hal/src/zutil/parser/Base64Decoder.java
2015-05-27 13:13:19 +00:00

204 lines
6.2 KiB
Java

/*
* Copyright (c) 2015 ezivkoc
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package zutil.parser;
import zutil.converters.Converter;
import zutil.io.DynamicByteArrayStream;
public class Base64Decoder {
public static final char[] B64_ENCODE_TABLE = {
'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I',
'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R',
'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i',
'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r',
's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
'0', '1', '2', '3', '4', '5', '6', '7', '8',
'9', '+', '/'
};
private DynamicByteArrayStream output;
private byte rest_data;
private int rest = 0;
public Base64Decoder(){
output = new DynamicByteArrayStream();
}
public static String decode( String data ){
Base64Decoder base64 = new Base64Decoder();
base64.write( data );
return base64.toString();
}
public static String decodeToHex( String data ){
Base64Decoder base64 = new Base64Decoder();
base64.write( data );
return Converter.toHexString( base64.getByte() );
}
public static byte[] decodeToByte( String data ){
Base64Decoder base64 = new Base64Decoder();
base64.write( data );
return base64.getByte();
}
public void write( String data ){
byte[] buffer = new byte[ (data.length()*6/8) + 1 ];
int buffi = 0;
if( rest != 0 )
buffer[0] = rest_data;
for( int i=0; i<data.length(); i++){
char c = data.charAt(i);
if( c == '='){
rest = (rest + 2) % 8;
continue;
}
byte b = getByte(c);
switch(rest){
case 0:
buffer[buffi] = (byte) ((b << 2) & 0xFC);
break;
case 2:
buffer[buffi] |= (byte) ((b >> 4) & 0x03);
buffer[++buffi] = (byte) ((b << 4) & 0xF0);
break;
case 4:
buffer[buffi] |= (byte) ((b >> 2) & 0x0F);
buffer[++buffi] = (byte) ((b << 6) & 0xC0);
break;
case 6:
buffer[buffi++]|= (byte) (b & 0x3F);
break;
}
rest = (rest + 2) % 8;
}
if( rest != 0 )
rest_data = buffer[buffi--];
output.append( buffer, 0, buffi );
}
public String toString(){
return output.toString();
}
public byte[] getByte(){
return output.getBytes();
}
public void clear(){
output.clear();
rest = 0;
rest_data = 0;
}
public static String addPadding( String data ){
int padding = 4 - (data.length() % 4);
switch( padding ){
case 0: return data;
case 1: return data + "=";
case 2: return data + "==";
case 3: return data + "===";
}
return null;
}
private byte getByte( char c ){
switch(c){
case 'A': return (byte)( 0 & 0xff);
case 'B': return (byte)( 1 & 0xff);
case 'C': return (byte)( 2 & 0xff);
case 'D': return (byte)( 3 & 0xff);
case 'E': return (byte)( 4 & 0xff);
case 'F': return (byte)( 5 & 0xff);
case 'G': return (byte)( 6 & 0xff);
case 'H': return (byte)( 7 & 0xff);
case 'I': return (byte)( 8 & 0xff);
case 'J': return (byte)( 9 & 0xff);
case 'K': return (byte)(10 & 0xff);
case 'L': return (byte)(11 & 0xff);
case 'M': return (byte)(12 & 0xff);
case 'N': return (byte)(13 & 0xff);
case 'O': return (byte)(14 & 0xff);
case 'P': return (byte)(15 & 0xff);
case 'Q': return (byte)(16 & 0xff);
case 'R': return (byte)(17 & 0xff);
case 'S': return (byte)(18 & 0xff);
case 'T': return (byte)(19 & 0xff);
case 'U': return (byte)(20 & 0xff);
case 'V': return (byte)(21 & 0xff);
case 'W': return (byte)(22 & 0xff);
case 'X': return (byte)(23 & 0xff);
case 'Y': return (byte)(24 & 0xff);
case 'Z': return (byte)(25 & 0xff);
case 'a': return (byte)(26 & 0xff);
case 'b': return (byte)(27 & 0xff);
case 'c': return (byte)(28 & 0xff);
case 'd': return (byte)(29 & 0xff);
case 'e': return (byte)(30 & 0xff);
case 'f': return (byte)(31 & 0xff);
case 'g': return (byte)(32 & 0xff);
case 'h': return (byte)(33 & 0xff);
case 'i': return (byte)(34 & 0xff);
case 'j': return (byte)(35 & 0xff);
case 'k': return (byte)(36 & 0xff);
case 'l': return (byte)(37 & 0xff);
case 'm': return (byte)(38 & 0xff);
case 'n': return (byte)(39 & 0xff);
case 'o': return (byte)(40 & 0xff);
case 'p': return (byte)(41 & 0xff);
case 'q': return (byte)(42 & 0xff);
case 'r': return (byte)(43 & 0xff);
case 's': return (byte)(44 & 0xff);
case 't': return (byte)(45 & 0xff);
case 'u': return (byte)(46 & 0xff);
case 'v': return (byte)(47 & 0xff);
case 'w': return (byte)(48 & 0xff);
case 'x': return (byte)(49 & 0xff);
case 'y': return (byte)(50 & 0xff);
case 'z': return (byte)(51 & 0xff);
case '0': return (byte)(52 & 0xff);
case '1': return (byte)(53 & 0xff);
case '2': return (byte)(54 & 0xff);
case '3': return (byte)(55 & 0xff);
case '4': return (byte)(56 & 0xff);
case '5': return (byte)(57 & 0xff);
case '6': return (byte)(58 & 0xff);
case '7': return (byte)(59 & 0xff);
case '8': return (byte)(60 & 0xff);
case '9': return (byte)(61 & 0xff);
case '+': return (byte)(62 & 0xff);
case '/': return (byte)(63 & 0xff);
default: return -1;
}
}
}