571 lines
24 KiB
Java
571 lines
24 KiB
Java
// Portions copyright 2002, Google, Inc.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package com.syncedsynapse.kore2.billing;
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// This code was converted from code at http://iharder.sourceforge.net/base64/
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// Lots of extraneous features were removed.
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/* The original code said:
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* <p>
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* I am placing this code in the Public Domain. Do with it as you will.
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* This software comes with no guarantees or warranties but with
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* plenty of well-wishing instead!
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* Please visit
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* <a href="http://iharder.net/xmlizable">http://iharder.net/xmlizable</a>
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* periodically to check for updates or to contribute improvements.
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* </p>
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*
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* @author Robert Harder
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* @author rharder@usa.net
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* @version 1.3
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*/
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/**
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* Base64 converter class. This code is not a complete MIME encoder;
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* it simply converts binary data to base64 data and back.
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*
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* <p>Note {@link CharBase64} is a GWT-compatible implementation of this
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* class.
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*/
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public class Base64 {
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/** Specify encoding (value is {@code true}). */
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public final static boolean ENCODE = true;
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/** Specify decoding (value is {@code false}). */
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public final static boolean DECODE = false;
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/** The equals sign (=) as a byte. */
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private final static byte EQUALS_SIGN = (byte) '=';
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/** The new line character (\n) as a byte. */
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private final static byte NEW_LINE = (byte) '\n';
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/**
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* The 64 valid Base64 values.
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*/
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private final static byte[] ALPHABET =
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{(byte) 'A', (byte) 'B', (byte) 'C', (byte) 'D', (byte) 'E', (byte) 'F',
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(byte) 'G', (byte) 'H', (byte) 'I', (byte) 'J', (byte) 'K',
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(byte) 'L', (byte) 'M', (byte) 'N', (byte) 'O', (byte) 'P',
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(byte) 'Q', (byte) 'R', (byte) 'S', (byte) 'T', (byte) 'U',
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(byte) 'V', (byte) 'W', (byte) 'X', (byte) 'Y', (byte) 'Z',
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(byte) 'a', (byte) 'b', (byte) 'c', (byte) 'd', (byte) 'e',
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(byte) 'f', (byte) 'g', (byte) 'h', (byte) 'i', (byte) 'j',
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(byte) 'k', (byte) 'l', (byte) 'm', (byte) 'n', (byte) 'o',
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(byte) 'p', (byte) 'q', (byte) 'r', (byte) 's', (byte) 't',
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(byte) 'u', (byte) 'v', (byte) 'w', (byte) 'x', (byte) 'y',
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(byte) 'z', (byte) '0', (byte) '1', (byte) '2', (byte) '3',
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(byte) '4', (byte) '5', (byte) '6', (byte) '7', (byte) '8',
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(byte) '9', (byte) '+', (byte) '/'};
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/**
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* The 64 valid web safe Base64 values.
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*/
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private final static byte[] WEBSAFE_ALPHABET =
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{(byte) 'A', (byte) 'B', (byte) 'C', (byte) 'D', (byte) 'E', (byte) 'F',
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(byte) 'G', (byte) 'H', (byte) 'I', (byte) 'J', (byte) 'K',
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(byte) 'L', (byte) 'M', (byte) 'N', (byte) 'O', (byte) 'P',
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(byte) 'Q', (byte) 'R', (byte) 'S', (byte) 'T', (byte) 'U',
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(byte) 'V', (byte) 'W', (byte) 'X', (byte) 'Y', (byte) 'Z',
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(byte) 'a', (byte) 'b', (byte) 'c', (byte) 'd', (byte) 'e',
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(byte) 'f', (byte) 'g', (byte) 'h', (byte) 'i', (byte) 'j',
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(byte) 'k', (byte) 'l', (byte) 'm', (byte) 'n', (byte) 'o',
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(byte) 'p', (byte) 'q', (byte) 'r', (byte) 's', (byte) 't',
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(byte) 'u', (byte) 'v', (byte) 'w', (byte) 'x', (byte) 'y',
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(byte) 'z', (byte) '0', (byte) '1', (byte) '2', (byte) '3',
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(byte) '4', (byte) '5', (byte) '6', (byte) '7', (byte) '8',
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(byte) '9', (byte) '-', (byte) '_'};
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/**
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* Translates a Base64 value to either its 6-bit reconstruction value
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* or a negative number indicating some other meaning.
