/// <summary>
/// Create new Datahasher with given algorithm
/// </summary>
/// <param name="algorithm">Hash algorithm</param>
public DataHasher(HashAlgorithm algorithm)
{
if (algorithm == null)
{
throw new ArgumentNullException(nameof(algorithm));
}
_algorithm = algorithm;
_digester = DigestProvider.GetDigest(algorithm);
}
/// <summary>
/// Calculate HMAC for data with given key.
/// </summary>
/// <param name="key">HMAC key</param>
/// <param name="data">data to calculate HMAC from</param>
/// <returns>HMAC data hash</returns>
public DataHash GetHash(byte[] key, byte[] data)
{
if (data == null)
{
throw new ArgumentNullException(nameof(data));
}
if (key == null)
{
throw new ArgumentNullException(nameof(key));
}
HMac hMac = new HMac(DigestProvider.GetDigest(_algorithm));
hMac.Init(new KeyParameter(key));
hMac.BlockUpdate(data, 0, data.Length);
byte[] value = new byte[_algorithm.Length];
hMac.DoFinal(value, 0);
return(new DataHash(_algorithm, value));
}