Spring security 4.2.3, OAUTH 2, /oauth/token endpoint, CORS not working - spring

Question

Angular 5 app needs to login a user. Token request is sent to /oauth/token. The preflight OPTIONS request(sent by Chrome) fails because of CORS.
I tried to follow the examples at Spring Security 4.2 and various questions and responses on Stackoverflow.
Here is my code :
#Configuration
#EnableWebSecurity
public class SecurityConfig extends WebSecurityConfigurerAdapter {
#Override
protected void configure(HttpSecurity http) throws Exception {
http
.cors().and()
.csrf().disable()
.anonymous().disable()
.sessionManagement()
.sessionCreationPolicy(SessionCreationPolicy.STATELESS)
.and()
.authorizeRequests()
.antMatchers("/signup").permitAll()
.antMatchers("/oauth/token").permitAll()
.antMatchers("/fapi/**").authenticated()
.and()
.httpBasic()
.realmName("MY_REALM");
}
#Bean
CorsConfigurationSource corsConfigurationSource() {
CorsConfiguration configuration = new CorsConfiguration();
configuration.setAllowedOrigins(Arrays.asList("http://example.com"));
configuration.setAllowedMethods(Arrays.asList("HEAD", "GET", "PUT", "POST", "DELETE", "PATCH", "OPTIONS"));
configuration.addAllowedHeader("*");
configuration.setAllowCredentials(true);
UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
source.registerCorsConfiguration("/**", configuration);
return source;
}
............
}
And here is the request from Chrome
General Headers
Request URL: http://api.example.com/oauth/token
Request Method: OPTIONS
Status Code: 401
Remote Address: 127.65.43.21:80
Referrer Policy: no-referrer-when-downgrade
Request headers
Accept: */*
Accept-Encoding: gzip, deflate
Accept-Language: en-US,en;q=0.9
Access-Control-Request-Headers: authorization
Access-Control-Request-Method: POST
Cache-Control: no-cache
Connection: keep-alive
Host: api.example.com
Origin: http://example.com
Pragma: no-cache
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/66.0.3359.139 Safari/537.36
Response:
Cache-Control: no-cache, no-store, max-age=0, must-revalidate
Content-Language: en
Content-Length: 1111
Content-Type: text/html;charset=utf-8
Date: Mon, 07 May 2018 03:23:15 GMT
Expires: 0
Pragma: no-cache
WWW-Authenticate: Basic realm="MY_REALM"
X-Content-Type-Options: nosniff
X-Frame-Options: DENY
X-XSS-Protection: 1; mode=block
And the error in console:
Failed to load http://api.example.com/oauth/token: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://example.com' is therefore not allowed access. The response had HTTP status code 401.

Answer 1

I could not make it work with the CorsFilter provided by Spring.
The work around here helped.
Spring security, cors error when enable Oauth2
The part of final code
#Component
#Order(Ordered.HIGHEST_PRECEDENCE)
#WebFilter("/*")
public class SimpleCORSFilter implements Filter {
public SimpleCORSFilter() {
}
#Override
public void init(FilterConfig fc) throws ServletException {
}
#Override
public void doFilter(ServletRequest req, ServletResponse resp,
FilterChain chain) throws IOException, ServletException {
System.out.println("doFilter");
HttpServletResponse response = (HttpServletResponse) resp;
HttpServletRequest request = (HttpServletRequest) req;
response.setHeader("Access-Control-Allow-Origin", "*");
response.setHeader("Access-Control-Allow-Credentials", "true");
response.setHeader("Access-Control-Allow-Methods", "POST, GET, OPTIONS, DELETE, PUT");
response.setHeader("Access-Control-Max-Age", "3600");
response.setHeader("Access-Control-Allow-Headers", "Origin, origin, x-requested-with, authorization, Content-Type, Authorization, credential, X-XSRF-TOKEN");
if ("OPTIONS".equalsIgnoreCase(request.getMethod())) {
response.setStatus(HttpServletResponse.SC_OK);
} else {
chain.doFilter(req, resp);
}
}
#Override
public void destroy() {
}
}
In the security configuration:
#Configuration
#EnableWebSecurity
public class SecurityConfig extends WebSecurityConfigurerAdapter {
#Override
public void configure(WebSecurity web) throws Exception {
web.ignoring().antMatchers(HttpMethod.OPTIONS, "/oauth/token");
}
#Override
protected void configure(HttpSecurity http) throws Exception {
http
//.cors().and()
.csrf().disable()
.anonymous().disable()
.sessionManagement()
.sessionCreationPolicy(SessionCreationPolicy.STATELESS)
.and()
.authorizeRequests()
.antMatchers("/signup").permitAll()
.antMatchers("/oauth/token").permitAll()
.antMatchers("/fapi/**").authenticated()
.and()
.httpBasic()
.realmName("MY_REALM");
}
/*
#Bean
CorsConfigurationSource corsConfigurationSource() {
CorsConfiguration configuration = new CorsConfiguration();
configuration.setAllowedOrigins(Arrays.asList("http://example.com"));
configuration.setAllowedMethods(Arrays.asList("HEAD", "GET", "PUT", "POST", "DELETE", "PATCH", "OPTIONS"));
configuration.addAllowedHeader("*");
configuration.setAllowCredentials(true);
UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
source.registerCorsConfiguration("/**", configuration);
return source;
}*/
............
}
I am still waiting for an example that makes it work with Spring Security's CorsFilter.

Answer 2

Instead of what you have done, write a custom cors filter like the following
#Component
#Order(Ordered.HIGHEST_PRECEDENCE)
public class SimpleCorsFilter implements Filter {
#Override
public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
HttpServletResponse response = (HttpServletResponse) res;
HttpServletRequest request = (HttpServletRequest) req;
response.setHeader("Access-Control-Allow-Origin", "*");
response.setHeader("Access-Control-Allow-Methods", "POST, GET, OPTIONS, DELETE, PUT");
response.setHeader("Access-Control-Max-Age", "3600");
response.setHeader("Access-Control-Allow-Headers", "Origin, x-requested-with, authorization, Content-Type, Authorization, credential, X-XSRF-TOKEN);
if ("OPTIONS".equalsIgnoreCase(request.getMethod())) {
response.setStatus(HttpServletResponse.SC_OK);
} else {
chain.doFilter(req, res);
}
}
#Override
public void init(FilterConfig filterConfig) {
}
#Override
public void destroy() {
}
}
And modify your configure(HttpSecurity http) override to
#Override
protected void configure(HttpSecurity http) throws Exception {
http
.and()
.csrf().disable()
.anonymous().disable()
.sessionManagement()
.sessionCreationPolicy(SessionCreationPolicy.STATELESS)
.and()
.authorizeRequests()
.antMatchers("/signup").permitAll()
.antMatchers("/oauth/token").permitAll()
.antMatchers("/fapi/**").authenticated()
.and()
.httpBasic()
.realmName("MY_REALM");
}