62 lines
2.5 KiB
Plaintext
62 lines
2.5 KiB
Plaintext
|
=pod
|
||
|
|
|
||
|
|
=head1 NAME
|
||
|
|
|
||
|
|
SSL_export_keying_material - obtain keying material for application use
|
||
|
|
|
||
|
|
=head1 SYNOPSIS
|
||
|
|
|
||
|
|
#include <openssl/ssl.h>
|
||
|
|
|
||
|
|
int SSL_export_keying_material(SSL *s, unsigned char *out, size_t olen,
|
||
|
|
const char *label, size_t llen,
|
||
|
|
const unsigned char *context,
|
||
|
|
size_t contextlen, int use_context);
|
||
|
|
|
||
|
|
=head1 DESCRIPTION
|
||
|
|
|
||
|
|
During the creation of a TLS or DTLS connection shared keying material is
|
||
|
|
established between the two endpoints. The function SSL_export_keying_material()
|
||
|
|
enables an application to use some of this keying material for its own purposes
|
||
|
|
in accordance with RFC5705.
|
||
|
|
|
||
|
|
An application may need to securely establish the context within which this
|
||
|
|
keying material will be used. For example this may include identifiers for the
|
||
|
|
application session, application algorithms or parameters, or the lifetime of
|
||
|
|
the context. The context value is left to the application but must be the same
|
||
|
|
on both sides of the communication.
|
||
|
|
|
||
|
|
For a given SSL connection B<s>, B<olen> bytes of data will be written to
|
||
|
|
B<out>. The application specific context should be supplied in the location
|
||
|
|
pointed to by B<context> and should be B<contextlen> bytes long. Provision of
|
||
|
|
a context is optional. If the context should be omitted entirely then
|
||
|
|
B<use_context> should be set to 0. Otherwise it should be any other value. If
|
||
|
|
B<use_context> is 0 then the values of B<context> and B<contextlen> are ignored.
|
||
|
|
Note that a zero length context is treated differently to no context at all, and
|
||
|
|
will result in different keying material being returned.
|
||
|
|
|
||
|
|
An application specific label should be provided in the location pointed to by
|
||
|
|
B<label> and should be B<llen> bytes long. Typically this will be a value from
|
||
|
|
the IANA Exporter Label Registry
|
||
|
|
(L<https://www.iana.org/assignments/tls-parameters/tls-parameters.xhtml#exporter-labels>).
|
||
|
|
Alternatively labels beginning with "EXPERIMENTAL" are permitted by the standard
|
||
|
|
to be used without registration.
|
||
|
|
|
||
|
|
Note that this function is only defined for TLSv1.0 and above, and DTLSv1.0 and
|
||
|
|
above. Attempting to use it in SSLv3 will result in an error.
|
||
|
|
|
||
|
|
=head1 RETURN VALUES
|
||
|
|
|
||
|
|
SSL_export_keying_material() returns 0 or -1 on failure or 1 on success.
|
||
|
|
|
||
|
|
=head1 COPYRIGHT
|
||
|
|
|
||
|
|
Copyright 2017 The OpenSSL Project Authors. All Rights Reserved.
|
||
|
|
|
||
|
|
Licensed under the OpenSSL license (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
|