def algorithm_suite_from_string_id(string_id):
# type: (str) -> AlgorithmSuite
"""Locate an :class:`AlgorithmSuite` by the hex string encoding of the algorithm ID.
:param string_id: Hex ID string of algorithm suite
:return: Correct algorithm suite for ``string_id``
:rtype: AlgorithmSuite
"""
bytes_id = unhexlify(string_id)
(numeric_id, ) = struct.unpack(">H", bytes_id)
return AlgorithmSuite.get_by_id(numeric_id)
def _verified_algorithm_from_id(algorithm_id):
# type: (int) -> AlgorithmSuite
"""Load a message :class:`AlgorithmSuite` for the specified algorithm suite ID.
:param int algorithm_id: Algorithm suite ID
:return: Algorithm suite
:rtype: AlgorithmSuite
:raises UnknownIdentityError: if unknown algorithm ID is received
:raises NotSupportedError: if unsupported algorithm ID is received
"""
try:
algorithm_suite = AlgorithmSuite.get_by_id(algorithm_id)
except KeyError as error:
raise UnknownIdentityError("Unknown algorithm {}".format(algorithm_id), error)
if not algorithm_suite.allowed:
raise NotSupportedError("Unsupported algorithm: {}".format(algorithm_suite))
return algorithm_suite