NAME

       OSSL_PARAM_dup, OSSL_PARAM_merge, OSSL_PARAM_free - OSSL_PARAM array copy functions

SYNOPSIS

        #include <openssl/params.h>

        OSSL_PARAM *OSSL_PARAM_dup(const OSSL_PARAM *params);
        OSSL_PARAM *OSSL_PARAM_merge(const OSSL_PARAM *params, const OSSL_PARAM *params1);
        void OSSL_PARAM_free(OSSL_PARAM *params);

DESCRIPTION

       Algorithm parameters can be exported/imported from/to providers using arrays of
       OSSL_PARAM. The following utility functions allow the parameters to be duplicated and
       merged with other OSSL_PARAM to assist in this process.

       OSSL_PARAM_dup() duplicates the parameter array params. This function does a deep copy of
       the data.

       OSSL_PARAM_merge() merges the parameter arrays params and params1 into a new parameter
       array. If params and params1 contain values with the same 'key' then the value from
       params1 will replace the param value. This function does a shallow copy of the parameters.
       Either params or params1 may be NULL. The behaviour of the merge is unpredictable if
       params and params1 contain the same key, and there are multiple entries within either
       array that have the same key.

       OSSL_PARAM_free() frees the parameter array params that was created using
       OSSL_PARAM_dup(), OSSL_PARAM_merge() or OSSL_PARAM_BLD_to_param().

RETURN VALUES

       The functions OSSL_PARAM_dup() and OSSL_PARAM_merge() return a newly allocated OSSL_PARAM
       array, or NULL if there was an error. If both parameters are NULL
        then NULL is returned.

SEE ALSO

       OSSL_PARAM(3), OSSL_PARAM_BLD(3)

HISTORY

       The functions were added in OpenSSL 3.0.

COPYRIGHT

       Copyright 2021 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 <https://www.openssl.org/source/license.html>.