TL;DR:

Sell registrations / roles in Drupal through digistore24 products.

Provides a separate Drupal user registration page (e.g. "user/register-digistore24" (editable)) which acts as thank you page for digistore24 sales and allows to set roles for valid registrations.

Functionality:

Provides a separate registration page with individual URL (defaults to "user/register-digistore24") based on the default registration form elements
Allows to set thank you page key via form (admin/config/people/registration-digistore-typ). Validates each submission using this page key. Prevents registration if validation fails and hides the form with an error message.
Allows to set role(s) for successfully registered digistore users automatically (admin/config/people/registration-digistore-typ)
Stores the digistore24 order ID in a custom user profile field (text) and on form submit validates the order id to be unique, otherwise prevents registration
Validates & decodes the encoded GET parameters (See https://docs.digistore24.com/knowledge-base/about-the-thank-you-page-key...)
Does NOT care for ending subscription, recurring, etc. - just handles registration. Feel free to add patches or submodules to extend the functionality.

Dependencies

No contrib module dependencies

Installation

Download and install the module
Create a text field (varchar 255, for example called "digistore24_order_id") as user profile field (admin/config/people/accounts/fields). Optionally you may want to use Field Permissions to hide the field entirely or only the edit display for users.
Set the required module settings at admin/config/people/registration-digistore-typ and compare them to your digistore settings.
Create a product at digistore24 and set the form url as "Thank you page" and "Second Thank you page"

Hooks

See registration_digistore_typ.api.php

Development proudly sponsored by German Drupal Friends & Companies:

webks: websolutions kept simple (https://www.webks.de)
and
DROWL: Drupalbasierte Lösungen aus Ostwestfalen-Lippe (https://www.drowl.de)

Registration Digistore Thank You Page [D7]

Issues