=pod =head1 NAME RAND_set_rand_method, RAND_get_rand_method, RAND_OpenSSL - select RAND method =head1 SYNOPSIS #include RAND_METHOD *RAND_OpenSSL(void); void RAND_set_rand_method(const RAND_METHOD *meth); const RAND_METHOD *RAND_get_rand_method(void); =head1 DESCRIPTION A B specifies the functions that OpenSSL uses for random number generation. RAND_OpenSSL() returns the default B implementation by OpenSSL. This implementation ensures that the PRNG state is unique for each thread. If an B is loaded that provides the RAND API, however, it will be used instead of the method returned by RAND_OpenSSL(). RAND_set_rand_method() makes B the method for PRNG use. If an ENGINE was providing the method, it will be released first. RAND_get_rand_method() returns a pointer to the current B. =head1 THE RAND_METHOD STRUCTURE typedef struct rand_meth_st { void (*seed)(const void *buf, int num); int (*bytes)(unsigned char *buf, int num); void (*cleanup)(void); void (*add)(const void *buf, int num, int randomness); int (*pseudorand)(unsigned char *buf, int num); int (*status)(void); } RAND_METHOD; The fields point to functions that are used by, in order, RAND_seed(), RAND_bytes(), internal RAND cleanup, RAND_add(), RAND_pseudo_rand() and RAND_status(). Each pointer may be NULL if the function is not implemented. =head1 RETURN VALUES RAND_set_rand_method() returns no value. RAND_get_rand_method() and RAND_OpenSSL() return pointers to the respective methods. =head1 SEE ALSO L, L, L =head1 COPYRIGHT Copyright 2000-2018 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 L. =cut