A secure web server must be capable of receiving mass amount of malicious input without misbehaving or performing illegal actions, such as stepping outside of a memory block or otherwise spilling the beans.

Continuous fuzzing under various sanitizers is done as part of the Google OSS-Fuzz project:

UndefinedBehaviorSanitizer
AddressSanitizer
MemorySanitizer

Currently the following parts are individually fuzzed:

WebSocket handshake generator
WebSocket message parser
WebSocket extensions parser & negotiator
WebSocket permessage-deflate compression/inflation helper
Http parser
Http method/url router

While entire (mocked) examples are fuzzed:

HelloWorld
EchoServer

No defects or issues are left unfixed, covered up or otherwise neglected. In fact we cannot cover up security issues as OSS-Fuzz automatically and publicly reports security issues as they happen.

Currently we are at ~80% total fuzz coverage and OSS-Fuzz is reporting zero issues whatsoever. The goal is to approach 90% total coverage.

Security awards

Google have sent us thousands of USD for the integration with OSS-Fuzz - we continue working on bettering the testing with every new release.