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also sweep "received" htlcs from "our" ctx also sweep htlcs from their ctx (non-breach) extract ctn; included_htlcs_in_their_latest_ctxsdependabot/pip/contrib/deterministic-build/ecdsa-0.13.3
SomberNight
6 years ago
committed by
ThomasV
ThomasV
9 changed files with 645 additions and 301 deletions
@ -0,0 +1,493 @@ |
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# 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 |
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from .util import bfh, bh2u, print_error |
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from .bitcoin import TYPE_ADDRESS, redeem_script_to_address, dust_threshold |
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from . import ecc |
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from .lnutil import (EncumberedTransaction, |
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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, |
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LOCAL, REMOTE, make_htlc_output_witness_script, UnknownPaymentHash, |
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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) |
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from .transaction import Transaction, TxOutput, construct_witness |
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from .simple_config import SimpleConfig, FEERATE_FALLBACK_STATIC_FEE |
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if TYPE_CHECKING: |
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from .lnchan import Channel, UpdateAddHtlc |
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def maybe_create_sweeptx_for_their_ctx_to_remote(ctx: Transaction, sweep_address: str, |
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our_payment_privkey: ecc.ECPrivkey) -> Optional[Transaction]: |
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our_payment_pubkey = our_payment_privkey.get_public_key_bytes(compressed=True) |
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to_remote_address = make_commitment_output_to_remote_address(our_payment_pubkey) |
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output_idx = ctx.get_output_idx_from_address(to_remote_address) |
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if output_idx is None: return None |
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sweep_tx = create_sweeptx_their_ctx_to_remote(sweep_address=sweep_address, |
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ctx=ctx, |
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output_idx=output_idx, |
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our_payment_privkey=our_payment_privkey) |
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return sweep_tx |
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def maybe_create_sweeptx_for_their_ctx_to_local(ctx: Transaction, revocation_privkey: bytes, |
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to_self_delay: int, delayed_pubkey: bytes, |
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sweep_address: str) -> Optional[EncumberedTransaction]: |
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revocation_pubkey = ecc.ECPrivkey(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, delayed_pubkey)) |
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to_local_address = redeem_script_to_address('p2wsh', witness_script) |
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output_idx = ctx.get_output_idx_from_address(to_local_address) |
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if output_idx is None: return None |
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sweep_tx = create_sweeptx_ctx_to_local(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=revocation_privkey, |
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is_revocation=True) |
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if sweep_tx is None: return None |
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return EncumberedTransaction('their_ctx_to_local', sweep_tx, csv_delay=0, cltv_expiry=0) |
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def create_sweeptxs_for_their_just_revoked_ctx(chan: 'Channel', ctx: Transaction, per_commitment_secret: bytes, |
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sweep_address: str) -> List[Tuple[Optional[str],EncumberedTransaction]]: |
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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 'lo_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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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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sweep_tx = maybe_create_sweeptx_for_their_ctx_to_local(ctx=ctx, |
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revocation_privkey=other_revocation_privkey, |
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to_self_delay=to_self_delay, |
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delayed_pubkey=this_delayed_pubkey, |
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sweep_address=sweep_address) |
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if sweep_tx: |
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txs.append((None, EncumberedTransaction('their_ctx_to_local', sweep_tx, csv_delay=0, cltv_expiry=0))) |
