gnutls_handshake_set_hook_function(3) gnutls NAME gnutls_handshake_set_hook_function - API function SYNOPSIS #include void gnutls_handshake_set_hook_function(gnutls_session_t session, unsigned int htype, int when, gnutls_handshake_hook_func func); ARGUMENTS gnutls_session_t session is a gnutls_session_t type unsigned int htype the gnutls_handshake_description_t of the message to hook at int when GNUTLS_HOOK_* depending on when the hook function should be called gnutls_handshake_hook_func func is the function to be called DESCRIPTION This function will set a callback to be called after or before the specified handshake message has been received or generated. This is a generalization of gnutls_handshake_set_post_client_hello_function(). To call the hook function prior to the message being generated or processed use GNUTLS_HOOK_PRE as when parameter, GNUTLS_HOOK_POST to call after, and GNUTLS_HOOK_BOTH for both cases. This callback must return 0 on success or a gnutls error code to terminate the handshake. To hook at all handshake messages use an htype of GNUTLS_HANDSHAKE_ANY. WARNING You should not use this function to terminate the handshake based on client input unless you know what you are doing. Before the handshake is finished there is no way to know if there is a man-in-the-middle attack being performed. REPORTING BUGS Report bugs to . Home page: https://www.gnutls.org COPYRIGHT Copyright (C) 2001-2023 Free Software Foundation, Inc., and others. Copying and distribution of this file, with or without modification, are permitted in any medium without royalty provided the copyright notice and this notice are preserved. SEE ALSO The full documentation for gnutls is maintained as a Texinfo manual. If the /usr/share/doc/gnutls/ directory does not contain the HTML form visit https://www.gnutls.org/manual/ gnutls 3.8.5 gnutls_handshake_set_hook_function(3)