# Auth Server Helper

Authentication middleware for express

## Usage

```js
const auth = require('@scode/auth-server-helper');
const password_helper = require('@scode/password_helper');

const users = {
  foo: {
    id: 0
    password: await password_helper.hash('bar'),
    salt: '123'
  }
}

// add cookieParser to allow session management via cookies
app.use(cookieParser());

// the middleware needs a function to determine user data
// this function can also return a promise
app.use(auth((user_name) => {
  if (!users[user_name])
    return null;
  return users[user_name];
}));

```

when a client logs in, it will set a header called 'session' that the client can use to authorize the following requests.
it also sets a cookie to make requesting from the client more simple. (cookie parser is needed to make authentication with cookies possible)