commit 83fcdbd561ee3a72a78eabe16cb9aee57fdf67b3
parent 00f15d491b3569549e6553b8cbb28ba8738bd39c
Author: SomberNight <somber.night@protonmail.com>
Date: Sat, 7 Sep 2019 07:37:13 +0200
lnchannel: handle htlc-address collisions
We were previously generating an incorrect commitment_signed msg if there were
multiple htlcs sharing the same scriptPubKey.
Diffstat:
4 files changed, 219 insertions(+), 157 deletions(-)
diff --git a/electrum/lnchannel.py b/electrum/lnchannel.py
@@ -46,7 +46,7 @@ from .lnutil import (Outpoint, LocalConfig, RemoteConfig, Keypair, OnlyPubkeyKey
HTLC_TIMEOUT_WEIGHT, HTLC_SUCCESS_WEIGHT, extract_ctn_from_tx_and_chan, UpdateAddHtlc,
funding_output_script, SENT, RECEIVED, LOCAL, REMOTE, HTLCOwner, make_commitment_outputs,
ScriptHtlc, PaymentFailure, calc_onchain_fees, RemoteMisbehaving, make_htlc_output_witness_script,
- ShortChannelID)
+ ShortChannelID, map_htlcs_to_ctx_output_idxs)
from .lnutil import FeeUpdate
from .lnsweep import create_sweeptxs_for_our_ctx, create_sweeptxs_for_their_ctx
from .lnsweep import create_sweeptx_for_their_revoked_htlc
@@ -291,24 +291,23 @@ class Channel(Logger):
self.config[REMOTE].next_per_commitment_point)
their_remote_htlc_privkey = their_remote_htlc_privkey_number.to_bytes(32, 'big')
- for_us = False
-
htlcsigs = []
- # they sent => we receive
- for we_receive, htlcs in zip([True, False], [self.included_htlcs(REMOTE, SENT, ctn=next_remote_ctn),
- self.included_htlcs(REMOTE, RECEIVED, ctn=next_remote_ctn)]):
- for htlc in htlcs:
- _script, htlc_tx = make_htlc_tx_with_open_channel(chan=self,
+ htlc_to_ctx_output_idx_map = map_htlcs_to_ctx_output_idxs(chan=self,
+ ctx=pending_remote_commitment,
pcp=self.config[REMOTE].next_per_commitment_point,
- for_us=for_us,
- we_receive=we_receive,
- commit=pending_remote_commitment,
- htlc=htlc)
- sig = bfh(htlc_tx.sign_txin(0, their_remote_htlc_privkey))
- htlc_sig = ecc.sig_string_from_der_sig(sig[:-1])
- htlc_output_idx = htlc_tx.inputs()[0]['prevout_n']
- htlcsigs.append((htlc_output_idx, htlc_sig))
-
+ subject=REMOTE,
+ ctn=next_remote_ctn)
+ for (direction, htlc), (ctx_output_idx, htlc_relative_idx) in htlc_to_ctx_output_idx_map.items():
+ _script, htlc_tx = make_htlc_tx_with_open_channel(chan=self,
+ pcp=self.config[REMOTE].next_per_commitment_point,
+ subject=REMOTE,
+ htlc_direction=direction,
+ commit=pending_remote_commitment,
+ ctx_output_idx=ctx_output_idx,
+ htlc=htlc)
+ sig = bfh(htlc_tx.sign_txin(0, their_remote_htlc_privkey))
+ htlc_sig = ecc.sig_string_from_der_sig(sig[:-1])
+ htlcsigs.append((ctx_output_idx, htlc_sig))
htlcsigs.sort()
htlcsigs = [x[1] for x in htlcsigs]
@@ -329,8 +328,9 @@ class Channel(Logger):
This docstring is from LND.
