#include <openssl/rand.h> int RAND_load_file(const char *filename, long max_bytes); int RAND_write_file(const char *filename); const char *RAND_file_name(char *buf, size_t num);
RAND_write_file() writes a number of random bytes (currently 128) to file filename which can be used to initialize the PRNG by calling RAND_load_file() in a later session.
RAND_file_name() generates a default path for the random seed file. buf points to a buffer of size num in which to store the filename.
On all systems, if the environment variable RANDFILE is set, its value will be used as the seed filename. Otherwise, the file is called ".rnd", found in platform dependent locations:
- On Windows (in order of preference)
%HOME%, %USERPROFILE%, %SYSTEMROOT%, C:\
- On VMS
- On all other systems
If $HOME (on non-Windows and non-VMS system) is not set either, or num is too small for the pathname, an error occurs.
RAND_write_file() returns the number of bytes written, or -1 if the bytes written were generated without appropriate seeding.
RAND_file_name() returns a pointer to buf on success, and NULL on error.
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.