public static byte[] DecryptChaCha20(byte[] cipherText, byte[] nonce, byte[] key)
{
//validate the length of the key
if (key == null || key.Length != CHACHA20_KEY_BYTES)
{
throw new Exception();
}
//throw new Exception("key", (key == null) ? 0 : key.Length,
// string.Format("key must be {0} bytes in length.", CHACHA20_KEY_BYTES));
//validate the length of the nonce
if (nonce == null || nonce.Length != CHACHA20_NONCEBYTES)
{
throw new Exception();
}
//throw new Exception("nonce", (nonce == null) ? 0 : nonce.Length,
// string.Format("nonce must be {0} bytes in length.", CHACHA20_NONCEBYTES));
var buffer = new byte[cipherText.Length];
var ret = NativeLibsodium.crypto_stream_chacha20_xor(buffer, cipherText, cipherText.Length, nonce, key);
if (ret != 0)
{
throw new Exception("Error derypting message.");
}
return(buffer);
}
unsafe public static byte[] EncryptChaCha20(byte[] message, byte[] nonce, byte[] key)
{
//validate the length of the key
if (key == null || key.Length != CHACHA20_KEY_BYTES)
{
throw new Exception();
}
//throw new Exception("key", (key == null) ? 0 : key.Length,
// string.Format("key must be {0} bytes in length.", CHACHA20_KEY_BYTES));
//validate the length of the nonce
if (nonce == null || nonce.Length != CHACHA20_NONCEBYTES)
{
throw new Exception();
}
//throw new Exception("nonce", (nonce == null) ? 0 : nonce.Length,
// string.Format("nonce must be {0} bytes in length.", CHACHA20_NONCEBYTES));
byte[] buffer = new byte[message.Length];
fixed(byte *bufferPtr = buffer)
{
int ret = NativeLibsodium.crypto_stream_chacha20_xor(bufferPtr, message, (ulong)message.Length, nonce, key);
if (ret != 0)
{
throw new Exception("Error encrypting message.");
}
}
return(buffer);
}