gnutls_handshake_set_hook_function(3) — Linux manual page



NAME         top

       gnutls_handshake_set_hook_function - API function

SYNOPSIS         top

       #include <gnutls/gnutls.h>

       void gnutls_handshake_set_hook_function(gnutls_session_t session,
       unsigned int htype, int when, gnutls_handshake_hook_func func);

ARGUMENTS         top

       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         top

       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

       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

       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

WARNING         top

       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         top

       Report bugs to <>.
       Home page:

COPYRIGHT         top

       Copyright © 2001- 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         top

       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 

COLOPHON         top

       This page is part of the GnuTLS (GnuTLS Transport Layer Security
       Library) project.  Information about the project can be found at
       ⟨⟩.  If you have a bug report for this
       manual page, send it to  This page was obtained
       from the tarball gnutls-3.7.8.tar.xz fetched from
       ⟨⟩ on 2022-12-17.  If you
       discover any rendering problems in this HTML version of the page,
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gnutls                            3.g7n.u8tls_handshake_set_hook_function(3)