ohif-viewer/docs/latest/deployment/recipes/user-account-control.md

# User Account Control

> DISCLAIMER! We make no claims or guarantees of this approach's security. If in
> doubt, enlist the help of an expert and conduct proper audits.

Making a viewer and its medical imaging data accessible on the open web can
provide a lot of benefits, but requires additional security to make sure
sensitive information can only be viewed by authorized individuals. Most image
archives are equipped with basic security measures, but they are not
robust/secure enough for the open web.

This guide covers one of many potential production setups that secure our
sensitive data.

## Overview

This guide builds on top of our
[Nginx + Image Archive guide](/deployment/recipes/nginx--image-archive.md),
wherein we used a [`reverse proxy`](https://en.wikipedia.org/wiki/Reverse_proxy)
to retrieve resources from our image archive (Orthanc).

To add support for "User Account Control" we introduce
[Keycloak](https://www.keycloak.org/about.html). Keycloak is an open source
Identity and Access Management solution that makes it easy to secure
applications and services with little to no code. We improve upon our
`reverse proxy` setup by integrating Keycloak and Nginx to create an
`authenticating reverse proxy`.

> An authenticating reverse proxy is a reverse proxy that only retrieves the
> resources on behalf of a client if the client has been authenticated. If a
> client is not authenticated they can be redirected to a login page.

This setup allows us to create a setup similar to the one pictured below:

{% include "./../_user-account-control-flow-diagram.md" %}

- All web requests are routed through `nginx` on our `OpenResty` image
- `/pacs` is a reverse proxy for `orthanc`'s `DICOM Web` endpoints
  - Requires valid `Authorization: Bearer <token>` header
- `/pacs-admin` is a reverse proxy for `orthanc`'s Web Admin
- `/auth` is a reverse proxy for `keycloak`
- All static resources for OHIF Viewer are unprotected and accessible. We have
  application logic that will redirect unauthenticated users to the appropriate
  `keycloak` login screen.

## Getting Started

### Requirements

- Docker
  - [Docker for Mac](https://docs.docker.com/docker-for-mac/)
  - [Docker for Windows](https://docs.docker.com/docker-for-windows/)

_Not sure if you have `docker` installed already? Try running `docker --version`
in command prompt or terminal_

### Setup

_Spin Things Up_

- Navigate to `<project-root>/docker/OpenResty-Orthanc-Keycloak` in your shell
- Run `docker-compose up`

_Create Your First User_

- Navigate to: `http://127.0.0.1/auth/admin`
- Sign in with: `admin`/`password`
- From the top left dropdown, select the `Ohif` realm (it should say `Master`)
- From the left sidebar, under `Manage`, select `Users`
- Click `Add User`
  - Username: `test`
  - Email Verified: `ON`
  - Click `Save`
- Click the `Credentials` Tab
  - New Pasword: `test`
  - Password Confirmation: `test`
  - Temporary: `OFF`
  - Click: `Reset Password`
- From the top right dropdown, select `Admin`, then `Sign Out`

_Sign In_

- Navigate to `http://127.0.0.1/`
- Username: `test`, Password: `test`
- Click `Log In`

_Upload Your First Study_

- Navigate to `http://127.0.0.1/pacs-admin`
- If you're not already logged in, use `test`/`test`
- From the top right, select "Upload"
- Click "Select files to upload..." (DICOM)
- Click "Start the upload"
- Navigate back to `http://127.0.0.1/` to view your studies in the Study List

### Troubleshooting

_Exit code 137_

This means Docker ran out of memory. Open Docker Desktop, go to the `advanced`
tab, and increase the amount of Memory available.

_Cannot create container for service X_

Use this one with caution: `docker system prune`

_X is already running_

Stop running all containers:

- Win: `docker ps -a -q | ForEach { docker stop $_ }`
- Linux: `docker stop $(docker ps -a -q)`

### Configuration

- [Env vars in Nginx](https://blog.doismellburning.co.uk/environment-variables-in-nginx-config/)

### Authentication Flow

- [Keycloak JavaScript Adapter](https://www.keycloak.org/docs/latest/securing_apps/index.html#_javascript_adapter)
  - Not used, as to not lock vendor
- [oidc-client-js](https://github.com/IdentityModel/oidc-client-js/wiki)
- [Diagrams of OpenID Connect Flows](https://medium.com/@darutk/diagrams-of-all-the-openid-connect-flows-6968e3990660)
- [KeyCloak: OpenID Connect Flows](https://www.keycloak.org/docs/latest/securing_apps/index.html#authorization-code)
  - [Good description on SSO Protocols](https://www.keycloak.org/docs/2.5/server_admin/topics/sso-protocols/oidc.html)
- [Lua Resty Openidc Docs](https://github.com/zmartzone/lua-resty-openidc)

### Create a new "Client" in Keycloak

- What is a realm?
- What is a client?
- OAuth 2.0 and implict flow; why?
- Can we set all of this up via config instead of manual?

