/**************************************************************** * 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 */ }; }