upstream: 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@

OpenBSD-Commit-ID: 1cc7885487a6754f63641d7d3279b0941890275b

.depend

@@ -60,8 +60,8 @@ gss-serv.o: includes.h config.h defines.h platform.h openbsd-compat/openbsd-comp
 hash.o: crypto_api.h includes.h config.h defines.h platform.h openbsd-compat/openbsd-compat.h openbsd-compat/base64.h openbsd-compat/sigact.h openbsd-compat/readpassphrase.h openbsd-compat/vis.h openbsd-compat/getrrsetbyname.h openbsd-compat/sha1.h openbsd-compat/sha2.h openbsd-compat/rmd160.h openbsd-compat/md5.h openbsd-compat/blf.h openbsd-compat/getopt.h openbsd-compat/bsd-misc.h openbsd-compat/bsd-setres_id.h openbsd-compat/bsd-signal.h openbsd-compat/bsd-statvfs.h openbsd-compat/bsd-waitpid.h openbsd-compat/bsd-poll.h openbsd-compat/fake-rfc2553.h openbsd-compat/bsd-cygwin_util.h openbsd-compat/port-aix.h openbsd-compat/port-irix.h openbsd-compat/port-linux.h openbsd-compat/port-solaris.h openbsd-compat/port-net.h openbsd-compat/port-uw.h openbsd-compat/bsd-nextstep.h entropy.h digest.h log.h ssherr.h
 hmac.o: includes.h config.h defines.h platform.h openbsd-compat/openbsd-compat.h openbsd-compat/base64.h openbsd-compat/sigact.h openbsd-compat/readpassphrase.h openbsd-compat/vis.h openbsd-compat/getrrsetbyname.h openbsd-compat/sha1.h openbsd-compat/sha2.h openbsd-compat/rmd160.h openbsd-compat/md5.h openbsd-compat/blf.h openbsd-compat/getopt.h openbsd-compat/bsd-misc.h openbsd-compat/bsd-setres_id.h openbsd-compat/bsd-signal.h openbsd-compat/bsd-statvfs.h openbsd-compat/bsd-waitpid.h openbsd-compat/bsd-poll.h openbsd-compat/fake-rfc2553.h openbsd-compat/bsd-cygwin_util.h openbsd-compat/port-aix.h openbsd-compat/port-irix.h openbsd-compat/port-linux.h openbsd-compat/port-solaris.h openbsd-compat/port-net.h openbsd-compat/port-uw.h openbsd-compat/bsd-nextstep.h entropy.h sshbuf.h digest.h hmac.h
 hostfile.o: includes.h config.h defines.h platform.h openbsd-compat/openbsd-compat.h openbsd-compat/base64.h openbsd-compat/sigact.h openbsd-compat/readpassphrase.h openbsd-compat/vis.h openbsd-compat/getrrsetbyname.h openbsd-compat/sha1.h openbsd-compat/sha2.h openbsd-compat/rmd160.h openbsd-compat/md5.h openbsd-compat/blf.h openbsd-compat/getopt.h openbsd-compat/bsd-misc.h openbsd-compat/bsd-setres_id.h openbsd-compat/bsd-signal.h openbsd-compat/bsd-statvfs.h openbsd-compat/bsd-waitpid.h openbsd-compat/bsd-poll.h openbsd-compat/fake-rfc2553.h openbsd-compat/bsd-cygwin_util.h openbsd-compat/port-aix.h openbsd-compat/port-irix.h openbsd-compat/port-linux.h openbsd-compat/port-solaris.h openbsd-compat/port-net.h openbsd-compat/port-uw.h openbsd-compat/bsd-nextstep.h entropy.h xmalloc.h match.h sshkey.h hostfile.h log.h misc.h ssherr.h digest.h hmac.h
