RAND_DRBG_set_ex_data

- NAME
- SYNOPSIS
- DESCRIPTION
- RETURN VALUES
- NOTES
- SEE ALSO
- COPYRIGHT

# 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.