This new `Transaction.verify_sig_for_txin` function is an instance method of `Transaction` instead of `PartialTransaction`.
It takes a complete txin, a pubkey and a signature, and verifies the signature.
- `get_preimage_script` is renamed to `get_scriptcode_for_sighash` and now effectively has two implementations:
- the old impl became `PartialTxInput.get_scriptcode_for_sighash`
- this assumes we are the ones constructing a spending txin and can have knowledge beyond what will be revealed onchain
- the new impl is in the base class, `TxInput.get_scriptcode_for_sighash`
- this assumes the txin is already "complete", and mimics a consensus-verifier by extracting the required fields
from the already complete witness/scriptSig and the scriptpubkey of the funding utxo
- `serialize_preimage` now does not require a PartialTransaction, it also works on the base class Transaction
-----
I intend to use this for debugging only atm: I noticed TxBatcher sometimes creates invalid signatures by seeing
that bitcoind rejects txs with `mandatory-script-verify-flag-failed (Signature must be zero for failed CHECK(MULTI)SIG operation)`.
However the txs in question have multiple txins, with some txins containing multiple signatures, and bitcoind does not tell us
which txin/signature is invalid. Knowing which signature is invalid would be a start, but I can now add some temp debug logging
to `serialize_preimage` to compare the message being signed with the message being verified.
As can be seen from the tests, the signature and the pubkey needs to be manually extracted from the txin to be verified:
we still don't have a script interpreter so we don't have logic to "verify a txin". However this new code adds logic
to verify a signature for a txin/pubkey combo (which is a small part of an interpreter/verifier).
adds some delay before detecting the scrollbar in the terms of use
dialog. This prevents it from falsely detecting a scrollbar and
disabling the "I Agree" button even if there is no scrollbar. I noticed this
issue on windows, the order in which the window is created seems to be
slightliy different from linux/wayland there.
- 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
tx_height comes from the `get_history` RPC, we then call the `get_transaction` RPC.
By the time the `get_transaction` RPC returns, we might have received another
scripthash status update, called `get_history` again, and updated height for the txid.
Synchronizer._get_transaction() should not call adb.receive_tx_callback() with
the old tx_height (but it was doing exactly that).
Patch to trigger, e.g. regtest failures:
(e.g. for tests.regtest.TestLightningAB.test_extract_preimage)
```
diff --git a/electrum/interface.py b/electrum/interface.py
index 8649652b9c..fce7a1c6de 100644
--- a/electrum/interface.py
+++ b/electrum/interface.py
@@ -991,6 +991,7 @@ class Interface(Logger):
return res
async def get_transaction(self, tx_hash: str, *, timeout=None) -> str:
+ await asyncio.sleep(3)
if not is_hash256_str(tx_hash):
raise Exception(f"{repr(tx_hash)} is not a txid")
raw = await self.session.send_request('blockchain.transaction.get', [tx_hash], timeout=timeout)
```
part configs
I noticed certain ln payments become very unreliable. These payments are ~21k sat, from gossip to gossip sender, with direct, unannounced channel.
Due to the recent fix https://github.com/spesmilo/electrum/pull/9723 `LNPathFinder.get_shortest_path_hops()` will not use channels for the last hop of a route anymore that aren't also passed to it in `my_sending_channels`:
```python
if edge_startnode == nodeA and my_sending_channels: # payment outgoing, on our channel
if edge_channel_id not in my_sending_channels:
continue
```
Conceptually this makes sense as we only want to send through `my_sending_channels`, however if the only channel between us and the receiver is a direct channel that we got from the r_tag and it's not passed in `my_sending_channel` it's not able to construct a route now.
Previously this type of payment worked as `get_shortest_path_hops()` knew of the direct channel between us and `nodeB` from the invoices r_tag and then just used this channel as the route, even though it was (often) not contained in `my_sending_channels`.
`my_sending_channels`, passed in `LNWallet.create_routes_for_payment()` is either a single channel or all our channels, depending on `is_multichan_mpp`:
```python
for sc in split_configurations:
is_multichan_mpp = len(sc.config.items()) > 1
```
This causes the unreliable, random behavior as `LNWallet.suggest_splits()` is supposed to `exclude_single_part_payments` if the amount is > `MPP_SPLIT_PART_MINAMT_SAT` (5000 sat).
As `mpp_split.py suggest_splits()` is selecting channels randomly, and then removes single part configs, it sometimes doesn't return a single configuration, as it removes single part splits, and also removes multi part splits if a part is below 10 000 sat:
```python
if target_parts > 1 and config.is_any_amount_smaller_than_min_part_size():
continue
```
This will result in a fallback to allow single part payments:
```python
split_configurations = get_splits()
if not split_configurations and exclude_single_part_payments:
exclude_single_part_payments = False
split_configurations = get_splits()
```
Then the payment works as all our channels are passed as `my_sending_channels` to `LNWallet.create_routes_for_payment()`.
However sometimes this fallback doesn't happen, because a few mpp configurations found in the first iteration of `suggest_splits` have been kept, e.g. [10500, 10500], but at the same time most others have been removed as they crossed the limit, e.g. [11001, 9999], (which happens sometimes with payments ~20k sat), this makes `suggest_splits` return very few usable channels/configurations (sometimes just one or two, even with way more available channels).
This makes payments in this range unreliable as we do not retry to generate new split configurations if the following path finding fails with `NoPathFound()`, and there is no single part configuration that allows the path finding to access all channels. Also this does not only affect direct channel payments, but all gossip payments in this amount range.
There seem to be multiple ways to fix this, i think one simple approach is to just disable `exclude_single_part_payments` if the splitting loop already begins to sort out configs on the second iteration (the first split), as this indicates that the amount may be too small to split within the given limits, and prevents the issue of having only few valid splits returned and not going into the fallback. However this also results in increased usage of single part payments.
the update_fee logic for lightning channels was not adapted to anchor
channels causing us to send update_fee with a eta target of 2 blocks.
This causes force closes when there are mempool spikes as the fees we
try to update to are a lot higher than e.g. eclair uses. Eclair will
force close if our fee is 10x > than their fee.
This is purely informational and optional, with the main immediate use to provide the
invoice description/message/label to the transaction dialog, so it can be stored
when saving the tx in history, or passed along with PSBTs sent to cosigners.
Before, the tx description was not saved in history when an invoice was not saved before
signing and saving the tx for sending later.
Checks if the pubkey of the author sending the psbt cosigning
request is in our list of cosigner pubkeys to prevent accepting
"fake" requests from other pubkeys.
lightning: implicit save of lightning invoice with override amount deferred until actual payment is accepted.
on-chain: for now, invoice is implicitly saved when override amount is passed to ConfirmTxDialog. (this is sooner
than current desktop client, which saves - and only saves - when Pay is clicked from ConfirmTxDialog)
disable the checkbox by default, so that if a user selects Enable Proxy
in the advanced network settings, and then just clicks next with the proxy
checkbox set, doesn't end up with a invalid proxy configuration which
doesn't connect to the server and has to be fixed manually.
