Encrypted Querystring

Hello friends When we are passing data between two asp.net pages we will use querystring. But the original value will be displayed there which is not a secure way to do. So we must encrypt that information.

I faced the same situation and searched GOOGLE and come across a nice article by Mr.Tiberius OsBurn of DEVCITY. The original article you can get at: http://www.devcity.net/PrintArticle.aspx?ArticleID=47.

Basically I am C# guy. I made some changes to that program and its working fine now.

First we will write a class file where Encrypt and Decrypt functions will be there.By using them we will execute that.

1) Create a class file in APP_CODE folder and paste this code.

Code Begins

“

using System;
using System.IO;
using System.Xml;
using System.Text;
using System.Security.Cryptography;

public class Encryption64
{
private byte[] key = { };
private byte[] IV = { 18, 52, 86, 120, 144, 171, 205, 239 };

public string Decrypt(string stringToDecrypt, string sEncryptionKey)
{
byte[] inputByteArray = new byte[stringToDecrypt.Length + 1];
try
{

//key = System.Text.Encoding.UTF8.GetBytes(Left(SEncryptionKey, 8));
key = System.Text.Encoding.UTF8.GetBytes(sEncryptionKey.ToCharArray(), 0, 8);
DESCryptoServiceProvider des = new DESCryptoServiceProvider();
inputByteArray = Convert.FromBase64String(stringToDecrypt);
MemoryStream ms = new MemoryStream();
CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(key, IV), CryptoStreamMode.Write);
cs.Write(inputByteArray, 0, inputByteArray.Length);
cs.FlushFinalBlock();
System.Text.Encoding encoding = System.Text.Encoding.UTF8;
return encoding.GetString(ms.ToArray());
}
catch (Exception e)
{
return e.Message;
}
}

public string Encrypt(string stringToEncrypt, string SEncryptionKey)
{

try
{
key = System.Text.Encoding.UTF8.GetBytes(SEncryptionKey.ToCharArray(), 0, 8);
DESCryptoServiceProvider des = new DESCryptoServiceProvider();
byte[] inputByteArray = Encoding.UTF8.GetBytes(stringToEncrypt);
MemoryStream ms = new MemoryStream();
CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(key, IV), CryptoStreamMode.Write);
cs.Write(inputByteArray, 0, inputByteArray.Length);
cs.FlushFinalBlock();
return Convert.ToBase64String(ms.ToArray());
}
catch (Exception e)
{
return e.Message;
}
}

}

“

Code Ends

Take an aspx page and write the code and write the code below.

“

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Security.Cryptography;

public partial class Test : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{

}
public string encryptQueryString(string strQueryString)
{
//ExtractAndSerialize.Encryption64 oES =
//    new ExtractAndSerialize.Encryption64();
Encryption64 oES = new Encryption64();
return oES.Encrypt(strQueryString, “!#$a54?3″);
}

public string decryptQueryString(string strQueryString)
{

Encryption64 oES = new Encryption64();
return oES.Decrypt(strQueryString, “!#$a54?3″);
}

protected void lnk_btn_Click(object sender, EventArgs e)
{
string strValues = “search”;
string strURL = “http://yoursite.com?search=”
+ encryptQueryString(strValues);

Response.Redirect(strURL);
}
}

“

In aspx

Take a link button with Id=”lnk_btn”.

when you click it will encrypt an you can decrypt by using the class file.

Bye

Hello When we have some 30 textboxes in a page where it has a master Page. If we want to erase all th data  in textboxes usuallywe will write TextBox1.Text==” “; But it s time consuming so I have the easy way to do it.    wait…….

“

private void getAllCtl(ControlCollection ctls)
{
foreach (Control c in ctls)
{
if (c is System.Web.UI.WebControls.TextBox)
{
TextBox txt = c as TextBox;
txt.Text = “”;

}
}
}
“

In the button code event please write to recognize contentplaceholder in masterpage

“

ContentPlaceHolder ContentPlaceHolder1=this.Master.FindControl(”ContentPlaceHolder1″) as ContentPlaceHolder;
getAllCtl(ContentPlaceHolder1.Controls);

“

I found something that works for me on the web after much looking.  In Page_Load, just add the 2 lines:

ibtnDelete.Attributes.Add(”language”, “javascript”)

ibtnDelete.Attributes.Add(”OnClick”, “return confirm(’Are you sure you want to delete this record?’);”)

This will bring up an OK/Cancel box when the button is clicked; if Cancel is then clicked the button’s click event code won’t run.

