This is a pythom impementation of the ODRE approach to enforce ODRL policices. You can play with this implementation in our demo.
pip install pyodrefrom 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)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.
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)| Operators | Implementation status | # |
|---|---|---|
| eq | supported | ✓ |
| gt | supported | ✓ |
| gteq | supported | ✓ |
| lt | supported | ✓ |
| lteq | supported | ✓ |
| neq | supported | ✓ |
| hasPart | unsupported | ✗ |
| isA | unsupported | ✗ |
| isAllOf | unsupported | ✗ |
| isAnyOf | unsupported | ✗ |
| isNoneOf | unsupported | ✗ |
| isPartOf | unsupported | ✗ |
- The available implemented Left Operands from those specified in the ODRL Vocabulary & Expression 2.2 are the following:
| Left Operands | Implementation status | # |
|---|---|---|
| absolutePosition | unsupported | ✗ |
| absoluteSize | unsupported | ✗ |
| absoluteSpatialPosition | unsupported | ✗ |
| absoluteTemporalPosition | unsupported | ✗ |
| count | unsupported | ✗ |
| dateTime | supported | ✓ |
| delayPeriod | unsupported | ✗ |
| deliveryChannel | unsupported | ✗ |
| device | unsupported | ✗ |
| elapsedTime | unsupported | ✗ |
| event | unsupported | ✗ |
| fileFormat | unsupported | ✗ |
| industry | unsupported | ✗ |
| language | unsupported | ✗ |
| media | unsupported | ✗ |
| meteredTime | unsupported | ✗ |
| payAmount | unsupported | ✗ |
| percentage | unsupported | ✗ |
| product | unsupported | ✗ |
| purpose | unsupported | ✗ |
| recipient | unsupported | ✗ |
| relativePosition | unsupported | ✗ |
| relativeSize | unsupported | ✗ |
| relativeSpatialPosition | unsupported | ✗ |
| relativeTemporalPosition | unsupported | ✗ |
| resolution | unsupported | ✗ |
| spatial | unsupported | ✗ |
| spatialCoordinates | unsupported | ✗ |
| system | unsupported | ✗ |
| systemDevice | unsupported | ✗ |
| timeInterval | unsupported | ✗ |
| unitOfCount | unsupported | ✗ |
| version | unsupported | ✗ |
| virtualLocation | unsupported | ✗ |
- The available implemented Right Operands from those specified in the ODRL Vocabulary & Expression 2.2 are the following:
| Right Operands | Implementation status | # |
|---|---|---|
| policyUsage | unsupported | ✗ |
- The available implemented Right Operands from those specified in the ODRL Vocabulary & Expression 2.2 are the following:
| Actions | Implementation status | # |
|---|---|---|
| policyUsage | unsupported | ✗ |
@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},
}