README

Passport-VKontakte

Passport strategy for authenticating with VK using the OAuth 2.0 API.

This module lets you authenticate using VK in your Node.js applications. By plugging into Passport, VK authentication can be easily and unobtrusively integrated into any application or framework that supports Connect-style middleware, including Express.

Installation

$ npm install passport-vkontakte

Usage

Configure Strategy

Using this strategy, you can authenticate users who have a VK account and access their data, given their access permission.

In order to be used, a strategy must be configured with two parameters.

import Strategy as VKStrategy from "passport-vkontakte";
passport.use(new VKStrategy(options, verify));

Parameter	Type	Desciption
`options`	object	App credentials and callback URL
`verify`	function	Strategy verification callback

Strategy options

The options objects provides the strategy with the information it needs to represent your app to VK API. It includes your app credentials (application id and secret), as well as the callback URL to which the user will be redirected after they complete the authentication process.

Field	Type	Description
`clientID`	string	Your app's client id
`clientSecret`	string	Your app's secret
`callbackURL`	string	The full URL to your authentication completion handler
`profileFields`	array	A list of profile fields
`apiVersion`	string	The version of VK API implementation
`lang`	string	The language which should be used to represent the profile data

Strategy `verify` callback

A verify callback function is called after resource owner (the user) has accepted or declined the authorization request. In the example below, this function is called myVerifyCallbackFn.

It can have one of four signatures:

function(accessToken, refreshToken, profile, done) {}
function(accessToken, refreshToken, params, profile, done) {}
function(req, accessToken, refreshToken, params, profile, done) {}

Parameter	Type	Description
`req`	object
`accessToken`	string	OAuth2 access token
`refreshToken`	string	OAuth2 refresh token
`params`	object
`profile`	object	User profile
`done`	function	"Done" callback

The verify function can use the profile and params fields to find, create or update any kind of information that corresponds to now authenticated user.

After the user has been successfully authenticated, the done function should be called, to supply Passport with the user data as seen by the application.

return done(null, user);

In case of authentication error, false should be supplied instead.

return done(null, false);

Additional info object can be provided to indicate the reason for failure.

return done(null, false, { message: "User account is suspended" });

For transient errors, pass the error object as the first parameter.

return done(new Error("User database is not available, try later"));

const VKontakteStrategy = require("passport-vkontakte").Strategy;

// User session support middlewares. Your exact suite might vary depending on your app's needs.
app.use(require("cookie-parser")());
app.use(require("body-parser").urlencoded({ extended: true }));
app.use(
    require("express-session")({
        secret: "keyboard cat",
        resave: true,
        saveUninitialized: true,
    })
);
app.use(passport.initialize());
app.use(passport.session());

passport.use(
    new VKontakteStrategy(
        {
            clientID: VKONTAKTE_APP_ID, // VK.com docs call it 'API ID', 'app_id', 'api_id', 'client_id' or 'apiId'
            clientSecret: VKONTAKTE_APP_SECRET,
            callbackURL: "http://localhost:3000/auth/vkontakte/callback",
        },
        function myVerifyCallbackFn(
            accessToken,
            refreshToken,
            params,
            profile,
            done
        ) {
            // Now that we have user's `profile` as seen by VK, we can
            // use it to find corresponding database records on our side.
            // Also we have user's `params` that contains email address (if set in
            // scope), token lifetime, etc.
            // Here, we have a hypothetical `User` class which does what it says.
            User.findOrCreate({ vkontakteId: profile.id })
                .then(function (user) {
                    done(null, user);
                })
                .catch(done);
        }
    )
);

// User session support for our hypothetical `user` objects.
passport.serializeUser(function (user, done) {
    done(null, user.id);
});

passport.deserializeUser(function (id, done) {
    User.findById(id)
        .then(function (user) {
            done(null, user);
        })
        .catch(done);
});

Authenticate Requests

Use passport.authenticate(), specifying the 'vkontakte' strategy, to authenticate requests.

For example, as route middleware in an Express application:

//This function will pass callback, scope and request new token
app.get("/auth/vkontakte", passport.authenticate("vkontakte"));

app.get(
    "/auth/vkontakte/callback",
    passport.authenticate("vkontakte", {
        successRedirect: "/",
        failureRedirect: "/login",
    })
);

app.get("/", function (req, res) {
    //Here you have an access to req.user
    res.json(req.user);
});

Display Mode

Set display in passport.authenticate() options to specify display mode. Refer to the OAuth dialog documentation for information on its usage.

app.get(
    "/auth/vkontakte",
    passport.authenticate("vkontakte", { display: "mobile" }),
    function (req, res) {
        // ...
    }
);

Extended Permissions

If you need extended permissions from the user, the permissions can be requested via the scope option to passport.authenticate().

For example, this authorization requests permission to the user's friends:

app.get(
    "/auth/vkontakte",
    passport.authenticate("vkontakte", {
        scope: ["status", "email", "friends", "notify"],
    }),
    function (req, res) {
        // The request will be redirected to vk.com for authentication, with
        // extended permissions.
    }
);

Profile Fields

The VK.com profile may contain a lot of information. The strategy can be configured with a profileFields parameter which specifies a list of additional fields your application needs. For example, to fetch users's city and bdate configure strategy like this.

Notice that requesting the user's email address requires an email access scope, which you should explicitly list as in following example:

passport.use(
    new VKontakteStrategy(
        {
            ...{ clientID, clientSecret, callbackURL },
            scope: ["email" /* ... and others, if needed */],
            profileFields: ["email", "city", "bdate"],
        },
        myVerifyCallbackFn
    )
);

Profile fields language

By default, profile fields such as name are returned in English. The strategy can be configured with a lang parameter which specifies language of value returned.

For example, this would configure the strategy to return name in Russian:

passport.use(
    new VkontakteStrategy(
        {
            ...{ clientID, clientSecret, callbackURL },
            lang: "ru",
        },
        myVerifyCallbackFn
    )
);

API version

The VK.com profile structure can differ from one API version to another. The specific version to use can be configured with a apiVersion parameter. The default is 5.110.

passport.use(
    new VKontakteStrategy(
        {
            ...{ clientID, clientSecret, callbackURL },
            apiVersion: "5.17",
        },
        myVerifyCallbackFn
    )
);

Tests

$ npm install --dev
$ make test

Credits

Special Thanks

To all the people who had to cope with idiosyncrasies of OAuth2 and VK API!

License

(The MIT License)

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Usage no npm install needed!