Fix some more ldap issues

Summary:
  - LDAP import needs to use envelopes.
  - Use ldap_sprintf().

Test Plan: Configured an LDAP server. Added an account. Imported it; logged in with it. Tried to login with accounts like ",", etc., got good errors.

Reviewers: vrana, btrahan

Reviewed By: btrahan

CC: aran

Differential Revision: https://secure.phabricator.com/D2995

src/applications/auth/controller/PhabricatorLDAPLoginController.php

@@ -35,10 +35,12 @@ final class PhabricatorLDAPLoginController extends PhabricatorAuthController {
     $current_user = $this->getRequest()->getUser();
     $request = $this->getRequest();
 
+    $ldap_username = $request->getCookie('phusr');
     if ($request->isFormPost()) {
+      $ldap_username = $request->getStr('username');
       try {
         $envelope = new PhutilOpaqueEnvelope($request->getStr('password'));
-        $this->provider->auth($request->getStr('username'), $envelope);
+        $this->provider->auth($ldap_username, $envelope);
       } catch (Exception $e) {
         $errors[] = $e->getMessage();
       }
@@ -124,7 +126,6 @@ final class PhabricatorLDAPLoginController extends PhabricatorAuthController {
       }
     }
 
-    $ldap_username = $request->getCookie('phusr');
     $ldap_form = new AphrontFormView();
     $ldap_form
       ->setUser($request->getUser())