- djm@cvs.openbsd.org 2013/12/30 23:52:28

     [auth2-hostbased.c auth2-pubkey.c compat.c compat.h ssh-rsa.c]
     [sshconnect.c sshconnect2.c sshd.c]
     refuse RSA keys from old proprietary clients/servers that use the
     obsolete RSA+MD5 signature scheme. it will still be possible to connect
     with these clients/servers but only DSA keys will be accepted, and we'll
     deprecate them entirely in a future release. ok markus@

1 files changed, 8 insertions, 5 deletions

diff --git a/sshd.c b/sshd.c
index 786d9ff90..87795bea5 100644
--- a/sshd.c
+++ b/sshd.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sshd.c,v 1.412 2013/12/06 13:39:49 markus Exp $ */
+/* $OpenBSD: sshd.c,v 1.413 2013/12/30 23:52:28 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -492,17 +492,19 @@ sshd_exchange_identification(int sock_in, int sock_out)
 
         compat_datafellows(remote_version);
 
-        if (datafellows & SSH_BUG_PROBE) {
+        if ((datafellows & SSH_BUG_PROBE) != 0) {
                 logit("probed from %s with %s.  Don't panic.",
                     get_remote_ipaddr(), client_version_string);
                 cleanup_exit(255);
         }
-
-        if (datafellows & SSH_BUG_SCANNER) {
+        if ((datafellows & SSH_BUG_SCANNER) != 0) {
                 logit("scanned from %s with %s.  Don't panic.",
                     get_remote_ipaddr(), client_version_string);
                 cleanup_exit(255);
         }
+        if ((datafellows & SSH_BUG_RSASIGMD5) != 0)
+                logit("Client version \"%.100s\" uses unsafe RSA signature "
+                    "scheme; disabling use of RSA keys", remote_version);
 
         mismatch = 0;
         switch (remote_major) {
@@ -2446,7 +2448,8 @@ do_ssh2_kex(void)
                 packet_set_rekey_limits((u_int32_t)options.rekey_limit,
                     (time_t)options.rekey_interval);
 
-        myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = list_hostkey_types();
+        myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = compat_pkalg_proposal(
+            list_hostkey_types());
 
         /* start key exchange */
         kex = kex_setup(myproposal);