Implement private branches

Fixes #514
Fixes #620

Author: xPaw

DepotDownloader/ContentDownloader.cs

@@ -231,59 +231,62 @@ static async Task<ulong> GetSteam3DepotManifest(uint depotId, uint appId, string
             }
 
             var manifests = depotChild["manifests"];
-            var manifests_encrypted = depotChild["encryptedmanifests"];
 
-            if (manifests.Children.Count == 0 && manifests_encrypted.Children.Count == 0)
+            if (manifests.Children.Count == 0)
                 return INVALID_MANIFEST_ID;
 
             var node = manifests[branch]["gid"];
 
-            if (node == KeyValue.Invalid && !string.Equals(branch, DEFAULT_BRANCH, StringComparison.OrdinalIgnoreCase))
-            {
-                var node_encrypted = manifests_encrypted[branch];
-                if (node_encrypted != KeyValue.Invalid)
-                {
-                    var password = Config.BetaPassword;
-                    while (string.IsNullOrEmpty(password))
-                    {
-                        Console.Write("Please enter the password for branch {0}: ", branch);
-                        Config.BetaPassword = password = Console.ReadLine();
-                    }
+            // Non passworded branch, found the manifest
+            if (node.Value != null)
+                return ulong.Parse(node.Value);
 
-                    var encrypted_gid = node_encrypted["gid"];
+            // If we requested public branch and it had no manifest, nothing to do
+            if (string.Equals(branch, DEFAULT_BRANCH, StringComparison.OrdinalIgnoreCase))
+                return INVALID_MANIFEST_ID;
 
-                    if (encrypted_gid != KeyValue.Invalid)
-                    {
-                        // Submit the password to Steam now to get encryption keys
-                        await steam3.CheckAppBetaPassword(appId, Config.BetaPassword);
+            // Either the branch just doesn't exist, or it has a password
+            var password = Config.BetaPassword;
 
-                        if (!steam3.AppBetaPasswords.TryGetValue(branch, out var appBetaPassword))
-                        {
-                            Console.WriteLine("Password was invalid for branch {0}", branch);
-                            return INVALID_MANIFEST_ID;
-                        }
+            if (string.IsNullOrEmpty(password))
+            {
+                Console.WriteLine($"Branch {branch} was not found, either it does not exist or it has a password.");
+            }
 
-                        var input = Util.DecodeHexString(encrypted_gid.Value);
-                        byte[] manifest_bytes;
-                        try
-                        {
-                            manifest_bytes = Util.SymmetricDecryptECB(input, appBetaPassword);
-                        }
-                        catch (Exception e)
-                        {
-                            Console.WriteLine("Failed to decrypt branch {0}: {1}", branch, e.Message);
-                            return INVALID_MANIFEST_ID;
-                        }
+            while (string.IsNullOrEmpty(password))
+            {
+                Console.Write($"Please enter the password for branch {branch}: ");
+                Config.BetaPassword = password = Console.ReadLine();
+            }
 
-                        return BitConverter.ToUInt64(manifest_bytes, 0);
-                    }
+            if (!steam3.AppBetaPasswords.ContainsKey(branch))
+            {
+                // Submit the password to Steam now to get encryption keys
+                await steam3.CheckAppBetaPassword(appId, Config.BetaPassword);
 
-                    Console.WriteLine("Unhandled depot encryption for depotId {0}", depotId);
+                if (!steam3.AppBetaPasswords.TryGetValue(branch, out var appBetaPassword))
+                {
+                    Console.WriteLine($"Error: Password was invalid for branch {branch} (or the branch does not exist)");
                     return INVALID_MANIFEST_ID;
                 }
+            }
+
+            // Got the password, request private depot section
+            // TODO: We're probably repeating this request for every depot?
+            var privateDepotSection = await steam3.GetPrivateBetaDepotSection(appId, branch);
 
+            // Now repeat the same code to get the manifest gid from depot section
+            depotChild = privateDepotSection[depotId.ToString()];
+
+            if (depotChild == KeyValue.Invalid)
                 return INVALID_MANIFEST_ID;
-            }
+
+            manifests = depotChild["manifests"];
+
+            if (manifests.Children.Count == 0)
+                return INVALID_MANIFEST_ID;
+
+            node = manifests[branch]["gid"];
 
             if (node.Value == null)
                 return INVALID_MANIFEST_ID;

DepotDownloader/DepotDownloader.csproj

@@ -4,7 +4,7 @@
     <TargetFramework>net9.0</TargetFramework>
     <EnforceCodeStyleInBuild>true</EnforceCodeStyleInBuild>
     <RollForward>LatestMajor</RollForward>
-    <Version>3.0.0</Version>
+    <Version>3.2.0</Version>
     <Description>Steam Downloading Utility</Description>
     <Authors>SteamRE Team</Authors>
     <Copyright>Copyright © SteamRE Team 2025</Copyright>
@@ -25,8 +25,8 @@
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
     </PackageReference>
-    <PackageReference Include="protobuf-net" Version="3.2.46" />
+    <PackageReference Include="protobuf-net" Version="3.2.52" />
     <PackageReference Include="QRCoder" Version="1.6.0" />
-    <PackageReference Include="SteamKit2" Version="3.0.2" />
+    <PackageReference Include="SteamKit2" Version="3.1.0" />
   </ItemGroup>
 </Project>

DepotDownloader/Program.cs

@@ -249,6 +249,12 @@ ex is ContentDownloaderException
                 var branch = GetParameter<string>(args, "-branch") ?? GetParameter<string>(args, "-beta") ?? ContentDownloader.DEFAULT_BRANCH;
                 ContentDownloader.Config.BetaPassword = GetParameter<string>(args, "-branchpassword") ?? GetParameter<string>(args, "-betapassword");
 
+                if (!string.IsNullOrEmpty(ContentDownloader.Config.BetaPassword) && string.IsNullOrEmpty(branch))
+                {
+                    Console.WriteLine("Error: Cannot specify -branchpassword when -branch is not specified.");
+                    return 1;
+                }
+
                 ContentDownloader.Config.DownloadAllPlatforms = HasParameter(args, "-all-platforms");
 
                 var os = GetParameter<string>(args, "-os");

DepotDownloader/Steam3Session.cs

@@ -310,6 +310,22 @@ public async Task CheckAppBetaPassword(uint appid, string password)
             }
         }
 
+        public async Task<KeyValue> GetPrivateBetaDepotSection(uint appid, string branch)
+        {
+            if (!AppBetaPasswords.TryGetValue(branch, out var branchPassword)) // Should be filled by CheckAppBetaPassword
+            {
+                return new KeyValue();
+            }
+
+            AppTokens.TryGetValue(appid, out var accessToken); // Should be filled by RequestAppInfo
+
+            var privateBeta = await steamApps.PICSGetPrivateBeta(appid, accessToken, branch, branchPassword);
+
+            Console.WriteLine($"Retrieved private beta depot section for {appid} with result: {privateBeta.Result}");
+
+            return privateBeta.DepotSection;
+        }
+
         public async Task<PublishedFileDetails> GetPublishedFileDetails(uint appId, PublishedFileID pubFile)
         {
             var pubFileRequest = new CPublishedFile_GetDetails_Request { appid = appId };