respect content-type header in finger request

5 files changed, 145 insertions, 73 deletions

diff --git a/lib/pleroma/web/web_finger.ex b/lib/pleroma/web/web_finger.ex
index 15002b29f..21b10e654 100644
--- a/lib/pleroma/web/web_finger.ex
+++ b/lib/pleroma/web/web_finger.ex
@@ -94,52 +94,56 @@ defmodule Pleroma.Web.WebFinger do
     |> XmlBuilder.to_doc()
   end
 
-  defp webfinger_from_xml(doc) do
-    subject = XML.string_from_xpath("//Subject", doc)
-
-    subscribe_address =
-      ~s{//Link[@rel="http://ostatus.org/schema/1.0/subscribe"]/@template}
-      |> XML.string_from_xpath(doc)
-
-    ap_id =
-      ~s{//Link[@rel="self" and @type="application/activity+json"]/@href}
-      |> XML.string_from_xpath(doc)
-
-    data = %{
-      "subject" => subject,
-      "subscribe_address" => subscribe_address,
-      "ap_id" => ap_id
-    }
+  defp webfinger_from_xml(body) do
+    with {:ok, doc} <- XML.parse_document(body) do
+      subject = XML.string_from_xpath("//Subject", doc)
+
+      subscribe_address =
+        ~s{//Link[@rel="http://ostatus.org/schema/1.0/subscribe"]/@template}
+        |> XML.string_from_xpath(doc)
+
+      ap_id =
+        ~s{//Link[@rel="self" and @type="application/activity+json"]/@href}
+        |> XML.string_from_xpath(doc)
+
+      data = %{
+        "subject" => subject,
+        "subscribe_address" => subscribe_address,
+        "ap_id" => ap_id
+      }
 
-    {:ok, data}
+      {:ok, data}
+    end
   end
 
-  defp webfinger_from_json(doc) do
-    data =
-      Enum.reduce(doc["links"], %{"subject" => doc["subject"]}, fn link, data ->
-        case {link["type"], link["rel"]} do
-          {"application/activity+json", "self"} ->
-            Map.put(data, "ap_id", link["href"])
+  defp webfinger_from_json(body) do
+    with {:ok, doc} <- Jason.decode(body) do
+      data =
+        Enum.reduce(doc["links"], %{"subject" => doc["subject"]}, fn link, data ->
+          case {link["type"], link["rel"]} do
+            {"application/activity+json", "self"} ->
+              Map.put(data, "ap_id", link["href"])
 
-          {"application/ld+json; profile=\"https://www.w3.org/ns/activitystreams\"", "self"} ->
-            Map.put(data, "ap_id", link["href"])
+            {"application/ld+json; profile=\"https://www.w3.org/ns/activitystreams\"", "self"} ->
+              Map.put(data, "ap_id", link["href"])
 
-          {nil, "http://ostatus.org/schema/1.0/subscribe"} ->
-            Map.put(data, "subscribe_address", link["template"])
+            {nil, "http://ostatus.org/schema/1.0/subscribe"} ->
+              Map.put(data, "subscribe_address", link["template"])
 
-          _ ->
-            Logger.debug("Unhandled type: #{inspect(link["type"])}")
-            data
-        end
-      end)
+            _ ->
+              Logger.debug("Unhandled type: #{inspect(link["type"])}")
+              data
+          end
+        end)
 
-    {:ok, data}
+      {:ok, data}
+    end
   end
 
   def get_template_from_xml(body) do
     xpath = "//Link[@rel='lrdd']/@template"
 
-    with doc when doc != :error <- XML.parse_document(body),
+    with {:ok, doc} <- XML.parse_document(body),
          template when template != nil <- XML.string_from_xpath(xpath, doc) do
       {:ok, template}
     end
@@ -192,15 +196,23 @@ defmodule Pleroma.Web.WebFinger do
              address,
              [{"accept", "application/xrd+xml,application/jrd+json"}]
            ),
-         {:ok, %{status: status, body: body}} when status in 200..299 <- response do
-      doc = XML.parse_document(body)
-
-      if doc != :error do
-        webfinger_from_xml(doc)
-      else
-        with {:ok, doc} <- Jason.decode(body) do
-          webfinger_from_json(doc)
-        end
+         {:ok, %{status: status, body: body, headers: headers}} when status in 200..299 <-
+           response do
+      case List.keyfind(headers, "content-type", 0) do
+        {_, content_type} ->
+          case Plug.Conn.Utils.media_type(content_type) do
+            {:ok, "application", subtype, _} when subtype in ~w(xrd+xml xml) ->
+              webfinger_from_xml(body)
+
+            {:ok, "application", subtype, _} when subtype in ~w(jrd+json json) ->
+              webfinger_from_json(body)
+
+            _ ->
+              {:error, {:content_type, content_type}}
+          end
+
+        _ ->
+          {:error, {:content_type, nil}}
       end
     else
       e ->
diff --git a/lib/pleroma/web/xml.ex b/lib/pleroma/web/xml.ex
index 2b34611ac..0ab6e9d32 100644
--- a/lib/pleroma/web/xml.ex
+++ b/lib/pleroma/web/xml.ex
@@ -31,7 +31,7 @@ defmodule Pleroma.Web.XML do
         |> :binary.bin_to_list()
         |> :xmerl_scan.string(quiet: true)
 
-      doc
+      {:ok, doc}
     rescue
       _e ->
         Logger.debug("Couldn't parse XML: #{inspect(text)}")
diff --git a/test/fixtures/tesla_mock/xn--q9jyb4c_host_meta b/test/fixtures/tesla_mock/xn--q9jyb4c_host_meta
deleted file mode 100644
index 45d260e55..000000000
--- a/test/fixtures/tesla_mock/xn--q9jyb4c_host_meta
+++ /dev/null
@@ -1,4 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<XRD xmlns="http://docs.oasis-open.org/ns/xri/xrd-1.0">
-    <Link rel="lrdd" template="https://zetsubou.xn--q9jyb4c/.well-known/webfinger?resource={uri}" type="application/xrd+xml" />
-</XRD>
diff --git a/test/pleroma/web/web_finger_test.exs b/test/pleroma/web/web_finger_test.exs
index 84477d5a1..2d7b4a40b 100644
--- a/test/pleroma/web/web_finger_test.exs
+++ b/test/pleroma/web/web_finger_test.exs
@@ -45,6 +45,26 @@ defmodule Pleroma.Web.WebFingerTest do
       assert {:error, _} = WebFinger.finger("pleroma.social")
     end
 
+    test "returns error when there is no content-type header" do
+      Tesla.Mock.mock(fn
+        %{url: "http://social.heldscal.la/.well-known/host-meta"} ->
+          {:ok,
+           %Tesla.Env{
+             status: 200,
+             body: File.read!("test/fixtures/tesla_mock/social.heldscal.la_host_meta")
+           }}
+
+        %{
+          url:
+            "https://social.heldscal.la/.well-known/webfinger?resource=acct:invalid_content@social.heldscal.la"
+        } ->
+          {:ok, %Tesla.Env{status: 200, body: ""}}
+      end)
+
+      user = "invalid_content@social.heldscal.la"
+      assert {:error, {:content_type, nil}} = WebFinger.finger(user)
+    end
+
     test "returns error when fails parse xml or json" do
       user = "invalid_content@social.heldscal.la"
       assert {:error, %Jason.DecodeError{}} = WebFinger.finger(user)
@@ -113,5 +133,52 @@ defmodule Pleroma.Web.WebFingerTest do
       ap_id = "https://" <> to_string(:idna.encode("zetsubou.みんな")) <> "/users/lain"
       {:ok, _data} = WebFinger.finger(ap_id)
     end
+
+    test "respects json content-type" do
+      Tesla.Mock.mock(fn
+        %{
+          url:
+            "https://mastodon.social/.well-known/webfinger?resource=acct:emelie@mastodon.social"
+        } ->
+          {:ok,
+           %Tesla.Env{
+             status: 200,
+             body: File.read!("test/fixtures/tesla_mock/webfinger_emelie.json"),
+             headers: [{"content-type", "application/jrd+json"}]
+           }}
+
+        %{url: "http://mastodon.social/.well-known/host-meta"} ->
+          {:ok,
+           %Tesla.Env{
+             status: 200,
+             body: File.read!("test/fixtures/tesla_mock/mastodon.social_host_meta")
+           }}
+      end)
+
+      {:ok, _data} = WebFinger.finger("emelie@mastodon.social")
+    end
+
+    test "respects xml content-type" do
+      Tesla.Mock.mock(fn
+        %{
+          url: "https://pawoo.net/.well-known/webfinger?resource=acct:pekorino@pawoo.net"
+        } ->
+          {:ok,
+           %Tesla.Env{
+             status: 200,
+             body: File.read!("test/fixtures/tesla_mock/https___pawoo.net_users_pekorino.xml"),
+             headers: [{"content-type", "application/xrd+xml"}]
+           }}
+
+        %{url: "http://pawoo.net/.well-known/host-meta"} ->
+          {:ok,
+           %Tesla.Env{
+             status: 200,
+             body: File.read!("test/fixtures/tesla_mock/pawoo.net_host_meta")
+           }}
+      end)
+
+      {:ok, _data} = WebFinger.finger("pekorino@pawoo.net")
+    end
   end
 end
diff --git a/test/support/http_request_mock.ex b/test/support/http_request_mock.ex
index 1328d6225..1e98020f0 100644
--- a/test/support/http_request_mock.ex
+++ b/test/support/http_request_mock.ex
@@ -122,7 +122,7 @@ defmodule HttpRequestMock do
      %Tesla.Env{
        status: 200,
        body: File.read!("test/fixtures/tesla_mock/mike@osada.macgirvin.com.json"),
-       headers: activitypub_object_headers()
+       headers: [{"content-type", "application/jrd+json"}]
      }}
   end
 
@@ -187,7 +187,8 @@ defmodule HttpRequestMock do
     {:ok,
      %Tesla.Env{
        status: 200,
-       body: File.read!("test/fixtures/tesla_mock/lain_squeet.me_webfinger.xml")
+       body: File.read!("test/fixtures/tesla_mock/lain_squeet.me_webfinger.xml"),
+       headers: [{"content-type", "application/xrd+xml"}]
      }}
   end
 
@@ -526,22 +527,6 @@ defmodule HttpRequestMock do
      }}
   end
 
-  def get("http://zetsubou.xn--q9jyb4c/.well-known/host-meta", _, _, _) do
-    {:ok,
-     %Tesla.Env{
-       status: 200,
-       body: File.read!("test/fixtures/tesla_mock/xn--q9jyb4c_host_meta")
-     }}
-  end
-
-  def get("https://zetsubou.xn--q9jyb4c/.well-known/host-meta", _, _, _) do
-    {:ok,
-     %Tesla.Env{
-       status: 200,
-       body: File.read!("test/fixtures/tesla_mock/xn--q9jyb4c_host_meta")
-     }}
-  end
-
   def get("http://pleroma.soykaf.com/.well-known/host-meta", _, _, _) do
     {:ok,
      %Tesla.Env{
@@ -786,7 +771,8 @@ defmodule HttpRequestMock do
     {:ok,
      %Tesla.Env{
        status: 200,
-       body: File.read!("test/fixtures/tesla_mock/shp@social.heldscal.la.xml")
+       body: File.read!("test/fixtures/tesla_mock/shp@social.heldscal.la.xml"),
+       headers: [{"content-type", "application/xrd+xml"}]
      }}
   end
 
@@ -796,7 +782,7 @@ defmodule HttpRequestMock do
         _,
         [{"accept", "application/xrd+xml,application/jrd+json"}]
       ) do
-    {:ok, %Tesla.Env{status: 200, body: ""}}
+    {:ok, %Tesla.Env{status: 200, body: "", headers: [{"content-type", "application/jrd+json"}]}}
   end
 
   def get("http://framatube.org/.well-known/host-meta", _, _, _) do
@@ -816,7 +802,7 @@ defmodule HttpRequestMock do
     {:ok,
      %Tesla.Env{
        status: 200,
-       headers: [{"content-type", "application/json"}],
+       headers: [{"content-type", "application/jrd+json"}],
        body: File.read!("test/fixtures/tesla_mock/framasoft@framatube.org.json")
      }}
   end
@@ -876,7 +862,7 @@ defmodule HttpRequestMock do
     {:ok,
      %Tesla.Env{
        status: 200,
-       headers: [{"content-type", "application/json"}],
+       headers: [{"content-type", "application/jrd+json"}],
        body: File.read!("test/fixtures/tesla_mock/kaniini@gerzilla.de.json")
      }}
   end
@@ -1074,7 +1060,8 @@ defmodule HttpRequestMock do
     {:ok,
      %Tesla.Env{
        status: 200,
-       body: File.read!("test/fixtures/lain.xml")
+       body: File.read!("test/fixtures/lain.xml"),
+       headers: [{"content-type", "application/xrd+xml"}]
      }}
   end
 
@@ -1087,7 +1074,16 @@ defmodule HttpRequestMock do
     {:ok,
      %Tesla.Env{
        status: 200,
-       body: File.read!("test/fixtures/lain.xml")
+       body: File.read!("test/fixtures/lain.xml"),
+       headers: [{"content-type", "application/xrd+xml"}]
+     }}
+  end
+
+  def get("http://zetsubou.xn--q9jyb4c/.well-known/host-meta", _, _, _) do
+    {:ok,
+     %Tesla.Env{
+       status: 200,
+       body: File.read!("test/fixtures/host-meta-zetsubou.xn--q9jyb4c.xml")
      }}
   end
 
@@ -1153,7 +1149,8 @@ defmodule HttpRequestMock do
     {:ok,
      %Tesla.Env{
        status: 200,
-       body: File.read!("test/fixtures/tesla_mock/kpherox@mstdn.jp.xml")
+       body: File.read!("test/fixtures/tesla_mock/kpherox@mstdn.jp.xml"),
+       headers: [{"content-type", "application/xrd+xml"}]
      }}
   end