From cc63ffa6bbdb0ead3cd03ec8294dc52cfc13e3e8 Mon Sep 17 00:00:00 2001
From: Jonas Jenwald <jonas.jenwald@gmail.com>
Date: Thu, 13 Mar 2025 09:57:50 +0100
Subject: [PATCH] Reduce duplication when checking the userPassword, in
 `CipherTransformFactory.prototype.#prepareKeyData`

Currently we duplicate the exact same code in both the `if`- and `else`-branches, which seems unnecessary, and we can also replace the manual loop.
---
 src/core/crypto.js | 14 +++-----------
 1 file changed, 3 insertions(+), 11 deletions(-)

diff --git a/src/core/crypto.js b/src/core/crypto.js
index c5ebdefbc..e11f579e0 100644
--- a/src/core/crypto.js
+++ b/src/core/crypto.js
@@ -916,23 +916,15 @@ class CipherTransformFactory {
         cipher = new ARCFourCipher(derivedKey);
         checkData = cipher.encryptBlock(checkData);
       }
-      for (j = 0, n = checkData.length; j < n; ++j) {
-        if (userPassword[j] !== checkData[j]) {
-          return null;
-        }
-      }
     } else {
       cipher = new ARCFourCipher(encryptionKey);
       checkData = cipher.encryptBlock(
         CipherTransformFactory._defaultPasswordBytes
       );
-      for (j = 0, n = checkData.length; j < n; ++j) {
-        if (userPassword[j] !== checkData[j]) {
-          return null;
-        }
-      }
     }
-    return encryptionKey;
+    return checkData.every((data, k) => userPassword[k] === data)
+      ? encryptionKey
+      : null;
   }
 
   #decodeUserPassword(password, ownerPassword, revision, keyLength) {