/// <summary>
/// Updates the specified <see cref="UpdateNonceType"/> with the specified nonce.
/// </summary>
/// <param name="nonce">Nonce to use for the update.</param>
/// <param name="nonceType">Nonce type to update.</param>
/// <exception cref="ArgumentNullException"><paramref name="nonce"/> is null.</exception>
/// <exception cref="ArgumentOutOfRangeException"><paramref name="nonce"/> length is not 24.</exception>
public void UpdateNonce(byte[] nonce, UpdateNonceType nonceType)
{
if (_cryptoState == CryptoState.SecoundKey)
{
throw new InvalidOperationException("Cannot update nonce after updated with shared key 'k'.");
}
if (nonce == null)
{
throw new ArgumentNullException(nameof(nonce));
}
if (nonce.Length != 24)
{
throw new ArgumentOutOfRangeException(nameof(nonce), "nonce must be 24 bytes in length.");
}
switch (nonceType)
{
case UpdateNonceType.Blake:
if (_cryptoState == CryptoState.InitialKey)
{
if (Direction == MessageDirection.Client) // order of keys is important. we're the server
{
_blake2bNonce = GenerateBlake2BNonce(nonce, _sharedKey, _keyPair.PublicKey);
}
else // we're the client
{
_blake2bNonce = GenerateBlake2BNonce(nonce, _keyPair.PublicKey, _sharedKey);
}
_cryptoState = CryptoState.BlakeNonce; // use blake nonce
}
break;
case UpdateNonceType.Decrypt:
_decryptNonce = nonce;
break;
case UpdateNonceType.Encrypt:
_encryptNonce = nonce;
break;
default:
throw new ArgumentException("Unexpected NonceType: " + nonceType, "nonceType");
}
}
/// <summary>
/// Updates the specified <see cref="UpdateNonceType"/> with the specified nonce.
/// </summary>
/// <param name="nonce">Nonce to use for the update.</param>
/// <param name="nonceType">Nonce type to update.</param>
/// <exception cref="ArgumentNullException"><paramref name="nonce"/> is null.</exception>
/// <exception cref="ArgumentOutOfRangeException"><paramref name="nonce"/> length is not 24.</exception>
public void UpdateNonce(byte[] nonce, UpdateNonceType nonceType)
{
if (_cryptoState == CryptoState.SecoundKey) // can only be updated twice
throw new InvalidOperationException("Cannot update nonce after updated with shared key 'k'.");
if (nonce == null)
throw new ArgumentNullException("nonce");
if (nonce.Length != CoCKeyPair.NonceLength)
throw new ArgumentOutOfRangeException("nonce", "nonce must be 24 bytes in length.");
switch (nonceType)
{
case UpdateNonceType.Blake:
if (_cryptoState == CryptoState.InitialKey)
{
if (Direction == MessageDirection.Client) // order of keys is important. we're the server
_blake2bNonce = GenerateBlake2BNonce(nonce, _sharedKey, _keyPair.PublicKey);
else // we're the client
_blake2bNonce = GenerateBlake2BNonce(nonce, _keyPair.PublicKey, _sharedKey);
_cryptoState = CryptoState.BlakeNonce; // use blake nonce
}
break;
case UpdateNonceType.Decrypt:
_decryptNonce = nonce;
break;
case UpdateNonceType.Encrypt:
_encryptNonce = nonce;
break;
default:
throw new ArgumentException("Unexpected NonceType: " + nonceType, "nonceType");
}
}