C# RSA with no padding

Question

I\'m busy trying to port Java code that looks like this

        Cipher rsa = Cipher.getInstance(\"RSA/ECB/nopadding\");
        rsa.init(Cipher.DECRYPT_MODE, RSA         


        

Answer 1

BouncyCastle will help us to make nopadding RSA encryption.

public string RsaEncryptWithPublic(string clearText, string publicKey)
    {
        //  analogue of Java:
        //  Cipher rsa = Cipher.getInstance("RSA/ECB/nopadding");
        try
        {
            var bytesToEncrypt = Encoding.ASCII.GetBytes(clearText);

            var encryptEngine = new RsaEngine(); // new Pkcs1Encoding (new RsaEngine());


            using (var txtreader = new StringReader("-----BEGIN PUBLIC KEY-----\n" + publicKey+ "\n-----END PUBLIC KEY-----"))
            {
                var keyParameter = (AsymmetricKeyParameter)new PemReader(txtreader).ReadObject();

                encryptEngine.Init(true, keyParameter);
            }

            var encrypted = Convert.ToBase64String(encryptEngine.ProcessBlock(bytesToEncrypt, 0, bytesToEncrypt.Length));
            return encrypted;
        }
        catch 
        {

            return "";
        }
    }

also dont forget to put it at top:

using Org.BouncyCastle.Crypto;
using Org.BouncyCastle.Crypto.Engines;
using Org.BouncyCastle.OpenSsl;