Perform breach remedy without sweepstore:

- add functions to lnsweep
 - lnworker: analyze candidate ctx and htlc_tx
 - watchtower will be optional
 - add test for breach remedy with spent htlcs
 - save tx name as label

electrum/lnchannel.py

@@ -46,7 +46,8 @@ from .lnutil import (Outpoint, LocalConfig, RemoteConfig, Keypair, OnlyPubkeyKey
                     HTLC_TIMEOUT_WEIGHT, HTLC_SUCCESS_WEIGHT, extract_ctn_from_tx_and_chan, UpdateAddHtlc,
                     funding_output_script, SENT, RECEIVED, LOCAL, REMOTE, HTLCOwner, make_commitment_outputs,
                     ScriptHtlc, PaymentFailure, calc_onchain_fees, RemoteMisbehaving, make_htlc_output_witness_script)
-from .lnsweep import create_sweeptxs_for_their_revoked_ctx, create_sweeptxs_for_our_ctx, create_sweeptxs_for_their_ctx
+from .lnsweep import create_sweeptxs_for_our_ctx, create_sweeptxs_for_their_ctx
+from .lnsweep import create_sweeptx_for_their_revoked_htlc
 from .lnhtlc import HTLCManager
 
 
@@ -165,7 +166,7 @@ class Channel(Logger):
         self.set_state('DISCONNECTED')
         self.local_commitment = None
         self.remote_commitment = None
-        self.sweep_info = None
+        self.sweep_info = {}
 
     def get_payments(self):
         out = {}
@@ -450,12 +451,6 @@ class Channel(Logger):
         point = secret_to_pubkey(int.from_bytes(secret, 'big'))
         return secret, point
 
-    def process_new_revocation_secret(self, per_commitment_secret: bytes):
-        outpoint = self.funding_outpoint.to_str()
-        ctx = self.remote_commitment_to_be_revoked  # FIXME can't we just reconstruct it?
-        sweeptxs = create_sweeptxs_for_their_revoked_ctx(self, ctx, per_commitment_secret, self.sweep_address)
-        return sweeptxs
-
     def receive_revocation(self, revocation: RevokeAndAck):
         self.logger.info("receive_revocation")
 
@@ -469,16 +464,7 @@ class Channel(Logger):
         # this might break
         prev_remote_commitment = self.pending_commitment(REMOTE)
         self.config[REMOTE].revocation_store.add_next_entry(revocation.per_commitment_secret)
-
-        # be robust to exceptions raised in lnwatcher
-        try:
-            sweeptxs = self.process_new_revocation_secret(revocation.per_commitment_secret)
-        except Exception as e:
-            self.logger.info("Could not process revocation secret: {}".format(repr(e)))
-            sweeptxs = []
-
         ##### start applying fee/htlc changes
-
         if self.pending_fee is not None:
             if not self.constraints.is_initiator:
                 self.pending_fee[FUNDEE_SIGNED] = True
@@ -501,8 +487,6 @@ class Channel(Logger):
 
         self.set_remote_commitment()
         self.remote_commitment_to_be_revoked = prev_remote_commitment
-        # return sweep transactions for watchtower
-        return sweeptxs
 
     def balance(self, whose, *, ctx_owner=HTLCOwner.LOCAL, ctn=None):
         """
@@ -810,19 +794,23 @@ class Channel(Logger):
         assert tx.is_complete()
         return tx
 
-    def get_sweep_info(self, ctx: Transaction):
-        if self.sweep_info is None:
+    def sweep_ctx(self, ctx: Transaction):
+        txid = ctx.txid()
+        if self.sweep_info.get(txid) is None:
             ctn = extract_ctn_from_tx_and_chan(ctx, self)
             our_sweep_info = create_sweeptxs_for_our_ctx(self, ctx, ctn, self.sweep_address)
             their_sweep_info = create_sweeptxs_for_their_ctx(self, ctx, ctn, self.sweep_address)
-            if our_sweep_info:
-                self.sweep_info = our_sweep_info
+            if our_sweep_info is not None:
+                self.sweep_info[txid] = our_sweep_info
                 self.logger.info(f'we force closed.')
-            elif their_sweep_info:
-                self.sweep_info = their_sweep_info
+            elif their_sweep_info is not None:
+                self.sweep_info[txid] = their_sweep_info
                 self.logger.info(f'they force closed.')
             else:
-                self.sweep_info = {}
+                self.sweep_info[txid] = {}
                 self.logger.info(f'not sure who closed {ctx}.')
-            self.logger.info(f'{repr(self.sweep_info)}')
-        return self.sweep_info
+        return self.sweep_info[txid]
+
+    def sweep_htlc(self, ctx:Transaction, htlc_tx: Transaction):
+        # look at the output address, check if it matches
+        return create_sweeptx_for_their_revoked_htlc(self, ctx, htlc_tx, self.sweep_address)

