Google Authentication API: How to get the user's gmail address - google-api

Question

I've been studying the Google authentication API (AuthSub)... My question is, how do I get the user's account information (at least their Gmail address) after the authentication has passed?
Because currently, all I get back from the authentication process is a token granting me access to which ever Google service I have specified in the scope, but there's no easy way to even get the user's login id (Gmail address) as far as I can tell...
If so, what Google service allows me to access the user's information?

Answer 1

Google Authentication API is a token based system to authenticate a valid user. It does not expose any of other interface that allows to get account holder information back to authorizer.

Answer 2

Using the Google AppEngine GData services, you can request the user to give you access to their Google Mail, Calendar, Picasa, etc. Check it out here.

Answer 3

You can get some of the data through the OpenID API, with the ax extension. If you are authenticating with other methods, best I found is calling https://www-opensocial.googleusercontent.com/api/people/#me/#self and it will get you name, email and picture. Be sure to have http://www-opensocial.googleusercontent.com/api in scopes when authenticating.

Answer 4

[ValidateInput(false)]
public ActionResult Authenticate(string returnUrl)
{
try
{
logger.Info("" + returnUrl + "] LoginController : Authenticate method start ");
var response = openid.GetResponse();
if (response == null)
{
try
{
string discoveryuri = "https://www.google.com/accounts/o8/id";
//OpenIdRelyingParty openid = new OpenIdRelyingParty();
var fetch = new FetchRequest();// new
var b = new UriBuilder(Request.Url) { Query = "" };
var req = openid.CreateRequest(discoveryuri, b.Uri, b.Uri);
fetch.Attributes.AddRequired(WellKnownAttributes.Contact.Email);
fetch.Attributes.AddRequired(WellKnownAttributes.Name.FullName);
req.AddExtension(fetch);
return req.RedirectingResponse.AsActionResult();
}
catch (ProtocolException ex)
{
logger.ErrorFormat(" LoginController : Authenticate method has error, Exception:" + ex.ToString());
ViewData["Message"] = ex.Message;
return View("Login");
}
}
else
{
logger.Info("" + returnUrl + "] LoginController : Authenticate method :when responce not null ");
switch (response.Status)
{
case AuthenticationStatus.Authenticated:
logger.Info("" + response.Status + "] LoginController : Authenticate method : responce status ");
var fetchResponse = response.GetExtension<FetchResponse>();
string email = fetchResponse.GetAttributeValue(WellKnownAttributes.Contact.Email);
string userIPAddress = HttpContext.Request.UserHostAddress;
SecurityManager manager = new SecurityManager();
int userID = manager.IsValidUser(email);
if (userID != 0)
{
ViewBag.IsFailed = "False";
logger.Info("" + userID + "] LoginController : Authenticate method : user id id not null ");
Session["FriendlyIdentifier"] = response.FriendlyIdentifierForDisplay;
Session["UserEmail"] = email;
FormsAuthentication.SetAuthCookie(email, false);
WebSession.UserEmail = email;
WebSession.UserID = userID;
UserManager userManager = new UserManager();
WebSession.AssignedSites = userManager.GetAssignedSites(userID);
if (!string.IsNullOrEmpty(returnUrl))
{
logger.Info("" + returnUrl + "] LoginController : Authenticate method : retutn url not null then return Redirect ");
return Redirect(returnUrl);
}
else
{
logger.Info("" + returnUrl + "] LoginController : Authenticate method : retutn url null then return RedirectToAction ");
//
return Redirect("/Home");
}
}
else
{
ViewBag.IsFailed = "True";
logger.Info("" + returnUrl + "] LoginController : Authenticate method :user id null ");
if (!string.IsNullOrEmpty(returnUrl))
{
logger.Info("" + returnUrl + "] LoginController : Authenticate method :and return Redirect ");
return Redirect(returnUrl);
}
else
{
logger.Info("" + returnUrl + "] LoginController : Authenticate method :and return RedirectToAction ");
return View("Index");
}
}
case AuthenticationStatus.Canceled:
logger.Info("" + response.Status + "] LoginController : Authenticate method : AuthenticationStatus.Canceled and return view ");
ViewData["Message"] = "Canceled at provider";
return View("Login");
case AuthenticationStatus.Failed:
logger.Info("" + response.Status + "] LoginController : Authenticate method : AuthenticationStatus.Failed and return view ");
logger.Error(response.Exception.Message);
ViewData["Message"] = response.Exception.Message;
return View("Login");
}
}
logger.Info("" + returnUrl + "] LoginController : Authenticate method end and return EmptyResult");
return new EmptyResult();
}
catch (Exception ex)
{
logger.Error(" LoginController : Authenticate method ", ex);
throw;
}
}