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lnpeer: refactor some checks re open_channel/accept_channel

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This commit is contained in:
SomberNight
2021-09-24 19:58:32 +02:00
parent 437a9e4358
commit 4af103378a
2 changed files with 74 additions and 55 deletions
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66
electrum/lnpeer.py
View File

@@ -33,7 +33,7 @@ from .lnonion import (new_onion_packet, OnionFailureCode, calc_hops_data_for_pay
OnionFailureCodeMetaFlag)
from .lnchannel import Channel, RevokeAndAck, RemoteCtnTooFarInFuture, ChannelState, PeerState
from . import lnutil
from .lnutil import (Outpoint, LocalConfig, RECEIVED, UpdateAddHtlc,
from .lnutil import (Outpoint, LocalConfig, RECEIVED, UpdateAddHtlc, ChannelConfig,
RemoteConfig, OnlyPubkeyKeypair, ChannelConstraints, RevocationStore,
funding_output_script, get_per_commitment_secret_from_seed,
secret_to_pubkey, PaymentFailure, LnFeatures,
@@ -42,7 +42,6 @@ from .lnutil import (Outpoint, LocalConfig, RECEIVED, UpdateAddHtlc,
LightningPeerConnectionClosed, HandshakeFailed,
RemoteMisbehaving, ShortChannelID,
IncompatibleLightningFeatures, derive_payment_secret_from_payment_preimage,
LN_MAX_FUNDING_SAT, calc_fees_for_commitment_tx,
UpfrontShutdownScriptViolation)
from .lnutil import FeeUpdate, channel_id_from_funding_tx
from .lntransport import LNTransport, LNTransportBase
@@ -600,17 +599,6 @@ class Peer(Logger):
if not self.lnworker.channel_db and not self.lnworker.is_trampoline_peer(self.pubkey):
raise Exception('Not a trampoline node: ' + str(self.their_features))
if funding_sat > LN_MAX_FUNDING_SAT:
raise Exception(
f"MUST set funding_satoshis to less than 2^24 satoshi. "
f"{funding_sat} sat > {LN_MAX_FUNDING_SAT}")
if push_msat > 1000 * funding_sat:
raise Exception(
f"MUST set push_msat to equal or less than 1000 * funding_satoshis: "
f"{push_msat} msat > {1000 * funding_sat} msat")
if funding_sat < lnutil.MIN_FUNDING_SAT:
raise Exception(f"funding_sat too low: {funding_sat} < {lnutil.MIN_FUNDING_SAT}")
feerate = self.lnworker.current_feerate_per_kw()
local_config = self.make_local_config(funding_sat, push_msat, LOCAL)
@@ -676,15 +664,13 @@ class Peer(Logger):
current_per_commitment_point=None,
upfront_shutdown_script=upfront_shutdown_script
)
remote_config.validate_params(funding_sat=funding_sat)
# if channel_reserve_satoshis is less than dust_limit_satoshis within the open_channel message:
# MUST reject the channel.
if remote_config.reserve_sat < local_config.dust_limit_sat:
raise Exception("violated constraint: remote_config.reserve_sat < local_config.dust_limit_sat")
