public static ReadOnlyMemory <byte> Decrypt(ReadOnlyMemory <byte> payload, CryptoContext cryptoContext)
{
IBufferedCipher cipher = cryptoContext.Decryptor;
ReadOnlyMemory <byte> clear = cipher.ProcessBytes(payload.ToArray());
//TODO: Verify hash!
return(clear.Slice(0, clear.Length - 8));
}
public static byte[] Decrypt(byte[] payload, CryptoContext cryptoContext)
{
IBufferedCipher cipher = cryptoContext.Decryptor;
byte[] clear = cipher.ProcessBytes(payload);
//TODO: Verify hash!
return(clear.AsSpan(0, clear.Length - 8).ToArray());
}
public static byte[] Encrypt(ReadOnlyMemory <byte> payload, CryptoContext cryptoContext)
{
// hash
int hashPoolLen = 8 + payload.Length + cryptoContext.Key.Length;
var hashBufferPooled = ArrayPool <byte> .Shared.Rent(hashPoolLen);
Span <byte> hashBuffer = hashBufferPooled.AsSpan();
BitConverter.GetBytes(Interlocked.Increment(ref cryptoContext.SendCounter)).CopyTo(hashBuffer.Slice(0, 8));
payload.Span.CopyTo(hashBuffer.Slice(8));
cryptoContext.Key.CopyTo(hashBuffer.Slice(8 + payload.Length));
using var hasher = new SHA256Managed();
Span <byte> validationCheckSum = hasher.ComputeHash(hashBufferPooled, 0, hashPoolLen).AsSpan(0, 8);
ArrayPool <byte> .Shared.Return(hashBufferPooled);
IBufferedCipher cipher = cryptoContext.Encryptor;
var encrypted = new byte[payload.Length + 8];
int length = cipher.ProcessBytes(payload.ToArray(), encrypted, 0);
cipher.ProcessBytes(validationCheckSum.ToArray(), encrypted, length);
return(encrypted);
}
