REST Second Factor

This plugin can be used to append a second factor authentication device like SMS or OTP. It uses an external web service to submit and validate the second factor.


All parameters are set in “General Parameters » Portal Parameters » Second Factors » REST 2nd Factor”.

  • Activation
  • Code regex: regular expression to create an OTP code. If this option is set, LemonLDAP::NG will generate the code and send it through the Init URL, then verify it internally.
  • Init URL (optional): REST URL to initialize dialog (send OTP). Leave it blank if your API doesn’t need any initialization
  • Init arguments: list of arguments to send (see below)
  • Verify URL (required): REST URL to verify code
  • Verify arguments: list of arguments to send (see below)
  • Re-send interval: Set this to a non-empty value to allow the user to re-send the code in case a transmission error occured. The value sets how many seconds the user has to wait before each attempt
  • Authentication level (Optional): if you want to overwrite the value sent by your authentication module, you can define here the new authentication level. Example: 5
  • Label (Optional): label that should be displayed to the user on the choice screen
  • Logo (Optional): logo file (in static/<skin> directory)


Arguments are a list of key/value. Key is the name of JSON entry, value is attribute or macro name.

REST Dialog

REST web services have just to reply with a “result” key in a JSON file. Auth/UserDB can add an “info” array. It will be stored in session data (without reading “Exported variables”).

If Code regex is set

URL Query Response
Init URL JSON body: {"user":$user,"code":"$code",...} JSON body: {"result":true/false}

The Verify URL is not called, since the code is checked against the internally saved value

If Code regex is not set

URL Query Response
Init URL JSON body: {"user":$user,...} JSON body: {"result":true/false}
Verify URL JSON body: {"user":$user,"code":"$code",...} JSON body: {"result":true/false}