=pod

=head1 NAME

SSL_in_before,
SSL_in_init,
SSL_is_init_finished,
SSL_in_connect_init,
SSL_in_accept_init,
SSL_get_state
- retrieve information about the handshake state machine

=head1 SYNOPSIS

 #include <openssl/ssl.h>

 int SSL_in_init(const SSL *s);
 int SSL_in_before(const SSL *s);
 int SSL_is_init_finished(const SSL *s);

 int SSL_in_connect_init(SSL *s);
 int SSL_in_accept_init(SSL *s);

 OSSL_HANDSHAKE_STATE SSL_get_state(const SSL *ssl);

=head1 DESCRIPTION

SSL_in_init() returns 1 if the SSL/TLS state machine is currently processing or
awaiting handshake messages, or 0 otherwise.

SSL_in_before() returns 1 if no SSL/TLS handshake has yet been initiated, or 0
otherwise.

SSL_is_init_finished() returns 1 if the SSL/TLS connection is in a state where
fully protected application data can be transferred or 0 otherwise.

Note that in some circumstances (such as when early data is being transferred)
SSL_in_init(), SSL_in_before() and SSL_is_init_finished() can all return 0.

B<s> B<MUST NOT> be NULL.

SSL_in_connect_init() returns 1 if B<s> is acting as a client and SSL_in_init()
would return 1, or 0 otherwise.

SSL_in_accept_init() returns 1 if B<s> is acting as a server and SSL_in_init()
would return 1, or 0 otherwise.

SSL_in_connect_init() and SSL_in_accept_init() are implemented as macros.

SSL_get_state() returns a value indicating the current state of the handshake
state machine. OSSL_HANDSHAKE_STATE is an enumerated type where each value
indicates a discrete state machine state. Note that future versions of OpenSSL
may define more states so applications should expect to receive unrecognised
state values. The naming format is made up of a number of elements as follows:

B<protocol>_ST_B<role>_B<message>

B<protocol> is one of TLS or DTLS. DTLS is used where a state is specific to the
DTLS protocol. Otherwise TLS is used.

B<role> is one of CR, CW, SR or SW to indicate "client reading",
"client writing", "server reading" or "server writing" respectively.

B<message> is the name of a handshake message that is being or has been sent, or
is being or has been processed.

Additionally there are some special states that do not conform to the above
format. These are:

=over 4

=item TLS_ST_BEFORE

No handshake messages have yet been been sent or received.

=item TLS_ST_OK

Handshake message sending/processing has completed.

=item TLS_ST_EARLY_DATA

Early data is being processed

=item TLS_ST_PENDING_EARLY_DATA_END

Awaiting the end of early data processing

=back

=head1 RETURN VALUES

SSL_in_init(), SSL_in_before(), SSL_is_init_finished(), SSL_in_connect_init()
and SSL_in_accept_init() return values as indicated above.

SSL_get_state() returns the current handshake state.


=head1 SEE ALSO

L<ssl(7)>,
L<SSL_read_early_data(3)>

=head1 COPYRIGHT

Copyright 2017-2018 The OpenSSL Project Authors. All Rights Reserved.

Licensed under the Apache License 2.0 (the "License").  You may not use
this file except in compliance with the License.  You can obtain a copy
in the file LICENSE in the source distribution or at
L<https://www.openssl.org/source/license.html>.

=cut
