- Added server-side e-mail address validation with 'email_dns_check' option (#1485857)

7 files changed, 79 insertions, 1 deletions

diff --git a/CHANGELOG b/CHANGELOG
index 86238b245..02e6a4c60 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,6 +1,7 @@
 CHANGELOG RoundCube Webmail
 ===========================
 
+- Added server-side e-mail address validation with 'email_dns_check' option (#1485857)
 - Fix login page loading into an iframe when session expires (#1485952)
 - added option 'force_https_port' in 'force_https' plugin (#1486091)
 - Option 'force_https' replaced by 'force_https' plugin
diff --git a/config/main.inc.php.dist b/config/main.inc.php.dist
index e184078a9..7fbf97132 100644
--- a/config/main.inc.php.dist
+++ b/config/main.inc.php.dist
@@ -364,6 +364,9 @@ $rcmail_config['delete_always'] = false;
 // Must be less than 'session_lifetime'
 $rcmail_config['min_keep_alive'] = 60;
 
+// Enable DNS checking for e-mail address validation
+$rcmail_config['email_dns_check'] = false;
+
 /***** these settings can be overwritten by user's preferences *****/
 
 // skin name: folder from skins/
diff --git a/plugins/managesieve/managesieve.php b/plugins/managesieve/managesieve.php
index 9a5e721c1..0c8c492e4 100644
--- a/plugins/managesieve/managesieve.php
+++ b/plugins/managesieve/managesieve.php
@@ -818,6 +818,9 @@ class managesieve extends rcube_plugin
 
   private function check_email($email)
   {
+    if (function_exists('check_email'));
+      return check_email($email);
+
     // Check for invalid characters
     if (preg_match('/[\x00-\x1F\x7F-\xFF]/', $email))
       return false;
diff --git a/program/include/main.inc b/program/include/main.inc
index e96840003..06d7780d1 100644
--- a/program/include/main.inc
+++ b/program/include/main.inc
@@ -1401,6 +1401,58 @@ function rcube_html_editor($mode='')
 
 
 /**
+ * E-mail address validation
+ */
+function check_email($email)
+{
+  // Check for invalid characters
+  if (preg_match('/[\x00-\x1F\x7F-\xFF]/', $email))
+    return false;
+
+  // Check that there's one @ symbol, and that the lengths are right
+  if (!preg_match('/^([^@]{1,64})@([^@]{1,255})$/', $email, $email_array))
+    return false;
+
+  // Check local part
+  $local_array = explode('.', $email_array[1]);
+  foreach ($local_array as $local_part)
+    if (!preg_match('/^(([A-Za-z0-9!#$%&\'*+\/=?^_`{|}~-]+)|("[^"]+"))$/', $local_part))
+      return false;
+
+  // Check domain part
+  if (preg_match('/^(25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])(\.(25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])){3}$/', $email_array[2]) 
+      || preg_match('/^\[(25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])(\.(25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])){3}\]$/', $email_array[2]))
+    return true; // If an IP address
+  else {
+    // If not an IP address
+    $domain_array = explode('.', $email_array[2]);
+    if (sizeof($domain_array) < 2)
+      return false; // Not enough parts to be a valid domain
+
+    foreach ($domain_array as $domain_part)
+      if (!preg_match('/^(([A-Za-z0-9][A-Za-z0-9-]{0,61}[A-Za-z0-9])|([A-Za-z0-9]))$/', $domain_part))
+        return false;
+
+    if (!rcmail::get_instance()->config->get('email_dns_check'))
+      return true;
+
+    if (strtoupper(substr(PHP_OS, 0, 3)) == 'WIN' && version_compare(PHP_VERSION, '5.3.0', '<'))
+      return true;
+
+    // find MX record(s)
+    if (getmxrr($email_array[2], $mx_records))
+      return true;
+
+    // find any DNS record
+    if (checkdnsrr($email_array[2], 'ANY'))
+      return true;
+  }
+
+  return false;
+}
+
+
+/**
  * Helper class to turn relative urls into absolute ones
  * using a predefined base
  */
diff --git a/program/localization/en_US/messages.inc b/program/localization/en_US/messages.inc
index 6fc7be862..b0a812ce7 100644
--- a/program/localization/en_US/messages.inc
+++ b/program/localization/en_US/messages.inc
@@ -106,5 +106,6 @@ $messages['smtpfromerror'] = 'SMTP Error ($code): Failed to set sender "$from"';
 $messages['smtptoerror'] = 'SMTP Error ($code): Failed to add recipient "$to"';
 $messages['smtprecipientserror'] = 'SMTP Error: Unable to parse recipients list';
 $messages['smtperror'] = 'SMTP Error: $msg';
+$messages['emailformaterror'] = 'Incorrect e-mail address: $email';
 
