mirror of
https://github.com/LBRYFoundation/LBRY-Vault.git
synced 2025-08-23 17:47:31 +00:00
810 lines
38 KiB
Python
810 lines
38 KiB
Python
# ported from lnd 42de4400bff5105352d0552155f73589166d162b
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from collections import namedtuple, defaultdict
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import binascii
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import json
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from enum import Enum, auto
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from typing import Optional
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from .util import bfh, PrintError, bh2u
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from .bitcoin import Hash, TYPE_SCRIPT, TYPE_ADDRESS
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from .bitcoin import redeem_script_to_address
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from .crypto import sha256
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from . import ecc
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from .lnutil import Outpoint, LocalConfig, RemoteConfig, Keypair, OnlyPubkeyKeypair, ChannelConstraints, RevocationStore, EncumberedTransaction
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from .lnutil import get_per_commitment_secret_from_seed
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from .lnutil import make_commitment_output_to_remote_address, make_commitment_output_to_local_witness_script
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from .lnutil import secret_to_pubkey, derive_privkey, derive_pubkey, derive_blinded_pubkey, derive_blinded_privkey
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from .lnutil import sign_and_get_sig_string
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from .lnutil import make_htlc_tx_with_open_channel, make_commitment, make_received_htlc, make_offered_htlc
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from .lnutil import HTLC_TIMEOUT_WEIGHT, HTLC_SUCCESS_WEIGHT
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from .lnutil import funding_output_script, LOCAL, REMOTE, HTLCOwner, make_closing_tx, make_outputs
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from .lnutil import ScriptHtlc, SENT, RECEIVED
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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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RevokeAndAck = namedtuple("RevokeAndAck", ["per_commitment_secret", "next_per_commitment_point"])
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class FeeUpdateProgress(Enum):
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FUNDEE_SIGNED = auto()
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FUNDEE_ACKED = auto()
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FUNDER_SIGNED = auto()
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FUNDEE_SIGNED = FeeUpdateProgress.FUNDEE_SIGNED
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FUNDEE_ACKED = FeeUpdateProgress.FUNDEE_ACKED
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FUNDER_SIGNED = FeeUpdateProgress.FUNDER_SIGNED
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class FeeUpdate(defaultdict):
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def __init__(self, chan, rate):
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super().__init__(lambda: False)
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self.rate = rate
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self.chan = chan
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def pending_feerate(self, subject):
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if self[FUNDEE_ACKED]:
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return self.rate
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if subject == REMOTE and self.chan.constraints.is_initiator:
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return self.rate
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if subject == LOCAL and not self.chan.constraints.is_initiator:
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return self.rate
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# implicit return None
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class UpdateAddHtlc(namedtuple('UpdateAddHtlc', ['amount_msat', 'payment_hash', 'cltv_expiry', 'locked_in', 'htlc_id'])):
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__slots__ = ()
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def __new__(cls, *args, **kwargs):
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if len(args) > 0:
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args = list(args)
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if type(args[1]) is str:
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args[1] = bfh(args[1])
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args[3] = {HTLCOwner(int(x)): y for x,y in args[3].items()}
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return super().__new__(cls, *args)
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if type(kwargs['payment_hash']) is str:
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kwargs['payment_hash'] = bfh(kwargs['payment_hash'])
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if 'locked_in' not in kwargs:
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kwargs['locked_in'] = {LOCAL: None, REMOTE: None}
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else:
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kwargs['locked_in'] = {HTLCOwner(int(x)): y for x,y in kwargs['locked_in'].items()}
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return super().__new__(cls, **kwargs)
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def decodeAll(d, local):
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for k, v in d.items():
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if k == 'revocation_store':
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yield (k, RevocationStore.from_json_obj(v))
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elif k.endswith("_basepoint") or k.endswith("_key"):
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if local:
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yield (k, Keypair(**dict(decodeAll(v, local))))
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else:
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yield (k, OnlyPubkeyKeypair(**dict(decodeAll(v, local))))
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elif k in ["node_id", "channel_id", "short_channel_id", "pubkey", "privkey", "current_per_commitment_point", "next_per_commitment_point", "per_commitment_secret_seed", "current_commitment_signature", "current_htlc_signatures"] and v is not None:
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yield (k, binascii.unhexlify(v))
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else:
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yield (k, v)
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def htlcsum(htlcs):
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return sum([x.amount_msat for x in htlcs])
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class HTLCStateMachine(PrintError):
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def diagnostic_name(self):
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return str(self.name)
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def __init__(self, state, name = None):
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assert 'local_state' not in state
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self.config = {}
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self.config[LOCAL] = state["local_config"]
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if type(self.config[LOCAL]) is not LocalConfig:
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conf = dict(decodeAll(self.config[LOCAL], True))
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self.config[LOCAL] = LocalConfig(**conf)
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assert type(self.config[LOCAL].htlc_basepoint.privkey) is bytes
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self.config[REMOTE] = state["remote_config"]
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if type(self.config[REMOTE]) is not RemoteConfig:
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conf = dict(decodeAll(self.config[REMOTE], False))
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self.config[REMOTE] = RemoteConfig(**conf)
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assert type(self.config[REMOTE].htlc_basepoint.pubkey) is bytes
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self.channel_id = bfh(state["channel_id"]) if type(state["channel_id"]) not in (bytes, type(None)) else state["channel_id"]
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self.constraints = ChannelConstraints(**state["constraints"]) if type(state["constraints"]) is not ChannelConstraints else state["constraints"]
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self.funding_outpoint = Outpoint(**dict(decodeAll(state["funding_outpoint"], False))) if type(state["funding_outpoint"]) is not Outpoint else state["funding_outpoint"]
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self.node_id = bfh(state["node_id"]) if type(state["node_id"]) not in (bytes, type(None)) else state["node_id"]
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self.short_channel_id = bfh(state["short_channel_id"]) if type(state["short_channel_id"]) not in (bytes, type(None)) else state["short_channel_id"]
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self.short_channel_id_predicted = self.short_channel_id
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self.onion_keys = {int(k): bfh(v) for k,v in state['onion_keys'].items()} if 'onion_keys' in state else {}
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# FIXME this is a tx serialised in the custom electrum partial tx format.
