pub unsafe extern "C" fn crypt_benchmark_pbkdf(
    cd: *mut crypt_device,
    pbkdf: *mut crypt_pbkdf_type,
    password: *const c_char,
    password_size: usize,
    salt: *const c_char,
    salt_size: usize,
    volume_key_size: usize,
    progress: Option<unsafe extern "C" fn(time_ms: u32, usrptr: *mut c_void) -> c_int>,
    usrptr: *mut c_void
) -> c_int