internal static unsafe extern int crypto_aead_chacha20poly1305_ietf_encrypt( byte *c, out ulong clen_p, byte *m, ulong mlen, byte *ad, ulong adlen, byte *nsec, Nonce12 *npub, byte *k);
internal static unsafe extern int crypto_aead_aes256gcm_encrypt( byte *c, out ulong clen_p, byte *m, ulong mlen, byte *ad, ulong adlen, byte *nsec, Nonce12 *npub, byte *k);