Authentication using passport

There are basically two steps to do so:

Configure:

Three part to configure:

    1. Application strategies

    2. Middleware

    3. Session (optional)

1. Strategies:

       Before authenticating request, strategy must be configured and are supplied via use function on passport object.

passport.use('strategy_name', new StrategyType(function(..,credentials, done));

where, function(..,credentials, done) is verify callback.

When passport authenticate request, it parses the request and pass those credentials to verify callback function.

Writing verify callback function:

If credentials are valid call done as:

           done(null, user); //here user is the user that authenticated.

If credentials are not valid call done as:

           done(null, false);

If exception occurred on verifying credentials call done as:

           done(err);

*You can pass additional info msg to indicate reason for failure:

           done(null, false, {message : 'user is not authenticated'});

2. Middleware:

Authenticate: