1 files changed, 252 insertions, 0 deletions
diff --git a/src/io-tls/tls.cpp b/src/io-tls/tls.cpp
new file mode 100644
index 0000000..9fa143c
--- /dev/null
+++ b/src/io-tls/tls.cpp
@@ -0,0 +1,252 @@
+#include "tls.h"
+
+#include <gnutls/gnutls.h>
+#include <gnutls/x509.h>
+
+#include <forstio/io/io_helpers.h>
+
+#include <cassert>
+
+#include <iostream>
+
+namespace saw {
+
+class tls::impl {
+public:
+	gnutls_certificate_credentials_t xcred;
+
+public:
+	impl() {
+		gnutls_global_init();
+		gnutls_certificate_allocate_credentials(&xcred);
+		gnutls_certificate_set_x509_system_trust(xcred);
+	}
+
+	~impl() {
+		gnutls_certificate_free_credentials(xcred);
+		gnutls_global_deinit();
+	}
+};
+
+static ssize_t forst_tls_push_func(gnutls_transport_ptr_t p, const void *data,
+						 size_t size);
+static ssize_t forst_tls_pull_func(gnutls_transport_ptr_t p, void *data, size_t size);
+
+tls::tls() : impl_{heap<tls::impl>()} {}
+
+tls::~tls() {}
+
+tls::impl &tls::get_impl() { return *impl_; }
+
+class tls_io_stream final : public io_stream {
+private:
+	own<io_stream> internal;
+	gnutls_session_t session_handle;
+
+public:
+	tls_io_stream(own<io_stream> internal_) : internal{std::move(internal_)} {}
+
+	~tls_io_stream() { gnutls_bye(session_handle, GNUTLS_SHUT_RDWR); }
+
+	error_or<size_t> read(void *buffer, size_t length) override {
+		ssize_t size = gnutls_record_recv(session_handle, buffer, length);
+		if (size < 0) {
+			if(gnutls_error_is_fatal(size) == 0){
+				return make_error<err::recoverable>("Recoverable error on read in gnutls. TODO better error msg handling");
+				// Leaving proper message handling done in previous error framework
+				//return recoverable_error([size](){return std::string{"Read recoverable Error "}+std::string{gnutls_strerror(size)};}, "Error read r");
+			}else{
+				return make_error<err::critical>("Fatal error on read in gnutls. TODO better error msg handling");
+			}
+		}else if(size == 0){
+			return make_error<err::disconnected>();
+		}
+
+		return static_cast<size_t>(length);
+	}
+
+	conveyor<void> read_ready() override { return internal->read_ready(); }
+
+	conveyor<void> on_read_disconnected() override {
+		return internal->on_read_disconnected();
+	}
+
+	error_or<size_t> write(const void *buffer, size_t length) override {
+		ssize_t size = gnutls_record_send(session_handle, buffer, length);
+		if(size < 0){
+			if(gnutls_error_is_fatal(size) == 0){
+				return make_error<err::recoverable>("Recoverable error on write in gnutls. TODO better error msg handling");
+			}else{
+				return make_error<err::critical>("Fatal error on write in gnutls. TODO better error msg handling");
+			}
+		}
+
+		return static_cast<size_t>(size);
+	}
+
+	conveyor<void> write_ready() override { return internal->write_ready(); }
+
+	gnutls_session_t &session() { return session_handle; }
+};
+
+tls_server::tls_server(own<server> srv) : internal{std::move(srv)} {}
+
+conveyor<own<io_stream>> tls_server::accept() {
+	SAW_ASSERT(internal) { return conveyor<own<io_stream>>{fix_void<own<io_stream>>{nullptr}}; }
+	return internal->accept().then([](own<io_stream> stream) -> own<io_stream> {
+		/// @todo handshake
+
+
+		return heap<tls_io_stream>(std::move(stream));
+	});
+}
+
+namespace {
+/*
+* Small helper for setting up the nonblocking connection handshake
+*/
+struct tls_client_stream_helper {
+public:
+	own<conveyor_feeder<own<io_stream>>> feeder;
+	conveyor_sink connection_sink;
+	conveyor_sink stream_reader;
+	conveyor_sink stream_writer;
+
+	own<tls_io_stream> stream = nullptr;
+public:
+	tls_client_stream_helper(own<conveyor_feeder<own<io_stream>>> f):
+		feeder{std::move(f)}
+	{}
+
+	void setupTurn(){
+		SAW_ASSERT(stream){
+			return;
+		}
+
+		stream_reader = stream->read_ready().then([this](){
