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  • Category: ASP.NET

    Encrypt/Decrypt the password in C# .net

    Hi Friends,
    My task is( using byte [])
    1)Taking string value from textbox and
    2)converting each character into ASCII and adding plus 2 to that individual ASCII value for individual character.
    3)afterwards converting that whole ASCII value into a new string.
    4)and storing the new string into one document.

    and same steps for decrypting means "converting new string to old string"

    Pls help me The whole code in ASP C# .Net
    I want User interface and coding
    -sabitha
  • #329870
    Use following Class for encrypting and decrypting!!!!
    ---------------------------------------------------------

    Enjoy Code!!!!!

    using System;
    using System.Configuration;
    using System.Security.Cryptography;
    using System.Text;

    namespace DCViewer.Cryptoghaphy
    {
    /// <summary>
    /// Represets the CryptorEngine for the <see cref="DCViewer"/>.
    /// </summary>
    public class CryptorEngine
    {
    #region Public Methods

    /// <summary>
    /// Encrypt a string using dual encryption method. Returns a encrypted text.
    /// </summary>
    /// <param name="toEncrypt">string to be encrypted</param>
    /// <param name="useHashing">use hashing? send to for extra secirity</param>
    /// <returns>Returns encrypted string.</returns>
    public static string Encrypt(string toEncrypt, bool useHashing)
    {
    try
    {
    byte[] keyArray;
    byte[] toEncryptArray = UTF8Encoding.UTF8.GetBytes(toEncrypt);

    System.Configuration.AppSettingsReader settingsReader = new AppSettingsReader();
    // Get the key from config file
    string key = (string)settingsReader.GetValue("SecurityKey", typeof(String));
    //System.Windows.Forms.MessageBox.Show(key);
    if (useHashing)
    {
    MD5CryptoServiceProvider hashmd5 = new MD5CryptoServiceProvider();
    keyArray = hashmd5.ComputeHash(UTF8Encoding.UTF8.GetBytes(key));
    hashmd5.Clear();
    }
    else
    keyArray = UTF8Encoding.UTF8.GetBytes(key);

    TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider();
    tdes.Key = keyArray;
    tdes.Mode = CipherMode.ECB;
    tdes.Padding = PaddingMode.PKCS7;

    ICryptoTransform cTransform = tdes.CreateEncryptor();
    byte[] resultArray = cTransform.TransformFinalBlock(toEncryptArray, 0, toEncryptArray.Length);
    tdes.Clear();
    return Convert.ToBase64String(resultArray, 0, resultArray.Length);
    }
    catch (Exception)
    {
    throw;
    }
    }

    /// <summary>
    /// DeCrypt a string using dual encryption method. Return a DeCrypted clear string
    /// </summary>
    /// <param name="cipherString">encrypted string</param>
    /// <param name="useHashing">Did you use hashing to encrypt this data? pass true is yes</param>
    /// <returns>Returns decrypted text.</returns>
    public static string Decrypt(string cipherString, bool useHashing)
    {
    try
    {
    byte[] keyArray;
    byte[] toEncryptArray = Convert.FromBase64String(cipherString);

    System.Configuration.AppSettingsReader settingsReader = new AppSettingsReader();
    //Get your key from config file to open the lock!
    string key = (string)settingsReader.GetValue("SecurityKey", typeof(String));

    if (useHashing)
    {
    MD5CryptoServiceProvider hashmd5 = new MD5CryptoServiceProvider();
    keyArray = hashmd5.ComputeHash(UTF8Encoding.UTF8.GetBytes(key));
    hashmd5.Clear();
    }
    else
    keyArray = UTF8Encoding.UTF8.GetBytes(key);

    TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider();
    tdes.Key = keyArray;
    tdes.Mode = CipherMode.ECB;
    tdes.Padding = PaddingMode.PKCS7;

    ICryptoTransform cTransform = tdes.CreateDecryptor();
    byte[] resultArray = cTransform.TransformFinalBlock(toEncryptArray, 0, toEncryptArray.Length);

    tdes.Clear();
    return UTF8Encoding.UTF8.GetString(resultArray);
    }
    catch (Exception)
    {
    throw;
    }
    }

    #endregion
    }
    }

  • #329986
    Since your encryption algorithm is very simple we can implement it directly in our code.

    The Interface
    -------------
    <%@ 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">

    <html xmlns="http://www.w3.org/1999/xhtml" >
    <head runat="server">
    <title>Untitled Page</title>
    </head>
    <body>
    <form id="form1" runat="server">
    <div>
    <asp:TextBox ID="TextBox1" runat="server" Style="z-index: 100; left: 72px; position: absolute;
    top: 115px"></asp:TextBox>
    <asp:Button ID="ButtonEncrypt" runat="server" OnClick="ButtonEncrypt_Click" Style="z-index: 101;
    left: 158px; position: absolute; top: 144px" Text="Encrypt" />
    <asp:Label ID="lblCypher" runat="server" Style="z-index: 102; left: 77px; position: absolute;
    top: 180px" Text="Label"></asp:Label>
    <asp:Label ID="lblPlain" runat="server" Style="z-index: 105; left: 493px; position: absolute;
    top: 148px" Text="Label"></asp:Label>
    <asp:Button ID="ButtonDecrypt" runat="server" Style="z-index: 104; left: 461px; position: absolute;
    top: 118px" Text="Decrypt" OnClick="ButtonDecrypt_Click" />

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





    And the code follows.
    It is too simple that it doesnt require any explanation.

    ------------
    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;

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

    }
    protected void ButtonEncrypt_Click(object sender, EventArgs e)
    {
    string s = TextBox1.Text,Cypher="";
    for (int i = 0; i < s.Length; i++)
    {
    char c = (char)(s[i] + 2);
    Cypher = Cypher + new string(c, 1);
    }
    lblCypher.Text = Cypher;
    }
    protected void ButtonDecrypt_Click(object sender, EventArgs e)
    {
    string s = lblCypher.Text, PlainText= "";
    for (int i = 0; i < s.Length; i++)
    {
    char c = (char)(s[i] - 2);
    PlainText = PlainText + new string(c, 1);
    }
    lblPlain.Text = PlainText;

    }
    }


    Hope this will help you.
    If you still need any explanation please do let me know.

    Regards
    -Jayesh

    Jayesh K.S.

  • #330362
    Hi Jayesh
    thank u very much.
    can we do this using byte array,if so pls tell me

    -sabitha


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