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<< Click to Display Table of Contents >> Criptografar QueryString |
  
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<< Click to Display Table of Contents >> Criptografar QueryString |
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Veja o exemplo. Você tem uma página que deverá passar para outra página uma informação confidencial, mas deve ser por query string.
Aqui vemos passando uma senha: 123456
Note na barra de endereços que o "id" está criptografado e no corpo da página novamente descriptografado (a titulo de exemplo):
CryptUtil.cs
using System;
using System.IO;
using System.Security.Cryptography;
using System.Text;
public class CryptUtil
{
private static Byte[] ConvertStringToByArray(string s)
{
return (new UnicodeEncoding()).GetBytes(s);
}
public static string MD5(string s)
{
if (string.IsNullOrEmpty(s))
{
return null;
}
Byte[] toHash = ConvertStringToByArray(s);
byte[] hashValue = ((HashAlgorithm)CryptoConfig.CreateFromName("MD5")).ComputeHash(toHash);
return BitConverter.ToString(hashValue);
}
public static string Base64Encode(string key)
{
if (string.IsNullOrEmpty(key))
return string.Empty;
byte[] buffer = Encoding.UTF8.GetBytes(key);
return Convert.ToBase64String(buffer);
}
public static string Base64Decode(string key)
{
if (string.IsNullOrEmpty(key))
return "";
byte[] buffer = Convert.FromBase64String(key);
return Encoding.UTF8.GetString(buffer);
}
// Arbitrary key and iv vector.
// You will want to generate (and protect) your own when using encryption.
private const string actionKey = "EA81AA1D5FC1EC53E84F30AA746139EEBAFF8A9B76638895";
private const string actionIv = "87AF7EA221F3FFF5";
private TripleDESCryptoServiceProvider des3;
public CryptUtil()
{
des3 = new TripleDESCryptoServiceProvider();
des3.Mode = CipherMode.CBC;
}
public string GenerateKey()
{
des3.GenerateKey();
return BytesToHex(des3.Key);
}
public string GenerateIV()
{
des3.GenerateIV();
return BytesToHex(des3.IV);
}
private byte[] HexToBytes(string hex)
{
byte[] bytes = new byte[hex.Length / 2];
for (int i = 0; i < hex.Length / 2; i++)
{
string code = hex.Substring(i * 2, 2);
bytes[i] = byte.Parse(code, System.Globalization.NumberStyles.HexNumber);
}
return bytes;
}
private string BytesToHex(byte[] bytes)
{
StringBuilder hex = new StringBuilder();
for (int i = 0; i < bytes.Length; i++)
hex.AppendFormat("{0:X2}", bytes[i]);
return hex.ToString();
}
public string Encrypt(string data, string key, string iv)
{
byte[] bdata = Encoding.UTF8.GetBytes(data);
byte[] bkey = HexToBytes(key);
byte[] biv = HexToBytes(iv);
MemoryStream stream = new MemoryStream();
CryptoStream encStream = new CryptoStream(stream,
des3.CreateEncryptor(bkey, biv), CryptoStreamMode.Write);
encStream.Write(bdata, 0, bdata.Length);
encStream.FlushFinalBlock();
encStream.Close();
return BytesToHex(stream.ToArray());
}
public string Decrypt(string data, string key, string iv)
{
byte[] bdata = HexToBytes(data);
byte[] bkey = HexToBytes(key);
byte[] biv = HexToBytes(iv);
MemoryStream stream = new MemoryStream();
CryptoStream encStream = new CryptoStream(stream,
des3.CreateDecryptor(bkey, biv), CryptoStreamMode.Write);
encStream.Write(bdata, 0, bdata.Length);
encStream.FlushFinalBlock();
encStream.Close();
return Encoding.UTF8.GetString(stream.ToArray());
}
public string ActionEncrypt(string data)
{
return Encrypt(data, actionKey, actionIv);
}
public string ActionDecrypt(string data)
{
return Decrypt(data, actionKey, actionIv);
}
}
Pagina1.aspx
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Pagina1.aspx.cs" Inherits="WebApplication1.Pagina1" %>
<!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></title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:TextBox ID="txtMensagem" runat="server"></asp:TextBox>
<asp:Button ID="Button1" runat="server" Text="Passar mensagem por QueryString" onclick="Button1_Click" />
</div>
</form>
</body>
</html>
Pagina1.aspx.cs
using System;
public partial class Pagina1 : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void Button1_Click(object sender, EventArgs e)
{
CryptUtil crypt = new CryptUtil();
string query = crypt.ActionEncrypt(txtMensagem.Text);
Response.Redirect("~/Pagina2.aspx?id=" + query);
}
}
Pagina2.aspx
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Pagina2.aspx.cs" Inherits="WebApplication1.Pagina2" %>
<!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></title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:Label ID="Label1" runat="server" Text="Label"></asp:Label>
</div>
</form>
</body>
</html>
Pagina2.aspx.cs
using System;
public partial class Pagina2 : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
if (Request.Params["id"] != null)
{
CryptUtil crypt = new CryptUtil();
string id = crypt.ActionDecrypt(Request.Params["id"].ToString());
Label1.Text = id;
}
}
}