[3.9] bpo-40791: Use CRYPTO_memcmp() for compare_digest (GH-20456) (GH-20461)
hashlib.compare_digest uses OpenSSL's CRYPTO_memcmp() function
when OpenSSL is available.
Note: The _operator module is a builtin module. I don't want to add
libcrypto dependency to libpython. Therefore I duplicated the wrapper
function and added a copy to _hashopenssl.c..
(cherry picked from commit db5aed931f8a617f7b63e773f62db468fe9c5ca1)
Co-authored-by: Christian Heimes <christian@python.org>
diff --git a/Doc/library/hmac.rst b/Doc/library/hmac.rst
index 5ad3484..897edc2 100644
--- a/Doc/library/hmac.rst
+++ b/Doc/library/hmac.rst
@@ -138,6 +138,11 @@
.. versionadded:: 3.3
+ .. versionchanged:: 3.9
+
+ The function uses OpenSSL's ``CRYPTO_memcmp()`` internally when
+ available.
+
.. seealso::