CFML Sessions for Dummies

A introduction to CFML sessions (with a bit of J2EE sessions sprinkled in).

Transcript

1. CFML Sessions for Dummies Eric Peterson
2. What this talk isn't ! · Live coding · Outlining best practices · For people who use sessions and either already know or don't care that much how they work
3. What this talk is ! · Theory — definitions and examples · Understanding the what and the why rather than the when would I use this · For people who use sessions and don't know how they work
4. Other Sessions Right Now · PostCSS: A Dumb Name For An Awesome Thing Room 238 · SQL Server Tips For Everyday Programmers Room 334 · Crash Course In Ionic & AngularJS Auditorium
5. Who am I? Eric Peterson ! Utah " O.C. Tanner # 1 wife, 1 kid
6. What is a session?
7. Disclaimer: Out of the box setup (Other setups later)
8. What is a session? · Data stored in memory on the server · Client variables used to access the data on the server
9. Data stored in memory on the server
10. Data stored in memory on the server · Data is lost when not accessed within a time-out period · Data is available only to a single client and application · Any CFML data type can be stored
11. Data stored in memory on the server Data is accessed by using a combination of a CFID and a CFTOKEN · CFID: A sequential client identifier · CFTOKEN: A random client security token
12. What do you get in the session scope by default?
13. And any data you add yourself! session.simpleValue = 5; session.complexValue = [ { id = 1, permissions = [/* ... */] } ]; session.user = new User(/* ... */);
14. Other Facts · CFID and CFTOKEN are reused by the client when starting new sessions (if possible) · Someone with your CFID and CFTOKEN could access your session · For this, reason it's bad to pass it in the query string. Use Client Variables instead
15. Client variables used to access the data on the server
16. Client Variables = Cookies
17. Default Cookies stored when using Sessions
18. Client variables used to access the data on the server If you didn't use cookies, you'd have to pass these values in the url or form every time Which makes them very easy to steal and hijack a session
19. So don't do that! !
20. Enabling Sessions in your CFML Applications
21. Enabling Sessions in your CFML Applications component { // Required this.name = 'MyAwesomeApp'; this.sessionManagement = true; // Optional: default timeout is 20 minutes this.sessionTimeout = createTimeSpan(0, 0, 45, 0); }
22. Session Lifecycle
23. What starts a session?
24. A user coming to your website
25. During a Session
26. Reading and Writing to the Session // write values to the session session.favorites = [1, 45, 67, 109]; // read values from the session local.favorites = session.favorites; // though, it is smart to check that // the value exists first. if (structKeyExists(session, 'favorites')) { local.favorites = session.favorites; } else { local.favorites = []; }
27. Session Locks
28. Session Locks function getProductCount() { lock scope="session" type="read" timeout="2" throwontimeout="true" { return session.items; } } function incrementProductCount(count) { lock scope="session" type="exclusive" timeout="2" throwontimeout="true" { session.items += count; } }
29. When do you use session locks? Race Conditions
30. SessionRotate() Available in ACF10+ and Lucee 4.5+ 1. Invalidates the current session 2. Creates a new session 3. Migrates the data from the old to the new 4. Overwrites the old cookies with the new
31. "Best Practices" · Keep your session scope small · Only store lookup values in your session scope (like userId) · Especially avoid storing values shared between users in the session scope · SessionRotate() a!er a successful login1 1 See Learn CF in a Week for more session security tips
32. Ending a Session
33. What does not end a session? · Logging out · Closing the browser · structClear(session)
34. What does end a session? · Session Timeout · sessionInvalidate() (ACF10+ and Lucee 4.5+)
35. Session Lifecycle Methods function onSessionStart() { // set defaults for session values // you want to make sure are available session.sessionStartedAt = Now(); } function onSessionEnd(applicationScope, sessionScope) { if (sessionScope.isShopping) { // clean up any long standing objects // Log any important messages applicationScope.shoppingInsightLogger.info( 'User timed out while shopping at #Now()#' ); } }
36. J2EE Sessions
37. J2EE Sessions · Uses the servlet (e.g. Tomcat) for session management · Share session information between ColdFusion and other servlet applications
38. J2EE Sessions · Does not reuse the session identifiers · Generates a new identifier for each session, reducing the impact of the the! of the token · Can terminate the session manually getPageContext().getSession().invalidate();
39. ColdFusion Sessions vs. J2EE Sessions Which should you use?
40. Storing your session data elsewhere (Not in memory on the server)
41. First off, Why?
42. Server Clusters
43. Server Clusters If your session information is being stored in the memory of a server, then only that one server can handle all your requests. In other words, you can't scale.
44. What are our options? · Don't use the session scope ! · Store the session scope somewhere else "
45. The Hard Way: Manual Session Management
46. Do it yourself ! function onRequestStart() { var urlToken = 'CFID=' & cookie.cfid & '&CFTOKEN=' & cookie.cftoken; var sessionClient = new cfcouchbase.CouchbaseClient({ bucketName = 'sessions' }); StructAppend( session, sessionClient.get(id = urlToken, deserialize = true), true ); } function onRequestEnd() { var urlToken = 'CFID=' & cookie.cfid & '&CFTOKEN=' & cookie.cftoken; var sessionClient = new cfcouchbase.CouchbaseClient({ bucketName = 'sessions' }); sessionClient.set(id = urlToken, session ); }
47. One Easy Way: Session Storages (Requires ColdFusion 2016+ or Lucee 4.5+)
48. Done
49. Another Easy Way: J2EE Sessions Sticky sessions at the servlet level
50. Done
51. Extras
52. First, Session Fixation An attacker provides the session identifiers in order to try and know them <a href="http://a-legitimate-site.com/?CFID=b1c8-30f3469ba7f7&CFTOKEN=2"> Click here for free stuff! </a>
53. How this can cause Session Loss More than one CFML application on the same domain2 2 Pete Freitag, Session Loss and Session Fixation in ColdFusion, March 01, 2013
54. HTTPOnly Cookies · These cookies are only available over HTTP connections, NOT Javascript
55. HTTPOnly Cookies Set once for the entire application // CF 10+ & Lucee 4.5+ this.sessioncookie.httponly = true; # Java JVM args (CF 9.0.1+) -Dcoldfusion.sessioncookie.httponly=true
56. HTTPOnly Cookies OR set them manually <!-- CF 9+ & Lucee 4.5+ --> <cfcookie name="CFID" value="#sessoin.cfid#" httponly="true" /> <!-- CF 8 and lower --> <cfheader name="Set-Cookie" value="CFID=#session.cfid#;path=/;HTTPOnly" />
57. SSL Enable the secure flag on your cookies // CF 10+ & Lucee 4.5+ this.sessioncookie.secure = true; <!-- CF 9+ & Lucee 4.5+ --> <cfcookie name="CFID" value="#sessoin.cfid#" httponly="true" secure="true" /> <!-- CF 8 and lower --> <cfheader name="Set-Cookie" value="CFID=#session.cfid#;path=/;HTTPOnly;secure" />
58. Turning off client management If you are setting your own cookies, remember to turn off client management // Application.cfc component { this.clientmanagement = false; }
59. Questions !
60. Other talks at dev.Objective() Live Testing a Legacy App Thursday 1:45 PM to 2:45 PM
61. Thank You!! elpete @_elpete ! dev.elpete.com