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// Version 1.0a
// Copyright (C) 1998, James R. Weeks and BioElectroMech.
// Visit BioElectroMech at www.obrador.com. Email [email protected].
// See license.txt for details about the allowed used of this software.
// This software is based in part on the work of the Independent JPEG Group.
// See IJGreadme.txt for details about the Independent JPEG Group's license.
// This encoder is inspired by the Java Jpeg encoder by Florian Raemy,
// studwww.eurecom.fr/~raemy.
// It borrows a great deal of code and structure from the Independent
// Jpeg Group's Jpeg 6a library, Copyright Thomas G. Lane.
// See license.txt for details.
package javajs.util;
public class Base64 {
// 0 1 2 3 4 5 6
// 0123456789012345678901234567890123456789012345678901234567890123
private static String base64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
// 41----------------------5A
// 61----------------------7A
// 30------39
// 2B
// 2F
// alternative "URL-SAFE" 2D and 5F -_
private static int[] decode64 = new int[] {
0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, //0x00-0x0F
0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, //0x10-0x1F
0,0,0,0, 0,0,0,0, 0,0,0,62, 0,62,0,63, //0x20-0x2F
52,53,54,55, 56,57,58,59, 60,61,0,0, 0,0,0,0, //0x30-0x3F
0,0,1,2, 3,4,5,6, 7,8,9,10, 11,12,13,14, //0x40-0x4F
15,16,17,18, 19,20,21,22, 23,24,25,0, 0,0,0,63, //0x50-0x5F
0,26,27,28, 29,30,31,32, 33,34,35,36, 37,38,39,40, //0x60-0x6F
41,42,43,44, 45,46,47,48, 49,50,51,0, 0,0,0,0, //0x70-0x7F
};
// public static void write(byte[] bytes, OutputChannel out) {
// SB sb = getBase64(bytes);
// int len = sb.length();
// byte[] b = new byte[1];
// for (int i = 0; i < len; i++) {
// b[0] = (byte) sb.charAt(i);
// out.write(b, 0, 1);
// }
// }
public static byte[] getBytes64(byte[] bytes) {
return getBase64(bytes).toBytes(0, -1);
}
/**
*
* @param bytes
* @return BASE64-encoded string, without ";base64,"
*/
public static SB getBase64(byte[] bytes) {
long nBytes = bytes.length;
SB sout = new SB();
if (nBytes == 0)
return sout;
for (int i = 0, nPad = 0; i < nBytes && nPad == 0;) {
if (i % 75 == 0 && i != 0)
sout.append("\r\n");
nPad = (i + 2 == nBytes ? 1 : i + 1 == nBytes ? 2 : 0);
int outbytes = ((bytes[i++] << 16) & 0xFF0000)
| ((nPad == 2 ? 0 : bytes[i++] << 8) & 0x00FF00)
| ((nPad >= 1 ? 0 : (int) bytes[i++]) & 0x0000FF);
//System.out.println(Integer.toHexString(outbytes));
sout.appendC(base64.charAt((outbytes >> 18) & 0x3F));
sout.appendC(base64.charAt((outbytes >> 12) & 0x3F));
sout.appendC(nPad == 2 ? '=' : base64.charAt((outbytes >> 6) & 0x3F));
sout.appendC(nPad >= 1 ? '=' : base64.charAt(outbytes & 0x3F));
}
return sout;
}
//Note: Just a simple decoder here. Nothing fancy at all
// Because of the 0s in decode64, this is not a VERIFIER
// Rather, it may decode even bad Base64-encoded data
//
// Bob Hanson 4/2007
public static byte[] decodeBase64(String strBase64) {
int nBytes = 0;
int ch;
int pt0 = strBase64.indexOf(";base64,") + 1;
if (pt0 > 0)
pt0 += 7;
char[] chars64 = strBase64.toCharArray();
int len64 = chars64.length;
if (len64 == 0)
return new byte[0];
for (int i = len64; --i >= pt0;)
nBytes += ((ch = chars64[i] & 0x7F) == 'A' || decode64[ch] > 0 ? 3 : 0);
nBytes = nBytes >> 2;
byte[] bytes = new byte[nBytes];
int offset = 18;
for (int i = pt0, pt = 0, b = 0; i < len64; i++) {
if (decode64[ch = chars64[i] & 0x7F] > 0 || ch == 'A' || ch == '=') {
b |= decode64[ch] << offset;
//System.out.println(chars64[i] + " " + decode64[ch] + " " + offset + " " + Integer.toHexString(b));
offset -= 6;
if (offset < 0) {
bytes[pt++] = (byte) ((b & 0xFF0000) >> 16);
if (pt < nBytes)
bytes[pt++] = (byte) ((b & 0xFF00) >> 8);
if (pt < nBytes)
bytes[pt++] = (byte) (b & 0xFF);
offset = 18;
b = 0;
}
}
}
return bytes;
}
}