From 37aa11f4c57e08bd3859c0de1c22f1d5296b6fdc Mon Sep 17 00:00:00 2001

From: Petr Viktorin <encukou@gmail.com>

Date: Wed, 11 Aug 2021 16:51:03 +0200

Subject: [PATCH 01/10] Backport PyModule_AddObjectRef as

 _PyModule_AddObjectRef

Having PyModule_AddObjectRef available should make backporting

newer patches easier. The new API is much safer.

The backport adds an underscore so that we don't break extension

modules that define PyModule_AddObjectRef themselves on Python<=3.9

(which would be a virtuous thing to do).

---

 Include/modsupport.h | 10 ++++++++++

 Python/modsupport.c  | 13 +++++++++++--

 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/Include/modsupport.h b/Include/modsupport.h

index 4c4aab6..d9fac52 100644

--- a/Include/modsupport.h

+++ b/Include/modsupport.h

@@ -136,7 +136,17 @@ PyAPI_FUNC(PyObject * const *) _PyArg_UnpackKeywords(

 void _PyArg_Fini(void);

 #endif   /* Py_LIMITED_API */

+// Add an attribute with name 'name' and value 'obj' to the module 'mod.

+// On success, return 0 on success.

+// On error, raise an exception and return -1.

+// Backported from Python 3.10, where it's available without the underscore

+// in the name, to ease porting patches to RHEL

+PyAPI_FUNC(int) _PyModule_AddObjectRef(PyObject *mod, const char *name, PyObject *value);

+

+// Similar to PyModule_AddObjectRef() but steal a reference to 'obj'

+// (Py_DECREF(obj)) on success (if it returns 0).

 PyAPI_FUNC(int) PyModule_AddObject(PyObject *, const char *, PyObject *);

+

 PyAPI_FUNC(int) PyModule_AddIntConstant(PyObject *, const char *, long);

 PyAPI_FUNC(int) PyModule_AddStringConstant(PyObject *, const char *, const char *);

 #if !defined(Py_LIMITED_API) || Py_LIMITED_API+0 >= 0x03090000

diff --git a/Python/modsupport.c b/Python/modsupport.c

index 13482c6..fca1083 100644

--- a/Python/modsupport.c

+++ b/Python/modsupport.c

@@ -631,7 +631,7 @@ va_build_stack(PyObject **small_stack, Py_ssize_t small_stack_len,

 int

-PyModule_AddObject(PyObject *m, const char *name, PyObject *o)

+_PyModule_AddObjectRef(PyObject *m, const char *name, PyObject *o)

 {

     PyObject *dict;

     if (!PyModule_Check(m)) {

@@ -655,10 +655,19 @@ PyModule_AddObject(PyObject *m, const char *name, PyObject *o)

     }

     if (PyDict_SetItemString(dict, name, o))

         return -1;

-    Py_DECREF(o);

     return 0;

 }

+int

+PyModule_AddObject(PyObject *mod, const char *name, PyObject *value)

+{

+    int res = _PyModule_AddObjectRef(mod, name, value);

+    if (res == 0) {

+        Py_DECREF(value);

+    }

+    return res;

+}

+

 int

 PyModule_AddIntConstant(PyObject *m, const char *name, long value)

 {

-- 

2.35.3

From 3fc28233b7244bb891499a974c3f3cda42454760 Mon Sep 17 00:00:00 2001

From: Petr Viktorin <encukou@gmail.com>

Date: Fri, 13 Aug 2021 13:16:43 +0200

Subject: [PATCH 02/10] _hashopenssl: Uncomment and use initialization function

 list

This simplifies backporting of future changes.

