From a3101f2cb90de6eb813b1436804e392a54d2b8f4 Mon Sep 17 00:00:00 2001
From: Damodar Lohani <dlohani48@gmail.com>
Date: Sun, 27 Jul 2025 03:29:58 +0000
Subject: [PATCH 01/12] Fix: improve encoder functions according to RFC

---
 src/DNS/Server.php | 135 +++++++++++++++++++++++++++++----------------
 1 file changed, 87 insertions(+), 48 deletions(-)

diff --git a/src/DNS/Server.php b/src/DNS/Server.php
index 7eff073..077d369 100644
--- a/src/DNS/Server.php
+++ b/src/DNS/Server.php
@@ -330,100 +330,139 @@ protected function resolve(array $question): array
         return $this->resolver->resolve($question);
     }
 
+    /**
+     * Encode an IPv4 address (A record) according to RFC 1035.
+     *
+     * @param string $ip
+     * @param int $ttl
+     * @return string
+     */
     protected function encodeIP(string $ip, int $ttl): string
     {
-        $result = \pack('Nn', $ttl, 4);
-
         $binaryIP = inet_pton($ip);
-        if ($binaryIP === false) {
+        if ($binaryIP === false || strlen($binaryIP) !== 4) {
             throw new \Exception("Invalid IPv4 address format: {$ip}");
         }
-
-        // Append the binary IPv4 address directly
-        $result .= $binaryIP;
-
+        $result = pack('Nn', $ttl, 4) . $binaryIP;
         return $result;
     }
 
+    /**
+     * Encode an IPv6 address (AAAA record) according to RFC 3596.
+     *
+     * @param string $ip
+     * @param int $ttl
+     * @return string
+     */
     protected function encodeIPv6(string $ip, int $ttl): string
     {
-        $result = \pack('Nn', $ttl, 16);
-
         $binaryIP = inet_pton($ip);
-        if ($binaryIP === false) {
+        if ($binaryIP === false || strlen($binaryIP) !== 16) {
             throw new \Exception("Invalid IPv6 address format: {$ip}");
         }
-
-        $result .= $binaryIP;
-
+        $result = pack('Nn', $ttl, 16) . $binaryIP;
         return $result;
     }
 
+    /**
+     * Encode a domain name (CNAME, NS, PTR) according to RFC 1035.
+     *
+     * @param string $domain
+     * @param int $ttl
+     * @return string
+     */
     protected function encodeDomain(string $domain, int $ttl): string
     {
+        $labels = explode('.', rtrim($domain, '.'));
         $result = '';
         $totalLength = 0;
-
-        foreach (\explode('.', $domain) as $label) {
-            $labelLength = \strlen($label);
-            $result .= \chr($labelLength);
-            $result .= $label;
+        foreach ($labels as $label) {
+            $labelLength = strlen($label);
+            if ($labelLength > 63) {
+                throw new \Exception("Label too long in domain: {$label}");
+            }
+            $result .= chr($labelLength) . $label;
             $totalLength += 1 + $labelLength;
         }
-
-        $result .= \chr(0);
+        $result .= chr(0);
         $totalLength += 1;
-
-        $result = \pack('Nn', $ttl, $totalLength) . $result;
-
+        $result = pack('Nn', $ttl, $totalLength) . $result;
         return $result;
     }
 
+    /**
+     * Encode a TXT record according to RFC 1035.
+     *
+     * @param string $text
+     * @param int $ttl
+     * @return string
+     */
     protected function encodeText(string $text, int $ttl): string
     {
-        $textLength = \strlen($text);
-        $result = \pack('Nn', $ttl, 1 + $textLength) . \chr($textLength) . $text;
-
+        $chunks = [];
+        $len = strlen($text);
+        for ($i = 0; $i < $len; $i += 255) {
+            $chunk = substr($text, $i, 255);
+            $chunks[] = chr(strlen($chunk)) . $chunk;
+        }
+        $txtData = implode('', $chunks);
+        $result = pack('Nn', $ttl, strlen($txtData)) . $txtData;
         return $result;
     }
 
+    /**
+     * Encode an MX record according to RFC 1035.
+     *
+     * @param string $domain
+     * @param int $ttl
+     * @param int $priority
+     * @return string
+     */
     protected function encodeMx(string $domain, int $ttl, int $priority): string
     {
-        $result = \pack('n', $priority);
+        $labels = explode('.', rtrim($domain, '.'));
+        $result = pack('n', $priority);
         $totalLength = 2;
-
-        foreach (\explode('.', $domain) as $label) {
-            $labelLength = \strlen($label);
-            $result .= \chr($labelLength);
-            $result .= $label;
+        foreach ($labels as $label) {
+            $labelLength = strlen($label);
+            if ($labelLength > 63) {
+                throw new \Exception("Label too long in MX domain: {$label}");
+            }
+            $result .= chr($labelLength) . $label;
             $totalLength += 1 + $labelLength;
         }
-
-        $result .= \chr(0);
+        $result .= chr(0);
         $totalLength += 1;
-
-        $result = \pack('Nn', $ttl, $totalLength) . $result;
-
+        $result = pack('Nn', $ttl, $totalLength) . $result;
         return $result;
     }
 
