+
+/**
+ * PHP stream filter to detect html/javascript code in attachments
+ */
+class rcube_content_filter extends php_user_filter
+{
+ private $buffer = '';
+ private $cutoff = 2048;
+
+ function onCreate()
+ {
+ $this->cutoff = rand(2048, 3027);
+ return true;
+ }
+
+ function filter($in, $out, &$consumed, $closing)
+ {
+ while ($bucket = stream_bucket_make_writeable($in)) {
+ $this->buffer .= $bucket->data;
+
+ // check for evil content and abort
+ if (preg_match('/<(script|iframe|object)/i', $this->buffer))
+ return PSFS_ERR_FATAL;
+
+ // keep buffer small enough
+ if (strlen($this->buffer) > 4096)
+ $this->buffer = substr($this->buffer, $this->cutoff);
+
+ $consumed += $bucket->datalen;
+ stream_bucket_append($out, $bucket);
+ }
+
+ return PSFS_PASS_ON;
+ }
+}
+