user.rb

# For using LDAP authentication with All Our Ideas
# The strategy is to do the authenticate via LDAP, but still create a local user 
# so that the rest of site still has a proper user object to use.
#
# You'll need to add net-ldap to the Gemfile and run `bundle install`
#
# Add this to app/models/user.rb
  module Clearance::User::ClassMethods
    def authenticate(email, password)
      ldap = Net::LDAP.new(
        :host => 'hostname.of.ldap.server',
        :auth => { :method => :simple, :username => email, :password => password }
      )
      begin
        return nil unless ldap.bind
      rescue
        return nil
      end
      user = find_by_email(email)
      if !user
        o = [('a'..'z'),('A'..'Z'), (0..9)].map{|i| i.to_a}.flatten
        new_password = (0...50).map{ o[rand(o.length)] }.join
        user = User.new
        user.email = email
        user.password = new_password
        user.email_confirmed = true
        user.save
      end
      return user
    end
  end