feat(chrome): hand snapshots to context mode

2026-08-28 08:35:57 +00:00 · 2026-08-28 14:45:37 +08:00
parent 221e978622
commit f3a2abe1e4
96 changed files with 12800 additions and 26 deletions
@@ -0,0 +1,76 @@
+<!doctype html>
+<meta charset="utf-8">
+<title>23 stack-trace fingerprint</title>
+<link rel="stylesheet" href="../_style.css">
+<script src="../_lib.js"></script>
+<body>
+<main>
+  <p>Goal: click the button. The page samples call stacks from inside several
+     instrumented globals (<code>Function.prototype.toString</code>,
+     <code>document.querySelector</code>, <code>Element.prototype.click</code>) and inspects
+     the stack of <em>this script's own</em> handler. It fails if it sees telltales of
+     evaluator-injected frames (e.g. <code>at &lt;anonymous&gt;</code> as the only frame, the
+     bridge's <code>new Function</code> wrapper, <code>callFunctionOn</code>,
+     <code>executeScript</code>, or extension URLs).</p>
+  <button id="go" style="padding:14px 22px;font-size:16px;background:#1f7a1f;color:#fff;border:0;border-radius:6px">Click me</button>
+</main>
+<script>
+Challenge.init({ id: "stack-trace-fingerprint", instructions: "click the button" });
+
+// Suspicious stack-frame patterns commonly observed when code is invoked via
+// CDP Runtime.evaluate / chrome.scripting.executeScript / new Function bodies
+// dispatched from an MV3 service worker.
+const SUSPICIOUS = [
+  /chrome-extension:\/\//i,
+  /\bnew Function\b/,
+  /Runtime\.evaluate/i,
+  /Runtime\.callFunctionOn/i,
+  /executeScript/i,
+  /content[_-]?script/i,
+  /^\s*at\s+eval\b/m,
+];
+
+function inspectStack(stack) {
+  if (!stack) return ["empty stack"];
+  const hits = SUSPICIOUS.filter(r => r.test(stack)).map(r => r.source);
+  const lines = stack.split("\n").filter(l => l.trim().startsWith("at "));
+  // Do not fail on generic <anonymous> frames alone: inline scripts, extensions,
+  // and browser versions vary here. This test should catch concrete automation
+  // tells, not punish legitimate stack formatting differences.
+  const reasons = [];
+  if (hits.length) reasons.push("suspicious frames: " + hits.join(","));
+  return reasons;
+}
+
+// Hook some commonly-touched APIs so any pre-click bridge instrumentation also
+// leaves a trail. Their stacks get inspected the moment the click handler fires.
+const probeStacks = [];
+const oTo = Function.prototype.toString;
+Function.prototype.toString = function () {
+  probeStacks.push({ where: "Function.toString", stack: new Error().stack });
+  return oTo.apply(this, arguments);
+};
+const oQS = Document.prototype.querySelector;
+Document.prototype.querySelector = function (sel) {
+  probeStacks.push({ where: "document.querySelector", sel, stack: new Error().stack });
+  return oQS.apply(this, arguments);
+};
+
+document.getElementById("go").addEventListener("click", (e) => {
+  const ownStack = new Error().stack || "";
+  const reasons = inspectStack(ownStack);
+  // Also check any probe stacks gathered before the click — the bridge often
+  // queries the DOM right before dispatching.
+  const probeBad = [];
+  for (const p of probeStacks) {
+    const r = inspectStack(p.stack);
+    if (r.length) probeBad.push(`${p.where}: ${r.join("; ")}`);
+  }
+  Challenge.log("stacks", { ownStack, probeStacks });
+  if (!e.isTrusted) return Challenge.fail("click isTrusted=false");
+  if (reasons.length) return Challenge.fail(...reasons);
+  if (probeBad.length) return Challenge.fail(...probeBad.slice(0, 3));
+  Challenge.pass("call stack matches an in-page event handler");
+});
+</script>
+</body>