WG_AUTHTAG_LEN
if (encrypted_len < WG_AUTHTAG_LEN) {
decrypted_len = encrypted_len - WG_AUTHTAG_LEN;
n = wg_get_mbuf(0, decrypted_len + WG_AUTHTAG_LEN);
encrypted_len - WG_AUTHTAG_LEN /* can be 0 */,
uint8_t wgmi_static[WG_STATIC_KEY_LEN + WG_AUTHTAG_LEN];
uint8_t wgmi_timestamp[WG_TIMESTAMP_LEN + WG_AUTHTAG_LEN];
uint8_t wgmr_empty[0 + WG_AUTHTAG_LEN];
uint8_t wgmc_cookie[WG_COOKIE_LEN + WG_AUTHTAG_LEN];
encrypted_len = padded_len + WG_AUTHTAG_LEN;