text: RAND_load_file, RAND_write_file, RAND_file_name - PRNG seed file
  #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);
  If $HOME (on non-Windows and non-VMS system) is not set either, or num is too small for the path name, an error occurs.
  RAND_load_file() returns the number of bytes read or -1 on error.
  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.
  RAND_add(3), RAND_bytes(3), RAND (7)
  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 <>.