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Python usage#

In this example, we will show an example Python script that calls the cedarling_python module and calls the authorize() function.

  • Before beginning, ensure that you have completed the building steps and are currently in a virtual Python environment that has the cedarling_python module installed. You can confirm this with pip list.
  • Run the script jans/jans-cedarling/bindings/cedarling_python/example.py from within the virtual environment.

Output#

(venv) $ python example.py
Policy store location not provided, use 'CEDARLING_LOCAL_POLICY_STORE' environment variable
Used default policy store path: example_files/policy-store.json

{"id":"0193414e-9672-786a-986c-57f48d41c4e4","time":1731967489,"log_type":"System","pdp_id":"c0ec33ff-9482-4bdc-83f6-2925a41a3280","msg":"configuration parsed successfully"}
{"id":"0193414e-9672-786a-986c-57f5379086c3","time":1731967489,"log_type":"System","pdp_id":"c0ec33ff-9482-4bdc-83f6-2925a41a3280","msg":"Cedarling Authz initialized successfully","application_id":"TestApp"}
{"id":"0193414e-9676-7d8a-b55b-3f0097355851","time":1731967489,"log_type":"Decision","pdp_id":"c0ec33ff-9482-4bdc-83f6-2925a41a3280","msg":"Result of authorize.","application_id":"TestApp","action":"Jans::Action::\"Read\"","resource":"Jans::Application::\"some_id\"","context":{"user_agent":"Linux","operating_system":"Linux","network_type":"Local","network":"127.0.0.1","geolocation":["America"],"fraud_indicators":["Allowed"],"device_health":["Healthy"],"current_time":1731967489},"person_principal":"Jans::User::\"qzxn1Scrb9lWtGxVedMCky-Ql_ILspZaQA6fyuYktw0\"","person_diagnostics":{"reason":["840da5d85403f35ea76519ed1a18a33989f855bf1cf8"],"errors":[]},"person_decision":"ALLOW","workload_principal":"Jans::Workload::\"d7f71bea-c38d-4caf-a1ba-e43c74a11a62\"","workload_diagnostics":{"reason":["444da5d85403f35ea76519ed1a18a33989f855bf1cf8"],"errors":[]},"workload_decision":"ALLOW","authorized":true}
Result of workload authorization: ALLOW
Policy ID used:
444da5d85403f35ea76519ed1a18a33989f855bf1cf8
Errors during authorization: 0

Result of person authorization: ALLOW
Policy ID used:
840da5d85403f35ea76519ed1a18a33989f855bf1cf8
Errors during authorization: 0

Explanation#

Cedarling creates principal entities from the access, ID and userinfo tokens. The action, resource and context entities are declared in code. These four entities together form the PARC format that cedarling evaluates against policies provided in the policy store. The principal entities can be either User, Workload or Role. After forming the entities, cedarling evaluates them against the policies provided in the policy store. If entity is explicitly permitted by a policy, the result of the evaluation is ALLOW, otherwise it is DENY.

In this case there are two policies in the store, one for User entities and one for Workload entities:

@444da5d85403f35ea76519ed1a18a33989f855bf1cf8
permit(
    principal is Jans::Workload,
    action in [Jans::Action::"Read"],
    resource is Jans::Application
)when{
    resource.name == "Some Application"
};

@840da5d85403f35ea76519ed1a18a33989f855bf1cf8
permit(
    principal is Jans::User,
    action in [Jans::Action::"Read"],
    resource is Jans::Application
)when{
    resource.name == "Some Application"
};

These two policies say that a Principal entity (User or Workload) is allowed to execute a Read action on an Application resource when the resource is named "Some Application". As there are no policies for Role entities, the result of the evaluation for the Role entity is DENY.

In the script, the action, resource and context entities are used to create the request and execute the authorize() call:

action = 'Jans::Action::"Read"'

resource = ResourceData.from_dict({
    "type": "Jans::Application",
    "id": "some_id",
    "app_id": "application_id",
    "name": "Some Application",
    "url": {
        "host": "jans.test",
        "path": "/protected-endpoint",
        "protocol": "http"
    }
})

context = {
    "current_time": int(time.time()),
    "device_health": ["Healthy"],
    "fraud_indicators": ["Allowed"],
    "geolocation": ["America"],
    "network": "127.0.0.1",
    "network_type": "Local",
    "operating_system": "Linux",
    "user_agent": "Linux"
}

request = Request(
    access_token,
    id_token,
    userinfo_token,
    action=action,
    resource=resource, context=context)

authorize_result = instance.authorize(request)
assert authorize_result.is_allowed()

Cedarling will return is_allowed() as True only if both the User and Workload entity evaluations are ALLOW.

Exposed functions#

The pyo3 binding for cedarling exposes a number of cedarling functions for you to use. The documentation on this can be found here.

Last update: 2024-12-12
Created: 2024-09-30