/*
* Copyright (c) 2008 Nokia Corporation and/or its subsidiary(-ies).
* All rights reserved.
* This component and the accompanying materials are made available
* under the terms of "Eclipse Public License v1.0"
* which accompanies this distribution, and is available
* at the URL "http://www.eclipse.org/legal/epl-v10.html".
*
* Initial Contributors:
* Nokia Corporation - initial contribution.
*
* Contributors:
*
* Description:
*
*/
package com.nokia.mj.impl.utils;
/**
* Base64 utility class originated from the public domain:
* see http://iharder.sourceforge.net/current/java/base64/
*/
public class Base64
{
private final static byte[] ENCODE_ALPHABET =
{
(byte)'A', (byte)'B', (byte)'C', (byte)'D', (byte)'E', (byte)'F', (byte)'G',
(byte)'H', (byte)'I', (byte)'J', (byte)'K', (byte)'L', (byte)'M', (byte)'N',
(byte)'O', (byte)'P', (byte)'Q', (byte)'R', (byte)'S', (byte)'T', (byte)'U',
(byte)'V', (byte)'W', (byte)'X', (byte)'Y', (byte)'Z',
(byte)'a', (byte)'b', (byte)'c', (byte)'d', (byte)'e', (byte)'f', (byte)'g',
(byte)'h', (byte)'i', (byte)'j', (byte)'k', (byte)'l', (byte)'m', (byte)'n',
(byte)'o', (byte)'p', (byte)'q', (byte)'r', (byte)'s', (byte)'t', (byte)'u',
(byte)'v', (byte)'w', (byte)'x', (byte)'y', (byte)'z',
(byte)'0', (byte)'1', (byte)'2', (byte)'3', (byte)'4', (byte)'5',
(byte)'6', (byte)'7', (byte)'8', (byte)'9', (byte)'+', (byte)'/'
};
private final static byte[] DECODE_ALPHABET =
{
-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 0 - 8
-5,-5, // Whitespace: Tab and Linefeed
-9,-9, // Decimal 11 - 12
-5, // Whitespace: Carriage Return
-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 14 - 26
-9,-9,-9,-9,-9, // Decimal 27 - 31
-5, // Whitespace: Space
-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 33 - 42
62, // Plus sign at decimal 43
-9,-9,-9, // Decimal 44 - 46
63, // Slash at decimal 47
52,53,54,55,56,57,58,59,60,61, // Numbers zero through nine
-9,-9,-9, // Decimal 58 - 60
-1, // Equals sign at decimal 61
-9,-9,-9, // Decimal 62 - 64
0,1,2,3,4,5,6,7,8,9,10,11,12,13, // Letters 'A' through 'N'
14,15,16,17,18,19,20,21,22,23,24,25, // Letters 'O' through 'Z'
-9,-9,-9,-9,-9,-9, // Decimal 91 - 96
26,27,28,29,30,31,32,33,34,35,36,37,38, // Letters 'a' through 'm'
39,40,41,42,43,44,45,46,47,48,49,50,51, // Letters 'n' through 'z'
-9,-9,-9,-9 // Decimal 123 - 126
};
private final static byte WHITE_SPACE_ENC = -5;
private final static byte EQUALS_SIGN_ENC = -1;
private final static byte EQUALS_SIGN = (byte)'=';
public static byte[] decode(String s)
{
if (s == null)
{
return null;
}
byte[] source = s.getBytes();
int len34 = source.length * 3 / 4;
byte[] outBuff = new byte[ len34 ];
int outBuffPosn = 0;
byte[] b4 = new byte[4];
int b4Posn = 0;
int i = 0;
byte sbiCrop = 0;
byte sbiDecode = 0;
for (i = 0; i < source.length; i++)
{
sbiCrop = (byte)(source[i] & 0x7f);
sbiDecode = DECODE_ALPHABET[ sbiCrop ];
if (sbiDecode >= WHITE_SPACE_ENC)
{
if (sbiDecode >= EQUALS_SIGN_ENC)
{
b4[ b4Posn++ ] = sbiCrop;
if (b4Posn > 3)
{
outBuffPosn += decode4to3(b4, 0, outBuff, outBuffPosn);
b4Posn = 0;
if (sbiCrop == EQUALS_SIGN)
