gh-141907: Better handle support for SHA3 for test_hashlib (GH-141908)

* test_hashlib: better handle support for SHA3

It's possible that the SSL library supports only SHA3 algo and doesn't
have SHAKE one.

The current test wrongly detect this and set both HASH and HASHXOF to
None expecting to have the extra SHA3 attributes present but this should
only be true for SHAKE algo.

To better handle this, move the HASH condition to a dedicated try-expect
condition and check if HASHXOF is None in the relevant code effectively
checking if SHA3 is supported by the SSL library but SHAKE algo needs to
use the sha3module one.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>

* rework the conditional import for all its attrs

---------

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Co-authored-by: Gregory P. Smith <greg@krypto.org>
This commit is contained in:
Christian Marangi 2025-11-24 18:35:58 +01:00 committed by GitHub
parent e1f1df4082
commit fee7782650
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@ -40,12 +40,15 @@
openssl_hashlib = import_fresh_module('hashlib', fresh=['_hashlib'])
try:
from _hashlib import HASH, HASHXOF, openssl_md_meth_names, get_fips_mode
import _hashlib
except ImportError:
HASH = None
HASHXOF = None
openssl_md_meth_names = frozenset()
_hashlib = None
# The extension module may exist but only define some of these. gh-141907
HASH = getattr(_hashlib, 'HASH', None)
HASHXOF = getattr(_hashlib, 'HASHXOF', None)
openssl_md_meth_names = getattr(_hashlib, 'openssl_md_meth_names', frozenset())
get_fips_mode = getattr(_hashlib, 'get_fips_mode', None)
if not get_fips_mode:
def get_fips_mode():
return 0
@ -631,9 +634,14 @@ def check_sha3(self, name, capacity, rate, suffix):
constructors = self.constructors_to_test[name]
for hash_object_constructor in constructors:
m = hash_object_constructor()
if HASH is not None and isinstance(m, HASH):
# _hashopenssl's variant does not have extra SHA3 attributes
continue
if name.startswith('shake_'):
if HASHXOF is not None and isinstance(m, HASHXOF):
# _hashopenssl's variant does not have extra SHA3 attributes
continue
else:
if HASH is not None and isinstance(m, HASH):
# _hashopenssl's variant does not have extra SHA3 attributes
continue
self.assertEqual(capacity + rate, 1600)
self.assertEqual(m._capacity_bits, capacity)
self.assertEqual(m._rate_bits, rate)
@ -1156,7 +1164,8 @@ def test_disallow_instantiation(self):
def test_hash_disallow_instantiation(self):
# internal types like _hashlib.HASH are not constructable
support.check_disallow_instantiation(self, HASH)
support.check_disallow_instantiation(self, HASHXOF)
if HASHXOF is not None:
support.check_disallow_instantiation(self, HASHXOF)
def test_readonly_types(self):
for algorithm, constructors in self.constructors_to_test.items():