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586 lines
26 KiB
586 lines
26 KiB
# Copyright (C) 2018 The Electrum developers
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# Distributed under the MIT software license, see the accompanying
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# file LICENCE or http://www.opensource.org/licenses/mit-license.php
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from typing import Optional, Dict, List, Tuple, TYPE_CHECKING, NamedTuple, Callable
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from enum import Enum, auto
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from .util import bfh, bh2u
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from .bitcoin import redeem_script_to_address, dust_threshold, construct_witness
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from . import ecc
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from .lnutil import (make_commitment_output_to_remote_address, make_commitment_output_to_local_witness_script,
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derive_privkey, derive_pubkey, derive_blinded_pubkey, derive_blinded_privkey,
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make_htlc_tx_witness, make_htlc_tx_with_open_channel, UpdateAddHtlc,
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LOCAL, REMOTE, make_htlc_output_witness_script,
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get_ordered_channel_configs, privkey_to_pubkey, get_per_commitment_secret_from_seed,
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RevocationStore, extract_ctn_from_tx_and_chan, UnableToDeriveSecret, SENT, RECEIVED,
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map_htlcs_to_ctx_output_idxs, Direction)
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from .transaction import (Transaction, TxOutput, PartialTransaction, PartialTxInput,
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PartialTxOutput, TxOutpoint)
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from .simple_config import SimpleConfig
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from .logging import get_logger, Logger
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if TYPE_CHECKING:
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from .lnchannel import Channel, AbstractChannel
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_logger = get_logger(__name__)
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class SweepInfo(NamedTuple):
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name: str
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csv_delay: int
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cltv_expiry: int
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gen_tx: Callable[[], Optional[Transaction]]
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def create_sweeptxs_for_watchtower(chan: 'Channel', ctx: Transaction, per_commitment_secret: bytes,
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sweep_address: str) -> List[Transaction]:
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"""Presign sweeping transactions using the just received revoked pcs.
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These will only be utilised if the remote breaches.
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Sweep 'to_local', and all the HTLCs (two cases: directly from ctx, or from HTLC tx).
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"""
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# prep
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ctn = extract_ctn_from_tx_and_chan(ctx, chan)
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pcp = ecc.ECPrivkey(per_commitment_secret).get_public_key_bytes(compressed=True)
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this_conf, other_conf = get_ordered_channel_configs(chan=chan, for_us=False)
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other_revocation_privkey = derive_blinded_privkey(other_conf.revocation_basepoint.privkey,
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per_commitment_secret)
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to_self_delay = other_conf.to_self_delay
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this_delayed_pubkey = derive_pubkey(this_conf.delayed_basepoint.pubkey, pcp)
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txs = []
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# to_local
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revocation_pubkey = ecc.ECPrivkey(other_revocation_privkey).get_public_key_bytes(compressed=True)
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witness_script = bh2u(make_commitment_output_to_local_witness_script(
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revocation_pubkey, to_self_delay, this_delayed_pubkey))
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to_local_address = redeem_script_to_address('p2wsh', witness_script)
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output_idxs = ctx.get_output_idxs_from_address(to_local_address)
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if output_idxs:
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output_idx = output_idxs.pop()
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sweep_tx = create_sweeptx_ctx_to_local(
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sweep_address=sweep_address,
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ctx=ctx,
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output_idx=output_idx,
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witness_script=witness_script,
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privkey=other_revocation_privkey,
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is_revocation=True,
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config=chan.lnworker.config)
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if sweep_tx:
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txs.append(sweep_tx)
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# HTLCs
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def create_sweeptx_for_htlc(*, htlc: 'UpdateAddHtlc', htlc_direction: Direction,
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ctx_output_idx: int) -> Optional[Transaction]:
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htlc_tx_witness_script, htlc_tx = make_htlc_tx_with_open_channel(
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chan=chan,
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pcp=pcp,
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subject=REMOTE,
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ctn=ctn,
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htlc_direction=htlc_direction,
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commit=ctx,
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htlc=htlc,
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ctx_output_idx=ctx_output_idx)
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return create_sweeptx_that_spends_htlctx_that_spends_htlc_in_ctx(
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to_self_delay=0,
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htlc_tx=htlc_tx,
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htlctx_witness_script=htlc_tx_witness_script,
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sweep_address=sweep_address,
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privkey=other_revocation_privkey,
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is_revocation=True,
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config=chan.lnworker.config)
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htlc_to_ctx_output_idx_map = map_htlcs_to_ctx_output_idxs(
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chan=chan,
