From 2743abb406ecde4c36d0c356aeaec3b6df51bb0d Mon Sep 17 00:00:00 2001
From: John Duprey <jwd@johnwduprey.com>
Date: Wed, 12 Apr 2023 15:33:46 -0400
Subject: [PATCH] Prevent infinite loop in includes

---
 DNSHealth/Public/Records/Read-SPFRecord.ps1 | 38 ++++++++++++---------
 1 file changed, 21 insertions(+), 17 deletions(-)

diff --git a/DNSHealth/Public/Records/Read-SPFRecord.ps1 b/DNSHealth/Public/Records/Read-SPFRecord.ps1
index 17788bd..b79595f 100644
--- a/DNSHealth/Public/Records/Read-SPFRecord.ps1
+++ b/DNSHealth/Public/Records/Read-SPFRecord.ps1
@@ -212,25 +212,29 @@ function Read-SpfRecord {
 
                     # Include mechanism
                     elseif ($Term -match '^(?<Qualifier>[+-~?])?include:(?<Value>.+)$') {
-                        $LookupCount++
-                        Write-Verbose '-----INCLUDE-----'
-                        Write-Verbose "Looking up include $($Matches.Value)"
-                        $IncludeLookup = Read-SpfRecord -Domain $Matches.Value -Level 'Include'
-
-                        if ([string]::IsNullOrEmpty($IncludeLookup.Record) -and $Level -eq 'Parent') {
-                            Write-Verbose '-----END INCLUDE (SPF MISSING)-----'
-                            $ValidationFails.Add("Include lookup for $($Matches.Value) does not contain a SPF record, this will result in a failure.") | Out-Null
+                        if ($Matches.Value -ne $Domain) {
+                            $LookupCount++
+                            Write-Verbose '-----INCLUDE-----'
+                            Write-Verbose "Looking up include $($Matches.Value)"
+                            $IncludeLookup = Read-SpfRecord -Domain $Matches.Value -Level 'Include'
+
+                            if ([string]::IsNullOrEmpty($IncludeLookup.Record) -and $Level -eq 'Parent') {
+                                Write-Verbose '-----END INCLUDE (SPF MISSING)-----'
+                                $ValidationFails.Add("Include lookup for $($Matches.Value) does not contain a SPF record, this will result in a failure.") | Out-Null
+                                $Status = 'permerror'
+                            } else {
+                                Write-Verbose '-----END INCLUDE (SPF FOUND)-----'
+                                $RecordList.Add($IncludeLookup) | Out-Null
+                                $ValidationFails.AddRange([string[]]$IncludeLookup.ValidationFails) | Out-Null
+                                $ValidationWarns.AddRange([string[]]$IncludeLookup.ValidationWarns) | Out-Null
+                                $ValidationPasses.AddRange([string[]]$IncludeLookup.ValidationPasses) | Out-Null
+                                $IPAddresses.AddRange([string[]]$IncludeLookup.IPAddresses) | Out-Null
+                            }
+                        } else {
+                            Write-Verbose "-----END INCLUDE (INFINITE LOOP -> $Domain SHOULD NOT INCLUDE ITSELF)-----"
+                            $ValidationFails.Add("Include lookup for $($Matches.Value) should not exist. It will cause an infinite loop.") | Out-Null
                             $Status = 'permerror'
                         }
-
-                        else {
-                            Write-Verbose '-----END INCLUDE (SPF FOUND)-----'
-                            $RecordList.Add($IncludeLookup) | Out-Null
-                            $ValidationFails.AddRange([string[]]$IncludeLookup.ValidationFails) | Out-Null
-                            $ValidationWarns.AddRange([string[]]$IncludeLookup.ValidationWarns) | Out-Null
-                            $ValidationPasses.AddRange([string[]]$IncludeLookup.ValidationPasses) | Out-Null
-                            $IPAddresses.AddRange([string[]]$IncludeLookup.IPAddresses) | Out-Null
-                        }
                     }
 
                     # Exists mechanism