def test_events_for_close():
""" Channel must be closed when the unsafe region is reached and the secret is known. """
amount = 3
block_number = 10
expiration = block_number + 30
initiator = HOP1
target_address = UNIT_TRANSFER_TARGET
from_channel = factories.make_channel(
our_address=target_address,
partner_address=UNIT_TRANSFER_SENDER,
partner_balance=amount,
)
from_route = factories.route_from_channel(from_channel)
from_transfer = factories.make_signed_transfer_for(
from_channel,
amount,
initiator,
target_address,
expiration,
UNIT_SECRET,
)
channel.handle_receive_mediatedtransfer(
from_channel,
from_transfer,
)
channel.register_secret(from_channel, UNIT_SECRET, UNIT_HASHLOCK)
safe_to_wait = expiration - from_channel.reveal_timeout - 1
unsafe_to_wait = expiration - from_channel.reveal_timeout
state = TargetTransferState(from_route, from_transfer)
events = target.events_for_close(state, from_channel, safe_to_wait)
assert not events
events = target.events_for_close(state, from_channel, unsafe_to_wait)
assert events
assert isinstance(events[0], ContractSendChannelClose)
assert events[0].channel_identifier == from_route.channel_identifier
def test_channelstate_withdraw():
"""Event close must be properly handled if there are no locks to unlock"""
our_model1, _ = create_model(70)
partner_model1, privkey2 = create_model(100)
channel_state = create_channel_from_models(our_model1, partner_model1)
payment_network_identifier = factories.make_address()
lock_amount = 10
lock_expiration = 100
lock_secret = sha3(b'test_channelstate_mediatedtransfer_overspent')
lock_hashlock = sha3(lock_secret)
lock = HashTimeLockState(
lock_amount,
lock_expiration,
lock_hashlock,
)
nonce = 1
transferred_amount = 0
receive_mediatedtransfer = make_receive_transfer_mediated(
channel_state,
privkey2,
nonce,
transferred_amount,
lock,
)
is_valid, msg = channel.handle_receive_mediatedtransfer(
channel_state,
receive_mediatedtransfer,
)
assert is_valid, msg
channel.register_secret(channel_state, lock_secret, lock_hashlock)
# If the channel is closed, withdraw must be done even if the lock is not
# at risk of expiring
closed_block_number = lock_expiration - channel_state.reveal_timeout - 1
state_change = ContractReceiveChannelClosed(
payment_network_identifier,
channel_state.token_address,
channel_state.identifier,
partner_model1.participant_address,
closed_block_number,
)
iteration = channel.handle_channel_closed(channel_state, state_change)
assert must_contain_entry(iteration.events, ContractSendChannelWithdraw,
{})
def handle_inittarget(state_change, channel_state, block_number):
""" Handles an ActionInitTarget state change. """
transfer = state_change.transfer
route = state_change.route
target_state = TargetTransferState(
route,
transfer,
)
assert channel_state.identifier == transfer.balance_proof.channel_address
is_valid, errormsg = channel.handle_receive_mediatedtransfer(
channel_state,
transfer,
)
safe_to_wait = is_safe_to_wait(
transfer.lock.expiration,
channel_state.reveal_timeout,
block_number,
)
# if there is not enough time to safely withdraw the token on-chain
# silently let the transfer expire.
if is_valid and safe_to_wait:
secret_request = SendSecretRequest(
transfer.identifier,
transfer.lock.amount,
transfer.lock.hashlock,
transfer.initiator,
)
iteration = TransitionResult(target_state, [secret_request])
else:
if not is_valid:
failure_reason = errormsg
elif not safe_to_wait:
failure_reason = 'lock expiration is not safe'
withdraw_failed = EventWithdrawFailed(
identifier=transfer.identifier,
hashlock=transfer.lock.hashlock,
reason=failure_reason,
)
iteration = TransitionResult(target_state, [withdraw_failed])
return iteration
def test_channelstate_mediatedtransfer_overspent():
"""Receiving a lock with an amount large than distributable must be
ignored.
"""
our_model1, _ = create_model(70)
partner_model1, privkey2 = create_model(100)
channel_state = create_channel_from_models(our_model1, partner_model1)
distributable = channel.get_distributable(channel_state.partner_state,
channel_state.our_state)
lock_amount = distributable + 1
lock_expiration = 10
lock_hashlock = sha3(b'test_channelstate_mediatedtransfer_overspent')
lock = HashTimeLockState(
lock_amount,
lock_expiration,
lock_hashlock,
)
nonce = 1
transferred_amount = 0
receive_mediatedtransfer = make_receive_transfer_mediated(
channel_state,
privkey2,
nonce,
transferred_amount,
lock,
)
is_valid, _ = channel.handle_receive_mediatedtransfer(
channel_state,
receive_mediatedtransfer,
)
assert not is_valid, 'message is invalid because it is spending more than the distributable'
assert_partner_state(channel_state.our_state, channel_state.partner_state,
our_model1)
assert_partner_state(channel_state.partner_state, channel_state.our_state,
partner_model1)
def test_interwoven_transfers():
"""Can keep doing transactions even if not all secrets have been released."""
