diff -u -r -x .DS_Store openvpn-2.4.7.old/src/openvpn/socket.h openvpn-2.4.7.new/src/openvpn/socket.h
--- openvpn-2.4.7.old/src/openvpn/socket.h	2019-02-27 06:02:54.000000000 -0500
+++ openvpn-2.4.7.new/src/openvpn/socket.h	2019-02-27 06:02:54.000000000 -0500
@@ -248,6 +248,10 @@
 #endif
 };
 
+int buffer_mask(struct buffer *buf, const char *xormask, int xormasklen);
+int buffer_xorptrpos(struct buffer *buf);
+int buffer_reverse(struct buffer *buf);
+
 /*
  * Some Posix/Win32 differences.
  */
@@ -1065,30 +1069,61 @@
 static inline int
 link_socket_read(struct link_socket *sock,
                  struct buffer *buf,
-                 struct link_socket_actual *from)
+                 struct link_socket_actual *from,
+                 int xormethod,
+                 const char *xormask,
+                 int xormasklen)
 {
+    int res;
     if (proto_is_udp(sock->info.proto)) /* unified UDPv4 and UDPv6 */
     {
-        int res;
 
 #ifdef _WIN32
         res = link_socket_read_udp_win32(sock, buf, from);
 #else
         res = link_socket_read_udp_posix(sock, buf, from);
 #endif
-        return res;
     }
     else if (proto_is_tcp(sock->info.proto)) /* unified TCPv4 and TCPv6 */
     {
         /* from address was returned by accept */
         addr_copy_sa(&from->dest, &sock->info.lsa->actual.dest);
-        return link_socket_read_tcp(sock, buf);
+        res = link_socket_read_tcp(sock, buf);
     }
     else
     {
         ASSERT(0);
         return -1; /* NOTREACHED */
     }
+    switch (xormethod)
+    {
+        case 0:
+            break;
+
+        case 1:
+            buffer_mask(buf,xormask,xormasklen);
+            break;
+
+        case 2:
+            buffer_xorptrpos(buf);
+            break;
+
+        case 3:
+            buffer_reverse(buf);
+            break;
+
+        case 4:
+            buffer_mask(buf,xormask,xormasklen);
+            buffer_xorptrpos(buf);
+            buffer_reverse(buf);
+            buffer_xorptrpos(buf);
+            break;
+
+        default:
+            ASSERT(0);
+            return -1; /* NOTREACHED */
+    }
+    return res;
 }
 
 /*
@@ -1178,8 +1213,39 @@
 static inline int
 link_socket_write(struct link_socket *sock,
                   struct buffer *buf,
-                  struct link_socket_actual *to)
+                  struct link_socket_actual *to,
+                  int xormethod,
+                  const char *xormask,
+                  int xormasklen)
 {
+    switch (xormethod)
+    {
+        case 0:
+            break;
+
+        case 1:
+            buffer_mask(buf,xormask,xormasklen);
+            break;
+
+        case 2:
+            buffer_xorptrpos(buf);
+            break;
+
+        case 3:
+            buffer_reverse(buf);
+            break;
+
+        case 4:
+            buffer_xorptrpos(buf);
+            buffer_reverse(buf);
+            buffer_xorptrpos(buf);
+            buffer_mask(buf,xormask,xormasklen);
+            break;
+
+        default:
+            ASSERT(0);
+            return -1; /* NOTREACHED */
+    }
     if (proto_is_udp(sock->info.proto)) /* unified UDPv4 and UDPv6 */
     {
         return link_socket_write_udp(sock, buf, to);