Get the user's e-mail address from Twitter

[Tratcher]

Getting the user's e-mail address from Twitter is a pain. You have to contact Twitter support to request the permission for your app. Then you have to send a request to an additional endpoint. The auth middleware should support optionally sending this request.

http://stackoverflow.com/questions/22627083/can-we-get-email-id-from-twitter-oauth-api/32852370#32852370
http://stackoverflow.com/questions/36330675/get-users-email-from-twitter-api-for-external-login-authentication-asp-net-mvc?lq=1

[Tratcher]

            app.UseTwitterAuthentication(options =>
            {
                options.ConsumerKey = Configuration["Authentication:Twitter:ConsumerKey"];
                options.ConsumerSecret = Configuration["Authentication:Twitter:ConsumerSecret"];
                options.Events = new TwitterEvents()
                {
                    OnCreatingTicket = async context =>
                    {                        
                        var nonce = Guid.NewGuid().ToString("N");

                        var authorizationParts = new SortedDictionary<string, string>
                        {
                            { "oauth_consumer_key", context.Options.ConsumerKey },
                            { "oauth_nonce", nonce },
                            { "oauth_signature_method", "HMAC-SHA1" },
                            { "oauth_timestamp", GenerateTimeStamp() },
                            { "oauth_token", context.AccessToken },
                            { "oauth_version", "1.0" }
                        };

                        var parameterBuilder = new StringBuilder();
                        foreach (var authorizationKey in authorizationParts)
                        {
                            parameterBuilder.AppendFormat("{0}={1}&", UrlEncoder.Default.UrlEncode(authorizationKey.Key), UrlEncoder.Default.UrlEncode(authorizationKey.Value));
                        }
                        parameterBuilder.Length--;
                        var parameterString = parameterBuilder.ToString();

                        var resource_url = "https://api.twitter.com/1.1/account/verify_credentials.json";
                        var resource_query = "include_email=true";
                        var canonicalizedRequestBuilder = new StringBuilder();
                        canonicalizedRequestBuilder.Append(HttpMethod.Get.Method);
                        canonicalizedRequestBuilder.Append("&");
                        canonicalizedRequestBuilder.Append(UrlEncoder.Default.UrlEncode(resource_url));
                        canonicalizedRequestBuilder.Append("&");
                        canonicalizedRequestBuilder.Append(UrlEncoder.Default.UrlEncode(resource_query));
                        canonicalizedRequestBuilder.Append("%26");
                        canonicalizedRequestBuilder.Append(UrlEncoder.Default.UrlEncode(parameterString));

                        var signature = ComputeSignature(context.Options.ConsumerSecret, context.AccessTokenSecret, canonicalizedRequestBuilder.ToString());
                        authorizationParts.Add("oauth_signature", signature);

                        var authorizationHeaderBuilder = new StringBuilder();
                        authorizationHeaderBuilder.Append("OAuth ");
                        foreach (var authorizationPart in authorizationParts)
                        {
                            authorizationHeaderBuilder.AppendFormat(
                                "{0}=\"{1}\", ", authorizationPart.Key, UrlEncoder.Default.UrlEncode(authorizationPart.Value));
                        }
                        authorizationHeaderBuilder.Length = authorizationHeaderBuilder.Length - 2;

                        var request = new HttpRequestMessage(HttpMethod.Get, resource_url + "?include_email=true");
                        request.Headers.Add("Authorization", authorizationHeaderBuilder.ToString());

                        var response = await Backchannel.SendAsync(request, context.HttpContext.RequestAborted);
                        response.EnsureSuccessStatusCode();
                        string responseText = await response.Content.ReadAsStringAsync();

                        var result = JObject.Parse(responseText);

                        var email = result.Value<string>("email");
                        var identity = (ClaimsIdentity)context.Principal.Identity;
                        if (!string.IsNullOrEmpty(email))
                        {
                            identity.AddClaim(new Claim(ClaimTypes.Email, email, ClaimValueTypes.String, "Twitter"));
                        }
                    },
                };
            });
...


        private static string GenerateTimeStamp()
        {
            var secondsSinceUnixEpocStart = DateTime.UtcNow - new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);
            return Convert.ToInt64(secondsSinceUnixEpocStart.TotalSeconds).ToString(CultureInfo.InvariantCulture);
        }

        private string ComputeSignature(string consumerSecret, string tokenSecret, string signatureData)
        {
            using (var algorithm = new HMACSHA1())
            {
                algorithm.Key = Encoding.ASCII.GetBytes(
                    string.Format(CultureInfo.InvariantCulture,
                        "{0}&{1}",
                        UrlEncoder.Default.UrlEncode(consumerSecret),
                        string.IsNullOrEmpty(tokenSecret) ? string.Empty : UrlEncoder.Default.UrlEncode(tokenSecret)));
                var hash = algorithm.ComputeHash(Encoding.ASCII.GetBytes(signatureData));
                return Convert.ToBase64String(hash);
            }
        }

[Eilon]

Let's add a specific option to the Twitter Options to enable grabbing the email.

[danielserafimovik]

you have to change your code to call the GET account/verify_credentials method after the user is logged in with twitter. And it is important to set the parameter include_email to true. When this is set to true email will be returned in the user objects as a string. I'm using this library https://www.nuget.org/packages/linqtotwitter so that I do not have to write code for handling twitter api requests

var twitterCtx = new TwitterContext(authTwitter); var verifyResponse = await (from acct in twitterCtx.Account where (acct.Type == AccountType.VerifyCredentials) && (acct.IncludeEmail == true) select acct) .SingleOrDefaultAsync();

see how I have done this here http://www.bigbrainintelligence.com/Post/get-users-email-address-from-twitter-oauth-ap

it is an easy and clean solution

[AlexOliinyk1]

Backchannel - can't resolve symbol. Any idea ?

[Tratcher]

@AlexOliinyk1, @danielserafimovik's advice no longer applies, you can set the RetrieveUserDetails property to handle this now.

[AlexOliinyk1]

@Tratcher thank you for quick update. But after enable I still can't to get email. http://prntscr.com/ggnq1m

[Tratcher]

Did you follow these instructions? The only way to enable it is to contact Twitter support.
https://stackoverflow.com/questions/22627083/can-we-get-email-id-from-twitter-oauth-api/32852370#32852370

[AlexOliinyk1]

@Tratcher code look like this

It is looks like it something wrong on the server side, but on the server side it is getting all data, except email.