From 48419d0e5c004a05cf52ffe8d64d25f8d654b757 Mon Sep 17 00:00:00 2001
From: angt <angt@users.noreply.github.com>
Date: Thu, 4 Feb 2016 09:35:37 +0100
Subject: [PATCH] First 4 bytes are AD

---
 mud.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/mud.c b/mud.c
index f129f7b..dcab258 100644
--- a/mud.c
+++ b/mud.c
@@ -365,14 +365,15 @@ int mud_encrypt (struct mud *mud, uint32_t nonce,
     mud_write32(npub, nonce);
 
     crypto_aead_aes256gcm_encrypt_afternm(
-            dst+4, NULL,
-            src, src_size,
-            NULL, 0,
+            dst+8, NULL,
+            src+4, src_size-4,
+            src, 4,
             NULL,
             npub,
             (const crypto_aead_aes256gcm_state *)&mud->crypto.key);
 
     memcpy(dst, npub, 4);
+    memcpy(dst+4, src, 4);
 
     return size;
 }
@@ -393,12 +394,13 @@ int mud_decrypt (struct mud *mud, uint32_t *nonce,
     unsigned char npub[crypto_aead_aes256gcm_NPUBBYTES] = {0};
 
     memcpy(npub, src, 4);
+    memcpy(dst, src+4, 4);
 
     if (crypto_aead_aes256gcm_decrypt_afternm(
-            dst, NULL,
+            dst+4, NULL,
             NULL,
-            src+4, src_size-4,
-            NULL, 0,
+            src+8, src_size-8,
+            src+4, 4,
             npub,
             (const crypto_aead_aes256gcm_state *)&mud->crypto.key))
         return -1;