hoodie-plugin-store-crypto

index	API	about cryptography	update	Contributing	Code of Conduct

hoodie-plugin-store-crypto

End-to-end crypto plugin for the Hoodie client store.

This Hoodie plugin adds methods, to add, read, update and delete encrypted documents in your users store, while still being able to add, read, update and delete un-encrypted documents.

It does this by adding an object to your Hoodie-client, with similar methods to the client's store. Those methods encrypt and decrypt objects, while using the corresponding methods from Hoodie to save them.

The PouchDB plugin pouchdb-hoodie-api is also supported!

There is no server side to this plugin!

Everything of a doc will get encrypted. Except for _id, _rev, _deleted, _attachments, _conflicts and the hoodie object! And all keys that start with an underscore (_) will not get encrypted!

Read more in the API Docs.

Example

hoodie.store.add({foo: 'bar'})
  .then(function (obj) { console.log(obj) })

hoodie.cryptoStore.setup('secret')
  .then(async () => {
    await hoodie.cryptoStore.unlock('secret')

    const obj = await hoodie.cryptoStore.add({ foo: 'bar' }) // add the object encrypted
    console.log(obj)                                         // returns it un-encrypted!

    const encrypted = await hoodie.store.find(obj._id) // returns the encrypted version of the object.
    /*
    encrypted = {
      // Added by Hoodie:
      _id: 'e261b431-9f8b-44d8-9835-97be550088d5',
      _rev: '1-b9c5a6b9353e4dfcaf5a9183da02a647',
      hoodie: {
        createdAt: 'An ISO-Date'
      },

      // Encrypted data:
      data: '09ae27028776974ef291030b85',
      nonce: 'f04ad8243a5ab2f59cc4a174',
      tag: '9b01f13a765ed9351d97a11bba48e7b4'
    }
    */
  })

Table of Contents

• Acknowledgments
• Usage
  • Add it to your Hoodie-Client
    • with the Hoodie Plugin API
    • with a Bundler
    • with PouchDB and pouchdb-hoodie-api
  • Get started
    • Sign up / setup / start of using encryption
    • Sign in / unlocking
    • Open a tap/instance of your web-app if they are already signed in
    • changing the password for encryption
    • reset the password
• Contributing
  • Setup for development
  • npm scripts

Acknowledgments

This project heavily uses code and inspiration by @calvinmetcalf's crypto-pouch and Hoodie's hoodie-store-client.

Thank you to those projects and their maintainers.

• To result the same behavior, this plugin uses some adjusted versions of hoodie-store-client tests.
• The Encryption used here is an inspired versions of @calvinmetcalf's crypto-pouch's encryption functions.

Usage

Add it to your Hoodie-Client

There are 3 ways to use this plugin in your app:

• Use it with the Hoodie Plugin API
• Use it with a bundler (Webpack or Browserify)
• Use it with PouchDB and pouchdb-hoodie-api

Usage with the Hoodie Plugin API

This will add the cryptoStore to your /hoodie/client.js if you use the hoodie package.

First, install the plugin as dependency of your Hoodie app:

npm install --save hoodie-plugin-store-crypto

Then add it to the hoodie.plugins array in your app’s package.json file.

{
  "name": "your-hoodie-app",
  ...
  "hoodie": {
    "plugins": [
      "hoodie-plugin-store-crypto"
    ]
  }
}

You can now start your app with npm start. There should now be an cryptoStore property on your client hoodie instance. You can access it with hoodie.cryptoStore.

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Usage with a Bundler

If you are using a client bundler (e.g. Browserify or Webpack), then you can import it manually.

First, install the plugin as dev-dependency of your Hoodie app:

npm install --save-dev hoodie-plugin-store-crypto

Then import it and set it up:

import Hoodie from '@hoodie/client'
import PouchDB from 'pouchdb'
import CryptoStore from 'hoodie-plugin-store-crypto'

const hoodie = new Hoodie({ // create an instance of the hoodie-client
  url: window.location.origin,
  PouchDB: PouchDB
})

// sets up cryptoStore
const cryptoStore = new CryptoStore(hoodie.store, { /* some options */})

cryptoStore.setup('test')
  .then(function () {
    console.log('done')
  })

// lock the cryptoStore on sign out
hoodie.account.on('signout', () => {
  cryptoStore.lock()
})

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Usage with PouchDB and pouchdb-hoodie-api

To use this plugin with PouchDB you must install the plugin pouchdb-hoodie-api.

npm install --save-dev pouchdb-hoodie-api

Setup is like the usage with Bundler, but you must pass the the db.hoodieApi() from pouchdb-hoodie-api. And optionally a remote PouchDB database (or its URL) for checking and fetching the existence of the encryption setup.

import PouchDB from 'pouchdb-browser'
import hoodieApiPlugin from 'pouchdb-hoodie-api'
import CryptoStore from 'hoodie-plugin-store-crypto'

PouchDB.plugin(hoodieApiPlugin)

const db = new PouchDB('local_db')
const remoteDb = new PouchDB('https://example.com/my_db', {
  auth: {
    username: 'user',
    password: 'geheim'
  }
})

// sets up cryptoStore
const cryptoStore = new CryptoStore(db.hoodieApi(), {
  remote: remoteDb
})

cryptoStore.setup('test')
  .then(() => {
    console.log('done')
  })

To use it in combination with PouchDB's APIs like db.query() and db.find() use cryptoStore.encrypt(jsonValue, aad) and cryptoStore.decrypt(encrypted, aad):

async function encryptedQuery (db, cryptoStore, viewName, options) {
  const result = await db.query(viewName, {
    ...options,
    include_docs: true
  })
  const decrypt = result.rows.map(row => {
    // hoodie-plugin-store-crypto uses the documents _id as an encryption-check (AAD).
    // Which makes it required for decryption!
    return cryptoStore.decrypt(row.doc, row.id)
  })
  return Promise.all(decrypt)
}

Fields required for a view/search must get stored un-encrypted to be usable for PouchDB. Tip: use random UUIDs (v4) for a key, and encrypt the human-readable version.

