import java.io.IOException;import java.security.GeneralSecurityException;import com.google.api.client.googleapis.auth.oauth2.GoogleIdToken;import com.google.api.client.googleapis.auth.oauth2.GoogleIdTokenVerifier;import com.google.api.client.http.javanet.NetHttpTransport;import com.google.api.client.json.JsonFactory;import com.google.api.client.json.gson.GsonFactory;public class Checker { private final List mClientIDs; private final String mAudience; private final GoogleIdTokenVerifier mVerifier; private final JsonFactory mJFactory; private String mProblem = "Verification failed. (Time-out?)"; public Checker(String[] clientIDs, String audience) { mClientIDs = Arrays.asList(clientIDs); mAudience = audience; NetHttpTransport transport = new NetHttpTransport(); mJFactory = new GsonFactory(); mVerifier = new GoogleIdTokenVerifier(transport, mJFactory); } public GoogleIdToken.Payload check(String tokenString) { GoogleIdToken.Payload payload = null; try { GoogleIdToken token = GoogleIdToken.parse(mJFactory, tokenString); if (mVerifier.verify(token)) { GoogleIdToken.Payload tempPayload = token.getPayload(); if (!tempPayload.getAudience().equals(mAudience)) mProblem = "Audience mismatch"; else if (!mClientIDs.contains(tempPayload.getIssuee())) mProblem = "Client ID mismatch"; else payload = tempPayload; } } catch (GeneralSecurityException e) { mProblem = "Security issue: " + e.getLocalizedMessage(); } catch (IOException e) { mProblem = "Network problem: " + e.getLocalizedMessage(); } return payload; } public String problem() { return mProblem; }}
require 'google-id-token'validator = GoogleIDToken::Validator.newjwt = validator.check(token, required_audience, required_client_id)if jwt email = jwt['email']else report "Cannot validate: #{validator.problem}"end
