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/*
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* Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved.
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This code is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 only, as
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* published by the Free Software Foundation. Oracle designates this
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* particular file as subject to the "Classpath" exception as provided
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* by Oracle in the LICENSE file that accompanied this code.
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*
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* This code is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* version 2 for more details (a copy is included in the LICENSE file that
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* accompanied this code).
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*
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* You should have received a copy of the GNU General Public License version
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* 2 along with this work; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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* or visit www.oracle.com if you need additional information or have any
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* questions.
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*/
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package org.txm.core.preferences;
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import java.io.FilterOutputStream;
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import java.io.IOException;
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import java.io.InputStream;
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import java.io.OutputStream;
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import java.nio.ByteBuffer;
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import java.nio.charset.StandardCharsets;
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import java.util.Arrays;
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import java.util.Objects;
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/**
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* This class consists exclusively of static methods for obtaining
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* encoders and decoders for the Base64 encoding scheme. The
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* implementation of this class supports the following types of Base64
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* as specified in
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* <a href="http://www.ietf.org/rfc/rfc4648.txt">RFC 4648</a> and
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* <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045</a>.
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*
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* <ul>
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* <li><a name="basic"><b>Basic</b></a>
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* <p> Uses "The Base64 Alphabet" as specified in Table 1 of
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* RFC 4648 and RFC 2045 for encoding and decoding operation.
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* The encoder does not add any line feed (line separator)
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* character. The decoder rejects data that contains characters
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* outside the base64 alphabet.</p></li>
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*
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* <li><a name="url"><b>URL and Filename safe</b></a>
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* <p> Uses the "URL and Filename safe Base64 Alphabet" as specified
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* in Table 2 of RFC 4648 for encoding and decoding. The
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* encoder does not add any line feed (line separator) character.
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* The decoder rejects data that contains characters outside the
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* base64 alphabet.</p></li>
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*
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* <li><a name="mime"><b>MIME</b></a>
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* <p> Uses the "The Base64 Alphabet" as specified in Table 1 of
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* RFC 2045 for encoding and decoding operation. The encoded output
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* must be represented in lines of no more than 76 characters each
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* and uses a carriage return {@code '\r'} followed immediately by
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* a linefeed {@code '\n'} as the line separator. No line separator
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* is added to the end of the encoded output. All line separators
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* or other characters not found in the base64 alphabet table are
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* ignored in decoding operation.</p></li>
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* </ul>
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*
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* <p> Unless otherwise noted, passing a {@code null} argument to a
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* method of this class will cause a {@link java.lang.NullPointerException
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* NullPointerException} to be thrown.
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*
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* @author Xueming Shen
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* @since 1.8
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*/
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//TODO: switch to Java 1.8 and drop this copy of java.util.Base64
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public class Base64 {
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private Base64() {}
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/**
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* Returns a {@link Encoder} that encodes using the
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* <a href="#basic">Basic</a> type base64 encoding scheme.
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*
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* @return A Base64 encoder.
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*/
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public static Encoder getEncoder() {
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return Encoder.RFC4648;
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}
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/**
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* Returns a {@link Encoder} that encodes using the
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* <a href="#url">URL and Filename safe</a> type base64
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* encoding scheme.
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*
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* @return A Base64 encoder.
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*/
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public static Encoder getUrlEncoder() {
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return Encoder.RFC4648_URLSAFE;
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}
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/**
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* Returns a {@link Encoder} that encodes using the
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* <a href="#mime">MIME</a> type base64 encoding scheme.
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*
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* @return A Base64 encoder.
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*/
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public static Encoder getMimeEncoder() {
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return Encoder.RFC2045;
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}
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/**
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* Returns a {@link Encoder} that encodes using the
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* <a href="#mime">MIME</a> type base64 encoding scheme
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* with specified line length and line separators.
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*
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* @param lineLength
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* the length of each output line (rounded down to nearest multiple
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* of 4). If {@code lineLength <= 0} the output will not be separated
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* in lines
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* @param lineSeparator
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* the line separator for each output line
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*
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* @return A Base64 encoder.
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*
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* @throws IllegalArgumentException if {@code lineSeparator} includes any
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* character of "The Base64 Alphabet" as specified in Table 1 of
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* RFC 2045.
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*/
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public static Encoder getMimeEncoder(int lineLength, byte[] lineSeparator) {
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Objects.requireNonNull(lineSeparator);
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int[] base64 = Decoder.fromBase64;
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for (byte b : lineSeparator) {
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if (base64[b & 0xff] != -1)
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throw new IllegalArgumentException(
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"Illegal base64 line separator character 0x" + Integer.toString(b, 16));
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}
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if (lineLength <= 0) {
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return Encoder.RFC4648;
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}
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return new Encoder(false, lineSeparator, lineLength >> 2 << 2, true);
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}
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/**
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* Returns a {@link Decoder} that decodes using the
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* <a href="#basic">Basic</a> type base64 encoding scheme.
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*
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* @return A Base64 decoder.