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# we should not persist txns in this format. we should persist htlcs, and be able to derive
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# any past commitment transaction and use that instead; until then...
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self.remote_commitment_to_be_revoked = Transaction(state["remote_commitment_to_be_revoked"])
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template = lambda: {'adds': {}, 'settles': []}
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self.log = {LOCAL: template(), REMOTE: template()}
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for strname, subject in [('remote_log', REMOTE), ('local_log', LOCAL)]:
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if strname not in state: continue
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for y in state[strname]:
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htlc = UpdateAddHtlc(**y)
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self.log[subject]['adds'][htlc.htlc_id] = htlc
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self.name = name
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self.fee_mgr = []
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self.local_commitment = self.pending_local_commitment
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self.remote_commitment = self.pending_remote_commitment
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self._is_funding_txo_spent = None # "don't know"
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self.set_state('DISCONNECTED')
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self.lnwatcher = None
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self.settled = {LOCAL: state.get('settled_local', []), REMOTE: state.get('settled_remote', [])}
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def set_state(self, state: str):
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self._state = state
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def get_state(self):
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return self._state
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def set_funding_txo_spentness(self, is_spent: bool):
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assert isinstance(is_spent, bool)
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self._is_funding_txo_spent = is_spent
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def should_try_to_reestablish_peer(self) -> bool:
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return self._is_funding_txo_spent is False and self._state == 'DISCONNECTED'
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def get_funding_address(self):
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script = funding_output_script(self.config[LOCAL], self.config[REMOTE])
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return redeem_script_to_address('p2wsh', script)
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def add_htlc(self, htlc):
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"""
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AddHTLC adds an HTLC to the state machine's local update log. This method
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should be called when preparing to send an outgoing HTLC.
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"""
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assert type(htlc) is dict
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htlc = UpdateAddHtlc(**htlc, htlc_id=self.config[LOCAL].next_htlc_id)
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self.log[LOCAL]['adds'][htlc.htlc_id] = htlc
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self.print_error("add_htlc")
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self.config[LOCAL]=self.config[LOCAL]._replace(next_htlc_id=htlc.htlc_id + 1)
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return htlc.htlc_id
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def receive_htlc(self, htlc):
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"""
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ReceiveHTLC adds an HTLC to the state machine's remote update log. This
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method should be called in response to receiving a new HTLC from the remote
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party.
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"""
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assert type(htlc) is dict
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htlc = UpdateAddHtlc(**htlc, htlc_id = self.config[REMOTE].next_htlc_id)
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self.log[REMOTE]['adds'][htlc.htlc_id] = htlc
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self.print_error("receive_htlc")
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self.config[REMOTE]=self.config[REMOTE]._replace(next_htlc_id=htlc.htlc_id + 1)
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return htlc.htlc_id
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def sign_next_commitment(self):
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"""
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SignNextCommitment signs a new commitment which includes any previous
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unsettled HTLCs, any new HTLCs, and any modifications to prior HTLCs
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committed in previous commitment updates. Signing a new commitment
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decrements the available revocation window by 1. After a successful method
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call, the remote party's commitment chain is extended by a new commitment
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which includes all updates to the HTLC log prior to this method invocation.
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The first return parameter is the signature for the commitment transaction
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itself, while the second parameter is a slice of all HTLC signatures (if
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any). The HTLC signatures are sorted according to the BIP 69 order of the
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HTLC's on the commitment transaction.