electrum/lnpeer.py

@@ -40,6 +40,7 @@ from .lnutil import (Outpoint, LocalConfig, RECEIVED, UpdateAddHtlc,
                      LightningPeerConnectionClosed, HandshakeFailed, NotFoundChanAnnouncementForUpdate,
                      MINIMUM_MAX_HTLC_VALUE_IN_FLIGHT_ACCEPTED, MAXIMUM_HTLC_MINIMUM_MSAT_ACCEPTED,
                      MAXIMUM_REMOTE_TO_SELF_DELAY_ACCEPTED, RemoteMisbehaving, DEFAULT_TO_SELF_DELAY)
+from .lnsweep import create_sweeptxs_for_watchtower
 from .lntransport import LNTransport, LNTransportBase
 from .lnmsg import encode_msg, decode_msg
 from .interface import GracefulDisconnect
@@ -1261,15 +1262,20 @@ class Peer(Logger):
         self.logger.info("on_revoke_and_ack")
         channel_id = payload["channel_id"]
         chan = self.channels[channel_id]
-        sweeptxs = chan.receive_revocation(RevokeAndAck(payload["per_commitment_secret"], payload["next_per_commitment_point"]))
+        ctx = chan.remote_commitment_to_be_revoked  # FIXME can't we just reconstruct it?
+        rev = RevokeAndAck(payload["per_commitment_secret"], payload["next_per_commitment_point"])
+        chan.receive_revocation(rev)
         self._remote_changed_events[chan.channel_id].set()
         self._remote_changed_events[chan.channel_id].clear()
         self.lnworker.save_channel(chan)
         self.maybe_send_commitment(chan)
-        asyncio.ensure_future(self._on_revoke_and_ack(chan, sweeptxs))
+        asyncio.ensure_future(self._on_revoke_and_ack(chan, ctx, rev.per_commitment_secret))
 
-    async def _on_revoke_and_ack(self, chan, sweeptxs):
+    @ignore_exceptions
+    @log_exceptions
+    async def _on_revoke_and_ack(self, chan, ctx, per_commitment_secret):
         outpoint = chan.funding_outpoint.to_str()
+        sweeptxs = create_sweeptxs_for_watchtower(chan, ctx, per_commitment_secret, chan.sweep_address)
         for tx in sweeptxs:
             await self.lnwatcher.add_sweep_tx(outpoint, tx.prevout(0), str(tx))
 

electrum/lnsweep.py

@@ -27,8 +27,8 @@ _logger = get_logger(__name__)
 
 
 
-def create_sweeptxs_for_their_revoked_ctx(chan: 'Channel', ctx: Transaction, per_commitment_secret: bytes,
-                                          sweep_address: str) -> Dict[str,Transaction]:
+def create_sweeptxs_for_watchtower(chan: 'Channel', ctx: Transaction, per_commitment_secret: bytes,
+                                   sweep_address: str) -> Dict[str,Transaction]:
     """Presign sweeping transactions using the just received revoked pcs.
     These will only be utilised if the remote breaches.
     Sweep 'to_local', and all the HTLCs (two cases: directly from ctx, or from HTLC tx).
@@ -75,8 +75,9 @@ def create_sweeptxs_for_their_revoked_ctx(chan: 'Channel', ctx: Transaction, per
             sweep_address=sweep_address,
             privkey=other_revocation_privkey,
             is_revocation=True)
+
     ctn = extract_ctn_from_tx_and_chan(ctx, chan)
-    assert ctn == chan.config[REMOTE].ctn
+    assert ctn == chan.config[REMOTE].ctn - 1
     # received HTLCs, in their ctx
     received_htlcs = chan.included_htlcs(REMOTE, RECEIVED, ctn)
     for htlc in received_htlcs:
@@ -92,6 +93,68 @@ def create_sweeptxs_for_their_revoked_ctx(chan: 'Channel', ctx: Transaction, per
     return txs
 
