proxmox-backup/src/backup/crypt_writer.rs

65 lines
1.8 KiB
Rust

use failure::*;
use std::sync::Arc;
use std::io::Write;
use super::CryptConfig;
pub struct CryptWriter<W> {
writer: W,
block_size: usize,
encr_buf: Box<[u8; 64*1024]>,
iv: [u8; 16],
crypter: openssl::symm::Crypter,
}
impl <W: Write> CryptWriter<W> {
pub fn new(writer: W, config: Arc<CryptConfig>) -> Result<Self, Error> {
let mut iv = [0u8; 16];
proxmox::sys::linux::fill_with_random_data(&mut iv)?;
let block_size = config.cipher().block_size();
let crypter = config.data_crypter(&iv, openssl::symm::Mode::Encrypt)?;
Ok(Self { writer, iv, crypter, block_size, encr_buf: Box::new([0u8; 64*1024]) })
}
pub fn finish(mut self) -> Result<(W, [u8; 16], [u8; 16]), Error> {
let rest = self.crypter.finalize(self.encr_buf.as_mut())?;
if rest > 0 {
self.writer.write_all(&self.encr_buf[..rest])?;
}
self.writer.flush()?;
let mut tag = [0u8; 16];
self.crypter.get_tag(&mut tag)?;
Ok((self.writer, self.iv, tag))
}
}
impl <W: Write> Write for CryptWriter<W> {
fn write(&mut self, buf: &[u8]) -> Result<usize, std::io::Error> {
let mut write_size = buf.len();
if write_size > (self.encr_buf.len() - self.block_size) {
write_size = self.encr_buf.len() - self.block_size;
}
let count = self.crypter.update(&buf[..write_size], self.encr_buf.as_mut())
.map_err(|err| {
std::io::Error::new(
std::io::ErrorKind::Other,
format!("crypter update failed - {}", err))
})?;
self.writer.write_all(&self.encr_buf[..count])?;
Ok(write_size)
}
fn flush(&mut self) -> Result<(), std::io::Error> {
Ok(())
}
}