def should_void_transfer(transfer, wallet_view_context: WalletTransferContext,
recipient_view_context: WalletTransferContext,
operator_eon_number, is_checkpoint_created):
if transfer.eon_number != operator_eon_number and is_checkpoint_created:
logger.error('Transfer {} eon mismatch ({}, {})'.format(
transfer.id, transfer.eon_number, operator_eon_number))
return True
if transfer.amount < 0:
logger.error('Transfer {} has negative amount'.format(transfer.id))
return True
# Unauthorized transfer
if transfer.sender_active_state is None:
logger.error('Transfer {} no authorization'.format(transfer.id))
return True
# Invalid signature by sender
if not transfer.sender_active_state.wallet_signature.is_valid():
logger.error('Transfer {} invalid sender signature.'.format(
transfer.id))
return True
# Ensure sender log consistency
can_append_to_sender_log = wallet_view_context.can_append_transfer()
if can_append_to_sender_log is not True:
logger.error('Sender: {}'.format(can_append_to_sender_log))
return True
# Ensure recipient log consistency
can_append_to_recipient_log = recipient_view_context.can_append_transfer()
if can_append_to_recipient_log is not True:
logger.error('Recipient: {}'.format(can_append_to_recipient_log))
return True
# Ensure transfer consistency
can_spend, currently_available_funds = wallet_view_context.can_send_transfer(
current_eon_number=operator_eon_number, using_only_appended_funds=True)
if can_spend is not True:
passively_received = wallet_view_context.off_chain_passively_received_amount(
eon_number=operator_eon_number, only_appended=True)
logger.error(can_spend)
logger.info(passively_received)
return True
last_active_transfer, last_active_transfer_is_outgoing = wallet_view_context.last_appended_active_transfer(
operator_eon_number)
last_active_state = WalletTransferContext.appropriate_transfer_active_state(
transfer=last_active_transfer,
is_outgoing=last_active_transfer_is_outgoing)
previous_spendings = last_active_state.updated_spendings if last_active_transfer else 0
updated_spendings = transfer.sender_active_state.updated_spendings
# Incorrect updated spendings
if last_active_transfer:
if updated_spendings != previous_spendings + transfer.amount:
logger.error(
'Transfer {} invalid updated spendings. Expected {}, found {}.'
.format(transfer.id, previous_spendings + transfer.amount,
updated_spendings))
return True
elif updated_spendings != transfer.amount:
logger.error(
'Transfer {} invalid initial spendings. Expected {}, found {}.'.
format(transfer.id, transfer.amount, updated_spendings))
return True
# Incorrect transfer position
last_passively_received = recipient_view_context.last_appended_incoming_passive_transfer(
operator_eon_number)
if last_passively_received:
if transfer.position != last_passively_received.position + last_passively_received.amount:
logger.error(
'Transfer {} invalid offset. Expected {}, found {}.'.format(
transfer.id, last_passively_received.position +
last_passively_received.amount, transfer.position))
return True
elif transfer.position != 0:
logger.error(
'Transfer {} invalid offset. Expected {}, found {}.'.format(
transfer.id, 0, transfer.position))
return True
if transfer.sender_balance_marker.amount > currently_available_funds - transfer.amount:
logger.error('Transfer {} invalid concise marker balance.'.format(
transfer.id))
return True
concise_balance_marker = MinimumAvailableBalanceMarker(
wallet=transfer.wallet,
eon_number=transfer.eon_number,
amount=transfer.sender_balance_marker.amount)
concise_balance_marker_checksum = hex_value(
concise_balance_marker.checksum())
if transfer.sender_balance_marker.signature.checksum != concise_balance_marker_checksum:
logger.error(
'Transfer {} invalid concise marker checksum worth: {}'.format(
transfer.id, currently_available_funds - transfer.amount))
passively_received = wallet_view_context.off_chain_passively_received_amount(
eon_number=operator_eon_number, only_appended=True)
