Merge branch 'fix/2473-purge-expired-activities-duplicates' into 'develop'
[akkoma] / lib / pleroma / web / web_finger.ex
1 # Pleroma: A lightweight social networking server
2 # Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
3 # SPDX-License-Identifier: AGPL-3.0-only
4
5 defmodule Pleroma.Web.WebFinger do
6 alias Pleroma.HTTP
7 alias Pleroma.User
8 alias Pleroma.Web
9 alias Pleroma.Web.Federator.Publisher
10 alias Pleroma.Web.XML
11 alias Pleroma.XmlBuilder
12 require Jason
13 require Logger
14
15 def host_meta do
16 base_url = Web.base_url()
17
18 {
19 :XRD,
20 %{xmlns: "http://docs.oasis-open.org/ns/xri/xrd-1.0"},
21 {
22 :Link,
23 %{
24 rel: "lrdd",
25 type: "application/xrd+xml",
26 template: "#{base_url}/.well-known/webfinger?resource={uri}"
27 }
28 }
29 }
30 |> XmlBuilder.to_doc()
31 end
32
33 def webfinger(resource, fmt) when fmt in ["XML", "JSON"] do
34 host = Pleroma.Web.Endpoint.host()
35 regex = ~r/(acct:)?(?<username>[a-z0-9A-Z_\.-]+)@#{host}/
36
37 with %{"username" => username} <- Regex.named_captures(regex, resource),
38 %User{} = user <- User.get_cached_by_nickname(username) do
39 {:ok, represent_user(user, fmt)}
40 else
41 _e ->
42 with %User{} = user <- User.get_cached_by_ap_id(resource) do
43 {:ok, represent_user(user, fmt)}
44 else
45 _e ->
46 {:error, "Couldn't find user"}
47 end
48 end
49 end
50
51 defp gather_links(%User{} = user) do
52 [
53 %{
54 "rel" => "http://webfinger.net/rel/profile-page",
55 "type" => "text/html",
56 "href" => user.ap_id
57 }
58 ] ++ Publisher.gather_webfinger_links(user)
59 end
60
61 defp gather_aliases(%User{} = user) do
62 [user.ap_id | user.also_known_as]
63 end
64
65 def represent_user(user, "JSON") do
66 {:ok, user} = User.ensure_keys_present(user)
67
68 %{
69 "subject" => "acct:#{user.nickname}@#{Pleroma.Web.Endpoint.host()}",
70 "aliases" => gather_aliases(user),
71 "links" => gather_links(user)
72 }
73 end
74
75 def represent_user(user, "XML") do
76 {:ok, user} = User.ensure_keys_present(user)
77
78 aliases =
79 user
80 |> gather_aliases()
81 |> Enum.map(&{:Alias, &1})
82
83 links =
84 gather_links(user)
85 |> Enum.map(fn link -> {:Link, link} end)
86
87 {
88 :XRD,
89 %{xmlns: "http://docs.oasis-open.org/ns/xri/xrd-1.0"},
90 [
91 {:Subject, "acct:#{user.nickname}@#{Pleroma.Web.Endpoint.host()}"}
92 ] ++ aliases ++ links
93 }
94 |> XmlBuilder.to_doc()
95 end
96
97 defp webfinger_from_xml(doc) do
98 subject = XML.string_from_xpath("//Subject", doc)
99
100 subscribe_address =
101 ~s{//Link[@rel="http://ostatus.org/schema/1.0/subscribe"]/@template}
102 |> XML.string_from_xpath(doc)
103
104 ap_id =
105 ~s{//Link[@rel="self" and @type="application/activity+json"]/@href}
106 |> XML.string_from_xpath(doc)
107
108 data = %{
109 "subject" => subject,
110 "subscribe_address" => subscribe_address,
111 "ap_id" => ap_id
112 }
113
114 {:ok, data}
115 end
116
117 defp webfinger_from_json(doc) do
118 data =
119 Enum.reduce(doc["links"], %{"subject" => doc["subject"]}, fn link, data ->
120 case {link["type"], link["rel"]} do
121 {"application/activity+json", "self"} ->
122 Map.put(data, "ap_id", link["href"])
123
124 {"application/ld+json; profile=\"https://www.w3.org/ns/activitystreams\"", "self"} ->
125 Map.put(data, "ap_id", link["href"])
126
127 {nil, "http://ostatus.org/schema/1.0/subscribe"} ->
128 Map.put(data, "subscribe_address", link["template"])
129
130 _ ->
131 Logger.debug("Unhandled type: #{inspect(link["type"])}")
132 data
133 end
134 end)
135
136 {:ok, data}
137 end
138
139 def get_template_from_xml(body) do
140 xpath = "//Link[@rel='lrdd']/@template"
141
142 with doc when doc != :error <- XML.parse_document(body),
143 template when template != nil <- XML.string_from_xpath(xpath, doc) do
144 {:ok, template}
145 end
146 end
147
148 def find_lrdd_template(domain) do
149 with {:ok, %{status: status, body: body}} when status in 200..299 <-
150 HTTP.get("http://#{domain}/.well-known/host-meta") do
151 get_template_from_xml(body)
152 else
153 _ ->
154 with {:ok, %{body: body, status: status}} when status in 200..299 <-
155 HTTP.get("https://#{domain}/.well-known/host-meta") do
156 get_template_from_xml(body)
157 else
158 e -> {:error, "Can't find LRDD template: #{inspect(e)}"}
159 end
160 end
161 end
162
163 defp get_address_from_domain(domain, encoded_account) when is_binary(domain) do
164 case find_lrdd_template(domain) do
165 {:ok, template} ->
166 String.replace(template, "{uri}", encoded_account)
167
168 _ ->
169 "https://#{domain}/.well-known/webfinger?resource=#{encoded_account}"
170 end
171 end
172
173 defp get_address_from_domain(_, _), do: nil
174
175 @spec finger(String.t()) :: {:ok, map()} | {:error, any()}
176 def finger(account) do
177 account = String.trim_leading(account, "@")
178
179 domain =
180 with [_name, domain] <- String.split(account, "@") do
181 domain
182 else
183 _e ->
184 URI.parse(account).host
185 end
186
187 encoded_account = URI.encode("acct:#{account}")
188
189 with address when is_binary(address) <- get_address_from_domain(domain, encoded_account),
190 response <-
191 HTTP.get(
192 address,
193 [{"accept", "application/xrd+xml,application/jrd+json"}]
194 ),
195 {:ok, %{status: status, body: body}} when status in 200..299 <- response do
196 doc = XML.parse_document(body)
197
198 if doc != :error do
199 webfinger_from_xml(doc)
200 else
201 with {:ok, doc} <- Jason.decode(body) do
202 webfinger_from_json(doc)
203 end
204 end
205 else
206 e ->
207 Logger.debug(fn -> "Couldn't finger #{account}" end)
208 Logger.debug(fn -> inspect(e) end)
209 {:error, e}
210 end
211 end
212 end