"""
+ # TODO in many failure cases below, we should "fail" the channel (force-close)
next_local_ctn = self.get_next_ctn(LOCAL)
- self.logger.info("receive_new_commitment")
+ self.logger.info(f"receive_new_commitment. ctn={next_local_ctn}, len(htlc_sigs)={len(htlc_sigs)}")
assert len(htlc_sigs) == 0 or type(htlc_sigs[0]) is bytes
@@ -342,45 +342,48 @@ class Channel(Logger):
htlc_sigs_string = b''.join(htlc_sigs)
- htlc_sigs = htlc_sigs[:] # copy cause we will delete now
- for htlcs, we_receive in [(self.included_htlcs(LOCAL, SENT, ctn=next_local_ctn), False),
- (self.included_htlcs(LOCAL, RECEIVED, ctn=next_local_ctn), True)]:
- # FIXME this is quadratic. BOLT-02: "corresponding to the ordering of the commitment transaction"
- for htlc in htlcs:
- idx = self.verify_htlc(htlc, htlc_sigs, we_receive, pending_local_commitment)
- del htlc_sigs[idx]
- if len(htlc_sigs) != 0: # all sigs should have been popped above
- raise Exception('failed verifying HTLC signatures: invalid amount of correct signatures')
+ _secret, pcp = self.get_secret_and_point(subject=LOCAL, ctn=next_local_ctn)
+
+ htlc_to_ctx_output_idx_map = map_htlcs_to_ctx_output_idxs(chan=self,
+ ctx=pending_local_commitment,
+ pcp=pcp,
+ subject=LOCAL,
+ ctn=next_local_ctn)
+ if len(htlc_to_ctx_output_idx_map) != len(htlc_sigs):
+ raise Exception(f'htlc sigs failure. recv {len(htlc_sigs)} sigs, expected {len(htlc_to_ctx_output_idx_map)}')
+ for (direction, htlc), (ctx_output_idx, htlc_relative_idx) in htlc_to_ctx_output_idx_map.items():
+ htlc_sig = htlc_sigs[htlc_relative_idx]
+ self.verify_htlc(htlc=htlc,
+ htlc_sig=htlc_sig,
+ htlc_direction=direction,
+ pcp=pcp,
+ ctx=pending_local_commitment,
+ ctx_output_idx=ctx_output_idx)
self.hm.recv_ctx()
self.config[LOCAL]=self.config[LOCAL]._replace(
current_commitment_signature=sig,
current_htlc_signatures=htlc_sigs_string)
- def verify_htlc(self, htlc: UpdateAddHtlc, htlc_sigs: Sequence[bytes], we_receive: bool, ctx) -> int:
- ctn = extract_ctn_from_tx_and_chan(ctx, self)
- secret = get_per_commitment_secret_from_seed(self.config[LOCAL].per_commitment_secret_seed, RevocationStore.START_INDEX - ctn)
- point = secret_to_pubkey(int.from_bytes(secret, 'big'))
-
+ def verify_htlc(self, *, htlc: UpdateAddHtlc, htlc_sig: bytes, htlc_direction: Direction,
+ pcp: bytes, ctx: Transaction, ctx_output_idx: int) -> None:
_script, htlc_tx = make_htlc_tx_with_open_channel(chan=self,
- pcp=point,
- for_us=True,
- we_receive=we_receive,
+ pcp=pcp,
+ subject=LOCAL,
+ htlc_direction=htlc_direction,
commit=ctx,
+ ctx_output_idx=ctx_output_idx,
htlc=htlc)
pre_hash = sha256d(bfh(htlc_tx.serialize_preimage(0)))
- remote_htlc_pubkey = derive_pubkey(self.config[REMOTE].htlc_basepoint.pubkey, point)
- for idx, sig in enumerate(htlc_sigs):
- if ecc.verify_signature(remote_htlc_pubkey, sig, pre_hash):
- return idx
- else:
- raise Exception(f'failed verifying HTLC signatures: {htlc}, sigs: {len(htlc_sigs)}, we_receive: {we_receive}')
+ remote_htlc_pubkey = derive_pubkey(self.config[REMOTE].htlc_basepoint.pubkey, pcp)
+ if not ecc.verify_signature(remote_htlc_pubkey, htlc_sig, pre_hash):
+ raise Exception(f'failed verifying HTLC signatures: {htlc} {htlc_direction}')
- def get_remote_htlc_sig_for_htlc(self, htlc: UpdateAddHtlc, we_receive: bool, ctx) -> bytes:
+ def get_remote_htlc_sig_for_htlc(self, *, htlc_relative_idx: int) -> bytes:
data = self.config[LOCAL].current_htlc_signatures
htlc_sigs = [data[i:i + 64] for i in range(0, len(data), 64)]
- idx = self.verify_htlc(htlc, htlc_sigs, we_receive=we_receive, ctx=ctx)
- remote_htlc_sig = ecc.der_sig_from_sig_string(htlc_sigs[idx]) + b'\x01'
+ htlc_sig = htlc_sigs[htlc_relative_idx]
+ remote_htlc_sig = ecc.der_sig_from_sig_string(htlc_sig) + b'\x01'
return remote_htlc_sig
def revoke_current_commitment(self):
@@ -491,10 +494,10 @@ class Channel(Logger):
else:
weight = HTLC_TIMEOUT_WEIGHT
htlcs = self.hm.htlcs_by_direction(subject, direction, ctn=ctn).values()
- fee_for_htlc = lambda htlc: htlc.amount_msat // 1000 - (weight * feerate // 1000)
- return list(filter(lambda htlc: fee_for_htlc(htlc) >= conf.dust_limit_sat, htlcs))
+ htlc_value_after_fees = lambda htlc: htlc.amount_msat // 1000 - (weight * feerate // 1000)
+ return list(filter(lambda htlc: htlc_value_after_fees(htlc) >= conf.dust_limit_sat, htlcs))
- def get_secret_and_point(self, subject, ctn) -> Tuple[Optional[bytes], bytes]:
+ def get_secret_and_point(self, subject: HTLCOwner, ctn: int) -> Tuple[Optional[bytes], bytes]:
assert type(subject) is HTLCOwner
assert ctn >= 0, ctn
offset = ctn - self.get_oldest_unrevoked_ctn(subject)
@@ -537,7 +540,7 @@ class Channel(Logger):
ctn = self.get_oldest_unrevoked_ctn(subject)
return self.get_commitment(subject, ctn)
- def create_sweeptxs(self, ctn):
+ def create_sweeptxs(self, ctn: int) -> List[Transaction]:
from .lnsweep import create_sweeptxs_for_watchtower
secret, ctx = self.get_secret_and_commitment(REMOTE, ctn)
return create_sweeptxs_for_watchtower(self, ctx, secret, self.sweep_address)
@@ -754,9 +757,8 @@ class Channel(Logger):
def sweep_ctx(self, ctx: Transaction):
txid = ctx.txid()
if self.sweep_info.get(txid) is None:
- ctn = extract_ctn_from_tx_and_chan(ctx, self)
- our_sweep_info = create_sweeptxs_for_our_ctx(self, ctx, ctn, self.sweep_address)
- their_sweep_info = create_sweeptxs_for_their_ctx(self, ctx, ctn, self.sweep_address)
+ our_sweep_info = create_sweeptxs_for_our_ctx(chan=self, ctx=ctx, sweep_address=self.sweep_address)
+ their_sweep_info = create_sweeptxs_for_their_ctx(chan=self, ctx=ctx, sweep_address=self.sweep_address)
if our_sweep_info is not None:
self.sweep_info[txid] = our_sweep_info
self.logger.info(f'we force closed.')
