org.openmdx.base.text.conversion.Base64 Maven / Gradle / Ivy
/*
* ====================================================================
* Project: openmdx, http://www.openmdx.org/
* Description: BASE64 encode/decode
* Owner: OMEX AG, Switzerland, http://www.omex.ch
* ====================================================================
*
* This software is published under the BSD license
* as listed below.
*
* Copyright (c) 2004, OMEX AG, Switzerland
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* * Neither the name of the openMDX team nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
* CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* ------------------
*
* This product includes software developed by the Apache Software
* Foundation (http://www.apache.org/).
*/
package org.openmdx.base.text.conversion;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.Writer;
/**
* BASE64 encode/decode
*/
public class Base64 {
/**
* Avoid instantiation
*/
private Base64(
) {
super();
}
private static final char[] S_BASE64CHAR = {
'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 static final char S_BASE64PAD = '=';
private static final byte[] S_DECODETABLE = new byte[128];
static {
for (int i = 0; i < S_DECODETABLE.length; i ++)
S_DECODETABLE[i] = Byte.MAX_VALUE; // 127
for (int i = 0; i < S_BASE64CHAR.length; i ++) // 0 to 63
S_DECODETABLE[S_BASE64CHAR[i]] = (byte)i;
}
private static int decode0(char[] ibuf, byte[] obuf, int _wp) {
int wp = _wp;
int outlen = 3;
if (ibuf[3] == S_BASE64PAD) outlen = 2;
if (ibuf[2] == S_BASE64PAD) outlen = 1;
int b0 = S_DECODETABLE[ibuf[0]];
int b1 = S_DECODETABLE[ibuf[1]];
int b2 = S_DECODETABLE[ibuf[2]];
int b3 = S_DECODETABLE[ibuf[3]];
switch (outlen) {
case 1:
obuf[wp] = (byte)(b0 << 2 & 0xfc | b1 >> 4 & 0x3);
return 1;
case 2:
obuf[wp++] = (byte)(b0 << 2 & 0xfc | b1 >> 4 & 0x3);
obuf[wp] = (byte)(b1 << 4 & 0xf0 | b2 >> 2 & 0xf);
return 2;
case 3:
obuf[wp++] = (byte)(b0 << 2 & 0xfc | b1 >> 4 & 0x3);
obuf[wp++] = (byte)(b1 << 4 & 0xf0 | b2 >> 2 & 0xf);
obuf[wp] = (byte)(b2 << 6 & 0xc0 | b3 & 0x3f);
return 3;
default:
throw new RuntimeException("Internal Errror");
}
}
/**
*
*/
public static byte[] decode(char[] data, int off, int len) {
char[] ibuf = new char[4];
int ibufcount = 0;
byte[] obuf = new byte[len/4*3+3];
int obufcount = 0;
for (int i = off; i < off+len; i ++) {
char ch = data[i];
if (ch == S_BASE64PAD
|| ch < S_DECODETABLE.length && S_DECODETABLE[ch] != Byte.MAX_VALUE) {
ibuf[ibufcount++] = ch;
if (ibufcount == ibuf.length) {
ibufcount = 0;
obufcount += decode0(ibuf, obuf, obufcount);
}
}
}
if (obufcount == obuf.length)
return obuf;
byte[] ret = new byte[obufcount];
System.arraycopy(obuf, 0, ret, 0, obufcount);
return ret;
}
/**
*
*/
public static byte[] decode(String data) {
char[] ibuf = new char[4];
int ibufcount = 0;
byte[] obuf = new byte[data.length()/4*3+3];
int obufcount = 0;
for (int i = 0; i < data.length(); i ++) {
char ch = data.charAt(i);
if (ch == S_BASE64PAD
|| ch < S_DECODETABLE.length && S_DECODETABLE[ch] != Byte.MAX_VALUE) {
ibuf[ibufcount++] = ch;
if (ibufcount == ibuf.length) {
ibufcount = 0;
obufcount += decode0(ibuf, obuf, obufcount);
}
}
}
if (obufcount == obuf.length)
return obuf;
byte[] ret = new byte[obufcount];
System.arraycopy(obuf, 0, ret, 0, obufcount);
return ret;
}
/**
*
*/
public static void decode(char[] data, int off, int len, OutputStream ostream) throws IOException {
char[] ibuf = new char[4];
int ibufcount = 0;
byte[] obuf = new byte[3];
for (int i = off; i < off+len; i ++) {
char ch = data[i];
if (ch == S_BASE64PAD
|| ch < S_DECODETABLE.length && S_DECODETABLE[ch] != Byte.MAX_VALUE) {
ibuf[ibufcount++] = ch;
if (ibufcount == ibuf.length) {
ibufcount = 0;
int obufcount = decode0(ibuf, obuf, 0);
ostream.write(obuf, 0, obufcount);
}
}
}
}
/**
*
*/
public static void decode(String data, OutputStream ostream) throws IOException {
char[] ibuf = new char[4];
int ibufcount = 0;
byte[] obuf = new byte[3];
for (int i = 0; i < data.length(); i ++) {
char ch = data.charAt(i);
if (ch == S_BASE64PAD
|| ch < S_DECODETABLE.length && S_DECODETABLE[ch] != Byte.MAX_VALUE) {
ibuf[ibufcount++] = ch;
if (ibufcount == ibuf.length) {
ibufcount = 0;
int obufcount = decode0(ibuf, obuf, 0);
ostream.write(obuf, 0, obufcount);
}
}
}
}
/**
* Returns base64 representation of specified byte array.
