X-Git-Url: http://git.squeep.com/?a=blobdiff_plain;f=lib%2Fpleroma%2Fweb%2Fmedia_proxy%2Fmedia_proxy.ex;h=217c3f92263c65fa76be6b51e1536f6ed081aa3c;hb=bdf57b8ef438f32999ef917777b13161320644a8;hp=cee6d8481a33942d1d41d51a0cb16ba6fb98ac0b;hpb=314758c25bbc0044afcec98710c36532a1dc7e0d;p=akkoma

diff --git a/lib/pleroma/web/media_proxy/media_proxy.ex b/lib/pleroma/web/media_proxy/media_proxy.ex
index cee6d8481..217c3f922 100644
--- a/lib/pleroma/web/media_proxy/media_proxy.ex
+++ b/lib/pleroma/web/media_proxy/media_proxy.ex
@@ -1,91 +1,182 @@
 # Pleroma: A lightweight social networking server
-# Copyright © 2017-2019 Pleroma Authors <https://pleroma.social/>
+# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
 # SPDX-License-Identifier: AGPL-3.0-only
 
 defmodule Pleroma.Web.MediaProxy do
+  alias Pleroma.Config
+  alias Pleroma.Upload
+  alias Pleroma.Web
+  alias Pleroma.Web.MediaProxy.Invalidation
+
   @base64_opts [padding: false]
 
-  def url(nil), do: nil
+  @spec in_banned_urls(String.t()) :: boolean()
+  def in_banned_urls(url), do: elem(Cachex.exists?(:banned_urls_cache, url(url)), 1)
+
+  def remove_from_banned_urls(urls) when is_list(urls) do
+    Cachex.execute!(:banned_urls_cache, fn cache ->
+      Enum.each(Invalidation.prepare_urls(urls), &Cachex.del(cache, &1))
+    end)
+  end
+
+  def remove_from_banned_urls(url) when is_binary(url) do
+    Cachex.del(:banned_urls_cache, url(url))
+  end
+
+  def put_in_banned_urls(urls) when is_list(urls) do
+    Cachex.execute!(:banned_urls_cache, fn cache ->
+      Enum.each(Invalidation.prepare_urls(urls), &Cachex.put(cache, &1, true))
+    end)
+  end
 
-  def url(""), do: nil
+  def put_in_banned_urls(url) when is_binary(url) do
+    Cachex.put(:banned_urls_cache, url(url), true)
+  end
 
+  def url(url) when is_nil(url) or url == "", do: nil
   def url("/" <> _ = url), do: url
 
   def url(url) do
-    if !enabled?() or local?(url) or whitelisted?(url) do
+    if not enabled?() or not url_proxiable?(url) do
       url
     else
       encode_url(url)
     end
   end
 
-  defp enabled?, do: Pleroma.Config.get([:media_proxy, :enabled], false)
+  @spec url_proxiable?(String.t()) :: boolean()
+  def url_proxiable?(url) do
+    if local?(url) or whitelisted?(url) do
+      false
+    else
+      true
+    end
+  end
+
+  # Note: routing all URLs to preview handler (even local and whitelisted).
+  #   Preview handler will call url/1 on decoded URLs, and applicable ones will detour media proxy.
+  def preview_url(url) do
+    if preview_enabled?() do
+      encode_preview_url(url)
+    else
+      url
+    end
+  end
+
+  def enabled?, do: Config.get([:media_proxy, :enabled], false)
+
+  # Note: media proxy must be enabled for media preview proxy in order to load all
+  #   non-local non-whitelisted URLs through it and be sure that body size constraint is preserved.
+  def preview_enabled?, do: enabled?() and Config.get([:media_preview_proxy, :enabled], false)
 
-  defp local?(url), do: String.starts_with?(url, Pleroma.Web.base_url())
+  def local?(url), do: String.starts_with?(url, Pleroma.Web.base_url())
 
-  defp whitelisted?(url) do
+  def whitelisted?(url) do
     %{host: domain} = URI.parse(url)
 
-    Enum.any?(Pleroma.Config.get([:media_proxy, :whitelist]), fn pattern ->
-      String.equivalent?(domain, pattern)
-    end)
+    mediaproxy_whitelist_domains =
+      [:media_proxy, :whitelist]
+      |> Config.get()
+      |> Enum.map(&maybe_get_domain_from_url/1)
+
+    whitelist_domains =
+      if base_url = Config.get([Upload, :base_url]) do
+        %{host: base_domain} = URI.parse(base_url)
+        [base_domain | mediaproxy_whitelist_domains]
+      else
+        mediaproxy_whitelist_domains
+      end
+
+    domain in whitelist_domains
   end
 
