gh-103256: Fix hmac algorithm to support fallback implementation

corona10 · corona10 · commit 6725ed98ffd4 · 2023-04-06T01:20:53.000+09:00
diff --git a/Lib/test/test_hmac.py b/Lib/test/test_hmac.py
@@ -373,6 +373,16 @@ def test_with_digestmod_no_default(self):
         with self.assertRaisesRegex(TypeError, r'required.*digestmod'):
             hmac.HMAC(key, msg=data, digestmod='')
 
+    def test_with_fallback(self):
+        cache = getattr(hashlib, '__builtin_constructor_cache')
+        try:
+            cache['foo'] = hashlib.md5
+            digest = hmac.digest(b'key', b'message', 'foo')
+            expected = binascii.unhexlify('4e4748e62b463521f6775fbf921234b5')
+            self.assertEqual(digest, expected)
+        finally:
+            cache.pop('foo')
+
 
 class ConstructorTestCase(unittest.TestCase):
 
diff --git a/Modules/_hashopenssl.c b/Modules/_hashopenssl.c
@@ -355,7 +355,7 @@ py_digest_by_name(PyObject *module, const char *name, enum Py_hash_type py_ht)
         }
     }
     if (digest == NULL) {
-        _setException(PyExc_ValueError, "unsupported hash type %s", name);
+        _setException(state->unsupported_digestmod_error, "unsupported hash type %s", name);
         return NULL;
     }
     return digest;

Original file line number	Diff line number	Diff line change
`@@ -355,7 +355,7 @@ py_digest_by_name(PyObject module, const char name, enum Py_hash_type py_ht)`
`355`	`355`	`}`
`356`	`356`	`}`
`357`	`357`	`if (digest == NULL) {`
`358`		`- _setException(PyExc_ValueError, "unsupported hash type %s", name);`
	`358`	`+ _setException(state->unsupported_digestmod_error, "unsupported hash type %s", name);`
`359`	`359`	`return NULL;`
`360`	`360`	`}`
`361`	`361`	`return digest;`