Security/LdapGuardAuthenticator.php
public function getCredentials(Request $request)
    {
        if (!$this->supports($request)) {
            return null;
        }
        $credentials = [
            'username' => $this->getRequestUsername($request),
            'password' => $this->getRequestPassword($request),
            'ldap_domain' => $this->getRequestDomain($request),
        ];
        $request->getSession()->set(Security::LAST_USERNAME, $credentials['username']);

        return $credentials;
    }
public function getCredentials(Request $request)
    {
        if (!$this->supports($request)) {
            return null;
        }
        $credentials = [
            'username' => $this->getRequestUsername($request),
            'password' => $this->getRequestPassword($request),
            'ldap_domain' => $this->getRequestDomain($request),
        ];
        $request->getSession()->set(Security::LAST_USERNAME, $credentials['username']);

        return $credentials;
    }
{@inheritdoc}