openethereum/util/mem/src/lib.rs
Toralf Wittner 41348dead4 Add type for passwords. (#8920)
* Add type for passwords.

* Fix test.

* Simplify `Drop` impls of `Password` and `Memzero`.

* Spaces to tabs.

* Custom `Drop` impl for `Password`.
2018-06-22 15:09:15 +02:00

55 lines
1.4 KiB
Rust

// Copyright 2015-2018 Parity Technologies (UK) Ltd.
// This file is part of Parity.
// Parity is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// Parity is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with Parity. If not, see <http://www.gnu.org/licenses/>.
use std::ops::{Deref, DerefMut};
use std::ptr;
/// Wrapper to zero out memory when dropped.
#[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
pub struct Memzero<T: AsMut<[u8]>> {
mem: T,
}
impl<T: AsMut<[u8]>> From<T> for Memzero<T> {
fn from(mem: T) -> Memzero<T> {
Memzero { mem }
}
}
impl<T: AsMut<[u8]>> Drop for Memzero<T> {
fn drop(&mut self) {
unsafe {
for byte_ref in self.mem.as_mut() {
ptr::write_volatile(byte_ref, 0)
}
}
}
}
impl<T: AsMut<[u8]>> Deref for Memzero<T> {
type Target = T;
fn deref(&self) -> &Self::Target {
&self.mem
}
}
impl<T: AsMut<[u8]>> DerefMut for Memzero<T> {
fn deref_mut(&mut self) -> &mut Self::Target {
&mut self.mem
}
}