Lithium OS Login

--[[
    Security Login using GravityScore's SHA-2 Encryption
    Security Login - by LegoStax
]]--
os.pullEvent = os.pullEventRaw
-- Load Login Image
bg = paintutils.loadImage(".programs/login_img")
paintutils.drawImage(bg, 1, 1)
-- Load Grav's SHA
os.loadAPI(".programs/sha")
-- check for user info
if fs.exists(".programs/user") then
    -- get table
    info = {
        cpass = nil;
        user = nil;
    }
    local file = fs.open(".programs/user", "r")
    info = textutils.unserialize(file.readAll())
    file.close()
end
-- Check Textboxes Function
function checkPass(user, msg)
    checkpass = sha.sha256(msg)
    if user == info.user and checkpass == info.cpass then
        shell.run("lithos")
    else
        paintutils.drawImage(bg, 1, 1)
    end
end
-- Main
term.setBackgroundColor(colors.lightGray)
while true do
    term.setCursorPos(14,12)
    write ""
    user = read()
    term.setCursorPos(14,17)
    write ""
    pass = read("*")
    checkPass(user, pass)
end