1212 lines
47 KiB
Java
1212 lines
47 KiB
Java
/*
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* Copyright (c) 2012, 2020, 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 java.util;
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import java.io.FilterOutputStream;
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import java.io.InputStream;
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import java.io.IOException;
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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 jdk.internal.vm.annotation.IntrinsicCandidate;
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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 id="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 id="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 id="mime"><b>MIME</b></a>
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* <p> Uses "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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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 the rounded down line length is not a positive value,
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* the output will not be separated 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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// round down to nearest multiple of 4
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lineLength &= ~0b11;
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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, 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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* <p> If the encoded byte output of the needed size can not
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* be allocated, the encode methods of this class will
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* cause an {@link java.lang.OutOfMemoryError OutOfMemoryError}
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* to 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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/**
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* Calculates the length of the encoded output bytes.
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*
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* @param srclen length of the bytes to encode
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* @param throwOOME if true, throws OutOfMemoryError if the length of
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* the encoded bytes overflows; else returns the
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* length
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* @return length of the encoded bytes, or -1 if the length overflows
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*
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*/
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private final int encodedOutLength(int srclen, boolean throwOOME) {
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int len = 0;
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try {
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if (doPadding) {
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len = Math.multiplyExact(4, (Math.addExact(srclen, 2) / 3));
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} else {
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int n = srclen % 3;
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len = Math.addExact(Math.multiplyExact(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 = Math.addExact(len, (len - 1) / linemax * newline.length);
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}
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} catch (ArithmeticException ex) {
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if (throwOOME) {
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throw new OutOfMemoryError("Encoded size is too large");
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} else {
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// let the caller know that encoded bytes length
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// is too large
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len = -1;
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}
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}
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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 = encodedOutLength(src.length, true); // 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 = encodedOutLength(src.length, false); // dst array size
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if (dst.length < len || len == -1)
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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 = encodedOutLength(buffer.remaining(), true);
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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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@IntrinsicCandidate
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private void encodeBlock(byte[] src, int sp, int sl, byte[] dst, int dp, boolean isURL) {
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char[] base64 = isURL ? toBase64URL : toBase64;
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for (int sp0 = sp, dp0 = dp ; sp0 < sl; ) {
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int bits = (src[sp0++] & 0xff) << 16 |
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(src[sp0++] & 0xff) << 8 |
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(src[sp0++] & 0xff);
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dst[dp0++] = (byte)base64[(bits >>> 18) & 0x3f];
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dst[dp0++] = (byte)base64[(bits >>> 12) & 0x3f];
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dst[dp0++] = (byte)base64[(bits >>> 6) & 0x3f];
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dst[dp0++] = (byte)base64[bits & 0x3f];
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}
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}
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private int encode0(byte[] src, int off, int end, byte[] dst) {
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char[] base64 = isURL ? toBase64URL : toBase64;
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int sp = off;
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int slen = (end - off) / 3 * 3;
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int sl = off + slen;
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if (linemax > 0 && slen > linemax / 4 * 3)
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slen = linemax / 4 * 3;
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int dp = 0;
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while (sp < sl) {
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int sl0 = Math.min(sp + slen, sl);
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encodeBlock(src, sp, sl0, dst, dp, isURL);
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int dlen = (sl0 - sp) / 3 * 4;
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dp += dlen;
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sp = sl0;
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if (dlen == linemax && sp < end) {
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for (byte b : newline){
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dst[dp++] = b;
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}
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}
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}
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if (sp < end) { // 1 or 2 leftover bytes
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int b0 = src[sp++] & 0xff;
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dst[dp++] = (byte)base64[b0 >> 2];
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if (sp == end) {
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dst[dp++] = (byte)base64[(b0 << 4) & 0x3f];
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if (doPadding) {
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dst[dp++] = '=';
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dst[dp++] = '=';
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}
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} else {
|
|
int b1 = src[sp++] & 0xff;
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dst[dp++] = (byte)base64[(b0 << 4) & 0x3f | (b1 >> 4)];
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dst[dp++] = (byte)base64[(b1 << 2) & 0x3f];
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|
if (doPadding) {
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dst[dp++] = '=';
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}
|
|
}
|
|
}
|
|
return dp;
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}
|
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}
|
|
|
|
/**
|
|
* This class implements a decoder for decoding byte data using the
|
|
* Base64 encoding scheme as specified in RFC 4648 and RFC 2045.
