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• I built a minimalist SPA tool using eBPF/XDP to keep ports invisible. First project in Go!

  Hi guys, I wanted to share a project I’ve been working on called xSpa. It’s an implementation of Single Packet Authorization that works at the XDP level. I built this because I wanted something faster and more DDoS-resilient than traditional port-knocking or SPA tools that rely on userspace processing or iptables. Here, the “drop-all” logic happens right at the driver level. Key bits: L1 verification (SipHash) in kernel space. L2 (ChaCha20-Poly1305) in Go userspace. It uses the eBPF...