logger.info(passively_received)
return True
return False
def should_void_swap(swap: Transfer,
wallet_view_context: WalletTransferContext,
recipient_view_context: WalletTransferContext,
operator_eon_number: int, is_checkpoint_created: bool):
if not settings.SWAPS_ENABLED:
logger.error('Swaps disabled. Voiding {}'.format(swap.id))
return True
if swap.amount < 1:
logger.error('Swap {} has less than 1 amount'.format(swap.id))
return True
if swap.amount_swapped < 1:
logger.error('Swap {} has less than 1 amount swapped'.format(swap.id))
return True
# Unauthorized transfer
if swap.sender_active_state is None:
logger.error('Swap {} no authorization'.format(swap.id))
return True
# Invalid signature by sender
if not swap.sender_active_state.wallet_signature.is_valid():
logger.error('Swap {} invalid sender signature.'.format(swap.id))
return True
# Unreceived transaction
if swap.recipient_active_state is None:
logger.error('Swap receipt for {} not provided.'.format(swap.id))
return True
# Invalid signature by recipient
if not swap.recipient_active_state.wallet_signature.is_valid():
logger.error('Swap {} invalid receipt signature.'.format(swap.id))
return True
# Ensure log consistency
can_append_to_sender_log = wallet_view_context.can_append_transfer()
if can_append_to_sender_log is not True:
logger.error('Sender: {}'.format(can_append_to_sender_log))
return True
can_append_to_recipient_log = recipient_view_context.can_append_transfer()
if can_append_to_recipient_log is not True:
logger.error('Recipient: {}'.format(can_append_to_recipient_log))
return True
# Skip consistency checks since they were done at least once before.
if swap.appended:
return False
# Overspending
sender_funds_remaining = wallet_view_context.loosely_available_funds_at_eon(
eon_number=swap.eon_number,
current_eon_number=operator_eon_number,
is_checkpoint_created=is_checkpoint_created,
only_appended=True)
# sender remaining funds should be more than remaining amount in order
matched_out, matched_in = swap.matched_amounts(all_eons=True)
if sender_funds_remaining < swap.amount - matched_out:
logger.error('Swap {} overspending.'.format(swap.id))
return True
# Prevent future overdrawing
# if swap.sender_balance_marker.amount > sender_funds_remaining - swap.amount:
if swap.sender_balance_marker.amount != 0:
logger.error('Swap {} invalid concise marker balance.'.format(swap.id))
return True
concise_balance_marker = MinimumAvailableBalanceMarker(
wallet=swap.wallet,
eon_number=swap.eon_number,
amount=swap.sender_balance_marker.amount)
concise_balance_marker_checksum = crypto.hex_value(
concise_balance_marker.checksum())
if swap.sender_balance_marker.signature.checksum != concise_balance_marker_checksum:
logger.error('Swap {} invalid concise marker checksum for {}.'.format(
swap.id, swap.sender_balance_marker.amount))
return True
highest_spendings, highest_gains = wallet_view_context.off_chain_actively_sent_received_amounts(
eon_number=swap.eon_number, only_appended=True)
# if this is a multi eon swap
if Transfer.objects.filter(eon_number=swap.eon_number - 1,
tx_id=swap.tx_id).exists():
# set balances to initial fixed balances stored in transfer eon state
sender_starting_balance = swap.sender_starting_balance
recipient_starting_balance = swap.recipient_starting_balance
# make sure this eon's starting balance is exactly the initial stored balance
# when matched amount is taken into consideration for both sender and receiver
if wallet_view_context.starting_balance_in_eon(
swap.eon_number) != sender_starting_balance - matched_out:
logger.error(
'Swap {} invalid sender starting balance of future state {} != {} - {}.'
.format(
swap.id,
wallet_view_context.starting_balance_in_eon(
swap.eon_number), sender_starting_balance,
matched_out))
if recipient_view_context.starting_balance_in_eon(
swap.eon_number) != recipient_starting_balance + matched_in:
logger.error(
'Swap {} invalid recipient starting balance of future state {} != {} + {}.'
