zenypass-account-model

immutable model with access-control for ZenyPass records of user bookmarks and corresponding identifiers.

immutable

all entries of Account instances are read-only. new instances with modified entries may be spawned from any Account instance through its Account.set method.

access-control

this module exposes a factory builder which may be called by a 'controlling' party:

• factories that the controlling party instantiates with default settings ignore _id and _rev entries from their input object. in that case, the _id entry of instantiated Account objects defaults to a string derived from the object's name, url and username entries. such factories may be publicly exposed.
• on the other hand, factories that the controlling party instantiates with a { include_docref: true } option import _id and _rev entries - if defined - into the instantiated Account objects. such factories may be restricted to private use by the controlling party.

additionally, when instantiating a factory, the controlling party supplies authorize and onEmit methods:

• the authorize method may restrict access to the password function when the unrestricted entry is false. in that case, updates to the _deleted and unrestricted properties are also restricted. when access is restricted, the authorize method is called with a passphrase supplied when calling the Account.password or Account.set methods. the authorize method should return a Promise that resolves to true when access is authorized, false or alternatively reject with a corresponding Error otherwise.
• finally, the onEmit method provides indirect but unrestricted access for the controlling party to private properties of an Account instance. when calling Account.emit, the controlling party's onEmit method is called with a plain object clone of the Account instance, including its private entries, followed by any arguments passed to Account.emit. if the controlling party's onEmit method returns a value, Account.emit returns that value as well.

note that the primary objective of this access-control scheme is to expose an API that encapsulates logic for handling of restricted data.

input sanitizing

Account factories only very basically sanitize inputs. HTML-sanitizing is left to client code, if required.

example

import getAccountFactory, { AccountFactoryBuilder } from 'zenypass-account-model'
import getPbkdf2OSha512 from 'pbkdf2sha512'
import debug = require('debug')
debug.enable('account-example:*')

const pbkdf2 = getPbkdf2OSha512({ iterations: 8192 }) // min iterations

const SECRET_HASH = pbkdf2('secret passphrase')

function authorize (passphrase: string): Promise<boolean> {
  return SECRET_HASH.then(secret => pbkdf2(passphrase)
  .then(digest => digest.value === secret.value)) // optionally reject with Error when unauthorized
}

function onEmit (doc: AccountDoc): void {
  debug('account-example:onEmit:')(doc)
}

const accountFromDoc = getAccountFactory(authorize, onEmit, { include_docref: true })

const doc = accountFromDoc({
  _id: 'id',
  _rev: 'rev',
  url: 'https://example.com'
})
debug('account-example:from-doc:')(doc)

const accountFromObject = getAccountFactory(authorize, onEmit) // ignores DocRef entries

const empty = accountFromObject({ unrestricted: true }) // otherwise restricted by default
debug('account-example:from-object:unrestricted-empty:')(empty)

const bookmark = empty.set({ url: 'https://zenyway.com' }) // with default _id and name
.then(debug('account-example:from-object:unrestricted-bookmark:'))

const account = accountFromObject({ // restricted by default
  _id: 'id', // ignored, forced to default
  _rev: 'rev', // ignored, forced to undefined
  url: 'https://secure.example.com',
  username: '[email protected]',
  password: 'secret password'
})

account
debug('account-example:from-object:restricted-account:')(account)

account.password('secret passphrase') // passphrase required
.then(debug('account-example:from-object:restricted-account:password:'))

const unrestricted = account
.set({ unrestricted: true }, 'secret passphrase') // passphrase required

unrestricted
.then(debug('account-example:from-object:unrestricted-account:'))

unrestricted
.then(unrestricted => unrestricted.password()) // no passphrase required
.then(debug('account-example:from-object:unrestricted-account:password:'))

unrestricted
.then(unrestricted => unrestricted.emit<void>()) // emit private account object to onEmit listener

the files of this example are available in this repository.

view a live version of this example in your browser console, or clone this repository and run the following commands from a terminal:

npm install
npm run example

API v1.0 stable

ES5 and Typescript compatible. coded in Typescript 2, transpiled to ES5.

for a detailed specification of the API, run the unit tests in your browser.

CONTRIBUTING

see the contribution guidelines

LICENSE

Copyright 2017 Stéphane M. Catala

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and Limitations under the License.