public AesHmacCryptoService(CryptoConfiguration config, ISerializationProvider serializationProvider)
{
if (serializationProvider == null)
{
throw new ArgumentNullException(nameof(serializationProvider));
}
if (!IsCryptoConfigurationValid(config))
{
throw new ArgumentException("All configuration properties must be valid.", nameof(config));
}
SerializationProvider = serializationProvider;
_lazyDerivedBytes = new Lazy <KeySaltPair>(() => GenerateDerivedBytes(config));
}
private static KeySaltPair GenerateDerivedBytes(CryptoConfiguration config)
{
var saltBytes = new byte[SaltSize];
var charSizeInBytes = sizeof(char);
var characterCount = Math.Min(SaltSize / charSizeInBytes, config.InitializationVector.Length);
Encoding.UTF8.GetBytes(config.InitializationVector, 0, characterCount, saltBytes, 0);
using (var derivePassword = new Rfc2898DeriveBytes(config.SecretKey, saltBytes))
{
using (var deriveDigest = new Rfc2898DeriveBytes(config.DigestKey, saltBytes))
{
return(new KeySaltPair
{
SymmetricKey = derivePassword.GetBytes(KeySize),
Salt = derivePassword.Salt,
HashKey = deriveDigest.GetBytes(KeySize)
});
}
}
}
private static bool IsCryptoConfigurationValid(CryptoConfiguration config)
{
return(!string.IsNullOrEmpty(config.DigestKey) &&
!string.IsNullOrEmpty(config.InitializationVector) &&
!string.IsNullOrEmpty(config.SecretKey));
}
