ContextS setupAuthS(XECPublicKey pkR, byte[] info, XECPrivateKey skS) {
        var encapped = kem.authEncap(pkR, skS);
        return new ContextS(encapped.enc(),
                keySchedule(MODE_AUTH, encapped.sharedSecret(), info, DEFAULT_PSK, DEFAULT_PSK_ID));
    }
Section 5.1.3. Authentication Using an Asymmetric Key:

<pre>
def SetupAuthS(pkR, info, skS):
  shared_secret, enc = AuthEncap(pkR, skS)
  return enc, KeyScheduleS(mode_auth, shared_secret, info,
                           default_psk, default_psk_id)
</pre>
security-utils/src/main/java/com/yahoo/security/hpke/Hpke.java