<?xml version="1.0"?>
<configuration>
	<connectionStrings>
		<add name="SqlServerName_impersonate" connectionString="data source=TestServer;Integrated Security=false;Database=base1;User ID=id1;password=password1" providerName="System.Data.SqlClient"/>		
	</connectionStrings>
	<system.web>
		<compilation debug="true" targetFramework="4.0" />
		<customErrors mode="Off" />
	</system.web>
	<system.serviceModel>
		<protocolMapping>
			<add scheme="https" binding="wsHttpBinding" />
		</protocolMapping>
		<bindings>
			<wsHttpBinding>
				<!-- configure wsHttp binding with Transport security mode and clientCredentialType as Certificate -->
				<binding>
					<security mode="Transport">
						<transport clientCredentialType="Certificate" />						
					</security>
				</binding>
			</wsHttpBinding>
		</bindings>
		<behaviors>
			<serviceBehaviors>
				<behavior>
					<!-- To avoid disclosing metadata information, set the value below to false and remove the metadata endpoint above before deployment -->					
					<!-- To receive exception details in faults for debugging purposes, set the value below to true.  Set to false before deployment to avoid disclosing exception information -->
					<serviceMetadata httpsGetEnabled="true" httpGetEnabled="false"/>
					<serviceDebug includeExceptionDetailInFaults="true"/>
				</behavior>
			</serviceBehaviors>
		</behaviors>
		<!-- включена совместимость aspNetCompatibilityEnabled для asp.net, возможности сессий кэша и.т.д.   -->
		<serviceHostingEnvironment multipleSiteBindingsEnabled="false" aspNetCompatibilityEnabled="true"/>
	</system.serviceModel>
	<system.webServer>
		<modules runAllManagedModulesForAllRequests="true"/>
	</system.webServer>
</configuration>

        private void button1_Click(object sender, EventArgs e)
        {
            try
            {
                // экземпляр службы
                ServiceReference1.PayServiceClient WS = new ServiceReference1.PayServiceClient();
                string urlWebService = "https://wwwserver:555/service.svc";
                WS.Endpoint.Address = new System.ServiceModel.EndpointAddress(urlWebService);
                X509Certificate2 cert = GetClientCertificate();
                WS.ClientCredentials.ClientCertificate.Certificate = cert;
                string req = "строка запроса";
                string str = WS.CheckAccount(req); // здесь получаю исключение.
                MessageBox.Show(str);
            }
            catch (Exception e)
            {
                MessageBox.Show(e.Message);
            }
        }

 
        /*
         *  Получение сертификата для доступа к веб-сервису. 
         *  Возвращает сертификат либо null
         *  В случае ошибки генерирется исключение и передается выше
        */
        private X509Certificate2 GetClientCertificate()
        {
            X509Certificate2 cert = null;
            try
            {
                string certName = "Certificate1"; // указано имя сертификата;
                X509Store store = new X509Store(StoreLocation.CurrentUser);
                store.Open(OpenFlags.ReadOnly);
                X509Certificate2Collection certCollection = store.Certificates.Find(X509FindType.FindBySubjectName, certName, true);
                if (certCollection.Count > 0)
                {
                    cert = certCollection[0];
                    string serialN = cert.GetSerialNumberString();
                    store.Close();
                }
            }
            catch (Exception ex)
            {
                throw new Exception("GetClientCertificate: " + ex.Message);
            }
            return cert;
        }