forked from dankogai/js-base64
-
Notifications
You must be signed in to change notification settings - Fork 0
/
base64.js
189 lines (187 loc) · 6.43 KB
/
base64.js
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
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
/*
* $Id: base64.js,v 2.15 2014/04/05 12:58:57 dankogai Exp dankogai $
*
* Licensed under the MIT license.
* http://opensource.org/licenses/mit-license
*
* References:
* http://en.wikipedia.org/wiki/Base64
*/
(function(global) {
'use strict';
// existing version for noConflict()
var _Base64 = global.Base64;
var version = "2.1.5";
// if node.js, we use Buffer
var buffer;
if (typeof module !== 'undefined' && module.exports) {
buffer = require('buffer').Buffer;
}
// constants
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 fromCharCode = String.fromCharCode;
// encoder stuff
var cb_utob = function(c) {
if (c.length < 2) {
var cc = c.charCodeAt(0);
return cc < 0x80 ? c
: cc < 0x800 ? (fromCharCode(0xc0 | (cc >>> 6))
+ fromCharCode(0x80 | (cc & 0x3f)))
: (fromCharCode(0xe0 | ((cc >>> 12) & 0x0f))
+ fromCharCode(0x80 | ((cc >>> 6) & 0x3f))
+ fromCharCode(0x80 | ( cc & 0x3f)));
} else {
var cc = 0x10000
+ (c.charCodeAt(0) - 0xD800) * 0x400
+ (c.charCodeAt(1) - 0xDC00);
return (fromCharCode(0xf0 | ((cc >>> 18) & 0x07))
+ fromCharCode(0x80 | ((cc >>> 12) & 0x3f))
+ fromCharCode(0x80 | ((cc >>> 6) & 0x3f))
+ fromCharCode(0x80 | ( cc & 0x3f)));
}
};
var re_utob = /[\uD800-\uDBFF][\uDC00-\uDFFFF]|[^\x00-\x7F]/g;
var utob = function(u) {
return u.replace(re_utob, cb_utob);
};
var cb_encode = function(ccc) {
var padlen = [0, 2, 1][ccc.length % 3],
ord = ccc.charCodeAt(0) << 16
| ((ccc.length > 1 ? ccc.charCodeAt(1) : 0) << 8)
| ((ccc.length > 2 ? ccc.charCodeAt(2) : 0)),
chars = [
b64chars.charAt( ord >>> 18),
b64chars.charAt((ord >>> 12) & 63),
padlen >= 2 ? '=' : b64chars.charAt((ord >>> 6) & 63),
padlen >= 1 ? '=' : b64chars.charAt(ord & 63)
];
return chars.join('');
};
var btoa = global.btoa ? function(b) {
return global.btoa(b);
} : function(b) {
return b.replace(/[\s\S]{1,3}/g, cb_encode);
};
var _encode = buffer
? function (u) { return (new buffer(u)).toString('base64') }
: function (u) { return btoa(utob(u)) }
;
var encode = function(u, urisafe) {
return !urisafe
? _encode(u)
: _encode(u).replace(/[+\/]/g, function(m0) {
return m0 == '+' ? '-' : '_';
}).replace(/=/g, '');
};
var encodeURI = function(u) { return encode(u, true) };
// decoder stuff
var re_btou = new RegExp([
'[\xC0-\xDF][\x80-\xBF]',
'[\xE0-\xEF][\x80-\xBF]{2}',
'[\xF0-\xF7][\x80-\xBF]{3}'
].join('|'), 'g');
var cb_btou = function(cccc) {
switch(cccc.length) {
case 4:
var cp = ((0x07 & cccc.charCodeAt(0)) << 18)
| ((0x3f & cccc.charCodeAt(1)) << 12)
| ((0x3f & cccc.charCodeAt(2)) << 6)
| (0x3f & cccc.charCodeAt(3)),
offset = cp - 0x10000;
return (fromCharCode((offset >>> 10) + 0xD800)
+ fromCharCode((offset & 0x3FF) + 0xDC00));
case 3:
return fromCharCode(
((0x0f & cccc.charCodeAt(0)) << 12)
| ((0x3f & cccc.charCodeAt(1)) << 6)
| (0x3f & cccc.charCodeAt(2))
);
default:
return fromCharCode(
((0x1f & cccc.charCodeAt(0)) << 6)
| (0x3f & cccc.charCodeAt(1))
);
}
};
var btou = function(b) {
return b.replace(re_btou, cb_btou);
};
var cb_decode = function(cccc) {
var len = cccc.length,
padlen = len % 4,
n = (len > 0 ? b64tab[cccc.charAt(0)] << 18 : 0)
| (len > 1 ? b64tab[cccc.charAt(1)] << 12 : 0)
| (len > 2 ? b64tab[cccc.charAt(2)] << 6 : 0)
| (len > 3 ? b64tab[cccc.charAt(3)] : 0),
chars = [
fromCharCode( n >>> 16),
fromCharCode((n >>> 8) & 0xff),
fromCharCode( n & 0xff)
];
chars.length -= [0, 0, 2, 1][padlen];
return chars.join('');
};
var atob = global.atob ? function(a) {
return global.atob(a);
} : function(a){
return a.replace(/[\s\S]{1,4}/g, cb_decode);
};
var _decode = buffer
? function(a) { return (new buffer(a, 'base64')).toString() }
: function(a) { return btou(atob(a)) };
var decode = function(a){
return _decode(
a.replace(/[-_]/g, function(m0) { return m0 == '-' ? '+' : '/' })
.replace(/[^A-Za-z0-9\+\/]/g, '')
);
};
var noConflict = function() {
var Base64 = global.Base64;
global.Base64 = _Base64;
return Base64;
};
// export Base64
global.Base64 = {
VERSION: version,
atob: atob,
btoa: btoa,
fromBase64: decode,
toBase64: encode,
utob: utob,
encode: encode,
encodeURI: encodeURI,
btou: btou,
decode: decode,
noConflict: noConflict
};
// if ES5 is available, make Base64.extendString() available
if (typeof Object.defineProperty === 'function') {
var noEnum = function(v){
return {value:v,enumerable:false,writable:true,configurable:true};
};
global.Base64.extendString = function () {
Object.defineProperty(
String.prototype, 'fromBase64', noEnum(function () {
return decode(this)
}));
Object.defineProperty(
String.prototype, 'toBase64', noEnum(function (urisafe) {
return encode(this, urisafe)
}));
Object.defineProperty(
String.prototype, 'toBase64URI', noEnum(function () {
return encode(this, true)
}));
};
}
// that's it!
})(this);
if (this['Meteor']) {
Base64 = global.Base64; // for normal export in Meteor.js
}