From c01cf5bf349516db36da9dcabafcf2f223f5e564 Mon Sep 17 00:00:00 2001
From: Lord Hepipud <contact@lordhepipud.de>
Date: Fri, 30 Jan 2026 16:37:05 +0100
Subject: [PATCH] Fixes Icinga Agent version detection by using the icinga2
 binary instead of the registry values

---
 doc/100-General/10-Changelog.md               |  1 +
 .../getters/Get-IcingaAgentInstallation.psm1  | 20 ++++++++++++++++++-
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/doc/100-General/10-Changelog.md b/doc/100-General/10-Changelog.md
index 86a30a0..e193966 100644
--- a/doc/100-General/10-Changelog.md
+++ b/doc/100-General/10-Changelog.md
@@ -21,6 +21,7 @@ Released closed milestones can be found on [GitHub](https://github.com/Icinga/ic
 * [#814](https://github.com/Icinga/icinga-powershell-framework/pull/814) Fixes random chars function to truly generate unpredictable character sequences and to replace `Get-Random` which is not entirely secure
 * [#815](https://github.com/Icinga/icinga-powershell-framework/pull/815) Fixes a possible crash for `Test-IcingaAddTypeExist`, causing the Icinga for Windows installation to fail when third party components are checked which are malfunctioning
 * [#816](https://github.com/Icinga/icinga-powershell-framework/issues/816) Fixes plugin execution error while using any `%IfNotMatch`/`%IfNotLike`/`%IfMatch`/`%IfLike` check function for strings containing special characters like `:`
+* [#820](https://github.com/Icinga/icinga-powershell-framework/issues/820) Fixes the version detection of the installed Icinga Agent by looking on the local installed `icinga2.exe` instead of fully relying on the registry version, printing an error in case the versions do not match
 * [#829](https://github.com/Icinga/icinga-powershell-framework/pull/829) Fixes `Set-IcingaCacheData` to properly remove cache files in case `$null` is passed as value
 * [#833](https://github.com/Icinga/icinga-powershell-framework/issues/833) Fixes registry lookup for Icinga Agent installation to check if the required `DisplayName` attribute is defined before checking
 * [#834](https://github.com/Icinga/icinga-powershell-framework/issues/834) Fixes security catalog compilation error on non-english Windows versions, while properly skipping checks on system SID's and improves security by always adding the `SeDenyNetworkLogonRight` and `SeDenyInteractiveLogonRight` privilege section for the JEA user SID
diff --git a/lib/core/icingaagent/getters/Get-IcingaAgentInstallation.psm1 b/lib/core/icingaagent/getters/Get-IcingaAgentInstallation.psm1
index a730de0..6d1ec4a 100644
--- a/lib/core/icingaagent/getters/Get-IcingaAgentInstallation.psm1
+++ b/lib/core/icingaagent/getters/Get-IcingaAgentInstallation.psm1
@@ -36,10 +36,28 @@ function Get-IcingaAgentInstallation()
         };
     }
 
+    # Sometimes it can happen that the DisplayVersion in the registry is not correct
+    # (e.g. after manual upgrades or installation failures), so we try to fetch the version from the binary itself
+    $IcingaVersion = $IcingaData.DisplayVersion;
+
+    try {
+        [string]$IcingaBinary = Join-Path -Path $IcingaData.InstallLocation -ChildPath 'sbin\icinga2.exe';
+
+        if (Test-Path -Path $IcingaBinary) {
+            $IcingaVersion = (Get-Item -Path $IcingaBinary).VersionInfo.FileVersion;
+        }
+
+        if ($IcingaVersion -ne $IcingaData.DisplayVersion) {
+            Write-IcingaConsoleError 'The Icinga version retrieved from the registry ({0}) differs from the version retrieved from the binary ({1}). Please make sure the installation went through and the Icinga Agent is properly updated.' -Objects $IcingaData.DisplayVersion, $IcingaVersion;
+        }
+    } catch {
+        Write-IcingaConsoleError 'Failed to determine Icinga version from binary located at "{0}": {1}' -Objects $IcingaBinary, $_.Exception.Message;
+    }
+
     return @{
         'Installed'    = $TRUE;
         'RootDir'      = $IcingaData.InstallLocation;
-        'Version'      = (Split-IcingaVersion $IcingaData.DisplayVersion);
+        'Version'      = (Split-IcingaVersion $IcingaVersion);
         'Architecture' = $architecture;
         'Uninstaller'  = $IcingaData.UninstallString.Replace("MsiExec.exe ", "");
         'InstallDate'  = $IcingaData.InstallDate;