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**/
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private final static byte[] DECODABET = {-9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 0 - 8
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-5, -5, // Whitespace: Tab and Linefeed
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-9, -9, // Decimal 11 - 12
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-5, // Whitespace: Carriage Return
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-9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 14 - 26
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-9, -9, -9, -9, -9, // Decimal 27 - 31
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-5, // Whitespace: Space
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-9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 33 - 42
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62, // Plus sign at decimal 43
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-9, -9, -9, // Decimal 44 - 46
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63, // Slash at decimal 47
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52, 53, 54, 55, 56, 57, 58, 59, 60, 61, // Numbers zero through nine
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-9, -9, -9, // Decimal 58 - 60
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-1, // Equals sign at decimal 61
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-9, -9, -9, // Decimal 62 - 64
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0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, // Letters 'A' through 'N'
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14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, // Letters 'O' through 'Z'
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-9, -9, -9, -9, -9, -9, // Decimal 91 - 96
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26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, // Letters 'a' through 'm'
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39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, // Letters 'n' through 'z'
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-9, -9, -9, -9, -9 // Decimal 123 - 127
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/* ,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 128 - 139
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-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 140 - 152
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-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 153 - 165
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-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 166 - 178
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-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 179 - 191
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-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 192 - 204
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-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 205 - 217
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-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 218 - 230
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-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 231 - 243
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-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9 // Decimal 244 - 255 */
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};
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/** The web safe decodabet */
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private final static byte[] WEBSAFE_DECODABET =
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{-9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 0 - 8
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-5, -5, // Whitespace: Tab and Linefeed
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-9, -9, // Decimal 11 - 12
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-5, // Whitespace: Carriage Return
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-9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 14 - 26
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-9, -9, -9, -9, -9, // Decimal 27 - 31
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-5, // Whitespace: Space
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-9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 33 - 44
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62, // Dash '-' sign at decimal 45
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-9, -9, // Decimal 46-47
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52, 53, 54, 55, 56, 57, 58, 59, 60, 61, // Numbers zero through nine
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-9, -9, -9, // Decimal 58 - 60
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-1, // Equals sign at decimal 61
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-9, -9, -9, // Decimal 62 - 64
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0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, // Letters 'A' through 'N'
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14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, // Letters 'O' through 'Z'
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-9, -9, -9, -9, // Decimal 91-94
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63, // Underscore '_' at decimal 95
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-9, // Decimal 96
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26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, // Letters 'a' through 'm'
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39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, // Letters 'n' through 'z'
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-9, -9, -9, -9, -9 // Decimal 123 - 127
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/* ,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 128 - 139
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-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 140 - 152
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-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 153 - 165
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-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 166 - 178
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-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 179 - 191
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-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 192 - 204
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-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 205 - 217
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-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 218 - 230
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-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 231 - 243
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-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9 // Decimal 244 - 255 */
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};
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// Indicates white space in encoding
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private final static byte WHITE_SPACE_ENC = -5;
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// Indicates equals sign in encoding
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private final static byte EQUALS_SIGN_ENC = -1;
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/** Defeats instantiation. */
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private Base64() {
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}
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/* ******** E N C O D I N G M E T H O D S ******** */
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/**
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* Encodes up to three bytes of the array <var>source</var>
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* and writes the resulting four Base64 bytes to <var>destination</var>.
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* The source and destination arrays can be manipulated
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* anywhere along their length by specifying
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* <var>srcOffset</var> and <var>destOffset</var>.