diff --git a/electrum/lnsweep.py b/electrum/lnsweep.py
@@ -2,7 +2,7 @@
# Distributed under the MIT software license, see the accompanying
# file LICENCE or http://www.opensource.org/licenses/mit-license.php
-from typing import Optional, Dict, List, Tuple, TYPE_CHECKING, NamedTuple
+from typing import Optional, Dict, List, Tuple, TYPE_CHECKING, NamedTuple, Callable
from enum import Enum, auto
from .util import bfh, bh2u
@@ -13,7 +13,8 @@ from .lnutil import (make_commitment_output_to_remote_address, make_commitment_o
make_htlc_tx_witness, make_htlc_tx_with_open_channel, UpdateAddHtlc,
LOCAL, REMOTE, make_htlc_output_witness_script, UnknownPaymentHash,
get_ordered_channel_configs, privkey_to_pubkey, get_per_commitment_secret_from_seed,
- RevocationStore, extract_ctn_from_tx_and_chan, UnableToDeriveSecret, SENT, RECEIVED)
+ RevocationStore, extract_ctn_from_tx_and_chan, UnableToDeriveSecret, SENT, RECEIVED,
+ map_htlcs_to_ctx_output_idxs, Direction)
from .transaction import Transaction, TxOutput, construct_witness
from .simple_config import estimate_fee
from .logging import get_logger
@@ -28,7 +29,7 @@ _logger = get_logger(__name__)
def create_sweeptxs_for_watchtower(chan: 'Channel', ctx: Transaction, per_commitment_secret: bytes,
- sweep_address: str) -> Dict[str,Transaction]:
+ sweep_address: str) -> List[Transaction]:
"""Presign sweeping transactions using the just received revoked pcs.
These will only be utilised if the remote breaches.
Sweep 'to_local', and all the HTLCs (two cases: directly from ctx, or from HTLC tx).
@@ -46,8 +47,9 @@ def create_sweeptxs_for_watchtower(chan: 'Channel', ctx: Transaction, per_commit
witness_script = bh2u(make_commitment_output_to_local_witness_script(
revocation_pubkey, to_self_delay, this_delayed_pubkey))
to_local_address = redeem_script_to_address('p2wsh', witness_script)
- output_idx = ctx.get_output_idx_from_address(to_local_address)
- if output_idx is not None:
+ output_idxs = ctx.get_output_idxs_from_address(to_local_address)
+ if output_idxs:
+ output_idx = output_idxs.pop()
sweep_tx = create_sweeptx_ctx_to_local(
sweep_address=sweep_address,
ctx=ctx,
@@ -58,15 +60,15 @@ def create_sweeptxs_for_watchtower(chan: 'Channel', ctx: Transaction, per_commit
if sweep_tx:
txs.append(sweep_tx)
# HTLCs
- def create_sweeptx_for_htlc(htlc: 'UpdateAddHtlc', is_received_htlc: bool) -> Tuple[Optional[Transaction],
- Optional[Transaction],
- Transaction]:
+ def create_sweeptx_for_htlc(*, htlc: 'UpdateAddHtlc', htlc_direction: Direction,
+ ctx_output_idx: int) -> Optional[Transaction]:
htlc_tx_witness_script, htlc_tx = make_htlc_tx_with_open_channel(chan=chan,
pcp=pcp,
- for_us=False,
- we_receive=not is_received_htlc,
+ subject=REMOTE,
+ htlc_direction=htlc_direction,
commit=ctx,
- htlc=htlc)
+ htlc=htlc,
+ ctx_output_idx=ctx_output_idx)
return create_sweeptx_that_spends_htlctx_that_spends_htlc_in_ctx(
'sweep_from_their_ctx_htlc_',
to_self_delay=0,
@@ -77,23 +79,22 @@ def create_sweeptxs_for_watchtower(chan: 'Channel', ctx: Transaction, per_commit
is_revocation=True)
ctn = extract_ctn_from_tx_and_chan(ctx, chan)
- # received HTLCs, in their ctx
- received_htlcs = chan.included_htlcs(REMOTE, RECEIVED, ctn)
- for htlc in received_htlcs:
