From fd5e64d653b8f0650c6ba4cebcc6a0fb78a7b1e6 Mon Sep 17 00:00:00 2001
From: "google-labs-jules[bot]"
 <161369871+google-labs-jules[bot]@users.noreply.github.com>
Date: Wed, 25 Mar 2026 12:10:47 +0000
Subject: [PATCH] =?UTF-8?q?=E2=9A=A1=20Optimize=20Regex=20performance=20in?=
 =?UTF-8?q?=20UsbManager.cs?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

- Replaced inline Regex.IsMatch calls with static readonly Regex instances.
- Enabled RegexOptions.Compiled for pre-compilation of patterns.
- Optimized validation of date, hash, and GUID formats in CheckUSBKey.

Co-authored-by: LDzik <63643405+LDzik@users.noreply.github.com>
---
 LWCredentialProvider/UsbManager.cs | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/LWCredentialProvider/UsbManager.cs b/LWCredentialProvider/UsbManager.cs
index 09b9af8..4144327 100644
--- a/LWCredentialProvider/UsbManager.cs
+++ b/LWCredentialProvider/UsbManager.cs
@@ -4,12 +4,17 @@
 using System.Linq;
 using System.Security.Cryptography;
 using System.Text;
+using System.Text.RegularExpressions;
 using System.Runtime.InteropServices;
 using Microsoft.Win32.SafeHandles;
 // namespace LWCredentialProvider
 // {
     public class USBManager
     {
+        private static readonly Regex DateRegex = new Regex(@"^\d{8}-\d{6}$", RegexOptions.Compiled);
+        private static readonly Regex HashRegex = new Regex(@"^[0-9A-F]{10}$", RegexOptions.Compiled);
+        private static readonly Regex GuidRegex = new Regex(@"^[0-9A-F]{1,32}$", RegexOptions.Compiled);
+
         [DllImport("kernel32.dll", SetLastError = true)]
         private static extern bool DeviceIoControl(
             SafeFileHandle hDevice,
@@ -138,20 +143,20 @@ public static bool CheckUSBKey(string usbKey)
 
 
             // Validate date format
-            if (!System.Text.RegularExpressions.Regex.IsMatch(date, @"^\d{8}-\d{6}$"))
+            if (!DateRegex.IsMatch(date))
                 return false;
 
             Console.WriteLine($"hash: {hash}");
 
 
             // Validate hash format
-            if (!System.Text.RegularExpressions.Regex.IsMatch(hash, @"^[0-9A-F]{10}$"))
+            if (!HashRegex.IsMatch(hash))
                 return false;
 
             Console.WriteLine($"guid: {guid}");
 
             // Validate GUID format
-            if (!System.Text.RegularExpressions.Regex.IsMatch(guid, @"^[0-9A-F]{1,32}$"))
+            if (!GuidRegex.IsMatch(guid))
                 return false;