gnutls_dtls_cookie_send

Section: gnutls (3)
Updated: 3.7.1
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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- 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.