mastodon/app/services/activitypub/verify_quote_service.rb

112 lines
3.8 KiB
Ruby

# frozen_string_literal: true
class ActivityPub::VerifyQuoteService < BaseService
include JsonLdHelper
# Optionally fetch quoted post, and verify the quote is authorized
def call(quote, fetchable_quoted_uri: nil, prefetched_body: nil, request_id: nil)
@request_id = request_id
@quote = quote
@fetching_error = nil
fetch_quoted_post_if_needed!(fetchable_quoted_uri)
return if fast_track_approval! || quote.approval_uri.blank?
@json = fetch_approval_object(quote.approval_uri, prefetched_body:)
return quote.reject! if @json.nil?
return if non_matching_uri_hosts?(quote.approval_uri, value_or_id(@json['attributedTo']))
return unless matching_type? && matching_quote_uri?
# Opportunistically import embedded posts if needed
return if import_quoted_post_if_needed!(fetchable_quoted_uri) && fast_track_approval!
# Raise an error if we failed to fetch the status
raise @fetching_error if @quote.status.nil? && @fetching_error
return unless matching_quoted_post? && matching_quoted_author?
quote.accept!
end
private
# FEP-044f defines rules that don't require the approval flow
def fast_track_approval!
return false if @quote.quoted_status_id.blank?
# Always allow someone to quote themselves
if @quote.account_id == @quote.quoted_account_id
@quote.accept!
true
end
# Always allow someone to quote posts in which they are mentioned
if @quote.quoted_status.active_mentions.exists?(mentions: { account_id: @quote.account_id })
@quote.accept!
true
else
false
end
end
def fetch_approval_object(uri, prefetched_body: nil)
if prefetched_body.nil?
fetch_resource(uri, true, @quote.account.followers.local.first, raise_on_error: :temporary)
else
body_to_json(prefetched_body, compare_id: uri)
end
end
def matching_type?
supported_context?(@json) && equals_or_includes?(@json['type'], 'QuoteAuthorization')
end
def matching_quote_uri?
ActivityPub::TagManager.instance.uri_for(@quote.status) == value_or_id(@json['interactingObject'])
end
def fetch_quoted_post_if_needed!(uri)
return if uri.nil? || @quote.quoted_status.present?
status = ActivityPub::TagManager.instance.uri_to_resource(uri, Status)
status ||= ActivityPub::FetchRemoteStatusService.new.call(uri, on_behalf_of: @quote.account.followers.local.first, request_id: @request_id)
@quote.update(quoted_status: status) if status.present?
rescue Mastodon::UnexpectedResponseError, *Mastodon::HTTP_CONNECTION_ERRORS => e
@fetching_error = e
end
def import_quoted_post_if_needed!(uri)
# No need to fetch if we already have a post
return if uri.nil? || @quote.quoted_status_id.present? || !@json['interactionTarget'].is_a?(Hash)
# NOTE: Replacing the object's context by that of the parent activity is
# not sound, but it's consistent with the rest of the codebase
object = @json['interactionTarget'].merge({ '@context' => @json['@context'] })
# It's not safe to fetch if the inlined object is cross-origin or doesn't match expectations
return if object['id'] != uri || non_matching_uri_hosts?(@quote.approval_uri, object['id'])
status = ActivityPub::FetchRemoteStatusService.new.call(object['id'], prefetched_body: object, on_behalf_of: @quote.account.followers.local.first, request_id: @request_id)
if status.present?
@quote.update(quoted_status: status)
true
else
false
end
end
def matching_quoted_post?
return false if @quote.quoted_status_id.blank?
ActivityPub::TagManager.instance.uri_for(@quote.quoted_status) == value_or_id(@json['interactionTarget'])
end
def matching_quoted_author?
ActivityPub::TagManager.instance.uri_for(@quote.quoted_account) == value_or_id(@json['attributedTo'])
end
end