|
|
*
|
|
* <p> The Base64 padding character {@code '='} is accepted and
|
|
* interpreted as the end of the encoded byte data, but is not
|
|
* required. So if the final unit of the encoded byte data only has
|
|
* two or three Base64 characters (without the corresponding padding
|
|
* character(s) padded), they are decoded as if followed by padding
|
|
* character(s). If there is a padding character present in the
|
|
* final unit, the correct number of padding character(s) must be
|
|
* present, otherwise {@code IllegalArgumentException} (
|
|
* {@code IOException} when reading from a Base64 stream) is thrown
|
|
* during decoding.
|
|
*
|
|
* <p> Instances of {@link Decoder} class are safe for use by
|
|
* multiple concurrent threads.
|
|
*
|
|
* <p> Unless otherwise noted, passing a {@code null} argument to
|
|
* a method of this class will cause a
|
|
* {@link java.lang.NullPointerException NullPointerException} to
|
|
* be thrown.
|
|
* <p> If the decoded byte output of the needed size can not
|
|
* be allocated, the decode methods of this class will
|
|
* cause an {@link java.lang.OutOfMemoryError OutOfMemoryError}
|
|
* to be thrown.
|
|
*
|
|
* @see Encoder
|
|
* @since 1.8
|
|
*/
|
|
public static class Decoder {
|
|
|
|
private final boolean isURL;
|
|
private final boolean isMIME;
|
|
|
|
private Decoder(boolean isURL, boolean isMIME) {
|
|
this.isURL = isURL;
|
|
this.isMIME = isMIME;
|
|
}
|
|
|
|
/**
|
|
* Lookup table for decoding unicode characters drawn from the
|
|
* "Base64 Alphabet" (as specified in Table 1 of RFC 2045) into
|
|
* their 6-bit positive integer equivalents. Characters that
|
|
* are not in the Base64 alphabet but fall within the bounds of
|
|
* the array are encoded to -1.
|
|
*
|
|
*/
|
|
private static final int[] fromBase64 = new int[256];
|
|
static {
|
|
Arrays.fill(fromBase64, -1);
|
|
for (int i = 0; i < Encoder.toBase64.length; i++)
|
|
fromBase64[Encoder.toBase64[i]] = i;
|
|
fromBase64['='] = -2;
|
|
}
|
|
|
|
/**
|
|
* Lookup table for decoding "URL and Filename safe Base64 Alphabet"
|
|
* as specified in Table2 of the RFC 4648.
|
|
*/
|
|
private static final int[] fromBase64URL = new int[256];
|
|
|
|
static {
|
|
Arrays.fill(fromBase64URL, -1);
|
|
for (int i = 0; i < Encoder.toBase64URL.length; i++)
|
|
fromBase64URL[Encoder.toBase64URL[i]] = i;
|
|
fromBase64URL['='] = -2;
|
|
}
|
|
|
|
static final Decoder RFC4648 = new Decoder(false, false);
|
|
static final Decoder RFC4648_URLSAFE = new Decoder(true, false);
|
|
static final Decoder RFC2045 = new Decoder(false, true);
|
|
|
|
/**
|
|
* Decodes all bytes from the input byte array using the {@link Base64}
|
|
* encoding scheme, writing the results into a newly-allocated output
|
|
* byte array. The returned byte array is of the length of the resulting
|
|
* bytes.
|
|
*
|
|
* @param src
|
|
* the byte array to decode
|
|
*
|
|
* @return A newly-allocated byte array containing the decoded bytes.
|
|
*
|
|
* @throws IllegalArgumentException
|
|
* if {@code src} is not in valid Base64 scheme
|
|
*/
|
|
public byte[] decode(byte[] src) {
|
|
byte[] dst = new byte[decodedOutLength(src, 0, src.length)];
|
|
int ret = decode0(src, 0, src.length, dst);
|
|
if (ret != dst.length) {
|
|
dst = Arrays.copyOf(dst, ret);
|
|
}
|
|
return dst;
|
|
}
|
|
|
|
/**
|
|
* Decodes a Base64 encoded String into a newly-allocated byte array
|
|
* using the {@link Base64} encoding scheme.
