commit 000e56d67e07c884384d954f0c933eb7d0a85914
parent 76bddb1ec29f89e0141a4973937525bb21be797f
Author: ThomasV <thomasv@electrum.org>
Date: Mon, 25 May 2020 20:06:23 +0200
submarine swaps: verify amounts
Diffstat:
2 files changed, 32 insertions(+), 22 deletions(-)
diff --git a/electrum/gui/qt/swap_dialog.py b/electrum/gui/qt/swap_dialog.py
@@ -182,13 +182,15 @@ class SwapDialog(WindowModalDialog):
if not self.exec_():
return
if self.is_reverse:
- amount_sat = self.send_amount_e.get_amount()
- coro = self.swap_manager.reverse_swap(amount_sat)
+ lightning_amount = self.send_amount_e.get_amount()
+ onchain_amount = self.recv_amount_e.get_amount() + self.claim_fee
+ coro = self.swap_manager.reverse_swap(lightning_amount, onchain_amount)
asyncio.run_coroutine_threadsafe(coro, self.network.asyncio_loop)
else:
- amount_sat = self.recv_amount_e.get_amount()
- self.window.protect(self.do_normal_swap, (amount_sat,))
+ lightning_amount = self.recv_amount_e.get_amount()
+ onchain_amount = self.send_amount_e.get_amount()
+ self.window.protect(self.do_normal_swap, (lightning_amount, onchain_amount))
- def do_normal_swap(self, amount_sat, password):
- coro = self.swap_manager.normal_swap(amount_sat, password)
+ def do_normal_swap(self, lightning_amount, onchain_amount, password):
+ coro = self.swap_manager.normal_swap(lightning_amount, onchain_amount, password)
asyncio.run_coroutine_threadsafe(coro, self.network.asyncio_loop)
diff --git a/electrum/submarine_swaps.py b/electrum/submarine_swaps.py
@@ -77,16 +77,18 @@ def create_claim_tx(txin, witness_script, preimage, privkey:bytes, address, amou
class SwapManager(Logger):
@log_exceptions
- async def _claim_swap(self, lockup_address, redeem_script, preimage, privkey, locktime):
+ async def _claim_swap(self, lockup_address, onchain_amount, redeem_script, preimage, privkey, locktime):
utxos = self.lnwatcher.get_addr_utxo(lockup_address)
if not utxos:
return
- if not preimage:
- delta = self.network.get_local_height() - locktime
- if delta < 0:
- self.logger.info(f'height not reached for refund {lockup_address} {delta}, {locktime}')
- return
+ delta = self.network.get_local_height() - locktime
+ if not preimage and delta < 0:
+ self.logger.info(f'height not reached for refund {lockup_address} {delta}, {locktime}')
+ return
for txin in list(utxos.values()):
+ if preimage and txin._trusted_value_sats < onchain_amount:
+ self.logger.info('amount too low, we should not reveal the preimage')
+ continue
amount_sat = txin._trusted_value_sats - self.get_tx_fee()
if amount_sat < dust_threshold():
self.logger.info('utxo value below dust threshold')
@@ -111,24 +113,26 @@ class SwapManager(Logger):
privkey = bytes.fromhex(data['privkey'])
if data.get('invoice'):
lockup_address = data['lockupAddress']
+ onchain_amount = data["onchainAmount"]
preimage = bytes.fromhex(data['preimage'])
else:
lockup_address = data['address']
+ onchain_amount = data["expectedAmount"]
preimage = 0
- self.add_lnwatcher_callback(lockup_address, redeem_script, preimage, privkey, locktime)
+ self.add_lnwatcher_callback(lockup_address, onchain_amount, redeem_script, preimage, privkey, locktime)
- def add_lnwatcher_callback(self, lockup_address, redeem_script, preimage, privkey, locktime):
- callback = lambda: self._claim_swap(lockup_address, redeem_script, preimage, privkey, locktime)
+ def add_lnwatcher_callback(self, lockup_address, onchain_amount, redeem_script, preimage, privkey, locktime):
