AaronFiore/electrum
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implement data_loss_protect

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so that we can spend their_ctx_to_remote even when we lost our state
but have an old backup
This commit is contained in:
SomberNight
2019-08-02 18:04:13 +02:00
committed by ThomasV
parent fdf8d8609b
commit 944e4f0ba0
3 changed files with 45 additions and 9 deletions
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36
electrum/lnpeer.py
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@@ -30,7 +30,7 @@ from .logging import Logger
from .lnonion import (new_onion_packet, decode_onion_error, OnionFailureCode, calc_hops_data_for_payment,
process_onion_packet, OnionPacket, construct_onion_error, OnionRoutingFailureMessage,
ProcessedOnionPacket)
from .lnchannel import Channel, RevokeAndAck, htlcsum
from .lnchannel import Channel, RevokeAndAck, htlcsum, RemoteCtnTooFarInFuture
from .lnutil import (Outpoint, LocalConfig, RECEIVED, UpdateAddHtlc,
RemoteConfig, OnlyPubkeyKeypair, ChannelConstraints, RevocationStore,
funding_output_script, get_per_commitment_secret_from_seed,
@@ -720,7 +720,8 @@ class Peer(Logger):
latest_remote_ctn = chan.hm.ctn_latest(REMOTE)
next_remote_ctn = latest_remote_ctn + 1
# send message
if self.localfeatures & LnLocalFeatures.OPTION_DATA_LOSS_PROTECT_OPT:
dlp_enabled = self.localfeatures & LnLocalFeatures.OPTION_DATA_LOSS_PROTECT_OPT
if dlp_enabled:
if oldest_unrevoked_remote_ctn == 0:
last_rev_secret = 0
else:
@@ -746,6 +747,8 @@ class Peer(Logger):
chan.set_state('OPENING')
their_next_local_ctn = int.from_bytes(channel_reestablish_msg["next_local_commitment_number"], 'big')
their_oldest_unrevoked_remote_ctn = int.from_bytes(channel_reestablish_msg["next_remote_revocation_number"], 'big')
their_local_pcp = channel_reestablish_msg.get("my_current_per_commitment_point")
their_claim_of_our_last_per_commitment_secret = channel_reestablish_msg.get("your_last_per_commitment_secret")
should_close_we_are_ahead = False
should_close_they_are_ahead = False
@@ -786,9 +789,34 @@ class Peer(Logger):
should_close_we_are_ahead = True
else:
should_close_they_are_ahead = True
# option_data_loss_protect
def are_datalossprotect_fields_valid() -> bool:
if their_local_pcp is None or their_claim_of_our_last_per_commitment_secret is None:
# if DLP was enabled, absence of fields is not OK
return not dlp_enabled
our_pcs, __ = chan.get_secret_and_point(LOCAL, their_oldest_unrevoked_remote_ctn - 1)
if our_pcs != their_claim_of_our_last_per_commitment_secret:
self.logger.error(f"channel_reestablish: (DLP) local PCS mismatch: {bh2u(our_pcs)} != {bh2u(their_claim_of_our_last_per_commitment_secret)}")
return False
try:
__, our_remote_pcp = chan.get_secret_and_point(REMOTE, their_next_local_ctn - 1)
except RemoteCtnTooFarInFuture:
pass
else:
if our_remote_pcp != their_local_pcp:
self.logger.error(f"channel_reestablish: (DLP) remote PCP mismatch: {bh2u(our_remote_pcp)} != {bh2u(their_local_pcp)}")
return False
return True
# TODO option_data_loss_protect
if not are_datalossprotect_fields_valid():
self.logger.error(f"channel_reestablish: data loss protect fields invalid.")
# TODO should we force-close?
return
else:
if dlp_enabled and should_close_they_are_ahead:
self.logger.warning(f"channel_reestablish: remote is ahead of us! luckily DLP is enabled. remote PCP: {bh2u(their_local_pcp)}")
chan.data_loss_protect_remote_pcp[their_next_local_ctn - 1] = their_local_pcp
self.lnworker.save_channel(chan)
if should_close_they_are_ahead:
self.logger.warning(f"channel_reestablish: remote is ahead of us! trying to get them to force-close.")
self.try_to_get_remote_to_force_close_with_their_latest(chan_id)