|
|
*
|
|
* <p> An invocation of this method has exactly the same effect as invoking
|
|
* {@code decode(src.getBytes(StandardCharsets.ISO_8859_1))}
|
|
*
|
|
* @param src
|
|
* the string to decode
|
|
*
|
|
* @return A newly-allocated byte array containing the decoded bytes.
|
|
*
|
|
* @throws IllegalArgumentException
|
|
* if {@code src} is not in valid Base64 scheme
|
|
*/
|
|
public byte[] decode(String src) {
|
|
// Android-changed: keep Java 8 implementation.
|
|
// return decode(src.getBytes(ISO_8859_1.INSTANCE));
|
|
return decode(src.getBytes(StandardCharsets.ISO_8859_1));
|
|
}
|
|
|
|
/**
|
|
* Decodes all bytes from the input byte array using the {@link Base64}
|
|
* encoding scheme, writing the results into the given output byte array,
|
|
* starting at offset 0.
|
|
*
|
|
* <p> It is the responsibility of the invoker of this method to make
|
|
* sure the output byte array {@code dst} has enough space for decoding
|
|
* all bytes from the input byte array. No bytes will be written to
|
|
* the output byte array if the output byte array is not big enough.
|
|
*
|
|
* <p> If the input byte array is not in valid Base64 encoding scheme
|
|
* then some bytes may have been written to the output byte array before
|
|
* IllegalargumentException is thrown.
|
|
*
|
|
* @param src
|
|
* the byte array to decode
|
|
* @param dst
|
|
* the output byte array
|
|
*
|
|
* @return The number of bytes written to the output byte array
|
|
*
|
|
* @throws IllegalArgumentException
|
|
* if {@code src} is not in valid Base64 scheme, or {@code dst}
|
|
* does not have enough space for decoding all input bytes.
|
|
*/
|
|
public int decode(byte[] src, byte[] dst) {
|
|
int len = decodedOutLength(src, 0, src.length);
|
|
if (dst.length < len || len == -1)
|
|
throw new IllegalArgumentException(
|
|
"Output byte array is too small for decoding all input bytes");
|
|
return decode0(src, 0, src.length, dst);
|
|
}
|
|
|
|
/**
|
|
* Decodes all bytes from the input byte buffer using the {@link Base64}
|
|
* encoding scheme, writing the results into a newly-allocated ByteBuffer.
|
|
*
|
|
* <p> Upon return, the source buffer's position will be updated to
|
|
* its limit; its limit will not have been changed. The returned
|
|
* output buffer's position will be zero and its limit will be the
|
|
* number of resulting decoded bytes
|
|
*
|
|
* <p> {@code IllegalArgumentException} is thrown if the input buffer
|
|
* is not in valid Base64 encoding scheme. The position of the input
|
|
* buffer will not be advanced in this case.
|
|
*
|
|
* @param buffer
|
|
* the ByteBuffer to decode
|
|
*
|
|
* @return A newly-allocated byte buffer containing the decoded bytes
|
|
*
|
|
* @throws IllegalArgumentException
|
|
* if {@code buffer} is not in valid Base64 scheme
|
|
*/
|
|
public ByteBuffer decode(ByteBuffer buffer) {
|
|
int pos0 = buffer.position();
|
|
try {
|
|
byte[] src;
|
|
int sp, sl;
|
|
if (buffer.hasArray()) {
|
|
src = buffer.array();
|
|
sp = buffer.arrayOffset() + buffer.position();
|
|
sl = buffer.arrayOffset() + buffer.limit();
|
|
buffer.position(buffer.limit());
|
|
} else {
|
|
src = new byte[buffer.remaining()];
|
|
buffer.get(src);
|
|
sp = 0;
|
|
sl = src.length;
|
|
}
|
|
byte[] dst = new byte[decodedOutLength(src, sp, sl)];
|
|
return ByteBuffer.wrap(dst, 0, decode0(src, sp, sl, dst));
|
|
} catch (IllegalArgumentException iae) {
|
|
buffer.position(pos0);
|
|
throw iae;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Returns an input stream for decoding {@link Base64} encoded byte stream.
