Mongoose password hashing

I am looking for a good way to save an Account to MongoDB using mongoose.

My problem is: The password is hashed asynchronously. A setter wont work here because it only works synchronous.

I thought about 2 ways:

• Create an instance of the model and save it in the callback of the hash function.

• Creating a pre hook on 'save'

Is there any good solution on this problem?

The mongodb blog has an excellent post detailing how to implement user authentication.

http://blog.mongodb.org/post/32866457221/password-authentication-with-mongoose-part-1

The following is copied directly from the link above:

User Model

var mongoose = require('mongoose'),
    Schema = mongoose.Schema,
    bcrypt = require('bcrypt'),
    SALT_WORK_FACTOR = 10;
     
var UserSchema = new Schema({
    username: { type: String, required: true, index: { unique: true } },
    password: { type: String, required: true }
});
     
UserSchema.pre('save', function(next) {
    var user = this;

    // only hash the password if it has been modified (or is new)
    if (!user.isModified('password')) return next();

    // generate a salt
    bcrypt.genSalt(SALT_WORK_FACTOR, function(err, salt) {
        if (err) return next(err);

        // hash the password using our new salt
        bcrypt.hash(user.password, salt, function(err, hash) {
            if (err) return next(err);
            // override the cleartext password with the hashed one
            user.password = hash;
            next();
        });
    });
});
     
UserSchema.methods.comparePassword = function(candidatePassword, cb) {
    bcrypt.compare(candidatePassword, this.password, function(err, isMatch) {
        if (err) return cb(err);
        cb(null, isMatch);
    });
};
     
module.exports = mongoose.model('User', UserSchema);

Usage

var mongoose = require(mongoose),
    User = require('./user-model');
     
var connStr = 'mongodb://localhost:27017/mongoose-bcrypt-test';
mongoose.connect(connStr, function(err) {
    if (err) throw err;
    console.log('Successfully connected to MongoDB');
});
     
// create a user a new user
var testUser = new User({
    username: 'jmar777',
    password: 'Password123'
});
     
// save the user to database
testUser.save(function(err) {
    if (err) throw err;
});
    
// fetch the user and test password verification
User.findOne({ username: 'jmar777' }, function(err, user) {
    if (err) throw err;
     
    // test a matching password
    user.comparePassword('Password123', function(err, isMatch) {
        if (err) throw err;
        console.log('Password123:', isMatch); // -> Password123: true
    });
     
    // test a failing password
    user.comparePassword('123Password', function(err, isMatch) {
        if (err) throw err;
        console.log('123Password:', isMatch); // -> 123Password: false
    });
});

For those who are willing to use ES6+ syntax can use this -

const bcrypt = require('bcryptjs');
const mongoose = require('mongoose');
const { isEmail } = require('validator');

const { Schema } = mongoose;
const SALT_WORK_FACTOR = 10;

const schema = new Schema({
  email: {
    type: String,
    required: true,
    validate: [isEmail, 'invalid email'],
    createIndexes: { unique: true },
  },
  password: { type: String, required: true },
});

schema.pre('save', async function save(next) {
  if (!this.isModified('password')) return next();
  try {
    const salt = await bcrypt.genSalt(SALT_WORK_FACTOR);
    this.password = await bcrypt.hash(this.password, salt);
    return next();
  } catch (err) {
    return next(err);
  }
});

schema.methods.validatePassword = async function validatePassword(data) {
  return bcrypt.compare(data, this.password);
};

const Model = mongoose.model('User', schema);

module.exports = Model;

TL;DR - Typescript solution

I have arrived here when I was looking for the same solution but using typescript. So for anyone interested in TS solution to the above problem, here is an example of what I ended up using.

imports && contants:

import mongoose, { Document, Schema, HookNextFunction } from 'mongoose';
import bcrypt from 'bcryptjs';

const HASH_ROUNDS = 10;

simple user interface and schema definition:

export interface IUser extends Document {
    name: string;
    email: string;
    password: string;
    validatePassword(password: string): boolean;
}

const userSchema = new Schema({
    name: { type: String, required: true },
    email: { type: String, required: true, unique: true },
    password: { type: String, required: true },
});

user schema pre-save hook implementation

userSchema.pre('save', async function (next: HookNextFunction) {
    // here we need to retype 'this' because by default it is 
    // of type Document from which the 'IUser' interface is inheriting 
    // but the Document does not know about our password property
    const thisObj = this as IUser;

    if (!this.isModified('password')) {
        return next();
    }

    try {
        const salt = await bcrypt.genSalt(HASH_ROUNDS);
        thisObj.password = await bcrypt.hash(thisObj.password, salt);
        return next();
    } catch (e) {
        return next(e);
    }
});

password validation method

userSchema.methods.validatePassword = async function (pass: string) {
    return bcrypt.compare(pass, this.password);
};

and the default export

export default mongoose.model<IUser>('User', userSchema);

note: don't forget to install type packages (@types/mongoose, @types/bcryptjs)

I think this is a good way by user Mongoose and bcrypt！

User Model

/**
 * Module dependences
*/

const mongoose = require('mongoose');
const Schema = mongoose.Schema;
const bcrypt = require('bcrypt');
const SALT_WORK_FACTOR = 10;

// define User Schema
const UserSchema = new Schema({
    username: {
        type: String,
        unique: true,
        index: {
            unique: true
        }
    },
    hashed_password: {
        type: String,
        default: ''
    }
});

// Virtuals
UserSchema
    .virtual('password')
    // set methods
    .set(function (password) {
        this._password = password;
    });

UserSchema.pre("save", function (next) {
    // store reference
    const user = this;
    if (user._password === undefined) {
        return next();
    }
    bcrypt.genSalt(SALT_WORK_FACTOR, function (err, salt) {
        if (err) console.log(err);
        // hash the password using our new salt
        bcrypt.hash(user._password, salt, function (err, hash) {
            if (err) console.log(err);
            user.hashed_password = hash;
            next();
        });
    });
});

/**
 * Methods
*/
UserSchema.methods = {
    comparePassword: function(candidatePassword, cb) {
        bcrypt.compare(candidatePassword, this.password, function(err, isMatch) {
            if (err) return cb(err);
            cb(null, isMatch);
        });
    };
}

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

Usage

signup: (req, res) => {
    let newUser = new User({
        username: req.body.username,
        password: req.body.password
    });
    // save user
    newUser.save((err, user) => {
        if (err) throw err;
        res.json(user);
    });
}

Result

Result

The Mongoose official solution requires the model to be saved before using the verifyPass method, which can cause confusion. Would the following work for you? (I am using scrypt instead of bcrypt).

userSchema.virtual('pass').set(function(password) {
    this._password = password;
});

userSchema.pre('save', function(next) {
    if (this._password === undefined)
        return next();

    var pwBuf = new Buffer(this._password);
    var params = scrypt.params(0.1);
    scrypt.hash(pwBuf, params, function(err, hash) {
        if (err)
            return next(err);
        this.pwHash = hash;
        next();
    });
});

userSchema.methods.verifyPass = function(password, cb) {
    if (this._password !== undefined)
        return cb(null, this._password === password);

    var pwBuf = new Buffer(password);
    scrypt.verify(this.pwHash, pwBuf, function(err, isMatch) {
        return cb(null, !err && isMatch);
    });
};