public static byte[] EncryptData(byte[] data, byte[] key)
{
long cipherTextLength = data.Length + 16;
byte[] cipherText = new byte[cipherTextLength];
byte[] nonce = StreamEncryption.GetRandomBytes(X_NONC_ESIZE);
int result = NativeLibsodium.crypto_aead_xchacha20poly1305_ietf_encrypt(
cipherText,
out cipherTextLength,
data,
data.Length,
null, 0, null,
nonce,
key);
if (result != 0)
{
throw new EncryptionError();
}
byte[] cipherTextWithNonce = ConcatNonceAndCipherText(nonce, cipherText);
return(cipherTextWithNonce);
}
/// <summary>
/// Encrypts data with the current session key.
/// </summary>
/// <returns>The encrypted data.</returns>
/// <param name="message">Data to encrypt.</param>
public byte[] EncryptWithSessionKey(byte[] message)
{
byte[] nonce = IEncryption.ConcatBytes(StreamEncryption.GetRandomBytes(X_NONC_ESIZE - 16), BitConverter.GetBytes(DateTime.UtcNow.Ticks), BitConverter.GetBytes(sessionSendKey.index));
byte[] cipherTextWithNonce = EncryptData(message, GetCurrentSendKey(), nonce);
// ratchat forward
RatchetSendKey();
return(cipherTextWithNonce);
}