We use this change instead of Python 3.10's:

    bpo-1635741: Port _hashlib to multiphase initialization (GH-23358)

---

 Modules/_hashopenssl.c | 30 +++++-------------------------

 1 file changed, 5 insertions(+), 25 deletions(-)

diff --git a/Modules/_hashopenssl.c b/Modules/_hashopenssl.c

index 4db058c..56dfff9 100644

--- a/Modules/_hashopenssl.c

+++ b/Modules/_hashopenssl.c

@@ -2227,7 +2227,6 @@ hashlib_init_hmactype(PyObject *module)

     return 0;

 }

-#if 0

 static PyModuleDef_Slot hashlib_slots[] = {

     /* OpenSSL 1.0.2 and LibreSSL */

     {Py_mod_exec, hashlib_openssl_legacy_init},

@@ -2238,7 +2237,6 @@ static PyModuleDef_Slot hashlib_slots[] = {

     {Py_mod_exec, hashlib_md_meth_names},

     {0, NULL}

 };

-#endif

 static struct PyModuleDef _hashlibmodule = {

     PyModuleDef_HEAD_INIT,

@@ -2266,29 +2264,11 @@ PyInit__hashlib(void)

         return NULL;

     }

-    if (hashlib_openssl_legacy_init(m) < 0) {

-        Py_DECREF(m);

-        return NULL;

-    }

-    if (hashlib_init_hashtable(m) < 0) {

-        Py_DECREF(m);

-        return NULL;

-    }

-    if (hashlib_init_evptype(m) < 0) {

-        Py_DECREF(m);

-        return NULL;

-    }

-    if (hashlib_init_evpxoftype(m) < 0) {

-        Py_DECREF(m);

-        return NULL;

-    }

-    if (hashlib_init_hmactype(m) < 0) {

-        Py_DECREF(m);

-        return NULL;

-    }

-    if (hashlib_md_meth_names(m) == -1) {

-        Py_DECREF(m);

-        return NULL;

+    for (int i=0; hashlib_slots[i].slot; i++) {

+        if (((int (*)(PyObject*))hashlib_slots[i].value)(m) < 0) {

+            Py_DECREF(m);

+            return NULL;

+        }

     }

     return m;

-- 

2.35.3

From 309e06621a9a8b8220c8f83d588cc76e1fa2380d Mon Sep 17 00:00:00 2001

From: Christian Heimes <christian@python.org>

Date: Sat, 27 Mar 2021 14:55:03 +0100

Subject: [PATCH 03/10] bpo-40645: use C implementation of HMAC (GH-24920,

 GH-25063, GH-26079)

This backports the feature and 2 subsequent bugfixes

from: https://bugs.python.org/issue40645

Signed-off-by: Christian Heimes <christian@python.org>

Co-authored-by: Erlend Egeberg Aasland <erlend.aasland@innova.no>

Co-Authored-By: Pablo Galindo <Pablogsal@gmail.com>

---

 Lib/hashlib.py                                |   1 +

 Lib/hmac.py                                   |  86 ++++++----

 Lib/test/test_hmac.py                         | 114 +++++++------

 .../2021-03-19-10-22-17.bpo-40645.5pXhb-.rst  |   2 +

 Modules/_hashopenssl.c                        | 150 ++++++++++++++++--

 Modules/clinic/_hashopenssl.c.h               |  38 +----

 6 files changed, 265 insertions(+), 126 deletions(-)

 create mode 100644 Misc/NEWS.d/next/Library/2021-03-19-10-22-17.bpo-40645.5pXhb-.rst

diff --git a/Lib/hashlib.py b/Lib/hashlib.py

index 58c340d..ffa3be0 100644

--- a/Lib/hashlib.py

+++ b/Lib/hashlib.py

@@ -173,6 +173,7 @@ try:

     algorithms_available = algorithms_available.union(

             _hashlib.openssl_md_meth_names)

 except ImportError:

+    _hashlib = None

     new = __py_new

     __get_hash = __get_builtin_constructor

diff --git a/Lib/hmac.py b/Lib/hmac.py

index 180bc37..8b4f920 100644

--- a/Lib/hmac.py

+++ b/Lib/hmac.py

@@ -8,11 +8,12 @@ try:

     import _hashlib as _hashopenssl

 except ImportError:

     _hashopenssl = None

-    _openssl_md_meths = None

+    _functype = None

     from _operator import _compare_digest as compare_digest

 else:

-    _openssl_md_meths = frozenset(_hashopenssl.openssl_md_meth_names)

     compare_digest = _hashopenssl.compare_digest

+    _functype = type(_hashopenssl.openssl_sha256)  # builtin type

+

 import hashlib as _hashlib

 trans_5C = bytes((x ^ 0x5C) for x in range(256))

@@ -23,7 +24,6 @@ trans_36 = bytes((x ^ 0x36) for x in range(256))

 digest_size = None

-

 class HMAC:

     """RFC 2104 HMAC class.  Also complies with RFC 4231.