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"""
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for htlc in self.log[LOCAL]['adds'].values():
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if htlc.locked_in[LOCAL] is None:
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htlc.locked_in[LOCAL] = self.config[LOCAL].ctn
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self.print_error("sign_next_commitment")
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pending_remote_commitment = self.pending_remote_commitment
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sig_64 = sign_and_get_sig_string(pending_remote_commitment, self.config[LOCAL], self.config[REMOTE])
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their_remote_htlc_privkey_number = derive_privkey(
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int.from_bytes(self.config[LOCAL].htlc_basepoint.privkey, 'big'),
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self.config[REMOTE].next_per_commitment_point)
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their_remote_htlc_privkey = their_remote_htlc_privkey_number.to_bytes(32, 'big')
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for_us = False
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htlcsigs = []
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for we_receive, htlcs in zip([True, False], [self.included_htlcs(REMOTE, REMOTE), self.included_htlcs(REMOTE, LOCAL)]):
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for htlc in htlcs:
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args = [self.config[REMOTE].next_per_commitment_point, for_us, we_receive, pending_remote_commitment, htlc]
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htlc_tx = make_htlc_tx_with_open_channel(self, *args)
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sig = bfh(htlc_tx.sign_txin(0, their_remote_htlc_privkey))
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htlc_sig = ecc.sig_string_from_der_sig(sig[:-1])
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htlcsigs.append((pending_remote_commitment.htlc_output_indices[htlc.payment_hash], htlc_sig))
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for pending_fee in self.fee_mgr:
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if not self.constraints.is_initiator:
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pending_fee[FUNDEE_SIGNED] = True
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if self.constraints.is_initiator and pending_fee[FUNDEE_ACKED]:
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pending_fee[FUNDER_SIGNED] = True
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self.process_new_offchain_ctx(pending_remote_commitment, ours=False)
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htlcsigs.sort()
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htlcsigs = [x[1] for x in htlcsigs]
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return sig_64, htlcsigs
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def receive_new_commitment(self, sig, htlc_sigs):
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"""
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ReceiveNewCommitment process a signature for a new commitment state sent by
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the remote party. This method should be called in response to the
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remote party initiating a new change, or when the remote party sends a
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signature fully accepting a new state we've initiated. If we are able to
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successfully validate the signature, then the generated commitment is added
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to our local commitment chain. Once we send a revocation for our prior
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state, then this newly added commitment becomes our current accepted channel
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state.
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"""
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self.print_error("receive_new_commitment")
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for htlc in self.log[REMOTE]['adds'].values():
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if htlc.locked_in[REMOTE] is None:
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htlc.locked_in[REMOTE] = self.config[REMOTE].ctn
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assert len(htlc_sigs) == 0 or type(htlc_sigs[0]) is bytes
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pending_local_commitment = self.pending_local_commitment
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preimage_hex = pending_local_commitment.serialize_preimage(0)
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pre_hash = Hash(bfh(preimage_hex))
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if not ecc.verify_signature(self.config[REMOTE].multisig_key.pubkey, sig, pre_hash):
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raise Exception('failed verifying signature of our updated commitment transaction: ' + bh2u(sig) + ' preimage is ' + preimage_hex)
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_, this_point, _ = self.points
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for htlcs, we_receive in [(self.included_htlcs(LOCAL, REMOTE), True), (self.included_htlcs(LOCAL, LOCAL), False)]:
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for htlc in htlcs:
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htlc_tx = make_htlc_tx_with_open_channel(self, this_point, True, we_receive, pending_local_commitment, htlc)
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pre_hash = Hash(bfh(htlc_tx.serialize_preimage(0)))
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remote_htlc_pubkey = derive_pubkey(self.config[REMOTE].htlc_basepoint.pubkey, this_point)
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for idx, sig in enumerate(htlc_sigs):
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if ecc.verify_signature(remote_htlc_pubkey, sig, pre_hash):
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del htlc_sigs[idx]
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break
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else:
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raise Exception(f'failed verifying HTLC signatures: {htlc}')
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if len(htlc_sigs) != 0: # all sigs should have been popped above
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raise Exception('failed verifying HTLC signatures: invalid amount of correct signatures')
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for pending_fee in self.fee_mgr:
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if not self.constraints.is_initiator:
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pending_fee[FUNDEE_SIGNED] = True
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if self.constraints.is_initiator and pending_fee[FUNDEE_ACKED]:
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pending_fee[FUNDER_SIGNED] = True
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self.process_new_offchain_ctx(pending_local_commitment, ours=True)
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def revoke_current_commitment(self):
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"""
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RevokeCurrentCommitment revokes the next lowest unrevoked commitment
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transaction in the local commitment chain. As a result the edge of our
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revocation window is extended by one, and the tail of our local commitment
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chain is advanced by a single commitment. This now lowest unrevoked
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commitment becomes our currently accepted state within the channel. This
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method also returns the set of HTLC's currently active within the commitment
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transaction. This return value allows callers to act once an HTLC has been
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locked into our commitment transaction.