break;
}
}
}
else
{
return null;
}
}
if (outBuffPosn == 0)
{
return null;
}
byte[] out = new byte[ outBuffPosn ];
System.arraycopy(outBuff, 0, out, 0, outBuffPosn);
return out;
}
public static String encode(byte[] source)
{
if (source == null)
{
return null;
}
int len = source.length;
int len43 = len * 4 / 3;
byte[] outBuff = new byte[(len43) + ((len % 3) > 0 ? 4 : 0)];
int d = 0;
int e = 0;
int len2 = len - 2;
int lineLength = 0;
for (; d < len2; d+=3, e+=4)
{
encode3to4(source, d, 3, outBuff, e);
lineLength += 4;
}
if (d < len)
{
encode3to4(source, d, len - d, outBuff, e);
e += 4;
}
if (outBuff.length == 0)
{
return null;
}
return new String(outBuff, 0, e);
}
private static int decode4to3(byte[] source, int srcOffset, byte[] destination, int destOffset)
{
if (source[ srcOffset + 2] == EQUALS_SIGN)
{
int outBuff = ((DECODE_ALPHABET[ source[ srcOffset ] ] & 0xFF) << 18)
| ((DECODE_ALPHABET[ source[ srcOffset + 1] ] & 0xFF) << 12);
destination[ destOffset ] = (byte)(outBuff >>> 16);
return 1;
}
else if (source[ srcOffset + 3 ] == EQUALS_SIGN)
{
int outBuff = ((DECODE_ALPHABET[ source[ srcOffset ] ] & 0xFF) << 18)
| ((DECODE_ALPHABET[ source[ srcOffset + 1 ] ] & 0xFF) << 12)
| ((DECODE_ALPHABET[ source[ srcOffset + 2 ] ] & 0xFF) << 6);
destination[ destOffset ] = (byte)(outBuff >>> 16);
destination[ destOffset + 1 ] = (byte)(outBuff >>> 8);
return 2;
}
else
{
try
{
int outBuff = ((DECODE_ALPHABET[ source[ srcOffset ] ] & 0xFF) << 18)
| ((DECODE_ALPHABET[ source[ srcOffset + 1 ] ] & 0xFF) << 12)
| ((DECODE_ALPHABET[ source[ srcOffset + 2 ] ] & 0xFF) << 6)
| ((DECODE_ALPHABET[ source[ srcOffset + 3 ] ] & 0xFF));
destination[ destOffset ] = (byte)(outBuff >> 16);
destination[ destOffset + 1 ] = (byte)(outBuff >> 8);
destination[ destOffset + 2 ] = (byte)(outBuff);
return 3;
}
catch (Exception e)
{
return -1;
}
}
}
private static byte[] encode3to4(byte[] source, int srcOffset, int numSigBytes, byte[] destination, int destOffset)
{
int inBuff = (numSigBytes > 0 ? ((source[ srcOffset ] << 24) >>> 8) : 0)
| (numSigBytes > 1 ? ((source[ srcOffset + 1 ] << 24) >>> 16) : 0)
| (numSigBytes > 2 ? ((source[ srcOffset + 2 ] << 24) >>> 24) : 0);
switch (numSigBytes)
{
case 3:
destination[ destOffset ] = ENCODE_ALPHABET[(inBuff >>> 18)];
destination[ destOffset + 1 ] = ENCODE_ALPHABET[(inBuff >>> 12) & 0x3f ];
destination[ destOffset + 2 ] = ENCODE_ALPHABET[(inBuff >>> 6) & 0x3f ];
destination[ destOffset + 3 ] = ENCODE_ALPHABET[(inBuff) & 0x3f ];
return destination;
case 2:
destination[ destOffset ] = ENCODE_ALPHABET[(inBuff >>> 18)];
destination[ destOffset + 1 ] = ENCODE_ALPHABET[(inBuff >>> 12) & 0x3f ];
destination[ destOffset + 2 ] = ENCODE_ALPHABET[(inBuff >>> 6) & 0x3f ];
destination[ destOffset + 3 ] = EQUALS_SIGN;
return destination;
case 1:
destination[ destOffset ] = ENCODE_ALPHABET[(inBuff >>> 18)];
destination[ destOffset + 1 ] = ENCODE_ALPHABET[(inBuff >>> 12) & 0x3f ];
destination[ destOffset + 2 ] = EQUALS_SIGN;
destination[ destOffset + 3 ] = EQUALS_SIGN;
return destination;
default:
return destination;
}
}
}