From 7fd8f5fcdfa6310787809a3828e887d48a16ae6e Mon Sep 17 00:00:00 2001
From: Guido Vranken <guidovranken@gmail.com>
Date: Mon, 26 Jun 2017 21:01:15 +0200
Subject: [PATCH] Prepare compression functions for fuzzing

---
 src/openvpn/comp-lz4.c |  5 ++++-
 src/openvpn/comp.c     |  5 ++++-
 src/openvpn/compstub.c | 10 ++++++++--
 src/openvpn/lzo.c      |  5 ++++-
 4 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/src/openvpn/comp-lz4.c b/src/openvpn/comp-lz4.c
index 6e40c325c..3d5ddaeda 100644
--- a/src/openvpn/comp-lz4.c
+++ b/src/openvpn/comp-lz4.c
@@ -139,7 +139,10 @@ lz4_compress(struct buffer *buf, struct buffer work,
         {
             uint8_t *head = BPTR(buf);
             uint8_t *tail  = BEND(buf);
-            ASSERT(buf_safe(buf, 1));
+            if ( !(buf_safe(buf, 1)) )
+            {
+                return;
+            }
             ++buf->len;
 
             /* move head byte of payload to tail */
diff --git a/src/openvpn/comp.c b/src/openvpn/comp.c
index 4cda7e5ee..2b8c2ec76 100644
--- a/src/openvpn/comp.c
+++ b/src/openvpn/comp.c
@@ -98,7 +98,10 @@ compv2_escape_data_ifneeded(struct buffer *buf)
     }
 
     /* Header is 0x50 */
-    ASSERT(buf_prepend(buf, 2));
+    if ( !(buf_prepend(buf, 2)) )
+    {
+        return;
+    }
 
     head = BPTR(buf);
     head[0] = COMP_ALGV2_INDICATOR_BYTE;
diff --git a/src/openvpn/compstub.c b/src/openvpn/compstub.c
index ca90924e6..a203767cc 100644
--- a/src/openvpn/compstub.c
+++ b/src/openvpn/compstub.c
@@ -60,7 +60,10 @@ stub_compress(struct buffer *buf, struct buffer work,
     {
         uint8_t *head = BPTR(buf);
         uint8_t *tail  = BEND(buf);
-        ASSERT(buf_safe(buf, 1));
+        if ( !(buf_safe(buf, 1)) )
+        {
+            return;
+        }
         ++buf->len;
 
         /* move head byte of payload to tail */
@@ -70,7 +73,10 @@ stub_compress(struct buffer *buf, struct buffer work,
     else
     {
         uint8_t *header = buf_prepend(buf, 1);
-        *header = NO_COMPRESS_BYTE;
+        if (header)
+        {
+            *header = NO_COMPRESS_BYTE;
+        }
     }
 }
 
diff --git a/src/openvpn/lzo.c b/src/openvpn/lzo.c
index f75486565..a9de5fa26 100644
--- a/src/openvpn/lzo.c
+++ b/src/openvpn/lzo.c
@@ -202,7 +202,10 @@ lzo_compress(struct buffer *buf, struct buffer work,
     else
     {
         uint8_t *header = buf_prepend(buf, 1);
-        *header = NO_COMPRESS_BYTE;
+        if (header)
+        {
+            *header = NO_COMPRESS_BYTE;
+        }
     }
 }
 
-- 
2.47.2