The redirect URI in the request, http://eng.skku.edu/sns/success.do, does not match the ones authorized for the OAuth client. To update the authorized redirect URIs, visit: https://console.developers.google.com/apis/credentials/oauthclient/971421139455-f99b3frr9s8bt722isq8ss5v08irj6lr.apps.googleusercontent.com?project=971421139455