-kex.o: includes.h config.h defines.h platform.h openbsd-compat/openbsd-compat.h openbsd-compat/base64.h openbsd-compat/sigact.h openbsd-compat/readpassphrase.h openbsd-compat/vis.h openbsd-compat/getrrsetbyname.h openbsd-compat/sha1.h openbsd-compat/sha2.h openbsd-compat/rmd160.h openbsd-compat/md5.h openbsd-compat/blf.h openbsd-compat/getopt.h openbsd-compat/bsd-misc.h openbsd-compat/bsd-setres_id.h openbsd-compat/bsd-signal.h openbsd-compat/bsd-statvfs.h openbsd-compat/bsd-waitpid.h openbsd-compat/bsd-poll.h openbsd-compat/fake-rfc2553.h openbsd-compat/bsd-cygwin_util.h openbsd-compat/port-aix.h openbsd-compat/port-irix.h openbsd-compat/port-linux.h openbsd-compat/port-solaris.h openbsd-compat/port-net.h openbsd-compat/port-uw.h openbsd-compat/bsd-nextstep.h entropy.h ssh2.h packet.h openbsd-compat/sys-queue.h dispatch.h opacket.h compat.h cipher.h cipher-chachapoly.h chacha.h poly1305.h cipher-aesctr.h rijndael.h sshkey.h kex.h mac.h log.h match.h misc.h monitor.h ssherr.h sshbuf.h
-kex.o: digest.h
+kex.o: includes.h config.h defines.h platform.h openbsd-compat/openbsd-compat.h openbsd-compat/base64.h openbsd-compat/sigact.h openbsd-compat/readpassphrase.h openbsd-compat/vis.h openbsd-compat/getrrsetbyname.h openbsd-compat/sha1.h openbsd-compat/sha2.h openbsd-compat/rmd160.h openbsd-compat/md5.h openbsd-compat/blf.h openbsd-compat/getopt.h openbsd-compat/bsd-misc.h openbsd-compat/bsd-setres_id.h openbsd-compat/bsd-signal.h openbsd-compat/bsd-statvfs.h openbsd-compat/bsd-waitpid.h openbsd-compat/bsd-poll.h openbsd-compat/fake-rfc2553.h openbsd-compat/bsd-cygwin_util.h openbsd-compat/port-aix.h openbsd-compat/port-irix.h openbsd-compat/port-linux.h openbsd-compat/port-solaris.h openbsd-compat/port-net.h openbsd-compat/port-uw.h openbsd-compat/bsd-nextstep.h entropy.h ssh.h ssh2.h atomicio.h version.h packet.h openbsd-compat/sys-queue.h dispatch.h opacket.h compat.h cipher.h cipher-chachapoly.h chacha.h poly1305.h cipher-aesctr.h rijndael.h sshkey.h kex.h mac.h log.h match.h misc.h
+kex.o: monitor.h ssherr.h sshbuf.h digest.h
 kexc25519.o: includes.h config.h defines.h platform.h openbsd-compat/openbsd-compat.h openbsd-compat/base64.h openbsd-compat/sigact.h openbsd-compat/readpassphrase.h openbsd-compat/vis.h openbsd-compat/getrrsetbyname.h openbsd-compat/sha1.h openbsd-compat/sha2.h openbsd-compat/rmd160.h openbsd-compat/md5.h openbsd-compat/blf.h openbsd-compat/getopt.h openbsd-compat/bsd-misc.h openbsd-compat/bsd-setres_id.h openbsd-compat/bsd-signal.h openbsd-compat/bsd-statvfs.h openbsd-compat/bsd-waitpid.h openbsd-compat/bsd-poll.h openbsd-compat/fake-rfc2553.h openbsd-compat/bsd-cygwin_util.h openbsd-compat/port-aix.h openbsd-compat/port-irix.h openbsd-compat/port-linux.h openbsd-compat/port-solaris.h openbsd-compat/port-net.h openbsd-compat/port-uw.h openbsd-compat/bsd-nextstep.h entropy.h sshbuf.h ssh2.h sshkey.h cipher.h cipher-chachapoly.h chacha.h poly1305.h cipher-aesctr.h rijndael.h kex.h mac.h log.h digest.h ssherr.h
 kexc25519c.o: includes.h config.h defines.h platform.h openbsd-compat/openbsd-compat.h openbsd-compat/base64.h openbsd-compat/sigact.h openbsd-compat/readpassphrase.h openbsd-compat/vis.h openbsd-compat/getrrsetbyname.h openbsd-compat/sha1.h openbsd-compat/sha2.h openbsd-compat/rmd160.h openbsd-compat/md5.h openbsd-compat/blf.h openbsd-compat/getopt.h openbsd-compat/bsd-misc.h openbsd-compat/bsd-setres_id.h openbsd-compat/bsd-signal.h openbsd-compat/bsd-statvfs.h openbsd-compat/bsd-waitpid.h openbsd-compat/bsd-poll.h openbsd-compat/fake-rfc2553.h openbsd-compat/bsd-cygwin_util.h openbsd-compat/port-aix.h openbsd-compat/port-irix.h openbsd-compat/port-linux.h openbsd-compat/port-solaris.h openbsd-compat/port-net.h openbsd-compat/port-uw.h openbsd-compat/bsd-nextstep.h entropy.h sshkey.h cipher.h cipher-chachapoly.h chacha.h poly1305.h cipher-aesctr.h rijndael.h kex.h mac.h log.h packet.h openbsd-compat/sys-queue.h dispatch.h opacket.h ssh2.h sshbuf.h digest.h ssherr.h