number_of_transfers = 100
balance_for_all_transfers = 11 * number_of_transfers
lock_amounts = cycle([1, 3, 5, 7, 11])
lock_secrets = [
format(i, '>032').encode()
for i in range(number_of_transfers)
]
our_model, _ = create_model(70)
partner_model, privkey2 = create_model(balance_for_all_transfers)
channel_state = create_channel_from_models(our_model, partner_model)
block_number = 1000
nonce = 0
transferred_amount = 0
our_model_current = our_model
partner_model_current = partner_model
for i, (lock_amount, lock_secret) in enumerate(zip(lock_amounts, lock_secrets)):
nonce += 1
block_number += 1
lock_expiration = block_number + channel_state.settle_timeout - 1
lock_secrethash = sha3(lock_secret)
lock = HashTimeLockState(
lock_amount,
lock_expiration,
lock_secrethash,
)
merkletree_leaves = list(partner_model_current.merkletree_leaves)
merkletree_leaves.append(lock.lockhash)
partner_model_current = partner_model_current._replace(
distributable=partner_model_current.distributable - lock_amount,
amount_locked=partner_model_current.amount_locked + lock_amount,
next_nonce=partner_model_current.next_nonce + 1,
merkletree_leaves=merkletree_leaves,
)
receive_mediatedtransfer = make_receive_transfer_mediated(
channel_state,
privkey2,
nonce,
transferred_amount,
lock,
merkletree_leaves=merkletree_leaves,
)
is_valid, msg = channel.handle_receive_mediatedtransfer(
channel_state,
receive_mediatedtransfer,
)
assert is_valid, msg
assert_partner_state(
channel_state.our_state,
channel_state.partner_state,
our_model_current,
)
assert_partner_state(
channel_state.partner_state,
channel_state.our_state,
partner_model_current,
)
# claim a transaction at every other iteration, leaving the current one
# in place
if i % 2:
# Update our model:
# - Increase nonce because the secret is a new balance proof
# - The lock is removed from the merkle tree, the balance proof must be updated
# - The locksroot must have unlocked lock removed
# - The transferred amount must be increased by the lock amount
# - This changes the balance for both participants:
# - the sender balance and locked amount is decremented by the lock amount
# - the receiver balance and distributable is incremented by the lock amount
nonce += 1
transferred_amount += lock_amount
merkletree_leaves = list(partner_model_current.merkletree_leaves)
merkletree_leaves.remove(lock.lockhash)
tree = compute_layers(merkletree_leaves)
locksroot = tree[MERKLEROOT][0]
partner_model_current = partner_model_current._replace(
amount_locked=partner_model_current.amount_locked - lock_amount,
balance=partner_model_current.balance - lock_amount,
next_nonce=partner_model_current.next_nonce + 1,
merkletree_leaves=merkletree_leaves,
)
our_model_current = our_model_current._replace(
balance=our_model_current.balance + lock_amount,
distributable=our_model_current.distributable + lock_amount,
)
secret_message = Secret(
identifier=nonce,
nonce=nonce,
channel=channel_state.identifier,
transferred_amount=transferred_amount,
locksroot=locksroot,
secret=lock_secret,
)
secret_message.sign(privkey2, channel_state.partner_state.address)
balance_proof = balanceproof_from_envelope(secret_message)
unlock_state_change = ReceiveUnlock(
lock_secret,
balance_proof,
)
is_valid, msg = channel.handle_unlock(channel_state, unlock_state_change)
assert is_valid, msg
assert_partner_state(
channel_state.our_state,
channel_state.partner_state,
our_model_current,
)
assert_partner_state(
channel_state.partner_state,
channel_state.our_state,
partner_model_current,
)
def test_channelstate_mediatedtransfer_overspend_with_multiple_pending_transfers():
"""Receiving a concurrent lock with an amount large than distributable
must be ignored.