 
+def create_sweeptx_for_their_revoked_ctx(chan: 'Channel', ctx: Transaction, per_commitment_secret: bytes,
+                                         sweep_address: str) -> Dict[str,Transaction]:
+    # prep
+    pcp = ecc.ECPrivkey(per_commitment_secret).get_public_key_bytes(compressed=True)
+    this_conf, other_conf = get_ordered_channel_configs(chan=chan, for_us=False)
+    other_revocation_privkey = derive_blinded_privkey(other_conf.revocation_basepoint.privkey,
+                                                      per_commitment_secret)
+    to_self_delay = other_conf.to_self_delay
+    this_delayed_pubkey = derive_pubkey(this_conf.delayed_basepoint.pubkey, pcp)
+    txs = []
+    # to_local
+    revocation_pubkey = ecc.ECPrivkey(other_revocation_privkey).get_public_key_bytes(compressed=True)
+    witness_script = bh2u(make_commitment_output_to_local_witness_script(
+        revocation_pubkey, to_self_delay, this_delayed_pubkey))
+    to_local_address = redeem_script_to_address('p2wsh', witness_script)
+    output_idx = ctx.get_output_idx_from_address(to_local_address)
+    if output_idx is not None:
+        sweep_tx = lambda: create_sweeptx_ctx_to_local(
+            sweep_address=sweep_address,
+            ctx=ctx,
+            output_idx=output_idx,
+            witness_script=witness_script,
+            privkey=other_revocation_privkey,
+            is_revocation=True)
+        return sweep_tx
+
+def create_sweeptx_for_their_revoked_htlc(chan: 'Channel', ctx: Transaction, htlc_tx: Transaction,
+                                          sweep_address: str) -> Dict[str,Transaction]:
+    x = analyze_ctx(chan, ctx)
+    if not x:
+        return
+    ctn, their_pcp, is_revocation, per_commitment_secret = x
+    if not is_revocation:
+        return
+    # prep
+    pcp = ecc.ECPrivkey(per_commitment_secret).get_public_key_bytes(compressed=True)
+    this_conf, other_conf = get_ordered_channel_configs(chan=chan, for_us=False)
+    other_revocation_privkey = derive_blinded_privkey(other_conf.revocation_basepoint.privkey,
+                                                      per_commitment_secret)
+    to_self_delay = other_conf.to_self_delay
+    this_delayed_pubkey = derive_pubkey(this_conf.delayed_basepoint.pubkey, pcp)
+    # same witness script as to_local
+    revocation_pubkey = ecc.ECPrivkey(other_revocation_privkey).get_public_key_bytes(compressed=True)
+    witness_script = bh2u(make_commitment_output_to_local_witness_script(
+        revocation_pubkey, to_self_delay, this_delayed_pubkey))
+    htlc_address = redeem_script_to_address('p2wsh', witness_script)
+    # check that htlc_tx is a htlc
+    if htlc_tx.outputs()[0].address != htlc_address:
+        return
+
+    gen_tx = lambda: create_sweeptx_ctx_to_local(
+        sweep_address=sweep_address,
+        ctx=htlc_tx,
+        output_idx=0,
+        witness_script=witness_script,
+        privkey=other_revocation_privkey,
+        is_revocation=True)
+
+    return 'redeem_htlc2', 0, 0, gen_tx
+
+
+
 def create_sweeptxs_for_our_ctx(chan: 'Channel', ctx: Transaction, ctn: int,
                                 sweep_address: str) -> Dict[str,Transaction]:
     """Handle the case where we force close unilaterally with our latest ctx.
@@ -99,6 +162,7 @@ def create_sweeptxs_for_our_ctx(chan: 'Channel', ctx: Transaction, ctn: int,
     'to_local' can be swept even if this is a breach (by us),
     but HTLCs cannot (old HTLCs are no longer stored).
     """
+    ctn = extract_ctn_from_tx_and_chan(ctx, chan)
     our_conf, their_conf = get_ordered_channel_configs(chan=chan, for_us=True)
     our_per_commitment_secret = get_per_commitment_secret_from_seed(
         our_conf.per_commitment_secret_seed, RevocationStore.START_INDEX - ctn)
@@ -116,12 +180,18 @@ def create_sweeptxs_for_our_ctx(chan: 'Channel', ctx: Transaction, ctn: int,
     to_local_address = redeem_script_to_address('p2wsh', to_local_witness_script)
     their_payment_pubkey = derive_pubkey(their_conf.payment_basepoint.pubkey, our_pcp)
     to_remote_address = make_commitment_output_to_remote_address(their_payment_pubkey)
-
     # test ctx
+    _logger.debug(f'testing our ctx: {to_local_address} {to_remote_address}')
     if ctx.get_output_idx_from_address(to_local_address) is None\
        and ctx.get_output_idx_from_address(to_remote_address) is None:
         return
-
+    # we have to_local, to_remote.
+    # other outputs are htlcs
+    # if they are spent, we need to generate the script
+    # so, second-stage htlc sweep should not be returned here
+    if ctn != our_conf.ctn:
+        _logger.info("we breached.")
+        return {}
     txs = {}
     # to_local
     output_idx = ctx.get_output_idx_from_address(to_local_address)
@@ -155,7 +225,7 @@ def create_sweeptxs_for_our_ctx(chan: 'Channel', ctx: Transaction, ctn: int,
             preimage=preimage,
             is_received_htlc=is_received_htlc)
         sweep_tx = lambda: create_sweeptx_that_spends_htlctx_that_spends_htlc_in_ctx(
-            'sweep_from_our_ctx_htlc_',
+            'our_ctx_htlc_',
             to_self_delay=to_self_delay,
             htlc_tx=htlc_tx,
             htlctx_witness_script=htlctx_witness_script,
@@ -165,6 +235,7 @@ def create_sweeptxs_for_our_ctx(chan: 'Channel', ctx: Transaction, ctn: int,
         # side effect
         txs[htlc_tx.prevout(0)] = ('first-stage-htlc', 0, htlc_tx.cltv_expiry, lambda: htlc_tx)
         txs[htlc_tx.txid() + ':0'] = ('second-stage-htlc', to_self_delay, 0, sweep_tx)
+
     # offered HTLCs, in our ctx --> "timeout"
     # received HTLCs, in our ctx --> "success"
     offered_htlcs = chan.included_htlcs(LOCAL, SENT, ctn)  # type: List[UpdateAddHtlc]
@@ -175,17 +246,11 @@ def create_sweeptxs_for_our_ctx(chan: 'Channel', ctx: Transaction, ctn: int,
         create_txns_for_htlc(htlc, is_received_htlc=True)
     return txs
 
