class Rack::Session::Cookie
Rack::Session::Cookie provides simple cookie
based session management. By default, the session is a Ruby Hash stored as
base64 encoded marshalled data set to :key (default: rack.session). The
object that encodes the session data is configurable and must respond to
encode
and decode
. Both methods must take a
string and return a string.
When the secret key is set, cookie data is checked for data integrity. The old secret key is also accepted and allows graceful secret rotation.
Example:
use Rack::Session::Cookie, :key => 'rack.session', :domain => 'foo.com', :path => '/', :expire_after => 2592000, :secret => 'change_me', :old_secret => 'also_change_me' All parameters are optional.
Example of a cookie with no encoding:
Rack::Session::Cookie.new(application, { :coder => Rack::Session::Cookie::Identity.new })
Example of a cookie with custom encoding:
Rack::Session::Cookie.new(application, { :coder => Class.new { def encode(str); str.reverse; end def decode(str); str.reverse; end }.new })
Attributes
coder[R]
Public Class Methods
new(app, options={})
click to toggle source
Calls superclass method
Rack::Session::Abstract::ID.new
# File lib/rack/session/cookie.rb, line 105 def initialize(app, options={}) @secrets = options.values_at(:secret, :old_secret).compact warn " SECURITY WARNING: No secret option provided to Rack::Session::Cookie. This poses a security threat. It is strongly recommended that you provide a secret to prevent exploits that may be possible from crafted cookies. This will not be supported in future versions of Rack, and future versions will even invalidate your existing user cookies. Called from: #{caller[0]}. " unless @secrets.size >= 1 @coder = options[:coder] ||= Base64::Marshal.new super(app, options.merge!(:cookie_only => true)) end
Private Instance Methods
destroy_session(env, session_id, options)
click to toggle source
# File lib/rack/session/cookie.rb, line 170 def destroy_session(env, session_id, options) # Nothing to do here, data is in the client generate_sid unless options[:drop] end
digest_match?(data, digest)
click to toggle source
# File lib/rack/session/cookie.rb, line 175 def digest_match?(data, digest) return unless data && digest @secrets.any? do |secret| Rack::Utils.secure_compare(digest, generate_hmac(data, secret)) end end
extract_session_id(env)
click to toggle source
# File lib/rack/session/cookie.rb, line 128 def extract_session_id(env) unpacked_cookie_data(env)["session_id"] end
generate_hmac(data, secret)
click to toggle source
# File lib/rack/session/cookie.rb, line 182 def generate_hmac(data, secret) OpenSSL::HMAC.hexdigest(OpenSSL::Digest::SHA1.new, secret, data) end
get_session(env, sid)
click to toggle source
# File lib/rack/session/cookie.rb, line 122 def get_session(env, sid) data = unpacked_cookie_data(env) data = persistent_session_id!(data) [data["session_id"], data] end
persistent_session_id!(data, sid=nil)
click to toggle source
# File lib/rack/session/cookie.rb, line 148 def persistent_session_id!(data, sid=nil) data ||= {} data["session_id"] ||= sid || generate_sid data end
set_session(env, session_id, session, options)
click to toggle source
# File lib/rack/session/cookie.rb, line 154 def set_session(env, session_id, session, options) session = session.merge("session_id" => session_id) session_data = coder.encode(session) if @secrets.first session_data << "--#{generate_hmac(session_data, @secrets.first)}" end if session_data.size > (4096 - @key.size) env["rack.errors"].puts("Warning! Rack::Session::Cookie data size exceeds 4K.") nil else session_data end end