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
"""
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
def test_verify_balance_proof_v0(channel_manager_address: str):
sig = sign_balance_proof(SENDER_PRIVATE_KEY, RECEIVER_ADDR, 312524, 11,
channel_manager_address)
sig = sig[:-1] + bytes([sig[-1] % 27])
assert is_same_address(
verify_balance_proof(RECEIVER_ADDR, 312524, 11, sig,
channel_manager_address), SENDER_ADDR)
def on_invalid_amount(self, method: str, url: str, response: Response,
**kwargs) -> bool:
log.debug('Server claims an invalid amount sent.')
balance_sig = response.headers.get(HTTPHeaders.BALANCE_SIGNATURE)
if balance_sig:
balance_sig = decode_hex(balance_sig)
last_balance = int(response.headers.get(HTTPHeaders.SENDER_BALANCE))
verified = balance_sig and is_same_address(
verify_balance_proof(self.channel.receiver, self.channel.block,
last_balance, balance_sig,
self.client.context.channel_manager.address),
self.channel.sender)
if verified:
if last_balance == self.channel.balance:
log.error(
'Server tried to disguise the last unconfirmed payment as a confirmed payment.'
)
return False
else:
log.debug(
'Server provided proof for a different channel balance ({}). Adopting.'
.format(last_balance))
self.channel.update_balance(last_balance)
else:
log.debug(
'Server did not provide proof for a different channel balance. Reverting to 0.'
)
self.channel.update_balance(0)
return self.on_payment_requested(method, url, response, **kwargs)
def test_verify_balance_proof(channel_manager_address: str):
sig = sign_balance_proof(
SENDER_PRIVATE_KEY, RECEIVER_ADDR, 315123, 8, channel_manager_address
)
assert is_same_address(verify_balance_proof(
RECEIVER_ADDR, 315123, 8, sig, channel_manager_address
), SENDER_ADDR)
def test_verify_balance_proof_v27(channel_manager_address: str):
# Should be default but test anyway.
sig = sign_balance_proof(SENDER_PRIVATE_KEY, RECEIVER_ADDR, 312524, 11,
channel_manager_address)
sig = sig[:-1] + b'\x1b'
assert verify_balance_proof(RECEIVER_ADDR, 312524, 11, sig,
channel_manager_address) == SENDER_ADDR
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
def test_verify_balance_proof(channel_manager_address: str):
sig = sign_balance_proof(
SENDER_PRIVATE_KEY, RECEIVER_ADDR, 315123, 8, channel_manager_address
)
assert verify_balance_proof(
RECEIVER_ADDR, 315123, 8, sig, channel_manager_address
) == SENDER_ADDR
def test_verify_balance_proof_v27(channel_manager_address: str):
# Should be default but test anyway.
sig = sign_balance_proof(SENDER_PRIVATE_KEY, RECEIVER_ADDR, 312524, 11,
channel_manager_address)
sig = sig[:-1] + bytes([sig[-1] % 27 + 27])
assert is_same_address(
verify_balance_proof(RECEIVER_ADDR, 312524, 11, sig,
channel_manager_address), SENDER_ADDR)
def test_verify_balance_proof_v0(channel_manager_address: str):
sig = sign_balance_proof(
SENDER_PRIVATE_KEY, RECEIVER_ADDR, 312524, 11, channel_manager_address
)
sig = sig[:-1] + bytes([sig[-1] % 27])
assert is_same_address(verify_balance_proof(
RECEIVER_ADDR, 312524, 11, sig, channel_manager_address
), SENDER_ADDR)
def test_verify_balance_proof_v0(channel_manager_address: str):
sig = sign_balance_proof(
SENDER_PRIVATE_KEY, RECEIVER_ADDR, 312524, 11, channel_manager_address
)
sig = sig[:-1] + b'\x00'
assert verify_balance_proof(
RECEIVER_ADDR, 312524, 11, sig, channel_manager_address
) == SENDER_ADDR
def test_verify_balance_proof_v27(channel_manager_address: str):
# Should be default but test anyway.
sig = sign_balance_proof(
SENDER_PRIVATE_KEY, RECEIVER_ADDR, 312524, 11, channel_manager_address
)
sig = sig[:-1] + bytes([sig[-1] % 27 + 27])
assert is_same_address(verify_balance_proof(
RECEIVER_ADDR, 312524, 11, sig, channel_manager_address
), SENDER_ADDR)
def on_invalid_amount(
self,
method: str,
url: str,
response: Response,
**kwargs
) -> bool:
log.debug('Server claims an invalid amount sent.')
balance_sig = response.headers.get(HTTPHeaders.BALANCE_SIGNATURE)
if balance_sig:
balance_sig = decode_hex(balance_sig)
last_balance = int(response.headers.get(HTTPHeaders.SENDER_BALANCE))
verified = balance_sig and is_same_address(
verify_balance_proof(
self.channel.receiver,
self.channel.block,
last_balance,
balance_sig,
self.client.context.channel_manager.address
),
self.channel.sender
)
if verified:
if last_balance == self.channel.balance:
log.error(
'Server tried to disguise the last unconfirmed payment as a confirmed payment.'
)
return False
else:
log.debug(
'Server provided proof for a different channel balance ({}). Adopting.'.format(
last_balance
)
)
self.channel.update_balance(last_balance)
else:
log.debug(
'Server did not provide proof for a different channel balance. Reverting to 0.'
)
self.channel.update_balance(0)
return self.on_payment_requested(method, url, response, **kwargs)
