/// <summary>
/// Initializes a new instance of the <see cref="RC4CryptoServiceProvider"/> class.
/// </summary>
public RC4CryptoServiceProvider() {
// acquire an RC4 context
m_Provider = CAPIProvider.Handle;
/* if (SspiProvider.CryptAcquireContext(ref m_Provider, IntPtr.Zero, null, SecurityConstants.PROV_RSA_FULL, 0) == 0) {
if (Marshal.GetLastWin32Error() == SecurityConstants.NTE_BAD_KEYSET)
SspiProvider.CryptAcquireContext(ref m_Provider, IntPtr.Zero, null, SecurityConstants.PROV_RSA_FULL, SecurityConstants.CRYPT_NEWKEYSET);
}*/
if (m_Provider != 0) {
int dwFlags = SecurityConstants.CRYPT_FIRST;
bool found = false;
IntPtr provEnum = Marshal.AllocHGlobal(100);
int dwSize;
do {
dwSize = 100;
if (SspiProvider.CryptGetProvParam(m_Provider, SecurityConstants.PP_ENUMALGS_EX, provEnum, ref dwSize, dwFlags) == 0)
break;
dwFlags = 0;
PROV_ENUMALGS_EX eax = (PROV_ENUMALGS_EX)Marshal.PtrToStructure(provEnum, typeof(PROV_ENUMALGS_EX));
if (eax.aiAlgid == SecurityConstants.CALG_RC4) {
found = true;
m_MinLen = eax.dwMinLen;
m_MaxLen = eax.dwMaxLen;
}
} while (!found);
Marshal.FreeHGlobal(provEnum);
/* if (!found) {
SspiProvider.CryptReleaseContext(m_Provider, 0);
m_Provider = 0;
}*/
}
m_Managed = new ARCFourManaged();
}
static void Main(string[] args)
{
Console.WriteLine("This example shows how to use the symmetric encryption classes from the Security Library.\r\n");
SymmetricAlgorithm algorithm;
ICryptoTransform encryptor, decryptor;
Console.WriteLine("Select the symmetric algorithm you want to use:");
Console.WriteLine(" [1] ARCFour [managed RC4]");
Console.WriteLine(" [2] RC4 [unmanaged]");
Console.WriteLine(" [3] Rijndael");
Console.Write("Your choice: ");
string input = Console.ReadLine().Trim();
// initialize the selected symmetric algorithm
switch(input) {
case "1":
algorithm = new ARCFourManaged();
break;
case "2":
algorithm = new RC4CryptoServiceProvider();
break;
case "3":
algorithm = new RijndaelCryptoServiceProvider();
break;
default:
Console.WriteLine("Invalid input.");
return;
}
Console.WriteLine("Enter some text that will be encrypted:");
input = Console.ReadLine();
byte[] plaintext = Encoding.ASCII.GetBytes(input);
// generate an IV that consists of bytes with the value zero
// in real life applications, the IV should not be set to
// an array of bytes with the value zero!
algorithm.IV = new byte[algorithm.BlockSize / 8];
// generate a new key
algorithm.GenerateKey();
// create the encryption and decryption objects
encryptor = algorithm.CreateEncryptor();
decryptor = algorithm.CreateDecryptor();
// encrypt the bytes
byte[] encrypted = encryptor.TransformFinalBlock(plaintext, 0, plaintext.Length);
// decrypt the encrypted bytes
byte[] decrypted = decryptor.TransformFinalBlock(encrypted, 0, encrypted.Length);
// write the byte arrays to the console
Console.WriteLine("\r\nResults:");
Console.WriteLine(" Input data: " + Encoding.ASCII.GetString(plaintext));
Console.WriteLine(" Key: " + BytesToHex(algorithm.Key));
Console.WriteLine(" Encrypted data: " + BytesToHex(encrypted));
Console.WriteLine(" Decrypted data: " + Encoding.ASCII.GetString(decrypted));
Console.WriteLine("\r\nPress ENTER to continue...");
Console.ReadLine();
// dispose of the resources
algorithm.Clear();
encryptor.Dispose();
decryptor.Dispose();
}
/// <summary>
/// Initializes a new instance of the <see cref="RC4CryptoServiceProvider"/> class.
/// </summary>
public RC4CryptoServiceProvider()
{
// acquire an RC4 context
m_Provider = CAPIProvider.Handle;
/* if (SspiProvider.CryptAcquireContext(ref m_Provider, IntPtr.Zero, null, SecurityConstants.PROV_RSA_FULL, 0) == 0) {
* if (Marshal.GetLastWin32Error() == SecurityConstants.NTE_BAD_KEYSET)
* SspiProvider.CryptAcquireContext(ref m_Provider, IntPtr.Zero, null, SecurityConstants.PROV_RSA_FULL, SecurityConstants.CRYPT_NEWKEYSET);
* }*/
if (m_Provider != 0)
{
int dwFlags = SecurityConstants.CRYPT_FIRST;
bool found = false;
IntPtr provEnum = Marshal.AllocHGlobal(100);
int dwSize;
do
{
dwSize = 100;
if (SspiProvider.CryptGetProvParam(m_Provider, SecurityConstants.PP_ENUMALGS_EX, provEnum, ref dwSize, dwFlags) == 0)
{
break;
}
dwFlags = 0;
PROV_ENUMALGS_EX eax = (PROV_ENUMALGS_EX)Marshal.PtrToStructure(provEnum, typeof(PROV_ENUMALGS_EX));
if (eax.aiAlgid == SecurityConstants.CALG_RC4)
{
found = true;
m_MinLen = eax.dwMinLen;
m_MaxLen = eax.dwMaxLen;
}
} while (!found);
Marshal.FreeHGlobal(provEnum);
/* if (!found) {
* SspiProvider.CryptReleaseContext(m_Provider, 0);
* m_Provider = 0;
* }*/
}
m_Managed = new ARCFourManaged();
}
/// <summary>
/// Releases all managed and unmanaged resources used by this class.
/// </summary>
private void _Dispose()
{
if (!m_Disposed) {
m_Disposed = true;
if (m_Managed != null) {
m_Managed.Clear();
m_Managed = null;
}
/* if (m_Provider != 0) {
SspiProvider.CryptReleaseContext(m_Provider, 0);
m_Provider = 0;
}*/
try {
GC.SuppressFinalize(this);
} catch {}
}
}
/// <summary>
/// Releases all managed and unmanaged resources used by this class.
/// </summary>
protected override void Dispose(bool disposing)
{
base.Dispose(disposing);
if (disposing && !m_Disposed) {
m_Disposed = true;
if (m_Managed != null) {
m_Managed.Clear();
m_Managed = null;
}
/* if (m_Provider != 0) {
SspiProvider.CryptReleaseContext(m_Provider, 0);
m_Provider = 0;
}*/
try {
GC.SuppressFinalize(this);
} catch { }
}
}
