Security settings

Important

You should not run JupyterHub without SSL encryption on a public network.

Security is the most important aspect of configuring Jupyter. Three configuration settings are the main aspects of security configuration:

  1. SSL encryption (to enable HTTPS)
  2. Cookie secret (a key for encrypting browser cookies)
  3. Proxy authentication token (used for the Hub and other services to authenticate to the Proxy)

The Hub hashes all secrets (e.g., auth tokens) before storing them in its database. A loss of control over read-access to the database should have minimal impact on your deployment; if your database has been compromised, it is still a good idea to revoke existing tokens.

Enabling SSL encryption

Since JupyterHub includes authentication and allows arbitrary code execution, you should not run it without SSL (HTTPS).

Using an SSL certificate

This will require you to obtain an official, trusted SSL certificate or create a self-signed certificate. Once you have obtained and installed a key and certificate you need to specify their locations in the jupyterhub_config.py configuration file as follows:

c.JupyterHub.ssl_key = '/path/to/my.key'
c.JupyterHub.ssl_cert = '/path/to/my.cert'

Some cert files also contain the key, in which case only the cert is needed. It is important that these files be put in a secure location on your server, where they are not readable by regular users.

If you are using a chain certificate, see also chained certificate for SSL in the JupyterHub Troubleshooting FAQ.

Using letsencrypt

It is also possible to use letsencrypt to obtain a free, trusted SSL certificate. If you run letsencrypt using the default options, the needed configuration is (replace mydomain.tld by your fully qualified domain name):

c.JupyterHub.ssl_key = '/etc/letsencrypt/live/{mydomain.tld}/privkey.pem'
c.JupyterHub.ssl_cert = '/etc/letsencrypt/live/{mydomain.tld}/fullchain.pem'

If the fully qualified domain name (FQDN) is example.com, the following would be the needed configuration:

c.JupyterHub.ssl_key = '/etc/letsencrypt/live/example.com/privkey.pem'
c.JupyterHub.ssl_cert = '/etc/letsencrypt/live/example.com/fullchain.pem'

If SSL termination happens outside of the Hub

In certain cases, for example if the hub is running behind a reverse proxy, and SSL termination is being provided by NGINX, it is reasonable to run the hub without SSL.

To achieve this, simply omit the configuration settings c.JupyterHub.ssl_key and c.JupyterHub.ssl_cert (setting them to None does not have the same effect, and is an error).

Proxy authentication token

The Hub authenticates its requests to the Proxy using a secret token that the Hub and Proxy agree upon. The value of this string should be a random string (for example, generated by openssl rand -hex 32).

Generating and storing token in the configuration file

Or you can set the value in the configuration file, jupyterhub_config.py:

c.JupyterHub.proxy_auth_token = '0bc02bede919e99a26de1e2a7a5aadfaf6228de836ec39a05a6c6942831d8fe5'

Generating and storing as an environment variable

You can pass this value of the proxy authentication token to the Hub and Proxy using the CONFIGPROXY_AUTH_TOKEN environment variable:

export CONFIGPROXY_AUTH_TOKEN=$(openssl rand -hex 32)

This environment variable needs to be visible to the Hub and Proxy.

Default if token is not set

If you don’t set the Proxy authentication token, the Hub will generate a random key itself, which means that any time you restart the Hub you must also restart the Proxy. If the proxy is a subprocess of the Hub, this should happen automatically (this is the default configuration).