Add invidious companion support (#4985)

* add support for invidious companion

* redirect latest_version and dash manifest to invidious companion

* fix Shadowing outer local variable `response`

* fixing condition for Content-Security-Policy

* throw error if inv_sig_helper and invidious_companion used same time

* Use sample instead of Random.rand

Co-authored-by: syeopite <70992037+syeopite@users.noreply.github.com>

* Remove debug puts functions

Co-authored-by: syeopite <70992037+syeopite@users.noreply.github.com>

* modify the description for config.example.yaml about invidious companion

* move config checks for invidious companion

* separate invidious_companion logic + better config.yaml config

* fixing "end" misplacement

* fix linting + use .empty?

* crystal handle decompression already by itself

* fix download function when invidious companion used

* fix linting

* invidious companion always used so always add CSP and redirect latest_version

* apply all the suggestions + rework invidious_companion parameter

* format watch.cr

* fix ameba Redundant use of `Object#to_s` in interpolation

* add ability for invidious companion to check request from invidious

* Better document private_url and public_url

* Better doc for invidious_companion_key

* !empty? to present?

* skip proxy for invidious companion

* fixing format

* missing ,

* add companion pooling http

* fix: don't use http proxy when sending requests to companion

* fix: logic where we want to have the invidious logic if companion is not used

* chore: remove baseurl usage from invidious companion

* chore: change from inv-sig-helper to companion for required playback

* fix: use puts + add warning for inv-sig-helper deprecated

---------

Co-authored-by: syeopite <70992037+syeopite@users.noreply.github.com>

src/invidious/helpers/utils.cr

@@ -383,3 +383,22 @@ def parse_link_endpoint(endpoint : JSON::Any, text : String, video_id : String)
   end
   return text
 end
+
+def encrypt_ecb_without_salt(data, key)
+  cipher = OpenSSL::Cipher.new("aes-128-ecb")
+  cipher.encrypt
+  cipher.key = key
+
+  io = IO::Memory.new
+  io.write(cipher.update(data))
+  io.write(cipher.final)
+  io.rewind
+
+  return io
+end
+
+def invidious_companion_encrypt(data)
+  timestamp = Time.utc.to_unix
+  encrypted_data = encrypt_ecb_without_salt("#{timestamp}|#{data}", CONFIG.invidious_companion_key)
+  return Base64.urlsafe_encode(encrypted_data)
+end