+    /**
+     * Encode an SRV record according to RFC 2782.
+     *
+     * @param string $domain
+     * @param int $ttl
+     * @param int $priority
+     * @param int $weight
+     * @param int $port
+     * @return string
+     */
     protected function encodeSrv(string $domain, int $ttl, int $priority, int $weight, int $port): string
     {
-        $result = \pack('nnn', $priority, $weight, $port);
+        $labels = explode('.', rtrim($domain, '.'));
+        $result = pack('nnn', $priority, $weight, $port);
         $totalLength = 6;
-
-        foreach (\explode('.', $domain) as $label) {
-            $labelLength = \strlen($label);
-            $result .= \chr($labelLength);
-            $result .= $label;
+        foreach ($labels as $label) {
+            $labelLength = strlen($label);
+            if ($labelLength > 63) {
+                throw new \Exception("Label too long in SRV domain: {$label}");
+            }
+            $result .= chr($labelLength) . $label;
             $totalLength += 1 + $labelLength;
         }
-
-        $result .= \chr(0);
+        $result .= chr(0);
         $totalLength += 1;
-
-        $result = \pack('Nn', $ttl, $totalLength) . $result;
-
+        $result = pack('Nn', $ttl, $totalLength) . $result;
         return $result;
     }
 

From be5f654a9bdbefa5a4feac087805a6ad501459bb Mon Sep 17 00:00:00 2001
From: Damodar Lohani <dlohani48@gmail.com>
Date: Sun, 27 Jul 2025 03:32:02 +0000
Subject: [PATCH 02/12] Fix zone tokenizer to handle quoted strings

---
 src/DNS/Zone.php | 37 +++++++++++++++++++++++++++++++------
 1 file changed, 31 insertions(+), 6 deletions(-)

diff --git a/src/DNS/Zone.php b/src/DNS/Zone.php
index 4b52bba..9054d48 100644
--- a/src/DNS/Zone.php
+++ b/src/DNS/Zone.php
@@ -360,22 +360,47 @@ protected function isComment(string $line): bool
      *
      * @return string[]
      */
+    /**
+     * Tokenize a line by whitespace, handling quoted strings and escapes per RFC 1035.
+     *
+     * @return string[]
+     */
     protected function tokenize(string $line): array
     {
         $tokens = [];
         $current = '';
-        $inSpace = true;
+        $inQuote = false;
+        $escape = false;
         for ($i = 0, $len = strlen($line); $i < $len; $i++) {
             $c = $line[$i];
-            if ($c === ' ' || $c === "\t") {
-                if (!$inSpace) {
+            if ($escape) {
+                $current .= $c;
+                $escape = false;
+                continue;
+            }
+            if ($c === '\\') {
+                $escape = true;
+                continue;
+            }
+            if ($inQuote) {
+                if ($c === '"') {
+                    $inQuote = false;
                     $tokens[] = $current;
                     $current = '';
+                } else {
+                    $current .= $c;
                 }
-                $inSpace = true;
             } else {
-                $current .= $c;
-                $inSpace = false;
+                if ($c === '"') {
+                    $inQuote = true;
+                } elseif ($c === ' ' || $c === "\t") {
+                    if ($current !== '') {
+                        $tokens[] = $current;
+                        $current = '';
+                    }
+                } else {
+                    $current .= $c;
+                }
             }
         }
         if ($current !== '') {

From bb861d0aaa2644dadd3ebbab930b499cfce46beb Mon Sep 17 00:00:00 2001
From: Damodar Lohani <dlohani48@gmail.com>
Date: Sun, 27 Jul 2025 03:44:29 +0000
Subject: [PATCH 03/12] fix validation

