Thanks to M. Deinum and thanks to this guide, I could find the solution.
First, I had a configuration problem with the login form itself. As the backend has a context-path set to /api, the custom form should have submitted the form params to /api/login but I was actually submitting the data to /api/login/ (Notice the extra / at the end).
As a result, I was unknowingly trying to access a protected resource! Hence, the request was handled by the default AuthenticationEntryPoint which default behavior is to redirect the user to the login page.
As a solution, I implemented a custom AuthenticationEntryPoint :
private AuthenticationEntryPoint authenticationEntryPoint() {
return new AuthenticationEntryPoint() {
@Override
public void commence(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, AuthenticationException e) throws IOException, ServletException {
httpServletResponse.getWriter().append("Not authenticated");
httpServletResponse.setStatus(401);
}
};
}
Then used it in the configuration :
http
.exceptionHandling()
.authenticationEntryPoint(authenticationEntryPoint())
and I did the same for the other handlers :
@Configuration
@Order(SecurityProperties.ACCESS_OVERRIDE_ORDER)
protected static class SecurityConfiguration extends WebSecurityConfigurerAdapter {
@Override
protected void configure(AuthenticationManagerBuilder auth) throws Exception {
auth.inMemoryAuthentication()
.withUser("user").password("password").roles("ADMIN");
}
@Override
public void configure(HttpSecurity http) throws Exception {
http
.authorizeRequests()
.anyRequest().authenticated()
.and()
.formLogin()
.successHandler(successHandler())
.failureHandler(failureHandler())
.and()
.exceptionHandling()
.accessDeniedHandler(accessDeniedHandler())
.authenticationEntryPoint(authenticationEntryPoint())
.and()
.csrf().csrfTokenRepository(csrfTokenRepository()).and().addFilterAfter(csrfHeaderFilter(), CsrfFilter.class)
;
}
private AuthenticationSuccessHandler successHandler() {
return new AuthenticationSuccessHandler() {
@Override
public void onAuthenticationSuccess(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Authentication authentication) throws IOException, ServletException {
httpServletResponse.getWriter().append("OK");
httpServletResponse.setStatus(200);
}
};
}
private AuthenticationFailureHandler failureHandler() {
return new AuthenticationFailureHandler() {
@Override
public void onAuthenticationFailure(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, AuthenticationException e) throws IOException, ServletException {
httpServletResponse.getWriter().append("Authentication failure");
httpServletResponse.setStatus(401);
}
};
}
private AccessDeniedHandler accessDeniedHandler() {
return new AccessDeniedHandler() {
@Override
public void handle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, AccessDeniedException e) throws IOException, ServletException {
httpServletResponse.getWriter().append("Access denied");
httpServletResponse.setStatus(403);
}
};
}
private AuthenticationEntryPoint authenticationEntryPoint() {
return new AuthenticationEntryPoint() {
@Override
public void commence(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, AuthenticationException e) throws IOException, ServletException {
httpServletResponse.getWriter().append("Not authenticated");
httpServletResponse.setStatus(401);
}
};
}
private Filter csrfHeaderFilter() {
return new OncePerRequestFilter() {
@Override
protected void doFilterInternal(HttpServletRequest request,
HttpServletResponse response, FilterChain filterChain)
throws ServletException, IOException {
CsrfToken csrf = (CsrfToken) request.getAttribute(CsrfToken.class
.getName());
if (csrf != null) {
Cookie cookie = WebUtils.getCookie(request, "XSRF-TOKEN");
String token = csrf.getToken();
if (cookie == null || token != null
&& !token.equals(cookie.getValue())) {
cookie = new Cookie("XSRF-TOKEN", token);
cookie.setPath("/");
response.addCookie(cookie);
}
}
filterChain.doFilter(request, response);
}
};
}
private CsrfTokenRepository csrfTokenRepository() {
HttpSessionCsrfTokenRepository repository = new HttpSessionCsrfTokenRepository();
repository.setHeaderName("X-XSRF-TOKEN");
return repository;
}
}
