Simple C# RSA Encryption Class

Well, you can figure this out yourself, use it if you like, tell me how much it sucks, what ever you want.

What it does is takes data and encrypts it using DES encryption and then encrypts the DES Keys using RSA and stores everything in an XML string to be saved for later decryption. There are also classes to hold the encrypted data and to create and save the RSA keys. This seems to be a pretty good solution for encrypting data or files.

I wrote this code and am now posting it because I did not find any simple snippets on the web for encrypting data in C#. Everything seemed too complicated or was not robust enough. I am sure that many people may have problems with this code or the lack of explaination in the code, but oh well... Its here for those who want to look it over. Remember, use at your own risk!

Code:
using System; using System.Xml; using System.Security.Cryptography; using System.Text; using System.IO; namespace SimpleEncryption { public class Crypto { private RSACryptoServiceProvider rsa; /// Loads the new object using an xml string that contains the key info public Crypto(string keyXml) { rsa = new RSACryptoServiceProvider(); rsa.FromXmlString(keyXml); } /// Loads the new object using an xml string or file that contains the key info /// loadFromFile: true if keyXmlOrFilePath is a path to an xml file with the key info public Crypto(string keyXmlOrFilePath, bool loadFromFile) { rsa = new RSACryptoServiceProvider(1024); if(loadFromFile) { TextReader reader = File.OpenText(keyXmlOrFilePath); rsa.FromXmlString(reader.ReadToEnd()); reader.Close(); } else { rsa.FromXmlString(keyXmlOrFilePath); } } /// Encrypts the data using DES with A new IV and Key, then encrypts /// the IV and Key with RSA encryption. public EncryptedDataInfo Encrypt(string data) { string encIV; string encKey; string encData; ICryptoTransform encryptor; CryptoStream cStream; MemoryStream mStream = new MemoryStream(); try { DESCryptoServiceProvider des = new DESCryptoServiceProvider(); des.GenerateIV(); des.GenerateKey(); encIV = Convert.ToBase64String(rsa.Encrypt(des.IV, false)); encKey = Convert.ToBase64String(rsa.Encrypt(des.Key, false)); encryptor = des.CreateEncryptor(des.Key, des.IV); cStream = new CryptoStream(mStream, encryptor, CryptoStreamMode.Write); byte[] bytesIn = Encoding.ASCII.GetBytes(data); cStream.Write(bytesIn, 0, bytesIn.Length); cStream.FlushFinalBlock(); cStream.Close(); byte[] bytesOut = mStream.ToArray(); mStream.Close(); encData = Convert.ToBase64String(bytesOut); return new EncryptedDataInfo(encData, encIV, encKey); } catch(Exception ex) { mStream.Close(); throw ex; } } /// Decrypts data from a xml representation of an EncryptedDataInfo object public string Decrypt(string encryptedDataInfoXml) { return Decrypt(new EncryptedDataInfo(encryptedDataInfoXml)); } /// Decrypts data from an EncryptedDataInfo object public string Decrypt(EncryptedDataInfo encryptedDataInfo) { return Decrypt(encryptedDataInfo.EncryptedData, encryptedDataInfo.EncryptedKey, encryptedDataInfo.EncryptedIV); } /// Decrypts the Key and IV using RSA and then decrypts the data using DES public string Decrypt(string encryptedData, string encryptedKey, string encryptedIV) { string returnValue; byte[] iv = rsa.Decrypt(Convert.FromBase64String(encryptedIV), false); byte[] key = rsa.Decrypt(Convert.FromBase64String(encryptedKey), false); byte[] data = Convert.FromBase64String(encryptedData); MemoryStream mStream = new MemoryStream(data); DESCryptoServiceProvider des = new DESCryptoServiceProvider(); ICryptoTransform decryptor = des.CreateDecryptor(key, iv); CryptoStream cStream = new CryptoStream(mStream, decryptor, CryptoStreamMode.Read); StreamReader reader = new StreamReader(cStream); returnValue = reader.ReadToEnd(); reader.Close(); mStream.Close(); cStream.Close(); return returnValue; } // Crypto /// Container for encrypted data public class EncryptedDataInfo { private string encData; private string encIV; private string encKey; public EncryptedDataInfo(string encryptedData, string encryptedIV, string encryptedKey) { encData = encryptedData; encIV = encryptedIV; encKey = encryptedKey; } public EncryptedDataInfo(string encryptedDataInfoXml) { XmlDocument xml = new XmlDocument(); xml.LoadXml(encryptedDataInfoXml); encData = xml.SelectSingleNode(@"/EncryptedDataInfo/EncryptedData").InnerText; encIV = xml.SelectSingleNode(@"/EncryptedDataInfo/EncryptedIV").InnerText; encKey = xml.SelectSingleNode(@"/EncryptedDataInfo/EncryptedKey").InnerText; } public string ToXml() { XmlDocument xml = new XmlDocument(); XmlElement root = xml.CreateElement("EncryptedDataInfo"); XmlElement data = xml.CreateElement("EncryptedData"); XmlElement iv = xml.CreateElement("EncryptedIV"); XmlElement key = xml.CreateElement("EncryptedKey"); data.InnerText = encData; iv.InnerText = encIV; key.InnerText = encKey; root.AppendChild((XmlNode)data); root.AppendChild((XmlNode)iv); root.AppendChild((XmlNode)key); xml.AppendChild((XmlNode)root); return xml.OuterXml; } public override string ToString() { return ToXml(); } public string EncryptedData { get { return encData; } } public string EncryptedIV { get { return encIV; } } public string EncryptedKey { get { return encKey; } } } //EncryptedDataInfo /// Used to create and save new keys public class RSAKeyCreator { private string publicKeyXml; private string privateKeyXml; public RSAKeyCreator() { RSACryptoServiceProvider rsa = new RSACryptoServiceProvider(1024); publicKeyXml = rsa.ToXmlString(false); privateKeyXml = rsa.ToXmlString(true); } public RSAKeyCreator(int keySize) { RSACryptoServiceProvider rsa = new RSACryptoServiceProvider(keySize); publicKeyXml = rsa.ToXmlString(false); privateKeyXml = rsa.ToXmlString(true); } public void SavePublicKeyToFile(string filePath) { TextWriter writer = File.CreateText(filePath); writer.Write(publicKeyXml); writer.Flush(); writer.Close(); } public void SavePrivateKeyToFile(string filePath) { TextWriter writer = File.CreateText(filePath); writer.Write(privateKeyXml); writer.Flush(); writer.Close(); } public string PublicKeyXml { get { return publicKeyXml; } } public string PrivateKeyXml { get { return privateKeyXml; } } } // RSAKeyCreator } }