|
|
*
|
|
* <p> The {@code read} methods of the returned {@code InputStream} will
|
|
* throw {@code IOException} when reading bytes that cannot be decoded.
|
|
*
|
|
* <p> Closing the returned input stream will close the underlying
|
|
* input stream.
|
|
*
|
|
* @param is
|
|
* the input stream
|
|
*
|
|
* @return the input stream for decoding the specified Base64 encoded
|
|
* byte stream
|
|
*/
|
|
public InputStream wrap(InputStream is) {
|
|
Objects.requireNonNull(is);
|
|
return new DecInputStream(is, isURL ? fromBase64URL : fromBase64, isMIME);
|
|
}
|
|
|
|
/**
|
|
* Calculates the length of the decoded output bytes.
|
|
*
|
|
* @param src the byte array to decode
|
|
* @param sp the source position
|
|
* @param sl the source limit
|
|
*
|
|
* @return length of the decoded bytes
|
|
*
|
|
*/
|
|
private int decodedOutLength(byte[] src, int sp, int sl) {
|
|
int[] base64 = isURL ? fromBase64URL : fromBase64;
|
|
int paddings = 0;
|
|
int len = sl - sp;
|
|
if (len == 0)
|
|
return 0;
|
|
if (len < 2) {
|
|
if (isMIME && base64[0] == -1)
|
|
return 0;
|
|
throw new IllegalArgumentException(
|
|
"Input byte[] should at least have 2 bytes for base64 bytes");
|
|
}
|
|
if (isMIME) {
|
|
// scan all bytes to fill out all non-alphabet. a performance
|
|
// trade-off of pre-scan or Arrays.copyOf
|
|
int n = 0;
|
|
while (sp < sl) {
|
|
int b = src[sp++] & 0xff;
|
|
if (b == '=') {
|
|
len -= (sl - sp + 1);
|
|
break;
|
|
}
|
|
if ((b = base64[b]) == -1)
|
|
n++;
|
|
}
|
|
len -= n;
|
|
} else {
|
|
if (src[sl - 1] == '=') {
|
|
paddings++;
|
|
if (src[sl - 2] == '=')
|
|
paddings++;
|
|
}
|
|
}
|
|
if (paddings == 0 && (len & 0x3) != 0)
|
|
paddings = 4 - (len & 0x3);
|
|
|
|
// If len is near to Integer.MAX_VALUE, (len + 3)
|
|
// can possibly overflow, perform this operation as
|
|
// long and cast it back to integer when the value comes under
|
|
// integer limit. The final value will always be in integer
|
|
// limits
|
|
return 3 * (int) ((len + 3L) / 4) - paddings;
|
|
}
|
|
|
|
/**
|
|
* Decodes base64 characters, and returns the number of data bytes
|
|
* written into the destination array.
|
|
*
|
|
* It is the fast path for full 4-byte to 3-byte decoding w/o errors.
|
|
*
|
|
* decodeBlock() can be overridden by an arch-specific intrinsic.
|
|
* decodeBlock can choose to decode all, none, or a variable-sized
|
|
* prefix of the src bytes. This allows the intrinsic to decode in
|
|
* chunks of the src that are of a favorable size for the specific
|
|
* processor it's running on.
|
|
*
|
|
* If any illegal base64 bytes are encountered in src by the
|
|
* intrinsic, the intrinsic must return the actual number of valid
|
|
* data bytes already written to dst. Note that the '=' pad
|
|
* character is treated as an illegal Base64 character by
|
|
* decodeBlock, so it will not process a block of 4 bytes
|
|
* containing pad characters. However, MIME decoding ignores
|
|
* illegal characters, so any intrinsic overriding decodeBlock
|
|
* can choose how to handle illegal characters based on the isMIME
|
|
* parameter.
|
|
*
|
|
* Given the parameters, no length check is possible on dst, so dst
|
|
* is assumed to be large enough to store the decoded bytes.
|
|
*
|
|
* @param src
|
|
* the source byte array of Base64 encoded bytes
|
|
* @param sp
|
|
* the offset into src array to begin reading
|
|
* @param sl
|
|
* the offset (exclusive) past the last byte to be converted.
