/// <summary>
/// Create a configuration for a stream cipher.
/// </summary>
/// <param name="cipher">Stream cipher to use.</param>
/// <param name="keySize">Key size to use, in bits.</param>
/// <returns>Stream cipher configuration DTO.</returns>
public static CipherConfiguration CreateStreamCipherConfiguration(StreamCipher cipher, int?keySize = null)
{
var config = new CipherConfiguration {
Type = CipherType.Stream
};
int keySizeNonNull = keySize ?? Athena.Cryptography.StreamCiphers[cipher].DefaultKeySizeBits;
if (keySize == null || Athena.Cryptography.StreamCiphers[cipher].AllowableKeySizesBits.Contains(keySizeNonNull))
{
config.KeySizeBits = keySizeNonNull;
}
else
{
throw new CipherKeySizeException(cipher, keySizeNonNull);
}
config.CipherName = cipher.ToString();
if (Athena.Cryptography.StreamCiphers[cipher].DefaultNonceSizeBits != -1)
{
config.InitialisationVector = new byte[Athena.Cryptography.StreamCiphers[cipher].DefaultNonceSizeBits / 8];
StratCom.EntropySupplier.NextBytes(config.InitialisationVector);
}
return(config);
}
public CipherKeySizeException(StreamCipher cipherEnum, int requestedSizeBits)
: this(cipherEnum.ToString(), requestedSizeBits, Athena.Cryptography.StreamCiphers[cipherEnum].AllowableKeySizesBits.ToList())
{
}
/// <summary>
/// Stream cipher to be used e.g. Salsa20, HC-128, etc.
/// </summary>
public void SetStreamCipher(StreamCipher value)
{
Configuration.CipherName = value.ToString();
}