Problem: Join fails error:20080078:BIO routines:bio_write_intern:uninitialized


Joining a UCS Server fails with:

Wed Jun 10 11:10:36 CEST 2020: starting /usr/sbin/univention-join
running version check
OK: UCS version on is higher or equal (4.44) to the local version (4.44).
Wed Jun 10 11:10:45 CEST 2020
univention-join-hooks: looking for hook type "join/pre-join" on master.schein.ig
Exception occurred: {'info': 'error:20080078:BIO routines:bio_write_intern:uninitialized', 'desc': 'Connect error'}

* Join failed!                                                           *
* Contact your system administrator                                      *


root@member:~# apt-cache policy openssl
  Installiert:           1.1.1g-1+0~20200421.17+debian9~1.gbpf6902f
  Installationskandidat: 1.1.1g-1+0~20200421.17+debian9~1.gbpf6902f
 *** 1.1.1g-1+0~20200421.17+debian9~1.gbpf6902f 500
        500 stretch/main amd64 Packages
        100 /var/lib/dpkg/status
     1.1.0l-1~deb9u1 500
        500 4.3-5/amd64/ Packages
        500 4.4-3/amd64/ Packages

You can also try a connection with
openssl s_client -connect $(hostname -f):7636 -showcerts -debug -state
and you can also compare the ciphers with a standard UCS system
openssl ciphers -v HIGH


Because of the use of php7 with a NON UCS appcenter Version of Nextcloud you have to use an external repository for openssl ( so also non UCS)
But this causes the problem with the join and also with ldap connections!

You may consider using a plain debian with nextcloud and php7 or a nextcloud docker container without app center integration.