SSL_get_default_timeout.3ssl man page

 #include <openssl/ssl.h>

 long SSL_get_default_timeout(const SSL *ssl);

SSL_get_default_timeout() returns the default timeout value assigned to SSL_SESSION objects negotiated for the protocol valid for ssl.

Whenever a new session is negotiated, it is assigned a timeout value, after which it will not be accepted for session reuse. If the timeout value was not explicitly set using SSL_CTX_set_timeout(3), the hardcoded default timeout for the protocol will be used.

SSL_get_default_timeout() return this hardcoded value, which is 300 seconds for all currently supported protocols (SSLv2, SSLv3, and TLSv1).

See description.

ssl(3), SSL_CTX_set_session_cache_mode(3), SSL_SESSION_get_time(3), SSL_CTX_flush_sessions(3), SSL_get_default_timeout(3)