Access User Info using Google APIs for .NET

Question

I'm using the Google APIs Preview (1.7.0) to authorize a user via OAuth2. I've been following the sample MVC code. This is my implementation of FlowMetadata:

private static readonly IAuthorizationCodeFlow flow = ...; // Implementation of tokens

public static async Task<Google.Apis.Auth.OAuth2.Web.AuthorizationCodeWebApp.AuthResult> GetCredentials(Controller controller, CancellationToken cancellationToken) {
    var result = await new AuthorizationCodeMvcApp(controller, new Models.Generic.AppFlowMetadata()).AuthorizeAsync(cancellationToken);
    if (result.Credential != null)
    {
         // Struggling here. How do I make a request to get the e-mail address?
    }
}

I now have a valid UserCredential and therefore Access Token, but I cannot find any managed APIs for accessing the user info. I did find this question, but this appears to assume I am just making raw requests, rather than using the official library.

How can I get the user's e-mail address?

Can you post code of `private static readonly IAuthorizationCodeFlow flow = ...; // Implementation of tokens`. Actually i'm stuck at that point and not getting any solution. Here's [link](https://stackoverflow.com/questions/44842813/google-calendar-api-working-fine-locally-but-not-raising-its-authentication-on-s) to my Question — Divya, Jul 19 '17 at 13:22
right now i'm getting this issue. [My Question](https://stackoverflow.com/questions/45103628/access-to-the-path-c-windows-system32-config-systemprofile-is-denied) — Divya, Jul 19 '17 at 13:23

peleyal · Accepted Answer · 2015-12-18T18:13:50.883

22

You should do the following:

In addition to Google.Apis.Auth NuGet package you should install the following page: https://www.nuget.org/packages/Google.Apis.Oauth2.v2
Add Google.Apis.Oauth2.v2.Oauth2Service.Scope.UserinfoProfile and also Google.Apis.Oauth2.v2.Oauth2Service.Scope.UserinfoEmail to the scopes list (When you initialize the AppFlowMetadata).
Now, add the following code:

if (result.Credential != null)
{
    var oauthSerivce = new Google.Apis.Oauth2.v2.Oauth2Service(
        new BaseClientService.Initializer()
        {
            HttpClientInitializer = credential,
            ApplicationName = "OAuth 2.0 Sample",
        });

    var userInfo = await oauthSerivce.Userinfo.Get().ExecuteAsync();
    // You can use userInfo.Email, Gender, FamilyName, ... 
}

edited Dec 18 '15 at 18:13

answered Jan 27 '14 at 18:52

peleyal

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1

Great work. Only minor adjustment I made to your answer was to add the `Google.Apis.Oauth2.v2.Oauth2Service.Scope.UserinfoEmail` scope :) – CodingIntrigue Jan 28 '14 at 08:29
1

What about credential? – Sebastián Rojas Jan 12 '17 at 17:00
@SebastiánRojas result.Credential – razon Apr 21 '17 at 10:20
what is result? please dont just copy/paste. it will be helpful if someone can explain as well – Dan Oct 28 '21 at 15:24

score 2 · Answer 2 · edited Sep 18 '17 at 06:08

2

Set your scopes to:

At: Google.Apis.Auth.OAuth2.Flows.AuthorizationCodeFlow.Scopes

And use this endpoint address: https://www.googleapis.com/oauth2/v1/userinfo?alt=json

That should help you to acquire the required information.

edited Sep 18 '17 at 06:08

RRTW

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answered Jan 25 '14 at 15:49

Yair Nevet

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Anurag Jain · Answer 3 · 2014-01-27T12:01:18.470

Here ,I edit my answere. Please look into this. On Default2.aspx page , I am displaying Session["username"] and Session["useremail"] value in label. I hope these will be help for you.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using DotNetOpenAuth.OpenId;
using DotNetOpenAuth.OpenId.RelyingParty;
using DotNetOpenAuth.OpenId.Extensions.SimpleRegistration;
using DotNetOpenAuth.OpenId.Extensions.AttributeExchange;

public partial class _Default : System.Web.UI.Page 
{

   protected void Page_Load(object sender, EventArgs e)
   {

       openIdAuth();

