38 lines
No EOL
1.2 KiB
JavaScript
38 lines
No EOL
1.2 KiB
JavaScript
/**
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* The code was extracted from:
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* https://github.com/davidchambers/Base64.js
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*/
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var chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=';
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function InvalidCharacterError(message) {
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this.message = message;
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}
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InvalidCharacterError.prototype = new Error();
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InvalidCharacterError.prototype.name = 'InvalidCharacterError';
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function polyfill (input) {
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var str = String(input).replace(/=+$/, '');
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if (str.length % 4 == 1) {
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throw new InvalidCharacterError("'atob' failed: The string to be decoded is not correctly encoded.");
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}
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for (
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// initialize result and counters
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var bc = 0, bs, buffer, idx = 0, output = '';
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// get next character
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buffer = str.charAt(idx++);
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// character found in table? initialize bit storage and add its ascii value;
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~buffer && (bs = bc % 4 ? bs * 64 + buffer : buffer,
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// and if not first of each 4 characters,
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// convert the first 8 bits to one ascii character
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bc++ % 4) ? output += String.fromCharCode(255 & bs >> (-2 * bc & 6)) : 0
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) {
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// try to find character in table (0-63, not found => -1)
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buffer = chars.indexOf(buffer);
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}
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return output;
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}
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module.exports = typeof window !== 'undefined' && window.atob || polyfill; |