Для базы
var mongoose = require('mongoose');
var User = require('./models/User').User;
//var config = require('./config');
//mongoose.connect('mongodb://127.0.0.1:27017/test');

//var db = mongoose.connection.db;
mongoose.connection.on('open', function () {
    var db = mongoose.connection.db;
    db.dropDatabase(function (err) {
        if (err) throw err;
        var vasya = new User({username:'Вася', password:'supervasya'});
        /*var petya = new User({username:'Петя', password:'123'});
        var admin = new User({username:'admin', password:'thetruehero'});

        vasya.save();
        petya.save();
        admin.save();
*/
        mongoose.disconnect();
    });
});

модель
ar crypto = require('crypto');
var mongoose = require('mongoose');

//var mongoose = require('./libs/mongoose');
mongoose.connect('mongodb://127.0.0.1:27017/test');
Schema = mongoose.Schema;

var schema = new Schema({

    username: {
        type: String,
        unique: true,
        required: true
    },
    hashedPassword: {
        type: String,
        require: true
    },
    salt: {
        type: String,
        require: true
    },
    created: {
        type: Date,
        default: Date.now
    }

    }
);

schema.methods.encryptPassword = function (password) {
    return crypto.createHmac('shal', this.salt).update(password).digest('hex');
};

schema.virtual('password')
    .set(function (password) {
    this._plainPassword = password;
    this.salt = Math.random() + ' ';
    this.hashedPassword = this.encryptPassword(password);
})
    .get(function () {
        return this._plainPassword;
    });

schema.methods.checkPassword = function (password) {
    return this.encryptPassword(password) === this.hashedPassword;
};

exports.User = mongoose.model('User', schema);