npm package: @hyperdx/passport-local-mongoose
Description: Mongoose plugin that simplifies building username and password login with Passport
Author: Christoph Walcher
Latest version: 9.0.1

# Passport-Local Mongoose

Passport-Local Mongoose is a [Mongoose](http://mongoosejs.com/) [plugin](http://mongoosejs.com/docs/plugins.html)
that simplifies building username and password login with [Passport](http://passportjs.org).

[![Node.js CI](https://github.com/saintedlama/passport-local-mongoose/actions/workflows/ci.yml/badge.svg)](https://github.com/saintedlama/passport-local-mongoose/actions/workflows/ci.yml)
[![Coverage Status](https://coveralls.io/repos/saintedlama/passport-local-mongoose/badge.png?branch=master)](https://coveralls.io/r/saintedlama/passport-local-mongoose?branch=master)

## Tutorials

Michael Herman gives a comprehensible walk through for setting up mongoose,
passport, passport-local and passport-local-mongoose for user authentication in his blog post [User Authentication With Passport.js](http://mherman.org/blog/2013/11/11/user-authentication-with-passport-dot-js/)

## Installation

```bash
> npm install passport-local-mongoose
```

Passport-Local Mongoose does not require `passport` or `mongoose` dependencies directly but expects you
to have these dependencies installed.

In case you need to install the whole set of dependencies

```bash
> npm install passport mongoose passport-local-mongoose
```

## Usage

### Plugin Passport-Local Mongoose

First you need to plugin Passport-Local Mongoose into your User schema

```javascript
const mongoose = require('mongoose');
const Schema = mongoose.Schema;
const passportLocalMongoose = require('passport-local-mongoose');

const User = new Schema({});

User.plugin(passportLocalMongoose);

module.exports = mongoose.model('User', User);
```

You're free to define your User how you like. Passport-Local Mongoose will add a username, hash and salt field to store the username, the hashed password and the salt value.

Additionally, Passport-Local Mongoose adds some methods to your Schema. See the [API Documentation](https://github.com/saintedlama/passport-local-mongoose#api-documentation) section for more details.

### Configure Passport/Passport-Local

You should configure Passport/Passport-Local as described in [the Passport Guide](http://passportjs.org/guide/configure/).

Passport-Local Mongoose supports this setup by implementing a `LocalStrategy` and serializeUser/deserializeUser functions.

To setup Passport-Local Mongoose use this code

```javascript
// requires the model with Passport-Local Mongoose plugged in
const User = require('./models/user');

// use static authenticate method of model in LocalStrategy
passport.use(new LocalStrategy(User.authenticate()));

// use static serialize and deserialize of model for passport session support
passport.serializeUser(User.serializeUser());
passport.deserializeUser(User.deserializeUser());
```

Make sure that you have mongoose connected to mongodb and you're done.

#### Simplified Passport/Passport-Local Configuration

Starting from version 0.2.1, passport-local-mongoose adds a helper method `createStrategy` as static method to your schema.
The `createStrategy` is responsible to setup passport-local `LocalStrategy` with the correct options.

```javascript
const User = require('./models/user');

// CHANGE: USE "createStrategy" INSTEAD OF "authenticate"
passport.use(User.createStrategy());

passport.serializeUser(User.serializeUser());
passport.deserializeUser(User.deserializeUser());
```

The reason for this functionality is that when using the `usernameField` option to specify an alternative usernameField name, for example "email" passport-local would still expect your frontend login form to contain an input field with name "username" instead of email. This can be configured for passport-local but this is double the work. So we got this shortcut implemented.

### Async/Await

Starting from version `5.0.0`, passport-local-mongoose is async/await enabled by returning
Promises for all instance and static methods except `serializeUser` and `deserializeUser`.

```js
const user = new DefaultUser({username: 'user'});
await user.setPassword('password');
await user.save();
const { user } = await DefaultUser.authenticate()('user', 'password');
```

### Options

When plugging in Passport-Local Mongoose plugin, additional options can be provided to configure
the hashing algorithm.

```javascript
User.plugin(passportLocalMongoose, options);
```

