mastodon/app/services/activitypub/fetch_remote_key_service.rb

77 lines
2.5 KiB
Ruby

# frozen_string_literal: true
class ActivityPub::FetchRemoteKeyService < BaseService
include JsonLdHelper
class Error < StandardError; end
# Returns actor that owns the key
def call(uri, id: true, prefetched_body: nil, suppress_errors: true)
raise Error, 'No key URI given' if uri.blank?
if prefetched_body.nil?
if id
@json = fetch_resource_without_id_validation(uri)
if actor_type?
@json = fetch_resource(@json['id'], true)
elsif uri != @json['id']
raise Error, "Fetched URI #{uri} has wrong id #{@json['id']}"
end
else
@json = fetch_resource(uri, id)
end
else
@json = body_to_json(prefetched_body, compare_id: id ? uri : nil)
end
raise Error, "Unable to fetch key JSON at #{uri}" if @json.nil?
raise Error, "Unsupported JSON-LD context for document #{uri}" unless supported_context?(@json)
raise Error, "Unexpected object type for key #{uri}" unless expected_type?
return find_actor(@json['id'], @json, suppress_errors) if actor_type?
@owner = fetch_resource(owner_uri, true)
raise Error, "Unable to fetch actor JSON #{owner_uri}" if @owner.nil?
raise Error, "Unsupported JSON-LD context for document #{owner_uri}" unless supported_context?(@owner)
raise Error, "Unexpected object type for actor #{owner_uri} (expected any of: #{SUPPORTED_TYPES})" unless expected_owner_type?
raise Error, "publicKey id for #{owner_uri} does not correspond to #{@json['id']}" unless confirmed_owner?
find_actor(owner_uri, @owner, suppress_errors)
rescue Error => e
Rails.logger.debug "Fetching key #{uri} failed: #{e.message}"
raise unless suppress_errors
end
private
def find_actor(uri, prefetched_body, suppress_errors)
actor = ActivityPub::TagManager.instance.uri_to_actor(uri)
actor ||= ActivityPub::FetchRemoteActorService.new.call(uri, prefetched_body: prefetched_body, suppress_errors: suppress_errors)
actor
end
def expected_type?
actor_type? || public_key?
end
def actor_type?
equals_or_includes_any?(@json['type'], ActivityPub::FetchRemoteActorService::SUPPORTED_TYPES)
end
def public_key?
@json['publicKeyPem'].present? && @json['owner'].present?
end
def owner_uri
@owner_uri ||= value_or_id(@json['owner'])
end
def expected_owner_type?
equals_or_includes_any?(@owner['type'], ActivityPub::FetchRemoteActorService::SUPPORTED_TYPES)
end
def confirmed_owner?
value_or_id(@owner['publicKey']) == @json['id']
end
end