From 2089d62dfdbce287b124026f5ee5c753dfb258ee Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Benjamin=20H=C3=B6glinger-Stelzer?= <nefarius@dhmx.at>
Date: Mon, 12 Nov 2018 02:15:47 +0100
Subject: [PATCH] Replaced call to BCDEdit.exe with proper WMI calls

---
 DerpingDrivers/Util/BcdHelper.cs | 60 ++++++++++++--------------------
 1 file changed, 22 insertions(+), 38 deletions(-)

diff --git a/DerpingDrivers/Util/BcdHelper.cs b/DerpingDrivers/Util/BcdHelper.cs
index fa60a3b..edb22c6 100644
--- a/DerpingDrivers/Util/BcdHelper.cs
+++ b/DerpingDrivers/Util/BcdHelper.cs
@@ -1,14 +1,14 @@
 using System;
-using System.Diagnostics;
 using System.Management;
 using DerpingDrivers.Exceptions;
 using ExceptionReporting;
-using Microsoft.Win32;
 
 namespace DerpingDrivers.Util
 {
     public static class BcdHelper
     {
+        private const uint BcdLibraryBoolean_AllowPrereleaseSignatures = 0x16000049;
+
         /// <summary>
         ///     Gets or sets the current value if BCDE_LIBRARY_TYPE_ALLOW_PRERELEASE_SIGNATURES from the default boot entry.
         /// </summary>
@@ -30,8 +30,8 @@ namespace DerpingDrivers.Util
                         "root\\WMI:BcdObject.Id=\"{fa926493-6f1c-4193-a414-58f0b2456d1e}\",StoreFilePath=\"\""), null))
                 {
                     var inParams = bootMgrObj.GetMethodParameters("GetElement");
-                
-                    inParams["Type"] = (uint) 0x16000049;
+
+                    inParams["Type"] = BcdLibraryBoolean_AllowPrereleaseSignatures;
                     var outParams = bootMgrObj.InvokeMethod("GetElement", inParams, null);
                     var outObj = (ManagementBaseObject) outParams?.Properties["Element"].Value;
 
@@ -45,47 +45,31 @@ namespace DerpingDrivers.Util
             {
                 try
                 {
-                    if (value)
-                    {
-                        // NOTE: haven't found an API for this (yet), so system() we go!
-                        var cmd = new Process
+                    var connectionOptions =
+                        new ConnectionOptions
                         {
-                            StartInfo =
-                            {
-                                FileName = @"C:\WINDOWS\system32\bcdedit.exe",
-                                Arguments = "-set TESTSIGNING ON",
-                                WindowStyle = ProcessWindowStyle.Hidden,
-                                CreateNoWindow = true,
-                                UseShellExecute = false
-                            }
+                            Impersonation = ImpersonationLevel.Impersonate,
+                            EnablePrivileges = true
                         };
 
-                        cmd.Start();
-                        cmd.WaitForExit();
+                    var managementScope = new ManagementScope(@"root\WMI", connectionOptions);
 
-                        if (cmd.ExitCode != 0)
-                            throw new BcdAlterAllowPrereleaseSignaturesFailedException("Couldn't enable TESTSIGNING");
-                    }
-                    else
+                    using (var bootMgrObj = new ManagementObject(managementScope,
+                        new ManagementPath(
+                            "root\\WMI:BcdObject.Id=\"{fa926493-6f1c-4193-a414-58f0b2456d1e}\",StoreFilePath=\"\""),
+                        null))
                     {
-                        // NOTE: haven't found an API for this (yet), so system() we go!
-                        var cmd = new Process
-                        {
-                            StartInfo =
-                            {
-                                FileName = @"C:\WINDOWS\system32\bcdedit.exe",
-                                Arguments = "-set TESTSIGNING OFF",
-                                WindowStyle = ProcessWindowStyle.Hidden,
-                                CreateNoWindow = true,
-                                UseShellExecute = false
-                            }
-                        };
+                        var inParams = bootMgrObj.GetMethodParameters("SetBooleanElement");
 
-                        cmd.Start();
-                        cmd.WaitForExit();
+                        inParams["Type"] = BcdLibraryBoolean_AllowPrereleaseSignatures;
+                        inParams["Boolean"] = value;
+                        var outParams = bootMgrObj.InvokeMethod("SetBooleanElement", inParams, null);
+                        var ret = outParams?.Properties["ReturnValue"].Value;
+                        var returnValue = ret != null && (bool) ret;
 
-                        if (cmd.ExitCode != 0)
-                            throw new BcdAlterAllowPrereleaseSignaturesFailedException("Couldn't disable TESTSIGNING");
+                        if (!returnValue)
+                            throw new BcdAlterAllowPrereleaseSignaturesFailedException(
+                                "Couldn't change TESTSIGNING state");
                     }
                 }
                 catch (Exception ex)