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ctx=ctx,
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pcp=pcp,
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subject=REMOTE,
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ctn=ctn)
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for (direction, htlc), (ctx_output_idx, htlc_relative_idx) in htlc_to_ctx_output_idx_map.items():
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secondstage_sweep_tx = create_sweeptx_for_htlc(
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htlc=htlc,
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htlc_direction=direction,
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ctx_output_idx=ctx_output_idx)
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if secondstage_sweep_tx:
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txs.append(secondstage_sweep_tx)
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return txs
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def create_sweeptx_for_their_revoked_ctx(
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chan: 'Channel',
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ctx: Transaction,
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per_commitment_secret: bytes,
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sweep_address: str) -> Optional[Callable[[], Optional[Transaction]]]:
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# prep
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pcp = ecc.ECPrivkey(per_commitment_secret).get_public_key_bytes(compressed=True)
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this_conf, other_conf = get_ordered_channel_configs(chan=chan, for_us=False)
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other_revocation_privkey = derive_blinded_privkey(other_conf.revocation_basepoint.privkey,
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per_commitment_secret)
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to_self_delay = other_conf.to_self_delay
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this_delayed_pubkey = derive_pubkey(this_conf.delayed_basepoint.pubkey, pcp)
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txs = []
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# to_local
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revocation_pubkey = ecc.ECPrivkey(other_revocation_privkey).get_public_key_bytes(compressed=True)
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witness_script = bh2u(make_commitment_output_to_local_witness_script(
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revocation_pubkey, to_self_delay, this_delayed_pubkey))
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to_local_address = redeem_script_to_address('p2wsh', witness_script)
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output_idxs = ctx.get_output_idxs_from_address(to_local_address)
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if output_idxs:
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output_idx = output_idxs.pop()
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sweep_tx = lambda: create_sweeptx_ctx_to_local(
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sweep_address=sweep_address,
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ctx=ctx,
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output_idx=output_idx,
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witness_script=witness_script,
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privkey=other_revocation_privkey,
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is_revocation=True,
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config=chan.lnworker.config)
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return sweep_tx
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return None
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def create_sweeptx_for_their_revoked_htlc(
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chan: 'Channel',
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ctx: Transaction,
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htlc_tx: Transaction,
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sweep_address: str) -> Optional[SweepInfo]:
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x = analyze_ctx(chan, ctx)
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if not x:
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return
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ctn, their_pcp, is_revocation, per_commitment_secret = x
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if not is_revocation:
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return
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# prep
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pcp = ecc.ECPrivkey(per_commitment_secret).get_public_key_bytes(compressed=True)
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this_conf, other_conf = get_ordered_channel_configs(chan=chan, for_us=False)
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other_revocation_privkey = derive_blinded_privkey(
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other_conf.revocation_basepoint.privkey,
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per_commitment_secret)
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to_self_delay = other_conf.to_self_delay
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this_delayed_pubkey = derive_pubkey(this_conf.delayed_basepoint.pubkey, pcp)
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# same witness script as to_local
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revocation_pubkey = ecc.ECPrivkey(other_revocation_privkey).get_public_key_bytes(compressed=True)
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witness_script = bh2u(make_commitment_output_to_local_witness_script(
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revocation_pubkey, to_self_delay, this_delayed_pubkey))
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htlc_address = redeem_script_to_address('p2wsh', witness_script)
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# check that htlc_tx is a htlc
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if htlc_tx.outputs()[0].address != htlc_address:
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return
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gen_tx = lambda: create_sweeptx_ctx_to_local(
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sweep_address=sweep_address,
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ctx=htlc_tx,
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output_idx=0,
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witness_script=witness_script,
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privkey=other_revocation_privkey,
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is_revocation=True,
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config=chan.lnworker.config)
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return SweepInfo(
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name='redeem_htlc2',
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csv_delay=0,
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cltv_expiry=0,
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gen_tx=gen_tx)
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def create_sweeptxs_for_our_ctx(
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*, chan: 'AbstractChannel',
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ctx: Transaction,
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sweep_address: str) -> Optional[Dict[str, SweepInfo]]:
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"""Handle the case where we force close unilaterally with our latest ctx.