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*/
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public static Decoder getDecoder() {
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return Decoder.RFC4648;
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}
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/**
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* Returns a {@link Decoder} that decodes using the
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* <a href="#url">URL and Filename safe</a> type base64
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* encoding scheme.
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*
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* @return A Base64 decoder.
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*/
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public static Decoder getUrlDecoder() {
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return Decoder.RFC4648_URLSAFE;
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}
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/**
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* Returns a {@link Decoder} that decodes using the
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* <a href="#mime">MIME</a> type base64 decoding scheme.
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*
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* @return A Base64 decoder.
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*/
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public static Decoder getMimeDecoder() {
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return Decoder.RFC2045;
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}
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/**
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* This class implements an encoder for encoding byte data using
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* the Base64 encoding scheme as specified in RFC 4648 and RFC 2045.
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*
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* <p> Instances of {@link Encoder} class are safe for use by
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* multiple concurrent threads.
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*
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* <p> Unless otherwise noted, passing a {@code null} argument to
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* a method of this class will cause a
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* {@link java.lang.NullPointerException NullPointerException} to
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* be thrown.
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*
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* @see Decoder
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* @since 1.8
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*/
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public static class Encoder {
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private final byte[] newline;
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private final int linemax;
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private final boolean isURL;
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private final boolean doPadding;
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private Encoder(boolean isURL, byte[] newline, int linemax, boolean doPadding) {
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this.isURL = isURL;
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this.newline = newline;
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this.linemax = linemax;
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this.doPadding = doPadding;
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}
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/**
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* This array is a lookup table that translates 6-bit positive integer
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* index values into their "Base64 Alphabet" equivalents as specified
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* in "Table 1: The Base64 Alphabet" of RFC 2045 (and RFC 4648).
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*/
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private static final char[] toBase64 = {
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'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
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'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
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'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
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'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
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'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/'
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};
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/**
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* It's the lookup table for "URL and Filename safe Base64" as specified
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* in Table 2 of the RFC 4648, with the '+' and '/' changed to '-' and
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* '_'. This table is used when BASE64_URL is specified.
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*/
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private static final char[] toBase64URL = {
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'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
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'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
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'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
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'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
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'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '-', '_'
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};
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private static final int MIMELINEMAX = 76;
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private static final byte[] CRLF = new byte[] {'\r', '\n'};
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static final Encoder RFC4648 = new Encoder(false, null, -1, true);
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static final Encoder RFC4648_URLSAFE = new Encoder(true, null, -1, true);
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static final Encoder RFC2045 = new Encoder(false, CRLF, MIMELINEMAX, true);
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private final int outLength(int srclen) {
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int len = 0;
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if (doPadding) {
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len = 4 * ((srclen + 2) / 3);
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} else {
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int n = srclen % 3;
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len = 4 * (srclen / 3) + (n == 0 ? 0 : n + 1);
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}
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if (linemax > 0) // line separators
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len += (len - 1) / linemax * newline.length;
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return len;
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}
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/**
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* Encodes all bytes from the specified byte array into a newly-allocated
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* byte array using the {@link Base64} encoding scheme. The returned byte
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* array is of the length of the resulting bytes.
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*
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* @param src
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* the byte array to encode
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* @return A newly-allocated byte array containing the resulting
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* encoded bytes.
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*/
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public byte[] encode(byte[] src) {
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int len = outLength(src.length); // dst array size
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byte[] dst = new byte[len];
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int ret = encode0(src, 0, src.length, dst);
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if (ret != dst.length)
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return Arrays.copyOf(dst, ret);
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return dst;
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}
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/**
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* Encodes all bytes from the specified byte array using the
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* {@link Base64} encoding scheme, writing the resulting bytes to the
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* given output byte array, starting at offset 0.
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*
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* <p> It is the responsibility of the invoker of this method to make
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* sure the output byte array {@code dst} has enough space for encoding
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* all bytes from the input byte array. No bytes will be written to the
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* output byte array if the output byte array is not big enough.
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*
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* @param src
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* the byte array to encode
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* @param dst
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* the output byte array
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* @return The number of bytes written to the output byte array
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*
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* @throws IllegalArgumentException if {@code dst} does not have enough
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* space for encoding all input bytes.
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*/
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public int encode(byte[] src, byte[] dst) {
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int len = outLength(src.length); // dst array size
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if (dst.length < len)
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throw new IllegalArgumentException(
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"Output byte array is too small for encoding all input bytes");
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return encode0(src, 0, src.length, dst);
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}
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/**
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* Encodes the specified byte array into a String using the {@link Base64}
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* encoding scheme.
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*
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* <p> This method first encodes all input bytes into a base64 encoded
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* byte array and then constructs a new String by using the encoded byte
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* array and the {@link java.nio.charset.StandardCharsets#ISO_8859_1
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* ISO-8859-1} charset.
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*
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* <p> In other words, an invocation of this method has exactly the same
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* effect as invoking
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* {@code new String(encode(src), StandardCharsets.ISO_8859_1)}.
