Restore derived key default exportable to false, provide option to ma…

…ke exportable (#38)

src/index.ts

@@ -55,7 +55,7 @@ export async function encryptWithDetail<R>(
   dataObj: R,
   salt = generateSalt(),
 ): Promise<DetailedEncryptionResult> {
-  const key = await keyFromPassword(password, salt);
+  const key = await keyFromPassword(password, salt, true);
   const exportedKeyString = await exportKey(key);
   const vault = await encrypt(password, dataObj, key, salt);
 
@@ -137,7 +137,7 @@ export async function decryptWithDetail(
 ): Promise<DetailedDecryptResult> {
   const payload = JSON.parse(text);
   const { salt } = payload;
-  const key = await keyFromPassword(password, salt);
+  const key = await keyFromPassword(password, salt, true);
   const exportedKeyString = await exportKey(key);
   const vault = await decrypt(password, text, key);
 
@@ -216,11 +216,13 @@ export async function exportKey(key: CryptoKey): Promise<string> {
  *
  * @param password - The password to use to generate key.
  * @param salt - The salt string to use in key derivation.
+ * @param exportable - Should the derived key be exportable.
  * @returns A CryptoKey for encryption and decryption.
  */
 export async function keyFromPassword(
   password: string,
   salt: string,
+  exportable = false,
 ): Promise<CryptoKey> {
   const passBuffer = Buffer.from(password, STRING_ENCODING);
   const saltBuffer = Buffer.from(salt, 'base64');
@@ -242,7 +244,7 @@ export async function keyFromPassword(
     },
     key,
     { name: DERIVED_KEY_FORMAT, length: 256 },
-    true,
+    exportable,
     ['encrypt', 'decrypt'],
   );
 

test/index.spec.ts

@@ -109,6 +109,7 @@ test('encryptor:encryptWithDetail returns vault', async ({ page }) => {
     { data, password },
   );
   expect(typeof encryptedDetail.vault).toBe('string');
+  expect(typeof encryptedDetail.exportedKeyString).toBe('string');
 });
 
 test('encryptor:encrypt & decrypt with wrong password', async ({ page }) => {
@@ -207,6 +208,9 @@ test('encryptor:decryptWithDetail returns same vault as decrypt', async ({
     JSON.stringify(decryptWithDetailResult.vault),
   );
   expect(Object.keys(decryptWithDetailResult).length).toBe(3);
+  expect(typeof decryptWithDetailResult.exportedKeyString).toStrictEqual(
+    'string',
+  );
 });
 
 test('encryptor:encrypt using key then decrypt', async ({ page }) => {
@@ -555,3 +559,30 @@ test('encryptor:encryptWithKey works with decryptWithKey', async ({ page }) => {
     JSON.stringify(newData),
   );
 });
+
+test('encryptor:keyFromPassword cannot be exported by default', async ({
+  page,
+}) => {
+  const password = 'a sample passw0rd';
+  const data = { foo: 'data to encrypt' };
+  const salt = await page.evaluate(() => window.encryptor.generateSalt());
+
+  const exportResult = await page.evaluate(
+    async (args) => {
+      const key = await window.encryptor.keyFromPassword(
+        args.password,
+        args.salt,
+      );
+
+      try {
+        const result = await window.encryptor.exportKey(key);
+        return result;
+      } catch (e) {
+        return 'error';
+      }
+    },
+    { data, password, salt },
+  );
+
+  expect(exportResult).toStrictEqual('error');
+});