upstream commit

Remove support for pre-authentication compression. Doing
compression early in the protocol probably seemed reasonable in the 1990s,
but today it's clearly a bad idea in terms of both cryptography (cf. multiple
compression oracle attacks in TLS) and attack surface.

Moreover, to support it across privilege-separation zlib needed
the assistance of a complex shared-memory manager that made the
required attack surface considerably larger.

Prompted by Guido Vranken pointing out a compiler-elided security
check in the shared memory manager found by Stack
(http://css.csail.mit.edu/stack/); ok deraadt@ markus@

NB. pre-auth authentication has been disabled by default in sshd
for >10 years.

Upstream-ID: 32af9771788d45a0779693b41d06ec199d849caf

1 files changed, 1 insertions, 5 deletions

diff --git a/monitor.h b/monitor.h
index 93b8b66dd..d68f67458 100644
--- a/monitor.h
+++ b/monitor.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: monitor.h,v 1.19 2015/01/19 19:52:16 markus Exp $ */
+/* $OpenBSD: monitor.h,v 1.20 2016/09/28 16:33:07 djm Exp $ */
 
 /*
  * Copyright 2002 Niels Provos <provos@citi.umich.edu>
@@ -67,21 +67,17 @@ enum monitor_reqtype {
 
 };
 
-struct mm_master;
 struct monitor {
         int                      m_recvfd;
         int                      m_sendfd;
         int                      m_log_recvfd;
         int                      m_log_sendfd;
-        struct mm_master        *m_zback;
-        struct mm_master        *m_zlib;
         struct kex              **m_pkex;
         pid_t                    m_pid;
 };
 
 struct monitor *monitor_init(void);
 void monitor_reinit(struct monitor *);
-void monitor_sync(struct monitor *);
 
 struct Authctxt;
 void monitor_child_preauth(struct Authctxt *, struct monitor *);