From c336d2f8a3560a8179650859983d33e3e1103ff0 Mon Sep 17 00:00:00 2001
From: Ian Moffett <ian@osmora.org>
Date: Thu, 26 Sep 2024 14:49:15 -0400
Subject: lib: net: Add message frame structure

Signed-off-by: Ian Moffett <ian@osmora.org>
---
 lib/include/net/stpsession.h | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

(limited to 'lib')

diff --git a/lib/include/net/stpsession.h b/lib/include/net/stpsession.h
index 1b22e1b..351be26 100644
--- a/lib/include/net/stpsession.h
+++ b/lib/include/net/stpsession.h
@@ -30,9 +30,17 @@
 #ifndef STP_SESSION_H_
 #define STP_SESSION_H_
 
+#include <crypto/aes.h>
 #include <stdint.h>
 #include <defs.h>
 
+/*
+ * 2^12 (4096) bytes is a common page size on
+ * modern systems, this could lead to potential
+ * optimizations.
+ */
+#define MESSAGE_SIZE (1 << 12)
+
 /*
  * The Session Request is sent from the client to the
  * server and contains a HOP (hash, options, pubkey)
@@ -72,4 +80,15 @@ struct session_request {
     uint8_t pad[8];
 } PACKED;
 
+/*
+ * OSTP Message Frame containing an IV, AES
+ * GCM tag, payload length and payload
+ * with encrypted data.
+ */
+struct msg_frame {
+    uint8_t iv[AES_IV_SIZE];
+    uint8_t tag[AES_GCM_TAG_SIZE];
+    uint16_t len;
+    uint8_t payload[MESSAGE_SIZE];
+};
 #endif  /* STP_SESSION_H_ */
-- 
cgit v1.2.3