*/
public static String encode(byte[] data) {
return encode(data, 0, data.length);
}
/**
* Returns base64 representation of specified byte array.
*/
public static String encode(byte[] data, int off, int len) {
if (len <= 0) return "";
char[] out = new char[len/3*4+4];
int rindex = off;
int windex = 0;
int rest = len-off;
while (rest >= 3) {
int i = ((data[rindex]&0xff)<<16)
+((data[rindex+1]&0xff)<<8)
+(data[rindex+2]&0xff);
out[windex++] = S_BASE64CHAR[i>>18];
out[windex++] = S_BASE64CHAR[(i>>12)&0x3f];
out[windex++] = S_BASE64CHAR[(i>>6)&0x3f];
out[windex++] = S_BASE64CHAR[i&0x3f];
rindex += 3;
rest -= 3;
}
if (rest == 1) {
int i = data[rindex]&0xff;
out[windex++] = S_BASE64CHAR[i>>2];
out[windex++] = S_BASE64CHAR[(i<<4)&0x3f];
out[windex++] = S_BASE64PAD;
out[windex++] = S_BASE64PAD;
} else if (rest == 2) {
int i = ((data[rindex]&0xff)<<8)+(data[rindex+1]&0xff);
out[windex++] = S_BASE64CHAR[i>>10];
out[windex++] = S_BASE64CHAR[(i>>4)&0x3f];
out[windex++] = S_BASE64CHAR[(i<<2)&0x3f];
out[windex++] = S_BASE64PAD;
}
return new String(out, 0, windex);
}
/**
* Outputs base64 representation of the specified byte array to a byte stream.
*/
public static void encode(byte[] data, int off, int len, OutputStream ostream) throws IOException {
if (len <= 0) return;
byte[] out = new byte[4];
int rindex = off;
int rest = len-off;
while (rest >= 3) {
int i = ((data[rindex]&0xff)<<16)
+((data[rindex+1]&0xff)<<8)
+(data[rindex+2]&0xff);
out[0] = (byte)S_BASE64CHAR[i>>18];
out[1] = (byte)S_BASE64CHAR[(i>>12)&0x3f];
out[2] = (byte)S_BASE64CHAR[(i>>6)&0x3f];
out[3] = (byte)S_BASE64CHAR[i&0x3f];
ostream.write(out, 0, 4);
rindex += 3;
rest -= 3;
}
if (rest == 1) {
int i = data[rindex]&0xff;
out[0] = (byte)S_BASE64CHAR[i>>2];
out[1] = (byte)S_BASE64CHAR[(i<<4)&0x3f];
out[2] = (byte)S_BASE64PAD;
out[3] = (byte)S_BASE64PAD;
ostream.write(out, 0, 4);
} else if (rest == 2) {
int i = ((data[rindex]&0xff)<<8)+(data[rindex+1]&0xff);
out[0] = (byte)S_BASE64CHAR[i>>10];
out[1] = (byte)S_BASE64CHAR[(i>>4)&0x3f];
out[2] = (byte)S_BASE64CHAR[(i<<2)&0x3f];
out[3] = (byte)S_BASE64PAD;
ostream.write(out, 0, 4);
}
}
/**
* Outputs base64 representation of the specified byte array to a character stream.
*/
private static void encode(
byte[] data,
int off,
int len,
Writer writer,
char[] tmp
) throws IOException {
if (len <= 0) return;
int rindex = off;
int rest = len-off;
int output = 0;
while (rest >= 3) {
int i = ((data[rindex]&0xff)<<16)
+((data[rindex+1]&0xff)<<8)
+(data[rindex+2]&0xff);
tmp[0] = S_BASE64CHAR[i>>18];
tmp[1] = S_BASE64CHAR[(i>>12)&0x3f];
tmp[2] = S_BASE64CHAR[(i>>6)&0x3f];
tmp[3] = S_BASE64CHAR[i&0x3f];
writer.write(tmp, 0, 4);
rindex += 3;
rest -= 3;
output += 4;
if (output % 76 == 0)
writer.write('\n');
}
if (rest == 1) {
int i = data[rindex]&0xff;
tmp[0] = S_BASE64CHAR[i>>2];
tmp[1] = S_BASE64CHAR[(i<<4)&0x3f];
tmp[2] = S_BASE64PAD;
tmp[3] = S_BASE64PAD;
writer.write(tmp, 0, 4);
} else if (rest == 2) {
int i = ((data[rindex]&0xff)<<8)+(data[rindex+1]&0xff);
tmp[0] = S_BASE64CHAR[i>>10];
tmp[1] = S_BASE64CHAR[(i>>4)&0x3f];
tmp[2] = S_BASE64CHAR[(i<<2)&0x3f];
tmp[3] = S_BASE64PAD;
writer.write(tmp, 0, 4);
}
}
/**
* Outputs base64 representation of the specified byte array to a character stream.
*/
public static void encode(
byte[] data,
int off,
int len,
Writer writer
) throws IOException {
char[] tmp = new char[4];
encode(data, off, len, writer, tmp);
}
/**
* Outputs base64 representation of the specified byte array to a character stream.
*/
public static void encode(
InputStream data,
Writer writer
) throws IOException {
char[] tmp = new char[4];
byte[] bytes = new byte[3];
int len = 0;
while((len = data.read(bytes, 0, 3)) != -1) {
encode(bytes, 0, len, writer, tmp);
}
}
}
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