Introduction

This situation is often explained by the fact that features are added/modified and no review of the authorizations was performed on the application before the publishing of the new release, for cost or time issue reason.

Context

In order to try to address this situation, it’s can be interesting to automate the evaluation of the authorizations definition and implementation on the application. This, to constantly ensure that implementation of the authorizations in the application is consistent with the authorizations definition.

An authorization is often composed by 2 elements (also named dimensions): The Feature and the Logical Role that can access it (sometime a third dimension named Data is added in order to define a access that include a filtering at business data level).

The representation of the different combinations of these 2 dimensions is often named an Authorization matrix and is often formalized in an Microsoft Excel file.

During a test of an authorization, a Logical Role is also called a Point Of View.

Objective

This article describe a proposition of implementation in order to automate the tests of an authorization matrix.

This article use the assumption that 2 dimensions are used to represents an authorization for the technical proposition described and take as example a application exposing REST services.

Proposition

In order to achieve the full automation of the evaluation of the authorization matrix, the following actions has been performed:

1. Formalize the authorization matrix in a pivot format file allowing:

   1. The processing by a program in a easy way.
   2. To be read and updated by a human for the follow-up of the authorization combinations.
   3. Hierarchy in the information in order to easily materialize the different combinations.

2. Create a set of integration tests that fully use the authorization matrix pivot file as input source in order to evaluate the different combinations with:

   1. The minimum possible of maintenance when the authorization matrix pivot file is updated.
   2. A clear indication, in case of failed test, of the source authorization combination that do not respect the authorization matrix.

The XML format has been used to formalize the authorization matrix.

The XML structure contains 3 main sections:

• Node roles: This node describe the possible logical roles used in the system, is used to provide a list and the explanation of the different roles (authorization level).
• Node services: This node list and describe the available services exposed by the system and the associated logical role(s) that can call them.

This is an example of the XML used to represents the authorization:

Placeholders (values between {}) are used to mark location where test value must be placed by the integration tests if needed

Integration tests

Parsing, object mapping and access to the authorization matrix information has been implemented using XML marshalling/unmarshalling built-in features provided by the technology used to implements the tests (JAXB here) in order to limit the code to the one in charge of performing the tests.

This the implementation of the integration tests case class:

In case of detection of a authorization issue(s) the output is the following:

Rendering of the authorization matrix for audit / review

Even if the authorization matrix is stored in a human readable format (XML), it can be interesting to provide an on-the-fly rendering representation of the XML file in order to facilitate the review, audit and discussion about the authorization matrix in order to spot potential inconsistencies.

The Following XSL stylesheet can be used:

Example of the rendering:

Sources of the prototype