Kevin Kelley                   //
//  //
//This library is free software; you can redistribute it and/or       //
//modify it under the terms of the GNU Lesser General Public          //
//License as published by the Free Software Foundation; either        //
//version 2.1 of the License, or (at your option) any later version.  //
//  //
//This library 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 Lesser General Public License for more details.                 //
//  //
//You should have received a copy of the GNU Lesser General Public    //
//License along with this library; if not, write to the Free Software //
//Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA           //
//02111-1307, USA, or contact the author:                             //
//  //
//Kevin Kelley <[e-mail]> - 30718 Rd. 28, La Junta, CO,    //
//81050  USA.                                                         //
//  //
////////////////////end license & copyright header///////////////////////

	
	/**
	* returns an array of base64-encoded characters to represent the
	* passed data array.
	*
	* @param data the array of bytes to encode
	* @return base64-coded character array.
	*/
	public static final char[] encode(byte[] data)
	{
	    char[] out = new char[((data.length + 2) / 3) * 4];

	    //
	    // 3 bytes encode to 4 chars.  Output is always an even
	    // multiple of 4 characters.
	    //
	    for (int i=0, index=0; i<data.length; i+=3, index+=4) {
	        boolean quad = false;
	        boolean trip = false;

	        int val = (0xFF & (int) data[i]);
	        val <<= 8;
	        if ((i+1) < data.length) {
	            val |= (0xFF & (int) data[i+1]);
	            trip = true;
	        }
	        val <<= 8;
	        if ((i+2) < data.length) {
	            val |= (0xFF & (int) data[i+2]);
	            quad = true;
	        }
	        out[index+3] = alphabet[(quad? (val & 0x3F): 64)];
	        val >>= 6;
	        out[index+2] = alphabet[(trip? (val & 0x3F): 64)];
	        val >>= 6;
	        out[index+1] = alphabet[val & 0x3F];
	        val >>= 6;
	        out[index+0] = alphabet[val & 0x3F];
	    }
	    return out;
	}

	  /**
	   * Decodes a BASE-64 encoded stream to recover the original
	   * data. White space before and after will be trimmed away,
	   * but no other manipulation of the input will be performed.
	   *
	   * As of version 1.2 this method will properly handle input
	   * containing junk characters (newlines and the like) rather
	   * than throwing an error. It does this by pre-parsing the
	   * input and generating from that a count of VALID input
	   * characters.
	   **/
	public static final byte[] decode(char[] data)
	{
	    // as our input could contain non-BASE64 data (newlines,
	    // whitespace of any sort, whatever) we must first adjust
	    // our count of USABLE data so that...
	    // (a) we don't misallocate the output array, and
	    // (b) think that we miscalculated our data length
	    //     just because of extraneous throw-away junk

	    int tempLen = data.length;
	    for( int ix=0; ix<data.length; ix++ )
	    {
	        if( (data[ix] > 255) || codes[ data[ix] ] < 0 )
	            --tempLen;  // ignore non-valid chars and padding
	    }
	    // calculate required length:
	    //  -- 3 bytes for every 4 valid base64 chars
	    //  -- plus 2 bytes if there are 3 extra base64 chars,
	    //     or plus 1 byte if there are 2 extra.

	    int len = (tempLen / 4) * 3;
	    if ((tempLen % 4) == 3) len += 2;
	    if ((tempLen % 4) == 2) len += 1;

	    byte[] out = new byte[len];



	    int shift = 0;   // # of excess bits stored in accum
	    int accum = 0;   // excess bits
	    int index = 0;

	    // we now go through the entire array (NOT using the 'tempLen' value)
	    for (int ix=0; ix<data.length; ix++)
	    {
	        int value = (data[ix]>255)? -1: codes[ data[ix] ];

	        if ( value >= 0 )           // skip over non-code
	        {
	            accum <<= 6;            // bits shift up by 6 each time thru
	            shift += 6;             // loop, with new bits being put in
	            accum |= value;         // at the bottom.
	            if ( shift >= 8 )       // whenever there are 8 or more shifted in,
	            {
	                shift -= 8;         // write them out (from the top, leaving any
	                out[index++] =      // excess at the bottom for next iteration.
	                    (byte) ((accum >> shift) & 0xff);
	            }
	        }
	        // we will also have skipped processing a padding null byte ('=') here;
	        // these are used ONLY for padding to an even length and do not legally
	        // occur as encoded data. for this reason we can ignore the fact that
	        // no index++ operation occurs in that special case: the out[] array is
	        // initialized to all-zero bytes to start with and that works to our
	        // advantage in this combination.
	    }

	    // if there is STILL something wrong we just have to throw up now!
	    if( index != out.length)
	    {
	        throw new Error("Miscalculated data length (wrote " + index + " instead of " + out.length + ")");
	    }

	    return out;
	}


	//
//	 code characters for values 0..63
	//
	private static  char[] alphabet =
	    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/="
	        .toCharArray();

	//
//	 lookup table for converting base64 characters to value in range 0..63
	//
	private static byte[] codes = new byte[256];
	static {
	    for (int i=0; i<256; i++) codes[i] = -1;
	    for (int i = 'A'; i <= 'Z'; i++) codes[i] = (byte)(     i - 'A');
	    for (int i = 'a'; i <= 'z'; i++) codes[i] = (byte)(26 + i - 'a');
	    for (int i = '0'; i <= '9'; i++) codes[i] = (byte)(52 + i - '0');
	    codes['+'] = 62;
	    codes['/'] = 63;
	}

}