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"""
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self.print_error("revoke_current_commitment")
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last_secret, this_point, next_point = self.points
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new_feerate = self.constraints.feerate
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for pending_fee in self.fee_mgr[:]:
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if not self.constraints.is_initiator and pending_fee[FUNDEE_SIGNED]:
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new_feerate = pending_fee.rate
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self.fee_mgr.remove(pending_fee)
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print("FEERATE CHANGE COMPLETE (non-initiator)")
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if self.constraints.is_initiator and pending_fee[FUNDER_SIGNED]:
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new_feerate = pending_fee.rate
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self.fee_mgr.remove(pending_fee)
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print("FEERATE CHANGE COMPLETE (initiator)")
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self.config[LOCAL]=self.config[LOCAL]._replace(
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ctn=self.config[LOCAL].ctn + 1,
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)
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self.constraints=self.constraints._replace(
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feerate=new_feerate
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)
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self.local_commitment = self.pending_local_commitment
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return RevokeAndAck(last_secret, next_point), "current htlcs"
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@property
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def points(self):
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last_small_num = self.config[LOCAL].ctn
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this_small_num = last_small_num + 1
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next_small_num = last_small_num + 2
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last_secret = get_per_commitment_secret_from_seed(self.config[LOCAL].per_commitment_secret_seed, RevocationStore.START_INDEX - last_small_num)
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this_secret = get_per_commitment_secret_from_seed(self.config[LOCAL].per_commitment_secret_seed, RevocationStore.START_INDEX - this_small_num)
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this_point = secret_to_pubkey(int.from_bytes(this_secret, 'big'))
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next_secret = get_per_commitment_secret_from_seed(self.config[LOCAL].per_commitment_secret_seed, RevocationStore.START_INDEX - next_small_num)
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next_point = secret_to_pubkey(int.from_bytes(next_secret, 'big'))
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return last_secret, this_point, next_point
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# TODO batch sweeps
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# TODO sweep HTLC outputs
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def process_new_offchain_ctx(self, ctx, ours: bool):
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if not self.lnwatcher:
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return
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outpoint = self.funding_outpoint.to_str()
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if ours:
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ctn = self.config[LOCAL].ctn + 1
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our_per_commitment_secret = get_per_commitment_secret_from_seed(
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self.config[LOCAL].per_commitment_secret_seed, RevocationStore.START_INDEX - ctn)
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our_cur_pcp = ecc.ECPrivkey(our_per_commitment_secret).get_public_key_bytes(compressed=True)
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encumbered_sweeptx = maybe_create_sweeptx_for_our_ctx_to_local(self, ctx, our_cur_pcp, self.sweep_address)
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else:
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their_cur_pcp = self.config[REMOTE].next_per_commitment_point
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encumbered_sweeptx = maybe_create_sweeptx_for_their_ctx_to_remote(self, ctx, their_cur_pcp, self.sweep_address)
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self.lnwatcher.add_sweep_tx(outpoint, ctx.txid(), encumbered_sweeptx)
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def process_new_revocation_secret(self, per_commitment_secret: bytes):
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if not self.lnwatcher:
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return
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outpoint = self.funding_outpoint.to_str()
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ctx = self.remote_commitment_to_be_revoked
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encumbered_sweeptx = maybe_create_sweeptx_for_their_ctx_to_local(self, ctx, per_commitment_secret, self.sweep_address)
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self.lnwatcher.add_sweep_tx(outpoint, ctx.txid(), encumbered_sweeptx)
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def receive_revocation(self, revocation):
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"""
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ReceiveRevocation processes a revocation sent by the remote party for the
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lowest unrevoked commitment within their commitment chain. We receive a
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revocation either during the initial session negotiation wherein revocation
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windows are extended, or in response to a state update that we initiate. If
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successful, then the remote commitment chain is advanced by a single
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commitment, and a log compaction is attempted.
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Returns the forwarding package corresponding to the remote commitment height
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that was revoked.
