mastodon/app/services/resolve_account_service.rb
Claire 1145dbd327
Improve error reporting and logging when processing remote accounts (#15605)
* Add a more descriptive PrivateNetworkAddressError exception class

* Remove unnecessary exception class to rescue clause

* Remove unnecessary include to JsonLdHelper

* Give more neutral error message when too many webfinger redirects

* Remove unnecessary guard condition

* Rework how “ActivityPub::FetchRemoteAccountService” handles errors

Add “suppress_errors” keyword argument to avoid raising errors in
ActivityPub::FetchRemoteAccountService#call (default/previous behavior).

* Rework how “ActivityPub::FetchRemoteKeyService” handles errors

Add “suppress_errors” keyword argument to avoid raising errors in
ActivityPub::FetchRemoteKeyService#call (default/previous behavior).

* Fix Webfinger::RedirectError not being a subclass of Webfinger::Error

* Add suppress_errors option to ResolveAccountService

Defaults to true (to preserve previous behavior). If set to false,
errors will be raised instead of caught, allowing the caller to be
informed of what went wrong.

* Return more precise error when failing to fetch account signing AP payloads

* Add tests

* Fixes

* Refactor error handling a bit

* Fix various issues

* Add specific error when provided Digest is not 256 bits of base64-encoded data

* Please CodeClimate

* Improve webfinger error reporting
2022-09-20 23:30:26 +02:00

147 lines
4.5 KiB
Ruby

# frozen_string_literal: true
class ResolveAccountService < BaseService
include DomainControlHelper
include WebfingerHelper
include Redisable
include Lockable
# Find or create an account record for a remote user. When creating,
# look up the user's webfinger and fetch ActivityPub data
# @param [String, Account] uri URI in the username@domain format or account record
# @param [Hash] options
# @option options [Boolean] :redirected Do not follow further Webfinger redirects
# @option options [Boolean] :skip_webfinger Do not attempt any webfinger query or refreshing account data
# @option options [Boolean] :suppress_errors When failing, return nil instead of raising an error
# @return [Account]
def call(uri, options = {})
return if uri.blank?
process_options!(uri, options)
# First of all we want to check if we've got the account
# record with the URI already, and if so, we can exit early
return if domain_not_allowed?(@domain)
@account ||= Account.find_remote(@username, @domain)
return @account if @account&.local? || @domain.nil? || !webfinger_update_due?
# At this point we are in need of a Webfinger query, which may
# yield us a different username/domain through a redirect
process_webfinger!(@uri)
@domain = nil if TagManager.instance.local_domain?(@domain)
# Because the username/domain pair may be different than what
# we already checked, we need to check if we've already got
# the record with that URI, again
return if domain_not_allowed?(@domain)
@account ||= Account.find_remote(@username, @domain)
if gone_from_origin? && not_yet_deleted?
queue_deletion!
return
end
return @account if @account&.local? || gone_from_origin? || !webfinger_update_due?
# Now it is certain, it is definitely a remote account, and it
# either needs to be created, or updated from fresh data
fetch_account!
rescue Webfinger::Error => e
Rails.logger.debug "Webfinger query for #{@uri} failed: #{e}"
raise unless @options[:suppress_errors]
end
private
def process_options!(uri, options)
@options = { suppress_errors: true }.merge(options)
if uri.is_a?(Account)
@account = uri
@username = @account.username
@domain = @account.domain
else
@username, @domain = uri.strip.gsub(/\A@/, '').split('@')
end
@domain = begin
if TagManager.instance.local_domain?(@domain)
nil
else
TagManager.instance.normalize_domain(@domain)
end
end
@uri = [@username, @domain].compact.join('@')
end
def process_webfinger!(uri)
@webfinger = webfinger!("acct:#{uri}")
confirmed_username, confirmed_domain = split_acct(@webfinger.subject)
if confirmed_username.casecmp(@username).zero? && confirmed_domain.casecmp(@domain).zero?
@username = confirmed_username
@domain = confirmed_domain
return
end
# Account doesn't match, so it may have been redirected
@webfinger = webfinger!("acct:#{confirmed_username}@#{confirmed_domain}")
@username, @domain = split_acct(@webfinger.subject)
unless confirmed_username.casecmp(@username).zero? && confirmed_domain.casecmp(@domain).zero?
raise Webfinger::RedirectError, "Too many webfinger redirects for URI #{uri} (stopped at #{@username}@#{@domain})"
end
rescue Webfinger::GoneError
@gone = true
end
def split_acct(acct)
acct.gsub(/\Aacct:/, '').split('@')
end
def fetch_account!
return unless activitypub_ready?
with_lock("resolve:#{@username}@#{@domain}") do
@account = ActivityPub::FetchRemoteAccountService.new.call(actor_url, suppress_errors: @options[:suppress_errors])
end
@account
end
def webfinger_update_due?
return false if @options[:check_delivery_availability] && !DeliveryFailureTracker.available?(@domain)
return false if @options[:skip_webfinger]
@account.nil? || @account.possibly_stale?
end
def activitypub_ready?
['application/activity+json', 'application/ld+json; profile="https://www.w3.org/ns/activitystreams"'].include?(@webfinger.link('self', 'type'))
end
def actor_url
@actor_url ||= @webfinger.link('self', 'href')
end
def gone_from_origin?
@gone
end
def not_yet_deleted?
@account.present? && !@account.local?
end
def queue_deletion!
@account.suspend!(origin: :remote)
AccountDeletionWorker.perform_async(@account.id, { 'reserve_username' => false, 'skip_activitypub' => true })
end
end