Fixes Issue #12059: Properly handle missing hash functions even when

the expected builtin modules are not present.

This includes a unittest for __get_builtin_constructor() in the face
of such an error.
This commit is contained in:
Gregory P. Smith 2011-05-14 15:15:49 -07:00
parent e670c889cc
commit 12c9d028ed
2 changed files with 41 additions and 20 deletions

View File

@ -64,26 +64,29 @@ __all__ = __always_supported + ('new', 'algorithms_guaranteed',
def __get_builtin_constructor(name): def __get_builtin_constructor(name):
if name in ('SHA1', 'sha1'): try:
import _sha1 if name in ('SHA1', 'sha1'):
return _sha1.sha1 import _sha1
elif name in ('MD5', 'md5'): return _sha1.sha1
import _md5 elif name in ('MD5', 'md5'):
return _md5.md5 import _md5
elif name in ('SHA256', 'sha256', 'SHA224', 'sha224'): return _md5.md5
import _sha256 elif name in ('SHA256', 'sha256', 'SHA224', 'sha224'):
bs = name[3:] import _sha256
if bs == '256': bs = name[3:]
return _sha256.sha256 if bs == '256':
elif bs == '224': return _sha256.sha256
return _sha256.sha224 elif bs == '224':
elif name in ('SHA512', 'sha512', 'SHA384', 'sha384'): return _sha256.sha224
import _sha512 elif name in ('SHA512', 'sha512', 'SHA384', 'sha384'):
bs = name[3:] import _sha512
if bs == '512': bs = name[3:]
return _sha512.sha512 if bs == '512':
elif bs == '384': return _sha512.sha512
return _sha512.sha384 elif bs == '384':
return _sha512.sha384
except ImportError:
pass # no extension module, this hash is unsupported.
raise ValueError('unsupported hash type %s' % name) raise ValueError('unsupported hash type %s' % name)

View File

@ -118,6 +118,24 @@ class HashLibTestCase(unittest.TestCase):
else: else:
self.assertTrue(0 == "hashlib didn't reject bogus hash name") self.assertTrue(0 == "hashlib didn't reject bogus hash name")
def test_get_builtin_constructor(self):
get_builtin_constructor = hashlib.__dict__[
'__get_builtin_constructor']
self.assertRaises(ValueError, get_builtin_constructor, 'test')
try:
import _md5
except ImportError:
pass
# This forces an ImportError for "import _md5" statements
sys.modules['_md5'] = None
try:
self.assertRaises(ValueError, get_builtin_constructor, 'md5')
finally:
if '_md5' in locals():
sys.modules['_md5'] = _md5
else:
del sys.modules['_md5']
def test_hexdigest(self): def test_hexdigest(self):
for name in self.supported_hash_names: for name in self.supported_hash_names:
h = hashlib.new(name) h = hashlib.new(name)