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# HTLCs |
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def create_sweeptx_for_htlc(htlc: UpdateAddHtlc, is_received_htlc: bool) -> Tuple[Optional[Transaction], |
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Optional[Transaction], |
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Transaction]: |
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htlc_tx_witness_script, htlc_tx = make_htlc_tx_with_open_channel(chan=chan, |
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pcp=pcp, |
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for_us=False, |
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we_receive=not is_received_htlc, |
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commit=ctx, |
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htlc=htlc) |
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htlc_tx_txin = htlc_tx.inputs()[0] |
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htlc_output_witness_script = bfh(Transaction.get_preimage_script(htlc_tx_txin)) |
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# sweep directly from ctx |
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direct_sweep_tx = maybe_create_sweeptx_for_their_ctx_htlc( |
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ctx=ctx, |
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sweep_address=sweep_address, |
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htlc_output_witness_script=htlc_output_witness_script, |
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privkey=other_revocation_privkey, |
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preimage=None, |
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is_revocation=True) |
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# sweep from htlc tx |
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secondstage_sweep_tx = create_sweeptx_that_spends_htlctx_that_spends_htlc_in_ctx( |
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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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return direct_sweep_tx, secondstage_sweep_tx, htlc_tx |
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# received HTLCs, in their ctx |
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# TODO consider carefully if "included_htlcs" is what we need here |
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received_htlcs = list(chan.included_htlcs(REMOTE, LOCAL)) # type: List[UpdateAddHtlc] |
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for htlc in received_htlcs: |
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direct_sweep_tx, secondstage_sweep_tx, htlc_tx = create_sweeptx_for_htlc(htlc, is_received_htlc=True) |
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if direct_sweep_tx: |
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txs.append((ctx.txid(), EncumberedTransaction(f'their_ctx_sweep_htlc_{bh2u(htlc.payment_hash)}', direct_sweep_tx, csv_delay=0, cltv_expiry=0))) |
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if secondstage_sweep_tx: |
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txs.append((htlc_tx.txid(), EncumberedTransaction(f'their_htlctx_{bh2u(htlc.payment_hash)}', secondstage_sweep_tx, csv_delay=0, cltv_expiry=0))) |
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# offered HTLCs, in their ctx |
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# TODO consider carefully if "included_htlcs" is what we need here |
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offered_htlcs = list(chan.included_htlcs(REMOTE, REMOTE)) # type: List[UpdateAddHtlc] |
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for htlc in offered_htlcs: |
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direct_sweep_tx, secondstage_sweep_tx, htlc_tx = create_sweeptx_for_htlc(htlc, is_received_htlc=False) |
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if direct_sweep_tx: |
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txs.append((ctx.txid(), EncumberedTransaction(f'their_ctx_sweep_htlc_{bh2u(htlc.payment_hash)}', direct_sweep_tx, csv_delay=0, cltv_expiry=0))) |
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if secondstage_sweep_tx: |
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txs.append((htlc_tx.txid(), EncumberedTransaction(f'their_htlctx_{bh2u(htlc.payment_hash)}', secondstage_sweep_tx, csv_delay=0, cltv_expiry=0))) |
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return txs |
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def create_sweeptxs_for_our_latest_ctx(chan: 'Channel', ctx: Transaction, |
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sweep_address: str) -> List[Tuple[Optional[str],EncumberedTransaction]]: |
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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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this_conf, other_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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our_per_commitment_secret = get_per_commitment_secret_from_seed( |
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this_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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# prep |
