Security-by-Contract for the OSGi platform

The natural business model of OSGi is dynamic loading and removal of bundles or services on an OSGi platform. If bundles can come from different stakeholders, how do we make sure that one's services will only be invoked by the authorized bundles? A simple solution is to interweave functional and security logic within each bundle, but this decreases the benefits of using a common platform for service deployment and is a well-known source of errors. Our solution is to use the Security-by-Contract methodology (SxC) for loading time security verification to separate the security from the business logic while controlling access to applications. The basic idea is that each bundle has a contract embedded into its manifest, that contains details on functional requirements and permissions for access by other bundles on the platform. During bundle installation the contract is matched with the platform security policy (aggregating the contracts of the installed bundles). We illustrate the SxC met...