UTF-8 checks added to prevent decoding of unencoded values #76

Webklex · Jan 21, 2021 · 27cb7e1 · 27cb7e1
1 parent de50ce3
commit 27cb7e1
Show file tree

Hide file tree

Showing 2 changed files with 19 additions and 4 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -8,6 +8,7 @@ Updates should follow the [Keep a CHANGELOG](http://keepachangelog.com/) princip
 ### Fixed
 - Attachment detection updated #82 #90
 - Timeout handling improved
+- Additional utf-8 checks added to prevent decoding of unencoded values #76
 
 ### Added
 - Auto reconnect option added to `Folder::idle()` #89
@@ -16,6 +17,7 @@ Updates should follow the [Keep a CHANGELOG](http://keepachangelog.com/) princip
 - [Folder::class](src/Folder.php)
 - [Part::class](src/Part.php)
 - [Client::class](src/Client.php)
+- [Header::class](src/Header.php)
 
 ### Breaking changes
 - NaN

diff --git a/src/Header.php b/src/Header.php
@@ -406,6 +406,16 @@ public function getEncoding($structure) {
         return $this->fallback_encoding;
     }
 
+    /**
+     * Test if a given value is utf-8 encoded
+     * @param $value
+     *
+     * @return bool
+     */
+    private function is_uft8($value) {
+        return strpos(strtolower($value), '=?utf-8?') === 0;
+    }
+
     /**
      * Try to decode a specific header
      * @param mixed $value
@@ -420,9 +430,12 @@ private function decode($value) {
         $decoder = $this->config['decoder']['message'];
 
         if ($value !== null) {
+            $is_utf8_base = $this->is_uft8($value);
+
             if($decoder === 'utf-8' && extension_loaded('imap')) {
                 $value = \imap_utf8($value);
-                if (strpos(strtolower($value), '=?utf-8?') === 0) {
+                $is_utf8_base = $this->is_uft8($value);
+                if ($is_utf8_base) {
                     $value = mb_decode_mimeheader($value);
                 }
                 if ($this->notDecoded($original_value, $value)) {
@@ -433,13 +446,13 @@ private function decode($value) {
                         }
                     }
                 }
-            }elseif($decoder === 'iconv') {
+            }elseif($decoder === 'iconv' && $is_utf8_base) {
                 $value = iconv_mime_decode($value);
-            }else{
+            }elseif($is_utf8_base){
                 $value = mb_decode_mimeheader($value);
             }
 
-            if (strpos(strtolower($value), '=?utf-8?') === 0) {
+            if ($this->is_uft8($value)) {
                 $value = mb_decode_mimeheader($value);
             }