From 4ef7675668d094b1f0ecc42b54d319be566ddd17 Mon Sep 17 00:00:00 2001
From: Xevion <xevioni@yandex.com>
Date: Fri, 26 Aug 2022 18:26:15 -0500
Subject: [PATCH] CheckExcludedPorts PowerShell script

---
 content/scripts/CheckExcludedPorts.ps1 | 36 ++++++++++++++++++++++++++
 content/scripts/excluded-ports.md      | 13 ++++++++++
 2 files changed, 49 insertions(+)
 create mode 100644 content/scripts/CheckExcludedPorts.ps1
 create mode 100644 content/scripts/excluded-ports.md

diff --git a/content/scripts/CheckExcludedPorts.ps1 b/content/scripts/CheckExcludedPorts.ps1
new file mode 100644
index 0000000..b8e0a7e
--- /dev/null
+++ b/content/scripts/CheckExcludedPorts.ps1
@@ -0,0 +1,36 @@
+<#
+    .Description
+    This script checks if the given port has been placed in a excluded port range.
+    This script utilizes the netsh command and only observes TCP exclusion ranges.
+#>
+param (
+    [Parameter(Mandatory=$true)]
+    [Int32]
+    $targetPort
+)
+
+# Filters excluded port range output to just the ports
+$rawPortRanges = netsh interface ipv4 show excludedportrange protocol=tcp | Select-String "\d+\s+\d+"
+# Cleans the output to include just start/end port with a single space
+$cleanPortRanges = $rawPortRanges -replace "\s+(\d+)\s+(\d+).*", '$1 $2'
+
+$found = $false
+$cleanPortRanges | % {
+    # Break apart the port, intrepret as int
+    $start, $end = $_.toString().split(' ')
+    $start = $start -as [int]
+    $end = $end -as [int]
+
+    # Complete the check
+    if ($targetPort -In $start..$end) {
+        $found = $true
+        Write-Host "${start} - ${end}"
+        Write-Host "`tPort ${targetPort} is in an excluded port range."
+        Break  # Assumption: Excluded port ranges do not overlap
+    }
+}
+
+# Default output
+if (!$found) {
+    Write-Host "Port ${targetPort} is not in an excluded port range."
+}
\ No newline at end of file
diff --git a/content/scripts/excluded-ports.md b/content/scripts/excluded-ports.md
new file mode 100644
index 0000000..122e353
--- /dev/null
+++ b/content/scripts/excluded-ports.md
@@ -0,0 +1,13 @@
++++
+title = "Check Excluded Port Ranges"
+summary = "Check if a specific port is in an excluded port range with this simple script."
+date = 2022-08-26
++++
+
+This script was built during an internship (and properly requested) to check excluded port ranges.
+
+Raw file available at  {{% absolute_url "./scripts/CheckExcludedPorts.ps1" %}}
+
+```powershell
+{{% file "/scripts/CheckExcludedPorts.ps1" %}}
+```
\ No newline at end of file