Recentry i had to implement authentication in an AngularJS application. For this pupose i found https://github.com/sahat/satellizer which supports different flows of authentication, one of these is username/password through JSON Web Token (JWT).
This small library combines firebase/php-jwt and two custom Symfony Security SimplePreAuthenticators in order to have a simple flow.
TokenExchangeAuthenticator only purpose is to take the username / password provided in a JSON request and return a
valid JWT token. Depending on the way it have been setup.
TokenAuthenticator assumes a Authorization: Bearer my-token header is present and will use a TokenUserProvider
implementation to authenticate the User.