   }

   protected void openIdAuth()
  {
       OpenIdAjaxRelyingParty rp = new OpenIdAjaxRelyingParty();
       var response = rp.GetResponse();

       if (response != null)
       {
         switch (response.Status)
         {
            case AuthenticationStatus.Authenticated:
                NotLoggedIn.Visible = false;
                Session["GoogleIdentifier"] = response.ClaimedIdentifier.ToString();

                var fetchResponse = response.GetExtension<FetchResponse>();
                Session["FetchResponse"] = fetchResponse;
                var response2 = Session["FetchResponse"] as FetchResponse;

                string UserName = response2.GetAttributeValue(WellKnownAttributes.Name.First) ?? "Guest"; // with the OpenID Claimed Identifier as their username.
                string UserEmail = response2.GetAttributeValue(WellKnownAttributes.Contact.Email) ?? "Guest";

                Session["username"] = UserName;
                Session["useremail"] = UserEmail;

                Response.Redirect("Default2.aspx");
                break;

            case AuthenticationStatus.Canceled:
                lblAlertMsg.Text = "Cancelled.";
                break;

            case AuthenticationStatus.Failed:
                lblAlertMsg.Text = "Login Failed.";
                break;
        }

    }
    var CommandArgument = "https://www.google.com/accounts/o8/id";
    string discoveryUri = CommandArgument.ToString();
    OpenIdRelyingParty openid = new OpenIdRelyingParty();

    var url = new UriBuilder(Request.Url) { Query = "" };
    var request = openid.CreateRequest(discoveryUri); // This is where you would add any OpenID extensions you wanted
    var fetchRequest = new FetchRequest(); // to fetch additional data fields from the OpenID Provider

    fetchRequest.Attributes.AddRequired(WellKnownAttributes.Contact.Email);
    fetchRequest.Attributes.AddRequired(WellKnownAttributes.Name.First);
    fetchRequest.Attributes.AddRequired(WellKnownAttributes.Name.Last);
    fetchRequest.Attributes.AddRequired(WellKnownAttributes.Contact.HomeAddress.Country);
    request.AddExtension(fetchRequest);

    request.RedirectToProvider();
   }
 }

This looks like it's retrieving the user's contacts? I only want the e-mail address of the authorized user — CodingIntrigue, Jan 24 '14 at 08:20
To clarify. I am asking the end user to authorize my application via [OAuth2 request](https://developers.google.com/accounts/docs/OAuth2#webserver). I would like the e-mail address of this user. — CodingIntrigue, Jan 24 '14 at 08:41
let us [continue this discussion in chat](http://chat.stackoverflow.com/rooms/45987/discussion-between-anurag-jain-and-rgraham) — Anurag Jain, Jan 24 '14 at 08:46
@RGraham In this solution, User will be authenticated via OAuth then I fetch the email addrss. I hope , I am wright. — Anurag Jain, Jan 27 '14 at 11:44

score -1 · Answer 4 · answered Dec 30 '20 at 09:25

Complete code to get UserProfile data.

var secrect = new ClientSecrets()
{
    ClientId = "myClientId",
    ClientSecret = "mySecret"
};

var scopes = new[] { Oauth2Service.Scope.UserinfoEmail, auth2Service.Scope.UserinfoProfile };

UserCredential credential = GoogleWebAuthorizationBroker.AuthorizeAsync(secrect, scopes, "user", CancellationToken.None).Result;
    
var oauthSerivce = new Oauth2Service(new BaseClientService.Initializer()
{
    HttpClientInitializer = credential,
    ApplicationName = "MyApplicationName",
});

var userInfo = oauthSerivce.Userinfo.Get().Execute();

Access User Info using Google APIs for .NET

4 Answers4

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