.format(
swap.id,
recipient_view_context.starting_balance_in_eon(
swap.eon_number), recipient_starting_balance,
matched_out))
assert (wallet_view_context.starting_balance_in_eon(
swap.eon_number) == sender_starting_balance - matched_out)
assert (recipient_view_context.starting_balance_in_eon(
swap.eon_number) == recipient_starting_balance + matched_in)
else:
sender_starting_balance = int(
wallet_view_context.starting_balance_in_eon(swap.eon_number))
recipient_starting_balance = int(
recipient_view_context.starting_balance_in_eon(swap.eon_number))
# Debit Authorization
tx_set_tree = wallet_view_context.optimized_authorized_transfers_tree(
only_appended=True, starting_balance=sender_starting_balance)
tx_set_hash = crypto.hex_value(tx_set_tree.root_hash())
transfer_index = tx_set_tree.merkle_tree_nonce_map.get(swap.nonce)
transfer_proof = tx_set_tree.proof(transfer_index)
highest_spendings, highest_gains = wallet_view_context.off_chain_actively_sent_received_amounts(
eon_number=swap.eon_number, only_appended=True)
debiting_active_state = ActiveState(wallet=swap.wallet,
updated_spendings=highest_spendings +
swap.amount,
updated_gains=highest_gains,
tx_set_hash=tx_set_hash,
tx_set_proof_hashes=transfer_proof,
tx_set_index=transfer_index,
eon_number=swap.eon_number)
debiting_active_state_checksum = crypto.hex_value(
debiting_active_state.checksum())
if swap.sender_active_state.wallet_signature.checksum != debiting_active_state_checksum:
logger.error('Swap {} invalid debit active state checksum.'.format(
swap.id))
return True
# Credit Authorization
tx_set_tree = recipient_view_context.optimized_authorized_transfers_tree(
only_appended=True, starting_balance=recipient_starting_balance)
tx_set_hash = crypto.hex_value(tx_set_tree.root_hash())
transfer_index = tx_set_tree.merkle_tree_nonce_map.get(swap.nonce)
transfer_proof = tx_set_tree.proof(transfer_index)
highest_spendings, highest_gains = recipient_view_context.off_chain_actively_sent_received_amounts(
eon_number=swap.eon_number, only_appended=True)
crediting_active_state = ActiveState(wallet=swap.recipient,
updated_spendings=highest_spendings,
updated_gains=highest_gains,
tx_set_hash=tx_set_hash,
tx_set_proof_hashes=transfer_proof,
tx_set_index=transfer_index,
eon_number=swap.eon_number)
crediting_active_state_checksum = crypto.hex_value(
crediting_active_state.checksum())
if swap.recipient_active_state.wallet_signature.checksum != crediting_active_state_checksum:
logger.error('Swap {} invalid credit active state checksum.'.format(
swap.id))
return True
# Finality Authorization
swap.complete = True
tx_set_tree = recipient_view_context.optimized_authorized_transfers_tree(
only_appended=True, starting_balance=recipient_starting_balance)
swap.complete = False
tx_set_hash = crypto.hex_value(tx_set_tree.root_hash())
transfer_index = tx_set_tree.merkle_tree_nonce_map.get(swap.nonce)
transfer_proof = tx_set_tree.proof(transfer_index)
recipient_fulfillment_active_state = ActiveState(
wallet=swap.recipient,
updated_spendings=highest_spendings,
updated_gains=highest_gains + swap.amount_swapped,
tx_set_hash=tx_set_hash,
tx_set_proof_hashes=transfer_proof,
tx_set_index=transfer_index,
eon_number=swap.eon_number)
recipient_fulfillment_active_state_checksum = crypto.hex_value(
recipient_fulfillment_active_state.checksum())
if swap.recipient_fulfillment_active_state.wallet_signature.checksum != recipient_fulfillment_active_state_checksum:
logger.error(
'Swap {} invalid finalization active state checksum.'.format(
swap.id))
return True
return False