//Function for encrypting propose
static string SymmetricEncryption(string str, byte[] key, byte[] IV)
{
MemoryStream ms = new MemoryStream();
try
{
//---creates a new instance of the RijndaelManaged class---
RijndaelManaged RMCrypto = new RijndaelManaged();
//---creates a new instance of the CryptoStream class---
CryptoStream cryptStream =new CryptoStream(ms, RMCrypto.CreateEncryptor(key, IV),
CryptoStreamMode.Write);
StreamWriter sWriter = new StreamWriter(cryptStream);
//---encrypting the string---
sWriter.Write(str);
sWriter.Close();
cryptStream.Close();
//---return the encrypted data as a string---
return System.Convert.ToBase64String(ms.ToArray());
}
catch (Exception ex)
{
Console.WriteLine(ex.ToString());
return (String.Empty);
}
}
//Function for Decrypting propose
static string SymmetricDecryption(string str, byte[] key, byte[] IV)
{
try
{
//---converts the encrypted string into a byte array---
byte[] b = System.Convert.FromBase64String(str);
//---converts the byte array into a memory stream for decryption---
MemoryStream ms = new MemoryStream(b);
//---creates a new instance of the RijndaelManaged class---
RijndaelManaged RMCrypto = new RijndaelManaged();
//---creates a new instance of the CryptoStream class---
CryptoStream cryptStream = new CryptoStream(ms, RMCrypto.CreateDecryptor(key, IV),
CryptoStreamMode.Read);
//---decrypting the stream---
StreamReader sReader = new StreamReader(cryptStream);
//---converts the decrypted stream into a string---
String s = sReader.ReadToEnd();
sReader.Close();
return s;
}
catch (Exception ex)
{
Console.WriteLine(ex.ToString());
return String.Empty;
}
}
//Main function execute the functions
RijndaelManaged RMCrypto = new RijndaelManaged();
//---generate key---
RMCrypto.GenerateKey();
byte[] key = RMCrypto.Key;
Console.WriteLine(“Key : “ + System.Convert.ToBase64String(key));
//---generate IV---
RMCrypto.GenerateIV();
byte[] IV = RMCrypto.IV;
Console.WriteLine(“IV : “ + System.Convert.ToBase64String(IV));
//---encrypt the string---
string cipherText = SymmetricEncryption(“This is a test string.”, key, IV);
Console.WriteLine(“Ciphertext: “ + cipherText);
//---decrypt the string---
Console.WriteLine(“Original string: “ + SymmetricDecryption(cipherText, key, IV));