/*
 * Base64.cs - A Base64 encoder
 *
 * Copyright (C) 2002  Gopal.V
 *
 * This program 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 of the License, or
 * (at your option) any later version.
 *
 * This program 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 program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

using System;

public abstract class Base64 
{

static private char[] base64chars = 
("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=").
                                                              ToCharArray();

static public char[] Encode(byte[] data)
{
    char[] encoded = new char[((data.Length + 2) / 3) * 4];

    for (int i=0, index=0; i<data.Length; i+=3, index+=4) 
	{
        bool quad = false;
        bool trip = false;
		
        int val = (0xFF & (int) data[i]);
        val = val << 8;
        if ((i+1) < data.Length) 
		{
            val |= (0xFF & (int) data[i+1]);
            trip = true;
        }
        val = val << 8;
        if ((i+2) < data.Length) 
		{
            val |= (0xFF & (int) data[i+2]);
            quad = true;
        }
        encoded[index+3] = base64chars[(quad? (val & 0x3F): 64)];
		// pad with = if !quad
        val = val >> 6;
        encoded[index+2] = base64chars[(trip? (val & 0x3F): 64)];
		// pad with = if !trip
        val = val >> 6;
        encoded[index+1] = base64chars[val & 0x3F];
        val = val >> 6;
        encoded[index+0] = base64chars[val & 0x3F];
    }
    return encoded;
}
}