test(wallet): add encryptorFactory unit tests

Export encryptorFactory so its returned functions can be tested directly
without constructing a full Wallet.

Add keyring-controller.test.ts with a describe block per factory:
- encrypt: round-trips and embeds the PBKDF2 iteration count
- encryptWithDetail: round-trips via the vault field and embeds the count
- isVaultUpdated: true for matching iterations, false for mismatched

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: grypez

packages/wallet/src/initialization/instances/keyring-controller.test.ts

@@ -0,0 +1,69 @@
+import { decrypt, encryptWithDetail, isVaultUpdated } from '@metamask/browser-passworder';
+
+import { encryptorFactory } from './keyring-controller';
+
+const PASSWORD = 'test-password';
+const DATA = { foo: 'bar' };
+// Use a low iteration count so tests run quickly; we are testing wiring, not
+// cryptographic strength.
+const ITERATIONS = 1_000;
+
+describe('encryptorFactory', () => {
+  describe('encrypt', () => {
+    it('produces ciphertext that decrypts back to the original data', async () => {
+      const { encrypt } = encryptorFactory(ITERATIONS);
+      const ciphertext = await encrypt(PASSWORD, DATA);
+      expect(await decrypt(PASSWORD, ciphertext)).toStrictEqual(DATA);
+    });
+
+    it('embeds the specified PBKDF2 iteration count', async () => {
+      const { encrypt } = encryptorFactory(ITERATIONS);
+      const ciphertext = await encrypt(PASSWORD, DATA);
+      expect(
+        isVaultUpdated(ciphertext, {
+          algorithm: 'PBKDF2',
+          params: { iterations: ITERATIONS },
+        }),
+      ).toBe(true);
+    });
+  });
+
+  describe('encryptWithDetail', () => {
+    it('returns a vault that decrypts back to the original data', async () => {
+      const { encryptWithDetail: encryptWithDetailFn } =
+        encryptorFactory(ITERATIONS);
+      const { vault } = await encryptWithDetailFn(PASSWORD, DATA);
+      expect(await decrypt(PASSWORD, vault)).toStrictEqual(DATA);
+    });
+
+    it('embeds the specified PBKDF2 iteration count in the vault', async () => {
+      const { encryptWithDetail: encryptWithDetailFn } =
+        encryptorFactory(ITERATIONS);
+      const { vault } = await encryptWithDetailFn(PASSWORD, DATA);
+      expect(
+        isVaultUpdated(vault, {
+          algorithm: 'PBKDF2',
+          params: { iterations: ITERATIONS },
+        }),
+      ).toBe(true);
+    });
+  });
+
+  describe('isVaultUpdated', () => {
+    it('returns true for a vault encrypted with the matching iteration count', async () => {
+      const { vault } = await encryptWithDetail(PASSWORD, DATA, undefined, {
+        algorithm: 'PBKDF2',
+        params: { iterations: ITERATIONS },
+      });
+      expect(encryptorFactory(ITERATIONS).isVaultUpdated(vault)).toBe(true);
+    });
+
+    it('returns false for a vault encrypted with a different iteration count', async () => {
+      const { vault } = await encryptWithDetail(PASSWORD, DATA, undefined, {
+        algorithm: 'PBKDF2',
+        params: { iterations: ITERATIONS - 1 },
+      });
+      expect(encryptorFactory(ITERATIONS).isVaultUpdated(vault)).toBe(false);
+    });
+  });
+});

packages/wallet/src/initialization/instances/keyring-controller.ts

@@ -124,7 +124,7 @@ const isVaultUpdatedFactory =
  * @param iterations - The number of iterations to use for the PBKDF2 algorithm.
  * @returns An encryptor set with the given number of iterations.
  */
-const encryptorFactory = (iterations: number): Encryptor => ({
+export const encryptorFactory = (iterations: number): Encryptor => ({
   encrypt: encryptFactory(iterations),
   encryptWithKey,
   encryptWithDetail: encryptWithDetailFactory(iterations),