def get_header_alg(self, header):
if 'alg' not in header:
raise MissingAlgorithmError()
alg = header['alg']
if self._algorithms and alg not in self._algorithms:
raise UnsupportedAlgorithmError()
if alg not in self.ALG_REGISTRY:
raise UnsupportedAlgorithmError()
return self.ALG_REGISTRY[alg]
def _prepare_algorithm_key(self, header, payload, key):
if 'alg' not in header:
raise MissingAlgorithmError()
alg = header['alg']
if self._algorithms and alg not in self._algorithms:
raise UnsupportedAlgorithmError()
if alg not in self.ALGORITHMS_REGISTRY:
raise UnsupportedAlgorithmError()
algorithm = self.ALGORITHMS_REGISTRY[alg]
if callable(key):
key = key(header, payload)
elif 'jwk' in header:
key = header['jwk']
key = algorithm.prepare_key(key)
return algorithm, key
def _validate_header(self, header):
if 'alg' not in header:
raise MissingAlgorithmError()
alg = header['alg']
if alg not in self._algorithms:
raise UnsupportedAlgorithmError()
names = self.REGISTERED_HEADER_PARAMETER_NAMES.copy()
if self._private_headers:
names = names.union(self._private_headers)
for k in header:
if k not in names:
raise InvalidHeaderParameterName(k)
def _validate_header(self, header):
if 'alg' not in header:
raise MissingAlgorithmError()
alg = header['alg']
if alg not in self._algorithms:
raise UnsupportedAlgorithmError()
# only validate private headers when developers set
# private headers explicitly
if self._private_headers is not None:
names = self.REGISTERED_HEADER_PARAMETER_NAMES.copy()
names = names.union(self._private_headers)
for k in header:
if k not in names:
raise InvalidHeaderParameterName(k)
def _pre_validate_header(self, header):
if 'alg' not in header:
raise MissingAlgorithmError()
alg = header['alg']
if alg not in self._alg_algorithms:
raise UnsupportedAlgorithmError()
if 'enc' not in header:
raise MissingEncryptionAlgorithmError()
enc = header['enc']
if enc not in self._enc_algorithms:
raise UnsupportedEncryptionAlgorithmError()
zip = header.get('zip')
if zip and zip not in self._zip_algorithms:
raise UnsupportedCompressionAlgorithmError()