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Construct sweep txns for 'to_local', and for all HTLCs (2 txns each).
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'to_local' can be swept even if this is a breach (by us),
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but HTLCs cannot (old HTLCs are no longer stored).
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"""
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ctn = extract_ctn_from_tx_and_chan(ctx, chan)
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our_conf, their_conf = get_ordered_channel_configs(chan=chan, for_us=True)
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our_per_commitment_secret = get_per_commitment_secret_from_seed(
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our_conf.per_commitment_secret_seed, RevocationStore.START_INDEX - ctn)
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our_pcp = ecc.ECPrivkey(our_per_commitment_secret).get_public_key_bytes(compressed=True)
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our_delayed_bp_privkey = ecc.ECPrivkey(our_conf.delayed_basepoint.privkey)
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our_localdelayed_privkey = derive_privkey(our_delayed_bp_privkey.secret_scalar, our_pcp)
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our_localdelayed_privkey = ecc.ECPrivkey.from_secret_scalar(our_localdelayed_privkey)
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their_revocation_pubkey = derive_blinded_pubkey(their_conf.revocation_basepoint.pubkey, our_pcp)
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to_self_delay = their_conf.to_self_delay
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our_htlc_privkey = derive_privkey(secret=int.from_bytes(our_conf.htlc_basepoint.privkey, 'big'),
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per_commitment_point=our_pcp).to_bytes(32, 'big')
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our_localdelayed_pubkey = our_localdelayed_privkey.get_public_key_bytes(compressed=True)
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to_local_witness_script = bh2u(make_commitment_output_to_local_witness_script(
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their_revocation_pubkey, to_self_delay, our_localdelayed_pubkey))
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to_local_address = redeem_script_to_address('p2wsh', to_local_witness_script)
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# to remote address
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bpk = their_conf.payment_basepoint.pubkey
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their_payment_pubkey = bpk if chan.is_static_remotekey_enabled() else derive_pubkey(their_conf.payment_basepoint.pubkey, our_pcp)
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to_remote_address = make_commitment_output_to_remote_address(their_payment_pubkey)
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# test ctx
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_logger.debug(f'testing our ctx: {to_local_address} {to_remote_address}')
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if not ctx.get_output_idxs_from_address(to_local_address) \
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and not ctx.get_output_idxs_from_address(to_remote_address):
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return
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# we have to_local, to_remote.
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# other outputs are htlcs
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# if they are spent, we need to generate the script
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# so, second-stage htlc sweep should not be returned here
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txs = {} # type: Dict[str, SweepInfo]
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# to_local
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output_idxs = ctx.get_output_idxs_from_address(to_local_address)
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if output_idxs:
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output_idx = output_idxs.pop()
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sweep_tx = lambda: create_sweeptx_ctx_to_local(
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sweep_address=sweep_address,
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ctx=ctx,
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output_idx=output_idx,
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witness_script=to_local_witness_script,
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privkey=our_localdelayed_privkey.get_secret_bytes(),
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is_revocation=False,
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to_self_delay=to_self_delay,
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config=chan.lnworker.config)
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prevout = ctx.txid() + ':%d'%output_idx
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txs[prevout] = SweepInfo(
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name='our_ctx_to_local',
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csv_delay=to_self_delay,
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cltv_expiry=0,
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gen_tx=sweep_tx)
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we_breached = ctn < chan.get_oldest_unrevoked_ctn(LOCAL)
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if we_breached:
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_logger.info("we breached.")
