SSL_export_keying_material(3)

SSL_export_keying_material(3)OpenSSLSSL_export_keying_material(3)

NAME

     SSL_export_keying_material - obtain keying material for
     application use

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);

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 s, olen bytes of data will be
     written to out. The application specific context should be
     supplied in the location pointed to by context and should be
     contextlen bytes long. Provision of a context is optional.
     If the context should be omitted entirely then use_context
     should be set to 0. Otherwise it should be any other value.
     If use_context is 0 then the values of context and
     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 label and should be llen bytes long.
     Typically this will be a value from the IANA Exporter Label
     Registry
     (<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.

RETURN VALUES

     SSL_export_keying_material() returns 0 or -1 on failure or 1
     on success.

1.0.2t               Last change: 2019-09-10                    1

SSL_export_keying_material(3)OpenSSLSSL_export_keying_material(3)

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
     <https://www.openssl.org/source/license.html>.

1.0.2t               Last change: 2019-09-10                    2