docs: document tor v2 onion handling in 0.21 release notes
What the developer wrote
Authored by Erick Cestari
docs: document tor v2 onion handling in 0.21 release notes
Add a 0.21 release-notes entry covering the `--tor.v2` removal, the
boundary rejection of v2 input on operator entry points, the
persisted-state filtering (self-node announcement, watchtower client,
autopilot, graph bootstrapper, SCB restore), the Tor controller's
v3-only ADD_ONION restriction, and the wire-faithful behavior that
preserves peer-signed v2 entries through `lnwire`, `graph/db`, and
the graph RPCs.
What changed, and why it matters
This commit only adds documentation to the 0.21.0 release notes. It describes how LND now rejects old-style Tor v2 onion addresses at configuration and command boundaries, filters them from several internal persisted-state paths, and preserves wire-faithful handling of peer-signed v2 announcements. There is no code change in this commit, so it does not itself fix or introduce a vulnerability.
No action required for this commit. Review PR #10813 and the actual implementation commits if assessing the security of the Tor v2 removal.
Security signals we found
Documentation-only change
Summarizes prior Tor v2 deprecation/removal behavior
No functional code diff
Evidence from the diff
The diff is a documentation-only addition to docs/release-notes/release-notes-0.21.0.md summarizing PR #10813. It explains the removal of the –tor.v2 flag and tor.OnionHostToFakeIP, boundary rejection of v2 .onion strings in –externalip, –listen, lncli connect, and lncli wtclient towers add, persisted-state filtering for self-node announcements, watchtower client tower addresses, autopilot, graph bootstrapper, and SCB restore, v3-only ADD_ONION in the Tor controller, and byte-for-byte round-tripping of peer-signed v2 addresses through lnwire/graph/db and graph RPCs. No executable code is modified.
Changed components
docs/release-notes/release-notes-0.21.0.mdInspect captured patch +26 / −0
diff --git a/docs/release-notes/release-notes-0.21.0.md b/docs/release-notes/release-notes-0.21.0.md
index 1f96ba1..d05d1bc 100644
--- a/docs/release-notes/release-notes-0.21.0.md
+++ b/docs/release-notes/release-notes-0.21.0.md
@@ -282,6 +282,32 @@
14 and 8 respectively, now reserved). Callers must use the multi-channel
`outgoing_chan_ids` field introduced in 0.20.
+* [Removed the deprecated `--tor.v2` configuration
+ flag](https://github.com/lightningnetwork/lnd/pull/10813). Tor stopped
+ serving v2 onion services in October 2021, and lnd no longer produces
+ v2 on any code path; `tor.OnionHostToFakeIP` is also gone. Operator
+ input is rejected at the boundary: `--externalip`, `--listen`,
+ `lncli connect`, and `lncli wtclient towers add` fail fast on a v2
+ `.onion` string, so operators upgrading with a v2 entry in
+ `lnd.conf` must remove it before lnd will start. Persisted state
+ carried over from a previous version is also filtered before use:
+ the self-node announcement strips any v2 entry from the source-node
+ record before signing; the watchtower client drops v2 entries from
+ each persisted tower's address list (skipping the tower entirely if
+ no non-v2 address remains, so the operator can attach a fresh v3
+ address); the autopilot connector, graph bootstrapper, and
+ static-channel backup restore paths skip v2 entries before attempting
+ outbound dials. The Tor controller's `ADD_ONION` path is restricted
+ to v3 keys, including the encrypted on-disk legacy-key fallback. The
+ on-disk records themselves are left intact.
+
+ Peer-signed announcements that still carry v2 are handled
+ byte-for-byte: the `lnwire` and `graph/db` codecs round-trip v2 so
+ `DataToSign` reproduces the signed bytes, signatures validate, and
+ the announcement is persisted and re-broadcast unchanged. RPCs like
+ `GetNodeInfo` and `DescribeGraph` still expose the full address
+ set.
+
## Performance Improvements
* Let the [channel graph cache be populated
Why this scored 15/100
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