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"""
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self.print_error("receive_revocation")
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cur_point = self.config[REMOTE].current_per_commitment_point
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derived_point = ecc.ECPrivkey(revocation.per_commitment_secret).get_public_key_bytes(compressed=True)
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if cur_point != derived_point:
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raise Exception('revoked secret not for current point')
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# FIXME not sure this is correct... but it seems to work
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# if there are update_add_htlc msgs between commitment_signed and rev_ack,
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# this might break
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prev_remote_commitment = self.pending_remote_commitment
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self.config[REMOTE].revocation_store.add_next_entry(revocation.per_commitment_secret)
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self.process_new_revocation_secret(revocation.per_commitment_secret)
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def mark_settled(subject):
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"""
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find pending settlements for subject (LOCAL or REMOTE) and mark them settled, return value of settled htlcs
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"""
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old_amount = htlcsum(self.htlcs(subject, False))
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for htlc_id in self.log[-subject]['settles']:
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adds = self.log[subject]['adds']
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htlc = adds.pop(htlc_id)
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|
self.settled[subject].append(htlc.amount_msat)
|
|
self.log[-subject]['settles'].clear()
|
|
|
|
return old_amount - htlcsum(self.htlcs(subject, False))
|
|
|
|
sent_this_batch = mark_settled(LOCAL)
|
|
received_this_batch = mark_settled(REMOTE)
|
|
|
|
next_point = self.config[REMOTE].next_per_commitment_point
|
|
|
|
print("RECEIVED", received_this_batch)
|
|
print("SENT", sent_this_batch)
|
|
self.config[REMOTE]=self.config[REMOTE]._replace(
|
|
ctn=self.config[REMOTE].ctn + 1,
|
|
current_per_commitment_point=next_point,
|
|
next_per_commitment_point=revocation.next_per_commitment_point,
|
|
amount_msat=self.config[REMOTE].amount_msat + (sent_this_batch - received_this_batch)
|
|
)
|
|
self.config[LOCAL]=self.config[LOCAL]._replace(
|
|
amount_msat = self.config[LOCAL].amount_msat + (received_this_batch - sent_this_batch)
|
|
)
|
|
|
|
for pending_fee in self.fee_mgr:
|
|
if self.constraints.is_initiator:
|
|
pending_fee[FUNDEE_ACKED] = True
|
|
|
|
self.local_commitment = self.pending_local_commitment
|
|
self.remote_commitment = self.pending_remote_commitment
|
|
self.remote_commitment_to_be_revoked = prev_remote_commitment
|
|
return received_this_batch, sent_this_batch
|
|
|
|
def balance(self, subject):
|
|
initial = self.config[subject].initial_msat
|
|
|
|
initial -= sum(self.settled[subject])
|
|
initial += sum(self.settled[-subject])
|
|
|
|
assert initial == self.config[subject].amount_msat
|
|
return initial
|
|
|
|
def amounts(self):
|
|
remote_settled= htlcsum(self.htlcs(REMOTE, False))
|
|
local_settled= htlcsum(self.htlcs(LOCAL, False))
|
|
unsettled_local = htlcsum(self.htlcs(LOCAL, True))
|
|
unsettled_remote = htlcsum(self.htlcs(REMOTE, True))
|
|
remote_msat = self.config[REMOTE].amount_msat -\
|
|
unsettled_remote + local_settled - remote_settled
|
|
local_msat = self.config[LOCAL].amount_msat -\
|
|
unsettled_local + remote_settled - local_settled
|
|
return remote_msat, local_msat
|
|
|
|
def included_htlcs(self, subject, htlc_initiator):
|
|
"""
|
|
return filter of non-dust htlcs for subjects commitment transaction, initiated by given party
|
|
"""
|
|
feerate = self.pending_feerate(subject)
|
|
conf = self.config[subject]
|
|
weight = HTLC_SUCCESS_WEIGHT if subject != htlc_initiator else HTLC_TIMEOUT_WEIGHT
|
|
htlcs = self.htlcs(htlc_initiator, only_pending=True)
|
|
fee_for_htlc = lambda htlc: htlc.amount_msat // 1000 - (weight * feerate // 1000)
|
|
return filter(lambda htlc: fee_for_htlc(htlc) >= conf.dust_limit_sat, htlcs)
|
|
|
|
@property
|
|
def pending_remote_commitment(self):
|
|
this_point = self.config[REMOTE].next_per_commitment_point
|
|
return self.make_commitment(REMOTE, this_point)
|
|
|
|
def pending_feerate(self, subject):
|
|
candidate = self.constraints.feerate
|
|
for pending_fee in self.fee_mgr:
|
|
x = pending_fee.pending_feerate(subject)
|
|
if x is not None:
|
|
candidate = x
|
|
|
|
return candidate
|
|
|
|
@property
|
|
def pending_local_commitment(self):
|
|
_, this_point, _ = self.points
|
|
return self.make_commitment(LOCAL, this_point)
|
|
|
|
def total_msat(self, sub):
|
|
return sum(self.settled[sub])
|
|
|
|
def htlcs(self, subject, only_pending):
|
|
"""
|
|
only_pending: require the htlc's settlement to be pending (needs additional signatures/acks)
|
|
"""
|
|
update_log = self.log[subject]
|
|
other_log = self.log[-subject]
|
|
res = []
|
|
for htlc in update_log['adds'].values():
|
|
locked_in = htlc.locked_in[subject]
|
|
|
|
if locked_in is None or only_pending == (htlc.htlc_id in other_log['settles']):
|
|
continue
|
|
res.append(htlc)
|
|
return res
|
|
|
|
def settle_htlc(self, preimage, htlc_id):
|
|
"""
|
|
SettleHTLC attempts to settle an existing outstanding received HTLC.