@@ -32,7 +32,7 @@ class HMAC:

     blocksize = 64  # 512-bit HMAC; can be changed in subclasses.

     __slots__ = (

-        "_digest_cons", "_inner", "_outer", "block_size", "digest_size"

+        "_hmac", "_inner", "_outer", "block_size", "digest_size"

     )

     def __init__(self, key, msg=None, digestmod=''):

@@ -55,15 +55,30 @@ class HMAC:

         if not digestmod:

             raise TypeError("Missing required parameter 'digestmod'.")

+        if _hashopenssl and isinstance(digestmod, (str, _functype)):

+            try:

+                self._init_hmac(key, msg, digestmod)

+            except _hashopenssl.UnsupportedDigestmodError:

+                self._init_old(key, msg, digestmod)

+        else:

+            self._init_old(key, msg, digestmod)

+

+    def _init_hmac(self, key, msg, digestmod):

+        self._hmac = _hashopenssl.hmac_new(key, msg, digestmod=digestmod)

+        self.digest_size = self._hmac.digest_size

+        self.block_size = self._hmac.block_size

+

+    def _init_old(self, key, msg, digestmod):

         if callable(digestmod):

-            self._digest_cons = digestmod

+            digest_cons = digestmod

         elif isinstance(digestmod, str):

-            self._digest_cons = lambda d=b'': _hashlib.new(digestmod, d)

+            digest_cons = lambda d=b'': _hashlib.new(digestmod, d)

         else:

-            self._digest_cons = lambda d=b'': digestmod.new(d)

+            digest_cons = lambda d=b'': digestmod.new(d)

-        self._outer = self._digest_cons()

-        self._inner = self._digest_cons()

+        self._hmac = None

+        self._outer = digest_cons()

+        self._inner = digest_cons()

         self.digest_size = self._inner.digest_size

         if hasattr(self._inner, 'block_size'):

@@ -79,13 +94,13 @@ class HMAC:

                            RuntimeWarning, 2)

             blocksize = self.blocksize

+        if len(key) > blocksize:

+            key = digest_cons(key).digest()

+

         # self.blocksize is the default blocksize. self.block_size is

         # effective block size as well as the public API attribute.

         self.block_size = blocksize

-        if len(key) > blocksize:

-            key = self._digest_cons(key).digest()

-

         key = key.ljust(blocksize, b'\0')

         self._outer.update(key.translate(trans_5C))

         self._inner.update(key.translate(trans_36))

@@ -94,23 +109,15 @@ class HMAC:

     @property

     def name(self):

-        return "hmac-" + self._inner.name

-

-    @property

-    def digest_cons(self):

-        return self._digest_cons

-

-    @property

-    def inner(self):

-        return self._inner

-

-    @property

-    def outer(self):

-        return self._outer

+        if self._hmac:

+            return self._hmac.name

+        else:

+            return f"hmac-{self._inner.name}"

     def update(self, msg):

         """Feed data from msg into this hashing object."""

-        self._inner.update(msg)

+        inst = self._hmac or self._inner

+        inst.update(msg)

     def copy(self):

         """Return a separate copy of this hashing object.

@@ -119,10 +126,14 @@ class HMAC:

         """

         # Call __new__ directly to avoid the expensive __init__.

         other = self.__class__.__new__(self.__class__)

-        other._digest_cons = self._digest_cons

         other.digest_size = self.digest_size

-        other._inner = self._inner.copy()

-        other._outer = self._outer.copy()

+        if self._hmac:

+            other._hmac = self._hmac.copy()

+            other._inner = other._outer = None

+        else:

+            other._hmac = None

+            other._inner = self._inner.copy()

+            other._outer = self._outer.copy()

         return other

     def _current(self):

@@ -130,9 +141,12 @@ class HMAC:

         To be used only internally with digest() and hexdigest().

