- djm@cvs.openbsd.org 2014/01/09 23:26:48

     [sshconnect.c sshd.c]
     ban clients/servers that suffer from SSH_BUG_DERIVEKEY, they are ancient,
     deranged and might make some attacks on KEX easier; ok markus@

1 files changed, 4 insertions, 1 deletions

diff --git a/sshconnect.c b/sshconnect.c
index 791b31c12..d21781ea4 100644
--- a/sshconnect.c
+++ b/sshconnect.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sshconnect.c,v 1.243 2013/12/30 23:52:27 djm Exp $ */
+/* $OpenBSD: sshconnect.c,v 1.244 2014/01/09 23:26:48 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -662,6 +662,9 @@ ssh_exchange_identification(int timeout_ms)
                 fatal("Protocol major versions differ: %d vs. %d",
                     (options.protocol & SSH_PROTO_2) ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1,
                     remote_major);
+        if ((datafellows & SSH_BUG_DERIVEKEY) != 0)
+                fatal("Server version \"%.100s\" uses unsafe key agreement; "
+                    "refusing connection", remote_version);
         if ((datafellows & SSH_BUG_RSASIGMD5) != 0)
                 logit("Server version \"%.100s\" uses unsafe RSA signature "
                     "scheme; disabling use of RSA keys", remote_version);