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* This method does not check to make sure your arrays
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* are large enough to accommodate <var>srcOffset</var> + 3 for
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* the <var>source</var> array or <var>destOffset</var> + 4 for
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* the <var>destination</var> array.
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* The actual number of significant bytes in your array is
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* given by <var>numSigBytes</var>.
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*
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* @param source the array to convert
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* @param srcOffset the index where conversion begins
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* @param numSigBytes the number of significant bytes in your array
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* @param destination the array to hold the conversion
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* @param destOffset the index where output will be put
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* @param alphabet is the encoding alphabet
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* @return the <var>destination</var> array
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* @since 1.3
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*/
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private static byte[] encode3to4(byte[] source, int srcOffset,
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int numSigBytes, byte[] destination, int destOffset, byte[] alphabet) {
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// 1 2 3
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// 01234567890123456789012345678901 Bit position
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// --------000000001111111122222222 Array position from threeBytes
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// --------| || || || | Six bit groups to index alphabet
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// >>18 >>12 >> 6 >> 0 Right shift necessary
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// 0x3f 0x3f 0x3f Additional AND
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// Create buffer with zero-padding if there are only one or two
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// significant bytes passed in the array.
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// We have to shift left 24 in order to flush out the 1's that appear
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// when Java treats a value as negative that is cast from a byte to an int.
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int inBuff =
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(numSigBytes > 0 ? ((source[srcOffset] << 24) >>> 8) : 0)
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| (numSigBytes > 1 ? ((source[srcOffset + 1] << 24) >>> 16) : 0)
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| (numSigBytes > 2 ? ((source[srcOffset + 2] << 24) >>> 24) : 0);
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switch (numSigBytes) {
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case 3:
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destination[destOffset] = alphabet[(inBuff >>> 18)];
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destination[destOffset + 1] = alphabet[(inBuff >>> 12) & 0x3f];
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destination[destOffset + 2] = alphabet[(inBuff >>> 6) & 0x3f];
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destination[destOffset + 3] = alphabet[(inBuff) & 0x3f];
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return destination;
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case 2:
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destination[destOffset] = alphabet[(inBuff >>> 18)];
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destination[destOffset + 1] = alphabet[(inBuff >>> 12) & 0x3f];
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destination[destOffset + 2] = alphabet[(inBuff >>> 6) & 0x3f];
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destination[destOffset + 3] = EQUALS_SIGN;
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return destination;
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case 1:
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destination[destOffset] = alphabet[(inBuff >>> 18)];
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destination[destOffset + 1] = alphabet[(inBuff >>> 12) & 0x3f];
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destination[destOffset + 2] = EQUALS_SIGN;
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destination[destOffset + 3] = EQUALS_SIGN;
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return destination;
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default:
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return destination;
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} // end switch
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} // end encode3to4
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/**
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* Encodes a byte array into Base64 notation.
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* Equivalent to calling
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* {@code encodeBytes(source, 0, source.length)}
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*
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* @param source The data to convert
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* @since 1.4
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*/
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public static String encode(byte[] source) {
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return encode(source, 0, source.length, ALPHABET, true);
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}
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/**
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* Encodes a byte array into web safe Base64 notation.
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*
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* @param source The data to convert
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* @param doPadding is {@code true} to pad result with '=' chars
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* if it does not fall on 3 byte boundaries
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*/
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public static String encodeWebSafe(byte[] source, boolean doPadding) {
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return encode(source, 0, source.length, WEBSAFE_ALPHABET, doPadding);
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}
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/**
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* Encodes a byte array into Base64 notation.
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*
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* @param source the data to convert
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* @param off offset in array where conversion should begin
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* @param len length of data to convert
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* @param alphabet the encoding alphabet
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* @param doPadding is {@code true} to pad result with '=' chars
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* if it does not fall on 3 byte boundaries
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* @since 1.4
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*/
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public static String encode(byte[] source, int off, int len, byte[] alphabet,
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boolean doPadding) {
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byte[] outBuff = encode(source, off, len, alphabet, Integer.MAX_VALUE);
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int outLen = outBuff.length;
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// If doPadding is false, set length to truncate '='
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// padding characters
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while (doPadding == false && outLen > 0) {
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if (outBuff[outLen - 1] != '=') {
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break;
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}
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outLen -= 1;
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}
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return new String(outBuff, 0, outLen);
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}
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/**
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* Encodes a byte array into Base64 notation.
