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Showing posts with the label iptables

Setting up wireguard

 Time has come to explore a new (well, it's not that new anymore, it was introduced in kernel 5.6) VPN technology that is more lightweight and faster on single-board computers (SBCs) than something like OpenVPN. I'm talking about Wireguard . The key takeaways for why Wireguard might be better than other VPN technologies (like OpenVPN, or IPSec) are: very small code, easier to audit runs in kernel space, not userspace  configuration can be done with standard linux tools (like ip, iproute, iptables), but there are some helper scripts that simplify setting up/starting up doesn't support cypher negotiation (thus preventing downgrade attacks) is quiet by default and doesn't reply to random packets from the Internet (difficult to scan for wireguard concentrators and try brute-force attacks) has better performance than userspace encryption (to be tested) All good network tutorials begin with a network diagram and end with a packet capture. So, let's say you want to host a ...

LG7304 "The One" Android Smart TV - tracking down the software update server

TL;DR: LG7304 Android Smart TV gets its software update server from somewhere in the Amazon cloud. The server name is not disclosed via regular DNS and most likely gets learned via some previous HTTPs connection. I have a LG7304 Android Smart TV that I want to prevent from getting updates (in the hopes it will become rootable in the future). I've been getting an annoying update message for weeks now (even though automatic updates are disabled in the menu), so I tried to suppress it via DNS. I set up port mirroring for the TV's ethernet port and captured boot traffic for analysis. It seems the TV communicates with several hosts located in Amazon AWS cloud, but without making DNS requests that return those IPs. So, it must either have them hardcoded in its firmware or must be getting them through an encrypted channel. You can get a list of IP addresses that your TV communicates with by using Wireshark -> Statistics -> Conversations -> IPv4. You can use whois (whoi...