# if channel_reserve_satoshis from the open_channel message is less than dust_limit_satoshis:
# MUST reject the channel.
if local_config.reserve_sat < remote_config.dust_limit_sat:
raise Exception("violated constraint: local_config.reserve_sat < remote_config.dust_limit_sat")
ChannelConfig.cross_validate_params(
local_config=local_config,
remote_config=remote_config,
funding_sat=funding_sat,
is_local_initiator=True,
initial_feerate_per_kw=feerate,
)
# -> funding created
# replace dummy output in funding tx
@@ -798,16 +784,6 @@ class Peer(Logger):
feerate = payload['feerate_per_kw'] # note: we are not validating this
temp_chan_id = payload['temporary_channel_id']
local_config = self.make_local_config(funding_sat, push_msat, REMOTE)
if funding_sat > LN_MAX_FUNDING_SAT:
raise Exception(
f"MUST set funding_satoshis to less than 2^24 satoshi. "
f"{funding_sat} sat > {LN_MAX_FUNDING_SAT}")
if push_msat > 1000 * funding_sat:
raise Exception(
f"MUST set push_msat to equal or less than 1000 * funding_satoshis: "
f"{push_msat} msat > {1000 * funding_sat} msat")
if funding_sat < lnutil.MIN_FUNDING_SAT:
raise Exception(f"funding_sat too low: {funding_sat} < {lnutil.MIN_FUNDING_SAT}")
upfront_shutdown_script = self.upfront_shutdown_script_from_payload(
payload, 'open')
@@ -829,26 +805,14 @@ class Peer(Logger):
current_per_commitment_point=None,
upfront_shutdown_script=upfront_shutdown_script,
)
ChannelConfig.cross_validate_params(
local_config=local_config,
remote_config=remote_config,
funding_sat=funding_sat,
is_local_initiator=False,
initial_feerate_per_kw=feerate,
)
remote_config.validate_params(funding_sat=funding_sat)
# The receiving node MUST fail the channel if:
# the funder's amount for the initial commitment transaction is not
# sufficient for full fee payment.
if remote_config.initial_msat < calc_fees_for_commitment_tx(
num_htlcs=0,
feerate=feerate,
is_local_initiator=False)[REMOTE]:
raise Exception(
"the funder's amount for the initial commitment transaction "
"is not sufficient for full fee payment")
# The receiving node MUST fail the channel if:
# both to_local and to_remote amounts for the initial commitment transaction are
# less than or equal to channel_reserve_satoshis (see BOLT 3).
if (local_config.initial_msat <= 1000 * payload['channel_reserve_satoshis']
and remote_config.initial_msat <= 1000 * payload['channel_reserve_satoshis']):
raise Exception(
"both to_local and to_remote amounts for the initial commitment "
"transaction are less than or equal to channel_reserve_satoshis")
# note: we ignore payload['channel_flags'], which e.g. contains 'announce_channel'.
# Notably if the remote sets 'announce_channel' to True, we will ignore that too,
# but we will not play along with actually announcing the channel (so we keep it private).

63
electrum/lnutil.py
View File

@@ -66,7 +66,7 @@ class Keypair(OnlyPubkeyKeypair):
privkey = attr.ib(type=bytes, converter=hex_to_bytes)
@attr.s
class Config(StoredObject):
class ChannelConfig(StoredObject):
# shared channel config fields
payment_basepoint = attr.ib(type=OnlyPubkeyKeypair, converter=json_to_keypair)
multisig_key = attr.ib(type=OnlyPubkeyKeypair, converter=json_to_keypair)
@@ -93,6 +93,14 @@ class Config(StoredObject):
):
if not (len(key.pubkey) == 33 and ecc.ECPubkey.is_pubkey_bytes(key.pubkey)):
raise Exception(f"{conf_name}. invalid pubkey in channel config")
if funding_sat < MIN_FUNDING_SAT:
raise Exception(f"funding_sat too low: {funding_sat} sat < {MIN_FUNDING_SAT}")
# MUST set funding_satoshis to less than 2^24 satoshi
if funding_sat > LN_MAX_FUNDING_SAT:
raise Exception(f"funding_sat too high: {funding_sat} sat > {LN_MAX_FUNDING_SAT}")
# MUST set push_msat to equal or less than 1000 * funding_satoshis
if not (0 <= self.initial_msat <= 1000 * funding_sat):
raise Exception(f"{conf_name}. insane initial_msat={self.initial_msat}. (funding_sat={funding_sat})")
if self.reserve_sat < self.dust_limit_sat:
raise Exception(f"{conf_name}. MUST set channel_reserve_satoshis greater than or equal to dust_limit_satoshis")
# technically this could be using the lower DUST_LIMIT_DEFAULT_SAT_SEGWIT
@@ -106,7 +114,7 @@ class Config(StoredObject):
HTLC_MINIMUM_MSAT_MIN = 0 # should be at least 1 really, but apparently some nodes are sending zero...