+ callback = lambda: self._claim_swap(lockup_address, onchain_amount, redeem_script, preimage, privkey, locktime)
self.lnwatcher.add_callback(lockup_address, callback)
@log_exceptions
- async def normal_swap(self, amount_sat, password):
+ async def normal_swap(self, lightning_amount, expected_onchain_amount, password):
privkey = os.urandom(32)
pubkey = ECPrivkey(privkey).get_public_key_bytes(compressed=True)
key = await self.lnworker._add_request_coro(amount_sat, 'swap', expiry=3600*24)
request = self.wallet.get_request(key)
invoice = request['invoice']
- lnaddr = self.lnworker._check_invoice(invoice, amount_sat)
+ lnaddr = self.lnworker._check_invoice(invoice, lightning_amount)
payment_hash = lnaddr.paymenthash
preimage = self.lnworker.get_preimage(payment_hash)
request_data = {
@@ -157,15 +161,17 @@ class SwapManager(Logger):
assert script_to_p2wsh(redeem_script.hex()) == lockup_address
assert hash_160(preimage) == parsed_script[1][1]
assert pubkey == parsed_script[9][1]
- # verify that they are not locking up funds for more than a day
assert locktime == int.from_bytes(parsed_script[6][1], byteorder='little')
+ # check that onchain_amount is what was announced
+ assert onchain_amount == expected_onchain_amount
+ # verify that they are not locking up funds for more than a day
assert locktime - self.network.get_local_height() < 144
# save swap data in wallet in case we need a refund
data['privkey'] = privkey.hex()
data['preimage'] = preimage.hex()
swaps = self.wallet.db.get_dict('submarine_swaps')
swaps[response_id] = data
- self.add_lnwatcher_callback(lockup_address, redeem_script, 0, privkey, locktime)
+ self.add_lnwatcher_callback(lockup_address, onchain_amount, redeem_script, 0, privkey, locktime)
outputs = [PartialTxOutput.from_address_and_value(lockup_address, onchain_amount)]
tx = self.wallet.create_transaction(outputs=outputs, rbf=False, password=password)
await self.network.broadcast_transaction(tx)
@@ -177,7 +183,7 @@ class SwapManager(Logger):
}
@log_exceptions
- async def reverse_swap(self, amount_sat):
+ async def reverse_swap(self, amount_sat, expected_amount):
privkey = os.urandom(32)
pubkey = ECPrivkey(privkey).get_public_key_bytes(compressed=True)
preimage = os.urandom(32)
@@ -209,8 +215,10 @@ class SwapManager(Logger):
assert script_to_p2wsh(redeem_script.hex()) == lockup_address
assert hash_160(preimage) == parsed_script[5][1]
assert pubkey == parsed_script[7][1]
- # verify that we will have enought time to get our tx confirmed
assert locktime == int.from_bytes(parsed_script[10][1], byteorder='little')
+ # check that the amount is what we expected
+ assert onchain_amount == expected_amount, (onchain_amount, expected_amount)
+ # verify that we will have enought time to get our tx confirmed
assert locktime - self.network.get_local_height() > 10
# verify invoice preimage_hash
lnaddr = self.lnworker._check_invoice(invoice, amount_sat)
@@ -222,7 +230,7 @@ class SwapManager(Logger):
swaps = self.wallet.db.get_dict('submarine_swaps')
swaps[response_id] = data
# add callback to lnwatcher
- self.add_lnwatcher_callback(lockup_address, redeem_script, preimage, privkey, locktime)
+ self.add_lnwatcher_callback(lockup_address, onchain_amount, redeem_script, preimage, privkey, locktime)
# initiate payment.
success, log = await self.lnworker._pay(invoice, attempts=5)
# discard data; this should be done by lnwatcher
