Kryptere og dekryptere med C#

8/21/2007 1:44:00 AM

Dette er en enkel klasse for kryptering og dekryptering av data. Dette er nok ikke den aller sikreste måten å kryptere på, men den holder ganske langt.

admin

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

public class Encrypt
{
//Dette er en kode som brukes til krypteringen og
//dekrypteringen. Denne setter du selv..
public static string Key = "HemmeligKode";

public static byte[] EncryptBytes(byte[] InputString, string EncryptionKey) 
{
  if (EncryptionKey == null)
    EncryptionKey = Key;

  TripleDESCryptoServiceProvider des =  new TripleDESCryptoServiceProvider();
  MD5CryptoServiceProvider hashmd5 = new MD5CryptoServiceProvider();

  des.Key = hashmd5.ComputeHash(Encoding.ASCII.GetBytes(EncryptionKey));
  des.Mode = CipherMode.ECB;
  
  ICryptoTransform Transform = des.CreateEncryptor();

  byte[] Buffer = InputString;
  return Transform.TransformFinalBlock(Buffer,0,Buffer.Length);
}

public static byte[] EncryptBytes(string DecryptString, string EncryptionKey) 
{
  return EncryptBytes(Encoding.ASCII.GetBytes(DecryptString),EncryptionKey);
}

public static string EncryptString(string InputString, string EncryptionKey) 
{
  return Convert.ToBase64String(EncryptBytes(Encoding.ASCII.GetBytes(InputString),EncryptionKey));
}

public static byte[] DecryptBytes(byte[] DecryptBuffer, string EncryptionKey) 
{
  if (EncryptionKey == null)
    EncryptionKey = Key;

  TripleDESCryptoServiceProvider des =  new TripleDESCryptoServiceProvider();
  MD5CryptoServiceProvider hashmd5 = new MD5CryptoServiceProvider();

  des.Key = hashmd5.ComputeHash(Encoding.ASCII.GetBytes(EncryptionKey));
  des.Mode = CipherMode.ECB;

  ICryptoTransform Transform = des.CreateDecryptor();
  return  Transform.TransformFinalBlock(DecryptBuffer,0,DecryptBuffer.Length);
}

public static byte[] DecryptBytes(string DecryptString, string EncryptionKey) 
{  
    return DecryptBytes(Convert.FromBase64String(DecryptString),EncryptionKey);
}

public static string DecryptString(string DecryptString, string EncryptionKey) 
{
  try 
  {
  return Encoding.ASCII.GetString(DecryptBytes(Convert.FromBase64String(DecryptString),EncryptionKey));
  }
  catch { return ""; }
}
}