Exploring the development of a firewall using Windows filtering platform

• Main Author: Pang, Willy Boon Tee.
• Other Authors: Woo Wing Keong
• Format: Final Year Project
• Language: English
• Published: 2009
• Subjects: DRNTU::Engineering::Computer science and engineering::Computer systems organization::Computer-communication networks
• Online Access: http://hdl.handle.net/10356/17030
• Institution: Nanyang Technological University

Due to the awareness of a need for personal firewall to protect their privacy, demand for personal firewall has been increasing exponentially. Different companies produce personal firewall in different ways, each promoting their best functionality. With the ongoing competition, the real need of the consumer has long been forgotten. It is no longer what the home user needs, it has become what they can provide, raising the standards of firewall. The closely guarded code for profit has also made it difficult for the open source community to enhance a firewall. This project aims to develop a truly personal firewall, not only for the fulfilment of requirements for FYP but also for the benefit of the open source community. A firewall can never be 100% safe from being compromised. In order to compensate for this shortcoming, a firewall should be built with a connection monitor. Using this monitor, the user is able to check his connection anytime for discrepancies. For filtering with the current state of technology, the days of simple packet filtering through ports or IP are gone. For a firewall to live up to today’s standard, filtering by application is required. This allows for faster filtering and more flexibility in internet applications. A firewall is also required to have learning mode, allowing the user the ability to block or allow an application to connect upon its initial execution. Last but not least, a firewall has to be able to save its data so it can be retrieved easily. Not only that, its saved file should be protected against tampering that could cripple the firewall if tampering goes uncovered. The data for the firewall should be rebuilt if saved data is being altered in any other way. A firewall application is modelled based on the above criteria. It has a connection monitor, an application list built from learning mode, the ability to permit/block specific applications that uses the same port, automatic loading and saving of data upon executing and closing of the program respectively. To improve the usability of the firewall, filters are added dynamically so that in times of crashes or illegal shut down, the program will not affect the operating system. The saved file is hashed to maintain the integrity of the data to prevent unauthorized programs from being added to the permit list. Although far from perfect, these components fulfil the requirements of the project and met the objective of developing a firewall in Windows Vista.