Add TLS::Stream code example

1 files changed, 133 insertions, 0 deletions

diff --git a/doc/manual/tls.rst b/doc/manual/tls.rst
index 199e03763..164b6b8d6 100644
--- a/doc/manual/tls.rst
+++ b/doc/manual/tls.rst
@@ -1709,3 +1709,136 @@ It offers the following interface:
          Policy*                policy;
          Server_Information     serverInfo;
          };
+
+
+Stream Code Example
+^^^^^^^^^^^^^^^^^^^^
+
+.. code-block:: cpp
+
+   #include <iostream>
+
+   #include <botan/asio_stream.h>
+   #include <botan/auto_rng.h>
+   #include <botan/certstor_system.h>
+
+   #include <boost/asio.hpp>
+   #include <boost/beast.hpp>
+   #include <boost/bind.hpp>
+
+   namespace http = boost::beast::http;
+   namespace _ = boost::asio::placeholders;
+
+   // very basic credentials manager
+   class Credentials_Manager : public Botan::Credentials_Manager
+      {
+      public:
+         Credentials_Manager() {}
+
+         std::vector<Botan::Certificate_Store*>
+         trusted_certificate_authorities(const std::string&, const std::string&) override
+            {
+            return {&cert_store_};
+            }
+
+      private:
+         Botan::System_Certificate_Store cert_store_;
+      };
+
+   // a simple https client based on TLS::Stream
+   class client
+      {
+      public:
+         client(boost::asio::io_context&                 io_context,
+                boost::asio::ip::tcp::resolver::iterator endpoint_iterator,
+                http::request<http::string_body>         req)
+            : request_(req)
+            , ctx_{&credentials_mgr_,
+                   &rng_,
+                   &session_mgr_,
+                   &policy_,
+                   Botan::TLS::Server_Information()}
+            , stream_(io_context, ctx_)
+            {
+            boost::asio::async_connect(stream_.lowest_layer(), endpoint_iterator,
+                                       boost::bind(&client::handle_connect, this, _::error));
+            }
+
+         void handle_connect(const boost::system::error_code& error)
+            {
+            if(error)
+               {
+               std::cout << "Connect failed: " << error.message() << "\n";
+               return;
+               }
+            stream_.async_handshake(Botan::TLS::Connection_Side::CLIENT,
+                                    boost::bind(&client::handle_handshake, this, _::error));
+            }
+
+         void handle_handshake(const boost::system::error_code& error)
+            {
+            if(error)
+               {
+               std::cout << "Handshake failed: " << error.message() << "\n";
+               return;
+               }
+            http::async_write(stream_, request_,
+                              boost::bind(&client::handle_write, this, _::error, _::bytes_transferred));
+            }
+
+         void handle_write(const boost::system::error_code& error, size_t)
+            {
+            if(error)
+               {
+               std::cout << "Write failed: " << error.message() << "\n";
+               return;
+               }
+            http::async_read(stream_, reply_, response_,
+                             boost::bind(&client::handle_read, this, _::error, _::bytes_transferred));
+            }
+
+         void handle_read(const boost::system::error_code& error, size_t)
+            {
+            if(!error)
+               {
+               std::cout << "Reply: ";
+               std::cout << response_.body() << "\n";
+               }
+            else
+               {
+               std::cout << "Read failed: " << error.message() << "\n";
+               }
+            }
+
+      private:
+         http::request<http::dynamic_body> request_;
+         http::response<http::string_body> response_;
+         boost::beast::flat_buffer         reply_;
+
+         Botan::TLS::Session_Manager_Noop session_mgr_;
+         Botan::AutoSeeded_RNG            rng_;
+         Credentials_Manager              credentials_mgr_;
+         Botan::TLS::Policy               policy_;
+
+         Botan::TLS::Context                              ctx_;
+         Botan::TLS::Stream<boost::asio::ip::tcp::socket> stream_;
+      };
+
+   int main()
+      {
+      boost::asio::io_context io_context;
+
+      boost::asio::ip::tcp::resolver           resolver(io_context);
+      boost::asio::ip::tcp::resolver::query    query("botan.randombit.net", "443");
+      boost::asio::ip::tcp::resolver::iterator iterator = resolver.resolve(query);
+
+      http::request<http::string_body> req;
+      req.version(11);
+      req.method(http::verb::get);
+      req.target("/news.html");
+      req.set(http::field::host, "botan.randombit.net");
+
+      client c(io_context, iterator, req);
+
+      io_context.run();
+      }