Fixing 'Invalid CSRF Token' Error in Spring: Tips and Solutions

If you're experiencing an "Invalid CSRF Token" error in your Spring application, don't worry - you're not alone. This error can be frustrating to deal with, but there are several tips and solutions you can try to fix it.

What is a CSRF Token?

Before we dive into the solutions, let's first understand what a CSRF token is. CSRF stands for Cross-Site Request Forgery, which is a type of attack that tricks a user into performing an action on a website without their knowledge or consent. A CSRF token is a security measure implemented in Spring to prevent such attacks.

Possible Solutions

1. Check the CSRF Token Configuration

The first thing you should do is check your Spring configuration to make sure that CSRF protection is enabled. This can be done by adding the @EnableWebSecurity annotation to your security configuration class and ensuring that the csrf() method is called.

@EnableWebSecurity
public class SecurityConfig extends WebSecurityConfigurerAdapter {
 
    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            .csrf().disable()
            .authorizeRequests()
            .anyRequest().authenticated()
            .and()
            .formLogin()
            .and()
            .httpBasic();
    }
}

2. Check the CSRF Token Parameter Name

If CSRF protection is enabled, the next thing to check is the parameter name for the CSRF token. By default, Spring expects the parameter name to be _csrf. If your application is using a different parameter name, you'll need to update your configuration to match.

@Override
protected void configure(HttpSecurity http) throws Exception {
    http
        .csrf()
            .csrfTokenRepository(CookieCsrfTokenRepository.withHttpOnlyFalse())
            .ignoringAntMatchers("/login/**")
            .and()
        .authorizeRequests()
            .antMatchers("/login/**").permitAll()
            .anyRequest().authenticated()
            .and()
        .formLogin()
            .loginPage("/login")
            .defaultSuccessUrl("/")
            .permitAll()
            .and()
        .logout()
            .logoutUrl("/logout")
            .permitAll();
}

3. Check the CSRF Token Value

If the parameter name is correct, the next thing to check is the actual value of the CSRF token. Make sure that the token is being generated and included in the request correctly. You can verify this by inspecting the HTTP headers in your browser's developer tools.

4. Check for Cross-Domain Requests

If your application is making cross-domain requests, you may need to configure CORS (Cross-Origin Resource Sharing) to allow the requests. This can be done by adding the @CrossOrigin annotation to your controller methods or by configuring CORS globally.

@RestController
@RequestMapping("/api")
@CrossOrigin(origins = "http://localhost:4200")
public class ApiController {
 
    @GetMapping("/users")
    public List<User> getUsers() {
        // ...
    }
 
    // ...
}

5. Disable CSRF Protection (As a Last Resort)

If none of the above solutions work, you may need to disable CSRF protection altogether. While this is not recommended, it may be necessary in some cases. You can disable CSRF protection by removing the csrf() method call in your security configuration.

@Override
protected void configure(HttpSecurity http) throws Exception {
    http
        .authorizeRequests()
            .anyRequest().authenticated()
            .and()
        .formLogin()
            .and()
        .httpBasic();
}

Conclusion

Fixing the "Invalid CSRF Token" error in Spring can be a tricky process, but by following the tips and solutions outlined above, you should be able to solve the issue. Remember to always keep your application's security in mind and to test your changes thoroughly before deploying to production.