Summary A .NET C# class for data encryption/decrytion

Additional information

using System; using System.Security.Cryptography; using System.IO; using System.Text; namespace FangHome_Crypto { /// <summary> /// SymmCrypto is a wrapper of System.Security.Cryptography.SymmetricAlgorithm classes /// and simplifies the interface. It supports customized SymmetricAlgorithm as well. /// </summary> public class SymmCrypto { /// <remarks> /// Supported .Net intrinsic SymmetricAlgorithm classes. /// </remarks> public enum SymmProvEnum : int { DES, RC2, Rijndael } private SymmetricAlgorithm mobjCryptoService; /// <remarks> /// Constructor for using an intrinsic .Net SymmetricAlgorithm class. /// </remarks> public SymmCrypto(SymmProvEnum NetSelected) { switch (NetSelected) { case SymmProvEnum.DES: mobjCryptoService = new DESCryptoServiceProvider(); break; case SymmProvEnum.RC2: mobjCryptoService = new RC2CryptoServiceProvider(); break; case SymmProvEnum.Rijndael: mobjCryptoService = new RijndaelManaged(); break; } } /// <remarks> /// Constructor for using a customized SymmetricAlgorithm class. /// </remarks> public SymmCrypto(SymmetricAlgorithm ServiceProvider) { mobjCryptoService = ServiceProvider; } private byte[~ GetLegalKey(string Key) { string sTemp = Key; mobjCryptoService.GenerateKey(); byte[~ bytTemp = mobjCryptoService.Key; int KeyLength = bytTemp.Length; if (sTemp.Length > KeyLength) sTemp = sTemp.Substring(0, KeyLength); else if (sTemp.Length < KeyLength) sTemp = sTemp.PadRight(KeyLength, ' '); return ASCIIEncoding.ASCII.GetBytes(sTemp); } private byte[~ GetLegalIV() { // The initial string of IV may be modified with any data you like string sTemp = "¾ÈÒÜæ§üéâ»"; mobjCryptoService.GenerateIV(); byte[~ bytTemp = mobjCryptoService.IV; int IVLength = bytTemp.Length; if (sTemp.Length > IVLength) sTemp = sTemp.Substring(0, IVLength); else if (sTemp.Length < IVLength) sTemp = sTemp.PadRight(IVLength, ' '); return ASCIIEncoding.ASCII.GetBytes(sTemp); } public string Encrypting(string Source, string Key) { // use UTF8 unicode conversion for two byte characters byte[~ bytIn = UTF8Encoding.UTF8.GetBytes(Source); // create a MemoryStream so that the process can be done without I/O files System.IO.MemoryStream ms = new System.IO.MemoryStream(); // set the private key mobjCryptoService.Key = GetLegalKey(Key); mobjCryptoService.IV = GetLegalIV(); // create an Encryptor from the Provider Service instance ICryptoTransform encrypto = mobjCryptoService.CreateEncryptor(); // create Crypto Stream that transforms a stream using the encryption CryptoStream cs = new CryptoStream(ms, encrypto, CryptoStreamMode.Write); // write out encrypted content into MemoryStream cs.Write(bytIn, 0, bytIn.Length); cs.FlushFinalBlock(); ms.Close(); byte[~ bytOut = ms.ToArray(); // convert into Base64 so that the result can be used in xml return System.Convert.ToBase64String(bytOut); } public string Decrypting(string Source, string Key) { // convert from Base64 to binary byte[~ bytIn = System.Convert.FromBase64String(Source); // create a MemoryStream with the input System.IO.MemoryStream ms = new System.IO.MemoryStream(bytIn, 0, bytIn.Length); // set the private key mobjCryptoService.Key = GetLegalKey(Key); mobjCryptoService.IV = GetLegalIV(); // create a Decryptor from the Provider Service instance ICryptoTransform encrypto = mobjCryptoService.CreateDecryptor(); // create Crypto Stream that transforms a stream using the decryption CryptoStream cs = new CryptoStream(ms, encrypto, CryptoStreamMode.Read); // read out the result from the Crypto Stream System.IO.StreamReader sr = new System.IO.StreamReader( cs ); return sr.ReadToEnd(); } } }