php code works with this url but the rubyCAS-Client gem's `validate_service_ticket()' seems to call an SSL Validation on this url which returns an error message.

'OpenSSL::SSL::SSLError in CassersController#index' ||'SSL_connect returned=1 errno=0 state=SSLv3 read server certificate B: certificate verify failed'  

require 'casclient'
require 'casclient/frameworks/rails/filter'
CASClient::Frameworks::Rails::Filter.configure(
   :cas_base_url => "https://auth.foo.com",
   :validate_url => "https://auth.foo.com/serviceValidate"
   )  

class CassersController < ApplicationController
  require 'casclient'
  require 'casclient/frameworks/rails/filter'
  before_filter CASClient::Frameworks::Rails::Filter    
  def index
    @username = session[:cas_user]
  end
end

Possibly just another requirement I need to make or a config file that needs changed, but any help about this error would be appreciated.