与充气城堡签名时的PKCS1填充

Question

我有以下c＃Bouncy Castle代码，可使用RSA / SHA512在C＃中对某些数据进行签名。有谁能告诉我如何在此过程中应用Pkcs1填充？

using (var txtreader = new StringReader(File.ReadAllText(_certificatePath)))

{

    var keyPair = (AsymmetricCipherKeyPair)new PemReader(txtreader).ReadObject();

    var key = keyPair.Private as RsaPrivateCrtKeyParameters;

    ISigner sig = SignerUtilities.GetSigner("SHA512withRSA");

    sig.Init(true, key);

    sig.BlockUpdate(requestToSign, 0, requestToSign.Length);

    byte[] signature = sig.GenerateSignature();

}