Login Source Code

Login Example, source code file login-page.aspx

<%@ Page Language="C#" %>
<%@ Import Namespace="System.IO" %>
<%@ Import Namespace="System.Text" %>
<%@ Import Namespace="System.Security.Cryptography" %>

public void btnLogin_Click(object sender, EventArgs e)
{
    // Get strings.
    string strUser = txtUser.Text;
    string strPw = txtPassword.Text;
    string strKey = "upwk1133557799#";
    
    // Convert to byte arrays of ASCII characters.
    byte[] pw = Encoding.ASCII.GetBytes(strPw.ToCharArray( ));
    byte[] key = Encoding.ASCII.GetBytes(strKey.ToCharArray( ));
    
    // Create hash object.
    HMACSHA1 hmac = new HMACSHA1(key);
    
    // Obtain login string to compare to password file.
    byte[] hash = hmac.ComputeHash(pw);
    string loginString = strUser + ";" + Convert.ToBase64String(hash);
    
    // Obtain reader to read password file. 
    StreamReader sr = new StreamReader
        ("e:/ectserver/sjost/Database/passwords.txt");

string line = "";
    
    while(sr.Peek( ) > -1)
    {
        line = sr.ReadLine( );
        litMessage.Text += line + " " + loginString + "<br />";
        if (line == loginString)
        {
            sr.Close( );
            Session["loggedin"] = true;
            Response.Redirect("page1.aspx");
        }
    }
    sr.Close( );
    litMessage.Text = "Login not successful. Please try again.";
}
</script>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Login Example -- Login Page</title>
<style type="text/css">
td { padding: 5px; }
.r { text-align: right }
</style>
<link rel="stylesheet" type="text/css" href="../examples.css" />

</head>
<body>
<h2>Login Example -- Login Page</h2>
<form id="form1" runat="server">
<table>
<tr> 
    <td class="r">Username:</td> 
    <td><asp:TextBox ID="txtUser" CssClass="ctrl" 
            Width="126px" runat="server" /></td>
</tr>
<tr> 
    <td class="r">Password:</td> 
    <td><asp:TextBox ID="txtPassword" CssClass="ctrl" 
            Width="126px" runat="server" TextMode="Password" /></td>
</tr>
<tr>
    <td> </td>
    <td><asp:Button ID="btnLogin" CssClass="ctrl" Text="Login" 
         OnClick="btnLogin_Click" runat="server" Width="126px" /></td>
</tr>
</table>

</form>
</body>
</html>

Login Example, source code file page1.aspx

<%@ Page Language="C#" %>

public void btnLogout_Click(object sender, EventArgs e)
{
    Session["loggedin"] = null;
    Response.Redirect("login-page.aspx");
}
</script>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Login Example: Page 1</title>
<link rel="stylesheet" type="text/css" href="../examples.css" />
</head>

<body>

<h2>Login Example: Page 1</h2>

<div style="background-color: #fff0f0;">
<p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. 
Etiam nec ipsum urna. Aliquam erat volutpat. Quisque mauris 
libero, pellentesque sit amet malesuada quis, mollis ut diam. 
Etiam pellentesque mi in lacus eleifend quis blandit tellus 
blandit. Duis at laoreet orci. Nam ac enim felis. Proin 
vehicula tristique neque a bibendum. Duis venenatis, dolor 
ac consectetur elementum, sapien nibh rutrum tortor, a 
tempus est justo at diam. Sed sed sapien in nisl 
condimentum molestie ac id odio. Phasellus eget orci vel 
est interdum facilisis. Duis hendrerit, erat eget vulputate 
facilisis, arcu dolor tristique leo, id facilisis sem tortor 
lacinia magna. Aliquam mollis, lorem nec laoreet dictum, 
lacus urna lobortis odio, blandit interdum dui dui ut dolor. 
Class aptent taciti sociosqu ad litora torquent per conubia 
nostra, per inceptos himenaeos.</p>
 
<p>Fusce semper, felis nec facilisis gravida, risus ante 
pulvinar dui, ullamcorper suscipit nibh libero hendrerit enim. 
Nunc ut nunc est, eget auctor metus. Proin ullamcorper tortor 
et sapien fermentum a eleifend eros pretium. Nulla justo nulla, 
dictum id iaculis sit amet, pulvinar eu ipsum. Etiam et metus 
lectus. Cras nisl arcu, rhoncus et interdum a, scelerisque 
at nisl. Maecenas felis felis, feugiat sed semper eget, 
hendrerit vitae augue. Cras venenatis posuere posuere. 
Etiam vitae velit lacus. Donec et lacus odio. Nam justo 
turpis, pretium vel viverra nec, porta ut erat. Sed interdum 
sollicitudin justo, et scelerisque felis imperdiet a. Vivamus 
posuere est dui, vel facilisis risus. Aliquam tempor felis 
ac est elementum volutpat.</p>
</div>
</form>
</body>
</html>

Login Example, source code file page2.aspx

<%@ Page Language="C#" %>

public void btnLogout_Click(object sender, EventArgs e)
{
    Session["loggedin"] = null;
    Response.Redirect("login-page.aspx");
}
</script>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
<title>Login Example: Page 2</title>
<link rel="stylesheet" type="text/css" href="../examples.css" />
</head>

<body>

<h2>Login Example: Page 2</h2>

<div style="background-color: #fff0f0;">
<p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. 
Nulla eget dolor in nisl fermentum porta ac eget nibh. 
Mauris nisi arcu, bibendum eu laoreet ac, sodales at magna. 
Pellentesque et sapien nulla. Ut posuere mattis lectus 
vulputate consectetur. Duis eu magna id augue aliquet ornare 
vehicula quis massa. Nulla a metus ipsum. Integer pulvinar 
purus vitae turpis luctus scelerisque. Nam aliquet, nulla 
non interdum placerat, diam nunc bibendum urna, eget 
suscipit lectus nibh ac metus. Fusce egestas mollis arcu 
et varius. Vivamus in augue neque, in euismod enim. 
Pellentesque purus mauris, egestas vitae luctus at, ornare 
non turpis. Donec eu sapien libero. Lorem ipsum dolor sit 
amet, consectetur adipiscing elit.</p>
 
<p>Suspendisse luctus pretium tellus ac dignissim. Etiam 
ac orci velit, nec porta dui. Nulla tempus tristique elit, 
non dictum ligula tempus non. Vestibulum convallis molestie 
diam, quis sagittis tortor elementum ut. Integer suscipit 
sollicitudin sapien at rhoncus. Ut lacus libero, convallis 
in commodo nec, luctus quis purus. Suspendisse mi tortor, 
consectetur eu sagittis at, vestibulum sit amet metus. 
Donec et orci nunc, eget vulputate ligula. Donec fermentum 
lobortis diam nec dapibus. In accumsan aliquet sem, ut 
mollis elit ullamcorper gravida. Vestibulum vitae lectus 
vel risus fermentum cursus.</p>
</div>
</form>
</body>
</html>