AaronFiore/electrum
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ln: remove unneeded forwarding htlc features, check commitment sig using lnhtlc while receiving

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This commit is contained in:
Janus
2018-06-11 19:53:15 +02:00
committed by ThomasV
parent 4d25933898
commit bd0f659f26
4 changed files with 92 additions and 95 deletions
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94
lib/lnhtlc.py
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@@ -1,9 +1,11 @@
# ported from lnd 42de4400bff5105352d0552155f73589166d162b
from ecdsa.util import sigencode_string_canonize, sigdecode_der
from .util import bfh, PrintError
from .bitcoin import Hash, address_to_script
from collections import namedtuple
from ecdsa.curves import SECP256k1
from .crypto import sha256
from . import ecc
SettleHtlc = namedtuple("SettleHtlc", ["htlc_id"])
RevokeAndAck = namedtuple("RevokeAndAck", ["height", "per_commitment_secret", "next_per_commitment_point"])
@@ -53,8 +55,6 @@ class HTLCStateMachine(PrintError):
self.name = name
self.l_current_height = 0
self.r_current_height = 0
self.total_msat_sent = 0
self.total_msat_received = 0
@@ -97,13 +97,9 @@ class HTLCStateMachine(PrintError):
HTLC's on the commitment transaction.
"""
from .lnbase import sign_and_get_sig_string, derive_privkey, make_htlc_tx_with_open_channel
self.l_current_height += 1
for htlc in self.local_update_log:
if not type(htlc) is UpdateAddHtlc: continue
if htlc.l_locked_in is None: htlc.l_locked_in = self.l_current_height
for htlc in self.remote_update_log:
if not type(htlc) is UpdateAddHtlc: continue
if htlc.r_locked_in is None: htlc.r_locked_in = self.r_current_height
if htlc.l_locked_in is None: htlc.l_locked_in = self.state.local_state.ctn
self.print_error("sign_next_commitment")
sig_64 = sign_and_get_sig_string(self.remote_commitment, self.state.local_config, self.state.remote_config)
@@ -126,7 +122,7 @@ class HTLCStateMachine(PrintError):
sig = bfh(htlc_tx.sign_txin(0, their_remote_htlc_privkey))
r, s = sigdecode_der(sig[:-1], SECP256k1.generator.order())
htlc_sig = sigencode_string_canonize(r, s, SECP256k1.generator.order())
htlcsigs.append((htlc_tx, htlc_sig))
htlcsigs.append(htlc_sig)
return sig_64, htlcsigs
@@ -141,8 +137,35 @@ class HTLCStateMachine(PrintError):
state, then this newly added commitment becomes our current accepted channel
state.
"""
from .lnbase import make_htlc_tx_with_open_channel , derive_pubkey
self.print_error("receive_new_commitment")
# TODO
for htlc in self.remote_update_log:
if not type(htlc) is UpdateAddHtlc: continue
if htlc.r_locked_in is None: htlc.r_locked_in = self.state.remote_state.ctn
assert len(htlc_sigs) == 0 or type(htlc_sigs[0]) is bytes
assert len(htlc_sigs) == len(self.local_commitment.outputs()) - 2, (len(htlc_sigs), len(self.local_commitment.outputs()) - 2, self.diagnostic_name())
preimage_hex = self.local_commitment.serialize_preimage(0)
pre_hash = Hash(bfh(preimage_hex))
if not ecc.verify_signature(self.state.remote_config.multisig_key.pubkey, sig, pre_hash):
raise Exception('failed verifying signature of our updated commitment transaction: ' + str(sig))
_, this_point, _ = self.points
if len(self.htlcs_in_remote) > 0:
print("CHECKING HTLC SIGS")
assert len(self.local_commitment.outputs()) == 3 # TODO
we_receive = True # TODO
payment_hash = self.htlcs_in_remote[0].payment_hash
amount_msat = self.htlcs_in_remote[0].amount_msat
cltv_expiry = self.htlcs_in_remote[0].cltv_expiry
htlc_tx = make_htlc_tx_with_open_channel(self.state, this_point, True, we_receive, amount_msat, cltv_expiry, payment_hash, self.local_commitment, 0)
pre_hash = Hash(bfh(htlc_tx.serialize_preimage(0)))
remote_htlc_pubkey = derive_pubkey(self.state.remote_config.htlc_basepoint.pubkey, this_point)
if not ecc.verify_signature(remote_htlc_pubkey, htlc_sigs[0], pre_hash):
raise Exception("failed verifying signature an HTLC tx spending from one of our commit tx'es HTLC outputs")
def revoke_current_commitment(self):
"""
@@ -155,10 +178,21 @@ class HTLCStateMachine(PrintError):
transaction. This return value allows callers to act once an HTLC has been
locked into our commitment transaction.
