def verify_balance_proof(self, sender, open_block_number, balance,
signature):
"""Verify that a balance proof is valid and return the sender.
Does not check the balance itself.
:returns: the channel
"""
if (sender, open_block_number) in self.unconfirmed_channels:
raise InsufficientConfirmations(
'Insufficient confirmations for the channel '
'(sender=%s, open_block_number=%d)' %
(sender, open_block_number))
try:
c = self.channels[sender, open_block_number]
except KeyError:
raise NoOpenChannel('Channel does not exist or has been closed'
'(sender=%s, open_block_number=%s)' %
(sender, open_block_number))
if c.is_closed:
raise NoOpenChannel('Channel closing has been requested already.')
if not is_same_address(
verify_balance_proof(self.receiver, open_block_number, balance,
decode_hex(signature)), sender):
raise InvalidBalanceProof(
'Recovered signer does not match the sender')
return c
def verify_balance_proof(self, sender, open_block_number, balance, signature):
"""Verify that a balance proof is valid and return the sender.
This method just verifies if the balance proof is valid - no state update is performed.
:returns: Channel, if it exists
"""
assert is_checksum_address(sender)
if (sender, open_block_number) in self.unconfirmed_channels:
raise InsufficientConfirmations(
'Insufficient confirmations for the channel '
'(sender=%s, open_block_number=%d)' % (sender, open_block_number))
try:
c = self.channels[sender, open_block_number]
except KeyError:
raise NoOpenChannel('Channel does not exist or has been closed'
'(sender=%s, open_block_number=%s)' % (sender, open_block_number))
if c.is_closed:
raise NoOpenChannel('Channel closing has been requested already.')
if not is_same_address(
verify_balance_proof(
self.receiver,
open_block_number,
balance,
decode_hex(signature),
self.channel_manager_contract.address
),
sender
):
raise InvalidBalanceProof('Recovered signer does not match the sender')
return c