/// <summary>Encrypt a string using a symmetric key algorithm where the key and IV are randomly generated.</summary>
/// <param name="plainText">The string to encrypt</param>
/// <param name="keySize">The key size to use</param>
public CipherMessage Encrypt(string plainText, int keySize)
{
if (String.IsNullOrWhiteSpace(plainText))
{
throw new ArgumentNullException(nameof(plainText));
}
// validate and set the key size
try
{
this._algo.KeySize = keySize;
}
catch (CryptographicException)
{
this._algo.KeySize = this._algo.LegalKeySizes[0].MinSize;
}
// make a IV and key
this._algo.GenerateIV();
this._algo.GenerateKey();
CipherMessage msg = new CipherMessage();
msg.IV = this._algo.IV;
msg.Key = this._algo.Key;
msg.CipherBytes = this.Encrypt(plainText, this._algo.Key, this._algo.IV);
return(msg);
}
/// <summary>Encrypt JUST plain bytes with some key</summary>
/// <param name="data"></param>
/// <param name="key"></param>
/// <returns></returns>
public CipherMessage Encrypt(byte[] data, byte[] key)
{
// validate arguments
if (data == null || data.Length < 1)
{
throw new System.ArgumentNullException(nameof(data));
}
// need better validation of the key size
if (key == null || key.Length < 1)
{
throw new System.ArgumentNullException(nameof(key));
}
// setup the algorithm
this.Algorithm.Mode = CipherMode.CBC;
//this.Algorithm.KeySize = 128;
//this.Algorithm.BlockSize = 128;
//this.Algorithm.FeedbackSize = 128;
//this.Algorithm.Padding = PaddingMode.Zeros;
this.Algorithm.GenerateIV();
this.Algorithm.Key = key;
CipherMessage results = new CipherMessage();
// create an encryptor
ICryptoTransform encryptor = this.Algorithm.CreateEncryptor(this.Algorithm.Key, this.Algorithm.IV);
using (var ms = new MemoryStream())
using (var cs = new CryptoStream(ms, encryptor, CryptoStreamMode.Write))
{
cs.Write(data, 0, data.Length);
cs.FlushFinalBlock();
results.CipherBytes = ms.ToArray();
}
results.IV = this.Algorithm.IV;
return(results);
}
/// <summary>Encrypt JUST plain bytes with some key</summary>
/// <param name="data"></param>
/// <param name="key"></param>
/// <returns></returns>
public CipherMessage Encrypt(byte[] data, byte[] key)
{
// validate arguments
if (data == null || data.Length < 1)
{
throw new System.ArgumentNullException(nameof(data));
}
// validation of the key
if (!IsKeySizeValid(key, this.KeySizes[0]))
{
throw new System.ArgumentNullException(nameof(key));
}
// setup the algorithm
this.Algorithm.GenerateIV();
this.Algorithm.Key = key;
CipherMessage results = new CipherMessage()
{
IV = this.Algorithm.IV,
};
try
{
// create an encryptor
ICryptoTransform encryptor = this.Algorithm.CreateEncryptor(this.Algorithm.Key, this.Algorithm.IV);
// decrypt
results.CipherBytes = this.DoCrypto(data, encryptor);
}
catch (System.Exception)
{
throw;
}
return(results);
}
/// <summary>Encrypt plain text with a known key but generate an IV</summary>
/// <param name="plainText">text to encrypt</param>
/// <param name="key">encryption key to use</param>
/// <returns>Encrypted bytes and the IV generated</returns>
public CipherMessage Encrypt(string plainText, byte[] key)
{
// validate arguments
if (String.IsNullOrWhiteSpace(plainText))
{
throw new System.ArgumentNullException(nameof(plainText));
}
if (key == null || key.Length < 1)
{
throw new System.ArgumentNullException(nameof(key));
}
CipherMessage results = new CipherMessage();
// generate an IV
this._algo.GenerateIV();
results.IV = this._algo.IV;
results.Key = key;
results.CipherBytes = this.Encrypt(plainText, results.Key, results.IV);
return(results);
}
/// <summary>Decrypt cipter text using a symmetric key algorithm.</summary>
public string Decrypt(CipherMessage msg)
{
return(this.Decrypt(msg.CipherBytes, msg.Key, msg.IV));
}
