Participants : Abdelkader Lahmadi [ contact ] , Olivier Festor.
SecSip  is developed by the team to defend SIP-based (The Session Initiation Protocol) services from known vulnerabilities. It presents a proactive point of defense between a SIP-based network of devices (servers, proxies, user agents) and the open Internet. Therefore, all SIP traffic is inspected and analyzed against authored Veto specification before it is forwarded to these devices. When initializing, the SecSIP runtime starts loading and parsing authored VeTo blocks to identify different variables, event patterns, operations and actions from each rule. It implements an input and output layer, to capture, inject, send and receive SIP packets from and to the network. Intercepted packets are moved to the SIP Packet parser module. The main function of this module is to extract different fields within a SIP message and trigger events specified within the definition blocks. During each execution cycle when a SIP message arrives, the SecSIP runtime uses a data flow acyclic graph network to find definition matching rules and triggers defined events.
The paired events in each operator node are propagated over the graph until a pattern is satisfied. When the pattern is satisfied, the respective rule is fired and the set of actions is executed. More details on SecSIP can be found on the web site of the tool(http://secsip.gforge.inria.fr ).