public static string Encrypt(string clearText, ICSPRNGServer csprng)
{
byte[] salt = new byte[16];
csprng.getRandomValues(salt);
byte[] encBytes = null;
byte[] clearBytes = Encoding.Unicode.GetBytes(clearText);
using (Aes encryptor = Aes.Create())
{
encryptor.KeySize = 256;
encryptor.BlockSize = 128;
encryptor.Mode = CipherMode.CBC;
encryptor.Padding = PaddingMode.PKCS7;
Rfc2898DeriveBytes pdb = new Rfc2898DeriveBytes(csprng.Key(), salt, 1);
encryptor.Key = pdb.GetBytes(32);
encryptor.IV = pdb.GetBytes(16);
using (MemoryStream ms = new MemoryStream())
{
using (CryptoStream cs = new CryptoStream(ms, encryptor.CreateEncryptor(), CryptoStreamMode.Write))
{
cs.Write(clearBytes, 0, clearBytes.Length);
}
encBytes = ms.ToArray();
}
}
byte[] saltAndCipher = salt.Concat(encBytes).ToArray();
string saltAndCipherText = Convert.ToBase64String(saltAndCipher);
return(saltAndCipherText);
}
public static string Decrypt(string clearText, ICSPRNGServer csprng)
{
byte[] baseclear = Convert.FromBase64String(clearText);
byte[] clearBytes = new byte[baseclear.Length - 16];
for (int i = 0; i < clearBytes.Length; i++)
{
clearBytes[i] = baseclear[i + 16];
}
byte[] salt = baseclear.Take(16).ToArray();
using (Aes encryptor = Aes.Create())
{
encryptor.KeySize = 256;
encryptor.BlockSize = 128;
encryptor.Mode = CipherMode.CBC;
encryptor.Padding = PaddingMode.PKCS7;
Rfc2898DeriveBytes pdb = new Rfc2898DeriveBytes(csprng.Key(), salt, 1);
encryptor.Key = pdb.GetBytes(32);
encryptor.IV = pdb.GetBytes(16);
using (MemoryStream ms = new MemoryStream(clearBytes))
{
using (CryptoStream cs = new CryptoStream(ms, encryptor.CreateDecryptor(), CryptoStreamMode.Read))
{
using (StreamReader srDecrypt = new StreamReader(cs))
{
clearText = srDecrypt.ReadToEnd();
}
}
}
}
clearText = clearText.Replace("\0", "");
return(clearText);
}