|
|
* @param dst
|
|
* the destination byte array of decoded data bytes
|
|
* @param dp
|
|
* the offset into dst array to begin writing
|
|
* @param isURL
|
|
* boolean, when true decode RFC4648 URL-safe base64 characters
|
|
* @param isMIME
|
|
* boolean, when true decode according to RFC2045 (ignore illegal chars)
|
|
* @return the number of destination data bytes produced
|
|
*/
|
|
@IntrinsicCandidate
|
|
private int decodeBlock(byte[] src, int sp, int sl, byte[] dst, int dp, boolean isURL, boolean isMIME) {
|
|
int[] base64 = isURL ? fromBase64URL : fromBase64;
|
|
int sl0 = sp + ((sl - sp) & ~0b11);
|
|
int new_dp = dp;
|
|
while (sp < sl0) {
|
|
int b1 = base64[src[sp++] & 0xff];
|
|
int b2 = base64[src[sp++] & 0xff];
|
|
int b3 = base64[src[sp++] & 0xff];
|
|
int b4 = base64[src[sp++] & 0xff];
|
|
if ((b1 | b2 | b3 | b4) < 0) { // non base64 byte
|
|
return new_dp - dp;
|
|
}
|
|
int bits0 = b1 << 18 | b2 << 12 | b3 << 6 | b4;
|
|
dst[new_dp++] = (byte)(bits0 >> 16);
|
|
dst[new_dp++] = (byte)(bits0 >> 8);
|
|
dst[new_dp++] = (byte)(bits0);
|
|
}
|
|
return new_dp - dp;
|
|
}
|
|
|
|
private int decode0(byte[] src, int sp, int sl, byte[] dst) {
|
|
int[] base64 = isURL ? fromBase64URL : fromBase64;
|
|
int dp = 0;
|
|
int bits = 0;
|
|
int shiftto = 18; // pos of first byte of 4-byte atom
|
|
|
|
while (sp < sl) {
|
|
if (shiftto == 18 && sp < sl - 4) { // fast path
|
|
int dl = decodeBlock(src, sp, sl, dst, dp, isURL, isMIME);
|
|
/*
|
|
* Calculate how many characters were processed by how many
|
|
* bytes of data were returned.
|
|
*/
|
|
int chars_decoded = ((dl + 2) / 3) * 4;
|
|
|
|
sp += chars_decoded;
|
|
dp += dl;
|
|
}
|
|
if (sp >= sl) {
|
|
// we're done
|
|
break;
|
|
}
|
|
int b = src[sp++] & 0xff;
|
|
if ((b = base64[b]) < 0) {
|
|
if (b == -2) { // padding byte '='
|
|
// = shiftto==18 unnecessary padding
|
|
// x= shiftto==12 a dangling single x
|
|
// x to be handled together with non-padding case
|
|
// xx= shiftto==6&&sp==sl missing last =
|
|
// xx=y shiftto==6 last is not =
|
|
if (shiftto == 6 && (sp == sl || src[sp++] != '=') ||
|
|
shiftto == 18) {
|
|
throw new IllegalArgumentException(
|
|
"Input byte array has wrong 4-byte ending unit");
|
|
}
|
|
break;
|
|
}
|
|
if (isMIME) // skip if for rfc2045
|
|
continue;
|
|
else
|
|
throw new IllegalArgumentException(
|
|
"Illegal base64 character " +
|
|
Integer.toString(src[sp - 1], 16));
|
|
}
|
|
bits |= (b << shiftto);
|
|
shiftto -= 6;
|
|
if (shiftto < 0) {
|
|
dst[dp++] = (byte)(bits >> 16);
|
|
dst[dp++] = (byte)(bits >> 8);
|
|
dst[dp++] = (byte)(bits);
|
|
shiftto = 18;
|
|
bits = 0;
|
|
}
|
|
}
|
|
// reached end of byte array or hit padding '=' characters.
|
|
if (shiftto == 6) {
|
|
dst[dp++] = (byte)(bits >> 16);
|
|
} else if (shiftto == 0) {
|
|
dst[dp++] = (byte)(bits >> 16);
|
|
dst[dp++] = (byte)(bits >> 8);
|
|
} else if (shiftto == 12) {
|
|
// dangling single "x", incorrectly encoded.
