fix(runtime): use process-owned credential-home locks

sdk/typescript/README.md

@@ -164,6 +164,16 @@ when the dedicated home does not already contain stored credentials. Logging
 out prevents later scans from automatically reimporting that ambient sign-in
 until you explicitly log in again.
 
+Scan runtime preparation uses a process-owned lock on this home. Pausing a
+process does not release its lock; exiting or crashing does. The internal
+`.codex-security-scan.sqlite3` file stays in the home between operations. Do not
+remove it while any operation is running.
+
+Older releases recorded only a PID. If an old `.codex-security-scan.lock`
+directory names a PID that has been reused, automatic recovery cannot safely
+distinguish it from a live owner. Stop all operations using that credential home
+before removing the old lock directory manually.
+
 An environment API key takes precedence over a stored sign-in by default.
 When both a stored ChatGPT sign-in and an environment API key are available, an
 interactive scan asks which credential to use. JSON output, dry runs, CI, and

sdk/typescript/scripts/fixtures/credential-lock.mjs

@@ -0,0 +1,99 @@
+import assert from "node:assert/strict";
+import { spawn } from "node:child_process";
+import { once } from "node:events";
+import { readFile, utimes, writeFile } from "node:fs/promises";
+import { join } from "node:path";
+import { createInterface } from "node:readline";
+
+const [runtimeUrl, directory, mode] = process.argv.slice(2);
+const {
+  acquireCodexSecurityCredentialHomeLock: acquire,
+  prepareCodexSecurityCredentialHome: prepare,
+} = await import(runtimeUrl);
+
+if (mode === "hold") {
+  const release = await acquire(directory);
+  process.stdout.write("locked\n");
+  await once(process.stdin, "data");
+  await new Promise((resolve) => process.stdout.write("blocked\n", resolve));
+  // Stall the actual owner, including any JavaScript heartbeat it might run.
+  Atomics.wait(new Int32Array(new SharedArrayBuffer(4)), 0, 0);
+  await release();
+} else {
+  const home = await prepare({ CODEX_SECURITY_STATE_DIR: directory });
+  const lock = join(home, ".codex-security-scan.lock");
+  const ownerPath = join(lock, "owner.json");
+  const holder = spawn(
+    process.execPath,
+    [process.argv[1], runtimeUrl, home, "hold"],
+    {
+      stdio: ["pipe", "pipe", "pipe"],
+      windowsHide: true,
+      timeout: 20_000,
+      killSignal: "SIGKILL",
+    },
+  );
+  const exited = once(holder, "exit");
+  let stderr = "";
+  holder.stderr.setEncoding("utf8").on("data", (chunk) => {
+    stderr += chunk;
+  });
+  const lines = createInterface({ input: holder.stdout });
+  const output = lines[Symbol.asyncIterator]();
+  async function expectOutput(expected) {
+    const line = await Promise.race([
+      output.next(),
+      exited.then(() => {
+        throw new Error(`Credential-lock holder exited early: ${stderr}`);
+      }),
+    ]);
+    assert.equal(line.value, expected);
+  }
+
+  let release;
+  try {
+    await expectOutput("locked");
+    holder.stdin.write("block\n");
+    await expectOutput("blocked");
+    const owner = JSON.parse(await readFile(ownerPath, "utf8"));
+    const stale = new Date(Date.now() - 60_000);
+    await utimes(lock, stale, stale);
+
+    const controller = new AbortController();
+    // Wait longer than the former five-second stale-heartbeat grace period.
+    const timeout = setTimeout(() => controller.abort(), 6_000);
+    try {
+      await assert.rejects(
+        async () => {
+          release = await acquire(home, controller.signal);
+        },
+        { name: "AbortError" },
+      );
+    } finally {
+      clearTimeout(timeout);
+    }
+    assert.deepEqual(JSON.parse(await readFile(ownerPath, "utf8")), owner);
+
+    holder.kill("SIGKILL");
+    await exited;
+    // Reuse a known live PID without relying on the OS to recycle one in a test.
+    await writeFile(ownerPath, JSON.stringify({ ...owner, pid: process.pid }));
+    const recovery = new AbortController();
+    const recoveryTimeout = setTimeout(() => recovery.abort(), 5_000);
+    try {
+      release = await acquire(home, recovery.signal);
+    } finally {
+      clearTimeout(recoveryTimeout);
+    }
+    await release();
+    release = undefined;
+    console.log(
+      "Paused owner protected; crashed owner with reused PID recovered.",
+    );
+  } finally {
+    holder.kill("SIGKILL");
+    await exited;
+    lines.close();
+    await release?.();
+  }
+}

sdk/typescript/scripts/smoke-package.mjs

@@ -518,10 +518,20 @@ try {
     /lin_api_|security@example\.test/u,
   );
 
+  run(
+    process.execPath,
+    [
+      join(packageRoot, "scripts", "fixtures", "credential-lock.mjs"),
+      pathToFileURL(join(installedRoot, "dist", "runtime.js")).href,
+      join(consumer, "credential-lock-state"),
+    ],
+    { cwd: consumer },
+  );
+
   await smokeNestedDeepScanWorker(installedRoot, consumer);
 
   console.log(
-    `Validated installed ${packageManifest.name}@${packageManifest.version}: public import, NodeNext types, CLI, ${expectedPluginFiles.length} bundled plugin files, bundled Codex version, and a nested worker without global codex.`,
+    `Validated installed ${packageManifest.name}@${packageManifest.version}: public import, NodeNext types, CLI, credential locking, ${expectedPluginFiles.length} bundled plugin files, bundled Codex version, and a nested worker without global codex.`,
   );
 } finally {
   await rm(consumer, {