Mercurial > eldonilo > lightstring
diff base64.js @ 0:96898e3812a5
initial push
author | Sonny Piers <sonny.piers@gmail.com> |
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date | Sun, 18 Dec 2011 19:03:28 +0100 |
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new file mode 100644 --- /dev/null +++ b/base64.js @@ -0,0 +1,80 @@ +// This code was written by Tyler Akins and has been placed in the +// public domain. It would be nice if you left this header intact. +// Base64 code from Tyler Akins -- http://rumkin.com + +var Base64 = (function () { + var keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/="; + + var obj = { + /** + * Encodes a string in base64 + * @param {String} input The string to encode in base64. + */ + encode: function (input) { + var output = ""; + var chr1, chr2, chr3; + var enc1, enc2, enc3, enc4; + var i = 0; + + do { + chr1 = input.charCodeAt(i++); + chr2 = input.charCodeAt(i++); + chr3 = input.charCodeAt(i++); + + enc1 = chr1 >> 2; + enc2 = ((chr1 & 3) << 4) | (chr2 >> 4); + enc3 = ((chr2 & 15) << 2) | (chr3 >> 6); + enc4 = chr3 & 63; + + if (isNaN(chr2)) { + enc3 = enc4 = 64; + } else if (isNaN(chr3)) { + enc4 = 64; + } + + output = output + keyStr.charAt(enc1) + keyStr.charAt(enc2) + + keyStr.charAt(enc3) + keyStr.charAt(enc4); + } while (i < input.length); + + return output; + }, + + /** + * Decodes a base64 string. + * @param {String} input The string to decode. + */ + decode: function (input) { + var output = ""; + var chr1, chr2, chr3; + var enc1, enc2, enc3, enc4; + var i = 0; + + // remove all characters that are not A-Z, a-z, 0-9, +, /, or = + input = input.replace(/[^A-Za-z0-9\+\/\=]/g, ""); + + do { + enc1 = keyStr.indexOf(input.charAt(i++)); + enc2 = keyStr.indexOf(input.charAt(i++)); + enc3 = keyStr.indexOf(input.charAt(i++)); + enc4 = keyStr.indexOf(input.charAt(i++)); + + chr1 = (enc1 << 2) | (enc2 >> 4); + chr2 = ((enc2 & 15) << 4) | (enc3 >> 2); + chr3 = ((enc3 & 3) << 6) | enc4; + + output = output + String.fromCharCode(chr1); + + if (enc3 != 64) { + output = output + String.fromCharCode(chr2); + } + if (enc4 != 64) { + output = output + String.fromCharCode(chr3); + } + } while (i < input.length); + + return output; + } + }; + + return obj; +})();