#### Main Options

* `saltlen`: specifies the salt length in bytes. Default: 32
* `iterations`: specifies the number of iterations used in pbkdf2 hashing algorithm. Default: 25000
* `keylen`: specifies the length in byte of the generated key. Default: 512
* `digestAlgorithm`: specifies the pbkdf2 digest algorithm. Default: sha256. (get a list of supported algorithms with crypto.getHashes())
* `interval`: specifies the interval in milliseconds between login attempts, which increases exponentially based on the number of failed attempts, up to maxInterval. Default: 100
* `maxInterval`: specifies the maximum amount of time an account can be locked. Default 300000 (5 minutes)
* `usernameField`: specifies the field name that holds the username. Defaults to 'username'. This option can be used if you want to use a different field to hold the username for example "email".
* `usernameUnique`: specifies if the username field should be enforced to be unique by a mongodb index or not. Defaults to true.
* `saltField`: specifies the field name that holds the salt value. Defaults to 'salt'.
* `hashField`: specifies the field name that holds the password hash value. Defaults to 'hash'.
* `attemptsField`: specifies the field name that holds the number of login failures since the last successful login. Defaults to 'attempts'.
* `lastLoginField`: specifies the field name that holds the timestamp of the last login attempt. Defaults to 'last'.
* `selectFields`: specifies the fields of the model to be selected from mongodb (and stored in the session). Defaults to 'undefined' so that all fields of the model are selected.
* `usernameCaseInsensitive`: specifies the usernames to be case insensitive. Defaults to 'false'.
* `usernameLowerCase`: convert username field value to lower case when saving an querying. Defaults to 'false'.
* `populateFields`: specifies fields to populate in findByUsername function. Defaults to 'undefined'.
* `encoding`: specifies the encoding the generated salt and hash will be stored in. Defaults to 'hex'.
* `limitAttempts`: specifies whether login attempts should be limited and login failures should be penalized. Default: false.
* `maxAttempts`: specifies the maximum number of failed attempts allowed before preventing login. Default: Infinity.
* `unlockInterval`: specifies the interval in milliseconds, which is for unlock user automatically after the interval is reached. Defaults to 'undefined' which means deactivated.
* `passwordValidator`: specifies your custom validation function for the password in the form:
    ```js
    passwordValidator = function(password,cb) {
      if (someValidationErrorExists(password)) {
        return cb('this is my custom validation error message')
      }
      // return an empty cb() on success
      return cb()
    }
    ```
    Default: validates non-empty passwords.
* `passwordValidatorAsync`: specifies your custom validation function for the password with promises in the form:
    ```js
    passwordValidatorAsync = function(password) {
      return someAsyncValidation(password)
        .catch(function(err){
          return Promise.reject(err)
        })
    }
    ```
* `usernameQueryFields`: specifies alternative fields of the model for identifying a user (e.g. email).
* `findByUsername`: Specifies a query function that is executed with query parameters to restrict the query with extra query parameters. For example query only users with field "active" set to `true`. Default: `function(model, queryParameters) { return model.findOne(queryParameters); }`. See the examples section for a use case.

**_Attention!_** Changing any of the hashing options (saltlen, iterations or keylen) in a production environment will prevent existing users from authenticating!

#### Error Messages

Override default error messages by setting `options.errorMessages`.

* `MissingPasswordError`: 'No password was given'
* `AttemptTooSoonError`: 'Account is currently locked. Try again later'
* `TooManyAttemptsError`: 'Account locked due to too many failed login attempts'
* `NoSaltValueStoredError`: 'Authentication not possible. No salt value stored'
* `IncorrectPasswordError`: 'Password or username are incorrect'
* `IncorrectUsernameError`: 'Password or username are incorrect'
* `MissingUsernameError`: 'No username was given'
* `UserExistsError`: 'A user with the given username is already registered'

### Hash Algorithm

Passport-Local Mongoose use the pbkdf2 algorithm of the node crypto library.
[Pbkdf2](http://en.wikipedia.org/wiki/PBKDF2) was chosen because platform independent
(in contrary to bcrypt). For every user a generated salt value is saved to make
rainbow table attacks even harder.

### Examples

For a complete example implementing a registration, login and logout see the
[login example](https://github.com/saintedlama/passport-local-mongoose/tree/master/examples/login).

## API Documentation

### Instance methods

#### setPassword(password, [cb])

Sets a user password. Does not save the user object. If no callback `cb` is provided a `Promise` is returned.

#### changePassword(oldPassword, newPassword, [cb])

Changes a user's password hash and salt, resets the user's number of failed password attempts and saves the user object (everything only if oldPassword is correct). If no callback `cb` is provided a `Promise` is returned. If oldPassword does not match the user's old password, an `IncorrectPasswordError` is passed to `cb` or the `Promise` is rejected.

