openserverless/security/validate_ow_auth.py

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# to you under the Apache License, Version 2.0 (the
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#
#   http://www.apache.org/licenses/LICENSE-2.0
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import logging
import openserverless.common.response_builder as res_builder

from functools import wraps
from openserverless.common.openwhisk_authorize import OpenwhiskAuthorize
from flask import request


def validate_ow_auth(ow_subject="whisk-system"):
    """
    Decorator to be applied when a rest API endpoints must be validated against the
    OpenServerless OpenWhisk whisk_system namespace using the Authorization headers, or anyway it is known in advance
    what OW authorization must be checked.
    """

    def decorator(func, **kwargs):

        @wraps(func)
        def decorated(*args, **kwargs):
            logging.info("**** validate_ow_auth start ****")
            if "authorization" not in request.headers:
                return res_builder.build_error_message(
                    "No valid authorization headers found", 401
                )

            ow_auth = OpenwhiskAuthorize()
            try:
                subject = ow_auth.subject_login(request.headers["authorization"])
                if ow_subject not in subject["subject"]:
                    return res_builder.build_error_message(
                        f"Invalid authorization for subject {ow_subject}. Access denied.",
                        401,
                    )

                return func(*args, **kwargs)
            except Exception as ex:
                return res_builder.build_error_message(
                    f"Could not validate authorization headers. Reason {ex}", 401
                )

        return decorated

    return decorator