svn commit: r363627 - head/crypto/openssh

[Ed Maste]

Author: emaste
Date: Tue Jul 28 00:24:12 2020
New Revision: 363627
URL: https://svnweb.freebsd.org/changeset/base/363627

Log:
  ssh: Remove AES-CBC ciphers from default server and client lists
  
  A base system OpenSSH update in 2016 or so removed a number of ciphers
  from the default lists offered by the server/client, due to known
  weaknesses.  This caused POLA issues for some users and prompted
  PR207679; the ciphers were restored to the default lists in r296634.
  
  When upstream removed these ciphers from the default server list, they
  moved them to the client-only default list.  They were subsequently
  removed from the client default, in OpenSSH 7.9p1.
  
  The change has persisted long enough.  Remove these extra ciphers from
  both the server and client default lists, in advance of FreeBSD 13.
  
  Reviewed by:	markm, rgrimes
  Sponsored by:	The FreeBSD Foundation
  Differential Revision:	https://reviews.freebsd.org/D25833

Modified:
  head/crypto/openssh/FREEBSD-upgrade
  head/crypto/openssh/myproposal.h
  head/crypto/openssh/sshd_config.5

Modified: head/crypto/openssh/FREEBSD-upgrade
==============================================================================
--- head/crypto/openssh/FREEBSD-upgrade	Mon Jul 27 23:19:46 2020	(r363626)
+++ head/crypto/openssh/FREEBSD-upgrade	Tue Jul 28 00:24:12 2020	(r363627)
@@ -168,13 +168,6 @@
    ignore HPN-related configuration options to avoid breaking existing
    configurations.
 
-9) AES-CBC
-
-   The AES-CBC ciphers were removed from the server-side proposal list
-   in 6.7p1 due to theoretical weaknesses and the availability of
-   superior ciphers (including AES-CTR and AES-GCM).  We have re-added
-   them for compatibility with third-party clients.
-
 

 
 This port was brought to you by (in no particular order) DARPA, NAI

Modified: head/crypto/openssh/myproposal.h
==============================================================================
--- head/crypto/openssh/myproposal.h	Mon Jul 27 23:19:46 2020	(r363626)
+++ head/crypto/openssh/myproposal.h	Tue Jul 28 00:24:12 2020	(r363627)
@@ -1,5 +1,4 @@
 /* $OpenBSD: myproposal.h,v 1.57 2018/09/12 01:34:02 djm Exp $ */
-/* $FreeBSD$ */
 
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
@@ -122,8 +121,7 @@
 #define KEX_SERVER_ENCRYPT \
 	"chacha20-poly1305 at openssh.com," \
 	"aes128-ctr,aes192-ctr,aes256-ctr" \
-	AESGCM_CIPHER_MODES \
-	",aes128-cbc,aes192-cbc,aes256-cbc"
+	AESGCM_CIPHER_MODES
 
 #define KEX_CLIENT_ENCRYPT KEX_SERVER_ENCRYPT
 

Modified: head/crypto/openssh/sshd_config.5
==============================================================================
--- head/crypto/openssh/sshd_config.5	Mon Jul 27 23:19:46 2020	(r363626)
+++ head/crypto/openssh/sshd_config.5	Tue Jul 28 00:24:12 2020	(r363627)
@@ -495,8 +495,7 @@ The default is:
 .Bd -literal -offset indent
 chacha20-poly1305 at openssh.com,
 aes128-ctr,aes192-ctr,aes256-ctr,
-aes128-gcm at openssh.com,aes256-gcm at openssh.com,
-aes128-cbc,aes192-cbc,aes256-cbc
+aes128-gcm at openssh.com,aes256-gcm at openssh.com
 .Ed
 .Pp
 The list of available ciphers may also be obtained using