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this_delayed_bp_privkey = ecc.ECPrivkey(this_conf.delayed_basepoint.privkey) |
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this_localdelayed_privkey = derive_privkey(this_delayed_bp_privkey.secret_scalar, our_pcp) |
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this_localdelayed_privkey = ecc.ECPrivkey.from_secret_scalar(this_localdelayed_privkey) |
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other_revocation_pubkey = derive_blinded_pubkey(other_conf.revocation_basepoint.pubkey, our_pcp) |
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to_self_delay = chan.config[REMOTE].to_self_delay |
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this_htlc_privkey = derive_privkey(secret=int.from_bytes(this_conf.htlc_basepoint.privkey, 'big'), |
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per_commitment_point=our_pcp).to_bytes(32, 'big') |
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txs = [] |
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# to_local |
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sweep_tx = maybe_create_sweeptx_that_spends_to_local_in_our_ctx(ctx=ctx, |
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sweep_address=sweep_address, |
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our_localdelayed_privkey=this_localdelayed_privkey, |
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remote_revocation_pubkey=other_revocation_pubkey, |
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to_self_delay=to_self_delay) |
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if sweep_tx: |
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txs.append((None, EncumberedTransaction('our_ctx_to_local', sweep_tx, csv_delay=to_self_delay, cltv_expiry=0))) |
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# HTLCs |
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def create_txns_for_htlc(htlc: UpdateAddHtlc, is_received_htlc: bool) -> Tuple[Optional[Transaction], Optional[Transaction]]: |
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if is_received_htlc: |
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try: |
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preimage, invoice = chan.get_preimage_and_invoice(htlc.payment_hash) |
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except UnknownPaymentHash as e: |
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print_error(f'trying to sweep htlc from our latest ctx but getting {repr(e)}') |
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return None, None |
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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=this_htlc_privkey, |
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preimage=preimage, |
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is_received_htlc=is_received_htlc) |
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to_wallet_tx = 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=this_localdelayed_privkey.get_secret_bytes(), |
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is_revocation=False) |
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return htlc_tx, to_wallet_tx |
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# offered HTLCs, in our ctx --> "timeout" |
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# TODO consider carefully if "included_htlcs" is what we need here |
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offered_htlcs = list(chan.included_htlcs(LOCAL, LOCAL)) # type: List[UpdateAddHtlc] |
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for htlc in offered_htlcs: |
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htlc_tx, to_wallet_tx = create_txns_for_htlc(htlc, is_received_htlc=False) |
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if htlc_tx and to_wallet_tx: |
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txs.append((htlc_tx.txid(), EncumberedTransaction(f'second_stage_to_wallet_{bh2u(htlc.payment_hash)}', to_wallet_tx, csv_delay=to_self_delay, cltv_expiry=0))) |
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txs.append((ctx.txid(), EncumberedTransaction(f'our_ctx_htlc_tx_{bh2u(htlc.payment_hash)}', htlc_tx, csv_delay=0, cltv_expiry=htlc.cltv_expiry))) |
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# received HTLCs, in our ctx --> "success" |
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# TODO consider carefully if "included_htlcs" is what we need here |
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received_htlcs = list(chan.included_htlcs(LOCAL, REMOTE)) # type: List[UpdateAddHtlc] |
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for htlc in received_htlcs: |
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htlc_tx, to_wallet_tx = create_txns_for_htlc(htlc, is_received_htlc=True) |
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if htlc_tx and to_wallet_tx: |
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txs.append((htlc_tx.txid(), EncumberedTransaction(f'second_stage_to_wallet_{bh2u(htlc.payment_hash)}', to_wallet_tx, csv_delay=to_self_delay, cltv_expiry=0))) |
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txs.append((ctx.txid(), EncumberedTransaction(f'our_ctx_htlc_tx_{bh2u(htlc.payment_hash)}', htlc_tx, csv_delay=0, cltv_expiry=0))) |
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return txs |
