SSL_CTX_set_quiet_shutdown, SSL_CTX_get_quiet_shutdown, SSL_set_quiet_shutdown, SSL_get_quiet_shutdown — manipulate shutdown behaviour
void SSL_CTX_set_quiet_shutdown(SSL_CTX *ctx, int mode); int SSL_CTX_get_quiet_shutdown(const SSL_CTX *ctx);
void SSL_set_quiet_shutdown(SSL *ssl, int mode); int SSL_get_quiet_shutdown(const SSL *ssl);
SSL_CTX_set_quiet_shutdown() sets the "quiet shutdown" flag for ctx to be mode. SSL objects created from ctx inherit the mode valid at the time SSL_new(3) is called. mode may be 0 or 1.
SSL_CTX_get_quiet_shutdown() returns the "quiet shutdown" setting of ctx.
SSL_set_quiet_shutdown() sets the "quiet shutdown" flag for ssl to be mode. The setting stays valid until ssl is removed with SSL_free(3) or SSL_set_quiet_shutdown() is called again. It is not changed when SSL_clear(3) is called. mode may be 0 or 1.
SSL_get_quiet_shutdown() returns the "quiet shutdown" setting of ssl.
Normally when a SSL connection is finished, the parties must send out "close notify" alert messages using SSL_shutdown(3) for a clean shutdown.
When setting the "quiet shutdown" flag to 1, SSL_shutdown(3) will set the internal flags to SSL_SENT_SHUTDOWN | SSL_RECEIVED_SHUTDOWN. (SSL_shutdown(3) then behaves like SSL_set_shutdown(3) called with SSL_SENT_SHUTDOWN | SSL_RECEIVED_SHUTDOWN.) The session is thus considered to be shutdown, but no "close notify" alert is sent to the peer. This behaviour violates the TLS standard.
The default is normal shutdown behaviour as described by the TLS standard.
SSL_CTX_set_quiet_shutdown() and SSL_set_quiet_shutdown() do not return diagnostic information.
SSL_CTX_get_quiet_shutdown() and SSL_get_quiet_shutdown return the current setting.