using System;

using System.Text;

using Org.BouncyCastle.Crypto;

using Org.BouncyCastle.Crypto.Parameters;

using Org.BouncyCastle.Security;

​

public class Program

{

    public static void Main()

    {

        Console.WriteLine($"SHA1withRSA:{Sign("Test WS", "67AA44E9BD7A73D006EF8C9A929FD00FE38AE417747DCC348AAB135D55B640E431BCB41EE24946E40BA60D2CD7C21B03A8D2E61493267518FBE31CAFD5601E67", "CBF78385216C61EFDA09FAD16D17AE8A7B09B2AF5BC6A81C2AAFC7456090F8CB11545153DA7FF5D0B73FB1531ADC6D745F1C7B0BE57D8CD791AC82816E03A22D", "SHA1withRSA")}");

        Console.WriteLine($"SHA1withRSAandMGF1:{Sign("Test WS", "67AA44E9BD7A73D006EF8C9A929FD00FE38AE417747DCC348AAB135D55B640E431BCB41EE24946E40BA60D2CD7C21B03A8D2E61493267518FBE31CAFD5601E67", "CBF78385216C61EFDA09FAD16D17AE8A7B09B2AF5BC6A81C2AAFC7456090F8CB11545153DA7FF5D0B73FB1531ADC6D745F1C7B0BE57D8CD791AC82816E03A22D", "SHA1withRSAandMGF1")}");

        Console.WriteLine($"SHA1withRSA/ISO9796-2:{Sign("Test WS", "67AA44E9BD7A73D006EF8C9A929FD00FE38AE417747DCC348AAB135D55B640E431BCB41EE24946E40BA60D2CD7C21B03A8D2E61493267518FBE31CAFD5601E67", "CBF78385216C61EFDA09FAD16D17AE8A7B09B2AF5BC6A81C2AAFC7456090F8CB11545153DA7FF5D0B73FB1531ADC6D745F1C7B0BE57D8CD791AC82816E03A22D", "SHA1withRSA/ISO9796-2")}");

        //Console.WriteLine($"SHA1withRSA/X9.31:{Sign("Test WS", "67AA44E9BD7A73D006EF8C9A929FD00FE38AE417747DCC348AAB135D55B640E431BCB41EE24946E40BA60D2CD7C21B03A8D2E61493267518FBE31CAFD5601E67", "CBF78385216C61EFDA09FAD16D17AE8A7B09B2AF5BC6A81C2AAFC7456090F8CB11545153DA7FF5D0B73FB1531ADC6D745F1C7B0BE57D8CD791AC82816E03A22D", "SHA1withRSA/X9.31")}");

    }

​

    private static RsaKeyParameters MakeKey(String modulusHexString, String exponentHexString, bool isPrivateKey)

    {

        var modulus = new Org.BouncyCastle.Math.BigInteger(modulusHexString, 16);

        var exponent = new Org.BouncyCastle.Math.BigInteger(exponentHexString, 16);

​

        return new RsaKeyParameters(isPrivateKey, modulus, exponent);

    }

​

    public static String Sign(String data, String privateModulusHexString, String privateExponentHexString, string algorithm)

    {

        /* Make the key */

        RsaKeyParameters key = MakeKey(privateModulusHexString, privateExponentHexString, true);

​

        /* Init alg */

        ISigner sig = SignerUtilities.GetSigner(algorithm);

​

        /* Populate key */

        sig.Init(true, key);

​

        /* Get the bytes to be signed from the string */

        var bytes = Encoding.ASCII.GetBytes(data);

​

        /* Calc the signature */

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

        byte[] signature = sig.GenerateSignature();

​

        return ByteArrayToString(signature);

    }

​

    public static string ByteArrayToString(byte[] ba)

    {

        StringBuilder hex = new StringBuilder(ba.Length * 2);

        foreach (byte b in ba)

            hex.AppendFormat("{0:X2}", b);

        return hex.ToString();

    }

}