git.squeep.com Git - akkoma/blob - lib/pleroma/web/web_finger/web_finger.ex

   1 defmodule Pleroma.Web.WebFinger do
   2   @httpoison Application.get_env(:pleroma, :httpoison)
   3
   4   alias Pleroma.{User, XmlBuilder}
   5   alias Pleroma.Web
   6   alias Pleroma.Web.{XML, Salmon, OStatus}
   7   require Jason
   8   require Logger
   9
  10   def host_meta do
  11     base_url = Web.base_url()
  12
  13     {
  14       :XRD,
  15       %{xmlns: "http://docs.oasis-open.org/ns/xri/xrd-1.0"},
  16       {
  17         :Link,
  18         %{
  19           rel: "lrdd",
  20           type: "application/xrd+xml",
  21           template: "#{base_url}/.well-known/webfinger?resource={uri}"
  22         }
  23       }
  24     }
  25     |> XmlBuilder.to_doc()
  26   end
  27
  28   def webfinger(resource, "JSON") do
  29     host = Pleroma.Web.Endpoint.host()
  30     regex = ~r/(acct:)?(?<username>\w+)@#{host}/
  31
  32     with %{"username" => username} <- Regex.named_captures(regex, resource) do
  33       user = User.get_by_nickname(username)
  34       {:ok, represent_user(user, "JSON")}
  35     else
  36       _e ->
  37         with user when not is_nil(user) <- User.get_cached_by_ap_id(resource) do
  38           {:ok, represent_user(user, "JSON")}
  39         else
  40           _e ->
  41             {:error, "Couldn't find user"}
  42         end
  43     end
  44   end
  45
  46   def webfinger(resource, "XML") do
  47     host = Pleroma.Web.Endpoint.host()
  48     regex = ~r/(acct:)?(?<username>\w+)@#{host}/
  49
  50     with %{"username" => username} <- Regex.named_captures(regex, resource) do
  51       user = User.get_by_nickname(username)
  52       {:ok, represent_user(user, "XML")}
  53     else
  54       _e ->
  55         with user when not is_nil(user) <- User.get_cached_by_ap_id(resource) do
  56           {:ok, represent_user(user, "XML")}
  57         else
  58           _e ->
  59             {:error, "Couldn't find user"}
  60         end
  61     end
  62   end
  63
  64   def represent_user(user, "JSON") do
  65     {:ok, user} = ensure_keys_present(user)
  66     {:ok, _private, public} = Salmon.keys_from_pem(user.info["keys"])
  67     magic_key = Salmon.encode_key(public)
  68
  69     %{
  70       "subject" => "acct:#{user.nickname}@#{Pleroma.Web.Endpoint.host()}",
  71       "aliases" => [user.ap_id],
  72       "links" => [
  73         %{
  74           "rel" => "http://schemas.google.com/g/2010#updates-from",
  75           "type" => "application/atom+xml",
  76           "href" => OStatus.feed_path(user)
  77         },
  78         %{
  79           "rel" => "http://webfinger.net/rel/profile-page",
  80           "type" => "text/html",
  81           "href" => user.ap_id
  82         },
  83         %{"rel" => "salmon", "href" => OStatus.salmon_path(user)},
  84         %{
  85           "rel" => "magic-public-key",
  86           "href" => "data:application/magic-public-key,#{magic_key}"
  87         },
  88         %{"rel" => "self", "type" => "application/activity+json", "href" => user.ap_id},
  89         %{
  90           "rel" => "http://ostatus.org/schema/1.0/subscribe",
  91           "template" => OStatus.remote_follow_path()
  92         }
  93       ]
  94     }
  95   end
  96
  97   def represent_user(user, "XML") do
  98     {:ok, user} = ensure_keys_present(user)
  99     {:ok, _private, public} = Salmon.keys_from_pem(user.info["keys"])
 100     magic_key = Salmon.encode_key(public)
 101
 102     {
 103       :XRD,
 104       %{xmlns: "http://docs.oasis-open.org/ns/xri/xrd-1.0"},
 105       [
 106         {:Subject, "acct:#{user.nickname}@#{Pleroma.Web.Endpoint.host()}"},
 107         {:Alias, user.ap_id},
 108         {:Link,
 109          %{
 110            rel: "http://schemas.google.com/g/2010#updates-from",
 111            type: "application/atom+xml",
 112            href: OStatus.feed_path(user)
 113          }},
 114         {:Link,
 115          %{rel: "http://webfinger.net/rel/profile-page", type: "text/html", href: user.ap_id}},
 116         {:Link, %{rel: "salmon", href: OStatus.salmon_path(user)}},
 117         {:Link,
 118          %{rel: "magic-public-key", href: "data:application/magic-public-key,#{magic_key}"}},
 119         {:Link, %{rel: "self", type: "application/activity+json", href: user.ap_id}},
 120         {:Link,
 121          %{rel: "http://ostatus.org/schema/1.0/subscribe", template: OStatus.remote_follow_path()}}
 122       ]
 123     }
 124     |> XmlBuilder.to_doc()
 125   end
 126
 127   # This seems a better fit in Salmon
 128   def ensure_keys_present(user) do
 129     info = user.info || %{}
 130
 131     if info["keys"] do