|
|
throw new IllegalArgumentException(
|
|
"Last unit does not have enough valid bits");
|
|
}
|
|
// anything left is invalid, if is not MIME.
|
|
// if MIME, ignore all non-base64 character
|
|
while (sp < sl) {
|
|
if (isMIME && base64[src[sp++] & 0xff] < 0)
|
|
continue;
|
|
throw new IllegalArgumentException(
|
|
"Input byte array has incorrect ending byte at " + sp);
|
|
}
|
|
return dp;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* An output stream for encoding bytes into the Base64.
|
|
*/
|
|
private static class EncOutputStream extends FilterOutputStream {
|
|
|
|
private int leftover = 0;
|
|
private int b0, b1, b2;
|
|
private boolean closed = false;
|
|
|
|
private final char[] base64; // byte->base64 mapping
|
|
private final byte[] newline; // line separator, if needed
|
|
private final int linemax;
|
|
private final boolean doPadding;// whether or not to pad
|
|
private int linepos = 0;
|
|
private byte[] buf;
|
|
|
|
EncOutputStream(OutputStream os, char[] base64,
|
|
byte[] newline, int linemax, boolean doPadding) {
|
|
super(os);
|
|
this.base64 = base64;
|
|
this.newline = newline;
|
|
this.linemax = linemax;
|
|
this.doPadding = doPadding;
|
|
this.buf = new byte[linemax <= 0 ? 8124 : linemax];
|
|
}
|
|
|
|
@Override
|
|
public void write(int b) throws IOException {
|
|
byte[] buf = new byte[1];
|
|
buf[0] = (byte)(b & 0xff);
|
|
write(buf, 0, 1);
|
|
}
|
|
|
|
private void checkNewline() throws IOException {
|
|
if (linepos == linemax) {
|
|
out.write(newline);
|
|
linepos = 0;
|
|
}
|
|
}
|
|
|
|
private void writeb4(char b1, char b2, char b3, char b4) throws IOException {
|
|
buf[0] = (byte)b1;
|
|
buf[1] = (byte)b2;
|
|
buf[2] = (byte)b3;
|
|
buf[3] = (byte)b4;
|
|
out.write(buf, 0, 4);
|
|
}
|
|
|
|
@Override
|
|
public void write(byte[] b, int off, int len) throws IOException {
|
|
if (closed)
|
|
throw new IOException("Stream is closed");
|
|
if (off < 0 || len < 0 || len > b.length - off)
|
|
throw new ArrayIndexOutOfBoundsException();
|
|
if (len == 0)
|
|
return;
|
|
if (leftover != 0) {
|
|
if (leftover == 1) {
|
|
b1 = b[off++] & 0xff;
|
|
len--;
|
|
if (len == 0) {
|
|
leftover++;
|
|
return;
|
|
}
|
|
}
|
|
b2 = b[off++] & 0xff;
|
|
len--;
|
|
checkNewline();
|
|
writeb4(base64[b0 >> 2],
|
|
base64[(b0 << 4) & 0x3f | (b1 >> 4)],
|
|
base64[(b1 << 2) & 0x3f | (b2 >> 6)],
|
|
base64[b2 & 0x3f]);
|
|
linepos += 4;
|
|
}
|
|
int nBits24 = len / 3;
|
|
leftover = len - (nBits24 * 3);
|
|
|
|
while (nBits24 > 0) {
|
|
checkNewline();
|
|
int dl = linemax <= 0 ? buf.length : buf.length - linepos;
|
|
int sl = off + Math.min(nBits24, dl / 4) * 3;
|
|
int dp = 0;
|
|
for (int sp = off; sp < sl; ) {
|
|
int bits = (b[sp++] & 0xff) << 16 |
|
|
(b[sp++] & 0xff) << 8 |
|
|
(b[sp++] & 0xff);
|
|
buf[dp++] = (byte)base64[(bits >>> 18) & 0x3f];
|
|
buf[dp++] = (byte)base64[(bits >>> 12) & 0x3f];
|
|
buf[dp++] = (byte)base64[(bits >>> 6) & 0x3f];
|
|
buf[dp++] = (byte)base64[bits & 0x3f];
|
|
}
|
|
out.write(buf, 0, dp);
|
|
off = sl;
|
|
linepos += dp;
|
|
nBits24 -= dp / 4;
|
|
}
|
|
if (leftover == 1) {
|
|
b0 = b[off++] & 0xff;
|
|
} else if (leftover == 2) {
|
|
b0 = b[off++] & 0xff;
|
|
b1 = b[off++] & 0xff;
|
|
}
|
|
}
|
|
|
|
@Override
|
|
public void close() throws IOException {
