/**
*
* Copyright 2003-2004 The Apache Software Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.geronimo.util.encoders;
import java.io.IOException;
import java.io.OutputStream;
public class Base64Encoder
implements Encoder
{
protected final byte[] encodingTable =
{
(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)'/'
};
protected byte padding = (byte)'=';
/*
* set up the decoding table.
*/
protected final byte[] decodingTable = new byte[128];
protected void initialiseDecodingTable()
{
for (int i = 0; i < encodingTable.length; i++)
{
decodingTable[encodingTable[i]] = (byte)i;
}
}
public Base64Encoder()
{
initialiseDecodingTable();
}
/**
* encode the input data producing a base 64 output stream.
*
* @return the number of bytes produced.
*/
public int encode(
byte[] data,
int off,
int length,
OutputStream out)
throws IOException
{
int modulus = length % 3;
int dataLength = (length - modulus);
int a1, a2, a3;
for (int i = off; i < off + dataLength; i += 3)
{
a1 = data[i] & 0xff;
a2 = data[i + 1] & 0xff;
a3 = data[i + 2] & 0xff;
out.write(encodingTable[(a1 >>> 2) & 0x3f]);
out.write(encodingTable[((a1 << 4) | (a2 >>> 4)) & 0x3f]);
out.write(encodingTable[((a2 << 2) | (a3 >>> 6)) & 0x3f]);
out.write(encodingTable[a3 & 0x3f]);
}
/*
* process the tail end.
*/
int b1, b2, b3;
int d1, d2;
switch (modulus)
{
case 0: /* nothing left to do */
break;
case 1:
d1 = data[off + dataLength] & 0xff;
b1 = (d1 >>> 2) & 0x3f;
b2 = (d1 << 4) & 0x3f;
out.write(encodingTable[b1]);
out.write(encodingTable[b2]);
out.write(padding);
out.write(padding);
break;
case 2:
d1 = data[off + dataLength] & 0xff;
d2 = data[off + dataLength + 1] & 0xff;
b1 = (d1 >>> 2) & 0x3f;
b2 = ((d1 << 4) | (d2 >>> 4)) & 0x3f;
b3 = (d2 << 2) & 0x3f;
out.write(encodingTable[b1]);
out.write(encodingTable[b2]);
out.write(encodingTable[b3]);
out.write(padding);
break;
}
return (dataLength / 3) * 4 + ((modulus == 0) ? 0 : 4);
}
private boolean ignore(
char c)
{
return (c == '\n' || c =='\r' || c == '\t' || c == ' ');
}
/**
* decode the base 64 encoded byte data writing it to the given output stream,
* whitespace characters will be ignored.
*
* @return the number of bytes produced.
*/
public int decode(
byte[] data,
int off,
int length,
OutputStream out)
throws IOException
{
byte[] bytes;
byte b1, b2, b3, b4;
int outLen = 0;
int end = off + length;
while (end > 0)
{
if (!ignore((char)data[end - 1]))
{
break;
}
end--;
}
int i = off;
int finish = end - 4;
while (i < finish)
{
while ((i < finish) && ignore((char)data[i]))
{
i++;
}
b1 = decodingTable[data[i++]];
while ((i < finish) && ignore((char)data[i]))
{
i++;
}
b2 = decodingTable[data[i++]];
while ((i < finish) && ignore((char)data[i]))
{
i++;
}
b3 = decodingTable[data[i++]];
while ((i < finish) && ignore((char)data[i]))
{
i++;
}
b4 = decodingTable[data[i++]];
out.write((b1 << 2) | (b2 >> 4));
out.write((b2 << 4) | (b3 >> 2));
out.write((b3 << 6) | b4);
outLen += 3;
}
if (data[end - 2] == padding)
{
b1 = decodingTable[data[end - 4]];
b2 = decodingTable[data[end - 3]];
out.write((b1 << 2) | (b2 >> 4));
outLen += 1;
}
else if (data[end - 1] == padding)
{
b1 = decodingTable[data[end - 4]];
b2 = decodingTable[data[end - 3]];
b3 = decodingTable[data[end - 2]];
out.write((b1 << 2) | (b2 >> 4));
out.write((b2 << 4) | (b3 >> 2));
outLen += 2;
}
else
{
b1 = decodingTable[data[end - 4]];
b2 = decodingTable[data[end - 3]];
b3 = decodingTable[data[end - 2]];
b4 = decodingTable[data[end - 1]];
out.write((b1 << 2) | (b2 >> 4));
out.write((b2 << 4) | (b3 >> 2));
out.write((b3 << 6) | b4);
outLen += 3;
}
return outLen;
}
/**
* decode the base 64 encoded String data writing it to the given output stream,
* whitespace characters will be ignored.
*
* @return the number of bytes produced.
*/
public int decode(
String data,
OutputStream out)
throws IOException
{
byte[] bytes;
byte b1, b2, b3, b4;
int length = 0;
int end = data.length();
while (end > 0)
{
if (!ignore(data.charAt(end - 1)))
{
break;
}
end--;
}
int i = 0;
int finish = end - 4;
while (i < finish)
{
while ((i < finish) && ignore(data.charAt(i)))
{
i++;
}
b1 = decodingTable[data.charAt(i++)];
while ((i < finish) && ignore(data.charAt(i)))
{
i++;
}
b2 = decodingTable[data.charAt(i++)];
while ((i < finish) && ignore(data.charAt(i)))
{
i++;
}
b3 = decodingTable[data.charAt(i++)];
while ((i < finish) && ignore(data.charAt(i)))
{
i++;
}
b4 = decodingTable[data.charAt(i++)];
out.write((b1 << 2) | (b2 >> 4));
out.write((b2 << 4) | (b3 >> 2));
out.write((b3 << 6) | b4);
length += 3;
}
if (data.charAt(end - 2) == padding)
{
b1 = decodingTable[data.charAt(end - 4)];
b2 = decodingTable[data.charAt(end - 3)];
out.write((b1 << 2) | (b2 >> 4));
length += 1;
}
else if (data.charAt(end - 1) == padding)
{
b1 = decodingTable[data.charAt(end - 4)];
b2 = decodingTable[data.charAt(end - 3)];
b3 = decodingTable[data.charAt(end - 2)];
out.write((b1 << 2) | (b2 >> 4));
out.write((b2 << 4) | (b3 >> 2));
length += 2;
}
else
{
b1 = decodingTable[data.charAt(end - 4)];
b2 = decodingTable[data.charAt(end - 3)];
b3 = decodingTable[data.charAt(end - 2)];
b4 = decodingTable[data.charAt(end - 1)];
out.write((b1 << 2) | (b2 >> 4));
out.write((b2 << 4) | (b3 >> 2));
out.write((b3 << 6) | b4);
length += 3;
}
return length;
}
}