public static string NDESEncrypt(string encryptString, string encKey, string number)
{
int[] divisors = NDes.Getdivisor(number);
//int[] divisors = new int[] { 1, 3 };
int m = int.Parse(number);
int i, j;
string cipherresult = string.Empty;
string t = string.Empty;
string subkey = string.Empty;
for (i = 1; i <= m; i++)
{
if (i <= divisors.Length)
{
if (i % 2 == 0)
{
subkey = rightmovekey(encKey, divisors[i - 1]);
t = encryptString;
cipherresult = DES.DEScipher.Encrypt(t, subkey);
encryptString = cipherresult;
}
else
{
subkey = leftmovekey(encKey, divisors[i - 1]);
t = encryptString;
cipherresult = DES.DEScipher.Encrypt(t, subkey);
encryptString = cipherresult;
}
}
else
{
j = i;
do
{
j = j - divisors.Length;
} while (j > divisors.Length);
if (i % 2 == 0)
{
subkey = NDes.rightmovekey(encKey, divisors[j - 1]);
t = encryptString;
cipherresult = DES.DEScipher.Encrypt(t, subkey);
encryptString = cipherresult;
}
else
{
subkey = NDes.leftmovekey(encKey, divisors[j - 1]);
t = encryptString;
cipherresult = DES.DEScipher.Encrypt(t, subkey);
encryptString = cipherresult;
}
}
}
return(encryptString);
}
public static string NDESDecrypt(string decryptString, string encKey, string number)
{
int[] divisors = NDes.Getdivisor(number);
int m = int.Parse(number);
int i, j;
string decipherresult = string.Empty;
string t = string.Empty;
string subkey = string.Empty;
for (i = m; i > 0; i--)
{
if (i <= divisors.Length)
{
if (i % 2 == 0)
{
subkey = rightmovekey(encKey, divisors[i - 1]);
t = decryptString;
decipherresult = DES.DEScipher.Decrypt(t, subkey);
decryptString = decipherresult;
}
else
{
subkey = leftmovekey(encKey, divisors[i - 1]);
t = decryptString;
decipherresult = DES.DEScipher.Decrypt(t, subkey);
decryptString = decipherresult;
}
}
else
{
j = i;
do
{
j = j - divisors.Length;
} while (j > divisors.Length);
if (i % 2 == 0)
{
subkey = NDes.rightmovekey(encKey, divisors[j - 1]);
t = decryptString;
decipherresult = DES.DEScipher.Decrypt(t, subkey);
decryptString = decipherresult;
}
else
{
subkey = NDes.leftmovekey(encKey, divisors[j - 1]);
t = decryptString;
decipherresult = DES.DEScipher.Decrypt(t, subkey);
decryptString = decipherresult;
}
}
}
return(decryptString);
}
public static string rightmovekey(string k1, int n)
{
string str1 = string.Empty;
string str2 = string.Empty;
string stringresult = string.Empty;
byte[] byte1 = Encoding.UTF8.GetBytes(k1);
string k = NDes.BytesToBit(byte1);
str1 = k.Substring(0, k.Length - n);
str2 = k.Substring(k.Length - n, n);
stringresult = str2 + str1;
string stringresult2 = NDes.BitToBytes(stringresult);
return(stringresult2);
}
