WIP secure transport using libsodium secretstreamlibsodium-transport

1 files changed, 38 insertions, 0 deletions

diff --git a/transport.h b/transport.h
new file mode 100644
index 0000000..21cebd3
--- /dev/null
+++ b/transport.h
@@ -0,0 +1,38 @@
+#pragma once
+
+#include <stddef.h>
+#include <stdbool.h>
+
+struct transport;
+
+// Takes ownership of socket.
+// Returns NULL and closes socket if setup fails.
+struct transport* tsp_start(int fd, bool is_server);
+
+// Also closes socket.
+void tsp_close(struct transport *tsp);
+
+// Get file descriptor that can be used in e.g. select(2) to detect possible
+// data on the transport. If there is data, the tsp_recv() function must be
+// used to handle it, because it may be protocol-level data for the integrity
+// of the transport.
+int tsp_select_fd(const struct transport *tsp);
+
+// If successful, returns true.
+// If unsuccessful, returns false and closes the transport (after which the
+// transport may not be used again).
+bool tsp_send(struct transport *tsp, const char *data, size_t length);
+
+struct received_data {
+	char *data;
+	size_t length;
+	bool error;
+};
+void received_data_nullify(struct received_data data);
+
+// If no data is avilable yet, returns {.data=NULL, length=0, error=false}.
+// If an error occurred, returns {.data=NULL, length=0, error=true}.
+// If data is avilable, returns {.data=..., length=(length of data), error=false}.
+// This function also handles protocol-level actions that do not actually
+// return application-level data, but that are indeed necessary.
+struct received_data tsp_recv(struct transport *tsp);