From 972af513f073a05456d6213631450d6a8657b405 Mon Sep 17 00:00:00 2001
From: max <max.holleman@hotmail.nl>
Date: Thu, 23 Oct 2025 20:08:02 +0200
Subject: [PATCH] [CHANGE] Linked decipher to video implementation

---
 .../Models/Innertube/StreamingFormat.cs       |  3 +-
 Manager.YouTube/Util/Cipher/CipherDecoder.cs  |  7 +++-
 Manager.YouTube/YouTubeClient.cs              | 33 ++++++++++++++++++-
 3 files changed, 40 insertions(+), 3 deletions(-)

diff --git a/Manager.YouTube/Models/Innertube/StreamingFormat.cs b/Manager.YouTube/Models/Innertube/StreamingFormat.cs
index fab8557..8d84adc 100644
--- a/Manager.YouTube/Models/Innertube/StreamingFormat.cs
+++ b/Manager.YouTube/Models/Innertube/StreamingFormat.cs
@@ -3,7 +3,7 @@ namespace Manager.YouTube.Models.Innertube;
 public class StreamingFormat
 {
     public int Itag { get; set; }
-    public string Url { get; set; } = "";
+    public string? Url { get; set; }
     public string MimeType { get; set; } = "";
     public uint Bitrate { get; set; }
     public uint? Width { get; set; }
@@ -26,5 +26,6 @@ public class StreamingFormat
     public int? AudioChannels { get; set; }
     public double? LoudnessDb { get; set; }
     public bool? IsDrc { get; set; }
+    public string? SignatureCipher { get; set; }
     public string QualityOrdinal { get; set; } = "";
 }
\ No newline at end of file
diff --git a/Manager.YouTube/Util/Cipher/CipherDecoder.cs b/Manager.YouTube/Util/Cipher/CipherDecoder.cs
index c917354..1dd39f3 100644
--- a/Manager.YouTube/Util/Cipher/CipherDecoder.cs
+++ b/Manager.YouTube/Util/Cipher/CipherDecoder.cs
@@ -31,8 +31,13 @@ public partial class CipherDecoder
         return decoder;
     }
 
-    public string Decipher(string signatureCipher)
+    public string Decipher(string? signatureCipher)
     {
+        if (string.IsNullOrEmpty(signatureCipher))
+        {
+            return "";
+        }
+
         var urlBuilder = new StringBuilder();
 
         var indexStart = signatureCipher.IndexOf("s=", StringComparison.Ordinal);
diff --git a/Manager.YouTube/YouTubeClient.cs b/Manager.YouTube/YouTubeClient.cs
index 83c4b7a..b8369fc 100644
--- a/Manager.YouTube/YouTubeClient.cs
+++ b/Manager.YouTube/YouTubeClient.cs
@@ -9,6 +9,7 @@ using Manager.YouTube.Models;
 using Manager.YouTube.Models.Innertube;
 using Manager.YouTube.Parsers;
 using Manager.YouTube.Parsers.Json;
+using Manager.YouTube.Util.Cipher;
 
 namespace Manager.YouTube;
 
@@ -351,8 +352,38 @@ public sealed class YouTubeClient : IDisposable
             return videoParseResult;
         }
         
-        //TODO: decipher stream urls
+        await DecipherSignatures(videoParseResult.Value);
 
         return videoParseResult.Value;
     }
+
+    private async Task DecipherSignatures(YouTubeVideo video)
+    {
+        var streamingData = video.StreamingData;
+        if (streamingData == null)
+        {
+            _logger.Debug("No streaming data available, skipping decipher.");
+            return;
+        }
+
+        var formatsWithCipher = streamingData.Formats.Concat(streamingData.AdaptiveFormats).Where(x => !string.IsNullOrWhiteSpace(x.SignatureCipher)).ToList();
+        if (formatsWithCipher.Count == 0)
+        {
+            _logger.Debug("Skipping decipher, no signatures found to decipher.");
+            return;
+        }
+
+        var decipherDecoderResult = await CipherManager.GetDecoderAsync(this);
+        if (!decipherDecoderResult.IsSuccess)
+        {
+            _logger.Warning(decipherDecoderResult.Error?.Description ?? "Failed to get the cipher decoder!");
+            return;
+        }
+        var decoder = decipherDecoderResult.Value;
+        
+        foreach (var format in formatsWithCipher)
+        {
+            format.Url = decoder.Decipher(format.SignatureCipher);
+        }
+    }
 }
\ No newline at end of file