-
-def create_sweeptxs_for_their_ctx(chan: 'Channel', ctx: Transaction, ctn: int,
-                                  sweep_address: str) -> Dict[str,Transaction]:
-    """Handle the case when the remote force-closes with their ctx.
-    Sweep outputs that do not have a CSV delay ('to_remote' and first-stage HTLCs).
-    Outputs with CSV delay ('to_local' and second-stage HTLCs) are redeemed by LNWatcher.
-    """
-    our_conf, their_conf = get_ordered_channel_configs(chan=chan, for_us=True)
-    ctn = extract_ctn_from_tx_and_chan(ctx, chan)
+def analyze_ctx(chan, ctx):
     # note: the remote sometimes has two valid non-revoked commitment transactions,
     # either of which could be broadcast (their_conf.ctn, their_conf.ctn+1)
+    our_conf, their_conf = get_ordered_channel_configs(chan=chan, for_us=True)
+    ctn = extract_ctn_from_tx_and_chan(ctx, chan)
     per_commitment_secret = None
     if ctn == their_conf.ctn:
         their_pcp = their_conf.current_per_commitment_point
@@ -200,9 +265,23 @@ def create_sweeptxs_for_their_ctx(chan: 'Channel', ctx: Transaction, ctn: int,
             return
         their_pcp = ecc.ECPrivkey(per_commitment_secret).get_public_key_bytes(compressed=True)
         is_revocation = True
-        our_revocation_privkey = derive_blinded_privkey(our_conf.revocation_basepoint.privkey, per_commitment_secret)
+        #_logger.info(f'tx for revoked: {list(txs.keys())}')
     else:
         return
+    return ctn, their_pcp, is_revocation, per_commitment_secret
+
+def create_sweeptxs_for_their_ctx(chan: 'Channel', ctx: Transaction, ctn: int,
+                                  sweep_address: str) -> Dict[str,Transaction]:
+    """Handle the case when the remote force-closes with their ctx.
+    Sweep outputs that do not have a CSV delay ('to_remote' and first-stage HTLCs).
+    Outputs with CSV delay ('to_local' and second-stage HTLCs) are redeemed by LNWatcher.
+    """
+    txs = {}
+    our_conf, their_conf = get_ordered_channel_configs(chan=chan, for_us=True)
+    x = analyze_ctx(chan, ctx)
+    if not x:
+        return
+    ctn, their_pcp, is_revocation, per_commitment_secret = x
     # to_local and to_remote addresses
     our_revocation_pubkey = derive_blinded_pubkey(our_conf.revocation_basepoint.pubkey, their_pcp)
     their_delayed_pubkey = derive_pubkey(their_conf.delayed_basepoint.pubkey, their_pcp)
@@ -211,10 +290,18 @@ def create_sweeptxs_for_their_ctx(chan: 'Channel', ctx: Transaction, ctn: int,
     to_local_address = redeem_script_to_address('p2wsh', witness_script)
     our_payment_pubkey = derive_pubkey(our_conf.payment_basepoint.pubkey, their_pcp)
     to_remote_address = make_commitment_output_to_remote_address(our_payment_pubkey)
-    # test ctx
+    # test if this is their ctx
+    _logger.debug(f'testing their ctx: {to_local_address} {to_remote_address}')
