private static AsymmetricCipherKeyPair GenerateKeyPair(int bits)
{
KeyGenerationParameters keyParameters = new KeyGenerationParameters(BouncyCastleRandomGenerator.CreateSecureRandom(), bits);
RsaKeyPairGenerator rsaGenerator = new RsaKeyPairGenerator();
rsaGenerator.Init(keyParameters);
AsymmetricCipherKeyPair keyPair = rsaGenerator.GenerateKeyPair();
return(keyPair);
}
public byte[] Transform(byte[] buffer)
{
if (buffer == null)
{
throw new ArgumentNullException("buffer");
}
int rsaKeyBitLength = ((RsaKeyParameters)Key).Modulus.BitLength;
IAsymmetricBlockCipher cipher = new OaepEncoding(new RsaBlindedEngine(), new BouncyCastleDigest(New <IAsymmetricFactory>().CreatePaddingHash(rsaKeyBitLength)));
cipher.Init(false, new ParametersWithRandom(Key, BouncyCastleRandomGenerator.CreateSecureRandom()));
return(TransformInternal(buffer, cipher));
}
public byte[] Transform(byte[] buffer)
{
if (buffer == null)
{
throw new ArgumentNullException("buffer");
}
int rsaKeyBitSize = ((RsaKeyParameters)Key).Modulus.BitLength;
ICryptoHash paddingHash = New <IAsymmetricFactory>().CreatePaddingHash(rsaKeyBitSize);
int requiredBits = (paddingHash.HashSize * 2 + buffer.Length + 1) * 8;
if (requiredBits > rsaKeyBitSize)
{
throw new InvalidOperationException("The RSA Key size is too small to fit the data + 1 + 2 times the padding hash size.");
}
IAsymmetricBlockCipher cipher = new OaepEncoding(new RsaBlindedEngine(), new BouncyCastleDigest(paddingHash));
cipher.Init(true, new ParametersWithRandom(Key, BouncyCastleRandomGenerator.CreateSecureRandom()));
return(TransformInternal(buffer, cipher));
}
