epee: implement handshake timeout for SSL connections

contrib/epee/include/net/net_helper.h

@@ -177,7 +177,7 @@ namespace net_utils
 					// SSL Options
 					if (m_ssl_options.support == epee::net_utils::ssl_support_t::e_ssl_support_enabled || m_ssl_options.support == epee::net_utils::ssl_support_t::e_ssl_support_autodetect)
 					{
-						if (!m_ssl_options.handshake(*m_ssl_socket, boost::asio::ssl::stream_base::client, addr))
+						if (!m_ssl_options.handshake(*m_ssl_socket, boost::asio::ssl::stream_base::client, addr, timeout))
 						{
 							if (m_ssl_options.support == epee::net_utils::ssl_support_t::e_ssl_support_autodetect)
 							{

contrib/epee/include/net/net_ssl.h

@@ -128,7 +128,11 @@ namespace net_utils
 
         \return True if the SSL handshake completes with peer verification
           settings. */
-    bool handshake(boost::asio::ssl::stream<boost::asio::ip::tcp::socket> &socket, boost::asio::ssl::stream_base::handshake_type type, const std::string& host = {}) const;
+    bool handshake(
+      boost::asio::ssl::stream<boost::asio::ip::tcp::socket> &socket,
+      boost::asio::ssl::stream_base::handshake_type type,
+      const std::string& host = {},
+      std::chrono::milliseconds timeout = std::chrono::seconds(15)) const;
   };
 
         // https://security.stackexchange.com/questions/34780/checking-client-hello-for-https-classification

contrib/epee/src/net_ssl.cpp

@@ -28,9 +28,11 @@
 
 #include <string.h>
 #include <boost/asio/ssl.hpp>
+#include <boost/lambda/lambda.hpp>
 #include <openssl/ssl.h>
 #include <openssl/pem.h>
 #include "misc_log_ex.h"
+#include "net/net_helper.h"
 #include "net/net_ssl.h"
 
 #undef MONERO_DEFAULT_LOG_CATEGORY
@@ -456,7 +458,11 @@ bool ssl_options_t::has_fingerprint(boost::asio::ssl::verify_context &ctx) const
   return false;
 }
 
-bool ssl_options_t::handshake(boost::asio::ssl::stream<boost::asio::ip::tcp::socket> &socket, boost::asio::ssl::stream_base::handshake_type type, const std::string& host) const
+bool ssl_options_t::handshake(
+  boost::asio::ssl::stream<boost::asio::ip::tcp::socket> &socket,
+  boost::asio::ssl::stream_base::handshake_type type,
+  const std::string& host,
+  std::chrono::milliseconds timeout) const
 {
   socket.next_layer().set_option(boost::asio::ip::tcp::no_delay(true));
 
@@ -502,8 +508,23 @@ bool ssl_options_t::handshake(boost::asio::ssl::stream<boost::asio::ip::tcp::soc
     });
   }
 
-  boost::system::error_code ec;
-  socket.handshake(type, ec);
+  auto& io_service = GET_IO_SERVICE(socket);
+  boost::asio::steady_timer deadline(io_service, timeout);
+  deadline.async_wait([&socket](const boost::system::error_code& error) {
+    if (error != boost::asio::error::operation_aborted)
+    {
+      socket.next_layer().close();
+    }
+  });
+
+  boost::system::error_code ec = boost::asio::error::would_block;
+  socket.async_handshake(type, boost::lambda::var(ec) = boost::lambda::_1);
+  while (ec == boost::asio::error::would_block)
+  {
+    io_service.reset();
+    io_service.run_one();
+  }
+
   if (ec)
   {
     MERROR("SSL handshake failed, connection dropped: " << ec.message());