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def create_sweeptxs_for_their_latest_ctx(chan: 'Channel', ctx: Transaction, |
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sweep_address: str) -> List[Tuple[Optional[str],EncumberedTransaction]]: |
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"""Handle the case when the remote force-closes with their ctx. |
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Regardless of it is a breach or not, construct sweep tx for 'to_remote'. |
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If it is a breach, also construct sweep tx for 'to_local'. |
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Sweep txns for HTLCs are only constructed if it is NOT a breach, as |
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lnchan does not store old HTLCs. |
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""" |
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this_conf, other_conf = get_ordered_channel_configs(chan=chan, for_us=False) |
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ctn = extract_ctn_from_tx_and_chan(ctx, chan) |
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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 (this_conf.ctn, this_conf.ctn+1) |
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per_commitment_secret = None |
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if ctn == this_conf.ctn: |
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their_pcp = this_conf.current_per_commitment_point |
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elif ctn == this_conf.ctn + 1: |
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their_pcp = this_conf.next_per_commitment_point |
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elif ctn < this_conf.ctn: # breach |
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try: |
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per_commitment_secret = this_conf.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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else: |
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return [] |
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# prep |
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other_revocation_pubkey = derive_blinded_pubkey(other_conf.revocation_basepoint.pubkey, their_pcp) |
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other_htlc_privkey = derive_privkey(secret=int.from_bytes(other_conf.htlc_basepoint.privkey, 'big'), |
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per_commitment_point=their_pcp) |
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other_htlc_privkey = ecc.ECPrivkey.from_secret_scalar(other_htlc_privkey) |
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this_htlc_pubkey = derive_pubkey(this_conf.htlc_basepoint.pubkey, their_pcp) |
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other_payment_bp_privkey = ecc.ECPrivkey(other_conf.payment_basepoint.privkey) |
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other_payment_privkey = derive_privkey(other_payment_bp_privkey.secret_scalar, their_pcp) |
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other_payment_privkey = ecc.ECPrivkey.from_secret_scalar(other_payment_privkey) |
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txs = [] |
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if per_commitment_secret: # breach |
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# to_local |
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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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this_delayed_pubkey = derive_pubkey(this_conf.delayed_basepoint.pubkey, their_pcp) |
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sweep_tx = maybe_create_sweeptx_for_their_ctx_to_local(ctx=ctx, |
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revocation_privkey=other_revocation_privkey, |
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to_self_delay=other_conf.to_self_delay, |
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delayed_pubkey=this_delayed_pubkey, |
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sweep_address=sweep_address) |
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if sweep_tx: |
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txs.append((None, EncumberedTransaction('their_ctx_to_local', sweep_tx, csv_delay=0, cltv_expiry=0))) |
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# to_remote |
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sweep_tx = maybe_create_sweeptx_for_their_ctx_to_remote(ctx=ctx, |
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sweep_address=sweep_address, |
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our_payment_privkey=other_payment_privkey) |
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if sweep_tx: |
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txs.append((None, EncumberedTransaction('their_ctx_to_remote', sweep_tx, csv_delay=0, cltv_expiry=0))) |
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# HTLCs |
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# from their ctx, we can only redeem HTLCs if the ctx was not revoked, |
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# as old HTLCs are not stored. (if it was revoked, then we should have presigned txns |
