1 | /*
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2 | * Copyright (c) 2009 Nicholas C. Zakas. All rights reserved.
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3 | *
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4 | * Permission is hereby granted, free of charge, to any person obtaining a copy
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5 | * of this software and associated documentation files (the "Software"), to deal
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6 | * in the Software without restriction, including without limitation the rights
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7 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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8 | * copies of the Software, and to permit persons to whom the Software is
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9 | * furnished to do so, subject to the following conditions:
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10 | *
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11 | * The above copyright notice and this permission notice shall be included in
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12 | * all copies or substantial portions of the Software.
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13 | *
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14 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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15 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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16 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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17 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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18 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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19 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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20 | * THE SOFTWARE.
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21 | */
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22 |
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23 | /*
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24 | * Base 64 implementation in JavaScript
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25 | * Original source available at https://raw.github.com/nzakas/computer-science-in-javascript/02a2745b4aa8214f2cae1bf0b15b447ca1a91b23/encodings/base64/base64.js
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26 | *
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27 | * Converted to AMD and linter refinement by Scott Andrews
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28 | */
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29 |
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30 | (function (define) {
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31 | ;
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32 |
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33 | /*jshint bitwise: false */
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34 | define(function (/* require */) {
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35 |
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36 | var digits = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';
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37 |
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38 | /**
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39 | * Base64-encodes a string of text.
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40 | *
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41 | * @param {string} text The text to encode.
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42 | * @return {string} The base64-encoded string.
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43 | */
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44 | function base64Encode(text) {
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45 |
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46 | if (/([^\u0000-\u00ff])/.test(text)) {
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47 | throw new Error('Can\'t base64 encode non-ASCII characters.');
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48 | }
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49 |
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50 | var i = 0,
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51 | cur, prev, byteNum,
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52 | result = [];
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53 |
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54 | while (i < text.length) {
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55 |
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56 | cur = text.charCodeAt(i);
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57 | byteNum = i % 3;
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58 |
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59 | switch (byteNum) {
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60 | case 0: //first byte
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61 | result.push(digits.charAt(cur >> 2));
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62 | break;
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63 |
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64 | case 1: //second byte
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65 | result.push(digits.charAt((prev & 3) << 4 | (cur >> 4)));
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66 | break;
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67 |
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68 | case 2: //third byte
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69 | result.push(digits.charAt((prev & 0x0f) << 2 | (cur >> 6)));
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70 | result.push(digits.charAt(cur & 0x3f));
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71 | break;
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72 | }
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73 |
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74 | prev = cur;
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75 | i += 1;
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76 | }
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77 |
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78 | if (byteNum === 0) {
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79 | result.push(digits.charAt((prev & 3) << 4));
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80 | result.push('==');
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81 | } else if (byteNum === 1) {
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82 | result.push(digits.charAt((prev & 0x0f) << 2));
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83 | result.push('=');
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84 | }
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85 |
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86 | return result.join('');
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87 | }
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88 |
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89 | /**
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90 | * Base64-decodes a string of text.
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91 | *
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92 | * @param {string} text The text to decode.
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93 | * @return {string} The base64-decoded string.
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94 | */
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95 | function base64Decode(text) {
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96 |
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97 | //ignore white space
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98 | text = text.replace(/\s/g, '');
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99 |
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100 | //first check for any unexpected input
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101 | if (!(/^[a-z0-9\+\/\s]+\={0,2}$/i.test(text)) || text.length % 4 > 0) {
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102 | throw new Error('Not a base64-encoded string.');
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103 | }
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104 |
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105 | //local variables
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106 | var cur, prev, digitNum,
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107 | i = 0,
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108 | result = [];
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109 |
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110 | //remove any equals signs
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111 | text = text.replace(/\=/g, '');
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112 |
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113 | //loop over each character
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114 | while (i < text.length) {
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115 |
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116 | cur = digits.indexOf(text.charAt(i));
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117 | digitNum = i % 4;
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118 |
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119 | switch (digitNum) {
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120 |
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121 | //case 0: first digit - do nothing, not enough info to work with
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122 |
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123 | case 1: //second digit
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124 | result.push(String.fromCharCode(prev << 2 | cur >> 4));
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125 | break;
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126 |
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127 | case 2: //third digit
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128 | result.push(String.fromCharCode((prev & 0x0f) << 4 | cur >> 2));
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129 | break;
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130 |
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131 | case 3: //fourth digit
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132 | result.push(String.fromCharCode((prev & 3) << 6 | cur));
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133 | break;
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134 | }
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135 |
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136 | prev = cur;
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137 | i += 1;
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138 | }
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139 |
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140 | //return a string
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141 | return result.join('');
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142 |
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143 | }
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144 |
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145 | return {
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146 | encode: base64Encode,
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147 | decode: base64Decode
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148 | };
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149 |
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150 | });
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151 |
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152 | }(
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153 | typeof define === 'function' && define.amd ? define : function (factory) { module.exports = factory(require); }
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154 | // Boilerplate for AMD and Node
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155 | ));
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