From 10e5788c212587b7c929c84580aea3e93b2f28ea Mon Sep 17 00:00:00 2001
From: Samantaz Fox <coding@samantaz.fr>
Date: Wed, 3 Jul 2024 21:15:13 +0200
Subject: [PATCH] Videos: Send player sts when required

---
 src/invidious/helpers/signatures.cr     |  9 +++++++++
 src/invidious/yt_backend/youtube_api.cr | 24 ++++++++++++++++++------
 2 files changed, 27 insertions(+), 6 deletions(-)

diff --git a/src/invidious/helpers/signatures.cr b/src/invidious/helpers/signatures.cr
index d9aab31c..b58af73f 100644
--- a/src/invidious/helpers/signatures.cr
+++ b/src/invidious/helpers/signatures.cr
@@ -34,4 +34,13 @@ struct Invidious::DecryptFunction
     LOGGER.trace(ex.inspect_with_backtrace)
     return nil
   end
+
+  def get_sts : UInt64?
+    self.check_update
+    return SigHelper::Client.get_sts
+  rescue ex
+    LOGGER.debug(ex.message || "Signature: Unknown error")
+    LOGGER.trace(ex.inspect_with_backtrace)
+    return nil
+  end
 end
diff --git a/src/invidious/yt_backend/youtube_api.cr b/src/invidious/yt_backend/youtube_api.cr
index c8b037c8..f4ee35e5 100644
--- a/src/invidious/yt_backend/youtube_api.cr
+++ b/src/invidious/yt_backend/youtube_api.cr
@@ -2,6 +2,8 @@
 # This file contains youtube API wrappers
 #
 
+private STS_FETCHER = IV::DecryptFunction.new
+
 module YoutubeAPI
   extend self
 
@@ -272,7 +274,7 @@ module YoutubeAPI
   # Return, as a Hash, the "context" data required to request the
   # youtube API endpoints.
   #
-  private def make_context(client_config : ClientConfig | Nil) : Hash
+  private def make_context(client_config : ClientConfig | Nil, video_id = "dQw4w9WgXcQ") : Hash
     # Use the default client config if nil is passed
     client_config ||= DEFAULT_CLIENT_CONFIG
 
@@ -292,7 +294,7 @@ module YoutubeAPI
 
     if client_config.screen == "EMBED"
       client_context["thirdParty"] = {
-        "embedUrl" => "https://www.youtube.com/embed/dQw4w9WgXcQ",
+        "embedUrl" => "https://www.youtube.com/embed/#{video_id}",
       } of String => String | Int64
     end
 
@@ -453,19 +455,29 @@ module YoutubeAPI
     params : String,
     client_config : ClientConfig | Nil = nil
   )
+    # Playback context, separate because it can be different between clients
+    playback_ctx = {
+      "html5Preference" => "HTML5_PREF_WANTS",
+      "referer"         => "https://www.youtube.com/watch?v=#{video_id}",
+    } of String => String | Int64
+
+    if {"WEB", "TVHTML5"}.any? { |s| client_config.name.starts_with? s }
+      if sts = STS_FETCHER.get_sts
+        playback_ctx["signatureTimestamp"] = sts.to_i64
+      end
+    end
+
     # JSON Request data, required by the API
     data = {
       "contentCheckOk" => true,
       "videoId"        => video_id,
-      "context"        => self.make_context(client_config),
+      "context"        => self.make_context(client_config, video_id),
       "racyCheckOk"    => true,
       "user"           => {
         "lockedSafetyMode" => false,
       },
       "playbackContext" => {
-        "contentPlaybackContext" => {
-          "html5Preference": "HTML5_PREF_WANTS",
-        },
+        "contentPlaybackContext" => playback_ctx,
       },
     }