added poll_write to EncryptedWriteHalf

Cargo.toml

@@ -12,3 +12,4 @@ chacha20stream = {version = "1.0", features=["async"]}
 openssl = "0.10.33"
 stackalloc = "1.1.0"
 pin-project = "1.0.6"
+bytes = "0.5.6"

src/stream.rs

@@ -2,7 +2,10 @@ use super::*;
 
 use tokio::io::{AsyncWrite, AsyncRead};
 use std::sync::Arc;
+
 use openssl::symm::Crypter;
+use openssl::error::ErrorStack;
+use ::bytes::{Buf, BufMut};
 
 use std::{
     pin::Pin,
@@ -48,6 +51,7 @@ where S: AsyncWrite
 }
 //TODO: WriteHalf's AsyncWrite impl should just forward to backing_write
 
+#[pin_project]
 pub struct EncryptedWriteHalf<'a, S>
 where S: AsyncWrite,
 {
@@ -83,7 +87,61 @@ pub struct EncryptedWriteHalf<'a, S>
     /// This exists so we don't have to transform the entire `buf` on every poll. We can just transform it once and then wait until it is `Ready` before discarding the data (`.empty()`) and allowing new data to fill it on the next, fresh `poll_write`.
     crypt_buffer: Vec<u8>,
     
-    backing: &'a mut WriteHalf<S>,
+    #[pin] backing: &'a mut WriteHalf<S>,
+}
+/// **Forcefully** transform `buf` into a transformed buffer.
+///
+/// # Does **not** do these things
+/// Doesn't check for ptr ident with `buf` against `crypt_buf_ptr`. You should do that yourself.
+/// Doesn't truncate `crypt_buffer` after transformation.
+fn transform_into(crypt_buffer: &mut Vec<u8>, cipher: &mut Crypter, buf: &[u8]) -> Result<usize, ErrorStack>
+{
+    if crypt_buffer.len() < buf.len() {
+	crypt_buffer.resize(buf.len(), 0);
+    }
+    let n = cipher.update(buf, &mut crypt_buffer[..buf.len()])?;
+    let _f = cipher.finalize(&mut crypt_buffer[..n])?;
+    debug_assert_eq!(_f, 0);
+
+    Ok(n)
+}
+impl<'a, S: AsyncWrite> EncryptedWriteHalf<'a, S>
+{
+    #[inline(always)] fn forward(self: Pin<&mut Self>) -> Pin<&mut WriteHalf<S>>
+    {
+	unsafe {self.map_unchecked_mut(|this| this.backing)}
+    }
+}
+
+impl<'a, S: AsyncWrite> AsyncWrite for EncryptedWriteHalf<'a, S>
+{
+    fn poll_write(mut self: Pin<&mut Self>, cx: &mut Context<'_>, buf: &[u8]) -> Poll<Result<usize, io::Error>> {
+	let this = self.as_mut().project();
+
+	if this.crypt_buffer.is_empty() || this.crypt_buf_ptr != buf {
+	    // Transform `buf` into self.crypt_buffer
+
+	    let n = transform_into(this.crypt_buffer, this.cipher, buf)?;
+	    *this.crypt_buf_ptr = buf.into();
+	    
+	    this.crypt_buffer.truncate(n);
+	} // else { /* No need to transform */ }
+	let poll = unsafe {this.backing.map_unchecked_mut(|this| *this)}.poll_write(cx, &this.crypt_buffer[..]);
+
+	if poll.is_ready()
+	{
+	    *this.crypt_buf_ptr = Default::default();
+	    this.crypt_buffer.clear();
+	}
+
+	poll
+    }
+    fn poll_flush(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), io::Error>> {
+	todo!()
+    }
+    fn poll_shutdown(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), io::Error>> {
+	todo!()
+    }
 }
 //TODO: EncryptedWriteHalf's AsyncWrite impl should en/decrypt the input buffer into `crypt_buffer` then send it to `backing`.
 
@@ -109,6 +167,36 @@ pub struct EncryptedReadHalf<'a, S>
 //TODO: EncryptedReadHalf's AsyncRead impl should en/decrypt the read from backing.
 
 
+impl<S: AsyncRead> AsyncRead for ReadHalf<S>
+{
+    #[inline] fn poll_read(self: Pin<&mut Self>, cx: &mut Context<'_>, buf: &mut [u8]) -> Poll<io::Result<usize>> {
+	self.project().backing_read.poll_read(cx, buf)
+    }
+    #[inline] fn poll_read_buf<B: BufMut>(self: Pin<&mut Self>, cx: &mut Context<'_>, buf: &mut B) -> Poll<io::Result<usize>>
+    where
+        Self: Sized, {
+	    self.project().backing_read.poll_read_buf(cx, buf)
+	}
+}
+
+impl<S: AsyncWrite> AsyncWrite for WriteHalf<S>
+{
+    #[inline] fn poll_write(self: Pin<&mut Self>, cx: &mut Context<'_>, buf: &[u8]) -> Poll<Result<usize, io::Error>> {
+	self.project().backing_write.poll_write(cx, buf)
+    }
+    #[inline] fn poll_flush(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), io::Error>> {	
+	self.project().backing_write.poll_flush(cx)
+    }
+    #[inline] fn poll_shutdown(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), io::Error>> {
+	self.project().backing_write.poll_shutdown(cx)	
+    }
+    #[inline] fn poll_write_buf<B: Buf>(self: Pin<&mut Self>, cx: &mut Context<'_>, buf: &mut B) -> Poll<Result<usize, io::Error>>
+    where
+        Self: Sized, {
+	    self.project().backing_write.poll_write_buf(cx, buf)
+	}
+}
+
 //TODO: Rework everything past this point:
 
 /*