ContextR setupAuthR(byte[] enc, XECPrivateKey skR, byte[] info, XECPublicKey pkS) {
        byte[] sharedSecret = kem.authDecap(enc, skR, pkS);
        return new ContextR(keySchedule(MODE_AUTH, sharedSecret, info, DEFAULT_PSK, DEFAULT_PSK_ID));
    }
Section 5.1.3. Authentication Using an Asymmetric Key:

<pre>
def SetupAuthR(enc, skR, info, pkS):
  shared_secret = AuthDecap(enc, skR, pkS)
  return KeyScheduleR(mode_auth, shared_secret, info,
                      default_psk, default_psk_id)
</pre>
security-utils/src/main/java/com/yahoo/security/hpke/Hpke.java