Add proof for a Wikimedia Unified Account

[jeblad]

Could be a simple blob with signature added to any page, given that a specific revision can be fetched, and that the user name is posted on that fetched revision. Any one of the sites can be used, but a separate fetch should be done to verify that the user has a unified entry. Otherwise the user is only valid on the given site. The value for "CentralAuth" gives the central identifier, the value for "local" gives the identifier for the local site. That is the "local" is the id for site the request hits, and "CentralAuth" is the id in common for all the unified accounts.

I am not sure how it si possible to verify if a specific wiki is within a wiki set. It is probably best to just use this as a prof for a specific wiki, and possibly for an unified account as such. Possibly call it a "Wikimedia Unified Account" or something similar.

There are other ways to do this, but this can be done in a non-cooperative fashion.

Example blob on a ordinary page https://no.wikipedia.org/w/api.php?action=query&prop=revisions&titles=Bruker:Jeblad/blob&rvprop=user|content
Example struct on a specific user https://no.wikipedia.org/w/api.php?action=query&list=users&ususers=Jeblad&usprop=centralids
API doc https://no.wikipedia.org/w/api.php
About unified login https://meta.wikimedia.org/wiki/Help:Unified_login
About CentralAuth https://www.mediawiki.org/wiki/Extension:CentralAuth