cbor_add_bytestring
if ((id->ptr && cbor_add_bytestring(item, "id", id->ptr, id->len) < 0) ||
cbor_add_bytestring(cbor_key, "id", pubkey->ptr, pubkey->len) < 0 ||
if (cbor_add_bytestring(item, "credBlob", blob->ptr,
int cbor_add_bytestring(cbor_item_t *, const char *, const unsigned char *,