Created
April 24, 2015 20:57
-
-
Save mgregoro/9fa29f5dfb36e88878ec to your computer and use it in GitHub Desktop.
Perl TOTP using Crypt::Sodium
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
#!/usr/bin/env perl | |
use Crypt::Sodium; | |
use MIME::Base32; | |
my $secret = join(' ', @ARGV); | |
my $skew_tolerance = 10; | |
my $interval = 60; | |
while (1) { | |
my $time_fragment = int(time / $interval); | |
my $remaining = ($interval - time % $interval); | |
my $announce_token = token_for($time_fragment . $secret); | |
my %candidates; | |
if ($skew_tolerance) { | |
$candidates{token_for($time_fragment . $secret)} = 1; | |
$candidates{token_for(int((time - $skew_tolerance) / $interval) . $secret)} = 1; | |
$candidates{token_for(int((time + $skew_tolerance) / $interval) . $secret)} = 1; | |
} else { | |
$candidates{token_for($time_fragment . $secret)} = 1; | |
} | |
my @candidates = sort {$a cmp $b} keys %candidates; | |
print "$remaining, ANNOUNCE $announce_token; ACCEPT [" . join(', ', @candidates) . "]\n"; | |
sleep 1; | |
} | |
sub token_for { | |
my $str = MIME::Base32::encode(crypto_hash(shift)); | |
my $token; | |
if (length($str) > 8) { | |
# the token is the first 4 and last 4 characters. | |
$token = substr($str, 0, 4) . substr($str, length($str) - 4, 4); | |
} else { | |
# the token is the string left zero padded. | |
$token = "0" x (8 - length($str)) . $str; | |
} | |
return $token; | |
} |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment