package pt.tumba.parser.swf; import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.io.OutputStream; import java.io.OutputStreamWriter; import java.io.Reader; import java.io.StringReader; import java.io.StringWriter; import java.io.Writer; import java.util.HashMap; /** * Base64 encoding/decoding utilities * *@author unknown *@created 15 de Setembro de 2002 */ public class Base64 { private static final Base64 _theInstance = new Base64(); private Base64() { } public static Base64 getInstance() { return _theInstance; } public final static char[] charset = { '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', '+', '/' }; public final static char paddingChar = '='; protected static HashMap charLookup = new HashMap(); static { //initialize the hashtable for (int i = 0; i < charset.length; i++) { charLookup.put(new Character(charset[i]), new Integer(i)); } } /** * Description of the Method * *@param in Description of the Parameter *@param out Description of the Parameter *@exception Exception Description of the Exception */ public static void decode(Reader in, OutputStream out) throws Exception { char[] chars = new char[4]; int[] sixbit = new int[4]; //--Process the input stream in 4-character chunks while (true) { int numread = 0; while (numread < 4) { int read = in.read(); if (read < 0) { break; } //end of input char aChar = (char) read; if (Character.isWhitespace(aChar)) { continue; } //skip w/s chars[numread++] = aChar; } if (numread == 0) { return; } //end of input if (numread != 4) { throw new Exception("Incomplete character quartet at end of Base64 input"); } //--Convert chars to six-bit values for (int i = 0; i < 4; i++) { Integer value = (Integer) charLookup.get(new Character(chars[i])); if (value == null) { if (chars[i] != '=' || i < 2) { throw new Exception("Invalid char (" + chars[i] + ") in Base64 data"); } sixbit[i] = -1; } else { sixbit[i] = value.intValue(); } } //--Write first 6 bits and top 2 bits from second value out.write((sixbit[0] << 2) + (sixbit[1] >> 4)); //System.out.println( (sixbit[0] << 2) + (sixbit[1] >> 4) ); //--Get bottom four bits of second value int val = (sixbit[1] & 0xf) << 4; if (sixbit[2] >= 0) { //third value is valid //--Add top four bits of third value val += sixbit[2] >> 2; out.write(val); //System.out.println( val ); //--Get bottom two bits of third value val = (sixbit[2] & 0x3) << 6; if (sixbit[3] >= 0) { //fourth value is valid val += sixbit[3]; out.write(val); //System.out.println( val ); } } } } /** * Description of the Method * *@param base64 Description of the Parameter *@return Description of the Return Value *@exception Exception Description of the Exception */ public static byte[] decode(String base64) throws Exception { //if base64 is invalid ByteArrayOutputStream out = new ByteArrayOutputStream(); StringReader in = new StringReader(base64); decode(in, out); in.close(); out.flush(); out.close(); return out.toByteArray(); } /** * Description of the Method * *@param in Description of the Parameter *@param out Description of the Parameter *@exception IOException Description of the Exception */ public static void encode(InputStream in, Writer out) throws IOException { int column = 0; //--Process 3 bytes in each loop - writing 4 base64 chars to the output while (true) { int byte1 = in.read(); int byte2 = in.read(); int byte3 = in.read(); if (byte1 < 0) { return; } //end-of-data //--Wrap output at column 72 if (column >= 72) { column = 0; out.write('\n'); } out.write(charset[byte1 >> 2]); //write top 6 bits of byte 1 int index = (byte1 & 0x3) << 4; //get bottom two bits of byte 1 if (byte2 < 0) { //no more data out.write(charset[index]); out.write(paddingChar); out.write(paddingChar); return; } index += byte2 >> 4; //add the top 4 bits of byte 2 out.write(charset[index]); index = (byte2 & 0xf) << 2; //get bottom 4 bits of byte 2 if (byte3 < 0) { //more more data out.write(charset[index]); out.write(paddingChar); return; } index += byte3 >> 6; //add top 2 bits of byte 3 out.write(charset[index]); out.write(charset[byte3 & 0x3f]); //write bottom 6 bits of byte 3 //--Advance column counter column += 4; } } /** * Description of the Method * *@param data Description of the Parameter *@return Description of the Return Value */ public static String encode(byte[] data) { try { return encode(data, 0, data.length); } catch (ArrayIndexOutOfBoundsException aiobe) { return aiobe.toString(); } } /** * Description of the Method * *@param data Description of the Parameter *@param start Description of the Parameter *@param length Description of the Parameter *@return Description of the Return * Value *@exception ArrayIndexOutOfBoundsException Description of the Exception */ public static String encode(byte[] data, int start, int length) throws ArrayIndexOutOfBoundsException { StringWriter out = new StringWriter(); ByteArrayInputStream in = new ByteArrayInputStream(data, start, length); try { encode(in, out); in.close(); out.flush(); out.close(); } catch (IOException ioe) { return ioe.toString(); } return out.toString(); } /** * If args.length > 0 then encode binary on stdin to base64 on stdout, else * decode base64 on stdin to binary on stdout * *@param args The command line arguments *@exception Exception Description of the Exception */ public static void main(String[] args) throws Exception { if (args.length > 0) { OutputStreamWriter out = new OutputStreamWriter(System.out); encode(System.in, out); out.flush(); return; } decode(new InputStreamReader(System.in), System.out); System.out.flush(); } }