 kexc25519s.o: includes.h config.h defines.h platform.h openbsd-compat/openbsd-compat.h openbsd-compat/base64.h openbsd-compat/sigact.h openbsd-compat/readpassphrase.h openbsd-compat/vis.h openbsd-compat/getrrsetbyname.h openbsd-compat/sha1.h openbsd-compat/sha2.h openbsd-compat/rmd160.h openbsd-compat/md5.h openbsd-compat/blf.h openbsd-compat/getopt.h openbsd-compat/bsd-misc.h openbsd-compat/bsd-setres_id.h openbsd-compat/bsd-signal.h openbsd-compat/bsd-statvfs.h openbsd-compat/bsd-waitpid.h openbsd-compat/bsd-poll.h openbsd-compat/fake-rfc2553.h openbsd-compat/bsd-cygwin_util.h openbsd-compat/port-aix.h openbsd-compat/port-irix.h openbsd-compat/port-linux.h openbsd-compat/port-solaris.h openbsd-compat/port-net.h openbsd-compat/port-uw.h openbsd-compat/bsd-nextstep.h entropy.h sshkey.h cipher.h cipher-chachapoly.h chacha.h poly1305.h cipher-aesctr.h rijndael.h digest.h kex.h mac.h log.h packet.h openbsd-compat/sys-queue.h dispatch.h opacket.h ssh2.h sshbuf.h ssherr.h
@@ -149,7 +149,7 @@ sshbuf-getput-crypto.o: includes.h config.h defines.h platform.h openbsd-compat/
 sshbuf-misc.o: includes.h config.h defines.h platform.h openbsd-compat/openbsd-compat.h openbsd-compat/base64.h openbsd-compat/sigact.h openbsd-compat/readpassphrase.h openbsd-compat/vis.h openbsd-compat/getrrsetbyname.h openbsd-compat/sha1.h openbsd-compat/sha2.h openbsd-compat/rmd160.h openbsd-compat/md5.h openbsd-compat/blf.h openbsd-compat/getopt.h openbsd-compat/bsd-misc.h openbsd-compat/bsd-setres_id.h openbsd-compat/bsd-signal.h openbsd-compat/bsd-statvfs.h openbsd-compat/bsd-waitpid.h openbsd-compat/bsd-poll.h openbsd-compat/fake-rfc2553.h openbsd-compat/bsd-cygwin_util.h openbsd-compat/port-aix.h openbsd-compat/port-irix.h openbsd-compat/port-linux.h openbsd-compat/port-solaris.h openbsd-compat/port-net.h openbsd-compat/port-uw.h openbsd-compat/bsd-nextstep.h entropy.h ssherr.h sshbuf.h
 sshbuf.o: includes.h config.h defines.h platform.h openbsd-compat/openbsd-compat.h openbsd-compat/base64.h openbsd-compat/sigact.h openbsd-compat/readpassphrase.h openbsd-compat/vis.h openbsd-compat/getrrsetbyname.h openbsd-compat/sha1.h openbsd-compat/sha2.h openbsd-compat/rmd160.h openbsd-compat/md5.h openbsd-compat/blf.h openbsd-compat/getopt.h openbsd-compat/bsd-misc.h openbsd-compat/bsd-setres_id.h openbsd-compat/bsd-signal.h openbsd-compat/bsd-statvfs.h openbsd-compat/bsd-waitpid.h openbsd-compat/bsd-poll.h openbsd-compat/fake-rfc2553.h openbsd-compat/bsd-cygwin_util.h openbsd-compat/port-aix.h openbsd-compat/port-irix.h openbsd-compat/port-linux.h openbsd-compat/port-solaris.h openbsd-compat/port-net.h openbsd-compat/port-uw.h openbsd-compat/bsd-nextstep.h entropy.h ssherr.h sshbuf.h misc.h
