NAME

       gnutls_dtls_cookie_send - API function

SYNOPSIS

       #include <gnutls/dtls.h>

       int   gnutls_dtls_cookie_send(gnutls_datum_t   *   key,  void  *  client_data,  size_t  client_data_size,
       gnutls_dtls_prestate_st * prestate, gnutls_transport_ptr_t ptr, gnutls_push_func push_func);

ARGUMENTS

       gnutls_datum_t * key
                   is a random key to be used at cookie generation

       void * client_data
                   contains data identifying the client (i.e. address)

       size_t client_data_size
                   The size of client's data

       gnutls_dtls_prestate_st * prestate
                   The previous cookie returned by gnutls_dtls_cookie_verify()

       gnutls_transport_ptr_t ptr
                   A transport pointer to be used by  push_func

       gnutls_push_func push_func
                   A function that will be used to reply

DESCRIPTION

       This function can be used to prevent denial of service attacks to a DTLS server by requiring  the  client
       to  reply  using  a  cookie  sent by this function. That way it can be ensured that a client we allocated
       resources for (i.e. gnutls_session_t) is the one that the original incoming packet was originated from.

       This function must be called at the first incoming packet, prior to allocating any resources and must  be
       succeeded by gnutls_dtls_cookie_verify().

RETURNS

       the number of bytes sent, or a negative error code.

SINCE

       3.0

REPORTING BUGS

       Report bugs to <bugs@gnutls.org>.
       Home page: https://www.gnutls.org

COPYRIGHT

       Copyright © 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                                                3.8.3                           gnutls_dtls_cookie_send(3)