Omejdn Configuration for the DAPS use case

This repository contains the necessary configuration templates to use an Omejdn instance as a DAPS as described in IDS-G. This document lists the necessary steps to adapt them to your use case.

Important Considerations

A Dynamic Attribute Provisioning System (DAPS) has the intent to assertain certain attributes to organizations and connectors. Hence, third parties do not need to trust the latter provided they trust the DAPS assertions. This is usually a matter of configuration on the verifying party's end which is not part of this document. In general, it requires registering both the DAPS certificate and its name as a trusted identity.

This document builds a DAPS for testing purposes only

Requirements

• Omejdn Server's dependencies
• OpenSSL
• Docker compose

This repository has submodules. Make sure to download them using git submodule update --init --remote

Minimal Configuration

The configuration consists of the following steps:

1. Adjusting configuration files
2. Registering connectors
3. Starting the server

All commands are to be run from the repository's root directory

Configuration Files

Edit the provided .env. The file includes many options you can play around with.

The default DAPS issuer identifier is http://localhost/auth, which you should register with your connectors to support server metadata.

The token_endpoint and jwks_uri should be retrieved by the connector from the metadata URL http://localhost/.well-known/oauth-authorization-server/auth (replace http, localhost and /auth by the values you specified in .env). You may use them as described in IDS-G.

They should default to http://localhost/auth/token and http://localhost/auth/jwks.json, respectively, though do not rely on this in production environments as they may change with every update. Only the metadata URL is guaranteed to stay constant.

Registering Connectors

Connectors can be registered at any point by adding clients to the config/clients.yml file and placing the certificate in the right place. To ease this process, use the provided script scripts/register_connector.sh

Usage:

$ scripts/register_connector.sh NAME SECURITY_PROFILE CERTIFICATE_FILE

The SECURITY_PROFILE and CERTIFICATE arguments are optional. Values for the former include:

• idsc:BASE_SECURITY_PROFILE (default)
• idsc:TRUST_SECURITY_PROFILE
• idsc:TRUST_PLUS_SECURITY_PROFILE

The script will automatically generate new client certificates (keys/NAME.cert) and keys (keys/NAME.key) if you do not provide a certificate manually.

Starting the server

To start the service, execute

$ docker compose up

If you navigate to http://localhost/, you should be greeted by Omejdn's UI. The UI is relatively new, so expect some bugs.

A script to quickly test your setup can be found in scripts (requires jq to be installed to format JSON). It takes the name of a connector and tries to request a DAT.

$ scripts/test.sh NAME

Hacking

There are a lot of ways one might want to extend Omejdn's functionality. Luckily, Omejdn is quite flexible. Below are just a few ideas.

Adding additional attributes

For example, adding additional attributes to the DAT is as simple as listing the key in config/scope_mapping.yml under the right scope and then provisioning each connector with the right attribute key and value in config/clients.yml.

Adding other attribute scopes

Currently, the only defined scope is idsc:IDS_CONNECTOR_ATTRIBUTES_ALL, but defining your own only requires you to specify them in config/scope_mapping.yml (along with the attribute keys you want to be included in that scope), and listing the new scope under the connector's scope property in config/clients.yml.

Additionally, each such client needs an attribute with key s for a scope s, and an attribute with key k and value v for a scope k:v

Clients can request several scopes at once (by space-separating them in the request) and the attributes for all of them are added to the DAT.

Adding custom functionality

Have a look at Omejdn's Plugin API. With just a bit of Ruby you can hook into the process and e.g. add anything you like to the DAT.

Here is a simple plugin example:

def my_awesome_function(bind)
    # 1. Get the newly created DAT body
    token = bind.local_variable_get(:token)
    
    # 2. Modify it whatever you want. This example statically adds a key `key` with value `value`,
    #    but this is ruby, so you can program in here whatever you like.
    token["key"] = "value"
end

# Execute this function whenever a new DAT body has been created
PluginLoader.register('TOKEN_CREATED_ACCESS_TOKEN', :my_awesome_function)

To load it into Omejdn, mount it to /opt/plugins/your_plugin_name/your_plugin_name.rb and add your_plugin_name to omejdn-plugins.yml as a key under plugins, then restart Omejdn.

Omejdn Config API

If you do not have Access to the DAPS and want to edit connectors (a.k.a. clients in OAuth language) and configuration remotely, you may use Omejdn's Config API.

Using the API requires an access token with the special scope omejdn:admin (to be added to a client like any other scope, see above)

The Omejdn Config API is documented here.