public static string FuncEncryptionMain(string plainTxt)//, out string encrypted, out string extractedIVTxt, out string error
{
string encrypted = "";
string extractedIVTxt = "";
string error = "";
int rngNum = 0;
var myDictionary = FuncOther.Generator();
var rng = new Random();
rngNum = rng.Next(0, myDictionary.Count - 1);
string strIV = myDictionary[rngNum].Key;
string strSH = myDictionary[rngNum].Value;
try
{
if (plainTxt == null || plainTxt.Length <= 0)
{
throw new ArgumentNullException("PLAINTEXT");
}
byte[] bytSalt = new byte[16];
byte[] bytIV = FuncOther.ConvertIVTextToIVByte(strIV);
var plainTextBytes = Encoding.UTF8.GetBytes(plainTxt);
byte[] bytSH = FuncOther.FinalHT(strSH.Split(' '));
var ivStringBytes = strIV;
for (int i = 0; i < bytSH.Length / 2; i++)
{
bytSalt[i] = bytSH[i];
}
var password = new Rfc2898DeriveBytes(bytIV, bytSalt, 500);
var keyBytes = password.GetBytes(128 / 8);
Aes rijAlg = Aes.Create();
if (!(strIV == null))
{
if (strIV.Length > 0)
{
rijAlg.IV = bytIV;
rijAlg.Key = keyBytes;
}
else
{
rijAlg.Mode = CipherMode.ECB;
}
}
else
{
rijAlg.Mode = CipherMode.ECB;
}
ICryptoTransform encryptor = rijAlg.CreateEncryptor();
List <byte> listCipherTextBytes = new List <byte>();
//List<byte> listbytSalt = new List<byte>(NewSH);
//listCipherTextBytes.AddRange(listbytSalt);
List <byte> listIvStringBytes = new List <byte>(bytIV);
listCipherTextBytes.AddRange(listIvStringBytes);
List <byte> listMemoryStream = new List <byte>(encryptor.TransformFinalBlock(plainTextBytes, 0, plainTextBytes.Length));
listCipherTextBytes.AddRange(listMemoryStream);
byte[] cipherTextBytes = listCipherTextBytes.ToArray();
extractedIVTxt = strIV;
encrypted = Convert.ToBase64String(cipherTextBytes);
}
catch (Exception e)
{
error = e.Message;
}
string result = encrypted + "▲" + extractedIVTxt;
return(!(string.IsNullOrEmpty(error))? error : result);
}
public static string FuncDecryptionMain(string cipherTxt, string keyTxt)
{
string decrypted = "";
string error = "";
string keyExtractText = "";
string strIV = "";
byte[] cipherBytesWithIv = null;
byte[] keyExtractByte = null;
byte[] bytIV = new byte[16];
try
{
if (cipherTxt == null || cipherTxt.Length <= 0)
{
throw new ArgumentNullException("CipherText");
}
cipherBytesWithIv = Convert.FromBase64String(cipherTxt);
}
catch
{
error = "No suitable inputs for doing encrypt";
return(error);
}
try
{
byte len = 0;
byte[] cipherBytes = new byte[cipherBytesWithIv.Length - 16];
System.Buffer.BlockCopy(cipherBytesWithIv, 0, bytIV, 0, 16);
System.Buffer.BlockCopy(cipherBytesWithIv, 16, cipherBytes, 0, cipherBytesWithIv.Length - 16);
if (bytIV.Length < 1 || cipherBytes.Length < 1)
{
return("Exception occured in BlockCopy -FuncDecryption");
}
strIV = FuncOther.ConvertIVByteToIVText(bytIV);
foreach (var item in bytIV)
{
if (item == 0)
{
len++;
}
}
if (len != 4)
{
return("No suitable length iv for doing encrypt - FuncDecryption");
}
var myDictionary = FuncOther.Generator();
if (!(string.IsNullOrEmpty(strIV)))
{
keyExtractText = myDictionary.Find(f => f.Key == strIV).Value.ToString();
}
else
{
return("Not found any IV -FuncDecryption");
}
if (!(string.IsNullOrEmpty(keyExtractText)))
{
if (!(keyExtractText.Equals(keyTxt)))
{
return("Not equal your key with assembly key -FuncDecryption");
}
}
else
{
return("Not found any key -FuncDecryption");
}
keyExtractByte = FuncOther.FinalHT(keyExtractText.Split(' '));
byte[] bytSalt = new byte[16];
for (int i = 0; i < keyExtractByte.Length / 2; i++)
{
bytSalt[i] = keyExtractByte[i];
}
var password = new Rfc2898DeriveBytes(bytIV, bytSalt, 500);
var keyBytes = password.GetBytes(128 / 8);
Aes rijAlg = Aes.Create();
rijAlg.Key = keyBytes;
rijAlg.Mode = CipherMode.CBC;
if (!(bytIV == null))
{
if (bytIV.Length > 0)
{
rijAlg.IV = bytIV;
}
else
{
rijAlg.Mode = CipherMode.ECB;
}
}
else
{
rijAlg.Mode = CipherMode.ECB;
}
ICryptoTransform decryptor = rijAlg.CreateDecryptor(rijAlg.Key, rijAlg.IV);
MemoryStream msDecrypt = new MemoryStream(cipherBytes);
CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read);
StreamReader srDecrypt = new StreamReader(csDecrypt);
decrypted = srDecrypt.ReadToEnd();
}
catch (Exception e)
{
error = e.Message;
if (error.Contains("Padding is invalid and cannot be removed."))
{
error = "In decryption function occured : Padding is invalid and cannot be removed.";
}
}
return(error != "" ? error : decrypted);
}
