What could cause the original 'OAuth2' state parameter to be null in org.springframework.social.connect.web.ConnectSupport? - oauth-2.0

Question

I am trying to use Spring Social on my application and I noticed while debugging that the original 'OAuth2' state parameter is always null on my app.
See Spring Social source code for org.springframework.social.connect.web.ConnectSupport below:
private void verifyStateParameter(NativeWebRequest request) {
String state = request.getParameter("state");
String originalState = extractCachedOAuth2State(request);//Always null...
if (state == null || !state.equals(originalState)) {
throw new IllegalStateException("The OAuth2 'state' parameter is missing or doesn't match.");
}
}
private String extractCachedOAuth2State(WebRequest request) {
String state = (String) sessionStrategy.getAttribute(request, OAUTH2_STATE_ATTRIBUTE);
sessionStrategy.removeAttribute(request, OAUTH2_STATE_ATTRIBUTE);
return state;
}
Can anyone please help?
edit: I do see the state parameter being passed back by facebook:
Request URL:https://www.facebook.com/v2.5/dialog/oauth?client_id=414113641982912&response_type=code&redirect_uri=http%3A%2F%2Flocalhost%3A8080%2Fconnect%2Ffacebook&scope=public_profile&state=0b7a97b5-b8d1-4f97-9b60-e3242c9c7eb9
Request Method:GET
Status Code:302
Remote Address:179.60.192.36:443
edit 2: By the way, the exception I get is the following:
Exception while handling OAuth2 callback (The OAuth2 'state' parameter is missing or doesn't match.). Redirecting to facebook connection status page.

Answer 1

It turned out that the issue was caused by the fact that I was relying on headers - as opposed to cookies - to manage the session.
By commenting out the following spring session configuration bean:
#Bean
public HttpSessionStrategy sessionStrategy(){
return new HeaderHttpSessionStrategy();
}
The oauth2 state parameter issue was sorted.
P.S. Now I have got to find a way to get Spring Social to work with my current configuration of Spring Session...
Edit: I managed to keep the HeaderHttpSessionStrategy (on the spring session side) and get it to work by implementing my own SessionStrategy (on the spring social side) as follows:
public class CustomSessionStrategy implements SessionStrategy {
public void setAttribute(RequestAttributes request, String name, Object value) {
request.setAttribute(name, value, RequestAttributes.SCOPE_SESSION);
}
public Object getAttribute(RequestAttributes request, String name) {
ServletWebRequest servletWebRequest = (ServletWebRequest) request;
return servletWebRequest.getParameter(name);
}
public void removeAttribute(RequestAttributes request, String name) {
request.removeAttribute(name, RequestAttributes.SCOPE_SESSION);
}
}

Answer 2

Try this work around and see if that works for you:
To my surprise I opened application in a 'incognito' browser and everything worked. Just like that. I think before something got cached and was causing the issue.
I ran into this issue today, My application was working perfectly fine. I just took a break for few hours and when I ran it again it started complaining about 'The OAuth2 'state' parameter is missing or doesn't match.'
The state param is first put into the session then the request goes out to facebook and the request comes back with the same state param but when spring is looking for session object to get the state param, it is not finding the session. I think it is not finding the session because when the request comes back it thinks that it is a different client (or host), even though the old HttpSession object still exists. The container maintains a HttpSession per client.

Answer 3

What you're getting from Facebook is not a request attribute , it's a request parameter.
You should get it by something like:
request.getParameter("state")