def _interface_signature(self):
if not self._interface_signature_object:
try:
self._sign_and_date_interface_info()
except NoSigningPower:
raise NoSigningPower("This Ursula is a stranger and cannot be used to verify.")
return self._interface_signature_object
def timestamp(self):
if not self._timestamp:
try:
self._sign_and_date_interface_info()
except NoSigningPower:
raise NoSigningPower("This Node is a Stranger; you didn't init with a timestamp, so you can't verify.")
return self._timestamp
def _interface_signature(self):
if not self._interface_signature_object:
try:
self._sign_interface_info()
except NoSigningPower:
raise NoSigningPower("This Ursula is a Stranger; you didn't init with an interface signature, so you can't verify.")
return self._interface_signature_object
def __call__(self, *args, **kwargs):
from nucypher.crypto.powers import NoSigningPower
message = "This isn't your SignatureStamp; it belongs to (a Stranger). You can't sign with it."
raise NoSigningPower(message)