fix docstring types
diff --git a/OpenSSL/crypto.py b/OpenSSL/crypto.py
index 74ebc24..7b2ce07 100644
--- a/OpenSSL/crypto.py
+++ b/OpenSSL/crypto.py
@@ -629,13 +629,13 @@
:param typename: The name of the type of extension to create. See
http://openssl.org/docs/apps/x509v3_config.html#STANDARD_EXTENSIONS
- :type typename: :py:data:`str`
+ :type typename: :py:data:`bytes`
:param bool critical: A flag indicating whether this is a critical
extension.
:param value: The value of the extension.
- :type value: :py:data:`str`
+ :type value: :py:data:`bytes`
:param subject: Optional X509 certificate to use as subject.
:type subject: :py:class:`X509`
@@ -1632,7 +1632,7 @@
the passphrase to use, or a callback for providing the
passphrase.
:return: The buffer with the dumped key in
- :rtype: :py:data:`str`
+ :rtype: :py:data:`bytes`
"""
bio = _new_mem_buf()