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Get started

To use the cryptoStore you need to set a password for encryption. This can be your users password to your app, a second password, or a derived password.

There are 5 use-cases you must put in place:

• Sign up / setup / start of using encryption
• Sign in / unlocking
• Open a tap/instance of your web-app if they are already signed in
• changing the password for encryption
• reset the password

Setup

The first use of the cryptoStore. Setup can get done in your sign up function, but also if you newly added this plugin.

Use cryptoStore.setup(password, [salt]) to set the encryption password. cryptoStore.setup(password, [salt]) will not unlock your cryptoStore instance (like hoodie.account.signUp)!

A salt is a second part of a password. cryptoStore.setup(password, [salt]) will save the generated salt in hoodiePluginCryptoStore/salt, and use it. More about what the salt is.

Example:

async function signUp (username, password, cryptoPassword) {
  const accountProperties = await hoodie.account.signUp({
    username: username,
    password: password
  })

  const resetKeys = await hoodie.cryptoStore.setup(cryptoPassword)

  displayResetKeys(resetKeys)

  return signIn(username, password, cryptoPassword) // Call your signIn function
}

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Sign in

Every time your user signs in you also need to unlock the cryptoStore.

Use cryptoStore.unlock(password) for unlocking.

unlock will try to pull hoodiePluginCryptoStore/salt from the server. To have the latest version of it.

Example:

async function signIn (username, password, cryptoPassword) {
  const accountProperties = await hoodie.account.signIn({
    username: username,
    password: password
  })

  await hoodie.cryptoStore.unlock(cryptoPassword)

  // now do what you do after sign in.
}

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Sign out

If you use hoodie's plugin system, then cryptoStore will automatically listen to account.on('signout') events. And locks itself if it emits an event. You don't need to add any setup for it.

Use-cases for the cryptoStore.lock() method are:

• a lock after a timeout functionality
• lock the store in a save way when closing an tab.
• lock on sign out, if you didn't use hoodie's plugin system.

window.addEventListener('beforeunload', function (event) {
  // do your cleanup
  // lock the cryptoStore in an cryptographic saver way.
  // It overwrites the key data 10 times.
  hoodie.cryptoStore.lock()
})

// or on sign out
hoodie.account.on('signout', () => {
  cryptoStore.lock()
})

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Open your app while signed in

This plugin doesn't save your users password! That results in you having to unlock the cryptoStore on every instance/tap of your web-app!

Example:

async function unlock (cryptoPassword) {
  await hoodie.cryptoStore.unlock(cryptoPassword) // then unlock

  // now do what you do after unlocking
}

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Changing the password

You can change the password and salt used for encryption with cryptoStore.changePassword(oldPassword, newPassword). This method also updates all documents, that got encrypted with the old password!

Please sync before the password change! To update all documents.

Example:

async function changePassword (oldPassword, newPassword) {
  await hoodie.connectionStatus.check() // check if your app is online

  if (hoodie.connectionStatus.ok) { // if your app is online: sync your users store
    await hoodie.store.sync()
  }

  const result = await hoodie.cryptoStore.changePassword(oldPassword, newPassword)

  console.log(result.notUpdated) // array of ids of all docs that weren't updated

  displayResetKeys(result.resetKeys)
}

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Reset the password

This works like changing the password. With the difference of: The user must enter a reset-key not the old password, and calling resetPassword()!

setup(), changePassword() and resetPassword() result 10 reset-keys. You should display them to your user. Or/and generate a text-file for your user to download.

// Generate a text file with the reset keys in it.
function generateResetKeysFile (resetKeys) {
  const text = resetKeys.join('\n')
  const file = new Blob([text], { type: 'text/plain' })
  const url = URL.createObjectURL(file)

  const a = document.getElementById('yourDownloadLink')
  a.href = url
  a.download = '[Your app name] reset-keys.txt' // This will be the standard file name.

  // then call later URL.revokeObjectURL(url) with the url of the file.
  // To remove it from memory.
}

Then, when the user did forget their encryption password, call cryptoStore.resetPassword(aResetKey, newPassword).

Every resetKey has a doc. Their _id starts with hoodiePluginCryptoStore/pwReset_, followed with the number 0 to 9. Please don't change them!

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Contributing

Contributions in all forms are welcome♡

Contributing might answer your questions about Contributing.

To create a welcoming project to all, this project uses a Code of Conduct. Please read it.

Setup development

hoodie-plugin-store-crypto is a node.js package. You need node version 6 or higher and npm version 5 or higher. Check your installed version with node -vand npm -v.

git clone https://github.com/Terreii/hoodie-plugin-store-crypto.git
cd hoodie-plugin-store-crypto
npm install

npm scripts

Scripts for development.

Command	What it does
npm start	Starts a Hoodie-server with this plugin attached.
npm test	Run all tests.
npm run textlint	Lint the documentation.
npm run fix:docs	Fix some lint errors in the documentation.
npm run fix:style	Fix some code-style errors.
npm run update-coc	Update the Code of Conduct.md.
npm run update-contrib	Update the Contributing.md.

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