From 03c01da74dc246358f397fb44e6280c3a766a3f7 Mon Sep 17 00:00:00 2001
From: Jens Diewald <jens.diewald@scai.fraunhofer.de>
Date: Thu, 16 Feb 2023 15:56:24 +0100
Subject: [PATCH] Make use of async_handshake being a coroutine

Before async_handshake was mostly a state machine and
the fact that it is also a coroutine was not used.
This removes the state machine part and makes use of the coroutine.
---
 include/wintls/detail/async_handshake.hpp | 35 ++++++-----------------
 1 file changed, 8 insertions(+), 27 deletions(-)

diff --git a/include/wintls/detail/async_handshake.hpp b/include/wintls/detail/async_handshake.hpp
index 8b42d48..e7f5e04 100644
--- a/include/wintls/detail/async_handshake.hpp
+++ b/include/wintls/detail/async_handshake.hpp
@@ -17,17 +17,16 @@
 namespace wintls {
 namespace detail {
 
-template <typename NextLayer>
+template<typename NextLayer>
 struct async_handshake : net::coroutine {
   async_handshake(NextLayer& next_layer, detail::sspi_handshake& handshake, handshake_type type)
-    : next_layer_(next_layer)
-    , handshake_(handshake)
-    , entry_count_(0)
-    , state_(state::idle) {
+      : next_layer_(next_layer)
+      , handshake_(handshake)
+      , entry_count_(0) {
     handshake_(type);
   }
 
-  template <typename Self>
+  template<typename Self>
   void operator()(Self& self, wintls::error_code ec = {}, std::size_t length = 0) {
     if (ec) {
       self.complete(ec);
@@ -39,35 +38,22 @@ struct async_handshake : net::coroutine {
       return entry_count_ > 1;
     };
 
-    switch(state_) {
-      case state::reading:
-        handshake_.size_read(length);
-        state_ = state::idle;
-        break;
-      case state::writing:
-        handshake_.size_written(length);
-        state_ = state::idle;
-        break;
-      case state::idle:
-        break;
-    }
-
     detail::sspi_handshake::state handshake_state;
     WINTLS_ASIO_CORO_REENTER(*this) {
-      while((handshake_state = handshake_()) != detail::sspi_handshake::state::done) {
+      while ((handshake_state = handshake_()) != detail::sspi_handshake::state::done) {
         if (handshake_state == detail::sspi_handshake::state::data_needed) {
           WINTLS_ASIO_CORO_YIELD {
-            state_ = state::reading;
             next_layer_.async_read_some(handshake_.in_buffer(), std::move(self));
           }
+          handshake_.size_read(length);
           continue;
         }
 
         if (handshake_state == detail::sspi_handshake::state::data_available) {
           WINTLS_ASIO_CORO_YIELD {
-            state_ = state::writing;
             net::async_write(next_layer_, handshake_.out_buffer(), std::move(self));
           }
+          handshake_.size_written(length);
           continue;
         }
 
@@ -99,11 +85,6 @@ struct async_handshake : net::coroutine {
   NextLayer& next_layer_;
   detail::sspi_handshake& handshake_;
   int entry_count_;
-  enum class state {
-    idle,
-    reading,
-    writing
-  } state_;
 };
 
 } // namespace detail