Section: gnutls (3)
gnutls_session_get_id - API function
int gnutls_session_get_id(gnutls_session_t session, void * session_id, size_t * session_id_size);
- gnutls_session_t session
is a gnutls_session_t type.
- void * session_id
is a pointer to space to hold the session id.
- size_t * session_id_size
initially should contain the maximum session_id size and will be updated.
Returns the TLS session identifier. The session ID is selected by the
server, and in older versions of TLS was a unique identifier shared
between client and server which was persistent across resumption.
In the latest version of TLS (1.3) or TLS with session tickets, the
notion of session identifiers is undefined and cannot be relied for uniquely
identifying sessions across client and server.
In client side this function returns the identifier returned by the
server, and cannot be assumed to have any relation to session resumption.
In server side this function is guaranteed to return a persistent
identifier of the session since GnuTLS 3.6.4, which may not necessarily
map into the TLS session ID value. Prior to that version the value
could only be considered a persistent identifier, under TLS1.2 or earlier
and when no session tickets were in use.
The session identifier value returned is always less than
On success, GNUTLS_E_SUCCESS
(0) is returned, otherwise
an error code is returned.
Report bugs to <firstname.lastname@example.org
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