Simple Login Form Using MD5 Hash Algorithm

Mohammed Ibrahim

13 Comments

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Randy Thon5y ago
Using MySQL - simply query the table properly: string chk_password = @"SELECT* FROM `mobile_logon` WHERE username = '" + textBox1.Text + "' and password = md5('" + textBox2.Text + "');";
Khawar Islam10y ago
Nice Article
Asfend Yar10y ago
very well
Arul R10y ago
Nice share
Santhakumar Munuswamy11y ago
Thanks for nice article:)
Pankaj Kumar Choudhary11y ago
Nice One Sir............
- Mohammed Ibrahim11y ago
  thank you...
Shridhar Sharma11y ago
good one
- Mohammed Ibrahim11y ago
  Thank you Shridhar Sharma
Rajeesh Menoth11y ago
Nice One
- Mohammed Ibrahim11y ago
  thank you
Harshad Pansuriya11y ago
Nice one
- Mohammed Ibrahim11y ago
  thank you Harshad Pansuriya

The hash algorithm is allowed to create larger number of data using the small number of data.

Step 1: Create a simple login form as in the following screenshot:

design

By using the following HTML code:

<asp:Table ID="Table1" runat="server" Width="418px" Height="209px">
<asp:TableRow>
<asp:TableCell>
User Name
</asp:TableCell>
<asp:TableCell>
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
</asp:TableCell>
</asp:TableRow>
<asp:TableRow>
<asp:TableCell>
Password
</asp:TableCell>
<asp:TableCell>
<asp:TextBox ID="TextBox2" runat="server" TextMode="Password"></asp:TextBox>
</asp:TableCell>
</asp:TableRow>
<asp:TableRow>
<asp:TableCell>
<asp:Button ID="Button1" runat="server" Text="Sign Up" OnClick="Message_click" />
</asp:TableCell>
<asp:TableCell>
<asp:Button ID="Button2" runat="server" Text="login" OnClick="login_click" />
</asp:TableCell>
<asp:TableCell>
<asp:Label ID="Label1" runat="server" />
</asp:TableCell>
</asp:TableRow>
</asp:Table>

Step 2: Now create the Database table as in the following screenshot:

Encrypt

Step 3: After creating the table use the following coding in Sign up button to get user name and password:

public void Message_click(object sender, EventArgs e)
{
string username = TextBox1.Text.ToString();
String password = TextBox2.Text;
//Get the encrypt the password by using the class
string pass = encryption(password);
Label1.Text = pass;
//Check whether the UseName and password are Empty
if (username.Length > 0 && password.Length > 0)
{
//creating the connection string
string connection = ConfigurationManager.ConnectionStrings["DefaultConnection"].ToString();
SqlConnection con = new SqlConnection(connection);
String passwords = encryption(password);
con.Open();
// Check whether the Username Found in the Existing DB
String search = "SELECT * FROM UserAccount WHERE (UserName = '" + username + "');";
SqlCommand cmds = new SqlCommand(search, con);
SqlDataReader sqldrs = cmds.ExecuteReader();
if (sqldrs.Read())
{
String passed = (string)sqldrs["Password"];
Label1.Text = "Username Already Taken";
}
else
{
try
{
// if the Username not found create the new user accound
string sql = "INSERT INTO UserAccount (UserName, Password) VALUES ('" + username + "','" + passwords + "');";
SqlCommand cmd = new SqlCommand(sql, con);
cmd.ExecuteNonQuery();
String Message = "saved Successfully";
Label1.Text = Message.ToString();
TextBox1.Text = "";
TextBox2.Text = "";
Response.Redirect("Default2.aspx");
}
catch (Exception ex)
{
Label1.Text = ex.ToString();
}
con.Close();
}
}
else
{
String Message = "Username or Password is empty";
Label1.Text = Message.ToString();
}
}

Step 4: Now encrypt the password by using the following method.

public string encryption(String password)
{
MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider();
byte[] encrypt;
UTF8Encoding encode = new UTF8Encoding();
//encrypt the given password string into Encrypted data
encrypt = md5.ComputeHash(encode.GetBytes(password));
StringBuilder encryptdata = new StringBuilder();
//Create a new string by using the encrypted data
for (int i = 0; i < encrypt.Length; i++)
{
encryptdata.Append(encrypt[i].ToString());
}
return encryptdata.ToString();
}

After inserting the values inside the DB it will be like the following:

In the above Database table the user name is given as it is but the password is in encrypted String format

Step 5: Now login by using already created username and password.

login

Add the following code in the Login button.

public void login_click(object sender, EventArgs e)
{
String username = TextBox1.Text.ToString();
String password = TextBox2.Text;
string con = ConfigurationManager.ConnectionStrings["DefaultConnection"].ToString();
SqlConnection connection = new SqlConnection(con);
connection.Open();
ncrypt the given password
string passwords = encryption(password);
String query = "SELECT UserName, Password FROM UserAccount WHERE (UserName = '" + username + "') AND (Password = '"+passwords+"');";
SqlCommand cmd = new SqlCommand(query, connection);
SqlDataReader sqldr = cmd.ExecuteReader();
if (sqldr.Read())
{
Response.Redirect("Default3.aspx");
}
else
{
Label1.Text = "User or password is in correct not found";
}
connection.Close();
}

If the Password is correct it will take us to the Default3.aspx page, else it will show a message in the following label box:

show a message in the below label box

Decryption is not possible using MD5, so I have again converted the entered password and then checked the value with the database.