main
1/* This Source Code Form is subject to the terms of the Mozilla Public
2 * License, v. 2.0. If a copy of the MPL was not distributed with this
3 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
4
5// From: http://hg.mozilla.org/mozilla-central/raw-file/ec10630b1a54/js/src/devtools/jint/sunspider/string-base64.js
6
7import * as Log from './util/logging.js';
8
9export default {
10 /* Convert data (an array of integers) to a Base64 string. */
11 toBase64Table: 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/='.split(''),
12 base64Pad: '=',
13
14 encode(data) {
15 "use strict";
16 let result = '';
17 const length = data.length;
18 const lengthpad = (length % 3);
19 // Convert every three bytes to 4 ascii characters.
20
21 for (let i = 0; i < (length - 2); i += 3) {
22 result += this.toBase64Table[data[i] >> 2];
23 result += this.toBase64Table[((data[i] & 0x03) << 4) + (data[i + 1] >> 4)];
24 result += this.toBase64Table[((data[i + 1] & 0x0f) << 2) + (data[i + 2] >> 6)];
25 result += this.toBase64Table[data[i + 2] & 0x3f];
26 }
27
28 // Convert the remaining 1 or 2 bytes, pad out to 4 characters.
29 const j = length - lengthpad;
30 if (lengthpad === 2) {
31 result += this.toBase64Table[data[j] >> 2];
32 result += this.toBase64Table[((data[j] & 0x03) << 4) + (data[j + 1] >> 4)];
33 result += this.toBase64Table[(data[j + 1] & 0x0f) << 2];
34 result += this.toBase64Table[64];
35 } else if (lengthpad === 1) {
36 result += this.toBase64Table[data[j] >> 2];
37 result += this.toBase64Table[(data[j] & 0x03) << 4];
38 result += this.toBase64Table[64];
39 result += this.toBase64Table[64];
40 }
41
42 return result;
43 },
44
45 /* Convert Base64 data to a string */
46 /* eslint-disable comma-spacing */
47 toBinaryTable: [
48 -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1,
49 -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1,
50 -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,62, -1,-1,-1,63,
51 52,53,54,55, 56,57,58,59, 60,61,-1,-1, -1, 0,-1,-1,
52 -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,10, 11,12,13,14,
53 15,16,17,18, 19,20,21,22, 23,24,25,-1, -1,-1,-1,-1,
54 -1,26,27,28, 29,30,31,32, 33,34,35,36, 37,38,39,40,
55 41,42,43,44, 45,46,47,48, 49,50,51,-1, -1,-1,-1,-1
56 ],
57 /* eslint-enable comma-spacing */
58
59 decode(data, offset = 0) {
60 let dataLength = data.indexOf('=') - offset;
61 if (dataLength < 0) { dataLength = data.length - offset; }
62
63 /* Every four characters is 3 resulting numbers */
64 const resultLength = (dataLength >> 2) * 3 + Math.floor((dataLength % 4) / 1.5);
65 const result = new Array(resultLength);
66
67 // Convert one by one.
68
69 let leftbits = 0; // number of bits decoded, but yet to be appended
70 let leftdata = 0; // bits decoded, but yet to be appended
71 for (let idx = 0, i = offset; i < data.length; i++) {
72 const c = this.toBinaryTable[data.charCodeAt(i) & 0x7f];
73 const padding = (data.charAt(i) === this.base64Pad);
74 // Skip illegal characters and whitespace
75 if (c === -1) {
76 Log.Error("Illegal character code " + data.charCodeAt(i) + " at position " + i);
77 continue;
78 }
79
80 // Collect data into leftdata, update bitcount
81 leftdata = (leftdata << 6) | c;
82 leftbits += 6;
83
84 // If we have 8 or more bits, append 8 bits to the result
85 if (leftbits >= 8) {
86 leftbits -= 8;
87 // Append if not padding.
88 if (!padding) {
89 result[idx++] = (leftdata >> leftbits) & 0xff;
90 }
91 leftdata &= (1 << leftbits) - 1;
92 }
93 }
94
95 // If there are any bits left, the base64 string was corrupted
96 if (leftbits) {
97 const err = new Error('Corrupted base64 string');
98 err.name = 'Base64-Error';
99 throw err;
100 }
101
102 return result;
103 }
104}; /* End of Base64 namespace */