71 lines
1.7 KiB
JavaScript
71 lines
1.7 KiB
JavaScript
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'use strict';
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// private property
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var _keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
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// public method for encoding
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exports.encode = function(input, utf8) {
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var output = "";
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var chr1, chr2, chr3, enc1, enc2, enc3, enc4;
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var i = 0;
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while (i < input.length) {
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chr1 = input.charCodeAt(i++);
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chr2 = input.charCodeAt(i++);
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chr3 = input.charCodeAt(i++);
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enc1 = chr1 >> 2;
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enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
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enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
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enc4 = chr3 & 63;
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if (isNaN(chr2)) {
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enc3 = enc4 = 64;
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}
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else if (isNaN(chr3)) {
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enc4 = 64;
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}
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output = output + _keyStr.charAt(enc1) + _keyStr.charAt(enc2) + _keyStr.charAt(enc3) + _keyStr.charAt(enc4);
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}
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return output;
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};
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// public method for decoding
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exports.decode = function(input, utf8) {
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var output = "";
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var chr1, chr2, chr3;
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var enc1, enc2, enc3, enc4;
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var i = 0;
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input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");
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while (i < input.length) {
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enc1 = _keyStr.indexOf(input.charAt(i++));
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enc2 = _keyStr.indexOf(input.charAt(i++));
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enc3 = _keyStr.indexOf(input.charAt(i++));
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enc4 = _keyStr.indexOf(input.charAt(i++));
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chr1 = (enc1 << 2) | (enc2 >> 4);
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chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
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chr3 = ((enc3 & 3) << 6) | enc4;
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output = output + String.fromCharCode(chr1);
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if (enc3 != 64) {
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output = output + String.fromCharCode(chr2);
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}
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if (enc4 != 64) {
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output = output + String.fromCharCode(chr3);
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}
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}
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return output;
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};
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