|
|
"""
|
|
self.print_error("settle_htlc")
|
|
htlc = self.log[REMOTE]['adds'][htlc_id]
|
|
assert htlc.payment_hash == sha256(preimage)
|
|
self.log[LOCAL]['settles'].append(htlc_id)
|
|
|
|
def receive_htlc_settle(self, preimage, htlc_index):
|
|
self.print_error("receive_htlc_settle")
|
|
htlc = self.log[LOCAL]['adds'][htlc_index]
|
|
assert htlc.payment_hash == sha256(preimage)
|
|
self.log[REMOTE]['settles'].append(htlc_index)
|
|
|
|
def receive_fail_htlc(self, htlc_id):
|
|
self.print_error("receive_fail_htlc")
|
|
self.log[LOCAL]['adds'].pop(htlc_id)
|
|
|
|
@property
|
|
def current_height(self):
|
|
return {LOCAL: self.config[LOCAL].ctn, REMOTE: self.config[REMOTE].ctn}
|
|
|
|
@property
|
|
def pending_local_fee(self):
|
|
return self.constraints.capacity - sum(x[2] for x in self.pending_local_commitment.outputs())
|
|
|
|
def update_fee(self, feerate):
|
|
if not self.constraints.is_initiator:
|
|
raise Exception("only initiator can update_fee, this counterparty is not initiator")
|
|
pending_fee = FeeUpdate(self, rate=feerate)
|
|
self.fee_mgr.append(pending_fee)
|
|
|
|
def receive_update_fee(self, feerate):
|
|
if self.constraints.is_initiator:
|
|
raise Exception("only the non-initiator can receive_update_fee, this counterparty is initiator")
|
|
pending_fee = FeeUpdate(self, rate=feerate)
|
|
self.fee_mgr.append(pending_fee)
|
|
|
|
def remove_uncommitted_htlcs_from_log(self, subject):
|
|
"""
|
|
returns
|
|
- the htlcs with uncommited (not locked in) htlcs removed
|
|
- a list of htlc_ids that were removed
|
|
"""
|
|
removed = []
|
|
htlcs = []
|
|
for i in self.log[subject]['adds'].values():
|
|
locked_in = i.locked_in[LOCAL] is not None or i.locked_in[REMOTE] is not None
|
|
if locked_in:
|
|
htlcs.append(i._asdict())
|
|
else:
|
|
removed.append(i.htlc_id)
|
|
return htlcs, removed
|
|
|
|
def to_save(self):
|
|
# need to forget about uncommited htlcs
|
|
# since we must assume they don't know about it,
|
|
# if it was not acked
|
|
remote_filtered, remote_removed = self.remove_uncommitted_htlcs_from_log(REMOTE)
|
|
local_filtered, local_removed = self.remove_uncommitted_htlcs_from_log(LOCAL)
|
|
to_save = {
|
|
"local_config": self.config[LOCAL],
|
|
"remote_config": self.config[REMOTE],
|
|
"channel_id": self.channel_id,
|
|
"short_channel_id": self.short_channel_id,
|
|
"constraints": self.constraints,
|
|
"funding_outpoint": self.funding_outpoint,
|
|
"node_id": self.node_id,
|
|
"remote_commitment_to_be_revoked": str(self.remote_commitment_to_be_revoked),
|
|
"remote_log": remote_filtered,
|
|
"local_log": local_filtered,
|
|
"onion_keys": {str(k): bh2u(v) for k, v in self.onion_keys.items()},
|
|
"settled_local": self.settled[LOCAL],
|
|
"settled_remote": self.settled[REMOTE],
|
|
}
|
|
|
|
# htlcs number must be monotonically increasing,
|
|
# so we have to decrease the counter
|
|
if len(remote_removed) != 0:
|
|
assert min(remote_removed) < to_save['remote_config'].next_htlc_id
|
|
to_save['remote_config'] = to_save['remote_config']._replace(next_htlc_id = min(remote_removed))
|
|
|
|
if len(local_removed) != 0:
|
|
assert min(local_removed) < to_save['local_config'].next_htlc_id
|
|
to_save['local_config'] = to_save['local_config']._replace(next_htlc_id = min(local_removed))
|
|
|
|
return to_save
|
|
|
|
def serialize(self):
|
|
namedtuples_to_dict = lambda v: {i: j._asdict() if isinstance(j, tuple) else j for i, j in v._asdict().items()}
|
|
serialized_channel = {k: namedtuples_to_dict(v) if isinstance(v, tuple) else v for k, v in self.to_save().items()}
|
|
class MyJsonEncoder(json.JSONEncoder):
|
|
def default(self, o):
|
|
if isinstance(o, bytes):
|
|
return binascii.hexlify(o).decode("ascii")
|
|
if isinstance(o, RevocationStore):
|
|
return o.serialize()
|
|
return super(MyJsonEncoder, self)
|
|
dumped = MyJsonEncoder().encode(serialized_channel)
|
|
roundtripped = json.loads(dumped)
|
|
reconstructed = HTLCStateMachine(roundtripped)
|
|
if reconstructed.to_save() != self.to_save():
|
|
from pprint import pformat
|
|
try:
|
|
