fix: handle unavailable browser cryptography

Detect insecure or unsupported browser contexts before account registration and show localized HTTPS guidance instead of leaking a SubtleCrypto runtime error. Fixes #320
2026-08-05 06:50:10 +00:00 · 2026-07-23 00:54:52 +08:00
parent f761fffd58
commit 82d9f61163
15 changed files with 165 additions and 22 deletions
@@ -0,0 +1,84 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+
+import { registerAccount } from '../webapp/src/lib/api/auth';
+import {
+  requireWebCrypto,
+  WebCryptoUnavailableError,
+} from '../webapp/src/lib/crypto';
+
+const supportedCrypto = {
+  subtle: {
+    importKey: () => Promise.reject(new Error('not used by capability checks')),
+  },
+  getRandomValues: <T>(array: T): T => array,
+} as unknown as Crypto;
+
+function restoreGlobalProperty(name: string, descriptor: PropertyDescriptor | undefined): void {
+  if (descriptor) {
+    Object.defineProperty(globalThis, name, descriptor);
+    return;
+  }
+  delete (globalThis as unknown as Record<string, unknown>)[name];
+}
+
+test('Web Crypto guard rejects insecure browser contexts', () => {
+  assert.throws(
+    () => requireWebCrypto({ crypto: supportedCrypto, isSecureContext: false }),
+    WebCryptoUnavailableError
+  );
+});
+
+test('Web Crypto guard rejects secure contexts without SubtleCrypto', () => {
+  const cryptoWithoutSubtle = {
+    getRandomValues: <T>(array: T): T => array,
+  } as unknown as Crypto;
+
+  assert.throws(
+    () => requireWebCrypto({ crypto: cryptoWithoutSubtle, isSecureContext: true }),
+    WebCryptoUnavailableError
+  );
+});
+
+test('Web Crypto guard accepts a secure supported browser', () => {
+  assert.equal(
+    requireWebCrypto({ crypto: supportedCrypto, isSecureContext: true }),
+    supportedCrypto
+  );
+});
+
+test('registration returns an actionable error without contacting the backend', async () => {
+  const cryptoDescriptor = Object.getOwnPropertyDescriptor(globalThis, 'crypto');
+  const secureContextDescriptor = Object.getOwnPropertyDescriptor(globalThis, 'isSecureContext');
+  const fetchDescriptor = Object.getOwnPropertyDescriptor(globalThis, 'fetch');
+  let fetchCalled = false;
+
+  Object.defineProperty(globalThis, 'crypto', { value: undefined, configurable: true });
+  Object.defineProperty(globalThis, 'isSecureContext', { value: false, configurable: true });
+  Object.defineProperty(globalThis, 'fetch', {
+    configurable: true,
+    value: async () => {
+      fetchCalled = true;
+      return new Response(null, { status: 500 });
+    },
+  });
+
+  try {
+    const result = await registerAccount({
+      email: 'first@example.test',
+      name: 'First Admin',
+      password: 'correct horse battery staple',
+      fallbackIterations: 600_000,
+    });
+
+    assert.deepEqual(result, {
+      ok: false,
+      message: 'Secure browser cryptography is unavailable. Open NodeWarden over HTTPS in a supported browser.',
+    });
+    assert.equal(fetchCalled, false);
+  } finally {
+    restoreGlobalProperty('crypto', cryptoDescriptor);
+    restoreGlobalProperty('isSecureContext', secureContextDescriptor);
+    restoreGlobalProperty('fetch', fetchDescriptor);
+  }
+});