m25400.pm should no longer recalculate $u

tools/test_modules/m25400.pm

@@ -171,6 +171,10 @@ sub module_generate_hash
 
 
   ################ USER PASSWORD #################
+  # do not change $u if it exists, keep this the same, as we don't know the user password,
+  #  we cannot calculate this part of the hash again
+  if("".$u eq "0000000000000000000000000000000000000000000000000000000000000000")
+  {
     my $res = pdf_compute_encryption_key_user($word, $padding, $id, $u, $o, $P, $V, $R, $enc);
 
     my $digest = md5 ($padding . pack ("H*", $id));
@@ -196,7 +200,12 @@ sub module_generate_hash
 
       $u = $m2->RC4 ($u);
     }
-
+    $u .= substr (pack ("H*", $u_save), 16, 16);
+  }
+  else
+  {
+    $u = pack("H*", $u)
+  }
 
   ################ OWNER PASSWORD #################
   my $o_key = pdf_compute_encryption_key_owner($word, $padding, $id, $u, $o, $P, $V, $R, $enc);
@@ -228,14 +237,11 @@ sub module_generate_hash
   }
 
   #printf("\$u = %s\n", unpack ("H*", $u));
-
-  $u .= substr (pack ("H*", $u_save), 16, 16);
-
   #printf("\$o = %s\n", unpack ("H*", $o));
   #printf("\$u = %s\n", unpack ("H*", $u));
 
   my $hash = sprintf ('$pdf$%d*%d*128*%d*%d*16*%s*32*%s*32*%s', $V, $R, $P, $enc, $id, unpack ("H*", $u), unpack ("H*", $o));
-
+  print("hash\n".$hash."\n");
   return $hash;
 }