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# return only our_ctx_to_local, because we don't keep htlc_signatures for old states
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return txs
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# HTLCs
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def create_txns_for_htlc(
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*, htlc: 'UpdateAddHtlc', htlc_direction: Direction,
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ctx_output_idx: int, htlc_relative_idx: int):
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if htlc_direction == RECEIVED:
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preimage = chan.lnworker.get_preimage(htlc.payment_hash)
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else:
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preimage = None
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htlctx_witness_script, htlc_tx = create_htlctx_that_spends_from_our_ctx(
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chan=chan,
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our_pcp=our_pcp,
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ctx=ctx,
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htlc=htlc,
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local_htlc_privkey=our_htlc_privkey,
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preimage=preimage,
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htlc_direction=htlc_direction,
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ctx_output_idx=ctx_output_idx,
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htlc_relative_idx=htlc_relative_idx)
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sweep_tx = lambda: create_sweeptx_that_spends_htlctx_that_spends_htlc_in_ctx(
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to_self_delay=to_self_delay,
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htlc_tx=htlc_tx,
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htlctx_witness_script=htlctx_witness_script,
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sweep_address=sweep_address,
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privkey=our_localdelayed_privkey.get_secret_bytes(),
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is_revocation=False,
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config=chan.lnworker.config)
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# side effect
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txs[htlc_tx.inputs()[0].prevout.to_str()] = SweepInfo(
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name='first-stage-htlc',
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csv_delay=0,
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cltv_expiry=htlc_tx.locktime,
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gen_tx=lambda: htlc_tx)
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txs[htlc_tx.txid() + ':0'] = SweepInfo(
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name='second-stage-htlc',
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csv_delay=to_self_delay,
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cltv_expiry=0,
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gen_tx=sweep_tx)
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# offered HTLCs, in our ctx --> "timeout"
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# received HTLCs, in our ctx --> "success"
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htlc_to_ctx_output_idx_map = map_htlcs_to_ctx_output_idxs(
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chan=chan,
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ctx=ctx,
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pcp=our_pcp,
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subject=LOCAL,
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ctn=ctn)
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for (direction, htlc), (ctx_output_idx, htlc_relative_idx) in htlc_to_ctx_output_idx_map.items():
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create_txns_for_htlc(
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htlc=htlc,
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htlc_direction=direction,
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ctx_output_idx=ctx_output_idx,
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htlc_relative_idx=htlc_relative_idx)
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return txs
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def analyze_ctx(chan: 'Channel', ctx: Transaction):
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# note: the remote sometimes has two valid non-revoked commitment transactions,
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# either of which could be broadcast
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our_conf, their_conf = get_ordered_channel_configs(chan=chan, for_us=True)
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ctn = extract_ctn_from_tx_and_chan(ctx, chan)
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per_commitment_secret = None
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oldest_unrevoked_remote_ctn = chan.get_oldest_unrevoked_ctn(REMOTE)
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if ctn == oldest_unrevoked_remote_ctn:
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their_pcp = their_conf.current_per_commitment_point
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is_revocation = False
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elif ctn == oldest_unrevoked_remote_ctn + 1:
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their_pcp = their_conf.next_per_commitment_point
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is_revocation = False
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elif ctn < oldest_unrevoked_remote_ctn: # breach
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try:
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per_commitment_secret = chan.revocation_store.retrieve_secret(RevocationStore.START_INDEX - ctn)
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except UnableToDeriveSecret:
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return
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their_pcp = ecc.ECPrivkey(per_commitment_secret).get_public_key_bytes(compressed=True)
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is_revocation = True
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#_logger.info(f'tx for revoked: {list(txs.keys())}')
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elif chan.get_data_loss_protect_remote_pcp(ctn):
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their_pcp = chan.get_data_loss_protect_remote_pcp(ctn)
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is_revocation = False
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else:
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return
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return ctn, their_pcp, is_revocation, per_commitment_secret
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def create_sweeptxs_for_their_ctx(
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*, chan: 'Channel',
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ctx: Transaction,
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sweep_address: str) -> Optional[Dict[str,SweepInfo]]:
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"""Handle the case when the remote force-closes with their ctx.
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Sweep outputs that do not have a CSV delay ('to_remote' and first-stage HTLCs).
