/usr/man/cat.3/RAND_write_file.3

RAND_load_file(3)            OpenSSL            RAND_load_file(3)

NAME

     RAND_load_file, RAND_write_file, RAND_file_name - PRNG seed
     file

SYNOPSIS

      #include <openssl/rand.h>

      const char *RAND_file_name(char *buf, size_t num);

      int RAND_load_file(const char *filename, long max_bytes);

      int RAND_write_file(const char *filename);

DESCRIPTION

     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. The seed file is $RANDFILE if that
     environment variable is set, $HOME/.rnd otherwise. If $HOME
     is not set either, or num is too small for the path name, an
     error occurs.

     RAND_load_file() reads a number of bytes from file filename
     and adds them to the PRNG. If max_bytes is non-negative, up
     to to max_bytes are read; starting with OpenSSL 0.9.5, if
     max_bytes is -1, the complete file is read.

     RAND_write_file() writes a number of random bytes (currently
     1024) to file filename which can be used to initialize the
     PRNG by calling RAND_load_file() in a later session.

RETURN VALUES

     RAND_load_file() returns the number of bytes read.

     RAND_write_file() returns the number of bytes written, and
     -1 if the bytes written were generated without appropriate
     seed.

     RAND_file_name() returns a pointer to buf on success, and
     NULL on error.

SEE ALSO

     rand(3), RAND_add(3), RAND_cleanup(3)

HISTORY

     RAND_load_file(), RAND_write_file() and RAND_file_name() are
     available in all versions of SSLeay and OpenSSL.

1.0.2t               Last change: 2019-09-10                    1

See also RAND_file_name(3)
See also RAND_load_file(3)