Instead of storing its own path, each StoredDict element stores
its own key and a pointer to its parent. If a dict is removed
from the db, its parent pointer is set to None. This makes
self.path return None for all branches that have been pruned.
This passes tests/tests_json_db.py and fixes issue #10000
If a force-close happens due to e.g. a feerate disagreement or an invalid signature, etc,
and the remote peer sends us an error, it can be useful if users can provide us with this error.
If the user does not have logging enabled when the error is sent, without this persistence it will likely get lost.
- was added when functions in lnsweep returned already signed tx, and signing is expensive
- get_ctx_sweep_info does not presign anymore
- cache invalidation is difficult here
- e.g. not only on new blocks, but we should e.g. also invalidate the cache when learning new preimages
- if password is needed, await future and request it from GUI
- run asyncio task for each TxBatch, so that batches can
request the password concurrently
The threshold was added a long time ago before we considered running electrum as a forwarding node.
(also, 500k sats are now worth 20x more in fiat terms, lol)
Against a forwarding node, it is actually exploitable.
- Wallet.make_unsigned_transaction takes a FeePolicy parameter
- fee sliders act on a FeePolicy instead of config
- different fee policies may be used for different purposes
- do not detect dust outputs in lnsweep, delegate that to lnwatcher
Ideally, given an on-chain backup, after the remote force-closes, we should be able to spend our anchor output,
to CPFP the remote commitment tx (assuming the channel used OPTION_ANCHORS).
To spend the anchor output, we need to be able to sign with the local funding_privkey.
Previously we derived the funding_key from the channel_seed (which comes from os.urandom).
Prior to anchors, there was no use case for signing with the funding_key given a channel backup.
Now with anchors, we should make its derivation deterministic somehow, in a way so that it can
be derived given just an on-chain backup.
- one way would be to put some more data into the existing OP_RETURN
- uses block space
- the OP_RETURNs can be disabled via "use_recoverable_channels"
- only the initiator can use OP_RETURNs (so what if channel is in incoming dir?)
- instead, new scheme for our funding_key:
- we derive the funding_privkey from the lnworker root secret (derived from our bip32 seed)
- for outgoing channels:
- lnworker_root_secret + remote_node_id + funding_tx_nlocktime
- for incoming channels:
- lnworker_root_secret + remote_node_id + remote_funding_pubkey
- a check is added to avoid reusing the same key between channels:
not letting to user open more than one channel with the same peer in a single block
- only the first 16 bytes of the remote_node_id are used, as the onchain backup OP_RETURNs only contain that
- as the funding_privkey cannot be derived from the channel_seed anymore, it is included in the
imported channel backups, which in turn need a new version defined
- a wallet db upgrade is used to update already stored imported cbs
- alternatively we could keep the imported cbs as-is, so no new version, no new funding_privkey field, as it is clearly somewhat redundant given on-chain backups can reconstruct it
- however adding the field seems easier
- otherwise the existing code would try to derive the funding_privkey from the channel_seed
- also note: atm there is no field in the imported backups to distinguish anchor channels vs static-remotekey channels
- txins have an optional make_witness method
- instead of gen_tx, SweepInfo has a txin and
an optional txout, for 1st stage HTLCs
- sweep transactions are created by lnwatcher
The purpose of this change is to allow combining several
inputs in the same sweep transaction.
Due to anchor channel's sighash.SINGLE and sighash.ANYONECANPAY,
several HTLC-transactions can be combined. This means we must watch for
revoked outputs in the HTLC transaction not only at index 0 but at any
index.
naming scheme: tx(s)_our/their_ctx/htlctx_output-description
function names are shortened to whether a single (tx) or several sweep
transactions (txs) are generated
* sets the weight of htlc transactions to zero, thereby putting a zero
fee for the htlc transactions
* add inputs to htlc-tx for fee bumping
* switches feature flags
* disable anchor test vectors, which are now partially invalid
* add a method for backups to sweep to_remote
* to_remote sweeping needs the payment_basepoint's private key
to sign the sweep transaction
* we restore the private key from our funding multisig pubkey
(pubished with the closing transaction) and a static payment key secret
* to_remote has now an additional csv lock of 1
* anchor outputs are added if to_local/remote outputs are present
* funder balance is reduced to accomodate anchors
* changes the htlc outputs' witness script to have a csv lock of 1
* send signatures for remote ctx with ANYONECANPAY|SINGLE
* refactor htlc weight (useful for zero-fee-htlc)
* in order to be able to sweep to_remote in an onchain backup scenario
we need to retain the private key for the payment_basepoint
* to facilitate the above, we open a channel derived from a static
secret (tied to the wallet seed), the static_payment_key combined with
the funding pubkey (multisig_key), which we can restore from the channel
closing transaction
This will be useful if we decide to ship lntransport as a separate
package. It is also a conceptual cleanup.
Notes:
- lntransport still requires crypto.py
- parsing node id from a bolt11 invoice is not supported.
We were already reserving wallet addresses for full channels.
Now we also do the same for imported channel backups.
(but not for onchain, as we don't have enough info for that)
Without this, if the same seed is used on multiple devices (with each
device having its own set of LN channels), the wallet instances will
reuse keys (specifically the payment_basepoint, which for
static_remotekey chans is used as the to_remote output).
Now with this change, at least if the wallet instances have imported
channel backups of each other, this reuse is avoided.
Instead of some functions operating with hex strings,
and others using bytes, this consolidates most things to use bytes.
This mainly focuses on bitcoin.py and transaction.py,
and then adapts the API usages in other files.
Notably,
- scripts,
- pubkeys,
- signatures
should be bytes in almost all places now.
