move client/server SSH-* banners to buffers under ssh->kex and factor

out the banner exchange. This eliminates some common code from the
client and server.

Also be more strict about handling \r characters - these should only
be accepted immediately before \n (pointed out by Jann Horn).

Inspired by a patch from Markus Schmidt.
(lots of) feedback and ok markus@

1 files changed, 6 insertions, 9 deletions

diff --git a/usr.bin/ssh/sshconnect.h b/usr.bin/ssh/sshconnect.h
index 890d857330c..44a5071c719 100644
--- a/usr.bin/ssh/sshconnect.h
+++ b/usr.bin/ssh/sshconnect.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: sshconnect.h,v 1.35 2018/07/19 10:28:47 dtucker Exp $ */
+/* $OpenBSD: sshconnect.h,v 1.36 2018/12/27 03:25:25 djm Exp $ */
 
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
@@ -37,21 +37,18 @@ int	 ssh_connect(struct ssh *, const char *, struct addrinfo *,
 	    struct sockaddr_storage *, u_short, int, int, int *, int);
 void	 ssh_kill_proxy_command(void);
 
-void	 ssh_login(Sensitive *, const char *, struct sockaddr *, u_short,
-    struct passwd *, int);
-
-void	 ssh_exchange_identification(int);
+void	 ssh_login(struct ssh *, Sensitive *, const char *,
+    struct sockaddr *, u_short, struct passwd *, int);
 
 int	 verify_host_key(char *, struct sockaddr *, struct sshkey *);
 
 void	 get_hostfile_hostname_ipaddr(char *, struct sockaddr *, u_short,
     char **, char **);
 
-void	 ssh_kex(char *, struct sockaddr *);
-void	 ssh_kex2(char *, struct sockaddr *, u_short);
+void	 ssh_kex2(struct ssh *ssh, char *, struct sockaddr *, u_short);
 
-void	 ssh_userauth1(const char *, const char *, char *, Sensitive *);
-void	 ssh_userauth2(const char *, const char *, char *, Sensitive *);
+void	 ssh_userauth2(struct ssh *ssh, const char *, const char *,
+    char *, Sensitive *);
 
 void	 ssh_put_password(char *);
 int	 ssh_local_cmd(const char *);