     if ctx.get_output_idx_from_address(to_local_address) is None \
        and ctx.get_output_idx_from_address(to_remote_address) is None:
         return
+
+    if is_revocation:
+        our_revocation_privkey = derive_blinded_privkey(our_conf.revocation_basepoint.privkey, per_commitment_secret)
+        gen_tx = create_sweeptx_for_their_revoked_ctx(chan, ctx, per_commitment_secret, chan.sweep_address)
+        if gen_tx:
+            tx = gen_tx()
+            txs[tx.prevout(0)] = ('to_local_for_revoked_ctx', 0, 0, gen_tx)
     # prep
     our_htlc_privkey = derive_privkey(secret=int.from_bytes(our_conf.htlc_basepoint.privkey, 'big'), per_commitment_point=their_pcp)
     our_htlc_privkey = ecc.ECPrivkey.from_secret_scalar(our_htlc_privkey)
@@ -223,7 +310,6 @@ def create_sweeptxs_for_their_ctx(chan: 'Channel', ctx: Transaction, ctn: int,
     our_payment_privkey = derive_privkey(our_payment_bp_privkey.secret_scalar, their_pcp)
     our_payment_privkey = ecc.ECPrivkey.from_secret_scalar(our_payment_privkey)
     assert our_payment_pubkey == our_payment_privkey.get_public_key_bytes(compressed=True)
-    txs = {}
     # to_local is handled by lnwatcher
     # to_remote
     output_idx = ctx.get_output_idx_from_address(to_remote_address)
@@ -268,7 +354,7 @@ def create_sweeptxs_for_their_ctx(chan: 'Channel', ctx: Transaction, ctn: int,
                 privkey=our_revocation_privkey if is_revocation else our_htlc_privkey.get_secret_bytes(),
                 is_revocation=is_revocation,
                 cltv_expiry=cltv_expiry)
-            name = f'their_ctx_sweep_htlc_{ctx.txid()[:8]}_{output_idx}'
+            name = f'their_ctx_htlc_{output_idx}'
             txs[prevout] = (name, 0, cltv_expiry, sweep_tx)
     # received HTLCs, in their ctx --> "timeout"
     received_htlcs = chan.included_htlcs(REMOTE, RECEIVED, ctn=ctn)  # type: List[UpdateAddHtlc]
@@ -327,7 +413,7 @@ def create_sweeptx_their_ctx_htlc(ctx: Transaction, witness_script: bytes, sweep
     if outvalue <= dust_threshold(): return None
     sweep_outputs = [TxOutput(TYPE_ADDRESS, sweep_address, outvalue)]
     tx = Transaction.from_io(sweep_inputs, sweep_outputs, version=2
-            , name=f'their_ctx_sweep_htlc_{ctx.txid()[:8]}_{output_idx}'
+            , name=f'their_ctx_htlc_{output_idx}'
             # note that cltv_expiry, and therefore also locktime will be zero when breach!
             , cltv_expiry=cltv_expiry, locktime=cltv_expiry)
     sig = bfh(tx.sign_txin(0, privkey))
@@ -431,7 +517,8 @@ def create_sweeptx_that_spends_htlctx_that_spends_htlc_in_ctx(
     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, name=name_prefix + htlc_tx.txid(), csv_delay=to_self_delay)
+    name = name_prefix + htlc_tx.txid()[0:4]
+    tx = Transaction.from_io(sweep_inputs, sweep_outputs, version=2, name=name, csv_delay=to_self_delay)
 
