fix(scripts): cap gh-read json bodies

scripts/gh-read.ts

@@ -2,6 +2,7 @@ import { execFileSync, spawnSync } from "node:child_process";
 import { createPrivateKey, createSign } from "node:crypto";
 import { readFileSync } from "node:fs";
 import { pathToFileURL } from "node:url";
+import { readBoundedResponseText } from "./lib/bounded-response.ts";
 import { parseStrictIntegerOption } from "./lib/dev-tooling-safety.ts";
 
 const APP_ID_ENV = "OPENCLAW_GH_READ_APP_ID";
@@ -11,6 +12,7 @@ const PERMISSIONS_ENV = "OPENCLAW_GH_READ_PERMISSIONS";
 const API_VERSION = "2022-11-28";
 const DEFAULT_GITHUB_FETCH_TIMEOUT_MS = 30_000;
 const GITHUB_ERROR_BODY_MAX_CHARS = 4096;
+const GITHUB_JSON_BODY_MAX_BYTES = 1024 * 1024;
 const DEFAULT_READ_PERMISSION_KEYS = [
   "actions",
   "checks",
@@ -230,6 +232,19 @@ export async function readBoundedGitHubErrorText(
   return truncated ? `${text}\n[truncated]` : text;
 }
 
+export async function readBoundedGitHubJson<T>(
+  response: Response,
+  maxBytes = GITHUB_JSON_BODY_MAX_BYTES,
+): Promise<T> {
+  const text = await readBoundedResponseText(response, "GitHub API", maxBytes, {
+    createTooLargeError: (message) =>
+      Object.assign(new Error(message), {
+        code: "ETOOBIG",
+      }),
+  });
+  return JSON.parse(text) as T;
+}
+
 export async function githubJson<T>(
   path: string,
   bearerToken: string,
@@ -263,7 +278,7 @@ export async function githubJson<T>(
         fail(`${init?.method ?? "GET"} ${path} failed (${response.status}): ${text}`);
       }
 
-      return (await response.json()) as T;
+      return await readBoundedGitHubJson<T>(response);
     },
   );
 }

test/scripts/gh-read.test.ts

@@ -6,6 +6,7 @@ import {
   parsePermissionKeys,
   parseRepoArg,
   readBoundedGitHubErrorText,
+  readBoundedGitHubJson,
   resolveGitHubFetchTimeoutMs,
 } from "../../scripts/gh-read.js";
 
@@ -68,11 +69,7 @@ describe("gh-read helpers", () => {
   });
 
   it("times out stalled GitHub API response body reads", async () => {
-    const response = {
-      ok: true,
-      status: 200,
-      json: () => new Promise(() => {}),
-    } as Response;
+    const response = new Response(new ReadableStream({}), { status: 200 });
     const request = githubJson("/app/installations", "token", undefined, {
       timeoutMs: 5,
       fetchImpl: (() => Promise.resolve(response)) as typeof fetch,
@@ -94,6 +91,53 @@ describe("gh-read helpers", () => {
     expect(text.length).toBeLessThan(4200);
   });
 
+  it("reads bounded GitHub API JSON responses", async () => {
+    await expect(readBoundedGitHubJson(new Response('{"id":123}'), 1024)).resolves.toEqual({
+      id: 123,
+    });
+  });
+
+  it("rejects oversized GitHub API JSON responses by content length", async () => {
+    let canceled = false;
+    const response = new Response(
+      new ReadableStream({
+        cancel() {
+          canceled = true;
+        },
+      }),
+      {
+        headers: {
+          "content-length": "1025",
+        },
+      },
+    );
+
+    await expect(readBoundedGitHubJson(response, 1024)).rejects.toMatchObject({
+      code: "ETOOBIG",
+      message: "GitHub API response body exceeded 1024 bytes",
+    });
+    expect(canceled).toBe(true);
+  });
+
+  it("rejects oversized streamed GitHub API JSON responses", async () => {
+    const encoder = new TextEncoder();
+    const response = new Response(
+      new ReadableStream({
+        start(controller) {
+          controller.enqueue(encoder.encode('{"body":"'));
+          controller.enqueue(encoder.encode("x".repeat(1024)));
+          controller.enqueue(encoder.encode('"}'));
+          controller.close();
+        },
+      }),
+    );
+
+    await expect(readBoundedGitHubJson(response, 1024)).rejects.toMatchObject({
+      code: "ETOOBIG",
+      message: "GitHub API response body exceeded 1024 bytes",
+    });
+  });
+
   it("rejects invalid GitHub API timeout values", () => {
     expect(resolveGitHubFetchTimeoutMs("1000")).toBe(1000);
     expect(() => resolveGitHubFetchTimeoutMs("1s")).toThrow(