Merge branch 'release-2.6.3' into 'stable'

Release 2.6.3

See merge request pleroma/pleroma!4115

2 files changed, 36 insertions, 5 deletions

diff --git a/lib/pleroma/application.ex b/lib/pleroma/application.ex
index e68a3c57e..385e3872d 100644
--- a/lib/pleroma/application.ex
+++ b/lib/pleroma/application.ex
@@ -210,7 +210,8 @@ defmodule Pleroma.Application do
         expiration: chat_message_id_idempotency_key_expiration(),
         limit: 500_000
       ),
-      build_cachex("rel_me", limit: 2500)
+      build_cachex("rel_me", limit: 2500),
+      build_cachex("host_meta", default_ttl: :timer.minutes(120), limit: 5000)
     ]
   end
 
diff --git a/lib/pleroma/web/web_finger.ex b/lib/pleroma/web/web_finger.ex
index f95dc2458..398742200 100644
--- a/lib/pleroma/web/web_finger.ex
+++ b/lib/pleroma/web/web_finger.ex
@@ -155,7 +155,16 @@ defmodule Pleroma.Web.WebFinger do
     end
   end
 
+  @cachex Pleroma.Config.get([:cachex, :provider], Cachex)
   def find_lrdd_template(domain) do
+    @cachex.fetch!(:host_meta_cache, domain, fn _ ->
+      {:commit, fetch_lrdd_template(domain)}
+    end)
+  rescue
+    e -> {:error, "Cachex error: #{inspect(e)}"}
+  end
+
+  defp fetch_lrdd_template(domain) do
     # WebFinger is restricted to HTTPS - https://tools.ietf.org/html/rfc7033#section-9.1
     meta_url = "https://#{domain}/.well-known/host-meta"
 
@@ -168,7 +177,7 @@ defmodule Pleroma.Web.WebFinger do
     end
   end
 
-  defp get_address_from_domain(domain, encoded_account) when is_binary(domain) do
+  defp get_address_from_domain(domain, "acct:" <> _ = encoded_account) when is_binary(domain) do
     case find_lrdd_template(domain) do
       {:ok, template} ->
         String.replace(template, "{uri}", encoded_account)
@@ -178,6 +187,11 @@ defmodule Pleroma.Web.WebFinger do
     end
   end
 
+  defp get_address_from_domain(domain, account) when is_binary(domain) do
+    encoded_account = URI.encode("acct:#{account}")
+    get_address_from_domain(domain, encoded_account)
+  end
+
   defp get_address_from_domain(_, _), do: {:error, :webfinger_no_domain}
 
   @spec finger(String.t()) :: {:ok, map()} | {:error, any()}
@@ -192,9 +206,7 @@ defmodule Pleroma.Web.WebFinger do
           URI.parse(account).host
       end
 
-    encoded_account = URI.encode("acct:#{account}")
-
-    with address when is_binary(address) <- get_address_from_domain(domain, encoded_account),
+    with address when is_binary(address) <- get_address_from_domain(domain, account),
          {:ok, %{status: status, body: body, headers: headers}} when status in 200..299 <-
            HTTP.get(
              address,
@@ -216,10 +228,28 @@ defmodule Pleroma.Web.WebFinger do
         _ ->
           {:error, {:content_type, nil}}
       end
+      |> case do
+        {:ok, data} -> validate_webfinger(address, data)
+        error -> error
+      end
     else
       error ->
         Logger.debug("Couldn't finger #{account}: #{inspect(error)}")
         error
     end
   end
+
+  defp validate_webfinger(request_url, %{"subject" => "acct:" <> acct = subject} = data) do
+    with [_name, acct_host] <- String.split(acct, "@"),
+         {_, url} <- {:address, get_address_from_domain(acct_host, subject)},
+         %URI{host: request_host} <- URI.parse(request_url),
+         %URI{host: acct_host} <- URI.parse(url),
+         {_, true} <- {:hosts_match, acct_host == request_host} do
+      {:ok, data}
+    else
+      _ -> {:error, {:webfinger_invalid, request_url, data}}
+    end
+  end
+
+  defp validate_webfinger(url, data), do: {:error, {:webfinger_invalid, url, data}}
 end