- Navigate to `http://127.0.0.1/auth/admin/` in your browser. You should see:

<!-- Login Screen -->

- Sign in with `admin`/`password`
- Configure: Clients --> Create Client
  - ClientID: `pacs`
  - Client Protocol: `openid-connect`
  - Click "save"

### Rebuild Client

- Set in `config/nginx.conf`?
  - Env variable???
  - `2dc6244a-1cba-4dbd-b3d6-f7409c2f68b3`
- stop, `docker-compose up`

## How it works

_reverse proxy_

A reverse proxy is a type of proxy server that retrieves resources on behalf of
a client from one or more servers. The resources from these servers are returned
to the client as if they originate from the Web server itself.

[OpenResty](https://openresty.org/en/)

> OpenResty® is a full-fledged web platform that integrates the standard Nginx
> core, LuaJIT, many carefully written Lua libraries, lots of high quality
> 3rd-party Nginx modules, and most of their external dependencies. It is
> designed to help developers easily build scalable web applications, web
> services, and dynamic web gateways.

[Lua Nginx Module](https://github.com/openresty/lua-nginx-module)
[access_by_lua_block](https://github.com/openresty/lua-nginx-module#access_by_lua_block)

## Next Steps

### Deploying to Production

While these configuration and docker-compose files model an environment suitable
for production, they are not easy to deploy "as is". You can either:

- Manually recreate this environment and deploy built application files **OR**
- Deploy to a cloud kubernetes provider like
  [Digital Ocean](https://www.digitalocean.com/products/kubernetes/) **OR**
  - [See a full list of cloud providers here](https://landscape.cncf.io/category=cloud&format=card-mode&grouping=category)
- Find and follow your preferred provider's guide on setting up
  [swarms and stacks](https://docs.docker.com/get-started/)

### Add SSL

Adding SSL registration and renewal for your domain with Let's Encrypt that
terminates at Nginx is an incredibly important step toward securing your data.
Here are some resources, specific to this setup, that may be helpful:

- [lua-resty-auto-ssl](https://github.com/GUI/lua-resty-auto-ssl)
- [Let's Encrypt + Nginx](https://www.nginx.com/blog/using-free-ssltls-certificates-from-lets-encrypt-with-nginx/)

While we terminate SSL at Nginx, it may be worth using self signed certificates
for communication between services.

- [SSL Termination for TCP Upstream Servers](https://docs.nginx.com/nginx/admin-guide/security-controls/terminating-ssl-tcp/)

## Resources

### Misc. Helpful Commands

_Check if `nginx.conf` is valid:_

`docker run --rm -t -a stdout --name my-openresty -v $PWD/config/:/usr/local/openresty/nginx/conf/:ro openresty/openresty:alpine-fat openresty -c /usr/local/openresty/nginx/conf/nginx.conf -t`

_Interact w/ running container:_

`docker exec -it CONTAINER_NAME bash`

_List running containers:_

`docker ps`

_Clear Keycloak DB so you can re-seed values:_

- `docker volume prune` OR
- `docker volume ls` and `docker volume rm VOLUME_NAME VOLUME_NAME`

### Referenced Articles

The inspiration for our setup was driven largely by these articles:

- [Securing Nginx with Keycloak](https://edhull.co.uk/blog/2018-06-06/keycloak-nginx)
- [Authenticating Reverse Proxy with Keycloak](https://eclipsesource.com/blogs/2018/01/11/authenticating-reverse-proxy-with-keycloak/)
- [Securing APIs with Kong and Keycloak](https://www.jerney.io/secure-apis-kong-keycloak-1/)

For more documentation on the software we've chosen to use, you may find the
following resources helpful:

- [Clientside library we use to manage OpenID-Connect `implicit` flow](https://github.com/maxmantz/redux-oidc)
- [Orthanc for Docker](http://book.orthanc-server.com/users/docker.html)
- [OpenResty Guide](http://www.staticshin.com/programming/definitely-an-open-resty-guide/)
- [Lua Ngx API](https://openresty-reference.readthedocs.io/en/latest/Lua_Nginx_API/)
- [Auth0: Picking a Grant Type](https://auth0.com/docs/api-auth/which-oauth-flow-to-use)