You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
201 lines
5.7 KiB
201 lines
5.7 KiB
//! Asyncronous `AsyncWrite` wrapper.
|
|
use super::*;
|
|
|
|
/// Async ChaCha Sink
|
|
///
|
|
/// # Encryption
|
|
/// To create an encrypting wrapper stream:
|
|
/// ```
|
|
/// # use chacha20stream::AsyncSink;
|
|
/// # use tokio::prelude::*;
|
|
/// # let (key, iv) = chacha20stream::keygen();
|
|
/// # let mut backing_stream = Vec::new();
|
|
/// # async move {
|
|
/// let mut stream = AsyncSink::encrypt(&mut backing_stream, key, iv).expect("Failed to create encryptor");
|
|
/// /* do work with `stream` */
|
|
///
|
|
/// // It is recommended to `flush` the stream to clear out any remaining data in the internal transformation buffer.
|
|
/// stream.flush().await.unwrap();
|
|
/// # };
|
|
/// ```
|
|
///
|
|
/// # Decryption
|
|
/// To create a decrypting wrapper stream:
|
|
/// ```
|
|
/// # use chacha20stream::AsyncSink;
|
|
/// # use tokio::prelude::*;
|
|
/// # let (key, iv) = chacha20stream::keygen();
|
|
/// # let mut backing_stream = Vec::new();
|
|
/// # async move {
|
|
/// let mut stream = AsyncSink::decrypt(&mut backing_stream, key, iv).expect("Failed to create decryptor");
|
|
/// /* do work with `stream` */
|
|
///
|
|
/// // It is recommended to `flush` the stream to clear out any remaining data in the internal transformation buffer.
|
|
/// stream.flush().await.unwrap();
|
|
/// # };
|
|
/// ```
|
|
///
|
|
///
|
|
/// # Note
|
|
/// When writing, a temporary buffer stored in the structure is used. This buffer is **not** cleared after a write, for efficiency reasons. This may leave sensitive information in the buffer after the write operation.
|
|
/// The `flush()` implementation *does* clear this buffer.
|
|
/// You can use the `prune()` function to zero out this buffer manually too.
|
|
//#[derive(Debug)]
|
|
#[pin_project]
|
|
pub struct Sink<W>
|
|
{
|
|
#[pin] stream: W,
|
|
|
|
crypter: Crypter, // for chacha, finalize does nothing it seems. we can also call it multiple times.
|
|
|
|
buffer: BufferVec, // used to buffer the operation
|
|
}
|
|
|
|
impl<W: fmt::Debug> fmt::Debug for Sink<W>
|
|
{
|
|
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result
|
|
{
|
|
write!(f, "Sink({:?}, ({} buffer cap))", self.stream, self.buffer.capacity())
|
|
}
|
|
}
|
|
|
|
/// Perform the cipher transform on this input to the inner buffer, returning the number of bytes updated.
|
|
fn transform(crypter: &mut Crypter, buffer: &mut BufferVec, buf: &[u8]) -> Result<(), ErrorStack>
|
|
{
|
|
//if buf.len() > self.buffer.len() {
|
|
buffer.resize(buf.len(), 0);
|
|
//}
|
|
|
|
let n = crypter.update(&buf[..], &mut buffer[..])?;
|
|
let _f = crypter.finalize(&mut buffer[..n])?; // I don't know if this is needed.
|
|
debug_assert_eq!(_f, 0);
|
|
|
|
buffer.resize(n, 0);
|
|
Ok(())
|
|
}
|
|
|
|
|
|
impl<W: AsyncWrite> Sink<W>
|
|
{
|
|
|
|
/// Create a new async Chacha Sink stream wrapper
|
|
#[inline] fn new(stream: W, crypter: Crypter) -> Self
|
|
{
|
|
Self{stream, crypter, buffer: BufferVec::new()}
|
|
}
|
|
|
|
/// Create an encrypting Chacha Sink stream wrapper
|
|
pub fn encrypt(stream: W, key: Key, iv: IV) -> Result<Self, Error>
|
|
{
|
|
Ok(Self::new(stream, cha::encrypter(key, iv)?))