if self.htlc_minimum_msat < HTLC_MINIMUM_MSAT_MIN:
raise Exception(f"{conf_name}. htlc_minimum_msat too low: {self.htlc_minimum_msat} msat < {HTLC_MINIMUM_MSAT_MIN}")
if self.max_accepted_htlcs < 1:
if self.max_accepted_htlcs < 5:
raise Exception(f"{conf_name}. max_accepted_htlcs too low: {self.max_accepted_htlcs}")
if self.max_accepted_htlcs > 483:
raise Exception(f"{conf_name}. max_accepted_htlcs too high: {self.max_accepted_htlcs}")
@@ -115,9 +123,56 @@ class Config(StoredObject):
if self.max_htlc_value_in_flight_msat < min(1000 * funding_sat, 100_000_000):
raise Exception(f"{conf_name}. max_htlc_value_in_flight_msat is too small: {self.max_htlc_value_in_flight_msat}")
@classmethod
def cross_validate_params(
cls,
*,
local_config: 'LocalConfig',
remote_config: 'RemoteConfig',
funding_sat: int,
is_local_initiator: bool, # whether we are the funder
initial_feerate_per_kw: int,
) -> None:
# first we validate the configs separately
local_config.validate_params(funding_sat=funding_sat)
remote_config.validate_params(funding_sat=funding_sat)
# now do tests that need access to both configs
if is_local_initiator:
funder, fundee = LOCAL, REMOTE
funder_config, fundee_config = local_config, remote_config
else:
funder, fundee = REMOTE, LOCAL
funder_config, fundee_config = remote_config, local_config
# if channel_reserve_satoshis is less than dust_limit_satoshis within the open_channel message:
# MUST reject the channel.
if remote_config.reserve_sat < local_config.dust_limit_sat:
raise Exception("violated constraint: remote_config.reserve_sat < local_config.dust_limit_sat")
# if channel_reserve_satoshis from the open_channel message is less than dust_limit_satoshis:
# MUST reject the channel.
if local_config.reserve_sat < remote_config.dust_limit_sat:
raise Exception("violated constraint: local_config.reserve_sat < remote_config.dust_limit_sat")
# The receiving node MUST fail the channel if:
# the funder's amount for the initial commitment transaction is not
# sufficient for full fee payment.
if funder_config.initial_msat < calc_fees_for_commitment_tx(
num_htlcs=0,
feerate=initial_feerate_per_kw,
is_local_initiator=is_local_initiator)[funder]:
raise Exception(
"the funder's amount for the initial commitment transaction "
"is not sufficient for full fee payment")
# The receiving node MUST fail the channel if:
# both to_local and to_remote amounts for the initial commitment transaction are
# less than or equal to channel_reserve_satoshis (see BOLT 3).
if (max(local_config.initial_msat, remote_config.initial_msat)
<= 1000 * max(local_config.reserve_sat, remote_config.reserve_sat)):
raise Exception(
"both to_local and to_remote amounts for the initial commitment "
"transaction are less than or equal to channel_reserve_satoshis")
@attr.s
class LocalConfig(Config):
class LocalConfig(ChannelConfig):
channel_seed = attr.ib(type=bytes, converter=hex_to_bytes) # type: Optional[bytes]
funding_locked_received = attr.ib(type=bool)
was_announced = attr.ib(type=bool)
@@ -150,7 +205,7 @@ class LocalConfig(Config):
raise Exception(f"{conf_name}. htlc_minimum_msat too low: {self.htlc_minimum_msat} msat < {HTLC_MINIMUM_MSAT_MIN}")
@attr.s
class RemoteConfig(Config):
class RemoteConfig(ChannelConfig):
next_per_commitment_point = attr.ib(type=bytes, converter=hex_to_bytes)
current_per_commitment_point = attr.ib(default=None, type=bytes, converter=hex_to_bytes)