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*
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* @param source the data to convert
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* @param off offset in array where conversion should begin
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* @param len length of data to convert
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* @param alphabet is the encoding alphabet
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* @param maxLineLength maximum length of one line.
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* @return the BASE64-encoded byte array
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*/
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public static byte[] encode(byte[] source, int off, int len, byte[] alphabet,
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int maxLineLength) {
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int lenDiv3 = (len + 2) / 3; // ceil(len / 3)
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int len43 = lenDiv3 * 4;
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byte[] outBuff = new byte[len43 // Main 4:3
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+ (len43 / maxLineLength)]; // New lines
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int d = 0;
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int e = 0;
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int len2 = len - 2;
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int lineLength = 0;
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for (; d < len2; d += 3, e += 4) {
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// The following block of code is the same as
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// encode3to4( source, d + off, 3, outBuff, e, alphabet );
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// but inlined for faster encoding (~20% improvement)
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int inBuff =
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((source[d + off] << 24) >>> 8)
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| ((source[d + 1 + off] << 24) >>> 16)
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| ((source[d + 2 + off] << 24) >>> 24);
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outBuff[e] = alphabet[(inBuff >>> 18)];
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outBuff[e + 1] = alphabet[(inBuff >>> 12) & 0x3f];
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outBuff[e + 2] = alphabet[(inBuff >>> 6) & 0x3f];
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outBuff[e + 3] = alphabet[(inBuff) & 0x3f];
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lineLength += 4;
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if (lineLength == maxLineLength) {
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outBuff[e + 4] = NEW_LINE;
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e++;
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lineLength = 0;
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} // end if: end of line
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} // end for: each piece of array
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if (d < len) {
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encode3to4(source, d + off, len - d, outBuff, e, alphabet);
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lineLength += 4;
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if (lineLength == maxLineLength) {
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// Add a last newline
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outBuff[e + 4] = NEW_LINE;
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e++;
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}
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e += 4;
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}
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assert (e == outBuff.length);
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return outBuff;
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}
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/* ******** D E C O D I N G M E T H O D S ******** */
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/**
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* Decodes four bytes from array <var>source</var>
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* and writes the resulting bytes (up to three of them)
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* to <var>destination</var>.
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* The source and destination arrays can be manipulated
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* anywhere along their length by specifying
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* <var>srcOffset</var> and <var>destOffset</var>.
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* This method does not check to make sure your arrays
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* are large enough to accommodate <var>srcOffset</var> + 4 for
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* the <var>source</var> array or <var>destOffset</var> + 3 for
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* the <var>destination</var> array.
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* This method returns the actual number of bytes that
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* were converted from the Base64 encoding.
