mirror of https://github.com/openssl/openssl.git
112 lines
4.5 KiB
Plaintext
112 lines
4.5 KiB
Plaintext
=pod
|
|
|
|
=head1 NAME
|
|
|
|
SSL_key_update,
|
|
SSL_get_key_update_type,
|
|
SSL_renegotiate,
|
|
SSL_renegotiate_abbreviated,
|
|
SSL_renegotiate_pending
|
|
- initiate and obtain information about updating connection keys
|
|
|
|
=head1 SYNOPSIS
|
|
|
|
#include <openssl/ssl.h>
|
|
|
|
int SSL_key_update(SSL *s, int updatetype);
|
|
int SSL_get_key_update_type(const SSL *s);
|
|
|
|
int SSL_renegotiate(SSL *s);
|
|
int SSL_renegotiate_abbreviated(SSL *s);
|
|
int SSL_renegotiate_pending(const SSL *s);
|
|
|
|
=head1 DESCRIPTION
|
|
|
|
SSL_key_update() schedules an update of the keys for the current TLS connection.
|
|
If the B<updatetype> parameter is set to B<SSL_KEY_UPDATE_NOT_REQUESTED> then
|
|
the sending keys for this connection will be updated and the peer will be
|
|
informed of the change. If the B<updatetype> parameter is set to
|
|
B<SSL_KEY_UPDATE_REQUESTED> then the sending keys for this connection will be
|
|
updated and the peer will be informed of the change along with a request for the
|
|
peer to additionally update its sending keys. It is an error if B<updatetype> is
|
|
set to B<SSL_KEY_UPDATE_NONE>.
|
|
|
|
SSL_key_update() must only be called after the initial handshake has been
|
|
completed and TLSv1.3 has been negotiated, at the same time, the application
|
|
needs to ensure that the writing of data has been completed. The key update
|
|
will not take place until the next time an IO operation such as SSL_read_ex()
|
|
or SSL_write_ex() takes place on the connection. Alternatively SSL_do_handshake()
|
|
can be called to force the update to take place immediately.
|
|
|
|
SSL_get_key_update_type() can be used to determine whether a key update
|
|
operation has been scheduled but not yet performed. The type of the pending key
|
|
update operation will be returned if there is one, or SSL_KEY_UPDATE_NONE
|
|
otherwise.
|
|
|
|
SSL_renegotiate() and SSL_renegotiate_abbreviated() should only be called for
|
|
connections that have negotiated TLSv1.2 or less. Calling them on any other
|
|
connection will result in an error.
|
|
|
|
When called from the client side, SSL_renegotiate() schedules a completely new
|
|
handshake over an existing SSL/TLS connection. The next time an IO operation
|
|
such as SSL_read_ex() or SSL_write_ex() takes place on the connection a check
|
|
will be performed to confirm that it is a suitable time to start a
|
|
renegotiation. If so, then it will be initiated immediately. OpenSSL will not
|
|
attempt to resume any session associated with the connection in the new
|
|
handshake.
|
|
|
|
When called from the client side, SSL_renegotiate_abbreviated() works in the
|
|
same was as SSL_renegotiate() except that OpenSSL will attempt to resume the
|
|
session associated with the current connection in the new handshake.
|
|
|
|
When called from the server side, SSL_renegotiate() and
|
|
SSL_renegotiate_abbreviated() behave identically. They both schedule a request
|
|
for a new handshake to be sent to the client. The next time an IO operation is
|
|
performed then the same checks as on the client side are performed and then, if
|
|
appropriate, the request is sent. The client may or may not respond with a new
|
|
handshake and it may or may not attempt to resume an existing session. If
|
|
a new handshake is started then this will be handled transparently by calling
|
|
any OpenSSL IO function.
|
|
|
|
If an OpenSSL client receives a renegotiation request from a server then again
|
|
this will be handled transparently through calling any OpenSSL IO function. For
|
|
a TLS connection the client will attempt to resume the current session in the
|
|
new handshake. For historical reasons, DTLS clients will not attempt to resume
|
|
the session in the new handshake.
|
|
|
|
The SSL_renegotiate_pending() function returns 1 if a renegotiation or
|
|
renegotiation request has been scheduled but not yet acted on, or 0 otherwise.
|
|
|
|
=head1 RETURN VALUES
|
|
|
|
SSL_key_update(), SSL_renegotiate() and SSL_renegotiate_abbreviated() return 1
|
|
on success or 0 on error.
|
|
|
|
SSL_get_key_update_type() returns the update type of the pending key update
|
|
operation or SSL_KEY_UPDATE_NONE if there is none.
|
|
|
|
SSL_renegotiate_pending() returns 1 if a renegotiation or renegotiation request
|
|
has been scheduled but not yet acted on, or 0 otherwise.
|
|
|
|
=head1 SEE ALSO
|
|
|
|
L<ssl(7)>, L<SSL_read_ex(3)>,
|
|
L<SSL_write_ex(3)>,
|
|
L<SSL_do_handshake(3)>
|
|
|
|
=head1 HISTORY
|
|
|
|
The SSL_key_update() and SSL_get_key_update_type() functions were added in
|
|
OpenSSL 1.1.1.
|
|
|
|
=head1 COPYRIGHT
|
|
|
|
Copyright 2017 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
|