Allow accessing a connection's verfied certificate chain (#894)
* Allow accessing a connection's verfied certificate chain
Add X509StoreContext.get_verified_chain using X509_STORE_CTX_get1_chain.
Add Connection.get_verified_chain using SSL_get0_verified_chain if
available (ie OpenSSL 1.1+) and X509StoreContext.get_verified_chain
otherwise.
Fixes #740.
* TLSv1_METHOD -> SSLv23_METHOD
* Use X509_up_ref instead of X509_dup
* Add _openssl_assert where appropriate
* SSL_get_peer_cert_chain should not be null
* Reformat with black
* Fix <OpenSSL.crypto.X509 object at 0x7fdbb59e8050> != <OpenSSL.crypto.X509 object at 0x7fdbb59daad0>
* Add Changelog entry
* Remove _add_chain
5 files changed