OAuth 1.0, javascript and server-to-server authentication - oauth

Question

We are trying to integrate a "sign in with twitter" function in our application and for this purpose we are using javascript (hello.js).
Unfortunately, twitter is using oauth 1.0 so we can't have only a javascript solution but we need to implement a server-to-server communication to sign the request. The hello.js author provided an auth-server implementation for demo purposes based on node.js.
In our application for the backend part we are using java and I was wondering if a java solution exists for this purpose. Could I use for instance signpost or similar to do the job of auth-server ?
[UPDATE]
I tried to set the proxy used by hello.js to a mine servlet (so, instead of herokuap now I'm using a localhost servlet with oauth in the buildpath).
This servlet is doing the following:
OAuthConsumer consumer = new DefaultOAuthConsumer(
"xxxx",
"yyyyyyyyyyy");
OAuthProvider provider = new DefaultOAuthProvider(
"https://api.twitter.com/oauth/request_token",
"https://api.twitter.com/oauth/access_token",
"https://api.twitter.com/oauth/authorize");
System.out.println("Fetching request token from Twitter...");
// we do not support callbacks, thus pass OOB
String authUrl = provider.retrieveRequestToken(consumer, "http://localhost:8080/oauth1/twitter/response_server");
URL url = new URL(authUrl);
HttpURLConnection req = (HttpURLConnection) url.openConnection();
req.setRequestMethod("GET");
req.connect();
BufferedReader rd = new BufferedReader(new InputStreamReader(req.getInputStream()));
StringBuilder d = new StringBuilder();
String line = null;
while ((line = rd.readLine()) != null){
d.append(line + '\n');
}
System.out.println(d);
PrintWriter out = response.getWriter();
out.println(d);
and it prints the twitter login page in the hello.js popup. In this way I got some encoding error but it is quite working.
Anyway the callback url is mapped to another servlet where I should simply "sign" the request but I think I am missing something because sometimes I got the error
"The server understand the request but it is still refusing it"
but if I close all browser window it works.
However the response servlet is similar to this one
OAuthConsumer consumer = new AbstractOAuthConsumer(
"xxxxx",
"yyyyyyyyyyy"){
#Override
protected HttpRequest wrap(Object arg0) {
return (HttpRequest)arg0;
}
};
consumer.sign(request);
But this code does not work because I don't know how to sign a tomcat request. In oauth homepage is explained how to sign jetty and apache common http request but not the tomcat one. However, is it correct my approach ?

Answer 1

Please checkout the spec of node-oauth-shim which is used my //auth-server and which HelloJS delivers.