I understand why nobody gave an answer to this question, because the crucial
hint was missing:
I am using the GLib GSocketService for handling incoming connections. The GLib
uses non-blocking
sockets under the hood which I was not aware of. Especially the
g_socket_set_blocking() function
does not affect the socket on the system layer but alters the behavior of the
GSocket wrapper.
The reason why my code did not work is that I should have used the
BIO_should_retry() function
whenever the {BIO_do_handshake(), BIO_puts(), BIO_gets(),...} functions
returned a return-code
less than zero. I attached a minimal example of my working implementation.
glib-tls-server.tbz
Description: Binary data