 sshconnect.o: includes.h config.h defines.h platform.h openbsd-compat/openbsd-compat.h openbsd-compat/base64.h openbsd-compat/sigact.h openbsd-compat/readpassphrase.h openbsd-compat/vis.h openbsd-compat/getrrsetbyname.h openbsd-compat/sha1.h openbsd-compat/sha2.h openbsd-compat/rmd160.h openbsd-compat/md5.h openbsd-compat/blf.h openbsd-compat/getopt.h openbsd-compat/bsd-misc.h openbsd-compat/bsd-setres_id.h openbsd-compat/bsd-signal.h openbsd-compat/bsd-statvfs.h openbsd-compat/bsd-waitpid.h openbsd-compat/bsd-poll.h openbsd-compat/fake-rfc2553.h openbsd-compat/bsd-cygwin_util.h openbsd-compat/port-aix.h openbsd-compat/port-irix.h openbsd-compat/port-linux.h openbsd-compat/port-solaris.h openbsd-compat/port-net.h openbsd-compat/port-uw.h openbsd-compat/bsd-nextstep.h entropy.h xmalloc.h hostfile.h ssh.h sshbuf.h packet.h openbsd-compat/sys-queue.h dispatch.h opacket.h compat.h sshkey.h sshconnect.h log.h misc.h readconf.h atomicio.h dns.h monitor_fdpass.h ssh2.h version.h authfile.h
-sshconnect.o: ssherr.h authfd.h
+sshconnect.o: ssherr.h authfd.h kex.h mac.h
 sshconnect2.o: includes.h config.h defines.h platform.h openbsd-compat/openbsd-compat.h openbsd-compat/base64.h openbsd-compat/sigact.h openbsd-compat/readpassphrase.h openbsd-compat/vis.h openbsd-compat/getrrsetbyname.h openbsd-compat/sha1.h openbsd-compat/sha2.h openbsd-compat/rmd160.h openbsd-compat/md5.h openbsd-compat/blf.h openbsd-compat/getopt.h openbsd-compat/bsd-misc.h openbsd-compat/bsd-setres_id.h openbsd-compat/bsd-signal.h openbsd-compat/bsd-statvfs.h openbsd-compat/bsd-waitpid.h openbsd-compat/bsd-poll.h openbsd-compat/fake-rfc2553.h openbsd-compat/bsd-cygwin_util.h openbsd-compat/port-aix.h openbsd-compat/port-irix.h openbsd-compat/port-linux.h openbsd-compat/port-solaris.h openbsd-compat/port-net.h openbsd-compat/port-uw.h openbsd-compat/bsd-nextstep.h entropy.h openbsd-compat/sys-queue.h xmalloc.h ssh.h ssh2.h sshbuf.h packet.h dispatch.h opacket.h compat.h cipher.h cipher-chachapoly.h chacha.h poly1305.h cipher-aesctr.h rijndael.h sshkey.h kex.h mac.h myproposal.h
 sshconnect2.o: sshconnect.h authfile.h dh.h authfd.h log.h misc.h readconf.h match.h canohost.h msg.h pathnames.h uidswap.h hostfile.h ssherr.h utf8.h
 sshd.o: includes.h config.h defines.h platform.h openbsd-compat/openbsd-compat.h openbsd-compat/base64.h openbsd-compat/sigact.h openbsd-compat/readpassphrase.h openbsd-compat/vis.h openbsd-compat/getrrsetbyname.h openbsd-compat/sha1.h openbsd-compat/sha2.h openbsd-compat/rmd160.h openbsd-compat/md5.h openbsd-compat/blf.h openbsd-compat/getopt.h openbsd-compat/bsd-misc.h openbsd-compat/bsd-setres_id.h openbsd-compat/bsd-signal.h openbsd-compat/bsd-statvfs.h openbsd-compat/bsd-waitpid.h openbsd-compat/bsd-poll.h openbsd-compat/fake-rfc2553.h openbsd-compat/bsd-cygwin_util.h openbsd-compat/port-aix.h openbsd-compat/port-irix.h openbsd-compat/port-linux.h openbsd-compat/port-solaris.h openbsd-compat/port-net.h openbsd-compat/port-uw.h openbsd-compat/bsd-nextstep.h entropy.h ./openbsd-compat/sys-tree.h openbsd-compat/sys-queue.h xmalloc.h ssh.h ssh2.h sshpty.h packet.h dispatch.h opacket.h log.h sshbuf.h misc.h match.h servconf.h uidswap.h compat.h cipher.h cipher-chachapoly.h chacha.h

