gnutls_handshake - API function
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
. 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.
DTLS sessions the non-fatal error GNUTLS_E_LARGE_PACKET
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
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.
on a successful handshake, otherwise a negative error
Report bugs to <firstname.lastname@example.org>.
Home page: https://www.gnutls.org
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