Httpwtf?

HTTP is a crucial part of modern development, but it harbors some lesser-known features and quirks. For instance, the "no-cache" directive can actually lead to caching, contrary to its name, while "private" restricts caching to end-client browsers only. Misusing cache control headers can inadvertently store sensitive data, as seen in Twitter's mishap with private messages. Additionally, HTTP trailers allow appending metadata after the message body, useful for protocols like gRPC. HTTP also supports 1XX codes like 100 for interim responses and 101 for protocol switching, commonly used for setting up websockets. Notably, websockets bypass CORS restrictions, potentially exposing vulnerabilities. The use of X-* headers for custom extensions in HTTP requests is a common practice, with examples like X-Shenanigans and X-Requested-With. Despite its quirks, HTTP remains a foundational technology in the digital landscape, facilitating communication and data exchange between clients and servers.