Makefile.in

@@ -186,7 +186,7 @@ ssh-agent$(EXEEXT): $(LIBCOMPAT) libssh.a ssh-agent.o ssh-pkcs11-client.o
 ssh-keygen$(EXEEXT): $(LIBCOMPAT) libssh.a ssh-keygen.o
 	$(LD) -o $@ ssh-keygen.o $(LDFLAGS) -lssh -lopenbsd-compat $(LIBS)
 
-ssh-keysign$(EXEEXT): $(LIBCOMPAT) libssh.a ssh-keysign.o readconf.o uidswap.o
+ssh-keysign$(EXEEXT): $(LIBCOMPAT) libssh.a ssh-keysign.o readconf.o uidswap.o compat.o
 	$(LD) -o $@ ssh-keysign.o readconf.o uidswap.o $(LDFLAGS) -lssh -lopenbsd-compat $(LIBS)
 
 ssh-pkcs11-helper$(EXEEXT): $(LIBCOMPAT) libssh.a ssh-pkcs11-helper.o ssh-pkcs11.o

atomicio.h

@@ -1,4 +1,4 @@
-/* $OpenBSD: atomicio.h,v 1.11 2010/09/22 22:58:51 djm Exp $ */
+/* $OpenBSD: atomicio.h,v 1.12 2018/12/27 03:25:25 djm Exp $ */
 
 /*
  * Copyright (c) 2006 Damien Miller.  All rights reserved.
@@ -29,6 +29,8 @@
 #ifndef _ATOMICIO_H
 #define _ATOMICIO_H
 
+struct iovec;
+
 /*
  * Ensure all of data on socket comes through. f==read || f==vwrite
  */