     sig = bfh(tx.sign_txin(0, privkey))
     witness = construct_witness([sig, int(is_revocation), htlctx_witness_script])

electrum/lnutil.py

@@ -359,7 +359,7 @@ def make_htlc_tx_with_open_channel(chan: 'Channel', pcp: bytes, for_us: bool,
     is_htlc_success = for_us == we_receive
     script, htlc_tx_output = make_htlc_tx_output(
         amount_msat = amount_msat,
-        local_feerate = chan.pending_feerate(LOCAL if for_us else REMOTE),
+        local_feerate = chan.pending_feerate(LOCAL if for_us else REMOTE), # uses pending feerate..
         revocationpubkey=other_revocation_pubkey,
         local_delayedpubkey=delayedpubkey,
         success = is_htlc_success,

electrum/lnwatcher.py

@@ -248,7 +248,7 @@ class LNWatcher(AddressSynchronizer):
             self.network.trigger_callback('channel_closed', funding_outpoint, spenders,
                                           funding_txid, funding_height, closing_txid,
                                           closing_height, closing_tx)  # FIXME sooo many args..
-            await self.do_breach_remedy(funding_outpoint, spenders)
+            #await self.do_breach_remedy(funding_outpoint, spenders)
         if not keep_watching:
             await self.unwatch_channel(address, funding_outpoint)
         else:
@@ -289,8 +289,7 @@ class LNWatcher(AddressSynchronizer):
                 continue
             sweep_txns = await self.sweepstore.get_sweep_tx(funding_outpoint, prevout)
             for tx in sweep_txns:
-                if not await self.broadcast_or_log(funding_outpoint, tx):
-                    self.logger.info(f'{tx.name} could not publish tx: {str(tx)}, prevout: {prevout}')
+                await self.broadcast_or_log(funding_outpoint, tx)
 
     async def broadcast_or_log(self, funding_outpoint, tx):
         height = self.get_tx_height(tx.txid()).height
@@ -299,9 +298,9 @@ class LNWatcher(AddressSynchronizer):
         try:
             txid = await self.network.broadcast_transaction(tx)
         except Exception as e:
-            self.logger.info(f'broadcast: {tx.name}: failure: {repr(e)}')
+            self.logger.info(f'broadcast failure: {tx.name}: {repr(e)}')
         else:
-            self.logger.info(f'broadcast: {tx.name}: success. txid: {txid}')
+            self.logger.info(f'broadcast success: {tx.name}')
             if funding_outpoint in self.tx_progress:
                 await self.tx_progress[funding_outpoint].tx_queue.put(tx)
             return txid