- secondstage_sweep_tx = create_sweeptx_for_htlc(htlc, is_received_htlc=True)
- if secondstage_sweep_tx:
- txs.append(secondstage_sweep_tx)
- # offered HTLCs, in their ctx
- offered_htlcs = chan.included_htlcs(REMOTE, SENT, ctn)
- for htlc in offered_htlcs:
- secondstage_sweep_tx = create_sweeptx_for_htlc(htlc, is_received_htlc=False)
+ htlc_to_ctx_output_idx_map = map_htlcs_to_ctx_output_idxs(chan=chan,
+ ctx=ctx,
+ pcp=pcp,
+ subject=REMOTE,
+ ctn=ctn)
+ for (direction, htlc), (ctx_output_idx, htlc_relative_idx) in htlc_to_ctx_output_idx_map.items():
+ secondstage_sweep_tx = create_sweeptx_for_htlc(htlc=htlc,
+ htlc_direction=direction,
+ ctx_output_idx=ctx_output_idx)
if secondstage_sweep_tx:
txs.append(secondstage_sweep_tx)
return txs
def create_sweeptx_for_their_revoked_ctx(chan: 'Channel', ctx: Transaction, per_commitment_secret: bytes,
- sweep_address: str) -> Dict[str,Transaction]:
+ sweep_address: str) -> Optional[Callable[[], Optional[Transaction]]]:
# prep
pcp = ecc.ECPrivkey(per_commitment_secret).get_public_key_bytes(compressed=True)
this_conf, other_conf = get_ordered_channel_configs(chan=chan, for_us=False)
@@ -107,8 +108,9 @@ def create_sweeptx_for_their_revoked_ctx(chan: 'Channel', ctx: Transaction, per_
witness_script = bh2u(make_commitment_output_to_local_witness_script(
revocation_pubkey, to_self_delay, this_delayed_pubkey))
to_local_address = redeem_script_to_address('p2wsh', witness_script)
- output_idx = ctx.get_output_idx_from_address(to_local_address)
- if output_idx is not None:
+ output_idxs = ctx.get_output_idxs_from_address(to_local_address)
+ if output_idxs:
+ output_idx = output_idxs.pop()
sweep_tx = lambda: create_sweeptx_ctx_to_local(
sweep_address=sweep_address,
ctx=ctx,
@@ -117,9 +119,10 @@ def create_sweeptx_for_their_revoked_ctx(chan: 'Channel', ctx: Transaction, per_
privkey=other_revocation_privkey,
is_revocation=True)
return sweep_tx
+ return None
def create_sweeptx_for_their_revoked_htlc(chan: 'Channel', ctx: Transaction, htlc_tx: Transaction,
- sweep_address: str) -> Dict[str,Transaction]:
+ sweep_address: str) -> Optional[Tuple[str, int, int, Callable]]:
x = analyze_ctx(chan, ctx)
if not x:
return
@@ -154,8 +157,8 @@ def create_sweeptx_for_their_revoked_htlc(chan: 'Channel', ctx: Transaction, htl
-def create_sweeptxs_for_our_ctx(chan: 'Channel', ctx: Transaction, ctn: int,
- sweep_address: str) -> Dict[str,Transaction]:
+def create_sweeptxs_for_our_ctx(*, chan: 'Channel', ctx: Transaction,
+ sweep_address: str) -> Optional[Dict[str, Tuple]]:
"""Handle the case where we force close unilaterally with our latest ctx.
Construct sweep txns for 'to_local', and for all HTLCs (2 txns each).
'to_local' can be swept even if this is a breach (by us),
@@ -181,8 +184,8 @@ def create_sweeptxs_for_our_ctx(chan: 'Channel', ctx: Transaction, ctn: int,
to_remote_address = make_commitment_output_to_remote_address(their_payment_pubkey)
# test ctx
_logger.debug(f'testing our ctx: {to_local_address} {to_remote_address}')
- if ctx.get_output_idx_from_address(to_local_address) is None\
- and ctx.get_output_idx_from_address(to_remote_address) is None:
+ if not ctx.get_output_idxs_from_address(to_local_address) \
+ and not ctx.get_output_idxs_from_address(to_remote_address):