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*
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*
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* @param source the array to convert
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* @param srcOffset the index where conversion begins
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* @param destination the array to hold the conversion
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* @param destOffset the index where output will be put
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* @param decodabet the decodabet for decoding Base64 content
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* @return the number of decoded bytes converted
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* @since 1.3
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*/
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private static int decode4to3(byte[] source, int srcOffset,
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byte[] destination, int destOffset, byte[] decodabet) {
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// Example: Dk==
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if (source[srcOffset + 2] == EQUALS_SIGN) {
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int outBuff =
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((decodabet[source[srcOffset]] << 24) >>> 6)
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| ((decodabet[source[srcOffset + 1]] << 24) >>> 12);
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destination[destOffset] = (byte) (outBuff >>> 16);
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return 1;
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} else if (source[srcOffset + 3] == EQUALS_SIGN) {
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// Example: DkL=
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int outBuff =
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((decodabet[source[srcOffset]] << 24) >>> 6)
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| ((decodabet[source[srcOffset + 1]] << 24) >>> 12)
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| ((decodabet[source[srcOffset + 2]] << 24) >>> 18);
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destination[destOffset] = (byte) (outBuff >>> 16);
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destination[destOffset + 1] = (byte) (outBuff >>> 8);
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return 2;
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} else {
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|
// Example: DkLE
|
|
int outBuff =
|
|
((decodabet[source[srcOffset]] << 24) >>> 6)
|
|
| ((decodabet[source[srcOffset + 1]] << 24) >>> 12)
|
|
| ((decodabet[source[srcOffset + 2]] << 24) >>> 18)
|
|
| ((decodabet[source[srcOffset + 3]] << 24) >>> 24);
|
|
|
|
destination[destOffset] = (byte) (outBuff >> 16);
|
|
destination[destOffset + 1] = (byte) (outBuff >> 8);
|
|
destination[destOffset + 2] = (byte) (outBuff);
|
|
return 3;
|
|
}
|
|
} // end decodeToBytes
|
|
|
|
|
|
/**
|
|
* Decodes data from Base64 notation.
|
|
*
|
|
* @param s the string to decode (decoded in default encoding)
|
|
* @return the decoded data
|
|
* @since 1.4
|
|
*/
|
|
public static byte[] decode(String s) throws Base64DecoderException {
|
|
byte[] bytes = s.getBytes();
|
|
return decode(bytes, 0, bytes.length);
|
|
}
|
|
|
|
/**
|
|
* Decodes data from web safe Base64 notation.
|
|
* Web safe encoding uses '-' instead of '+', '_' instead of '/'
|
|
*
|
|
* @param s the string to decode (decoded in default encoding)
|
|
* @return the decoded data
|
|
*/
|
|
public static byte[] decodeWebSafe(String s) throws Base64DecoderException {
|
|
byte[] bytes = s.getBytes();
|
|
return decodeWebSafe(bytes, 0, bytes.length);
|
|
}
|
|
|
|
/**
|
|
* Decodes Base64 content in byte array format and returns
|
|
* the decoded byte array.
|
|
*
|
|
* @param source The Base64 encoded data
|
|
* @return decoded data
|
|
* @since 1.3
|
|
* @throws Base64DecoderException
|
|
*/
|
|
public static byte[] decode(byte[] source) throws Base64DecoderException {
|
|
return decode(source, 0, source.length);
|
|
}
|
|
|
|
/**
|
|
* Decodes web safe Base64 content in byte array format and returns
|
|
* the decoded data.
|
|
* Web safe encoding uses '-' instead of '+', '_' instead of '/'
|
|
*
|
|
* @param source the string to decode (decoded in default encoding)
|
|
* @return the decoded data
|
|
*/
|
|
public static byte[] decodeWebSafe(byte[] source)
|
|
throws Base64DecoderException {
|
|
return decodeWebSafe(source, 0, source.length);
|
|
}
|
|
|
|
/**
|
|
* Decodes Base64 content in byte array format and returns
|
|
* the decoded byte array.
|
|
*
|
|
* @param source the Base64 encoded data
|
|
* @param off the offset of where to begin decoding
|
|
* @param len the length of characters to decode
|
|
* @return decoded data
|
|
* @since 1.3
|
|
* @throws Base64DecoderException
|
|
*/
|
|
public static byte[] decode(byte[] source, int off, int len)
|
|
throws Base64DecoderException {
|
|
return decode(source, off, len, DECODABET);
|
|
}
|
|
|
|
/**
|
|
* Decodes web safe Base64 content in byte array format and returns
|
|
* the decoded byte array.
|
|
* Web safe encoding uses '-' instead of '+', '_' instead of '/'
|
|
*
|
|
* @param source the Base64 encoded data
|
|
* @param off the offset of where to begin decoding
|
|
* @param len the length of characters to decode
|
|
* @return decoded data
|
|
*/
|
|
public static byte[] decodeWebSafe(byte[] source, int off, int len)
|
|
throws Base64DecoderException {
|
|
return decode(source, off, len, WEBSAFE_DECODABET);
|
|
}
|
|
|
|
/**
|
|
* Decodes Base64 content using the supplied decodabet and returns
|
|
* the decoded byte array.
