security:
    encoders:
        AppBundleEntityUser:
            algorithm: bcrypt

$encoder = $this->container->get('security.password_encoder');
        $encoded = $encoder->encodePassword($user, $password);

$form->handleRequest ( $request );

$form->add ( 'oldpassword', 'password', array('label'=>'old password', 'required'=>true, 'error_bubbling'=>true, 'mapped' => false)  );

$form->get('oldpassword')->getData()

$form->handleRequest ( $request );
        if ($form->isSubmitted ()) {

        if ( !$functions->passwordVerify($user, $form->get('oldpassword')->getData()) ) {
            $form->get ( 'oldpassword' ) ->addError ( new FormError ( "Your current password is invalid" ) );
        }

public function passwordVerify($user=null, $oldpassword=null) {
        $encoder = $this->container->get('security.password_encoder');
        $valid = $encoder->isPasswordValid($user, $oldpassword);
        return $valid;
    }

$valid = $encoder->isPasswordValid($user, $oldpassword);

public function getSalt() {
}