====Troubleshooting====

==VERIFY ERROR: depth=0, error=CA signature digest algorithm too weak==

Soluce : 

in /etc/NetworkManager/system-connections/vpn.nmconnection add 

  tls-cipher=DEFAULT:@SECLEVEL=0

then 

  sudo systemctl restart NetworkManager

==same error on android with openvpn==

under "server list" -> Custom options

  tls-cipher "DEFAULT:@SECLEVEL=0"