 ?>
diff --git a/program/localization/pl_PL/messages.inc b/program/localization/pl_PL/messages.inc
index 69b9b4285..1fc765982 100644
--- a/program/localization/pl_PL/messages.inc
+++ b/program/localization/pl_PL/messages.inc
@@ -110,5 +110,6 @@ $messages['smtptoerror'] = 'Błąd SMTP ($code): Nie można dodać odbiorcy "$to
 $messages['smtprecipientserror'] = 'Błąd SMTP: Parsowanie listy odbiorców nie powiodło się';
 $messages['smtperror'] = 'Błąd SMTP: $msg';
 $messages['invalidrequest'] = 'Błędne żądanie! Nie zapisano danych.';
+$messages['emailformaterror'] = 'Błędny adres e-mail: $email';
 
 ?>
diff --git a/program/steps/mail/sendmail.inc b/program/steps/mail/sendmail.inc
index e8ef47a55..e8445aa4c 100644
--- a/program/steps/mail/sendmail.inc
+++ b/program/steps/mail/sendmail.inc
@@ -151,6 +151,8 @@ function rcmail_attach_emoticons(&$mime_message)
 // parse email address input
 function rcmail_email_input_format($mailto)
 {
+  global $EMAIL_FORMAT_ERROR;
+
   $regexp = array('/[,;]\s*[\r\n]+/', '/[\r\n]+/', '/[,;]\s*$/m', '/;/', '/(\S{1})(<\S+@\S+>)/U');
   $replace = array(', ', ', ', '', ',', '\\1 \\2');
 
@@ -181,8 +183,16 @@ function rcmail_email_input_format($mailto)
         $address = '<'.$address.'>';
 
       $result[] = $name.' '.$address;
+      $item = $address;
     } else if (trim($item)) {
-      // @TODO: handle errors
+      continue;
+    }
+
+    // check address format
+    $item = trim($item, '<>');
+    if ($item && !check_email($item)) {
+      $EMAIL_FORMAT_ERROR = $item;
+      return;
     }
   }
 
@@ -200,10 +210,17 @@ $message_id = sprintf('<%s@%s>', md5(uniqid('rcmail'.mt_rand(),true)), $RCMAIL->
 $input_charset = $OUTPUT->get_charset();
 $message_charset = isset($_POST['_charset']) ? $_POST['_charset'] : $input_charset;
 
+$EMAIL_FORMAT_ERROR = NULL;
+
 $mailto = rcmail_email_input_format(get_input_value('_to', RCUBE_INPUT_POST, TRUE, $message_charset));
 $mailcc = rcmail_email_input_format(get_input_value('_cc', RCUBE_INPUT_POST, TRUE, $message_charset));
 $mailbcc = rcmail_email_input_format(get_input_value('_bcc', RCUBE_INPUT_POST, TRUE, $message_charset));
 
+if ($EMAIL_FORMAT_ERROR) {
+  $OUTPUT->show_message('emailformaterror', 'error', array('email' => $EMAIL_FORMAT_ERROR)); 
+  $OUTPUT->send('iframe');
+}
+
 if (empty($mailto) && !empty($mailcc)) {
   $mailto = $mailcc;
   $mailcc = null;