From 39ff28c3f36673e373dac6d2a8a12f0bf0dfceff Mon Sep 17 00:00:00 2001
From: Darren 'Tadgy' Austin <darren@afterdark.org.uk>
Date: Mon, 8 Mar 2021 22:58:01 +0000
Subject: Fix domain name validation checks.  Thanks to xbeastx74 on LQ for the
 report.

---
 netconfig | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/netconfig b/netconfig
index a33b85d..bb5a5ac 100644
--- a/netconfig
+++ b/netconfig
@@ -492,8 +492,11 @@ EOF
   DOMAIN="`cat $TMP/SeTdom`"
   rm -f $TMP/SeTdom $TMP/tempmsg
   # These regexes doon't catch everything, just basic syntax mistakes.
-  if [ "$DOMAIN" = "" ] || [[ ! "$DOMAIN" =~ ^([[:alnum:]]+[-.]*[[:alnum:]]+)+$ ]] || \
-      [[ "${DOMAIN:0:1}" =~ ^[.-]$ ]] || [[ "${DOMAIN: -1:1}" == ^[.-]$ ]]; then
+  DN="${DOMAIN%.*}"
+  TLD="${DOMAIN##*.}"
+  if [ -z "$DOMAIN" ] || [ -z "$TLD" ] || [ -z "$DN" ] || [[ ! "$DOMAIN" =~ ^[^.-][[:alnum:].-]+[^.-]$ ]] || \
+      [[ ! "$DN" =~ ^[^.-][[:alnum:].-]+[^.-]$ ]] || [[ "$DN" =~ \.\. ]] || [[ "$DN" =~ -- ]] || \
+      [[ ! "$TLD" =~ ^[^-][[:alnum:]-]+[^-]$ ]]; then
     dialog --title "DOMAINNAME" --ok-button "Back" --msgbox \
       "That doesn't appear to be a valid domain name.\n
 Domain names can only contain letters and numbers, hyphens
-- 
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