/// <summary>
/// Initializes a new instance of the SessionKey class.
/// </summary>
/// <param name="keyData">Delegate that procures key data on demand, cannot be null.</param>
/// <exception cref="ArgumentNullException">The keyData argument is null.</exception>
/// <exception cref="CryptographicException">The encryption key could not be created, probably due to malformed key data.</exception>
public SessionKey(Func <string> keyData)
: this()
{
// omitting arg validation since this type in private
this.keyData = keyData;
this.algorithm = AsymmetricDataEncryptor.InstantiateAlgorithm(this.keyData);
}
/// <summary>
/// Decrypts a cipher into the original data.
/// </summary>
/// <param name="key">The key to the data to be used as entropy, cannot be null but can be empty.</param>
/// <param name="cipher">The cipher to decrypt, cannot be null but can be empty.</param>
/// <returns>The resulting data, cannot be null but can be empty.</returns>
/// <exception cref="ArgumentNullException">The key or cipher argument is null.</exception>
/// <exception cref="CryptographicException">The encryption operation failed, probably due to malformed key or key mismatch.</exception>
public byte[] Decrypt(string key, byte[] cipher)
{
if (key == null)
{
throw new ArgumentNullException("key");
}
if (cipher == null)
{
throw new ArgumentNullException("cipher", string.Format(CultureInfo.InvariantCulture, "Object cannot be null for key {0}", key));
}
using (RSACryptoServiceProvider algorithm = AsymmetricDataEncryptor.InstantiateAlgorithm(this.keyData))
{
return(AsymmetricDataEncryptor.Decrypt(algorithm, cipher));
}
}
