Function libcryptsetup_sys::crypt_volume_key_get

pub unsafe extern "C" fn crypt_volume_key_get(
    cd: *mut crypt_device, 
    keyslot: c_int, 
    volume_key: *mut c_char, 
    volume_key_size: *mut size_t, 
    passphrase: *const c_char, 
    passphrase_size: size_t
) -> c_int