103 lines
2.8 KiB
JavaScript
103 lines
2.8 KiB
JavaScript
function Base64() {
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// private property
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_keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
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// public method for encoding
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this.encode = function (input) {
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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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input = _utf8_encode(input);
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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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} else if (isNaN(chr3)) {
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enc4 = 64;
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}
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output = output +
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_keyStr.charAt(enc1) + _keyStr.charAt(enc2) +
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_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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this.decode = function (input) {
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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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output = _utf8_decode(output);
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return output;
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}
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// private method for UTF-8 encoding
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_utf8_encode = function (string) {
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string = string.replace(/\r\n/g,"\n");
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var utftext = "";
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for (var n = 0; n < string.length; n++) {
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var c = string.charCodeAt(n);
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if (c < 128) {
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utftext += String.fromCharCode(c);
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} else if((c > 127) && (c < 2048)) {
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utftext += String.fromCharCode((c >> 6) | 192);
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utftext += String.fromCharCode((c & 63) | 128);
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} else {
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utftext += String.fromCharCode((c >> 12) | 224);
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utftext += String.fromCharCode(((c >> 6) & 63) | 128);
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utftext += String.fromCharCode((c & 63) | 128);
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}
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}
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return utftext;
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}
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// private method for UTF-8 decoding
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_utf8_decode = function (utftext) {
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var string = "";
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var i = 0;
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var c = c1 = c2 = 0;
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while ( i < utftext.length ) {
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c = utftext.charCodeAt(i);
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if (c < 128) {
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string += String.fromCharCode(c);
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i++;
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} else if((c > 191) && (c < 224)) {
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c2 = utftext.charCodeAt(i+1);
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string += String.fromCharCode(((c & 31) << 6) | (c2 & 63));
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i += 2;
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} else {
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c2 = utftext.charCodeAt(i+1);
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c3 = utftext.charCodeAt(i+2);
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string += String.fromCharCode(((c & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63));
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i += 3;
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}
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}
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return string;
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}
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} |