oracular (3) RAND_set0_public.3ssl.gz

Provided by: libssl-doc_3.3.1-2ubuntu2.1_all bug

NAME
       RAND_get0_primary, RAND_get0_public, RAND_get0_private, RAND_set0_public, RAND_set0_private - get access
       to the global EVP_RAND_CTX instances


SYNOPSIS
        #include <openssl/rand.h>

        EVP_RAND_CTX *RAND_get0_primary(OSSL_LIB_CTX *ctx);
        EVP_RAND_CTX *RAND_get0_public(OSSL_LIB_CTX *ctx);
        EVP_RAND_CTX *RAND_get0_private(OSSL_LIB_CTX *ctx);
        int RAND_set0_public(OSSL_LIB_CTX *ctx, EVP_RAND_CTX *rand);
        int RAND_set0_private(OSSL_LIB_CTX *ctx, EVP_RAND_CTX *rand);


DESCRIPTION
       The default RAND API implementation (RAND_OpenSSL()) utilizes three shared DRBG instances which are
       accessed via the RAND API:

       The public and private DRBG are thread-local instances, which are used by RAND_bytes() and
       RAND_priv_bytes(), respectively.  The primary DRBG is a global instance, which is not intended to be used
       directly, but is used internally to reseed the other two instances.

       The three get functions provide access to the shared DRBG instances.

       The two set functions allow the public and private DRBG instances to be replaced by another random number
       generator.


RETURN VALUES
       RAND_get0_primary() returns a pointer to the primary DRBG instance for the given OSSL_LIB_CTX ctx.

       RAND_get0_public() returns a pointer to the public DRBG instance for the given OSSL_LIB_CTX ctx.

       RAND_get0_private() returns a pointer to the private DRBG instance for the given OSSL_LIB_CTX ctx.

       RAND_set0_public() and RAND_set0_private() return 1 on success and 0 on error.


NOTES
       It is not thread-safe to access the primary DRBG instance.  The public and private DRBG instance can be
       accessed safely, because they are thread-local. Note however, that changes to these two instances apply
       only to the current thread.

       For that reason it is recommended not to change the settings of these three instances directly.  Instead,
       an application should change the default settings for new DRBG instances at initialization time, before
       creating additional threads.

       During initialization, it is possible to change the reseed interval and reseed time interval.  It is also
       possible to exchange the reseeding callbacks entirely.

       To set the type of DRBG that will be instantiated, use the RAND_set_DRBG_type(3) call before accessing
       the random number generation infrastructure.

       The two set functions, operate on the the current thread.  If you want to use the same random number
       generator across all threads, each thread must individually call the set functions.


SEE ALSO
       EVP_RAND(3), RAND_set_DRBG_type(3)


HISTORY
       RAND_set0_public() and RAND_set0_private() were added in OpenSSL 3.1.

       The remaining functions were added in OpenSSL 3.0.


       Copyright 2020-2021 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>.