         """

-        h = self._outer.copy()

-        h.update(self._inner.digest())

-        return h

+        if self._hmac:

+            return self._hmac

+        else:

+            h = self._outer.copy()

+            h.update(self._inner.digest())

+            return h

     def digest(self):

         """Return the hash value of this hashing object.

@@ -179,9 +193,11 @@ def digest(key, msg, digest):

             A hashlib constructor returning a new hash object. *OR*

             A module supporting PEP 247.

     """

-    if (_hashopenssl is not None and

-            isinstance(digest, str) and digest in _openssl_md_meths):

-        return _hashopenssl.hmac_digest(key, msg, digest)

+    if _hashopenssl is not None and isinstance(digest, (str, _functype)):

+        try:

+            return _hashopenssl.hmac_digest(key, msg, digest)

+        except _hashopenssl.UnsupportedDigestmodError:

+            pass

     if callable(digest):

         digest_cons = digest

diff --git a/Lib/test/test_hmac.py b/Lib/test/test_hmac.py

index 6daf22c..adf52ad 100644

--- a/Lib/test/test_hmac.py

+++ b/Lib/test/test_hmac.py

@@ -11,14 +11,21 @@ from test.support import hashlib_helper

 from _operator import _compare_digest as operator_compare_digest

 try:

+    import _hashlib as _hashopenssl

     from _hashlib import HMAC as C_HMAC

     from _hashlib import hmac_new as c_hmac_new

     from _hashlib import compare_digest as openssl_compare_digest

 except ImportError:

+    _hashopenssl = None

     C_HMAC = None

     c_hmac_new = None

     openssl_compare_digest = None

+try:

+    import _sha256 as sha256_module

+except ImportError:

+    sha256_module = None

+

 def ignore_warning(func):

     @functools.wraps(func)

@@ -32,22 +39,27 @@ def ignore_warning(func):

 class TestVectorsTestCase(unittest.TestCase):

-    def asssert_hmac(

-        self, key, data, digest, hashfunc, hashname, digest_size, block_size

+    def assert_hmac_internals(

+            self, h, digest, hashname, digest_size, block_size

     ):

-        h = hmac.HMAC(key, data, digestmod=hashfunc)

         self.assertEqual(h.hexdigest().upper(), digest.upper())

         self.assertEqual(h.digest(), binascii.unhexlify(digest))

         self.assertEqual(h.name, f"hmac-{hashname}")

         self.assertEqual(h.digest_size, digest_size)

         self.assertEqual(h.block_size, block_size)

+    def assert_hmac(

+        self, key, data, digest, hashfunc, hashname, digest_size, block_size

+    ):

+        h = hmac.HMAC(key, data, digestmod=hashfunc)

+        self.assert_hmac_internals(

+            h, digest, hashname, digest_size, block_size

+        )

+

         h = hmac.HMAC(key, data, digestmod=hashname)

-        self.assertEqual(h.hexdigest().upper(), digest.upper())

-        self.assertEqual(h.digest(), binascii.unhexlify(digest))

-        self.assertEqual(h.name, f"hmac-{hashname}")

-        self.assertEqual(h.digest_size, digest_size)

-        self.assertEqual(h.block_size, block_size)

+        self.assert_hmac_internals(

+            h, digest, hashname, digest_size, block_size

+        )

         h = hmac.HMAC(key, digestmod=hashname)

         h2 = h.copy()

@@ -56,11 +68,9 @@ class TestVectorsTestCase(unittest.TestCase):

         self.assertEqual(h.hexdigest().upper(), digest.upper())

         h = hmac.new(key, data, digestmod=hashname)

-        self.assertEqual(h.hexdigest().upper(), digest.upper())

-        self.assertEqual(h.digest(), binascii.unhexlify(digest))

-        self.assertEqual(h.name, f"hmac-{hashname}")

-        self.assertEqual(h.digest_size, digest_size)

-        self.assertEqual(h.block_size, block_size)

+        self.assert_hmac_internals(

+            h, digest, hashname, digest_size, block_size

+        )

         h = hmac.new(key, None, digestmod=hashname)

         h.update(data)

