Gateway: add safer password-file input for gateway run (#39067)

* CLI: add gateway password-file option

* Docs: document safer gateway password input

* Update src/cli/gateway-cli/run.ts

Co-authored-by: greptile-apps[bot] <165735046+greptile-apps[bot]@users.noreply.github.com>

* Tests: clean up gateway password temp dirs

* CLI: restore gateway password warning flow

* Security: harden secret file reads

---------

Co-authored-by: greptile-apps[bot] <165735046+greptile-apps[bot]@users.noreply.github.com>

src/acp/secret-file.test.ts

@@ -0,0 +1,54 @@
+import { mkdir, symlink, writeFile } from "node:fs/promises";
+import path from "node:path";
+import { afterEach, describe, expect, it } from "vitest";
+import { createTrackedTempDirs } from "../test-utils/tracked-temp-dirs.js";
+import { MAX_SECRET_FILE_BYTES, readSecretFromFile } from "./secret-file.js";
+
+const tempDirs = createTrackedTempDirs();
+const createTempDir = () => tempDirs.make("openclaw-secret-file-test-");
+
+afterEach(async () => {
+  await tempDirs.cleanup();
+});
+
+describe("readSecretFromFile", () => {
+  it("reads and trims a regular secret file", async () => {
+    const dir = await createTempDir();
+    const file = path.join(dir, "secret.txt");
+    await writeFile(file, " top-secret \n", "utf8");
+
+    expect(readSecretFromFile(file, "Gateway password")).toBe("top-secret");
+  });
+
+  it("rejects files larger than the secret-file limit", async () => {
+    const dir = await createTempDir();
+    const file = path.join(dir, "secret.txt");
+    await writeFile(file, "x".repeat(MAX_SECRET_FILE_BYTES + 1), "utf8");
+
+    expect(() => readSecretFromFile(file, "Gateway password")).toThrow(
+      `Gateway password file at ${file} exceeds ${MAX_SECRET_FILE_BYTES} bytes.`,
+    );
+  });
+
+  it("rejects non-regular files", async () => {
+    const dir = await createTempDir();
+    const nestedDir = path.join(dir, "secret-dir");
+    await mkdir(nestedDir);
+
+    expect(() => readSecretFromFile(nestedDir, "Gateway password")).toThrow(
+      `Gateway password file at ${nestedDir} must be a regular file.`,
+    );
+  });
+
+  it("rejects symlinks", async () => {
+    const dir = await createTempDir();
+    const target = path.join(dir, "target.txt");
+    const link = path.join(dir, "secret-link.txt");
+    await writeFile(target, "top-secret\n", "utf8");
+    await symlink(target, link);
+
+    expect(() => readSecretFromFile(link, "Gateway password")).toThrow(
+      `Gateway password file at ${link} must not be a symlink.`,
+    );
+  });
+});

src/acp/secret-file.ts

@@ -1,11 +1,32 @@
 import fs from "node:fs";
 import { resolveUserPath } from "../utils.js";
 
+export const MAX_SECRET_FILE_BYTES = 16 * 1024;
+
 export function readSecretFromFile(filePath: string, label: string): string {
   const resolvedPath = resolveUserPath(filePath.trim());
   if (!resolvedPath) {
     throw new Error(`${label} file path is empty.`);
   }
+
+  let stat: fs.Stats;
+  try {
+    stat = fs.lstatSync(resolvedPath);
+  } catch (err) {
+    throw new Error(`Failed to inspect ${label} file at ${resolvedPath}: ${String(err)}`, {
+      cause: err,
+    });
+  }
+  if (stat.isSymbolicLink()) {
+    throw new Error(`${label} file at ${resolvedPath} must not be a symlink.`);
+  }
+  if (!stat.isFile()) {
+    throw new Error(`${label} file at ${resolvedPath} must be a regular file.`);
+  }
+  if (stat.size > MAX_SECRET_FILE_BYTES) {
+    throw new Error(`${label} file at ${resolvedPath} exceeds ${MAX_SECRET_FILE_BYTES} bytes.`);
+  }
+
   let raw = "";
   try {
     raw = fs.readFileSync(resolvedPath, "utf8");