Change installer for install on full encrypted hard

[samisecure]

hi all
I want change installer code. I want install pfsense on full encrypted hard by geom_eli. I can not find src code related to installer for do that.
any one can tell me how I can do that? bsdinstaller in FreeBSD is capable for this purpose, but pfsense installer don't have it. I must enable shell switch in partitioning page.

[jimp]

The installer code is in github with all the other code. Check in the tools repository.