1function base64Encode(baseSting) {
2 var base64Chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
3 var length = baseSting.length;
4 var chara1, chara2, chara3;
5 var out = "",
6 i = 0;
7 while (i < length) {
8 chara1 = baseSting.charCodeAt(i++) & 0xff;
9 out += base64Chars.charAt(chara1 >> 2);
10 if (i == length) {
11 out += base64Chars.charAt((chara1 & 0x3) << 4);
12 out += "==";
13 break;
14 }
15 chara2 = baseSting.charCodeAt(i++);
16 if (i == length) {
17 out += base64Chars.charAt(((chara1 & 0x3) << 4) | ((chara2 & 0xF0) >> 4));
18 out += base64Chars.charAt((chara2 & 0xF) << 2);
19 out += "=";
20 break;
21 }
22 chara3 = baseSting.charCodeAt(i++);
23 out += base64Chars.charAt(((chara1 & 0x3) << 4) | ((chara2 & 0xF0) >> 4));
24 out += base64Chars.charAt(((chara2 & 0xF) << 2) | ((chara3 & 0xC0) >> 6));
25 out += base64Chars.charAt(chara3 & 0x3F);
26 }
27 return out;
28}