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*
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* @param src
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* the byte array to encode
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* @return A String containing the resulting Base64 encoded characters
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*/
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@SuppressWarnings("deprecation")
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public String encodeToString(byte[] src) {
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byte[] encoded = encode(src);
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return new String(encoded, 0, 0, encoded.length);
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}
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/**
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* Encodes all remaining bytes from the specified byte buffer into
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* a newly-allocated ByteBuffer using the {@link Base64} encoding
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* scheme.
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*
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* Upon return, the source buffer's position will be updated to
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* its limit; its limit will not have been changed. The returned
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* output buffer's position will be zero and its limit will be the
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* number of resulting encoded bytes.
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*
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* @param buffer
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* the source ByteBuffer to encode
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* @return A newly-allocated byte buffer containing the encoded bytes.
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*/
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public ByteBuffer encode(ByteBuffer buffer) {
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int len = outLength(buffer.remaining());
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byte[] dst = new byte[len];
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int ret = 0;
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if (buffer.hasArray()) {
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ret = encode0(buffer.array(),
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buffer.arrayOffset() + buffer.position(),
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buffer.arrayOffset() + buffer.limit(),
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dst);
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buffer.position(buffer.limit());
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} else {
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byte[] src = new byte[buffer.remaining()];
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buffer.get(src);
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ret = encode0(src, 0, src.length, dst);
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}
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if (ret != dst.length)
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dst = Arrays.copyOf(dst, ret);
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return ByteBuffer.wrap(dst);
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}
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/**
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* Wraps an output stream for encoding byte data using the {@link Base64}
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* encoding scheme.
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*
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* <p> It is recommended to promptly close the returned output stream after
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* use, during which it will flush all possible leftover bytes to the underlying
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* output stream. Closing the returned output stream will close the underlying
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* output stream.
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*
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* @param os
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* the output stream.
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* @return the output stream for encoding the byte data into the
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* specified Base64 encoded format
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*/
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public OutputStream wrap(OutputStream os) {
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Objects.requireNonNull(os);
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return new EncOutputStream(os, isURL ? toBase64URL : toBase64,
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newline, linemax, doPadding);
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}
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/**
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* Returns an encoder instance that encodes equivalently to this one,
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* but without adding any padding character at the end of the encoded
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* byte data.
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*
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* <p> The encoding scheme of this encoder instance is unaffected by
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* this invocation. The returned encoder instance should be used for
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* non-padding encoding operation.
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*
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* @return an equivalent encoder that encodes without adding any
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* padding character at the end
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*/
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public Encoder withoutPadding() {
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if (!doPadding)
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return this;
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return new Encoder(isURL, newline, linemax, false);
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}
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|
393 |
private int encode0(byte[] src, int off, int end, byte[] dst) {
|
|
394 |
char[] base64 = isURL ? toBase64URL : toBase64;
|
|
395 |
int sp = off;
|
|
396 |
int slen = (end - off) / 3 * 3;
|
|
397 |
int sl = off + slen;
|
|
398 |
if (linemax > 0 && slen > linemax / 4 * 3)
|
|
399 |
slen = linemax / 4 * 3;
|
|
400 |
int dp = 0;
|
|
401 |
while (sp < sl) {
|
|
402 |
int sl0 = Math.min(sp + slen, sl);
|
|
403 |
for (int sp0 = sp, dp0 = dp ; sp0 < sl0; ) {
|
|
404 |
int bits = (src[sp0++] & 0xff) << 16 |
|
|
405 |
(src[sp0++] & 0xff) << 8 |
|
|
406 |
(src[sp0++] & 0xff);
|
|
407 |
dst[dp0++] = (byte)base64[(bits >>> 18) & 0x3f];
|
|
408 |
dst[dp0++] = (byte)base64[(bits >>> 12) & 0x3f];
|
|
409 |
dst[dp0++] = (byte)base64[(bits >>> 6) & 0x3f];
|
|
410 |
dst[dp0++] = (byte)base64[bits & 0x3f];
|
|
411 |
}
|
|
412 |
int dlen = (sl0 - sp) / 3 * 4;
|
|
413 |
dp += dlen;
|
|
414 |
sp = sl0;
|
|
415 |
if (dlen == linemax && sp < end) {
|
|
416 |
for (byte b : newline){
|
|
417 |
dst[dp++] = b;
|
|
418 |
}
|
|
419 |
}
|
|
420 |
}
|
|
421 |
if (sp < end) { // 1 or 2 leftover bytes
|
|
422 |
int b0 = src[sp++] & 0xff;
|
|
423 |
dst[dp++] = (byte)base64[b0 >> 2];
|
|
424 |
if (sp == end) {
|
|
425 |
dst[dp++] = (byte)base64[(b0 << 4) & 0x3f];
|
|
426 |
if (doPadding) {
|
|
427 |
dst[dp++] = '=';
|
|
428 |
dst[dp++] = '=';
|
|
429 |
}
|
|
430 |
} else {
|
|
431 |
int b1 = src[sp++] & 0xff;
|
|
432 |
dst[dp++] = (byte)base64[(b0 << 4) & 0x3f | (b1 >> 4)];
|
|
433 |
dst[dp++] = (byte)base64[(b1 << 2) & 0x3f];
|
|
434 |
if (doPadding) {
|
|
435 |
dst[dp++] = '=';
|
|
436 |
}
|
|
437 |
}
|
|
438 |
}
|
|
439 |
return dp;
|
|
440 |
}
|
|
441 |
}
|
|
442 |
|
|
443 |
/**
|
|
444 |
* This class implements a decoder for decoding byte data using the
|
|
445 |
* Base64 encoding scheme as specified in RFC 4648 and RFC 2045.