In gridview header write like this:

“

<HeaderTemplate>
<asp:CheckBox runat=”server” ID=”cboxhead” AutoPostBack=”true” OnCheckedChanged=”HeaderCheckedChanged”/>
</HeaderTemplate>
“

In cs file

“

protected void HeaderCheckedChanged(object sender, EventArgs e)//this is for header checkbox changed event
{

CheckBox cbSelectedHeader = (CheckBox)GridView1.HeaderRow.FindControl(”cboxhead”);//if u checked header checkbox automatically all the check boxes will be checked,viseversa
foreach (GridViewRow row in GridView1.Rows)
{
CheckBox cbSelected = (CheckBox)row.FindControl(”CheckBox1″);
if (cbSelectedHeader.Checked == true)
{
cbSelected.Checked = true;

}
else
{
cbSelected.Checked = false;
}

}

}

“

Hello If you want to validate a textbox where we can only enter numbers.

Fisrt write the javascript function in .aspx file.

eg:

“

<SCRIPT language=Javascript>
<!–
function isNumberKey(evt)
{
var charCode = (evt.which) ? evt.which : event.keyCode
if (charCode > 31 && (charCode < 48 || charCode > 57))
return false;

return true;

}
//–>
</SCRIPT>

“

In the code behind in page_load event write the code for the text box control.

<!–

TextBox1.Attributes.Add(”Onkeypress”, “return isNumberKey(event)”);

>

Hello friends,

While we are doing some big entry screens after submitting we will erase all the content in textboxes.For that we will do erasing each and every textbox.

It will takes a lot of time . To Reduce the difficulty use the simple code below:

Control myForm = Page.FindControl(”Form1″);

foreach (Control ctl in myForm.Controls)

{

if (ctl.GetType().ToString().Equals(”System.Web.UI.WebControls.TextBox”))

(TextBox)ctl).Text = “”;

}

SELECT TABLE_NAME FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME =
‘table Name’ AND TABLE_TYPE = ‘BASE TABLE’

Loading Excel values to database

If you want to load the excel values to database (eg:SQL server database) follow the steps:

1) Create a empty table with columns.

CREATE TABLE [dbo].[users](

[user_name] [varchar](50) NOT NULL,

[Password] [nchar](10) NULL )

Check the data must be empty.

2) Create an excel sheet with your data. In the excel the top row

must contain same column names as table created by us and

remember that you have your data in Sheet1 of excel sheet.

3) In code behind page write this code:

This code can be written in the event you like.

For now I am writing this code in Button_click

Event.

string excelConnectionString = @”Provider=Microsoft.Jet.OLEDB.4.0;Data Source=D:\users.xls;Extended Properties=”"Excel 8.0;HDR=YES;”"”;

OleDbConnection conn = new

OleDbConnection(excelConnectionString);

//Here Sheet1 means the current sheet in excel file If your data is in sheet2 you can give Sheet2.

string selqry = “select * from [Sheet1$]“;

OleDbCommand cmd = new OleDbCommand(selqry, conn);

conn.Open();

OleDbDataReader dr;

dr = cmd.ExecuteReader();

string sqlConnectionString = “Data Source=MNCXP08;Initial

Catalog=test;Persist Security Info=True;User

ID=sa;Password=admin123″;

SqlBulkCopy bcp = new SqlBulkCopy(sqlConnectionString);

//Here users is the table we created

bcp.DestinationTableName = “users”;

bcp.WriteToServer(dr);

4) Check the users table you will get all the results.

If you want to display the Total in the footer of a gridview. Follow the steps:

1) Create a table of employees with salary.

2) Select ename,esalary from emptbl

ename esalary

Bharath 18000

krishna 20000

3) Now in gridview the total of salary must come in footer.

4) .aspx code

<%@ Page Language=”C#” AutoEventWireup=”true” CodeFile=”Default.aspx.cs” Inherits=”_Default” %>
<!DOCTYPE html PUBLIC “-//W3C//DTD XHTML 1.0 Transitional//EN” “http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd”>

</div>
<asp:SqlDataSource ID=”SqlDataSource1″ runat=”server” ConnectionString=”<%$ ConnectionStrings:TestConnectionString %>”
SelectCommand=”SELECT [ename], [esalary] FROM [emptbl]“></asp:SqlDataSource>
</form>
</body>
</html>

5) Code behind:

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

if (e.Row.RowType == DataControlRowType.Footer)
{
Label lbltotal = e.Row.FindControl(”Label2″) as Label;
lbltotal.Text = Total.ToString();
}
}
}

Any doubts mail me.