The Dutch government uses several login methods: SMS verification, Username and password, Identity card reader and a specific application: DigiD app, which is presented as the easiest way to log in securely. This is because users no longer have to remember a complicated password, but only a device PIN code of their choice.

DigiD app users can arrange everything for their digital ID, such as changing their e-mail address or the language setting. The app can be used on up to 5 different devices.

The DigiD source code has been disclosed on GitHub in response to a request under the Dutch Open Government Act ("Wet open Overheid"). The Act is in force as from 01-08-2022 and states (Art 1.1 access right) that anyone has the right to have access to information created/owned by Public sector, without needing to justify some legitimate interest, except if specific restrictions are fixed in the Act.

This Act is an implementation of the PSI Directive (initially 2003/98/EC, re-casted Directive (EU) 2019/1024), knowing that if the Directive states that the definition of ‘document’ is not intended to cover computer programmes, Member States may extend the application of the Directive to computer programmes or omit to create an exception for such programmes.

As reported by forum comments, such publication was primarily driven by the need for transparency imposed by Law, meaning that re-use and maintaining a downloadable application for third parties was not the first government priority. However, re-use is permitted as the Dutch government has made the publication under the EUPL licence, with the exception of source files that may contain a different license.”

It appears that some source code fragments remain secret because, for example, they can pose a security risk. These fragments have been replaced by the letter S, for security. Other fragments from which developers' personal data can be traced have been replaced by the letter P, for privacy.

For more information:

https://www.digid.nl/en

https://tweakers.net/nieuws/205640/ministerie-maakt-broncode-van-digid-app-open-source.html

https://github.com/MinBZK/woo-besluit-broncode-digid-app