|
|
if (!closed) {
|
|
closed = true;
|
|
if (leftover == 1) {
|
|
checkNewline();
|
|
out.write(base64[b0 >> 2]);
|
|
out.write(base64[(b0 << 4) & 0x3f]);
|
|
if (doPadding) {
|
|
out.write('=');
|
|
out.write('=');
|
|
}
|
|
} else if (leftover == 2) {
|
|
checkNewline();
|
|
out.write(base64[b0 >> 2]);
|
|
out.write(base64[(b0 << 4) & 0x3f | (b1 >> 4)]);
|
|
out.write(base64[(b1 << 2) & 0x3f]);
|
|
if (doPadding) {
|
|
out.write('=');
|
|
}
|
|
}
|
|
leftover = 0;
|
|
out.close();
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* An input stream for decoding Base64 bytes
|
|
*/
|
|
private static class DecInputStream extends InputStream {
|
|
|
|
private final InputStream is;
|
|
private final boolean isMIME;
|
|
private final int[] base64; // base64 -> byte mapping
|
|
private int bits = 0; // 24-bit buffer for decoding
|
|
|
|
/* writing bit pos inside bits; one of 24 (left, msb), 18, 12, 6, 0 */
|
|
private int wpos = 0;
|
|
|
|
/* reading bit pos inside bits: one of 24 (left, msb), 16, 8, 0 */
|
|
private int rpos = 0;
|
|
|
|
private boolean eof = false;
|
|
private boolean closed = false;
|
|
|
|
DecInputStream(InputStream is, int[] base64, boolean isMIME) {
|
|
this.is = is;
|
|
this.base64 = base64;
|
|
this.isMIME = isMIME;
|
|
}
|
|
|
|
private byte[] sbBuf = new byte[1];
|
|
|
|
@Override
|
|
public int read() throws IOException {
|
|
return read(sbBuf, 0, 1) == -1 ? -1 : sbBuf[0] & 0xff;
|
|
}
|
|
|
|
private int leftovers(byte[] b, int off, int pos, int limit) {
|
|
eof = true;
|
|
|
|
/*
|
|
* We use a loop here, as this method is executed only a few times.
|
|
* Unrolling the loop would probably not contribute much here.
|
|
*/
|
|
while (rpos - 8 >= wpos && pos != limit) {
|
|
rpos -= 8;
|
|
b[pos++] = (byte) (bits >> rpos);
|
|
}
|
|
return pos - off != 0 || rpos - 8 >= wpos ? pos - off : -1;
|
|
}
|
|
|
|
private int eof(byte[] b, int off, int pos, int limit) throws IOException {
|
|
/*
|
|
* pos != limit
|
|
*
|
|
* wpos == 18: x dangling single x, invalid unit
|
|
* accept ending xx or xxx without padding characters
|
|
*/
|
|
if (wpos == 18) {
|
|
throw new IOException("Base64 stream has one un-decoded dangling byte.");
|
|
}
|
|
rpos = 24;
|
|
return leftovers(b, off, pos, limit);
|
|
}
|
|
|
|
private int padding(byte[] b, int off, int pos, int limit) throws IOException {
|
|
/*
|
|
* pos != limit
|
|
*
|
|
* wpos == 24: = (unnecessary padding)
|
|
* wpos == 18: x= (dangling single x, invalid unit)
|
|
* wpos == 12 and missing last '=': xx= (invalid padding)
|
|
* wpos == 12 and last is not '=': xx=x (invalid padding)
|
|
*/
|
|
if (wpos >= 18 || wpos == 12 && is.read() != '=') {
|
|
throw new IOException("Illegal base64 ending sequence:" + wpos);
|
|
}
|
|
rpos = 24;
|
|
return leftovers(b, off, pos, limit);
|
|
}
|
|
|
|
@Override
|
|
public int read(byte[] b, int off, int len) throws IOException {
|
|
if (closed) {
|
|
throw new IOException("Stream is closed");
|
|
}
|
|
Objects.checkFromIndexSize(off, len, b.length);
|
|
if (len == 0) {
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Rather than keeping 2 running vars (e.g., off and len),
|
|
* we only keep one (pos), while definitely fixing the boundaries
|
|
* of the range [off, limit).
