launcher: auto-strip SteamStub DRM before patching

Steam-purchased Rec Room ships with SteamStub Variant 3.1 wrapping Recroom_Release.exe so it refuses to launch without Steam loaded. DorkNet spawns the exe directly, so for Steam installs we have to unwrap it first or the user gets a silent crash on Launch. - SteamDrmStripper.StripIfNeededAsync: PE-walks the exe's section table looking for the .bind section SteamStub adds, and only invokes Steamless when that section is present. Re-runs detect the already-unwrapped exe and short-circuit. Backs up the original next to the exe as Recroom_Release.exe.steamwrapped. - SteamlessInstaller: resolves a usable Steamless.CLI.exe via side-by-side -> %LOCALAPPDATA%\DorkNet\Steamless\ cache -> download v3.1.0.5 from atom0s/Steamless GitHub releases. Same pattern as CloudflaredInstaller. - Inserted as a step between "Download client patcher" and "Patch your Rec Room install" in both host (5 -> 6 steps) and join (2 -> 3 steps). Step detail reports Stripped / AlreadyUnpacked / NotApplicable so the user sees what happened. Oculus / Quest builds and already-unwrapped installs skip the Steamless download entirely.
2026-10-27 07:58:45 -07:00 · 2026-05-27 12:10:27 +03:00
parent de98ea694f
commit 26786527cd
4 changed files with 273 additions and 0 deletions
@@ -0,0 +1,107 @@
+using System.IO;
+using System.IO.Compression;
+using System.Net.Http;
+
+namespace DorkNet.Launcher.Backend;
+
+/// <summary>Resolves a usable <c>Steamless.CLI.exe</c>: prefers a
+/// side-by-side install, falls back to the cached copy under
+/// <c>%LOCALAPPDATA%\DorkNet\Steamless\</c>, otherwise downloads the
+/// pinned release zip from atom0s/Steamless on GitHub.
+///
+/// <para>Steamless strips the SteamStub Variant 3.1 DRM wrapper from
+/// Rec Room's <c>Recroom_Release.exe</c> so the launcher can run it
+/// without Steam loaded. Rec Room users on Oculus or non-Steam builds
+/// don't need this; we detect the wrapper presence in
+/// <see cref="SteamDrmStripper"/> and only invoke Steamless when the
+/// .bind section is actually present.</para>
+///
+/// <para>Pinned to v3.1.0.5 — current stable that handles 2020-era
+/// Steam DRM. Newer versions are drop-in compatible but we pin so a
+/// breaking upstream change doesn't surprise hosts.</para></summary>
+public static class SteamlessInstaller
+{
+    private const string PinnedVersion = "v3.1.0.5";
+    private const string ZipUrl =
+        "https://github.com/atom0s/Steamless/releases/download/" +
+        PinnedVersion + "/Steamless." + PinnedVersion + ".zip";
+
+    private static readonly HttpClient Http = new()
+    {
+        Timeout = TimeSpan.FromMinutes(5),
+    };
+
+    public static async Task<string> EnsureAsync(
+        IProgress<DownloadProgress>? progress = null,
+        CancellationToken ct = default)
+    {
+        if (TryFindLocal(out var existing)) return existing;
+
+        var cacheDir = Path.Combine(AppPaths.LocalRoot, "Steamless");
+        var zipPath = Path.Combine(AppPaths.LocalRoot, $"Steamless.{PinnedVersion}.zip");
+        Directory.CreateDirectory(AppPaths.LocalRoot);
+
+        await DownloadAsync(ZipUrl, zipPath, progress, ct);
+        if (!File.Exists(zipPath) || new FileInfo(zipPath).Length < 500_000)
+            throw new InvalidOperationException(
+                $"Steamless download produced an unexpectedly small file at {zipPath}. " +
+                "Check internet connection + retry.");
+
+        if (Directory.Exists(cacheDir)) Directory.Delete(cacheDir, recursive: true);
+        Directory.CreateDirectory(cacheDir);
+        ZipFile.ExtractToDirectory(zipPath, cacheDir);
+
+        var cli = Path.Combine(cacheDir, "Steamless.CLI.exe");
+        if (!File.Exists(cli))
+            throw new InvalidOperationException(
+                $"Extracted Steamless is missing Steamless.CLI.exe at {cli} — release layout may have changed");
+        return cli;
+    }
+
+    private static bool TryFindLocal(out string path)
+    {
+        var sideBySide = Path.Combine(AppContext.BaseDirectory, "Steamless", "Steamless.CLI.exe");
+        if (File.Exists(sideBySide)) { path = sideBySide; return true; }
+
+        var cached = Path.Combine(AppPaths.LocalRoot, "Steamless", "Steamless.CLI.exe");
+        if (File.Exists(cached)) { path = cached; return true; }
+
+        path = string.Empty;
+        return false;
+    }
+
+    private static async Task DownloadAsync(
+        string url, string destPath,
+        IProgress<DownloadProgress>? progress,
+        CancellationToken ct)
+    {
+        var temp = destPath + ".download";
+        try
+        {
+            using var resp = await Http.GetAsync(url, HttpCompletionOption.ResponseHeadersRead, ct);
+            resp.EnsureSuccessStatusCode();
+            var total = resp.Content.Headers.ContentLength ?? -1L;
+
+            await using (var src = await resp.Content.ReadAsStreamAsync(ct))
+            await using (var dst = File.Create(temp))
+            {
+                var buf = new byte[81920];
+                long readTotal = 0;
+                int read;
+                while ((read = await src.ReadAsync(buf, ct)) > 0)
+                {
+                    await dst.WriteAsync(buf.AsMemory(0, read), ct);
+                    readTotal += read;
+                    progress?.Report(new DownloadProgress(readTotal, total));
+                }
+            }
+            if (File.Exists(destPath)) File.Delete(destPath);
+            File.Move(temp, destPath);
+        }
+        catch
+        {
+            try { if (File.Exists(temp)) File.Delete(temp); } catch { }
+            throw;
+        }
+    }
+}