extern bool ecdh_generate_public(ecdh_t *ecdh, void *pubkey);
extern bool ecdh_compute_shared(ecdh_t *ecdh, const void *pubkey, void *shared);
extern bool ecdh_generate_public(ecdh_t *ecdh, void *pubkey);
extern bool ecdh_compute_shared(ecdh_t *ecdh, const void *pubkey, void *shared);