ODRE Framework

This is a pythom impementation of the ODRE approach to enforce ODRL policices. You can play with this implementation in our demo.

Quickstart

Install

pip install pyodre

Enforce ODRL policies

from pyodre.odre import ODRE

policy = """
{
    "@context": "http://www.w3.org/ns/odrl.jsonld",
    "@type": "Offer",
    "uid": "http://example.com/policy:6163",
    "profile": "http://example.com/odrl:profile:10",
    "permission": [{
       "target": "http://example.com/document:1234",
       "assigner": "http://example.com/org:616",
       "action": "distribute",
       "constraint": [{
           "leftOperand": "dateTime",
           "operator": "lt",
           "rightOperand":  { "@value": "2025-01-01", "@type": "xsd:date" }
       }]
   }]
}
"""
usage_decision = ODRE().enforce(policy)
print(usage_decision)

In the case a user wants to activate the DEBUG mode that shows the interpretable policies, the actions and the usage decision the following excerpt must be used. In addition, note that the interpreter can be modified

usage_decision = ODRE().set_debug(True).set_interpreter(PythonInterpreter()).enforce(policy)
print(usage_decision)

Register new functions (descriptive + interpretable)

In order to include new operators or operands a user must provide the name space and a function prefix for the terms in the ontology extensions that is been integrated in ODRE. To do this, the user must include this information in the Interpreter class; for instance, a new function namespace prefix fnc: <http://organiation.org/namespace> and its function prefix fnc_. Then, the user must implement the function fnc_XX in the file python functions considering that XX should meet the term in the ontology, for instance the python function fnc_time will be called if the policy contains the term fnc:time.

Interpolation

The policy templating is based on the Jinja language, it can be used to pass data variables that are not hardcoded in the policy increasing its privacy or it can be used to pass python native functions so they can be expressed in the policy and invoked during the enforcement.

In the following example a variable {{token}} is expressed in the policy and, as left operand, the function {{retrieve_token()}} is used. Note that the value of both is passed to the ODRE object under the parameter interpolations

policy = """
{
    "@context": "http://www.w3.org/ns/odrl.jsonld",
    "@type": "Offer",
    "uid": "http://example.com/policy:6163",
    "profile": "http://example.com/odrl:profile:10",
    "permission": [{
       "target": "http://example.com/document:1234",
       "assigner": "http://example.com/org:616",
       "action": "distribute",
       "constraint": [{
           "leftOperand": "dateTime",
           "operator": "lt",
           "rightOperand":  { "@value": "2025-01-01", "@type": "xsd:date" }
       },{
           "leftOperand": { "@value": "{{retrieve_token()}}" , "@type": "xsd:string" },
           "operator": "eq",
           "rightOperand":  { "@value": "{{token}}", "@type": "xsd:string" }
       }]
   }]
}
"""

def get_token():
    return "AAA"

usage_decision = ODRE().set_debug(True).enforce(policy, interpolations={'token' : 'AAA', 'retrieve_token' : get_token})
print(usage_decision)

Supported features

ODRL operantors

ODRL operands

• The available implemented Left Operands from those specified in the ODRL Vocabulary & Expression 2.2 are the following:

• The available implemented Right Operands from those specified in the ODRL Vocabulary & Expression 2.2 are the following:

ODRL actions

• The available implemented Right Operands from those specified in the ODRL Vocabulary & Expression 2.2 are the following:

BibTeX Citation

@misc{cimmino2024opendigitalrightsenforcement,
      title={Open Digital Rights Enforcement Framework (ODRE): from descriptive to enforceable policies}, 
      author={Andrea Cimmino and Juan Cano-Benito and Raúl García-Castro},
      year={2024},
      eprint={2409.17602},
      archivePrefix={arXiv},
      primaryClass={cs.CR},
      url={https://arxiv.org/abs/2409.17602}, 
}