1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
|
# frozen_string_literal: true
class ResolveAccountService < BaseService
include JsonLdHelper
include DomainControlHelper
include WebfingerHelper
include Redisable
# 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
# @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, Oj::ParseError => e
Rails.logger.debug "Webfinger query for #{@uri} failed: #{e}"
nil
end
private
def process_options!(uri, options)
@options = 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, "The URI #{uri} tries to hijack #{@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?
RedisLock.acquire(lock_options) do |lock|
if lock.acquired?
@account = ActivityPub::FetchRemoteAccountService.new.call(actor_url)
else
raise Mastodon::RaceConditionError
end
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
def lock_options
{ redis: redis, key: "resolve:#{@username}@#{@domain}", autorelease: 15.minutes.seconds }
end
end
|
