mastodon/app/services/fetch_remote_account_service.rb
ThibG d19ed18388 Get handle from atom feed's author/email field instead of guessing from URL (#1344)
The goal of this change is to enhance Mastodon's handling of remote domains
for which the APIs reside on a different host (see issue #1032).

Indeed, when a remote user unknown to Mastodon is mentionned, only its profile
URL (e.g. https://social.example.org/users/User) is known, and Mastodon has to
build a @username@domain handle for it. To do so, Mastodon fetches the user's
atom feed (e.g., https://social.example.org/users/User.atom) and uses its
content to get the username part of the handle, and the URL's host part to
build the domain (e.g., @User@social.example.org). This handle is then used
for a Webfinger request.

In the case where example.org serves the Webfinger info for @User@example.org
and all feeds and APIs are hosted at social.example.org, Mastodon will still
build @User@social.example.org and fail at resolving the account's details
through Webfinger.

This patch changes this behaviour by using the author's email address from
the atom feed to build the handle. In Mastodon-generated atom feeds, the
email address is always the handle it expects for federation.
2017-04-09 18:43:48 +02:00

45 lines
1.2 KiB
Ruby

# frozen_string_literal: true
class FetchRemoteAccountService < BaseService
def call(url, prefetched_body = nil)
if prefetched_body.nil?
atom_url, body = FetchAtomService.new.call(url)
else
atom_url = url
body = prefetched_body
end
return nil if atom_url.nil?
process_atom(atom_url, body)
end
private
def process_atom(url, body)
xml = Nokogiri::XML(body)
xml.encoding = 'utf-8'
email = xml.at_xpath('//xmlns:author/xmlns:email').try(:content)
if email.nil?
url_parts = Addressable::URI.parse(url)
username = xml.at_xpath('//xmlns:author/xmlns:name').try(:content)
domain = url_parts.host
else
username, domain = email.split('@')
end
return nil if username.nil? || domain.nil?
Rails.logger.debug "Going to webfinger #{username}@#{domain}"
account = FollowRemoteAccountService.new.call("#{username}@#{domain}")
UpdateRemoteProfileService.new.call(xml, account) unless account.nil?
account
rescue TypeError
Rails.logger.debug "Unparseable URL given: #{url}"
nil
rescue Nokogiri::XML::XPath::SyntaxError
Rails.logger.debug 'Invalid XML or missing namespace'
nil
end
end