|
|
446 |
*
|
|
447 |
* <p> The Base64 padding character {@code '='} is accepted and
|
|
448 |
* interpreted as the end of the encoded byte data, but is not
|
|
449 |
* required. So if the final unit of the encoded byte data only has
|
|
450 |
* two or three Base64 characters (without the corresponding padding
|
|
451 |
* character(s) padded), they are decoded as if followed by padding
|
|
452 |
* character(s). If there is a padding character present in the
|
|
453 |
* final unit, the correct number of padding character(s) must be
|
|
454 |
* present, otherwise {@code IllegalArgumentException} (
|
|
455 |
* {@code IOException} when reading from a Base64 stream) is thrown
|
|
456 |
* during decoding.
|
|
457 |
*
|
|
458 |
* <p> Instances of {@link Decoder} class are safe for use by
|
|
459 |
* multiple concurrent threads.
|
|
460 |
*
|
|
461 |
* <p> Unless otherwise noted, passing a {@code null} argument to
|
|
462 |
* a method of this class will cause a
|
|
463 |
* {@link java.lang.NullPointerException NullPointerException} to
|
|
464 |
* be thrown.
|
|
465 |
*
|
|
466 |
* @see Encoder
|
|
467 |
* @since 1.8
|
|
468 |
*/
|
|
469 |
public static class Decoder {
|
|
470 |
|
|
471 |
private final boolean isURL;
|
|
472 |
private final boolean isMIME;
|
|
473 |
|
|
474 |
private Decoder(boolean isURL, boolean isMIME) {
|
|
475 |
this.isURL = isURL;
|
|
476 |
this.isMIME = isMIME;
|
|
477 |
}
|
|
478 |
|
|
479 |
/**
|
|
480 |
* Lookup table for decoding unicode characters drawn from the
|
|
481 |
* "Base64 Alphabet" (as specified in Table 1 of RFC 2045) into
|
|
482 |
* their 6-bit positive integer equivalents. Characters that
|
|
483 |
* are not in the Base64 alphabet but fall within the bounds of
|
|
484 |
* the array are encoded to -1.
|
|
485 |
*
|
|
486 |
*/
|
|
487 |
private static final int[] fromBase64 = new int[256];
|
|
488 |
static {
|
|
489 |
Arrays.fill(fromBase64, -1);
|
|
490 |
for (int i = 0; i < Encoder.toBase64.length; i++)
|
|
491 |
fromBase64[Encoder.toBase64[i]] = i;
|
|
492 |
fromBase64['='] = -2;
|
|
493 |
}
|
|
494 |
|
|
495 |
/**
|
|
496 |
* Lookup table for decoding "URL and Filename safe Base64 Alphabet"
|
|
497 |
* as specified in Table2 of the RFC 4648.
|
|
498 |
*/
|
|
499 |
private static final int[] fromBase64URL = new int[256];
|
|
500 |
|
|
501 |
static {
|
|
502 |
Arrays.fill(fromBase64URL, -1);
|
|
503 |
for (int i = 0; i < Encoder.toBase64URL.length; i++)
|
|
504 |
fromBase64URL[Encoder.toBase64URL[i]] = i;
|
|
505 |
fromBase64URL['='] = -2;
|
|
506 |
}
|
|
507 |
|
|
508 |
static final Decoder RFC4648 = new Decoder(false, false);
|
|
509 |
static final Decoder RFC4648_URLSAFE = new Decoder(true, false);
|
|
510 |
static final Decoder RFC2045 = new Decoder(false, true);
|
|
511 |
|
|
512 |
/**
|
|
513 |
* Decodes all bytes from the input byte array using the {@link Base64}
|
|
514 |
* encoding scheme, writing the results into a newly-allocated output
|
|
515 |
* byte array. The returned byte array is of the length of the resulting
|
|
516 |
* bytes.
|
|
517 |
*
|
|
518 |
* @param src
|
|
519 |
* the byte array to decode
|
|
520 |
*
|
|
521 |
* @return A newly-allocated byte array containing the decoded bytes.
|
|
522 |
*
|
|
523 |
* @throws IllegalArgumentException
|
|
524 |
* if {@code src} is not in valid Base64 scheme
|
|
525 |
*/
|
|
526 |
public byte[] decode(byte[] src) {
|
|
527 |
byte[] dst = new byte[outLength(src, 0, src.length)];
|
|
528 |
int ret = decode0(src, 0, src.length, dst);
|
|
529 |
if (ret != dst.length) {
|
|
530 |
dst = Arrays.copyOf(dst, ret);
|
|
531 |
}
|
|
532 |
return dst;
|
|
533 |
}
|
|
534 |
|
|
535 |
/**
|
|
536 |
* Decodes a Base64 encoded String into a newly-allocated byte array
|
|
537 |
* using the {@link Base64} encoding scheme.
