git.squeep.com Git - squeep-mystery-box/blob - lib/common.js

   1 'use strict';
   2
   3 const path = require('path');
   4 const { randomBytes } = require('crypto');
   5 const { promisify } = require('util');
   6 const randomBytesAsync = promisify(randomBytes);
   7
   8
   9 /**
  10  * Return a function which combines a part of the filename with a scope, for use in logging.
  11  * @param {string} filename
  12  */
  13 const fileScope = (filename) => {
  14   let fScope = path.basename(filename, '.js');
  15   if (fScope === 'index') {
  16     fScope = path.basename(path.dirname(filename));
  17   }
  18   return (scope) => `${fScope}:${scope}`;
  19 }
  20
  21
  22 /**
  23  * Convert Base64 to Base64URL.
  24  * @param {String} input
  25  * @returns {String}
  26  */
  27 const base64ToBase64URL = (input) => {
  28   return input
  29     .replace(/=/g, '')
  30     .replace(/\+/g, '-')
  31     .replace(/\//g, '_');
  32 };
  33
  34
  35 /**
  36  * Convert Base64URL to normal Base64.
  37  * @param {String} input
  38  * @returns {String}
  39  */
  40 const base64URLToBase64 = (input) => {
  41   return base64RePad(input)
  42     .replace(/-/g, '+')
  43     .replace(/_/, '/');
  44 };
  45
  46
  47 /**
  48  * Add any missing trailing padding which may have been removed from Base64URL encoding.
  49  * @param {String} input
  50  */
  51 const base64RePad = (input) => {
  52   const blockSize = 4;
  53   const lastBlockSize = input.length % blockSize;
  54   if (lastBlockSize) {
  55     const missing = blockSize - lastBlockSize;
  56     return input + '='.repeat(missing);
  57   }
  58   return input;
  59 };
  60
  61
  62 module.exports = {
  63   base64ToBase64URL,
  64   base64URLToBase64,
  65   base64RePad,
  66   fileScope,
  67   randomBytesAsync,
  68 };