The case for crypto protocol awareness inside the OS kernel

Abstract

Separation of control and data plane is a principle increasingly used to improve the performance of network protocols and applications, such as the Web. Use of security mechanisms, such as the SSL/TLS protocol, can negate these performance gains, since such mechanisms need to be located on the data path. We argue that the same principle of separation can be applied to security mechanisms, by removing the web server from the secure data path.We present a minimal operating system extension that can improve the performance of web servers using SSL/TLS by up to 27%. Our intuition is that protocol framing and cryptographic transforms can be applied to incoming and outgoing data frames by the operating system under a policy specified by the web server. In this way, we can reduce the number of system calls and context switches to a small constant number, and the amount of data copying that involves the web server by 100%. We describe our prototype implementation for the OpenBSD operating system and quantify its performance implications.

Implementing the TLS Protocol on a Bare PC

“…In [12], performance of a TLS Web server is improved by an operating system extension implemented in OpenBSD that reduces system calls, context switching, and data copying. The bare PC implementation also eliminates system calls and OS-related overhead, and allows all protocol layers to manipulate a single copy of the data (i.e., with zero data copying), but there is no OS present.…”

“…Thu connection to port 443 is established (re connection as specified in [9]), a TLS Task the TLS Task Stack (7) and inserted into a This TLS Task, which runs when it is sched Task, is only used for handshake mess handshake is completed, the task will be ret pool (7). The entire TLS handshake is mo Transition Diagram (STD) (12), which is Object (10). This object contains the ne perform all TLS operations.…”