Custom Authentication provider does not work in Spring Security - spring-security

Question

I want to add spring security(using Java config) into my application with custom authentication provider, however I cannot make it work. It seems that the authenticationProvider was not well configured, coz I cannot debug into the method authenticate(Authentication), and the println doesn't print anything. And every request responsed with 403.
Please anyone can help me with this, I've been struck by this for the whoele weekend.
#Configuration
#EnableWebMvcSecurity
public class SecurityConfig extends WebSecurityConfigurerAdapter {
#Override
protected void configure(HttpSecurity http) throws Exception {
http
.authorizeRequests()
.anyRequest().authenticated();
}
#Override
protected void configure(AuthenticationManagerBuilder auth) throws Exception {
auth.authenticationProvider(new AuthenticationProvider(){
#Override
public Authentication authenticate(Authentication arg0) throws AuthenticationException {
System.out.println("authenticating...");
return arg0;
}
#Override
public boolean supports(Class<?> arg0) {
return true;
}
});
}
}

Answer 1

The authenticate() function of the class must return an UsernamePasswordAuthenticationToken instance if the authentication is successful or null otherwise.
**
The org.springframework.security.authentication.ProviderManager and configure is (set its providers) to a custom
org.springframework.security.authentication.AuthenticationProvider;
This should return on its authenticate method a Authentication, which
should be setted with the GrantedAuthority
**
Here is a sample authentication manager code that sets authorities and returns an authentication object.
Can you try injecting the customAUthenticationProvider class you have and then use that in the configure method?
#Autowired
private CustomAuthenticationProvider customAuthenticationProvider;
#Override
protected void configure(AuthenticationManagerBuilder auth) throws Exception {
auth.authenticationProvider(customAuthenticationProvider);
}
Are the web xml mappings in place for spring security?
<listener>
<listener-class>
org.springframework.web.context.ContextLoaderListener
</listener-class>
</listener>
<!-- use the springSecurityFilterChain -->
<filter>
<filter-name>springSecurityFilterChain</filter-name>
<filter- class>org.springframework.web.filter.DelegatingFilterProxy</filter-class>
<!-- NOTE This does not specify its own configuration it is
loaded by the ContextLoaderListener instead -->
<!-- NOTE by default the filter name is used to
look up the Spring Security Filter Chain if you like you
can use any filter name you want, but you must specify
the bean name instead in this instance. Since we use the
springSecurityFilterChain as the filter name this is not
necessary
<init-param>
<param-name>targetBeanName</param-name>
<param-value>springSecurityFilterChain</param-value>
</init-param> -->
</filter>
<filter-mapping>
<filter-name>springSecurityFilterChain</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
Here is a sample spring security project : https://github.com/spring-projects/spring-security-javaconfig