From ba0af8cc20e762ef6addeefaa96f951a995bafb1 Mon Sep 17 00:00:00 2001
From: angt <angt@users.noreply.github.com>
Date: Tue, 29 Dec 2015 18:31:23 +0100
Subject: [PATCH] Define VERSION_MAJOR and use it in handshake

---
 configure.ac | 1 +
 src/main.c   | 6 ++++--
 version.sh   | 2 ++
 3 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/configure.ac b/configure.ac
index 4093f23..181a4e8 100644
--- a/configure.ac
+++ b/configure.ac
@@ -4,6 +4,7 @@ AC_INIT([glorytun],
         [https://github.com/angt/glorytun/issues],
         [glorytun],
         [https://github.com/angt/glorytun])
+AC_DEFINE_UNQUOTED([VERSION_MAJOR], [m4_esyscmd([./version.sh major])])
 AC_CONFIG_SRCDIR([src/common.h])
 AC_CONFIG_AUX_DIR([build-aux])
 AC_CONFIG_MACRO_DIR([m4])
diff --git a/src/main.c b/src/main.c
index 031ba07..2e934a3 100644
--- a/src/main.c
+++ b/src/main.c
@@ -651,6 +651,8 @@ static int gt_setup_secretkey (struct crypto_ctx *ctx, char *keyfile)
 
 static int gt_setup_crypto (struct crypto_ctx *ctx, int fd, int listener)
 {
+    const uint8_t gt[] = {'G', 'T', VERSION_MAJOR, 0 };
+
     const size_t size = 96;
     const size_t hash_size = 32;
 
@@ -673,7 +675,7 @@ static int gt_setup_crypto (struct crypto_ctx *ctx, int fd, int listener)
     randombytes_buf(secret, sizeof(secret));
     crypto_scalarmult_base(&data_w[nonce_size], secret);
 
-    byte_cpy(&data_w[size-hash_size-4], "GT\0\0", 4);
+    byte_cpy(&data_w[size-hash_size-sizeof(gt)], gt, sizeof(gt));
 
     crypto_generichash(&data_w[size-hash_size], hash_size,
             data_w, size-hash_size, ctx->skey, sizeof(ctx->skey));
@@ -684,7 +686,7 @@ static int gt_setup_crypto (struct crypto_ctx *ctx, int fd, int listener)
     if (fd_read_all(fd, data_r, size)!=size)
         return -1;
 
-    if (memcmp(&data_r[size-hash_size-4], &data_w[size-hash_size-4], 4))
+    if (memcmp(&data_r[size-hash_size-sizeof(gt)], gt, sizeof(gt)))
         return -2;
 
     crypto_generichash(hash, hash_size,
diff --git a/version.sh b/version.sh
index 1d90245..c6ae5ec 100755
--- a/version.sh
+++ b/version.sh
@@ -6,4 +6,6 @@
 [ -z "${VERSION}" ] && VERSION=`basename \`pwd\`` \
                     && VERSION=${VERSION#*-}
 
+[ "$1" = "major"  ] && VERSION=${VERSION%%.*}
+
 printf ${VERSION}