Added `ESock::transfer_state()`: Change the `tx` and `rx` types in a encrypted socket while maintaining its keys and other encryption state.

Fortune for rsh's current commit: Half blessing − 半吉

Cargo.lock

@@ -23,6 +23,12 @@ version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f26201604c87b1e01bd3d98f8d5d9a8fcbb815e8cedb41ffccbeb4bf593a35fe"
 
+[[package]]
+name = "atomic_refcell"
+version = "0.1.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "681b971236e0f76b20fcafca0236b8718c9186ee778d67cd78bd5f28fd85427f"
+
 [[package]]
 name = "autocfg"
 version = "1.0.1"
@@ -112,9 +118,9 @@ checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
 [[package]]
 name = "chacha20stream"
-version = "2.1.0"
+version = "2.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "54c8d48b47fa0a89a94b80d32b1b3fc9ffc1a232a5201ff5a2d14ac77bc7561d"
+checksum = "87df7ca03a990f2bb57c659b78c8f2fbc48fd2c6ed5ecc764e239a7ad7e9cfa1"
 dependencies = [
  "base64 0.13.0",
  "getrandom 0.2.3",
@@ -800,6 +806,7 @@ name = "rsh"
 version = "0.1.0"
 dependencies = [
  "ad-hoc-iter",
+ "atomic_refcell",
  "base64 0.13.0",
  "bytes 1.0.1",
  "chacha20stream",

Cargo.toml

@@ -7,9 +7,10 @@ edition = "2018"
 
 [dependencies]
 ad-hoc-iter = "0.2.3"
+atomic_refcell = "0.1.7"
 base64 = "0.13.0"
 bytes = { version = "1.0.1", features = ["serde"] }
-chacha20stream = { version = "2.1.0", features = ["async", "serde"] }
+chacha20stream = { version = "2.2.1", features = ["async", "serde"] }
 color-eyre = "0.5.11"
 cryptohelpers = { version = "1.8.2" , features = ["serialise", "full"] }
 futures = "0.3.16"

src/ext/mod.rs

@@ -13,6 +13,8 @@ pub use hex::*;
 mod base64;
 pub use self::base64::*;
 
+pub mod sync;
+
 /// A maybe-atom that can spill into a vector.
 pub type MaybeVec<T> = SmallVec<[T; 1]>;
 

src/ext/sync.rs

@@ -0,0 +1,2 @@
+//! Syncronisation helpers
+

src/sock/enc.rs

@@ -182,6 +182,29 @@ pub struct ESock<W, R> {
 
 impl<W: AsyncWrite, R: AsyncRead> ESock<W, R>
 {
+    /// Move this `ESock`'s state into another, returning the new `ESock` and the old streams
+    pub fn transfer_state<Wx, Rx>(self, tx: Wx, rx: Rx) -> (ESock<Wx, Rx>, (W, R))
+    where Wx: AsyncWrite,
+	  Rx: AsyncRead
+    {
+	let ESock { info, state, tx: otx, rx: orx } = self;
+
+	let (otx, tx) = {
+	    let (s, c) = otx.into_parts();
+
+	    (s, AsyncSink::from_parts(tx, c))
+	};
+	let (orx, rx) = {
+	    let (s, c) = orx.into_parts();
+
+	    (s, AsyncSource::from_parts(rx, c))
+	};
+	
+	(ESock {
+	    info, state, tx, rx
+	}, (otx, orx))
+    }
+    
     fn inner(&self) -> (&W, &R)
     {
 	(self.tx.inner(), self.rx.inner())

src/sock/pipe.rs

@@ -11,6 +11,9 @@ use std::{
 	PhantomData,
     },
 };
+use futures::{
+    Future,
+};
 use tokio::sync::{
     mpsc,
 };
@@ -27,10 +30,22 @@ pub const DEFAULT_BUFFER_SIZE: usize = 32;
 /// Task-based buffered piping to/from encrypted sockets.
 pub struct BufferedESock<W, R>
 {
+    
     bufsz: usize,
     _backing: PhantomData<ESock<W, R>>,
 }
 
+/// `tx`: ESock-wrapped network output socket.
+/// `rx`: Reading half of the user's fake stream
+fn bsock_writer<'a, Raw, Fake>(mut tx: ESockWriteHalf<Raw>, mut rx: Fake) -> impl Future<Output = ()> + 'a
+where Raw: AsyncWrite + Unpin + 'a,
+Fake: AsyncRead + Unpin + 'a,
+{
+    async move {
+	
+    }
+}
+
 impl<W, R> BufferedESock<W, R>
 where W: AsyncWrite + Unpin + Send + 'static,
       R: AsyncRead + Unpin + Send + 'static