Is there a way to retrieve the certificate from SSL_CTX?

[Paul Smith]

I'm trying to write a simple function to dump the expiration date of
the certificates in my SSL_CTX cert store.

I've managed to retrieve and show the CA certificates from the
certificate store, and the certificate chain, but I can't find a method
that retrieves the certificate itself from SSL_CTX.  Is this something
that is retrievable?

E.g., I'm adding my certificate with SSL_CTX_use_certificate(); is
there a way to get it back out?