|
|
538 |
*
|
|
539 |
* <p> An invocation of this method has exactly the same effect as invoking
|
|
540 |
* {@code decode(src.getBytes(StandardCharsets.ISO_8859_1))}
|
|
541 |
*
|
|
542 |
* @param src
|
|
543 |
* the string to decode
|
|
544 |
*
|
|
545 |
* @return A newly-allocated byte array containing the decoded bytes.
|
|
546 |
*
|
|
547 |
* @throws IllegalArgumentException
|
|
548 |
* if {@code src} is not in valid Base64 scheme
|
|
549 |
*/
|
|
550 |
public byte[] decode(String src) {
|
|
551 |
return decode(src.getBytes(StandardCharsets.ISO_8859_1));
|
|
552 |
}
|
|
553 |
|
|
554 |
/**
|
|
555 |
* Decodes all bytes from the input byte array using the {@link Base64}
|
|
556 |
* encoding scheme, writing the results into the given output byte array,
|
|
557 |
* starting at offset 0.
|
|
558 |
*
|
|
559 |
* <p> It is the responsibility of the invoker of this method to make
|
|
560 |
* sure the output byte array {@code dst} has enough space for decoding
|
|
561 |
* all bytes from the input byte array. No bytes will be be written to
|
|
562 |
* the output byte array if the output byte array is not big enough.
|
|
563 |
*
|
|
564 |
* <p> If the input byte array is not in valid Base64 encoding scheme
|
|
565 |
* then some bytes may have been written to the output byte array before
|
|
566 |
* IllegalargumentException is thrown.
|
|
567 |
*
|
|
568 |
* @param src
|
|
569 |
* the byte array to decode
|
|
570 |
* @param dst
|
|
571 |
* the output byte array
|
|
572 |
*
|
|
573 |
* @return The number of bytes written to the output byte array
|
|
574 |
*
|
|
575 |
* @throws IllegalArgumentException
|
|
576 |
* if {@code src} is not in valid Base64 scheme, or {@code dst}
|
|
577 |
* does not have enough space for decoding all input bytes.
|
|
578 |
*/
|
|
579 |
public int decode(byte[] src, byte[] dst) {
|
|
580 |
int len = outLength(src, 0, src.length);
|
|
581 |
if (dst.length < len)
|
|
582 |
throw new IllegalArgumentException(
|
|
583 |
"Output byte array is too small for decoding all input bytes");
|
|
584 |
return decode0(src, 0, src.length, dst);
|
|
585 |
}
|
|
586 |
|
|
587 |
/**
|
|
588 |
* Decodes all bytes from the input byte buffer using the {@link Base64}
|
|
589 |
* encoding scheme, writing the results into a newly-allocated ByteBuffer.
|
|
590 |
*
|
|
591 |
* <p> Upon return, the source buffer's position will be updated to
|
|
592 |
* its limit; its limit will not have been changed. The returned
|
|
593 |
* output buffer's position will be zero and its limit will be the
|
|
594 |
* number of resulting decoded bytes
|
|
595 |
*
|
|
596 |
* <p> {@code IllegalArgumentException} is thrown if the input buffer
|
|
597 |
* is not in valid Base64 encoding scheme. The position of the input
|
|
598 |
* buffer will not be advanced in this case.
|
|
599 |
*
|
|
600 |
* @param buffer
|
|
601 |
* the ByteBuffer to decode
|
|
602 |
*
|
|
603 |
* @return A newly-allocated byte buffer containing the decoded bytes
|
|
604 |
*
|
|
605 |
* @throws IllegalArgumentException
|
|
606 |
* if {@code src} is not in valid Base64 scheme.
|
|
607 |
*/
|
|
608 |
public ByteBuffer decode(ByteBuffer buffer) {
|
|
609 |
int pos0 = buffer.position();
|
|
610 |
try {
|
|
611 |
byte[] src;
|
|
612 |
int sp, sl;
|
|
613 |
if (buffer.hasArray()) {
|
|
614 |
src = buffer.array();
|
|
615 |
sp = buffer.arrayOffset() + buffer.position();
|
|
616 |
sl = buffer.arrayOffset() + buffer.limit();
|
|
617 |
buffer.position(buffer.limit());
|
|
618 |
} else {
|
|
619 |
src = new byte[buffer.remaining()];
|
|
620 |
buffer.get(src);
|
|
621 |
sp = 0;
|
|
622 |
sl = src.length;
|
|
623 |
}
|
|
624 |
byte[] dst = new byte[outLength(src, sp, sl)];
|
|
625 |
return ByteBuffer.wrap(dst, 0, decode0(src, sp, sl, dst));
|
|
626 |
} catch (IllegalArgumentException iae) {
|
|
627 |
buffer.position(pos0);
|
|
628 |
throw iae;
|
|
629 |
}
|
|
630 |
}
|
|
631 |
|
|
632 |
/**
|
|
633 |
* Returns an input stream for decoding {@link Base64} encoded byte stream.
