1=pod
2
3=head1 NAME
4
5RAND_load_file, RAND_write_file, RAND_file_name - PRNG seed file
6
7=head1 SYNOPSIS
8
9 #include <openssl/rand.h>
10
11 const char *RAND_file_name(char *buf, size_t num);
12
13 int RAND_load_file(const char *filename, long max_bytes);
14
15 int RAND_write_file(const char *filename);
16
17=head1 DESCRIPTION
18
19RAND_file_name() generates a default path for the random seed
20file. B<buf> points to a buffer of size B<num> in which to store the
21filename. The seed file is $RANDFILE if that environment variable is
22set, $HOME/.rnd otherwise. If $HOME is not set either, or B<num> is
23too small for the path name, an error occurs.
24
25RAND_load_file() reads a number of bytes from file B<filename> and
26adds them to the PRNG. If B<max_bytes> is non-negative,
27up to to B<max_bytes> are read; starting with OpenSSL 0.9.5,
28if B<max_bytes> is -1, the complete file is read.
29
30RAND_write_file() writes a number of random bytes (currently 1024) to
31file B<filename> which can be used to initialize the PRNG by calling
32RAND_load_file() in a later session.
33
34=head1 RETURN VALUES
35
36RAND_load_file() returns the number of bytes read.
37
38RAND_write_file() returns the number of bytes written, and -1 if the
39bytes written were generated without appropriate seed.
40
41RAND_file_name() returns a pointer to B<buf> on success, and NULL on
42error.
43
44=head1 SEE ALSO
45
46L<rand(3)|rand(3)>, L<RAND_add(3)|RAND_add(3)>, L<RAND_cleanup(3)|RAND_cleanup(3)>
47
48=head1 HISTORY
49
50RAND_load_file(), RAND_write_file() and RAND_file_name() are available in
51all versions of SSLeay and OpenSSL.
52
53=cut
54