"""
our_model1, _ = create_model(70)
partner_model1, privkey2 = create_model(100)
channel_state = create_channel_from_models(our_model1, partner_model1)
# Step 1: Create a lock with an amount of 1
# - this wont be unlocked
lock1_amount = 1
lock1_expiration = 1 + channel_state.settle_timeout
lock1_secrethash = sha3(b'test_receive_cannot_overspend_with_multiple_pending_transfers1')
lock1 = HashTimeLockState(
lock1_amount,
lock1_expiration,
lock1_secrethash,
)
nonce1 = 1
transferred_amount = 0
receive_mediatedtransfer1 = make_receive_transfer_mediated(
channel_state,
privkey2,
nonce1,
transferred_amount,
lock1,
)
is_valid, msg = channel.handle_receive_mediatedtransfer(
channel_state,
receive_mediatedtransfer1,
)
assert is_valid, msg
our_model2 = our_model1
partner_model2 = partner_model1._replace(
distributable=partner_model1.distributable - lock1.amount,
amount_locked=lock1.amount,
next_nonce=2,
merkletree_leaves=[lock1.lockhash],
)
# The valid transfer is handled normally
assert_partner_state(channel_state.our_state, channel_state.partner_state, our_model2)
assert_partner_state(channel_state.partner_state, channel_state.our_state, partner_model2)
# Step 2: Create a lock with the current *distributable + 1*
# - This must be ignored
distributable = channel.get_distributable(channel_state.partner_state, channel_state.our_state)
lock2_amount = distributable + 1
lock2_expiration = channel_state.settle_timeout
lock2_secrethash = sha3(b'test_receive_cannot_overspend_with_multiple_pending_transfers2')
lock2 = HashTimeLockState(
lock2_amount,
lock2_expiration,
lock2_secrethash,
)
leaves = [lock1.lockhash, lock2.lockhash]
nonce2 = 2
receive_mediatedtransfer2 = make_receive_transfer_mediated(
channel_state,
privkey2,
nonce2,
transferred_amount,
lock2,
merkletree_leaves=leaves,
)
is_valid, msg = channel.handle_receive_mediatedtransfer(
channel_state,
receive_mediatedtransfer2,
)
assert not is_valid, 'message is invalid because its expending more than the distributable'
# The overspending transfer must be ignored
assert_partner_state(channel_state.our_state, channel_state.partner_state, our_model2)
assert_partner_state(channel_state.partner_state, channel_state.our_state, partner_model2)
def test_channelstate_receive_mediatedtransfer():
"""Tests receiving a mediated transfer.
The transfer is done in three steps:
- a mediated transfer including a lock in its balance proof is sent
- the secret is revealed
- the unlocked balance proof is sent updating the transferred_amount
"""
our_model1, _ = create_model(70)
partner_model1, privkey2 = create_model(100)
channel_state = create_channel_from_models(our_model1, partner_model1)
# Step 1: Simulate receiving a transfer
# - The receiver end state doesnt change
# - The lock must be registered with the sender end
lock_amount = 30
lock_expiration = 10
lock_secret = sha3(b'test_end_state')
lock_secrethash = sha3(lock_secret)
lock = HashTimeLockState(
lock_amount,
lock_expiration,
lock_secrethash,
)
nonce = 1
transferred_amount = 0
receive_mediatedtransfer = make_receive_transfer_mediated(
channel_state,
privkey2,
nonce,
transferred_amount,
lock,
)
is_valid, msg = channel.handle_receive_mediatedtransfer(
channel_state,
receive_mediatedtransfer,
)
assert is_valid, msg
our_model2 = our_model1
partner_model2 = partner_model1._replace(
distributable=partner_model1.distributable - lock_amount,
amount_locked=lock_amount,
next_nonce=2,
merkletree_leaves=[lock.lockhash],
)
assert_partner_state(channel_state.our_state, channel_state.partner_state, our_model2)
assert_partner_state(channel_state.partner_state, channel_state.our_state, partner_model2)
# Step 2: Simulate learning the secret
# - Registers the secret, this must not change the balance/locked amount
channel.register_secret(channel_state, lock_secret, lock_secrethash)
assert_partner_state(channel_state.our_state, channel_state.partner_state, our_model2)
assert_partner_state(channel_state.partner_state, channel_state.our_state, partner_model2)
# Step 3: Simulate unlocking the lock
# - Update the balances
transferred_amount = 0
secret_message = Secret(
identifier=1,
nonce=2,
channel=channel_state.identifier,
transferred_amount=transferred_amount + lock_amount,
locksroot=EMPTY_MERKLE_ROOT,
secret=lock_secret,
)
secret_message.sign(privkey2, channel_state.partner_state.address)
balance_proof = balanceproof_from_envelope(secret_message)
unlock_state_change = ReceiveUnlock(
lock_secret,
balance_proof,
)
is_valid, msg = channel.handle_unlock(channel_state, unlock_state_change)
assert is_valid, msg
our_model3 = our_model2._replace(
balance=our_model2.balance + lock_amount,
distributable=our_model2.balance + lock_amount,
)
partner_model3 = partner_model2._replace(
balance=partner_model2.balance - lock_amount,
amount_locked=0,
next_nonce=3,
merkletree_leaves=[],
)
assert_partner_state(channel_state.our_state, channel_state.partner_state, our_model3)
assert_partner_state(channel_state.partner_state, channel_state.our_state, partner_model3)