keep sessions while switching domains

Hello,

Our rails app has several domains. We are now implementing a single https connection https://secure.domain.xx. All other domains need to switch to that new secure domain in certain circumstances. We only have one ssl cert and it is not possible to create and use a ssl cert for all domains!

Now when switching domains we loose the session, that was previously used and I was not able to restore my old session. I was trying to send the old session id via the url and then reuse it by setting it again like this:

redirect_to :host => '127.0.0.1:3000' , :session_key => request.cookies['_xxx_session_id'][0] unless (request.env['HTTP_HOST'] == '127.0.0.1:3000')

cookies[:_xxx_session_id] = params[:session_key]

This failed since rails seems to regenerate a new session id somehow at a later stage. The new session cookie will have this newly generated id.

How can I tell Rails to use my session id ? Has anybody an idea on how to do this? I must get the old session transferred to the new domain in order to access the session data.

Many thanks in advance for any help on this. migo