|
|
634 |
*
|
|
635 |
* <p> The {@code read} methods of the returned {@code InputStream} will
|
|
636 |
* throw {@code IOException} when reading bytes that cannot be decoded.
|
|
637 |
*
|
|
638 |
* <p> Closing the returned input stream will close the underlying
|
|
639 |
* input stream.
|
|
640 |
*
|
|
641 |
* @param is
|
|
642 |
* the input stream
|
|
643 |
*
|
|
644 |
* @return the input stream for decoding the specified Base64 encoded
|
|
645 |
* byte stream
|
|
646 |
*/
|
|
647 |
public InputStream wrap(InputStream is) {
|
|
648 |
Objects.requireNonNull(is);
|
|
649 |
return new DecInputStream(is, isURL ? fromBase64URL : fromBase64, isMIME);
|
|
650 |
}
|
|
651 |
|
|
652 |
private int outLength(byte[] src, int sp, int sl) {
|
|
653 |
int[] base64 = isURL ? fromBase64URL : fromBase64;
|
|
654 |
int paddings = 0;
|
|
655 |
int len = sl - sp;
|
|
656 |
if (len == 0)
|
|
657 |
return 0;
|
|
658 |
if (len < 2) {
|
|
659 |
if (isMIME && base64[0] == -1)
|
|
660 |
return 0;
|
|
661 |
throw new IllegalArgumentException(
|
|
662 |
"Input byte[] should at least have 2 bytes for base64 bytes");
|
|
663 |
}
|
|
664 |
if (isMIME) {
|
|
665 |
// scan all bytes to fill out all non-alphabet. a performance
|
|
666 |
// trade-off of pre-scan or Arrays.copyOf
|
|
667 |
int n = 0;
|
|
668 |
while (sp < sl) {
|
|
669 |
int b = src[sp++] & 0xff;
|
|
670 |
if (b == '=') {
|
|
671 |
len -= (sl - sp + 1);
|
|
672 |
break;
|
|
673 |
}
|
|
674 |
if ((b = base64[b]) == -1)
|
|
675 |
n++;
|
|
676 |
}
|
|
677 |
len -= n;
|
|
678 |
} else {
|
|
679 |
if (src[sl - 1] == '=') {
|
|
680 |
paddings++;
|
|
681 |
if (src[sl - 2] == '=')
|
|
682 |
paddings++;
|
|
683 |
}
|
|
684 |
}
|
|
685 |
if (paddings == 0 && (len & 0x3) != 0)
|
|
686 |
paddings = 4 - (len & 0x3);
|
|
687 |
return 3 * ((len + 3) / 4) - paddings;
|
|
688 |
}
|
|
689 |
|
|
690 |
private int decode0(byte[] src, int sp, int sl, byte[] dst) {
|
|
691 |
int[] base64 = isURL ? fromBase64URL : fromBase64;
|
|
692 |
int dp = 0;
|
|
693 |
int bits = 0;
|
|
694 |
int shiftto = 18; // pos of first byte of 4-byte atom
|
|
695 |
while (sp < sl) {
|
|
696 |
int b = src[sp++] & 0xff;
|
|
697 |
if ((b = base64[b]) < 0) {
|
|
698 |
if (b == -2) { // padding byte '='
|
|
699 |
// = shiftto==18 unnecessary padding
|
|
700 |
// x= shiftto==12 a dangling single x
|
|
701 |
// x to be handled together with non-padding case
|
|
702 |
// xx= shiftto==6&&sp==sl missing last =
|
|
703 |
// xx=y shiftto==6 last is not =
|
|
704 |
if (shiftto == 6 && (sp == sl || src[sp++] != '=') ||
|
|
705 |
shiftto == 18) {
|
|
706 |
throw new IllegalArgumentException(
|
|
707 |
"Input byte array has wrong 4-byte ending unit");
|
|
708 |
}
|
|
709 |
break;
|
|
710 |
}
|
|
711 |
if (isMIME) // skip if for rfc2045
|
|
712 |
continue;
|
|
713 |
else
|
|
714 |
throw new IllegalArgumentException(
|
|
715 |
"Illegal base64 character " +
|
|
716 |
Integer.toString(src[sp - 1], 16));
|
|
717 |
}
|
|
718 |
bits |= (b << shiftto);
|
|
719 |
shiftto -= 6;
|
|
720 |
if (shiftto < 0) {
|
|
721 |
dst[dp++] = (byte)(bits >> 16);
|
|
722 |
dst[dp++] = (byte)(bits >> 8);
|
|
723 |
dst[dp++] = (byte)(bits);
|
|
724 |
shiftto = 18;
|
|
725 |
bits = 0;
|
|
726 |
}
|
|
727 |
}
|
|
728 |
// reached end of byte array or hit padding '=' characters.
|
|
729 |
if (shiftto == 6) {
|
|
730 |
dst[dp++] = (byte)(bits >> 16);
|
|
731 |
} else if (shiftto == 0) {
|
|
732 |
dst[dp++] = (byte)(bits >> 16);
|
|
733 |
dst[dp++] = (byte)(bits >> 8);
|
|
734 |
} else if (shiftto == 12) {
|
|
735 |
// dangling single "x", incorrectly encoded.
