From 68ac05fb7e2849db38f3a50ee3ad096a9d94e93d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christian=20K=C3=B6nig?= <ckoenig@posteo.de>
Date: Thu, 5 Jan 2023 23:16:53 +0100
Subject: [PATCH] Do not fail if IDNA<->UNICODE conversion fails
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Signed-off-by: Christian König <ckoenig@posteo.de>
---
 scripts/pi-hole/php/func.php   | 26 ++++++++++++++++++--------
 scripts/pi-hole/php/groups.php | 16 +++++-----------
 2 files changed, 23 insertions(+), 19 deletions(-)

diff --git a/scripts/pi-hole/php/func.php b/scripts/pi-hole/php/func.php
index 10f899bac..6a7ed0f5a 100644
--- a/scripts/pi-hole/php/func.php
+++ b/scripts/pi-hole/php/func.php
@@ -640,7 +640,7 @@ function getGateway()
 }
 
 // Try to convert possible IDNA domain to Unicode
-function convertIDNAToUnicode($unicode)
+function convertIDNAToUnicode($IDNA)
 {
     if (extension_loaded('intl')) {
         // we try the UTS #46 standard first
@@ -652,32 +652,42 @@ function convertIDNAToUnicode($unicode)
             // to ensure sparkasse-gießen.de is not converted into
             // sparkass-giessen.de but into xn--sparkasse-gieen-2ib.de
             // as mandated by the UTS #46 standard
-            $unicode = idn_to_utf8($unicode, IDNA_NONTRANSITIONAL_TO_ASCII, INTL_IDNA_VARIANT_UTS46);
+            $unicode = idn_to_utf8($IDNA, IDNA_NONTRANSITIONAL_TO_ASCII, INTL_IDNA_VARIANT_UTS46);
         } elseif (defined('INTL_IDNA_VARIANT_2003')) {
             // If conversion failed, try with the (deprecated!) IDNA 2003 variant
             // We have to check for its existence as support of this variant is
             // scheduled for removal with PHP 8.0
             // see https://wiki.php.net/rfc/deprecate-and-remove-intl_idna_variant_2003
-            $unicode = idn_to_utf8($unicode, IDNA_DEFAULT, INTL_IDNA_VARIANT_2003);
+            $unicode = idn_to_utf8($IDNA, IDNA_DEFAULT, INTL_IDNA_VARIANT_2003);
         }
     }
 
-    return $unicode;
+    // if the conversion failed (e.g. domain to long) return the original domain
+    if ($unicode == false) {
+        return $IDNA;
+    } else {
+        return $unicode;
+    }
 }
 
 // Convert a given (unicode) domain to IDNA ASCII
-function convertUnicodeToIDNA($IDNA)
+function convertUnicodeToIDNA($unicode)
 {
     if (extension_loaded('intl')) {
         // Be prepared that this may fail and see our comments about convertIDNAToUnicode()
         if (defined('INTL_IDNA_VARIANT_UTS46')) {
-            $IDNA = idn_to_ascii($IDNA, IDNA_NONTRANSITIONAL_TO_ASCII, INTL_IDNA_VARIANT_UTS46);
+            $IDNA = idn_to_ascii($unicode, IDNA_NONTRANSITIONAL_TO_ASCII, INTL_IDNA_VARIANT_UTS46);
         } elseif (defined('INTL_IDNA_VARIANT_2003')) {
-            $IDNA = idn_to_ascii($IDNA, IDNA_DEFAULT, INTL_IDNA_VARIANT_2003);
+            $IDNA = idn_to_ascii($unicode, IDNA_DEFAULT, INTL_IDNA_VARIANT_2003);
         }
     }
 
-    return $IDNA;
+    // if the conversion failed (e.g. domain to long) return the original domain
+    if ($IDNA == false) {
+        return $unicode;
+    } else {
+        return $IDNA;
+    }
 }
 
 // Return PID of FTL (used in settings.php)
diff --git a/scripts/pi-hole/php/groups.php b/scripts/pi-hole/php/groups.php
index 7357b037c..7cd418609 100644
--- a/scripts/pi-hole/php/groups.php
+++ b/scripts/pi-hole/php/groups.php
@@ -510,14 +510,11 @@ function verify_ID_array($arr)
             $res['groups'] = $groups;
             if ($res['type'] === LISTTYPE_WHITELIST || $res['type'] === LISTTYPE_BLACKLIST) {
                 // Convert domain name to international form
-                // Skip this for the root zone `.`
-                if ($res['domain'] != '.') {
-                    $utf8_domain = convertIDNAToUnicode($res['domain']);
+                $utf8_domain = convertIDNAToUnicode($res['domain']);
 
-                    // if domain and international form are different, show both
-                    if ($res['domain'] !== $utf8_domain) {
-                        $res['domain'] = $utf8_domain.' ('.$res['domain'].')';
-                    }
+                // if domain and international form are different, show both
+                if ($res['domain'] !== $utf8_domain) {
+                    $res['domain'] = $utf8_domain.' ('.$res['domain'].')';
                 }
             }
             // Prevent domain and comment fields from returning any arbitrary javascript code which could be executed on the browser.
@@ -600,10 +597,7 @@ function verify_ID_array($arr)
                 // If not adding a RegEx....
                 $input = $domain;
                 // Convert domain name to IDNA ASCII form for international domains
-                // Skip this for the root zone `.`
-                if ($domain != '.') {
-                    $domain = convertUnicodeToIDNA($domain);
-                }
+                $domain = convertUnicodeToIDNA($domain);
                 // convert the domain lower case and check whether it is valid
                 $domain = strtolower($domain);
                 $msg = '';