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ab7674ff JM |
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 | |
b5537b60 | 6 | |
a0035359 | 7 | import * as Log from './util/logging.js'; |
d595e656 | 8 | |
6d6f0db0 | 9 | export default { |
f8e9b9f1 | 10 | /* Convert data (an array of integers) to a Base64 string. */ |
942a3127 PO |
11 | toBase64Table: 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/='.split(''), |
12 | base64Pad: '=', | |
f8e9b9f1 | 13 | |
0e4808bf | 14 | encode(data) { |
f8e9b9f1 | 15 | "use strict"; |
2b5f94fa JD |
16 | let result = ''; |
17 | const length = data.length; | |
18 | const lengthpad = (length % 3); | |
f8e9b9f1 SR |
19 | // Convert every three bytes to 4 ascii characters. |
20 | ||
2b5f94fa JD |
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]; | |
f8e9b9f1 | 26 | } |
b5537b60 | 27 | |
f8e9b9f1 | 28 | // Convert the remaining 1 or 2 bytes, pad out to 4 characters. |
2b5f94fa | 29 | const j = length - lengthpad; |
f8e9b9f1 | 30 | if (lengthpad === 2) { |
2b5f94fa JD |
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]; | |
f8e9b9f1 | 35 | } else if (lengthpad === 1) { |
2b5f94fa JD |
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]; | |
5d8e7ec0 | 40 | } |
b5537b60 | 41 | |
f8e9b9f1 SR |
42 | return result; |
43 | }, | |
44 | ||
45 | /* Convert Base64 data to a string */ | |
6786fd87 | 46 | /* eslint-disable comma-spacing */ |
942a3127 | 47 | toBinaryTable: [ |
f8e9b9f1 SR |
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 | ], | |
6786fd87 | 57 | /* eslint-enable comma-spacing */ |
f8e9b9f1 | 58 | |
9d2c9d1a | 59 | decode(data, offset = 0) { |
2b5f94fa | 60 | let data_length = data.indexOf('=') - offset; |
f8e9b9f1 SR |
61 | if (data_length < 0) { data_length = data.length - offset; } |
62 | ||
63 | /* Every four characters is 3 resulting numbers */ | |
2b5f94fa JD |
64 | const result_length = (data_length >> 2) * 3 + Math.floor((data_length % 4) / 1.5); |
65 | const result = new Array(result_length); | |
f8e9b9f1 SR |
66 | |
67 | // Convert one by one. | |
2b5f94fa JD |
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); | |
f8e9b9f1 SR |
74 | // Skip illegal characters and whitespace |
75 | if (c === -1) { | |
a0035359 | 76 | Log.Error("Illegal character code " + data.charCodeAt(i) + " at position " + i); |
f8e9b9f1 SR |
77 | continue; |
78 | } | |
ae510306 | 79 | |
f8e9b9f1 SR |
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; | |
d595e656 | 92 | } |
cc0410a3 | 93 | } |
b5537b60 | 94 | |
f8e9b9f1 SR |
95 | // If there are any bits left, the base64 string was corrupted |
96 | if (leftbits) { | |
2b5f94fa | 97 | const err = new Error('Corrupted base64 string'); |
f8e9b9f1 SR |
98 | err.name = 'Base64-Error'; |
99 | throw err; | |
100 | } | |
b5537b60 | 101 | |
f8e9b9f1 SR |
102 | return result; |
103 | } | |
b5537b60 | 104 | }; /* End of Base64 namespace */ |