|
|
736 |
throw new IllegalArgumentException(
|
|
737 |
"Last unit does not have enough valid bits");
|
|
738 |
}
|
|
739 |
// anything left is invalid, if is not MIME.
|
|
740 |
// if MIME, ignore all non-base64 character
|
|
741 |
while (sp < sl) {
|
|
742 |
if (isMIME && base64[src[sp++]] < 0)
|
|
743 |
continue;
|
|
744 |
throw new IllegalArgumentException(
|
|
745 |
"Input byte array has incorrect ending byte at " + sp);
|
|
746 |
}
|
|
747 |
return dp;
|
|
748 |
}
|
|
749 |
}
|
|
750 |
|
|
751 |
/*
|
|
752 |
* An output stream for encoding bytes into the Base64.
|
|
753 |
*/
|
|
754 |
private static class EncOutputStream extends FilterOutputStream {
|
|
755 |
|
|
756 |
private int leftover = 0;
|
|
757 |
private int b0, b1, b2;
|
|
758 |
private boolean closed = false;
|
|
759 |
|
|
760 |
private final char[] base64; // byte->base64 mapping
|
|
761 |
private final byte[] newline; // line separator, if needed
|
|
762 |
private final int linemax;
|
|
763 |
private final boolean doPadding;// whether or not to pad
|
|
764 |
private int linepos = 0;
|
|
765 |
|
|
766 |
EncOutputStream(OutputStream os, char[] base64,
|
|
767 |
byte[] newline, int linemax, boolean doPadding) {
|
|
768 |
super(os);
|
|
769 |
this.base64 = base64;
|
|
770 |
this.newline = newline;
|
|
771 |
this.linemax = linemax;
|
|
772 |
this.doPadding = doPadding;
|
|
773 |
}
|
|
774 |
|
|
775 |
@Override
|
|
776 |
public void write(int b) throws IOException {
|
|
777 |
byte[] buf = new byte[1];
|
|
778 |
buf[0] = (byte)(b & 0xff);
|
|
779 |
write(buf, 0, 1);
|
|
780 |
}
|
|
781 |
|
|
782 |
private void checkNewline() throws IOException {
|
|
783 |
if (linepos == linemax) {
|
|
784 |
out.write(newline);
|
|
785 |
linepos = 0;
|
|
786 |
}
|
|
787 |
}
|
|
788 |
|
|
789 |
@Override
|
|
790 |
public void write(byte[] b, int off, int len) throws IOException {
|
|
791 |
if (closed)
|
|
792 |
throw new IOException("Stream is closed");
|
|
793 |
if (off < 0 || len < 0 || off + len > b.length)
|
|
794 |
throw new ArrayIndexOutOfBoundsException();
|
|
795 |
if (len == 0)
|
|
796 |
return;
|
|
797 |
if (leftover != 0) {
|
|
798 |
if (leftover == 1) {
|
|
799 |
b1 = b[off++] & 0xff;
|
|
800 |
len--;
|
|
801 |
if (len == 0) {
|
|
802 |
leftover++;
|
|
803 |
return;
|
|
804 |
}
|
|
805 |
}
|
|
806 |
b2 = b[off++] & 0xff;
|
|
807 |
len--;
|
|
808 |
checkNewline();
|
|
809 |
out.write(base64[b0 >> 2]);
|
|
810 |
out.write(base64[(b0 << 4) & 0x3f | (b1 >> 4)]);
|
|
811 |
out.write(base64[(b1 << 2) & 0x3f | (b2 >> 6)]);
|
|
812 |
out.write(base64[b2 & 0x3f]);
|
|
813 |
linepos += 4;
|
|
814 |
}
|
|
815 |
int nBits24 = len / 3;
|
|
816 |
leftover = len - (nBits24 * 3);
|
|
817 |
while (nBits24-- > 0) {
|
|
818 |
checkNewline();
|
|
819 |
int bits = (b[off++] & 0xff) << 16 |
|
|
820 |
(b[off++] & 0xff) << 8 |
|
|
821 |
(b[off++] & 0xff);
|
|
822 |
out.write(base64[(bits >>> 18) & 0x3f]);
|
|
823 |
out.write(base64[(bits >>> 12) & 0x3f]);
|
|
824 |
out.write(base64[(bits >>> 6) & 0x3f]);
|
|
825 |
out.write(base64[bits & 0x3f]);
|
|
826 |
linepos += 4;
|
|
827 |
}
|
|
828 |
if (leftover == 1) {
|
|
829 |
b0 = b[off++] & 0xff;
|
|
830 |
} else if (leftover == 2) {
|
|
831 |
b0 = b[off++] & 0xff;
|
|
832 |
b1 = b[off++] & 0xff;
|
|
833 |
}
|
|
834 |
}
|
|
835 |
|
|
836 |
@Override
|
|
837 |
public void close() throws IOException {
|
|
838 |
if (!closed) {
|
|
839 |
closed = true;
|
|
840 |
if (leftover == 1) {
|
|
841 |
checkNewline();
|
|
842 |
out.write(base64[b0 >> 2]);
