base64.js
3.46 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
/*
* $Id: base64.js,v 1.2 2011/12/27 14:34:49 dankogai Exp dankogai $
*
* Licensed under the MIT license.
* http://www.opensource.org/licenses/mit-license.php
*
*/
(function(global){
if (global.Base64) return;
var b64chars
= 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';
var b64tab = function(bin){
var t = {};
for (var i = 0, l = bin.length; i < l; i++) t[bin.charAt(i)] = i;
return t;
}(b64chars);
var sub_toBase64 = function(m){
var n = (m.charCodeAt(0) << 16)
| (m.charCodeAt(1) << 8)
| (m.charCodeAt(2) );
return b64chars.charAt( n >>> 18)
+ b64chars.charAt((n >>> 12) & 63)
+ b64chars.charAt((n >>> 6) & 63)
+ b64chars.charAt( n & 63);
};
var toBase64 = function(bin){
if (bin.match(/[^\x00-\xFF]/)) throw 'unsupported character found' ;
var padlen = 0;
while(bin.length % 3) {
bin += '\0';
padlen++;
};
var b64 = bin.replace(/[\x00-\xFF]{3}/g, sub_toBase64);
if (!padlen) return b64;
b64 = b64.substr(0, b64.length - padlen);
while(padlen--) b64 += '=';
return b64;
};
var btoa = global.btoa || toBase64;
var sub_fromBase64 = function(m){
var n = (b64tab[ m.charAt(0) ] << 18)
| (b64tab[ m.charAt(1) ] << 12)
| (b64tab[ m.charAt(2) ] << 6)
| (b64tab[ m.charAt(3) ]);
return String.fromCharCode( n >> 16 )
+ String.fromCharCode( (n >> 8) & 0xff )
+ String.fromCharCode( n & 0xff );
};
var fromBase64 = function(b64){
b64 = b64.replace(/[^A-Za-z0-9\+\/]/g, '');
var padlen = 0;
while(b64.length % 4){
b64 += 'A';
padlen++;
}
var bin = b64.replace(/[A-Za-z0-9\+\/]{4}/g, sub_fromBase64);
if (padlen >= 2)
bin = bin.substring(0, bin.length - [0,0,2,1][padlen]);
return bin;
};
var atob = global.atob || fromBase64;
var re_char_nonascii = /[^\x00-\x7F]/g;
var sub_char_nonascii = function(m){
var n = m.charCodeAt(0);
return n < 0x800 ? String.fromCharCode(0xc0 | (n >>> 6))
+ String.fromCharCode(0x80 | (n & 0x3f))
: String.fromCharCode(0xe0 | ((n >>> 12) & 0x0f))
+ String.fromCharCode(0x80 | ((n >>> 6) & 0x3f))
+ String.fromCharCode(0x80 | (n & 0x3f))
;
};
var utob = function(uni){
return uni.replace(re_char_nonascii, sub_char_nonascii);
};
var re_bytes_nonascii
= /[\xC0-\xDF][\x80-\xBF]|[\xE0-\xEF][\x80-\xBF]{2}|[\xF0-\xF7][\x80-\xBF]{3}/g;
var sub_bytes_nonascii = function(m){
var c0 = m.charCodeAt(0);
var c1 = m.charCodeAt(1);
if(c0 < 0xe0){
return String.fromCharCode(((c0 & 0x1f) << 6) | (c1 & 0x3f));
}else{
var c2 = m.charCodeAt(2);
return String.fromCharCode(
((c0 & 0x0f) << 12) | ((c1 & 0x3f) << 6) | (c2 & 0x3f)
);
}
};
var btou = function(bin){
return bin.replace(re_bytes_nonascii, sub_bytes_nonascii);
};
global.exports = {
fromBase64:fromBase64,
toBase64:toBase64,
atob:atob,
btoa:btoa,
utob:utob,
btou:btou,
encode:function(u){ return btoa(utob(u)) },
encodeURI:function(u){
return btoa(utob(u)).replace(/[+\/]/g, function(m0){
return m0 == '+' ? '-' : '_';
}).replace(/=+$/, '');
},
decode:function(a){
return btou(atob(a.replace(/[-_]/g, function(m0){
return m0 == '-' ? '+' : '/';
})));
}
};
})(module);