File: vendor/symfony/symfony/src/Symfony/Bundle/FrameworkBundle/Resources/config/security_csrf.xml

<?xml version="1.0" ?>

<container xmlns="http://symfony.com/schema/dic/services"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://symfony.com/schema/dic/services http://symfony.com/schema/dic/services/services-1.0.xsd">

    <parameters>
        <parameter key="security.csrf.token_generator.class">Symfony\Component\Security\Csrf\TokenGenerator\UriSafeTokenGenerator</parameter>
        <parameter key="security.csrf.token_storage.class">Symfony\Component\Security\Csrf\TokenStorage\SessionTokenStorage</parameter>
        <parameter key="security.csrf.token_manager.class">Symfony\Component\Security\Csrf\CsrfTokenManager</parameter>
    </parameters>

    <services>
        <service id="security.csrf.token_generator" class="%security.csrf.token_generator.class%" public="false" />

        <service id="security.csrf.token_storage" class="%security.csrf.token_storage.class%" public="false">
            <argument type="service" id="session" />
        </service>

        <service id="security.csrf.token_manager" class="%security.csrf.token_manager.class%">
            <argument type="service" id="security.csrf.token_generator" />
            <argument type="service" id="security.csrf.token_storage" />
        </service>
    </services>
</container>