|
|
*
|
|
* @param source the Base64 encoded data
|
|
* @param off the offset of where to begin decoding
|
|
* @param len the length of characters to decode
|
|
* @param decodabet the decodabet for decoding Base64 content
|
|
* @return decoded data
|
|
*/
|
|
public static byte[] decode(byte[] source, int off, int len, byte[] decodabet)
|
|
throws Base64DecoderException {
|
|
int len34 = len * 3 / 4;
|
|
byte[] outBuff = new byte[2 + len34]; // Upper limit on size of output
|
|
int outBuffPosn = 0;
|
|
|
|
byte[] b4 = new byte[4];
|
|
int b4Posn = 0;
|
|
int i = 0;
|
|
byte sbiCrop = 0;
|
|
byte sbiDecode = 0;
|
|
for (i = 0; i < len; i++) {
|
|
sbiCrop = (byte) (source[i + off] & 0x7f); // Only the low seven bits
|
|
sbiDecode = decodabet[sbiCrop];
|
|
|
|
if (sbiDecode >= WHITE_SPACE_ENC) { // White space Equals sign or better
|
|
if (sbiDecode >= EQUALS_SIGN_ENC) {
|
|
// An equals sign (for padding) must not occur at position 0 or 1
|
|
// and must be the last byte[s] in the encoded value
|
|
if (sbiCrop == EQUALS_SIGN) {
|
|
int bytesLeft = len - i;
|
|
byte lastByte = (byte) (source[len - 1 + off] & 0x7f);
|
|
if (b4Posn == 0 || b4Posn == 1) {
|
|
throw new Base64DecoderException(
|
|
"invalid padding byte '=' at byte offset " + i);
|
|
} else if ((b4Posn == 3 && bytesLeft > 2)
|
|
|| (b4Posn == 4 && bytesLeft > 1)) {
|
|
throw new Base64DecoderException(
|
|
"padding byte '=' falsely signals end of encoded value "
|
|
+ "at offset " + i);
|
|
} else if (lastByte != EQUALS_SIGN && lastByte != NEW_LINE) {
|
|
throw new Base64DecoderException(
|
|
"encoded value has invalid trailing byte");
|
|
}
|
|
break;
|
|
}
|
|
|
|
b4[b4Posn++] = sbiCrop;
|
|
if (b4Posn == 4) {
|
|
outBuffPosn += decode4to3(b4, 0, outBuff, outBuffPosn, decodabet);
|
|
b4Posn = 0;
|
|
}
|
|
}
|
|
} else {
|
|
throw new Base64DecoderException("Bad Base64 input character at " + i
|
|
+ ": " + source[i + off] + "(decimal)");
|
|
}
|
|
}
|
|
|
|
// Because web safe encoding allows non padding base64 encodes, we
|
|
// need to pad the rest of the b4 buffer with equal signs when
|
|
// b4Posn != 0. There can be at most 2 equal signs at the end of
|
|
// four characters, so the b4 buffer must have two or three
|
|
// characters. This also catches the case where the input is
|
|
// padded with EQUALS_SIGN
|
|
if (b4Posn != 0) {
|
|
if (b4Posn == 1) {
|
|
throw new Base64DecoderException("single trailing character at offset "
|
|
+ (len - 1));
|
|
}
|
|
b4[b4Posn++] = EQUALS_SIGN;
|
|
outBuffPosn += decode4to3(b4, 0, outBuff, outBuffPosn, decodabet);
|
|
}
|
|
|
|
byte[] out = new byte[outBuffPosn];
|
|
System.arraycopy(outBuff, 0, out, 0, outBuffPosn);
|
|
return out;
|
|
}
|
|
}
|