snowplow-javascript-tracker/src/js/lib/base64.js at master · pkallos/snowplow-javascript-tracker · GitHub

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
/*
 * base64.js
 *
 * @description Base64 encoding function for JavaScript
 * @version     N/A
 * @author      Various (see below)
 * @license     MIT / GPL v2
 * @link        http://phpjs.org/functions/base64_encode
 *
 * Modifications:
 * - Various (see below)
 *
 * Authors & Modifications:
 * http://kevin.vanzonneveld.net
 *   original by: Tyler Akins (http://rumkin.com)
 *   improved by: Bayron Guevara
 *   improved by: Thunder.m
 *   improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
 *   bugfixed by: Pellentesque Malesuada
 *   improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
 *   improved by: Rafał Kukawski (http://kukawski.pl)
 */

SnowPlow.base64encode = function(data) {
  if (!data) return data;
  if (typeof window['btoa'] == 'function') return btoa(data);

  var b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
  var o1, o2, o3, h1, h2, h3, h4, bits,
      i = 0,
      ac = 0,
      enc = "",
      tmp_arr = [];

  do {
    o1 = data.charCodeAt(i++);
    o2 = data.charCodeAt(i++);
    o3 = data.charCodeAt(i++);

    bits = o1 << 16 | o2 << 8 | o3;

    h1 = bits >> 18 & 0x3f;
    h2 = bits >> 12 & 0x3f;
    h3 = bits >> 6 & 0x3f;
    h4 = bits & 0x3f;

    tmp_arr[ac++] = b64.charAt(h1) + b64.charAt(h2) + b64.charAt(h3) + b64.charAt(h4);
  } while (i < data.length);

  enc = tmp_arr.join('');
  var r = data.length % 3;
  return (r ? enc.slice(0, r - 3) : enc) + '==='.slice(r || 3);
};

/*
 * Bas64 encode data with URL and Filename Safe Alphabet (base64url)
 *
 * See: http://tools.ietf.org/html/rfc4648#page-7
 */
SnowPlow.base64urlencode = function(data) {
  if (!data) return data;

  var enc = SnowPlow.base64encode(data);
  return enc.replace(/=/g, '')
            .replace(/\+/g, '-')
            .replace(/\//g, '_');
};

/*
 * Base64 decode data
 */
SnowPlow.base64decode = function(data) {
  var keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
  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 =
  var base64test = /[^A-Za-z0-9\+\/\=]/g;

  data = data.replace(/[^A-Za-z0-9\+\/\=]/g, "");

  do {
    enc1 = keyStr.indexOf(data.charAt(i++));
    enc2 = keyStr.indexOf(data.charAt(i++));
    enc3 = keyStr.indexOf(data.charAt(i++));
    enc4 = keyStr.indexOf(data.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);
    }

    chr1 = chr2 = chr3 = "";
    enc1 = enc2 = enc3 = enc4 = "";
  } while (i < data.length);

  return unescape(output);
};