mirror of
https://github.com/github/codeql-action.git
synced 2025-12-28 02:00:12 +08:00
a196a714b8
Co-authored-by: Andrew Eisenberg <aeisenberg@github.com> Co-authored-by: Henry Mercer <henrymercer@github.com>
119 lines
3.8 KiB
JavaScript
119 lines
3.8 KiB
JavaScript
"use strict";
|
|
Object.defineProperty(exports, "__esModule", { value: true });
|
|
exports.base64encode = exports.base64decode = void 0;
|
|
// lookup table from base64 character to byte
|
|
let encTable = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'.split('');
|
|
// lookup table from base64 character *code* to byte because lookup by number is fast
|
|
let decTable = [];
|
|
for (let i = 0; i < encTable.length; i++)
|
|
decTable[encTable[i].charCodeAt(0)] = i;
|
|
// support base64url variants
|
|
decTable["-".charCodeAt(0)] = encTable.indexOf("+");
|
|
decTable["_".charCodeAt(0)] = encTable.indexOf("/");
|
|
/**
|
|
* Decodes a base64 string to a byte array.
|
|
*
|
|
* - ignores white-space, including line breaks and tabs
|
|
* - allows inner padding (can decode concatenated base64 strings)
|
|
* - does not require padding
|
|
* - understands base64url encoding:
|
|
* "-" instead of "+",
|
|
* "_" instead of "/",
|
|
* no padding
|
|
*/
|
|
function base64decode(base64Str) {
|
|
// estimate byte size, not accounting for inner padding and whitespace
|
|
let es = base64Str.length * 3 / 4;
|
|
// if (es % 3 !== 0)
|
|
// throw new Error('invalid base64 string');
|
|
if (base64Str[base64Str.length - 2] == '=')
|
|
es -= 2;
|
|
else if (base64Str[base64Str.length - 1] == '=')
|
|
es -= 1;
|
|
let bytes = new Uint8Array(es), bytePos = 0, // position in byte array
|
|
groupPos = 0, // position in base64 group
|
|
b, // current byte
|
|
p = 0 // previous byte
|
|
;
|
|
for (let i = 0; i < base64Str.length; i++) {
|
|
b = decTable[base64Str.charCodeAt(i)];
|
|
if (b === undefined) {
|
|
// noinspection FallThroughInSwitchStatementJS
|
|
switch (base64Str[i]) {
|
|
case '=':
|
|
groupPos = 0; // reset state when padding found
|
|
case '\n':
|
|
case '\r':
|
|
case '\t':
|
|
case ' ':
|
|
continue; // skip white-space, and padding
|
|
default:
|
|
throw Error(`invalid base64 string.`);
|
|
}
|
|
}
|
|
switch (groupPos) {
|
|
case 0:
|
|
p = b;
|
|
groupPos = 1;
|
|
break;
|
|
case 1:
|
|
bytes[bytePos++] = p << 2 | (b & 48) >> 4;
|
|
p = b;
|
|
groupPos = 2;
|
|
break;
|
|
case 2:
|
|
bytes[bytePos++] = (p & 15) << 4 | (b & 60) >> 2;
|
|
p = b;
|
|
groupPos = 3;
|
|
break;
|
|
case 3:
|
|
bytes[bytePos++] = (p & 3) << 6 | b;
|
|
groupPos = 0;
|
|
break;
|
|
}
|
|
}
|
|
if (groupPos == 1)
|
|
throw Error(`invalid base64 string.`);
|
|
return bytes.subarray(0, bytePos);
|
|
}
|
|
exports.base64decode = base64decode;
|
|
/**
|
|
* Encodes a byte array to a base64 string.
|
|
* Adds padding at the end.
|
|
* Does not insert newlines.
|
|
*/
|
|
function base64encode(bytes) {
|
|
let base64 = '', groupPos = 0, // position in base64 group
|
|
b, // current byte
|
|
p = 0; // carry over from previous byte
|
|
for (let i = 0; i < bytes.length; i++) {
|
|
b = bytes[i];
|
|
switch (groupPos) {
|
|
case 0:
|
|
base64 += encTable[b >> 2];
|
|
p = (b & 3) << 4;
|
|
groupPos = 1;
|
|
break;
|
|
case 1:
|
|
base64 += encTable[p | b >> 4];
|
|
p = (b & 15) << 2;
|
|
groupPos = 2;
|
|
break;
|
|
case 2:
|
|
base64 += encTable[p | b >> 6];
|
|
base64 += encTable[b & 63];
|
|
groupPos = 0;
|
|
break;
|
|
}
|
|
}
|
|
// padding required?
|
|
if (groupPos) {
|
|
base64 += encTable[p];
|
|
base64 += '=';
|
|
if (groupPos == 1)
|
|
base64 += '=';
|
|
}
|
|
return base64;
|
|
}
|
|
exports.base64encode = base64encode;
|