 132       {:ok, user}
 133     else
 134       {:ok, pem} = Salmon.generate_rsa_pem()
 135       info = Map.put(info, "keys", pem)
 136
 137       Ecto.Changeset.change(user, info: info)
 138       |> User.update_and_set_cache()
 139     end
 140   end
 141
 142   defp webfinger_from_xml(doc) do
 143     magic_key = XML.string_from_xpath(~s{//Link[@rel="magic-public-key"]/@href}, doc)
 144     "data:application/magic-public-key," <> magic_key = magic_key
 145
 146     topic =
 147       XML.string_from_xpath(
 148         ~s{//Link[@rel="http://schemas.google.com/g/2010#updates-from"]/@href},
 149         doc
 150       )
 151
 152     subject = XML.string_from_xpath("//Subject", doc)
 153     salmon = XML.string_from_xpath(~s{//Link[@rel="salmon"]/@href}, doc)
 154
 155     subscribe_address =
 156       XML.string_from_xpath(
 157         ~s{//Link[@rel="http://ostatus.org/schema/1.0/subscribe"]/@template},
 158         doc
 159       )
 160
 161     ap_id =
 162       XML.string_from_xpath(
 163         ~s{//Link[@rel="self" and @type="application/activity+json"]/@href},
 164         doc
 165       )
 166
 167     data = %{
 168       "magic_key" => magic_key,
 169       "topic" => topic,
 170       "subject" => subject,
 171       "salmon" => salmon,
 172       "subscribe_address" => subscribe_address,
 173       "ap_id" => ap_id
 174     }
 175
 176     {:ok, data}
 177   end
 178
 179   defp webfinger_from_json(doc) do
 180     data =
 181       Enum.reduce(doc["links"], %{"subject" => doc["subject"]}, fn link, data ->
 182         case {link["type"], link["rel"]} do
 183           {"application/activity+json", "self"} ->
 184             Map.put(data, "ap_id", link["href"])
 185
 186           {_, "magic-public-key"} ->
 187             "data:application/magic-public-key," <> magic_key = link["href"]
 188             Map.put(data, "magic_key", magic_key)
 189
 190           {"application/atom+xml", "http://schemas.google.com/g/2010#updates-from"} ->
 191             Map.put(data, "topic", link["href"])
 192
 193           {_, "salmon"} ->
 194             Map.put(data, "salmon", link["href"])
 195
 196           {_, "http://ostatus.org/schema/1.0/subscribe"} ->
 197             Map.put(data, "subscribe_address", link["template"])
 198
 199           _ ->
 200             Logger.debug("Unhandled type: #{inspect(link["type"])}")
 201             data
 202         end
 203       end)
 204
 205     {:ok, data}
 206   end
 207
 208   def get_template_from_xml(body) do
 209     xpath = "//Link[@rel='lrdd' and @type='application/xrd+xml']/@template"
 210
 211     with doc when doc != :error <- XML.parse_document(body),
 212          template when template != nil <- XML.string_from_xpath(xpath, doc) do
 213       {:ok, template}
 214     end
 215   end
 216
 217   def find_lrdd_template(domain) do
 218     with {:ok, %{status_code: status_code, body: body}} when status_code in 200..299 <-
 219            @httpoison.get("http://#{domain}/.well-known/host-meta", [], follow_redirect: true) do
 220       get_template_from_xml(body)
 221     else
 222       _ ->
 223         with {:ok, %{body: body}} <- @httpoison.get("https://#{domain}/.well-known/host-meta", []) do
 224           get_template_from_xml(body)
 225         else
 226           e -> {:error, "Can't find LRDD template: #{inspect(e)}"}
 227         end
 228     end
 229   end
 230
 231   def finger(account) do
 232     account = String.trim_leading(account, "@")
 233
 234     domain =
 235       with [_name, domain] <- String.split(account, "@") do
 236         domain
 237       else
 238         _e ->
 239           URI.parse(account).host
 240       end
 241
 242     case find_lrdd_template(domain) do
 243       {:ok, template} ->
 244         address = String.replace(template, "{uri}", URI.encode(account))
 245
 246       _ ->
 247         address = "http://#{domain}/.well-known/webfinger?resource=acct:#{account}"
 248     end
 249
 250     with response <-
 251            @httpoison.get(
 252              address,
 253              [Accept: "application/xrd+xml,application/jrd+json"],
 254              follow_redirect: true
 255            ),
 256          {:ok, %{status_code: status_code, body: body}} when status_code in 200..299 <- response do
 257       doc = XML.parse_document(body)
 258
 259       if doc != :error do
 260         webfinger_from_xml(doc)
 261       else
 262         {:ok, doc} = Jason.decode(body)
 263         webfinger_from_json(doc)
 264       end
 265     else
 266       e ->
 267         Logger.debug(fn -> "Couldn't finger #{account}" end)
 268         Logger.debug(fn -> inspect(e) end)
 269         {:error, e}
 270     end
 271   end
 272 end