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# to handle the breach already; out of scope here) |
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if ctn not in (this_conf.ctn, this_conf.ctn + 1): |
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return txs |
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def create_sweeptx_for_htlc(htlc: UpdateAddHtlc, is_received_htlc: bool) -> Optional[Transaction]: |
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if not is_received_htlc: |
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try: |
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preimage, invoice = chan.get_preimage_and_invoice(htlc.payment_hash) |
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except UnknownPaymentHash as e: |
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print_error(f'trying to sweep htlc from their latest ctx but getting {repr(e)}') |
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return None |
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else: |
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preimage = None |
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htlc_output_witness_script = make_htlc_output_witness_script( |
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is_received_htlc=is_received_htlc, |
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remote_revocation_pubkey=other_revocation_pubkey, |
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remote_htlc_pubkey=other_htlc_privkey.get_public_key_bytes(compressed=True), |
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local_htlc_pubkey=this_htlc_pubkey, |
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payment_hash=htlc.payment_hash, |
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cltv_expiry=htlc.cltv_expiry) |
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sweep_tx = maybe_create_sweeptx_for_their_ctx_htlc( |
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ctx=ctx, |
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sweep_address=sweep_address, |
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htlc_output_witness_script=htlc_output_witness_script, |
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privkey=other_htlc_privkey.get_secret_bytes(), |
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preimage=preimage, |
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is_revocation=False) |
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return sweep_tx |
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# received HTLCs, in their ctx --> "timeout" |
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received_htlcs = chan.included_htlcs_in_their_latest_ctxs(LOCAL)[ctn] # type: List[UpdateAddHtlc] |
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for htlc in received_htlcs: |
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sweep_tx = create_sweeptx_for_htlc(htlc, is_received_htlc=True) |
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if sweep_tx: |
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txs.append((ctx.txid(), EncumberedTransaction(f'their_ctx_sweep_htlc_{bh2u(htlc.payment_hash)}', sweep_tx, csv_delay=0, cltv_expiry=htlc.cltv_expiry))) |
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# offered HTLCs, in their ctx --> "success" |
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offered_htlcs = chan.included_htlcs_in_their_latest_ctxs(REMOTE)[ctn] # type: List[UpdateAddHtlc] |
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for htlc in offered_htlcs: |
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sweep_tx = create_sweeptx_for_htlc(htlc, is_received_htlc=False) |
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if sweep_tx: |
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txs.append((ctx.txid(), EncumberedTransaction(f'their_ctx_sweep_htlc_{bh2u(htlc.payment_hash)}', sweep_tx, csv_delay=0, cltv_expiry=0))) |
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return txs |
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|
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|
||||
|
def maybe_create_sweeptx_that_spends_to_local_in_our_ctx( |
||||
|
ctx: Transaction, sweep_address: str, our_localdelayed_privkey: ecc.ECPrivkey, |
||||
|
remote_revocation_pubkey: bytes, to_self_delay: int) -> Optional[Transaction]: |
||||
|
our_localdelayed_pubkey = our_localdelayed_privkey.get_public_key_bytes(compressed=True) |
||||
|
to_local_witness_script = bh2u(make_commitment_output_to_local_witness_script( |
||||
|
remote_revocation_pubkey, to_self_delay, our_localdelayed_pubkey)) |
||||
|
to_local_address = redeem_script_to_address('p2wsh', to_local_witness_script) |
||||
|
output_idx = ctx.get_output_idx_from_address(to_local_address) |
||||
|
if output_idx is None: return None |
||||
|
sweep_tx = create_sweeptx_ctx_to_local(sweep_address=sweep_address, |
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|
ctx=ctx, |
||||
|
output_idx=output_idx, |
||||
|
witness_script=to_local_witness_script, |
||||
|
privkey=our_localdelayed_privkey.get_secret_bytes(), |
||||
|
is_revocation=False, |
||||
|
to_self_delay=to_self_delay) |
||||
|
if sweep_tx is None: return None |
||||
|
return sweep_tx |
||||
|
|
||||
|
|
||||
|
def create_htlctx_that_spends_from_our_ctx(chan: 'Channel', our_pcp: bytes, |
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|
