protected override async Task <AuthenticationTicket> AuthenticateCoreAsync()
        {
            AuthenticationProperties properties = new AuthenticationProperties();

            try
            {
                string code  = null;
                string state = null;

                IReadableStringCollection query  = Request.Query;
                IList <string>            values = query.GetValues("code");
                if (values != null && values.Count == 1)
                {
                    code = values[0];
                }
                values = query.GetValues("state");
                if (values != null && values.Count == 1)
                {
                    state = values[0];
                }

                properties = Options.StateDataFormat.Unprotect(state);
                if (properties == null)
                {
                    return(null);
                }

                // OAuth2 10.12 CSRF
                if (!ValidateCorrelationId(properties, _logger))
                {
                    return(new AuthenticationTicket(null, properties));
                }

                string requestPrefix = Request.Scheme + "://" + Request.Host;
                string redirectUri   = requestPrefix + Request.PathBase + Options.CallbackPath;

                // Build up the body for the token request
                var body = new List <KeyValuePair <string, string> >();
                body.Add(new KeyValuePair <string, string>("code", code));
                body.Add(new KeyValuePair <string, string>("redirect_uri", redirectUri));
                body.Add(new KeyValuePair <string, string>("client_id", Options.ClientId));
                body.Add(new KeyValuePair <string, string>("client_secret", Options.ClientSecret));
                body.Add(new KeyValuePair <string, string>("grant_type", "authorization_code"));

                // Request the token
                var requestMessage = new HttpRequestMessage(HttpMethod.Post, Options.Endpoints.TokenEndpoint);
                requestMessage.Headers.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
                requestMessage.Content = new FormUrlEncodedContent(body);
                HttpResponseMessage tokenResponse = await _httpClient.SendAsync(requestMessage);

                tokenResponse.EnsureSuccessStatusCode();
                string text = await tokenResponse.Content.ReadAsStringAsync();

                // Deserializes the token response
                dynamic response     = JsonConvert.DeserializeObject <dynamic>(text);
                string  accessToken  = (string)response.access_token;
                string  refreshToken = (string)response.refresh_token;

                // Get the Salesforce user using the user info endpoint, which is part of the token - response.id
                HttpRequestMessage userRequest = new HttpRequestMessage(HttpMethod.Get, (string)response.id + "?access_token=" + Uri.EscapeDataString(accessToken));
                userRequest.Headers.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
                HttpResponseMessage userResponse = await _httpClient.SendAsync(userRequest, Request.CallCancelled);

                userResponse.EnsureSuccessStatusCode();
                text = await userResponse.Content.ReadAsStringAsync();

                JObject user = JObject.Parse(text);

                var context = new SalesforceAuthenticatedContext(Context, user, accessToken, refreshToken);
                context.Identity = new ClaimsIdentity(
                    Options.AuthenticationType,
                    ClaimsIdentity.DefaultNameClaimType,
                    ClaimsIdentity.DefaultRoleClaimType);

                if (!string.IsNullOrEmpty(context.UserId))
                {
                    context.Identity.AddClaim(new Claim(ClaimTypes.NameIdentifier, context.UserId, XmlSchemaString, Options.AuthenticationType));
                }
                if (!string.IsNullOrEmpty(context.UserName))
                {
                    context.Identity.AddClaim(new Claim(ClaimsIdentity.DefaultNameClaimType, context.UserName, XmlSchemaString, Options.AuthenticationType));
                }

                if (!string.IsNullOrEmpty(context.Email))
                {
                    context.Identity.AddClaim(new Claim(ClaimTypes.Email, context.Email, XmlSchemaString, Options.AuthenticationType));
                }

                if (!string.IsNullOrEmpty(context.FirstName))
                {
                    context.Identity.AddClaim(new Claim(ClaimTypes.GivenName, context.FirstName, XmlSchemaString, Options.AuthenticationType));
                }

                if (!string.IsNullOrEmpty(context.LastName))
                {
                    context.Identity.AddClaim(new Claim(ClaimTypes.Surname, context.LastName, XmlSchemaString, Options.AuthenticationType));
                }

                if (!string.IsNullOrEmpty(context.DisplayName))
                {
                    context.Identity.AddClaim(new Claim(ClaimTypes.Name, context.DisplayName, XmlSchemaString, Options.AuthenticationType));
                }

                if (!string.IsNullOrEmpty(context.DisplayName))
                {
                    context.Identity.AddClaim(new Claim("urn:Salesforce:name", context.DisplayName, XmlSchemaString, Options.AuthenticationType));
                }

                context.Properties = properties;

                await Options.Provider.Authenticated(context);

                return(new AuthenticationTicket(context.Identity, context.Properties));
            }
            catch (Exception ex)
            {
                _logger.WriteError(ex.Message);
            }
            return(new AuthenticationTicket(null, properties));
        }
 public virtual Task Authenticated(SalesforceAuthenticatedContext context)
 {
     return(OnAuthenticated(context));
 }