import functools import hashlib import unittest try: import _hashlib except ImportError: _hashlib = None def requires_hashdigest(digestname, openssl=None, usedforsecurity=True): """Decorator raising SkipTest if a hashing algorithm is not available The hashing algorithm could be missing or blocked by a strict crypto policy. If 'openssl' is True, then the decorator checks that OpenSSL provides the algorithm. Otherwise the check falls back to built-in implementations. The usedforsecurity flag is passed to the constructor. ValueError: [digital envelope routines: EVP_DigestInit_ex] disabled for FIPS ValueError: unsupported hash type md4 """ def decorator(func_or_class): if isinstance(func_or_class, type): setUpClass = func_or_class.__dict__.get('setUpClass') if setUpClass is None: def setUpClass(cls): super(func_or_class, cls).setUpClass() setUpClass.__qualname__ = func_or_class.__qualname__ + '.setUpClass' setUpClass.__module__ = func_or_class.__module__ else: setUpClass = setUpClass.__func__ setUpClass = classmethod(decorator(setUpClass)) func_or_class.setUpClass = setUpClass return func_or_class @functools.wraps(func_or_class) def wrapper(*args, **kwargs): try: if openssl and _hashlib is not None: _hashlib.new(digestname, usedforsecurity=usedforsecurity) else: hashlib.new(digestname, usedforsecurity=usedforsecurity) except ValueError: raise unittest.SkipTest( f"hash digest '{digestname}' is not available." ) return func_or_class(*args, **kwargs) return wrapper return decorator