@@ -81,23 +91,18 @@ class TestVectorsTestCase(unittest.TestCase):

             hmac.digest(key, data, digest=hashfunc),

             binascii.unhexlify(digest)

         )

-        with unittest.mock.patch('hmac._openssl_md_meths', {}):

-            self.assertEqual(

-                hmac.digest(key, data, digest=hashname),

-                binascii.unhexlify(digest)

-            )

-            self.assertEqual(

-                hmac.digest(key, data, digest=hashfunc),

-                binascii.unhexlify(digest)

-            )

+

+        h = hmac.HMAC.__new__(hmac.HMAC)

+        h._init_old(key, data, digestmod=hashname)

+        self.assert_hmac_internals(

+            h, digest, hashname, digest_size, block_size

+        )

         if c_hmac_new is not None:

             h = c_hmac_new(key, data, digestmod=hashname)

-            self.assertEqual(h.hexdigest().upper(), digest.upper())

-            self.assertEqual(h.digest(), binascii.unhexlify(digest))

-            self.assertEqual(h.name, f"hmac-{hashname}")

-            self.assertEqual(h.digest_size, digest_size)

-            self.assertEqual(h.block_size, block_size)

+            self.assert_hmac_internals(

+                h, digest, hashname, digest_size, block_size

+            )

             h = c_hmac_new(key, digestmod=hashname)

             h2 = h.copy()

@@ -105,12 +110,24 @@ class TestVectorsTestCase(unittest.TestCase):

             h.update(data)

             self.assertEqual(h.hexdigest().upper(), digest.upper())

+            func = getattr(_hashopenssl, f"openssl_{hashname}")

+            h = c_hmac_new(key, data, digestmod=func)

+            self.assert_hmac_internals(

+                h, digest, hashname, digest_size, block_size

+            )

+

+            h = hmac.HMAC.__new__(hmac.HMAC)

+            h._init_hmac(key, data, digestmod=hashname)

+            self.assert_hmac_internals(

+                h, digest, hashname, digest_size, block_size

+            )

+

     @hashlib_helper.requires_hashdigest('md5', openssl=True)

     def test_md5_vectors(self):

         # Test the HMAC module against test vectors from the RFC.

         def md5test(key, data, digest):

-            self.asssert_hmac(

+            self.assert_hmac(

                 key, data, digest,

                 hashfunc=hashlib.md5,

                 hashname="md5",

@@ -150,7 +167,7 @@ class TestVectorsTestCase(unittest.TestCase):

     @hashlib_helper.requires_hashdigest('sha1', openssl=True)

     def test_sha_vectors(self):

         def shatest(key, data, digest):

-            self.asssert_hmac(

+            self.assert_hmac(

                 key, data, digest,

                 hashfunc=hashlib.sha1,

                 hashname="sha1",

@@ -191,7 +208,7 @@ class TestVectorsTestCase(unittest.TestCase):

         def hmactest(key, data, hexdigests):

             digest = hexdigests[hashfunc]

-            self.asssert_hmac(

+            self.assert_hmac(

                 key, data, digest,

                 hashfunc=hashfunc,

                 hashname=hash_name,

@@ -427,6 +444,15 @@ class ConstructorTestCase(unittest.TestCase):

         ):

             C_HMAC()

+    @unittest.skipUnless(sha256_module is not None, 'need _sha256')

+    def test_with_sha256_module(self):

+        h = hmac.HMAC(b"key", b"hash this!", digestmod=sha256_module.sha256)

+        self.assertEqual(h.hexdigest(), self.expected)

+        self.assertEqual(h.name, "hmac-sha256")

+

+        digest = hmac.digest(b"key", b"hash this!", sha256_module.sha256)

+        self.assertEqual(digest, binascii.unhexlify(self.expected))

+

 class SanityTestCase(unittest.TestCase):

@@ -447,21 +473,21 @@ class SanityTestCase(unittest.TestCase):

 class CopyTestCase(unittest.TestCase):

     @hashlib_helper.requires_hashdigest('sha256')

-    def test_attributes(self):

+    def test_attributes_old(self):

         # Testing if attributes are of same type.

-        h1 = hmac.HMAC(b"key", digestmod="sha256")

+        h1 = hmac.HMAC.__new__(hmac.HMAC)

+        h1._init_old(b"key", b"msg", digestmod="sha256")

         h2 = h1.copy()

-        self.assertTrue(h1._digest_cons == h2._digest_cons,

-            "digest constructors don't match.")

         self.assertEqual(type(h1._inner), type(h2._inner),

             "Types of inner don't match.")

         self.assertEqual(type(h1._outer), type(h2._outer),

             "Types of outer don't match.")

