From 91d7e66cd2d6d7bfb30e97ebda3837d2bf7efc15 Mon Sep 17 00:00:00 2001
From: Felix Fontein <felix@fontein.de>
Date: Sat, 9 Oct 2021 11:16:06 +0200
Subject: [PATCH] Add changelog entry and documentation.

---
 CHANGELOG.rst           | 2 ++
 docs/x509/reference.rst | 8 ++++++++
 2 files changed, 10 insertions(+)

diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index ea5ab1647173f..805b5a44dbe52 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -13,6 +13,8 @@ Changelog
   :func:`~cryptography.hazmat.primitives.serialization.pkcs12.load_pkcs12`,
   which will return an object of type
   :class:`~cryptography.hazmat.primitives.serialization.pkcs12.PKCS12KeyAndCertificates`.
+* Extension values can now be serialized to a DER byte string by calling
+  :func:`~cryptography.x509.ExtensionType.to_der_string`.
 
 .. _v35-0-0:
 
diff --git a/docs/x509/reference.rst b/docs/x509/reference.rst
index 36dbd6db68a7a..d6e79870a844d 100644
--- a/docs/x509/reference.rst
+++ b/docs/x509/reference.rst
@@ -1589,6 +1589,14 @@ X.509 Extensions
 
         Returns the OID associated with the given extension type.
 
+    .. method:: to_der_string
+
+        .. versionadded:: 36.0
+
+        :return bytes:
+
+            A bytes string representing the extension's DER encoded value.
+
 .. class:: KeyUsage(digital_signature, content_commitment, key_encipherment, data_encipherment, key_agreement, key_cert_sign, crl_sign, encipher_only, decipher_only)
 
     .. versionadded:: 0.9