---
 src/DNS/Server.php | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/src/DNS/Server.php b/src/DNS/Server.php
index 077d369..616b86c 100644
--- a/src/DNS/Server.php
+++ b/src/DNS/Server.php
@@ -378,6 +378,9 @@ protected function encodeDomain(string $domain, int $ttl): string
         $totalLength = 0;
         foreach ($labels as $label) {
             $labelLength = strlen($label);
+            if ($labelLength === 0) {
+                throw new \Exception("Empty label in domain: '{$domain}'");
+            }
             if ($labelLength > 63) {
                 throw new \Exception("Label too long in domain: {$label}");
             }
@@ -449,11 +452,24 @@ protected function encodeMx(string $domain, int $ttl, int $priority): string
      */
     protected function encodeSrv(string $domain, int $ttl, int $priority, int $weight, int $port): string
     {
+        // Validate SRV parameters
+        if ($priority < 0 || $priority > 65535) {
+            throw new \Exception("SRV priority out of range: {$priority}");
+        }
+        if ($weight < 0 || $weight > 65535) {
+            throw new \Exception("SRV weight out of range: {$weight}");
+        }
+        if ($port < 0 || $port > 65535) {
+            throw new \Exception("SRV port out of range: {$port}");
+        }
         $labels = explode('.', rtrim($domain, '.'));
         $result = pack('nnn', $priority, $weight, $port);
         $totalLength = 6;
         foreach ($labels as $label) {
             $labelLength = strlen($label);
+            if ($labelLength === 0) {
+                throw new \Exception("Empty label in SRV domain: '{$domain}'");
+            }
             if ($labelLength > 63) {
                 throw new \Exception("Label too long in SRV domain: {$label}");
             }

From 56bc8cc3fce72a5a7c44976c9ddabdb905997b6f Mon Sep 17 00:00:00 2001
From: Damodar Lohani <dlohani48@gmail.com>
Date: Sun, 27 Jul 2025 03:51:05 +0000
Subject: [PATCH 04/12] add test

---
 tests/DNS/ClientTest.php   | 3 ++-
 tests/DNS/ServerMemory.php | 4 ++++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/tests/DNS/ClientTest.php b/tests/DNS/ClientTest.php
index 23f1c56..c18b786 100644
--- a/tests/DNS/ClientTest.php
+++ b/tests/DNS/ClientTest.php
@@ -105,9 +105,10 @@ public function testTXTRecords(): void
 
         $records = $this->client->query('dev2.appwrite.io', 'TXT');
 
-        $this->assertCount(2, $records);
+        $this->assertCount(3, $records);
         $this->assertEquals('key with "$\'- symbols', $records[0]->getRdata());
         $this->assertEquals('key with spaces', $records[1]->getRdata());
+        $this->assertEquals('v=DMARC1; p=none; rua=mailto:jon@snow.got; ruf=mailto:jon@snow.got; fo=1;', $records[2]->getRdata());
 
         $records = $this->client->query('dev3.appwrite.io', 'TXT');
         $this->assertCount(0, $records);
diff --git a/tests/DNS/ServerMemory.php b/tests/DNS/ServerMemory.php
index 36c29ac..5a747cc 100644
--- a/tests/DNS/ServerMemory.php
+++ b/tests/DNS/ServerMemory.php
@@ -60,6 +60,10 @@
     'value' => 'key with spaces'
 ]);
 
+$resolver->addRecord('dev2.appwrite.io', 'TXT', [
+    'value' => 'v=DMARC1; p=none; rua=mailto:jon@snow.got; ruf=mailto:jon@snow.got; fo=1;'
+]);
+
 $resolver->addRecord('dev.appwrite.io', 'CAA', [
     'value' => 'issue "letsencrypt.org"',
     'ttl' => 50

From fdf0efc3cb90e42dd04f82119620383cb9b9f7a3 Mon Sep 17 00:00:00 2001
From: Damodar Lohani <dlohani48@gmail.com>
Date: Sun, 27 Jul 2025 04:54:52 +0000
Subject: [PATCH 05/12] update client

---
 src/DNS/Client.php | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/DNS/Client.php b/src/DNS/Client.php
index 7eb3eb4..ba23536 100644
--- a/src/DNS/Client.php
+++ b/src/DNS/Client.php
@@ -226,10 +226,15 @@ private function parseRdata(string $packet, int &$offset, int $type, int $rdleng
                 while ($offset < $end) {
                     $len = ord($packet[$offset]);
                     $offset++;
-                    $txts[] = substr($packet, $offset, $len);
+                    if ($len > 0) {
+                        $txts[] = substr($packet, $offset, $len);
+                    } else {
+                        $txts[] = '';
+                    }
                     $offset += $len;
                 }
-                return implode(' ', $txts);
+                // Concatenate chunks directly, no separator
+                return implode('', $txts);
             case 33: // SRV record
                 $priority = unpack('n', substr($packet, $offset, 2));
                 $weight = unpack('n', substr($packet, $offset + 2, 2));

From 665646803250d22e6714fd5f99464ed238804c9f Mon Sep 17 00:00:00 2001
From: Damodar Lohani <dlohani48@gmail.com>
Date: Sun, 27 Jul 2025 05:15:59 +0000
Subject: [PATCH 06/12] improve client

---
 src/DNS/Client.php | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/src/DNS/Client.php b/src/DNS/Client.php
index ba23536..51db7db 100644
--- a/src/DNS/Client.php
+++ b/src/DNS/Client.php
@@ -226,15 +226,16 @@ private function parseRdata(string $packet, int &$offset, int $type, int $rdleng
                 while ($offset < $end) {
                     $len = ord($packet[$offset]);
                     $offset++;
-                    if ($len > 0) {
-                        $txts[] = substr($packet, $offset, $len);
-                    } else {
-                        $txts[] = '';
-                    }
+                    $chunk = ($len > 0) ? substr($packet, $offset, $len) : '';
+                    $txts[] = $chunk;
                     $offset += $len;
                 }
-                // Concatenate chunks directly, no separator
-                return implode('', $txts);
+                // If you want to match dig output, wrap in quotes and escape embedded quotes
+                $txtValue = implode('', $txts);
+                if (strpos($txtValue, '"') !== false) {
+                    $txtValue = str_replace('"', '\\"', $txtValue);
+                }
+                return '"' . $txtValue . '"';
             case 33: // SRV record
                 $priority = unpack('n', substr($packet, $offset, 2));
                 $weight = unpack('n', substr($packet, $offset + 2, 2));

From 614b63dd5864855f668bcd83460e13c87a9417e5 Mon Sep 17 00:00:00 2001
From: Damodar Lohani <dlohani48@gmail.com>
Date: Sun, 27 Jul 2025 05:19:14 +0000
Subject: [PATCH 07/12] improve client

---
 src/DNS/Client.php | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/src/DNS/Client.php b/src/DNS/Client.php
index 51db7db..e17c340 100644
--- a/src/DNS/Client.php
+++ b/src/DNS/Client.php
@@ -230,12 +230,7 @@ private function parseRdata(string $packet, int &$offset, int $type, int $rdleng
                     $txts[] = $chunk;
                     $offset += $len;
                 }
-                // If you want to match dig output, wrap in quotes and escape embedded quotes
-                $txtValue = implode('', $txts);
-                if (strpos($txtValue, '"') !== false) {
-                    $txtValue = str_replace('"', '\\"', $txtValue);
-                }
-                return '"' . $txtValue . '"';
+                return implode('', $txts);
             case 33: // SRV record
                 $priority = unpack('n', substr($packet, $offset, 2));
                 $weight = unpack('n', substr($packet, $offset + 2, 2));

From 957e01e1f6a85578859337bbff89d877cfad6c22 Mon Sep 17 00:00:00 2001
From: Damodar Lohani <dlohani48@gmail.com>
Date: Sun, 27 Jul 2025 05:39:01 +0000
Subject: [PATCH 08/12] fix zone import/export

---
 src/DNS/Zone.php       |  9 ++++++++-
 tests/DNS/ZoneTest.php | 13 +++++++++++++
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/src/DNS/Zone.php b/src/DNS/Zone.php
index 9054d48..1cc6fc9 100644
--- a/src/DNS/Zone.php
+++ b/src/DNS/Zone.php
@@ -219,7 +219,14 @@ public function import(string $domain, string $content): array
             }
             $type = strtoupper($tokens[$pos++]);
             $dataParts = array_slice($tokens, $pos);
-            $data = implode(' ', $dataParts);
+            if ($type === 'TXT') {
+                $data = '';
+                foreach ($dataParts as $part) {
+                    $data .= $part;
+                }
+            } else {
+                $data = implode(' ', $dataParts);
+            }
             if ($owner !== '@' && !str_ends_with($owner, '.')) {
                 $owner .= '.' . rtrim($this->defaultOrigin, '.');
             }
diff --git a/tests/DNS/ZoneTest.php b/tests/DNS/ZoneTest.php
index fb0157e..a888eaa 100644
--- a/tests/DNS/ZoneTest.php
+++ b/tests/DNS/ZoneTest.php
@@ -337,4 +337,17 @@ public function testImportExportRoundTrip(): void
         $this->assertSame($records1[2]->getPriority(), $records2[2]->getPriority());
         $this->assertSame($records1[2]->getRdata(), $records2[2]->getRdata());
     }
+
+     public function testImportTxtWithSpecialChars()
+     {
+         $zone = new Zone();
+         $zonefile = <<<ZONE
+@ 3600 IN TXT "v=DMARC1; p=none; rua=mailto:jon@snow.got; ruf=mailto:jon@snow.got; fo=1;"
+ZONE;
+         $records = $zone->import('example.com', $zonefile);
+         $this->assertCount(1, $records);
+         $rec = $records[0];
+         $this->assertEquals('TXT', $rec->getTypeName());
+         $this->assertEquals('v=DMARC1; p=none; rua=mailto:jon@snow.got; ruf=mailto:jon@snow.got; fo=1;', trim($rec->getRdata(), '"'));
+     }
 }

From 23ff4294bd42c2ac83641d272fa44ef7e3a91956 Mon Sep 17 00:00:00 2001
From: Damodar Lohani <dlohani48@gmail.com>
Date: Sun, 27 Jul 2025 06:07:31 +0000
Subject: [PATCH 09/12] fix zone

---
 src/DNS/Zone.php       | 54 ++++++++++++++++++++++++++++++++----------
 tests/DNS/ZoneTest.php | 12 +++++++++-
 2 files changed, 53 insertions(+), 13 deletions(-)

diff --git a/src/DNS/Zone.php b/src/DNS/Zone.php
index 1cc6fc9..11cd951 100644
--- a/src/DNS/Zone.php
+++ b/src/DNS/Zone.php
@@ -178,7 +178,17 @@ public function import(string $domain, string $content): array
         $lastOwner = null;
         $logicalLines = $this->collectLogicalLines($content);
         foreach ($logicalLines as $rawLine) {
-            $line = trim($this->stripTrailingComment($rawLine));
+            // For TXT records, only strip comments at #, not at semicolons
+            $isTxt = false;
+            $peekTokens = $this->tokenize($rawLine);
+            if (count($peekTokens) >= 4 && strtoupper($peekTokens[3]) === 'TXT') {
+                $isTxt = true;
+            }
+            if ($isTxt) {
+                $line = trim($this->stripTrailingComment($rawLine, true));
+            } else {
+                $line = trim($this->stripTrailingComment($rawLine, false));
+            }
             if ($line === '' || $this->isComment($line)) {
                 continue;
             }
@@ -272,11 +282,21 @@ public function export(string $domain, array $records): string
                 $data = "{$r->getPriority()} {$r->getRdata()}";
             } elseif ($type === 'SRV' && $r->getPriority() !== null && $r->getWeight() !== null && $r->getPort() !== null) {
                 $data = "{$r->getPriority()} {$r->getWeight()} {$r->getPort()} {$r->getRdata()}";
+            } elseif ($type === 'TXT') {
+                // Encode TXT records with double quotes and escape embedded quotes and backslashes
+                $escaped = str_replace(['\\', '"'], ['\\\\', '\\"'], $data);
+                $data = '"' . $escaped . '"';
             }
 
             $lines[] = sprintf("%s %d %s %s %s", $owner, $ttl, $class, $type, $data);
         }
-        return implode("\n", $lines) . "\n";
+        // Remove any empty lines at the end
+        while (!empty($lines) && trim(end($lines)) === '') {
+            array_pop($lines);
+        }
+        $output = implode("\n", $lines);
+        // Guarantee only a single newline at the end
+        return rtrim($output, "\n") . "\n";
     }
 
     /**
@@ -300,7 +320,7 @@ protected function collectLogicalLines(string $content): array
         $parenDepth = 0;
         foreach ($rawLines as $rawLine) {
             // Remove trailing comments from the physical line.
-            $line = trim($this->stripTrailingComment($rawLine));
+            $line = trim($this->stripTrailingComment($rawLine, false));
             if ($line === '') {
                 continue;
             }
@@ -343,17 +363,26 @@ protected function collectLogicalLines(string $content): array
     /**
      * Remove trailing comments (anything after '#' or ';') from a line.
      */
-    protected function stripTrailingComment(string $line): string
+
+    /**
+     * Remove trailing comments (anything after '#' or ';') from a line.
+     * If $txtMode is true, only strip at #, not at semicolons.
+     */
+    protected function stripTrailingComment(string $line, bool $txtMode): string
     {
-        $hashPos = strpos($line, '#');
-        if ($hashPos !== false) {
-            $line = substr($line, 0, $hashPos);
-        }
-        $semiPos = strpos($line, ';');
-        if ($semiPos !== false) {
-            $line = substr($line, 0, $semiPos);
+        $inQuote = false;
+        $result = '';
+        for ($i = 0, $len = strlen($line); $i < $len; $i++) {
+            $c = $line[$i];
+            if ($c === '"') {
+                $inQuote = !$inQuote;
+            }
+            if (!$inQuote && ($c === '#' || (!$txtMode && $c === ';'))) {
+                break;
+            }
+            $result .= $c;
         }
-        return $line;
+        return $result;
     }
 
     protected function isComment(string $line): bool
@@ -374,6 +403,7 @@ protected function isComment(string $line): bool
      */
     protected function tokenize(string $line): array
     {
+        // Manual tokenizer: handles quoted strings and escapes
         $tokens = [];
         $current = '';
         $inQuote = false;
diff --git a/tests/DNS/ZoneTest.php b/tests/DNS/ZoneTest.php
index a888eaa..c5db471 100644
--- a/tests/DNS/ZoneTest.php
+++ b/tests/DNS/ZoneTest.php
@@ -338,7 +338,7 @@ public function testImportExportRoundTrip(): void
         $this->assertSame($records1[2]->getRdata(), $records2[2]->getRdata());
     }
 
-     public function testImportTxtWithSpecialChars()
+     public function testImportTxtWithSpecialChars(): void
      {
          $zone = new Zone();
          $zonefile = <<<ZONE
@@ -350,4 +350,14 @@ public function testImportTxtWithSpecialChars()
          $this->assertEquals('TXT', $rec->getTypeName());
          $this->assertEquals('v=DMARC1; p=none; rua=mailto:jon@snow.got; ruf=mailto:jon@snow.got; fo=1;', trim($rec->getRdata(), '"'));
      }
+
+    public function testExportTxtWithSpecialChars(): void
+    {
+        $zone = new Zone();
+        $txt = 'v=DMARC1; p=none; rua=mailto:jon@snow.got; ruf=mailto:jon@snow.got; fo=1; text="quoted"; backslash=\\';
+        $rec = new Record('@', 3600, 'IN', 'TXT', $txt);
+        $exported = $zone->export('example.com', [$rec]);
+        $expected = '@ 3600 IN TXT "v=DMARC1; p=none; rua=mailto:jon@snow.got; ruf=mailto:jon@snow.got; fo=1; text=\\"quoted\\"; backslash=\\\\"' . "\n";
+        $this->assertSame($expected, $exported);
+    }
 }

From eddb5d8af2f94a63b940881a02866d01f2cf77b6 Mon Sep 17 00:00:00 2001
From: Damodar Lohani <dlohani48@gmail.com>
Date: Sun, 27 Jul 2025 06:17:16 +0000
Subject: [PATCH 10/12] fix reviews

---
 src/DNS/Zone.php | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/src/DNS/Zone.php b/src/DNS/Zone.php
index 11cd951..b93abb7 100644
--- a/src/DNS/Zone.php
+++ b/src/DNS/Zone.php
@@ -181,8 +181,11 @@ public function import(string $domain, string $content): array
             // For TXT records, only strip comments at #, not at semicolons
             $isTxt = false;
             $peekTokens = $this->tokenize($rawLine);
-            if (count($peekTokens) >= 4 && strtoupper($peekTokens[3]) === 'TXT') {
-                $isTxt = true;
+            foreach ($peekTokens as $tok) {
+                if (strtoupper($tok) === 'TXT') {
+                    $isTxt = true;
+                    break;
+                }
             }
             if ($isTxt) {
                 $line = trim($this->stripTrailingComment($rawLine, true));
@@ -374,8 +377,17 @@ protected function stripTrailingComment(string $line, bool $txtMode): string
         $result = '';
         for ($i = 0, $len = strlen($line); $i < $len; $i++) {
             $c = $line[$i];
+            // Check for unescaped quote
             if ($c === '"') {
-                $inQuote = !$inQuote;
+                $escaped = false;
+                $j = $i - 1;
+                while ($j >= 0 && $line[$j] === '\\') {
+                    $escaped = !$escaped;
+                    $j--;
+                }
+                if (!$escaped) {
+                    $inQuote = !$inQuote;
+                }
             }
             if (!$inQuote && ($c === '#' || (!$txtMode && $c === ';'))) {
                 break;

From 7650f282c5d8e585e38dff2693bfd346d9a79d12 Mon Sep 17 00:00:00 2001
From: Damodar Lohani <dlohani48@gmail.com>
Date: Mon, 28 Jul 2025 07:51:59 +0000
Subject: [PATCH 11/12] improvements with validation and constants

---
 src/DNS/Server.php | 46 +++++++++++++++++++++++++++++++++-------------
 1 file changed, 33 insertions(+), 13 deletions(-)

diff --git a/src/DNS/Server.php b/src/DNS/Server.php
index 616b86c..613be9a 100644
--- a/src/DNS/Server.php
+++ b/src/DNS/Server.php
@@ -51,7 +51,18 @@
  */
 
 class Server
+// DNS protocol constants
 {
+    public const IPV4_LEN = 4;
+    public const IPV6_LEN = 16;
+    public const MAX_LABEL_LEN = 63;
+    public const MAX_LABELS = 127;
+    public const MAX_DOMAIN_NAME_LEN = 255; // RFC 1035: max length of domain name in wire format
+    public const MAX_PRIORITY = 65535;
+    public const MAX_WEIGHT = 65535;
+    public const MAX_PORT = 65535;
+    public const MAX_CAA_FLAGS = 255;
+    public const MAX_TXT_CHUNK = 255;
     protected Adapter $adapter;
     protected Resolver $resolver;
     /** @var array<int, callable> */
@@ -340,10 +351,10 @@ protected function resolve(array $question): array
     protected function encodeIP(string $ip, int $ttl): string
     {
         $binaryIP = inet_pton($ip);
-        if ($binaryIP === false || strlen($binaryIP) !== 4) {
+        if ($binaryIP === false || strlen($binaryIP) !== self::IPV4_LEN) {
             throw new \Exception("Invalid IPv4 address format: {$ip}");
         }
-        $result = pack('Nn', $ttl, 4) . $binaryIP;
+        $result = pack('Nn', $ttl, self::IPV4_LEN) . $binaryIP;
         return $result;
     }
 
@@ -357,10 +368,10 @@ protected function encodeIP(string $ip, int $ttl): string
     protected function encodeIPv6(string $ip, int $ttl): string
     {
         $binaryIP = inet_pton($ip);
-        if ($binaryIP === false || strlen($binaryIP) !== 16) {
+        if ($binaryIP === false || strlen($binaryIP) !== self::IPV6_LEN) {
             throw new \Exception("Invalid IPv6 address format: {$ip}");
         }
-        $result = pack('Nn', $ttl, 16) . $binaryIP;
+        $result = pack('Nn', $ttl, self::IPV6_LEN) . $binaryIP;
         return $result;
     }
 
@@ -381,7 +392,7 @@ protected function encodeDomain(string $domain, int $ttl): string
             if ($labelLength === 0) {
                 throw new \Exception("Empty label in domain: '{$domain}'");
             }
-            if ($labelLength > 63) {
+            if ($labelLength > self::MAX_LABEL_LEN) {
                 throw new \Exception("Label too long in domain: {$label}");
             }
             $result .= chr($labelLength) . $label;
@@ -389,6 +400,9 @@ protected function encodeDomain(string $domain, int $ttl): string
         }
         $result .= chr(0);
         $totalLength += 1;
+        if ($totalLength > self::MAX_DOMAIN_NAME_LEN) {
+            throw new \Exception("Encoded domain name too long: {$domain}");
+        }
         $result = pack('Nn', $ttl, $totalLength) . $result;
         return $result;
     }
@@ -404,8 +418,8 @@ protected function encodeText(string $text, int $ttl): string
     {
         $chunks = [];
         $len = strlen($text);
-        for ($i = 0; $i < $len; $i += 255) {
-            $chunk = substr($text, $i, 255);
+        for ($i = 0; $i < $len; $i += self::MAX_TXT_CHUNK) {
+            $chunk = substr($text, $i, self::MAX_TXT_CHUNK);
             $chunks[] = chr(strlen($chunk)) . $chunk;
         }
         $txtData = implode('', $chunks);
@@ -428,7 +442,7 @@ protected function encodeMx(string $domain, int $ttl, int $priority): string
         $totalLength = 2;
         foreach ($labels as $label) {
             $labelLength = strlen($label);
-            if ($labelLength > 63) {
+            if ($labelLength > self::MAX_LABEL_LEN) {
                 throw new \Exception("Label too long in MX domain: {$label}");
             }
             $result .= chr($labelLength) . $label;
@@ -436,6 +450,9 @@ protected function encodeMx(string $domain, int $ttl, int $priority): string
         }
         $result .= chr(0);
         $totalLength += 1;
+        if ($totalLength > self::MAX_DOMAIN_NAME_LEN) {
+            throw new \Exception("Encoded MX domain name too long: {$domain}");
+        }
         $result = pack('Nn', $ttl, $totalLength) . $result;
         return $result;
     }
@@ -453,13 +470,13 @@ protected function encodeMx(string $domain, int $ttl, int $priority): string
     protected function encodeSrv(string $domain, int $ttl, int $priority, int $weight, int $port): string
     {
         // Validate SRV parameters
-        if ($priority < 0 || $priority > 65535) {
+        if ($priority < 0 || $priority > self::MAX_PRIORITY) {
             throw new \Exception("SRV priority out of range: {$priority}");
         }
-        if ($weight < 0 || $weight > 65535) {
+        if ($weight < 0 || $weight > self::MAX_WEIGHT) {
             throw new \Exception("SRV weight out of range: {$weight}");
         }
-        if ($port < 0 || $port > 65535) {
+        if ($port < 0 || $port > self::MAX_PORT) {
             throw new \Exception("SRV port out of range: {$port}");
         }
         $labels = explode('.', rtrim($domain, '.'));
@@ -470,7 +487,7 @@ protected function encodeSrv(string $domain, int $ttl, int $priority, int $weigh
             if ($labelLength === 0) {
                 throw new \Exception("Empty label in SRV domain: '{$domain}'");
             }
-            if ($labelLength > 63) {
+            if ($labelLength > self::MAX_LABEL_LEN) {
                 throw new \Exception("Label too long in SRV domain: {$label}");
             }
             $result .= chr($labelLength) . $label;
@@ -478,6 +495,9 @@ protected function encodeSrv(string $domain, int $ttl, int $priority, int $weigh
         }
         $result .= chr(0);
         $totalLength += 1;
+        if ($totalLength > self::MAX_DOMAIN_NAME_LEN) {
+            throw new \Exception("Encoded SRV domain name too long: {$domain}");
+        }
         $result = pack('Nn', $ttl, $totalLength) . $result;
         return $result;
     }
@@ -515,7 +535,7 @@ protected function encodeCAA(array|string $rdata, int $ttl): string
             }
         }
         // Validate flags (must be 0-255)
-        $flags = max(0, min(255, $flags));
+        $flags = max(0, min(self::MAX_CAA_FLAGS, $flags));
         $tagLen = strlen($tag);
         $valueLen = strlen($value);
         $rdataBin = chr($flags) . chr($tagLen) . $tag . $value;

