0.8.0 • Public • Published


Wrapper around node fs module that encrypts the files on the fly

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npm install crypto-fs --save


Node.js 4+


var fs = require('crypto-fs');
  baseFs: require('fs'),
  algorithm: 'aes-256-ctr',
  prefix: '',
  password: '1234',
  root: './test/dest',
  iv: null,
  realSize: false,
  dontEncPath : false


  • baseFs (default: require("fs"))
    • What fs module should be used
  • algorithm (default: "aes-256-ctr")
    • Any algorithm supported by node.js crypto module.
  • prefix (default: "")
    • Encrypted filename prefix.
  • password (no default)
    • Please don't use 1234 as your password :)
  • root (no default)
    • Root directory of the encrypted files.
  • iv (default: null)
    • If initialization vector is given, Cipheriv will be used.
  • realSize (default: false)
    • Encrypted files have marginaly bigger file size than the normal sizes. To get the real file size, the file needs to be decrypted, so set this to true only if you need to.
  • dontEncPath (default: false)
    • If true, the filename will not be encrypted. Might solve issues of path in Windows.

Base FS

By default, this module relies on the native fs module, but this can be changed. If you have a different module that exposes the same methods (e.g. ftp-fs, s3-fs), you can set it as the base fs. For every exposed method, it will be documented which methods does it require from the base fs (except for the same method, readlink/readlinkSync and lstat/lstatSync). readlink/readlinkSync and lstat/lstatSync are used to determine if the given path is a symlink, and in this case follow the symlink.

If you're using the default fs module, you can ignore this info.

Implemented methods

  • init (non-standard)

    • used to initialize the module (documented above)
    • required baseFs methods: existsSync
  • readFile, readFileSync

  • writeFile, writeFileSync

  • exists, existsSync

  • access, accessSync

  • mkdir, mkdirSync

  • rmdir, rmdirSync

  • unlink, unlinkSync

  • stat, statSync

  • readdir ,readdirSync

  • readlink, readlinkSync

  • symlink, symlinkSync

  • lstat, lstatSync

  • rename

    • required: fs.readFile, fs.writeFile, fs.unlink
  • renameSync

    • required: fs.readFileSync, fs.writeFileSync, fs.unlinkSync
  • appendFile

    • required: access (or exists), readFile, writeFile
  • appendFileSync

    • required: accessSync (or existsSync), readFileSync, writeFileSync
  • createReadStream

  • createWriteStream

  • watchFile

  • unwatchFile

  • watch

Not tested

  • close, closeSync
  • fstat, fstatSync
  • futimes, futimesSync
  • fchown, fchownSync
  • fchmod, fchmodSync
  • utimes, utimesSync
  • chown, chownSync
  • chmod, chmodSync
  • lchown, lchownSync
  • lchmod, lchmodSync

Limitations / known issues

  • all paths should be relative to the root folder and they should be inside of the root folder
  • watch filename will be incorect if it's not in the root folder - should be possible to fix
  • rename and renameSync create a new file and remove the old so the watch might not behave as expected (would it be better to actually rename the file and write the new content?)
  • Renaming of folders isn't currently supported. You should create a new folder and move all the files in it.
  • symlinks only work if both the file and symlink are inside of the root folder
  • folder or symlink rename will probably corrupt the file - don't use it yet


  • link and linkSync can't work because the filename would be wrong and therefore the file content couldn't be decrypted. Not yet sure if it's possible to solve this.


  • Add more tests based on (fs & crypto)
  • More efficient appendFile
  • Support for relative & absolute paths
    • Use the base fs if outside of the root path
  • skip symlink check if baseFs doesn't suport either lstat or readlink
  • do normal rename if the file is a symlink
  • rename all files inside of a folder on folder rename
  • remove ./ from the file paths

Methods (Sync and async)

  • ftruncate

  • truncate

  • realpath

  • fsync

  • link

  • open

  • write

  • read


  • Stream functionality based on node-efs
  • Internal "deep" readlink based on readlink



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  • darkokukovec