Hello lee,
See codesnippet below
using System;
using System.Security.Cryptography;
public sealed class CryptoString
{
private CryptoString( ) {}
private static byte[] savedKey = null;
private static byte[] savedIV = null;
public static byte[] Key
{
get { return savedKey; }
set { savedKey = value; }
}
public static byte[] IV
{
get { return savedIV; }
set { savedIV = value; }
}
private static void RdGenerateSecretKey(RijndaelManaged rdProvider)
{
if (savedKey == null)
{
rdProvider.KeySize = 256;
rdProvider.GenerateKey( );
savedKey = rdProvider.Key;
}
}
private static void RdGenerateSecretInitVector(RijndaelManaged rdProvider)
{
if (savedIV == null)
{
rdProvider.GenerateIV( );
savedIV = rdProvider.IV;
}
}
public static string Encrypt(string originalStr)
{
// Encode data string to be stored in memory.
byte[] originalStrAsBytes = Encoding.ASCII.GetBytes(originalStr);
byte[] originalBytes = {};
// Create MemoryStream to contain output.
using (MemoryStream memStream = new
MemoryStream(originalStrAsBytes.Length))
{
using (RijndaelManaged rijndael = new RijndaelManaged( ))
{
// Generate and save secret key and init vector.
RdGenerateSecretKey(rijndael);
RdGenerateSecretInitVector(rijndael);
if (savedKey == null || savedIV == null)
{
throw (new NullReferenceException(
"savedKey and savedIV must be non-null."));
}
// Create encryptor and stream objects.
using (ICryptoTransform rdTransform =
rijndael.CreateEncryptor((byte[])savedKey.
Clone( ),(byte[])savedIV.Clone( )))
{
using (CryptoStream cryptoStream = new CryptoStream(memStream,
rdTransform, CryptoStreamMode.Write))
{
// Write encrypted data to the MemoryStream.
cryptoStream.Write(originalStrAsBytes, 0,
originalStrAsBytes.Length);
cryptoStream.FlushFinalBlock( );
originalBytes = memStream.ToArray( );
}
}
}
}
// Convert encrypted string.
string encryptedStr = Convert.ToBase64String(originalBytes);
return (encryptedStr);
}
public static string Decrypt(string encryptedStr)
{
// Unconvert encrypted string.
byte[] encryptedStrAsBytes = Convert.FromBase64String(encryptedStr);
byte[] initialText = new Byte[encryptedStrAsBytes.Length];
using (RijndaelManaged rijndael = new RijndaelManaged( ))
{
using (MemoryStream memStream = new MemoryStream(encryptedStrAsBytes))
{
if (savedKey == null || savedIV == null)
{
throw (new NullReferenceException(
"savedKey and savedIV must be non-null."));
}
// Create decryptor, and stream objects.
using (ICryptoTransform rdTransform =
rijndael.CreateDecryptor((byte[])savedKey.
Clone( ),(byte[])savedIV.Clone( )))
{
using (CryptoStream cryptoStream = new CryptoStream(memStream,
rdTransform, CryptoStreamMode.Read))
{
// Read in decrypted string as a byte[].
cryptoStream.Read(initialText, 0, initialText.Length);
}
}
}
}
// Convert byte[] to string.
string decryptedStr = Encoding.ASCII.GetString(initialText);
return (decryptedStr);
}
}
l> Does anyone have any recommendation for encrypting simple strings to
l> be stored in a db?
l>
l> Thank you,
l>
l> "Upon further investigation it appears that your software is missing
l> just one thing. It definitely needs more cow bell..."
l>
---
WBR,
Michael Nemtsev :: blog:
http://spaces.msn.com/laflour
"At times one remains faithful to a cause only because its opponents do not
cease to be insipid." (c) Friedrich Nietzsche