from deepdiff import DeepDiff
|
|
except ImportError:
|
|
raise Exception("Channels did not roundtrip serialization without changes:\n" + pformat(reconstructed.to_save()) + "\n" + pformat(self.to_save()))
|
|
else:
|
|
raise Exception("Channels did not roundtrip serialization without changes:\n" + pformat(DeepDiff(reconstructed.to_save(), self.to_save())))
|
|
return roundtripped
|
|
|
|
def __str__(self):
|
|
return self.serialize()
|
|
|
|
def make_commitment(self, subject, this_point) -> Transaction:
|
|
remote_msat, local_msat = self.amounts()
|
|
assert local_msat >= 0
|
|
assert remote_msat >= 0
|
|
this_config = self.config[subject]
|
|
other_config = self.config[-subject]
|
|
other_htlc_pubkey = derive_pubkey(other_config.htlc_basepoint.pubkey, this_point)
|
|
this_htlc_pubkey = derive_pubkey(this_config.htlc_basepoint.pubkey, this_point)
|
|
other_revocation_pubkey = derive_blinded_pubkey(other_config.revocation_basepoint.pubkey, this_point)
|
|
htlcs = []
|
|
for htlc in self.included_htlcs(subject, -subject):
|
|
htlcs.append( ScriptHtlc( make_received_htlc(
|
|
other_revocation_pubkey,
|
|
other_htlc_pubkey,
|
|
this_htlc_pubkey,
|
|
htlc.payment_hash,
|
|
htlc.cltv_expiry), htlc))
|
|
for htlc in self.included_htlcs(subject, subject):
|
|
htlcs.append(
|
|
ScriptHtlc( make_offered_htlc(
|
|
other_revocation_pubkey,
|
|
other_htlc_pubkey,
|
|
this_htlc_pubkey,
|
|
htlc.payment_hash), htlc))
|
|
if subject != LOCAL:
|
|
remote_msat, local_msat = local_msat, remote_msat
|
|
payment_pubkey = derive_pubkey(other_config.payment_basepoint.pubkey, this_point)
|
|
return make_commitment(
|
|
self.config[subject].ctn + 1,
|
|
this_config.multisig_key.pubkey,
|
|
other_config.multisig_key.pubkey,
|
|
payment_pubkey,
|
|
self.config[LOCAL].payment_basepoint.pubkey,
|
|
self.config[REMOTE].payment_basepoint.pubkey,
|
|
other_revocation_pubkey,
|
|
derive_pubkey(this_config.delayed_basepoint.pubkey, this_point),
|
|
other_config.to_self_delay,
|
|
*self.funding_outpoint,
|
|
self.constraints.capacity,
|
|
local_msat,
|
|
remote_msat,
|
|
this_config.dust_limit_sat,
|
|
self.pending_feerate(subject),
|
|
subject == LOCAL,
|
|
self.constraints.is_initiator,
|
|
htlcs=htlcs)
|
|
|
|
def make_closing_tx(self, local_script: bytes, remote_script: bytes, fee_sat: Optional[int] = None) -> (bytes, int):
|
|
if fee_sat is None:
|
|
fee_sat = self.pending_local_fee
|
|
|
|
_, outputs = make_outputs(fee_sat * 1000, True,
|
|
self.config[LOCAL].amount_msat,
|
|
self.config[REMOTE].amount_msat,
|
|
(TYPE_SCRIPT, bh2u(local_script)),
|
|
(TYPE_SCRIPT, bh2u(remote_script)),
|
|
[], self.config[LOCAL].dust_limit_sat)
|
|
|
|
closing_tx = make_closing_tx(self.config[LOCAL].multisig_key.pubkey,
|
|
self.config[REMOTE].multisig_key.pubkey,
|
|
self.config[LOCAL].payment_basepoint.pubkey,
|
|
self.config[REMOTE].payment_basepoint.pubkey,
|
|
# TODO hardcoded we_are_initiator:
|
|
True, *self.funding_outpoint, self.constraints.capacity,
|
|
outputs)
|
|
|
|
der_sig = bfh(closing_tx.sign_txin(0, self.config[LOCAL].multisig_key.privkey))
|
|
sig = ecc.sig_string_from_der_sig(der_sig[:-1])
|
|
return sig, fee_sat
|
|
|
|
def maybe_create_sweeptx_for_their_ctx_to_remote(chan, ctx, their_pcp: bytes,
|
|
sweep_address) -> Optional[EncumberedTransaction]:
|
|
assert isinstance(their_pcp, bytes)
|
|
payment_bp_privkey = ecc.ECPrivkey(chan.config[LOCAL].payment_basepoint.privkey)
|
|
our_payment_privkey = derive_privkey(payment_bp_privkey.secret_scalar, their_pcp)
|
|
our_payment_privkey = ecc.ECPrivkey.from_secret_scalar(our_payment_privkey)
|
|
our_payment_pubkey = our_payment_privkey.get_public_key_bytes(compressed=True)
|
|
to_remote_address = make_commitment_output_to_remote_address(our_payment_pubkey)
|
|
for output_idx, (type_, addr, val) in enumerate(ctx.outputs()):
|
|
if type_ == TYPE_ADDRESS and addr == to_remote_address:
|
|
break
|
|
else:
|
|
return None
|
|
sweep_tx = create_sweeptx_their_ctx_to_remote(address=sweep_address,
|
|
ctx=ctx,
|
|
output_idx=output_idx,
|
|
our_payment_privkey=our_payment_privkey)
