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   if (!input) {
  29     return input;
  30   }
  31   return input
  32     .replace(/=/g, '')
  33     .replace(/\+/g, '-')
  34     .replace(/\//g, '_');
  35 };
  36
  37
  38 /**
  39  * Convert Base64URL to normal Base64.
  40  * @param {String} input
  41  * @returns {String}
  42  */
  43 const base64URLToBase64 = (input) => {
  44   if (!input) {
  45     return input;
  46   }
  47   return base64RePad(input)
  48     .replace(/-/g, '+')
  49     .replace(/_/, '/');
  50 };
  51
  52
  53 /**
  54  * Add any missing trailing padding which may have been removed from Base64URL encoding.
  55  * @param {String} input
  56  */
  57 const base64RePad = (input) => {
  58   const blockSize = 4;
  59   const lastBlockSize = input.length % blockSize;
  60   if (lastBlockSize) {
  61     const missing = blockSize - lastBlockSize;
  62     return input + '='.repeat(missing);
  63   }
  64   return input;
  65 };
  66
  67
  68 module.exports = {
  69   base64ToBase64URL,
  70   base64URLToBase64,
  71   base64RePad,
  72   fileScope,
  73   randomBytesAsync,
  74 };