shield

# Shield

*Shield* is a comprehensive Identity & Access Management solution for [*Lucky* framework](https://luckyframework.org). It features robust authentication and authorization, including user registrations, logins and logouts, password resets and more.

*Shield* is secure by default, and exploits defence-in-depth strategies, including the option to pin an authentication session to the IP address that started it -- the session is invalidated if the IP address changes.

User IDs are never saved in session. Instead, each authentication gets a unique ID and token, which is saved in session, and checked against their corresponding salted SHA-256 digests in the database.

When a user changes their password, *Shield* logs out the user on all devices (except the current one), to ensure that an attacker no longer has access to a previously compromised account.

*Shield* supports API authentication, with regular passwords or with user-generated bearer tokens. In addition, *Shield* comes with tools to build your own OAuth 2.0 authorization server.

*Shield* is designed to be resilient against critical application vulnerabilities, including brute force, user enumeration, denial of service and timing attacks.

On top of these, *Shield* offers seamless integration with your application. For the most part, `include` a bunch of `module`s in the appropriate `class`es, and you are good to go!

### Design principles

- #### Zero knowledge

  *Shield* maintains no knowledge of any secrets, and stores them such that they are irrecoverable, either by the application or by the user, if the user loses them.

- #### Hashing over encryption

  In line with the *Zero Knowledge* principle, *Shield* prefers hashing to encryption, keeping knowledge of all secrets to the user that generated them.

- #### Handles over assertions

  In *Shield*, the server is the source of truth, ensuring that all secrets can be revoked server-side, and instantly, whenever the need arises.

- #### Deny by default

  *Shield* locks everything down, by default, and requires explicit action by the developer. This posture makes it difficult for an application to be *insecure by accident*.

## Quick Start

Get started quickly using [*Penny*](https://github.com/GrottoPress/penny). *Penny* is a *Lucky* application scaffold that gets you up and running with *Shield*.

## Documentation

Find the complete documentation of *Shield* in the `docs/` directory of this repository.

## Development

Create a `.env` file:

```env
DATABASE_URL=postgres://postgres:password@localhost:5432/shield_spec
```

Update the file with your own details. Then run tests with `crystal spec`.

## Contributing

1. [Fork it](https://github.com/GrottoPress/shield/fork)
1. Switch to the `master` branch: `git checkout master`
1. Create your feature branch: `git checkout -b my-new-feature`
1. Make your changes, updating changelog and documentation as appropriate.
1. Commit your changes: `git commit`
1. Push to the branch: `git push origin my-new-feature`
1. Submit a new *Pull Request* against the `GrottoPress:master` branch.