Lighttpd

I have a requirement to assign a cookie for authentication AuthCookie(). I would like to protect a normal static page directory with this method. I was thinking about modifying mod_auth to support a new "cookie" method or I could create a new plugin.

the cookie method would create a cookie that has the form cookie_name=hex(hash[0:31])DATA
where hash is md5/sha256(secret+DATA)
if valid store DATA in an environ variable

How do you store a variable into the environment?

(auth/cookie).require = ( "/directory" =>
..(
...."method" => "cookie",
...."realm" => "download archiv",
...."require" => "valid-user" # valid cookie
...."secret" => "secret"
...."name" => "cookie_name"
..)
)

This is the last thing I need to get working before I can switch from apache to lighttpd.