electrum/lnworker.py

@@ -514,45 +514,66 @@ class LNWallet(LNWorker):
         # remove from channel_db
         if chan.short_channel_id is not None:
             self.channel_db.remove_channel(chan.short_channel_id)
-
         # detect who closed and set sweep_info
-        sweep_info = chan.get_sweep_info(closing_tx)
-
+        sweep_info = chan.sweep_ctx(closing_tx)
         # create and broadcast transaction
         for prevout, e_tx in sweep_info.items():
             name, csv_delay, cltv_expiry, gen_tx = e_tx
-            if spenders.get(prevout) is not None:
-                self.logger.info(f'outpoint already spent {prevout}')
-                continue
-            prev_txid, prev_index = prevout.split(':')
-            broadcast = True
-            if cltv_expiry:
-                local_height = self.network.get_local_height()
-                remaining = cltv_expiry - local_height
-                if remaining > 0:
-                    self.logger.info('waiting for {}: CLTV ({} > {}), funding outpoint {} and tx {}'
-                                     .format(name, local_height, cltv_expiry, funding_outpoint[:8], prev_txid[:8]))
-                    broadcast = False
-            if csv_delay:
-                prev_height = self.network.lnwatcher.get_tx_height(prev_txid)
-                remaining = csv_delay - prev_height.conf
-                if remaining > 0:
-                    self.logger.info('waiting for {}: CSV ({} >= {}), funding outpoint {} and tx {}'
-                                     .format(name, prev_height.conf, csv_delay, funding_outpoint[:8], prev_txid[:8]))
-                    broadcast = False
-            tx = gen_tx()
-            if tx is None:
-                self.logger.info(f'{name} could not claim output: {prevout}, dust')
-            if broadcast:
-                if not await self.network.lnwatcher.broadcast_or_log(funding_outpoint, tx):
-                    self.logger.info(f'{name} could not publish encumbered tx: {str(tx)}, prevout: {prevout}')
+            spender = spenders.get(prevout)
+            if spender is not None:
+                spender_tx = await self.network.get_transaction(spender)
+                spender_tx = Transaction(spender_tx)
+                e_htlc_tx = chan.sweep_htlc(closing_tx, spender_tx)
+                if e_htlc_tx:
+                    spender2 = spenders.get(spender_tx.outputs()[0])
+                    if spender2:
+                        self.logger.info(f'htlc is already spent {name}: {prevout}')
+                    else:
+                        self.logger.info(f'trying to redeem htlc {name}: {prevout}')
+                        await self.try_redeem(spender+':0', e_htlc_tx)
+                else:
+                    self.logger.info(f'outpoint already spent {name}: {prevout}')
             else:
-                # it's OK to add local transaction, the fee will be recomputed
-                try:
-                    self.wallet.add_future_tx(tx, remaining)
-                    self.logger.info(f'adding future tx: {name}. prevout: {prevout}')
-                except Exception as e:
-                    self.logger.info(f'could not add future tx: {name}. prevout: {prevout} {str(e)}')
+                self.logger.info(f'trying to redeem {name}: {prevout}')
+                await self.try_redeem(prevout, e_tx)
+
+    @log_exceptions
+    async def try_redeem(self, prevout, e_tx):
+        name, csv_delay, cltv_expiry, gen_tx = e_tx
+        prev_txid, prev_index = prevout.split(':')
+        broadcast = True
+        if cltv_expiry:
+            local_height = self.network.get_local_height()
+            remaining = cltv_expiry - local_height
+            if remaining > 0:
+                self.logger.info('waiting for {}: CLTV ({} > {}), prevout {}'
+                                 .format(name, local_height, cltv_expiry, prevout))
+                broadcast = False
+        if csv_delay:
+            prev_height = self.network.lnwatcher.get_tx_height(prev_txid)
+            remaining = csv_delay - prev_height.conf
+            if remaining > 0:
+                self.logger.info('waiting for {}: CSV ({} >= {}), prevout: {}'
+                                 .format(name, prev_height.conf, csv_delay, prevout))
+                broadcast = False
+        tx = gen_tx()
+        self.wallet.set_label(tx.txid(), name)
+        if tx is None:
+            self.logger.info(f'{name} could not claim output: {prevout}, dust')
+        if broadcast:
+            try:
+                await self.network.broadcast_transaction(tx)
+            except Exception as e:
+                self.logger.info(f'could NOT publish {name} for prevout: {prevout}, {str(e)}')
+            else:
+                self.logger.info(f'success: broadcasting {name} for prevout: {prevout}')
+        else:
+            # it's OK to add local transaction, the fee will be recomputed
+            try:
+                self.wallet.add_future_tx(tx, remaining)
+                self.logger.info(f'adding future tx: {name}. prevout: {prevout}')
+            except Exception as e:
+                self.logger.info(f'could not add future tx: {name}. prevout: {prevout} {str(e)}')
 
     def is_dangerous(self, chan):
         for x in chan.get_unfulfilled_htlcs():