|
|
}
|
|
|
|
/// Create a decrypting Chacha Sink stream wrapper
|
|
pub fn decrypt(stream: W, key: Key, iv: IV) -> Result<Self, Error>
|
|
{
|
|
Ok(Self::new(stream, cha::decrypter(key, iv)?))
|
|
}
|
|
|
|
|
|
/// Consume into the inner stream
|
|
#[inline] pub fn into_inner(self) -> W
|
|
{
|
|
self.stream
|
|
}
|
|
|
|
/// Consume into the inner stream and crypter
|
|
#[inline] pub fn into_parts(self) -> (W, Crypter)
|
|
{
|
|
(self.stream, self.crypter)
|
|
}
|
|
|
|
/// Create a sink from a stream and a crypter
|
|
///
|
|
/// The counterpart to `into_parts()`.
|
|
#[inline] pub fn from_parts(stream: W, crypter: Crypter) -> Self
|
|
{
|
|
Self::new(stream, crypter)
|
|
}
|
|
|
|
/// The crypter of this instance
|
|
#[inline] pub fn crypter(&self) -> &Crypter
|
|
{
|
|
&self.crypter
|
|
}
|
|
|
|
/// The crypter of this instance
|
|
#[inline] pub fn crypter_mut(&mut self) -> &mut Crypter
|
|
{
|
|
&mut self.crypter
|
|
}
|
|
|
|
/// The inner stream
|
|
#[inline] pub fn inner(&self) -> &W
|
|
{
|
|
&self.stream
|
|
}
|
|
|
|
/// The inner stream
|
|
#[inline] pub fn inner_mut(&mut self) -> &mut W
|
|
{
|
|
&mut self.stream
|
|
}
|
|
|
|
/// Clear the internal buffer while keeping it allocated for further use.
|
|
///
|
|
/// This does not affect operations at all, all it does is 0 out the left-over temporary buffer from the last operation(s).
|
|
#[inline]
|
|
pub fn prune(&mut self)
|
|
{
|
|
#[cfg(feature="explicit_clear")]
|
|
{
|
|
bytes::explicit_prune(&mut self.buffer[..]);
|
|
return;
|
|
}
|
|
#[cfg(not(feature="explicit_clear"))]
|
|
unsafe {
|
|
std::ptr::write_bytes(self.buffer.as_mut_ptr(), 0, self.buffer.len());
|
|
}
|
|
}
|
|
}
|
|
|
|
//When implementing `poll`, we check if buffer is empty on poll, and if it isn't, poll backing stream to write it. Then, clear buffer after `Poll::Ready` on backing stream's write.
|
|
impl<W: AsyncWrite> AsyncWrite for Sink<W>
|
|
{
|
|
fn poll_write(self: Pin<&mut Self>, cx: &mut Context<'_>, buf: &[u8]) -> Poll<Result<usize, io::Error>> {
|
|
let this = self.project();
|
|
if this.buffer.is_empty() {
|
|
transform(this.crypter, this.buffer, buf)?;
|
|
}
|
|
let poll = this.stream.poll_write(cx, &this.buffer[..]);
|
|
if poll.is_ready() {
|
|
#[cfg(feature="explicit_clear")]
|
|
bytes::explicit_prune(&mut this.buffer[..]);
|
|
this.buffer.clear();
|
|
}
|
|
poll
|
|
}
|
|
fn poll_flush(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), io::Error>> {
|
|
let this = self.project();
|
|
|
|
let poll = this.stream.poll_flush(cx);
|
|
if poll.is_ready() {
|
|
#[cfg(feature="explicit_clear")]
|
|
bytes::explicit_prune(&mut this.buffer[..]);
|
|
this.buffer.clear();
|
|
}
|
|
poll
|
|
}
|
|
fn poll_shutdown(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), io::Error>> {
|
|
let this = self.project();
|
|
|
|
let poll = this.stream.poll_shutdown(cx);
|
|
if poll.is_ready() {
|
|
#[cfg(feature="explicit_clear")]
|
|
bytes::explicit_prune(&mut this.buffer[..]);
|
|
this.buffer.clear();
|
|
}
|
|
poll
|
|
}
|
|
}
|