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* Licensed to the Apache Software Foundation (ASF) under one * | |
* or more contributor license agreements. See the NOTICE file * | |
* distributed with this work for additional information * | |
* regarding copyright ownership. The ASF licenses this file * | |
* to you 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. * | |
****************************************************************/ | |
/** | |
* Modified for Exchange attachment decoding 5/12/11. Changes are bracketed with START EAS CHANGES | |
* and END EAS CHANGES | |
* | |
* Without the included changes, the final bytes of the input stream will be read here and thrown | |
* away; in that case, the WBXML parser will lose information necessary to determine that the | |
* entire stream has been processed correctly. Since inline WBXML text is terminated with a zero | |
* byte, and since zero is not valid Base64, we terminate reading when we find a zero byte, leaving | |
* the remainder of the stream untouched (to be read by the Parser that created the | |
* Base64InputStream. | |
*/ | |
package com.android.exchange.adapter; | |
import java.io.IOException; | |
import java.io.InputStream; | |
/** | |
* Performs Base-64 decoding on an underlying stream. | |
* | |
* | |
* @version $Id: Base64InputStream.java,v 1.3 2004/11/29 13:15:47 ntherning Exp $ | |
*/ | |
public class Base64InputStream extends InputStream { | |
private final InputStream s; | |
private int outCount = 0; | |
private int outIndex = 0; | |
private final int[] outputBuffer = new int[3]; | |
private final byte[] inputBuffer = new byte[4]; | |
private boolean done = false; | |
// START EAS CHANGES | |
private boolean padSeen = false; | |
// END EAS CHANGES | |
public Base64InputStream(InputStream s) { | |
this.s = s; | |
} | |
/** | |
* Closes the underlying stream. | |
* | |
* @throws IOException on I/O errors. | |
*/ | |
@Override | |
public void close() throws IOException { | |
s.close(); | |
} | |
@Override | |
public int read() throws IOException { | |
if (outIndex == outCount) { | |
fillBuffer(); | |
if (outIndex == outCount) { | |
return -1; | |
} | |
} | |
return outputBuffer[outIndex++]; | |
} | |
/** | |
* Retrieve data from the underlying stream, decode it, | |
* and put the results in the byteq. | |
* @throws IOException | |
*/ | |
private void fillBuffer() throws IOException { | |
outCount = 0; | |
outIndex = 0; | |
int inCount = 0; | |
int i; | |
// "done" is needed for the two successive '=' at the end | |
while (!done) { | |
switch (i = s.read()) { | |
// START EAS CHANGES | |
case 0: | |
// In EAS, a zero will indicate the end of the (inline) base64 string | |
// Stop reading at this point, so that we can continue with WBXML | |
done = true; | |
return; | |
// END EAS CHANGES | |
case -1: | |
// No more input - just return, let outputBuffer drain out, and be done | |
return; | |
case '=': | |
// START EAS CHANGES | |
// Allow for a second '=' before we're really done (we should get a zero next) | |
if (padSeen) { | |
return; | |
} | |
// We've seen a (first) end padding character, flush what's in the buffer | |
padSeen = true; | |
// END EAS CHANGES | |
// PRE-EAS LINE COMMENTED OUT | |
//done = true; | |
decodeAndEnqueue(inCount); | |
return; | |
default: | |
byte sX = TRANSLATION[i]; | |
if (sX < 0) continue; | |
inputBuffer[inCount++] = sX; | |
if (inCount == 4) { | |
decodeAndEnqueue(inCount); | |
return; | |
} | |
break; | |
} | |
} | |
} | |
private void decodeAndEnqueue(int len) { | |
int accum = 0; | |
accum |= inputBuffer[0] << 18; | |
accum |= inputBuffer[1] << 12; | |
accum |= inputBuffer[2] << 6; | |
accum |= inputBuffer[3]; | |
// There's a bit of duplicated code here because we want to have straight-through operation | |
// for the most common case of len==4 | |
if (len == 4) { | |
outputBuffer[0] = (accum >> 16) & 0xFF; | |
outputBuffer[1] = (accum >> 8) & 0xFF; | |
outputBuffer[2] = (accum) & 0xFF; | |
outCount = 3; | |
return; | |
} else if (len == 3) { | |
outputBuffer[0] = (accum >> 16) & 0xFF; | |
outputBuffer[1] = (accum >> 8) & 0xFF; | |
outCount = 2; | |
return; | |
} else { // len == 2 | |
outputBuffer[0] = (accum >> 16) & 0xFF; | |
outCount = 1; | |
return; | |
} | |
} | |
private static byte[] TRANSLATION = { | |
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 0x00 */ | |
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 0x10 */ | |
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63, /* 0x20 */ | |
52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1, /* 0x30 */ | |
-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, /* 0x40 */ | |
15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1, /* 0x50 */ | |
-1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, /* 0x60 */ | |
41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1, /* 0x70 */ | |
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 0x80 */ | |
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 0x90 */ | |
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 0xA0 */ | |
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 0xB0 */ | |
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 0xC0 */ | |
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 0xD0 */ | |
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 0xE0 */ | |
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 /* 0xF0 */ | |
}; | |
} |