From 2790d34ccde25b0bd219c302a116550ba7092faa Mon Sep 17 00:00:00 2001
From: willrnch <1873880+willrnch@users.noreply.github.com>
Date: Mon, 3 Nov 2025 14:01:39 +0100
Subject: [PATCH] permessage-deflate

---
 Cargo.lock        |  5 +++--
 Cargo.toml        |  1 +
 autobahn/Makefile |  6 +++---
 src/error.rs      |  2 ++
 src/lib.rs        | 37 +++++++++++++++++++++++++++++++++++--
 5 files changed, 44 insertions(+), 7 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 7025f80..fc103cf 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -409,6 +409,7 @@ dependencies = [
  "http-body-util",
  "hyper",
  "hyper-util",
+ "miniz_oxide",
  "pin-project",
  "rand",
  "rustls-pemfile",
@@ -726,9 +727,9 @@ checksum = "6877bb514081ee2a7ff5ef9de3281f14a4dd4bceac4c09388074a6b5df8a139a"
 
 [[package]]
 name = "miniz_oxide"
-version = "0.8.3"
+version = "0.8.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b8402cab7aefae129c6977bb0ff1b8fd9a04eb5b51efc50a70bea51cda0c7924"
+checksum = "1fa76a2c86f704bdb222d66965fb3d63269ce38518b83cb0575fca855ebb6316"
 dependencies = [
  "adler2",
 ]
diff --git a/Cargo.toml b/Cargo.toml
index 13bb401..37ac357 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -54,6 +54,7 @@ utf-8 = "0.7.5"
 rand = "0.8.4"
 thiserror = "1.0.40"
 bytes = "1.5.0"
+miniz_oxide = "0.8.9"
 
 # Axum integration
 axum-core = { version = "0.5.0", optional = true }
diff --git a/autobahn/Makefile b/autobahn/Makefile
index 9e20c4b..54c09e3 100644
--- a/autobahn/Makefile
+++ b/autobahn/Makefile
@@ -1,7 +1,7 @@
 AUTOBAHN_TESTSUITE_DOCKER := crossbario/autobahn-testsuite:0.8.2@sha256:5d4ba3aa7d6ab2fdbf6606f3f4ecbe4b66f205ce1cbc176d6cdf650157e52242
 
 build-server:
-	sudo cargo build --release --example echo_server --features "upgrade"
+	cargo build --release --example echo_server --features "upgrade"
 
 run-server: build-server
 	echo ${PWD}
@@ -18,7 +18,7 @@ run-server: build-server
 	../target/release/examples/echo_server
 
 build-client:
-	sudo cargo build --release --example autobahn_client --features "upgrade"
+	cargo build --release --example autobahn_client --features "upgrade"
 
 run-client: build-client
 	echo ${PWD}
@@ -34,4 +34,4 @@ run-client: build-client
 	sleep 5
 	../target/release/examples/autobahn_client
 
-.PHONY: build-server run-server build-client run-client
\ No newline at end of file
+.PHONY: build-server run-server build-client run-client
diff --git a/src/error.rs b/src/error.rs
index 848116a..460703f 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -34,6 +34,8 @@ pub enum WebSocketError {
   InvalidSecWebsocketVersion,
   #[error("Invalid value")]
   InvalidValue,
+  #[error("Invalid encoding")]
+  InvalidEncoding,
   #[error("Sec-WebSocket-Key header is missing")]
   MissingSecWebSocketKey,
   #[error(transparent)]
diff --git a/src/lib.rs b/src/lib.rs
index eefc955..7955fea 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -175,6 +175,9 @@ use tokio::io::AsyncReadExt;
 use tokio::io::AsyncWrite;
 use tokio::io::AsyncWriteExt;
 
+use miniz_oxide::{DataFormat, MZFlush};
+use miniz_oxide::inflate::stream::{InflateState, inflate};
+
 pub use crate::close::CloseCode;
 pub use crate::error::WebSocketError;
 pub use crate::fragment::FragmentCollector;
@@ -681,7 +684,11 @@ impl ReadHalf {
     let rsv2 = self.buffer[0] & 0b00100000 != 0;
     let rsv3 = self.buffer[0] & 0b00010000 != 0;
 
-    if rsv1 || rsv2 || rsv3 {
+    let mut compressed = false;
+
+    if rsv1 && !rsv2 && !rsv3 {
+      compressed = true;
+    } else if rsv1 || rsv2 || rsv3 {
       return Err(WebSocketError::ReservedBitsNotZero);
     }
 
@@ -743,7 +750,11 @@ impl ReadHalf {
     }
 
     // if we read too much it will stay in the buffer, for the next call to this method
-    let payload = self.buffer.split_to(payload_len);
+    let mut payload = self.buffer.split_to(payload_len);
+    if compressed {
+      payload = BytesMut::from(inflate_payload(&payload.to_vec())?.as_slice());
+    }
+
     let frame = Frame::new(fin, opcode, mask, Payload::Bytes(payload));
     Ok(frame)
   }
@@ -820,3 +831,25 @@ mod tests {
     assert_unsync::<WebSocket<tokio::net::TcpStream>>();
   };
 }
+
+fn inflate_payload(
+  payload: &Vec<u8>
+) -> Result<Vec<u8>, WebSocketError>
+{
+  let max_output_size = usize::max_value();
+  let mut out: Vec<u8> = vec![0; payload.len().saturating_mul(2).min(max_output_size)];
+  let mut state = InflateState::new_boxed(DataFormat::Raw);
+
+  let payload = [payload.as_slice(), [0x00, 0x00, 0xff, 0xff].as_slice()].concat();
+  let res = inflate(&mut state, &payload, &mut out, MZFlush::Partial);
+
+  match res.status {
+    Ok(_) => {
+      out.truncate(res.bytes_written);
+      Ok(out)
+    }
+    Err(_) => {
+      Err(WebSocketError::InvalidEncoding)
+    }
+  }
+}