From 8aa639a450c94fc3fb8ea812b334892324ffd51a Mon Sep 17 00:00:00 2001
From: William Pitcock <nenolod@dereferenced.org>
Date: Wed, 21 Mar 2018 17:58:31 +0000
Subject: [PATCH] webfinger: support JSON output

---
 lib/pleroma/web/router.ex                     |  2 +-
 lib/pleroma/web/web_finger/web_finger.ex      | 41 +++++++++++++++++--
 .../web/web_finger/web_finger_controller.ex   | 23 ++++++++---
 test/web/web_finger/web_finger_test.exs       |  4 +-
 4 files changed, 57 insertions(+), 13 deletions(-)

diff --git a/lib/pleroma/web/router.ex b/lib/pleroma/web/router.ex
index 3e9a8ba7b..8835239c5 100644
--- a/lib/pleroma/web/router.ex
+++ b/lib/pleroma/web/router.ex
@@ -39,7 +39,7 @@ defmodule Pleroma.Web.Router do
   end
 
   pipeline :well_known do
-    plug :accepts, ["xml", "xrd+xml"]
+    plug :accepts, ["xml", "xrd+xml", "json", "jrd+json"]
   end
 
   pipeline :config do
diff --git a/lib/pleroma/web/web_finger/web_finger.ex b/lib/pleroma/web/web_finger/web_finger.ex
index 019210124..378e544ba 100644
--- a/lib/pleroma/web/web_finger/web_finger.ex
+++ b/lib/pleroma/web/web_finger/web_finger.ex
@@ -17,22 +17,55 @@ defmodule Pleroma.Web.WebFinger do
     |> XmlBuilder.to_doc
   end
 
-  def webfinger(resource) do
+  def webfinger(resource, "JSON") do
     host = Pleroma.Web.Endpoint.host
     regex = ~r/(acct:)?(?<username>\w+)@#{host}/
     with %{"username" => username} <- Regex.named_captures(regex, resource) do
       user = User.get_by_nickname(username)
-      {:ok, represent_user(user)}
+      {:ok, represent_user(user, "JSON")}
     else _e ->
       with user when not is_nil(user) <- User.get_cached_by_ap_id(resource) do
-        {:ok, represent_user(user)}
+        {:ok, represent_user(user, "JSON")}
       else _e ->
         {:error, "Couldn't find user"}
       end
     end
   end
 
-  def represent_user(user) do
+  def webfinger(resource, "XML") do
+    host = Pleroma.Web.Endpoint.host
+    regex = ~r/(acct:)?(?<username>\w+)@#{host}/
+    with %{"username" => username} <- Regex.named_captures(regex, resource) do
+      user = User.get_by_nickname(username)
+      {:ok, represent_user(user, "XML")}
+    else _e ->
+      with user when not is_nil(user) <- User.get_cached_by_ap_id(resource) do
+        {:ok, represent_user(user, "XML")}
+      else _e ->
+        {:error, "Couldn't find user"}
+      end
+    end
+  end
+
+  def represent_user(user, "JSON") do
+    {:ok, user} = ensure_keys_present(user)
+    {:ok, _private, public} = Salmon.keys_from_pem(user.info["keys"])
+    magic_key = Salmon.encode_key(public)
+    %{
+      "subject" => "acct:#{user.nickname}@#{Pleroma.Web.Endpoint.host}",
+      "aliases" => [user.ap_id],
+      "links" => [
+        %{"rel" => "http://schemas.google.com/g/2010#updates-from", "type" => "application/atom+xml", "href" => OStatus.feed_path(user)},
+        %{"rel" => "http://webfinger.net/rel/profile-page", "type" => "text/html", "href" => user.ap_id},
+        %{"rel" => "salmon", "href" => OStatus.salmon_path(user)},
+        %{"rel" => "magic-public-key", "href" => "data:application/magic-public-key,#{magic_key}"},
+        %{"rel" => "self", "type" => "application/activity+json", "href" => user.ap_id},
+        %{"rel" => "http://ostatus.org/schema/1.0/subscribe", "template" => OStatus.remote_follow_path()}
+      ]
+    }
+  end
+
+  def represent_user(user, "XML") do
     {:ok, user} = ensure_keys_present(user)
     {:ok, _private, public} = Salmon.keys_from_pem(user.info["keys"])
     magic_key = Salmon.encode_key(public)
diff --git a/lib/pleroma/web/web_finger/web_finger_controller.ex b/lib/pleroma/web/web_finger/web_finger_controller.ex
index d4536fc46..eb54346c1 100644
--- a/lib/pleroma/web/web_finger/web_finger_controller.ex
+++ b/lib/pleroma/web/web_finger/web_finger_controller.ex
@@ -12,12 +12,23 @@ defmodule Pleroma.Web.WebFinger.WebFingerController do
   end
 
   def webfinger(conn, %{"resource" => resource}) do
-    with {:ok, response} <- WebFinger.webfinger(resource) do
-      conn
-      |> put_resp_content_type("application/xrd+xml")
-      |> send_resp(200, response)
-    else
-      _e -> send_resp(conn, 404, "Couldn't find user")
+    case get_format(conn) do
+      n when n in ["xml", "xrd+xml"] ->
+        with {:ok, response} <- WebFinger.webfinger(resource, "XML") do
+          conn
+          |> put_resp_content_type("application/xrd+xml")
+          |> send_resp(200, response)
+        else
+          _e -> send_resp(conn, 404, "Couldn't find user")
+        end
+      n when n in ["json", "jrd+json"] ->
+        with {:ok, response} <- WebFinger.webfinger(resource, "JSON") do
+          json(conn, response)
+        else
+          _e -> send_resp(conn, 404, "Couldn't find user")
+        end
+      _ ->
+        send_resp(conn, 404, "Unsupported format")
     end
   end
 end
diff --git a/test/web/web_finger/web_finger_test.exs b/test/web/web_finger/web_finger_test.exs
index ccca737f0..0be424c7a 100644
--- a/test/web/web_finger/web_finger_test.exs
+++ b/test/web/web_finger/web_finger_test.exs
@@ -15,14 +15,14 @@ defmodule Pleroma.Web.WebFingerTest do
     test "works for fqns" do
       user = insert(:user)
 
-      {:ok, result} = WebFinger.webfinger("#{user.nickname}@#{Pleroma.Web.Endpoint.host}")
+      {:ok, result} = WebFinger.webfinger("#{user.nickname}@#{Pleroma.Web.Endpoint.host}", "XML")
       assert is_binary(result)
     end
 
     test "works for ap_ids" do
       user = insert(:user)
 
-      {:ok, result} = WebFinger.webfinger(user.ap_id)
+      {:ok, result} = WebFinger.webfinger(user.ap_id, "XML")
       assert is_binary(result)
     end
   end