use std::io::{Read, Seek, Write};
pub struct XoredStream<T> {
reader: T,
key: u8,
}
impl<T> XoredStream<T> {
pub fn new(reader: T, key: u8) -> Self {
XoredStream { reader, key }
}
}
impl<T: Read> Read for XoredStream<T> {
fn read(&mut self, buf: &mut [u8]) -> std::io::Result<usize> {
let read_bytes = self.reader.read(buf)?;
for byte in &mut buf[..read_bytes] {
*byte ^= self.key;
}
Ok(read_bytes)
}
}
impl<T: Seek> Seek for XoredStream<T> {
fn seek(&mut self, pos: std::io::SeekFrom) -> std::io::Result<u64> {
self.reader.seek(pos)
}
fn rewind(&mut self) -> std::io::Result<()> {
self.reader.rewind()
}
fn stream_position(&mut self) -> std::io::Result<u64> {
self.reader.stream_position()
}
}
impl<T: Write> Write for XoredStream<T> {
fn write(&mut self, buf: &[u8]) -> std::io::Result<usize> {
let mut encrypted_buf = buf.to_vec();
for byte in &mut encrypted_buf {
*byte ^= self.key;
}
self.reader.write(&encrypted_buf)
}
fn flush(&mut self) -> std::io::Result<()> {
self.reader.flush()
}
}
impl<T: std::fmt::Debug> std::fmt::Debug for XoredStream<T> {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
f.debug_struct("XoredStream")
.field("reader", &self.reader)
.field("key", &self.key)
.finish()
}
}
pub struct XoredKeyStream<T> {
inner: T,
key: Vec<u8>,
base_position: u64,
}
impl<T> XoredKeyStream<T> {
pub fn new(inner: T, key: Vec<u8>, base_position: u64) -> Self {
XoredKeyStream {
inner,
key,
base_position,
}
}
}
impl<T: Read + Seek> Read for XoredKeyStream<T> {
fn read(&mut self, buf: &mut [u8]) -> std::io::Result<usize> {
let key_len = self.key.len();
let start_pos =
((self.inner.stream_position()? + self.base_position) % (key_len as u64)) as usize;
let readed = self.inner.read(buf)?;
for i in 0..readed {
buf[i] ^= self.key[(start_pos + i) % key_len];
}
Ok(readed)
}
}
impl<T: Seek> Seek for XoredKeyStream<T> {
fn seek(&mut self, pos: std::io::SeekFrom) -> std::io::Result<u64> {
self.inner.seek(pos)
}
fn rewind(&mut self) -> std::io::Result<()> {
self.inner.rewind()
}
fn stream_position(&mut self) -> std::io::Result<u64> {
self.inner.stream_position()
}
}
impl<T: Write + Seek> Write for XoredKeyStream<T> {
fn write(&mut self, buf: &[u8]) -> std::io::Result<usize> {
let key_len = self.key.len();
let start_pos =
((self.inner.stream_position()? + self.base_position) % (key_len as u64)) as usize;
let mut encrypted_buf = buf.to_vec();
for i in 0..buf.len() {
encrypted_buf[i] ^= self.key[(start_pos + i) % key_len];
}
self.inner.write(&encrypted_buf)
}
fn flush(&mut self) -> std::io::Result<()> {
self.inner.flush()
}
}
impl<T: std::fmt::Debug> std::fmt::Debug for XoredKeyStream<T> {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
f.debug_struct("XoredKeyStream")
.field("inner", &self.inner)
.field("base_position", &self.base_position)
.finish()
}
}