return
# we have to_local, to_remote.
# other outputs are htlcs
@@ -193,8 +196,9 @@ def create_sweeptxs_for_our_ctx(chan: 'Channel', ctx: Transaction, ctn: int,
return {}
txs = {}
# to_local
- output_idx = ctx.get_output_idx_from_address(to_local_address)
- if output_idx is not None:
+ output_idxs = ctx.get_output_idxs_from_address(to_local_address)
+ if output_idxs:
+ output_idx = output_idxs.pop()
sweep_tx = lambda: create_sweeptx_ctx_to_local(
sweep_address=sweep_address,
ctx=ctx,
@@ -206,13 +210,14 @@ def create_sweeptxs_for_our_ctx(chan: 'Channel', ctx: Transaction, ctn: int,
prevout = ctx.txid() + ':%d'%output_idx
txs[prevout] = ('our_ctx_to_local', to_self_delay, 0, sweep_tx)
# HTLCs
- def create_txns_for_htlc(htlc: 'UpdateAddHtlc', is_received_htlc: bool) -> Tuple[Optional[Transaction], Optional[Transaction]]:
- if is_received_htlc:
+ def create_txns_for_htlc(*, htlc: 'UpdateAddHtlc', htlc_direction: Direction,
+ ctx_output_idx: int, htlc_relative_idx: int):
+ if htlc_direction == RECEIVED:
try:
preimage = chan.lnworker.get_preimage(htlc.payment_hash)
except UnknownPaymentHash as e:
_logger.info(f'trying to sweep htlc from our latest ctx but getting {repr(e)}')
- return None, None
+ return
else:
preimage = None
htlctx_witness_script, htlc_tx = create_htlctx_that_spends_from_our_ctx(
@@ -222,7 +227,9 @@ def create_sweeptxs_for_our_ctx(chan: 'Channel', ctx: Transaction, ctn: int,
htlc=htlc,
local_htlc_privkey=our_htlc_privkey,
preimage=preimage,
- is_received_htlc=is_received_htlc)
+ htlc_direction=htlc_direction,
+ ctx_output_idx=ctx_output_idx,
+ htlc_relative_idx=htlc_relative_idx)
sweep_tx = lambda: create_sweeptx_that_spends_htlctx_that_spends_htlc_in_ctx(
'our_ctx_htlc_',
to_self_delay=to_self_delay,
@@ -237,12 +244,16 @@ def create_sweeptxs_for_our_ctx(chan: 'Channel', ctx: Transaction, ctn: int,
# offered HTLCs, in our ctx --> "timeout"
# received HTLCs, in our ctx --> "success"
- offered_htlcs = chan.included_htlcs(LOCAL, SENT, ctn) # type: List[UpdateAddHtlc]
- received_htlcs = chan.included_htlcs(LOCAL, RECEIVED, ctn) # type: List[UpdateAddHtlc]
- for htlc in offered_htlcs:
- create_txns_for_htlc(htlc, is_received_htlc=False)
- for htlc in received_htlcs:
- create_txns_for_htlc(htlc, is_received_htlc=True)
+ htlc_to_ctx_output_idx_map = map_htlcs_to_ctx_output_idxs(chan=chan,
+ ctx=ctx,
+ pcp=our_pcp,
+ subject=LOCAL,
+ ctn=ctn)
+ for (direction, htlc), (ctx_output_idx, htlc_relative_idx) in htlc_to_ctx_output_idx_map.items():
+ create_txns_for_htlc(htlc=htlc,
+ htlc_direction=direction,
+ ctx_output_idx=ctx_output_idx,
+ htlc_relative_idx=htlc_relative_idx)
return txs
def analyze_ctx(chan: 'Channel', ctx: Transaction):
@@ -273,8 +284,8 @@ def analyze_ctx(chan: 'Channel', ctx: Transaction):
return
return ctn, their_pcp, is_revocation, per_commitment_secret
-def create_sweeptxs_for_their_ctx(chan: 'Channel', ctx: Transaction, ctn: int,
- sweep_address: str) -> Dict[str,Transaction]:
+def create_sweeptxs_for_their_ctx(*, chan: 'Channel', ctx: Transaction,
+ sweep_address: str) -> Optional[Dict[str,Tuple]]:
"""Handle the case when the remote force-closes with their ctx.
Sweep outputs that do not have a CSV delay ('to_remote' and first-stage HTLCs).
Outputs with CSV delay ('to_local' and second-stage HTLCs) are redeemed by LNWatcher.
@@ -295,8 +306,8 @@ def create_sweeptxs_for_their_ctx(chan: 'Channel', ctx: Transaction, ctn: int,
to_remote_address = make_commitment_output_to_remote_address(our_payment_pubkey)
# test if this is their ctx
_logger.debug(f'testing their ctx: {to_local_address} {to_remote_address}')
- if ctx.get_output_idx_from_address(to_local_address) is None \
- and ctx.get_output_idx_from_address(to_remote_address) is None:
+ if not ctx.get_output_idxs_from_address(to_local_address) \
+ and not ctx.get_output_idxs_from_address(to_remote_address):
return
if is_revocation:
@@ -315,8 +326,9 @@ def create_sweeptxs_for_their_ctx(chan: 'Channel', ctx: Transaction, ctn: int,
assert our_payment_pubkey == our_payment_privkey.get_public_key_bytes(compressed=True)
# to_local is handled by lnwatcher
# to_remote
- output_idx = ctx.get_output_idx_from_address(to_remote_address)
- if output_idx is not None:
+ output_idxs = ctx.get_output_idxs_from_address(to_remote_address)
+ if output_idxs:
+ output_idx = output_idxs.pop()
prevout = ctx.txid() + ':%d'%output_idx
sweep_tx = lambda: create_sweeptx_their_ctx_to_remote(
sweep_address=sweep_address,
@@ -325,13 +337,14 @@ def create_sweeptxs_for_their_ctx(chan: 'Channel', ctx: Transaction, ctn: int,
our_payment_privkey=our_payment_privkey)
txs[prevout] = ('their_ctx_to_remote', 0, 0, sweep_tx)
# HTLCs
- def create_sweeptx_for_htlc(htlc: 'UpdateAddHtlc', is_received_htlc: bool) -> Optional[Transaction]:
+ def create_sweeptx_for_htlc(htlc: 'UpdateAddHtlc', is_received_htlc: bool,
+ ctx_output_idx: int) -> None:
if not is_received_htlc and not is_revocation:
try:
preimage = chan.lnworker.get_preimage(htlc.payment_hash)
except UnknownPaymentHash as e:
_logger.info(f'trying to sweep htlc from their latest ctx but getting {repr(e)}')
- return None
+ return
else:
preimage = None
htlc_output_witness_script = make_htlc_output_witness_script(
@@ -341,50 +354,51 @@ def create_sweeptxs_for_their_ctx(chan: 'Channel', ctx: Transaction, ctn: int,
local_htlc_pubkey=their_htlc_pubkey,
payment_hash=htlc.payment_hash,
cltv_expiry=htlc.cltv_expiry)
- htlc_address = redeem_script_to_address('p2wsh', bh2u(htlc_output_witness_script))
- # FIXME handle htlc_address collision
- # also: https://github.com/lightningnetwork/lightning-rfc/issues/448
- output_idx = ctx.get_output_idx_from_address(htlc_address)
- if output_idx is not None:
- cltv_expiry = htlc.cltv_expiry if is_received_htlc and not is_revocation else 0
- prevout = ctx.txid() + ':%d'%output_idx
- sweep_tx = lambda: create_sweeptx_their_ctx_htlc(
- ctx=ctx,
- witness_script=htlc_output_witness_script,
- sweep_address=sweep_address,
- preimage=preimage,
- output_idx=output_idx,
- privkey=our_revocation_privkey if is_revocation else our_htlc_privkey.get_secret_bytes(),
- is_revocation=is_revocation,
- cltv_expiry=cltv_expiry)
- name = f'their_ctx_htlc_{output_idx}'
- txs[prevout] = (name, 0, cltv_expiry, sweep_tx)
+
+ cltv_expiry = htlc.cltv_expiry if is_received_htlc and not is_revocation else 0
+ prevout = ctx.txid() + ':%d'%ctx_output_idx
+ sweep_tx = lambda: create_sweeptx_their_ctx_htlc(
+ ctx=ctx,
+ witness_script=htlc_output_witness_script,
+ sweep_address=sweep_address,
+ preimage=preimage,
+ output_idx=ctx_output_idx,
+ privkey=our_revocation_privkey if is_revocation else our_htlc_privkey.get_secret_bytes(),
+ is_revocation=is_revocation,
+ cltv_expiry=cltv_expiry)
+ name = f'their_ctx_htlc_{ctx_output_idx}'
+ txs[prevout] = (name, 0, cltv_expiry, sweep_tx)
+
# received HTLCs, in their ctx --> "timeout"
- received_htlcs = chan.included_htlcs(REMOTE, RECEIVED, ctn=ctn) # type: List[UpdateAddHtlc]
- for htlc in received_htlcs:
- create_sweeptx_for_htlc(htlc, is_received_htlc=True)
# offered HTLCs, in their ctx --> "success"
- offered_htlcs = chan.included_htlcs(REMOTE, SENT, ctn=ctn) # type: List[UpdateAddHtlc]
- for htlc in offered_htlcs:
- create_sweeptx_for_htlc(htlc, is_received_htlc=False)
+ htlc_to_ctx_output_idx_map = map_htlcs_to_ctx_output_idxs(chan=chan,
+ ctx=ctx,
+ pcp=their_pcp,
+ subject=REMOTE,
+ ctn=ctn)
+ for (direction, htlc), (ctx_output_idx, htlc_relative_idx) in htlc_to_ctx_output_idx_map.items():
+ create_sweeptx_for_htlc(htlc=htlc,
+ is_received_htlc=direction == RECEIVED,
+ ctx_output_idx=ctx_output_idx)
return txs
def create_htlctx_that_spends_from_our_ctx(chan: 'Channel', our_pcp: bytes,
ctx: Transaction, htlc: 'UpdateAddHtlc',
local_htlc_privkey: bytes, preimage: Optional[bytes],
- is_received_htlc: bool) -> Tuple[bytes, Transaction]:
- assert is_received_htlc == bool(preimage), 'preimage is required iff htlc is received'
+ htlc_direction: Direction, htlc_relative_idx: int,
+ ctx_output_idx: int) -> Tuple[bytes, Transaction]:
+ assert (htlc_direction == RECEIVED) == bool(preimage), 'preimage is required iff htlc is received'
preimage = preimage or b''
witness_script, htlc_tx = make_htlc_tx_with_open_channel(chan=chan,
pcp=our_pcp,
- for_us=True,
- we_receive=is_received_htlc,
+ subject=LOCAL,
+ htlc_direction=htlc_direction,
commit=ctx,
htlc=htlc,
- name=f'our_ctx_htlc_tx_{bh2u(htlc.payment_hash)}',
- cltv_expiry=0 if is_received_htlc else htlc.cltv_expiry)
