OSSL_HPKE_MAX_PRIVATE
unsigned char privbuf[OSSL_HPKE_MAX_PRIVATE];
unsigned char tmpbuf[OSSL_HPKE_MAX_PRIVATE];
unsigned char dhkm[OSSL_HPKE_MAX_PRIVATE * 2];
unsigned char tmpbuf[OSSL_HPKE_MAX_PRIVATE];