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Outputs with CSV delay ('to_local' and second-stage HTLCs) are redeemed by LNWatcher.
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"""
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txs = {} # type: Dict[str, SweepInfo]
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our_conf, their_conf = get_ordered_channel_configs(chan=chan, for_us=True)
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x = analyze_ctx(chan, ctx)
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if not x:
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return
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ctn, their_pcp, is_revocation, per_commitment_secret = x
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# to_local and to_remote addresses
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our_revocation_pubkey = derive_blinded_pubkey(our_conf.revocation_basepoint.pubkey, their_pcp)
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their_delayed_pubkey = derive_pubkey(their_conf.delayed_basepoint.pubkey, their_pcp)
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witness_script = bh2u(make_commitment_output_to_local_witness_script(
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our_revocation_pubkey, our_conf.to_self_delay, their_delayed_pubkey))
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to_local_address = redeem_script_to_address('p2wsh', witness_script)
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# to remote address
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bpk = our_conf.payment_basepoint.pubkey
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our_payment_pubkey = bpk if chan.is_static_remotekey_enabled() else derive_pubkey(bpk, their_pcp)
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to_remote_address = make_commitment_output_to_remote_address(our_payment_pubkey)
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# test if this is their ctx
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_logger.debug(f'testing their ctx: {to_local_address} {to_remote_address}')
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if not ctx.get_output_idxs_from_address(to_local_address) \
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and not ctx.get_output_idxs_from_address(to_remote_address):
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return
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if is_revocation:
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our_revocation_privkey = derive_blinded_privkey(our_conf.revocation_basepoint.privkey, per_commitment_secret)
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gen_tx = create_sweeptx_for_their_revoked_ctx(chan, ctx, per_commitment_secret, chan.sweep_address)
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if gen_tx:
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tx = gen_tx()
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txs[tx.inputs()[0].prevout.to_str()] = SweepInfo(
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name='to_local_for_revoked_ctx',
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csv_delay=0,
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cltv_expiry=0,
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gen_tx=gen_tx)
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# prep
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our_htlc_privkey = derive_privkey(secret=int.from_bytes(our_conf.htlc_basepoint.privkey, 'big'), per_commitment_point=their_pcp)
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our_htlc_privkey = ecc.ECPrivkey.from_secret_scalar(our_htlc_privkey)
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their_htlc_pubkey = derive_pubkey(their_conf.htlc_basepoint.pubkey, their_pcp)
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# to_local is handled by lnwatcher
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# to_remote
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if not chan.is_static_remotekey_enabled():
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our_payment_bp_privkey = ecc.ECPrivkey(our_conf.payment_basepoint.privkey)
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our_payment_privkey = derive_privkey(our_payment_bp_privkey.secret_scalar, their_pcp)
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our_payment_privkey = ecc.ECPrivkey.from_secret_scalar(our_payment_privkey)
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assert our_payment_pubkey == our_payment_privkey.get_public_key_bytes(compressed=True)
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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,