- remote_htlc_sig = chan.get_remote_htlc_sig_for_htlc(htlc, we_receive=is_received_htlc, ctx=ctx)
+ ctx_output_idx=ctx_output_idx,
+ name=f'our_ctx_{ctx_output_idx}_htlc_tx_{bh2u(htlc.payment_hash)}')
+ remote_htlc_sig = chan.get_remote_htlc_sig_for_htlc(htlc_relative_idx=htlc_relative_idx)
local_htlc_sig = bfh(htlc_tx.sign_txin(0, local_htlc_privkey))
txin = htlc_tx.inputs()[0]
witness_program = bfh(Transaction.get_preimage_script(txin))
diff --git a/electrum/lnutil.py b/electrum/lnutil.py
@@ -5,7 +5,7 @@
from enum import IntFlag, IntEnum
import json
from collections import namedtuple
-from typing import NamedTuple, List, Tuple, Mapping, Optional, TYPE_CHECKING, Union, Dict
+from typing import NamedTuple, List, Tuple, Mapping, Optional, TYPE_CHECKING, Union, Dict, Set
import re
from .util import bfh, bh2u, inv_dict
@@ -50,7 +50,7 @@ class LocalConfig(NamedTuple):
funding_locked_received: bool
was_announced: bool
current_commitment_signature: Optional[bytes]
- current_htlc_signatures: List[bytes]
+ current_htlc_signatures: bytes
class RemoteConfig(NamedTuple):
@@ -383,10 +383,63 @@ def get_ordered_channel_configs(chan: 'Channel', for_us: bool) -> Tuple[Union[Lo
return conf, other_conf
-def make_htlc_tx_with_open_channel(chan: 'Channel', pcp: bytes, for_us: bool,
- we_receive: bool, commit: Transaction,
- htlc: 'UpdateAddHtlc', name: str = None, cltv_expiry: int = 0) -> Tuple[bytes, Transaction]:
+def possible_output_idxs_of_htlc_in_ctx(*, chan: 'Channel', pcp: bytes, subject: 'HTLCOwner',
+ htlc_direction: 'Direction', ctx: Transaction,
+ htlc: 'UpdateAddHtlc') -> Set[int]:
amount_msat, cltv_expiry, payment_hash = htlc.amount_msat, htlc.cltv_expiry, htlc.payment_hash
+ for_us = subject == LOCAL
+ conf, other_conf = get_ordered_channel_configs(chan=chan, for_us=for_us)
+
+ other_revocation_pubkey = derive_blinded_pubkey(other_conf.revocation_basepoint.pubkey, pcp)
+ other_htlc_pubkey = derive_pubkey(other_conf.htlc_basepoint.pubkey, pcp)
+ htlc_pubkey = derive_pubkey(conf.htlc_basepoint.pubkey, pcp)
+ preimage_script = make_htlc_output_witness_script(is_received_htlc=htlc_direction == RECEIVED,
+ remote_revocation_pubkey=other_revocation_pubkey,
+ remote_htlc_pubkey=other_htlc_pubkey,
+ local_htlc_pubkey=htlc_pubkey,
+ payment_hash=payment_hash,
+ cltv_expiry=cltv_expiry)
+ htlc_address = redeem_script_to_address('p2wsh', bh2u(preimage_script))
+ candidates = ctx.get_output_idxs_from_address(htlc_address)
+ return {output_idx for output_idx in candidates
+ if ctx.outputs()[output_idx].value == htlc.amount_msat // 1000}
+
+
+def map_htlcs_to_ctx_output_idxs(*, chan: 'Channel', ctx: Transaction, pcp: bytes,
+ subject: 'HTLCOwner', ctn: int) -> Dict[Tuple['Direction', 'UpdateAddHtlc'], Tuple[int, int]]:
+ """Returns a dict from (htlc_dir, htlc) to (ctx_output_idx, htlc_relative_idx)"""
+ htlc_to_ctx_output_idx_map = {} # type: Dict[Tuple[Direction, UpdateAddHtlc], int]
+ unclaimed_ctx_output_idxs = set(range(len(ctx.outputs())))
+ offered_htlcs = chan.included_htlcs(subject, SENT, ctn=ctn)
+ offered_htlcs.sort(key=lambda htlc: htlc.cltv_expiry)
+ received_htlcs = chan.included_htlcs(subject, RECEIVED, ctn=ctn)
+ received_htlcs.sort(key=lambda htlc: htlc.cltv_expiry)
+ for direction, htlcs in zip([SENT, RECEIVED], [offered_htlcs, received_htlcs]):
+ for htlc in htlcs:
+ cands = sorted(possible_output_idxs_of_htlc_in_ctx(chan=chan,
+ pcp=pcp,
+ subject=subject,
+ htlc_direction=direction,
+ ctx=ctx,
+ htlc=htlc))
+ for ctx_output_idx in cands:
+ if ctx_output_idx in unclaimed_ctx_output_idxs:
+ unclaimed_ctx_output_idxs.discard(ctx_output_idx)
+ htlc_to_ctx_output_idx_map[(direction, htlc)] = ctx_output_idx
+ break
+ # calc htlc_relative_idx
+ inverse_map = {ctx_output_idx: (direction, htlc)
+ for ((direction, htlc), ctx_output_idx) in htlc_to_ctx_output_idx_map.items()}
+
+ return {inverse_map[ctx_output_idx]: (ctx_output_idx, htlc_relative_idx)
+ for htlc_relative_idx, ctx_output_idx in enumerate(sorted(inverse_map))}
+
+
+def make_htlc_tx_with_open_channel(*, chan: 'Channel', pcp: bytes, subject: 'HTLCOwner',
+ htlc_direction: 'Direction', commit: Transaction, ctx_output_idx: int,
+ htlc: 'UpdateAddHtlc', name: str = None) -> Tuple[bytes, Transaction]:
+ amount_msat, cltv_expiry, payment_hash = htlc.amount_msat, htlc.cltv_expiry, htlc.payment_hash
+ for_us = subject == LOCAL
conf, other_conf = get_ordered_channel_configs(chan=chan, for_us=for_us)
delayedpubkey = derive_pubkey(conf.delayed_basepoint.pubkey, pcp)
@@ -395,8 +448,8 @@ def make_htlc_tx_with_open_channel(chan: 'Channel', pcp: bytes, for_us: bool,
htlc_pubkey = derive_pubkey(conf.htlc_basepoint.pubkey, pcp)
# HTLC-success for the HTLC spending from a received HTLC output
# if we do not receive, and the commitment tx is not for us, they receive, so it is also an HTLC-success
- is_htlc_success = for_us == we_receive
- script, htlc_tx_output = make_htlc_tx_output(
+ is_htlc_success = htlc_direction == RECEIVED
+ witness_script_of_htlc_tx_output, htlc_tx_output = make_htlc_tx_output(
amount_msat = amount_msat,
local_feerate = chan.get_next_feerate(LOCAL if for_us else REMOTE),
revocationpubkey=other_revocation_pubkey,
@@ -409,20 +462,15 @@ def make_htlc_tx_with_open_channel(chan: 'Channel', pcp: bytes, for_us: bool,
local_htlc_pubkey=htlc_pubkey,
payment_hash=payment_hash,
cltv_expiry=cltv_expiry)
- htlc_address = redeem_script_to_address('p2wsh', bh2u(preimage_script))
- # FIXME handle htlc_address collision
- # also: https://github.com/lightningnetwork/lightning-rfc/issues/448
- prevout_idx = commit.get_output_idx_from_address(htlc_address)
- assert prevout_idx is not None, (htlc_address, commit.outputs(), extract_ctn_from_tx_and_chan(commit, chan))
htlc_tx_inputs = make_htlc_tx_inputs(
- commit.txid(), prevout_idx,
+ commit.txid(), ctx_output_idx,
amount_msat=amount_msat,
witness_script=bh2u(preimage_script))
if is_htlc_success:
cltv_expiry = 0
htlc_tx = make_htlc_tx(cltv_expiry, inputs=htlc_tx_inputs, output=htlc_tx_output,
name=name, cltv_expiry=cltv_expiry)
- return script, htlc_tx
+ return witness_script_of_htlc_tx_output, htlc_tx
def make_funding_input(local_funding_pubkey: bytes, remote_funding_pubkey: bytes,
funding_pos: int, funding_txid: bytes, funding_sat: int):
diff --git a/electrum/transaction.py b/electrum/transaction.py
@@ -31,7 +31,8 @@ import struct
import traceback
import sys
from typing import (Sequence, Union, NamedTuple, Tuple, Optional, Iterable,
- Callable, List, Dict)
+ Callable, List, Dict, Set)
+from collections import defaultdict
from . import ecc, bitcoin, constants, segwit_addr
from .util import profiler, to_bytes, bh2u, bfh
@@ -1174,7 +1175,7 @@ class Transaction:
sig = self.sign_txin(i, sec, bip143_shared_txdigest_fields=bip143_shared_txdigest_fields)
self.add_signature_to_txin(i, j, sig)
- _logger.info(f"is_complete {self.is_complete()}")
+ _logger.debug(f"is_complete {self.is_complete()}")
self.raw = self.serialize()
def sign_txin(self, txin_index, privkey_bytes, *, bip143_shared_txdigest_fields=None) -> str:
@@ -1201,27 +1202,24 @@ class Transaction:
return (addr in (o.address for o in self.outputs())) \
or (addr in (txin.get("address") for txin in self.inputs()))
- def get_output_idx_from_scriptpubkey(self, script: str) -> Optional[int]:
- """Returns the index of an output with given script.
- If there are no such outputs, returns None;
- if there are multiple, returns one of them.
- """
+ def get_output_idxs_from_scriptpubkey(self, script: str) -> Set[int]:
+ """Returns the set indices of outputs with given script."""
assert isinstance(script, str) # hex
# build cache if there isn't one yet
# note: can become stale and return incorrect data
# if the tx is modified later; that's out of scope.
if not hasattr(self, '_script_to_output_idx'):
- d = {}
+ d = defaultdict(set)
for output_idx, o in enumerate(self.outputs()):
o_script = self.pay_script(o.type, o.address)
assert isinstance(o_script, str)
- d[o_script] = output_idx
+ d[o_script].add(output_idx)
self._script_to_output_idx = d
- return self._script_to_output_idx.get(script)
+ return set(self._script_to_output_idx[script]) # copy
- def get_output_idx_from_address(self, addr: str) -> Optional:
+ def get_output_idxs_from_address(self, addr: str) -> Set[int]:
script = bitcoin.address_to_script(addr)
- return self.get_output_idx_from_scriptpubkey(script)
+ return self.get_output_idxs_from_scriptpubkey(script)
def as_dict(self):
if self.raw is None:
