From 6e33cfb59d22fff20dbf1ee429308e1587c62ab3 Mon Sep 17 00:00:00 2001
From: David Dreschner <github-2017@dreschner.net>
Date: Tue, 13 Jan 2026 17:21:57 +0100
Subject: [PATCH] fix: Make c= flag optional, remove requirement of two
 canonical rules and fix broken raw message for c=simple

---
 src/DKIM.php      |  8 ++++----
 src/Validator.php | 21 +++++++++++++++++++--
 2 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/src/DKIM.php b/src/DKIM.php
index 616dc38..7481b14 100644
--- a/src/DKIM.php
+++ b/src/DKIM.php
@@ -82,7 +82,7 @@ abstract class DKIM
      *
      * @throws DKIMException
      */
-    protected function canonicalizeHeaders(array $headers, string $style = 'relaxed'): string
+    protected function canonicalizeHeaders(array $headers, string $style): string
     {
         if (count($headers) === 0) {
             throw new DKIMException('Attempted to canonicalize empty header array');
@@ -124,7 +124,7 @@ abstract class DKIM
      *
      * @return string
      */
-    protected function canonicalizeBody(string $body, string $style = 'relaxed', int $length = -1): string
+    protected function canonicalizeBody(string $body, string $style, int $length = -1): string
     {
         if ($body === '') {
             return self::CRLF;
@@ -245,7 +245,7 @@ abstract class DKIM
                         'unfolded'   => $currentHeaderValue,
                         'decoded'    => self::rfc2047Decode($currentHeaderValue),
                         'rawarray'   => $currentRawHeaderLines,
-                        'raw'        => implode(self::CRLF . ' ', $currentRawHeaderLines), //Refold lines
+                        'raw'        => implode(self::CRLF, $currentRawHeaderLines), //Refold lines
                     ];
                 }
                 $currentHeaderLabel = $matches[1];
@@ -257,7 +257,7 @@ abstract class DKIM
                 }
                 //This is a folded continuation of the current header
                 $currentHeaderValue .= $matches[1];
-                $currentRawHeaderLines[] = $matches[1];
+                $currentRawHeaderLines[] = $matches[0];
             }
             ++$headerLineIndex;
             if ($headerLineIndex >= $headerLineCount) {
diff --git a/src/Validator.php b/src/Validator.php
index fc558c0..62b7340 100644
--- a/src/Validator.php
+++ b/src/Validator.php
@@ -83,8 +83,24 @@ class Validator extends DKIM
                 ];
             }
 
-            //Validate canonicalization algorithms for header and body
-            [$headerCA, $bodyCA] = explode('/', $dkimTags['c']);
+            //Validate optional canonicalization algorithms for header and body
+            //Use simple/simple as default unless defined differently
+            $headerCA = 'simple';
+            $bodyCA = 'simple';
+
+            if (array_key_exists('c', $dkimTags)) {
+                $containsBodyAndHeaderAlgorithm = strpos($dkimTags['c'], '/') !== false;
+
+                if ($containsBodyAndHeaderAlgorithm) {
+                    $rules = explode('/', $dkimTags['c']);
+
+                    $headerCA = $rules[0];
+                    $bodyCA = $rules[1];
+                } else {
+                    $headerCA = $dkimTags['c'];
+                }
+            }
+
             if ($headerCA !== 'relaxed' && $headerCA !== 'simple') {
                 $output[$signatureIndex][] = [
                     'status' => 'PERMFAIL',
@@ -298,6 +314,7 @@ class Validator extends DKIM
         $host = sprintf('%s._domainkey.%s', $selector, $domain);
         $textRecords = dns_get_record($host, DNS_TXT);
 
+
         if ($textRecords === false) {
             return false;
         }
-- 
2.43.0