cbor_add_string
if ((rp->id && cbor_add_string(item, "id", rp->id) < 0) ||
(rp->name && cbor_add_string(item, "name", rp->name) < 0)) {
(user->icon && cbor_add_string(item, "icon", user->icon) < 0) ||
(user->name && cbor_add_string(item, "name", user->name) < 0) ||
(display && cbor_add_string(item, "displayName", display) < 0)) {
cbor_add_string(body, "type", "public-key") < 0 ||
cbor_add_string(cbor_key, "type", "public-key") < 0) {
int cbor_add_string(cbor_item_t *, const char *, const char *);