title: Stateless CAS - The supplied proxy callback url j_spring_cas_security_proxyreceptor' could not be authenticated
body: <p>I need to secure my RESTful stateless webservices with CAS and right now I'm trying to follow this <a href="https://github.com/btpka3/btpka3.github.com/tree/master/java/spring/first-sso/first-spring-stateless" rel="nofollow noreferrer">Spring Stateless CAS</a> demo but continuously getting a following error:</p>
  
  <pre><code>22:42:27.885 [http-nio-8443-exec-8] [first-spring-stateless] DEBUG o.s.s.c.web.CasAuthenticationFilter - Authentication request failed: org.springframework.security.authentication.BadCredentialsException: 
              The supplied proxy callback url 'https://localhost:8443/first-spring-stateless/j_spring_cas_security_proxyreceptor' could not be authenticated.
  </code></pre>
  
  <p>when accessing <code>https://localhost:8443/first-spring-cas/testProxy.do</code> url</p>
  
  <p>This is for example my <code>appointmentServiceUrl</code> - <a href="https://localhost:8443/first-spring-stateless/appointment.jsp?ticket=PT-110-a2a6eOE3lwImcwGpZ2Jp-cas.example.com" rel="nofollow noreferrer">https://localhost:8443/first-spring-stateless/appointment.jsp?ticket=PT-110-a2a6eOE3lwImcwGpZ2Jp-cas.example.com</a></p>
  
  <p><a href="https://i.stack.imgur.com/9HEbs.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/9HEbs.png" alt="enter image description here"></a></p>
  
  <p>What can be a reason of that ?</p>