VLANs decide which networks can talk. They say nothing about which people can. Part 5 of the homelab series: a central identity service in its own VM, Tailscale as the front door, and why the break-glass path matters more than the lock.
One round trip now negotiates keys, proves identity, and encrypts everything after the first message. What actually happens in a TLS 1.3 handshake, why it's structurally safer than 1.2, and where the remaining sharp edges live.
A classic stack smash overwrites the return address and hijacks execution. Stack canaries are the cheap, clever defense your compiler inserts automatically — and understanding them explains a whole class of exploits.
The same pattern runs in microseconds in Go and hangs for years in JavaScript, on the same input. The reason is a fork in engine design made in the 1970s — automata vs backtracking — and it's why one regex took Cloudflare's edge offline.
Exposing one service teaches you TLS. Exposing ten teaches you reverse proxies, DNS, network segmentation, and the uncomfortable truth that your smart bulbs are on the same wire as your NAS. A field guide to the plumbing.
Every packet's last hop is decided not by routing but by a 1982 protocol with no authentication, a cache with quirks, and failure modes — gratuitous ARP, proxy ARP, spoofing — that explain a shocking fraction of 'the network is weird' tickets.
UB doesn't mean 'returns garbage' — it means the optimizer may assume it never happens and reason backwards from that. How signed overflow checks get deleted, why time-travel is real, and the sanitizer workflow that catches it.
Every exploit needs an address; ASLR's bet is that the attacker shouldn't know any. How Linux randomizes stack, heap, and libraries, why PIE took years to become default, and the leak-one-pointer reality that keeps ASLR a speed bump, not a wall.
A single unbounded copy can hand an attacker your instruction pointer. The classic stack smash, then the 25-year arms race — stack canaries, NX, ASLR — that turned a reliable exploit into a hard research problem.