private void CreateAcryptoEngine()
{
IAsymmetricBlockCipher engine;
switch (_MSec.Algorithm)
{
case ESec.ACRYPTO_ELGAMAL:
engine = new ElGamalEngine();
break;
case ESec.ACRYPTO_NACCACHESTERN:
engine = new NaccacheSternEngine();
break;
case ESec.ACRYPTO_RSABLINDED:
engine = new RsaBlindedEngine();
break;
case ESec.ACRYPTO_RSABLINDING:
engine = new RsaBlindingEngine();
break;
case ESec.ACRYPTO_RSA:
engine = new RsaEngine();
break;
}
}
public virtual byte[] ProcessBlock(byte[] inBytes, int inOff, int length)
{
if (this.key == null)
{
throw new InvalidOperationException("NaccacheStern engine not initialised");
}
if (length > this.GetInputBlockSize() + 1)
{
throw new DataLengthException("input too large for Naccache-Stern cipher.\n");
}
if (!this.forEncryption && length < this.GetInputBlockSize())
{
throw new InvalidCipherTextException("BlockLength does not match modulus for Naccache-Stern cipher.\n");
}
BigInteger bigInteger = new BigInteger(1, inBytes, inOff, length);
if (this.debug)
{
Console.WriteLine("input as BigInteger: " + bigInteger);
}
byte[] result;
if (this.forEncryption)
{
result = this.Encrypt(bigInteger);
}
else
{
IList list = Platform.CreateArrayList();
NaccacheSternPrivateKeyParameters naccacheSternPrivateKeyParameters = (NaccacheSternPrivateKeyParameters)this.key;
IList smallPrimesList = naccacheSternPrivateKeyParameters.SmallPrimesList;
for (int i = 0; i < smallPrimesList.Count; i++)
{
BigInteger bigInteger2 = bigInteger.ModPow(naccacheSternPrivateKeyParameters.PhiN.Divide((BigInteger)smallPrimesList[i]), naccacheSternPrivateKeyParameters.Modulus);
IList list2 = this.lookup[i];
if (this.lookup[i].Count != ((BigInteger)smallPrimesList[i]).IntValue)
{
if (this.debug)
{
Console.WriteLine(string.Concat(new object[]
{
"Prime is ",
smallPrimesList[i],
", lookup table has size ",
list2.Count
}));
}
throw new InvalidCipherTextException(string.Concat(new object[]
{
"Error in lookup Array for ",
((BigInteger)smallPrimesList[i]).IntValue,
": Size mismatch. Expected ArrayList with length ",
((BigInteger)smallPrimesList[i]).IntValue,
" but found ArrayList of length ",
this.lookup[i].Count
}));
}
int num = list2.IndexOf(bigInteger2);
if (num == -1)
{
if (this.debug)
{
Console.WriteLine("Actual prime is " + smallPrimesList[i]);
Console.WriteLine("Decrypted value is " + bigInteger2);
Console.WriteLine(string.Concat(new object[]
{
"LookupList for ",
smallPrimesList[i],
" with size ",
this.lookup[i].Count,
" is: "
}));
for (int j = 0; j < this.lookup[i].Count; j++)
{
Console.WriteLine(this.lookup[i][j]);
}
}
throw new InvalidCipherTextException("Lookup failed");
}
list.Add(BigInteger.ValueOf((long)num));
}
BigInteger bigInteger3 = NaccacheSternEngine.chineseRemainder(list, smallPrimesList);
result = bigInteger3.ToByteArray();
}
return(result);
}
