Find the public and private keys using RSACryptoServiceProvider in c#

Question

I have the following code.

RSACryptoServiceProvider RSA = new RSACryptoServiceProvider();
//Save the public key information to an RSAParameters structure.
RSAParameters RSAKeyInfo = RSA.ExportParameters(true);

byte[] toEncryptData = Encoding.ASCII.GetBytes("hello world");
byte[] encryptedRSA = RSAEncrypt(toEncryptData, RSAKeyInfo, false);
string EncryptedResult = System.Text.Encoding.Default.GetString(encryptedRSA);

byte[] decryptedRSA = RSADecrypt(encryptedRSA, RSAKeyInfo, false);
string originalResult = System.Text.Encoding.Default.GetString(decryptedRSA);
return userDetails.ToString();

When I use the RSAEncrypt method it takes the parameter "RSAKeyInfo" (Public key for encryption and Private key for decryption).

How can I get the value of private and public keys, which this method used for encryption and decryption.

Thanks,

Answer 1

You need to use RSA.ToXmlString

Code below uses two different RSA instances with a shared string containing public and private keys. To obtain only public key, use a false parameters, true parameter will return public + private key.

class Program
{
    public static void Main(string[] args)
    {
        //Encrypt and export public and private keys
        var rsa1 = new RSACryptoServiceProvider();
        string publicPrivateXml = rsa1.ToXmlString(true);   // <<<<<<< HERE
        byte[] toEncryptData = Encoding.ASCII.GetBytes("hello world");
        byte[] encryptedRSA = rsa1.Encrypt(toEncryptData, false);
        string EncryptedResult = Encoding.Default.GetString(encryptedRSA);

        //Decrypt using exported keys
        var rsa2 = new RSACryptoServiceProvider();
        rsa2.FromXmlString(publicPrivateXml);    
        byte[] decryptedRSA = rsa2.Decrypt(encryptedRSA, false);
        string originalResult = Encoding.Default.GetString(decryptedRSA);

    }
}