- 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, 7 insertions, 1 deletions

diff --git a/auth2-hostbased.c b/auth2-hostbased.c
index a344dcc1f..488008f62 100644
--- a/auth2-hostbased.c
+++ b/auth2-hostbased.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: auth2-hostbased.c,v 1.16 2013/06/21 00:34:49 djm Exp $ */
+/* $OpenBSD: auth2-hostbased.c,v 1.17 2013/12/30 23:52:27 djm Exp $ */
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  *
@@ -100,6 +100,12 @@ userauth_hostbased(Authctxt *authctxt)
                     "(received %d, expected %d)", key->type, pktype);
                 goto done;
         }
+        if (key_type_plain(key->type) == KEY_RSA &&
+            (datafellows & SSH_BUG_RSASIGMD5) != 0) {
+                error("Refusing RSA key because peer uses unsafe "
+                    "signature format");
+                goto done;
+        }
         service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" :
             authctxt->service;
         buffer_init(&b);