+			turn();
+		}).sink();
+
+		stream_writer = stream->write_ready().then([this](){
+			turn();
+		}).sink();
+	}
+
+	void turn(){
+		if(stream){
+			// Guarantee that the receiving end is already setup
+			SAW_ASSERT(feeder){
+				return;
+			}
+
+			auto &session = stream->session();
+
+			int ret;
+			do {
+				ret = gnutls_handshake(session);
+			} while ( (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED) && gnutls_error_is_fatal(ret) == 0);
+
+			if(gnutls_error_is_fatal(ret)){
+				feeder->fail(make_error<err::critical>("Couldn't create Tls connection"));
+				stream = nullptr;
+			}else if(ret == GNUTLS_E_SUCCESS){
+				feeder->feed(std::move(stream));
+			}
+		}
+	}
+};
+}
+
+own<server> tls_network::listen(network_address& address) {
+	return heap<tls_server>(internal.listen(address));
+}
+
+conveyor<own<io_stream>> tls_network::connect(network_address& address) {
+	// Helper setups
+	auto caf = new_conveyor_and_feeder<own<io_stream>>();
+	own<tls_client_stream_helper> helper = heap<tls_client_stream_helper>(std::move(caf.feeder));
+	tls_client_stream_helper* hlp_ptr = helper.get();
+	
+	// Conveyor entangled structure
+	auto prim_conv = internal.connect(address).then([this, hlp_ptr, addr = address.address()](
+										own<io_stream> stream) -> error_or<void> {
+		io_stream* inner_stream = stream.get();
+		auto tls_stream = heap<tls_io_stream>(std::move(stream));
+
+		auto &session = tls_stream->session();
+
+		gnutls_init(&session, GNUTLS_CLIENT);
+
+		gnutls_server_name_set(session, GNUTLS_NAME_DNS, addr.c_str(),
+							   addr.size());
+
+		gnutls_set_default_priority(session);
+		gnutls_credentials_set(session, GNUTLS_CRD_CERTIFICATE,
+							   tls_.get_impl().xcred);
+		gnutls_session_set_verify_cert(session, addr.c_str(), 0);
+
+		gnutls_transport_set_ptr(session, reinterpret_cast<gnutls_transport_ptr_t>(inner_stream));
+		gnutls_transport_set_push_function(session, forst_tls_push_func);
+		gnutls_transport_set_pull_function(session, forst_tls_pull_func);
+
+		// gnutls_handshake_set_timeout(session, GNUTLS_DEFAULT_HANDSHAKE_TIMEOUT);
+
+		hlp_ptr->stream = std::move(tls_stream);
+		hlp_ptr->setupTurn();
+		hlp_ptr->turn();
+
+		return void_t{};
+	});
+
+	helper->connection_sink = prim_conv.sink();
+
+	return caf.conveyor.attach(std::move(helper));
+}
+
+own<datagram> tls_network::datagram(network_address& address){
+	///@unimplemented
+	return nullptr;
+}
+
+static ssize_t forst_tls_push_func(gnutls_transport_ptr_t p, const void *data,
+						 size_t size) {
+	io_stream *stream = reinterpret_cast<io_stream *>(p);
+	if (!stream) {
+		return -1;
+	}
+
+	error_or<size_t> length = stream->write(data, size);
+	if (length.is_error() || !length.is_value()) {
+		return -1;
+	}
+
+	return static_cast<ssize_t>(length.get_value());
+}
+
+static ssize_t forst_tls_pull_func(gnutls_transport_ptr_t p, void *data, size_t size) {
+	io_stream *stream = reinterpret_cast<io_stream *>(p);
+	if (!stream) {
+		return -1;
+	}
+
+	error_or<size_t> length = stream->read(data, size);
+	if (length.is_error() || !length.is_value()) {
+		return -1;
+	}
+
+	return static_cast<ssize_t>(length.get_value());
+}
+
+tls_network::tls_network(tls& tls_, network &network) : tls_{tls_},internal{network} {}
+
+conveyor<own<network_address>> tls_network::resolve_address(const std::string &addr,
+													   uint16_t port) {
+	/// @todo tls server name needed. Check validity. Won't matter later on, because gnutls should fail anyway. But
+	/// it's better to find the error source sooner rather than later
+	return internal.resolve_address(addr, port);
+}
+
+std::optional<own<tls_network>> setup_tls_network(network &network) {
+	return std::nullopt;
+}
+} // namespace saw