ContextR setupBaseR(byte[] enc, XECPrivateKey skR, byte[] info) {
        byte[] sharedSecret = kem.decap(enc, skR);
        return new ContextR(keySchedule(MODE_BASE, sharedSecret, info, DEFAULT_PSK, DEFAULT_PSK_ID));
    }
Section 5.1.1 Encryption to a Public Key:

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