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, 6 deletions

diff --git a/packet.h b/packet.h
index 464d83b1a..690f2ec7e 100644
--- a/packet.h
+++ b/packet.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: packet.h,v 1.71 2016/03/07 19:02:43 djm Exp $ */
+/* $OpenBSD: packet.h,v 1.72 2016/09/28 16:33:07 djm Exp $ */
 
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
@@ -120,11 +120,6 @@ void     ssh_packet_send_debug(struct ssh *, const char *fmt, ...) __attribute__
 int      ssh_set_newkeys(struct ssh *, int mode);
 void     ssh_packet_get_bytes(struct ssh *, u_int64_t *, u_int64_t *);
 
-typedef void *(ssh_packet_comp_alloc_func)(void *, u_int, u_int);
-typedef void (ssh_packet_comp_free_func)(void *, void *);
-void     ssh_packet_set_compress_hooks(struct ssh *, void *,
-    ssh_packet_comp_alloc_func *, ssh_packet_comp_free_func *);
-
 int      ssh_packet_write_poll(struct ssh *);
 int      ssh_packet_write_wait(struct ssh *);
 int      ssh_packet_have_data_to_write(struct ssh *);