如何在Laravel 4中使用SHA1加密而不是BCrypt？

I'm developing a so called AAC (Automatic Account Creator) for a game, it's basically a site with functions to create accounts, players and several more things for players. The server only supports SHA1 and plain - which is totally unsafe. I can't dive into the source code and make changes. If there's anyway to use SHA1 I would be grateful. I just read about BCrypt, it's great but I can't really change the source code to suit BCrypt. I managed to put SHA1 on registration like this:I'm developing a so called AAC (Automatic Accou