1#!/usr/bin/perl
2
3use bytes;
4use Digest::SHA1;
5use MIME::Base64;
6
7sub random_bytes($) {
8    my($n) = @_;
9    my($v, $i);
10
11    if ( open(RANDOM, '<', '/dev/random') ||
12	 open(RANDOM, '<', '/dev/urandom') ) {
13	read(RANDOM, $v, $n);
14    } else {
15	# No real RNG available...
16	srand($$ ^ time);
17	$v = '';
18	for ( $i = 0 ; $i < $n ; $i++ ) {
19	    $v .= ord(int(rand() * 256));
20	}
21    }
22
23    return $v;
24}
25
26
27($pass, $salt) = @ARGV;
28
29unless (defined($salt)) {
30    $salt = MIME::Base64::encode(random_bytes(6), '');
31}
32$pass = Digest::SHA1::sha1_base64($salt, $pass);
33
34print '$4$', $salt, '$', $pass, "\$\n";
35