NAME

       RAND_DRBG_set_ex_data, RAND_DRBG_get_ex_data, RAND_DRBG_get_ex_new_index - store and
       retrieve extra data from the DRBG instance

SYNOPSIS

        #include <openssl/rand_drbg.h>

        int RAND_DRBG_set_ex_data(RAND_DRBG *drbg, int idx, void *data);

        void *RAND_DRBG_get_ex_data(const RAND_DRBG *drbg, int idx);

        int RAND_DRBG_get_ex_new_index(long argl, void *argp,
                                       CRYPTO_EX_new *new_func,
                                       CRYPTO_EX_dup *dup_func,
                                       CRYPTO_EX_free *free_func);

DESCRIPTION

       RAND_DRBG_set_ex_data() enables an application to store arbitrary application specific
       data data in a RAND_DRBG instance drbg. The index idx should be a value previously
       returned from a call to RAND_DRBG_get_ex_new_index().

       RAND_DRBG_get_ex_data() retrieves application specific data previously stored in an
       RAND_DRBG instance drbg. The idx value should be the same as that used when originally
       storing the data.

       For more detailed information see CRYPTO_get_ex_data(3) and CRYPTO_set_ex_data(3) which
       implement these functions and CRYPTO_get_ex_new_index(3) for generating a unique index.

RETURN VALUES

       RAND_DRBG_set_ex_data() returns 1 for success or 0 for failure.

       RAND_DRBG_get_ex_data() returns the previously stored value or NULL on failure. NULL may
       also be a valid value.

NOTES

       RAND_DRBG_get_ex_new_index(...) is implemented as a macro and equivalent to
       CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_DRBG,...).

SEE ALSO

       CRYPTO_get_ex_data(3), CRYPTO_set_ex_data(3), CRYPTO_get_ex_new_index(3), RAND_DRBG(7)

COPYRIGHT

       Copyright 2017-2018 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>.