OS Fundamentals - Kernel TLS | The Backend Engineering Show

Fundamentals of Operating Systems Course https://oscourse.win ktls is brilliant. TLS encryption/decryption often happens in userland. While TCP lives in the kernel. With ktls, userland can hand the keys to the kernel and the kernel does crypto. When calling write, the kernel encrypts the packet and send it to the NIC. When calling read, the kernel decrypts the packet and handed it to the userspace. This mode still taxes the host’s CPU of course, so there is another mode where the kernel offloads the crypto to the NIC device! Host CPU becomes free. Incoming packets to the NIC are decrypted in device before they are DMAed to the kernel. outgoing packets are encrypted before they leave the NIC to the network. ktls still need handshake to happen in userspace. There is also enabling zerocopy in some cases (now that kernel has context) Deserves a video. So much good stuff. 0:00 Intro 2:00 Userspace SSL Libraries 3:00 ktls 6:00 Kernel Encrypts/Decrypts (TLS_SW) 8:20 NIC offload mode (TLS_HW) 10:15 NIC does it all (TLS_HW_RECORD) 12:00 Write TX Example 13:50 Read RX Example 17:00 Zero copy (sendfile) https://docs.kernel.org/networking/tls-offload.html NodeJS Internals and Architecture https://node.win Backend Troubleshooting Course https://performance.husseinnasser.com Fundamentals of Backend Engineering https://backend.win Fundamentals of Networking for Effective Backends udemy course (link redirects to udemy with coupon) https://network.husseinnasser.com Fundamentals of Database Engineering udemy course (link redirects to udemy with coupon) https://database.husseinnasser.com Follow me on Medium https://medium.com/@hnasr/membership Introduction to NGINX (link redirects to udemy with coupon) https://nginx.husseinnasser.com Python on the Backend (link redirects to udemy with coupon) https://python.husseinnasser.com Become a Member on YouTube https://www.youtube.com/channel/UC_ML5xP23TOWKUcc-oAE_Eg/join Buy me a coffee if you liked this https://www.buymeacoffee.com/hnasr Arabic Software Engineering Channel https://www.youtube.com/channel/UChWZsjdoRvZ0T9QWZOD6UpA 🔥 Members Only Content https://www.youtube.com/playlist?list=UUMO_ML5xP23TOWKUcc-oAE_Eg 🏭 Backend Engineering Videos in Order https://backend.husseinnasser.com 💾 Database Engineering Videos https://www.youtube.com/playlist?list=PLQnljOFTspQXjD0HOzN7P2tgzu7scWpl2 🎙️Listen to the Backend Engineering Podcast https://husseinnasser.com/podcast Gears and tools used on the Channel (affiliates) 🖼️ Slides and Thumbnail Design Canva https://partner.canva.com/c/2766475/647168/10068 Stay Awesome, Hussein