diff --git a/tools/test_modules/m31800.pm b/tools/test_modules/m31800.pm
index 91311cfe1..a4f4fecfb 100644
--- a/tools/test_modules/m31800.pm
+++ b/tools/test_modules/m31800.pm
@@ -13,26 +13,20 @@ use Crypt::AuthEnc::GCM;
 use MIME::Base64 qw (decode_base64 encode_base64);
 use Crypt::KeyDerivation ':all';
 
-sub module_constraints { [[0, 256], [32, 32], [-1, -1], [-1, -1], [-1, -1]] }
+sub module_constraints { [[0, 256], [64, 64], [-1, -1], [-1, -1], [-1, -1]] }
 
 sub module_generate_hash
 {
-  my $word              = shift;
-  my $salt              = shift;
-  my $iterations        = shift;
-  my $email             = shift;
-  my $algorithm         = shift;
-  my $secret_key        = shift;
-  my $ct                = shift;
-  my $plaintext_length  = shift;
-  my $iv                = shift;
-  my $cryptext          = shift;
-  my $expected_hmac     = shift;
-  my $hmac_d_data       = shift;
-
-  my $salt_bin = pack ("H*", $salt);
-
-  my $hkdf_pass_salt = hkdf ($salt_bin, $email, 'SHA256', 32, "PBES2g-HS256");
+  my $word        = shift;
+  my $hkdf_salt   = shift;
+  my $hkdf_key    = shift // random_hex_string (64);
+  my $iterations  = shift // 100000;
+  my $iv          = shift // random_hex_string (32);
+  my $ct          = shift;
+  my $tag         = shift;
+  my $email       = shift // "31800\@hashcat.net";
+
+  my $hkdf_salt_bin = pack ("H*", $hkdf_salt);
 
   my $kdf = Crypt::PBKDF2->new
   (
@@ -41,28 +35,25 @@ sub module_generate_hash
     output_len => 32
   );
 
-  my $password_key = $kdf->PBKDF2 ($hkdf_pass_salt, $word);
+  my $password_key = $kdf->PBKDF2 ($hkdf_salt_bin, $word);
 
-  my $hkdf_key = hkdf ("798JRYLJVD423DC286TVMH43EB", "ASWWYB", 'SHA256', 32, "A3");
+  my $hkdf_key_bin = pack ("H*", $hkdf_key);
 
-  my $muk = xor_len ($password_key, $hkdf_key, 32);
+  my $muk = xor_len ($password_key, $hkdf_key_bin, 32);
 
   my $pt;
 
-  my $iv_bin;
+  my $iv_bin = pack ("H*", $iv);
 
   if (defined $ct)
   {
     my $ct_bin = pack ("H*", $ct);
 
-    $iv_bin = substr ($ct_bin, 0 + length ("opdata01"), 16);
-
-    my $data_bin = substr ($ct_bin, 0 + length ("opdata01") + 16, -16);
-    my $tag_bin  = substr ($ct_bin, -16);
+    my $tag_bin = pack ("H*", $tag);
 
     my $aes = Crypt::AuthEnc::GCM->new ("AES", $muk, $iv_bin);
 
-    $pt = $aes->decrypt_add ($data_bin);
+    $pt = $aes->decrypt_add ($ct_bin);
 
     my $result_tag = $aes->decrypt_done ($tag_bin);
 
@@ -88,14 +79,7 @@ sub module_generate_hash
 
   ## so far so good
 
-  my $hash = sprintf
-  (
-    '$mobilekeychain$%s',
-
-     unpack ("H*", "opdata01" . $iv_bin . $ct_bin . $tag_bin)
-  );
-
-
+  my $hash = sprintf ('$mobilekeychain$%s$%s$%s$%u$%s$%s$%s', $email, unpack ("H*", $hkdf_salt_bin), unpack ("H*", $hkdf_key_bin), $iterations, unpack ("H*", $iv_bin), unpack ("H*", $ct_bin), unpack ("H*", $tag_bin));
 
   return $hash;
 }
@@ -113,44 +97,20 @@ sub module_verify_hash
 
   return unless substr ($hash, 0, 16) eq '$mobilekeychain$';
 
-  my (undef, $signature, $email, $salt_len, $salt, $algorithm, $secret_key, $iterations, $ct_len, $ct, $plaintext_length, $iv_len, $iv, $cryptext_len, $cryptext, $expected_hmac_len, $expected_hmac, $hmac_d_data_len, $hmac_d_data) = split '\$', $hash;
+  my (undef, $signature, $email, $hkdf_salt, $hkdf_key, $iterations, $iv, $ct, $tag) = split '\$', $hash;
 
   return unless defined $signature;
   return unless defined $email;
-  return unless defined $salt_len;
-  return unless defined $salt;
-  return unless defined $algorithm;
-  return unless defined $secret_key;
+  return unless defined $hkdf_salt;
+  return unless defined $hkdf_key;
   return unless defined $iterations;
-  return unless defined $ct_len;
-  return unless defined $ct;
-  return unless defined $plaintext_length;
-  return unless defined $iv_len;
   return unless defined $iv;
-  return unless defined $cryptext_len;
-  return unless defined $cryptext;
-  return unless defined $expected_hmac_len;
-  return unless defined $expected_hmac;
-  return unless defined $hmac_d_data_len;
-  return unless defined $hmac_d_data;
-
-  my $salt_bin          = pack ("H*", $salt);
-  my $ct_bin            = pack ("H*", $ct);
-  my $iv_bin            = pack ("H*", $iv);
-  my $cryptext_bin      = pack ("H*", $cryptext);
-  my $expected_hmac_bin = pack ("H*", $expected_hmac);
-  my $hmac_d_data_bin   = pack ("H*", $hmac_d_data);
-
-  return unless length ($salt_bin)          == $salt_len;
-  return unless length ($ct_bin)            == $ct_len;
-  return unless length ($iv_bin)            == $iv_len;
-  return unless length ($cryptext_bin)      == $cryptext_len;
-  return unless length ($expected_hmac_bin) == $expected_hmac_len;
-  return unless length ($hmac_d_data_bin)   == $hmac_d_data_len;
+  return unless defined $ct;
+  return unless defined $tag;
 
   my $word_packed = pack_if_HEX_notation ($word);
 
-  my $new_hash = module_generate_hash ($word_packed, $salt, $iterations, $email, $algorithm, $secret_key, $ct, $plaintext_length, $iv, $cryptext, $expected_hmac, $hmac_d_data);
+  my $new_hash = module_generate_hash ($word_packed, $hkdf_salt, $hkdf_key, $iterations, $iv, $ct, $tag, $email);
 
   return ($new_hash, $word);
 }