-  def encode_url(url) do
-    secret = Pleroma.Config.get([Pleroma.Web.Endpoint, :secret_key_base])
+  defp maybe_get_domain_from_url("http" <> _ = url) do
+    URI.parse(url).host
+  end
 
-    # Must preserve `%2F` for compatibility with S3
-    # https://git.pleroma.social/pleroma/pleroma/issues/580
-    replacement = get_replacement(url, ":2F:")
+  defp maybe_get_domain_from_url(domain), do: domain
 
-    # The URL is url-decoded and encoded again to ensure it is correctly encoded and not twice.
-    base64 =
-      url
-      |> String.replace("%2F", replacement)
-      |> URI.decode()
-      |> URI.encode()
-      |> String.replace(replacement, "%2F")
+  defp base64_sig64(url) do
+    base64 = Base.url_encode64(url, @base64_opts)
+
+    sig64 =
+      base64
+      |> signed_url()
       |> Base.url_encode64(@base64_opts)
 
-    sig = :crypto.hmac(:sha, secret, base64)
-    sig64 = sig |> Base.url_encode64(@base64_opts)
+    {base64, sig64}
+  end
+
+  def encode_url(url) do
+    {base64, sig64} = base64_sig64(url)
 
     build_url(sig64, base64, filename(url))
   end
 
-  def decode_url(sig, url) do
-    secret = Pleroma.Config.get([Pleroma.Web.Endpoint, :secret_key_base])
-    sig = Base.url_decode64!(sig, @base64_opts)
-    local_sig = :crypto.hmac(:sha, secret, url)
+  def encode_preview_url(url) do
+    {base64, sig64} = base64_sig64(url)
+
+    build_preview_url(sig64, base64, filename(url))
+  end
 
-    if local_sig == sig do
+  def decode_url(sig, url) do
+    with {:ok, sig} <- Base.url_decode64(sig, @base64_opts),
+         signature when signature == sig <- signed_url(url) do
       {:ok, Base.url_decode64!(url, @base64_opts)}
     else
-      {:error, :invalid_signature}
+      _ -> {:error, :invalid_signature}
     end
   end
 
+  defp signed_url(url) do
+    :crypto.hmac(:sha, Config.get([Web.Endpoint, :secret_key_base]), url)
+  end
+
   def filename(url_or_path) do
     if path = URI.parse(url_or_path).path, do: Path.basename(path)
   end
 
-  def build_url(sig_base64, url_base64, filename \\ nil) do
+  defp proxy_url(path, sig_base64, url_base64, filename) do
     [
-      Pleroma.Config.get([:media_proxy, :base_url], Pleroma.Web.base_url()),
-      "proxy",
+      Config.get([:media_proxy, :base_url], Web.base_url()),
+      path,
       sig_base64,
       url_base64,
       filename
     ]
-    |> Enum.filter(fn value -> value end)
+    |> Enum.filter(& &1)
     |> Path.join()
   end
 
-  defp get_replacement(url, replacement) do
-    if String.contains?(url, replacement) do
-      get_replacement(url, replacement <> replacement)
+  def build_url(sig_base64, url_base64, filename \\ nil) do
+    proxy_url("proxy", sig_base64, url_base64, filename)
+  end
+
+  def build_preview_url(sig_base64, url_base64, filename \\ nil) do
+    proxy_url("proxy/preview", sig_base64, url_base64, filename)
+  end
+
+  def verify_request_path_and_url(
+        %Plug.Conn{params: %{"filename" => _}, request_path: request_path},
+        url
+      ) do
+    verify_request_path_and_url(request_path, url)
+  end
+
+  def verify_request_path_and_url(request_path, url) when is_binary(request_path) do
+    filename = filename(url)
+
+    if filename && not basename_matches?(request_path, filename) do
+      {:wrong_filename, filename}
     else
-      replacement
+      :ok
     end
   end
+
+  def verify_request_path_and_url(_, _), do: :ok
+
+  defp basename_matches?(path, filename) do
+    basename = Path.basename(path)
+    basename == filename or URI.decode(basename) == filename or URI.encode(basename) == filename
+  end
 end