From d8064364b7e137e5ce8b2cf8eedf82ae10d2589b Mon Sep 17 00:00:00 2001
From: Damodar Lohani <dlohani48@gmail.com>
Date: Mon, 28 Jul 2025 07:55:22 +0000
Subject: [PATCH 12/12] relevant RFC links

---
 src/DNS/Server.php | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/src/DNS/Server.php b/src/DNS/Server.php
index 613be9a..b11fe3f 100644
--- a/src/DNS/Server.php
+++ b/src/DNS/Server.php
@@ -10,7 +10,7 @@
 use Utopia\Telemetry\Histogram;
 
 /**
- * Refference about DNS packet:
+ * Reference about DNS packet:
  *
  * HEADER
  * > 16 bits identificationField (1-65535. 0 means no ID). ID provided by client. Helps to match async responses. Usage may allow DNS Cache Poisoning
@@ -29,7 +29,7 @@
  * > 16 bits numberOfAdditionals (0-65535)
  *
  * QUESTIONS SECTION
- * > Each question contians:
+ * > Each question contains:
  * > -- dynamic-length name. Includes domain name we are looking for. Split into labels. To get domain, join labels with dot symbol.
  * > -- -- Following pattern repeats:
  * > -- -- -- 8 bits labelLength (0-255). Defines length of label. We use it in next step
@@ -42,12 +42,18 @@
  * ANSWERS SECTION
  * > Follows same pattern as questions section.
  * > Each answer also has (at the end):
- * > -- 32 bits ttl. Time to live of the naswer
+ * > -- 32 bits ttl. Time to live of the answer
  * > -- 16 bit length. Length of the answer data.
  * > -- X bits data X length is length from above. Gives answer itself. Structure changes based on type.
  *
  * AUTHORITIES SECTION
  * ADDITIONALS SECTION
+ *
+ * RFCs:
+ * - RFC 1035: https://datatracker.ietf.org/doc/html/rfc1035
+ * - RFC 3596: https://datatracker.ietf.org/doc/html/rfc3596
+ * - RFC 6844: https://datatracker.ietf.org/doc/html/rfc6844
+ * - RFC 2782: https://datatracker.ietf.org/doc/html/rfc2782
  */
 
 class Server
@@ -343,6 +349,7 @@ protected function resolve(array $question): array
 
     /**
      * Encode an IPv4 address (A record) according to RFC 1035.
+     * @see https://datatracker.ietf.org/doc/html/rfc1035
      *
      * @param string $ip
      * @param int $ttl
@@ -360,6 +367,7 @@ protected function encodeIP(string $ip, int $ttl): string
 
     /**
      * Encode an IPv6 address (AAAA record) according to RFC 3596.
+     * @see https://datatracker.ietf.org/doc/html/rfc3596
      *
      * @param string $ip
      * @param int $ttl
@@ -377,6 +385,7 @@ protected function encodeIPv6(string $ip, int $ttl): string
 
     /**
      * Encode a domain name (CNAME, NS, PTR) according to RFC 1035.
+     * @see https://datatracker.ietf.org/doc/html/rfc1035
      *
      * @param string $domain
      * @param int $ttl
@@ -409,6 +418,7 @@ protected function encodeDomain(string $domain, int $ttl): string
 
     /**
      * Encode a TXT record according to RFC 1035.
+     * @see https://datatracker.ietf.org/doc/html/rfc1035
      *
      * @param string $text
      * @param int $ttl
@@ -429,6 +439,7 @@ protected function encodeText(string $text, int $ttl): string
 
     /**
      * Encode an MX record according to RFC 1035.
+     * @see https://datatracker.ietf.org/doc/html/rfc1035
      *
      * @param string $domain
      * @param int $ttl
@@ -459,6 +470,7 @@ protected function encodeMx(string $domain, int $ttl, int $priority): string
 
     /**
      * Encode an SRV record according to RFC 2782.
+     * @see https://datatracker.ietf.org/doc/html/rfc2782
      *
      * @param string $domain
      * @param int $ttl
@@ -504,6 +516,7 @@ protected function encodeSrv(string $domain, int $ttl, int $priority, int $weigh
 
     /**
      * Encode a CAA record according to RFC 6844.
+     * @see https://datatracker.ietf.org/doc/html/rfc6844
      *
      * @param array{flags?:int,tag?:string,value?:string}|string $rdata
      * @param int $ttl