js/base64_decode.js
function base64_decode(data) {
// discuss at: http://phpjs.org/functions/base64_decode/
// original by: Tyler Akins (http://rumkin.com)
// improved by: Thunder.m
// improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
// improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
// input by: Aman Gupta
// input by: Brett Zamir (http://brett-zamir.me)
// bugfixed by: Onno Marsman
// bugfixed by: Pellentesque Malesuada
// bugfixed by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
// example 1: base64_decode('S2V2aW4gdmFuIFpvbm5ldmVsZA==');
// returns 1: 'Kevin van Zonneveld'
// example 2: base64_decode('YQ===');
// returns 2: 'a'
// example 3: base64_decode('4pyTIMOgIGxhIG1vZGU=');
// returns 3: '✓ à la mode'
var b64 = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=';
var o1, o2, o3, h1, h2, h3, h4, bits, i = 0,
ac = 0,
dec = '',
tmp_arr = [];
if (!data) {
return data;
}
data += '';
do { // unpack four hexets into three octets using index points in b64
h1 = b64.indexOf(data.charAt(i++));
h2 = b64.indexOf(data.charAt(i++));
h3 = b64.indexOf(data.charAt(i++));
h4 = b64.indexOf(data.charAt(i++));
bits = h1 << 18 | h2 << 12 | h3 << 6 | h4;
o1 = bits >> 16 & 0xff;
o2 = bits >> 8 & 0xff;
o3 = bits & 0xff;
if (h3 == 64) {
tmp_arr[ac++] = String.fromCharCode(o1);
} else if (h4 == 64) {
tmp_arr[ac++] = String.fromCharCode(o1, o2);
} else {
tmp_arr[ac++] = String.fromCharCode(o1, o2, o3);
}
} while (i < data.length);
dec = tmp_arr.join('');
return decodeURIComponent(escape(dec.replace(/\0+$/, '')));
}