ecdsa_t mykey, hiskey;
-static bool send_data(void *handle, const char *data, size_t len) {
+static bool send_data(void *handle, uint8_t type, const char *data, size_t len) {
char hex[len * 2 + 1];
bin2hex(data, hex, len);
fprintf(stderr, "Sending %d bytes of data:\n%s\n", (int)len, hex);