     @hashlib_helper.requires_hashdigest('sha256')

-    def test_realcopy(self):

+    def test_realcopy_old(self):

         # Testing if the copy method created a real copy.

-        h1 = hmac.HMAC(b"key", digestmod="sha256")

+        h1 = hmac.HMAC.__new__(hmac.HMAC)

+        h1._init_old(b"key", b"msg", digestmod="sha256")

         h2 = h1.copy()

         # Using id() in case somebody has overridden __eq__/__ne__.

         self.assertTrue(id(h1) != id(h2), "No real copy of the HMAC instance.")

@@ -469,17 +495,15 @@ class CopyTestCase(unittest.TestCase):

             "No real copy of the attribute 'inner'.")

         self.assertTrue(id(h1._outer) != id(h2._outer),

             "No real copy of the attribute 'outer'.")

-        self.assertEqual(h1._inner, h1.inner)

-        self.assertEqual(h1._outer, h1.outer)

-        self.assertEqual(h1._digest_cons, h1.digest_cons)

+        self.assertIs(h1._hmac, None)

+    @unittest.skipIf(_hashopenssl is None, "test requires _hashopenssl")

     @hashlib_helper.requires_hashdigest('sha256')

-    def test_properties(self):

-        # deprecated properties

-        h1 = hmac.HMAC(b"key", digestmod="sha256")

-        self.assertEqual(h1._inner, h1.inner)

-        self.assertEqual(h1._outer, h1.outer)

-        self.assertEqual(h1._digest_cons, h1.digest_cons)

+    def test_realcopy_hmac(self):

+        h1 = hmac.HMAC.__new__(hmac.HMAC)

+        h1._init_hmac(b"key", b"msg", digestmod="sha256")

+        h2 = h1.copy()

+        self.assertTrue(id(h1._hmac) != id(h2._hmac))

     @hashlib_helper.requires_hashdigest('sha256')

     def test_equality(self):

diff --git a/Misc/NEWS.d/next/Library/2021-03-19-10-22-17.bpo-40645.5pXhb-.rst b/Misc/NEWS.d/next/Library/2021-03-19-10-22-17.bpo-40645.5pXhb-.rst

new file mode 100644

index 0000000..a9ab1c0

--- /dev/null

+++ b/Misc/NEWS.d/next/Library/2021-03-19-10-22-17.bpo-40645.5pXhb-.rst

@@ -0,0 +1,2 @@

+The :mod:`hmac` module now uses OpenSSL's HMAC implementation when digestmod

+argument is a hash name or builtin hash function.

diff --git a/Modules/_hashopenssl.c b/Modules/_hashopenssl.c

index 56dfff9..ca9fea9 100644

--- a/Modules/_hashopenssl.c

+++ b/Modules/_hashopenssl.c

@@ -260,6 +260,8 @@ typedef struct {

     PyTypeObject *EVPXOFtype;

 #endif

     _Py_hashtable_t *hashtable;

+    PyObject *constructs;

+    PyObject *unsupported_digestmod_error;

 } _hashlibstate;

 static inline _hashlibstate*

@@ -420,6 +422,48 @@ py_digest_by_name(PyObject *module, const char *name, enum Py_hash_type py_ht)

     return digest;

 }

+/* Get digest EVP from object

+ *

+ * * string

+ * * _hashopenssl builtin function

+ *

+ * on error returns NULL with exception set.