|
|
ctx=ctx,
|
|
output_idx=output_idx,
|
|
our_payment_privkey=our_payment_privkey,
|
|
config=chan.lnworker.config)
|
|
txs[prevout] = SweepInfo(
|
|
name='their_ctx_to_remote',
|
|
csv_delay=0,
|
|
cltv_expiry=0,
|
|
gen_tx=sweep_tx)
|
|
# HTLCs
|
|
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:
|
|
preimage = chan.lnworker.get_preimage(htlc.payment_hash)
|
|
else:
|
|
preimage = None
|
|
htlc_output_witness_script = make_htlc_output_witness_script(
|
|
is_received_htlc=is_received_htlc,
|
|
remote_revocation_pubkey=our_revocation_pubkey,
|
|
remote_htlc_pubkey=our_htlc_privkey.get_public_key_bytes(compressed=True),
|
|
local_htlc_pubkey=their_htlc_pubkey,
|
|
payment_hash=htlc.payment_hash,
|
|
cltv_expiry=htlc.cltv_expiry)
|
|
|
|
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,
|
|
config=chan.lnworker.config)
|
|
txs[prevout] = SweepInfo(
|
|
name=f'their_ctx_htlc_{ctx_output_idx}',
|
|
csv_delay=0,
|
|
cltv_expiry=cltv_expiry,
|
|
gen_tx=sweep_tx)
|
|
# received HTLCs, in their ctx --> "timeout"
|
|
# offered HTLCs, in their ctx --> "success"
|
|
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],
|
|
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''
|
|
ctn = extract_ctn_from_tx_and_chan(ctx, chan)
|
|
witness_script, htlc_tx = make_htlc_tx_with_open_channel(
|
|
chan=chan,
|
|
pcp=our_pcp,
|
|
subject=LOCAL,
|
|
ctn=ctn,
|
|
htlc_direction=htlc_direction,
|
|
commit=ctx,
|
|
htlc=htlc,
|
|
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))
|
|
txin.witness = make_htlc_tx_witness(remote_htlc_sig, local_htlc_sig, preimage, witness_program)
|
|
return witness_script, htlc_tx
|
|
|
|
|
|
def create_sweeptx_their_ctx_htlc(
|
|
ctx: Transaction, witness_script: bytes, sweep_address: str,
|
|
preimage: Optional[bytes], output_idx: int,
|
|
privkey: bytes, is_revocation: bool,
|
|
cltv_expiry: int, config: SimpleConfig) -> Optional[PartialTransaction]:
|
|
assert type(cltv_expiry) is int
|
|
preimage = preimage or b'' # preimage is required iff (not is_revocation and htlc is offered)
|
|
val = ctx.outputs()[output_idx].value
|
|
prevout = TxOutpoint(txid=bfh(ctx.txid()), out_idx=output_idx)
|
|
txin = PartialTxInput(prevout=prevout)
|
|
txin._trusted_value_sats = val
|
|
txin.witness_script = witness_script
|
|
txin.script_sig = b''
|
|
sweep_inputs = [txin]
|
|
tx_size_bytes = 200 # TODO (depends on offered/received and is_revocation)
|
|
fee = config.estimate_fee(tx_size_bytes, allow_fallback_to_static_rates=True)
|
|
outvalue = val - fee
|
|
if outvalue <= dust_threshold(): return None
|
|
sweep_outputs = [PartialTxOutput.from_address_and_value(sweep_address, outvalue)]
|
|
tx = PartialTransaction.from_io(sweep_inputs, sweep_outputs, version=2, locktime=cltv_expiry)
|
|
sig = bfh(tx.sign_txin(0, privkey))
|
|
if not is_revocation:
|
|
witness = construct_witness([sig, preimage, witness_script])
|
|
else:
|
|
revocation_pubkey = privkey_to_pubkey(privkey)
|
|
witness = construct_witness([sig, revocation_pubkey, witness_script])
|
|
tx.inputs()[0].witness = bfh(witness)
|
|
assert tx.is_complete()
|
|
return tx
|
|
|
|
|
|
def create_sweeptx_their_ctx_to_remote(
|
|
sweep_address: str, ctx: Transaction, output_idx: int,
|
|
our_payment_privkey: ecc.ECPrivkey,
|
|
config: SimpleConfig) -> Optional[PartialTransaction]:
|
|
our_payment_pubkey = our_payment_privkey.get_public_key_hex(compressed=True)
|
|
val = ctx.outputs()[output_idx].value
|
|
prevout = TxOutpoint(txid=bfh(ctx.txid()), out_idx=output_idx)
|
|
txin = PartialTxInput(prevout=prevout)
|
|
txin._trusted_value_sats = val
|
|
txin.script_type = 'p2wpkh'
|
|
txin.pubkeys = [bfh(our_payment_pubkey)]
|
|
txin.num_sig = 1
|
|
sweep_inputs = [txin]
|
|
tx_size_bytes = 110 # approx size of p2wpkh->p2wpkh
|
|
fee = config.estimate_fee(tx_size_bytes, allow_fallback_to_static_rates=True)
|
|
outvalue = val - fee
|
|
if outvalue <= dust_threshold(): return None
|
|
sweep_outputs = [PartialTxOutput.from_address_and_value(sweep_address, outvalue)]
|
|
sweep_tx = PartialTransaction.from_io(sweep_inputs, sweep_outputs)
|
|
sweep_tx.set_rbf(True)
|
|
sweep_tx.sign({our_payment_pubkey: (our_payment_privkey.get_secret_bytes(), True)})
|
|
if not sweep_tx.is_complete():
|
|
raise Exception('channel close sweep tx is not complete')
|
|
return sweep_tx
|
|
|
|
|
|
def create_sweeptx_ctx_to_local(
|
|
*, sweep_address: str, ctx: Transaction, output_idx: int, witness_script: str,
|
|
privkey: bytes, is_revocation: bool, config: SimpleConfig,
|
|
to_self_delay: int=None) -> Optional[PartialTransaction]:
|
|
"""Create a txn that sweeps the 'to_local' output of a commitment
|
|
transaction into our wallet.
