.\"	$OpenBSD: RAND_load_file.3,v 1.3 2016/11/25 16:34:08 jmc Exp $
.\"
.Dd $Mdocdate: November 25 2016 $
.Dt RAND_LOAD_FILE 3
.Os
.Sh NAME
.Nm RAND_file_name ,
.Nm RAND_load_file ,
.Nm RAND_write_file
.Nd PRNG seed file
.Sh SYNOPSIS
.In openssl/rand.h
.Ft const char *
.Fo RAND_file_name
.Fa "char *buf"
.Fa "size_t num"
.Fc
.Ft int
.Fo RAND_load_file
.Fa "const char *filename"
.Fa "long max_bytes"
.Fc
.Ft int
.Fo RAND_write_file
.Fa "const char *filename"
.Fc
.Sh DESCRIPTION
.Fn RAND_file_name
returns a default path for the random seed file.
.Fa buf
points to a buffer of size
.Fa num
in which to store the filename.
If
.Fa num
is too small for the path name, an error occurs.
.Pp
.Fn RAND_load_file
used to allow for the state of the random number generator to be
controlled by external sources.
.Pp
It is kept for ABI compatibility but is no longer functional, and should
not be used in new programs.
.Pp
.Fn RAND_write_file
writes a number of random bytes (currently 1024) to file
.Fa filename .
.Sh RETURN VALUES
.Fn RAND_load_file
always returns 0.
.Pp
.Fn RAND_write_file
returns the number of bytes written, and -1 if the bytes written were
generated without appropriate seed.
.Pp
.Fn RAND_file_name
returns a pointer to
.Fa buf
on success, and
.Dv NULL
on error.
.Sh SEE ALSO
.Xr RAND_add 3 ,
.Xr RAND_cleanup 3
.Sh HISTORY
.Fn RAND_load_file ,
.Fn RAND_write_file ,
and
.Fn RAND_file_name
are available in all versions of SSLeay and OpenSSL.