=head1 NAME

Deliantra::Util - utility cruft

=head1 SYNOPSIS

   use Deliantra::Util;

=head1 DESCRIPTION

Various utilities that come in handy when dealing with Deliantra.

=over 4

=cut

package Deliantra::Util;

use Digest::SHA;
use Digest::SHA3;

=item Deliantra::Util::hash_pw $cleartext

Hashes a cleartext password into the binary password used in the protocol.

=cut

sub hash_pw($) {
   # we primarily want to protect the password itself, and
   # secondarily want to protect us against pre-image attacks.
   # we trust nist, but not a single hash function, so we
   # use both sha and sha3

   my $pw = shift;

   for (0..20) {
      $pw = Digest::SHA3::sha3_512 $pw;
      $pw = "deliantrakdf$pw" x 32;
      $pw = Digest::SHA::sha512 $pw;
   }

   $pw
}

=item Deliantra::Util::auth_pw $hash, $nonce1, $nonce2

Authenticates a (hashed) password using the given nonce.

=cut

sub auth_pw($$) {
   my ($pass, $nonce1, $nonce2) = @_;

   # simple HMAC application
   Digest::SHA3::sha3_512 $nonce1 . Digest::SHA3::sha3_512 $nonce2 . $hash
}

=back

=head1 AUTHOR

 Marc Lehmann <schmorp@schmorp.de>
 http://home.schmorp.de/

=cut

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