|
|
843 |
out.write(base64[(b0 << 4) & 0x3f]);
|
|
844 |
if (doPadding) {
|
|
845 |
out.write('=');
|
|
846 |
out.write('=');
|
|
847 |
}
|
|
848 |
} else if (leftover == 2) {
|
|
849 |
checkNewline();
|
|
850 |
out.write(base64[b0 >> 2]);
|
|
851 |
out.write(base64[(b0 << 4) & 0x3f | (b1 >> 4)]);
|
|
852 |
out.write(base64[(b1 << 2) & 0x3f]);
|
|
853 |
if (doPadding) {
|
|
854 |
out.write('=');
|
|
855 |
}
|
|
856 |
}
|
|
857 |
leftover = 0;
|
|
858 |
out.close();
|
|
859 |
}
|
|
860 |
}
|
|
861 |
}
|
|
862 |
|
|
863 |
/*
|
|
864 |
* An input stream for decoding Base64 bytes
|
|
865 |
*/
|
|
866 |
private static class DecInputStream extends InputStream {
|
|
867 |
|
|
868 |
private final InputStream is;
|
|
869 |
private final boolean isMIME;
|
|
870 |
private final int[] base64; // base64 -> byte mapping
|
|
871 |
private int bits = 0; // 24-bit buffer for decoding
|
|
872 |
private int nextin = 18; // next available "off" in "bits" for input;
|
|
873 |
// -> 18, 12, 6, 0
|
|
874 |
private int nextout = -8; // next available "off" in "bits" for output;
|
|
875 |
// -> 8, 0, -8 (no byte for output)
|
|
876 |
private boolean eof = false;
|
|
877 |
private boolean closed = false;
|
|
878 |
|
|
879 |
DecInputStream(InputStream is, int[] base64, boolean isMIME) {
|
|
880 |
this.is = is;
|
|
881 |
this.base64 = base64;
|
|
882 |
this.isMIME = isMIME;
|
|
883 |
}
|
|
884 |
|
|
885 |
private byte[] sbBuf = new byte[1];
|
|
886 |
|
|
887 |
@Override
|
|
888 |
public int read() throws IOException {
|
|
889 |
return read(sbBuf, 0, 1) == -1 ? -1 : sbBuf[0] & 0xff;
|
|
890 |
}
|
|
891 |
|
|
892 |
@Override
|
|
893 |
public int read(byte[] b, int off, int len) throws IOException {
|
|
894 |
if (closed)
|
|
895 |
throw new IOException("Stream is closed");
|
|
896 |
if (eof && nextout < 0) // eof and no leftover
|
|
897 |
return -1;
|
|
898 |
if (off < 0 || len < 0 || len > b.length - off)
|
|
899 |
throw new IndexOutOfBoundsException();
|
|
900 |
int oldOff = off;
|
|
901 |
if (nextout >= 0) { // leftover output byte(s) in bits buf
|
|
902 |
do {
|
|
903 |
if (len == 0)
|
|
904 |
return off - oldOff;
|
|
905 |
b[off++] = (byte)(bits >> nextout);
|
|
906 |
len--;
|
|
907 |
nextout -= 8;
|
|
908 |
} while (nextout >= 0);
|
|
909 |
bits = 0;
|
|
910 |
}
|
|
911 |
while (len > 0) {
|
|
912 |
int v = is.read();
|
|
913 |
if (v == -1) {
|
|
914 |
eof = true;
|
|
915 |
if (nextin != 18) {
|
|
916 |
if (nextin == 12)
|
|
917 |
throw new IOException("Base64 stream has one un-decoded dangling byte.");
|
|
918 |
// treat ending xx/xxx without padding character legal.
|
|
919 |
// same logic as v == '=' below
|
|
920 |
b[off++] = (byte)(bits >> (16));
|
|
921 |
len--;
|
|
922 |
if (nextin == 0) { // only one padding byte
|
|
923 |
if (len == 0) { // no enough output space
|
|
924 |
bits >>= 8; // shift to lowest byte
|
|
925 |
nextout = 0;
|
|
926 |
} else {
|
|
927 |
b[off++] = (byte) (bits >> 8);
|
|
928 |
}
|
|
929 |
}
|
|
930 |
}
|
|
931 |
if (off == oldOff)
|
|
932 |
return -1;
|
|
933 |
else
|
|
934 |
return off - oldOff;
|
|
935 |
}
|
|
936 |
if (v == '=') { // padding byte(s)
|
|
937 |
// = shiftto==18 unnecessary padding
|
|
938 |
// x= shiftto==12 dangling x, invalid unit
|
|
939 |
// xx= shiftto==6 && missing last '='
|
|
940 |
// xx=y or last is not '='
|
|
941 |
if (nextin == 18 || nextin == 12 ||
|
|
942 |
nextin == 6 && is.read() != '=') {
|
|
943 |
throw new IOException("Illegal base64 ending sequence:" + nextin);
|