Form replay

Presentation

Form replay allows you to open a session on a protected application by filling a HTML POST login form and autosubmitting it, without asking anything to the user.

This kind of SSO mechanism is not clean, and can lead to problems, like local password blocking, local session not well closed, etc.

Please always try to find another solution to protect your application with LL::NG. At least, check if it is not a known application, or try to adapt its source code.

If you configure form replay with LL::NG, the Handler will detect forms to fill, add a javascript in the html page to fill form fields with dummy datas and submit it, then intercept the POST request and add POST data in the request body.

POST data can be static values or computed from user's session.

To post user's password, you must enable password storing. In this case you will be able to use $_password to fill any password POST field.

Configuration

You should grab some information:

  • URI of the html page which contains the form
  • URI the html form is sent to
  • Does the html page load jQuery ? If not, grab a jQuery URL reachable by user (any version over jQuery 1.0 is suitable)
  • are there several html forms in the page ? If so, get a jQuery selector for the form you want to post
  • is user required to click on a button, for example in order to perform some script ? If so, get a jQuery selector for that button
  • names and values of the fields you want to control

If you don't know jQuery selector, just be aware that they are similar to css selectors: for example, button#foo points to the html button whose id is “foo”, and .bar points to all html elements of css class “bar”.

For example:

  • Form page URI: /login.php
  • Target URI: /process.php (if you let this parameter empty, target URI is supposed to be the same as form page URI)
  • jQuery URL: http://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js (if you let this parameter empty, jQuery is supposed to be already loaded; you can also set default to point to jQuery URL of LL::NG portal)
  • jQuery form selector: #loginForm (if you let this parameter empty, browser will fill and submit any html form)
  • jQuery button selector: button.validate (if you let this parameter empty, the form will be submitted but no button will be clicked; if you set it to “none”, no button will be clicked and the form will be filled but not submitted)
  • Fields:
    • postuid: $uid
    • postmail: $mail
    • poststatic: 'static'

Go in Manager, “Virtual Hosts” » virtualhost » “Form replay” and click on “New form replay”.

Fill values here:

  • Form URL: /login.php
  • Target URL: /process.php
  • jQuery URL: http://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js
  • jQuery form selector: #loginForm
  • jQuery button selector: button.validate

Then click on New variable and add all data with their values, for example:

You can define more than one form replay URL per virtual host.