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' |
||||
|
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, |
||||
|
commit=ctx, |
||||
|
htlc=htlc) |
||||
|
remote_htlc_sig = chan.get_remote_htlc_sig_for_htlc(htlc, we_receive=is_received_htlc) |
||||
|
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'] = bh2u(make_htlc_tx_witness(remote_htlc_sig, local_htlc_sig, preimage, witness_program)) |
||||
|
return witness_script, htlc_tx |
||||
|
|
||||
|
|
||||
|
def maybe_create_sweeptx_for_their_ctx_htlc(ctx: Transaction, sweep_address: str, |
||||
|
htlc_output_witness_script: bytes, |
||||
|
privkey: bytes, is_revocation: bool, |
||||
|
preimage: Optional[bytes]) -> Optional[Transaction]: |
||||
|
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 None: return None |
||||
|
sweep_tx = create_sweeptx_their_ctx_htlc(ctx=ctx, |
||||
|
witness_script=htlc_output_witness_script, |
||||
|
sweep_address=sweep_address, |
||||
|
preimage=preimage, |
||||
|
output_idx=output_idx, |
||||
|
privkey=privkey, |
||||
|
is_revocation=is_revocation) |
||||
|
return sweep_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, |
||||
|
fee_per_kb: int=None) -> Optional[Transaction]: |
||||
|
preimage = preimage or b'' # preimage is required iff (not is_revocation and htlc is offered) |
||||
|
val = ctx.outputs()[output_idx].value |
||||
|
sweep_inputs = [{ |
||||
|
'scriptSig': '', |
||||
|
'type': 'p2wsh', |
||||
|
'signatures': [], |
||||
|
'num_sig': 0, |
||||
|
'prevout_n': output_idx, |
||||
|
'prevout_hash': ctx.txid(), |
||||
|
'value': val, |
||||
|
'coinbase': False, |
||||
|
'preimage_script': bh2u(witness_script), |
||||
|
}] |
||||
|
tx_size_bytes = 200 # TODO (depends on offered/received and is_revocation) |
||||
|
if fee_per_kb is None: fee_per_kb = FEERATE_FALLBACK_STATIC_FEE |
||||
|
fee = SimpleConfig.estimate_fee_for_feerate(fee_per_kb, tx_size_bytes) |
||||
|
outvalue = val - fee |
||||
|
if outvalue <= dust_threshold(): return None |
||||
|
sweep_outputs = [TxOutput(TYPE_ADDRESS, sweep_address, outvalue)] |
||||
|
tx = Transaction.from_io(sweep_inputs, sweep_outputs, version=2) |
||||
|
|
||||
|
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'] = 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, |
||||
|
fee_per_kb: int=None) -> Optional[Transaction]: |
||||
|
our_payment_pubkey = our_payment_privkey.get_public_key_hex(compressed=True) |
||||
|
val = ctx.outputs()[output_idx].value |
||||
|
sweep_inputs = [{ |
||||
|
'type': 'p2wpkh', |
||||
|
'x_pubkeys': [our_payment_pubkey], |
||||
|
'num_sig': 1, |
||||
|
'prevout_n': output_idx, |
||||
|
'prevout_hash': ctx.txid(), |
||||
|
'value': val, |
||||
|
'coinbase': False, |
||||
|
'signatures': [None], |
||||
|
}] |
||||
|
tx_size_bytes = 110 # approx size of p2wpkh->p2wpkh |
||||
|
if fee_per_kb is None: fee_per_kb = FEERATE_FALLBACK_STATIC_FEE |
||||
|
fee = SimpleConfig.estimate_fee_for_feerate(fee_per_kb, tx_size_bytes) |
||||
|
outvalue = val - fee |
||||
|
if outvalue <= dust_threshold(): return None |
||||
|
sweep_outputs = [TxOutput(TYPE_ADDRESS, sweep_address, outvalue)] |
||||
|
sweep_tx = Transaction.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, |
||||
|
to_self_delay: int=None, |
||||
|
fee_per_kb: int=None) -> Optional[Transaction]: |
||||
|
"""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 |
||||
|
sweep_inputs = [{ |
||||
|
'scriptSig': '', |
||||
|
'type': 'p2wsh', |
||||
|
'signatures': [], |
||||
|
'num_sig': 0, |
||||
|
'prevout_n': output_idx, |
||||
|
'prevout_hash': ctx.txid(), |
||||
|
'value': val, |
||||
|
'coinbase': False, |
||||
|
'preimage_script': witness_script, |
||||
|
}] |
||||
|
if not is_revocation: |
||||
|
assert isinstance(to_self_delay, int) |
||||
|
sweep_inputs[0]['sequence'] = to_self_delay |
||||
|
tx_size_bytes = 121 # approx size of to_local -> p2wpkh |
||||
|
if fee_per_kb is None: fee_per_kb = FEERATE_FALLBACK_STATIC_FEE |
||||
|
fee = SimpleConfig.estimate_fee_for_feerate(fee_per_kb, tx_size_bytes) |
||||
|
outvalue = val - fee |
||||
|
if outvalue <= dust_threshold(): return None |
||||
|
sweep_outputs = [TxOutput(TYPE_ADDRESS, sweep_address, outvalue)] |
||||
|
sweep_tx = Transaction.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'] = 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=None, |
||||
|
fee_per_kb: int=None) -> Optional[Transaction]: |
||||
|
val = htlc_tx.outputs()[0].value |
||||
|
sweep_inputs = [{ |
||||
|
'scriptSig': '', |
||||
|
'type': 'p2wsh', |
||||
|
'signatures': [], |
||||
|
'num_sig': 0, |
||||
|
'prevout_n': 0, |
||||
|
'prevout_hash': htlc_tx.txid(), |
||||
|
'value': val, |
||||
|
'coinbase': False, |
||||
|
'preimage_script': bh2u(htlctx_witness_script), |
||||
|
}] |
||||
|
if not is_revocation: |
||||
|
assert isinstance(to_self_delay, int) |
||||
|
sweep_inputs[0]['sequence'] = to_self_delay |
||||
|
tx_size_bytes = 200 # TODO |
||||
|
if fee_per_kb is None: fee_per_kb = FEERATE_FALLBACK_STATIC_FEE |
||||
|
fee = SimpleConfig.estimate_fee_for_feerate(fee_per_kb, tx_size_bytes) |
||||
|
outvalue = val - fee |
||||
|
if outvalue <= dust_threshold(): return None |
||||
|
sweep_outputs = [TxOutput(TYPE_ADDRESS, sweep_address, outvalue)] |
||||
|
tx = Transaction.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'] = witness |
||||
|
assert tx.is_complete() |
||||
|
return tx |
||||
Loading…
Reference in new issue