|
NAME | SYNOPSIS | ARGUMENTS | DESCRIPTION | RETURNS | REPORTING BUGS | COPYRIGHT | SEE ALSO | COLOPHON |
gnutls_handshake(3) gnutls gnutls_handshake(3)
gnutls_handshake - API function
#include <gnutls/gnutls.h>
int gnutls_handshake(gnutls_session_t session);
gnutls_session_t session
is a gnutls_session_t type.
This function performs the handshake of the TLS/SSL protocol, and
initializes the TLS session parameters.
The non-fatal errors expected by this function are:
GNUTLS_E_INTERRUPTED, GNUTLS_E_AGAIN,
GNUTLS_E_WARNING_ALERT_RECEIVED. When this function is called for
re-handshake under TLS 1.2 or earlier, the non-fatal error code
GNUTLS_E_GOT_APPLICATION_DATA may also be returned.
The former two interrupt the handshake procedure due to the transport
layer being interrupted, and the latter because of a "warning" alert
that was sent by the peer (it is always a good idea to check any
received alerts). On these non-fatal errors call this function again,
until it returns 0; cf. gnutls_record_get_direction() and
gnutls_error_is_fatal(). In DTLS sessions the non-fatal error
GNUTLS_E_LARGE_PACKET is also possible, and indicates that the MTU
should be adjusted.
When this function is called by a server after a rehandshake request
under TLS 1.2 or earlier the GNUTLS_E_GOT_APPLICATION_DATA error code
indicates that some data were pending prior to peer initiating the
handshake. Under TLS 1.3 this function when called after a
successful handshake, is a no-op and always succeeds in server side;
in client side this function is equivalent to
gnutls_session_key_update() with GNUTLS_KU_PEER flag.
This function handles both full and abbreviated TLS handshakes
(resumption). For abbreviated handshakes, in client side, the
gnutls_session_set_data() should be called prior to this function to
set parameters from a previous session. In server side, resumption
is handled by either setting a DB back-end, or setting up keys for
session tickets.
GNUTLS_E_SUCCESS on a successful handshake, otherwise a negative
error code.
Report bugs to <bugs@gnutls.org>.
Home page: https://www.gnutls.org
Copyright © 2001-2019 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.
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/
This page is part of the GnuTLS (GnuTLS Transport Layer Security
Library) project. Information about the project can be found at
⟨http://www.gnutls.org/⟩. If you have a bug report for this manual
page, send it to bugs@gnutls.org. This page was obtained from the
tarball gnutls-3.6.9.tar.xz fetched from
⟨http://www.gnutls.org/download.html⟩ on 2020-08-13. 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 the page, or
you have corrections or improvements to the information in this
COLOPHON (which is not part of the original manual page), send a mail
to man-pages@man7.org
gnutls 3.6.9 gnutls_handshake(3)