|
|
* More specifically, each use of pos as an index in b meets
|
|
* pos - off >= 0 & limit - pos > 0
|
|
*
|
|
* Note that limit can overflow to Integer.MIN_VALUE. However,
|
|
* as long as comparisons with pos are as coded, there's no harm.
|
|
*/
|
|
int pos = off;
|
|
final int limit = off + len;
|
|
if (eof) {
|
|
return leftovers(b, off, pos, limit);
|
|
}
|
|
|
|
/*
|
|
* Leftovers from previous invocation; here, wpos = 0.
|
|
* There can be at most 2 leftover bytes (rpos <= 16).
|
|
* Further, b has at least one free place.
|
|
*
|
|
* The logic could be coded as a loop, (as in method leftovers())
|
|
* but the explicit "unrolling" makes it possible to generate
|
|
* better byte extraction code.
|
|
*/
|
|
if (rpos == 16) {
|
|
b[pos++] = (byte) (bits >> 8);
|
|
rpos = 8;
|
|
if (pos == limit) {
|
|
return len;
|
|
}
|
|
}
|
|
if (rpos == 8) {
|
|
b[pos++] = (byte) bits;
|
|
rpos = 0;
|
|
if (pos == limit) {
|
|
return len;
|
|
}
|
|
}
|
|
|
|
bits = 0;
|
|
wpos = 24;
|
|
for (;;) {
|
|
/* pos != limit & rpos == 0 */
|
|
final int i = is.read();
|
|
if (i < 0) {
|
|
return eof(b, off, pos, limit);
|
|
}
|
|
final int v = base64[i];
|
|
if (v < 0) {
|
|
/*
|
|
* i not in alphabet, thus
|
|
* v == -2: i is '=', the padding
|
|
* v == -1: i is something else, typically CR or LF
|
|
*/
|
|
if (v == -1) {
|
|
if (isMIME) {
|
|
continue;
|
|
}
|
|
throw new IOException("Illegal base64 character 0x" +
|
|
Integer.toHexString(i));
|
|
}
|
|
return padding(b, off, pos, limit);
|
|
}
|
|
wpos -= 6;
|
|
bits |= v << wpos;
|
|
if (wpos != 0) {
|
|
continue;
|
|
}
|
|
if (limit - pos >= 3) {
|
|
/* frequently taken fast path, no need to track rpos */
|
|
b[pos++] = (byte) (bits >> 16);
|
|
b[pos++] = (byte) (bits >> 8);
|
|
b[pos++] = (byte) bits;
|
|
bits = 0;
|
|
wpos = 24;
|
|
if (pos == limit) {
|
|
return len;
|
|
}
|
|
continue;
|
|
}
|
|
|
|
/* b has either 1 or 2 free places */
|
|
b[pos++] = (byte) (bits >> 16);
|
|
if (pos == limit) {
|
|
rpos = 16;
|
|
return len;
|
|
}
|
|
b[pos++] = (byte) (bits >> 8);
|
|
/* pos == limit, no need for an if */
|
|
rpos = 8;
|
|
return len;
|
|
}
|
|
}
|
|
|
|
@Override
|
|
public int available() throws IOException {
|
|
if (closed)
|
|
throw new IOException("Stream is closed");
|
|
return is.available(); // TBD:
|
|
}
|
|
|
|
@Override
|
|
public void close() throws IOException {
|
|
if (!closed) {
|
|
closed = true;
|
|
is.close();
|
|
}
|
|
}
|
|
}
|
|
}
|