IPC control

The Kaspersky Security Module is integrated into the IPC implementation mechanism. The security module is aware of the contents of IPC messages for all possible interactions because IDL, CDL and EDL descriptions are used to generate the source code of this module. This enables the security module to verify that the interactions between processes comply with the solution security policy.

The KasperskyOS kernel queries the security module each time a process sends an IPC message to another process. The security module operating scenario includes the following steps:

1. The security module verifies that the IPC message complies with the called method of the endpoint (the size of the IPC message is verified along with the size and location of certain structural elements).
2. If the IPC message is incorrect, the security module makes the "deny" decision and the next step of the scenario is not carried out. If the IPC message is correct, the next step of the scenario is carried out.
3. The security module checks whether the security rules allow the requested action. If allowed, the security module makes the "granted" decision. Otherwise it makes the "denied" decision.

The kernel executes the security module decision. In other words, it either delivers the IPC message to the recipient process or rejects its delivery. If delivery of an IPC message is rejected, the sender process receives an error code via the return code of the Call() or Reply() system call.

The security module checks IPC requests as well as IPC responses. The figure below depicts the controlled exchange of IPC messages between a client and a server.

Controlled exchange of IPC messages between a client and a server