scenario:
- user opens a lightning channel and exports an "imported channel backup"
- user closes channel via local-force-close
- local ctx is published, to_local output has user's funds and they are CSV-locked for days
- user restores wallet file from seed and imports channel backup
- new wallet file should be able to sweep coins from to_local output (after CSV expires)
This was not working previously, as the local_payment_basepoint was not included in the
imported channel backups, and the code was interpreting the lack of this as the channel not
having option_static_remotekey enabled. This resulted in lnutil.extract_ctn_from_tx
using an incorrect funder_payment_basepoint, and lnsweep not recognising the ctx due to
the garbage ctn value.
The imported channel backup serialisation format is slightly changed to include the
previously missing field, and its version number is bumped (0->1). We allow importing
both version 0 and version 1 backups, however v0 backups cannot handle the above
described scenario (they can only be used to request a remote-force-close).
Note that we were/are setting the missing local_payment_basepoint to the pubkey of
one of the wallet change addresses, which is bruteforceable if necessary, but I
think it is not worth the complexity to add this bruteforce logic. Also note
that the bruteforcing could only be done after the local-force-close was broadcast.
Ideally people with existing channels and already exported v0 backups should re-export
v1 backups... Not sure how to handle this.
closes https://github.com/spesmilo/electrum/issues/8516
The few other cases that used SimpleConfig.get_instance() now
either get passed a config instance, or they try to get a reference
to something else that has a reference to a config.
(see lnsweep, qt/qrcodewidget, qt/qrtextedit)
- This was added because we did not store the complete htlc history.
- It makes the result dependent on the current channel state
- That creates a race condition in sweep_info, because the result is cached.
- As a result, test_breach_with_spent_htlc was randomly failing.
"current" used to be "oldest_unrevoked"; and pending was "oldest_unrevoked + 1"
but this was very confusing...
so now we have "oldest_unrevoked", "latest", and "next"
where "next" is "latest + 1"
"oldest_unrevoked" and "latest" are either the same or are offset by 1
(but caller should know which one they need)
rm "got_sig_for_next" - it was a redundant sanity check, that really
just complicated things
rm "local_commitment", "remote_commitment", "set_local_commitment",
"set_remote_commitment" - just use "get_latest_commitment" instead
- remove remote_commitment_to_be_revoked
- pass old ctns to lnsweep.create_sweeptxs_for_watchtower
- store the ctn of sweeptxs in sweepStore database
- request the highest ctn from sweepstore using get_ctn
- send sweeptxs asynchronously in LNWallet.sync_with_watchtower
- add functions to lnsweep
- lnworker: analyze candidate ctx and htlc_tx
- watchtower will be optional
- add test for breach remedy with spent htlcs
- save tx name as label
- fix bug in lnsweep: lnwatcher transactions were indexed by prev_txid
- add test for breach remedy with unsettled htlcs
- add timeout option to lnpay, and replace DO_NOT_SETTLE with SETTLE_DELAY
so that we can read intermediate commitment tx in regtest
- use detect_who_closed; this allows us to redeem to_remote of breach ctx
- do not redeem to_local of breach ctx, because it is redundant with lnwatcher
- rename a few methods
SomberNight