electrum/tests/regtest/regtest.sh

@@ -157,7 +157,7 @@ if [[ $1 == "redeem_htlcs" ]]; then
 fi
 
 
-if [[ $1 == "breach_with_htlc" ]]; then
+if [[ $1 == "breach_with_unspent_htlc" ]]; then
     $bob daemon stop
     ELECTRUM_DEBUG_LIGHTNING_SETTLE_DELAY=3 $bob daemon -s 127.0.0.1:51001:t start
     $bob daemon load_wallet
@@ -218,3 +218,84 @@ if [[ $1 == "breach_with_htlc" ]]; then
 	exit 1
     fi
 fi
+
+
+if [[ $1 == "breach_with_spent_htlc" ]]; then
+    $bob daemon stop
+    ELECTRUM_DEBUG_LIGHTNING_SETTLE_DELAY=3 $bob daemon -s 127.0.0.1:51001:t start
+    $bob daemon load_wallet
+    while alice_balance=$($alice getbalance | jq '.confirmed' | tr -d '"') && [ $alice_balance != "1" ]; do
+	echo "waiting for alice balance"
+	sleep 1
+    done
+    echo "alice opens channel"
+    bob_node=$($bob nodeid)
+    channel=$($alice open_channel $bob_node 0.15)
+    new_blocks 3
+    channel_state=""
+    while channel_state=$($alice list_channels | jq '.[] | .state' | tr -d '"') && [ $channel_state != "OPEN" ]; do
+	echo "waiting for channel open"
+	sleep 1
+    done
+    echo "alice pays bob"
+    invoice=$($bob addinvoice 0.05 "test")
+    $alice lnpay $invoice --timeout=1 || true
+    settled=$($alice list_channels | jq '.[] | .local_htlcs | .settles | length')
+    if [[ "$settled" != "0" ]]; then
+	echo "SETTLE_DELAY did not work, $settled != 0"
+        exit 1
+    fi
+    ctx=$($alice get_channel_ctx $channel | jq '.hex' | tr -d '"')
+    cp /tmp/alice/regtest/wallets/default_wallet /tmp/alice/regtest/wallets/toxic_wallet
+    sleep 5
+    settled=$($alice list_channels | jq '.[] | .local_htlcs | .settles | length')
+    if [[ "$settled" != "1" ]]; then
+	echo "SETTLE_DELAY did not work, $settled != 1"
+        exit 1
+    fi
+    echo $($bob getbalance)
+    echo "bob goes offline"
+    $bob daemon stop
+    ctx_id=$($bitcoin_cli sendrawtransaction $ctx)
+    echo "alice breaches with old ctx:" $ctx_id
+    new_blocks 1
+    if [[ $($bitcoin_cli gettxout $ctx_id 0 | jq '.confirmations') != "1" ]]; then
+	echo "breach tx not confirmed"
+	exit 1
+    fi
+    echo "wait for cltv_expiry blocks"
+    # note: this will let alice redeem to_local
+    # because cltv_delay is the same as csv_delay
+    new_blocks 144
+    echo "alice spends to_local and htlc outputs"
+    $alice daemon stop
+    cp /tmp/alice/regtest/wallets/toxic_wallet /tmp/alice/regtest/wallets/default_wallet
+    $alice daemon -s 127.0.0.1:51001:t start
+    $alice daemon load_wallet
+    # wait until alice has spent both ctx outputs
+    while [[ $($bitcoin_cli gettxout $ctx_id 0) ]]; do
+	echo "waiting until alice spends ctx outputs"
+	sleep 1
+    done
+    while [[ $($bitcoin_cli gettxout $ctx_id 1) ]]; do
+	echo "waiting until alice spends ctx outputs"
+	sleep 1
+    done
+    new_blocks 1
+    echo "bob comes back"
+    $bob daemon -s 127.0.0.1:51001:t start
+    $bob daemon load_wallet
+    while [[ $($bitcoin_cli getmempoolinfo | jq '.size') != "1" ]]; do
+	echo "waiting for bob's transaction"
+	sleep 1
+    done
+    echo "mempool has 1 tx"
+    new_blocks 1
+    sleep 5
+    balance=$($bob getbalance | jq '.confirmed')
+    if (( $(echo "$balance < 0.049" | bc -l) )); then
+	echo "htlc not redeemed."
+	exit 1
+    fi
+    echo "bob balance $balance"
+fi

electrum/tests/test_regtest.py

@@ -33,5 +33,8 @@ class TestLightning(unittest.TestCase):
     def test_redeem_htlcs(self):
         self.run_shell(['redeem_htlcs'])
 
-    def test_breach_with_htlc(self):
-        self.run_shell(['breach_with_htlc'])
+    def test_breach_with_unspent_htlc(self):
+        self.run_shell(['breach_with_unspent_htlc'])
+
+    def test_breach_with_spent_htlc(self):
+        self.run_shell(['breach_with_spent_htlc'])