#### authenticate(password, [cb])

Authenticates a user object. If no callback `cb` is provided a `Promise` is returned.

#### resetAttempts([cb])

Resets a user's number of failed password attempts and saves the user object. If no callback `cb` is provided a `Promise` is returned. This method is only defined if `options.limitAttempts` is `true`.

### Callback Arguments

* `err`
  * null unless the hashing algorithm throws an error
* `thisModel`
  * the model getting authenticated **_if_** authentication was successful otherwise false
* `passwordErr`
  * an instance of `AuthenticationError` describing the reason the password failed, else undefined.

Using `setPassword()` will only update the document's password fields, but will not save the document.
To commit the changed document, remember to use Mongoose's `document.save()` after using `setPassword()`.

### Error Handling

* `IncorrectPasswordError`: specifies the error message returned when the password is incorrect. Defaults to 'Incorrect password'.
* `IncorrectUsernameError`: specifies the error message returned when the username is incorrect. Defaults to 'Incorrect username'.
* `MissingUsernameError`: specifies the error message returned when the username has not been set during registration. Defaults to 'Field %s is not set'.
* `MissingPasswordError`: specifies the error message returned when the password has not been set during registration. Defaults to 'Password argument not set!'.
* `UserExistsError`: specifies the error message returned when the user already exists during registration. Defaults to 'User already exists with name %s'.
* `NoSaltValueStored`: Occurs in case no salt value is stored in the MongoDB collection.
* `AttemptTooSoonError`: Occurs if the option `limitAttempts` is set to true and a login attept occures while the user is still penalized.
* `TooManyAttemptsError`: Returned when the user's account is locked due to too many failed login attempts.

All those errors inherit from `AuthenticationError`, if you need a more general error class for checking.

### Static methods

Static methods are exposed on the model constructor. For example to use createStrategy function use

```javascript
const User = require('./models/user');
User.createStrategy();
```

* `authenticate()` Generates a function that is used in Passport's LocalStrategy
* `serializeUser()` Generates a function that is used by Passport to serialize users into the session
* `deserializeUser()` Generates a function that is used by Passport to deserialize users into the session
* `register(user, password, cb)` Convenience method to register a new user instance with a given password. Checks if username is unique. See [login example](https://github.com/saintedlama/passport-local-mongoose/tree/master/examples/login).
* `findByUsername()` Convenience method to find a user instance by it's unique username.
* `createStrategy()` Creates a configured passport-local `LocalStrategy` instance that can be used in passport.

## Examples

### Allow only "active" users to authenticate

First, we define a schema with an additional field `active` of type Boolean.

```javascript
const UserSchema = new Schema({
  active: Boolean
});
```

When plugging in Passport-Local Mongoose, we set `usernameUnique` to avoid creating a unique mongodb index on field `username`. To avoid
non active users being queried by mongodb, we can specify the option `findByUsername` that allows us to restrict a query. In our case
we want to restrict the query to only query users with field `active` set to `true`. The `findByUsername` MUST return a Mongoose query.

```javascript
UserSchema.plugin(passportLocalMongoose, {
  // Set usernameUnique to false to avoid a mongodb index on the username column!
  usernameUnique: false,

  findByUsername: function(model, queryParameters) {
    // Add additional query parameter - AND condition - active: true
    queryParameters.active = true;
    return model.findOne(queryParameters);
  }
});
```

To test the implementation, we can simply create (register) a user with field `active` set to `false` and try to authenticate this user
in a second step:

```javascript
const User = mongoose.model('Users', UserSchema);

User.register({username:'username', active: false}, 'password', function(err, user) {
  if (err) { ... }

  const authenticate = User.authenticate();
  authenticate('username', 'password', function(err, result) {
    if (err) { ... }

    // Value 'result' is set to false. The user could not be authenticated since the user is not active
  });
});
```

## Updating from 1.x to 2.x

The default digest algorithm was changed due to security implications from **sha1** to **sha256**. If you decide to upgrade a production system from 1.x to 2.x, your users **will not be able to login** since the digest algorithm was changed! In these cases plan some migration strategy and/or use the **sha1** option for the digest algorithm.

## License

Passport-Local Mongoose is licensed under the [MIT license](http://opensource.org/licenses/MIT).