gohpenc is incompatible with hpenc and much simpler:
* it uses only ChaCha20-Poly1305 algorithm
-* no random data generation mode -- just encrypt /dev/zero. Poly1305
- still be used, but it is fast enough to close eyes on it
+* no random data generation mode
* no metadata in output stream and no structure validation. Only blocks
authentication
* simpler key derivation -- new key for each block