SigHelper: Make signature server optional and configurable

src/invidious/helpers/sig_helper.cr

@@ -72,8 +72,12 @@ module Invidious::SigHelper
   #  High-level functions
   # ----------------------
 
-  module Client
-    extend self
+  class Client
+    @mux : Multiplexor
+
+    def initialize(uri_or_path)
+      @mux = Multiplexor.new(uri_or_path)
+    end
 
     # Forces the server to re-fetch the YouTube player, and extract the necessary
     # components from it (nsig function code, sig function code, signature timestamp).
@@ -148,7 +152,7 @@ module Invidious::SigHelper
     end
 
     private def send_request(request : Request, &)
-      channel = Multiplexor::INSTANCE.send(request)
+      channel = @mux.send(request)
       slice = channel.receive
       return yield slice
     rescue ex
@@ -172,10 +176,8 @@ module Invidious::SigHelper
 
     @conn : Connection
 
-    INSTANCE = new("")
-
-    def initialize(url : String)
-      @conn = Connection.new(url)
+    def initialize(uri_or_path)
+      @conn = Connection.new(uri_or_path)
       listen
     end
 
@@ -275,13 +277,14 @@ module Invidious::SigHelper
     {% end %}
 
     def initialize(host_or_path : String)
-      if host_or_path.empty?
-        host_or_path = "/tmp/inv_sig_helper.sock"
-      end
-
       case host_or_path
       when .starts_with?('/')
-        @socket = UNIXSocket.new(host_or_path)
+        # Make sure that the file exists
+        if File.exists?(host_or_path)
+          @socket = UNIXSocket.new(host_or_path)
+        else
+          raise Exception.new("SigHelper: '#{host_or_path}' no such file")
+        end
       when .starts_with?("tcp://")
         uri = URI.parse(host_or_path)
         @socket = TCPSocket.new(uri.host.not_nil!, uri.port.not_nil!)

src/invidious/helpers/signatures.cr

@@ -1,10 +1,11 @@
 require "http/params"
 require "./sig_helper"
 
-struct Invidious::DecryptFunction
+class Invidious::DecryptFunction
   @last_update : Time = Time.utc - 42.days
 
-  def initialize
+  def initialize(uri_or_path)
+    @client = SigHelper::Client.new(uri_or_path)
     self.check_update
   end
 
@@ -16,19 +17,18 @@ struct Invidious::DecryptFunction
 
     # Get the time when the player was updated, in the event where
     # multiple invidious processes are run in parallel.
-    player_ts = Invidious::SigHelper::Client.get_player_timestamp
-    player_time = Time.unix(player_ts || 0)
+    player_time = Time.unix(@client.get_player_timestamp || 0)
 
     if (now - player_time) > 5.minutes
       LOGGER.debug("Signature: Player might be outdated, updating")
-      Invidious::SigHelper::Client.force_update
+      @client.force_update
       @last_update = Time.utc
     end
   end
 
   def decrypt_nsig(n : String) : String?
     self.check_update
-    return SigHelper::Client.decrypt_n_param(n)
+    return @client.decrypt_n_param(n)
   rescue ex
     LOGGER.debug(ex.message || "Signature: Unknown error")
     LOGGER.trace(ex.inspect_with_backtrace)
@@ -37,7 +37,7 @@ struct Invidious::DecryptFunction
 
   def decrypt_signature(str : String) : String?
     self.check_update
-    return SigHelper::Client.decrypt_sig(str)
+    return @client.decrypt_sig(str)
   rescue ex
     LOGGER.debug(ex.message || "Signature: Unknown error")
     LOGGER.trace(ex.inspect_with_backtrace)
@@ -46,7 +46,7 @@ struct Invidious::DecryptFunction
 
   def get_sts : UInt64?
     self.check_update
-    return SigHelper::Client.get_signature_timestamp
+    return @client.get_signature_timestamp
   rescue ex
     LOGGER.debug(ex.message || "Signature: Unknown error")
     LOGGER.trace(ex.inspect_with_backtrace)