Login Form in 3-Tier Architecture With Lock in ASP.Net

Introduction

This article explains how to implement a login form using ASP.NET C# in a three-tier architecture. I have described it in details. You will also get many new and known concepts to learn in this article whether on the SQL Server Stored Procedure side or C# code side.

The following are the features of the Login Forms:

• Developed in a three-tier architecture
• Determines whether username and password exists
• Maintains a count of incorrect login attempts
• Locks the password after 4 unsuccessful attempts

I have already explained how to create a registration form in ASP.NET C#. You can check this link.
 
Database design



Stored Procedure

Create PROCEDURE [dbo].[usp_LoginVerification]
    @UserId nvarchar(50),
    @Password nvarchar(20),
    @ERROR VARCHAR(100) OUT
AS
Begin
If exists (select 1 from MemberRegistration where UserId=@UserId and Password=@Password and IsLocked='0')
Begin
--declare
    update MemberRegistration set WrongLoginAttempt=0,IsLocked='0' Where UserId=@UserId
    set @ERROR=1
    select UserId,FirstName,MiddleName,LastName from MemberRegistration Where UserId=@UserId
End
Else
   Begin
       declare @LoginAttempt int;
       SET @LoginAttempt= (select WrongLoginAttempt from MemberRegistration where UserId=@UserId )
       update MemberRegistration set WrongLoginAttempt=@LoginAttempt+1 Where UserId=@UserId
       Set @ERROR='Your have entered wrong password'
       if @LoginAttempt>=4
       Begin
          update MemberRegistration set IsLocked='1' Where UserId=@UserId
          set @ERROR='Your Password is locked'
      End
    End
      Select @ERROR
End

The following is the step-by-step procedure for development of the feature-enriched login form in a 3-tier architecture.

Step 1

Design your layered solution as below.



Step 2

Open BELogin.cs and modify the code as below.

namespace ABMS.BE
{
   public class BELogin
    {
        private string userId;
        private string password;

        private string firstName;

        public string FirstName
        {
            get { return firstName; }
            set { firstName = value; }
        }
        private string middleName;

        public string MiddleName
        {
            get { return middleName; }
            set { middleName = value; }
        }
        private string lastName;

        public string LastName
        {
            get { return lastName; }
            set { lastName = value; }
        }
        public string Password
        {
            get { return password; }
            set { password = value; }
        }
        public string UserId
        {
            get { return userId; }
            set { userId = value; }
        }
    }
}

Step 3

Modify the BL layer BLLogin.cs as below:

using System.Data;

namespace ABMS.BL
{
    public class BLLogin
    {
        ABMS.DL.DLLogin  objdal = new ABMS.DL.DLLogin();
        BE.BELogin objbeLogin = new BE.BELogin();
        public DataSet UserLogin(BE.BELogin objbeLogin)
        {
            try
            {

                return objdal.LoginCredential(objbeLogin);
            }
            catch
            {
                throw;
            }
        }
    }
}

Step 4

 

Modify the DL Layer DLLogin.cs code as below:

using System.Data.SqlClient;
using System.Data;

namespace ABMS.DL
{
   public class DLLogin
   {
       SqlDBHelper sql = new SqlDBHelper();
       public DataSet LoginCredential(BE.BELogin belogin)
       {
           string connectionString = sql.ConnectionString();
           SqlConnection con = new SqlConnection();
           con.ConnectionString = connectionString;
           con.Open();
           SqlCommand cmd = new SqlCommand("usp_LoginVerification", con);
           cmd.CommandType = CommandType.StoredProcedure;
           cmd.Parameters.AddWithValue("@UserId", belogin.UserId);
           cmd.Parameters.AddWithValue("@Password", belogin.Password);
           cmd.Parameters.Add("@ERROR", SqlDbType.Char, 500);
           cmd.Parameters["@ERROR"].Direction = ParameterDirection.Output;
           SqlDataAdapter da = new SqlDataAdapter();
           DataSet ds = new DataSet();
           da = new SqlDataAdapter(cmd);
           da.Fill(ds);
           con.Close();
           return ds;

       }
    }
}

Step 5

 

Design the UI as below:



Step 6

 

Modify the code of the UI Login.aspx.cs as below:

using System;
using System.Data;
namespace ABMS.UI.Account
{
    public partial class Login : System.Web.UI.Page
    {
        ABMS.BL.BLLogin objBL = new ABMS.BL.BLLogin();
        protected void Page_Load(object sender, EventArgs e)
        {
        }
        protected void btnLogin_Click(object sender, EventArgs e)
        {
            ABMS.BE.BELogin obJBE = new BE.BELogin();
            obJBE.UserId = UserName.Text.Trim();
            obJBE.Password = Password.Text.Trim();
            DataSet ds = new DataSet();
            ds = objBL.UserLogin(obJBE);
            if (ds.Tables.Count == 1)
            {
                lblErrorMsg.Text = ds.Tables[0].Rows[0][0].ToString();
            }
            else if (ds.Tables[1].Rows[0][0].ToString() == "1")
            {
                lblErrorMsg.Text = string.Empty;
                Session["UserId"] = ds.Tables[0].Rows[0][0].ToString();
                String name=null;
                if (!string.IsNullOrEmpty( ds.Tables[0].Rows[0][1].ToString()))
                {
                    name = name + ds.Tables[0].Rows[0][1].ToString();
                }
                if (!string.IsNullOrEmpty(ds.Tables[0].Rows[0][2].ToString()))
                {
                    name = name +" "+ ds.Tables[0].Rows[0][2].ToString();
                }
                if (!string.IsNullOrEmpty(ds.Tables[0].Rows[0][3].ToString()))
                {
                    name = name + " "+ds.Tables[0].Rows[0][3].ToString();
                }
                Session["Name"] = name;
                Response.Redirect("~/Default.aspx");
            }
        }
    }
}

Step 7

 

Run the application and enter the wrong password for multiple times. You will prompt the message as below:



Step 8

 

After attempting 4 times your password will be locked.



Conclusion

In this article I have explained how to develop a feature-enriched Login form in a 3-tier architecture in ASP.NET C#.