Published on: 2021-09-22T23:03:50+00:00
Recent logs indicate that some newer Tor clients are refusing to connect to v2 onion services. As a result, the Lightning Network daemon (lnd) is planning to disallow users from creating v2 onion services in its next major release and may upgrade them to v3 onion service if their node supports it. To address this change, a tracking issue has been created. To determine the extent of Tor usage on the network, a script was run, revealing that out of 12,844 nodes, 8,793 were found to be using Tor. However, only around 60 v2 addresses were advertised on the network, indicating that the transition away from v2 should not cause significant disruption. It is worth noting that over half of all advertised addresses on the network are now onion services, potentially affecting payment latency, connection stability, and gossip announcement propagation.Tor v2 hidden services have already been deprecated for nearly nine months, with the Tor project planning to drop support by October 2021. Bitcoin Core has already defaulted to v3 since version 0.21.0 and intends to remove v2 support in version 0.22. Similarly, the Lightning network is likely to follow suit. C-lightning, for instance, will deprecate the configuration of Tor v2 services starting with its next release. According to the deprecation policy, C-lightning should be able to completely drop support for v2 three releases after that. However, the plans of other implementations of the Lightning network regarding Tor v2 support have not yet been shared.At the specification level, it is suggested to advise implementations to ignore the v2 addr type in the node_announcement message's addrs section. This means that nodes need to start disregarding v2 addresses, although they will still need to know the length/parse v2 Onion addresses indefinitely and store and forward them. While amending the spec to discourage the production of v2 addresses may not significantly change the receiving and processing end, it would contribute to the overall deprecation effort.In summary, the Tor Project plans to drop support for v2 hidden services in its latest release, with all supported releases expected to follow suit by October. Bitcoin Core has already transitioned to v3 and intends to remove v2 support in its upcoming release. C-lightning is also taking steps to deprecate the configuration of Tor v2 services, with other implementations of the Lightning network yet to announce their plans. The transition away from v2 will have implications for Tor users, particularly those relying on v2 hidden services, but aligning with Tor's stated deadlines and discontinuing support for v2 is considered necessary.
Updated on: 2023-07-31T23:27:59.897917+00:00