+ */

+static PY_EVP_MD*

+py_digest_by_digestmod(PyObject *module, PyObject *digestmod, enum Py_hash_type py_ht) {

+    PY_EVP_MD* evp;

+    PyObject *name_obj = NULL;

+    const char *name;

+

+    if (PyUnicode_Check(digestmod)) {

+        name_obj = digestmod;

+    } else {

+        _hashlibstate *state = get_hashlib_state(module);

+        // borrowed ref

+        name_obj = PyDict_GetItem(state->constructs, digestmod);

+    }

+    if (name_obj == NULL) {

+        _hashlibstate *state = get_hashlib_state(module);

+        PyErr_Clear();

+        PyErr_Format(

+            state->unsupported_digestmod_error,

+            "Unsupported digestmod %R", digestmod);

+        return NULL;

+    }

+

+    name = PyUnicode_AsUTF8(name_obj);

+    if (name == NULL) {

+        return NULL;

+    }

+

+    evp = py_digest_by_name(module, name, py_ht);

+    if (evp == NULL) {

+        return NULL;

+    }

+

+    return evp;

+}

+

 static EVPobject *

 newEVPobject(PyTypeObject *type)

 {

@@ -1238,7 +1282,6 @@ pbkdf2_hmac_impl(PyObject *module, const char *hash_name,

     PY_EVP_MD *digest = py_digest_by_name(module, hash_name, Py_ht_pbkdf2);

     if (digest == NULL) {

-        PyErr_SetString(PyExc_ValueError, "unsupported hash type");

         goto end;

     }

@@ -1443,25 +1486,21 @@ _hashlib.hmac_digest as _hashlib_hmac_singleshot

     key: Py_buffer

     msg: Py_buffer

-    digest: str

+    digest: object

 Single-shot HMAC.

 [clinic start generated code]*/

 static PyObject *

 _hashlib_hmac_singleshot_impl(PyObject *module, Py_buffer *key,

-                              Py_buffer *msg, const char *digest)

-/*[clinic end generated code: output=15658ede5ab98185 input=019dffc571909a46]*/

+                              Py_buffer *msg, PyObject *digest)

+/*[clinic end generated code: output=82f19965d12706ac input=0a0790cc3db45c2e]*/

 {

     unsigned char md[EVP_MAX_MD_SIZE] = {0};

     unsigned int md_len = 0;

     unsigned char *result;

     PY_EVP_MD *evp;

-    evp = py_digest_by_name(module, digest, Py_ht_mac);

-    if (evp == NULL) {

-        return NULL;

-    }

     if (key->len > INT_MAX) {

         PyErr_SetString(PyExc_OverflowError,

                         "key is too long.");

@@ -1473,7 +1512,7 @@ _hashlib_hmac_singleshot_impl(PyObject *module, Py_buffer *key,

         return NULL;

     }

-    evp = py_digest_by_name(module, digest, Py_ht_mac);

+    evp = py_digest_by_digestmod(module, digest, Py_ht_mac);

     if (evp == NULL) {

         return NULL;

     }

@@ -1505,15 +1544,15 @@ _hashlib.hmac_new

     key: Py_buffer

     msg as msg_obj: object(c_default="NULL") = b''

-    digestmod: str(c_default="NULL") = None

+    digestmod: object(c_default="NULL") = None

 Return a new hmac object.

 [clinic start generated code]*/

 static PyObject *

 _hashlib_hmac_new_impl(PyObject *module, Py_buffer *key, PyObject *msg_obj,

-                       const char *digestmod)

-/*[clinic end generated code: output=9a35673be0cbea1b input=a0878868eb190134]*/

+                       PyObject *digestmod)

+/*[clinic end generated code: output=c20d9e4d9ed6d219 input=5f4071dcc7f34362]*/

 {

     PyTypeObject *type = get_hashlib_state(module)->HMACtype;

     PY_EVP_MD *digest;

@@ -1527,14 +1566,14 @@ _hashlib_hmac_new_impl(PyObject *module, Py_buffer *key, PyObject *msg_obj,

         return NULL;

     }

-    if ((digestmod == NULL) || !strlen(digestmod)) {

+    if (digestmod == NULL) {

         PyErr_SetString(

             PyExc_TypeError, "Missing required parameter 'digestmod'.");

         return NULL;

     }