Identifying NotificationReceiver

[csarven]

Action of https://github.com/solid/notifications-panel/blob/main/meetings/2023-02-02.md#add-ldn-channel-2023-ed .

In https://solid.github.io/notifications/protocol , it is possible to indicate a NotificationServer with the notify:sender property.

The proposal is to introduce the notify:receiver property to indicate a NotificationReceiver.

#147 proposes to add vocab and JSON-LD context with:

#http://www/w3.org/ns/solid/notifications
notify:receiver
    a rdf:Property ;
    rdfs:label "receiver"@en ;
    rdfs:comment "The property used to identify the party that receives notifications."@en ;
    rdfs:isDefinedBy <http://www.w3.org/ns/solid/notifications#> ;
    vs:term_status "testing" .

#https://www.w3.org/ns/solid/notification/v1
    "receiver": {
      "@id": "notify:receiver",
      "@type": "@id" },

[elf-pavlik]

As discussed during the last meeting for cases where the subscription was made by a malicious party, intending to spam the receiver, we can't trust any information in the subscription request. The sendTo channel receiver could be discoverable by following one's nose from the sendTo URI. This could also be used to verify if the Subscription Client was authorized by the receiver to create a subscription on their behalf in the first place.