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67 lines
2.0 KiB
67 lines
2.0 KiB
// http://ntt.cc/2008/01/19/base64-encoder-decoder-with-javascript.html |
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// window.atob and window.btoa |
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(function (window) { |
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var keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/="; |
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window.btoa || (window.btoa = function encode64(input) { |
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input = escape(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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do { |
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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 + keyStr.charAt(enc1) + keyStr.charAt(enc2) + keyStr.charAt(enc3) + keyStr.charAt(enc4); |
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chr1 = chr2 = chr3 = ""; |
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enc1 = enc2 = enc3 = enc4 = ""; |
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} while (i < input.length); |
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return output; |
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}); |
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window.atob || (window.atob = 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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// remove all characters that are not A-Z, a-z, 0-9, +, /, or = |
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var base64test = /[^A-Za-z0-9\+\/\=]/g; |
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if (base64test.exec(input)) { |
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alert("There were invalid base64 characters in the input text.\n" + "Valid base64 characters are A-Z, a-z, 0-9, '+', '/',and '='\n" + "Expect errors in decoding."); |
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} |
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input = input.replace(/[^A-Za-z0-9\+\/\=]/g, ""); |
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do { |
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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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chr1 = chr2 = chr3 = ""; |
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enc1 = enc2 = enc3 = enc4 = ""; |
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} while (i < input.length); |
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return unescape(output); |
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}); |
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}(this)); |