// The bytes encapsulated here will be used by RijndaelManaged and TripleDESCryptoServiceProvider objects
//They are created from a plain string passed in the constructor ( key that you provide and use to encrypt and decrypt)
//It is the responsability of the client of this class to destroy that key after this object is created.
// Call Clear() when finished with an object of Key3IV3 type.
using System;
using System.Security.Cryptography;
public class Key3IV3
{
private byte[] keyRij;
private byte[] key3des;
private byte[] ivRij;
private byte[] iv3des;
internal byte[] KeyRij
{
get { return keyRij; }
}
internal byte[] IVRij
{
get { return ivRij; }
}
internal byte[] Key3des
{
get { return key3des; }
}
internal byte[] IV3des
{
get { return iv3des; }
}
public Key3IV3(string txtPlain)
{
byte[] salt = System.Text.UTF8Encoding.UTF8.GetBytes(txtPlain);
SHA1 hash = new SHA1Managed();
for (int i = 0; i < 200; ++i)
{
salt = hash.ComputeHash(salt, 0, salt.Length);
hash.Initialize();
}
PasswordDeriveBytes pdb = new PasswordDeriveBytes(txtPlain, salt, "SHA512", 1000);
Array.Clear(salt, 0, salt.Length);
hash.Clear();
keyRij = pdb.GetBytes(32);
key3des = pdb.GetBytes(24);
ivRij = pdb.GetBytes(16);
iv3des = pdb.GetBytes(8);
}
public void Clear()
{
Array.Clear(keyRij, 0, keyRij.Length);
Array.Clear(ivRij, 0, ivRij.Length);
Array.Clear(key3des, 0, key3des.Length);
Array.Clear(iv3des, 0, iv3des.Length);
}
~Key3IV3()
{
}using System;
using System.IO;
using System.Text;
using System.Security.Permissions;
using System.Security.Cryptography;
public class Util
{
public Util()
{
}
// Encrypt a string
public static string EncryptAndBase64(string val, ICryptoTransform trans)
{
byte[] buf = UnicodeEncoding.Unicode.GetBytes(val);
MemoryStream memStream = new MemoryStream();
CryptoStream cryptStream = new CryptoStream(memStream, trans, CryptoStreamMode.Write);
cryptStream.Write(buf, 0, buf.Length);
cryptStream.FlushFinalBlock();
cryptStream.Clear();
Array.Clear(buf, 0, buf.Length);
buf = memStream.GetBuffer();
val = Convert.ToBase64String(buf, 0, (int)memStream.Length);
Array.Clear(buf, 0, (int)memStream.Length);
return val;
}
// Decrypt an encrypted string
public static string DecryptFromBase64(string base64str, ICryptoTransform trans)
{
byte[] buf = Convert.FromBase64String(base64str);
MemoryStream memStream = new MemoryStream();
CryptoStream cryptStream = new CryptoStream(memStream, trans, CryptoStreamMode.Write);
cryptStream.Write(buf, 0, buf.Length);
cryptStream.FlushFinalBlock();
cryptStream.Clear();
Array.Clear(buf, 0, buf.Length);
buf = memStream.GetBuffer();
string ret = UnicodeEncoding.Unicode.GetString(buf, 0, (int)memStream.Length);
Array.Clear(buf, 0, (int)memStream.Length);
memStream.Close();
return ret;
}
// Encrypt to File
public static void Encrypt2File(MemoryStream memStream, ICryptoTransform ict, string filePath)
{
FileIOPermission perm = new FileIOPermission(FileIOPermissionAccess.Write, filePath);
perm.Demand();
Stream fileStream = new FileStream(filePath, FileMode.Create, FileAccess.Write, FileShare.None);
try
{
CryptoStream cryptStream = new CryptoStream(memStream, ict, CryptoStreamMode.Read);
int read = 0;
byte[] buf = new byte[4096];
while (true)
{
read = cryptStream.Read(buf, 0, buf.Length);
if (read == 0)
break;
fileStream.Write(buf, 0, read);
}
cryptStream.Clear();
}
finally
{
fileStream.Close();
}
}
}/// Encryption objects
ICryptoTransform encRij;
ICryptoTransform enc3des;
ICryptoTransform decRij;
ICryptoTransform dec3des;
//...
Key3IV3 k3iv3 = new Key3IV3("string key you should to provide and will be used by encrypt/decrypt processes");
RijndaelManaged aes = null; //SymmetricAlgorithm
TripleDESCryptoServiceProvider des3 = null;
try
{
aes = new RijndaelManaged();
des3 = new TripleDESCryptoServiceProvider();
encRij = aes.CreateEncryptor(k3iv3.KeyRij, k3iv3.IVRij);
enc3des = des3.CreateEncryptor(k3iv3.Key3des, k3iv3.IV3des);
decRij = aes.CreateDecryptor(k3iv3.KeyRij, k3iv3.IVRij);
dec3des = des3.CreateDecryptor(k3iv3.Key3des, k3iv3.IV3des);
}
catch (Exception e)
{
string sMsg = "...Error ..." + e.GetType() + e.Message;
//Util.WriteToEventLog(sMsg);
}
finally
{
if (des3 != null)
des3.Clear();
if (aes != null)
aes.Clear();
}
string encName = Util.EncryptAndBase64(dlg.Name, enc3des);
string encSSN = Util.EncryptAndBase64(dlg.SSN, enc3des);
//
string decName = Util.EncryptAndBase64(encName, dec3des);
string decSSN = Util.DecryptFromBase64(encSSN, dec3des);
// Fill a MemoryStream object using a XmlTextWriter to populate it
// or other method
MemoryStream memStream = new MemoryStream();
XmlTextWriter xtw = new XmlTextWriter(memStream, null);
// ... Fill here the memStream object with encrypted encName, encSSN
Util.Encrypt2File(memStream,encRij, "myfile.dat");
byte[] buf = memStream.GetBuffer();
Array.Clear(buf, 0, (int)memStream.Length);
xtw.Flush();
xtw.Close();
memStream.Close();
// Read from encrypted file into MemoryStream using decRij
try
{
Stream fileStream = new FileStream("myfile.dat", FileMode.Open, FileAccess.Read, FileShare.None);
MemoryStream memStream = new MemoryStream((int)fileStream.Length);
CryptoStream cryptoStream = new CryptoStream(fileStream, decRij, CryptoStreamMode.Read);
byte[] buf = new byte[4096];
int read = 0;
while(true)
{
read = cryptoStream.Read(buf, 0, buf.Length);
if(read == 0)
break;
memStream.Write(buf, 0, read);
}
cryptoStream.Clear();
fileStream.Close();
fileStream = null;
memStream.Position = 0;
}
catch (Exception ex)
{
}
//...
encRij.Dispose();
enc3des.Dispose();
decRij.Dispose();
dec3des.Dispose();
k3iv3.Clear();
