Spring Boot, Freemarker, MVC Unit Tests, Csrf

Question

Im using Freemarker with Spring Boot and do mvc unit tests. In my freemarker template I have a hidden input field for the csrf token like this:

<input type="hidden" name="${_csrf.parameterName}" value="${_csrf.token}"/>

Then I also have a mvc unit test :

        @RunWith(SpringJUnit4ClassRunner.class)
@SpringApplicationConfiguration(classes = MyApplication.class)
@WebAppConfiguration
@ActiveProfiles("test")
public class MvcTests {

    @Autowired
    WebApplicationContext ctx;

    MockMvc mvc;

    HttpSessionCsrfTokenRepository httpSessionCsrfTokenRepository;

    @Before
    public void setUp() throws Exception {
        mvc = webAppContextSetup(ctx).build();
        httpSessionCsrfTokenRepository = new HttpSessionCsrfTokenRepository();
    }


    @Test
    public void testInValidVoucherNumber() throws Exception {
        CsrfToken csrfToken = httpSessionCsrfTokenRepository.generateToken(new MockHttpServletRequest());
        mvc.perform(post("/voucher/claim")
                .sessionAttr("_csrf.parameterName", "_csrf")
                .sessionAttr("_csrf.token", csrfToken.getToken())
                .contentType(MediaType.APPLICATION_FORM_URLENCODED)
                .param("code", "ABC")
                .param("_csrf", csrfToken.getToken()))
                .andExpect(status().isOk())
                .andExpect(view().name("claim-voucher"))
                .andExpect(content().string(containsString("Code is invalid")));
    }
}

When I run the unit test I get the following freemarker error:

    testInValidVoucherNumber(MvcTests)  Time elapsed: 0.904 sec  <<< ERROR!
org.springframework.web.util.NestedServletException: Request processing failed; nested exception is freemarker.core.InvalidReferenceException: The following has evaluated to null or missing:
==> _csrf  [in template "claim-voucher.ftl" at line 25, column 34]

----
Tip: If the failing expression is known to be legally refer to something that's null or missing, either specify a default value like myOptionalVar!myDefault, or use <#if myOptionalVar??>when-present<#else>when-missing</#if>. (These only cover the last step of the expression; to cover the whole expression, use parenthesis: (myOptionalVar.foo)!myDefault, (myOptionalVar.foo)??
----

----
FTL stack trace ("~" means nesting-related):
    - Failed at: ${_csrf.parameterName}  [in template "claim-voucher.ftl" at line 25, column 32]
    ~ Reached through: #nested  [in template "layout.ftl" in macro "basic" at line 16, column 9]

Here is the controller:

@RequestMapping(value = "/voucher/claim", method = RequestMethod.POST)
public String checkVoucherCode(@Valid ClaimVoucherForm claimVoucherForm, Model model)  {
    //Business logic
}

It seems like freemarker does not have access to the csrf parameterName and csrf token. Is there a way to include the csrf information without changing the controller or is there a problem with the unit test?

Answer 1

Instead of:

.sessionAttr("_csrf.parameterName", "_csrf")
.sessionAttr("_csrf.token", csrfToken.getToken())

Try:

.sessionAttr("_csrf", csrfToken)

When you write ${_csrf.parameterName}, FreeMarker looks for the field "parameterName" on the model variable "_csrf". Not for the model variable "_csrf.parameterName".

That said, it's weird that you have to add those parameters as session attributes in your test. Shouldn't Spring Security's CsrfFilter do that for you?