Decryption in ruby

I have a decryption doutes in ruby.

A person encrypts the data in c# language using
RSACryptoServiceProvider class.
Example RSA decryption in c# Language

Deryption Algorithm in C#

public static string DecryptData(string data2Decrypt)
byte[] getpassword = Convert.FromBase64String(data2Decrypt);
StreamReader reader = new StreamReader(@“C:\Keys\privatekey.xml”);
string publicPrivateKeyXML = reader.ReadToEnd();
//read ciphertext, decrypt it to plaintext
byte[] plain = rsa.Decrypt(getpassword, false);
return System.Text.Encoding.UTF8.GetString(plain);

How to do c# Decryption in ruby.