|
|
return EncumberedTransaction(sweep_tx, csv_delay=0)
|
|
|
|
|
|
def maybe_create_sweeptx_for_their_ctx_to_local(chan, ctx, per_commitment_secret: bytes,
|
|
sweep_address) -> Optional[EncumberedTransaction]:
|
|
assert isinstance(per_commitment_secret, bytes)
|
|
per_commitment_point = ecc.ECPrivkey(per_commitment_secret).get_public_key_bytes(compressed=True)
|
|
revocation_privkey = derive_blinded_privkey(chan.config[LOCAL].revocation_basepoint.privkey,
|
|
per_commitment_secret)
|
|
revocation_pubkey = ecc.ECPrivkey(revocation_privkey).get_public_key_bytes(compressed=True)
|
|
to_self_delay = chan.config[LOCAL].to_self_delay
|
|
delayed_pubkey = derive_pubkey(chan.config[REMOTE].delayed_basepoint.pubkey,
|
|
per_commitment_point)
|
|
witness_script = bh2u(make_commitment_output_to_local_witness_script(
|
|
revocation_pubkey, to_self_delay, delayed_pubkey))
|
|
to_local_address = redeem_script_to_address('p2wsh', witness_script)
|
|
for output_idx, o in enumerate(ctx.outputs()):
|
|
if o.type == TYPE_ADDRESS and o.address == to_local_address:
|
|
break
|
|
else:
|
|
return None
|
|
sweep_tx = create_sweeptx_ctx_to_local(address=sweep_address,
|
|
ctx=ctx,
|
|
output_idx=output_idx,
|
|
witness_script=witness_script,
|
|
privkey=revocation_privkey,
|
|
is_revocation=True)
|
|
return EncumberedTransaction(sweep_tx, csv_delay=0)
|
|
|
|
|
|
def maybe_create_sweeptx_for_our_ctx_to_local(chan, ctx, our_pcp: bytes,
|
|
sweep_address) -> Optional[EncumberedTransaction]:
|
|
assert isinstance(our_pcp, bytes)
|
|
delayed_bp_privkey = ecc.ECPrivkey(chan.config[LOCAL].delayed_basepoint.privkey)
|
|
our_localdelayed_privkey = derive_privkey(delayed_bp_privkey.secret_scalar, our_pcp)
|
|
our_localdelayed_privkey = ecc.ECPrivkey.from_secret_scalar(our_localdelayed_privkey)
|
|
our_localdelayed_pubkey = our_localdelayed_privkey.get_public_key_bytes(compressed=True)
|
|
revocation_pubkey = derive_blinded_pubkey(chan.config[REMOTE].revocation_basepoint.pubkey,
|
|
our_pcp)
|
|
to_self_delay = chan.config[REMOTE].to_self_delay
|
|
witness_script = bh2u(make_commitment_output_to_local_witness_script(
|
|
revocation_pubkey, to_self_delay, our_localdelayed_pubkey))
|
|
to_local_address = redeem_script_to_address('p2wsh', witness_script)
|
|
for output_idx, o in enumerate(ctx.outputs()):
|
|
if o.type == TYPE_ADDRESS and o.address == to_local_address:
|
|
break
|
|
else:
|
|
return None
|
|
sweep_tx = create_sweeptx_ctx_to_local(address=sweep_address,
|
|
ctx=ctx,
|
|
output_idx=output_idx,
|
|
witness_script=witness_script,
|
|
privkey=our_localdelayed_privkey.get_secret_bytes(),
|
|
is_revocation=False,
|
|
to_self_delay=to_self_delay)
|
|
|
|
return EncumberedTransaction(sweep_tx, csv_delay=to_self_delay)
|
|
|
|
|
|
def create_sweeptx_their_ctx_to_remote(address, ctx, output_idx: int, our_payment_privkey: ecc.ECPrivkey,
|
|
fee_per_kb: int=None) -> 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)
|
|
sweep_outputs = [TxOutput(TYPE_ADDRESS, address, val-fee)]
|
|
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(address, ctx, output_idx: int, witness_script: str,
|
|
privkey: bytes, is_revocation: bool,
|
|
to_self_delay: int=None,
|
|
fee_per_kb: int=None) -> 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 to_self_delay is not None:
|
|
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)
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sweep_outputs = [TxOutput(TYPE_ADDRESS, address, val - fee)]
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sweep_tx = Transaction.from_io(sweep_inputs, sweep_outputs, version=2)
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sig = sweep_tx.sign_txin(0, privkey)
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witness = construct_witness([sig, int(is_revocation), witness_script])
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sweep_tx.inputs()[0]['witness'] = witness
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return sweep_tx
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