mastodon/app/services/activitypub/process_account_service.rb
ThibG f29918e707 [WiP] Whenever a remote keypair changes, unfollow them and re-subscribe to … (#4907)
* Whenever a remote keypair changes, unfollow them and re-subscribe to them

In Mastodon (it could be different for other OStatus or AP-enabled software),
a keypair change is indicative of whole user (or instance) data loss. In this
situation, the “new” user might be different, and almost certainly has an empty
followers list. In this case, Mastodon instances will disagree on follower
lists, leading to unreliable delivery and “shadow followers”, that is users
believed by a remote instance to be followers, without the affected user
knowing.

Drawbacks of this change are:
1. If an user legitimately changes public key for some reason without losing
   data (not possible in Mastodon at the moment), they will have their remote
   followers unsubscribed/re-subscribed needlessly.
2. Depending of the number of remote followers, this may generate quite some
   traffic.
3. If the user change is an attempt at usurpation, the remote followers will
   unknowingly follow the usurper. Note that this is *not* a change of
   behavior, Mastodon already behaves like that, although delivery might be
   unreliable, and the usurper would not have known the former user's
   followers.

* Rename ResubscribeWorker to RefollowWorker

* Process followers in batches
2017-09-12 23:10:40 +02:00

137 lines
3.8 KiB
Ruby

# frozen_string_literal: true
class ActivityPub::ProcessAccountService < BaseService
include JsonLdHelper
# Should be called with confirmed valid JSON
# and WebFinger-resolved username and domain
def call(username, domain, json)
return if json['inbox'].blank?
@json = json
@uri = @json['id']
@username = username
@domain = domain
@account = Account.find_by(uri: @uri)
@collections = {}
create_account if @account.nil?
upgrade_account if @account.ostatus?
old_public_key = @account.public_key
update_account
RefollowWorker.perform_async(@account.id) if old_public_key != @account.public_key
@account
rescue Oj::ParseError
nil
end
private
def create_account
@account = Account.new
@account.protocol = :activitypub
@account.username = @username
@account.domain = @domain
@account.uri = @uri
@account.suspended = true if auto_suspend?
@account.silenced = true if auto_silence?
@account.private_key = nil
@account.save!
end
def update_account
@account.last_webfingered_at = Time.now.utc
@account.protocol = :activitypub
@account.inbox_url = @json['inbox'] || ''
@account.outbox_url = @json['outbox'] || ''
@account.shared_inbox_url = (@json['endpoints'].is_a?(Hash) ? @json['endpoints']['sharedInbox'] : @json['sharedInbox']) || ''
@account.followers_url = @json['followers'] || ''
@account.url = url || @uri
@account.display_name = @json['name'] || ''
@account.note = @json['summary'] || ''
@account.avatar_remote_url = image_url('icon') unless skip_download?
@account.header_remote_url = image_url('image') unless skip_download?
@account.public_key = public_key || ''
@account.locked = @json['manuallyApprovesFollowers'] || false
@account.statuses_count = outbox_total_items if outbox_total_items.present?
@account.following_count = following_total_items if following_total_items.present?
@account.followers_count = followers_total_items if followers_total_items.present?
@account.save_with_optional_media!
end
def upgrade_account
ActivityPub::PostUpgradeWorker.perform_async(@account.domain)
end
def image_url(key)
value = first_of_value(@json[key])
return if value.nil?
return value['url'] if value.is_a?(Hash)
image = fetch_resource(value)
image['url'] if image
end
def public_key
value = first_of_value(@json['publicKey'])
return if value.nil?
return value['publicKeyPem'] if value.is_a?(Hash)
key = fetch_resource(value)
key['publicKeyPem'] if key
end
def url
return if @json['url'].blank?
value = first_of_value(@json['url'])
return value if value.is_a?(String)
value['href']
end
def outbox_total_items
collection_total_items('outbox')
end
def following_total_items
collection_total_items('following')
end
def followers_total_items
collection_total_items('followers')
end
def collection_total_items(type)
return if @json[type].blank?
return @collections[type] if @collections.key?(type)
collection = fetch_resource(@json[type])
@collections[type] = collection.is_a?(Hash) && collection['totalItems'].present? && collection['totalItems'].is_a?(Numeric) ? collection['totalItems'] : nil
rescue HTTP::Error, OpenSSL::SSL::SSLError
@collections[type] = nil
end
def skip_download?
@account.suspended? || domain_block&.reject_media?
end
def auto_suspend?
domain_block && domain_block.suspend?
end
def auto_silence?
domain_block && domain_block.silence?
end
def domain_block
return @domain_block if defined?(@domain_block)
@domain_block = DomainBlock.find_by(domain: @domain)
end
end