internal static string EncryptValue(string value)
{
if (String.IsNullOrWhiteSpace(value))
{
return String.Empty;
}
using (var symmetricProvider = new Symmetric(SymmetricProvider.Rijndael, false))
{
string result;
try
{
symmetricProvider.IntializationVector = IV;
result = symmetricProvider.Encrypt(new Data(value), SymmetricKey).Bytes.ToBase64();
}
catch (CryptographicException)
{
// return the value as is
result = value;
}
return result;
}
}
/// <summary>
/// test using auto-generated keys
/// </summary>
private static string SymmetricLoopback(SymmetricProvider p, string targetString)
{
Data decryptedData;
using (var sym = new Symmetric(p))
{
Data encryptedData = sym.Encrypt(new Data(targetString));
using (var sym2 = new Symmetric(p))
{
decryptedData = sym2.Decrypt(encryptedData, sym.Key);
}
}
////-- the data will be padded to the encryption blocksize, so we need to trim it back down.
//return decryptedData.ToString().Substring(0, _TargetData.Bytes.Length);
return decryptedData.ToString();
}
/// <summary>
/// test using user-provided keys and init vectors
/// </summary>
private static string SymmetricWithKey(SymmetricProvider p, string targetString)
{
var keyData = new SymmetricKeyData("MySecretPassword");
var ivData = new SymmetricKeyData("MyInitializationVector");
Data encryptedData;
using (var sym = new Symmetric(p, false))
{
sym.IntializationVector = ivData;
encryptedData = sym.Encrypt(new Data(targetString), keyData);
}
Data decryptedData;
using (var sym2 = new Symmetric(p, false))
{
sym2.IntializationVector = ivData;
decryptedData = sym2.Decrypt(encryptedData, keyData);
}
////-- the data will be padded to the encryption blocksize, so we need to trim it back down.
//return decryptedData.ToString().Substring(0, _TargetData.Bytes.Length);
return decryptedData.ToString();
}
private static string SymmetricFilePrivate(SymmetricProvider p, string fileName, string key)
{
string encryptedFilePath = Path.GetFileNameWithoutExtension(fileName) + ".encrypted";
string decryptedFilePath = Path.GetFileNameWithoutExtension(Path.GetFileNameWithoutExtension(fileName)) + "-decrypted" + Path.GetExtension(fileName);
// encrypt the file to memory
Data encryptedData;
using (var sym = new Symmetric(p))
{
sym.Key = new SymmetricKeyData(key);
using (var stream = File.OpenRead(fileName))
{
encryptedData = sym.Encrypt(stream);
}
}
// write encrypted data to a new binary file
using (var stream = File.Open(encryptedFilePath, FileMode.Create))
using (var bw = new BinaryWriter(stream))
{
bw.Write(encryptedData.Bytes);
}
// decrypt this binary file
Data decryptedData;
using (var sym2 = new Symmetric(p))
{
sym2.Key = new SymmetricKeyData(key);
using (var stream = File.OpenRead(encryptedFilePath))
{
decryptedData = sym2.Decrypt(stream);
}
}
// write decrypted data to a new binary file
using (var stream = File.Open(decryptedFilePath, FileMode.Create))
using (var bw = new BinaryWriter(stream))
{
bw.Write(decryptedData.Bytes);
}
// get the MD5 hash of the returned data
using (var h = new Hash(HashProvider.MD5))
{
return h.Calculate(decryptedData).Bytes.ToHex();
}
}