"""
from .lnbase import get_per_commitment_secret_from_seed, secret_to_pubkey
self.r_current_height += 1
self.print_error("revoke_current_commitment")
last_secret, this_point, next_point = self.points
self.state = self.state._replace(
local_state=self.state.local_state._replace(
ctn=self.state.local_state.ctn + 1
)
)
return RevokeAndAck(self.state.local_state.ctn - 1, last_secret, next_point), "current htlcs"
@property
def points(self):
from .lnbase import get_per_commitment_secret_from_seed, secret_to_pubkey
chan = self.state
last_small_num = chan.local_state.ctn
next_small_num = last_small_num + 2
@@ -168,13 +202,7 @@ class HTLCStateMachine(PrintError):
this_point = secret_to_pubkey(int.from_bytes(this_secret, 'big'))
next_secret = get_per_commitment_secret_from_seed(chan.local_state.per_commitment_secret_seed, 2**48-next_small_num-1)
next_point = secret_to_pubkey(int.from_bytes(next_secret, 'big'))
self.state = chan._replace(
local_state=chan.local_state._replace(
ctn=chan.local_state.ctn + 1
)
)
return RevokeAndAck(self.r_current_height, last_secret, next_point), "current htlcs"
return last_secret, this_point, next_point
def receive_revocation(self, revocation):
"""
@@ -196,13 +224,6 @@ class HTLCStateMachine(PrintError):
continue
settle_fails2.append(x)
if revocation.height is not None:
adds2 = list(x for x in self.htlcs_in_remote if x.r_locked_in == revocation.height)
class FwdPkg:
adds = adds2
settle_fails = settle_fails2
for x in settle_fails2:
self.total_msat_sent += self.lookup_htlc(self.local_update_log, x.htlc_id).amount_msat
@@ -219,6 +240,9 @@ class HTLCStateMachine(PrintError):
for x in filter(lambda x: type(x) is SettleHtlc, self.remote_update_log):
to_remove += [y for y in self.local_update_log if y.htlc_id == x.htlc_id]
if to_remove != []:
print("REMOVING")
# assert that we should have compacted the log earlier
assert len(to_remove) <= 1, to_remove
if len(to_remove) == 1:
@@ -246,11 +270,6 @@ class HTLCStateMachine(PrintError):
)
)
if revocation.height is not None:
return FwdPkg
else:
return None
@staticmethod
def htlcsum(htlcs):
return sum(x.amount_msat for x in htlcs), sum(x.total_fee for x in htlcs)
@@ -295,18 +314,14 @@ class HTLCStateMachine(PrintError):
from .lnbase import make_commitment_using_open_channel, make_received_htlc, make_offered_htlc, derive_pubkey, derive_blinded_pubkey, get_per_commitment_secret_from_seed, secret_to_pubkey
htlc_value_local, total_fee_local = self.htlcsum(self.htlcs_in_local)
htlc_value_remote, total_fee_remote = self.htlcsum(self.htlcs_in_remote)
print("htlc_value_local, total_fee_local", htlc_value_local, total_fee_local)
local_msat = self.state.local_state.amount_msat -\
htlc_value_local
print("htlc_value_remote, total_fee_remote", htlc_value_remote, total_fee_remote)
remote_msat = self.state.remote_state.amount_msat -\
htlc_value_remote
assert local_msat > 0
assert remote_msat > 0
this_small_num = self.state.local_state.ctn + 1
this_secret = get_per_commitment_secret_from_seed(self.state.local_state.per_commitment_secret_seed, 2**48-this_small_num-1)
this_point = secret_to_pubkey(int.from_bytes(this_secret, 'big'))
_, this_point, _ = self.points
remote_htlc_pubkey = derive_pubkey(self.state.remote_config.htlc_basepoint.pubkey, this_point)
local_htlc_pubkey = derive_pubkey(self.state.local_config.htlc_basepoint.pubkey, this_point)
@@ -315,13 +330,11 @@ class HTLCStateMachine(PrintError):
htlcs_in_local = []
for htlc in self.htlcs_in_local:
print("adding local htlc", htlc)
htlcs_in_local.append(
( make_offered_htlc(local_revocation_pubkey, local_htlc_pubkey, remote_htlc_pubkey, htlc.payment_hash), htlc.amount_msat + total_fee_local))
htlcs_in_remote = []
for htlc in self.htlcs_in_remote:
print("adding remote htlc", htlc)
htlcs_in_remote.append(
( make_received_htlc(remote_revocation_pubkey, remote_htlc_pubkey, local_htlc_pubkey, htlc.payment_hash, htlc.cltv_expiry), htlc.amount_msat + total_fee_remote))
@@ -338,10 +351,11 @@ class HTLCStateMachine(PrintError):
for htlc in update_log:
if type(htlc) is not UpdateAddHtlc:
continue
height = (self.r_current_height if subject == "remote" else self.l_current_height)
locked_in = (htlc.r_locked_in if subject == "remote" else htlc.l_locked_in)
height = (self.state.local_state.ctn if subject == "remote" else self.state.remote_state.ctn)
locked_in = (htlc.r_locked_in if subject == "remote" else htlc.l_locked_in)
if locked_in is None or locked_in < height:
if locked_in is None:
print("skipping", locked_in, height)
continue
res.append(htlc)
return res