Login

Overview and Scope

This @co-digital/login aims to provide a simple solution for implementing user authentication within within CO Node.js applications. With a focus on security and ease of integration, our solution incorporates a middleware that connects to our internal Identity provider COLA and relatively soon OneLogin.

Installing

npm i @co-digital/login

Config variables

Following configs will need to be added as environment variables to the application

Key	Description	Example Value
USER_POOL_ID	ID of the user pool in Amazon Cognito	secret
USER_POOL_CLIENT_ID	Client ID of an app registered with the user pool in Amazon Cognito	secret
AUTH_SIGN_IN_URL	Authentication sign in URL	https://cola.service.cabinetoffice.gov.uk/v2/<YOUR_SERVICE>/login
COOKIE_ID_NAME	The name of the cookie	github-requests for github-requests-app
COOKIE_PARSER_SECRET	Secret used in validating/calculating the cookie signature	secret
COOKIE_SESSION_SECRET	Secret key for signing the session cookie	secret
LOG_LEVEL	Logging levels	info (Log only if info.level is less than or equal to this level)
HUMAN	Formatting messages form (default JSON)	true (Enable human formatting for log messages)

Files Structure

Directory Path	Description
./config/	This folder contains configuration settings for the login module. It is essential for fetching sensitive information such as COOKIE_PARSER_SECRET or COOKIE_SESSION_SECRET.
./utils/	This folder contains utility functions used throughout the login module, including Session and Cookie utils.
./index.ts	This file will expose the authentication middleware and Session and Cookie utils.
./test	Jest Test files (*.spec.ts, setup.ts, and *.mocks.ts)
Others files	Other files related to modules dependency, CI/CD, *git, lint, test/typescript configs …

Integration and Getting Started

To integrate our login solution into your Node.js application, follow these simple steps:

• Install Dependencies: Begin by installing the necessary dependencies using npm. Ensure that you have express, cookie-parser and cookie-session installed in your project.

npm i @co-digital/login

• Middleware Configuration: Configure the module to utilise the associated authentication middleware by incorporating the appropriate environment data and enabling cookieParser and cookieSession within the application configuration file.

// On app.ts
...
app.use(cookieParser(COOKIE_PARSER_SECRET));
app.use(cookieSession({ secret: COOKIE_SESSION_SECRET }));
...

• Route Setup: Define routes for any authentication-related endpoints required by your application and utilise the middleware to protect routes that require authentication.

// On any endpoint when auth is required (eg. home route)
...
import { authentication } from "@co-digital/login";

const homePageRouter = Router();
homePageRouter.get(config.HOME_URL, authentication, get);
...

• Frontend Integration: COLA has already developed user interface components for login, logout, and other authentication-related actions. However, for integration with other Identity Providers (IdPs) such as GOV.UK One Login, you'll need to implement these components within your application.

Note

• COLA service that is hosted under the cabinetoffice.gov.uk domain. Under the hood, it utilises and abstracts AWS Cognito for user management.

• cookieParser method from cookie-parser module parses cookie header and populates req.cookies with an object keyed by the cookie names. The middleware will parse the cookie header on the request and expose the cookie data as the property req.signedCookies if a secret was provided.

• cookieParser.signedCookie(str, secret) parses a cookie value as a signed cookie. This will return the parsed unsigned value if it was a signed cookie and the signature was valid. If the value was not signed, the original value is returned. If the value was signed but the signature could not be validated, false is returned.

• After the server sends a cookie to a client, the client might modify the cookie before sending it back to the server in a future request. So you sign a cookie if you want assurance that the data being returned in the cookie has not been modified by the client.

• cookieSession creates a new cookie session middleware. This middleware will attach the property session to req, which provides an object representing the loaded session. This session is either a new session if no valid session was provided in the request, or a loaded session from the request. The req.session represents the session for the given request.

app.use(
  cookieSession({
    // A string which will be used as single key if keys is not provided.
    secret: process.env.COOKIE_SESSION_SECRET,
  })
);

Purpose of cookie-session module

• cookie-session does not require any database/resources on the server side, though the total session data cannot exceed the browser's max cookie size.
• cookie-session can simplify certain load-balanced scenarios.
• cookie-session can be used to store a "light" session and include an identifier to look up a database-backed secondary store to reduce database lookups.

Contributing

## Set Node/NPM env
nvm use

## Installing & Building
make build

## Testing & Coverage
make test
#or
make coverage