gnutls_handshake_set_post_client_hello_function(3) — Linux manual page



NAME         top

       gnutls_handshake_set_post_client_hello_function - API function

SYNOPSIS         top

       #include <gnutls/gnutls.h>

       session, gnutls_handshake_simple_hook_func func);

ARGUMENTS         top

       gnutls_session_t session
                   is a gnutls_session_t type.

       gnutls_handshake_simple_hook_func func
                   is the function to be called

DESCRIPTION         top

       This function will set a callback to be called after the client
       hello has been received (callback valid in server side only).
       This allows the server to adjust settings based on received

       Those settings could be ciphersuites, requesting certificate, or
       anything else except for version negotiation (this is done before
       the hello message is parsed).

       This callback must return 0 on success or a gnutls error code to
       terminate the handshake.

       Since GnuTLS 3.3.5 the callback is allowed to return
       GNUTLS_E_AGAIN or GNUTLS_E_INTERRUPTED to put the handshake on
       hold. In that case gnutls_handshake() will return
       GNUTLS_E_INTERRUPTED and can be resumed when needed.

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-3.7.2.tar.xz fetched from
       ⟨⟩ on 2021-08-27.  If you
       discover any rendering problems in this HTML version of the page,
       or you believe there is a better or more up-to-date source for
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       manual page), send a mail to

gnutls                gnutls_hands3h.a7k.e2_set_post_client_hello_function(3)