|
|
|
|
privkey: either revocation_privkey or localdelayed_privkey
|
|
is_revocation: tells us which ^
|
|
"""
|
|
val = ctx.outputs()[output_idx].value
|
|
prevout = TxOutpoint(txid=bfh(ctx.txid()), out_idx=output_idx)
|
|
txin = PartialTxInput(prevout=prevout)
|
|
txin._trusted_value_sats = val
|
|
txin.script_sig = b''
|
|
txin.witness_script = bfh(witness_script)
|
|
sweep_inputs = [txin]
|
|
if not is_revocation:
|
|
assert isinstance(to_self_delay, int)
|
|
sweep_inputs[0].nsequence = to_self_delay
|
|
tx_size_bytes = 121 # approx size of to_local -> p2wpkh
|
|
fee = config.estimate_fee(tx_size_bytes, allow_fallback_to_static_rates=True)
|
|
outvalue = val - fee
|
|
if outvalue <= dust_threshold():
|
|
return None
|
|
sweep_outputs = [PartialTxOutput.from_address_and_value(sweep_address, outvalue)]
|
|
sweep_tx = PartialTransaction.from_io(sweep_inputs, sweep_outputs, version=2)
|
|
sig = sweep_tx.sign_txin(0, privkey)
|
|
witness = construct_witness([sig, int(is_revocation), witness_script])
|
|
sweep_tx.inputs()[0].witness = bfh(witness)
|
|
return sweep_tx
|
|
|
|
|
|
def create_sweeptx_that_spends_htlctx_that_spends_htlc_in_ctx(
|
|
*, htlc_tx: Transaction, htlctx_witness_script: bytes, sweep_address: str,
|
|
privkey: bytes, is_revocation: bool, to_self_delay: int,
|
|
config: SimpleConfig) -> Optional[PartialTransaction]:
|
|
val = htlc_tx.outputs()[0].value
|
|
prevout = TxOutpoint(txid=bfh(htlc_tx.txid()), out_idx=0)
|
|
txin = PartialTxInput(prevout=prevout)
|
|
txin._trusted_value_sats = val
|
|
txin.script_sig = b''
|
|
txin.witness_script = htlctx_witness_script
|
|
sweep_inputs = [txin]
|
|
if not is_revocation:
|
|
assert isinstance(to_self_delay, int)
|
|
sweep_inputs[0].nsequence = to_self_delay
|
|
tx_size_bytes = 200 # TODO
|
|
fee = config.estimate_fee(tx_size_bytes, allow_fallback_to_static_rates=True)
|
|
outvalue = val - fee
|
|
if outvalue <= dust_threshold(): return None
|
|
sweep_outputs = [PartialTxOutput.from_address_and_value(sweep_address, outvalue)]
|
|
tx = PartialTransaction.from_io(sweep_inputs, sweep_outputs, version=2)
|
|
sig = bfh(tx.sign_txin(0, privkey))
|
|
witness = construct_witness([sig, int(is_revocation), htlctx_witness_script])
|
|
tx.inputs()[0].witness = bfh(witness)
|
|
assert tx.is_complete()
|
|
return tx
|
|
|