SSL connection to MySQL suddenly not working anymore SSL connections where running smoothly til last week, now I can't connect anymore.
I have a MySQL installation on a virtual machine running Ubuntu. The machine is hosted on a Windows 2012 R2 Server. MySQL is configured for SSL, we have generated keys and everything I see on the side of MySQL looks fine:

+---------------+----------------------------+
| Variable_name | Value                      |
+---------------+----------------------------+
| have_openssl  | YES                        |
| have_ssl      | YES                        |
| ssl_ca        | /etc/mysql/ca-cert.pem     |
| ssl_capath    |                            |
| ssl_cert      | /etc/mysql/server-cert.pem |
| ssl_cipher    |                            |
| ssl_key       | /etc/mysql/server-key.pem  |
+---------------+----------------------------+


On the client side I use FileMaker Pro and a PHP plugin to make a connection. Checking the server from the client with telnet 192.168.87.30 3306 I get the usual answer

5.5.54-0ubuntu0.14.04.1¯`%2nS4IQ└;tZC}o5YBzb\mysql_native_password


As long as I deactivate SSL I can still connect to and work with the database. With SSL active all I get is an error


  Connection to database failed: 2026 (SSL connection error)


The exact same configuration on the client works perfectly well with another MySQL installation on a different server, so the client is certainly not the problem. Something must have changed either on the Ubuntu machine or on the Windows server, but I'm totally lost what this could be.
Checking the expiration date of the certificates helped a lot :)
Case closed.